WO2007114381A1

WO2007114381A1 - Cam follower device

Info

Publication number: WO2007114381A1
Application number: PCT/JP2007/057246
Authority: WO
Inventors: Noriyuki Takeo
Original assignee: Nsk Ltd.
Priority date: 2006-03-31
Filing date: 2007-03-30
Publication date: 2007-10-11
Also published as: US20090173300A1; EP2003295A2

Abstract

A cam follower device has a pair of plate-like rocker arms (17, 17) disposed in parallel with each other, a support shaft (7a) having both ends fixedly press-fitted into support holes (8a, 8a) formed at one end of each rocker arm (17, 17), and a tappet roller (9) supported so as to be rotatable around an intermediate part of the support shaft (7a). With the cam follower device assembled in a valve train, the rotatinal motion of a cam (2) formed on a camshaft is transmitted by the tappet roller (9) and the pair of rocker arms (17, 17) to the valve elements (12, 12) which are two intake valves (or exhaust valves), and as a result these two valve elements (12, 12) are reciprocated in the axial direction. This configuration can reduce the number of the parts composing the valve train of an engine where the number of at least either the intake valves or the exhaust valves installed in one cylinder is two or more.

Description

Specification

Technical field of cam follower equipment

[0001] The cam follower device according to the present invention has two or more of at least one of an intake valve and an exhaust valve provided in one cylinder, such as a 3-valve engine, a 4-valve engine, and a 5-valve engine. It is built into the valve mechanism of the engine and used to convert the rotation of the camshaft into reciprocating motion of two intake valves or two exhaust valves.

Background art

[0002] A reciprocating engine (reciprocating piston engine) is provided with an intake valve and an exhaust valve that open and close in synchronization with the rotation of the crankshaft, except for some two-cycle engines. In such a reciprocating engine, the movement of the camshaft that rotates in synchronization with the rotation of the crankshaft (at a rotational speed of 1Z2 in the case of a 4-cycle engine) is transmitted to the intake and exhaust valves by the rocker arm. The intake valve and the exhaust valve are reciprocated in the axial direction. In order to reduce friction inside the engine and reduce the fuel consumption rate, a tappet roller is generally incorporated between the camshaft and the rocker arm.

[0003] FIGS. 30 to 31 illustrate a first example of a conventional structure of a cam follower device including such a rocker arm and a tappet roller, which is described in Patent Document 1. FIG. A rocker arm 3 constituting the cam follower device is provided at a portion facing the cam 2 fixed to the camshaft 1 that rotates in synchronization with the crankshaft of the engine. A rocker shaft 5, which is a fixed shaft provided in parallel with the camshaft 1, is passed through the through hole 4 formed in the intermediate portion of the rocker arm 3. As a result, the rocker arm 3 can be oscillated and displaced with the rocker shaft 5 as the center. A pair of support wall portions 6 and 6 parallel to each other are provided at one end portion (right end portion in FIG. 30) of the rocker arm 3 as shown in detail in FIG. At the same time, the support shaft 7 is fixed in a state where the support wall portions 6 and 6 are spanned. For this purpose, both end portions of the support shaft 7 are fitted and fixed to a pair of support holes 8 and 8 formed at positions where the both support wall portions 6 and 6 are aligned with each other. This support A tappet roller 9 is rotatably supported around a middle portion of the shaft 7 via a radial-one dollar bearing 10. The outer peripheral surface of the tappet roller 9 is brought into contact with the outer peripheral surface of the cam 2. Further, a screw hole (not shown) is provided at the other end portion (left end portion in FIG. 30) of the rocker arm 3, and an adjustment screw 11 is screwed and fixed to the screw hole. The distal end portion (pressing portion) of the adjustment screw 11 is abutted against the base end surface of the valve body 12 that is an intake valve or an exhaust valve.

[0004] During operation of the engine, as the cam 2 rotates, the rocker arm 3 force swings and displaces about the mouth shaft 5 as a center (fulcrum), and the valve body 12 is moved against the pressing force of the adjustment screw 11. It is reciprocated in the axial direction by the elasticity of the return spring 13. At this time, since the frictional force acting between the cam 2 and the rocker arm 3 can be reduced by the tappet roller 9, the fuel consumption rate during engine operation can be reduced.

[0005] Next, FIGS. 32 to 34 show a second example of a conventional structure of a cam follower device including a rocker arm and a tappet roller, which is also described in Patent Document 1. FIG. The rocker arm 3a constituting the cam follower device of the second example of this conventional structure is subjected to plastic working such as punching processing for removing unnecessary portions and drawing processing for obtaining a desired shape on a metal plate such as a steel plate. Made. Such a rocker arm 3a includes a pair of support wall portions 6a and 6a that are parallel to each other, and a first link that connects one end portion of each of the support wall portions 6a and 6a (the right end portion in FIGS. 32 to 34). The connection part 14 and the 2nd connection part 15 which similarly connects other end parts (left end part of FIGS. 32-34) are provided. A tappet roller 9 is disposed between the support wall portions 6a and 6a and between the first and second connecting portions 14 and 15. The tappet roller 9 is rotatably supported directly or via a radial needle bearing around an intermediate portion of the support shaft 7 fixed in a state of being stretched over the both support wall portions 6a and 6a. In order to fix the support shaft 7 to the support wall portions 6a, 6a, a pair of support holes 8 formed at positions where the support wall portions 6a, 6a are aligned with each other are provided on the support shaft 7. Both ends are fixed by internal fitting.

As shown in FIG. 34, when the engine is mounted on the valve mechanism, a lash adjuster is installed in the spherical recess (receiving portion) provided on one side (the lower surface in FIG. 34) of the first connecting portion 14. The distal end surface of the plunger 16 that constitutes the end of the second connecting portion 15 (pressing portion) is connected to one side (the lower surface in FIG. ) And the base end portion of the valve body 12 that is an intake valve or an exhaust valve, respectively. At the same time, the outer peripheral surface of the cam 2 fixed to the intermediate portion of the camshaft 1 is brought into contact with the outer peripheral surface of the tappet roller 9. When the engine is in operation, the rocker arm 3a is rotated with the cam 2, and the state indicated by the solid line in FIG. 34 is centered on the contact portion between the tip end surface of the plunger 16 and the spherical recess. Similarly, the valve body 12 is oscillated and displaced between the state indicated by the chain line, and the valve body 12 is reciprocated in the axial direction by the pressing force of the second connecting portion 15 and the elastic force of the return spring 13. At this time, since the frictional force acting between the cam 2 and the rocker arm 3a can be reduced by the tappet roller 9, the fuel consumption rate during engine operation can be reduced.

[0007] In any of the conventional structures described above, both end portions of the support shaft 7 are fitted and fixed to the support holes 8 and 8 formed in the pair of support wall portions 6 and 6 (6a and 6a). It is conceivable to adopt a method in which both ends of the support shaft 7 are press-fitted into the support holes 8 and 8. However, in any of the conventional structures described above, the support wall portions 6 and 6 (6a, 6a) are integrally formed with the rocker arm 3 (3a), and the support wall portions 6, 6 (6a , 6a) The distance between each other cannot be increased. For this reason, when both ends of the support shaft 7 are press-fitted into the support holes 8 and 8, the intermediate portion of the support shaft 7 is press-fitted into one of the support holes 8 in the process. It must pass through one of the support holes 8. As a result, the outer peripheral surface of the intermediate portion of the support shaft 7 may be damaged. However, the outer peripheral surface of the intermediate portion of the support shaft 7 serves as an inner ring raceway (or an inner sliding surface of the sliding bearing) of the radial-dollar bearing 10 that rotatably supports the tape roller 9. It is not preferable that the surface is scratched as described above. Therefore, conventionally, such a problem is avoided that only the outer peripheral surface of the intermediate portion of the support shaft 7 is hardened by induction hardening, and then both end portions of the support shaft 7 are fixed to the both support holes 8. The outer peripheral edge of both end surfaces of the support shaft 7 is applied to the opening peripheral edge of the support holes 8 and 8 in a state where the inner periphery of the support shaft 7 is fitted with no looseness without looseness. The fixing method is adopted. However, such a fixing method causes a cost increase due to a large number of steps.

[0008] By the way, when only the conventional cam follower device as described above is used as the cam follower device incorporated in the valve operating mechanism when configuring the valve operating mechanism of the engine, the same number of cams as the valve bodies 12 are used. 2 and tappet roller 9 are required. However, recent engines As the number of valves increases, the number of intake valves and exhaust valves provided in one cylinder is gradually increasing to 2 and 3, respectively. For this reason, in the case of configuring a valve operating mechanism of an engine having such multiple valves, if only the conventional cam follower device as described above is used, the number of parts of the valve operating mechanism becomes too large, and this valve operating mechanism Inconveniences such as increase in size, weight, friction, and cost are likely to occur.

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-100499

Disclosure of the invention

Problems to be solved by the invention

[0010] In view of the circumstances as described above, the cam follower device of the present invention is an invention for realizing a structure capable of reducing the number of cams and tappet rollers to be used when configuring a valve operating mechanism of a multi-valve engine. It is a thing. Means for solving the problem

The present invention is achieved by the following configuration.

(1) A cam follower device used by being incorporated in a valve operating mechanism of an engine in which at least one of an intake valve and an exhaust valve provided in one cylinder is two or more, and having a predetermined interval A pair of rocker arms that are arranged in parallel with each other and that form a pair of concentric support holes at positions that are aligned with each other at one end or in the middle,

Support shafts fixed in a state of being spanned between the two rocker arms by fitting both ends into the both support holes;

A tappet port having an outer peripheral surface that is rotatably supported around the intermediate portion of the support shaft and can be brought into contact with an outer peripheral surface of a cam fixed to the camshaft while being incorporated in the valve mechanism. ■ ~ "

The rocker arm is provided directly at the other end of the rocker arm or through a separate member, and in a state where it is incorporated in the valve operating mechanism, it projects one by one into the base end face of two intake valves or two exhaust valves. A cam follower device comprising a pair of pressing portions that can be applied.

(2) The cam follower device according to (1), wherein the pair of rocker arms are formed separately. (3) The pair of support holes are formed at one end of the pair of rocker arms, and are incorporated in the valve mechanism at positions where they are aligned with each other at an intermediate portion of the rocker arms. Thus, a pair of concentric through holes that can pass through the rocker shaft provided in parallel with the camshaft are formed, and the swinging displacement of the both mouths of the rocker shaft around the rocker shaft is possible. The cam follower device described in (2).

(4) By making the thickness dimension of the rocker arms relatively large at one end of the rocker arms and relatively small at the other end, the inner surfaces of the rocker arms facing each other The cam follower device according to (3), wherein the distance between the rocker arms is relatively narrow at one end and relatively wide at the other end.

(5) By providing a non-parallel plate portion that is non-parallel to the intermediate portion at a portion between the one end portion and the intermediate portion of the both rocker arms or a portion between the intermediate portion and the other end portion. The cam follower device according to (3), wherein the spacing force S between the inner side surfaces of the one arm facing each other is relatively narrow at one end of the rocker arms and relatively wide at the other end.

(6) The cam follower device according to (3), wherein both ends of a cylindrical sleeve are fitted and fixed to the pair of through holes, and a rocker shaft is threaded inside the sleeve.

(7) The pair of support holes are formed in an intermediate portion of the pair of rocker arms, and one end portions of both the rocker arms are provided directly or via another member, and the valve mechanism The two rockers having a pair of receiving portions capable of abutting the distal end surfaces of the pair of plungers in a state where they are assembled, and having a contact portion between the both receiving portions and the distal end surfaces of the plungers as fulcrums The cam follower device described in (2), which enables swinging of the arm.

(8) By making the thickness dimensions of the rocker arms relatively large at the middle part of the rocker arms and relatively small at the one end part and the other end part, it is possible to The cam follower device according to (7), wherein the spacing force S between the opposing inner surfaces is relatively narrow at the intermediate portion between the rocker arms and relatively wide at one end and the other end.

(9) By providing a non-parallel plate portion that is non-parallel to the intermediate portion at a portion between the one end portion and the intermediate portion of the both rocker arms and a portion between the intermediate portion and the other end portion. The spacing force between the inner surfaces of the rocker arms facing each other The rocker arms The cam follower device according to (7), which is relatively narrow at an intermediate portion and relatively wide at one end and the other end.

(10) An axial direction allowed for the tappet roller by disposing spacers fitted on the support shaft between the inner side surfaces of the rocker arms and both axial side surfaces of the tappet roller. The cam follower device according to (1), wherein the amount of displacement is restricted to a desired size.

(11) The thickness dimension of a part of the rocker arms that needs to be stronger than the surrounding part is larger than the thickness dimension of the surrounding part. Cam follower device.

(12) The cam follower device according to (2), wherein each of the pair of rocker arms is formed by punching one metal plate.

(13) The cam follower device according to (1), wherein the pair of rocker arms are incapable of relative displacement by at least one connecting portion.

(14) The pair of support holes are formed at one end of the pair of rocker arms, and in a state where the pair of support holes are aligned with each other at an intermediate portion of the rocker arms, A pair of concentric through-holes that can pass through a rocker shaft provided in parallel with the camshaft are formed, and the swinging displacement of the both mouths of the rocker shaft around the rocker shaft is enabled. The cam follower device described in (13).

(15) The pair of rocker arms, which are coupled so as not to be displaced relative to each other by the at least one continuous portion, are formed by punching and bending a single metal plate. ) Cam follower device.

The invention's effect

If the cam follower device of the present invention configured as described above is used to configure an engine valve mechanism in which at least one of the intake valves and exhaust valves provided in one cylinder is two or more. Two intake valves or two exhaust valves can be opened and closed at the same time by installing only one cam and tappet roller. For this reason, as compared with the case where only the conventional cam follower device as described above is used as the cam follower device incorporated in the valve operating mechanism, this valve operating device is used. The number of parts can be reduced. Therefore, the valve operating mechanism can be reduced in size (space saving), reduced in weight, reduced in friction, reduced in cost, and the like.

In the case of the cam follower device of the present invention, as a method of fitting and fixing both ends of the support shaft in a pair of support holes, a method of press-fitting both ends of the support shaft into these support holes is used. Can be adopted. Even when this method is employed, the outer peripheral surface of the intermediate portion of the support shaft {the inner ring raceway of the radial needle bearing (or the inner sliding surface of the sliding bearing) for rotatably supporting the tape roller} is damaged. Can be prevented. This is because a pair of rocker arms arranged in parallel with each other at a predetermined interval (same pitch as the pitch of the two valve bodies to be opened and closed at the same time) to form the above-mentioned pair of support holes. In the case of the present invention, both ends of the support shaft can be press-fitted into the insides of the support holes through the openings of the support holes facing each other. In other words, in the case of the present invention, unlike the conventional structures described above, in the process of press-fitting both ends of the support shaft into the pair of support holes, the intermediate portion of the support shaft is set to one of the support holes. This is because it is not necessary to perform the operation of passing the support shaft through the inside of one of the support holes in a state of being press-fitted into (inserted with an interference fit).

[0014] Further, when assembling the cam follower device of the present invention, if a method of press-fitting (fitting with an interference fit) both ends of the support shaft into a pair of support holes as described above is adopted. Since there is no need to force and spread the edges at both ends, it is not necessary to leave the edges of the support shaft in a raw state (a state in which no curing treatment is applied). Therefore, quenching of the support shaft can be performed by so-called submerged heating in which the entire support shaft is heated and then immersed in the quenching oil. Since the quenching process by sub-firing can be performed at a lower cost than the induction quenching process, the manufacturing cost can be reduced accordingly.

[0015] The pair of rocker arms of the present invention capable of preventing the outer peripheral surface of the intermediate portion of the support shaft from being damaged may be separate parts or may be relatively displaced by at least one continuous portion. However, the distance between the portion where the support holes are formed and the connecting portion can be made relatively large, and the distance between the rocker arms can be increased. Also good.

[0016] In addition, the rocker arms may not be relatively displaced by at least one continuous portion. If they are combined, the conventional phase adjustment work becomes unnecessary when assembling the cam follower device to the engine.

[0017] When the cam follower device described in the above (3) is implemented, if the configuration described in the above (4) and (5) is adopted, two intakes to be pressed by a pair of pressing portions Even if the distance between the base end faces of the valve or the two exhaust valves is significantly larger than the axial dimension of the tappet roller used as a component, the pair of base end faces can be pressed accurately. And the distance between the both side surfaces in the axial direction of the tappet roller and the inner surfaces of the pair of rocker arms can be made sufficiently small (the amount of axial displacement allowed for the tappet roller can be set to a desired size). Can be controlled). In other words, it is not necessary to increase the axial dimension of the tappet roller in accordance with the distance between the two end surfaces.

[0018] Also, when the cam follower device described in (3) to (5) above is implemented, if the configuration described in (6) above is adopted, both the cam follower devices provided in the middle portion of the pair of rocker arms are used. Since both end portions of the sleeve are fitted and fixed to the through holes, it is possible to effectively prevent the positional relationship between the two rocker arms from deviating from an appropriate positional relationship force. Therefore, there are inconveniences associated with such deviations (for example, it is difficult to insert the rocker shaft into the two through holes, such as inconveniences that occur when assembling the cam follower device, displacement between the two intake valves or exhaust valves that are pressed during use. The tappet roller's center axis is tilted and the outer surface of the tappet roller and the outer surface of the cam are not in parallel contact with each other. It can be effectively prevented. In addition, the outer peripheral surface of the rocker shaft is in sliding contact with the inner peripheral surface of the sleeve, which has a small axial dimension and a sufficiently large axial dimension that does not exceed the inner peripheral surfaces of the through holes. Therefore, a sufficient sliding area with respect to the outer peripheral surface of the rocker shaft can be secured, and the amount of wear on the outer peripheral surface of the rocker shaft can be sufficiently reduced. As a result, the durability life of the rocker shaft can be improved. In addition, since it is not necessary to make the inner peripheral surfaces of the two through holes slidably contact the outer peripheral surface of the rocker shaft, the thickness of the rocker arms can be reduced accordingly.

[0019] When the cam follower device described in the above (7) is implemented, if the configuration described in the above (8) and (9) is adopted, two intakes to be pressed by a pair of pressing portions Valve or 2 exhausts The distance between the base end faces of the air valve and the distance between the tip faces of the pair of plungers that should be abutted against the pair of receiving parts are significantly larger than the axial dimension of the tappet roller used as a component. A pair of pressing portions that can accurately press both the base end surfaces, and a pair of receiving portions that can accurately abut both the end surfaces, and both sides of the tape roller in the axial direction. A structure can be realized in which the distance between the surface and the inner surface of the pair of rocker arms can be made sufficiently small (the axial displacement allowed for the tappet roller can be regulated to a desired size). In other words, it is not necessary to increase the axial dimension of the tappet roller in accordance with the distance between the two base end faces and the distance between the two front end faces.

[0020] When the configuration described in (10) above is adopted when the cam follower device described in (1) is implemented, the distance between the inner surfaces of the pair of rocker arms is used as a component. Even when the axial dimension of the tappet roller is significantly larger, the axial displacement allowed for this tappet roller can be regulated to a desired size. Therefore, if the configuration described in the above (10) is adopted, a common tappet roller (and a radial needle bearing provided radially inward of this tappet roller, etc.) is used for a pair of rocker arms having various shapes. Rolling bearings can be used. The shape of a pair of rocker arms can be determined according to the engine layout.

[0021] Further, when the cam follower device described in (1) above is implemented, if the configuration described in (11) above is employed, the thickness dimension of the pair of rocker arms is generally increased. In addition, the strength of a part of both the rocker arms can be increased accurately without causing unnecessary weight increase.

Brief Description of Drawings

FIG. 1 is a side view showing a first example of an embodiment of the present invention in a state where the first example is incorporated in a valve mechanism of an engine.

FIG. 2 is a view from above of FIG.

FIG. 3 is a cross-sectional view taken along the line の in FIG.

[FIG. 4] FIG. 4 is an enlarged view of part IV of FIG.

FIG. 5 is a view similar to FIG. 4, showing a first example of another structure of the rocker arm. [Fig. 6] Fig. 6 (a) is a diagram showing the second example with a part cut away, as viewed from the same direction as Fig. 2, and Fig. 6 (b) is an end view thereof. .

[Fig. 7] Fig. 7 (a) is a diagram showing the third example in a partially cut state as seen from the same direction as Fig. 2, and Fig. 7 (b) is an end view thereof. .

[FIG. 8] FIG. 8 is a diagram showing the same fourth direction force as FIG.

[FIG. 9] FIG. 9 is a diagram showing the fifth example with the same direction force as FIG.

FIG. 10 is a view similar to FIG. 2, showing a second example of the embodiment of the present invention.

FIG. 11 is a view of the left end portion of the upper rocker arm in FIG. 10 as viewed from the inner surface side of the left end portion.

FIG. 12 is a view similar to FIG. 2, showing a third example of the embodiment of the present invention.

FIG. 13 is a view similar to FIG. 2, showing the fourth example in a partially cut state.

FIG. 14 is a perspective view showing a structure which is not preferable as compared with the structure of the fourth example.

FIG. 15 is a view similar to FIG. 2, showing a fifth example of the embodiment of the invention with a part thereof cut away.

FIG. 16 is a view similar to FIG. 2, showing the sixth example.

FIG. 17 is a view similar to FIG. 1, showing a seventh example of the embodiment of the present invention.

FIG. 18 is a view from above of FIG. 17, showing a part cut away.

FIG. 19 is a diagram corresponding to the central portion of FIG. 18, showing an eighth example of the embodiment of the present invention.

FIG. 20 is a side view showing the ninth example in a state where the ninth example is incorporated in a valve operating mechanism of an engine.

FIG. 21 is a view from above of FIG. 20, with a part omitted.

22 is a cross-sectional view taken along the line XXII-XXII in FIG.

FIG. 23 is a view similar to FIG. 2, showing a tenth example of the embodiment of the present invention.

FIG. 24 (a) is a diagram similar to FIG. 2 showing a modification of the tenth example, and FIG. 24 (b) is a diagram showing another modification of the tenth example. FIG. FIG. 25 is a side view showing an eleventh example of the embodiment of the present invention in a state where the eleventh example is incorporated in a valve operating mechanism of an engine.

FIG. 26 is a view from above of FIG.

[FIG. 27] FIG. 27 (a) is a diagram for explaining the first step of punching a piece of metal to form a rocker arm, and FIG. 27 (b) is a diagram showing the bending force after the punching force. It is a figure explaining the 2nd process of giving rockers and forming a rocker arm.

FIG. 28 is a view of the rocker arm having a structure in which a cylindrical portion is formed in the through-hole, also showing the upper force.

FIG. 29 is a perspective view of a rocker arm having a structure in which a cylindrical portion is formed in a through hole.

FIG. 30 is a partial side view of a valve operating mechanism of an engine assembled with a first example of a conventional cam follower device.

FIG. 31 is an enlarged XXXI-XXXI sectional view of FIG. 30.

FIG. 32 is a perspective view showing a second example of a conventional cam follower device.

FIG. 33 is a cross-sectional view taken along the line の in FIG.

FIG. 34 is a partial cross-sectional view of a valve operating mechanism of an engine assembled with a second example of a conventional cam follower device.

Explanation of symbols

1 Camshaft

2 cam

3, 3a rocker arm

4, 4a through hole

5 Rocker shaft

6, 6a Support wall

7, 7a Support shaft

8, 8a Support hole

9 Tape roller

10 Radial-one dollar bearing

11 Adjustment screw Disc

Return spring 1st connecting part 2nd connecting part Plunger

, 17a-17r Rocker convex part

Holding piece

Recess

Press plate

Flat plate

Cylindrical part

Through hole (or screw hole) Cylindrical part

Cylindrical part

Cylindrical member

sleeve

Spherical recess

31a Thick part

Annular spacer Cylindrical spacer Thick part

35a, 35b Inclined plate part Radial needle bearing Annular plate

Connecting part

Cylindrical part BEST MODE FOR CARRYING OUT THE INVENTION

[First example of embodiment]

1 to 4 show a first example of the embodiment of the present invention. The cam follower device of this example is an engine (OHC type) in which at least one of an intake valve and an exhaust valve provided in one cylinder is two or more, such as a 3-valve engine, a 4-valve engine, and a 5-valve engine. Or DOHC type). Such a cam follower device of this example includes a pair of plate-like rocker arms 17, 17 having the same shape and the same size, one support shaft 7 a, and one tappet roller 9.

[0025] A pair of plate-like rocker arms 17 and 17 are formed into a substantially boomerang shape by punching a metal plate such as a steel plate separately. Such double-ended door arms 17 and 17 are arranged in parallel to each other with a predetermined interval. In addition, the support shaft 7a is fixed in a state of being hung between one end portions (the right end portions in FIGS. 1 and 2) of the both-end kucker arms 17 and 17. For this purpose, a pair of support holes 8a, 8a that are concentric with each other are formed at positions where the one ends of the rocker arms 17, 17 are aligned with each other. Then, after hardening the entire surface of the support shaft 7a by quenching, both ends of the support shaft 7a are placed inside the support holes 8a and 8a, and the support holes 8a and 8a are connected to each other. It press-fits through the opening on the opposite side.

[0026] In the case of this example, the male selection (not shown) formed on the outer peripheral surface of the both ends of the support shaft 7a and the support holes 8a, 8a in the press-fitted state as described above. It is effective that relative rotation occurs in the press-fitting part by engaging a female serration (not shown) formed on the peripheral surface (or letting the peak part of the male selection bite into the inner peripheral surface of the support hole). To prevent. In other words, the rocker arms 17 and 17 are effectively prevented from relatively swinging around the support shaft 7a. When both ends of the support shaft 7a are press-fitted into the pair of support holes 8a, 8a, at least one of the outer peripheral surfaces of both ends of the support shaft 7a and the inner peripheral surfaces of the support holes 8a, 8a A selection may be provided on the peripheral surface.

In addition, the tappet roller 9 is rotatably supported on the outer peripheral surface of the intermediate portion of the support shaft 7 a via a radial-dollar bearing 10. In addition, a pair of concentric through holes 4, 4 are formed at positions where they are aligned with each other at an intermediate portion between the rocker arms 17, 17. Also, the above A pair of convex portions 18 and 18 (pressing portions) are provided on the lower surfaces of the other end portions of the rocker arms 17 and 17 (left end portions in FIGS. 1 and 2). The front end surfaces of these convex portions 18 and 18 are each a partial cylindrical surface. The tappet roller 9 is supported around the intermediate portion of the support shaft 7a through a radial rolling bearing such as a radial-single-bearing bearing 10 so as to be rotatable, or directly or via a radial sliding bearing. May be. By using a radial rolling bearing as in this example, the rocking resistance of the pair of rocker arms 17, 17 centering on the rocker shaft 5 can be reduced, and the fuel consumption rate during engine operation can be reduced. .

[0028] In the assembled state to the valve mechanism of the engine, as shown in FIGS. 1 and 2, the rocker shaft 5 which is a fixed shaft is not rattled to each of the through holes 4 and 4 without tightening. The rocker arms 17 and 17 can be oscillated and displaced with the rocker shaft 5 as the center. At the same time, the outer peripheral surface of the tappet roller 9 is brought into contact with the outer peripheral surface of the cam 2 fixed to the camshaft 1, and the tip surfaces of the both convex portions 18, 18 are connected to the two valve bodies 12, 12 Butt one by one against the base end face of two intake valves or two exhaust valves on the same cylinder. During the operation of the engine, as the cam 2 rotates, the rocker arms 17, 17 1S swing and displace around the rocker shaft 5, and the two valve bodies 12, 12 are moved to the both convex portions 18, It is reciprocated in the axial direction by the pressing force of 18 and the elasticity of the return spring 13 (omitted in Figs. 1 to 4; see Figs. 30 and 34).

[0029] As described above, if the cam follower device of this example is used, the reciprocating movement of the two valve bodies 12, 12 can be performed simultaneously by providing only one set of the cam 2 and the tappet roller 9. For this reason, as compared with the case where only the conventional cam follower device as described above is used as the cam follower device incorporated in the valve operating mechanism (an independent cam follower device is incorporated for each valve element), The score can be reduced. Therefore, the valve mechanism can be reduced in size (space saving), reduced in weight, reduced in friction, reduced in cost, and the like. In this example, both ends of the support shaft 7a can be press-fitted into the pair of support holes 8a and 8a without scratching the outer peripheral surface of the intermediate portion of the support shaft 7a. For this reason, as a method of hardening the surface of the support shaft 7a, it is possible to employ submerged quenching that is cheaper than induction hardening. Therefore, the manufacturing cost can be reduced accordingly.

[0030] Further, as described above, as long as both rocker arms 17 and 17 are formed in the same shape and size, this is not necessary. It is possible to effectively prevent a difference in the contact state between the rocker arms 17 and 17 and the other parts such as valves by making the positional relationship between the rocker arms 17 and 17 appropriate.

[0031] When the cam follower device of this example as described above is implemented, rocker arms 17a to 17e as shown in Figs. 5 to 9 can be used as a pair of rocker arms, respectively. . Each of these rocker arms 17a to 17e is different from the rocker arm 17 described above in the shape of at least the other end (the left end in FIGS. 5 to 9). First of all, the rocker arm 17a shown in FIG. 5 has a pair of holding pieces 19 and 19 protruding from both sides of the convex portion 18 provided on the lower surface of the other end portion (left and right in FIG. 5). ing. Further, the rocker arm 17b shown in FIG. 6 is provided with a pressing plate portion 21 having a U-shaped cross section with a recess 20 on the lower surface at the other end, and the bottom surface of the recess 20 abuts against the base end surface of the valve body. The pressing part. In addition, the rocker arm 17c shown in FIG. 7 is provided with a flat plate portion 22 perpendicular to the one end portion (right end portion in FIG. 7) or the middle portion at the other end portion, and a perforation is formed in the central portion of the flat plate portion 22. A cylindrical portion 23 is formed by performing a paring process on the portion subjected to the punching force and applying a force. The inside of the cylindrical portion 23 is a through hole (or screw hole) 24. When such a rocker arm 17c is used, the tip of the adjusting pin (or adjusting screw), not shown in the figure, fitted in (or screwed into) the through hole (or screw hole) 24, is attached to the valve body. It is set as the press part which abuts against the base end surface.

In addition, the rocker arm 17d shown in FIG. 8 is formed integrally with the cylindrical portion 25 at the other end by bending. The inside of the cylindrical portion 25 is used as a through hole (or screw hole) 24 for internally fitting (or screwing) an unillustrated adjusting bin (or adjusting screw). Further, in order to secure the length of the rocker shaft 5 (see FIG. 2) with respect to the through hole 4 provided in the middle part of the rocker arm 17d, a burring force is applied to the peripheral part of the through hole 4. To form a cylindrical portion 26. Further, a rocker arm 17e shown in FIG. 9 has a cylindrical member 27 joined and fixed to the other end by welding, electrodeposition or the like. The inside of the cylindrical member 27 is used as a through hole (or screw hole) 24 for fixing (or screwing) an adjustment pin (or adjustment screw) (not shown) described above. In addition, in order to secure the length of the rocker shaft 5 (see FIG. 2) with respect to the through hole 4 provided in the middle part of the rocker arm 17e, a sleeve 28 is fitted and fixed inside the through hole 4, The rocker shaft 5 is passed through the inside of the sleeve 28. [Second Example of Embodiment]

Next, FIGS. 10 to 11 show a second example of the embodiment of the present invention. In the case of this example, in order to increase the strength of the other end portion (left end portion in FIG. 10) provided with the convex portions 18 and 18 of the pair of rocker arms 17h and 17h, The thick parts are 31 and 31, respectively. In order to form these thick portions 31 and 31, in the case of this example, the inner side surfaces of the other end portions of the two-mouth cker arms 17h and 17h are bulged. Then, the thickness dimension T of the other end portions of the rocker arms 17h, 17h (both the thick wall portions 31, 31) is set to be larger than the thickness dimension t of one end portion (the right end portion in FIG. 10) and the intermediate portion. It is large (T> t). In the case of this example configured as described above, the strength of the other end portions without causing a wasteful weight increase is obtained as compared with the structure in which the thickness dimensions of the rocker arms 17h and 17h are increased as a whole. It can be raised accurately. Other configurations and operations are the same as those of the first example of the embodiment described above.

[Third example of embodiment]

Next, FIG. 12 shows a third example of the embodiment of the present invention. Also in this example, in order to increase the strength of the other end portion (left end portion in FIG. 12) provided with the convex portions 18 and 18 of the pair of rocker arms 17i and 17i, The thick parts are 31a and 31a, respectively. However, in order to form these thick portions 31a and 31a, in the case of this example, the both side surfaces of the other end portions of the two-mouth cker arms 17i and 17i are bulged. Other configurations and operations are the same as those of the second example of the embodiment described above.

[Fourth example of embodiment]

Next, FIG. 13 shows a fourth example of the embodiment of the present invention. In the case of this example, the distance between the pair of valve bodies 12 and 12 to be pressed is significantly larger than in the case of each of the embodiments described above. For this reason, in this example, the distance between the pair of rocker arms 17i, 17i is greatly increased compared to the case of each of the above-described embodiments in accordance with the distance between the two valve bodies 12, 12. To make it bigger. On the other hand, in the case of this example, the tappet roller 9 disposed between the one end portions (the right end portion in FIG. 13) of both the rocker arms 17i and 17i has the same axis as in the above-described embodiments. Those with directional dimensions are used. For this reason, in this example, the inner surface of one end of the rocker arms 17i, 17i and the axial direction of the tappet roller 9 The width of the gap existing between the opposite side surfaces is significantly larger than the axial displacement amount that should be allowed for the tappet roller 9.

[0036] Here, as shown in FIG. 14, each of the rocker arms 17i, 17i is provided on the inner surface of one end portion (the right end portion in FIG. 14) and between the both side surfaces of the tappet roller 9, respectively. If a structure in which no parts are arranged is employed, the tappet roller 9 can be displaced in the axial direction by the width of the gap existing between these two parts. As a result, during operation of the engine, the tappet roller 9 is greatly displaced in the axial direction, and the radial-dollar bearing 10 disposed on the radially inner side of the tappet roller 9 falls off or the tappet roller 9 This is not preferable because it may cause problems such as coming off the cam 2. In order to avoid such a situation, the axial dimension of the tappet roller 9 may be increased in accordance with the distance between the inner surfaces of the rocker arms 17i and 17i. However, such a structure is adopted. This increases the weight of the tappet roller 9 and makes it difficult to operate the engine at a high speed, or causes a problem such as an increase in the fuel consumption rate during operation of the engine. .

[0037] Therefore, in the case of this example shown in Fig. 13, which is slid so as to prevent the occurrence of the above-described problems, the inner surface of one end of both the rocker arms 17i, 17i and the tappet roller 9 The annular spacer 32 and the cylindrical spacer 33 that are externally fitted to the support shaft 7a, respectively, between the two axial side surfaces of the taper roller 9 and the side force of the tappet roller 9 in this order also cause large backlash in the axial direction. Arranged in a lost state. Then, by the annular spacers 32, 32 and the cylindrical spacers 33, 33 arranged in this way, the axial displacement amount allowed for the tappet roller 9 (and the radial-dollar bearing 10) is determined. , It is regulated to the desired size (small amount). Other configurations and operations are the same as those of the third example of the embodiment described above.

[0038] [Fifth example of embodiment]

Next, FIG. 15 shows a fifth example of the embodiment of the present invention. In this example, instead of omitting the pair of cylindrical spacers 33 and 33 (see Fig. 13), one end of the pair of rocker arms 17k and 17k (the right end in Fig. 15) The thick parts 34 and 34 are bulged on the sides. As a result, the distance between the inner surfaces of the one end portions of both the rocker arms 17 and 17 is narrowed, and the axial displacement amount allowed for the tappet roller 9 is regulated to a desired size (a minute amount). It is controlled. Other configurations and operations are the same as in the case of the fourth example of the above-described embodiment, except that a thick-walled portion is not provided at the other end portion (left end portion in FIG. 15) of both the rocker arms 17k and 17k. It is.

[Sixth example of embodiment]

Next, FIG. 16 shows a sixth example of the embodiment of the present invention. In this example, instead of omitting the pair of annular spacers 32 and 32 and the cylindrical spacers 33 and 33 (see FIG. 13), one end of the pair of rocker arms 17m and 17m (see FIG. Inclined plate portions 35, 35 (non-parallel plate portions) that are inclined in the direction of approaching each other toward the one end side between the middle portion and the other end portion (left end portion in FIG. 16). ) Is formed. As a result, the distance between the inner surfaces of the one end portions of both the rocker arms 17m and 17m is narrowed, and the amount of axial displacement allowed for the tappet roller 9 is restricted to a desired size (a minute amount). . Other configurations and operations are the same as those of the embodiment shown in FIG. 13 except that a thick wall portion is not provided at the other end portion (the left end portion in FIG. 15) of the double-ended cker arms 17m and 17m. Same as for 4 cases

[0040] [Seventh example of embodiment]

Next, FIGS. 17 to 18 show a seventh example of the embodiment of the invention. In the case of this example, both ends of the cylindrical sleeve 29 are press-fitted inside the through-holes 4a, 4a formed in the middle part of the pair of rocker arms 17f, 17f, so that both the sleeves 29 are inserted. The rocker arms 17f and 17f are fixed in a state of being hung between each other. In this state, a male selection (not shown) formed on the outer peripheral surfaces of both ends of the sleeve 29 and a female selection (not shown) formed on the inner peripheral surfaces of the through holes 4a and 4a are provided. Engagement effectively prevents relative rotation from occurring in the press-fitting part. The rocker shaft 5 is passed through the sleeve 29 thus provided.

[0041] In the case of the cam follower device of the present example configured as described above, the pair of rocker arms 17f and 17f are connected by the sleeve 29 as described above, so that both the rocker arms 17f and 17f are connected to each other. It is possible to more effectively prevent inconveniences such as relative displacement. That is, it is possible to effectively prevent the positional relationship force between the rocker arms 17f and 17f from deviating from the proper positional relationship. Therefore, there are inconveniences associated with such deviations (for example, the two through holes 4a 4a, it is difficult to pass the rocker shaft 5 through, etc. It is possible to effectively prevent the center axis of 9 from inclining and the outer peripheral surface of the tappet roller 9 and the outer peripheral surface of the cam 2 from being in parallel contact with each other, causing inconveniences such as a single contact. In addition, the outer circumferential surface of the rocker shaft 5 has a small axial dimension, and the axial dimension that is sufficiently larger than the inner circumferential surface of the through holes 4a and 4a is sufficiently large. Sliding contact. Therefore, a sufficient sliding area with respect to the outer peripheral surface of the rocker shaft 5 can be secured, and the amount of wear on the outer peripheral surface of the rocker shaft 5 can be sufficiently reduced. As a result, the durable life of the rocker shaft 5 can be improved. Further, since it is not necessary to make the inner peripheral surfaces of the two through holes 4a and 4a slidingly contact the outer peripheral surface of the rocker shaft 5, the thicknesses of the rocker arms 17f and 17f can be reduced accordingly.

[0042] Further, during operation of the engine, lubricating oil is also supplied between the inner peripheral surface of the sleeve 29 and the outer peripheral surface of the rocker shaft 5, and the end opening partial force of the sleeve 29 is also supplied to both the peripheral surfaces. The frictional force acting between them is sufficiently reduced. In the case of carrying out this example, if one or a plurality of intermediate portions of the sleeve 29 are formed with oil passage holes that penetrate the portions in the radial direction, the peripheral surfaces are connected to each other through the oil passage holes. During this time, the lubricating oil can be supplied more sufficiently. Also in this example, as the shape of the other end of the pair of rocker arms, the shape of the other end of the rocker arms 17a to 17e, 17h and 17i shown in FIGS. Can do. Other configurations and operations are the same as those of the first example of the embodiment shown in FIGS.

[Eighth example of embodiment]

Next, FIG. 19 shows an eighth example of the embodiment of the present invention. In the case of this example, a radial-dollar bearing 36 is provided between the inner peripheral surface of the cylindrical sleeve 29 and the outer peripheral surface of the rocker shaft 5. At the same time, a pair of circular rings in which the inner peripheral edges of the outer surfaces of the pair of rocker arms 17f, 17f are opposed to the outer peripheral surface of the rocker shaft 5 at the peripheral portions of the through holes 4a, 4a. Plates 37 and 37 are connected and fixed. The radial-single bearing 36 is prevented from falling outside through the openings at both ends of the sleeve 29 by the inner peripheral edge portions of the two circular plates 37 and 37. The cam follower of this example configured in this way According to the device, the radial-dollar bearing 36 can reduce the rocking resistance of the pair of rocker arms 17f and 17f centered on the rocker shaft 5, thereby reducing the fuel consumption rate during engine operation. Can be planned. Other configurations and operations are the same as in the seventh example of the embodiment described above.

[0044] [Ninth example of embodiment]

Next, FIGS. 20 to 22 show a ninth example of the embodiment of the invention. In this example, unlike the first to eighth examples of the above-described embodiment, a pair of tappet rollers 9 rotatably supported via a radial-single bearing 10 around the support shaft 7a. The plate-like rockerarms 17g and 17g are arranged in the middle part of each other. For this reason, in the case of this example, both ends of the support shaft 7a are press-fitted (engaged with the selection), and a pair of support holes 8a and 8a are connected to each other at an intermediate portion of the pair of plate-like rocker arms 17g and 17g They are concentrically formed at aligned positions. Further, spherical recesses 30 and 30 (receiving portions) are provided on the lower surfaces of one end portions (right end portions in FIGS. 20 to 21) of both rocker arms 17g and 17g, respectively. On the other hand, on the lower surface of the other end portion (the left end portion in FIGS. 20 to 21) of the double-ended kicker arms 17g and 17g, the same convex portion 18 as in the first and second examples of the above-described embodiment, respectively. 18 is provided.

[0045] In the state where the engine is mounted on the valve operating mechanism, as shown in FIGS. 20 to 21, the tip surfaces of the pair of plungers 16 and 16 constituting the lash adjuster in the spherical recesses 30 and 30 are The base end surfaces of the two valve bodies 12 and 12 (two intake valves or two exhaust valves provided in the same cylinder) are brought into contact with the front end surfaces of the both convex portions 18 and 18, respectively. At the same time, the outer peripheral surface of the cam 2 fixed to the intermediate portion of the camshaft 1 is brought into contact with the outer peripheral surface of the tappet roller 9. During operation of the engine, as the cam 2 rotates, the rocker arms 17g, 17g force swing around the abutment between the tip surfaces of the plungers 16, 16 and the spherical recesses 30, 30 (center). The two valve bodies 12 and 12 are moved in the axial direction by the pressing force of both the convex portions 18 and 18 and the elasticity of the return spring 13 (not shown in FIGS. 20 to 22; see FIGS. 30 and 34). Move back and forth.

[0046] As described above, when the valve operating mechanism is configured by using the cam follower device of this example, the two valve bodies 12, 12 are reciprocated only by providing one set of the cam 2 and the tappet roller 9. Can be performed simultaneously. For this reason, as a cam follower device incorporated in the valve operating mechanism, Compared to the case where only the conventional cam follower device as described above is used, the number of parts of this valve operating mechanism can be reduced. Therefore, the valve mechanism can be reduced in size (space saving), reduced in weight, reduced in friction, reduced in cost, and the like. Also in the case of this example, as in the case of the first to eighth examples of the above-described embodiment, a pair of both ends of the support shaft 7a that does not damage the outer peripheral surface of the intermediate portion of the support shaft 7a is paired. It can be press-fitted into the support holes 8a and 8a. For this reason, as a method for hardening the surface of the support shaft 7a, it is possible to employ submerged quenching which is cheaper than induction quenching. Therefore, the manufacturing cost can be reduced accordingly. Also in this example, the shape of the other end of the rocker arms 17a to 17e, 17h and 17i shown in FIGS. 5 to 12 can be adopted as the shape of the other end of the pair of rocker arms. it can. Also, the receiving part provided at one end of a pair of rocker arms can be formed in various structures, including whether it is formed directly at one end of both rocker arms or via a separate member. Can be adopted. For example, it is also possible to employ a structure in which screw holes are provided at one end portions of both the mouther arm, and an adjustment screw having a tip portion as a receiving portion is screwed and fixed to each screw hole portion.

[Tenth example of embodiment]

Next, FIG. 23 shows a tenth example of the embodiment of the present invention. In the case of this example, compared to the case of the ninth example of the embodiment described above, the pair of plungers 16 serving as fulcrums, the distance between the tip surfaces of the 16 and the pair of valve bodies to be pressed The distance between the base end faces of 12 and 12 is greatly increased. On the other hand, in the case of this example, the tappet roller 9 disposed between the intermediate portions of the pair of rocker arms 17η and 17η has the same axial dimension as in the ninth example of the above-described embodiment. I am using something. For this reason, in the case of this example, between the one end portions (the right end portion in FIG. 23) of the both rocker arms 17η and 17η and the intermediate portion, and the other end portions of the rocker arms 17η and 17η (see FIG. 23). Inclined plate portions 35a and 35b (non-parallel plate portions) that are inclined in a direction in which they approach each other toward the intermediate portion are formed between the intermediate portion and the left end portion). Thereby, the interval between the one end portions of both the rocker arms 17η, 17η is widened according to the interval between the tip surfaces of the plungers 16, 16, and the other end portions of the rocker arms 17η, 17η are Is widened in accordance with the distance between the base end surfaces of the valve bodies 12 and 12. At the same time, the gap between the inner side surfaces of the intermediate portions of the two-necked cker arms 17 η, 17η is narrowed and allowed by the tappet roller 9. The amount of axial displacement is regulated to the desired size (small amount). In the case of this example configured as described above, the axial direction of the tappet roller 9 is adjusted in accordance with the interval between the distal end surfaces of the plungers 16 and 16 and the interval between the proximal end surfaces of the valve bodies 12 and 12. The effect that it is not necessary to increase the dimensions can be obtained. Other configurations and operations are the same as those of the ninth example of the embodiment described above.

[0048] As described above, the axial dimension of the tappet roller 9 is increased in accordance with the interval between the distal end surfaces of the plungers 16 and 16 and the interval between the proximal end surfaces of the valve bodies 12 and 12. The effect of not having to do this can be achieved with other structures. As such a structure, for example, as shown in FIG. 24 (a), the thickness dimension of a pair of rocker arms 17ο and 17ο is relatively large at the intermediate part between both rocker arms 17ο and 17ο. In addition, by making it relatively small at one end and the other end, the distance between the inner surfaces of the two rocker arms 17ο and 17ο facing each other is relatively narrow at the intermediate part between these rocker arms 17ο and 17ο. In addition, a structure that is relatively wide at one end and the other end can be considered. Alternatively, as shown in FIG. 24 (b), between the inner side surfaces of the pair of rocker arms 17p and 17p and both axial side surfaces of the tappet roller 9, spacers 32 fitted around the support shafts 7a, respectively. , 33 is adopted.

[0049] [Eleventh example of embodiment]

25 to 27 show an eleventh example of the embodiment of the present invention. The cam follower device of this example is an engine in which at least one of an intake valve and an exhaust valve provided in one cylinder is two or more (for example, a 3-valve engine, a 4-valve engine, a 5-valve engine, etc.) O HC type or DOHC type) Such a cam follower device of this example includes a pair of plate-like rocker arms 17q and 17q that are the same shape and the same size as each other, one support shaft 7a, and one tappet roller 9.

[0050] Of these, the pair of plate-like rocker arms 17q, 17q are arranged in parallel with each other at a predetermined interval (at the same pitch as that of the pair of valve bodies 12, 12), and at least one place The connecting portion 38 is connected so that relative displacement is impossible. Further, the support shaft 7a is fixed in a state where it is suspended between one end portions (the right end portions in FIGS. 25 to 26) of both the rocker arms 17q and 17q. For this purpose, the rocker arms 17q and 17q are aligned with each other at one end. A pair of support holes 8a and 8a are formed concentrically with each other. Then, after subjecting the entire surface of the support shaft 7a to hardening treatment by squeezing and quenching, the both rocker arms 17q, 17q are widened so that both end portions of the support shaft 7a are connected to the both support holes 8a, The two support holes 8a and 8a are press-fitted into the inside of 8a through the openings on the sides facing each other. In addition, in order to widen the gap between the two-mouth cker arms 17q, 17q, the angle of the continuous portion between the rocker arms 17q, 17q and the connecting portion 38 is increased (a size exceeding 90 degrees). In this example, the connecting portion 38 prevents the rocker arms 17q and 17q from swinging relative to the support shaft 7a. The tappet roller 9 is rotatably supported on the outer peripheral surface of the intermediate portion of the support shaft 7a via a radial-dollar bearing 10 (see FIG. 3). A pair of through-holes 4 and 4 are formed concentrically with each other at a position where they are aligned with each other at the intermediate portion between the rocker arms 17q and 17q. Further, a pair of convex portions 18 and 18 (pressing portions) are provided on the lower surface of the other end portions (the left end portions in FIGS. 25 to 26) of the rocker arms 17q and 17q. The tip surfaces of both convex portions 18 and 18 are partially cylindrical surfaces.

[0051] The rocker arms 17q and 17q as described above are manufactured as follows. First, as shown in FIG. 27 (a), by punching a single plate-like metal, a pair of the same shape and the same size are integrated by at least one connecting portion 38. Plate-shaped rocker arms 17q and 17q are formed. After that, until the pair of rocker arms are parallel to each other, both ends of the connecting portion 38 are bent by 90 degrees and arranged in parallel with each other at a predetermined interval as shown in FIG. A pair of plate-like rocker arms 17q and 17q are formed, which are connected to each other by at least one connecting portion 38 so that relative displacement is impossible. In the process of the bending force, both end portions of the support shaft 7a provided with the tappet roller 9 around the intermediate portion can be fitted into the support holes 8a and 8a.

[0052] In the state where the rocker arms 17q and 17q as described above are assembled in the valve operating mechanism of the engine, as shown in FIGS. The rocker arms 17q and 17q around the rocker shaft 5 can be oscillated and displaced by passing through the rocker shaft 5 without rattling. At the same time, the outer peripheral surface of the tappet roller 9 is brought into contact with the outer peripheral surface of the cam 2 fixed to the camshaft 1, and the both convex portions are The tip surfaces of 18 and 18 are brought into contact with the base end surfaces of the two valve bodies 12 and 12 (two intake valves or two exhaust valves provided in the same cylinder) one by one. When the engine is in operation, the rocker arms 17q and 17q are swung in synchronization with each other about the rocker shaft 5 as the cam 2 rotates, and the two valve bodies 12 and 12 are It is reciprocated in the axial direction by the pressing force of both convex portions 18 and 18 and the elasticity of the return spring 13 (not shown, see FIGS. 30 and 34).

[0053] As described above, if the cam follower device of this example is used, the two valve bodies 12, 12 can be reciprocated simultaneously by providing only one set of the cam 2 and the tappet roller 9. Therefore, as compared with the case where only the conventional cam follower device as described above is used as the cam follower device to be incorporated in the valve operating mechanism (independent cam follower device is incorporated for each valve element), The number of parts can be reduced. Therefore, the valve mechanism can be reduced in size (space saving), reduced in weight, reduced in friction, reduced in cost, and the like. Further, in the case of this example, by increasing the angle of the bent portion with the connecting portion 38, it is possible to widen the interval between the two mouth stopper single arms 17q, 17q. Both ends of the support shaft 7a can be press-fitted into the pair of support holes 8a and 8a without damaging the outer peripheral surface of the intermediate portion of the support shaft 7a. For this reason, as a method of hardening the surface of the support shaft 7a, it is possible to employ submerged quenching that can be performed at a lower cost than induction quenching. Therefore, the manufacturing cost can be reduced accordingly. The support shaft 7a may be formed in a circular tube shape, and an oil supply hole may be provided in an axially intermediate portion to supply oil to the radial-dollar bearing 10. Similarly, the rocker shaft 5 is formed in a circular tube shape, and an oil supply hole is provided in a portion located inside the through holes 4 and 4 at an intermediate portion in the axial direction of the rocker shaft 5. It is also possible to lubricate the sliding contact portion between the inner peripheral surface of the rocker and the outer peripheral surface of the rocker shaft 5.

[Twelfth example of embodiment]

28 to 29 show a twelfth example of the embodiment of the present invention. In the case of this example, it is provided in the middle part of a pair of rocker arms 17r, 17r which are arranged in parallel with each other at a predetermined interval and which are connected to each other by at least one connecting part 38 so that relative displacement is impossible. The cylindrical portions 39 and 39 are formed by applying a burring force to the peripheral portions of the through holes 4b and 4b. These cylindrical portions 39, 39 are the length of the rocker shaft 5 (see Fig. 26) through the above-mentioned through holes 4b, 4b. And has a role of suppressing wear of the swinging support portion. Since the structure and operation of the other parts are the same as those of the cam follower device shown in the embodiment 11, the description of the equivalent parts is omitted.

[0055] In the present invention, the connecting portion for integrally connecting a pair of rocker arms is formed on the edge of the rocker arm at the time of assembling the cam follower device, assembling to the engine, or in the assembled state. And can be formed at a position where there is no problem. However, considering the performance improvement of the engine incorporating the rocker arm (followability at high rotation), the position where the connecting part is formed is preferably closer to the through hole through which the rocker shaft is inserted. This is because the moment of inertia around the rocker shaft can be reduced as the position is closer to the through hole.

In each of the above-described embodiments, a structure (single roller type) in which one tappet roller around the support shaft is arranged is employed. However, when carrying out the present invention, a structure in which two tappet rollers of an outer diameter side and an inner diameter side, which are concentrically combined with each other so as to be relatively rotatable, are arranged around the support shaft (double roller type) ) Can also be adopted. Although not shown, the structure of the present invention can be applied to a screw type adjuster method, an HLA method combined with a lash adjuster, or the like.

[0057] This application consists of a Japanese patent application filed on March 31, 2006 (Japanese Patent Application No. 2006-96399), a Japanese patent application filed on September 4, 2006 (Japanese Patent Application No. 2006-238741), and an October 2006 application. This is based on a Japanese patent application (Japanese Patent Application No. 2006-282123) filed on the 17th, the contents of which are incorporated herein by reference.

Claims

The scope of the claims

[1] A cam follower device used by being incorporated in a valve operating mechanism of an engine in which at least one of an intake valve and an exhaust valve provided in one cylinder is two or more, and having a predetermined interval A pair of rocker arms that are arranged in parallel with each other and that form a pair of concentric support holes at positions that are aligned with each other at one end or in the middle,

[2] The cam follower device according to claim 1, wherein the pair of rocker arms are formed separately.

[3] The pair of support holes are formed at one end of the pair of rocker arms, and are incorporated in the valve mechanism at a position where they are aligned with each other at an intermediate portion of the rocker arms. Thus, a pair of concentric through holes that can pass through the rocker shaft provided in parallel with the camshaft are formed, and the swinging displacement of the both mouths of the rocker shaft around the rocker shaft is possible. The cam follower device according to claim 2.

[4] By making the thickness dimension of both rocker arms relatively large at one end of both rocker arms and relatively small at the other end, inner surfaces of the rocker arms facing each other. 4. The cam follower device according to claim 3, wherein an interval between the rocker arms is relatively narrow at one end portion and relatively wide at the other end portion.

[5] By providing a non-parallel plate portion that is non-parallel to the intermediate portion at a portion between the one end portion and the intermediate portion of the both rocker arms or between the intermediate portion and the other end portion, Spacing force between the inner surfaces of the two rocker arms facing each other. The cam follower device according to claim 3, wherein the cam follower device is relatively narrow and relatively wide at the other end.

6. The cam follower device according to claim 3, wherein both ends of a cylindrical sleeve are fitted and fixed to the pair of through holes, and a rocker shaft is passed through the sleeve.

[7] The pair of support holes are formed in an intermediate portion of the pair of rocker arms, and one end portions of the rocker arms are provided directly or via another member, and the valve mechanism The two rockers having a pair of receiving portions capable of abutting the distal end surfaces of the pair of plungers in a state where they are assembled, and having a contact portion between the both receiving portions and the distal end surfaces of the plungers as fulcrums The cam follower device according to claim 2, wherein the arm can swing and displace.

[8] The thickness dimensions of the two rocker arms are made relatively large at the middle part of the two rocker arms and relatively small at the one end and the other end, so that the two rocker arms face each other. The cam follower device according to claim 7, wherein the spacing force between the inner side surfaces is relatively narrow at an intermediate portion between the two rocker arms and relatively wide at one end and the other end.

[9] By providing a non-parallel plate portion that is non-parallel to the intermediate portion at a portion between the one end portion and the intermediate portion of both the rocker arms and a portion between the intermediate portion and the other end portion, The cam follower device according to claim 7, wherein the spacing force between the inner surfaces of the two rocker arms facing each other is relatively narrow at the middle portion of the rocker arms and relatively wide at one end and the other end.

[10] By disposing spacers that are externally fitted to the support shaft between the inner side surfaces of the rocker arms and both axial side surfaces of the tappet roller, the tappet roller is allowed. 2. The cam follower device according to claim 1, wherein the amount of axial displacement is regulated to a desired size.

[11] The part according to claim 1, wherein, in a part of the rocker arms, a thickness dimension of a part that needs to be higher in strength than a surrounding part thereof is larger than a thickness dimension of the surrounding part. Cam follower device.

12. The cam follower device according to claim 2, wherein each of the pair of rocker arms is formed by punching one metal plate.

[13] The pair of rocker arms cannot be relatively displaced by at least one connecting portion. The cam follower device according to claim 1, wherein the cam follower device is combined.

[14] The pair of support holes are formed at one end of the pair of rocker arms, and are incorporated in the valve mechanism at positions where they are aligned with each other at an intermediate portion of the rocker arms. Thus, a pair of concentric through holes that can pass through the rocker shaft provided in parallel with the camshaft are formed, and the swinging displacement of the both mouths of the rocker shaft around the rocker shaft is possible. The cam follower device according to claim 13.

[15] The pair of rocker arms, which are coupled to each other so that relative displacement is impossible by the at least one continuous portion, is formed by punching and bending a single metal plate. The cam follower device described in 1.