JP4730373B2 - Fuel injection valve - Google Patents

Description

  The present invention relates to a fuel injection valve, and is suitable for application to a fuel injection valve used in, for example, a common rail fuel injection device.

  In a diesel engine, a common rail type fuel injection device that accumulates high-pressure fuel by providing a common rule common to each cylinder is known. High pressure fuel is pumped from the fuel supply pump to the common rail and controlled to a predetermined pressure, and the fuel injection valve of each cylinder is driven at a predetermined timing to inject the fuel. This type of fuel injection valve generally has a structure in which the nozzle needle is raised and lowered to open and close the nozzle hole by driving the control valve with an actuator such as a piezo actuator to increase or decrease the pressure in the control chamber.

  The fuel injection valve is formed with a high-pressure fuel passage that passes through the plurality of body members and supplies high-pressure fuel from the common rail to the control chamber and the injection hole. Therefore, a sealing method is adopted in which the body end surfaces of two adjacent body members are brought into close contact with each other by an axial force generated by screw fastening such as a nut to keep oil tight against high pressure fuel (see Patent Document 1).

Patent Document 1 discloses a technique in which the fuel leaked from the high-pressure fuel passage is recovered in the recess and does not leak out of the fuel injection valve by providing a recess in one of the body end surfaces of the two body members. Has been. In this technique, a concave portion is formed on substantially the entire surface so as to surround the high-pressure fuel passage at the end face of the body. In order to collect the fuel leaking into the recess, a fuel recovery passage (fuel return passage) is opened in the recess.
European Patent No. 1166591

  However, in the prior art disclosed in Patent Document 1, since a concave portion is formed on one of the body end surfaces of the two body members, there is a great restriction on the arrangement of the high pressure fuel passage and the fuel recovery passage. There is a risk that the degree of freedom in arranging the fuel recovery passages will be reduced.

  Moreover, in the said prior art, since the recessed part is formed in the substantially whole surface other than the opening peripheral part of a high pressure fuel passage, the shape of the recessed part formed in one body end surface may become complicated. For example, a positioning hole or groove into which the positioning member (pin) is inserted for the purpose of preventing the positional deviation of the passage communicating between the body members when the concave portion between the outer peripheral edge portion and the high-pressure fuel passage is narrow in the concave portion. May be formed on the end face of the body. This is because the hole or groove needs to have a sealing structure.

  The present invention has been made in view of the above points, and an object of the present invention is to improve the degree of freedom of arrangement of components such as a high-pressure fuel passage and a fuel recovery passage, and to provide the same body end surface. An object of the present invention is to provide a fuel injection valve that can suppress the concave portion formed in the shape of a complicated shape.

  In order to achieve the above object, the present invention comprises the following technical means.

That is, in the inventions according to claims 1 to 6 , a plurality of body members are provided, and two adjacent body members are brought into close contact with each other at the end surface of the body so that the passage for the fuel flowing through the body member is communicated. A fuel injection valve,
A first recess and a fuel recovery passage are provided on a portion of the body end surface where the two body members are in close contact with each other except for the outer peripheral edge and the high-pressure fuel passage, and the first recess and the fuel recovery passage communicate with each other. And a second recess that wraps with both the first recess and the fuel recovery passage to communicate with each other on the other body end surface. It is characterized by being formed only in the vicinity of the shortest distance portion including the shortest distance (δ1) portion determined by the arrangement relationship between the recess and the fuel recovery passage.

  In such an invention, the first recess formed in one body end surface of the body end surfaces of two adjacent body members is disposed so as to surround the high pressure fuel passage, but is spaced from the fuel recovery passage. In this case, since the first recess is arranged so as not to communicate with the first recess, the shape of the first recess only needs to satisfy the condition that it does not communicate with the high-pressure fuel passage and the fuel recovery passage, and can have a relatively simple shape. .

  In addition, when both the body end surfaces are brought into close contact with both the fuel recovery passage and the first recess that are not communicated with each other on the one body end surface, the second recess formed on the other body end surface wraps on both. For example, in the arrangement of the high-pressure fuel passage and the fuel recovery passage on the one end face of the body, no matter what the arrangement relationship is, the leakage from the high-pressure fuel passage occurs between the two body end faces. The fuel can be recovered in the first recess, and the recovered fuel can be returned to the fuel recovery passage through the second recess. In other words, in the case where the first recess, the high pressure fuel passage, and the fuel recovery passage are formed on the same body end face, the degree of freedom in arranging the components such as the high pressure fuel passage and the fuel recovery passage can be improved.

According to the first to sixth aspects of the present invention, it is possible to improve the degree of freedom of arrangement of components such as the high-pressure fuel passage and the fuel recovery passage and to prevent the shape of the first recess from becoming complicated. .

Further, in the invention according to claim 2 , on the body end surfaces of the two body members, a portion excluding the high pressure fuel passage, the fuel recovery passage, the first recess, and the second recess is used as a sealing surface, and the opposing sealing surfaces are arranged to face each other. It is characterized by sealing between the end faces of the body by close contact.

  According to this, since the peripheral portion and the outer peripheral edge portion of the high-pressure fuel passage are sealed at least at the end surface of the body, the sealing surfaces are brought into close contact with each other to increase the surface pressure, thereby sealing between the end surfaces of the body. Sealability can be improved.

In the invention according to claim 3 , the high-pressure fuel passage includes a fuel supply passage for supplying high-pressure fuel to the nozzle hole of the nozzle body member formed at the tip of the plurality of body members, and the inside of the nozzle body member. And a control pressure passage communicating with a control chamber for providing a driving force for opening and closing the nozzle hole at an end opposite to the nozzle hole of the valve member accommodated in an axially movable manner. .

  Here, as one type of fuel injection valve, there is one that gives a driving force to a valve member that opens and closes the injection hole by increasing or decreasing the pressure in the control chamber. In such a fuel injection valve, the injection pressure is used as a high-pressure fuel passage. A body including a nozzle body member includes a fuel supply passage that allows the high-pressure fuel to be constantly supplied to the hole, and a control pressure passage that communicates with the control chamber and supplies a high-pressure fuel that reduces and restores the pressure corresponding to the pressure increase / decrease amount. It will be provided on the member. These body members increase the degree of freedom of arrangement of the high-pressure fuel passage and the fuel recovery passage, thereby suppressing the leaked fuel leaking from the high-pressure fuel passage to the fuel recovery passage at the end face of the body, and thus high-efficiency high-pressure fuel injection is desired. .

On the other hand, as described in claim 3 , in the fuel injection valve of the present invention having the high-pressure fuel passage having the fuel supply passage and the control pressure passage, the degree of freedom of arrangement of components such as the high-pressure fuel passage and the fuel recovery passage. Therefore, the fuel leaking from the high pressure fuel passage to the fuel recovery passage at the end face of the body can be suppressed, and the efficiency of high pressure fuel injection can be improved.

The inventions according to claims 4 to 5 are characterized in that the opening of the control pressure passage is disposed on the inner peripheral side of the fuel supply passage at the body end surfaces of two adjacent body members.

  According to this, as a configuration form of the high pressure fuel passage, in the control pressure passage and the fuel supply passage, the opening of the control pressure passage is arranged on the inner peripheral side of the fuel supply passage. According to such a configuration, the configuration path lengths of the control pressure passage and the fuel supply passage can be substantially shortened while increasing the degree of freedom of arrangement of the high pressure fuel passage and the fuel recovery passage, and as a result, the fuel is supplied to the high pressure fuel passage. The efficiency of the fuel injection valve that injects high-pressure fuel from the injection hole can be improved.

In particular, as in the fifth aspect of the invention, a control chamber is disposed on the inner peripheral side of the fuel supply passage, and a cylindrical partition member is provided between the control chamber and the fuel supply passage. It is preferable.

  According to this, the opening part of the control pressure passage and the control chamber are arranged on the inner peripheral side of the fuel supply passage, and the control chamber and the fuel supply passage are separated from each other by the cylindrical partition member. Therefore, the control passages connected to the control pressure passage and the fuel supply passage are not in direct communication with each other, and the constituent passage lengths of the control pressure passage and the fuel supply passage are reliably shortened.

Further, the invention according to claim 6 is characterized in that the control pressure passage and the fuel supply passage are arranged in the radial direction so as not to communicate with each other on the body end faces of two adjacent body members.

  Here, in general, a control unit that increases or decreases the pressure in the control chamber is provided.For example, as one type of control unit, the control unit is slidably accommodated in a guide hole, and is oil-tight in a sliding gap with the guide hole. A maintaining spool type three-way control valve may be used. With such a three-way control valve, the control pressure passage and the fuel supply passage may be complicated. If the constituent passage is complicated, it becomes difficult to process the constituent passage, and therefore it is necessary to increase the degree of freedom of arrangement of the constituent passage.

On the other hand, according to the configuration of the sixth aspect, the control pressure passage and the fuel supply passage are arranged on the body end face so as to be separated from each other in the radial direction without communicating with each other. In the case of using a three-way control valve of the type, a sufficient volume for forming the constituent passage is secured in the internal region that can be occupied by the separated control pressure passage and the fuel supply passage, and thus the degree of freedom of arrangement of the constituent passage is increased. It is done.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment.

(First embodiment)
FIG. 1 is a cross-sectional view of a main part of a fuel injection valve 1 according to an embodiment of the present invention. A fuel injection valve 1 shown in FIG. 1 is used, for example, in an accumulator fuel injection system for a diesel engine, and injects high-pressure fuel supplied from a common rail (not shown) into a cylinder of the diesel engine. The nozzle part, back pressure control part, and piezo drive part which are described in (1) are provided.

  The nozzle portion includes a nozzle body 10, a needle 16 slidably held on the nozzle body 10, a cylinder 19 into which the needle 16 is inserted, and a nozzle spring 20 that urges the needle 16 in the closing direction.

  The nozzle body 10 is a bottomed cylindrical housing having a needle accommodation hole 11 that accommodates a needle 16, a cylinder 19, and a nozzle spring 20 in a substantially central portion. A nozzle hole 13 through which high-pressure fuel is injected into a cylinder of a diesel engine is formed at the bottom of the nozzle body 10, and a conical valve seat 12 is formed at the upstream side of the nozzle hole 13.

  The needle 16 is a substantially cylindrical valve body having a conical seat portion 18 at the tip, which controls whether or not high pressure fuel is ejected from the nozzle hole 13. The needle 16 is provided so as to be able to reciprocate, and the injection of high-pressure fuel from the injection hole 13 can be controlled by seating the seat portion 18 on the valve seat 12. A flange 17 that receives the urging force of the nozzle spring 20 is formed in the middle of the needle 16.

  The cylinder 19 is a substantially cylindrical part, and is accommodated in the needle accommodation hole 11 in the same manner as the needle 16. An inner peripheral wall 19e of the cylinder 19 slidably supports the upper portion of the needle 16. Clearances 23 and 24 are formed between the outer peripheral wall 19 c of the cylinder 19 and the inner wall of the needle accommodation hole 11. A lower end surface 19 b of the cylinder 19 is a surface facing the flange 17 and supports the other end of the nozzle spring 20. On the upper end surface 19a side of the outer peripheral wall 19c of the cylinder 19, an inclined surface 19d is formed such that the outer diameter decreases as the upper end surface 19a is approached.

  Above the nozzle body 10, a cylindrical plate 30 is provided adjacently so that the plate-side end face 15 of the nozzle body 10 and the body-side end face 34 of the plate 30 are in close contact with each other. When the needle 16 is inserted into the cylinder 19 and accommodated in the needle accommodation hole 11, the needle accommodation hole 11 is divided into three spaces: a back pressure chamber 22, a high pressure chamber 21, and an annular passage 23.

  As shown in FIG. 1, the back pressure chamber 22 is a space defined by the upper end surface of the needle 16, the inner peripheral wall 19e of the cylinder 19, and the body side end surface 34 of the plate 30, and has a predetermined pressure in this space. The force that presses the needle 16 against the nozzle hole 13 is changed by introducing the high-pressure fuel and changing the pressure.

  The annular passage 23 is a space defined by the inner wall of the needle accommodation hole 11 and the inclined surface 19d of the cylinder 19, and is supplied with high-pressure fuel in the common rail at least during operation of the diesel engine.

  The high pressure chamber 21 is a space defined by the inner wall of the needle accommodation hole 11 and the lower end surface 19 b of the cylinder 19. The high pressure chamber 21 communicates with the annular passage 23 via the injection hole 13 and the fourth high pressure fuel passage 24 formed by the outer peripheral wall 19c of the cylinder 19 and the inner wall of the needle housing hole 11 facing the outer peripheral wall 19c. ing. For this reason, the high-pressure chamber 21 is supplied with the high-pressure fuel in the common rail through the fourth high-pressure fuel passage 24 at least during the operation of the diesel engine, and when the seat portion 18 of the needle 16 is separated from the valve seat 12, High-pressure fuel is injected from the injection hole 13.

  The back pressure control unit controls the pressure in the back pressure chamber 22 and includes a plate 30, a valve body 40, a valve needle 45 as a valve body, and a spring 46. The plate 30 and the valve body 40 are formed with various fuel passages for controlling the pressure of the back pressure chamber 22 and supplying fuel to the annular passage 23 and the high pressure chamber 21 and a valve chamber 41 for accommodating the valve needle 45. Has been. The plate 30 is provided adjacent to the nozzle body 10, and the valve body 40 is provided adjacent to the plate 30.

  The plate 30 is a substantially columnar member, and a third high-pressure fuel passage 33, a first communication passage 31, a second communication passage 32, and an annular groove 35 are formed therein. The third high-pressure fuel passage 33 is a passage for supplying high-pressure fuel in the common rail to the annular passage 23, and is formed along the axial direction of the fuel injection valve 1. The first communication passage 31 is a passage that supplies high-pressure fuel to a valve chamber 41 formed in the valve body 40, and the second communication passage 32 is a passage that communicates the valve chamber 41 and the back pressure chamber 22. . The annular groove 35 is connected to the third high-pressure fuel passage 33 and the annular passage 23 and allows the third high-pressure fuel passage 33 and the annular passage 23 to communicate with each other.

  In the valve body 40, the high pressure fuel in the common rail is supplied to the valve chamber 41 that can accommodate the valve needle 45, the low pressure fuel passage 48 for discharging the fuel in the valve chamber 41 to the low pressure side, and the third high pressure fuel passage 33. A second high-pressure fuel passage 42 to be supplied is formed. The valve chamber 41 is connected to the first communication passage 31, the second communication passage 32, the valve piston accommodation hole 44, and the low pressure fuel passage 43. The valve needle 45 has a function as a so-called three-way valve. The valve needle 45 has a first position for supplying high-pressure fuel in the first communication passage 31 to the back pressure chamber 22 via the second communication passage 32. This is a control valve that reciprocates in a second position for discharging the fuel in the pressure chamber 22 to the low pressure fuel passage 48. The valve chamber 41 is provided with a spring 46 that biases the valve needle 45 in the direction of the first position.

  The valve needle 45 is in contact with a valve piston 55 that is accommodated in the valve piston accommodation hole 44 and that transmits the driving force of the piezo drive unit to the valve needle 45. When the valve piston 55 reciprocates, the valve needle 45 is controlled to the first and second positions.

  The piezo drive unit includes a low pressure chamber 51 filled with low pressure fuel in a lower body 50 provided adjacent to the valve body 40, and a first high pressure fuel passage 52 that supplies high pressure fuel in the common rail to the second high pressure fuel passage 42. The piezoelectric stack (not shown) P accommodated in the upper portion of the low-pressure chamber 51 and the driving force transmission unit 5 accommodated in the lower side of the piezoelectric stack P are configured.

  The low-pressure chamber 51 is partitioned by forming a vertical hole with a circular cross section inside the lower body 50, disposing the valve body 40 on the lower end surface of the lower body 50 where the vertical hole opens, and closing the opening of the vertical hole. The low pressure chamber 51 communicates with the valve chamber 41 through the valve piston accommodation hole 44. The low pressure chamber 51 communicates with the valve chamber 41 through the low pressure fuel passage 48 separately from the housing hole 44. Further, the low pressure chamber 51 is connected to a pipe that leads to a fuel tank (not shown).

  The piezo stack P has a general capacitor structure in which, for example, piezoelectric ceramic layers such as PZT and electrode layers are alternately stacked, and is charged and discharged via a drive circuit (not shown). By being charged and discharged, it expands and contracts in the vertical direction of FIG.

  The driving force transmission unit 5 transmits the displacement of the piezo stack P to the valve piston 55, and includes a piston cylinder 56 provided in the low pressure chamber 51, a first piston 53 and a second piston 54 inserted in the cylinder 56. , The oil-tight chamber 59 formed between the pistons 53, 54, and the oil-tight chamber 59, one is supported by the first piston 53 and the other is supported by the piston cylinder 59, and the first piston 53 and the piston cylinder The first piston spring 57 generates a biasing force that pushes 59 in the opposite direction, and the second piston spring 58 generates a biasing force that pushes both pistons 53 and 54 in the opposite direction.

  The first piston 53 is disposed below the piezo stack P and is pressed against the lower end of the piezo stack P by the first piston spring 57. According to the displacement of the piezo stack P, the piston cylinder 56 is reciprocated.

  The second piston 54 is disposed below the first piston 53 via the oil tight chamber 59. The second piston 54 reciprocates in the piston cylinder 56 according to the displacement of the first piston 53. Since the valve piston 55 is disposed below the second piston 54, the valve piston 55 reciprocates according to the displacement of the second piston 54. The reciprocating movement of the valve piston 55 is transmitted to the valve needle 45. As a result, the valve needle 45 reciprocates in the valve chamber 41 and is controlled to the first and second positions.

  The nozzle body 10, the plate 30, the valve body 40 and the lower body 50 are formed with pin holes 37 and 14 for locking the pins 60 for aligning the circumferential positions of the respective parts. After the components are combined in the axial direction, the circumferential positions of the components are fixed by locking the pins 60 in the pin holes 37 and 14. Furthermore, each component is firmly fixed by the retaining nut 70.

  Here, the back pressure chamber 22 corresponds to the control chamber described in the claims. The annular groove 35, the annular passage 23, the high pressure chamber 21, the first communication passage 31, the second communication passage 32, and the back pressure chamber 22 are respectively a fifth high pressure fuel passage, a sixth high pressure fuel passage, and a seventh high pressure. The fuel passage, the eighth high-pressure fuel passage, the ninth high-pressure fuel passage, and the tenth high-pressure fuel passage constitute the first to tenth high-pressure fuel passages 21, 22, 23, 24, 31, 32, 33, 35. , 42 and 52 correspond to the high-pressure fuel passages described in the claims.

  The back pressure chamber 22 and the second communication passage 32 correspond to the control pressure passage described in the claims. The first to eighth high-pressure fuel passages 21, 23, 24, 31, 33, 35, 42, and 52 correspond to the fuel supply passages recited in the claims. The cylinder 19 corresponds to the partition member described in the claims.

  Next, the operation of the fuel injection valve 1 having the above configuration will be described.

  When the piezo stack P is energized through the drive circuit and the piezo stack P expands, the displacement is transmitted from the first piston 53 to the second piston 54 via the fuel in the oil-tight chamber 59 and further to the valve piston 55. The The valve piston 55 moves in the valve piston accommodating hole 44 to the anti-low pressure chamber 51 side (lower side in FIG. 1), and moves the valve needle 45 from the first position to the second position.

  Then, the flow of fuel from the first communication path 31 to the second communication path 32 is blocked, and the fuel in the back pressure chamber 22 is discharged to the low pressure fuel path 48. As a result, the pressure in the back pressure chamber 22 decreases, so that the force that presses the needle 16 against the injection hole side (valve closing force) lifts the needle 16 by the fuel pressure supplied to the high pressure chamber 21 toward the counter injection hole side. Since it is lower than the force (valve opening force) to be attempted, the seat portion 18 is separated from the valve seat 12, and the fuel in the high pressure chamber 21 is injected from the injection hole 13.

  Thereafter, when the energization of the piezo stack P is stopped, the electric charge of the piezo stack P is released, and when the piezo stack P contracts, the force acting on the valve piston 55 via the driving force transmission unit 5 is released. For this reason, the valve needle 45 is moved to the first position by the urging force of the spring 46 and the high pressure fuel pressure from the first communication path 31, and the high pressure fuel passes through the first and second communication paths 31 and 32. It is supplied to the back pressure chamber 22. As a result, since the pressure in the back pressure chamber 22 rises again, the seat portion 18 is seated on the valve seat 12 when the valve closing force exceeds the valve opening force, and fuel is injected from the injection hole 13. finish.

  Here, the end surfaces of the body members of the lower body 50, the valve body 40, the plate 30, and the nozzle body 10 are in close contact with the fuel injection valve 1. High pressure fuel passages 52, 42, 31, 33, and 21 are formed in the members 10, 30, 40, and 50 so that the opposing end surfaces of the members 10, 30, 40, and 50 are in close contact with each other. This is because the high-pressure fuel passage is in oil-tight communication between the end faces. Specifically, in the present embodiment, these members 10, 30, 40, and 50 are stacked in the order shown in the drawing, and the retaining nut 70 is inserted into the outer periphery and screwed to be fastened and fixed in an oil-tight manner. .

  Hereinafter, the configuration of the end surfaces 15 and 34 that are sealed in an oil-tight manner will be described with reference to FIGS. 1 to 3 by taking the end surfaces 15 and 34 of the nozzle body 10 and the plate 30 as an example. 2 shows the body side end face 34 of the plate 30 viewed from the II direction in FIG. 1, and FIG. 2 shows the plate side end face 15 of the nozzle body 10 viewed from the III direction in FIG. 1 is a cross-sectional view taken along the line II in FIG. 2 and FIG.

  The end surfaces 15 and 34 of the nozzle body 10 and the plate 30 are provided with fuel supply passages 22, 23, 31, 33, 35 and control pressure passages 22, 32, that is, high-pressure fuel passages in the figure, as shown in FIGS. (Inside the dot hatching in the figure) communicates. Specifically, an annular groove 35 and a second communication passage 31 are opened on the body side end surface 34 of the plate 30 as shown in FIGS. 1 and 2, and the needle housing hole 11 is formed on the plate side end surface 15 of the nozzle body 10. And an inner peripheral wall 19e of another cylinder 19 is opened in the needle accommodation hole 11. In the fuel supply passage, a third high-pressure fuel passage 33 communicates with the annular passage 23 via an annular groove 35 and is connected to a fourth high-pressure fuel passage 24 and a high-pressure chamber 21 (not shown) on the downstream side of the annular passage 23. -ing In the control pressure passage, the first communication passage 31 opened in the annular groove 35 is connected to the second communication passage 31 via the valve needle 45.

  Regarding the fuel supply passages 22, 23, 31, 33, 35 and the control pressure passages 22, 32, the pin holes 14 and 37 on the nozzle body 10 side and the plate 30 side are coupled using the pin 60 at the time of assembly. When the end surfaces 15, 34 of the nozzle body 10 and the plate 30 are brought into close contact with each other, the fuel supply passages 22, 23, 31, 33, 35 and the control pressure passages 22, 32 become continuous passages as shown in the figure.

  Further, as shown in FIGS. 1 and 2, a substantially annular recess (hereinafter referred to as a first recess) 36 is formed on the outer peripheral side of the annular groove 35 on the body side end face 34 of the plate 30. 36 and the annular groove 35, that is, the high-pressure fuel passage, are arranged at an interval (hereinafter referred to as a third interval) δ 3 along the outer peripheral side of the high-pressure fuel passage. The first recess 36 is a meat stealer for increasing the surface pressure between the nozzle body 10 and the plate 30.

  The first recessed portion 36 having a substantially annular shape includes a substantially arc-shaped recessed large portion 361 and a recessed small portion 362 having a smaller radial width than the recessed large portion 361, and the recessed small portions 362 are adjacent recessed large portions. 361 are connected. Due to the outer peripheral side shape of the adjacent concave large portion 361 and concave small portion 362 as shown in FIG. 2, it is avoided that the arrangement of the first concave portion 36 and the pin hole 34 interferes with the body side end surface 34.

  According to the arrangement configuration of the first recess 36 and the annular groove 35, that is, the high-pressure fuel passage, the high-pressure fuel in the annular groove 35 travels between the body-side end face 34 and the plate-side end face 15 from the annular groove 35. Even if it flows out, the fuel can be temporarily stored in the first recess 36.

  Further, a leak passage 38 as a fuel recovery passage is opened on the body side end face 34, and the leak passage 38 penetrates the plate 30 in the vertical direction in FIG. The leak passage 38 is a fuel recirculation passage for returning surplus fuel such as leaked fuel to the fuel tank, and is connected to the low pressure fuel passage 48 through a communication passage (not shown) of the valve body 40 and communicates with the low pressure chamber 51. is doing.

  Here, the leak passage 38 and the first recess 36 are in direct communication with the leak passage 38 and the first recess 36 on the body-side end surface 34 because of the arrangement of the components such as the high-pressure fuel passage and the pin hole. It may be difficult to make the configuration to be

  On the other hand, in the present embodiment, as shown in FIGS. 2 and 3, the first recess 36 and the leak passage 38 are arranged at an interval (hereinafter referred to as a first interval) δ1 on the body side end surface 34 of the plate 30. At the same time, a second recess 28 is provided at a portion (corresponding to the two-dot chain line in FIG. 2) that wraps on both the at least part 361 of the first recess 36 and the leak passage 38 on the plate-side end surface 15 of the nozzle body 10. The configuration. In addition, the 1st space | interval (delta) 1 and 3rd space | interval (delta) 3 have shown the site | part used as the shortest distance in a figure.

  According to such a configuration, even when there is a restriction condition or the like that cannot realize a configuration in which the leak passage 38 and the first recess 36 are directly communicated with each other on the same end surface 34, the first and second wraps are arranged so as to overlap each other. Since the two recesses, the first recess 36 and the leak passage 38 form a continuous fuel recovery space, the fuel stored in the first recess 36 can be returned to the fuel tank via the leak passage 38. As a result, fuel leakage to the outside of the fuel injection valve 1 can be prevented.

  The shape of the second recess is not limited to the oval shape as shown in FIG. 3 of this embodiment as long as it forms a fuel recovery space by wrapping in the first recess 36 and the leak passage 38 when assembled. Further, it may be formed in a shape such as an arc or a straight line. Such second recess 28 and first recess 36 can each be formed in a relatively simple shape.

  In the present embodiment described above, in the plurality of body members 10, 30, there is a restriction condition that cannot realize a configuration in which the leak passage 38 and the first recess 36 are directly communicated with each other on the same end surface 34 of the body member. Even in this case, the second end surface 15 adjacent to the end surface 34 is provided with the second recessed portion disposed in the first recessed portion 36 and the leak passage 38 so as to leak from the high-pressure fuel passage. The fuel is recovered in the first recess 36, and the recovered fuel is further returned to the leak passage 38 via the second recess 28.

  In other words, in the case where the first recess 36, the high-pressure fuel passage, the leak passage 38, and the like are formed on the same body end surface, the degree of freedom in arranging the components such as the high-pressure fuel passage and the leak passage 38 can be improved. .

  Therefore, it is possible to suppress an improvement in the degree of freedom of arrangement of components such as the high-pressure fuel passage and the leak passage 38 on the same end surface 34 and to complicate the shape of the first recess 36 formed in the end surface 34. .

  Further, in the present embodiment described above, the portions excluding the high pressure fuel passage, the leak passage 38, the first concave portion 36, and the second concave portion 28 on the end surfaces 15, 34 of the adjacent nozzle body 10 and the plate 30 are the fuel. It is set as the sealing surface which prevents leak prevention, and the said end surfaces 15 and 34 are made into the structure sealed between the said end surfaces 15 and 34 closely_contact | adhering. According to such a configuration, since the peripheral portion and the outer peripheral edge portion of the high-pressure fuel passage are sealed at least at the end surfaces 15 and 34, the sealing surface portions of the end surfaces 15 and 35 are brought into close contact with each other. The surface pressure can be increased, and as a result, the sealing performance for sealing between the end surfaces 15 and 34 can be improved.

  In the present embodiment described above, the fuel supply passages 22, 23, 31, 33, 35 and the control pressure passage 22 constituting the high-pressure fuel passage are taken as an example between the end surfaces 15, 34 of the nozzle body 10 and the plate 30. 32, the fuel supply passage and the control pressure passage have been described as having a configuration in which the opening of the control pressure passage is disposed in the fuel supply passage.

  According to such a configuration, it is possible to substantially shorten the constituent path lengths of the control pressure passage and the fuel supply passage while increasing the degree of freedom of arrangement of the high pressure fuel passage and the leak passage 38, and consequently to the high pressure fuel passage. High efficiency of the fuel injection valve 1 that injects the supplied high-pressure fuel from the injection hole 13 can be achieved.

  Here, the plate-side end face 15 and the valve-side end face 34 correspond to the body end face described in the claims.

(Second Embodiment)
A second embodiment is shown in FIGS. The second embodiment shows an example applied to a fuel injection valve in which a fuel supply passage and a control pressure passage constituting a high-pressure fuel passage are spaced apart in the radial direction. FIG. 6 shows an example of a fuel injection valve in which the fuel supply passage and the control pressure passage are spaced apart from each other in the radial direction. In the body members 10 and 140 adjacent to the fuel injection valve, FIG. FIG. 5 shows the end face 15 of the nozzle body 10. In FIG. 6, the fuel injection valve 1 is oil-tightly fastened and fixed by laminating body members 10, 140, 130, and 50 in the order shown in the drawing, and inserting and retaining a retaining nut 70 on the outer periphery. .

  Here, the valve needle 45 is a so-called spool-type three-way valve that is accommodated in the guide hole of the valve body 140 and is slidably instructed. A valve chamber 41 is formed at the upper end of the valve body 140, and a large-diameter valve portion at the upper end of the valve needle 45 is accommodated. A low pressure port communicating with the leak passage 38 formed in the plate 130 is connected to the top surface of the valve chamber 41, and a third high pressure valve portion is connected to the first high pressure fuel passage 52 on the bottom surface side of the large diameter valve portion. A distribution passage (hereinafter referred to as a high pressure port) 423 is connected. The valve chamber 41 is always in communication with the back pressure chamber 22 and the second communication passage 32. The low pressure port communicates with a low pressure passage 49 via a low pressure fuel passage (hereinafter referred to as a second leak passage) 48, and the high pressure port 423 communicates with a first high pressure fuel passage 52, depending on the seat position of the valve needle 45, A valve chamber 41 selectively communicates with one of these ports.

  The valve needle 45 is configured such that the lower half portion of the spool shape slides in the guide hole, and is urged upward by a spring 46 disposed at the lower end portion of the guide hole. In the spring chamber that houses the spring 46, the second leak passage 48 passes through the valve body 140 in an obliquely downward direction in the figure, and the second leak passage 48 opens on the body side end surface 34 of the valve body 140.

  A second distribution passage 422 that always communicates the high pressure port 423 and the back pressure chamber 22 is connected to the high pressure port 423 and the second distribution passage 422 and the eleventh high pressure fuel passage 29 on the nozzle body 10 side. One distribution passage 52 is connected and is always in communication with the first high-pressure fuel passage 52. The high pressure port 423, the second distribution passage 422, and the first partial distribution passage 421 constitute a second high pressure fuel passage 42 formed in the valve body 140.

  Here, the first high-pressure fuel passage 52, the third high-pressure fuel passage 33, the second high-pressure fuel passage 42, and the eleventh high-pressure fuel passage 29 correspond to the fuel supply passage described in the claims, and the back pressure chamber 22, The two communicating passages 32 correspond to the control pressure passages described in the claims. In other words, the fuel supply passage and the control pressure passage are spaced apart in the radial direction on the end surfaces 15 and 34 of the nozzle body 10 and the valve body 140.

  Hereinafter, the detailed structure of the said end surfaces 15 and 34 of the nozzle body 10 and the valve body 140 is demonstrated based on FIG.4 and FIG.5.

  As shown in FIGS. 4 and 5, the control pressure passage (specifically, the back pressure chamber 22) and the fuel supply passage (first distribution passage 421) are spaced apart in the radial direction on the end faces 15 and 34. The

  The first recess 36 is composed of a plurality of (two in this embodiment) concave large portions 361, and the concave large portions 361 are spaced apart by an interval (hereinafter, referred to as a second interval) δ 2. The part 361 does not communicate with the end face 34. The recessed large portion 361 is disposed at a third interval δ3 from the fuel supply passage (first distribution passage 421), and is disposed at a first interval δ1 from the second leak passage 48.

  In such a configuration, since the high-pressure fuel passage is discretely arranged in the two fuel supply passages and the control pressure passage on the end surfaces 15 and 34 in the radial direction, the first concave portion 36 including the concave large portion 361 is: It will be arranged close to the outer peripheral edge side of the body side end face 34. For this reason, it is difficult to provide a communication path that connects the concave large portions 361 on the same end surface 34 and to form the first concave portion 36 in an annular shape, and even if formed, the shape becomes excessively complicated. There are concerns.

  On the other hand, in the present embodiment, the second end surface 15 is provided with an arc-shaped second recess 28 along the outer peripheral edge of the end surface 15, and the second recess 28 is formed by the first recess 36 and the second recess 28. The configuration is such that the leak passage 48 is wrapped. Since the second recess 28 is formed into an arc-shaped narrow groove along the outer peripheral edge, the narrow groove interferes with the fuel supply passage (specifically, the ninth high-pressure fuel passage 29) and the pin hole 34. Is avoided.

  According to this configuration, the first concave portion 36 is configured to be the two concave large portions 361 having the second interval δ2 that do not communicate with each other on the same end surface 34, and therefore, the same end surface 34 is formed by the second interval δ2. Interference between the other component such as the pin hole 34 formed in the first recess 36 and the first recess 36 is easily avoided, and the shape of the first recess 36 is surely formed into a simple shape.

  In addition, the second end surface 15 is formed with a second recess 28 that presents an arc-shaped groove extending along the inner circumferential direction of the outer peripheral edge, and the second recess 28 is a large recess 361, that is, the first recess 36. And the second leak passage 48 so as to wrap and communicate with each other (corresponding to the two-dot chain line in FIG. 4), the high pressure fuel passage (specifically, the radial direction) is formed by the first recess 36 and the second recess 28. The fuel supply passage and the control pressure passage which are spaced apart from each other can be easily surrounded. Therefore, an improvement in the degree of freedom of arrangement of the components such as the high-pressure fuel passage and the second leak passage 48 on the same end surface 34 and suppression of a complicated shape of the first recess 36 formed in the end surface 34 are suppressed. Can do it.

  Further, in the present embodiment described above, the control pressure passage and the fuel supply passage are arranged on the end surfaces 15 and 34 so as to be spaced apart from each other in the radial direction without communicating with each other. According to such a configuration, for example, even if the constituent passages of the control pressure passage and the fuel supply passage may have complicated structures, the nozzle body 10 and the valve body 140 may have the internal regions other than the end surfaces 15 and 34 in the inner region. It is easy to reliably ensure a sufficient volume for forming the constituent passages. Therefore, the degree of freedom in arranging the constituent passages in the internal regions other than the end surfaces 15 and 34 of the nozzle body 10 and the valve body 140 is increased while increasing the degree of freedom in arranging the high-pressure fuel passage and the second leak passage 48.

(Third embodiment)
A third embodiment is shown in FIGS. The third embodiment shows another example applied to a fuel injection valve in which a fuel supply passage and a control pressure passage constituting a high-pressure fuel passage are spaced apart in the radial direction.

  As shown in FIGS. 7 and 8, on the end faces 15 and 34, the control pressure passage (specifically, the back pressure chamber 22) and the fuel supply passage (first distribution passage 421) are spaced apart in the radial direction. The

  In the end surface 34 of the valve body 140, the first recess 36 is composed of a recessed small portion 362, and the annular recessed small portion 362 surrounds the fuel supply passage and the control pressure passage that are spaced apart in the radial direction. It is out.

  Further, in the end face 15 of the nozzle body 10, the oval second concave portion 28 is provided in a portion that wraps around both the concave small portion 362 and the second leak passage 48 (corresponding to the two-dot chain line in FIG. 7). did.

  Even with such a configuration, it is possible to improve the degree of freedom in arranging the components such as the high-pressure fuel passage and the second leak passage 48 on the same end surface 34, and the shape of the first recess 36 formed in the end surface 34 is complicated. It is suppressed.

(Other embodiments)
(1) In the present embodiment described above, the fuel injection valve 1 is composed of a plurality of body members 10, 30, 40, 50, etc., and two adjacent body members are brought into close contact with each other at the body end faces. The first embodiment is an example of the end surfaces 15 and 34 of the adjacent nozzle body 10 and the plate 30, and the second and third embodiments are described by examples of the end surfaces 15 and 34 of the adjacent nozzle body 10 and the valve body 140. did. Not limited to this, as long as two adjacent body members are located between the body end faces, any body end face may be used, and any structure having the following configuration may be used between the body end faces.

  That is, the first recess and the leak passage are provided on one end face of the body without communication, and the second recess is provided on the other end face of the body so as to wrap on both the first recess and the leak path and communicate with each other. Having

  (2) In the first embodiment described above, the leak passage 38 and the fuel supply passage such as the third high-pressure fuel passage 33 are separated from each other in the first recess 36 by the separate first gap δ1 corresponding to the recess small portion 362. Arranged. Not limited to this, the leak passage 38 and the fuel supply passage can be disposed in the same first gap δ1 as in another example shown in FIGS. 9 and 10. In the same body end surface 34, it is possible to improve the degree of freedom of arrangement of components such as the high-pressure fuel passage such as the fuel supply passage and the leak passage 38, and the shape of the first recess 36 formed in the body end surface 34 is complicated. This is because it is suppressed.

It is sectional drawing which shows the principal part of the fuel injection valve by 1st Embodiment of this invention. It is a top view of the plate side end surface of the nozzle body seen from the II direction in FIG. It is a top view of the nozzle body side end surface of the plate seen from the III direction of FIG. It is a top view of the valve body side end surface of the nozzle body by 2nd Embodiment. It is a top view of the nozzle body side end surface of the valve body by 2nd Embodiment. It is sectional drawing which shows an example of the fuel injection valve by 2nd Embodiment. It is a top view of the valve body side end surface of the nozzle body by 3rd Embodiment. It is a top view of the nozzle body side end surface of the valve body by 3rd Embodiment. It is a top view of the plate side end surface of the nozzle body by other embodiment. It is a top view of the nozzle body side end surface of the plate by other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel injection valve 10 Nozzle body 11 Needle accommodation hole 13 Injection hole 14 Pin hole 15 Plate side end surface 16 Needle 19 Cylinder (partition wall member)
19c outer peripheral wall 19d inclined surface 19e inner peripheral wall 20 nozzle spring 21 high pressure chamber (fifth high pressure fuel passage)
22 Back pressure chamber (6th high pressure fuel passage)
23 annular passage 24 fourth high pressure fuel passage 30 plate 31 first communication passage 32 second communication passage 33 third high pressure fuel passage (fuel passage)
34 Body-side end face 35 Annular groove 36 Recessed part
37 Pin hole 38 Leakage passage (Fuel recovery passage)
40 Valve body 41 Valve chamber 42 Second high pressure fuel passage 44 Valve piston accommodation hole 45 Valve needle 46 Spring 48 Low pressure fuel passage 50 Lower body 5 Driving force transmission part 51 Low pressure chamber 52 First high pressure fuel passage 53 First piston 54 Second piston 55 Valve Piston 56 Piston Cylinder 57 First Piston Spring 58 Second Piston Spring 59 Oiltight Chamber 60 Pin 70 Retaining Nut (Nut)

Claims (6)

A fuel injection valve comprising a plurality of body members, wherein two adjacent body members are brought into close contact with each other at a body end surface so as to communicate a passage for fuel flowing through the body member,
Of the body end surfaces where the two body members are in close contact,
On one end face of the body, a first recess and a fuel recovery passage are provided in a portion excluding the outer peripheral edge and the high-pressure fuel passage, and the first recess and the fuel recovery passage are arranged at intervals without communicating with each other. With
In other body end face, a second recess is provided which communicates both with both and the lap of the first recess and the fuel return passage, the second recess is arranged between the fuel return passage and said first recess A fuel injection valve characterized in that it is formed only in the vicinity of the shortest distance portion including the portion of the shortest distance (δ1) between the two determined by the relationship . In the body end surfaces of the two body members, a portion excluding the high pressure fuel passage, the fuel recovery passage, the first recess, and the second recess is a sealing surface,
2. The fuel injection valve according to claim 1, wherein the opposite sealing surfaces are brought into close contact with each other to seal between the body end surfaces. The high-pressure fuel passage is
A fuel supply passage for supplying high-pressure fuel to the nozzle hole of the nozzle body member having a nozzle hole formed at a tip of the plurality of body members;
A control pressure passage communicating with a control chamber for providing a driving force for opening and closing the nozzle hole at an end opposite to the nozzle hole of the valve member accommodated axially movable in the nozzle body member;
The fuel injection valve according to claim 1 , wherein the fuel injection valve is provided. In the body end surfaces of the two adjacent body members,
The fuel injection valve according to claim 3 , wherein an opening of the control pressure passage is disposed on an inner peripheral side of the fuel supply passage. The control chamber is disposed on the inner peripheral side of the fuel supply passage,
The fuel injection valve according to claim 4 , wherein a partition member having a cylindrical shape is provided between the control chamber and the fuel supply passage. In the body end surfaces of the two adjacent body members,
4. The fuel injection valve according to claim 3 , wherein the control pressure passage and the fuel supply passage are arranged to be spaced apart from each other in a radial direction without being communicated with each other.

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