JPH07643Y2 - Camshaft thrust receiving device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a device for receiving thrust (thrust) generated in a camshaft used in an internal combustion engine or the like.

<Prior Art> The cam shaft is provided on the cylinder head 3 of the internal combustion engine 2 on the bearing member 4, like the cam shaft 1 in FIG.
4'is rotatably supported and is rotated by a crank shaft (not shown) via a power transmission member such as a chain wheel 6 and a chain 7 fixed to the end of the cam shaft 1 by bolts 5, The intake / exhaust valves 8 and 9 provided in the cylinder head 3 are opened and closed by the portion 1a.

The cam shaft 1 uses a helical gear instead of the chain wheel 6, and a suction member that contacts a plurality of cam portions 1a,
Thrust is generated in the axial direction by the reaction force of the exhaust valves 8 and 9.

In order to suppress this, (1) as shown in FIG. 7, attach the end of the journal portion 1b of the camshaft 1 to the bearing member 4 with a small screw.
Stopper member 11 fixed as 10 as a thrust receiving member
And (2) the journal portion of the camshaft 1 as shown in FIGS. 4 to 6.
One flange 12 is provided on 1b, and the bearing member side,
That is, the upper bearing member 13 and the lower bearing member 14 form a thrust receiving member by forming angular grooves 13a and 14a in which the flange 12 can be inserted and rotated with a small clearance, and a bolt 15 inserted into the upper bearing member 13 is formed. By screwing the lower bearing member 14 to both bearing members 13,
(3) A flange that faces the thrust bearing surface of the bearing member to two cam shafts connected by gears, as in the thrust bearing structure shown in Japanese Utility Model Laid-Open No. 62-76205. And the hydraulic chambers are formed on both sides of the flange in the cam axis direction with the thrust bearing surface of the opposing bearing member, and the hydraulic chambers on both sides of both flanges of both cam shafts have the same pressure behavior between the cam shafts. Connect each other by connecting passages, and connect these connecting passages to the oil supply source through the check valve so that the oil can flow only in the direction from the oil supply source to the hydraulic chamber. There is a device in which the axial displacement is absorbed by the hydraulic pressure in the hydraulic chamber.

<Problems to be Solved by the Invention> However, both (1) and (2) described above have the drawback that they require many highly accurate machining operations, which significantly increases the machining cost.

That is, in the above (1), the journal portion of the camshaft 1
It is necessary to process the end surface of 1b, the end surface of the bearing member 4, and both side surfaces of the stopper member 11 with high accuracy.

Further, in the above (2), as shown in FIG. 6, the journal portion 1b () of the cam shaft 1 and both side surfaces of the flange 12 (,
) And the outer peripheral surface (), the upper and lower bearing members 13, 14 of the square groove 13
Both inner side surfaces (a) and (a) and inner peripheral surface () of a and 14a, and the recesses () facing the journal portion 1b in the upper and lower bearing members 13 and 14 and the like need to be processed with high accuracy,
In particular, it is difficult to machine the square grooves 13a and 14a.

Further, in the above (2), when the cam shaft 1 is assembled on the cylinder head 3, the intake and exhaust valves 8 and 9 are already assembled, so that the cam nose (Cam) of the cam portion 1a of the cam shaft 1 is mounted. Nose) contacts either of the intake and exhaust valve springs of the exhaust valves 8 and 9 and presses them down, so that this part receives a reaction force upward, and the part that does not receive such a reaction force is reversed. When the cam shaft 1 is depressed, the cam shaft 1 is bent and the flange 12 is inclined with respect to the vertical line. When the flange 12 is inserted into the square grooves 13a and 14a in this state, the inner side surface of the square groove 14a is damaged by the corner formed by one side surface of the flange 12 and the outer peripheral surface, and the flange is formed after the camshaft 1 is assembled. 12 outer surface and square groove 14
There is a possibility that the inner surface of a may partially contact and the rotation of the cam 1 may become unsmooth, or noise may be generated.

Further, in the case of the above (3), there is a problem that it cannot be realized unless the cam shaft has two axes, and the structure is complicated and the cost is high.

The present invention has been devised in view of the above, and in particular, the machining cost is reduced by omitting highly accurate machining on the bearing member side.
Another object of the present invention is to provide a camshaft thrust receiving device in which the mounting bolts for connecting the upper and lower bearing members are also used as the thrust receiving member to downsize the bearing member and simplify the assembly.

<Means for Solving Problems> A structure of the present invention for achieving the above-mentioned object is a pair of flanges formed in parallel with each other with a space provided on a cam shaft, and a lower support for rotatably supporting both flanges. A bearing member, an upper bearing member that covers both flanges, and a mounting bolt that mounts the upper bearing member to the lower bearing member, and at least one of the bolts is inserted with a slight gap left between the flanges. It's a brutal thing.

<Operation> Since the thrust receiving device of the present invention has the above-described structure, the inner surfaces and outer peripheral surfaces of the flanges 21 and 22 and the outer diameter surface of the journal portion 20b of the cam shaft 20 can be easily formed by a bite or the like. Can be finished. Also, mounting bolt 2
5 and 26 are machined bolts, and in particular, the stem portion of the bolt 26 is finished with the same precision as the flanges 21 and 22.

In the upper and lower bearing members 24 and 23, the recesses 24a and 23a () and the insertion holes 24b () of the mounting bolts 26 are finished to the same degree as above.

Then, first, on the cylinder head 3 on which the camshaft 20 is sucked and the exhaust valves 8 and 9 are assembled, the flanges 21 and 22 are inserted into the recesses 23a of the lower bearing member 23, and then the flanges 21 and 22 are covered. Place the upper bearing member 24 on the lower bearing member 23, and
5 and 26 are inserted into the bolt holes 24b to screw the tip screw portions 25a and 26a into the screw holes 23b. At this time, mounting bolt 26
Is inserted and tightened between the flanges 21 and 22.

As a result, even when the internal combustion engine rotates and a thrust force acts on the camshaft 20, the thrust force is transmitted from the inner surface of the flange 21 or 22 to the mounting bolt 26 and absorbed by a slight movement.

<Embodiment> The thrust receiving device of the present invention will be described in detail with reference to FIGS. 1 to 3. Reference numeral 20 denotes a cam shaft of the present invention in which a plurality of cam portions 20a are formed, and its journal portion 20b has a mounting bolt 26 to be described later.
With a gap so that they can intervene leaving a slight gap,
A pair of flanges 21 and 22 are formed at right angles to and parallel to the axis.

23 is a recessed portion 23 that rotatably supports both flanges 21 and 22.
In the lower bearing member having a formed therein, as shown in the figure, the recess 23a is formed in the cylinder head 3 to serve also as the lower bearing member 23. However, the lower bearing member may be mounted on the cylinder head 3 as an independent member. May be.

Reference numeral 24 denotes an upper bearing member having a recess 24a formed to cover both the flanges 21 and 22, and mounting bolts 25 and 26 are respectively inserted into the bolt holes 24b at both ends thereof so that the tip screw portions 25a and 26a are attached to the lower bearing member 2 respectively.
The upper bearing member 24 is attached to the lower bearing member 23 by screwing it into the screw hole 23b formed in 3, and at this time,
The book 26 is inserted into the space S between the utilization flanges 21 and 22.

As shown in FIG. 3, for the flanges 21 and 22,
The inner surface and the outer peripheral surface of the cam shaft 20 and the outer surface of the jar part 20b of the cam shaft 20 are the same as those described in the sixth item.
It has the same finishing accuracy as that shown in Figures 1 to 6, but is easily finished. The mounting bolts 25 and 26 are machined bolts, and in particular, the stem portion of the bolt 26 is finished in the same manner as above.

Regarding the upper and lower bearing members 24 and 23, the recesses 24a and 23a ()
And the insertion holes 24b () of the mounting bolts 26 are
It is finished to the same extent as.

In the thrust receiving device of the present invention constructed as described above, the camshaft 20 (flange 21, 22
], Upper and lower bearing members 24, 23 and mounting bolts 25, 26
First, the camshaft 20 is sucked in as shown in FIG. 7, and the exhaust valves 8 and 9 are used.
On the assembled cylinder head 3, the flange 21,
22 into the recess 23a of the lower bearing member 23, and then the flange 22
The upper bearing member 24 is placed on the lower bearing member 23 so as to cover, and the mounting bolts 25 and 26 are inserted into the bolt holes 24b, and the tip screw portion 25
The a and 26a are screwed into the screw hole 23b. At this time, the mounting bolt 26 is inserted into the space S between the flanges 21 and 22 and tightened.

As a result, even when the internal combustion engine rotates and a thrust force acts on the camshaft 20, the thrust force is transmitted from the inner surface of the flange 21 or 22 to the mounting bolt 26 and absorbed by a slight movement.

<Advantages of the Invention> In the thrust receiving device of the present invention, the pair of flanges formed in parallel with each other with the cam shafts spaced from each other as described above, the lower bearing member rotatably supporting the both flanges, and the both flanges. An upper bearing member for covering the upper bearing member and a mounting bolt for mounting the upper bearing member on the lower bearing member, and at least one of the bolts is inserted with a slight gap between the flanges. High-precision machining on the bearing member side is omitted to reduce machining cost, and the mounting bolts that connect the upper and lower bearing members can be inserted with a slight gap left between the flanges. There is also an effect that size reduction and simplification of assembly can be achieved.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view of a thrust receiving device of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is an enlarged view of a main part of FIG. 1, and FIG. Horizontal sectional view of thrust receiving device,
FIG. 5 is a sectional view taken along the line BB in FIG. 4, and FIG. 6 is an enlarged view of a main part of FIG. 4, and FIG. 7 is a vertical section near a cam shaft of an engine equipped with a conventional thrust receiving device. It is a side view. 20: cam shaft according to the present invention, 20a: cam portion, 20b: journal portion, 21, 22; flange, 23; lower bearing member, 24; upper bearing member, 25, 26; mounting bolts.

Claims (1)

[Scope of utility model registration request] 1. A pair of flanges formed on a cam shaft in parallel with each other at intervals, a lower bearing member for rotatably supporting the both flanges, an upper bearing member for covering the both flanges, and the upper bearing. A thrust receiving device for a camshaft, comprising a mounting bolt for mounting a member on the lower bearing member, and at least one of the bolts being inserted with a slight gap between the flanges.