JP2013167236A - Cam follower device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a structure which has excellent assembling performance while securing durability, improves design flexibility; and can achieve reduction in size, weight, and manufacturing cost.SOLUTION: Both ends of a support shaft 3a are relatively rotatably supported with respect to both support walls 12b and 12c while being inserted in both support holes 15b and 15c of both the support walls 12b and 12c through a minute opening. An inner ring 16 having an outer diameter Dthat is larger than inner diameters dof the support holes 15b and 15c fitted to the outer peripheral surface of an intermediate portion in the axial direction of the support shaft 9a so as to be rotatable together with the support shaft 9a. Furthermore, a plurality of cylindrical rollers 13 and 13 are rollably disposed between an inner ring raceway 17 formed on the outer peripheral surface of the inner ring 16 and an outer ring raceway 18 formed on the inner peripheral surface of a tappet roller 8b provided at the outer diameter side of the inner ring 16.

Description

  The present invention relates to a cam follower device that is incorporated in a valve mechanism of an engine used for driving an automobile, etc., and reduces the friction of the valve mechanism to reduce the fuel consumption rate during engine operation. Regarding improvements.

  As a valve operating device for transmitting the movement of a cam fixed to a camshaft that rotates in synchronization with the crankshaft of an engine to a valve, a cam follower device has been widely described, for example, in Patent Documents 1 and 2 Known and widely implemented. 12-13 has shown the 1st example of the conventional structure of the cam follower apparatus described in patent document 1 among these. A rocker arm 1 that is a main body of the cam follower is rotatable to a cylinder head (not shown) of an engine by a rocker shaft 3 inserted into a shaft hole 2 formed in an intermediate portion in the length direction (left-right direction in FIG. 12). Supported. Further, an adjusting bolt 4 is screwed into a screw hole formed in the base end portion and fixed to the base end portion (left end portion in FIG. 12) of the rocker arm 1 and a lock nut 5 is tightened. A base end surface (upper end surface in FIG. 12) of the engine valve 6 that is an intake valve or an exhaust valve supported so as to be reciprocally movable by the cylinder head is provided on the front end surface (lower end surface in FIG. 12) of the adjustment bolt 4. It is in contact. The engine valve 6 is always urged by a return spring 7 in a valve closing direction (a contact direction with the adjusting bolt 4). Accordingly, the rocker arm 1 is given a clockwise elasticity with the rocker shaft 3 as the center in FIG.

  On the other hand, a tappet roller 8 is rotatably supported by a tip end portion (right end portion in FIG. 12) of the rocker arm 1 via a support shaft 9, and the outer peripheral surface of the tappet roller 8 is made elastic by the return spring 7. Based on this, the outer peripheral surface of the cam 10 is brought into contact. The cam 10 is formed integrally with a camshaft 11 that rotates in conjunction with a crankshaft (not shown), and is rotatably supported by the cylinder head. With such a configuration, the rotation of the cam shaft 11 is converted into a reciprocating swinging motion of the rocker arm 1 about the rocker shaft 3, and the engine valve 6 is connected to the return spring by the rocker arm 1. 7 is reciprocated in the axial direction against the elasticity of 7 or based on this elasticity. And the opening / closing operation | movement of the inlet port or exhaust port provided in the cylinder top part of the said engine is performed.

  In the valve operating apparatus as described above, a portion for rotatably supporting the tappet roller 8 via the support shaft 9 with respect to the rocker arm 1 is configured as shown in FIG. The support shaft 9 is spanned between a pair of support wall portions 12, 12 provided in parallel at a distance from each other at the distal end portion of the rocker arm 1. The tappet roller 8 is composed of a plurality of cylindrical rollers (needles) 13 and 13 around a portion located between the inner side surfaces of the support wall portions 12 and 12 at an intermediate portion of the support shaft 9. A radial roller (needle) bearing 14 is rotatably supported. Both end portions of the support shaft 9 are fitted and supported in circular support holes 15 and 15 provided concentrically with the support wall portions 12 and 12, respectively. In this state, the outer peripheral edge of both ends is plastically deformed radially outward by abutting the leading edge of a caulking jig such as a punch against the outer diameter of the both ends of the support shaft 9, thereby supporting the support. The shaft 9 is firmly fixed to the support holes 15 and 15. The radial roller bearing 14 is omitted, a so-called single roller type, or a so-called double roller type in which a cylindrical member is provided between the inner peripheral surface of the tappet roller and the outer peripheral surface of the support shaft so as to be relatively rotatable. A structure can also be adopted. Since such a structure is described in Patent Document 2, detailed description thereof is omitted.

  In the case of the first example of the conventional structure shown in FIGS. 12 to 13 described above, the intermediate portion in the longitudinal direction of the rocker arm 1 is a fulcrum, and the tappet roller 8 and the engine valve 6 are driven at both ends. The adjusting bolt 4 is provided. On the other hand, in Patent Document 3, as shown in FIGS. 14 and 15, a tappet roller is provided around a support shaft 9 a fixed to an intermediate portion in the length direction of the rocker arm 1 a (the left-right direction in FIGS. A structure in which 8a is rotatably supported by a radial roller bearing 14 is described. Both ends of the support shaft 9a are fitted and supported in circular support holes 15a and 15a provided concentrically with each other on the pair of support walls 12a and 12a, respectively. In the case of the second example of such a conventional structure, in the assembled state to the engine, the tip of the lash adjuster serving as a fulcrum is provided on one side of the one end of the rocker arm 1a (the bottom of the left end of FIGS. 14 to 15). The base end surface of the engine valve is abutted against one surface of the other end (the lower surface of the right end in FIGS. 14 to 15).

In any structure, the outer peripheral surface of the intermediate portion of the support shaft 9 (9a) serves as an inner ring raceway of the radial roller bearing 14 for rotatably supporting the tappet roller 8 (8a). It is not preferable that the outer peripheral surface of the intermediate portion is scratched. Therefore, the structure in which the support shaft 9 (9a) is press-fitted into the support holes 15 and 15 (15a and 15a) formed in the support wall portions 12 and 12 (12a and 12a) is from the viewpoint of preventing scratches. It is disadvantageous.
Therefore, in order to prevent damage to the outer peripheral surface of the intermediate portion of the support shaft 9 (9a), the entire support shaft 9 (9a) is heated and then immersed in quenching oil, so-called submerged firing. The entire support shaft 9 (9a) is hardened. However, in this case, the entire support shaft 9 (9a) is cured. For this reason, when caulking both ends of the support shaft 9 (9a), the tip of the jig such as a punch that presses against the both end surfaces of the support shaft 9 (9a) is damaged, so that it is frequently replaced. Cost. As a result, the processing cost increases, and the manufacturing cost of the cam follower device may increase.

  On the other hand, in order to solve the above-described problems, it is possible to cure by induction hardening only on the outer peripheral surface of the intermediate portion while leaving the raw (unquenched) portions at both ends of the support shaft 9 (9a). Has been done. However, this induction hardening causes an increase in processing cost. Further, even if both ends of the support shaft 9 (9a) are left raw, the durability of the jig used in the work of caulking these both ends is limited, and the cost is increased, and the cam follower device Increases manufacturing costs.

  In the case of the structure of the cam follower device described above, the radial roller bearing 14 provided between the inner peripheral surface of the tappet roller 8 (8a) and the outer peripheral surface of the intermediate portion of the support shaft 9 (9a) is provided with a load capacity. For this reason, a so-called full roller bearing without a cage is often used. When assembling the cam follower device having such a structure, first, the inner peripheral surface of the tappet roller 8 (8a) and the outer peripheral surface of a shaft member (so-called stopper plug) disposed on the inner diameter side of the tappet roller 8 (8a) A roller assembly in which a plurality of cylindrical rollers are arranged in the space between is assembled.

Next, the roller assembly is placed between the inner surfaces in the width direction of the two support wall portions 12 and 12 (12a and 12a), both end surfaces of the stopper plug, and both the support wall portions 12 and 12 (12a and 12a). The support holes 15 and 15 (15a and 15a) are aligned with each other. Next, the support shaft 9 (9a) is inserted into the support hole 15 (15a) of one support wall portion 12 (12a) of the support wall portions 12, 12 (12a, 12a). It inserts from the width direction outer side of the part 12 (12a). Next, while pushing out the stopper plug by the support shaft 9 (9a), one end of the support shaft 9 (9a) is inserted into the support hole 15 (15a) of the other support wall portion 12 (12a). Push until Further, the both ends of the support shaft 9 (9a) are caulked and spread. In this state, the support shaft 9 (9a) is supported in a state in which relative rotation is prevented with respect to the support wall portions 12 and 12 (12a and 12a).
In such a structure, it is troublesome to insert the support shaft 9 (9a) into the inner diameter side of the tappet roller 8 (8a) while pushing out the stopper plug. In addition, the number of parts and the number of assembling steps of the assembling equipment are increased by using this stopcock, and the cost is increased.

In the case of the structure of each cam follower device described above, the outer diameter of the support shaft 9 (9a) and the support holes 15 and 15 (15a and 15a) of the support wall portions 12 and 12 (12a and 12a). The inner diameter is determined based on the diameter of the inscribed circle of each of the cylindrical rollers 13 and 13 constituting the radial roller bearing 14. For this reason, the freedom degree of the design regarding the said support shaft 9 (9a) and the said both support wall parts 12 and 12 (12a, 12a) is low.
In the case of each cam follower device described above, when the diameter of the inscribed circle of each of the cylindrical rollers 13 and 13 constituting the radial roller bearing 14 is large, the support shaft 9 ( 9a) The entire outer diameter needs to be increased. For this reason, weight may increase.
In the case of the cam follower device described above, the support shaft 9 (9a) is supported in a state in which relative rotation is prevented with respect to the support wall portions 12 and 12 (12a and 12a). For this reason, the load zone of the support shaft 9 (9a) is limited to a certain range. That is, the radial load acting at the time of use is always loaded (supported) at the same position on the support shaft 9 (9a). As a result, a load is repeatedly applied to the portion of the support shaft 9 (9a) where the radial load is applied, and durability may be reduced.

JP 2006-183856 A JP 2005-326023 A JP 2009-79569 A

  In view of the circumstances as described above, the present invention realizes a structure that ensures durability and is easy to assemble, has improved design freedom, is small and light, and can reduce manufacturing costs. Invented accordingly.

The cam follower device of the present invention includes a rocker arm, a support shaft, and a tappet roller.
Of these, the rocker arm is provided with a pair of support walls provided in a state of being spaced apart from each other, and is provided to face a cam fixed to a camshaft that rotates in synchronization with the crankshaft of the engine. In response to the movement of the cam, the displacement is oscillated.
The support shaft is supported so as to span between the two support wall portions in a state where both ends thereof are inserted into a pair of support holes formed at positions where the both support wall portions are aligned with each other. ing.
The tappet roller is rotatably supported around an intermediate portion of the support shaft.

In particular, in the case of the cam follower device of the present invention, an inner ring equivalent member having an outer diameter larger than the inner diameters of the two support holes is prevented from rotating relative to the support shaft at an intermediate portion in the axial direction of the support shaft. It is externally fitted with an interference fit.
And the said tappet roller is arrange | positioned around the said inner ring equivalent member so that relative rotation with respect to this inner ring equivalent member is possible.

Specifically, when implementing such a cam follower device of the present invention, as in the invention described in claim 2, both end portions of the support shaft are connected to the both support holes inside the support holes. It is possible to rotate the inner part with a gap fit.
Further, when the cam follower device of the present invention as described above is implemented, specifically, as in the invention described in claim 3, the inner peripheral surface of the tappet roller and the outer peripheral surface of the inner ring equivalent member A radial roller bearing is provided between them. The radial roller bearing is a full roller type without a cage.

Further, when the invention described in claim 3 is carried out, preferably, as in the invention described in claim 4, the opening portions at both ends of the bearing space of the radial roller bearing are provided in the width direction inner side of the both support wall portions. A pair of washers each having an annular shape are provided. The outer diameters of both washers are made larger than the dimensions of the support wall portions in the height direction of the support wall portions.
Further, when implementing the cam follower device of the present invention as described above, specifically, as in the invention described in claim 5, the inner peripheral surface of the tappet roller and the outer peripheral surface of the inner ring equivalent member are provided. It is possible to make a structure such as a so-called double roller type (functionally a single roller type) by sliding contact.
Alternatively, as in the invention described in claim 6, between the inner peripheral surface of the tappet roller and the outer peripheral surface of the inner ring equivalent member, a cylindrical member is rotated relative to the tappet roller and the inner ring equivalent member. It is also possible to adopt a so-called triple roller type structure (functionally a double roller type).

According to the cam follower device of the present invention configured as described above, while ensuring durability, it is possible to improve assembly, improve design freedom, reduce size and weight, and reduce manufacturing costs.
First, the durability can be improved by subjecting the entire support shaft to a quenching process by squeezing. That is, in the case of the cam follower device of the present invention, the outer diameter of the inner ring equivalent member is made larger than the inner diameters of the two support holes of the two support wall portions, whereby the support shaft in the axial direction relative to the two support wall portions I try to keep it from falling out. Therefore, it is not necessary to crimp both ends of the support shaft, and it is not necessary to leave the both ends of the support shaft in a raw state (a state in which no curing treatment is performed). For this reason, 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 quenching oil. As a result, the strength and rigidity of the entire support shaft can be sufficiently ensured, and the support shaft can be effectively prevented from being plastically deformed based on the radial load received during use.
In the case of the invention described in claim 2, the support shaft is supported so as to be rotatable with respect to the both support wall portions. For this reason, the load zone of this support shaft is not limited to a certain range. That is, the position of the support shaft that applies a radial load during use is not always the same. As a result, it is possible to prevent the load from being repeatedly applied to the same position of the support shaft, thereby extending the life of the support shaft.
In the case of the invention described in claim 4, a pair of annular washers is provided on the inner side in the width direction of the both supporting wall portions so as to close both end openings of the bearing space of the radial roller bearing. . For this reason, it is possible to prevent the inner surfaces in the width direction of the both support plate portions from being worn by rubbing with the respective rollers constituting the radial roller bearing, thereby extending the life of the both support wall portions.

  In addition, the assembling property can be improved by providing the inner ring equivalent member. That is, in a state where the roller assembly in which this inner ring equivalent member, tappet roller, or other constituent member (for example, cylindrical roller constituting a radial roller bearing) is assembled is disposed between the two support wall portions, The support shaft is inserted and assembled in the order of the support hole of one of the support wall portions, the inner peripheral surface of the inner ring equivalent member, and the support hole of the other support wall portion. For this reason, unlike the conventional structure described above, there is no need to insert the stopper plug disposed on the inner diameter side of the tappet roller so as to be pushed out by the support shaft.

  In addition, the degree of freedom in design can be improved by providing the inner ring equivalent member. That is, in the case of the above-described conventional structure, the outer diameter of the support shaft and the inner diameters of both support holes of the both support walls are restricted by the diameter of the inscribed circle of the cylindrical roller constituting the radial roller bearing. . On the other hand, in the case of the present invention, the outer diameter of the inner ring equivalent member corresponds to the diameter of the inscribed circle of the cylindrical roller of the radial roller bearing, and the inner diameter of the inner ring equivalent member is set to the outer diameter of the support shaft and the both It can set suitably corresponding to the internal diameter of both the support holes of a support wall part. As a result, it is possible to improve the degree of freedom in designing the outer diameter of the support shaft and the inner diameters of the support holes of the support wall portions.

  Further, the size and weight can be reduced by providing the inner ring equivalent member. That is, in order to ensure the desired rigidity of the two support wall portions, it is necessary to ensure a predetermined width dimension in the radial direction of the two support holes around the support holes of the two support wall portions. In the case of the present invention, the outer diameter of the support shaft can be reduced by changing the inner diameter of the inner ring equivalent member. For this reason, while securing a certain width dimension with respect to the radial direction of the two support holes around the support holes of the two support wall parts, the height direction of the two support wall parts of the two support wall parts The dimensions regarding can be reduced. As a result, it is possible to reduce the size and weight of both the supporting wall portions, and thus the rocker arm.

  Particularly, in the case of the invention described in claim 4, a pair of annular washers is provided on the inner side in the width direction of the both support wall portions so as to close both end openings of the bearing space of the radial roller bearing. . For this reason, these both washers can prevent each roller constituting the radial roller bearing from coming out of the bearing space in the axial direction. As a result, it is possible to further reduce the dimensions of the both support wall portions with respect to the height direction of the both support wall portions.

  In addition, by reducing the dimensions of the two support wall portions in the height direction of the two support wall portions as described above, the inner side surfaces in the width direction of the two support wall portions and the both end surfaces in the axial direction of the tappet roller. The area of the overlapping portion in the axial direction can be reduced. For this reason, the space in which each roller of the radial roller bearing is arranged from the outside through a portion between the inner side surface in the width direction of the both support wall portions and the both axial end surfaces of the tappet roller. It becomes easy to enter inside.

  Further, the manufacturing cost can be reduced by eliminating the need for caulking work, and by applying quenching treatment to harden the support shaft, and without the need for a stopper plug as in the conventional structure described above. I can plan things. In other words, in the case of the present invention, the caulking work is unnecessary, and a jig such as a punch for forming the caulking portion is also unnecessary. In addition, the quenching process by submerged baking can be performed at a lower cost than the induction hardening process. Furthermore, the stopcock is unnecessary. As a result, it is possible to reduce the processing cost and the assembly equipment cost, and consequently the manufacturing cost of the entire cam follower device.

The figure equivalent to the AA cross section of FIG. 12, or the BB cross section of FIG. 14 which shows the 1st example of embodiment of this invention. The figure similar to FIG. 1 which shows the 2nd example. The figure similar to FIG. 1 which shows the 3rd example. The figure similar to FIG. 1 which shows the 4th example. Similarly, the figure seen from the side of FIG. The figure similar to FIG. 1 which shows the 5th example of embodiment of this invention. Similarly, the figure seen from the side of FIG. The figure similar to FIG. 1 which shows the 6th example of embodiment of this invention. Similarly, the figure seen from the side of FIG. The figure similar to FIG. 1 which shows the 7th example of embodiment of this invention. Similarly, the figure seen from the side of FIG. The side view which shows the 1st example of the conventional cam follower apparatus. FIG. 13 is an enlarged CC cross-sectional view of FIG. 12. The side view which shows the 2nd example of the conventional cam follower apparatus. The figure seen from the upper part of FIG.

[First example of embodiment]
FIG. 1 shows a first example of an embodiment of the present invention corresponding to claims 1 to 3. The features of the cam follower device of the present invention, including this example, are described in the claims between the support structure for the support wall portions 12b and 12c of the support shaft 9b and the support shaft 9b and the tappet roller 8b. The inner ring 16 corresponding to the inner ring equivalent member is provided. The structure other than the characteristic part of the present invention and the assembled state to the engine are substantially the same as the structure of a conventionally known cam follower device including the structure shown in FIGS. The illustrations and explanations are omitted or simplified for the parts to be performed, and hereinafter, the characteristic parts of this example will be mainly described.

In the case of the cam follower device of this example, both end portions of the steel hollow or solid support shaft 9b are inserted into the support holes 15b and 15c of the both support wall portions 12b and 12c made of steel through a minute gap. In this state (gap fitting), the two support wall portions 12b and 12c are supported in a state capable of relative rotation. That is, the outer diameter _{D 9} of the support shaft 9b, the both supporting holes 15b, slightly smaller than the inner diameter _{d 15} of _{15c (D 9 <d 15)} .
Further, the support shaft 9b is heated by so-called submerged heating, in which the entire support shaft 9b is heated and then immersed in quenching oil in order to sufficiently secure the overall strength and rigidity of the support shaft 9b. It is cured. Although the processing cost is higher than quenching by sub-bake, it can be hardened by induction hardening only on the outer peripheral surface of the intermediate part while leaving raw parts at both ends of the support shaft 9b. Further, by hardening the inner peripheral surfaces of the support holes 15b and 15c such as quenching, the inner peripheral surfaces of the support holes 15b and 15c and the outer peripheral surfaces of both end portions of the support shaft 9b are slid. It is also possible to prevent the contact portion from being damaged such as wear. An annular slide bearing member may be provided between the outer peripheral surfaces of both ends of the support shaft 9b and the inner peripheral surfaces of the support holes 15b and 15c. Moreover, it can also be set as the structure which press-fits the both ends of the said support shaft 9b in the support holes 15b and 15c of the said support wall parts 12b and 12c.

The cylindrical inner ring 16 is tightly fitted on the outer peripheral surface of the intermediate portion in the axial direction of the support shaft 9b in a state in which relative rotation with respect to the support shaft 9b is prevented (rotatable with the support shaft 9b). It is fitted. Outer diameter _{D 16} of the inner ring 16, the two support holes 15b, greater than the inner diameter _{d 15} of _{15c (D 16> d 15)} . In this way, the support shaft 9b is prevented from coming off in the axial direction with respect to the support wall portions 12b and 12c.
An inner ring raceway 17 is formed on the outer peripheral surface of the inner ring 16. Further, the tappet roller 8 b is disposed on the outer diameter side of the inner ring 16 so as to be concentric with the inner ring 16. An outer ring raceway 18 is formed on the inner peripheral surface of the tappet roller 8b. A plurality of cylindrical rollers 13 and 13 are rotatably arranged between the inner ring raceway 17 and the outer ring raceway 18 to constitute a radial roller bearing 14a.

  When assembling the cam follower device of the present invention as described above, first, a space (bearing space 21) between the inner peripheral surface of the tappet roller 8b and the outer peripheral surface of the inner ring 16 provided on the inner diameter side of the tappet roller 8b. ), A roller assembly 19 having a plurality of cylindrical rollers 13 and 13 constituting the radial roller bearing 14a is assembled.

  Next, the roller assembly 19 is disposed between the inner side surfaces of the support wall portions 12b and 12c in the width direction between both axial openings at the inner peripheral surface of the inner ring 16, and the support wall portions 12b and 12c. It arrange | positions in the state which aligned both support holes 15b and 15c. Next, the support shaft 9b is inserted into the support hole 15b of one of the support wall portions 12b and 12c from the width direction outside of the one support wall portion 12b. Next, the support shaft 9b is pushed into the inner peripheral surface of the inner ring 16 (with an interference fit), and the support shaft 9b has one end portion (left end portion in FIG. 1) as the other support wall portion 12c. Until it is inserted into the support hole 15c. In such a state, a slight gap is provided between the outer peripheral surfaces of both end portions of the support shaft 9b and the inner peripheral surfaces of the support holes 15b and 15c of the support wall portions 12b and 12c. The direction in which the support shaft 3a is assembled may be opposite to the direction described above.

In the case of the cam follower device of this example as described above, it is possible to improve the assembling property, improve the degree of design freedom, reduce the size and weight, and reduce the manufacturing cost while ensuring the durability.
First, the durability can be ensured by subjecting the entire support shaft 9b to a quenching process by submerged baking. That is, when the cam follower apparatus of the present invention, both supporting walls 12b, two support holes 15b of 12c, than the inner diameter _{d 15} of 15c, by increasing the outer diameter _{D 16} of the inner ring 16, the support shaft 9b In this case, the support walls 12b and 12c are prevented from coming off in the axial direction. Therefore, it is not necessary to caulk both ends of the support shaft 9b, and it is not necessary to leave both ends of the support shaft 9b in a raw state (a state where the curing process is not performed). For this reason, quenching of the support shaft 9b can be performed by so-called submerged heating in which the entire support shaft 9b is heated and then immersed in oil for quenching. As a result, the strength and rigidity of the entire support shaft 9b can be sufficiently secured, and the support shaft 9b can be effectively prevented from being plastically deformed based on the radial load received during use.

  In the case of the cam follower device of the present invention, the support shaft 9b is supported so as to be rotatable with respect to the support wall portions 12b and 12c. For this reason, the load zone of the support shaft 9b is not limited to a certain range. That is, the position of the support shaft 9b that applies a radial load during use is not always the same. As a result, it is possible to prevent the load from being repeatedly applied to the same position of the support shaft 9b, thereby extending the life of the support shaft 9b.

  Further, the ease of assembly can be improved by providing the inner ring 16. That is, in the state where the roller assembly 19 is disposed between the support wall portions 12b and 12c, the support shaft 9b is connected to the support wall portion 12b of one of the support wall portions 12b and 12c. The support hole 15b, the inner peripheral surface of the inner ring 16, and the support hole 15c of the other support wall portion 12c are inserted and assembled in this order. Therefore, as in the conventional structure described above, there is no need to insert the stopper plug disposed on the inner diameter side of the tappet roller 8 (8a) (see FIGS. 12 to 15) by pushing it out by the support shaft 9 (9a). It is.

In addition, the degree of freedom in design can be improved by providing the inner ring 16. That is, in the case of the above-described conventional structure, the outer diameter of the support shaft 9 (9a) and the both support wall portions 12, based on the diameters of the inscribed circles of the cylindrical rollers 13 and 13 constituting the radial roller bearing 14. The inner diameters of both support holes 15 and 15 (15a and 15a) of 12 (12a and 12a) are restricted. On the other hand, in the present invention, the outer diameter _{D 16} of the inner ring 16, together correspond to the diameter of the inscribed circle of the cylindrical rollers 13 and 13 constituting the radial roller bearing 14a, the inner diameter inner diameter _{d 16} of the inner ring 16 , And can be appropriately set corresponding to the outer diameter of the support shaft 9b. As a result, it is possible to improve the degree of freedom in designing the outer diameter of the support shaft 9b and the inner diameters of the support holes 15b and 15c of the support wall portions 12b and 12c. If the support shaft 3a and the support wall portions 4a and 4b are reduced in size as the degree of freedom in design increases, the lubricity of the radial roller bearing 14a can be improved.

Further, the size and weight can be reduced by providing the inner ring 16. That is, in order to ensure the desired rigidity of the support wall portions 12b and 12c, the support wall portions 12b and 12c are provided around the support holes 15b and 15c in the radial direction of the support holes 15b and 15c. , it is necessary to secure a predetermined width L _12. For the present invention, by changing the inner diameter d ₁₆ of the inner ring 16, it is possible to reduce the outer diameter D ₉ of the support shaft 9b. For this reason, the both support wall portions 12b, 12c are secured around the support holes 15b, 15c of the both support wall portions 12b, 12c with a certain width dimension in the radial direction of the support holes 15b, 15c. of 12c, it can reduce the size _{H 12} on these two support walls 12b, 12c in the height direction (vertical direction in FIG. 1). As a result, it is possible to reduce the size and weight of both the supporting wall portions 12b and 12c, and thus the rocker arm 1b.
Also, the two support walls 12b, and 12c as described above, these two support walls 12b, by reducing the size _{H 12} regarding the height direction 12c, these two support walls 12b, 12c the width direction in the It is possible to reduce the area of the overlapping portion in the axial direction between the side surface and both end surfaces in the axial direction of the tappet roller 8b. For this reason, the lubricating oil is disposed from the outside between the inner surfaces in the width direction of the both support wall portions 12b and 12c and both end surfaces in the axial direction of the tappet roller 8b, and each roller of the radial roller bearing is disposed from the outside. It becomes easy to enter the space that has been.

  Furthermore, to reduce the manufacturing cost, the caulking work is not necessary, and the support shaft 9b is hardened by a quenching process by the squeezing, and the stopper is not required as in the conventional structure described above. It can be planned by a certain thing. In other words, in the case of the present invention, the caulking work is unnecessary, and a jig such as a punch for forming the caulking portion is also unnecessary. In addition, the quenching process by submerged baking can be performed at a lower cost than the induction hardening process. Furthermore, the stopcock is unnecessary. As a result, it is possible to reduce processing costs and component costs, and in turn reduce the manufacturing cost of the entire cam follower device.

[Second Example of Embodiment]
FIG. 2 shows a second example of an embodiment of the present invention corresponding to claims 1, 2, and 5. In the case of the cam follower device of this example, the outer ring surface of the inner ring 16a fitted on the outer circumferential surface of the intermediate portion in the axial direction of the support shaft 9b and the outer diameter side of the inner ring 16a can be rotated relative to the inner ring 16a. The tappet roller 8b provided is in sliding contact with the inner peripheral surface. The shape and dimensions of the tappet roller 8b are substantially the same as those in the first example of the above-described embodiment.

  That is, the cam follower device of this example has a so-called double roller type structure in which the radial roller bearing 14a of the first example of the embodiment described above is omitted. However, the inner ring 16a constituting the cam follower device of the present example rotates together with the support shaft 9b on the outer peripheral surface of the intermediate portion in the axial direction of the support shaft 9b, like the inner ring 16 of the first example of the embodiment described above. In a possible state (relative rotation with respect to the support shaft 9b is prevented), it is externally fitted with an interference fit. Therefore, from a functional viewpoint, the cam follower device of the present example functions as a so-called single roller type cam follower device. Other structures, operations and effects are the same as those of the first example of the embodiment described above.

[Third example of embodiment]
FIG. 3 shows a third example of an embodiment of the present invention corresponding to claims 1, 2, and 6. In the case of the cam follower device of this example, the inner diameter side roller 20 is placed between the outer peripheral surface of the inner ring 16 fitted on the outer peripheral surface of the intermediate portion in the axial direction of the support shaft 9b and the inner peripheral surface of the tappet roller 8b. 16 and the tappet roller 8b are provided in a state capable of relative rotation. The shapes and dimensions of the tappet roller 8b and the inner ring 16 are substantially the same as in the first example of the embodiment described above.

  That is, the cam follower device of this example has a so-called triple roller type structure in which the inner diameter side roller 20 is provided instead of the radial roller bearing 14a of the first example of the above-described embodiment. However, the inner ring 16 constituting the cam follower device of this example also prevents relative rotation with respect to the support shaft 9b on the outer peripheral surface of the intermediate portion in the axial direction of the support shaft 9b, as in the first example of the embodiment described above. In the state of being made (rotatable with the support shaft 9b), it is externally fitted. Therefore, from a functional viewpoint, the cam follower device of this example functions as a so-called double roller type cam follower device. Other structures, operations and effects are the same as those of the first example of the embodiment described above.

[Fourth Example of Embodiment]
FIGS. 4-5 has shown the 4th example of embodiment of this invention corresponding to Claims 1-4. In the case of the cam follower device of this example, an annular shape made of hard metal or synthetic resin between the inner side surface in the width direction of the pair of support walls 12d and 12e and both end surfaces in the axial direction of the inner ring 16 in the axial direction. A pair of washers 22 and 22 are provided. The outer diameter _{D 22} of both washers 22 and 22 is greater than the inner diameter _{d 8} of the tappet rollers _{8b (D 22> d 8)} . That is, these washers 22 and 22 are provided in a state of closing both axial end openings of the bearing space 21 in which the cylindrical rollers 13 and 13 constituting the radial roller bearing 14a are arranged. In the case of this example, the outer diameter D22 of the washers 22 and _{22 is set} to the height direction of the support wall portions 12d and 12e (the vertical direction in FIGS. 4 and 5). ) _Is larger than the dimension H _12d (D ₂₂ > H _12d ).

According to the cam follower device of this example, it is possible to further reduce the size and weight as compared with the structure of the first example of the embodiment described above. In other words, in the case of this example, both the washers 22, 22 block the both ends of the bearing space 21 in the axial direction and prevent the cylindrical rollers 13, 13 from coming out of the bearing space 21 in the axial direction. I am trying. For this reason, it is not necessary to prevent the cylindrical rollers 13 and 13 from coming off in the axial direction by the support wall portions 12d and 12e. As a result, the size H _12d of the support wall portions 12d and 12e in the height direction of the support wall portions 12d and 12e is reduced, and the rocker arm including the support wall portions 12d and 12e is small and lightweight. Can be realized.
In the case of this example, both the washers 22 and 22 close both axial end openings of the bearing space 21. For this reason, the inner side surfaces in the width direction of the both support plate portions 12d and 12e are prevented from being worn by rubbing with the rollers 13 and 13 constituting the radial roller bearing 14a, and the both support wall portions 12d. , 12e can be extended. Other structures, operations and effects are the same as those of the first example of the embodiment described above.

[Fifth Example of Embodiment]
6 to 7 also show a fifth example of the embodiment of the invention corresponding to claims 1 to 4. For the cam follower apparatus of this example, compared to the dimension L ₁₆ in the axial direction of the inner ring 16 of the first example of the embodiment described above (see FIG. 1), and increasing the size L _16b in the axial direction of the inner ring 16b (L _16b > L ₁₆ ). The shape and dimensions of the tappet roller 8b are substantially the same as those in the first example of the above-described embodiment. Accordingly, both end portions in the axial direction of the inner ring 16b are positioned on the outer side in the width direction than both end portions in the axial direction of the tappet roller 8b.

Further, both the supporting wall portions 12d and 12e are located on the inner side in the width direction with respect to the inner side surface in the width direction, and on both ends in the axial direction of the outer peripheral surface of the inner ring 16b. A pair of annular washers 22a and 22a are provided in a certain portion. These two washers 22a, the outer diameter _{D 22a} of 22a is greater than the inner diameter _{d 8} of the tappet rollers _{8b (D 22a> d 8)} . Therefore, both the washers 22a and 22a are provided in a state in which both end portions in the axial direction of the bearing space 21 in which the cylindrical rollers 13 and 13 constituting the radial roller bearing 14b are arranged are closed.
In the case of this example, the outer diameter D _22a of the both washers 22a and 22a is set to the height direction of the both support wall portions 12d and 12e (the vertical direction in FIGS. 6 and 7). ) _Is larger than the dimension H _12d (D _22a > H _12d ). Other structures, operations and effects are the same as those in the fourth example of the embodiment described above.

[Sixth Example of Embodiment]
8 to 9 also show a sixth example of the embodiment of the invention corresponding to claims 1 to 4. For the cam follower apparatus of this example, compared to the dimension L ₈ in the axial direction of the tappet roller 8b of the first example of the embodiment described above, and increasing the size L _8c in the axial direction of the tappet roller 8c (L _8c > _L 8). The shape and dimensions of the inner ring 16 are substantially the same as those in the first example of the embodiment described above. Therefore, both end portions in the axial direction of the tappet roller 8c are located on the outer side in the width direction than both end portions in the axial direction of the inner ring 16.

Further, both support wall portions with respect to the inner diameter side of both end portions in the axial direction of the tappet roller 8c (portions on the outer side in the width direction than both end surfaces in the axial direction of the inner ring 16) and the axial direction of the outer peripheral surface of the support shaft 9b. A pair of annular washers 22b and 22b are provided between the inner side surfaces of 12d and 12e in the width direction and both end surfaces of the inner ring 16 in the axial direction. Moreover, these two washers 22b, the outer diameter _{D 22b} and 22b is slightly smaller than the inner diameter _{d 8} of the tappet rollers _{8c (D 22b <d 8)} . That is, these washers 22b and 22b are provided in a state in which both axial ends of the bearing space 21 in which the cylindrical rollers 13 and 13 constituting the radial roller bearing 14c are arranged are closed.
In the case of this example, the outer diameter D _22b of the washers 22b and 22b is made larger than the dimension H _{12d of the} support wall portions 12d and 12e in the height direction of the support wall portions 12d and 12e. (D _22b > H _12d ). Other structures, operations and effects are the same as those in the fourth example of the embodiment described above.

[Seventh example of embodiment]
10 to 11 also show a seventh example of the embodiment of the invention corresponding to claims 1 to 4. In the case of the cam follower device of this example, the inner ring 16b (see FIG. 6) of the fifth example of the embodiment described above and the tappet roller 8c (see FIG. 8) of the sixth example of the embodiment described above are combined in a radial manner. A roller bearing 14d is configured. That, in this example, compared to the dimension L ₈ in the axial direction of the tappet roller 8b of the first example of the embodiment described above (see FIG. 1), to increase the size L _8c, the axial direction of the tappet roller 8c with _(L 8c> _{L 8),} as well as compared to the dimension _{L 16} in the axial direction of the first example of the inner ring 16 (see FIG. 1), and increasing the size _{L 16b} in the axial direction of the inner ring 16b _{(L 16b>} L _16). The dimensions of the tappet roller and the inner ring in the axial direction are the same as those in the first example of the embodiment, and the dimensions of the cylindrical rollers in the axial direction are the same as the cylindrical rollers 13 and 13 of the first example of this embodiment. (See FIG. 1).

A pair of annular washers 22c and 22c are provided between both axial ends of the outer peripheral surface of the inner ring 16b and both axial ends of the inner peripheral surface of the tappet roller 8c. That is, these washers 22c and 22c are provided in a state in which both axial end openings of the bearing space 21 in which the cylindrical rollers 13 and 13 constituting the radial roller bearing 14d are arranged are closed.
In the case of this example, the outer diameter D _22c of the washers 22c and 22c is set to the height direction of the support wall portions 12d and 12e of the both support wall portions 12d and 12e (the vertical direction in FIGS. 10 and 11). ) _Is larger than the dimension H _12d (D _22c > H _12d ). Other structures, operations and effects are the same as those in the fourth example of the embodiment described above.

  In each example of the embodiments, the support shaft 9b is supported in a rotatable state with respect to the support wall portions 12b and 12c. However, both the support wall portions 12b and 12c can be supported by supporting both the support wall portions 12b and 12c by press-fitting both ends of the support shaft 9b into the support holes 15b and 15c. A structure in which the rotation of the shaft 9b is prevented can also be adopted.

DESCRIPTION OF SYMBOLS 1, 1a, 1b Rocker arm 2 Shaft hole 3 Rocker shaft 4 Adjust bolt 5 Lock nut 6 Engine valve 7 Return spring 8, 8a, 8b Tappet roller 9, 9a, 9b, 9c Support shaft 10 Cam 11 Cam shaft 12, 12a, 12b, 12c, 12d, 12e Support wall part 13 Cylindrical roller 14, 14a, 14b, 14c, 14d Radial roller bearing 15, 15a, 15b, 15c, 15d, 15e Support hole 16, 16a, 16b Inner ring 17 Inner ring raceway 18 Outer ring raceway 19 Roller assembly 20 Inner diameter side roller 21 Bearing space 22, 22a, 22b, 22c Washer

Claims (6)

A pair of support walls provided at a distance from each other is provided, and is provided opposite to a cam fixed to a camshaft that rotates in synchronization with the crankshaft of the engine. Rocker arm that swings and displaces,
A support shaft supported in a state where both end portions are inserted between a pair of support holes formed at positions where the both support wall portions are aligned with each other, and spanned between the two support wall portions;
In a cam follower device provided with a tappet roller rotatably supported around an intermediate portion of the support shaft,
An inner ring equivalent member having an outer diameter larger than the inner diameters of the two support holes is externally fitted with an interference fit in a state where relative rotation with respect to the support shaft is prevented.
A cam follower device, wherein the tappet roller is arranged around the inner ring equivalent member so as to be capable of relative rotation with respect to the inner ring equivalent member.   2. The cam follower device according to claim 1, wherein both end portions of the support shaft are fitted into the two support holes with gap fitting so as to be able to rotate inside the two support holes.   A radial roller bearing is provided between an inner peripheral surface of the tappet roller and an outer peripheral surface of the inner ring equivalent member, and the radial roller bearing is a full roller type without a cage. The cam follower device described in any one of 2.   A pair of circular washers are provided on the inner side in the width direction of the both support wall portions so as to close both end openings of the bearing space of the radial roller bearing. The cam follower device according to claim 3, wherein the wall portion is larger than a dimension of the support wall portions in the height direction.   The cam follower device according to any one of claims 1 to 2, wherein an inner peripheral surface of the tappet roller and an outer peripheral surface of the inner ring equivalent member are in sliding contact.   The cylindrical member is arrange | positioned between the inner peripheral surface of the said tappet roller, and the outer peripheral surface of the said inner ring equivalent member so that relative rotation with respect to this tappet roller and an inner ring equivalent member is possible. The cam follower apparatus described in any one of them.

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