JPS59162325A - Fuel injection device - Google Patents

Abstract

PURPOSE:To control a quantity of injection to be optionally further easily set, by longitudinally actuating the regulating shaft of a corrector bar for a fuel injection device through a cam operated by a pressure in the fuel injection device. CONSTITUTION:Providing a regulating shaft 38, which adjusts a corrector bar 30 cotrolling a quantity of fuel, this regulating shaft 38 is longitudinally actuated by a cam 40 of prescribed shape. The cam 40 is connected to an actuator 48 interposing a cam shaft 46, while the pressure in a fuel injection device is introduced into a pressure chamber 56 of the actuator 48. Corresponding to a change of the pressure in the fuel injection device, the cam 40 is turned adjusting a quantity of injection. In such way, the quantity of injection can be optionally further easily set in accordance with the condition of load in an engine.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a fuel injection device, and in particular to a fuel injection device that can set fuel flow characteristics as desired and that is easy to set and achieves an engine-required fuel flow rate. Regarding.

[Technical Background of the Invention] An internal combustion engine, for example, a diesel engine, is an engine that compresses only air and injects fuel into a hot cylinder to cause self-ignition, and a predetermined amount of fuel is injected into the cylinder. It is equipped with a fuel injection device for this purpose.

This fuel injection device consists of a fuel injection system consisting of an injection pump and an injection timing regulator to inject the appropriate amount of fuel at the right time, and a control system consisting of a speed governor to stabilize engine rotation. ing.

FIGS. 1 and 2 are partial sectional views showing a control system of a conventional fuel injection device. The fuel injection amount is determined by the plunger stroke at which the cant-off port 4 of the plunger 2 is closed.
It is changed and controlled by the operation of the spill ring 6. The spill ring 6 is a support lever 1 that interlocks with the tension lever 8.
0, and by swinging the tension lever 8 with the accelerator lever 12, the spill ring 6 is moved in the axial direction of the plunger. The idle spring 14 increases the fuel injection amount by pushing back the tension lever 8 when the engine is idling.

In FIG. 1, when the accelerator lever 12 is turned to the fully open position, the idle spring 14 is compressed, and the tension lever 8 rotates in the direction of arrow a around the governor pin 15, comes into contact with the stopper 16, and stops. At this time, since the reverse Angleich spring 20 of the control lever 18 is not compressed, both the fulcrum 22 and the rond tip 24 abut against the tension lever 8, and the spill ring 6 is maintained at a constant position. Therefore, the spill ring 6 moves in the direction indicated by the arrow by a certain distance, that is, by a pumping stroke S, and the injection amount increases to a predetermined amount.

When the rotational speed further increases from the above state, the flyweight 26 opens in the direction of arrow C, as shown in FIG. 2, and propels the governor sleeve 28 toward the control lever 18.

When this thrust becomes larger than the spring load of the reverse Angleich spring 20, the control lever 18 rotates about the fulcrum 22 in the direction of arrow d. Therefore, the support lever 10 also rotates in the direction of the arrow d about the support shaft 7, and the spill ring 6 is further moved in the direction of the arrow to increase the injection amount. The amount of increase at this time is determined by the stroke S2 in which the control lever 18 moves by compressing the reverse Angleich spring 20.

[Problems with the Background Art] As described above, conventional fuel injection devices use the idle spring 14 or reverse angle control to reduce the injection amount due to leakage from around the plunger 2 on the low speed side of the engine or due to fluid resistance on the high speed side. By compensating with the spring 20 and the like, the fuel flow rate characteristics at full load as shown by the thick line in FIG. 3 are obtained.

However, since the spring load of the spring is used for its operation, only a linear flow characteristic as shown in the figure can be obtained. Further, the tension lever 8 and the support lever 16 are pivotally supported by a collector lever 30, and the collector lever 30 is pivotally supported by a support shaft 32 on the housing side of the fuel injection device. A collector spring 34 is interposed on one side of the support shaft 32, and an adjustment screw 36 is abutted on the other side, and the collector lever 30 is adjusted by the adjustment screw 36 to set the flow rate at full load. was. Therefore, it was not possible to easily change the set flow rate to respond to engine load fluctuations.

As described above, in the past, fuel flow characteristics were linear and the fuel flow rate could not be easily set, making it impossible to achieve the flow characteristics required by the engine.

[Specific Object of the Invention] Therefore, an object of the present invention is to provide a fuel injection device that allows the fuel flow rate characteristics to be arbitrarily set and also allows the fuel flow rate to be easily set in order to achieve the previously required fuel flow rate. It is in the realization.

[Structure of the Invention] To achieve this object, the present invention provides an adjustment shaft for adjusting a collector lever in a fuel injection device that moves a governor sleeve back and forth depending on the engine rotational speed and operates a spill ring to control the fuel injection amount. The fuel injection device is characterized in that it is configured to be moved forward and backward by a cam having a predetermined shape, and that the cam is configured to be operated by pressure within the fuel injection device.

[Embodiments of the invention] Next, embodiments of the present invention will be described in detail based on the drawings.

FIG. 4 is a partial sectional view of the control system of the fuel injection device according to the present invention. In the figure, the same parts as in FIGS. 1 and 2 are given the same reference numerals. That is, the spill ring 6 attached to the plunger 2 adjusts the plunger stroke at which the cant-off port 4 is closed, and controls the injection amount. This spill ring 6 is engaged with one end of the support lever 10. The support lever 10 swings around the governor pin 15 together with the tension lever 8, and moves the spill ring 6 in the plunger axial direction. These tension lever 8 and support lever 10 are pivotally supported by a collector lever 30. The collector lever 30 is pivotally supported by a support shaft 32 on the housing side of the fuel injection device. Offset from this support shaft 32, the tension lever 8
A governor bin 15 that pivotally supports the support lever 10 is also provided. The collector lever 30 is adjusted so that the collector spring 34 is compressed on one side with the support shaft 32 in between, and the collector spring 34 is compressed on the other side in a direction that opposes the resilient force of the collector spring 34, as shown in FIGS. 1 and 2. A screw 36 is provided,
The flow rate was set by adjusting the collector lever 78 by rotating a screw.

This invention provides an adjustment shaft 3 for adjusting the collector lever 8.
8 is provided so as to be able to move forward and backward by a cam 40 of a predetermined shape, and this cam 40 is actuated by the pressure within the fuel injection device. To explain further details, the collector lever 30
An adjustment shaft 38 is provided at a position opposite to the elastic force of the collector spring 34 with the support shaft 32 interposed therebetween. Adjustment shaft 38
is slidably inserted into the housing 42 of the fuel injection device in the axial direction, and has one end in contact with the collector lever 30. The other end of the adjustment shaft 38 is in contact with a cam 40 having a cam surface 44 of a predetermined shape. The cam 40 is provided to be swingable by a cam shaft 46. The cam surface 44 is provided at one end of the cam 40 across the camshaft 46, and the other end is connected to an actuator 48 to operate the cam 40.

The actuator 48 has a piston 52 built into the main body 50. A spring 54 is interposed between one end of the piston 52 and the main body 50, and a pressure chamber 56 is partitioned and provided at the other end. This pressure chamber 56 communicates with the inside of the fuel injection device and pressure is introduced into it. A support hole 58 formed in the piston 52 is slidably fitted with a support end holder 62 that rotatably holds a cam support end 60 .

Next, the effect will be explained.

When the engine speed increases and the fuel pressure within the fuel injection device increases, the pressure in the pressure chamber 56 of the actuator 48 increases.

As the pressure in the pressure chamber 56 increases, the piston 52 and the spring 5
4 in the direction of arrow e, and rotates the cam 40 in the direction of arrow f. With this rotation, the adjustment shaft 38 that contacts the cam surface 44 moves forward and backward in the direction of arrow X depending on its shape. As the adjustment shaft 38 moves back and forth, the collector lever 30 swings about the support shaft 32, and moves the spill ring 6 in the plunger axial direction. This movement changes the pumping stroke of the plunger 2, increasing or decreasing the injection amount.

At this time, the tension lever 8 that is linked to the accelerator,
In conjunction with the operation of the support lever 10 that operates at high speed rotation, the injection amount can be set based on the engine speed. That is, when the tension lever 8 or the support lever 10 is activated, the cam 40 is activated by the pressure inside the fuel injection device corresponding to the engine speed, and the injection amount is set by the collector lever 30. Since the characteristics can be set easily by simply changing the shape, the fuel flow characteristics required by the engine can be achieved.

When the engine speed decreases and the pressure in the pressure chamber 56 decreases, the piston 52 is pushed back by the spring 54 and the cam 40
rotates in the direction of arrow g. This rotation causes the adjustment shaft 38 to move back and forth in the direction of arrow X along the cam surface 44, swinging the collector lever 30 and moving the spill ring 6 in the direction of the plunger axis.

Then, as described above, the injection amount is increased or decreased depending on the shape of the cam surface 44, and the injection amount is set together with the tension lever 8 and the support lever 10.

[Effects of the Invention] As described above, according to the present invention, a cam of a predetermined shape is actuated by the pressure inside the fuel injection device, and the collector lever is adjusted by an adjustment shaft that moves forward and backward with this cam. The flow rate characteristics can be set as follows. Furthermore, the fuel flow rate can be easily set to any desired flow rate by changing the cam shape.

In this way, the flow rate characteristics can be arbitrarily and easily set, and since the collector lever is adjusted based on the pressure inside the fuel injection system, the fuel flow rate required by the engine can be achieved depending on the full load or load condition, improving output. can be achieved.

In addition, in accordance with the device according to the present invention, it is also possible to use the adjustment shaft and cam for adjusting the collector lever, and the means for operating the cam by the pressure inside the fuel injection device, by attaching them to an existing fuel injection device. .

[Brief explanation of drawings]

Figures 1 and 2 show the control system of a conventional fuel injection device. Figure 1 is a partial cross-sectional view of the accelerator lever in the fully open position, Figure 2 is a partial cross-sectional view of the governor sleeve in the forward position, and Figure 3 is a conventional control system. It is a figure which shows the graph of the fuel flow characteristic of a device. FIG. 4 is a partial sectional view of the fuel injection device according to the present invention. In the figure, 2 is a plunger, 6 is a spill ring, 8 is a tension lever, 10 is a support lever, 26 is a fly weight, 28 is a governor sleeve, 30 is a collector lever, 38 is an adjustment shaft, 40 is a cam, and 44 is a cam surface , 48
is an actuator, and 56 is a pressure chamber. Agent Patent Attorney Yoshimi Saigo

Claims (1)

[Claims] In a fuel injection device that controls the amount of fuel injection by moving a governor sleeve back and forth depending on the engine speed and operating a spill ring, an adjustment shaft for adjusting a collector lever is configured to move back and forth with a cam of a predetermined shape, and the cam is A fuel injection device characterized in that the fuel injection device is configured to be activated by pressure within the fuel injection device.