JP6427023B2 - Locker arm - Google Patents

Description

  The present invention relates to a rocker arm.

  Conventionally, in a vehicle engine, a rocker arm is known which transmits a pressure from a cam to a valve (for example, Patent Document 1). The rocker arm is provided with a roller (turning portion) that abuts on the cam. As such a roller attachment structure, one shown in FIG. 4 is known. In the configuration shown in FIG. 4, the roller 93 is attached to the support shaft 95 via the bearing 94, and each end of the support shaft 95 corresponds to the pair of wall portions 92 A and 92 B constituting the rocker arm 91. It is fixed by caulking. Specifically, locking portions 96 respectively formed at respective end portions of the support shaft 95 are configured to lock on the inner surface of the wall portion 92A (or the wall portion 92B).

JP, 2008-075482, A

  In the configuration in which the support shaft is fixed by caulking, in order to secure caulking strength, it is necessary to increase the outer diameter of the support shaft and increase the overall length (length in the circumferential direction) of the locking portion. Further, in order to lock the locking portion more securely, it is necessary to secure the thickness of the wall portion to which the locking portion locks. Therefore, in the configuration in which the support shaft is fixed by caulking, there is a problem that the rocker arm is increased in size.

  The present invention has been completed based on the above circumstances, and it is an object of the present invention to provide a rocker arm which can be miniaturized.

  In order to solve the above problems, according to the present invention, there are provided a roller abutting against a cam, a pair of wall portions arranged along the rotational axis of the roller and disposed so as to sandwich the roller, and One end portion of the pair of wall portions inserted into the first through hole formed in one of the pair of wall portions, and the other wall of the pair of wall portions. A hollow support shaft having the other end inserted into the second through hole formed in the support and rotatably supporting the roller, and a bearing interposed between the support shaft and the roller And a fixing member for fixing the support shaft to the pair of wall portions, wherein the support shaft is configured to be rotatable around the pivot shaft with respect to the pair of wall portions. The fixing member has a longitudinal shape extending along the axial direction, and is inserted into the support shaft. A main body portion, a first locking portion provided at one end in the longitudinal direction of the main body portion and engaged with a surface of the one wall portion opposite to the other wall portion, and a length of the main body portion And a second locking portion provided at the other end in the direction and locking to a surface of the other wall opposite to the one wall.

  According to the present invention, the support shaft can be fixed to the pair of wall portions by the fixing member. If the support shaft is directly caulked to the pair of wall portions (see FIG. 4), the outer diameter of the support shaft needs to be increased in order to increase the caulking strength. In the present invention, since the support shaft can be fixed by the fixing member, the outer diameter of the support shaft can be further reduced, and the rocker arm can be miniaturized. When the support shaft is directly crimped to the pair of wall portions, the rotation of the support shaft with respect to the pair of wall portions is restricted, and there is a concern that friction or stress may occur when the roller rotates. Ru. In the present invention, since the support shaft is rotatable with respect to the pair of wall portions, it is possible to reduce the stress acting on the support shaft and the wear of the support shaft when the roller rotates.

  According to the present invention, it is possible to provide a rocker arm that can be miniaturized.

Sectional drawing which shows the engine for vehicles which concerns on Embodiment 1 of this invention Sectional view showing the rocker arm of FIG. 1 Cross sectional view showing a rocker arm (corresponding to a view cut along the line III-III in FIG. 1) Cross section showing a conventional example Sectional drawing which shows the rocker arm which concerns on Embodiment 2.

First Embodiment
Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 4. As shown in FIG. 1, the vehicle engine 5 of the present embodiment includes a cylinder head 1, a cam housing 17 attached to the upper portion of the cylinder head 1, and a valve gear 20. An intake valve 10 for opening and closing the intake port 3 and an exhaust valve (not shown) for opening and closing the exhaust port are attached to the cylinder head 1 respectively. Hereinafter, the intake valve 10 and the valve gear 20 on the intake side for opening and closing the intake valve 10 will be described in detail. The exhaust valve and the valve operating device on the exhaust side have the same configuration as that on the intake side.

  The intake valve 10 includes a disc-like valve member 11 and a round rod-like valve stem 12 extending upward from the top surface of the valve member 11. The valve member 11 is provided in the cylinder head 1 and is disposed in the intake passage 2 communicating with the internal space of the cylinder (not shown), and can open and close the intake port 3 communicating the cylinder and the intake passage 2. . The valve stem 12 penetrates the outer wall of the intake passage 2, and the end opposite to the valve member 11 protrudes outward (upper side in FIG. 1).

  Near the upper end of the valve stem 12, a disk-shaped spring retainer 13 is attached. A valve spring 14 is incorporated between the outer surface (upper surface) of the cylinder head 1 and the spring retainer 13 in a state of being compressed more than the natural length. By the elastic force of the valve spring 14, the intake valve 10 is biased toward the rocker arm 40 (upper side in FIG. 1), and the valve member 11 is biased so as to close the intake port 3.

  The valve operating device 20 is configured to open and close the intake valve 10. The valve gear 20 includes a cam shaft 30 having a cam 31, a rocker arm 40, and a pivot 50. The rocker arm 40 is a member that pivots according to the rotation of the cam 31 and converts the rotational motion of the cam 31 into an up and down motion and transmits it to the intake valve 10. The pivot 50 is a member for supporting the rocking fulcrum of the rocker arm 40, and is attached to the cam housing 17, for example. A lash adjuster may be provided instead of the pivot 50.

  The cam shaft 30 is a hollow round bar and is disposed vertically to the valve stem 12 at a position slightly away from the tip of the valve stem 12 and between the cam housing 17 and a cam cap (not shown). Is rotatably supported. The cam 31 is fixed to the cam shaft 30. The cam 31 is a plate-like cam having a substantially egg shape in a front view, and is provided with a shaft hole 32 for inserting the cam shaft 30. The shaft hole 32 is a through hole penetrating from one plate surface of the cam 31 to the other plate surface. The cam 31 is fixed to the camshaft 30 and can rotate with the camshaft 30. The cam 31 has a base circular portion 33 which is a circle having a constant distance from the rotation center (the center of the shaft hole 32) to the outer peripheral surface, and a distance from the rotation center (the center of the shaft hole 32) to the outer peripheral surface is the base circle And a cam nose portion (not shown) larger than 33.

  The rocker arm 40 has a long shape in a direction (left and right direction in FIG. 1) orthogonal to the rotation axis of the cam 31 and is disposed between the cam 31 and the valve stem 12. The rocker arm 40 includes a roller 49 and an arm main body 41 that rotatably holds the roller 49. One end of the arm main body 41 is a swing fulcrum 42 supported swingably by the pivot 50. On the other hand, at the other end of the arm main body 41, a valve contact portion 44 that contacts the intake valve 10 via the shim 60 is provided.

  The shim 60 is a spacer member interposed between the valve stem 12 and the valve contact portion 44. As the shim 60, an appropriate one is selected from a plurality of shims having different thicknesses. By adjusting the thickness of the shim 60, the clearance S1 between the cam 31 and the roller 49 can be adjusted. The shim 60 attached to the valve stem 12 as in this embodiment is also called a stem cap or a stem end cap.

  The rocking fulcrum portion 42 has a shape that follows the tip shape of the pivot 50, and a spherical recess 43 (shown by a broken line in FIG. 1) is formed on the lower surface thereof. The distal end portion 51 of the pivot 50 is fitted in the spherical recess 43. The lower surface of the valve contact portion 44 is a valve receiving surface 45 that contacts the shim 60 as shown in FIG. The valve receiving surface 45 is a curved surface slightly protruding toward the shim 60 side.

  In the present embodiment, in a state (base state) in which the base circular portion 33 of the cam 31 faces the roller 49, the intake valve 10 is biased upward by the biasing force of the valve spring 14, and the closed state (valve member 11 is a state where the intake port 3 is closed). Further, while the cam nose portion of the cam 31 is in contact with the roller 49 (at the time of lift), the rocker arm 40 is pushed down by the cam 31. Along with this, the intake valve 10 is pushed down by the valve contact portion 44, and the intake valve 10 is opened.

  As shown in FIG. 3, the arm body 41 has a pair of wall portions 46A, 46B which are disposed to face each other with the roller 49 interposed therebetween. The wall portions 46A and 46B are arranged along the axial direction (left and right direction in FIG. 3) of the rotation axis R1 of the roller 49. A support shaft 47 is attached to the pair of wall portions 46A and 46B. The support shaft 47 rotatably supports the roller 49, and is a shaft member constituting a rotation axis R1 of the roller 49. The support shaft 47 is a long and hollow cylindrical member extending in the axial direction of the rotation axis R1. One end 47A of the support shaft 47 is inserted into a first through hole 48A formed in the wall 46A (one wall), and the other end 47B of the support shaft 47 is a wall 46B (other wall Section) is inserted through a second through hole 48B formed in the Thus, the support shaft 47 is fixed in the direction orthogonal to the rotation axis R1, and is rotatable around the rotation axis R1 with respect to the pair of wall portions 46A and 46B.

  The roller 49 has a cylindrical shape as shown in FIG. 2, and a bearing 54 is interposed between the roller 49 and the support shaft 47. The bearing 54 is, for example, a roller bearing, and is configured of cylindrical rolling elements 52 (rollers) arrayed in a ring shape around the rotation axis R1. Thus, the roller 49 can rotate around the rotation axis R1 with respect to the support shaft 47. Further, as shown in FIG. 3, the upper end of the roller 49 is disposed at a position higher than the upper surfaces of the wall portions 46A and 46B. Thereby, the roller 49 is in contact with the outer peripheral surface of the cam 31 at the upper end thereof.

  The fixing member 70 is attached to the support shaft 47. The fixing member 70 has a function of fixing the support shaft 47 to the pair of wall portions 46A and 46B. The fixing member 70 is formed by bending a solid bar, and has a U-shape. The fixing member 70 includes a longitudinal main body 71 inserted into the support shaft 47 (insertion hole 47D), a first locking portion 72A provided at one longitudinal end of the main body 71, and the main body 71. And a second locking portion 72B provided at the other end in the longitudinal direction.

  The main body 71 has a longitudinal shape extending along the axial direction of the rotation axis R1. The first locking portion 72A is bent with respect to the main body portion 71, and extends downward from one end of the main body portion 71 (in the direction opposite to the cam 31). The first locking portion 72A is locked to the outer surface 53A (surface opposite to the wall portion 46B) of the wall portion 46A. The second locking portion 72B is bent with respect to the main body 71, and extends downward from the other end of the main body 71. The second locking portion 72B is locked to the outer surface 53B of the wall 46B (surface opposite to the wall 46A). Thereby, the displacement of the fixing member 70 in the direction (left and right direction in FIG. 3) along the rotation axis R1 is restricted. The support shaft 47 is prevented from coming off with respect to the pair of wall portions 46A and 46B as a result of the displacement of the direction along the rotation axis R1 being restricted by the fixing member 70.

  Next, the effects of the present embodiment will be described. According to the present embodiment, the support shaft 47 can be fixed to the pair of wall portions 46A and 46B by the fixing member 70. As shown in the rocker arm 91 (see FIG. 4) of the conventional example, when the support shaft 95 is directly crimped to the pair of wall portions 92A and 92B, both ends of the support shaft 95 are crimped by caulking. As a result of the diameter expansion deformation, the locking portion 96 is locked to the inner peripheral surface of the first through hole 97A and the inner peripheral surface of the second through hole 97B. Therefore, in order to secure the caulking strength, it is necessary to increase the outer diameter of the support shaft 95 and secure the circumferential length of the locking portion 96.

  In the present embodiment, the support shaft 47 can be fixed by the fixing member 70. In order to secure the fixing strength of the fixing member 70, for example, the length and thickness of the first locking portion 72A and the second locking portion 72B may be increased. Since the first locking portion 72A and the second locking portion 72B are disposed outside the support shaft 47, the size of the support shaft 47 does not increase even if the sizes thereof are increased. Therefore, the outer diameter of the support shaft 47 can be reduced as compared with the configuration of FIG. 4, and the rocker arm 40 can be miniaturized.

  Further, as shown in FIG. 4, when the support shaft 95 is directly crimped to the pair of wall portions 92A and 92B, the rotation of the support shaft 95 about the rotation axis R1 is restricted. There is concern that stress or friction may occur when the roller rotates. In the present embodiment, since the support shaft 47 is rotatable with respect to the pair of wall portions 46A and 46B, the stress acting on the support shaft 47 and the wear of the support shaft 47 at the time of roller rotation are reduced. Can. Moreover, the fixing member 70 of the present embodiment can be formed by bending a bar, and can be easily manufactured.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIG. In the rocker arm 140 of this embodiment, the configuration of the fixing member 170 is different from that of the above embodiment. As shown in FIG. 5, the fixing member 170 has a longitudinal main body 171 inserted into the support shaft 47, a first locking portion 172A locked to the outer surface 53A of the wall 46A, and a wall And a second locking portion 172B that locks to the outer surface 53B of the portion 46B. The first locking portion 172A and the second locking portion 172B are formed, for example, by crushing each end of the fixing member 170. For example, the first locking portion 172A is locked over the entire circumference of the hole edge of the first through hole 48A, and the second locking portion 172B is, for example, a hole edge of the second through hole 48B. It is locked over the entire circumference of.

Other Embodiments
The present invention is not limited to the embodiments described above with reference to the drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the said embodiment, although the roller bearing was illustrated as the bearing 54, it is not limited to this. For example, a ball bearing may be used as the bearing 54.
(2) In the said embodiment, although illustrated about the rocker arm 40 with which the valve operating apparatus 20 by the side of suction is provided, it is not limited to this. For example, the rocker arm 40 may be used as a valve gear on the exhaust side.

31: cam, 40: rocker arm, 46A: wall portion (one of the pair of wall portions), 46B: wall portion (the other of the pair of wall portions), 47: support shaft, 47A, one end Section (one end of support shaft), 47B: other end, 48A: first through hole, 48B: second through hole, 49: roller, 54: bearing, 53A: outer surface of wall 46A (one wall ... the other wall (the surface opposite to the other wall), 53B ... the outer surface of the wall 46B (the surface of the other wall opposite the one wall), 70, 170 ... fixing members, 71, 171 ... Body portion 72A, 172A: first locking portion, 72B, 172B: second locking portion, R1: rotation shaft of roller

Claims (1)

A roller in contact with the cam,
A pair of wall portions which are arranged along the axial direction of the rotation shaft of the roller, and are disposed to face each other with the roller interposed therebetween;
An elongated portion extending along the axial direction, one end portion of the pair of wall portions inserted through the first through hole formed in one of the wall portions, and the other wall portion of the pair of wall portions A hollow support shaft having the other end portion inserted into the second through hole formed in the support and rotatably supporting the roller;
A bearing interposed between the support shaft and the roller;
And a rod-like fixing member for fixing the support shaft in the axial direction with respect to the pair of wall portions,
The support shaft is configured to be rotatable around the pivot shaft with respect to the pair of wall portions,
The fixing member is
A main body portion which has a longitudinal shape extending along the axial direction and which is inserted into an insertion hole in the support shaft, and a gap is formed over the entire circumference with the inner peripheral surface of the insertion hole A main body having an outer peripheral surface disposed
A first locking portion provided at one end in the longitudinal direction of the main body portion and bent with respect to the main body portion and locked to a surface of the one wall portion opposite to the other wall portion;
A second locking portion provided at the other end in the longitudinal direction of the main body portion and bent with respect to the main body portion and locked to a surface of the other wall portion opposite to the one wall portion; Rocker arm with.

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