JP2613491B2 - Injection timing fine adjustment device for flange mounted fuel injection pump of diesel engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an injection timing fine adjustment device for a flange-mounted fuel injection pump of a diesel engine.

<< Conventional Technology >> A conventional injection timing fine adjustment device for a flange-mounted fuel injection pump for a diesel engine is disclosed in
There is one disclosed in JP-A-18.

As shown in FIG. 8, the mounting surface 15 of the pump flange 8 of the fuel injection pump 7 with respect to the pump housing 2 is inclined with respect to a surface H orthogonal to the central axis C of the fuel injection pump 7. This is a method of moving the mounting position of the device to make it adjustable.

<< Problems to be Solved by the Invention >> The above prior art has the following problems.

As shown in FIG. 8, the fuel injection pump 7 is
When the fuel injection timing is adjusted by moving along the line D, the distance between the fuel injection pump 7 and the fuel injection cam shaft 6 changes. However, there is a problem that the performance is adversely affected, such as a decrease in output of the device or an increase in noise.

SUMMARY OF THE INVENTION It is an object of the present invention to solve such problems of the related art so that the fuel injection rate does not change when the fuel injection timing is finely adjusted.

<< Means for Solving the Problems >> In order to solve the above problems, the present invention, as shown in FIG. 1, for example, uses a pump body 9 of a fuel injection pump 7 to inject fuel from a pump insertion hole 3 of a pump housing 2. The fuel injection pump 7 is inserted toward the camshaft 6, and the pump flange 8 of the fuel injection pump 7 is orthogonal to the camshaft center T of the fuel injection camshaft 6 with respect to the mounting seat 4 formed on the outer surface of the peripheral wall 11 of the pump insertion hole 3. In the injection timing fine-adjustment device for a flange-mounted fuel injection pump of a diesel engine, which is fixed so as to be adjustable in the injection timing adjustment directions D to D, a seating surface 15 between the mounting seat 4 and the pump flange 8 is provided with a fuel injection device. An arcuate surface R that is convex toward the pump flange 8 along the rotation direction of the camshaft 6 is formed on the arcuate surface R of the seating surface 15.
The mounting seat 4 is formed as an independent part with respect to the pump housing 2 as an independent part, and is fixed by fixing means 17b. The flange 8 is formed in two halves, and the upper flange portion 8a of the two halves is formed integrally with the pump body 9, and the lower flange portion 19 is formed as an independent part with respect to the upper flange portion 8a. It is characterized in that it is formed separately, brought into contact with a plane, and fixed by fixing means 17a.

<< Operation / Effect of the Invention >> The present invention has the following operation / effect.

As shown in FIG. 1, when the fuel injection pump 7 is moved in the injection timing adjustment directions D to D to adjust the fuel injection timing, the fuel injection pump 7 is concentric with the cam shaft center T of the fuel injection cam shaft 6. Since it moves, the pre-stroke does not change and the fuel injection rate does not change. That is, even if the fuel injection timing is finely adjusted to any position, the distance between the fuel injection pump and the fuel injection cam shaft does not change, and the fuel injection rate can be kept constant.

Further, in the present invention, the mounting seat 4 is formed separately and fixed to the pump housing 2 as an independent part, and the pump flange 8 is formed in a vertically split shape, of which an upper flange portion 8a is formed as a pump body. 9 and the lower flange portion 19 is separately formed and fixed as an independent part to the upper flange portion 8a, so that the uneven surface is directly formed on the pump housing 2 and the pump flange 8. In comparison with the above, since the fuel injection pump 7 and the pump housing 2 can be used as they are in the conventional form, and the mounting seat 4 and the lower flange portion 19 can be processed and manufactured as parts, there is an advantage that the productivity is improved and the cost is reduced.

<< Example >> Hereinafter, an example of the present invention will be described with reference to the drawings.

1 to 7, reference numeral 1 denotes a crankcase of an engine, 2 denotes a pump housing formed integrally with the crankcase 1, 3 denotes a pump insertion hole opened at an upper portion of the pump housing 2, and 4 denotes a pump insertion hole. A mounting seat 5 formed on the outer surface of the peripheral wall 11 is a pump driving cam, 6 is a fuel injection cam shaft in which the pump driving cams 5 are arranged, and the fuel injection cam shaft 6 is connected to a crankshaft via a gear (not shown). It is configured to be able to rotate synchronously.

7 is a fuel injection pump, 8 is a pump flange for mounting the pump 7, 9 is a pump body, 10 is a tappet roller mounted on the bottom of the pump body 9, and the tappet roller 10 is the fuel injection cam shaft described above. Pump drive cam 5 accompanying rotation of 6
The pump element in the fuel injection pump 7 is operated following the vertical displacement of the pump.

In the embodiment shown in FIG. 1, the pump flange 8 is formed in an upper and lower halved shape, of which the upper flange portion 8a is formed integrally with the pump body 9 and the lower flange portion 19 is formed. Is formed separately as an independent part having an arcuate surface R which is concave toward the pump flange 8 along the rotation direction of the fuel injection camshaft 6 in the direction of rotation of the fuel injection camshaft 6, and is flat with respect to the upper flange portion 8a. And fixed with bolts 17a as fixing means as shown in FIG.

Further, the mounting seat 4 has its seating surface 15 formed as an independent component having an arcuate surface R protruding toward the pump flange 8 along the rotation direction of the fuel injection camshaft 6 and fixed separately. Pump housing 2 with bolt 17b as means
Fixed to

In this embodiment, the fuel injection pump 7 and the pump housing 2 can be used as they are in the conventional manner, as compared with the case where the uneven surface is directly formed on the pump housing 2 and the pump flange 8 as shown in FIG. And the lower flange portion 19 can be processed and manufactured as a part, so that there is an advantage that productivity is improved and cost is reduced.

Reference numeral 12 denotes a pump boss formed on the upper part of the pump flange 8, and a fuel delivery pipe 13 is connected to an upper surface thereof, and a fuel introduction pipe 14 is connected to a side face thereof.

The fuel injection pump 7 having such a configuration is inserted from the pump insertion hole 3 of the pump housing 2 toward the fuel injection camshaft 6 and is joined to the mounting seat 4 of the pump housing 2 at the seating surface 15 of the pump flange 8. , Pump flange 8
The fuel injection camshaft 6 can be moved in the injection timing adjustment directions D to D orthogonal to the camshaft center T by the elongated hole 18 as the adjustment movement permitting means with respect to the mounting seat 4, and also as the fixing means. The fuel injection pump 7 is fixed to the pump housing 2 by mounting bolts 17.

The mounting seat 4 and the seating surface 15 of the pump flange 8 are arcuate surfaces R that protrude toward the pump flange 8 along the rotation direction of the fuel injection camshaft 6, and define a center axis S of the arcuate surface R. The fuel injection camshaft 6 is formed so as to substantially coincide with the camshaft center T, and when the fuel injection timing is to be adjusted by an adjustment mechanism described later, the fuel injection pump 7 is moved in the injection timing adjustment directions D to D. Even if it moves, the distance between the fuel injection pump 7 and the fuel injection camshaft 6 does not change.

The adjustment mechanism is as follows, as shown in FIGS.

Numeral 20 denotes a crank angle scale engraved on the mounting seat 4, and a mark 21 provided on the pump flange 8 indicates an adjustment amount of the fuel injection timing.

Reference numeral 22 denotes an adjustment screw holding portion protruding from the pump housing 2, reference numeral 23 denotes an adjustment screw, reference numeral 24 denotes a fixing nut, and the tip of the adjustment screw 23 pushes the pump flange 8 to cause the fuel injection pump 7 to adjust the injection timing D to D.
You can move to D.

Reference numeral 25 denotes a slot-shaped movement restricting groove provided in the pump flange 8 and parallel to the injection timing adjustment directions D to D. Reference numeral 26 denotes a rectangular section provided to protrude from the mounting seat 4 and fitted to the movement restricting groove 25. With the movement restricting key, the movement restricting groove 25 and the movement restricting key 26 are slid on contacting surfaces to inject the injection timing adjusting directions D to D
It can be moved only to

When the fuel injection timing is to be adjusted by the above-described adjustment mechanism, the mounting bolt 17 for fixing the fuel injection pump 7 and the fixing nut 24 for fixing the adjustment screw 23 are loosened. Is read in accordance with the crank angle scale 20, the adjusting screw 23 is rotated to push the pump flange 8 to move the fuel injection pump 7 in the injection timing adjusting directions D to D. Then, the mounting bolt 17 and the fixing nut 24 are again And tighten.

In this case, in the related art, a long hole 18 as a means for allowing the adjustment movement of the pump flange 8 and a mounting bolt 17 as a fixing means are conventionally provided.
Since there is a play gap between the fuel injection pump 7 and the pump housing 2, there is a possibility that the fuel injection pump 7 may be mounted at an angle of rotation with respect to the pump housing 2, and the pump drive cam 5, the tappet roller 10, etc. may be unevenly worn and the fuel Although the injection timing may be out of order, in the present invention, the movement restricting groove 25 and the movement restricting key
26, the fuel injection pump 7 cannot be moved in any direction other than the injection timing adjustment directions D to D. Therefore, the fuel injection pump 7 is not attached with a rotation angle, and uneven wear does not occur. It can be adjusted and maintained accurately.

4 and 5 show another embodiment of the adjusting mechanism.

In this embodiment, an eccentric cam 27 and a fixing bolt 28 are provided instead of the adjusting screw holding portion 22, the adjusting screw 23 and the fixing nut 24.

The eccentric cam 27 has a small hole on its side as shown in FIG.
It is also possible to open the opening 27a and engrave a matching mark 21 on the upper surface, and engrave the crank angle scale 20 on the mounting seat 4 in accordance with the matching mark 21 on the eccentric cam.

When adjusting the fuel injection timing, the eccentric cam 27 is rotated by inserting the rotating rod 27b into the small hole 27a of the eccentric cam 27, and the pump flange 8 is pushed to move the fuel injection pump 7 in the injection timing adjustment direction D ~. After moving to D, the eccentric cam 27 is fixed with the fixing bolt 28.

FIG. 6 shows another embodiment of the adjusting mechanism, in which the fuel injection pump 7 is moved by a rack 29 provided at the end of the pump flange 8 and a pinion 30 provided on the mounting seat 4. It is.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an injection timing fine-adjustment device of a flange-mounted fuel injection pump for a diesel engine according to an embodiment of the present invention, and FIGS. 2 to 6 show an adjustment mechanism of the injection timing fine-adjustment device. 2 and 4 are longitudinal sectional views of the main part of the mechanism, FIGS. 3, 5, and 6 are plan views of the main part of the mechanism, and FIG. 7 is the fixing of the mounting seat and the pump flange. It is principal part sectional drawing which shows a state. FIG. 8 shows a conventional example and is equivalent to FIG. 2 ... Pump housing, 3 ... Pump insertion hole, 4 ...
Mounting seat, 6: fuel injection cam shaft, 7: fuel injection pump, 8: pump flange, 8a: upper flange portion,
9 ... pump body, 11 ... peripheral wall, 15 ... seating surface, 17.
17a / 17b: fixing means, 18: adjustment movement permitting means, 19 ...
... lower flange part, D to D ... injection timing adjustment direction, R
…… arc surface, S …… center axis, T… cam shaft center.

Continued on the front page (72) Inventor Yuzo Umeda 64 Ishizukita-machi, Sakai City, Osaka Prefecture Inside Kubota Sakai Works (72) Inventor Kazuyoshi Morioka 64 Ishizukita-machi, Sakai City, Osaka Prefecture 64 Inside Kubota Sakai Works, Ltd. Opened Showa 52-170918 (JP, U) Opened Showa 55-85560 (JP, U) Opened Showa 60-73845 (JP, U) Opened Showa 60-73846 (JP, U)

Claims (1)

(57) [Claims] 1. A pump body (9) of a fuel injection pump (7).
Is inserted from the pump insertion hole (3) of the pump housing (2) toward the fuel injection cam shaft (6), and the pump flange (8) of the fuel injection pump (7) is inserted into the peripheral wall of the pump insertion hole (3). (11) The fuel injection camshaft (6) is fixed to the mounting seat (4) formed on the outer surface so as to be adjustable in the injection timing adjustment direction (D to D) perpendicular to the camshaft center (T) of the fuel injection camshaft (6). In the fuel injection pump fine-adjustment device for a flange-mounted fuel injection pump of a diesel engine, the seating surface (15) between the mounting seat (4) and the pump flange (8)
Is formed on an arc surface (R) that protrudes toward the pump flange (8) along the rotation direction of the fuel injection cam shaft (6), and the center axis of the arc surface (R) of the seating surface (15) is formed. (S) is made substantially coincident with the camshaft center (T) of the fuel injection camshaft (6), and the mounting seat (4) is formed as an independent part with respect to the pump housing (2), and is fixed separately. (17b), and the pump flange (8) is formed into upper and lower halves,
The upper flange portion (8a) of the split shape is formed integrally with the pump body (9), and the lower flange portion (19) is separate from the upper flange portion (8a) as an independent part. , And abut on a flat surface to fix it (17
An injection timing fine-adjustment device for a flange-mounted fuel injection pump for a diesel engine, wherein the injection timing fine adjustment device is configured to be fixed in a).