WO2019216201A1

WO2019216201A1 - Injector

Info

Publication number: WO2019216201A1
Application number: PCT/JP2019/017229
Authority: WO
Inventors: 友基藤野
Original assignee: 株式会社デンソー
Priority date: 2018-05-08
Filing date: 2019-04-23
Publication date: 2019-11-14

Abstract

An injector (20) that comprises a housing (30), a fixed core (41), a mobile core (42), a coil (44), a needle (50), and a spring (61). A shaft part (51) has a first protruding part (53) and a second protruding part (54) that sandwich the mobile core, the first protruding part being on a valve part (52) side, and the second protruding part being on the fixed core side. A surface of the mobile core that is on an injection hole (32) side has a first recessed part (46) that surrounds a through hole (43) and can house the first protruding part. The distance in the axial direction (AX) between a bottom surface of the first recessed part and a surface of the mobile core that is on the fixed core side is shorter than the distance in the axial direction between a surface of the first protruding part that is on the fixed core side and a surface of the second protruding part that is on the valve part side, and fuel can be sealed in a space (110) that is enclosed by the shaft part, the first protruding part, and the first recessed part.

Description

Injector

Cross-reference of related applications

This application is filed on May 8, 2018, Japanese application number 2018-089807, Japanese application number 2018-206208, filed on November 1, 2018, and filed on March 11, 2019. Which is based on Japanese Patent Application No. 2019-043266, which is incorporated herein by reference.

This disclosure relates to an injector.

For example, Patent Document 1 discloses a fuel injection valve that includes a needle valve that opens and closes a nozzle hole and a movable core that is provided separately from the needle valve. In this fuel injection valve, the needle valve moves in the valve opening direction together with the movable core that receives the magnetic attractive force from the fixed core. After the movable core contacts the fixed core, the needle valve moves away from the movable core due to inertia and further moves in the valve opening direction. Thereafter, the needle valve is pushed back by the spring, moves in the valve closing direction, and again contacts the movable core.

JP 2016-65545 A

In the fuel injection valve (injector) described above, when the needle is pushed back by the spring and comes into contact with the movable core, a large impact force may be generated and the contact portion between the needle and the movable core may be worn. Suppressing wear at the contact portion is an important issue regardless of whether it is an injector that injects liquid fuel or an injector that injects gaseous fuel. In particular, in an injector that injects gaseous fuel, compared to an injector that injects liquid fuel, the squeeze force caused by the fuel received by the contact portion when the needle and the movable core come into contact with each other is reduced, and the impact force is increased. The problem becomes more prominent.

This disclosure can be realized as the following forms.

According to the first aspect of the present disclosure, an injector is provided. The injector has an injection hole for injecting fuel, a cylindrical housing having a first flow path communicating with the injection hole, a first housing fixed in the housing and communicating with the first flow path. A cylindrical fixed core having two flow paths, and a reciprocating movement in the first flow path on the nozzle hole side of the fixed core along the axial direction of the housing. A movable core having an outer diameter larger than the inner diameter and having a through-hole smaller than the inner diameter of the fixed core; a coil that generates a magnetic field that moves the movable core toward the fixed core by energization; A needle having a shaft passing through a through-hole in a reciprocating manner in the axial direction, and a valve formed at an end of the shaft on the nozzle hole side and capable of opening and closing the nozzle, and the needle A spray that biases toward the nozzle hole side Provided grayed and, the. The shaft portion has a first protrusion on the valve portion side and a second protrusion on the fixed core across the movable core, and the first protrusion is formed in the radial direction of the movable core. The second protrusion protrudes outward from the edge of the through hole, and protrudes outward from the edge of the through hole of the movable core and inward of the inner periphery of the fixed core in the radial direction. The surface of the movable core on the nozzle hole side has a first recess capable of accommodating the first protrusion around the through hole, and the surface of the first protrusion on the fixed core side, The distance along the axial direction between the bottom surface of the first recess and the surface on the fixed core side of the movable core than the distance along the axial direction with the valve-side surface of the second protrusion. Is smaller. The injector is configured such that the fuel can be sealed in a space surrounded by the shaft portion, the first protrusion, and the first recess.

According to the injector of this embodiment, when the nozzle hole is opened and closed by the needle, the fuel filled in the space surrounded by the shaft portion of the needle, the first protrusion, and the first recess of the movable core is pressurized, By decelerating the needle, the impact force when the first projecting portion collides with the movable core is reduced. Along with this, the impact force when the second protrusion and the movable core collide is also reduced. Therefore, wear at the contact portion between the first protrusion and the movable core and the contact portion between the second protrusion and the movable core can be suppressed.

According to the second embodiment of the present disclosure, an injector is provided. The injector has an injection hole for injecting fuel, a cylindrical housing having a first flow path communicating with the injection hole, a first housing fixed in the housing and communicating with the first flow path. A cylindrical fixed core having two flow paths, and a reciprocating movement in the first flow path on the nozzle hole side of the fixed core along the axial direction of the housing. A movable core having an outer diameter larger than the inner diameter and having a through-hole smaller than the inner diameter of the fixed core; a coil that generates a magnetic field that moves the movable core toward the fixed core by energization; A needle having a shaft passing through a through-hole in a reciprocating manner in the axial direction, and a valve formed at an end of the shaft on the nozzle hole side and capable of opening and closing the nozzle, and the needle A spray that biases toward the nozzle hole side Provided grayed and, the. The shaft portion has a first protrusion on the valve portion side and a second protrusion on the fixed core across the movable core, and the first protrusion is formed in the radial direction of the movable core. The second protrusion protrudes outward from the edge of the through hole, and protrudes outward from the edge of the through hole of the movable core and inward of the inner periphery of the fixed core in the radial direction. The surface of the movable core on the fixed core side has a recess capable of accommodating the second protrusion around the through hole, and the surface of the first protrusion on the fixed core side and the second The distance along the axial direction between the surface on the nozzle hole side of the movable core and the bottom surface of the recess is smaller than the distance along the axial direction with the surface on the valve part side of the protrusion. . The injector is characterized in that the fuel can be sealed in a space surrounded by the shaft portion, the second projecting portion, and the concave portion.

According to the injector of this aspect, when the nozzle hole is opened by the needle, the fuel filled in the space surrounded by the shaft portion of the needle, the second projecting portion, and the concave portion of the movable core is made negative pressure. By decelerating the needle, the impact force when the first projecting portion collides with the movable core is reduced. Along with this, the impact force when the second protrusion and the movable core collide is also reduced. Therefore, wear at the contact portion between the first protrusion and the movable core and the contact portion between the second protrusion and the movable core can be suppressed.

According to the third aspect of the present disclosure, an injector is provided. The injector has an injection hole for injecting fuel, a cylindrical housing having a first flow path communicating with the injection hole, a first housing fixed in the housing and communicating with the first flow path. A cylindrical fixed core having two flow paths, and a reciprocating movement in the first flow path on the nozzle hole side of the fixed core along the axial direction of the housing. A movable core having a through-hole smaller than the inner diameter, a coil that generates a magnetic field that moves the movable core toward the fixed core when energized, and a shaft that passes through the through-hole in a reciprocating manner in the axial direction. A needle formed at an end of the shaft portion on the nozzle hole side and capable of opening and closing the nozzle hole, and a first spring for biasing the needle toward the nozzle hole side . The shaft portion has a first protrusion on the valve portion side and a second protrusion on the fixed core across the movable core, and the first protrusion is formed in the radial direction of the movable core. The second protrusion protrudes outward from the edge of the through hole, and protrudes outward from the edge of the through hole of the movable core and inward of the inner periphery of the fixed core in the radial direction. The movable core includes a large-diameter portion having a large outer diameter, and a small-diameter portion that is provided closer to the nozzle hole than the large-diameter portion and has a smaller outer diameter than the large-diameter portion. And a first sliding portion facing the first sliding portion provided in the housing, wherein the large diameter portion is a second sliding facing the second sliding portion provided in the housing. Part. The injector is configured such that the fuel can be sealed in a space surrounded by the movable core and the housing between the first sliding portion and the second sliding portion in the axial direction. It is characterized by that.

According to the injector of this embodiment, when the nozzle hole is opened by the needle, the fuel filled in the space surrounded by the movable core and the housing is made negative pressure, and the movable core and the needle are decelerated. Thus, the impact force when the movable core and the fixed core collide and the impact force when the first protrusion and the movable core collide are reduced. Along with this, the impact force when the second protrusion and the movable core collide is also reduced. In addition, during the valve closing operation of the nozzle hole by the needle, the fuel filled in the space surrounded by the movable core and the housing is pressurized, and the movable core and the needle are decelerated, so that the valve portion and the nozzle hole periphery The impact force when the housing collides and the impact force when the movable core collides with the first projecting portion are reduced. In connection with this, the impact force at the time of a collision between a movable core and a 2nd protrusion part is also reduced. Therefore, the contact portion between the movable core and the fixed core, the contact portion between the first protrusion and the movable core, the contact portion between the second protrusion and the movable core, and the contact between the valve portion and the housing around the injection hole. Wear on the part can be suppressed.

The present disclosure can be realized in various forms other than the injector. For example, it is realizable with forms, such as a fuel injection device and a fuel injection method.

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing
FIG. 1 is an explanatory diagram showing a schematic configuration of an injector in the first embodiment. FIG. 2 is a first explanatory view showing the valve opening operation of the injector in the first embodiment, FIG. 3 is a second explanatory view showing the valve opening operation of the injector in the first embodiment, FIG. 4 is a third explanatory view showing the valve opening operation of the injector in the first embodiment, FIG. 5 is a first explanatory view showing the valve closing operation of the injector in the first embodiment, FIG. 6 is a second explanatory view showing the valve closing operation of the injector in the first embodiment, FIG. 7 is a third explanatory diagram showing the valve closing operation of the injector in the first embodiment, FIG. 8 is an explanatory diagram showing a schematic configuration of an injector in the second embodiment. FIG. 9 is an explanatory diagram showing a schematic configuration of an injector in the third embodiment. FIG. 10 is an explanatory diagram showing a schematic configuration of the injector in the fourth embodiment. FIG. 11 is an explanatory view showing the valve opening operation of the injector in the fourth embodiment, FIG. 12 is an explanatory diagram showing a schematic configuration of the injector in the fifth embodiment. FIG. 13 is an explanatory diagram showing a schematic configuration of an injector in the sixth embodiment. FIG. 14 is an explanatory diagram showing a schematic configuration of an injector in the seventh embodiment. FIG. 15 is a first explanatory view showing the valve opening operation of the injector in the seventh embodiment, FIG. 16 is a second explanatory view showing the valve opening operation of the injector in the seventh embodiment, FIG. 17 is a third explanatory view showing the valve opening operation of the injector in the seventh embodiment, FIG. 18 is a first explanatory view showing the valve closing operation of the injector in the seventh embodiment, FIG. 19 is a second explanatory diagram showing the valve closing operation of the injector in the seventh embodiment, FIG. 20 is a third explanatory diagram showing the valve closing operation of the injector in the seventh embodiment, FIG. 21 is an explanatory diagram showing a schematic configuration of an injector in the eighth embodiment. FIG. 22 is a partially enlarged view of the elastic member and the low friction member in the eighth embodiment, FIG. 23 is an explanatory diagram showing a schematic configuration of an injector in the ninth embodiment. FIG. 24 is an explanatory diagram showing a schematic configuration of an injector in the tenth embodiment.

A. First embodiment:
As shown in FIG. 1, the injector 20 of the first embodiment includes a housing 30, a fixed core 41, a movable core 42, a coil 44, a needle 50, a first spring 61, and a second spring 62. I have. The injector 20 is a device for injecting fuel. Injector 20 of this embodiment injects hydrogen gas which is gaseous fuel as fuel.

The housing 30 is a cylindrical member in which a nozzle hole 32 for injecting fuel and a first flow path 101 communicating with the nozzle hole 32 are formed. The housing 30 of the present embodiment includes, in order from the nozzle hole 32 side, the nozzle tip part 31 in which the nozzle holes 32 are formed, the first magnetic part 34, the nonmagnetic part 36, the second magnetic part 35, and the inlet part. 37. A valve seat 33 is provided around the nozzle hole 32 on the inner surface of the housing 30 of the nozzle tip portion 31. Between the nozzle tip part 31 and the first magnetic part 34, between the first magnetic part 34 and the nonmagnetic part 36, between the nonmagnetic part 36 and the second magnetic part 35, and between the second magnetic part 35 and the inlet part. 37 is welded at a welded portion 38. In the present embodiment, the nozzle tip portion 31 is made of martensitic stainless steel that is a nonmagnetic material. The first magnetic part 34 and the second magnetic part 35 are made of a ferritic stainless steel that is a magnetic material. The nonmagnetic portion 36 is formed of austenitic stainless steel that is a nonmagnetic material.

A supply pipe (not shown) for supplying fuel to the injector 20 is connected to the inlet portion 37. The supply pipe is connected so as to contact a backup ring 72 provided at the inlet portion 37. A gap between the supply pipe and the inlet portion 37 is sealed by an O-ring 73 provided on the backup ring 72. An inlet channel 103 is formed in the inlet portion 37. A filter 71 is provided in the inlet channel 103. The filter 71 collects foreign matter contained in the fuel supplied from the supply pipe and suppresses the foreign matter from flowing into the housing 30.

The fixed core 41 is a cylindrical member fixed in the housing 30. A second flow path 102 communicating with the first flow path 101 is formed in the fixed core 41. The opposite side of the second channel 102 from the first channel 101 communicates with the inlet channel 103. In the present embodiment, the fixed core 41 is made of a ferritic stainless steel that is a magnetic material.

The movable core 42 is a cylindrical member provided so as to be capable of reciprocating along the axial direction AX of the housing 30 in the first flow path 101 closer to the injection hole 32 than the fixed core 41. The movable core 42 has an outer diameter larger than the inner diameter of the fixed core 41 and has a through hole 43 smaller than the inner diameter of the fixed core 41. The surface of the movable core 42 on the nozzle hole 32 side has a first recess 46 around the through hole 43. The first recess 46 is a circular depression formed on the surface of the movable core 42 on the nozzle hole 32 side. The movable core 42 and the fixed core 41 are configured to be contactable in the axial direction AX. In the present embodiment, the movable core 42 is made of a ferritic stainless steel that is a magnetic material.

The coil 44 is wound around the outer periphery of the housing 30. The outer periphery of the coil 44 is covered with a yoke 45 formed of ferritic stainless steel, which is a magnetic material. The coil 44 generates a magnetic field that moves the movable core 42 toward the fixed core 41 when energized. The current flowing through the coil 44 is supplied from, for example, a power supply source (not shown) such as a battery. The voltage applied from the power supply source is controlled by a control unit (not shown).

The needle 50 includes a shaft portion 51, a valve portion 52, a stopper portion 53, and a flange portion 54. The stopper portion 53 may be referred to as a first projecting portion, and the flange portion 54 may be referred to as a second projecting portion. The shaft portion 51 is provided so as to reciprocate along the axial direction AX in the through hole 43 of the movable core 42. The central axis of the shaft portion 51 is the same as the central axis of the fixed core 41 and the central axis of the movable core 42. A communication channel 104 through which fuel flows from the second channel 102 toward the first channel 101 is formed inside the shaft portion 51.

The valve part 52 is formed at the end of the shaft part 51 on the nozzle hole 32 side. The valve portion 52 is configured to be able to come into contact with a valve seat 33 provided in the nozzle tip portion 31, and is a valve body that opens and closes the injection hole 32 when the shaft portion 51 reciprocates along the axial direction AX. . The fuel that has flowed through the housing 30 in the order of the inlet channel 103, the second channel 102, the communication channel 104, and the first channel 101 is injected from the nozzle hole 32 when the nozzle hole 32 is opened. .

The stopper portion 53 is a disk-shaped member located on the valve portion 52 side with the movable core 42 in the shaft portion 51 interposed therebetween. The stopper portion 53 protrudes larger than the diameter of the through hole 43 in the radial direction of the shaft portion 51. In the present embodiment, the stopper portion 53 is formed of austenitic stainless steel, which is a nonmagnetic material, and is press-fitted into the shaft portion 51. In the present embodiment, the stopper portion 53 is configured to be accommodated in the first recess 46 of the movable core 42. By accommodating the stopper 53 in the first recess 46 of the movable core 42, a space surrounded by the shaft 51, the stopper 53, and the first recess 46 of the movable core 42 is formed. This space is also called an airtight chamber 110. The airtight chamber 110 is a space in which fuel can be enclosed. The size of the gap between the stopper 53 and the side surface of the first recess 46 is such that the fuel can be supplied into the hermetic chamber 110 at least when the valve is closed, and the fuel in the hermetic chamber 110 is boosted to a predetermined pressure or higher. When set, the fuel can be discharged. In addition, the magnitude | size of the clearance gap between the stopper part 53 and the side surface of the 1st recessed part 46 is set according to the kind of fuel. In the present embodiment, hydrogen gas is used as the fuel, and the gap between the stopper portion 53 and the side surface of the first recess 46 is about 2 to 3 μm. When liquid fuel is used as the fuel, the gap between the stopper portion 53 and the side surface of the first recess 46 is set larger.

The flange portion 54 is a disk-shaped member located on the fixed core 41 side with the movable core 42 in the shaft portion 51 interposed therebetween. The flange portion 54 protrudes in the radial direction of the shaft portion 51 larger than the diameter of the through hole 43 and smaller than the inner diameter of the fixed core 41. The bottom surface of the first recess 46 and the fixed core 41 side of the movable core 42 than the distance along the axial direction AX between the surface of the stopper portion 53 on the fixed core 41 side and the surface of the flange portion 54 on the valve portion 52 side. The distance along the axial direction AX with respect to the surface is smaller. In other words, the thickness of the movable core 42 in the portion where the first recess 46 is formed is along the axial direction AX between the surface on the fixed core 41 side of the stopper portion 53 and the surface on the valve portion 52 side of the flange portion 54. Smaller than the interval. In the present embodiment, the shaft portion 51, the valve portion 52, and the flange portion 54 are integrally formed. The shaft portion 51, the valve portion 52, and the flange portion 54 are made of martensitic stainless steel, which is a nonmagnetic material.

The first spring 61 is disposed in the second flow path 102. The first spring 61 urges the flange portion 54 from the fixed core 41 side toward the injection hole 32 side. In the present embodiment, the first spring 61 is a coil spring. An adjusting pipe 63 is provided upstream of the first spring 61 in the second flow path 102. The force with which the first spring 61 pushes the flange portion 54 is configured to be adjustable by adjusting the position of the end portion of the adjusting pipe 63 on the injection hole 32 side.

The second spring 62 is disposed in the first flow path 101 and urges the movable core 42 from the injection hole 32 side toward the fixed core 41 side. The second spring 62 of the present embodiment is a coil spring. In the valve closed state, the movable core 42 is pushed by the second spring 62 and the flange portion 54 and the movable core 42 come into contact with each other.

The valve opening operation performed in the injector 20 of this embodiment is demonstrated using FIGS. 1-4. As shown in FIG. 1, the valve portion 52 is in contact with the valve seat 33 in the valve closed state. In the closed state, the coil 44 is not energized. The flange portion 54 is pushed from the fixed core 41 side toward the nozzle hole 32 side by the first spring 61. The movable core 42 is pushed by the second spring 62 from the nozzle hole 32 side toward the fixed core 41 side. Therefore, the flange portion 54 and the movable core 42 are in contact with each other. A predetermined interval necessary for opening the valve is secured between the movable core 42 and the fixed core 41 in the valve-closed state. The fuel in the airtight chamber 110 is filled with the fuel flowing in the first flow path 101 from the gap between the stopper 53 and the side surface of the first recess 46. This state is also called an initial state.

As shown in FIG. 2, when energization to the coil 44 is started, a magnetic attractive force from the fixed core 41 acts on the movable core 42, and the movable core 42 moves from the injection hole 32 side toward the fixed core 41 side. The movable core 42 collides with the fixed core 41 by moving. This magnetic attraction force is generated by a magnetic field formed around the fixed core 41 as the coil 44 is energized. In the initial state, since the flange portion 54 and the movable core 42 are in contact with each other, when the movable core 42 moves from the nozzle hole 32 side toward the fixed core 41 side, the flange portion 54 is pushed by the movable core 42. The needle 50 moves together with the movable core 42. Therefore, the valve part 52 moves away from the valve seat 33 and fuel injection from the injection hole 32 is started. As the needle 50 moves, the first spring 61 is pushed by the flange portion 54 and contracts, so that elastic energy is stored in the first spring 61.

As shown in FIG. 3, after the movable core 42 collides with the fixed core 41, the needle 50 is detached from the movable core 42 due to inertia and continues to move further toward the upstream side of the second flow path 102. The stopper 53 and the bottom surface of the first recess 46 approach each other in the axial direction AX, and the volume of the hermetic chamber 110 is reduced. As the volume of the hermetic chamber 110 is reduced, the fuel in the hermetic chamber 110 is pressurized. As the fuel in the hermetic chamber 110 is pressurized, the movement of the needle 50 is decelerated. When the fuel in the hermetic chamber 110 is increased to a predetermined pressure or higher, the fuel in the hermetic chamber 110 is gradually discharged from the gap between the stopper portion 53 and the side surface of the first recess 46, and 1 The bottom surface of the recess 46 collides at a low speed. That is, the hermetic chamber 110 serves as a damper. Therefore, the impact force when the stopper part 53 and the movable core 42 collide is reduced. When the stopper portion 53 and the bottom surface of the first recess 46 collide, a part of the fuel may remain in the airtight chamber 110. That is, the stopper 53 and the bottom surface of the first recess 46 may collide with each other through the fuel remaining in the hermetic chamber 110. Further, the impact force caused by the collision between the movable core 42 and the fixed core 41 is reduced by the needle 50 being detached from the movable core 42.

As shown in FIG. 4, after the stopper portion 53 and the movable core 42 collide, the elastic energy stored in the first spring 61 is released as power to push back the needle 50, so that the needle 50 is fixed to the fixed core 41. Moving from the side toward the injection hole 32 side, the flange portion 54 collides with the movable core 42. At this time, since the fuel in the hermetic chamber 110 is pressurized, the impact force when the stopper portion 53 and the movable core 42 collide with each other is reduced, so that the rebound of the needle 50 is suppressed. Further, the needle 50 is decelerated as the needle 50 is pushed back, the volume of the hermetic chamber 110 is expanded, and the inside of the hermetic chamber 110 is set to a negative pressure. Therefore, the impact force when the flange portion 54 and the movable core 42 collide is reduced. Thereafter, the flange portion 54 is supported by the movable core 42, thereby ensuring a lift amount between the valve portion 52 and the valve seat 33. The valve opening operation in the injector 20 is completed by the series of operations described above.

The valve closing operation performed in the injector 20 of the present embodiment will be described with reference to FIGS. As shown in FIG. 5, when the energization to the coil 44 is stopped, the magnetic attractive force from the fixed core 41 that has worked on the movable core 42 is unloaded, and the needle biased by the first spring 61. The valve portion 52 collides with the valve seat 33 by moving 50 from the fixed core 41 side toward the nozzle hole 32 side. Therefore, the valve is closed and the fuel injection from the nozzle hole 32 is stopped. When the needle 50 moves, the movable core 42 moves together with the needle 50 by being pushed by the flange portion 54. The fuel in the first flow path 101 flows into the airtight chamber 110 through a gap between the stopper portion 53 and the side surface of the first recess 46.

As shown in FIG. 6, after the valve portion 52 collides with the valve seat 33, the movable core 42 continues to move from the fixed core 41 side toward the injection hole 32 side due to inertia, so that the stopper portion 53 and As the bottom surface of the first recess 46 approaches in the axial direction AX, the volume of the hermetic chamber 110 is reduced. As the volume of the hermetic chamber 110 is reduced, the fuel in the hermetic chamber 110 is pressurized. As the fuel in the hermetic chamber 110 is pressurized, the movement of the needle 50 is decelerated. When the fuel in the hermetic chamber 110 is increased to a predetermined pressure or higher, the fuel in the hermetic chamber 110 is gradually discharged from the gap between the stopper portion 53 and the side surface of the first recess 46, and 1 The bottom surface of the recess 46 collides at a low speed. Therefore, the impact force when the stopper part 53 and the movable core 42 collide is reduced. The impact force due to the collision between the valve portion 52 and the valve seat 33 is reduced by the movement of the movable core 42 separately from the needle 50.

As shown in FIG. 7, the movable core 42 is moved to the nozzle hole 32 side by an impact force when the stopper portion 53 and the movable core 42 collide and a force by which the second spring 62 pushes the movable core 42 back to the fixed core 41 side. Bounces toward the fixed core 41 side, and the flange portion 54 and the movable core 42 collide with each other. At this time, as the fuel in the hermetic chamber 110 is boosted, the impact force when the stopper portion 53 and the movable core 42 collide with each other is reduced, so that the rebound of the movable core 42 is suppressed. Further, the needle 50 is decelerated as the needle 50 is pushed back, the volume of the hermetic chamber 110 is expanded, and the inside of the hermetic chamber 110 is set to a negative pressure. Therefore, the impact force when the flange portion 54 and the movable core 42 collide is reduced. Thereafter, the movable core 42 is supported by the second spring 62 and returns to the initial state. The valve closing operation in the injector 20 is completed by the series of operations described above.

According to the injector 20 of the present embodiment described above, the stopper portion 53 and the bottom surface of the first recess 46 of the movable core 42 approach each other, the fuel in the hermetic chamber 110 is pressurized, and the needle 50 is decelerated. Thus, the impact force when the stopper portion 53 and the movable core 42 collide with each other is reduced. Accordingly, the impact force when the flange portion 54 and the movable core 42 collide with each other is also reduced. Therefore, wear at the contact portion between the stopper portion 53 and the movable core 42 and at the contact portion between the flange portion 54 and the movable core 42 can be suppressed. In particular, as in the present embodiment, when the injector 20 is configured to inject gaseous fuel, the contact portion between the stopper portion 53 and the movable core 42 and the flange portion 54 are compared to the configuration in which liquid fuel is injected. Since the squeeze force by the fuel when the contact portion with the movable core 42 collides is small, the impact force at each contact portion becomes large. Therefore, the effect of suppressing wear of each contact portion due to the provision of the hermetic chamber 110 is great.

In the present embodiment, by adjusting the diameter of the stopper portion 53, the magnitude of the flow path resistance in the gap between the stopper portion 53 and the side surface of the first recess 46 of the movable core 42 can be adjusted. Therefore, the speed when the stopper 53 and the bottom surface of the first recess 46 collide with each other with a simple structure can be adjusted.

B. Second embodiment:
As shown in FIG. 8, in the injector 20B of the second embodiment, the stopper portion 53 has a first orifice 111 that communicates from the surface on the fixed core 41 side to the surface on the valve portion 52 side. And different. In the second embodiment, the gap between the stopper portion 53 and the side surface of the first recess 46 is smaller than in the first embodiment. Other configurations and opening / closing operations are the same as those in the first embodiment unless otherwise specified.

According to the injector 20B of this form, when the volume of the hermetic chamber 110 is reduced and the fuel in the hermetic chamber 110 is pressurized, the fuel in the hermetic chamber 110 is provided in the stopper portion 53 of the needle 50. It is discharged through the first orifice 111. Therefore, by adjusting the number and shape of the first orifices 111, the magnitude of the flow path resistance in the first orifices 111 can be adjusted, and the fuel in the hermetic chamber 110 is transferred to the side surfaces of the stopper 53 and the first recess 46. The deceleration degree of the needle 50 can be adjusted more easily than in the form of discharging from the gap.

Further, in the present embodiment, since the first orifice 111 is provided in the stopper portion 53 of the needle 50, the orifice provided from the bottom surface of the first recess 46 of the movable core 42 to the surface on the fixed core 41 side is provided. In contrast, the degree of deceleration of the needle 50 can be adjusted while ensuring the magnetic attractive force that the movable core 42 receives from the fixed core 41.

C. Third embodiment:
As shown in FIG. 9, in the injector 20C of the third embodiment, the movable core 42 has a second orifice 112 that communicates from the bottom surface of the first recess 46 to the surface on the fixed core 41 side. And different. In 3rd Embodiment, the clearance gap between the stopper part 53 and the side surface of the 1st recessed part 46 is smaller than 1st Embodiment. Other configurations and opening / closing operations are the same as those in the first embodiment unless otherwise specified.

According to the injector 20C of this form, when the volume of the hermetic chamber 110 is reduced and the fuel in the hermetic chamber 110 is pressurized, the fuel in the hermetic chamber 110 is supplied to the second orifice provided in the movable core 42. It is discharged through 112. Therefore, by adjusting the number and shape of the second orifices 112, the magnitude of the flow path resistance in the second orifice 112 can be adjusted, and the fuel in the hermetic chamber 110 is transferred to the side surfaces of the stopper 53 and the first recess 46. The deceleration degree of the needle 50 can be adjusted more easily than in the form of discharging from the gap.

Further, in the present embodiment, the opening on the fixed core 41 side of the second orifice 112 provided in the movable core 42 is sealed by the flange portion 54 of the needle 50 in the valve closed state. Therefore, in the valve opening operation, when the flange portion 54 of the needle 50 is detached from the movable core 42, the needle 50 can be decelerated even when the second orifice 112 is set to a negative pressure.

D. Fourth embodiment:
As shown in FIG. 10, in the injector 20 D of the fourth embodiment, the surface on the injection hole 32 side of the movable core 42 does not have the first recess 46 around the through hole 43, and the fixed core 41 of the movable core 42. The side surface is different from the first embodiment in having a second recess 47 that can accommodate the flange portion 54 around the through-hole 43. The surface on the injection hole 32 side of the movable core 42 and the second recess 47 are larger than the distance along the axial direction AX between the surface on the fixed core 41 side of the stopper portion 53 and the surface on the valve portion 52 side of the flange portion 54. The distance along the axial direction AX with respect to the bottom surface is smaller. In other words, the thickness of the movable core 42 in the portion where the second recess 47 is formed is along the axial direction AX between the surface on the fixed core 41 side of the stopper portion 53 and the surface on the valve portion 52 side of the flange portion 54. Smaller than the interval. In the present embodiment, the hermetic chamber 110 D is surrounded by the shaft portion 51, the flange portion 54, and the second concave portion 47 of the movable core 42 by accommodating the flange portion 54 in the second concave portion 47 of the movable core 42. It is formed as a space. In the valve-closed body, the force by which the flange portion 54 is pushed from the fixed core 41 side toward the injection hole 32 side by the first spring 61 and the flange portion 54 from the injection hole 32 side by the fuel in the hermetic chamber 110D. A small gap is formed between the flange portion 54 and the bottom surface of the second recess 47 by balancing the force pushed toward the fixed core 41 side. Other configurations and opening / closing operations are the same as those in the first embodiment unless otherwise specified.

As shown in FIG. 11, after the movable core 42 collides with the fixed core 41, the needle 50 is detached from the movable core 42 due to inertia and continues to move further toward the upstream side of the second flow path 102. The distance between the flange portion 54 and the bottom surface of the second recess 47 in the axial direction AX is increased, and the volume of the hermetic chamber 110D is increased. As the volume of the hermetic chamber 110D is increased, the fuel in the hermetic chamber 110D is set to a negative pressure, whereby the needle 50 is decelerated. Thereafter, the stopper portion 53 of the needle 50 and the surface of the movable core 42 on the injection hole 32 side collide, and further, the flange portion 54 of the needle 50 and the bottom surface of the second recess 47 of the movable core 42 collide.

The impact force when the stopper portion 53 and the movable core 42 collide is also reduced by the injector 20D of this form. Accordingly, the impact force when the flange portion 54 and the movable core 42 collide with each other is also reduced. Therefore, wear at the contact portion between the stopper portion 53 and the movable core 42 and at the contact portion between the flange portion 54 and the movable core 42 can be suppressed.

E. Fifth embodiment:
As shown in FIG. 12, the injector 20E of the fifth embodiment is different from the first embodiment in that liquid fuel is injected as fuel. Examples of the liquid fuel include gasoline and light oil. Further, the nozzle tip portion 31E is different from the first embodiment in that a plurality of nozzle holes 32 are provided. In this embodiment, since liquid fuel is used as the fuel, the gap between the stopper portion 53 and the side surface of the first recess 46 is larger than that in the first embodiment. In the injector 20E of the present embodiment, not the gaseous fuel but the liquid fuel is sealed in the hermetic chamber 110, so that the hermetic chamber 110 can also be called a liquid-tight chamber. The hermetic chamber 110 can also be called a fuel enclosure chamber or a damper chamber. Other configurations and opening / closing operations are the same as those in the first embodiment unless otherwise specified.

According to the injector 20E of this form, since it is a form which injects liquid fuel, compared with the form which injects gaseous fuel, the contact part of the stopper part 53 and the movable core 42, and the flange part 54 and the movable core 42 The squeeze force by the fuel when the contact portion collides with the fuel increases, and the impact force at each contact portion decreases.

F. Sixth embodiment:
As shown in FIG. 13, in the injector 20F of the seventh embodiment, the movable core 42F has a magnetic attraction portion 141 that contacts the fixed core 41 when the injector 20F is opened, and has a higher hardness than the magnetic attraction portion 141. The first embodiment is different from the first embodiment in that the first recess 46 is provided in the high hardness portion 142. Other configurations and opening / closing operations are the same as those in the first embodiment unless otherwise specified.

In the present embodiment, the surface of the movable core 42F that comes into contact with the needle 50 is configured by the high hardness portion 142. That is, the inner peripheral portion of the surface of the movable core 42F on the fixed core 41 side, the surface in the through hole 43 of the movable core 42F, and the surface of the first recess 46 of the movable core 42F are configured by the high hardness portion 142. ing. The surface on the injection hole 32 side of the movable core 42 F is configured by a high hardness portion 142. A region on the side of the fixed core 41 on the side surface of the movable core 42F is configured by the magnetic attraction portion 141, and a region on the side of the injection hole 32 on the side surface of the movable core 42F is configured by the high hardness portion 142. The outer diameter of the high hardness portion 142 is larger than the outer diameter of the magnetic attraction portion 141. That is, the gap between the high hardness portion 142 of the movable core 42F and the housing 30 is smaller than the gap between the magnetic attraction portion 141 of the movable core 42F and the housing 30. A region in contact with the fixed core 41 in the movable core 42 F is configured by the magnetic attraction unit 141. In order to suppress a decrease in magnetic attractive force from the fixed core 41 with respect to the movable core 42F, it is preferable that the high hardness portion 142 is not provided in a region of the movable core 42F that contacts the fixed core 41.

In the present embodiment, the magnetic attraction portion 141 is made of a ferritic stainless steel that is a magnetic material, and the high hardness portion 142 is made of a martensitic stainless steel that is a nonmagnetic material. The high hardness part 142 and the magnetic attraction part 141 are joined by press fitting or welding, for example.

The hardness of the magnetic attraction portion 141 and the hardness of the high hardness portion 142 can be examined by a Vickers hardness test (JIS Z 2244). The Vickers hardness of the magnetic attraction portion 141 formed of ferritic stainless steel is 200 HV or less, and the Vickers hardness of the high hardness portion 142 formed of martensitic stainless steel is 633 HV to 772 HV.

According to the injector 20F of the present embodiment described above, the first recess 46 is provided in the high hardness portion 142 having a hardness higher than that of the magnetic attraction portion 141. Therefore, the first recess 46 is formed by grinding or the like. It can be formed with high dimensional accuracy. Therefore, since the gap between the stopper portion 53 and the side surface of the first recess 46 can be made smaller, the movement of the needle 50 can be decelerated more effectively. In particular, in the present embodiment, by providing the high hardness portion 142 having a hardness higher than that of the magnetic attraction portion 141 at the contact portion between the movable core 42F and the needle 50 and the contact portion between the movable core 42F and the housing 30, these are provided. The wear of the movable core 42F at the contact portion can be suppressed.

G. Seventh embodiment:
As shown in FIG. 14, in the injector 20G of the seventh embodiment, the airtight chamber 110 surrounded by the shaft portion 51, the stopper portion 53, and the first concave portion 46 of the movable core 42 is not provided, and the movable core 42G Unlike the first embodiment, an airtight chamber 110G surrounded by the housing 30G is provided. Other configurations and opening / closing operations are the same as those in the first embodiment unless otherwise specified.

The housing 30G in the present embodiment includes, in order from the nozzle hole 32 side, the nozzle tip part 31G in which the nozzle holes 32 are formed, the integrally formed part 131, the first magnetic part 34, the nonmagnetic part 36, and the second magnetic part. The part 35 and the inlet part 37 are comprised. In the present embodiment, the nozzle tip portion 31G and the integral forming portion 131 are integrally formed without being welded. Between the integrally formed portion 131 and the first magnetic portion 34, between the first magnetic portion 34 and the nonmagnetic portion 36, between the nonmagnetic portion 36 and the second magnetic portion 35, and between the second magnetic portion 35 and the entrance portion. 37 is welded at a welded portion 38. The nozzle tip portion 31G may be referred to as a nozzle hole forming portion.

The integral forming part 131 has an inner diameter reducing part 135 having a smaller inner diameter and an inner diameter expanding part 136 having a larger inner diameter than the inner diameter reducing part 135 and provided on the fixed core 41 side with respect to the inner diameter reducing part 135. The inner diameter reduced portion 135 and the inner diameter enlarged portion 136 are connected by a step portion 39. The inner diameter reduction part 135 has a first sliding part 137 facing a first sliding part 147 of the movable core 42G described later. The inner diameter enlarged portion 136 has a second sliding portion 138 that faces a second sliding portion 148 of the movable core 42G described later. That is, the nozzle hole 32, the first sliding portion 137, and the second sliding portion 138 are formed in one component. The sliding means that the movable core 42G moves in the axial direction AX in a state where fuel is interposed between the movable core 42G and the housing 30G or in a state where fuel is not interposed between the movable core 42G and the housing 30G. Along the inner surface of the housing 30G.

In the present embodiment, the nozzle tip portion 31G and the integrally formed portion 131 are formed of martensitic stainless steel that is a nonmagnetic material. The first magnetic part 34 and the second magnetic part 35 are made of ferritic stainless steel, which is a magnetic material. The nonmagnetic portion 36 is formed of austenitic stainless steel that is a nonmagnetic material.

The movable core 42G in the present embodiment has a cylindrical large-diameter portion 146 having a large outer diameter and a cylindrical shape having a smaller outer diameter than the large-diameter portion 146 provided on the injection hole 32 side of the large-diameter portion 146. A small diameter portion 145. The through hole 43 passes through the large diameter portion 146 and the small diameter portion 145 in the axial direction AX. The small diameter portion 145 has a first sliding portion 147 facing the first sliding portion 137 provided in the housing 30G, and the large diameter portion 146 is a second sliding portion provided in the housing 30G. A second sliding portion 148 facing the portion 138 is provided. The first sliding portion 147 is provided on the side surface of the small diameter portion 145, and the second sliding portion 148 is provided on the side surface of the large diameter portion 146.

In the present embodiment, the movable core 42G has a magnetic attracting portion 141 that contacts the fixed core 41 when the injector 20G is opened, and a high hardness portion 142 that is harder than the magnetic attracting portion 141. The first sliding portion 147 and the second sliding portion 148 are provided in the high hardness portion 142. In the present embodiment, the small diameter portion 145 is configured only by the high hardness portion 142. The large diameter portion 146 includes a high hardness portion 142 and a magnetic attraction portion 141. An inner peripheral portion of the surface of the large diameter portion 146 on the fixed core 41 side is configured by a high hardness portion 142. The surface on the nozzle hole 32 side of the large diameter portion 146 is constituted by the high hardness portion 142. The surface in the through hole 43 of the large diameter portion 146 is configured by the high hardness portion 142. The region on the side of the fixed core 41 on the side surface of the large diameter portion 146 is configured by the magnetic attraction portion 141, and the region on the side of the injection hole 32 on the side surface of the large diameter portion 146 is configured by the high hardness portion 142. The outer diameter of the high hardness portion 142 is larger than the outer diameter of the magnetic attraction portion 141. That is, the gap between the high hardness portion 142 of the movable core 42G and the housing 30G is smaller than the gap between the magnetic attraction portion 141 of the movable core 42G and the housing 30G. A region in contact with the fixed core 41 in the movable core 42 G is configured by the magnetic attraction unit 141.

In the present embodiment, the stopper portion 53 of the needle 50 is provided between the nozzle hole 32 and the small diameter portion 145 of the movable core 42G provided with the first sliding portion 147 in the axial direction AX. For example, when a foreign matter such as metal powder is caught between the shaft portion 51 of the needle 50 and the movable core 42G, the distance between the flange portion 54 and the movable core 42G in the axial direction AX is the first in the valve-closed state. There is a possibility that an open failure of the injector 20G that does not return from a state that is longer than the length of the two springs 62 and remains closed while the valve is open may occur. Therefore, the stopper portion 53 causes the flange portion 54 and the movable core 42G to move relative to each other so that the distance between the flange portion 54 and the movable core 42G in the axial direction AX is equal to or less than the length of the second spring 62 in the valve-closed state. Movement amount is regulated.

In the present embodiment, the magnetic attraction portion 141 is made of a ferritic stainless steel that is a magnetic material, and the high hardness portion 142 is made of a martensitic stainless steel that is a nonmagnetic material. The high hardness part 142 and the magnetic attraction part 141 are joined by press fitting or welding, for example. In addition, the hardness of the magnetic attraction part 141 and the hardness of the high hardness part 142 can be investigated by a Vickers hardness test (JIS Z 2244).

In the present embodiment, between the first sliding portion 137 and the second sliding portion 148 in the axial direction AX, the surface on the nozzle hole 32 side of the large-diameter portion 146 of the movable core 42G and the movable core 42 A space surrounded by the side surface of the small diameter portion 145, the stepped portion 39 in the integrally formed portion 131 of the housing 30G, and the inner diameter enlarged portion 136 in the integrally formed portion 131 of the housing 30G is formed. This space is also called an airtight chamber 110G. The airtight chamber 110G is a space in which fuel can be enclosed. The size of the gap between the first sliding portion 147 and the first sliding portion 137 and the size of the gap between the second sliding portion 148 and the second sliding portion 138 are at least the movement of the movable core 42G. In the stopped state, the fuel can be supplied into the hermetic chamber 110G, and the fuel can be discharged from the hermetic chamber 110G when the fuel in the hermetic chamber 110G is boosted to a predetermined pressure or higher.

In the hermetic chamber 110G, a second spring 62 that urges the movable core 42G toward the fixed core 41 is provided. The second spring 62 biases the surface on the nozzle hole 32 side in the large diameter portion 146 of the movable core 42G.

The valve opening operation performed in the injector 20G of the present embodiment will be described with reference to FIGS. As shown in FIG. 14, the valve portion 52 is in contact with the valve seat 33 in the valve closing state. In the closed state, the coil 44 is not energized. The flange portion 54 is pushed from the fixed core 41 side toward the nozzle hole 32 side by the first spring 61. The large diameter portion 146 of the movable core 42G is pushed by the second spring 62 from the injection hole 32 side toward the fixed core 41 side. Therefore, the flange portion 54 and the large diameter portion 146 of the movable core 42G are in contact with each other. A predetermined interval necessary for opening the valve is secured between the large-diameter portion 146 of the movable core 42G and the fixed core 41 in the valve-closed state. In the airtight chamber 110 G, the first flow path 101 is formed from a gap between the first sliding portion 147 and the first sliding portion 137 and a gap between the second sliding portion 148 and the second sliding portion 138. The fuel is filled by the inflow of the fuel inside. The pressure of the fuel in the hermetic chamber 110G at this time is approximately the same as the pressure of the fuel in the first flow path 101. In this embodiment, this state is also called an initial state.

As shown in FIG. 15, when energization to the coil 44 is started, the magnetic attractive force from the fixed core 41 acts on the magnetic attractive portion 141 of the movable core 42G, and the movable core 42G is fixed from the injection hole 32 side. By moving toward the core 41 side, the large-diameter portion 146 of the movable core 42G collides with the fixed core 41. This magnetic attraction force is generated by a magnetic field formed around the fixed core 41 as the coil 44 is energized. In the initial state, since the flange portion 54 and the large-diameter portion 146 of the movable core 42G are in contact with each other, the flange portion 54 is movable when the movable core 42G moves from the injection hole 32 side toward the fixed core 41 side. The needle 50 moves together with the movable core 42G by being pushed by the large diameter portion 146 of the core 42G. As the movable core 42G moves, the surface of the large-diameter portion 146 of the movable core 42G on the injection hole 32 side and the stepped portion 39 of the housing 30G are separated in the axial direction AX, whereby the volume of the hermetic chamber 110G is expanded. The By expanding the volume of the hermetic chamber 110G, the fuel sealed in the hermetic chamber 110G is set to a negative pressure, so that the movement of the movable core 42G and the needle 50 is decelerated. Therefore, the impact force when the large-diameter portion 146 of the movable core 42G collides with the fixed core 41 is reduced. That is, the hermetic chamber 110G serves as a damper. When the needle 50 moves together with the movable core 42G, the valve portion 52 moves away from the valve seat 33, and fuel injection from the injection hole 32 is started. As the needle 50 moves, the first spring 61 is pushed by the flange portion 54 and contracts, so that elastic energy is stored in the first spring 61.

As shown in FIG. 16, after the large-diameter portion 146 of the movable core 42G collides with the fixed core 41, the needle 50 is detached from the movable core 42G due to inertia and further moves toward the upstream side of the second flow path 102. Continue. While the needle 50 moves together with the movable core 42G, the fuel in the hermetic chamber 110G is made negative pressure, so that the movement of the needle 50 is decelerated, so that the stopper portion 53 and the small diameter portion of the movable core 42G 145 collides at low speed. Therefore, the impact force when the stopper part 53 and the small diameter part 145 of the movable core 42G collide is reduced. The impact force caused by the collision between the large-diameter portion 146 of the movable core 42G and the fixed core 41 is also reduced by the needle 50 being detached from the movable core 42G. After the large-diameter portion 146 of the movable core 42G collides with the fixed core 41 and the movement of the movable core 42G stops, the fuel flows into the hermetic chamber 110G from the first flow path 101, so that the inside of the hermetic chamber 110G. The fuel pressure returns to the same level as the fuel pressure in the first flow path 101.

As shown in FIG. 17, after the stopper portion 53 and the small diameter portion 145 of the movable core 42G collide, the elastic energy stored in the first spring 61 is released as power to push back the needle 50, thereby causing the needle 50 moves from the fixed core 41 side toward the injection hole 32 side, and the flange portion 54 collides with the large-diameter portion 146 of the movable core 42G. At this time, bounce of the needle 50 is suppressed as the impact force when the stopper portion 53 and the small diameter portion 145 of the movable core 42G collide with each other is reduced. Therefore, the impact force when the flange portion 54 and the large-diameter portion 146 of the movable core 42G collide is reduced. Thereafter, the flange portion 54 is supported by the large-diameter portion 146 of the movable core 42G, so that a lift amount between the valve portion 52 and the valve seat 33 is ensured. The valve opening operation in the injector 20G is completed by the series of operations described above.

A valve closing operation performed in the injector 20G of the present embodiment will be described with reference to FIGS. As shown in FIG. 18, when the energization of the coil 44 is stopped, the magnetic attractive force from the fixed core 41 that has been acting on the magnetic attractive portion 141 of the movable core 42 G is unloaded, and the first spring 61 is loaded. When the urged needle 50 moves from the fixed core 41 side toward the nozzle hole 32 side, the valve portion 52 collides with the valve seat 33. Therefore, the valve is closed and the fuel injection from the nozzle hole 32 is stopped. When the needle 50 moves, the large-diameter portion 146 of the movable core 42G is pushed by the flange portion 54, so that the movable core 42G moves together with the needle 50. As the movable core 42G moves, the surface of the large-diameter portion 146 of the movable core 42G closer to the injection hole 32 and the stepped portion 39 of the housing 30G approach each other in the axial direction AX, thereby reducing the volume of the hermetic chamber 110G. The By reducing the volume of the hermetic chamber 110G, the fuel sealed in the hermetic chamber 110G is pressurized, so that the movement of the movable core 42G and the needle 50 is decelerated. Therefore, the impact force when the valve part 52 and the valve seat 33 collide is reduced. Note that when the fuel in the hermetic chamber 110G is increased to a predetermined pressure or higher, the fuel in the hermetic chamber 110G becomes a gap between the first sliding portion 147 and the first sliding portion 137 or the second sliding. It is gradually discharged from the gap between the portion 148 and the second sliding portion 138.

As shown in FIG. 19, after the valve portion 52 collides with the valve seat 33, the movable core 42G continues to move from the fixed core 41 side toward the injection hole 32 side due to inertia, thereby The small diameter portion 145 of the movable core 42G collides. By further reducing the volume of the hermetic chamber 110G, the fuel in the hermetic chamber 110G is further pressurized. As the fuel in the hermetic chamber 110G is further pressurized, the movement of the movable core 42G is decelerated. Therefore, the impact force when the stopper part 53 and the small diameter part 145 of the movable core 42G collide is reduced. The impact force caused by the collision between the valve portion 52 and the valve seat 33 is also reduced by the movement of the movable core 42G separately from the needle 50.

As shown in FIG. 20, the movable core 42G is affected by the impact force when the stopper 53 and the small diameter portion 145 of the movable core 42G collide, or by the force by which the second spring 62 pushes the movable core 42G back to the fixed core 41 side. Rebounds from the injection hole 32 side toward the fixed core 41 side, and the flange portion 54 and the large-diameter portion 146 of the movable core 42G collide. By boosting the fuel in the hermetic chamber 110G, the impact force when the stopper 53 and the small diameter portion 145 of the movable core 42G collide with each other is reduced, so that the rebound of the movable core 42G is suppressed. Yes. Therefore, the impact force when the large-diameter portion 146 of the movable core 42G collides with the flange portion 54 is reduced. Thereafter, the movable core 42G is supported by the second spring 62 and returns to the initial state. The valve closing operation in the injector 20G is completed by the series of operations described above.

According to the injector 20G of the present embodiment described above, the fuel in the hermetic chamber 110G is made negative pressure during the valve opening operation, and the movement of the movable core 42G and the needle 50 is decelerated. The impact force when the large-diameter portion 146 of the core 42G collides with the fixed core 41 and the impact force when the stopper portion 53 and the small-diameter portion 145 of the movable core 42G collide are reduced. Accordingly, the impact force when the flange portion 54 and the large-diameter portion 146 of the movable core 42G collide is also reduced. Further, during the valve closing operation, the fuel in the hermetic chamber 110G is increased in pressure, and the movement of the movable core 42G and the needle 50 is decelerated, whereby the impact force when the valve portion 52 and the valve seat 33 collide with each other. And the impact force at the time of the small diameter part 145 of the movable core 42G and the stopper part 53 colliding is reduced. Accordingly, the impact force when the large-diameter portion 146 of the movable core 42G collides with the flange portion 54 is also reduced. Therefore, the contact portion between the large diameter portion 146 of the movable core 42G and the fixed core 41, the contact portion between the stopper portion 53 and the small diameter portion 145 of the movable core 42G, the flange portion 54, and the large diameter portion 146 of the movable core 42G And the wear at the contact portion between the valve portion 52 and the valve seat 33 can be suppressed.

In the present embodiment, the first sliding portion 147 and the second sliding portion 148 are provided in the high hardness portion 142 having a higher hardness than the magnetic attraction portion 141 of the movable core 42G, and the magnetic attraction portion 141 of the movable core 42G. Since the first sliding portion 137 and the second sliding portion 138 are provided in the integrally formed portion 131 of the housing 30G having higher hardness, the first sliding portion 147 and the second sliding portion are provided by grinding or the like. The moving part 148, the first sliding part 137, and the second sliding part 138 can be formed with high dimensional accuracy. Therefore, the gap between the first sliding part 147 and the first sliding part 137 and the gap between the second sliding part 148 and the second sliding part 138 can be made smaller, so that the movable core 42G and the needle 50 can be reduced. Can be decelerated more effectively.

In the present embodiment, the integrally formed portion 131 having the first sliding portion 137 and the nozzle tip portion 31G having the injection hole 32 are integrally formed. Therefore, as compared with the injector 20 of the first embodiment, the number of welds 38 provided on the nozzle hole 32 side with respect to the support surface SP can be reduced. In particular, in the present embodiment, the first sliding portion 137 can be configured by a member having a relatively high hardness without increasing the number of welded portions 38 in the housing 30G as compared with the injector 20 of the first embodiment. Note that the number of welds 38 on the fixed core 41 side of the support surface SP is larger than that of the injector 20 of the first embodiment, but the support surface can be obtained by pressing the injector 20G toward the support surface SP and fixing it. Since the compressive stress can be applied to the welded portion 38 on the fixed core 41 side from the SP in advance, the welded portion 38 is damaged by the tensile stress caused by the valve portion 52 colliding with the valve seat 33. This can be suppressed.

Further, in the present embodiment, since the second spring 62 is provided in the hermetic chamber 110G, the shaft is more than the configuration in which the second spring 62 is provided closer to the injection hole 32 than the small diameter portion 145 of the movable core 42G. Miniaturization of the injector 20G in the direction AX can be achieved.

In the present embodiment, the stopper portion 53 of the needle 50 is provided between the nozzle hole 32 in the axial direction AX and the small diameter portion 145 of the movable core 42G. Therefore, an open failure of the injector 20G can be suppressed with a simple configuration while ensuring a pressure receiving area on the injection hole 32 side in the large diameter portion 146 of the movable core 42G.

H. Eighth embodiment:
As shown in FIG. 21, in the injector 20H of the eighth embodiment, the movable core 42H includes a first elastic member 201, a second elastic member 202, a first low friction member 211, and a second low friction member 212. Is different from the first embodiment. Other configurations and opening / closing operations are the same as those in the first embodiment unless otherwise specified.

The first elastic member 201 and the second elastic member 202 are disposed in the gap between the movable core 42H and the needle 50 in the radial direction of the shaft portion 51 of the needle 50. The first elastic member 201 and the second elastic member 202 each have an annular outer shape. The diameter of the first elastic member 201 is larger than the diameter of the second elastic member 202. The first elastic member 201 is disposed so as to surround the outer periphery of the stopper portion 53 of the needle 50. The second elastic member 202 is disposed so as to surround the outer periphery of the shaft portion 51 of the needle 50 between the stopper portion 53 and the flange portion 54. A first groove 241 is provided on the inner wall surface of the first recess 46 in the movable core 42H. A second groove 242 is provided on the inner wall surface of the through-hole 43 in the movable core 42H. The first groove portion 241 and the second groove portion 242 are each an annular groove provided along the circumferential direction of the movable core 42H. The first elastic member 201 is fitted in the first groove portion 241. The second elastic member 202 is fitted in the second groove portion 242.

The first elastic member 201 and the second elastic member 202 are made of an elastic material. In the present embodiment, the first elastic member 201 and the second elastic member 202 are each formed of rubber. As the rubber, for example, fluorine rubber, ethylene propylene rubber (EPDM), or silicon rubber (VMQ) can be used. The first elastic member 201 and the second elastic member 202 may be formed of a thermoplastic elastomer. For the thermoplastic elastomer, for example, thermoplastic polyurethane can be used.

The first low friction member 211 is disposed between the first elastic member 201 and the stopper portion 53. The second low friction member 212 is disposed between the second elastic member 202 and the shaft portion 51 between the stopper portion 53 and the flange portion 54. The first low friction member 211 and the second low friction member 212 each have an annular outer shape. The diameter of the first low friction member 211 is larger than the diameter of the second low friction member 212. The first elastic member 201 is in contact with the stopper portion 53 via the first low friction member 211 and receives a compressive force from the stopper portion 53 via the first low friction member 211. The second elastic member 202 is in contact with the shaft portion 51 between the stopper portion 53 and the flange portion 54 via the second low friction member 212, and from the shaft portion 51 via the second low friction member 212. It receives compressive force.

The friction coefficient of the first low friction member 211 is smaller than the friction coefficient of the first elastic member 201. The friction coefficient of the second low friction member 212 is smaller than the friction coefficient of the second elastic member 202. In the present embodiment, the first low friction member 211 and the second low friction member 212 are each formed of Teflon resin (Teflon is a registered trademark). The first low friction member 211 and the second low friction member 212 may be formed of polyamide or polyester.

FIG. 22 shows a part of the first elastic member 201 and the first low friction member 211 in FIG. 21 in an enlarged manner. In FIG. 22, illustration of the movable core 42H etc. is omitted, and only the first elastic member 201 and the first low friction member 211 are shown. The first low friction member 211 has a support portion 221 protruding toward the outer periphery. The support portion 221 is configured to be able to accommodate a portion on the inner peripheral side of the first elastic member 201. Since the first elastic member 201 is fitted in the first groove portion 241 of the movable core 42H, the movement in the axial direction AX with respect to the movable core 42H is restricted. Since the first elastic member 201 is fitted in the support portion 221, the first low friction member 211 is restricted from moving in the axial direction AX with respect to the movable core 42H. The configurations of the second elastic member 202 and the second low friction member 212 are the same as the configurations of the first elastic member 201 and the first low friction member 211.

According to the injector 20 H of the present embodiment described above, the first low friction member 211 is pressed against the stopper portion 53 by the pressing force with which the first elastic member 201 pushes back the stopper portion 53 via the first low friction member 211. Therefore, the clearance between the first low friction member 211 and the stopper portion 53 communicating with the hermetic chamber 110 is reduced, and the second elastic member 202 presses the shaft portion 51 through the second low friction member 212, thereby exerting a pressing force. Since the second low friction member 212 is pressed against the shaft portion 51, the gap between the second low friction member 212 communicating with the airtight chamber 110 and the shaft portion 51 is reduced. Therefore, since the airtightness of the airtight chamber 110 can be improved, the impact force when the stopper portion 53 and the movable core 42 collide, and the impact force when the flange portion 54 and the movable core 42 collide, It can be further reduced. In particular, in the present embodiment, since the gap communicating with the airtight chamber 110 can be reduced without processing the movable core 42H and the needle 50 with high dimensional accuracy, the processing of the movable core 42H and the needle 50 can be facilitated. it can.

Further, in the present embodiment, when the movable core 42H and the needle 50 move relative to each other, the first elastic member 201 slides with the stopper portion 53 via the first low friction member 211, and the second elastic member 202 slides with the shaft portion 51 via the second low friction member 212. Therefore, resistance due to friction when the movable core 42H and the needle 50 move relative to each other can be reduced. Therefore, by providing the first low friction member 211 and the second low friction member 212, it is possible to suppress the wear of the movable core 42H and the needle 50 even if the movable core 42H and the needle 50 are not formed of a material having high hardness. Can do.

I. Ninth embodiment:
As shown in FIG. 23, in the injector 20I of the ninth embodiment, a second elastic member 202, a third elastic member 203, a second low friction member 212, and a third low friction member 213 are provided. This is different from the fourth embodiment. The configuration of the second elastic member 202, the configuration of the second low friction member 212, and the configuration of the second groove portion 242 of the movable core 42I are the same as in the eighth embodiment. Other configurations and opening / closing operations are the same as those in the fourth embodiment unless otherwise specified.

The third elastic member 203 is disposed in the gap between the movable core 42I and the needle 50 in the radial direction of the shaft portion 51 of the needle 50. The third elastic member 203 has an annular outer shape. The diameter of the third elastic member 203 is larger than the diameter of the second elastic member 202. The third elastic member 203 is disposed so as to surround the outer periphery of the flange portion 54 of the needle 50. A third groove 243 is provided on the inner wall surface of the second recess 47 in the movable core 42I. The third groove portion 243 is an annular groove provided along the circumferential direction of the movable core 42I. The third elastic member 203 is fitted in the third groove 243. The material of the third elastic member 203 is the same as the material of the second elastic member 202.

The third low friction member 213 is disposed between the third elastic member 203 and the flange portion 54. The third low friction member 213 has an annular outer shape. The diameter of the third low friction member 213 is larger than the diameter of the second low friction member 212. The third elastic member 203 is in contact with the flange portion 54 via the third low friction member 213 and receives a compressive force from the flange portion 54 via the third low friction member 213. The material of the third low friction member 213 is the same as that of the second low friction member 212.

According to the injector 20I of the present embodiment described above, the third low friction member 213 is pressed against the flange portion 54 by the pressing force of the third elastic member 203. Therefore, the third low friction member that communicates with the hermetic chamber 110D. Since the gap between 213 and the flange portion 54 is reduced and the second low friction member 212 is pressed against the shaft portion 51 by the pressing force of the second elastic member 202, the second low friction member 212 communicating with the hermetic chamber 110D A gap with the shaft portion 51 is reduced. Therefore, the airtightness of the airtight chamber 110D can be improved.

In this embodiment, when the movable core 42I and the needle 50 move relatively, the second elastic member 202 slides with the shaft portion 51 via the second low friction member 212, and the third elastic member 203 slides on the flange portion 54 via the third low friction member 213. Therefore, resistance due to friction when the movable core 42I and the needle 50 move relative to each other can be reduced.

J. et al. Tenth embodiment:
As shown in FIG. 24, in the injector 20J of the tenth embodiment, a fourth elastic member 204, a fifth elastic member 205, a fourth low friction member 214, and a fifth low friction member 215 are provided. The seventh embodiment differs from the seventh embodiment in that the high hardness portion 142 is not provided on the movable core 42J and the configuration of the housing 30 is the same as that of the first embodiment. Other configurations and opening / closing operations are the same as those in the seventh embodiment unless otherwise specified.

The fourth elastic member 204 and the fifth elastic member 205 are arranged in the gap between the movable core 42J and the housing 30 in the radial direction of the movable core 42J. The fourth elastic member 204 and the fifth elastic member 205 each have an annular outer shape. The diameter of the fifth elastic member 205 is larger than the diameter of the fourth elastic member 204. The fourth elastic member 204 is disposed along the outer periphery of the movable core 42J between the first sliding portion 147 of the movable core 42J and the first sliding portion 137 of the housing 30. The fifth elastic member 205 is disposed along the outer periphery of the movable core 42J between the second sliding portion 148 of the movable core 42J and the second sliding portion 138 of the housing 30. A fourth groove portion 244 is provided in the first sliding portion 147 of the movable core 42J. A fifth groove 245 is provided in the second sliding portion 148 of the movable core 42J. Each of the fourth groove portion 244 and the fifth groove portion 245 is an annular groove provided along the circumferential direction of the movable core 42J. The fourth elastic member 204 is fitted in the fourth groove portion 244. The fifth elastic member 205 is fitted in the fifth groove 245. The material of the fourth elastic member 204 and the material of the fifth elastic member 205 are the same as the material of the first elastic member 201 and the material of the second elastic member 202.

The fourth low friction member 214 is disposed between the fourth elastic member 204 and the first sliding portion 137 of the housing 30. The fifth low friction member 215 is disposed between the fifth elastic member 205 and the second sliding portion 138 of the housing 30. The fourth low friction member 214 and the fifth low friction member 215 each have an annular outer shape. The diameter of the fifth low friction member 215 is larger than the diameter of the fourth low friction member 214. The fourth elastic member 204 is in contact with the first sliding portion 137 via the fourth low friction member 214 and receives a compressive force from the first sliding portion 137 via the fourth low friction member 214. ing. The fifth elastic member 205 is in contact with the second sliding portion 138 via the fifth low friction member 215 and receives a compressive force from the second sliding portion 138 via the fifth low friction member 215. ing. The friction coefficient of the fourth low friction member 214 is smaller than the friction coefficient of the fourth elastic member 204. The friction coefficient of the fifth low friction member 215 is smaller than the friction coefficient of the fifth elastic member 205. The material of the fourth low friction member 214 and the material of the fifth low friction member 215 are the same as the material of the first low friction member 211 and the material of the second low friction member 212.

According to the injector 20J of the present embodiment described above, the fourth low friction member 214 is pressed against the first sliding portion 137 by the tightening force of the fourth elastic member 204, so that the first communication with the hermetic chamber 110G is performed. 4 The gap between the low friction member 214 and the first sliding portion 137 is reduced, and the fifth low friction member 215 is pressed against the second sliding portion 138 by the tight force of the fifth elastic member 205. The gap between the fifth low friction member 215 communicating with the closed chamber 110G and the second sliding portion 138 is reduced. Therefore, the airtightness of the airtight chamber 110G can be improved.

In the present embodiment, when the movable core 42J and the housing 30 move relative to each other, the fourth elastic member 204 slides with the first sliding portion 137 via the fourth low friction member 214, The fifth elastic member 205 slides with the second sliding portion 138 via the fifth low friction member 215. Therefore, it is possible to reduce resistance due to friction when the movable core 42J and the housing 30 move relative to each other.

K. Other embodiments:
(K-1) In the

injectors

20, 20B, 20C, 20D, 20E, and 20F in the first to sixth embodiments described above, the

movable cores

42, 42D, and 42F include the first recess 46, the second recess 47, and the like. Either one is provided. On the other hand, the

movable cores

42, 42 D, 42 F may include both the first recess 46 and the second recess 47. The distance between the bottom surface of the first recess 46 and the bottom surface of the second recess 47 is greater than the distance along the axial direction AX between the surface of the stopper portion 53 on the fixed core 41 side and the surface of the flange portion 54 on the valve portion 52 side. The interval along the axial direction AX may be smaller. In other words, the thickness of the

movable cores

42, 42D, and 42F in the portion where the first concave portion 46 and the second concave portion 47 are formed is such that the surface of the stopper portion 53 on the fixed core 41 side and the flange portion 54 on the valve portion 52 side. It may be smaller than the distance between the surface and the axial direction AX. In this case, the airtight chamber 110 is formed on the

movable cores

42, 42D, and 42F on the nozzle hole 32 side, and the airtight chamber 110D is formed on the fixed core 41 side, whereby the stopper portion 53 and the

movable cores

42, 42D, The impact force at each contact portion when the contact portion with 42F and the contact portion between the flange portion 54 and the

movable cores

42, 42D, and 42F collide with each other is reduced.

(K-2) In the

injectors

20B and 20C in the second to third embodiments described above, the stopper portion 53 may include the first orifice 111, and the movable core may include the second orifice 112. In this case, the degree of deceleration of the needle 50 can be adjusted by adjusting the number and shape of the first orifice 111 and the second orifice 112.

(K-3) In the injector 20D in the fourth embodiment described above, an orifice may be provided in the flange portion 54 and the movable core 42D. In this case, the degree of deceleration of the needle 50 can be adjusted by adjusting the number and shape of the orifices.

(K-4) In the injector 20F in the sixth embodiment described above, the stopper portion 53 may include the first orifice 111, and the movable core 42F may include the second orifice 112. The stopper portion 53 may include a first orifice 111, and the movable core 42F may include a second orifice 112. In this case, the degree of deceleration of the needle 50 can be adjusted by adjusting the number and shape of the first orifice 111 and the second orifice 112.

(K-5) In the injector 20G in the seventh embodiment described above, the high hardness portion 142 may not be provided in the movable core 42G. That is, the movable core 42 G may be composed of only the same magnetic material as that of the magnetic attraction part 141, and the first sliding part 147 and the second sliding part 148 may be composed of the same magnetic material as that of the magnetic attraction part 141. Even in this case, the movement of the movable core 42G and the needle 50 can be decelerated by the hermetic chamber 110G.

(K-6) In the injector 20G in the seventh embodiment described above, at least one of the first sliding portion 147, the second sliding portion 148, the first sliding portion 137, and the second sliding portion 138. Any one hardness may be below the hardness of the magnetic attraction part 141 of the movable core 42G.

(K-7) In the injector 20G in the seventh embodiment described above, the nozzle tip portion 31G and the integral forming portion 131 may not be formed integrally. For example, the housing 30G may have the same configuration as the housing 30 in the injector 20 of the first embodiment.

(K-8) In the injector 20G in the seventh embodiment described above, the second spring 62 may not be provided in the hermetic chamber 110G. For example, the second spring 62 may be provided closer to the injection hole 32 than the small diameter portion 145 of the movable core 42G.

(K-9) In the injector 20G in the seventh embodiment described above, the stopper portion 53 of the needle 50 may not be provided between the injection hole 32 and the small diameter portion 145 in the axial direction AX. The needle 50 may not be provided with the stopper portion 53.

(K-10) In the injector 20H in the above-described eighth embodiment, the movable core 42H includes the first elastic member 201, the second elastic member 202, the first low friction member 211, and the second low friction member 212. Is provided. In contrast, the first elastic member 201, the second elastic member 202, the first low friction member 211, and the second low friction member 212 may be provided on the needle 50 instead of the movable core 42H. . That is, the movable core 42H is not provided with the first groove portion 241 and the second groove portion 242, but the needle 50 is provided with two annular grooves, and the first elastic member 201 and the second elastic member 201 are provided in the groove of the needle 50. The first elastic member 201 slides on the movable core 42H via the first low friction member 211, and the second elastic member 202 slides on the movable core 42H via the second low friction member 212. You may move. Further, the first elastic member 201 and the first low friction member 211 may be provided on the movable core 42H, and the second elastic member 202 and the second low friction member 212 may be provided on the needle 50. The needle 50 may be provided with the first elastic member 201 and the first low friction member 211, and the movable core 42H may be provided with the second elastic member 202 and the second low friction member 212. Even in these cases, the airtightness of the airtight chamber 110 can be improved.

(K-11) In the injector 20I in the ninth embodiment described above, the movable core 42I includes the second elastic member 202, the third elastic member 203, the second low friction member 212, and the third low friction member 213. Is provided. In contrast, the second elastic member 202, the third elastic member 203, the second low friction member 212, and the third low friction member 213 may be provided on the needle 50 instead of the movable core 42I. . Further, the movable core 42I may be provided with the second elastic member 202 and the second low friction member 212, and the needle 50 may be provided with the third elastic member 203 and the third low friction member 213. The needle 50 may be provided with the second elastic member 202 and the second low friction member 212, and the movable core 42I may be provided with the third elastic member 203 and the third low friction member 213.

(K-12) In the injector 20J according to the tenth embodiment described above, the movable core 42J includes the fourth elastic member 204, the fifth elastic member 205, the fourth low friction member 214, and the fifth low friction member 215. Is provided. In contrast, the fourth elastic member 204, the fifth elastic member 205, the fourth low friction member 214, and the fifth low friction member 215 may be provided on the needle 50 instead of the movable core 42J. . Further, the fourth elastic member 204 and the fourth low friction member 214 may be provided on the movable core 42J, and the fifth elastic member 205 and the fifth low friction member 215 may be provided on the needle 50. The needle 50 may be provided with the fourth elastic member 204 and the fourth low friction member 214, and the movable core 42J may be provided with the fifth elastic member 205 and the fifth low friction member 215.

(K-13) In the injector 20H in the eighth embodiment described above, at least one of the first low friction member 211 and the second low friction member 212 may not be provided. That is, the first elastic member 201 may be in direct contact with the stopper portion 53 of the needle 50, or the second elastic member 202 may be in direct contact with the shaft portion 51 of the needle 50. In the injector 20I according to the ninth embodiment described above, at least one of the second low friction member 212 and the third low friction member 213 may not be provided. That is, the second elastic member 202 may be in direct contact with the shaft portion 51 of the needle 50, or the third elastic member 203 may be in direct contact with the flange portion 54 of the needle 50. In the injector 20J in the tenth embodiment described above, at least one of the fourth low friction member 214 and the fifth low friction member 215 may not be provided. That is, the fourth elastic member 204 may be in direct contact with the first sliding portion 137 of the housing 30, or the fifth elastic member 205 may be in direct contact with the second sliding portion 138 of the housing 30. Even in these cases, the airtightness of the

airtight chambers

110, 110D, and 110G can be improved. In these cases, the elastic members 201 to 205 that slide without using the low friction members 211 to 215 have elasticity, such as thermoplastic polyurethane, and have excellent wear resistance. It is preferable to form with a material.

(K-14) In the injector 20H in the above-described eighth embodiment, the stopper portion 53 and the movable core 42H may be provided with an orifice. In this case, the degree of deceleration of the needle 50 can be adjusted by adjusting the number and shape of the orifices.

(K-15) In the injector 20I in the ninth embodiment described above, an orifice may be provided in the flange portion 54 and the movable core 42I. In this case, the degree of deceleration of the needle 50 can be adjusted by adjusting the number and shape of the orifices.

(K-16) In the injector 20H in the above-described eighth embodiment, the movable core 42H is provided with the same high hardness portion 142 as in the sixth embodiment, and the first elastic member 201 and the second elastic member 202 are the high hardness portion. It may be fitted in a groove provided in 142.

(K-17) In the injector 20J in the tenth embodiment described above, the movable core 42J is provided with the same high hardness portion 142 as in the seventh embodiment, and the fourth elastic member 204 and the fifth elastic member 205 are the high hardness portion. It may be fitted in a groove provided in 142. Further, the injector 20J in the above-described tenth embodiment may include the same housing 30G as in the seventh embodiment.

The present disclosure is not limited to the above-described embodiment, and can be realized with various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments are appropriately replaced or combined to solve part or all of the above-described problems or to achieve part or all of the above-described effects. Is possible. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

Claims

An injector (20, 20B, 20C, 20E, 20F, 20H),
A cylindrical housing (30) having a nozzle hole (32) for injecting fuel and having a first flow path (101) communicating with the nozzle hole;
A cylindrical fixed core (41) fixed in the housing and formed with a second channel (102) communicating with the first channel;
The inside of the first flow path on the nozzle hole side of the fixed core is provided so as to be able to reciprocate along the axial direction (AX) of the housing, and has an outer diameter larger than the inner diameter of the fixed core, A movable core (42, 42F, 42H) having a through hole (43) smaller than the inner diameter of the fixed core;
A coil (44) for generating a magnetic field for moving the movable core toward the fixed core by energization;
A shaft portion (51) passing through the through hole so as to be reciprocally movable in the axial direction, and a valve portion (52) formed at an end portion of the shaft portion on the nozzle hole side and capable of opening and closing the nozzle hole. A needle (50) having;
A spring (61) for urging the needle toward the nozzle hole;
With
The shaft portion has a first protrusion (53) on the valve portion side and a second protrusion (54) on the fixed core side with the movable core interposed therebetween,
The first protrusion protrudes outward from the edge of the through hole in the movable core in the radial direction,
The second projecting portion protrudes outward in the radial direction from an edge of the through-hole in the movable core and inward from an inner peripheral edge of the fixed core,
The surface on the nozzle hole side of the movable core has a first recess (46) capable of accommodating the first protrusion around the through hole,
The bottom surface of the first recess and the movable core are spaced apart from each other along the axial direction between the surface of the first protrusion on the fixed core side and the surface of the second protrusion on the valve part side. The distance along the axial direction with the surface on the fixed core side is smaller,
An injector configured to be able to enclose the fuel in a space (110) surrounded by the shaft portion, the first protrusion, and the first recess.
An injector (20F) according to claim 1,
The movable core has a high hardness portion (142) having a higher hardness than the magnetic attraction portion (141) in contact with the fixed core,
The first recess is an injector provided in the high hardness portion.
An injector (20H) according to claim 1,
Either one of the movable core and the needle is provided with an elastic member (201, 202),
The said elastic member is an injector arrange | positioned in the clearance gap between the said movable core and the said needle in the said radial direction.
The injector according to claim 3, wherein
The said elastic member is an injector which contact | connects the other of the said movable core and the said needle through the low friction members (211 and 212) whose friction coefficient is smaller than the said elastic member.
The injector according to any one of claims 1 to 4, wherein
The first projecting portion has an injector having a first orifice (111) communicating from the surface on the fixed core side to the surface on the valve portion side.
An injector according to any one of claims 1 to 5,
The movable core includes an injector having a second orifice (112) communicating from the bottom surface of the first recess to the surface on the fixed core side.
The injector according to any one of claims 1 to 6, wherein
The surface of the movable core on the fixed core side is an injector having a second recess (47) that can accommodate the second protrusion around the through hole.
An injector (20D, 20I),
A cylindrical housing (30) having a nozzle hole (32) for injecting fuel and having a first flow path (101) communicating with the nozzle hole;
A cylindrical fixed core (41) fixed in the housing and formed with a second channel (102) communicating with the first channel;
The inside of the first flow path on the nozzle hole side of the fixed core is provided so as to be able to reciprocate along the axial direction (AX) of the housing, and has an outer diameter larger than the inner diameter of the fixed core, A movable core (42D, 42I) having a through hole (43) smaller than the inner diameter of the fixed core;
A coil (44) for generating a magnetic field for moving the movable core toward the fixed core by energization;
A shaft portion (51) passing through the through hole so as to be reciprocally movable in the axial direction, and a valve portion (52) formed at an end portion of the shaft portion on the nozzle hole side and capable of opening and closing the nozzle hole. A needle (50) having;
A spring (61) for urging the needle toward the nozzle hole;
With
The shaft portion has a first protrusion (53) on the valve portion side and a second protrusion (54) on the fixed core side with the movable core interposed therebetween,
The first protrusion protrudes outward from the edge of the through hole in the movable core in the radial direction,
The second projecting portion protrudes outward in the radial direction from an edge of the through-hole in the movable core and inward from an inner peripheral edge of the fixed core,
The surface on the fixed core side of the movable core has a recess (47) that can accommodate the second protrusion around the through hole,
More than the space along the axial direction between the surface on the fixed core side of the first protrusion and the surface on the valve part side of the second protrusion, the surface on the nozzle hole side of the movable core, The distance along the axial direction with the bottom surface of the recess is smaller,
An injector configured to be able to enclose the fuel in a space (110D) surrounded by the shaft portion, the second projecting portion, and the concave portion.
An injector (20I) according to claim 8,
Either one of the movable core and the needle is provided with an elastic member (202, 203),
The said elastic member is an injector arrange | positioned in the clearance gap between the said movable core and the said needle in the said radial direction.
The injector according to claim 9, wherein
The injector, wherein the elastic member is in contact with the other of the movable core and the needle through low friction members (212, 213) having a smaller friction coefficient than the elastic member.
An injector (20G, 20J),
A cylindrical housing (30G) having a nozzle hole (32) for injecting fuel and having a first flow path (101) communicating with the nozzle hole;
A cylindrical fixed core (41) fixed in the housing and formed with a second channel (102) communicating with the first channel;
It has a through hole (43) that is reciprocally movable along the axial direction (AX) of the housing in the first flow path on the nozzle hole side of the fixed core and is smaller than the inner diameter of the fixed core. A movable core (42G, 42J);
A coil (44) for generating a magnetic field for moving the movable core toward the fixed core by energization;
A shaft portion (51) passing through the through hole so as to be reciprocally movable in the axial direction, and a valve portion (52) formed at an end portion of the shaft portion on the nozzle hole side and capable of opening and closing the nozzle hole. A needle (50) having;
A first spring (61) for urging the needle toward the nozzle hole;
With
The shaft portion has a first protrusion (53) on the valve portion side and a second protrusion (54) on the fixed core side with the movable core interposed therebetween,
The first protrusion protrudes outward from the edge of the through hole in the movable core in the radial direction,
The second projecting portion protrudes outward in the radial direction from an edge of the through-hole in the movable core and inward from an inner peripheral edge of the fixed core,
The movable core includes a large-diameter portion (146) having a large outer diameter, and a small-diameter portion (145) that is provided closer to the nozzle hole than the large-diameter portion and has a smaller outer diameter than the large-diameter portion. ,
The small diameter portion has a first sliding portion (147) facing a first sliding portion (137) provided in the housing,
The large diameter portion has a second sliding portion (148) facing a second sliding portion (138) provided in the housing,
The fuel can be enclosed in a space (110G) surrounded by the movable core and the housing between the first sliding portion and the second sliding portion in the axial direction. Injector.
An injector according to claim 11, comprising:
The movable core has a high hardness portion (142) having a higher hardness than the magnetic attraction portion (141) in contact with the fixed core,
The first sliding part and the second sliding part are injectors provided in the high hardness part.
An injector according to claim 11 or claim 12,
The first sliding part is an injector formed integrally with an injection hole forming part (31G) of the housing having the injection hole.
An injector (20J) according to claim 11,
Either one of the movable core and the needle is provided with an elastic member (204, 204),
The said elastic member is an injector arrange | positioned in the clearance gap between the said movable core and the said needle in the said radial direction.
An injector according to claim 14,
The said elastic member is an injector which contact | connects the other of the said movable core and the said housing via the low friction member (214,215) whose friction coefficient is smaller than the said elastic member.
An injector according to any one of claims 11 to 15,
The injector, wherein a second spring (62) for urging the movable core toward the fixed core is provided in the space.
The injector according to any one of claims 11 to 16, wherein
The first protrusion is an injector provided between the nozzle hole and the small diameter portion in the axial direction.
An injector according to any one of claims 1 to 17,
An injector for injecting gas as the fuel.
Injectors (20, 20B, 20C, 20D, 20E, 20F, 20G, 20H, 20I, 20J),
A cylindrical housing (30, 30G) having a nozzle hole (32) for injecting fuel and having a first flow path (101) communicating with the nozzle hole;
A cylindrical fixed core (41) fixed in the housing and formed with a second channel (102) communicating with the first channel;
The inside of the first flow path on the nozzle hole side of the fixed core is provided so as to be able to reciprocate along the axial direction (AX) of the housing, and has an outer diameter larger than the inner diameter of the fixed core, A movable core (42, 42D, 42F, 42G, 42H, 42I, 42J) having a through hole (43) smaller than the inner diameter of the fixed core;
A coil (44) for generating a magnetic field for moving the movable core toward the fixed core by energization;
A shaft portion (51) passing through the through hole so as to be reciprocally movable in the axial direction, and a valve portion (52) formed at an end portion of the shaft portion on the nozzle hole side and capable of opening and closing the nozzle hole. A needle (50) having;
A spring (61) for urging the needle toward the nozzle hole;
With
The shaft portion has a first protrusion (53) on the valve portion side and a second protrusion (54) on the fixed core side with the movable core interposed therebetween,
The first protrusion protrudes outward in the radial direction from the edge of the through hole of the movable core,
The second projecting portion protrudes in the radial direction outside the edge of the through hole of the movable core and inside the inner peripheral edge of the fixed core,
An injector configured to be able to enclose the fuel in a space (110, 110D, 110G) at least partially defined by the movable core.