JP2011026971A - High pressure fuel pump and internal combustion engine having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a durable and reliable high pressure fuel pump with a pausing mechanism having a simple structure and an internal combustion engine having the high pressure fuel pump. <P>SOLUTION: The high pressure fuel pump 41 for pressurizing fuel supplied to the internal combustion engine 100 includes a pump casing 41b for forming a compressing chamber 41e for compressing the fuel, a plunger 41a stored in the pump casing 41b advancingly and contractedly, and a lifter 6 arranged between a pump cam 11b formed at a camshaft 11a of the internal combustion engine 100 and the plunger 41a, and advancing and retreating in the same axial direction with the plunger 41a by the pump cam 11b. The lifter 6 includes shutting means 61, 62, 63, 64, 65, 66 for shutting the transmission of the drive of the pump cam 11b to the plunger 41b according to the operation state of the internal combustion engine 100. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a high-pressure fuel pump with a pause mechanism and an internal combustion engine including the same.

2. Description of the Related Art Conventionally, an in-cylinder internal combustion engine that directly injects fuel into a combustion chamber is known. In this cylinder injection internal combustion engine, the fuel injection pressure is increased using a high-pressure fuel pump so that fuel can be injected into the combustion chamber in the latter half of the compression stroke in which the cylinder pressure increases.
For example, Patent Document 1 discloses a plunger that is driven by a rotating cam provided on a camshaft of an internal combustion engine, a cylinder in which the plunger slides, and a first check that allows only fuel to flow into the cylinder. A high-pressure fuel pump comprising: a valve; a second check valve that allows only fuel outflow from the cylinder; and a plunger rocker arm that is interposed between the rotary cam and the plunger to vary the lift amount of the plunger. Is described. According to this, by changing the swing angle of the plunger rocker arm, the lift amount of the plunger can be changed to change the fuel discharge amount.

JP 2004-218479 A

  However, since the high-pressure fuel pump described in Patent Document 1 requires a mechanism for changing the swing angle of the plunger rocker arm, the structure and control are complicated, and the reliability of the apparatus may be reduced. Further, when the lift amount of the plunger is increased to increase the fuel discharge amount, the lift load (bending load) acting on the plunger rocker arm increases, and there is a concern about the durability of the plunger rocker arm. Therefore, there is a possibility that the lift amount of the plunger may be restricted or the size of the plunger rocker arm may be increased.

  On the other hand, for example, in a cylinder deactivation type internal combustion engine in which some cylinders are deactivated during low-load operation or idling, it has been desired to deactivate the high-pressure fuel pump. However, in the high-pressure fuel pump described in Patent Document 1, even though the lift amount of the plunger can be changed, the lift of the plunger cannot be stopped.

  The present invention has been made in view of these points, and it is an object of the present invention to provide a high-pressure fuel pump with a pause mechanism with a simple configuration and high durability and an internal combustion engine including the same.

  The present invention is a high-pressure fuel pump for pressurizing fuel supplied to an internal combustion engine, a pump case forming a pressurizing chamber for pressurizing the fuel, a plunger accommodated in the pump case so as to be able to advance and retreat, and the internal combustion engine A lifter disposed between a pump cam formed on a camshaft of the engine and the plunger, and advancing and retreating coaxially with the plunger by the pump cam, the lifter according to an operating state of the internal combustion engine, It has a shut-off means for shutting off transmission of the drive of the pump cam to the plunger.

According to this configuration, the lifter has the blocking means for blocking the transmission of the drive of the pump cam to the plunger in accordance with the operating state of the internal combustion engine. The drive of the pump cam is not transmitted to the plunger, and the plunger does not advance or retract even if the pump cam is driven. Therefore, the high-pressure fuel pump can be stopped according to the operating state of the internal combustion engine.
Further, since the lifter having the blocking means is disposed between the pump cam and the plunger, a load acts in the advancing and retracting direction of the lifter, so that the durability can be improved without increasing the size of the lifter and the blocking mechanism. Further, since the plunger rocker arm and the special swing arm that makes the lift amount variable as in Patent Document 1 are not required, the device can be simplified and reduced in weight, and the reliability can be improved.

  The blocking means may be switching means for switching the lifter between a transmission state in which the drive of the pump cam can be transmitted to the plunger and a non-transmission state in which the drive of the pump cam cannot be transmitted to the plunger. Good.

  Further, the blocking means is slidably disposed in the lifter, and has a contact portion that contacts an end portion on the lifter side of the plunger and an accommodating portion that houses an end portion on the lifter side of the plunger. And a slide mechanism that switches and arranges the abutment portion and the accommodating portion at a position corresponding to an end portion on the lifter side of the plunger by sliding the member and the slide member. Is preferred.

  According to such a configuration, by sliding the slide member to a position where the contact portion comes into contact with the plunger, the drive of the pump cam is transmitted to the plunger via the lifter, and the plunger moves forward and backward together with the lifter. On the other hand, by sliding the slide member so that the accommodating portion is disposed at a position corresponding to the plunger, the plunger is accommodated (inserted) into the accommodating portion of the lifter, and contact between the plunger and the lifter is avoided. Therefore, even if the lifter moves back and forth, the drive of the pump cam is not transmitted to the plunger, and the plunger remains at rest.

  Further, the present invention is an internal combustion engine having a plurality of high-pressure fuel pumps, wherein at least one of the plurality of high-pressure fuel pumps includes a high-pressure fuel pump including the above-described cutoff means, and the cutoff means is the internal combustion engine It is operated according to the operating state of the engine.

  According to such a configuration, the driving of the high-pressure fuel pump including the cutoff means among the plurality of high-pressure fuel pumps can be stopped by operating the cutoff means according to the operating state of the internal combustion engine.

  Further, the internal combustion engine includes a required fuel amount calculating unit that calculates a required fuel amount according to an operating state of the internal combustion engine, and a required fuel amount calculated by the required fuel amount calculating unit is smaller than a preset threshold value. In addition, it is preferable to have a shut-off control means for operating the shut-off means.

According to such a configuration, when the required fuel amount is small, for example, when the cylinder is stopped, the driving of the high-pressure fuel pump can be stopped using the shut-off means. Thereby, the friction accompanying the drive of the pump is reduced, and the fuel efficiency can be improved. Moreover, when it is set as the structure provided with the interruption | blocking means in several high pressure fuel pumps, the product life of a high pressure fuel pump can be extended by switching the high pressure fuel pump to pause.
Moreover, since the high-pressure fuel pump can be reduced in size and weight, the internal combustion engine itself can be reduced in size and weight.

  According to the present invention, it is possible to provide a high-pressure fuel pump with a pause mechanism with high durability and reliability with a simple configuration, and an internal combustion engine including the same.

It is a schematic block diagram of an internal combustion engine. It is a partial expanded sectional view of a 1st high pressure fuel pump. It is the perspective view which looked at the pin holder from the top. It is the perspective view which looked at the pin holder from the bottom. It is a perspective view of a slide pin. It is a partial expanded sectional view of the 1st high pressure fuel pump which the slide pin slid to the spring chamber side. It is a flowchart for demonstrating operation | movement of an internal combustion engine.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same elements are assigned the same numbers, and duplicate descriptions are omitted.

  As shown in FIG. 1, in the internal combustion engine 100 according to the present embodiment, two delivery pipes 2 (a first delivery pipe 21 and a second delivery pipe 22) are provided in two banks, a first bank 11 and a second bank 12. An internal combustion engine body 1, a fuel tank T that stores fuel Fu, a feed pump 5 that pumps fuel Fu from the fuel tank T, and two high-pressure fuel pumps 4 that supply fuel Fu to two delivery pipes 2 (first high-pressure fuel pump 41 , The second high-pressure fuel pump 42), and the control device 9 that controls each part of the internal combustion engine 100.

The internal combustion engine body 1 mainly includes a cylinder block, a cylinder head, a cylinder head cover, and the like. The internal combustion engine body 1 is, for example, a V-type 6-cylinder engine having six cylinders, in which three cylinders 3 are arranged in the first bank 11 and the second bank 12, respectively, and the fuel Fu of one delivery pipe 2 is supplied. It is configured to be injected into three cylinders 3.
The number of cylinders 3 provided in the internal combustion engine body 1 is not limited, and may be 4 cylinders, 8 cylinders, or the like.

The delivery pipe 2 includes a first delivery pipe 21 and a second delivery pipe 22, and the first delivery pipe 21 is provided in each of the three cylinders 3 (31 a, 31 b, 31 c) disposed in the first bank 11. The fuel Fu is distributed to the fuel injection valves 21a, 21b, and 21c that inject the fuel Fu.
The second delivery pipe 22 distributes the fuel Fu to the fuel injection valves 22a, 22b, and 22c that inject the fuel Fu into the three cylinders 3 (32a, 32b, and 32c) disposed in the second bank 12, respectively. Configured.

A first high-pressure fuel pump 41 is connected to the first delivery pipe 21 via a connection pipe 52 (first connection pipe), and the fuel Fu discharged from the first high-pressure fuel pump 41 is a first pressure at a predetermined pressure. 21 is supplied.
A second high pressure fuel pump 42 is connected to the second delivery pipe 22 via a connection pipe 53 (second connection pipe), and the fuel Fu discharged from the second high pressure fuel pump 42 is a second pressure at a predetermined pressure. Supplied to delivery pipe 22. Hereinafter, the pressure of the fuel Fu may be referred to as fuel pressure.

Further, the first delivery pipe 21 and the second delivery pipe 22 are provided with fuel pressure sensors Se1 and Se2, respectively.
The fuel pressure sensors Se1 and Se2 measure the fuel pressures of the first delivery pipe 21 and the second delivery pipe 22, respectively, and output measurement signals. The measurement signals output from the fuel pressure sensors Se1 and Se2 are input to the control device 9. The control device 9 is the measurement signal input from the fuel pressure sensors Se1 and Se2, and determines the fuel pressure of the first delivery pipe 21 and the second delivery pipe 22. It can be detected.

Further, in the internal combustion engine 100 according to the present embodiment, a communication pipe 54 that connects the first delivery pipe 21 and the second delivery pipe 22 is provided to connect the first delivery pipe 21 and the second delivery pipe 22. The fuel Fu discharged from the first high-pressure fuel pump 41 can be supplied to the second delivery pipe 22.
The communication pipe 54 may be piped so as to directly connect the connection pipe 52 and the connection pipe 53.

  The control device 9 includes, for example, a microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, which are not shown, and a peripheral circuit. The CPU executes a program to control each part of the internal combustion engine 100.

Next, the configuration of the first high-pressure fuel pump 41 will be described.
The first high-pressure fuel pump 41 is installed so as to be able to advance and retract in the same direction as the plunger 41a, a pump case 41b that constitutes a pressurizing chamber 41e that pressurizes fuel while accommodating the plunger 41a so as to advance and retract. And a lifter 6 that advances and retracts the plunger 41a by contacting the plunger 41a.

The plunger 41a is configured to advance and retreat (reciprocate) inside the pressurizing chamber 41e as the lifter 6 described later advances and retreats (reciprocating). As shown in FIG. 2, a retainer 41a1 is attached to the lower end side of the plunger 41a. An inner spring SPi is interposed between the pump case 41b and the retainer 41a1. The inner spring SPi biases the plunger 41a in the direction of expanding the volume of the pressurizing chamber 41e.
The pump case 41b has a recess having an inner diameter substantially equal to the outer diameter of the plunger 41a, and a space surrounded by the recess and the plunger 41a is a pressurizing chamber 41e. The pressurizing chamber 41e is formed so that the volume increases and decreases by the reciprocating motion of the plunger 41a.

As shown in FIG. 1, the lifter 6 is interposed between a pump cam 11b formed on the camshaft 11a and a plunger 41a. That is, the plunger 41a, the lifter 6, and the pump cam 11b are arranged along the axial direction (the direction in which the plunger 41a moves back and forth). As shown in FIG. 2, the lifter 6 is slidably installed in a support hole 13 provided at a predetermined position of the internal combustion engine body 1, for example, and is urged toward the pump cam 11b by an outer spring SPo. . As a result, the lifter 6 advances and retracts in the same direction as the plunger 41 a by the rotation of the pump cam 11 b that contacts the bottom of the lifter 6.
The pump cam 11b also serves as a valve cam for opening and closing an intake valve and an exhaust valve (not shown) provided in the three cylinders 3 (31a, 31b, 31c) disposed in the first bank 11.
The configuration of the lifter 6 will be described in detail later.

The pressurizing chamber 41e of the first high-pressure fuel pump 41 is connected to the feed pump 5 by an oil feed pipe 51, and the fuel Fu pumped from the fuel tank T by the feed pump 5 is supplied to the pressurizing chamber 41e.
Further, the pressurizing chamber 41e is connected to the first delivery pipe 21 by the connecting pipe 52, and the fuel Fu that has been pressurized in the pressurizing chamber 41e and whose fuel pressure has increased is discharged from the first high-pressure fuel pump 41 and is first. Supplied to delivery pipe 21.

Further, the first high-pressure fuel pump 41 is provided with a spill valve 41f including a solenoid valve 41c for connecting / blocking the pressurizing chamber 41e and the oil feeding pipe 51 by an opening / closing operation and an electromagnetic solenoid 41d for driving the solenoid valve 41c. .
The spill valve 41f is an electromagnetic valve having a function of controlling the intake of the fuel Fu into the first high-pressure fuel pump 41.

A spill valve drive circuit 40 is connected to the electromagnetic solenoid 41d of the spill valve 41f. The spill valve drive circuit 40 controls the opening / closing of the spill valve 41f by controlling the state (excitation / demagnetization) of the electromagnetic solenoid 41d by supplying and stopping the exciting current for exciting the electromagnetic solenoid 41d.
The spill valve drive circuit 40 is connected to the control device 9, and controls the opening and closing of the spill valve 41f in accordance with a control signal output from the control device 9.

The control device 9 inputs a control signal for closing the spill valve 41f to the spill valve drive circuit 40 when the plunger 41a moves in the direction in which the volume of the pressurizing chamber 41e decreases, and closes the spill valve 41f. The pressurizing chamber 41e and the oil feeding pipe 51 are shut off.
When the spill valve 41f is closed, the fuel Fu in the pressurizing chamber 41e is compressed as the volume of the pressurizing chamber 41e decreases and the fuel pressure increases.
Then, the fuel Fu whose fuel pressure has increased in the pressurizing chamber 41 e is supplied to the first delivery pipe 21.

Next, the configuration of the second high pressure fuel pump 42 will be described.
The second high-pressure fuel pump 42 is configured substantially the same as the first high-pressure fuel pump 41, and the same components as the first high-pressure fuel pump 41 will be described briefly.
The second high-pressure fuel pump 42 is not provided with the lifter 6 and is different from the first high-pressure fuel pump 41 in that the pump cam 12b is in direct contact with the plunger 42a.

  The plunger 42a accommodated in the pump case 42b of the second high-pressure fuel pump 42 opens and closes intake valves and exhaust valves (not shown) provided in the three cylinders 3 (32a, 32b, 32c) disposed in the second bank 12. The inside of the pressurizing chamber 42e is reciprocated by the rotation of the pump cam 12b formed on the camshaft 12a, and the pressurizing chamber 42e is formed so that the volume is increased or decreased by the reciprocating motion of the plunger 42a.

  The fuel Fu pumped from the fuel tank T by the feed pump 5 is supplied to the pressurizing chamber 42e to which the oil feeding pipe 51 and the connecting pipe 53 are connected, and the fuel Fu whose fuel pressure has increased in the pressurizing chamber 42e is supplied to the second delivery pipe. 22 is supplied.

Further, the second high-pressure fuel pump 42 is provided with a spill valve 42f including a solenoid valve 42c for connecting / blocking the pressurizing chamber 42e and the oil feeding pipe 51 by an opening / closing operation and an electromagnetic solenoid 42d for driving the solenoid valve 42c. .
The spill valve 42f is an electromagnetic valve having a function of controlling the intake of the fuel Fu into the second high-pressure fuel pump 42.

  A spill valve drive circuit 40 is connected to the spill valve 42f. The spill valve drive circuit 40 controls the opening and closing of the spill valve 42f by controlling the operation of the solenoid valve 42c by supplying and stopping the exciting current that excites the electromagnetic solenoid 42d.

The control device 9 inputs a control signal for closing the spill valve 42f to the spill valve drive circuit 40 when the plunger 42a moves in the direction in which the volume of the pressurizing chamber 42e decreases, and closes the spill valve 42f. The pressurizing chamber 42e and the oil feeding pipe 51 are shut off.
When the spill valve 42f is closed, the fuel Fu in the pressurizing chamber 42e is compressed as the volume of the pressurizing chamber 42e decreases, and the fuel pressure increases.
Then, the fuel Fu whose fuel pressure has increased in the pressurizing chamber 42e is supplied to the second delivery pipe 22.

  Next, the configuration of the lifter 6 provided in the first high-pressure fuel pump 41 will be described in detail with reference to FIGS.

As shown in FIG. 2, the lifter 6 includes a bottomed cylindrical lifter case 61 having one end opened, a pin holder 62 slidably fitted to the lifter case 61, and the inner surface of the lifter case 61. A slide pin 63 that is a slide member that is slidably fitted to the pin holder 62 by forming the hydraulic chamber 66 and a slide that exerts a spring force that biases the slide pin 63 in a direction to reduce the volume of the hydraulic chamber 66 A return spring 64 provided between the pin 63 and the pin holder 62 and a stopper pin 65 provided between the pin holder 62 and the slide pin 63 to prevent rotation of the slide pin 63 around the axis line are provided.
The lifter case 61, the pin holder 62, the slide pin 63, the return spring 64, the stopper pin 65, the hydraulic chamber 66, and the like that constitute the lifter 6 constitute a “blocking means” in the claims.

  As shown in FIGS. 2 to 4, the pin holder 62 includes a ring portion 62a that is slidably fitted in the lifter case 61, and an inner circumference of the ring portion 62a along one diameter line of the ring portion 62a. And a bridging portion 62b that connects the two. The inner circumference of the ring portion 62a and the space between both side surfaces of the bridging portion 62b are thinned in order to reduce the weight. Such a pin holder 62 is formed by lost wax casting or forging of iron or aluminum alloy, or is formed of synthetic resin, and the outer peripheral surface of the pin holder 62 made of metal, that is, the outer peripheral surface of the ring portion 62a, and the lifter case Carburizing treatment is applied to the inner peripheral surface of 61.

  An annular groove 69 is provided on the outer periphery of the pin holder 62, that is, on the outer periphery of the ring portion 62a. The bridging portion 62b is provided with a bottomed cylindrical sliding hole 70 having an axis line along one diameter line of the ring portion 62a, that is, an axis line orthogonal to the axis line of the lifter case 61. One end of the sliding hole 70 opens into the annular groove 69 and the other end of the sliding hole 70 is closed. In addition, an insertion hole 71 for inserting the lower end portion of the plunger 41a is formed at the upper center of the bridging portion 62b. The insertion hole 71 communicates with the sliding hole 70. Further, an extension hole 72 sandwiching the sliding hole 70 between the bridge portion 62b and the insertion hole 71 is provided coaxially with the insertion hole 71 so as to accommodate the lower end portion of the plunger 41a.

Arc-shaped protrusions 85, 85 for positioning the lower end portion of the outer spring SPo for urging the lifter 6 toward the pump cam 11b in a direction perpendicular to the axis of the plunger 41a are integrally formed on the upper portion of the bridging portion 62b of the pin holder 62. Is formed to protrude.
In addition, a cylindrical accommodation cylinder portion 73 that is coaxial with the axis of the extension hole 72 is integrally provided in the bridging portion 62 b of the pin holder 62 at a portion facing the closed end of the lifter case 61. A part of a disc-shaped shim 74 that closes the end portion of the extension hole 72 on the closed end side of the lifter case 61 is fitted into the housing cylinder portion 73. A protrusion 75 that abuts against the shim 74 is integrally provided at the central portion of the inner surface of the closed end of the lifter case 61.

  A slide pin 63 as a slide member is slidably fitted in the slide hole 70 of the pin holder 62. As shown in FIG. 5, the slide pin 63 is formed by cutting a cylindrical member made of metal or synthetic resin. When the pin holder 62 is made of synthetic resin, only the sliding contact portion with the slide pin 63 may be made of metal.

  A hydraulic chamber 66 communicating with the annular groove 69 is formed between one end of the slide pin 63 and the inner surface of the lifter case 61, and is formed between the other end of the slide pin 63 and the closed end of the slide hole 70. A return spring 64 is accommodated in the spring chamber 76.

As shown in FIGS. 2 and 5, an accommodation hole 77 that can accommodate the lower end portion of the plunger 41 a is provided in the axially intermediate portion of the slide pin 63. The housing hole 77 is coaxial with the insertion hole 71 and the extension hole 72 when the slide pin 63 slides toward the spring chamber 76 against the spring force of the return spring 64 due to the high pressure in the hydraulic chamber 66. Formed in position.
The end of the accommodation hole 77 on the insertion hole 71 side is opened to a flat contact surface 78 formed on the upper outer surface of the slide pin 63 so as to face the insertion hole 71. The contact surface 78 is formed relatively long along the axial direction of the slide pin 63, and the accommodation hole 77 is opened at a portion of the contact surface 78 on the hydraulic chamber 66 side.
On one end side of the slide pin 63 (opening end side of the slide hole 70), a slit 81 extends along the axial direction. Further, a recess 82 in which the return spring 64 is fitted is provided on the other end side (spring chamber 76 side) of the slide pin 63.

Here, the slide mechanism of the lifter 6 will be described.
When the hydraulic pressure in the hydraulic chamber 66 is low, the slide pin 63 shifts the receiving hole 77 from the axis of the insertion hole 71 and the extension hole 72 so that the lower end of the plunger 41a is brought into contact with the contact surface 78, as shown in FIG. It moves to the left side of FIG. As shown in FIG. 6, the slide pin 63 accommodates the lower end portion of the plunger 41 a inserted through the insertion hole 71 in the accommodation hole 77 and the extension hole 72 when the hydraulic pressure in the hydraulic chamber 66 is high. It moves to the right side of FIG.
In addition, the depth dimension of the accommodating part combining the accommodating hole 77 and the extension hole 72 is formed such that the shim 74 does not contact the plunger 41a when the pump cam 11b pushes up the lifter 6 most.

When the slide pin 63 moves to a position where the lower end portion of the plunger 41a comes into contact with the contact surface 78, the pin holder 62 and the slide pin 63 corresponding to the lifter case 61 sliding by the pressing force acting from the pump cam 11b. As the plunger 41a moves toward the plunger 41a, a pressing force acts on the plunger 41a, so that the plunger 41a reciprocates according to the rotation of the pump cam 11b. That is, the lifter 6 is in a transmission state in which the rotation of the pump cam 11b can be transmitted to the plunger 41a.
When the slide pin 63 is moved to a position where the accommodation hole 77 is coaxially connected to the insertion hole 71 and the extension hole 72, the lifter 6 is moved by the pressing force acting from the pump cam 11b, but the lower end portion of the plunger 41a. Is accommodated in the accommodation hole 77 and the extension hole 72, and the pressing force in the valve opening direction does not act on the plunger 41a from the lifter 6, and the plunger 41a remains at rest. That is, the lifter 6 is in a non-transmitting state in which the rotation of the pump cam 11b cannot be transmitted to the plunger 41a.

  The stopper pin 65 is attached to the bridging portion 62 b of the pin holder 62 so as to straddle the sliding hole 70. Both end portions of the stopper pin 65 are respectively mounted in mounting holes 79 and 80 provided coaxially in the bridging portion 62b. The stopper pin 65 passes through the slit 81 of the slide pin 63 installed in the slide hole 70. As a result, the stopper pin 65 prevents the slide pin 63 from rotating about the axis while allowing the slide pin 63 to move in the axial direction. The stopper pin 65 also regulates the moving end of the slide pin 63 toward the hydraulic chamber 66 side by the stopper pin 65 coming into contact with the inner end blocking portion of the slit 81.

  The slide pin 63 is provided with a communication hole 83 that allows the spring chamber 76 to communicate with the receiving hole 77 in order to prevent pressure increase / decrease of the spring chamber 76 due to the axial movement of the slide pin 63. The pin holder 62 is provided with a communication hole 84 that allows the space to communicate with the spring chamber 76 in order to prevent the pressure in the space between the pin holder 62 and the lifter case 61 from changing due to a temperature change.

  The internal combustion engine body 1 is provided with a support hole 13 in which the lifter case 61 is fitted so that the lifter case 61 can be slidably supported. An inner surface of the support hole 13 surrounds the lifter case 61. A recess 14 is provided. The internal combustion engine main body 1 is provided with a lubricating oil supply passage 15 that communicates with the annular recess 14. The position where the support hole 13 is formed in the internal combustion engine main body 1 may be appropriately selected according to the installation position of the first high-pressure fuel pump 41, and may be, for example, a cylinder head or a cylinder head cover.

The lifter case 61 is provided with a communication hole 61 a that allows the annular recess 14 to communicate with the annular groove 69 of the pin holder 62 regardless of sliding in the support hole 13 of the lifter case 61. That is, the lubricating oil supplied from the lubricating oil supply passage 15 is supplied to the hydraulic chamber 66 through the annular recess 14, the communication passage 61a, and the annular groove 69 in this order.
The lifter case 61 is provided with a release hole 61 b for supplying lubricating oil into the lifter case 61. When the lifter case 61 moves to the lowermost position as shown in FIG. 2, the release hole 61b allows the annular recess 14 to pass into the lifter case 61 above the pin holder 62, but the lifter case 61 is in the lowermost position. The lifter case 61 is provided at a position where the communication with the annular recess 14 is blocked as it moves upward.

  As shown in FIG. 1, the lubricating oil supply passage 15 is provided with a shut-off valve 92 that blocks supply of lubricating oil from a hydraulic pump (not shown) to the lifter 6. In addition, a purge valve 93 for discharging the lubricating oil to the outside is provided in the lubricating oil supply passage 15 on the downstream side (lifter 6 side) from the shutoff valve 92.

For example, an accelerator opening detection device 91 that detects the accelerator opening of an automobile on which the internal combustion engine 100 is mounted is connected to the control device 9. Although not shown, the control device 9 is connected to a crank angle sensor for detecting the crank angle of the crank arm, an intake air amount sensor for detecting the intake air amount flowing into the internal combustion engine 100, and the like.
Based on the accelerator opening detected by the accelerator opening detecting device 91, the control device 9 calculates a required fuel amount calculation unit 95 for calculating the required fuel amount Q of the internal combustion engine 100, and a request calculated by the required fuel amount calculation unit 95. When the fuel amount Q is smaller than a preset threshold value, a shutoff control unit 96 that shuts off the drive of the pump cam 11b from being transmitted to the plunger 41a is provided.
The shut-off control unit 96 is connected to the shut-off valve 92 and the purge valve 93 so that an operation signal can be transmitted.

  The control device 9 stores a threshold value serving as a determination criterion for the shutoff control unit 96 in a memory device (not shown). The threshold value can be set based on the maximum discharge amount of the first high-pressure fuel pump 41 or the second high-pressure fuel pump 42, for example. The threshold is preferably set to a value smaller than the maximum discharge amount. This is to reduce the burden on the second high-pressure fuel pump 42 when the first high-pressure fuel pump is stopped.

  Next, the operation of the first high-pressure fuel pump 41 according to this embodiment will be described with reference to FIG. 7 (FIGS. 1 to 6 as appropriate).

  First, when the operation of the automobile equipped with the internal combustion engine 100 according to the present embodiment is started, the accelerator opening detection device 91 detects the accelerator opening of the automobile (step S1), and the control device 9 opens the accelerator. The accelerator opening signal including the degree is transmitted.

Next, the required fuel amount calculation unit 95 calculates the required fuel amount Q in the first bank 11 based on the accelerator opening degree transmitted from the accelerator opening degree detecting device 91 (step S2).
For example, at the time of acceleration or the like, the accelerator opening is larger than that at idling or the like, and the required fuel amount Q is also a relatively large value. On the other hand, in the idling state and the high-speed cruise state, the accelerator opening is smaller than that during acceleration and the required fuel amount Q is also a relatively small value.

Next, the cutoff control unit 96 compares the threshold value stored in advance in the memory device with the required fuel amount Q (step S3). Here, it is assumed that the threshold is set to about 90% of the maximum discharge amount of the second high-pressure fuel pump 42.
When the required fuel amount Q is larger than the threshold value (step S3, Yes), the second high pressure fuel pump 42 alone cannot cover the fuel in the first bank 11 and the second bank 12. It is determined that the first high-pressure fuel pump 41 is not stopped, and a valve closing signal is transmitted to the shutoff valve 92 and a valve opening signal is transmitted to the purge valve 93.

  When the shut-off valve 92 is closed and the purge valve 93 is opened (step S4), the hydraulic chamber 66 of the lifter 6 is in a low pressure state, and the slide pin 63 is slid toward the hydraulic chamber 66 by the return spring 64. The contact surface 78 contacts the lower end portion of the plunger 41a. Thereby, the drive of the pump cam 11b is transmitted to the plunger 41a through the lifter 6, and the first high-pressure fuel pump 41 is operated (step S5).

  On the other hand, when the required fuel amount Q is equal to or less than the threshold (No in step S3), the cutoff control unit can cover the fuel in the first bank 11 and the second bank 12 only by the second high-pressure fuel pump 42. 96 determines that the first high-pressure fuel pump 41 is to be stopped, transmits a valve opening signal to the shut-off valve 92 and transmits a valve closing signal to the purge valve 93.

  When the shut-off valve 92 is closed and the purge valve 93 is opened (step S6), the hydraulic chamber 66 of the lifter 6 is in a high pressure state, and the slide pin 63 moves against the spring force of the return spring 64. It slides to the 76 side, and it will be in the state by which the accommodation hole 77 was arrange | positioned in the lower end part of the plunger 41a.

In this state, even if the lifter 6 moves to the plunger 41a side by the pressing force acting from the pump cam 11b, the lower end portion of the plunger 41a is accommodated in the insertion hole 71, the accommodation hole 77, and the extension hole 72. Therefore, the pressing force does not act on the plunger 41a. Therefore, the plunger 41a is in a paused state, and as a result, the first high-pressure fuel pump 41 is paused (step S7).
The fuel Fu supplied from the second high-pressure fuel pump 42 to the second delivery pipe 22 is also supplied to the first delivery pipe 21 through the communication pipe 54.

According to the first high-pressure fuel pump 41 configured as described above, the lifter 6 constituting the shut-off mechanism is arranged in the axial direction of the plunger 41a and is configured to advance and retract in the same direction as the plunger 41a. Has been. The members such as the slide pins 63 constituting the lifter 6 generally have a higher compressive strength (rigidity) than a bending strength (rigidity), so that a large lift load (axial load) can be achieved without increasing the size of the member cross section. Can withstand. Therefore, the first high-pressure fuel pump 41 can be reduced in size and weight, and durability and reliability can be improved.
In addition, since the pausing mechanism can be configured without using a plunger rocker arm or a special swing arm that tends to be complicated, the apparatus can be simplified, the number of members can be reduced, and the reliability can be improved. .

  Further, according to the internal combustion engine 100 including the first high-pressure fuel pump 41 with a pause mechanism, the first high-pressure fuel pump 41 can be paused when the required fuel amount Q is small, so that friction caused by pump driving is reduced. This can reduce the fuel consumption.

  Further, since the lubricating oil supply passage 15 for supplying the lubricating oil to the hydraulic chamber 66 of the lifter 6 is formed in the internal combustion engine body 1, there is no need to greatly change the layout of the valve operating mechanism, and the first structure including the lifter 6 is included. The configuration of the one high pressure fuel pump 1 can be simplified.

  As mentioned above, although embodiment of this invention was described in detail with reference to drawings, this invention is not limited to this, In the range which does not deviate from the main point of invention, it can change suitably.

  For example, in the present embodiment, the lifter 6 is provided only in the first high-pressure fuel pump 41, but the lifter 6 may be provided also in the second high-pressure fuel pump 42. According to this configuration, for example, the product life of the high-pressure fuel pump can be extended by alternately stopping the first high-pressure fuel pump 41 and the second high-pressure fuel pump 42.

  Further, for example, the first bank 11 is provided with a known cylinder deactivation mechanism (not shown), and the supply of fuel to the cylinder 31a and the opening / closing of the valve are deactivated during idling or high-speed cruising, and the first high-pressure fuel pump 41 may be configured to pause. In this case, the communication pipe 54 is not necessary.

  In this embodiment, the slide pin 63 is slid by hydraulic pressure, but the present invention is not limited to this, and other fluids such as air and water may be used. An electromagnetic solenoid or the like may be provided on the base plate and slid by electromagnetic means.

Moreover, in this embodiment, it was set as the structure which avoids that the plunger 41a contact | abuts to the lifter 6 by providing the accommodation hole 77 which accommodates the lower end part of the plunger 41a in the slide pin 63 of the lifter 6. If it is the structure which can interrupt | block transmitting the drive of the pump cam 11b to a plunger, it will not be limited to this.
For example, although not shown in the figure, the lifter 6 is provided with a contact portion that contacts the pump cam 11b and a housing portion that houses the pump cam 11b so as to be switchable, and the two may be switched according to the state of the internal combustion engine. Good. In this way, when the first high-pressure fuel pump 41 is stopped, the lifter 6 can be stopped while avoiding contact between the lifter 6 and the pump cam 11b.

  In the present embodiment, the shut-off means is operated based on the required fuel amount Q that changes according to the operating state of the internal combustion engine 100, but the present invention is not limited to this. For example, the shut-off means may be configured to operate in a predetermined low load operation region set by the engine speed of the internal combustion engine 100 and the throttle opening. In an internal combustion engine having a cylinder deactivation mechanism, the shut-off means may be operated based on a cylinder deactivation signal.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine main body 11 1st bank 11a Cam shaft 11b Pump cam 12 2nd bank 4 High pressure fuel pump 41 1st high pressure fuel pump 41a Plunger 41b Pump case 41e Pressurization chamber 42 2nd high pressure fuel pump 6 Lifter 61 Lifter case 62 Pin holder 63 Slide pin 65 Stopper pin 66 Hydraulic chamber 70 Sliding hole 71 Insertion hole 72 Extension hole 76 Spring chamber 77 Housing hole 78 Contact surface 81 Slit 9 Controller 91 Accelerator opening detector 92 Shutoff valve 93 Purge valve 95 Calculation of required fuel amount Part 96 shut-off control part 100 internal combustion engine

Claims (4)

A high-pressure fuel pump that pressurizes fuel supplied to an internal combustion engine,
A pump case forming a pressurizing chamber for pressurizing the fuel;
A plunger accommodated in the pump case so as to be able to advance and retreat;
A lifter disposed between a pump cam formed on the camshaft of the internal combustion engine and the plunger, and advanced and retracted coaxially with the plunger by the pump cam;
The high-pressure fuel pump according to claim 1, wherein the lifter includes a blocking unit that blocks transmission of the drive of the pump cam to the plunger according to an operating state of the internal combustion engine. The blocking means is
A slide member that is slidably disposed in the lifter, and has a contact portion that contacts an end portion on the lifter side of the plunger and an accommodating portion that houses an end portion on the lifter side of the plunger;
A slide mechanism that switches and arranges the contact portion and the accommodating portion at a position corresponding to an end portion on the lifter side of the plunger by sliding the slide member;
The high-pressure fuel pump according to claim 1, comprising: An internal combustion engine having a plurality of high-pressure fuel pumps,
At least one of the plurality of high-pressure fuel pumps is constituted by the high-pressure fuel pump according to claim 1 or claim 2,
The internal combustion engine, wherein the shut-off means is operated according to an operating state of the internal combustion engine. An internal combustion engine according to claim 3,
A required fuel amount calculating means for calculating a required fuel amount according to an operating state of the internal combustion engine;
An internal combustion engine comprising: a cutoff control unit that activates the cutoff unit when the required fuel amount calculated by the required fuel amount calculation unit is smaller than a preset threshold value.

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