JPH0526272Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a distributed fuel injection pump for Deidel engines, and in particular a governor mechanism that controls the amount of fuel injection by controlling the rotation angle position of the control lever. This invention relates to a distribution type fuel injection pump of the type equipped with.

(Prior Art) A distribution type fuel injection pump (hereinafter referred to as an injection pump) uses a single plunger to distribute and pressure feed fuel to each cylinder of a multi-cylinder engine. A pressure control device such as a spill valve is provided, and the amount of fuel injection is controlled by controlling the rotational angle position of a pivotable control lever connected to this device using a governor mechanism according to the engine speed. It is determined. On the other hand, the rotational fulcrum of the control lever is also provided on a rotatably mounted guide lever, which is biased by a spring force so as to abut the full load stopper at one end thereof. The full load stopper is provided so that its contact position with the guide lever can be adjusted, and the rotation of the guide lever displaces the rotational fulcrum of the control lever, thereby regulating the maximum injection amount of the injection pump. ing.

However, with this conventional configuration, the maximum fuel injection amount is regulated to a constant level regardless of the engine speed, so it is difficult to satisfy the maximum injection amount characteristics required by the engine at maximum load in the medium and high speed range. was difficult.

To improve this problem, Japanese Utility Model Application Publication No. 57-134332 provides an actuator operated by the fuel pressure in the injection pump at the full load stopper, which rotates the guide lever according to the engine speed. A configuration is proposed.

(Problem to be solved by the invention) The injection pump proposed in Japanese Utility Model Application Publication No. 57-134332 has a maximum injection amount that increases or decreases depending on the engine speed, and has a maximum injection amount characteristic in the medium and high speed range. Although improvements can be seen, the maximum fuel injection amount in both medium and high speed ranges must be adjusted at a single full load stopper, so the control range and degree of freedom in adjusting the maximum injection amount is limited due to the structure.

The present invention solves the problems of these conventional techniques,
It is an object of the present invention to provide a distribution type fuel injection pump that can satisfy the maximum injection quantity characteristics required by an engine.

(Means and effects for solving the problem) In order to achieve the above-mentioned object, the distributed fuel injection pump of the present invention reciprocates a single plunger equipped with a pressurization control device to inject each cylinder in a multi-cylinder engine. While distributing fuel to the cylinders, the rotation angle position of a control lever connected to the pressurization control device is controlled in a direction opposite to that of the governor mechanism in conjunction with a governor mechanism corresponding to the rotational speed of the engine and an accelerator of the engine. The fuel injection amount is controlled by a tension lever that acts on the control lever, and further, the rotational support of the control lever and the tension lever is disposed coaxially on a rotatable guide lever so that the guide lever can be displaced. A torque control lever that rotates around a rotational fulcrum of the guide lever, in which the torque control lever is biased so as to come into contact with an adjustable full load stopper to regulate its rotation and determine the amount of fuel injection at maximum load. and an actuator that operates in relation to the rotational speed of the engine and whose operation timing can be adjusted, and when the actuator operates, the rotational fulcrum of the control lever and the tension lever resists the deflection of the guide lever. One end of the torque control lever is connected to the actuator so that the lever is displaced at It is characterized in that it increases in relation to.

With this configuration, the governor mechanism controls the rotation angle position of the control lever to adjust the fuel injection amount of the injection pump according to the engine rotation speed. In addition, regarding the fuel injection amount at maximum load, the full load stopper contacts the biased guide lever to regulate it to a constant level regardless of the engine speed, and the actuator moves the rotational fulcrum of the control lever to the guide lever. increases relative to the engine speed. The actuator can adjust its operating timing, and increases the fixed maximum injection amount determined by the full load stopper as appropriate depending on the maximum injection amount characteristics required by the engine.

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

(Embodiment) Fig. 1 is a schematic cross-sectional view of the main parts showing an embodiment of the present invention, and the overall structure of the injection pump of the present invention will be explained with reference to the figure. A conventional configuration may be used except for the adjustment mechanism, and the configuration of these parts will only be briefly described. In Figure 1, a cross-sectional view of the fuel pump 3 is shown to make the structure easier to understand.
The cross section is shown rotated by 90°.

In Fig. 1, a drive shaft 1 and a rotary fuel pump connected to this shaft are rotatably provided in a housing 2 of the injection pump. Pump 3 is activated. The fuel pump 3 introduces and pressurizes fuel from a tank 4, regulates the pressure with a pressure control valve 5, and then supplies it to a fuel chamber 6 formed within the housing. Incidentally, in order to facilitate understanding of the structure of the rotary fuel pump 3, a plane thereof is shown in FIG. 1 together with a side cross section of the pump 3.

A barrel 50 is attached to the housing portion on the opposite side of the drive shaft 1 so as to extend coaxially with the shaft 1, and the plunger 8 is slidably mounted within this barrel. The plunger 8 is connected at one end to the drive shaft 1 via a coupling 7, and the coupling 7 has a structure that transmits rotational driving force and allows the plunger 8 to move in the axial direction.
Further, the plunger 8 is provided with a face cam 9 at a position adjacent to the coupling ring 7 and is pressed toward the drive shaft 1 by a spring, while a roller ring 31 disposed so as to surround the coupling ring 7 has a face cam 9 cam roller 1 that rolls into contact with
0 is supported. The face cam 9 is formed with a cam ridge corresponding to the number of cylinders of the engine to which the injection pump is installed, and therefore the plunger 8 reciprocates a plurality of times according to the number of cylinders each time it is driven one revolution.

The plunger 8 has a plurality of suction grooves 11 formed at the other end thereof and spaced apart from each other in the circumferential direction;
It has a supply port 16 formed on a side surface of the plunger axially apart from the supply port 16, and a spill port 22 opening on a side surface further axially separated from this port. The ports 16 and 22 communicate with each other by a vertical hole 15 in the plunger 8;
One end of the plunger 5 is open to the other end surface of the plunger 8. Further, on the barrel 50 side, there is an intake port 12 communicating with the fuel chamber 6 via an introduction passage 13, and a discharge port 17 connected to an injection valve 20 on the engine side via an injection passage 18 and a delivery valve 19. It is formed. The suction port 12 is provided at a position where it communicates with one of the suction grooves 11 during the suction stroke of the plunger 8, and the discharge port 17 is provided at a position where it communicates with the supply port 16 during the compression stroke of the plunger 8.

The roller ring 31 described above is rotatable in its circumferential direction, and by rotating the rod 32 connected to the ring in the circumferential direction with an adjustment piston 33, the fuel injection timing is changed. . This adjustment piston 33 introduces pressurized fuel from the fuel chamber 6 into the pressure chamber 34 and is operated according to the pressure. In FIG. 1, the adjustment piston 33 is depicted as being able to move left and right within the plane of the figure in order to clearly show its structure, but as explained above, it is arranged perpendicularly to the plane of the figure. It is understood that there are

Furthermore, a spill port 2 is provided on the plunger 8.
A spill ring 21 is slidably fitted to open and close the plunger 2, and together with the spill port 22 constitutes a pressure control device for the plunger. This spill ring 2
1 is a control lever 23 arranged adjacent to the
and a tension lever 24. These levers 23 and 24 are each rotatably mounted on a pin 36 as a fulcrum, and the control lever and spill ring engage a ball joint fixed to one end of the lever 23 with a groove formed on the outer periphery of the spill ring 21. connected by. In addition, the control lever 23
A governor mechanism is provided to control the rotational angular position of. This governor mechanism includes a driven gear 27 that meshes with a drive gear 26 attached to the drive shaft 1.
and fly weight 2 connected to this driven gear.
8 and a governor sleeve 25 which is slidable in the axial direction on the shaft of the driven gear and whose one end is engaged with the flyweight 28, and the drive gear 26 rotates the flyweight 28 via the driven gear 27. Then, the flyweight 28 moves the governor sleeve 25 toward the control lever 23 by its centrifugal force. On the other hand, a plate spring is attached to the other end side of the control lever 23, and comes into contact with the tension lever 24 so that the lever 23
is pressed against the governor sleeve 25. Further, the tension lever 24 is connected to an adjusting lever 30 via a main spring 29, and is pulled in a direction approaching the control lever 23 by the tensile force of the spring 29, and comes into contact with a stopper 51 fixed to the housing 2. There is. This adjuster steering lever 30 is an engine operating device,
For example, in conjunction with the accelerator pedal in a car,
The restraining force of the tension lever 24 by the spring 29 is changed according to engine operation such as idling or maximum acceleration.

The rotational fulcrum, or pin 36, of the control lever 23 and the tension lever 24 is fixed on a guide lever 35 provided adjacent to these levers. The guide lever 35 is supported by a pin 37 fixed to the housing 2 so as to rotate in parallel with the levers 23 and 24, and is disposed between the guide lever 35 and the housing 2 so that one end contacts the full load stopper 39. The other end is pressed by a pressing spring 40. The full load stopper 39 is composed of an adjusting screw and a locking nut, and is attached to the housing 2 so that the position of contact with the guide lever 35 can be adjusted.

Furthermore, a torque control lever 38 is provided at a position opposite to the levers 23 and 24 and adjacent to the guide lever 35. Similar to the guide lever 35, the torque control lever 38 rotates around the levers 23 and 2 with the pin 37 as a rotational fulcrum.
It is installed so that it can rotate parallel to 4. As shown in detail in FIG.
5, and one end of the torque control lever 38 is formed with a cutout portion for receiving the pin 36. Also, adjacent to the other end of the torque control lever 38, a pressure operating section 42 including a piston 41 and a spring 43 is provided.
will be placed. This piston 41 has an elongated pin 52 at one end, and by passing the pin 52 through a hole drilled at the other end of the torque control lever 38 and attaching a retaining pin to its tip, the piston 41 can be attached to the torque control lever 38. connected.
The pressure operating portion 42 communicates with the fuel chamber 6 so as to apply fuel pressure within the fuel chamber 6 to the end of the piston 41 on the side where the pin 52 is provided. On the other hand, a spring 43 is arranged on the other end side of the piston 41,
A low pressure chamber 44 formed at the other end of the piston 41 within the pressure operating portion 42 by the pressure of the spring 43 communicates with the low pressure side of the fuel pump 3 via a conduit 45 . Therefore, the piston 41 moves according to the difference between the fuel pressure in the fuel chamber 6 acting on one end of the piston 41 and the low pressure fuel pressure and the pressing force of the spring 43 acting on the other end, and the pressure actuating section is controlled by the torque control. It operates as an actuator that rotates the lever 38.

Regarding the operation of this actuator,
A plurality of grooves for attaching the retaining pin are formed in the pin 52, and by changing the attachment position of the retaining pin, the operation starting point, that is, the piston 41
It is possible to adjust the timing at which the torque control lever 38 substantially begins to rotate.

Next, the operation of this embodiment will be explained with reference to the drawings from FIG. 1 to FIG. 5.

First, to explain the state of the injection pump before starting the engine, in this state there is no driving force input and the fuel pump 3 is not operating, so the differential pressure acting on both ends of the piston 41 of the pressure operating section 42 is at a minimum. As shown in FIG. 3, the piston 41 is pushed by a spring 43 and is located at the rightmost end within the pressure operating section 42. Therefore, the torque control lever 38 is in the inoperative position, and the guide lever 35 is in the inoperative position.
is biased by a pressing spring 40, one end of which abuts the full load stopper 39, and the other end of the pin 36 is at the leftmost position of its displacement path. On the other hand, the tension lever 24 is connected to the main spring 2
It is in contact with the stopper 51 due to the tensile force of 9. Furthermore, since the governor mechanism is not operating, the control lever 23 is pressed by the plate spring and comes into contact with the governor sleeve 25, and is at the leftmost rotational position in FIG. It is located in the opposite direction.

When the shaft 1 is driven to rotate when the engine is started, the fuel pump 3 is activated to supply fuel to the fuel chamber 6, and at the same time, the plunger 8 is reciprocated. 1 of the suction groove 11 at the tip of the plunger during the suction stroke of the plunger 8.
When the intake port 12 is opened, the fuel in the fuel chamber 6 is sucked into the pressure pump chamber 14 through the introduction passage 13. The fuel in the pressure pump chamber 14 pressurized by the compression stroke of the plunger 8 is pushed out into the vertical hole 15, and the spill port 22 is connected to the spill ring 21 at the rightmost position.
Therefore, when the supply port 16 communicates with the discharge port 17 , the fuel is force-fed from the injection passage 18 to the fuel injection valve 20 via the delivery valve 19 .

Note that the governor mechanism operates simultaneously with the rotation of the drive shaft 1 and rotates the control lever 23 clockwise via the governor sleeve 25. However, as the engine speed increases, the spill ring 21 The maximum fuel injection amount of the injection pump remains almost constant until the injection pump is moved to the position where it starts to open. This state corresponds to area A in the diagram of FIG.

When the speed of the engine continues to increase, the spill ring 21 moves to the control lever 23 as the rotational speed increases.
1 to the left in FIG. 1, and the timing at which the spill port 22 opens gradually becomes earlier. The fuel supply to the injection valve 20 gradually decreases as shown in area B of FIG. The gradual reduction of the fuel supply continues until the control lever 23 is pressed against the governor sleeve 25 and abuts against the tension lever 24. At this point, the pressing force of the governor mechanism is weaker than the tension of the main spring 29, and the control lever 2
3 stops rotating when it comes into contact with the tension lever 24, and therefore the maximum fuel injection amount is the same as the 5th one.
As shown in area C in the figure, it remains almost constant over the medium speed range. The maximum fuel injection amount in this area is adjusted by adjusting the full load stopper 39 and moving the position of the pin 36 via the guide lever 35.

Next, as the engine speed increases and reaches the high speed range shown by D in FIG.
The fuel pressure inside operates the piston 41, which rotates the torque control lever 38 counterclockwise about the pin 37 as a fulcrum, as shown in FIG. The torque control lever 38 presses the pin 36 against the pressing spring 40 of the guide lever 35 and displaces it to the right. As a result, Spilling 21
is also moved to the right, and the maximum fuel injection amount of the injection pump increases by ΔQ compared to the injection amount in the medium speed range shown by the broken line in FIG.

As the engine speed continues to increase, the pushing force of the governor mechanism finally overcomes the pulling force of the main spring 29, rotating the control lever 23 together with the tension lever 24 in the clockwise direction.
As a result, the spill port 22 of the plunger 8 is constantly open, and the fuel supply to the injection valve 20 is stopped as shown in area E of FIG.

In the above description of the embodiment, it is assumed that the maximum fuel injection amount of the injection pump in the high speed range increases by ΔQ and remains constant compared to the injection amount in the medium speed range, but the tension of the spring 43 and the pressure received by the piston 41 By appropriately selecting the area, it is also possible to configure the piston 41 to operate from a medium speed range and to gradually increase the maximum fuel injection amount from the medium speed range to the high speed range as the engine speed increases. . Further, in the above embodiment, the actuator is of a type that is operated by fuel pressure, but it may be of the type that operates according to the engine rotation speed, and can be operated according to the rotation speed signal as shown in Fig. 6. A modification may be made to use an electric actuator 46.

(Effect of the invention) As is clear from the explanation based on the embodiment, the present invention is capable of controlling the fuel injection amount at the maximum load determined by the full load stopper in relation to the engine speed in the distribution type fuel injection pump. It is something that increases. This increase in injection quantity can be achieved using only a few additions, such as a torque control lever that is separate from the guide lever and an adjustable actuator that operates in relation to engine speed. This can be achieved without major changes. With this configuration, the maximum fuel injection amount can be adjusted separately with the full load stopper in the medium speed range and with the actuator in the high speed range, providing a greater control range and degree of freedom in adjustment of the maximum fuel injection amount, compared to conventional It is possible to provide a distribution type fuel injection pump at a relatively low cost that can satisfy the maximum injection amount characteristics required by an engine, which cannot be satisfied by an injection pump.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view showing the overall configuration of a distribution type fuel injection pump that is an embodiment of the present invention, and Fig.
FIGS. 3 and 4 are enlarged perspective views showing the main parts of the embodiment shown in FIG. 1; FIGS. This figure is a diagram showing the maximum injection amount characteristics of the distribution type fuel injection pump shown in FIG. 1, and FIG. 6 is a schematic diagram showing another embodiment. In the figure, 1...drive shaft, 2...housing, 3...
... Fuel pump, 8 ... Plunger, 21 ... Spill ring, 22 ... Spill port, 23 ... Control lever, 24 ... Tension lever, 2
5... Cabana sleeve, 35... Guide lever,
36, 37...Pin, 38...Torque control lever, 39...Full load stopper, 40...
...Press spring, 42...Pressure operating part.

Claims (1)

[Claims for Utility Model Registration] (1) A single plunger equipped with a pressure control device is reciprocally driven to distribute and pressure feed fuel to each cylinder of a multi-cylinder engine, and a plunger connected to the pressure control device The rotation angle position of the control lever is controlled by a governor mechanism that responds to the rotational speed of the engine and a tension lever that operates in the opposite direction to the governor mechanism in conjunction with the accelerator of the engine to adjust the fuel injection amount; Furthermore, the rotational fulcrums of the control lever and tension lever are disposed coaxially on a rotatable guide lever so that they can be displaced, and the guide lever is biased so as to come into contact with an adjustable full load stopper to allow the rotation thereof. A distribution type fuel injection pump that regulates the amount of fuel to be injected at maximum load by regulating the amount of fuel injected at maximum load includes a torque control lever that rotates around a rotational fulcrum of the guide lever, and a torque control lever that operates in relation to the rotational speed of the engine. and an actuator whose actuation timing can be adjusted, and one end of the torque control lever is arranged so that the rotation support of the control lever and the tension lever is displaced against the deflection of the guide lever by the operation of the actuator. The fuel injection valve is connected to an actuator and has its other end engaged with a rotational fulcrum of the control lever and the tension lever, so that the fuel injection amount at maximum load is increased in relation to the rotational speed of the engine. Distribution type fuel injection pump. (2) Utility model registration Scope of claims 1. The distribution type fuel injection pump according to claim 1, wherein the actuator has a piston operated by fuel pressure within the injection pump that increases or decreases depending on the rotation speed of the engine. type fuel injection pump. (3) Utility Model Registration The distribution type fuel injection pump according to claim 1, wherein the actuator is an electric actuator that operates in response to a rotational speed signal of the engine.