JP2017066883A - Fuel injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection device which, when switching operation of a valve element into plural stages, can improve control accuracy of the operation of the valve element.SOLUTION: A fuel injection device 20 for injecting fuel into a combustion chamber comprises: a nozzle 23 for injecting fuel; a core 36 and a needle 24, for opening and closing the nozzle 23; a solenoid 33 for operating the core 36 and the needle 24 in a direction of a center line A1 of the nozzle 23; a stopper 35 which comes into contact with the core 36 to stop the core 36; and a switching mechanism which, by relatively rotating the core 36 and the stopper 35 around the center line A1, switches the position at which the core 36 comes into contact with the stopper 35 and is stopped, between a first stop position and a second stop position which are the positions different from each other in the direction of the center line A1.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fuel injection device that injects fuel into a combustion chamber.

  Patent Documents 1 and 2 describe fuel injection devices that inject fuel into a combustion chamber. The fuel injection device described in Patent Document 1 includes a needle that is supported by a nozzle portion and can operate linearly, a first spring that applies a biasing force to the needle via a push rod, and the needle has operated a predetermined distance or more. A second spring that applies a biasing force to the needle, and a nozzle chamber, a sub-nozzle, and a main nozzle provided in the nozzle portion. Further, a fuel injection pump that supplies tank fuel of the fuel tank to the nozzle chamber is provided. The fuel injection pump has a solenoid valve, and high pressure fuel is pumped to the nozzle chamber by the solenoid valve.

  In the fuel injection device described in Patent Document 1, when fuel is not supplied to the nozzle chamber, the needle is pressed against the seat surface of the nozzle portion by the urging force of the first spring, and both the sub nozzle and the main nozzle are closed. ing. On the other hand, when fuel is supplied to the nozzle chamber and the needle operates against the urging force of the first spring, the nozzle portion is separated from the seat surface, the sub nozzle is opened, and fuel is injected. When the pressure of the fuel supplied to the nozzle chamber is low, the operation amount of the needle is not more than a predetermined distance, and the main nozzle is closed.

  Furthermore, when the pressure of the fuel supplied to the nozzle chamber rises due to the control of the solenoid valve and the needle moves more than a predetermined air distance, the needle operates against the urging force of the first spring and the second spring. In addition to the sub nozzle, the main nozzle is also opened.

  The fuel injection device described in Patent Document 2 is formed on a main body having a low-pressure passage and a high-pressure passage, a piston, an inner needle valve, an outer needle valve, and a closing member disposed in the main body, and a front end side of the main body. The first injection hole and the second injection hole, a control chamber formed in the main body, a first compression spring disposed in the control chamber and biasing the piston, and disposed between the closing member and the inner needle valve A second compression spring.

  In the fuel injection valve described in Patent Document 2, when the pressure of the high-pressure fuel supplied to the control chamber is high, the piston, the inner needle valve, and the outer needle valve are driven by the force of the first compression spring and the second compression spring. Energized, the first injection hole and the second injection hole are closed.

  When the pressure of the high-pressure fuel supplied to the control chamber decreases, the urging force applied to the piston and the outer needle valve decreases. Further, the pressure of the fuel supplied to the high pressure passage rises, and the outer needle valve operates against the force of the first compression spring at that pressure, and the second injection hole is opened. For this reason, the fuel in the high-pressure passage is injected from the second injection hole.

  Further, when the pressure of the fuel supplied to the high pressure passage rises and the amount of movement of the outer needle valve exceeds a predetermined amount, the shoulder of the outer needle valve engages with the shoulder of the inner needle valve, and the inner needle The valve moves against the force of the second compression spring, and the first injection hole is opened. For this reason, the fuel in the high-pressure passage is injected from the first injection hole and the second injection hole.

JP 2002-188541 A JP 2002-322969 A

  However, the fuel injection devices described in Patent Documents 1 and 2 operate the valve body using the pressure of the fuel to control the fuel injection amount in two stages. For this reason, the operation switching of the valve body depends on the fuel pressure, and there is a problem that the accuracy of the control is lowered.

  The objective of this invention is providing the fuel-injection apparatus which can improve a control precision, when switching operation | movement of a valve body in multiple steps.

  The present invention is a fuel injection device that injects fuel into a combustion chamber, wherein the fuel is injected into a nozzle, an operating member including a valve element that opens and closes the nozzle, and the operating member is disposed in the center line direction of the nozzle. An operating mechanism to be operated; a stopper that contacts the operating member to stop the operation of the operating member; and the operating member and the stopper are rotated relative to each other about the center line so that the operating member is moved to the stopper And a switching mechanism that switches the position that stops in contact with the first stop position and the second stop position that are different from each other in the center line direction.

  The nozzle in the present invention has a first injection port and a second injection port for injecting fuel, and the valve body opens the first injection port when the operation member stops at the first stop position, and When the second injection port is closed and the operation member stops at the second stop position, the first injection port and the second injection port are opened.

  In the present invention, the stopper has a first convex portion protruding in the center line direction, and the operating member has a second convex portion protruding in the center line direction and in contact with the first convex portion. The operating member stops at the first stop position when the first convex portion and the second convex portion are in the same position in the rotation direction about the center line, and the operating member is When the first convex portion and the second convex portion are at different positions in the rotation direction around the center line, the second stop position is stopped.

  The switching mechanism according to the present invention includes a hydraulic chamber that generates a force for rotating the operation member relative to the stopper, and a hydraulic control unit that controls the pressure of the hydraulic chamber.

  The present invention is provided with a controller for switching the combustion state in the combustion chamber between homogeneous combustion and stratified combustion, and the operation member stops at the first stop position when the combustion state in the combustion chamber is set to homogeneous combustion. The operating member stops at the second stop position when the combustion state in the combustion chamber is stratified combustion.

  In the present invention, the position at which the valve body stops in the direction of the center line of the nozzle can be switched by changing the relative position between the operation member including the valve body and the stopper. The control accuracy in the case can be improved.

It is a mimetic diagram of an engine provided with a fuel injection device of the present invention. (A), (B) is sectional drawing which shows the injection state of the fuel by the fuel-injection apparatus of this invention. (A) is sectional drawing which shows the fuel-injection apparatus of this invention, (B) is sectional drawing which shows the principal part of the fuel-injection apparatus of this invention. It is a bottom view of the nozzle used for the fuel-injection apparatus of this invention. (A), (B) is typical sectional drawing of the switching mechanism used for the fuel-injection apparatus of this invention. It is an expanded view of the core and stator which are used for the fuel-injection apparatus of this invention. (A) is sectional drawing which shows the fuel-injection apparatus of this invention, (B) is sectional drawing which shows the principal part of the fuel-injection apparatus of this invention. (A) is sectional drawing which shows the fuel-injection apparatus of this invention, (B) is sectional drawing which shows the principal part of the fuel-injection apparatus of this invention. (A)-(C) are sectional drawings which show the structural example of the nozzle used for the fuel-injection apparatus of this invention. FIG. 10 is a bottom view of the nozzle shown in FIG. 9. (A), (B) is sectional drawing which shows the injection state of the fuel by the fuel-injection apparatus of this invention. (A)-(C) are sectional drawings which show the structural example of the nozzle and needle used for the fuel-injection apparatus of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  An engine 10 shown in FIG. 1 is mounted as a driving force source of a vehicle. The engine 10 is provided with an intake device 11, an exhaust device 12, and a fuel supply device 13. The engine 10 is assumed to be a gasoline engine. The fuel supply device 13 includes a fuel tank 13A for storing gasoline, a pump 13B, a fuel supply pipe 13C, and the like. The intake device 11 includes an air cleaner, a throttle valve, an intake manifold, and the like. The exhaust device 12 includes a catalytic converter, an exhaust pipe, and the like.

  The engine 10 includes a cylinder 14 shown in FIG. 2, and a piston 15 is accommodated in the cylinder 14 so as to be able to reciprocate, and a combustion chamber 16 is formed in the cylinder 14. The cylinder 14 is provided with an intake port 17 and an exhaust port 18. The intake port 17 is connected to the combustion chamber 16 and the intake manifold. Further, an intake valve that opens and closes the intake port 17 is provided. The exhaust port 18 is connected to the combustion chamber 16 and the catalytic converter. Further, an exhaust valve for opening and closing the exhaust port 18 is provided.

A spark plug 19 is provided in the cylinder 14. Further, the fuel injection device 20 is provided in the cylinder 14, and a controller 55 for controlling the spark plug 19 and the fuel injection device 20 is provided in the engine room. The fuel injection device 20 is attached to a location where the combustion chamber 16 is formed on the inner surface of the cylinder 14. For example, the fuel injection device 20 is disposed substantially in the center in the plan view of the combustion chamber 16. As shown in FIG. 3A, the fuel injection device 20 includes a cylindrical casing 21, a nozzle 23 attached to the casing 21 via an annular holder 22, and the casing 21, the holder 22, and the nozzle 23. And a needle 24 as a valve body disposed over the same. The needle 24 can reciprocate linearly in the direction of the center line A1.
As shown in FIG. 3B, the nozzle 23 is provided on the opposite side of the inclined portion 26 in the small diameter portion 27, the small diameter portion 27 continuing to the large diameter portion 25 via the inclined portion 26, and the small diameter portion 27. And an inclined portion 28. The large diameter portion 25 and the small diameter portion 27 have a cylindrical shape, and the inner diameter of the large diameter portion 25 is larger than the inner diameter of the small diameter portion 27.

  A plurality of first injection ports 29 penetrating the inclined portion 26 are provided, the inclined portion 28 is inclined in a conical shape, and a plurality of second injection ports 30 penetrating the inclined portion 28 are provided. As shown in FIG. 4, the plurality of first injection ports 29 are arranged on the same circumference around the center line A1, and the plurality of second injection ports 30 are arranged on the same circumference. The plurality of first injection ports 29 and the plurality of second injection ports 30 are both connected to the inside and outside of the nozzle 23.

  The needle 24 has a large diameter part 31 and a small diameter part 32, and the large diameter part 31 and the small diameter part 32 are arranged concentrically. The outer diameter of the large diameter portion 31 is smaller than the inner diameter of the large diameter portion 25 and larger than the inner diameter of the small diameter portion 27. The small diameter portion 32 is smaller than the inner diameter of the small diameter portion 27. A passage 23 </ b> A is formed between the outer peripheral surface of the large-diameter portion 31 and the inner peripheral surface of the nozzle 23. The fuel in the fuel tank 13A is sucked and discharged by the pump 13B, and the fuel discharged from the pump 13B is supplied to the passage 23A through the fuel supply pipe 13C.

  The diameter of the annular seal portion 31 </ b> A formed at the location closest to the small diameter portion 32 in the large diameter portion 31 is larger than the diameter of the circumscribed circle of the plurality of first injection ports 29 on the inner surface 26 </ b> A of the inclined portion 26. The seal portion 31 </ b> A is an edge formed on the needle 24. The needle 24 is movable in the direction of the center line A1 in a state where the outer peripheral surface of the small diameter portion 32 is in contact with the outer peripheral surface of the small diameter portion 27. The center line A1 is the same as the center line when the piston 15 operates in FIG.

  As shown in FIG. 3A, a solenoid 33 is attached to the inner periphery of the casing 21. The solenoid 33 is obtained by winding an electromagnetic coil around a core of nonmagnetic material. The controller 55 controls the voltage applied to the solenoid 33. An annular stator 34 is provided in the casing 21. The stator 34 is a magnetic material and is fixed to the casing 21 so as not to move in the direction of the center line A1. A stopper 35 is fixed in the stator 34. The stopper 35 is annular, and a part of the needle 24 is disposed in the stopper 35.

  An annular core 36 is attached to the outer peripheral surface of the needle 24. The core 36 has a shaft hole 37 as shown in FIGS. 3A and 5, and the needle 24 is disposed in the shaft hole 37. The shaft hole 37 is formed concentrically with the center line A1. The core 36 can rotate around the center line A1 with respect to the needle 24, and the core 36 and the needle 24 can move in the direction of the center line A1 with respect to the casing 21, the holder 22, and the nozzle 23. The core 36 and the needle 24 constitute an operation member including a needle as a valve body. The core 36 is a magnetic body, and when a voltage is applied to the solenoid 33, a magnetic field passing through the stator 34 and the core 36 is formed, and the core 36 and the needle 24 are urged toward the stator 34 by a magnetic attractive force.

  The casing 21 is fixed so as not to move in the center line A1 direction and the circumferential direction with respect to the cylinder 14. An annular fixing member 38 is provided in the casing 21, and a sleeve 39 is fixed in the fixing member 38. A receiving portion 40 is attached to a portion of the needle 24 disposed in the stopper 35. The receiving portion 40 is disposed between the sleeve 39 and the core 36 in the center line A1 direction, and the receiving portion 40 is attached to the outer peripheral surface of the needle 24. The receiving portion 40 is made of resin or metal and has a cylindrical shape. The receiving portion 40 is movable with respect to the needle 24 in the direction of the center line A1. The receiving part 40 has an outward flange 41, and a first compression spring 42 is interposed between the flange 41 and the sleeve 39. A second compression spring 43 is interposed between the flange 41 and the core 36. The first compression spring 42 and the second compression spring 43 are coil springs that generate an urging force in the direction of the center line A1. The spring constant of the first compression spring 42 is larger than the spring constant of the second compression spring 43.

  Next, a mechanism for controlling the fuel injection amount of the fuel injection device 20, that is, a mechanism for controlling the position of the needle 24 in the direction of the center line A1 will be described with reference to FIGS. The annular holder 22 includes a plurality of walls 44 protruding inward from the inner peripheral surface 22A. The plurality of walls 44 are arranged at intervals in the circumferential direction around the center line A1. The inner diameters of the plurality of walls 44 are larger than the outer diameter of the core 36, and the plurality of walls 44 do not hinder the rotation of the core 36 when the core 36 rotates about the center line A <b> 1.

  On the other hand, a plurality of walls 45 projecting outward from the outer peripheral surface 36A of the core 36 are provided. The number of the plurality of walls 44 and the number of the plurality of walls 45 are the same, and the walls 44 and the walls 45 are alternately arranged in the circumferential direction around the center line A1. The outer diameters of the plurality of walls 45 are smaller than the inner diameter of the holder 22, and when the core 36 rotates about the center line A <b> 1, the plurality of walls 45 do not hinder the rotation of the core 36.

  A hydraulic chamber 46 is formed between the wall 44 and the wall 45, with one wall 44 and one wall 45 as a set. That is, a plurality of hydraulic chambers 46 are formed along the circumferential direction between the outer peripheral surface 36A and the inner peripheral surface 22A. Seal members are disposed between the tip of the wall 45 and the inner peripheral surface 22A, and between the wall 44 and the outer peripheral surface 36A to seal the hydraulic chamber 46 in a liquid-tight manner. The holder 22 also includes an oil passage 47 that communicates with the hydraulic chamber 46.

  Further, a hydraulic control unit 48 is provided, and the hydraulic control unit 48 and the oil passage 47 are connected by an oil passage 54. The hydraulic control unit 48 includes a hydraulic circuit through which oil discharged from an oil pump (not shown) passes, a pressure control valve that controls the hydraulic pressure of the hydraulic circuit, and the like. The controller 55 outputs a signal for controlling the hydraulic control unit 48. The hydraulic control unit 48 can switch the hydraulic pressure in the hydraulic chamber 46 between the first control hydraulic pressure and the second control hydraulic pressure. The second control hydraulic pressure is higher than the first control hydraulic pressure.

  Further, tension springs 49 are respectively disposed in the hydraulic chambers 46. The tension spring 49 generates a biasing force in a direction in which the pair of walls 44 and 45 forming the hydraulic chamber 46 are brought close to each other in the circumferential direction. The tension spring 49 is disposed outside the outer peripheral surface 36A of the core 36 in the radial direction centered on the center line A1. The holder 22 is fixed to the casing 21. Therefore, in FIG. 5, the core 36 is urged clockwise by the urging force of the tension spring 49.

  Further, as shown in FIG. 6, a convex portion 50 is provided at an end portion of the core 36 which is closer to the stopper 35. As shown in FIG. 5, a plurality of convex portions 50 are arranged on the same circumference centered on the center line A <b> 1, and a concave portion 51 is formed between the convex portions 50. A convex portion 52 is provided at the end of the stopper 35 that is closer to the core 36. A plurality of the convex portions 52 are arranged on the same circumference centered on the center line A1, and a concave portion 53 is formed between the convex portions 52. Both the convex portions 50 and 52 and the concave portions 51 and 53 are arranged on the same circumference. The circumferential length of the convex portion 50 is smaller than the circumferential length of the concave portion 53, and the circumferential length of the convex portion 52 is smaller than the circumferential length of the concave portion 51. Moreover, the height of the convex parts 50 and 52 and the depth of the concave parts 51 and 53 are the same.

  Next, control and operation of the engine 10 will be described. With the intake valve open and the exhaust valve closed, air is drawn into the combustion chamber via the intake device and the intake port 17 and the intake valve is closed and fuel is injected from the fuel injection device 20. Is done. Further, the exhaust valve is opened after the piston 15 is operated and the air-fuel mixture is ignited by the spark plug 19 and burned, and the exhaust gas generated in the combustion chamber 16 is discharged into the atmosphere via the exhaust device 12. Is done.

  The controller 55 controls the fuel injection device 20 based on the state of the vehicle, specifically, the load of the engine 10, and switches the combustion state of the air-fuel mixture in the combustion chamber 16 between the stratified combustion region and the homogeneous combustion region. be able to. In the fuel injection device 20, the fuel injection amount in the stratified combustion region is smaller than the fuel injection amount in the homogeneous combustion. The controller 55 detects a condition for switching between the stratified combustion region and the homogeneous combustion region. The condition for setting the homogeneous combustion region is established, for example, when the engine 10 has a high load. In homogeneous combustion, the fuel is spread over a wide area of the combustion chamber 16 when air is mixed with the fuel. In homogeneous combustion, fuel is injected below the atmospheric pressure of the first half of the intake stroke, the heat of vaporization of the fuel is used for cooling the intake air to increase volumetric efficiency, and the air-fuel ratio is close to the theoretical air-fuel ratio, for example, about 12 to 15 The engine 10 is set to high output.

  On the other hand, the condition for the stratified combustion region is established, for example, when the load on the engine 10 is lower than the load in the homogeneous combustion region. In the stratified combustion region, the air flow in the cylinder 14 accompanying the lowering of the piston 15 is used to prevent the fuel and air from being mixed uniformly, the fuel is diffused in the vicinity of the spark plug 19 in an umbrella shape, and the spark plug 19 Stay in the vicinity. A recess is formed in the top surface of the piston 15, and the fuel injected into the combustion chamber 16 flows in a vortex in the combustion chamber 16. The fuel is injected into the combustion chamber 16 in a high-pressure atmosphere at the latter stage of the compression stroke. The air-fuel ratio of stratified combustion is, for example, about 22 to 55.

  Hereinafter, control and operation of the fuel injection device 20 will be described. First, when the condition for not injecting fuel into the combustion chamber 16 of the engine 10 is established, no voltage is applied to the solenoid 33 shown in FIG. 3A, and the stator 34 does not generate a magnetic attractive force. Further, mainly the urging force of the first compression spring 42 is transmitted to the needle 24 through the core 36, and the seal portion 31A of the needle 24 is pressed against the inner surface 26A of the inclined portion 26 as shown in FIG. Yes. For this reason, the core 36 stops at the initial position farthest from the stator 34, and the needle 24 also stops at the initial position in the direction of the center line A <b> 1 with respect to the nozzle 23.

  When the needle 24 is stopped at the initial position, the first injection port 29 and the second injection port 30 are blocked from the passage 23 </ b> A by the needle 24, and thus from either the first injection port 29 or the second injection port 30. But no fuel is injected.

  When the condition for injecting fuel into the combustion chamber 16 is satisfied and the condition for setting the homogeneous combustion region is satisfied, the first voltage is applied to the solenoid 33 and the stator 34 generates a magnetic attractive force. Then, the core 36 moves in the direction of the center line A1 in the direction approaching the stator 34 from the initial position against the urging force of the first compression spring 42. In addition, when the condition for the homogeneous combustion region is satisfied, the hydraulic control unit 48 sets the hydraulic pressure in the hydraulic chamber 46 to the first control hydraulic pressure. Therefore, the wall 45 stops at the first control position that is closest to the wall 44 by the biasing force of the tension spring 49 as shown in FIG. That is, the core 36 is stopped at the first rotation position, and the convex portion 50 and the convex portion 52 are at the same position in the circumferential direction as shown in FIG.

  Then, when the core 36 moves from the initial position toward the center line A1 in a direction approaching the stator 34 and the convex portion 50 comes into contact with the convex portion 52, the core 36 and the needle 24 are in the first state shown in FIG. Stop at the stop position. When the core 36 and the needle 24 start moving from the initial position toward the first stop position, the seal portion 31A is separated from the inner surface 26A and the passage 23A is connected to the first injection port 29 as shown in FIG. . Accordingly, the fuel in the passage 23 </ b> A is injected from the first injection port 29. That is, the fuel injected from the first injection port 29 diffuses throughout the combustion chamber 16 as shown in FIG.

  When the condition for injecting fuel into the combustion chamber 16 is satisfied and the condition for the stratified combustion region is satisfied, the second voltage applied to the solenoid 33 is the first voltage applied to the solenoid 33 in the homogeneous combustion region. It is set higher than the voltage. For this reason, the magnetic attraction force generated by the stator 34 is stronger in the stratified combustion region than in the homogeneous combustion region. Further, when the condition for the stratified combustion region is established, the hydraulic control unit 48 sets the hydraulic pressure in the hydraulic chamber 46 to the second control hydraulic pressure.

  For this reason, the wall 45 moves by a predetermined amount against the urging force of the tension spring 49 in a direction away from the wall 44 connected by the tension spring 49. As a result, the core 36 rotates by a predetermined angle counterclockwise from the first position in FIG. 5A and stops at the second rotational position shown in FIG. When the core 36 stops at the second rotational position, the convex portion 50 and the concave portion 53 are in the same position in the rotational direction of the core 36, and the convex portion 52 and the concave portion 51 are in the same position. That is, the position of the convex part 50 and the position of the convex part 52 differ in the rotation direction of the core 36.

  Then, the core 36 moves in a direction closer to the stator 34 from the first stop position shown in FIG. 7A by the magnetic attractive force formed by the stator 34. In this case, the core 36 and the stator 34 mainly move against the urging force of the first compression spring 42. When the core 36 further moves from the first stop position and the small diameter portion 32 of the needle 24 comes out of the small diameter portion 27, the first injection port 29 and the second injection port 30 are both connected to the passage 23A. For this reason, the fuel injected from the fuel injection device 20 has an injection pressure lower than that in the case where the fuel is injected only from the first injection port 29, and the ignition plug 19 in the combustion chamber 16 as shown in FIG. Distributed in the vicinity of.

  6B, when the tip of the convex portion 50 comes into contact with the bottom of the concave portion 53 and the tip of the convex portion 52 comes into contact with the bottom of the concave portion 51, as shown in FIG. Stops at the second stop position. When the core 36 stops at the second stop position, as shown in FIG. 8B, the first injection port 29 and the second injection port 30 are maintained in a state connected to the passage 23A.

  On the other hand, when the condition of the stratified combustion region is switched to the condition of the homogeneous combustion region, the voltage applied to the solenoid 33 is reduced from the second voltage to the first voltage. Then, the magnetic attractive force generated by the stator 34 is reduced, and the core 36 is moved away from the stator 34 mainly by the urging force of the first compression spring 42. Then, the small diameter portion 32 enters the small diameter portion 27 as shown in FIG. 7B, the second injection port 30 is blocked from the passage 23A, and the core 36 and the needle 24 are in the first stop shown in FIG. 7A. Stop at position.

  The hydraulic control unit 48 switches the hydraulic pressure in the hydraulic chamber 46 from the second control hydraulic pressure to the first control hydraulic pressure. For this reason, the core 36 rotates clockwise from the second rotation position shown in FIG. 5B by the urging force of the tension spring 49, and stops at the first rotation position shown in FIG. 5A. That is, in the rotation direction of the core 36, the convex portion 50 and the convex portion 52 are at the same position, and the concave portion 51 and the concave portion 53 are at the same position.

  Furthermore, if the condition for not injecting fuel into the combustion chamber 16 is satisfied, no voltage is applied to the solenoid 33 and the stator 34 does not generate a magnetic attractive force. For this reason, the core 36 moves in a direction away from the stator 34 mainly by the urging force of the second compression spring 43. 3B, the seal portion 31A comes into contact with the inner surface 26A of the inclined portion 26, and the first injection port 29 and the second injection port 30 are blocked from the passage 23A.

  The fuel injection device 20 can execute fuel injection control in which the combustion state in the combustion chamber 16 is set to either the homogeneous combustion region or the stratified combustion region while the piston 15 reciprocates a plurality of times in the cylinder 14. Further, the fuel injection device 20 alternately performs the homogeneous combustion region and the stratified combustion region while the piston 15 makes one reciprocation in the cylinder 14, and sets the homogeneous combustion region during the intake air to the combustion chamber 16. It is also possible to set the stratified combustion region immediately before the ignition control.

  As described above, the fuel injection device 20 of the present invention can switch the fuel injection state for the combustion chamber 16 between the homogeneous combustion region and the stratified combustion region. A stopper 35 that determines the first stop position and the second stop position as the stop positions of the needle 24 and the core 36 in the direction of the center line A1 is fixed to the stator 34 so as not to move in the direction of the center line A1. . Then, when the core 36 is rotated so that the positions of the convex portion 50 and the concave portion 53 are the same and the positions of the convex portion 52 and the concave portion 51 are the same, the core 36 is moved from the first stop position to the second stop position. be able to.

  For this reason, even if the force that brings the core 36 and the needle 24 closer to the stator 34 increases, as long as the convex portion 50 of the core 36 and the convex portion 52 of the stopper 35 are in contact with each other, the core 36 moves from the first stop position. There is no movement to the second stop position. For this reason, the position of the needle 24 in the direction of the center line A1 can be controlled with high accuracy, and the fuel injection amount of the fuel injection device 20 can be adjusted with high accuracy.

  For example, when the core 36 and the needle 24 are stopped at the first stop position, the pressure of the passage 23A is increased, or the magnetic attraction force of the solenoid 33 is increased unexpectedly. Even if the force in the direction to bring the needle 36 and the needle 24 closer to the stator 34 increases, the core 36 and the needle 24 will not move unless the hydraulic pressure control unit 48 switches the hydraulic pressure in the hydraulic chamber 46 from the first control hydraulic pressure to the second control hydraulic pressure. Therefore, it is possible to prevent movement from the first stop position to the second Stoke position, and the reliability of control is improved.

  Next, another structural example of the nozzle 23 will be described with reference to FIGS. The nozzle 23 has a plurality of first injection ports 29 as described above. Moreover, the 2nd injection port 56 which penetrates the inclination part 28 is provided in only one place in the circumferential direction centering on centerline A1. The second injection port 56 is disposed at a location closest to the spark plug 19 in a circumferential direction centered on the center line A1. Also, the inner diameter of the second injection port 56 is larger than the inner diameter of the second injection port 30, and the center line of the second injection port 56 is in relation to the center line A 1 so that the injected fuel faces the spark plug 19. Is inclined.

  FIG. 9A shows a case where the needle 24 is stopped at the first stop position. When the needle 24 is stopped at the first stop position, both the first injection port 29 and the second injection port 56 are blocked from the passage 23A. For this reason, fuel is not injected from the first injection port 29 and the second injection port 56.

  FIG. 9B shows a case where the needle 24 is stopped at the first stop position, or a case where the needle 24 is between the first stop position and the second stop position. When the needle 24 is in the position shown in FIG. 9B, since the seal portion 31A is separated from the inner surface 26A, the first injection port 29 is connected to the passage 23A, and the second injection port 56 is blocked from the passage 23A. Is done. For this reason, the fuel is injected from the first injection port 29 and is not injected from the second injection port 56. When the needle 24 is in the position shown in FIG. 9B, the fuel injected by the fuel injection device 20 diffuses into the combustion chamber 16 while facing the spark plug 19 as shown in FIG. For this reason, a rich air-fuel mixture can be supplied in the vicinity of the spark plug 19.

  Further, FIG. 9C shows a state in which the small diameter portion 32 is removed from the small diameter portion 27, for example, a case where the needle 24 is stopped at the second stop position. When the small diameter portion 32 comes out of the small diameter portion 27, the first injection port 29 and the second injection port 56 are both connected to the passage 23A. For this reason, the fuel is injected from the first injection port 29 and the second injection port 56. When the needle 24 is in the position shown in FIG. 9C, the fuel injected by the fuel injection device 20 is distributed in the vicinity of the spark plug 19 as shown in FIG. 11B.

  Therefore, when the condition for the stratified combustion region is established and the air-fuel ratio in the combustion chamber 16 is set to a rich air-fuel ratio, that is, a value smaller than the stoichiometric air-fuel ratio, the needle 24 is shown in FIG. When in the position, the air-fuel mixture can be transported to the vicinity of the spark plug 19.

  Next, another structural example of the nozzle 23 and the needle 24 used in the fuel injection device 20 will be described with reference to FIG. The nozzle 23 has a cylindrical portion 57 and an inclined portion 58 formed at the end of the cylindrical portion 57 in the direction of the center line A1. The inclined portion 58 is inclined in a conical shape with respect to the center line A1, and a first injection port 59 and a second injection port 60 penetrating the inclined portion 58 are provided. The first injection port 59 and the second injection port 60 connect the inside and outside of the nozzle 23. A plurality of the first injection ports 59 are arranged on the same circumference around the center line A1, and a plurality of the second injection ports 60 are arranged on the same circumference around the center line A1. The plurality of second injection ports 60 are arranged inside the plurality of first injection ports 59 in the radial direction of the nozzle 23.

  Furthermore, the needle 24 has a cylindrical portion 61 at a place arranged in the nozzle 23. The cylindrical portion 61 is disposed around the center line A <b> 1, and the ball 62 is disposed in the cylindrical portion 61. The diameter of the ball 62 is smaller than the inner diameter of the cylindrical portion 61, and the ball 62 and the needle 24 are relatively movable in the direction of the center line A1. In the cylindrical portion 61, an annular seal portion 24 </ b> A is formed at the end closest to the inclined portion 58. The seal portion 24 </ b> A is disposed outside the opening portion of the first injection port 59 on the inner surface 58 </ b> A of the inclined portion 58.

  Further, in the cylindrical portion 61, a locking portion 63 that protrudes inward from the inner peripheral surface of the cylindrical portion 61 is provided at the end closest to the inclined portion 58. The locking portion 63 protrudes inward in the radial direction from the inner peripheral surface of the cylindrical portion 61. The diameter of the inscribed circle of the locking portion 63 is smaller than the diameter of the ball 62. A compression spring 64 is disposed in the cylindrical portion 61, and the ball 62 is biased toward the inclined portion 58 by the biasing force of the compression spring 64. A part of the ball 62 is exposed to the outside from the end of the needle 24 in the direction of the center line A1. Other configurations of the fuel injection device 20 are the same as the configurations of FIGS. 3, 5, 7, and 8.

  The operation of the fuel injection device 20 of FIG. 12 will be described. When the core 36 is stopped at the initial position shown in FIG. 3A, as shown in FIG. 12A, the seal portion 24A of the needle 24 contacts the inclined portion 58, and the needle 24 is in the first stop position. Stop at. When the needle 24 stops at the first stop position, the passage 23 </ b> A is blocked from the first injection port 59 and the second injection port 60. For this reason, fuel is not injected from the first injection port 59 and the second injection port 60.

  Further, when the core 36 moves from the initial position shown in FIG. 5A toward the first stop position shown in FIG. 7A, the seal portion 24A of the needle 24 is inclined as shown in FIG. 12B. Leave part 58. Then, the passage 23 </ b> A is connected to the first injection port 59. Further, the ball 62 is pressed against the inner surface 58 </ b> A of the inclined portion 58 by the urging force of the compression spring 64. The ball 62 is in annular contact with the inner surface 58 </ b> A between the first injection port 59 and the second injection port 60, and the passage 23 </ b> A is blocked from the second injection port 60. For this reason, fuel is injected from the first injection port 59, and fuel is not injected from the second injection port 60.

  Further, when the core 36 moves from the first stop position shown in FIG. 7A toward the second stop position shown in FIG. 8A, the locking portion 63 contacts the ball 62. Then, as the needle 24 moves, the ball 62 moves away from the inner surface 58A of the inclined portion 58 as shown in FIG. 12C, and the needle 24 stops at the second stop position. When the ball 62 is separated from the inner surface 58 </ b> A of the inclined portion 58, the passage 23 </ b> A is connected to the first injection port 59 and the second injection port 60. For this reason, the fuel is injected from the first injection port 59 and the second injection port 60. Therefore, the fuel injection device 20 shown in FIG. 12 can obtain the same effect as the fuel injection device 20 shown in FIGS.

  The correspondence between the matters described in the embodiment and the configuration of the present invention will be described. The fuel injection device 20 corresponds to the fuel injection device of the present invention, and the combustion chamber 16 corresponds to the combustion chamber of the present invention. The nozzle 23 corresponds to the nozzle of the present invention, the core 36 and the needle 24 correspond to the operating member of the present invention, the solenoid 33 corresponds to the operating mechanism structure and the solenoid of the present invention, and the stopper 35 corresponds to the present invention. The hydraulic chamber 46, the tension spring 49, and the hydraulic control unit 48 correspond to the stopper of the invention, and correspond to the switching mechanism of the invention. The first injection ports 29 and 59 and the second injection ports 30, 56 and 60 correspond to the fuel injection port of the present invention, the needle 24 and the ball 62 correspond to the valve body of the present invention, and the core 36. The convex portion 52 corresponds to the first convex portion of the present invention, the convex portion 50 corresponds to the second convex portion of the present invention, and the hydraulic chamber 46 corresponds to the magnetic member of the present invention. It corresponds to a hydraulic chamber, the hydraulic control unit 48 corresponds to the hydraulic control unit of the present invention, and the controller 55 corresponds to the controller of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. The switching mechanism of the present invention is a mechanism that regulates the operating range of the operating position in the center line direction. In other words, the switching mechanism rotates the core 36 with respect to the stopper 35 to switch the operating range of the core 36 and the needle 24 in two stages, and does not rotate the core 36 and the stopper 35 with respect to the casing 21. It includes a structure that switches the operation range of the core 36 and the needle 24 in two stages by rotating. In addition, the switching mechanism that relatively rotates the core 36 and the stopper 35 may use a solenoid that relatively rotates the core 36 and the stopper 35 with a magnetic attraction force instead of the hydraulic chamber 46 and the hydraulic control unit 48.

  The operation member of the present invention includes valve elements such as a needle, a plunger, and a spool that operate linearly in the direction of the center line to open and close the fuel injection port. The operation mechanism according to the present invention adjusts the urging force in the center line direction applied to the operation member by hydraulic pressure or air pressure in addition to the solenoid for adjusting the urging force in the center line direction applied to the operation member by controlling the magnetic attraction force. Including hydraulic actuators and pneumatic actuators. In this case, the core may be a nonmagnetic material. The engine is not limited to a gasoline engine, and may be a diesel engine. In this case, no spark plug is provided, the piston operates, the mixture becomes high temperature and pressure, and the fuel burns by spontaneous ignition.

DESCRIPTION OF SYMBOLS 10 Engine 11 Intake device 12 Exhaust device 13 Fuel supply device 13A Fuel tank 13B Pump 13C Fuel supply pipe 14 Cylinder 15 Piston 16 Combustion chamber 17 Intake port 18 Exhaust port 19 Spark plug 20 Fuel injection device 21 Casing 22 Holder 22A Inner peripheral surface 23 Nozzle 23A Passage 24 Needle 24A, 31A Seal portion 25, 31 Large diameter portion 26, 28 Inclined portion 26A, 58A Inner surface 27, 32 Small diameter portion 29, 59 First injection port 30, 56, 60 Second injection port 33 Solenoid 34 Stator 35 Stopper 36 Core 36A Outer peripheral surface 37 Shaft hole 38 Fixing member 39 Sleeve 40 Receiving portion 41 Flange 42 First compression spring 43 Second compression spring 44, 45 Wall 46 Hydraulic chamber 47, 54 Oil path 48 Hydraulic control portion 49 Tension spring 50 , 52 Convex part 51, 53 Concave part 55 Over La 56 second injection port 57 cylindrical portion 58 inclined portion 61 cylindrical portion 62 the ball 63 engaging portion 64 compression spring A1 centerline

Claims (5)

A fuel injection device for injecting fuel into a combustion chamber,
A nozzle for injecting the fuel;
An operation member including a valve body for opening and closing the nozzle;
An operating mechanism for operating the operating member in the direction of the center line of the nozzle;
A stopper that contacts the operating member and stops the operation of the operating member;
By relatively rotating the operating member and the stopper around the center line, the position where the operating member comes into contact with the stopper and stops is a first stop position that is different from each other in the center line direction. A switching mechanism for switching to the second stop position;
A fuel injection device. The fuel injection device according to claim 1, wherein
The nozzle has a first injection port and a second injection port for injecting fuel,
The valve body opens the first injection port when the operation member stops at the first stop position, and closes the second injection port,
A fuel injection device that opens the first injection port and the second injection port when the operation member stops at the second stop position. The fuel injection device according to claim 2, wherein
The stopper has a first convex portion protruding in the center line direction,
The operating member has a second convex portion that protrudes in the direction of the center line and contacts the first convex portion,
The operating member stops at the first stop position when the first convex portion and the second convex portion are at the same position in the rotation direction about the center line,
The operating member is a fuel injection device that stops at the second stop position when the first convex portion and the second convex portion are at different positions in a rotational direction about the center line. The fuel injection device according to claim 3, wherein
The switching mechanism is
A hydraulic chamber for generating a force for rotating the operating member relative to the stopper;
A hydraulic control unit for controlling the pressure of the hydraulic chamber;
A fuel injection device. The fuel injection device according to any one of claims 1 to 4,
A controller is provided for switching the combustion state in the combustion chamber between homogeneous combustion and stratified combustion,
The operating member stops at the first stop position when the combustion state in the combustion chamber is a homogeneous combustion,
The operating member stops at the second stop position when the combustion state in the combustion chamber is stratified combustion.

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