JPH10176509A - Cam follower device for valve train of engine and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: To prevent line contact between an axial end surface of a roller (10) and a pair of support plates (7, 7) provided on a rocker arm (3). Then, occurrence of abnormal wear and poor lubrication is prevented. SOLUTION: Inner side surfaces of a pair of support plate portions 7 are inclined surfaces 14,14. Both ends of the shaft 8 supporting the roller 10 are swaged and widened, and the two inclined surfaces 14 are made parallel to each other in a state where the interval between the two support plate portions 7 is reduced. As a result, both the inclined surfaces 14, 14 and the roller 10
Surface contact with the end face in the axial direction, and abnormal wear can be prevented.
Further, the gap between the inclined surfaces 14, 14 and the axial end surface of the roller 10 is prevented from being partially narrowed, and the roller 1
The lubricating oil can be smoothly taken into the inside of the cylinder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A cam follower for a valve train of an engine, which is an object of the present invention, is incorporated in a valve train of an engine used for running an automobile, etc., to reduce friction of the valve train. Thus, the fuel consumption rate during engine operation is reduced. The present invention is intended to improve the lubricity in such a cam follower for a valve train of an engine, thereby improving the durability of the constituent members.

[0002]

2. Description of the Related Art There are various types of engines used for driving automobiles and the like. In the case of a reciprocating piston engine, except for some two-cycle engines,
All are provided with intake and exhaust valves that open and close in synchronization with the rotation of the crankshaft. Conventionally, there are various types of valve operating mechanisms for driving the intake valve and the exhaust valve. For example, the SOHC type shown in FIG. 4 will be described. In this valve mechanism, the intake valve 4 and the exhaust valve 5 reciprocate through the rocker arms 3 and 3 by one camshaft 2 rotating at half the speed of the crankshaft 1 (in the case of a four-cycle engine). Drive.
The cams 6, 6 fixed to the camshaft 2 reciprocally drive the intake valve 4 and the exhaust valve 5 while slidingly contacting the ends of the rocker arms 3, 3.

In recent years, the frictional force between the peripheral surfaces of the cams 6 and 6 and the opposing parts of the opposing members such as the rocker arms 3 and 3 during engine operation has been reduced to reduce the fuel consumption rate during engine operation. In order to reduce the size, a cam follower device that rotates with the rotation of the cams 6 and 6 is provided in the facing portion. Conventionally, such a cam follower device is disclosed in, for example, Japanese Utility Model Laid-Open No. 3-12700.
No. 4, JP-B-4-44803, 6-236
Nos. 86 and 6-25606 are known. FIGS. 5 and 6 show actual open square 3-1 of these.
No. 27004 is described.

At the end of the rocker arm 3 facing the cam 6, a pair of support plates 7, 7 are provided at an interval from each other. Then, both ends of the shaft 8 are supported and fixed to these two support plate portions 7 and 7. A short cylindrical roller 10 is provided around the shaft 8 via rollers 9 and 9. The outer peripheral surface of the roller 10 and the outer peripheral surface of the cam 6 are brought into contact with each other so that the roller 1
0 rotates around the axis 8. The shaft 8 is often hollow as shown in the figure to reduce the weight. By providing such a roller 10 and changing the friction between the cam 6 and the member opposed thereto from the sliding friction to the rolling friction,
Fuel consumption rate is reduced.

In order to assemble the conventional cam follower for a valve operating mechanism of an engine configured and operated as described above, in order to support and fix both ends of the shaft 8 to the pair of support plates 7, 7, first, The constituent members are arranged as shown in FIG.
That is, the roller 10 and the rollers 9, 9 are inserted between the pair of support plate parts 7, 7. The rollers 9 and 9 are adhered to the inner peripheral surface of the roller 10 with lubricating and sticky grease. Further, in the illustrated example, annular thrust washers 11, 11 are arranged at positions on the inner peripheral surfaces of both ends of the roller 10 so as to sandwich the rollers 9, 9 from both sides in the axial direction. Each of the thrust washers 11, 11 made of hard metal such as steel, and each of the above-mentioned support plates 9 and 9 made of a hard metal such as bearing steel, has end faces made of a soft metal such as an aluminum alloy. It is provided to prevent the inner surfaces of the portions 7, 7 from abrading the inner surfaces.

The above members 9-1 combined in the above manner
1 is inserted between the pair of support plates 7, 7, and the support holes 1, which are formed concentrically in the support plates 7, 7, respectively.
If the centers of the rollers 2 and 12 are aligned with the center of the roller 10, the support holes 12 and 12 and the roller 10
The shaft 8 is inserted through the inside. Then, with both ends of the shaft 8 positioned in the pair of support holes 12, 12,
A punch is pressed against both end surfaces of the shaft 8. Then, based on this pressing, the outer peripheral edges of both ends of the shaft 8 are plastically deformed diametrically outward, and the contact pressure between the outer peripheral surfaces of both ends of the shaft 8 and the inner peripheral surfaces of the support holes 12 and 12 is reduced. Then, both ends of the shaft 8 are supported and fixed inside the support holes 12, 12. That is, the outer peripheral edges of both ends of the shaft 8 are swaged and widened in a direction in which the outer diameter increases toward the edge. Then, the outer peripheral surface of the swaged portion and each of the support holes 12, 1
2. The chamfered portions 13, 13 formed on the edge of the opening 2 are strongly contacted.

[0007]

In the case of a conventional cam follower for a valve train of an engine which is assembled as described above and constructed and operates as described above, a pair of support plates 7 and 7 are provided with a shaft 8. When both ends of the roller are supported and fixed, there is a possibility that one or both of the support plate portions 7, 7 and the roller 10 may be worn. This reason will be described with reference to FIG.

When the both ends of the shaft 8 are positioned inside the support holes 12 and 12 and both ends of the shaft 8 are swaged,
The outer peripheral surface of the swaged portion and each of the support holes 12, 1
Based on the contact with the chamfered portions 13 formed on the edge of the opening 2, a force is applied in a direction in which the pair of support plate portions 7 are brought closer to each other. The pair of support plates 7, 7, which are made of a soft metal such as an aluminum alloy and whose free end is a free end whose free end is not restricted by other parts, is easily deformed. For this reason, based on the above-mentioned force, each of these support plate parts 7, 7
As shown exaggeratedly in (A), the tip tends to be inclined and deformed in a direction approaching each other toward the tip end (the upper end in FIG. 8A). In particular, each of the support plate portions 7 is a fixed end whose base end is fixedly connected to the main body of the rocker arm 3 and each end is a free end which is not restrained by other portions. In the case of the cantilever type, such deformation tends to be large.

When such a deformation occurs, the peripheral edge of the inner surface on the front end portion of one of the support plates 7 comes into line contact with the axial end surface of the roller 10, and the soft support plates 7, 7 are easily worn. Become. Further, the gap between the inner side surface of each of the support plate portions 7, 7 and both end surfaces in the axial direction of the roller 10 is partially narrowed. Therefore, depending on the lubrication structure of the engine, the gap between the rollers 9, 9 may be reduced. Lubricating oil supply to the installation portion may not be performed smoothly. Further, when the deformation is remarkable, the inner surfaces of the tip portions of the pair of support plates 7, 7 are fixed to the rollers 1
0 may be pinched from both sides in the axial direction, and the rotation of the roller 10 may be deteriorated. The cam follower apparatus for a valve train of an engine and the method of manufacturing the same according to the present invention have been invented in order to eliminate any of these disadvantages.

[0010]

A cam follower for a valve operating mechanism of an engine according to the present invention is, like the conventional cam follower for a valve operating mechanism of an engine described above, a camshaft which rotates in synchronization with a crankshaft of the engine. A cam fixed to the cam and a displacement member provided opposite to the cam and displaced by the movement of the cam are formed at an interval, and their respective base ends are fixedly connected to the main body of the displacement member. A pair of support plates, each of which has a fixed end and a free end whose free end is not restrained by another portion, and both ends are internally fitted into mutually concentric support holes formed in the pair of support plates. Further, the outer peripheral edges of both ends are plastically deformed diametrically outward, so that the shaft is fixed in a state of being bridged between the pair of support plate portions, and is rotatably supported around the shaft. Short cylindrical Consisting of a roller.

In particular, in the cam follower device for the valve operating mechanism of the engine according to the first aspect, the outer peripheral edges of both ends of the shaft are provided at least on the inner surfaces of the pair of support plate portions facing each other at a position near the front end. In a state before the portion is plastically deformed outward in the diametrical direction, an inclined surface is formed in which the interval becomes narrower toward the base end of each of the support plate portions. The inclined surfaces are made substantially parallel to each other on the basis of the deformation of the pair of support plates caused by the plastic deformation of the outer peripheral edges of both ends of the shaft in the diametrically outward direction.

A method of manufacturing a cam follower for a valve operating mechanism of an engine according to a second aspect of the present invention is the same as the method of manufacturing a cam follower for a valve operating mechanism of an engine described above. The base end portion is provided opposite to a cam fixed to a rotating camshaft, and is formed with an interval between displacement members that are displaced by the movement of the cam. A pair of concentric support holes formed in a pair of support plates, each of which is a fixed end that is fixed and fixed, and each end is a free end that is not restrained by another portion, between the pair of support plates. After the shaft is inserted through the inside of the arranged short cylindrical roller, both ends of the shaft are plastically deformed diametrically outward to support both ends of the shaft inside the above-described support holes. Solid To.

In particular, in the method of manufacturing a cam follower device for an engine valve operating mechanism according to the second aspect, at least a portion of the inner surfaces of the pair of support plate portions facing each other near the front end is formed of the shaft. Before the ends are plastically deformed diametrically outward, the inclined surfaces are formed such that the distance between them becomes smaller toward the base end of each support plate. Then, the above-mentioned 1 accompanying the plastic deformation of both ends of the shaft in the diametrically outward direction.
The respective inclined surfaces are made substantially parallel to each other based on the deformation of the pair of support plate portions.

[0014]

According to the cam follower apparatus for a valve train of an engine and the method of manufacturing the same according to the present invention, the inner peripheral surface of the pair of support plates at the front end and the axial end face of the roller are linear. This prevents the contact or the inner surfaces of the distal ends of the two support plates from sandwiching the roller from both sides in the axial direction. That is, in order to rotatably support the roller between the pair of support plate portions, both ends of a shaft passing through the inside of the roller are plastically deformed diametrically outward, and the pair of support plate portions are deformed. Is deformed, the inclined surfaces formed on the inner surfaces of both support plate portions become parallel. For this reason, the inconvenience of the above-mentioned line contact or pinching of the roller by both support plate portions does not occur.

[0015]

FIG. 1 shows a first embodiment of the present invention. It should be noted that a feature of the present invention is that a pair of support plate portions 7 provided at an end of the rocker arm 3, which is a displacement member,
When the assembling work for rotatably supporting the roller 10 between the rollers 7 is completed, the peripheral edge portions on the inner side surfaces at the distal end portions of the support plates 7 and 7 and the both axial end surfaces of the roller 10 are in line contact (edge). ). The other parts are the same as those in the conventional structure or the conventional method described above, so that illustration and description of the equivalent parts are omitted or simplified, and the following description will focus on the characteristic parts of the present invention.

The rocker arms 3 are cantilevered at the ends thereof and are formed so as to face each other.
As shown in FIG. 1 (A), the inner side surfaces of the pair of support plate portions 7 and 7 are formed before the outer peripheral edges at both ends of the shaft 8 (see FIG. 1 (B)) are plastically deformed radially outward. In this state, the slopes 14, the spacing of which becomes smaller toward the base end of each of the support plates 7, 7,
It is set to 14. For this reason, in the case of the present example, the thickness of each of the support plates 7, 7 is reduced toward the front end (the upper end in FIG. 1), and the support plates 7, 7 are wedge-shaped. It is formed in a shape.

The inclination angle θ of each of the inclined surfaces 14, 14 is:
It is regulated in accordance with the amount of deformation of each of the support plates 7, 7 caused by plastically deforming both ends of the shaft 8. In other words, as shown in FIG. 8 (A), the distal ends of the support plates 7, 7 are each δ by plastically deforming both ends of the shaft 8 radially outward. Displace in directions approaching each other.
The inclination angle θ is controlled so that the tip portions of the support plates 7 are offset by δ in a direction approaching each other, and the inclined surfaces 14 are regulated so as to be substantially parallel to each other.

Since the inner side surfaces of the support plates 7, 7 are formed as such inclined surfaces 14, 14, both the support plates 7, 7 are provided.
In order to rotatably support the roller 10 between them, when the pair of support plates 7, 7 are deformed by plastically deforming both ends of the shaft 8 radially outward, The inclined surfaces 14 are substantially parallel to each other. Therefore, the roller 10 is in the axial direction {right and left direction in FIG. 1 (B)}.
When the axial end surface of the roller 10 comes into contact with the inner surface of any of the support plate portions 7, the contact state is a surface contact. As a result, no significant abrasion occurs on the inner surface of each of the support plates 7,7.

Further, since the gap between the inner surface of each of the support plates 7, 7 and both end surfaces in the axial direction of the roller 10 is substantially uniform over the entire circumference, regardless of the lubrication structure of the engine. Through this gap, sufficient lubrication oil can be smoothly supplied to the rotation supporting portion of the roller 10. Therefore, the durability of the cam follower device for the valve train of the engine can be sufficiently ensured. Furthermore, the inner surfaces of the distal end portions of the pair of support plates 7, 7 sandwich the roller 10 from both sides in the axial direction, and the rotation of the roller 10 is not deteriorated.

FIG. 2 shows a second embodiment of the present invention.
An example is shown. In the case of this example, a pair of support plate portions 7,
The thickness of the support plate 7, 7 is made substantially uniform from the base end (the lower end in FIG. 2) to the tip, and the entire support plate 7, 7 is inclined in such a direction that the interval becomes wider toward the tip. The other configurations and operations are the same as those of the first example described above, and therefore, the same parts are denoted by the same reference numerals, and redundant description will be omitted.

Next, FIG. 3 shows a third embodiment of the present invention.
An example is shown. In the case of this example, a pair of support plate portions 7,
7, the inclined surfaces 14a, 14
a. In order to rotatably support the roller 10 between the pair of support plates 7, 7, both ends of the shaft 8 are plastically deformed diametrically outward, and the pair of support plates 7 , 7 are deformed, the inclined surfaces 14
a and 14a are substantially parallel to each other. Therefore, also in the case of this example, the same operation and effect as in the case of the above-described first example can be obtained.

Further, in the case of the present embodiment, the roller 10 is rotatably supported between the pair of support plates 7, 7 and the inner side surfaces of the support plates 7, 7 are used for the above described operation. There are gaps 15, 15 between the portions closer to the base end than the inclined surfaces 14 a, 14 a and both end surfaces in the axial direction of the roller 10 than in the first and second examples described above. That is, in order to prevent the amount of displacement of the roller 10 in the axial direction from becoming excessive, both end surfaces in the axial direction of the roller 10 and the inclined surfaces 14 and 14 opposite to both end surfaces (see FIGS. 1 and 2). In the case of the first and second examples), 14a, 14a (the third
Distance in the example) cannot be too large. Therefore,
In the case of the first and second examples, the area of the flow path for taking in the lubricating oil inside the roller 10 is limited to some extent. On the other hand, in the case of this example, the pair of inclined surfaces 14a, 14
a is brought close to both axial end surfaces of the roller 10 to suppress the displacement of the roller 10, secure the area of the gaps 15, 15, and form a flow path for taking lubricating oil into the inside of the roller 10. The area can be secured. As a result, lubricating oil can be more smoothly supplied to the rotation supporting portion of the roller 10, and the durability of the cam follower device for the valve operating mechanism of the engine can be further improved.

[0023]

As described above, the cam follower apparatus for a valve train of an engine and the method of manufacturing the same according to the present invention are constructed and operated as described above, and therefore do not cause significant wear, poor lubrication, and poor roller rotation. , Excellent durability and reliability can be secured.

[Brief description of the drawings]

FIG. 1 shows a first example of an embodiment of the present invention;
(A) is a cross-sectional view of the end of the rocker arm before mounting the roller and the shaft, and (B) is a cross-sectional view of the end of the rocker arm mounted with the roller and the shaft.

FIG. 2 shows a second example of the embodiment of the present invention,
(A) is a cross-sectional view of the end of the rocker arm before mounting the roller and the shaft, and (B) is a cross-sectional view of the end of the rocker arm mounted with the roller and the shaft.

FIG. 3 shows a third example of the embodiment of the present invention,
(A) is a cross-sectional view of the end of the rocker arm before mounting the roller and the shaft, and (B) is a cross-sectional view of the end of the rocker arm mounted with the roller and the shaft.

FIG. 4 is a schematic perspective view showing an example of a valve train of the engine.

FIG. 5 is a sectional view showing an example of a conventional cam follower device for a valve train of an engine.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is a sectional view showing a state in which the cam follower device for the valve operating mechanism of the engine is assembled.

FIG. 8 shows a support plate portion deformed during assembly.
(A) is a view similar to (B) of FIGS. 1 to 3, and (B) is (A).
The figure seen from the side of.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crankshaft 2 Camshaft 3 Rocker arm 4 Intake valve 5 Exhaust valve 6 Cam 7 Support plate part 8 Shaft 9 Roller 10 Roller 11 Thrust washer 12 Support hole 13 Chamfer part 14, 14a Inclined surface 15 Gap

Claims (2)

[Claims] 1. A cam fixed to a camshaft that rotates in synchronization with a crankshaft of an engine, and a displacement member formed opposite to the cam and displaced by the movement of the cam, with a gap therebetween. A pair of support plate portions each having a base end portion as a fixed end connected and fixed to the main body portion of the displacement member, and a tip end portion as a free end not restricted by another portion, A state in which both ends are fitted in concentric support holes formed in the support plate portion, and the outer peripheral edges of both ends are plastically deformed diametrically outward so as to bridge between the pair of support plate portions. Inner surfaces of the pair of support plate portions opposing each other in a cam follower device for a valve train mechanism of an engine, comprising a shaft fixed by the above and a short cylindrical roller rotatably supported around the shaft. At least towards the tip In the part, before the outer peripheral edges of both ends of the shaft are plastically deformed diametrically outward, by forming an inclined surface whose interval becomes narrower toward the base end of each of the support plate portions, A valve operating mechanism for an engine, wherein the inclined surfaces are made substantially parallel to each other based on deformation of the pair of support plates caused by plastic deformation of the outer peripheral edges of both ends of the pair in the radial direction. Cam follower device. And a displacement member which is provided opposite to a cam fixed to a camshaft which rotates in synchronization with a crankshaft of the engine and which is displaced in response to the movement of the cam. A pair of support holes formed concentrically with each other are formed on a pair of support plate portions whose base end portions are fixed ends connected and fixed to the main body portion of the displacement member, and whose respective tip end portions are free ends which are not restrained by other portions. After the shaft is inserted through the inside of a short cylindrical roller disposed between the pair of support plate portions, the outer peripheral edges of both ends of the shaft are plastically deformed diametrically outward, thereby forming the shaft. In the method for manufacturing a cam follower device for a valve train mechanism of an engine in which both end portions of the support plate are supported and fixed inside the support holes, at least portions of the inner surfaces of the pair of support plate portions opposed to each other are close to the tip. Shaft ends Before the plastic deformation in the diametric direction outward, the slope is set so that the interval becomes narrower toward the base end of each support plate, and both ends of the shaft are plastically deformed diametrically outward. A method of manufacturing a cam follower device for a valve train of an engine, wherein the respective inclined surfaces are made substantially parallel to each other based on the deformation of the pair of support plate portions.