JPH05179997A - Lead angle adjusting method for fuel injection pump - Google Patents

Abstract

PURPOSE:To reduce a working load, and reduce adjusting miss of a lead angle. CONSTITUTION:In a fuel injection pump 1 provided with a pump driving gear 7 which is installed on the cam shaft 4 of the injection pump 1 in order to adjust the injection timing of the fuel injection pump 1 and being provided rotatably in a prescribed angle range, the pump driving gear 7 is rotated by a set angle in delay angle direction in relation to the cam shaft 4, and then it is fixed on the cam shaft 4. After that, the pump driving gear 7 is returned to the first rotational position to be rotated, and the cam shaft 4 is advanced relatively, and then the fuel injection pump 1 is assembled to an engine after that advancement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an advance angle adjusting method for adjusting the injection timing of a fuel injection pump used in a diesel engine or the like.

[0002]

2. Description of the Related Art Generally, in a diesel engine, fuel is injected just before the top dead center of a piston.
When attaching the fuel injection pump to the engine, it is necessary to advance the pump by a predetermined amount. Conventionally, such advance angle adjustment has been performed as follows.

As shown in FIG. 7, the fuel injection pump a has a pump body b in which a plunger, a cam shaft and the like are housed, a flywheel d attached to the end of the camshaft c, and a flywheel. It is composed of a pump drive gear screwed to d by a bolt e and f.
The bolt e has a long hole g formed in the pump drive gear f.
And is screwed to the flywheel d. Therefore, the pump drive gear f can adjust the mounting angle relative to the camshaft c within the range of the elongated hole g.

When adjusting the advance angle of the pump a, first, the bolt e is loosened to make the pump drive gear f rotatable with respect to the shaft c within the range of the elongated hole g. And FIG. 7 (c)
As shown in FIG. 5, the matching mark h engraved on the flywheel d of the fuel injection pump a and the matching mark i engraved on the pump body b are matched. At this time, the plunger (not shown) in the pump body b is set to be located at the top dead center. At this time, the tip j of the pump drive gear f
The gear mark k recessed in is located at the top of the gear f.

Next, as shown in FIG. 8, the matching marks h, i
Is set to the engine m. At this time, the pump drive gear f of the fuel injection pump a meshes with the ring gear o attached to the crankshaft n of the engine m. In the figure, h and i are match marks and k is a gear mark.

Next, as shown in FIG. 9, an arm-shaped dedicated handle p is attached to the ring gear o, and the crankshaft n is rotated by a specified advance angle while observing the advance scale q. Along with this, only the pump drive gear f meshed with the ring gear o rotates in the retard direction with respect to the pump cam shaft c. That is, only the pump drive gear f has the long hole g while the match mark h formed on the flywheel d of the pump a and the match mark i formed on the pump body b are aligned.
It rotates in the retard direction within the range. At this time, the gear mark k of the pump drive gear f rotationally moves counterclockwise in the figure.

In this state, the bolt e is screwed in and the pump drive gear f is fastened and fixed to the flywheel d. As a result, the ring gear o is reversely rotated and the pump drive gear f
When the gear mark k is returned to the initial rotation position (the uppermost part of the gear), the match mark h engraved on the flywheel d of the pump a is advanced from the match mark i engraved on the pump body b. Then, the lead angle is adjusted accordingly.

[0008]

However, in the pump advance adjusting method as described above, the fuel injection pump a is replaced by the engine m.
Since the crankshaft n of the engine m is rotated to shift the pump drive gear f with respect to the pump camshaft c, the crankshaft n having a large torque is mounted.
Had to be rotated via the dedicated handle p, and this work placed a heavy load on the worker.

Particularly, since the assembly of the automobile engine m of this type is usually a flow work by the belt conveyor, the advance angle adjustment of the fuel injection pump a is also performed on the belt conveyor. In other words, the crankshaft n
When the dedicated handle p is attached to and is rotated, it must be performed while checking the advance angle scale q of the engine m moving on the conveyor, and an error in the advance angle adjustment is likely to occur.

An object of the present invention, which has been devised in view of the above circumstances, is to provide a method for adjusting the advance angle of a fuel injection pump which has a small work load and can reduce misadjustment of the advance angle.

[0011]

To achieve the above object, the present invention provides a pump drive gear mounted on a camshaft of an injection pump so as to adjust the injection timing of the fuel injection pump so as to be rotatable within a predetermined angle range. In the fuel injection pump, the pump drive gear is rotated to the camshaft in the retard direction by the set angle, and then fixed to the camshaft,
After that, the pump drive gear is returned to the initial rotational position and rotated to relatively advance the camshaft, and after the advance, the fuel injection pump is assembled to the engine. This is the angle adjustment method.

[0012]

According to the above-mentioned advance angle adjusting method, the fuel injection pump is adjusted in advance and then mounted on the engine, so that the work load is small and the advance angle adjusting error can be reduced.

[0013]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

First, as shown in FIG. 1, the fuel injection pump 1
Is set on the jig 2. The fuel injection pump 1 includes a pump main body 3 in which a plunger, a cam shaft, etc. are housed, a flywheel 5 attached to an end of the camshaft 4, and a pump screwed to the flywheel 5 with bolts 6. It is composed of a drive gear 7. As shown in FIG. 4, the bolt 6 is inserted into an elongated hole 8 formed in a pump drive gear 7 and loosely screwed to the flywheel 5. Therefore, the pump drive gear 7 is rotatable relative to the camshaft 4 within the range of the elongated hole 8. In FIG. 4, 9 is a cam mountain and 10 is a plunger.

On the other hand, the jig 1 has a frame 11 on which the fuel injection pump 1 is mounted, as shown in FIGS. 1 (a) (b) (C).
And a lead angle adjusting portion 12 which is provided on the frame 11 so as to be freely drawn out and which substantially adjusts the lead angle of the pump 1. Specifically, when setting the fuel injection pump 1, set the fuel injection pump 1 on the frame 11 after pulling out the advance angle adjusting section 12 as shown by the dashed line in FIG. 1 (b). , The advance angle adjusting portion 12 is pushed toward the frame 11 side so that the pump driving gear 7 is inserted into and supported by the hole portion 13.

At this time, as shown in FIG. 2, the matching mark 14 engraved on the flywheel 5 of the pump 1 and the pump body 2
It is made to coincide with the match mark 15 engraved on. At this time, the plunger 10 in the pump body 2 is set so as to be located at its top dead center, and the gear mark 16 recessed at the tooth tip of the pump drive gear 7 is located at the uppermost part of the gear 7. It has become.

Next, as shown in FIG. 3, the fuel injection pump 1
Only the pump drive gear 7 is rotated in the retard direction 17 with respect to the camshaft 4 of the pump 1 by a predetermined angle. That is,
Without rotating the camshaft 4, flywheel 5 and bolt 6 of the pump 1, only the pump drive gear 7 is rotated within the range of the elongated hole 8 in the retard direction 17 by a specified angle. Then, the claw member 18 of the jig 2 is hooked on the tooth portion of the pump drive gear 7 to fix the drive gear 7. At this time, the gear mark 16 of the pump drive gear 7 is located beside the claw member 18. This gear mark 16 is provided from the top of the gear 7 to the claw member 1
The rotation angle that moves to the side of 8 is the advance angle angle to be adjusted.

As shown in FIG. 1, one end of the claw member 18 is attached to the advance angle adjusting section 12 of the jig 2 by a pin 19, and the other end of the claw member 18 is attached to the pump drive gear 7 by rotating. It is supposed to be meshed. After the engagement, the pawl member 18 is pressed from above by the pressing bolt 20 to completely prevent the rotational movement of the pump drive gear 7 and position it.

After that, the bolt 6 is screwed in and the pump drive gear 7 is fastened and fixed to the flywheel 5. Then, the pump 1 is removed from the jig 2, and the pump drive gear 7 is returned and rotated 21 (advancing direction) so that the gear mark 16 of the pump drive gear 7 is again located at the uppermost portion of the gear 7 as shown in FIG. .. Along with this, the flywheel 5 of the pump 1 fastened to the pump drive gear 7 by the bolt 6 also rotates in the advance direction 21 with respect to the pump body 2, and the advance adjustment is achieved. That is, the fuel injection pump 1 is advanced from the top dead center position of the plunger 10 by the phase difference 22 in FIG. 5 (b).

After the advance angle of the fuel injection pump 1 is adjusted in this way, the pump 1 is moved to the engine 23 as shown in FIG.
The drive gear 7 of the pump 1 is engaged with the ring gear 25 attached to the crankshaft 24 of the engine 23. At this time, the crankshaft 24 of the engine 23 is in the advance angle zero, that is, the piston top dead center position, as shown by the advance angle scale 26. As a result, when the engine 23 is at the piston top dead center position, the pump 1 is advanced from the top dead center of the plunger by the phase difference 22, and the advance adjustment is achieved.

As described above, the fuel injection pump 1 is mounted on the engine 23 after the advance angle is adjusted in advance by using the jig 2, so that the work load on the advance angle adjustment worker is reduced and the advance angle is adjusted. Misadjustment of the angle can be reduced.

Incidentally, as a related technology, the actual development is 55-85562.
However, this technique is to adjust the injection timing after the fuel injection pump is attached to the engine, and the technical idea is different from the present invention.

[0023]

As described above, according to the method for adjusting the advance angle of the fuel injection pump according to the present invention, it is possible to exert the excellent effects that the work load is small and the misadjustment of the advance angle can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a jig used in a method for adjusting the advance angle of a fuel injection pump as one embodiment of the present invention and a fuel injection pump set on the jig, (a) being a side view,
(b) is a front view and (c) is a plan view.

2A and 2B are diagrams showing a first step of the method for adjusting the advance angle of the fuel injection pump, wherein FIG. 2A is a front view of the pump and FIG. 2B is a side view.

3A and 3B are diagrams showing a second step of the method for adjusting the advance angle of the fuel injection pump, wherein FIG. 3A is a front view of the pump and FIG.

FIG. 4 is an explanatory view of a main part of the fuel injection pump, (a)
Is a front view and (b) is a side sectional view.

5A and 5B are diagrams showing a third step of the method for adjusting the advance angle of the fuel injection pump, wherein FIG. 5A is a front view of the pump and FIG. 5B is a side view.

6A and 6B are diagrams showing a fourth step of the method for adjusting the advance angle of the fuel injection pump, wherein FIG. 6A is a plan view of the pump, and FIG. 6B is a front view of the pump and the engine.

FIG. 7 is a diagram showing a first step of a conventional method for adjusting the advance angle of a fuel injection pump, in which (a) is a front view of the pump and (b) is a side view.

FIG. 8 is a view showing a second step of the conventional method for adjusting the advance angle of the fuel injection pump, and is a front view of the engine and the pump.

FIG. 9 is a view showing a third step of the conventional method for adjusting the advance angle of the fuel injection pump, and is a front view of the engine and the pump.

[Explanation of symbols]

 1 Fuel Injection Pump 2 Jig 4 Cam Shaft 6 Bolt 7 Pump Drive Gear 8 Long Hole 23 Engine

Claims (1)

[Claims] 1. A fuel injection pump in which a pump drive gear attached to a camshaft of the injection pump is provided so as to be rotatable within a predetermined angle range in order to adjust the injection timing of the fuel injection pump. After rotating it by a set angle in the retard direction, fix it on the camshaft, then return this pump drive gear to the initial rotation position and rotate it to advance the camshaft relatively, and then move the fuel injection pump after the advance. A method for adjusting the advance angle of a fuel injection pump, characterized in that it is mounted on an engine.