JP2600256Y2 - Camshaft support structure for fuel injection pump - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camshaft support structure for a fuel injection pump which does not cause so-called slip on an outer ring of a bearing when hot.

[0002]

2. Description of the Related Art Generally, an in-line type fuel injection pump having a governor housing adjacent to a pump housing,
A camshaft support structure of a row type fuel injection pump in which a camshaft is fitted into a continuous opening of both housings and the camshaft is supported by a bearing at the opening is known (for example, Japanese Patent Laid-Open No. 62-26372). Gazette).

[0003] As shown in FIG. 2, this type of conventional device has an inner ring 55 b provided in an opening 53 of a pump housing 51.
Ring 5 of thrust bearing 55 in which cam shaft 57 is fitted
The governor housing 59 is press-fitted into the governor housing 59 so as to press the outer ring 55a thereon.
Are fixed to the pump housing 51 via fixing bolts 61. 63 is a gasket.

[0004]

In the conventional camshaft support structure constructed as described above, the outer race 5 of the thrust bearing 55 is not provided.
Since 5a is held by the shoulder 51a of the pump housing 51 and the shoulder 59a of the governor housing 59, there is a problem in that, when assembling the same, it is necessary to shim the axial gap.

When the housings 51 and 59 are made of aluminum, the bearing 55 and the camshaft 57 are made of cast iron. Therefore, the thermal expansion coefficients of the housings 51 and 59 are larger than those of the bearing 55, and A gap is formed in the outer ring 55a of the bearing 55 between the shoulders 51a and 59a when hot.
There is a problem that slip occurs.

If the outer ring 55a slips during the operation of the fuel injection pump, that is, when the fuel injection pump is hot, the life of the bearing 55 is shortened, and the fly weight 65a of the governor 65 moves, resulting in its durability. Is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bearing support structure for a fuel injection pump which solves the above-mentioned problems of the prior art and prevents the outer ring of the bearing from slipping when hot. .

[0008]

SUMMARY OF THE INVENTION To achieve the above object, the present invention is to mount a governor housing adjacent to a pump housing, and to press a governor housing into a continuous opening of both housings with a flange . Fit the flanged ring, press-fit the outer ring of the thrust bearing with the camshaft fitted to the inner ring into this ring, and do not abut the flanged ring of the iron bearing fixing plate that holds the outer ring of this thrust bearing. Thus, the bearing fixing plate is fixed to the pump housing via fixing bolts.

[0009]

According to the present invention, when thermal expansion occurs during operation,
If, looking at the Shin beauty radial thrust bearing, thrust
Elongation of bearing, ring of flanged ring and
Since the elongation substantially coincides with the elongation, no gap is formed in the radial direction. S
Looking at the axial extension of the last bearing, the pump housing
Ring with thrust, thrust bearing, bearing
The elongations of the fixing plate and the fixing bolt are almost the same. Provisional
Governor housing interposed between pump housing
If the coefficient of thermal expansion is larger than the others, it corresponds to the difference
The brim of the brim ring is pushed by
There is a gap between the flange of the bearing and the bearing fixing plate
The elongation is absorbed by this gap, so there is no gap in the axial direction.
No pauses occur. Therefore, the outer ring of the thrust bearing does not slip when hot, and its life is improved, and the flyweight of the governor does not move, so that its durability is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bearing support structure for a fuel injection pump according to the present invention will be described below with reference to FIG.

In FIG. 1, reference numeral 1 denotes a pump housing of a fuel injection pump. The pump housing 1 is made of aluminum and has a camshaft 3 made of cast iron inside.
Is supported. When the tappet 5 comes into contact with the cam 3 a of the camshaft 3 and the camshaft 3 is rotated, the cam 3
The plunger 7 moves up and down via the tappet 5 along the profile of a.

A governor housing 11 made of aluminum is mounted on the pump housing 1 with a gasket 9 interposed therebetween. The camshaft 3 is housed in the pump housing 1 through continuous openings 1a and 11a of the housings 1 and 11. Have been.

A continuous opening 1 of both housings 1 and 11
A ring 13 made of cast iron is fitted into the a and 11a so as to press the governor housing 11 from the outside with a collar 13a. A gap is formed between the ring 13 with the collar and the shoulder 1b of the pump housing 1. A minute gap δ in the axial direction
1 is provided.

The outer ring 15 of the self-aligning roller bearing 15 in which the camshaft 3 is fitted to the inner ring 15b
a into the outer ring 15a.
The bearing fixing plate 17 is fixed to the pump housing 1 via fixing bolts 19.

The outer ring 15a of the self-aligning roller bearing 15 constituting the thrust bearing is held between the shoulder 13b of the flanged ring 13 and the shoulder 17a of the bearing fixing plate 17. A small gap δ2 is provided in the axial direction between the flange 13a of the thirteen and the surface 17b of the bearing fixing plate 17.

Next, the order of assembly will be described.

First, the outer ring 15a of the self-aligning roller bearing 15 is press-fitted into the flanged ring 13 and its inner ring 15b
The camshaft 3 is fitted into the shaft and prepared as an assembly. Next, the governor housing 11 is brought into contact with the pump housing 1, and the prepared camshaft 3 is inserted into the continuous openings 1 a, 11 a of the two housings 1, 11 from the governor housing 11 side.

Then, a collar ring 13 is fitted into the openings 1a and 11a. At this time, the ring 13
The flange 13a is located inside the governor housing 11, and presses the governor housing 11 toward the pump housing 1.

Thereafter, the bearing fixing plate 17 is connected to the outer race 5a.
And fix the bearing fixing plate 17 to the fixing bolt 1.
9 to fix.

At the time of assembly, the self-aligning roller bearings 15,
The flanged ring 13 and the bearing fixing plate 17 are integrated.
And the fixing bolt 19 with the governor housing 11 in between.
More fixed to the pump housing 1, with a brim at this time
Face of the ring 13 collar 13a and bearings fixed plate 17 1
7b is δ2. Pump housing 1,
The governor housing 11 is made of aluminum and has a flange.
Ring 13, self-aligning roller bearing 15, bearing fixing play
And the fixing bolt 19 are made of iron. Therefore, the pump
Housing 1 and governor housing 11 are rings with flanges
13, self-aligning roller bearing 15, bearing fixing plate 17,
The coefficient of thermal expansion is larger than that of the fixing bolt 19, and it is easy to extend. operation
If thermal expansion occurs during operation, the diameter of the spherical roller bearing 15
Looking at the elongation in the direction, the elongation and
Elongation of collar ring 13 and elongation of bearing fixing plate 17
Therefore, there is no gap in the radial direction. Automatic adjustment
Looking at the axial expansion of the roller bearing 15, the pump housing
Ring 13 with collar, self-centering based on ring 1
Roller bearing 15, bearing fixing plate 17, fixing bolt 19
Each elongation of the pump housing 1
A governor housing 11 having a large coefficient of thermal expansion intervenes between them.
Therefore, the amount of the ring 13 with the collar corresponding to the difference
The ring 13a is pushed to the right in FIG.
13, the flange 13a and the surface 17b of the bearing fixing plate 17
There is a gap δ2 between the
Is absorbed, so that no gap is formed in the axial direction.

Therefore, even if there is thermal expansion during hot time, the outer ring 15a of the self-aligning roller bearing 15 does not slide, so that its life is improved and the fly weight 21a of the governor 21 does not move. Therefore, its durability is improved.

In this embodiment, the above-mentioned gap δ is set in advance.
Since 1 and δ2 are provided, a shim which has been conventionally used becomes unnecessary when the above-mentioned assembly is incorporated, and the number of parts can be reduced.

Furthermore, in the case of the conventional configuration, a bearing 15 having an outer diameter corresponding to the size of the openings 1a and 11a of both housings 1 and 11 is required. In this embodiment, the openings 1a and 11a are used. Since the collar ring 13 is interposed, the outer shape of the bearing 15 can be reduced by that amount, and the cost can be reduced.

Also, as in the prior art, the pump housing 1
In the type in which a bearing is press-fitted, a special tool is required for bearing press-fitting. In this embodiment, a bearing is press-fitted into a flanged ring 13 and the flanged ring 13 is Since it is fitted into the openings 1a and 11a, special tools are not required, and effects such as extremely easy disassembly and assembly can be obtained.

Although the present invention has been described based on one embodiment, it is apparent that the present invention is not limited to this. Then, other thrust bearings (for example, thrust fixed type of cylindrical roller bearings) are used for spherical roller bearings.
It goes without saying that the above may be applied.

[0026]

[Effects of the present invention] As is clear from the above description, the present invention
According to this, the outer ring of the thrust bearing does not slip when hot, and the flyweight of the governor does not move,
The durability of each can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a camshaft support structure according to the present invention.

FIG. 2 is a cross-sectional view showing a conventional camshaft support structure.

[Explanation of symbols]

 Reference Signs List 1 pump housing 1a opening 3 camshaft 11 governor housing 11a opening 13 flange ring 13a collar 15 self-aligning roller bearing 15a outer ring 15b inner ring 17 bearing fixing plate 19 fixing bolt

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02M 59/44 F16C 35/07 F02M 39/02

Claims (1)

(57) [Scope of request for utility model registration] 1. A governor housing is mounted adjacent to a pump housing, and an iron collar ring is fitted into a continuous opening of both housings so as to press the governor housing with a collar. Press the outer ring of the thrust bearing into which the shaft is fitted, and place the iron bearing fixing plate that presses the outer ring of the thrust bearing so that it does not abut against the brim of the flanged ring, and fix this bearing fixing plate to the pump housing. A camshaft support structure for a fuel injection pump fixed by bolts.