JPS5985430A - Fuel injection device of diesel engine - Google Patents

Abstract

PURPOSE:To prevent irregular injection during idling by furnishing a fluid pressure operated actuator, which works the governor lever mechanism in the direction of reduced injection with rising rotational speed of the engine, and thereby eliminating necessity for use of a governor weight. CONSTITUTION:At the top of a governor lever mechanism 37, a control lever 22 is coupled with a governor spring interposed, and the governor lever mechanism 37 is shifted in the direction of increased injection through the action of rotating control lever 22. A fluid pressure operated actuator 45 is furnished to lead the fuel discharged by a feed pump 8 to a pulsation absorbing chamber 53, and a sleeve 51 is pressed to the governor lever mechanism 37 by a pressure corresponding to the rotational speed of the engine. The fuel pressure introduced into a chamber 48 of actuator 45 can have a stable value, being free from influence of variation in the engine revolutions.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an FUQt injection device for a diesel engine.

Conventionally, fuel injection devices for diesel engines have been equipped with a plunger that is driven by the engine, rotates and reciprocates, and distributes and pumps fuel.

It is equipped with a control sleeve that is slidably fitted into the plunger and controls the effective stroke of the plunger, and a control lever that is linked to the accelerator pedal of the automobile (the biasing force of the lever up assembly and the governor weight of the mechanical governor are adjusted by this). It is generally well known that the position of the control sleeve is controlled by balancing the urging force of the control sleeve with the biasing force of the control sleeve via the governor sleeve, thereby controlling the fuel injection amount.

By the way, in this type of diesel engine fuel injection system, due to uneven rotation of the engine during idling, the governor weight expands and contracts and vibrates, making the positions of the governor sleeve and control sleeve unstable.
This results in irregular injection of fuel, and furthermore, this irregular injection causes torque fluctuations, which aggravates irregular rotation of the engine, resulting in significant idling vibration.

Therefore, as a means to reduce the idling vibration caused by such irregular fuel injection, it is possible to increase the mass of the governor weight to reduce the expansion/contraction vibration of the governor weight. The problem is that it is difficult to implement due to large dimensions and space constraints. In addition, as another means, by reducing the cross-sectional area of the damper passage communicating with the damper chamber formed between the inner circumferential surface of the governor sleeve and the tip of the governor shaft, the movement of the governor sleeve during idle rotation can be reduced. Apply the brakes to Cabanas IJ
-7" It may be possible to stabilize the operation of the control sleeve, but if this is done, braking will also be applied to the governor sleeve when you want the governor sleeve to operate quickly, such as during acceleration. As a result, the control sleeve cannot be operated quickly, and there is a problem in that the response and followability to increases or decreases in the amount of fuel injection are poor.

Therefore, as a fuel injection device for a diesel engine that solves these problems, a taper is formed on the governor shaft so that the tip is tapered toward the tip side, and the taper of the governor shaft and the inner circumferential surface of the governor sleeve are The structure allows the cross-sectional area of the damper passage formed between the governor sleeve and the governor sleeve to be adjusted according to the position of the governor sleeve. To stabilize the operation of the control sleeve and eliminate irregular fuel injection, during high-speed rotation, the cross-sectional area of the damper passage is increased so that the governor sleeve and control sleeve can operate quickly. @ A method with improved responsiveness and followability of radiation amount control has been proposed (Utility Model Application No. 57-25131).

However, in the diesel engine fuel injection device mentioned above, the small-diameter governor shaft is tapered toward the tip, so it is difficult to provide a relief passage for the timer mechanism in the governor shaft due to the size. In processing,
The problem is that it is difficult and difficult to implement.

Therefore, an object of the present invention is to eliminate the use of a governor weight and prevent uneven engine rotation from affecting the governor lever mechanism, thereby preventing irregular fuel injection during idling and reducing idling vibration. It is an object of the present invention to provide a fuel injection device for a diesel engine that can reduce the amount of fuel injected, speed up the responsiveness and followability of fuel injection amount control, and be practical.

In order to achieve the above object, the structure and operation of the present invention are such that a control sleeve that controls the effective stroke of the plunger is attached to a plunger that is driven by an engine, rotates and reciprocates, and distributes and pumps fuel. At the same time, the control sleeve is connected to the control sleeve, and the operation of the governor lever mechanism is controlled by the engine rotation speed of the control lever that is linked to the accelerator pedal of the automobile. hand,
In a diesel engine fuel injection device that controls the fuel injection amount, when the control lever and the governor lever mechanism are connected via an elastic mechanism, the governor lever mechanism is moved in the direction of decreasing the fuel injection amount as the engine speed increases. By providing a fluid-type actuator that operates during engine rotation, it is possible to prevent uneven engine rotation from affecting the governor lever mechanism and control sleeve, prevent irregular injection during idling, and reduce idling vibration. It is characterized by being able to quickly control the response and followability of the fuel injection amount.

Hereinafter, this invention will be explained in detail with reference to illustrated embodiments.

In Fig. 1, 1 is the fuel injection pump main body, 2 is the main body l
5 is a drive shaft that rotates at a rate of 100 revolutions per revolution of the crankshaft of the engine; 6 is a number plate formed inside the main body 1; This cam disk is located between the drive shaft 5 and the plunger 2 and transmits the driving force of the drive shaft 5 to the plunger 2.

Fuel is supplied into the cam chamber 7 through a passage 10 from a discharge port 9a of a wide pump 8, which is a vane pump connected to the drive shaft 5, driven by the engine, and generates a discharge pressure according to the engine speed. . Further, a cam disk 6 is connected to the drive shaft 5 via a drive disk 11 as a joint, and the cam disk 6 is rotated together with the drive shaft 5 and is axially oriented with respect to the drive shaft 5. G) so that it can be moved freely forward and backward.

On the outer periphery of the cam disc 6 on the drive shaft 5 side, there are face cams 12.12 of the same number as the number of engine cylinders.
This face cam 12.12.
... is urged toward a plurality of rollers 16 (only - ones are shown) supported by a ring-shaped roller holder 15 by the force of a plunger spring (not shown),
The cam disk 6 is moved forward and backward in the same axial direction by bringing the cam surface of the cam 12 into contact with the roller 16.

Therefore, the cam disk 6 rotates together with the drive shaft 5, and repeats the same number of axial reciprocating movements as the number of face cams 12 per rotation.

Further, the plunger 2 is pressed and connected to the center of the cam disc 6 by a plunger spring, so that the plunger 2 rotates together with the cam disc 6.
It is designed to reciprocate in the axial direction.

On the outer periphery of the head portion of the plunger 2, there are slits 21, 21 extending in the axial direction as inlet shades, the same number as the face cams 12, 12, at regular intervals.
, . , the working chamber 231 between the head surface of the plunger 2 and the cylinder 3 is guided.

A fuel passage 24 is provided at the axial center of the plunger 2 and opens into the working chamber 23i.

An axial outlet port 25 formed on the outer periphery of the axially intermediate portion of the plunger 2 communicates with the outlet port 25, and a force port is provided on the rear outer periphery of the plunger 2 so that it can open into the cam chamber 7. The off port 26 is communicated.

The outlet port 25 is connected to the cylinder 3 and the main body l when the plunger 2 moves forward and is in the pressure feeding stroke.
The inlet port 21 is closed at the inner circumferential surface of the cylinder 3 so as to communicate with the distribution passage 27i formed in the working chamber 23.
The number of the distribution passages 27 is the same as the number of cylinders, and the number of the distribution passages 27 is the same as the number of cylinders. The delivery valve 28 is opened at equal intervals on the inner circumferential surface of the cylinder, and communicated with the injection nozzle of each cylinder.The delivery valve 28 is opened when the fuel pressure exceeds a certain pressure, and the fuel is delivered to the injection nozzle G. It is designed to guide you.

In addition, a control sleeve 31 is fitted into the rear part of the plunger 2 so as to be slidable in the axial direction, and the cut-off port 26 is opened and closed on the inner circumferential surface of the control IJ-b 31 to enable the plunger 2 to operate. The fuel injection amount is controlled by controlling the stroke. That is, the control sleeve controls the dimming of the cutoff port 26 to control the fuel injection amount.
).

The mass amount of fuel 1 can be controlled in this manner because the fuel in the working chamber 23 is closed when the cutoff port 26 is closed by the inner peripheral surface of the control sleeve 31 during the forward pumping stroke of the plunger 2 The fuel in the working chamber 23 can be fed under pressure to the outlet port 251 through the fuel passage 24, but when the cut-off port 26 and the cam chamber 7 are in communication, the fuel in the working chamber 23 passes through the fuel passage 24 and the cut-off port 26 to the cam chamber. 7, and the pumping of fuel is stopped.

The recess 35 provided in the control sleeve 31 includes:
The pole portion of the rad pin 38 is engaged with and connected to the 1-t ball at the lower end of the lever assembly 37 as a force-receiving mechanism that swings about the fulcrum 36, and is connected to the upper end of the lever assembly 37. The control lever 22, which is linked to the accelerator pedal of the automobile, is connected through the governor spring 41 as an elastic mechanism, and when the engine is in the high mode, the governor spring 41 and the lever assembly 37 are activated by the rotation of the control lever 42. 1, the control sleeve 31 is moved in the direction of increasing the amount of fuel (tributary), that is, to the right in FIG.

As described below, the lever assembly 37 is provided with a hydraulic actuator 45 on the main body 1, which biases the fuel injection device in a direction to decrease the fuel injection device as the engine speed increases.

The fluid pressure actuator 45 has a piston 47 slidably fitted into a cylinder chamber 46 formed in the main body 1, dividing the cylinder chamber 46 into two chambers 48° and 49, and integrally formed with the piston 47. A bag-shaped sleeve 51 is made to protrude in the axial direction from within the cam chamber 7. 2. The chamber 481 of the fluid pressure chamber actuator 45 leads the fuel discharged from the discharge port 9b of the feed pump 8 through a passage 54 with a pulsation absorption chamber 53 provided in the middle, and the sleeve 51 is connected to the engine. The lever assembly 37 is suppressed by a pressure corresponding to the engine speed, and the lever assembly 37 is operated in a direction to decrease the fuel injector in response to an increase in the engine speed.

The pulsation absorbing chamber 53 divides the inside of the housing 52 into a fuel chamber 56 and an atmospheric pressure chamber 57 (not shown in the figure) by dividing the inside of the housing 52 into a fuel chamber 56 and an atmospheric pressure chamber 57 (not shown). Suction boat 9c with no fuel tank and phyto pump 8.

The coil spring 61 communicates with the suction passage 58 communicating with the atmospheric pressure chamber 571 through the throttle 59.
The fuel pulsation is absorbed by the operation of the diaphragm 55 and the throttle 59.

Therefore, the chamber 48 of the hydraulic actuator 45
The fuel pressure guided by the internal pump is controlled by the action of the pulsation absorption chamber 53 (Thus, even if the rotation of the feed pump 81 is uneven due to uneven rotation of the engine, it will not be affected by the rotation unevenness (N stable). Note that the chamber 49 of the hydraulic actuator 45 is communicated with the fuel tank via the drain passage 62 to prevent back pressure from building up in the chamber 49.

Also, the piston 47 of the fluid pressure actuator 45
The sleeve 51 is slidably fitted onto a governor shaft 65 fixed to the main body 1, and the position t of the sleeve 51 relative to the governor shaft 65 is controlled by a fuel pressure corresponding to the engine rotation speed that presses the piston 47. It is determined based on the balance with the biasing force of the arm assembly 37 (depending on the load). Then, the relief passage 66 formed in the shaft 651 of the above-mentioned size is communicated with the load timer hole 67 formed in the sleeve 51 at the time of low load, and the cam chamber 7
By lowering the fuel pressure in the cylinder at low load, a timer piston (not shown) is displaced, and the roller holder 15 connected thereto is rotated! In order to improve sales, a load timer is configured that delays the lift timing of the cam disc 6 and delays the fuel injection timing as the load decreases.

Note that 71 is the sleeve 5 of the fluid pressure actuator 45.
1, 72 is a sealing member provided on the outer periphery of the piston 47, and 73 is a sleeve 51.
This is a sealing member that seals between the outer periphery of the main body 1 and the main body 1.

In the diesel engine fuel injection device having the above configuration, the engine is currently in the idle state of 1,
Assume that the engine has a slight uneven rotational force S.

At this time, since the feed pump 8 is rotated by the engine, its discharge pressure fluctuates; however, due to the action of the pulsation absorbing channel 53, the pressure acting on the piston 47f of the fluid pressure actuator 45 does not pulsate. The pressure is smoothed and corresponds to the engine rotational speed, eliminating irregularities in transmission.

Therefore, the assembly IJ 37 i,
A pressing force is applied by the piston 47 through the sleeve 51 and does not change even if there is uneven rotation, and an engine load is applied through the governor spring 41 depending on the rotation angle of the control lever 42. The position is stably determined by the balance with the biasing force according to .

The control sleeve 31 does not move in the axial direction even if there is uneven rotation of the engine, preventing irregular injection of fuel and preventing uneven engine rotation. As a result, idling vibrations are reduced.

In this way, by using the hydraulic actuator 4!245, it is possible to easily eliminate the influence of uneven rotation of the engine.

In addition, in the entire operating range of the engine, the fluid pressure actuator 45 has a throttle in the passage 54 communicating with the chamber 48 on one side of the piston 47, and the damper passage 71 has a large cross-sectional area. It can operate quickly without being affected. therefore,
The control sleeve 31 is quickly actuated via the hydraulic actuator 45 and the lever assembly 37, ensuring quick responsiveness and followability in controlling the fuel injection amount.

In the above embodiment, the feed pump 8 is driven directly by the engine, but if the feed pump is driven by a motor powered by the interior, the output of the engine speed sensor will For example, the output from the control circuit input via a smoothing circuit etc. controls the speed so that it is proportional to the engine rotation speed and is not affected by uneven engine rotation, and the discharge pressure of the feed pump is adjusted to the engine speed. It is proportional to the rotational speed and is not affected by uneven rotation of the engine. Therefore, irregular fuel injection during idling can be prevented from rain without impairing the responsiveness and followability of fuel injection amount control, and idling vibration can therefore be reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of the present invention. 2... Plunger, 8... Feed pump 0.
31... Control sleeve, 37... Lenoy assembly, 41... Gun nut spring, 42 Control lever, 45... Fluid pressure actuator, 53... Pulsation absorption channel/<.

Claims (1)

[Claims] (1) Driven by an engine, rotating and reciprocating;
The device includes a plunger that distributes and pumps fuel, a control sleeve that is slidably fitted into the plunger and controls the effective stroke of the plunger, and a governor lever mechanism that is connected to the control sleeve and is linked to the accelerator pedal of the automobile. A fuel injection device for a diesel engine that controls the operation of the governor lever mechanism based on the movement of the control lever and the engine rotational speed. 1. A fuel injection device for a diesel engine, comprising a fluid pressure actuator that operates in a direction to decrease the amount of fuel to be injected as the number of fuel injection increases.