JPS628322Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rocker arm, and more particularly, to provide a rocker arm in which a chip of sintered alloy or the like is brazed to the contact surface with a cam.

As is well known, the above-mentioned Rocker arm is supported by a Rocker shaft, and one arm swings when receiving an impact force from a cam, and the other arm transmits the impact force to an intake valve or an exhaust valve to open and close the valve. Therefore, the contact surface of the rocker arm with the cam must have sufficient wear resistance properties.

As a means of imparting this wear resistance property, for example, thermal spraying of self-fusing alloy powder as shown in Japanese Patent Publication No. 45-32607, chill cast iron or baking as shown in Japanese Patent Publication No. 46-6647, etc. Products for brazing chips such as alloys have been developed, but the former has the drawbacks of complicated process control, large product variations, and high costs, while the latter has the drawbacks of being expensive. Although there are no such drawbacks, the unevenness of heat in each part of the chip during heating during the chip brazing process may cause an imbalance in the hardness of the chip itself, or the hardening of the rocker arm body may become sluggish. This has the disadvantage that the stability of product quality cannot be ensured.

In order to prevent the imbalance in the hardness of the chip itself or the hardening of the rocker arm body becoming dull, it is possible to maintain heat uniformly at the required temperature especially in the rocker arm where the chip is brazed. Therefore, it is important to equalize the heating to the above-mentioned areas and to prevent heat transfer and diffusion from the above-mentioned areas to other areas as much as possible.

In this sense, as in the rocker arm disclosed in JP-A-50-112614, simply changing the thickness of the ribs that extend from the insertion part with the main shaft hole to the contact part and the swinging part, respectively, is not enough to avoid heating during the chip brazing process. However, the above-mentioned problems cannot be satisfactorily solved.

The present invention has been developed in view of these points, and it is possible to minimize the adverse effects of heating during the brazing process when brazing the chip as described above to the rocker arm. Unevenness of heat in each part of the chip during heating during the chip brazing process may cause an imbalance in the hardness of the chip itself, or the hardening of the rocker arm may become sluggish, or even worse. The purpose is to provide a rocker arm structure that can prevent the deterioration of quality stability caused by defects, and the gist is that the rocker arm is integrally molded with the swinging part and the arm part is integrally formed from the insertion part on the opposite side. A pedestal having a width approximately equal to the width of the chip to be brazed and having a convex portion smaller than the width of the chip formed at the inner and outer end of the contact portion, the back surface of the pedestal, and the insertion portion. The rocker arm has a rib thinner than the rib of the rocking part connecting the rocker arm, and the width of the arm part is smaller than the width of the pedestal.

An embodiment of the present invention shown in the drawings will be described below. In FIGS. 1 and 2, 10 is a rocker arm and an insertion part 12 into which the rocker shaft is inserted.
A contact portion 13 that receives an impact force from a camshaft (not shown) is integrally formed on one side, and a swinging portion 14 that transmits the impact force to an intake valve or an exhaust valve (not shown) is formed on the other side. The rocker arm 10 can swing around the center C of the insertion section 12 as shown by the arrow.

Reference numeral 15 denotes a pedestal formed on the contact part 13, which is firmly connected to the insertion part 12 by a vertical rib 16 on the back side and a horizontally extending arm part 17 integrated at the lower part of the pedestal. Pedestal 15
A rectangular flat surface 3 is used to braze a chip 18 made of chilled cast iron or hardened alloy with high wear resistance.
2 are available. Further, the swinging part 14 is also firmly connected to the insertion part 12 by a vertical rib 19 and a horizontally extending connecting arm 20 integrated at the lower part thereof.

Furthermore, as is clear from FIG. 2, in the rocker arm 10, the thickness t of the rib 16 extending from the insertion portion 12 to the pedestal 15 is made thinner than the thickness T of the rib 19 extending to the swinging portion 14. Insertion part 12 from contact part 13 side in the above-mentioned heating process
This reduces heat transfer to the sides.

Further, as shown in an enlarged view in FIG.
is approximately the same size as that of the chip, while the direction perpendicular to the width direction, that is, the outer end 23 of the base 15
On the inside end 24, protrusions 25 and 26 for supporting the chip 18 are provided only in the center of the pedestal, and the protrusions are not provided in the part corresponding to the corner K of the chip 18. . That is, as shown by the one-dot chain line in FIG. This portion is indicated by X and Y in the figure), and the width m between the pedestal end surfaces 27 and 28 is approximately the same dimension as that of the chip 18 in the portion where the convex portion is removed.

Furthermore, as shown by the dashed line in FIG.
5, and is cut off so as to be continuous with the back surface 30 of the pedestal 15 (this portion is indicated by Z in the figure).

Further, the width n of the arm portion 17 that connects the insertion portion 12 and the pedestal 15 is also approximately smaller than the width l of the pedestal 15.
It is made about 20% thinner to minimize heat transfer during the brazing process mentioned above.

Note that when the width l' of the insertion portion 12 is smaller than the width l of the pedestal 15, the width n may be smaller than the width l'.

After forming the rocker arm 10 having the shape described above, heat treatment such as carburizing and quenching is performed on the necessary parts, degreasing is performed, flux is applied to the flat surface 21, and a brazing material (not shown) is applied thereon. After applying flux, the chip 18 is assembled there, and the chip 18 is heated under high frequency while being pressurized.
is glued to the pedestal 15.

In this case, the base 15 including the chip 18 becomes hot, and the heat is transferred to the rib 16 and the arm portion 17.
However, in the rocker arm of the present invention, the thickness t of the rib 16 is thinner than that of the rib 19, and the outer end 23 near the rib 16 The convex portion 25 of the pedestal 15 and the convex portion 26 of the inner end portion 24 connected to the arm portion 17 are each thinned by removing the X portion or the Y portion, and furthermore, the width n of the arm portion 17 is made thin. Transfer of heat from the to the insertion portion 12 side is significantly reduced.

Since the outflow of heat can be minimized in this manner, the chip 18 and the base 15 are heated uniformly, and an imbalance in hardness of the chip itself is prevented. At the same time, since there is little heat transfer to the insertion portion 12 side, it is possible to prevent the hardening of that portion from becoming dull. Furthermore, since it is possible to heat the necessary parts effectively, shortening the heating time also saves energy.

As described above, the rocker arm according to the present invention has a contact part integrally molded from the insertion part through the arm part on the opposite side of the swing part, and has a width approximately equal to the width of the chip to be brazed. The arm comprises a pedestal having a convex portion smaller than the width of the chip formed on the outer end of the contact portion, and a rib thinner than the rib of the swinging portion connecting the back surface of the pedestal and the insertion portion; Since the width of the portion is smaller than the width of the pedestal, the following effects can be obtained.

First, since it is possible to minimize the outflow of heat during the process of brazing the chips, it is possible to uniformly heat the chips and the pedestal, thereby preventing imbalances in the hardness of the chips themselves. can be prevented.

Next, since heat transfer to the insertion portion side of the rocker arm is reduced, it is possible to prevent the hardening of the rocker arm from becoming sluggish.

Furthermore, the quality stability of the product is improved due to these defect prevention effects.

Further, as described above, by minimizing the outflow of heat, it is possible to effectively heat the necessary parts, so that the heating time in the brazing process can be shortened, resulting in a large energy saving effect.

[Brief explanation of the drawing]

Figure 1 is a front view of the Rotsuker arm of the present invention, Figure 2
The figure is a view in the direction of arrow A in FIG. 1, and FIG. 3 is an enlarged cross-sectional view of B in FIG. 10; Rocker arm, 12; insertion portion, 13;
Contact part, 14; Swing part, 15; Pedestal, 16, 1
9; Rib, 17, 20; Arm portion, 18; Chip, 25, 26; Convex portion.

Claims (1)

[Scope of utility model registration request] A contact part integrally molded from the insertion part via the arm part on the opposite side of the swinging part, and having a width approximately equal to the width of the chip to be brazed, and at the inner and outer ends of the contact part. It is composed of a pedestal having a convex portion smaller than the width of the formed chip, and a rib thinner than the rib of the swinging portion that connects the back surface of the pedestal and the insertion portion, and the width of the arm portion is smaller than the width of the pedestal. A smaller Rotscar arm.