JP2521723Y2 - Injection timing control device for fuel injection pump - Google Patents

Description

[Detailed description of the invention] << Industrial application field >> The present invention relates to a control device for a fuel injection timing in a fuel injection pump, and in particular, a connecting rod having an injection timing adjustment operating tool and a speed adjusting lever of a governor mechanism. The present invention relates to a fuel injection timing control device configured to be able to operate in conjunction with the fuel injection timing.

<< Prior Art >> As an example in which a governing mechanism of a governor mechanism and an injection timing adjustment operating tool are interlocked via a connecting rod, there is a conventional one disclosed in, for example, Japanese Utility Model Laid-Open No. 57-47765.

This is because the pin engaged with the control sleeve is eccentrically protruded from the oscillating wheel, and the input end of the oscillating wheel is connected to the governing lever with a connecting rod. The control sleeve is moved up and down in conjunction with the speed control lever by transmitting the control sleeve to the oscillating wheel.

<< Problem to be Solved >> However, in the above-mentioned conventional device, the speed adjusting lever and the swinging wheel are connected by the connecting rod, and the pin is eccentrically mounted on the swinging wheel, so that the swinging lever is The amount of operation and the amount of elevation of the control sleeve change linearly with the change in the number of revolutions, as shown by the broken line in FIG. Since the amount of advance of the fuel injection timing is set based on the operating range, there is a problem that the injection timing is not appropriate near the idling rotation range and loud noise is generated.

The above problem will be described in more detail. Figure 10 shows the actual opening 57
FIG. 1 is an overall side view of a fuel injection pump disclosed in JP-47765B. In this device, a connecting rod 102 is pivotally connected to a governing lever 101, and the tip of the connecting rod 102 is connected to an arm 10
3. It is configured to interlock with a swinging wheel (not shown) provided with a pin that moves the control sleeve up and down via the shaft 104. Then, by operating the speed control lever 101 indicated by an arrow caused by a change in the engine speed, the connecting rod 102 is moved in the left-right direction, and the swing wheel is rotated to set the advance amount corresponding to the engine speed. I have to.

In such a configuration, since the amount of vertical movement of the control sleeve changes in proportion to the amount of operation of the governing lever 101, a linear characteristic proportional to the engine speed is obtained as shown by the broken line in FIG. . That is, the actual opening 57-477
With the device disclosed in Japanese Patent Publication No. 65, the amount of advance is increased by a constant amount according to the number of revolutions.If the amount of advance is set to be small to reduce noise in the idling rotation range, a predetermined output can be obtained at the maximum revolution. If the amount of advance is set large in order to obtain a predetermined output at the time of maximum rotation, loud noise is generated in the idling rotation range. As described above, the injection period of the engine is usually set so as to obtain a predetermined output in the engine operating region. Therefore, if the advance amount decreases by a fixed amount according to the rotational speed, it is indicated by a broken line in FIG. In the curve, the noise level in the idling rotation range becomes the noise value T, and cannot be reduced to the noise value T or less with the characteristic that the advance amount increases by a constant amount.

Therefore, in the device disclosed in Japanese Utility Model Laid-Open No. 57-47765, the effect of suppressing noise generation is small in the idling rotation range, and the amount of advance is increased by a constant amount in the range from middle speed to high speed. The result is that the stickiness cannot be obtained. Further, in the device disclosed in Japanese Utility Model Laid-Open No. 57-47765, it is described that the change of the fuel injection timing characteristic can be handled by changing the length of each lever of the link device, Just by changing the length of the lever,
In FIG. 6, even though the characteristics indicated by the broken lines can be translated in parallel as indicated by the alternate long and short dash line, the advance amount cannot be flexibly controlled according to the rotational speed. Therefore, there is a problem that it is difficult to change the engine operation characteristics according to the needs of the application (construction work machine, agricultural work machine, etc.) of the diesel engine to which the fuel injection pump is applied.

The present invention has the above problems, namely, the noise increases in the low engine speed range, the engine cannot be made sticky in the medium to high speed range, and the operating characteristics of the engine easily change according to needs. It is an object of the present invention to provide a fuel injection timing control device that solves the problem that cannot be performed.

<< Means for Solving the Problems >> In order to achieve the above object, the present invention provides a fuel injection timing adjusting device in which a speed control lever and an input portion of a fuel injection timing adjusting device are connected by a connecting rod. The input arm is fixed to the input end of the control rod connected to the
An interlocking pin is interlocked with the output of the adjustment actuator, and a non-constant speed cam is interposed in the power transmission system from the input of the adjustment actuator to the input arm of the control rod. The shape of the non-constant speed cam is characterized in that the change in the amount of elevating is changed rapidly from the idling rotation speed to the low rotation speed range, and is changed gradually from the middle rotation speed to the high rotation speed range. .

<< Operation >> In the present invention, a non-constant speed cam is interposed in the power transmission system from the input part of the adjustment actuator to the input arm of the control rod, and the change in the amount of elevation of the control sleeve with respect to the engine speed is changed by idling rotation. The shape of the non-constant speed cam is formed so that it changes abruptly from the low speed range to the middle speed range and gradually changes from the middle speed range to the high speed range. The amount of rise and fall of the control sleeve with respect to (number) becomes an upwardly bent or curved curve (see the solid line in FIG. 6), and in the range from the idling rotation range to the low rotation range, the lifting and lowering amount is increased with respect to slight movement of the speed control lever. In the range from the middle rotation range to the high rotation range, control can be performed so as to slightly change the elevating amount with respect to a large movement of the governing lever. So, for example,
Even if the advance angle is set so as to correspond to the maximum rotation so that the maximum output of the engine can be obtained, the noise level in the idling rotation range is significantly reduced as compared with the conventional configuration as shown by the solid line in FIG. be able to. Further, since the advance angle change is gradual from the middle rotation range to the high rotation range, the output of the engine can be maintained in the rotation range, and the engine can be made sticky.

In the case of a diesel engine, the characteristics of the engine speed-advance angle are often changed depending on the type of vehicle to which the same type of engine is applied, for example, an engine for a construction work vehicle or an engine for an agricultural work vehicle. Further, even in the same vehicle type, it is necessary to adjust the characteristic of the rotation speed-advance angle according to the environment used by the user. Even in such a case, according to the present invention, the non-constant velocity cam is interposed in the power transmission system from the input portion of the adjusting operator to the input arm of the control rod, and the amount of elevation of the control sleeve with respect to the engine speed is increased. The change of the speed is suddenly changed from the idling rotation range to the low rotation range, and gradually changed from the middle rotation range to the high rotation range is performed only by the shape of the non-constant speed cam. Significant changes can be made by simply replacing the non-constant velocity cam with another shape, and the engine characteristics can be easily changed according to user needs.

<< Embodiment >> Drawings show an embodiment of the present invention, FIG. 1 is a perspective view of a main part taken out, FIG. 2 is a fuel injection system diagram of a diesel engine,
FIG. 3 is a vertical sectional front view of the fuel injection device, FIG. 4 is a plan view thereof, and FIG. 5 is a sectional view taken along line VV of FIG.

This diesel engine (1) has a combustion chamber (4) formed above a piston (3) inserted into a cylinder (2). The combustion chamber (4) has a fuel injection pump (6) and a fuel injection. The fuel which flows in order through the pipe (7) and the fuel injector (8) is supplied. The plunger (9) of the fuel injection pump (6) is vertically reciprocated by a pump driving cam (13) via a crank gear (10), an intermediate gear (11) and a pump driving gear (12).

This fuel injection pump (6) is a known one and is configured to be capable of adjusting the injection timing. That is, the plunger (9)
Has a suction port (15) communicating with the high-pressure chamber (14), and a spill port (17) formed on a control sleeve (16) fitted to the plunger (9). The pre-stroke can be changed by adjusting the control sleeve (16) up and down with respect to the plunger (9) via the control rod (19) with the fuel injection timing adjustment operating tool (18). It is. The fuel injection amount is adjusted by rotating the plunger (9) through the control rack (21) of the fuel injection pump (6) with the governor lever (20) that swings according to the engine speed.
This is done by changing the phase of the notch groove (22).

In the fuel injection pump having such a structure, the present invention has a fuel injection timing adjusting mechanism configured as described below.

That is, an input arm (24) is fixed to the input end of the control rod (19), and an interlocking pin (25) is erected on the input arm (24) to adjust the fuel injection timing formed on the end cam (26). The output end of the actuator (18) is brought into contact with the interlocking pin (25), and the input arm (27) fixed to the input end of the fuel injection timing adjustment actuator (18) is adjusted by the governor mechanism (G). It is linked to the speed lever (28) by a connecting rod (29).
One end of a governor spring (30) is attached to the inner arm of the governing lever (28), and the governor spring (30) is swung by an operating device such as an accelerator pedal to thereby control the governor spring (28). The governor lever (20) is swung by changing the tension of (30).

A connecting rod (29) connecting the speed control lever (28) and the input arm (27) of the fuel injection timing adjustment operating tool (18) is connected to the speed control lever (28) as shown in FIG. Arm (27)
Rod end (31) with spherical connection structure at the connection with
Is engaged and fixed to each rod end (31).
9) is screwed and fixed. In addition, both ends of the connecting rod (29) are formed with reverse threads, and by controlling the screwing amount of the rod end (31) of the connecting rod (29), the injection timing is controlled according to the intended use. In addition, since both ends of the connecting rod (29) are fixed to each lever via the rod end (31), even if there is a three-dimensional displacement between both levers, the displacement is absorbed and accurate. Will work.

Further, the shape of the end face cam (26) formed at the output end of the fuel injection timing adjuster (18) is such that the engine speed varies from the idling rotation range to the low rotation range as shown by the solid line in FIG. The non-constant velocity cam (C) showing an upwardly convex curved shape in which the amount of rise and fall of the control sleeve changes rapidly between the middle rotation range and the high rotation range. Is formed. In this case, the idling rotational speed is retarded more than in the conventional linear control, and is advanced earlier in the state of low speed and high load rotation than in the conventional case.

7 and 8 show another embodiment of the present invention, in which the speed control lever (28) is disposed on the side surface of the fuel injection pump installation portion, and the fuel injection timing adjustment operating tool is used. (1
8) is formed in a piston structure which advances and retreats in a straight line. An output lever (33) is fixed to the lower end of the piston (32) of the fuel injection timing adjusting device (18), and the output lever (33) and the control rod ( The input lever (24) fixed to (19) is interlocked and connected by a connecting pin (25), and the piston (32) is formed so as to be able to move up and down by a peripheral cam (34). ) The input arm (27) fixed to the shaft end and the speed control lever (28) are interlocked and connected by the connecting rod (29), so that the fuel injection is interlocked with the swing operation of the speed control lever (28). The timing is controlled. The cam shape of the peripheral cam (34) in this case also changes the amount of rise and fall of the control sleeve abruptly when the engine speed is between the idling rotation range and the low rotation range, as in the previous embodiment, and changes from the middle rotation range. The non-constant speed cam (C) is formed to have an upwardly convex curved shape in which the amount of rise and fall of the control sleeve gradually changes between the high rotation ranges.

<< Effects >> The present invention has the following specific effects.

(A) A non-constant speed cam is interposed in the power transmission system from the input part of the adjustment actuator to the input arm of the control rod, which can achieve both noise reduction and high output.
The shape of the non-constant speed cam is changed so that the change in the amount of elevation of the control sleeve with respect to the engine speed changes abruptly from the idling speed range to the low speed range and gradually changes from the middle speed range to the high speed range. Because it is forming
The amount of rise and fall of the control sleeve with respect to the amount of operation (rotational speed) of the governing lever becomes a bulge or curve that swells upward, and the amount of rise and fall for slight movement of the governing lever in the range from idling rotation range to low rotation range. When the speed control lever is largely moved in the range from the middle rotation range to the high rotation range, the amount of elevation can be slightly changed. Therefore, the engine can be made more viscous in the range from the middle rotation speed to the high rotation speed while providing a quiet engine with reduced noise generation in the idling rotation range.

(B) Easy change of engine characteristics A non-constant speed cam is interposed in the power transmission system from the input part of the adjusting actuator to the input arm of the control rod, and the change in the amount of elevation of the control sleeve with respect to the engine speed is changed. The effect of changing the engine speed drastically from the idling speed range to the low speed range and gently from the middle speed range to the high speed range is performed only by the shape of the non-constant speed cam. The change can be made only by replacing the non-constant velocity cam with one having a different shape, and the engine characteristics can be easily changed according to user needs.

[Brief description of the drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a perspective view of a main part taken out, FIG. 2 is a diagram of a fuel injection system of a diesel engine, FIG. 3 is a vertical sectional front view of a fuel injection device, and FIG. FIG. 5, FIG. 5 is a sectional view taken along line VV of FIG. 4, FIG. 6 is a graph showing the relationship between the engine speed and the advance amount, FIG. 7 and FIG. FIG. 8 is a longitudinal sectional front view of a main part, FIG. 8 is a longitudinal sectional side view, FIG. 9 is a diagram showing a relationship between engine speed and noise, and FIG. 10 is an overall side view of a conventional fuel injection pump. 1 ... diesel engine, 6 ... fuel injection pump, 9
... (6) plunger, 16 ... control sleeve, 18 ... adjustment actuator, 19 ... control rod, 24
... (19) Input arm, 25 ... Link pin, 27 ... (1
8) Input part, 28 ... governing lever, 29 ... connecting rod,
G: governor mechanism, C: non-constant speed cam.

Claims (1)

(57) [Scope of request for utility model registration] 1. A control sleeve (16) is removably fitted to a plunger (9) of a fuel injection pump (6) mounted on a diesel engine (1), and the control sleeve (16) is connected to a control rod (19). ), The input part of the control rod (19) is connected to the output part of the adjusting actuator (18), and the input part (27) of the adjusting actuator (18) is controlled by the governor mechanism (G). The lever (28) and the connecting rod (29) can be operated in conjunction with each other, and can be adjusted according to the operation of the speed control lever (28).
, And the operation of the adjusting operation tool (18) is controlled via the control rod (19) by the control sleeve (16).
In the fuel injection pump injection timing control device configured to adjust the fuel injection timing of the fuel injection pump (6) by transmitting the control arm to the input arm (2) at the input end of the control rod (19).
4) Fix the input arm (24) and the interlocking pin (25)
And the interlocking pin (25) is connected to the output of the adjustment tool (18) in an interlocked manner, from the input (27) of the adjustment tool (18) to the input arm (24) of the control rod (19). A non-constant speed cam (C) is interposed in the power transmission system during the period of time, and the change of the amount of elevation of the control sleeve (16) with respect to the engine speed is rapidly changed from the idling rotation range to the low rotation range. A non-constant velocity cam (C) having a shape that changes gently between a high speed range and a high speed range.