JPH0742643A - Injection timing adjusting device for distributor type pump - Google Patents

Abstract

PURPOSE:To provide an injection timing adjusting device for a distributor type pump capable of preventing a timer piston from coming into sudden collision with high pressure chamber wall surface without giving any effect to the operational characteristic. CONSTITUTION:A servo valve timer 11 is equipped with a servo valve 15, which controls the motion of a timer piston 13 in accordance with the pressure of the a pump room 25, and the surface side of one end of the timer piston 13 is provided with a high pressure room 21 composed of a pump housing 1 and a timer cover 3 while the surface side of the other end is provided with a low pressure room 23. Now the interior of the timer cover 3 is provided with a damper piston 53 and a spring 55, which energizes the damper piston 53 to the timer piston 13 side, while the damper piston 53 is provided with an orifice 57 which communicates with the spring 55 side and the timer piston 13 side. When a timer piston 13 makes a sudden move to the timer cover 3 side, such moving speed is sufficiently damped down by the damper piston 53 abutting on the timer piston 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection timing adjusting device for adjusting the injection timing of a distributed fuel injection pump of a diesel engine, and more particularly, it is provided with a timer piston and a servo valve for controlling the movement of the timer piston. The present invention relates to an injection timing adjusting device for a distributed fuel injection pump.

[0002]

2. Description of the Related Art Conventionally, a so-called servo valve timer has been known as an injection timing adjusting device for a distribution type fuel injection pump of this type. The servo valve timer includes a timer piston slidably provided in a pump housing of a fuel injection pump, and a servo valve that switches a fuel flow path by moving relative to the timer piston. A high pressure chamber is provided on one end surface side of the timer piston, and a low pressure chamber is provided on the other end surface side thereof. In addition, a timer spring for urging the timer piston toward the high pressure chamber is provided in the low pressure chamber.

In the timer piston, a first passage that connects the pump chamber to which the fuel pumped according to the engine speed is supplied is connected to the servo valve, and a first passage that connects the high pressure chamber to the servo valve. Two passages are provided, and the servo valve is connected to the first and second passages and is connected to the low pressure chamber.

In such a servo valve timer,
First, when the engine speed is low, the hydraulic pressure of the oil pump is low, and the servo valve is in a position that connects the high pressure chamber and the low pressure chamber and shuts off the high pressure chamber and the pump chamber. Therefore, the fuel in the pump chamber is not supplied to the high pressure chamber, and the timer piston is pushed toward the high pressure chamber by the timer spring.

On the other hand, when the engine speed increases and the hydraulic pressure of the oil pump rises, the servo valve is pushed and displaced by the pressure in the pump chamber to connect the pump chamber and the high pressure chamber, and at the same time to the high pressure chamber and the low pressure chamber. Cut off the passage to the room. As a result, fuel is supplied from the pump chamber to the high pressure chamber, and the timer piston is pushed from the high pressure chamber side and moves to the low pressure chamber side.

When the engine speed decreases and the hydraulic pressure of the oil pump decreases, the servo valve displaces in the opposite direction to the above case, disconnecting the pump chamber from the high pressure chamber and reducing the high pressure chamber to the low pressure chamber. Connect with the room. As a result, the fuel in the high pressure chamber flows into the low pressure chamber, and the timer piston moves to the high pressure chamber side by the action of the timer spring.

Next, how the fuel injection timing is adjusted by such a servo valve timer will be described with reference to FIG. 5 shows a portion of the cross section of the distribution type fuel injection pump related to the operation of the servo valve timer, and the timer piston is indicated by T, and it is assumed that the timer piston moves in the direction perpendicular to the paper surface in FIG. .

As shown in FIG. 5, the timer piston is connected to a roller ring 84 holding a number of rollers 82 corresponding to the number of cylinders of the engine by an operation pin 80 as an adjusting member. Each roller 82 of the roller ring 84 is in contact with a cam disk 88 that rotates together with a drive shaft 86 that is rotationally driven by the engine, the cam disk 88 rotates, and the roller 82 causes the cam crest 88 a of the cam disk 88. By moving up and down, the plunger 90 for fuel pressure feeding connected to the cam disc 88 moves left and right in FIG. 5 while rotating, and fuel is injected from the delivery valve 92.

When the timer piston moves to the high pressure chamber side (retard angle side) or the low pressure chamber side (advance angle side), the operating pin 8
The position of the roller ring 84 changes via 0, and the roller 8
Since the contact position between the cam 2 and the cam crest 88a of the cam disk 88 changes, the movement timing of the plunger 90 with respect to the engine rotation, that is, the fuel injection timing is retarded or advanced.

Here, when the injection of fuel is completed and the plunger 90 is returned to the left side in FIG. 5, that is, when the cam disk 88 rotates and the roller 82 of the roller ring 84 contacts the downward side of the cam crest 88a. The force of the low pressure chamber side (advance side) is applied to the timer piston via the operation pin 80 by the urging force of the plunger spring 94 that urges the cam disc 88 toward the roller ring 84, and When the engine speed is low and the hydraulic pressure of the oil pump is low, the high pressure chamber is shut off from the pump chamber by the action of the servo valve and fuel does not flow into the high pressure chamber.
At this time, a phenomenon occurs in which the high pressure chamber becomes negative pressure and fuel vapor is generated in the high pressure chamber.

Then, when the plunger 90 is pushed to the right side in FIG. 5 for the next fuel injection, that is, the cam disk 88 rotates and the roller 8 of the roller ring 84 is rotated.
When 2 hits the up side of the cam mountain 88a, this time,
Since a force on the high pressure chamber side (retard side) is applied to the timer piston via the operation pin 80, if fuel vapor is generated in the high pressure chamber at this time, the timer piston vigorously collides with the wall surface of the high pressure chamber. There was a problem that abnormal noise was generated. Also, when fuel vapor is generated in the high pressure chamber and the high pressure chamber is rapidly compressed by the timer piston, in the worst case,
There has been a problem that the pressure in the high-pressure chamber is abnormally increased by the water hammer action, and the O-ring, the bolt, etc. that seal the servo valve timer are damaged.

Therefore, conventionally, in this type of injection timing adjusting device (servo valve timer), the roller 82 of the roller ring 84 is set by setting a large biasing force of the timer spring for biasing the timer piston toward the high pressure chamber.
Of the timer piston is prevented from moving to the low pressure chamber side when the cam peak 88a is applied to the down side of the cam mountain 88a, so that the high pressure chamber is prevented from becoming negative pressure and the fuel vapor is prevented from being generated in the high pressure chamber. I was trying to do it.

[0013]

However, when the urging force of the timer spring is increased as in the conventional device, the operating force of the timer piston toward the low pressure chamber becomes insufficient,
As indicated by the solid line in FIG. 6 showing the operating characteristic of the timer piston, the position of the timer piston is shifted to the retard side when the engine speed is low, and the linear operating characteristic as shown by the dotted line in FIG. 6 is obtained. There was a problem that I could not be.

The present invention has been made in view of the above problems, and prevents the timer piston from abruptly colliding with the wall surface of the high-pressure chamber without significantly affecting the operating characteristics of the timer piston, and at the same time, prevents the high-pressure chamber from colliding. It is an object of the present invention to provide an injection timing adjusting device for a distributed fuel injection pump that can prevent the abnormal pressure rise of the above.

[0015]

SUMMARY OF THE INVENTION That is, the present invention made to achieve the above object is to provide a timer piston slidably provided in a pump housing and engaged with an adjusting member capable of adjusting an injection timing. A high-pressure chamber provided in the pump housing and facing one end face of the timer piston, a low-pressure chamber provided in the pump housing and facing the other end face of the timer piston, and provided in the low-pressure chamber. A timer spring for urging the timer piston toward the high pressure chamber, and a timer spring provided in the pump housing,
A pump chamber to which fuel whose pressure changes in accordance with the number of revolutions from an oil feed pump rotated by an internal combustion engine is supplied, and when the pressure in the pump chamber is higher than a predetermined pressure, the pump chamber moves to the high pressure chamber. The fuel passage from the high pressure chamber to the low pressure chamber, and when the pressure in the pump chamber is lower than a predetermined pressure, the fuel passage from the high pressure chamber to the low pressure chamber is opened. A servo valve that shuts off a fuel passage from the pump chamber to the high-pressure chamber, and an injection timing adjusting device for a distributed fuel injection pump, wherein the high-pressure chamber is slidable in the same direction as the timer piston. In addition, the return spring attached to the wall surface of the high-pressure chamber facing the timer piston is urged toward the timer piston, and the timer piston is A damper piston that comes into contact with the timer piston when moved to a fixed position; and a throttle portion that communicates the timer piston side of the damper piston and the opposite side of the timer piston in the high-pressure chamber. The gist is an injection timing adjusting device for a distributed fuel injection pump.

[0016]

In the injection timing adjusting device of the present invention thus constructed, when the engine speed increases and the pressure of the fuel supplied to the pump chamber becomes higher than a predetermined pressure, the servo The valve connects the pump chamber and the high pressure chamber to each other and disconnects the high pressure chamber and the low pressure chamber. Therefore, fuel is supplied from the pump chamber to the high pressure chamber, and the timer piston is moved to the low pressure chamber side (advance side). Also,
When the engine speed decreases and the pressure of the fuel supplied to the pump chamber becomes lower than a predetermined pressure, the servo valve connects the high pressure chamber and the low pressure chamber and disconnects the high pressure chamber from the pump chamber. Therefore, the fuel in the high pressure chamber flows into the low pressure chamber, and the timer piston is moved to the high pressure chamber side (retard side) by the urging force of the timer spring.

In the injection timing adjusting device of the present invention,
When the timer piston is positioned near the wall surface of the high pressure chamber and is suddenly pushed toward the high pressure chamber by the adjusting member, the timer piston comes into contact with the damper piston slidably provided in the high pressure chamber. Then, the pressure on the side opposite to the timer piston of the damper piston increases in the high-pressure chamber, fuel flows from the side opposite to the timer piston of the damper piston to the timer piston side through the throttle portion, and the damper piston moves in accordance with the flow rate. Moves slowly to the high pressure chamber side.
Therefore, the timer piston slowly moves to the high pressure chamber side together with the damper piston.

Therefore, according to the injection timing adjusting device of the present invention, when the timer piston is pushed to the high pressure chamber side by the adjusting member, it is possible to prevent the timer piston from vigorously colliding with the wall surface of the high pressure chamber. Further, it is possible to prevent the high pressure chamber from being rapidly compressed in a state where the fuel vapor is generated in the high pressure chamber, so that the pressure inside the high pressure chamber does not rise abnormally and the O-ring, the bolt, etc. are not damaged. .

On the other hand, when the timer piston moves to the high pressure chamber side or the low pressure chamber side according to the pressure of the fuel supplied to the pump chamber, or when the timer piston is suddenly pushed to the low pressure chamber side by the adjusting member. If the damper piston is
Since the return spring attached to the wall surface of the high pressure chamber only gently urges it toward the low pressure chamber, it may shift the operating characteristics of the timer piston to the advance side,
Further, it does not promote the rapid movement of the timer piston to the low pressure chamber side.

That is, according to the injection timing adjusting device of the present invention, it is possible to prevent the generation of abnormal noise due to the collision of the timer piston with the wall surface of the high pressure chamber without impairing the operating characteristics of the timer piston, and to generate the noise in the high pressure chamber. It is possible to prevent abnormal pressure rise.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a state in which a servo valve timer according to a first embodiment of the present invention is incorporated in a distributed fuel injection pump.

In FIG. 1, the pump housing 1 is oil-tightly closed by a timer cover 3 provided at one end, a cover 5 provided at the other end, and O-rings 7 and 9. The servo valve timer 11 controls the movement of the timer piston 13 that is slidable in the pump housing 1 in the directions of the arrow A and the arrow B, and the movement of the timer piston 13 according to the rotation speed of an oil pump (not shown). 15
And timer piston 13 and servo valve 15,
It is provided with springs 17 and 19 that bias in the direction of arrow B. The directions of arrows A and B are orthogonal to the drive shaft of the diesel engine, the direction of arrow A is the advance side, and the direction of arrow B is the retard side.

A high pressure chamber 21 is formed by the arrow B side end surface of the timer piston 13, the pump housing 1 and the timer cover 3, and a low pressure chamber 23 is formed by the arrow A side end surface of the timer piston 13, the pump housing 1 and the cover 5. Are formed. The low pressure chamber 23 is maintained in a pressure state of substantially atmospheric pressure.

Here, in the central portion of the timer piston 13, there is formed a concave portion 27 which opens toward the pump chamber 25 side and whose bottom portion forms a cylindrical surface.
One end of the operation pin 80 shown in FIG. 5 is fitted into the shaft, as in the conventional injection timing adjusting device. The timer piston 13 is connected to the roller ring 84 shown in FIG. 5 via the operation pin 80.

At the end of the timer piston 13 in the direction of arrow A, holes 33 and 35 having different diameters are formed via a step portion 31, and the hole 3 has a through hole 37 in the bush 3.
9 is fitted. The tip of the hole 35 communicates with the pump chamber 25 through a passage 41 provided inside the timer piston 13, and the side portion of the hole 35 has a high pressure through a passage 43 provided inside the timer piston 13. It communicates with the chamber 21.

The servo valve 15 has the bush 3
9 is slidably inserted. An annular groove 44 is formed on the outer circumference of the servo valve 15, and a passage 45 communicating with the annular groove 44 and communicating with the low pressure chamber 23 is formed inside the servo valve 15. A flange 47 is formed at the rear end of the servo valve 15, and the servo valve 15 has a snap ring 49 fitted in the hole 33 from the position where the flange 47 abuts the step 31.
It is possible to move within the range up to the position where it abuts. Incidentally, the snap ring 49 and the step portion 3 in the hole 33.
A collar 50 is disposed between the collar 50 and the collar 1.

On the other hand, one end of the spring 17 is supported by the step portion 31 via the snap ring 49 and the collar 50, and the other end is supported by the cover 5, so that the timer piston 13 is biased in the direction of arrow B, One end of the spring 19 is supported by the flange 47 and the other end thereof is supported by the cover 5, thereby urging the servo valve 15 in the arrow B direction.

The passage 41 is enlarged beside the operation pin 80, and a filter 51 for removing foreign matters from the fuel flowing from the pump chamber 25 to the high pressure chamber 21 and the low pressure chamber 23 is provided therein. There is. Here, in the servo valve timer 11 of the present embodiment, inside the timer cover 3,
A damper piston 53 slidable within the timer cover 3,
A return spring 55 that urges the damper piston 53 toward the timer piston 13 side is provided, and the damper piston 53 has an orifice 57 that connects the timer piston 13 side in the timer cover 3 and the return spring 55 side. It is provided.

The sliding amount of the damper piston 53 with respect to the timer cover 3 is set so that the tip of the damper piston 53 can project from the end position of the timer cover 3 by a predetermined amount. Further, the urging force applied to the damper piston 53 by the return spring 55 is generated by the spring 17 so that the end portion of the timer piston 13 comes into contact with the timer cover 3 and the maximum retarding operation is ensured when the engine speed is low. It is set to be sufficiently small with respect to the urging force applied to 13.

Next, the operation of the servo valve timer 11 of the present embodiment constructed as described above will be described. Fuel is supplied to the pump chamber 25 from an oil feed pump (not shown), and the pressure in the pump chamber 25 is a pressure corresponding to the engine speed. First, when the engine speed is low, the hydraulic pressure of the oil pump is low, and as shown in FIG. 1 corresponding to this state, the front end surface 15a of the servo valve 15 is connected to the pump chamber 25 through the passage 41. Hydraulic pressure is applied.
Therefore, the servo valve 15 is located at a position where this hydraulic pressure and the spring force of the spring 19 are in balance, that is, at the position where the passage 45 and the through hole 37 communicate with each other, and the high pressure chamber 2
1 communicates with the low pressure chamber 23 via the passage 43, the through hole 37, the annular groove 44 and the passage 45, so that the high pressure chamber 21 is in a low pressure state, and the timer piston 13 causes the spring 17 to cause the high pressure chamber 21. Is pushed to the side (retard side).

At this time, the damper piston 53 inside the timer cover 3 is pushed by the timer piston 13 and retracts toward the timer cover 3 side against the return spring 55. On the other hand, when the engine speed increases and the hydraulic pressure of the oil pump increases, the pressure applied to the tip end surface 15a of the servo valve 15 increases, and as shown in FIG. 43 to the position where it communicates. As a result, the high pressure chamber 21 communicates with the pump chamber 25 via the passage 43, the through hole 37 and the passage 41, and is disconnected from the low pressure chamber 23. Therefore, fuel is supplied to the high pressure chamber 21 from the pump chamber 25,
The timer piston 13 is pushed from the high pressure chamber 21 side and moves to the low pressure chamber 23 side (advance side).

Then, the damper piston 53 slides in the direction of arrow A while contacting the timer piston 13 by the urging force of the return spring 55, and the timer piston 13
When is moved to the low pressure chamber 23 side, it is separated from the end surface of the timer piston 13. Further, when the engine speed decreases and the hydraulic pressure of the hydraulic pump decreases, the pressure applied to the tip surface 15a of the servo valve 15 decreases, and as shown in FIG. 3, the servo valve 15 is different from the above case. The passage 43 and the passage 45 are communicated by moving in the opposite direction. As a result, the fuel in the high pressure chamber 21 flows into the low pressure chamber 23, and the timer piston 13 is again moved to the high pressure chamber 21 side (retard side) by the spring 17.

When the timer piston 13 comes into contact with the damper piston 53, the damper piston 53 is pushed by the timer piston 13 and retracts toward the timer cover 3 side. In this way, when the timer piston 13 moves to the high pressure chamber 21 side or the low pressure chamber 23 side according to the engine speed, as shown in FIG. Since the position of the roller ring 84 changes and the contact position between the roller 82 of the roller ring 84 and the cam crest 88a of the cam disk 88 changes, the movement timing of the plunger 90 with respect to the engine rotation, that is, the fuel injection timing is retarded. Or it will be advanced.

During such an operation, the engine speed is low and the timer piston 13 moves to the timer cover 3
When the roller 82 of the roller ring 84 shown in FIG. 5 is applied to the ascending side of the cam crest 88a when it is located near the end of the cam piston 88a, as described above, the timer piston 13 passes through the operation pin 80. Force in the direction of arrow B is applied, and the timer piston 13 comes into contact with the tip end portion of the damper piston 53 protruding from the end portion of the timer cover 3.

Then, in the timer cover 3, the pressure of the damper piston 53 on the side opposite to the timer piston 13 (return spring 55 side) rises, and the timer piston 1 from the return spring 55 side via the orifice 57.
Fuel flows to the 3 side, and the damper piston 53 gently moves to the high pressure chamber side according to the flow rate. Therefore, the timer piston 13 slowly moves to the timer cover 3 side together with the damper piston 53.

That is, the servo valve timer 11 of the present embodiment.
In the case where the engine speed is low and the hydraulic pressure of the oil pump is low, the roller 82 of the roller ring 84 shown in FIG. Force in the direction of arrow A is applied, the high pressure chamber 21 becomes negative pressure, and fuel vapor is generated in the high pressure chamber 21, and then the roller 82 is applied to the up side of the cam crest 88a, and this time, the timer piston When the force in the direction of arrow B is applied to 13 and the timer piston 13 moves to the timer cover 3 side, the moving speed can be sufficiently damped. The damping action prevents the timer piston 13 from colliding with the end surface of the timer cover 3 with a strong force, and the high pressure chamber 21 is rapidly compressed in a state where fuel vapor is generated in the high pressure chamber 21. As a result, the pressure in the high-pressure chamber 21 does not rise abnormally and the O-ring 7 and fixing bolts (not shown) are not damaged.

On the other hand, when the timer piston 13 moves to the high pressure chamber 21 side or the low pressure chamber 23 side according to the engine speed, or when the timer piston 13 is suddenly pushed to the low pressure chamber 23 side by the operation pin 80. If the damper piston 53 is used, the return spring 55 causes the low pressure chamber 23 to move.
Since it is only gently urged to the side, it has an adverse effect such as shifting the operating characteristics of the timer piston 13 to the advance side, and also causes the timer piston 13 to move to the low pressure chamber 2
It does not encourage abrupt movement to the 3rd side.

That is, the servo valve timer 11 of the present embodiment.
According to this, it is possible to prevent the generation of abnormal noise due to the collision of the timer piston 13 with the timer cover 3 without impairing the operating characteristics of the timer piston 13, and it is also possible to prevent the abnormal pressure rise occurring in the high pressure chamber 21. Of.

Next, as a second embodiment, an injection timing adjusting device applicable to a distribution type fuel injection pump having a higher fuel injection pressure will be described with reference to FIG. Normally, in order to increase the fuel injection pressure in this type of distributed fuel injection pump, the cam crest 88a of the cam disk 88 shown in FIG.
Is set to be high and the biasing force of the plunger spring 94 is set to be large, the force with which the timer piston 13 is moved to the high pressure chamber 21 side or the low pressure chamber 23 side by the operation pin 80 is also increased. Therefore, it is desirable to prevent the generation of fuel vapor in the high pressure chamber 21 as much as possible.

Therefore, as shown in FIG. 4, in the servo valve timer 61 of the second embodiment, the timer piston 1
3, a passage 6 that connects the pump chamber 25 and the high-pressure chamber 21 to each other.
3 is formed, and an orifice 65 is provided in the passage 63. The other configurations are exactly the same as those of the servo valve timer 11 of the first embodiment.

According to the servo valve timer 61 of the second embodiment thus constructed, the engine speed is low,
When the pump chamber 25 and the high pressure chamber 21 are shut off by the servo valve 15, the timer piston 13 is instantaneously returned to the low pressure chamber 23 side by the operation pin 80, and the high pressure chamber 2
Even if the pressure is reduced to 1, the fuel is introduced from the pump chamber 25 to the high pressure chamber 21 via the passage 63 and the orifice 65, so that generation of fuel vapor in the high pressure chamber 21 is suppressed. is there. Further, since the diameter of the orifice 65 is small, the pressure in the pump chamber 25 at the time of fuel pressure feeding does not decrease.

Even if the operation pin 80 has a large stress and some fuel vapor is generated in the high pressure chamber 21, the damper piston 53 prevents the timer piston 13 from abruptly moving to the high pressure chamber 21 side. Therefore, even if the fuel injection pump has a high fuel injection pressure, the timer piston 13
It is possible to completely prevent a sudden collision with the end surface of the timer cover 3 and an abnormal pressure rise in the high pressure chamber 21.

As described above, the servo valve timer 61 of the second embodiment can be applied to the distribution type fuel injection pump having a higher injection pressure.
In the servo valve timers 11 and 61 of the first and second embodiments described above, the orifice 57 is provided in the damper piston 53, so that the return spring 55 side of the damper piston 53 and the timer piston 13 side are provided in the timer cover 3. However, the fuel passage may be formed in the side wall of the timer cover 3 and the orifice may be provided in the passage.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state where a servo valve timer according to a first embodiment is incorporated in a distribution type fuel injection pump.

FIG. 2 is an explanatory diagram of an operation during advancement of the first embodiment.

FIG. 3 is an explanatory diagram of an operation during retardation of the first embodiment.

FIG. 4 is a cross-sectional view showing a state where the servo valve timer according to the second embodiment is incorporated in a distribution type fuel injection pump.

FIG. 5 is a sectional view showing a section of a distribution type fuel injection pump.

FIG. 6 is an explanatory diagram illustrating a problem in a conventional injection timing adjustment device.

[Explanation of symbols]

1 ... Pump housing 3 ... Timer cover 13
… Timer piston 15… Servo valve 17… Spring 21
… High pressure chamber 23… Low pressure chamber 25… Pump chamber 4
1, 43, 45 ... Passage 44 ... Annular groove 53 ... Damper piston 55
… Return spring 57… Orifice

Claims (1)

[Claims] 1. A timer piston slidably provided in a pump housing and engaged with an adjusting member capable of adjusting injection timing; and a timer piston provided in the pump housing and facing one end surface of the timer piston. A high-pressure chamber, a low-pressure chamber provided in the pump housing and facing the other end surface of the timer piston, a timer spring provided in the low-pressure chamber for urging the timer piston toward the high-pressure chamber, the pump A pump chamber provided in the housing, to which fuel whose pressure changes according to the number of revolutions from an oil pump rotated by an internal combustion engine is supplied, and the pump chamber when the pressure in the pump chamber is higher than a predetermined pressure. Opening a fuel passage from the chamber to the high pressure chamber and blocking the fuel passage from the high pressure chamber to the low pressure chamber, so that the pressure in the pump chamber is lower than a predetermined pressure. In this case, a fuel valve from the high pressure chamber to the low pressure chamber is opened, and a fuel valve from the pump chamber to the high pressure chamber is shut off. In the device, the high-pressure chamber is slidably provided in the same direction as the timer piston, and is biased toward the timer piston by a return spring attached to a wall surface of the high-pressure chamber facing the timer piston. A damper piston that comes into contact with the timer piston when the timer piston moves to a predetermined position; and a throttle portion that connects the timer piston side of the damper piston and the opposite side of the timer piston in the high pressure chamber, An injection timing adjusting device for a distributed fuel injection pump, characterized in that