JPS6025626B2 - Diesel engine fuel injection pump - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fuel injection pump for a diesel engine.
Specifically, the present invention relates to a Bosch type fuel injection pump in which the fuel injection timing is given as a single timing for a certain operating state of a diesel engine under a specific structure having a reverse lead type plunger.

In general, diesel engines adjust the fuel injection timing to obtain the best combustion conditions at rated output, rated rotation speed, and high temperature conditions, so under partial load, rotation speed, and low temperature conditions, It is normal for fuel efficiency and exhaust smoke concentration to deteriorate.

Further, the same result may occur depending on the fuel used, and in this case, it is better to change the injection timing. Therefore, there is a need for something that can freely adjust the injection timing depending on the engine speed, load, or fuel used during startup and operation. Advantageously, this type of fuel injection pump is equipped with a top notch b (reverse lead type) plunger a, as shown in Figure 1, in order to be able to change the injection timing according to changes in load during engine operation. However, this type has a structure in which only one injection timing can be found for a certain load, so the drawback is that the injection timing cannot be changed freely. The object of the invention is to provide a fuel injection pump for a diesel engine that does not have the disadvantages of the conventional ones mentioned above.

According to this invention, ``A Borsch type fuel injection pump in which the fuel injection timing is given as a single timing for a certain operating state of a diesel engine under a specific structure with a reverse lead type plunger, In order to control the fuel injection amount, the control rack 2 is mechanically connected to the cabana of the engine, and the pinion 3 engages with the controller rack 2 within the injection pump body 25, so that it can be rotated freely. On the other hand, a control mechanism 17 which is activated by a command from a sensor 16 that can monitor and detect the operating state of the engine so that the fuel injection timing can be arbitrarily changed; According to the operation, the outer circumference of the inner plunger 1 at a predetermined position is formed to be rotatable by a timing rack 6 that is mechanically linked and a pinion 7 that engages with the timing rack 6 within the injection pump body 25, and a top part is formed so as to be rotatable. an outer plunger 4 on which a diagonal cutout control edge 5 is formed, the inner plunger 1 and the outer plunger 4 cooperate in vertical movement within the injection pump body 25, so that the inner plunger 1 is injected with fuel. While opening and closing the injection amount control suction hole 9, the diagonal notch control edge 5 at the top of the outer plunger 4 closes the fuel injection amount control suction hole 9 with the inner plunger 1, and then closes the fuel compression start control hole. 10, and is characterized by being combined into a double structure that can be operated independently from each other in the rotating direction.

Hereinafter, the fuel injection pump according to the present invention will be explained with reference to FIGS. 2 to 5. FIG. 2 shows the state before the start of fuel injection.

In the figure, 1 is an inner plunger, which is slidably installed adjacent to the barrel 8 provided vertically in the center of the injection pump body 25, and controls the fuel injection amount (discharge amount) according to the load. It is allowed. 2 is the control rack, this one is
It is slidably mounted on the injection pump body 25 and is controlled by a governor (not shown) of the engine via a common rod 24 mechanically linked and a lever mechanism 23.

Reference numeral 3 denotes a control pinion, which is provided so as to be rotatable on the outside of the timing pinion 7, and is engaged with the control rack 2.

The inner plunger 1 is made rotatable together with the control pinion 3 by having a drive piece 15 fixedly attached to the lower part of the control pinion 3 in the figure. The engaging portion of the control pinion 3 is configured to move in the vertical direction in the figure to the extent that at least the vertical movement distance in the figure of the drive piece 15 corresponding to the IJ foot of the fuel cam (not shown) relative to the inner plunger 1 can be avoided. A gap configuration is provided for the lower part of the control pinion 3. The fixation of the driving piece 15 to the inner plunger 1 is performed by fastening the retainer 26, which also serves as a receiver for the return counter 13, to the threaded portion of the inner plunger 1. Reference numeral 4 denotes an outer plunger, which has a diagonal notch control green 5 on its top and is iron-mounted between the barrel 8 and the inner plunger 1, and the fuel injection timing can be set arbitrarily according to changes in engine operating conditions such as load. It is possible to change to

Reference numeral 6 denotes a timing rack, which is slidably mounted on the injection pump body 25 on the opposite side of the control rack 2, and receives commands from a sensor 16 that enables monitoring and detection of the operating state of the engine (not shown). In accordance with the control mechanism 17 operated by the control mechanism 17, the injection timing is automatically activated via the mechanically linked lever 20, timing rod 21, and lever mechanism 22.

The sensor 16 is capable of electrically detecting room temperature, intake air temperature, load, rotational speed, cooling water temperature, fuel type, etc. in a certain operating state of the engine, and is installed at a suitable location in the engine. Each sensor 16a, 16b, 16c... Electric signals are sent to a control box 18 as a control mechanism 17 and a drop transformer 19 (or electromagnetic servo, positioner, etc.) so as to give a mechanical operation. . Along with this operation, the lever 20 moves an appropriate amount, and as described above, the timing rack 6 is moved via the timing rod 21 etc.
The amount of movement is transmitted to. It should be noted that the sensor 16 and the control mechanism 17 may be entirely or partially powered by hydraulic pressure or other systems. The timing pinion 7 is rotatably provided inside the control pinion 3 and is engaged with the timing rack 6. The outer plunger 4 is made rotatable together with the timing pinion 7 by engaging the flange portion 28 at the lower end in the figure with the timing pinion 7 at a lower part in the figure. In the above-mentioned engagement portion of the timing pinion 7, as in the case of the engagement portion of the control pinion 3, the movement distance of the flange portion 28 corresponding to the lift of the fuel cam (not shown) relative to the outer plunger 4 can be at least avoided. , a shape with a gap in the vertical direction in the figure is given to the lower part of the timing pinion 7. Further, due to the lift of the fuel cam, the inner plunger 1 and the outer plunger 4 are required to have a structure that allows them to be moved up and down by the same distance at the same time. According to the figure, in this structure, the outer plunger 4 is held between the upper end of the drive piece 16 and the lower end of the head 29 of the inner plunger 1,
The position in the vertical direction is fixed. As a result, as the lift of the cam transmitted via the tab 14 is transmitted to the inner plunger, the outer plunger 4 can also be moved up and down at the same time. In barrel 8,
A suction hole 9 and a compression start control hole 10 are provided.

In addition, fuel is supplied from a fuel oil pump (not shown) to pipe 2.
7, it fills into the barrel 8 via the bush hand 11 and the suction hole 9. Note that 12 is a discharge valve. As mentioned above, both the inner plunger 1 and the outer plunger 4 are vertically movable, but each can be rotated separately by the control rack 2 and timing rack 6.

Next, the effect will be explained.

During engine operation, the tab 14 is raised by the IJ foot of a cam (not shown), which causes the inner plunger to close the suction hole 9, and at the same time, the diagonal notch control green 5 at the top of the outer plunger 4 starts compression. When closed, the fuel is compressed and delivered from the discharge valve 12.

Therefore, fuel injection is determined by the movement of the inner plunger quantity 1. On the other hand, the timing of the start of fuel injection is determined by the timing when the diagonal notch control green 5 of the outer plunger 4 closes the compression start control hole 10.

Therefore, by appropriately rotating the outer plunger 4 within an arbitrary range, the injection timing can be changed as desired. In this case, sensors 16a, 16b, etc. for load rotation speed, room temperature, intake temperature, water temperature, usage fee, etc. detect the engine operating state at each position, and as the control mechanism 17 is operated, The timing rack 6 is moved via the lever 20, timing rod 21, and lever mechanism 22.
As a result, the outer plunger 4 is rotated within a desired range via the timing rapinion 7. In order to provide this desired range of rotation, operations are performed in advance using the sensor 16 and control mechanism 17 group, such as, for example, accelerating the start of injection when the load is high and slowing down the slowing of the injection when the load is low.
If the above-mentioned injection start is made earlier, the desired range in terms of crank angle will be in a larger search direction (direction to move forward when viewed from the top position), and if the injection start is delayed, the same range will be smaller in terms of crank angle. direction (the direction of retreat when viewed from the top position). When the fuel injection stroke ends, the inner plunger 1 and the outer plunger 4 are returned to their original starting positions by the cam by the stretching force of the return imitation 13. As above,
According to the fuel injection pump for a diesel engine according to the present invention, the plunger has a double structure, and the outer plunger, which is formed with a diagonal notch at the top, can be rotated during operation, independently of the inner plunger for controlling the injection amount. By adopting a configuration that allows the fuel injection amount to be adjusted to suit all engine operating conditions, the intake hole 9 for controlling the fuel injection amount can be opened and closed by the movement of only the inner plunger 1.
Regardless of the timing of the start of fuel injection, it can be set independently and with high precision so that it can be changed arbitrarily even during engine operation. By opening and closing the fuel compression start control hole 10 by the movement of It can be constructed as a very effective device that can ensure each fuel injection timing and perform control with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front sectional view showing a reverse lead type plunger of a conventional Bosch type fuel injection pump, FIG. 2 is a sectional view showing a fuel injection pump according to the present invention, and FIG. -1 line sectional view, Figure 4 is a sectional view of Figure 2.
FIG. 2 is a schematic explanatory diagram showing a control mechanism of the pump shown in the figure.

1...Inner plunger, 2...Control rack, 3
... Control pinion, 4 ... Outer plunger, 5 ... Diagonal notch control edge, 6 ... Timing rack, 7 ... Timing pinion, 16. ...Sensor, 17...Control mechanism, 25. …,．． Injection pump body. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1 The fuel injection amount can be controlled in a boiler-type fuel injection pump in which the fuel injection timing is given as a single timing for a certain operating state of the diesel engine under a specific structure with a reverse lead type plunger. The control rack 2, which is mechanically received from the engine cabana,
The control rack 2 is provided with an inner plunger 1 which is rotatably formed by a pinion 3 that meshes within the injection pump body 25, and an inner plunger 1 is provided so that the fuel injection timing can be changed arbitrarily. a control mechanism 17 that operates in response to a command from a sensor 16 that enables monitoring and detection of the operating state of the engine; a timing rack 6 that is mechanically linked in accordance with the operation of the control mechanism 17; and a timing rack 6.
By means of the pinion 7 that meshes within the injection pump body 25,
An outer plunger 4 is provided on the outer periphery of the inner plunger 1 at a predetermined position so as to be rotatable and has a diagonal notch control edge 5 formed at the top thereof, and the inner plunger 1 and the outer plunger 4 are arranged so as to be able to rotate. Inside the pump body 25,
The inner plunger 1 opens and closes the fuel injection amount control suction hole 9 by working together in the vertical direction, while the outer plunger 4
The diagonal notch control edge 5 at the top of the holder is opened and closed so that the inner plunger 1 closes the fuel injection amount control suction hole 9 and then closes the fuel compression start control hole 10. A fuel injection pump for a diesel engine, characterized in that the pumps are combined in a double structure that allows their operations to be independent of each other.