JPH04102753A - Double cam fabrication method - Google Patents

Abstract

PURPOSE:To acquire a double cam provided with high impact strength at a low cost without drifting of both cams by applying such work processes to a workpiece as machining its outer diameter and thickness dimensions and its grindstone clearance groove, shaping it into upper and lower surface cams, together with thereto, so as to determine predetermined hardness given thereto and applying plane polishing, thick dimensions, and remove distortion. CONSTITUTION:A workpiece 8 is cut off from a metal round bar having its outer diameter dimension not less than maximum outer diameter dimensions of upper and lower surface cams 1 and 2 of a double cam, set to be slightly thicker than the cam, processed to have predetermined outer diameter and thick dimension which is needed to the double cam processing by an NC lathe, subjected to a processing of a round grindstone clearance groove 3, and provided with a cam center reference hole 7, a cam attaching hole 5 and a reference hole 6 drilled therein. The double cam is processed in a machining center so as to provide the contours of the upper and lower surface cams 1 and 2 with polishing margins to be worked, subjected to vacuum harden ing to have predetermined hardness, and to a flat plane polishing additionally serving as determined thickness. dimension and removing distortion, subjected to a finishing process at the cam center reference hole 7, and the upper and lower surface cams 1 and 2 are simultaneously finished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a W cam in which an upper cam and a lower cam are integrated.

[Prior Art] Conventionally, as shown in FIG. 3.4, the W cam 20 is manufactured by caulking an upper cam 21 and a lower cam 22 of the same shape with a circular spacer 23 interposed therebetween in the following steps.

Two pieces of 4 having vertical and horizontal dimensions that are greater than the maximum outer diameter dimensions of the upper surface cam 21 and the lower surface cam 22, and a thickness that is greater than the thickness of each cam.
The first step is to process a rectangular plate from a raw material, with a circular reference hole 27 at the center, four mounting holes 25 arranged at equal intervals in the circumferential direction around it, and two opposing holes 25. a circular spacer 23 with a predetermined thickness and a reference hole 26;
The two square plates that have gone through the first process are processed using a machining center, and a polishing allowance is added to form the upper surface cam 21 and the lower surface cam 22. Circular reference hole 27
, four slot holes 25 arranged circumferentially at equal intervals around it, and two opposing reference holes (accuracy holes) 2.
6, a fourth step of hardening the workpiece after the third step to a predetermined hardness by vacuum hardening, and determining the thickness of the upper cam 21 and the lower cam 22. Surface polishing 1 for fixing and removing distortion
In the fifth 1- step, the standard measure 27 is finished using the plane finished in step 1 as a reference, and the reference hole 27 of the spacer 23 that has gone through the second process and the meat processing j1 that has gone through the fifth process is used as a standard.
Spacer 23 and each precision hole 26 of both workpieces
The spacer 23 and both processed pieces that have gone through the sixth process are mounted on each cam mounting CTJ with the spacer 23 sandwiched between both processed pieces.
-Insert the precision bottle into the precision hole 26 and swage it, -
and a seventh step in which the W cam 20 is brought to rest.

[Problems to be Solved by the Invention] The above-mentioned conventional W cam manufacturing method has the following drawbacks.

(a) There are many processed parts and processing, and manufacturing takes time, resulting in an increase in speed.

(b) Connect the upper cam 21 and the lower cam 22 with the spacer 23.
It's connected via the first node, so it's a big n.
If it is scratched or there is a weak spot in the caulking T, the connection will loosen and the W cam will no longer function properly.

The object of the present invention is to provide a method for manufacturing an integrated W cam that does not have the above-mentioned drawbacks.

[Technical Means for Solving the Problems] In order to solve the above problems, the present invention provides a workpiece made from a raw material having an outer diameter and thickness that are equal to or larger than the outer diameter and thickness of the W cam. a first step of machining, and processing the outer diameter of the W cam for the workpiece that has undergone the first step;
The second process involves machining the thickness dimension and machining the whetstone relief groove, and the workpiece that has gone through the second process is processed into the shape of a face cam and a bottom cam, and is integrated into a single-piece cam. A fourth step of hardening the workpiece that has gone through the third step to a predetermined hardness by hardening the workpiece that has gone through the third step, and flat-polishing the IKJ workpiece that has gone through the fourth step to reduce the thickness. The fifth step is to determine the dimensions and remove distortion.

[Operation] In the first step, a workpiece having a thickness equal to the thickness of the W cam is cut from a metal round bar having an outer diameter equal to the outer diameter of the W cam.

The second step is performed on an NC lathe.

The third step is performed by a machining center.

The fourth step is performed by vacuum hardening.

The fifth step is carried out using a polishing disk or the like.Examples The present invention will be explained below with reference to FIGS. 1 and 2 without providing examples. The work piece 8 is cut from a metal round bar with an outer diameter h" that is greater than or equal to the maximum outer diameter of the upper cam 1 and upper cam 2 of the W cam, and its thickness is slightly thicker than that of the W cam. has been set (first step).

The h■ work piece 8 is machined by an NC lathe to the predetermined outer diameter and thickness required for the h0 machining of the W cam, and a circular grindstone relief groove 3 is also machined (second step).

The workpiece that has undergone this second step has a cam center reference hole 7,
There are four cam mounting holes arranged circumferentially at equal intervals around it (hole 5) and two opposing 12% holes (precision holes) 6.
and are drilled.

The machined piece obtained in the second step is attached to a mounting base through the cam mounting hole 5, and the contours of the upper cam 1 and lower cam 2 (C grinding allowance are added) are machined by a machining center, and this is A W cam 4 in which the upper cam 1 and the lower cam 2 are integrated is obtained (third step).

The workpiece that has undergone the third step is hardened to a specified hardness by vacuum quenching (fourth step).

The workpiece that has gone through the fourth step is plane-polished to determine the thickness and eliminate distortion, and the cam center reference hole 7 is finished using the finished plane as a reference (fifth step).

The workpiece that has undergone the fifth step is the cam center reference hole 7 and the reference hole 6.
The upper surface cam 1 and the lower surface cam 2 are simultaneously subjected to finishing processing based on the above.

[Effects] Since the present invention is comprised of the above-mentioned steps 1 to 5, the number of parts and the number of processing steps are smaller than in the case of manufacturing a conventional W cam, so the cost is low. Also, unlike conventional W cams, the top cam and bottom cam are integrated, so both cams do not shift while using the W cam, and it has sufficient strength against shocks and is highly durable. .

[Brief explanation of the drawing]

FIG. 1 shows a front view of one embodiment, and FIG. 2 shows a side view of FIG. FIG. 3 shows a front view of a conventional W cam, and FIG. 4 shows a side view of FIG. 3. 1... Upper cam 2... Lower cam 3... Grinding wheel relief groove 4... W cam 8... Processed piece

Claims (1)

[Claims] A method for manufacturing an integrated W cam consisting of an upper cam and a lower cam of the same shape, the work piece having an outer diameter and thickness greater than the outer diameter and thickness of the W cam. A first process of machining from the raw material; machining the outer diameter of the W cam on the workpiece that has gone through the first process;
A second process of processing the thickness dimension and machining a whetstone relief groove, and a second process of processing the workpiece after the second process into the shapes of an upper cam and a lower cam with a grinding allowance to form an integrated cam. Step 3: A fourth step in which the work piece that has gone through the third step is hardened to a predetermined hardness by quenching, and the work piece that has gone through the fourth step is surface polished to determine the thickness and remove distortion. A method for manufacturing a W cam, comprising a fifth step of performing.