Rocker arm and manufacturing method thereof

#The present invention relates to a rocker arm and a manufacturing method thereof.

#In general, the rocker arm includes a body and a roller pivotally attached to the body through a support shaft. The body includes a pair of side walls opposed to each other in the axial direction and a pair of connecting walls for connecting the side walls with each other at both end portions of the side walls in the longitudinal direction.

#The valve engaging portion is constituted by valve guide walls, which are arranged at one end side of the side walls in the longitudinal direction, and a connecting wall arranged on one end side for connecting both the valve guide walls. The pivot receiving portion for receiving an upper end portion of the lash adjuster is formed on the connecting wall on the other end side of the side walls in the longitudinal direction.

#FIG. 1 is a side view showing a state of the use of the rocker arm of the embodiment of the present invention.

#FIG. 2 is a plan view showing a first intermediate product in the case of manufacturing the rocker arm of the embodiment of the present invention.

#FIG. 3 is a perspective view showing a second intermediate product in the case of manufacturing the rocker arm of the embodiment of the present invention.

#Referring to the drawings, the rocker arm of the present invention will be explained as follows. FIG. 1 is a side view showing a state of use of the rocker arm of the present invention, FIG. 2 is a plan view showing a first intermediate product in the case of manufacturing the rocker arm, FIG. 3 is a perspective view of the second intermediate product, FIG. 4 is a perspective view of the third intermediate product, FIG. 5 is a perspective view of the fourth intermediate product, FIG. 6 is a process drawing of manufacturing a valve engaging portion, FIG. 7 is a perspective view of the fifth intermediate product, FIGS. 8A to 8C are views showing a change in the shape of the valve engaging portion in the manufacturing process, FIG. 9 is a perspective view of the rocker arm that is a product, and FIG. 10 is an enlarged view showing the continuity of a metal flow in the valve engaging portion.

#As shown in FIG. 1, this rocker arm 1 is of the end pivot type having the constitution in which the body 4 is tilted by the rotation of the cam 3 as one end side in the longitudinal direction of the rocker arm supported by the lash adjuster 2a serves as a fulcrum. According to the tilting motion of this rocker arm 1, a valve not shown in the drawing is opened and closed.

#This rocker arm 1 includes the body 4 and the roller 5. This body 4 includes a pair of side walls 6, 7 which are opposed to each other in the axial direction of the roller 5. The body 4 further includes the connecting walls 8, 9 for connecting the side walls 6, 7 with each other, arranged on one end side and the other end side in the longitudinal direction. The body 4 further includes the valve engaging portion 10 arranged on one end side in the longitudinal direction. The body 4 further includes the pivot receiving portion 11 arranged on the other end side in the longitudinal direction. In the middle of the side walls 6, 7, there are formed insertion holes 13, 14 into which the support shaft 12 is inserted.