JPS6388230A - Fuel injection pump of diesel internal combustion engine for automobile - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fuel injection pump for an automobile diesel internal combustion engine, which includes an injection pump unit for delivering fuel and an adjustment device for metering the amount of fuel delivered by the injection pump unit. parts and
It is equipped with a supply mechanism that supplies fuel to the injection pump unit at a conveying pressure related to the rotational speed, and an adjustment mechanism that has one adjustment lever and operates the adjustment member, and the adjustment mechanism can be arbitrarily controlled in one aspect. It concerns a type loaded by a control spring mechanism which is tensioned, and on the other hand by a centrifugal governor.

PRIOR ART With known fuel injection pumps of this type, the fuel delivery of the fuel injection pump is zero when the internal combustion engine is under engine braking, i.e. when the accelerator pedal is fully released for downhill driving or for braking the vehicle. Reduced to 9. As a result, when the gasoline engine resumes acceleration, a load shock is caused to the engine and, in some cases, a shocking reaction occurs to the vehicle.

The fuel injection pump according to the present invention is of the type mentioned at the beginning and is characterized by the following points.

That is, the adjusting mechanism is provided with a stopper mechanism which can be adjusted by means of a conveying pressure that is dependent on the rotational speed, and which limits the position of the adjusting mechanism as a function of the rotational speed for the intended minimum delivery amount. It is.

With such an arrangement, the driving characteristics of the motor vehicle are significantly improved due to the rotational speed-related residual output limitation. This is particularly true in that the magnitude of the residual delivery volume follows as a function of the rotational speed.

Embodiment Next, the present invention will be explained according to an embodiment shown in the drawings: A syringe 3 is moved reciprocatingly and simultaneously rotationally in a barrel hole 2 in a fuel injection pump 1 by a drive device (not shown). arise. The pump working chamber 4 in the barrel bore 2 is provided during the suction stroke of the syringe 3 via a plurality of longitudinal grooves 5 formed in the circumferential surface of the plunger 30 and a passage 6 formed in the housing 1. Fuel is supplied from a suction chamber 7 within the housing 1. During the delivery stroke of the plunger 3, the fuel in the pump working chamber 4 is delivered into a longitudinal channel 8 in the plunger 3, and then, depending on the rotational position of the syringe 3, the fuel is piped through a distribution longitudinal groove 10. Road 1
1, that is, to one of the pipes 11 that are distributed around the bore hole 2 depending on the number of cylinders of the internal combustion engine. A supply pump 12 is used to supply fuel into the suction chamber 7, which supply pump 12 supplies fuel from a fuel tank 13 into the suction chamber 7. A pressure control valve 14 connected in parallel to this supply pump 12 controls the pressure in the suction chamber 7 as a function of the rotational speed of the fuel injection pump and increases with increasing rotational speed.

A ring-shaped control sleeve 16 is movable on the plunger 3 as an adjustment element. This control sleeve 16 controls the opening of one horizontal hole 17 connected to the vertical passage 8 during the delivery stroke of the plunger 3, thus creating direct communication between the pump working chamber 4 and the suction chamber 7,
As a result of this, the remaining fuel delivered by the plunger 3 is no longer supplied to the line 11 from this opening point. In this way, depending on the position of the control sleeve 16, after a variable amount of stroke of the plunger 3, the connection to the suction chamber 7 is opened and the fuel delivery is cut off. The more the control sleeve 16 moves in the direction towards the top dead center of the syringe 3, the more the amount of fuel delivered from the plunger 3 to the line 11 and thus to the injection nozzle (not shown) increases.

The control sleeve 16 is adjusted by a two-armed adjustment lever 18. This adjusting lever 18 is pivotable about the axis 19, and its head 20 at one end engages in a recess 21 in the control sleeve 16. A further lever 22 is pivotable about the axis 19. A control spring 24 having a constant idle stroke acts on this lever 22. This control spring 24 has one end fastened to one rotational speed adjusting lever 25, and the other end passes through a hole 26 in the outer end of the lever 22 and has a stop 77.
It has two circular plates 27. control spring 24
The governor sleeve 29 of the centrifugal governor 30 is in contact with the lever 22 in the opposite direction to the force. The centrifugal speed governor 30 is driven by a transmission device (not shown) in accordance with the rotational speed of the sylanger moving device.

This centrifugal speed governor 30 is equipped with many flyweights 33 in a casing 32, and these flyweights 3
3 acts on the lower edge of the regulating sleeve 29 which is longitudinally movable on the shaft 35 by means of the weight section 34 . The pivoting movement of the lever 22 toward the centrifugal governor 30 is caused by the pump housing 1
It is limited by a stopper 36 fixed to.

A second arm 40 of the adjustment lever 18 extends beside the lever 22. This arm 40Fi has a stopper 41 on the side facing the lever 22, and this stopper E! 41
has a spacing relative to -22 when the fuel injection pump is stopped. The end of this arm 40 has two fork-like ends.
It is branched into. One end of an idling spring 44 is fixed to one branch arm 42, and this idling spring 44Fi is weaker than the control spring 24. The other end of the idling spring 44 is connected to one idle adjustment lever 45, which is rotatably supported within the pump housing 1 and can adjust the idling speed.

An adjusting cylinder 50 is arranged near the free end of the arm 40 of the adjusting lever 18 .

This adjusting cylinder 50 has a piston 52 which slides in its bore 51, the piston rod 53 of which is directed towards the pivoting range of the branch arm 43 of the adjusting lever 18. Free end 54 of this piston rod 53
serves as a movable stopper for adjustment/18. This stop results in a restriction of the swiveling range in relation to the rotational speed of the adjusting lever 18, and also in the direction of zero pumping amount. In a chamber 56 partitioned into the bore 51 by the piston 52 and relieved of pressure via a conduit 55, a pressure spring 57 supported at the end of the cylinder moves the piston 52 into a pressure chamber 59 on the opposite side. It is crimped onto the inner strut horn ξ58. When the piston 52 is in contact with the stopper 58, the end 54 of the piston rod 53 is in contact with the adjustment lever 18.
Allows the full maximum turning range. As the pressure builds up in the pressure chamber 59, which is connected to the suction chamber 7 via the passage 63, the piston 52 is pushed against the force of the pressure spring 57, so that the end 54 of the piston rod 53 moves towards the adjusting lever. 18
Gradually limit the turning range of the vehicle.

The above-mentioned adjustment mechanism and residual quantity limiting mechanism operate as follows: During start-up, the adjusting mechanism and residual quantity limiting mechanism for the control sleeve 16 occupy the position shown in FIG. The lever 22Vi contacts the speed regulating sleeve 29 and is held with play by the control spring 24, so that the stroke 772 of the control spring 24 and the disc 27
and a distance from the stop horn ξ41 of the adjustment lever 18. Adjustment Renomer 18Fi idling spring 4
4, the control sleeve 16 is held in the uppermost position in the figure, that is, the position corresponding to the maximum injection amount. After starting, the regulating sleeve 29 is pushed out by the flyweight that opens outward as the rotational speed increases, so that the lever 22 comes into contact with the stopper 41 of the adjusting lever 18. If the rotational speed increases further, the idling spring 44 acting on the adjusting wheel ζ-18 performs a control function.

That is, this idling spring 44 is connected to the centrifugal governor 30.
This results in the control sleeve 16 being held in the reference position for the idling speed, counterbalanced against the forces caused by this. Lever 22 against stopper disc 27 when the rotation speed exceeds the entire idling range
1'l[Mofi<nari, lever 22Fi comes into contact with stopper disc 27 of control spring 24.

At a rotation speed that is higher than the entire idling rotation speed, the lever 22 is pressed against the stopper 41 of the adjustment lever 18 by the speed control sleeve 29 of the centrifugal speed governor 30, and therefore the lever 22 is connected to the idling spring 44 and the control spring. Adjusting lever 1 under the force of 24
Together with 8, it forms one lever assembly. Depending on the tension of the control spring 24 adjusted by the rotation speed adjustment lever 25 and the position of the speed governor sleeve 29 adjusted by the centrifugal speed governor 30, the adjustment speed of the reno z-22 and the adjustment reno ζ-
18 moves control sleeve 161 to a predetermined position corresponding to a predetermined fuel delivery amount.

For example, when driving downhill, the accelerator pedal and, by extension, the rotation speed adjustment lever 25 are returned to loosen the tension on the control spring 24. In other words, when the internal combustion engine is driven from the vehicle body side (during engine braking), the engine will fly. The weight 33 presses the regulating sleeve 29 onto the lever 22 and the adjustment lever 18. These two pressure gauges change their position and cause the control sleeve 16 to move in a decreasing direction, so that a reduced delivery volume is adjusted in accordance with the current load situation. In this case, the end 54 of the piston rod 53 of the adjusting cylinder 50 limits the pivoting of the adjusting lever 18 and the movement of the control sleeve 16 into the limit position in order to avoid the limit position "zero delivery amount". This limitation is related to the rotational speed and also the suction chamber 7.
It is based on the pressure controlled in the pressure chamber 59 of the inner machining adjustment cylinder 50 in relation to the rotational speed. That is,
As the pressure within the pressure chamber 59 increases, the piston 52 moves toward the adjustment lever 18 against the force of the push spring 57.
In response to the increased pressure, the end 54 of the piston rod 53 acts as a stop and limits the amount of pivoting of the adjusting lever 18 in the direction of decreasing the delivery amount to a greater or lesser extent. In this way, the residual output quantity adapted to the rotational speed prevents excessive braking of the internal combustion engine during engine braking, and also avoids load shocks when restarting the acceleration operation.

The embodiment of the residual quantity limiting mechanism shown in FIG. 2 is constructed almost in the same way as the example shown in FIG. There is. This safety device prevents the maximum permissible rotation speed from being exceeded due to malfunction. What is the safety effect? piston rod 5
This is caused by the fact that one flexible member 60 is arranged at the end 54 of the adjustment lever 18, which acts as a stop ξ of the adjustment lever 18. The flexible member 6o consists of a sleeve 61 which is supported in a slidable manner on the piston rod 53 and which is pushed away from the piston rod 53 by a pressure spring 62. The push spring 62 is set to such an extent that the force of the centrifugal governor 30 can overcome the force of the push spring 62 even if the piston 52 is pushed out when the maximum allowable rotation speed is exceeded.
Even if it comes into contact with the sleeve 61, the adjustment lever 18 can be turned in the direction of decreasing the delivery amount.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the fuel injection pump of the present invention, and FIG. 2 is a longitudinal sectional view showing another embodiment of the residual amount limiting mechanism in FIG. 1.

Claims (1)

[Claims] 1. A fuel injection pump for an automobile diesel internal combustion engine, the injection pump unit (2, 3,
4), an adjusting member (16) for metering the amount of fuel delivered to the injection pump unit (2, 3, 4), and a control member (16) for controlling the amount of fuel delivered to the injection pump unit (2, 3, 4) at a conveying pressure related to the rotational speed. A supply mechanism (12, 14) and one adjustment lever (1
8) for operating said adjustment member (16), said adjustment mechanism being optionally tensioned on one side by one control spring mechanism (24) and on the other side. In the case of the type each loaded by one centrifugal speed governor (30), the adjustment mechanism includes one stopper mechanism (50, 54, 60) adjustable by the conveying pressure related to the rotational speed. ), the stopper mechanism (50, 54, 60) limiting the position of the adjustment mechanism in relation to the rotational speed for a minimum delivery quantity. Fuel according to claim 1, in which the adjustable stopper mechanism (54, 60) belongs to a hydraulic cylinder (50) which receives a conveying pressure and acts against a spring force (57). Injection pump 3. 4. Fuel injection pump according to claim 2, wherein the hydraulic cylinder (50) has a piston rod (53) that limits the amount of pivoting of the adjusting lever (18) of the adjusting mechanism. Fuel injection pump according to claim 3, in which a flexible stop (60) is arranged on the piston rod (53).