JPS5824892Y2 - Sizing equipment for sintered mechanical parts - Google Patents

Description

[Detailed description of the invention] This invention relates to a device for sizing shaft holes molded into mechanical parts such as sintered gears and sintered oil-impregnated bearings when they are manufactured by powder metallurgy. be.

The dimensions of the holes cast into the sintered part generally vary more than the allowable tolerances of the product due to springback during compaction and expansion and contraction associated with sintering.

Therefore, as a correction method, the pore size of the sintered body is made smaller than the specified product size by selecting the dimensions of the molding core and the molding/sintering conditions, and then press-fitting the sizing core into this allows the sintered body to have the regular size. A method of expansion correction is generally adopted.

FIG. 1 shows the simplest example of a sizing device for this purpose, and shows a sintered body to be processed (hereinafter referred to as a work).

) 10 is placed on the chifurle 20 of the press via a spacer 21, and the hole 11 of the workpiece 10 is corrected by lowering a sizing core 40 attached to the upper ram 30 of the press.

Incidentally, at the time of FIG. 3, the workpiece 10 and the core 40 are tightly fitted together, so a stripper 22 is provided above the spacer 21 to remove this and return only the core 40 to the upper position.

However, in the case of this method, the workpiece 10 is
When placing the workpiece on the sizing core 40, it is necessary to align the center of the hole 11 of the workpiece with the center of the sizing core 40, and if the contour of the hole is not a perfect circle, the phase must also be completely aligned. It is extremely difficult to

Therefore, the application of this method is almost limited to slow sizing of holes with a perfect circular profile.

For the reasons mentioned above, when the contour of the hole requires consideration of the phase, such as a shaft hole with a keyway or a spline shaft hole, the method shown in FIG. 2, that is, the sizing core 40 is used.
A method is used in which the workpiece 10 is placed upright on the table 20 of the press, the workpiece 10 is fitted in phase with the guide portion at the tip of the workpiece 10, and the workpiece 10 is pushed down by a punch 50 attached to the upper ram 30 of the press for sizing.

However, in the case of this method, since the workpiece 10 remains firmly attached to the sizing core 40 even after the upper ram 30 returns, it is necessary to separately provide a device for removing it.

Also, since an automatic work supply device is attached to the table 20 side of the press, it is desirable to provide it on the upper ram side of the press from the viewpoint of space buttons and workability.

This invention will be explained below with reference to embodiments shown in the drawings.

In FIG. 3, 60 is a frame extending downward from the upper ram 30 of the press, and its lower end has two parallel shafts 61 and 61.
is provided horizontally, and the stripper plate 70 is supported by this shaft so as to be able to slide back and forth.

This plate 70 is provided with a daruma-shaped or convex-shaped hole whose longitudinal direction coincides with the sliding direction of the plate 70, that is, the direction of the shaft 61, and the large diameter portion 71 of this hole is larger than the outer diameter of the workpiece 10. The large diameter portion 72 is made smaller than the outer diameter of the workpiece 10.

Various devices can be used to slide this plate 70, but in this embodiment, the small diameter portion 72
In order to move the cylinder 80 in the direction of , that is, from right to left in the figure, an inclined cam 90 and a roller 91 are used to move the cylinder 80 in the opposite direction, that is, in the direction of the large diameter portion γ1.

Now, the plate 70 is positioned so that its large diameter portion 71 is concentric with the sizing core 40 as shown in FIG. 3, and the upper ram 30 is lowered.

Then, the work 10 goes under the large diameter part of the plate 70 (the fourth
), then punch 50 to punch the sizing core 4
It is pressed to 0.

Meanwhile, the stripper plate 70 is moved to the right by the action of the roller 91 provided at its end and the inclined cam 900 provided on the press table 20, and the small diameter portion 72 of the hole is located directly below the workpiece 10 (No. (See Figure 5).

Then, when the upper ram 30 is raised, the workpiece 10 is pushed up by the small diameter portion 72 of the plate 70 and extracted from the core 40 (see FIG. 6).

After that, remove the workpiece 10 by appropriate means and remove the cylinder 8.
0 to return the plate 70 to the left, that is, to the state shown in FIG. 3A, and one cycle of sizing is completed.

As described above, according to this invention, it is possible to efficiently size sintered machine parts having holes with complicated contours.

Although the button cylinder 80 may be used for both pushing and pulling,
By using the cam 90, the opening timing can be ensured during high-speed operation.

[Brief explanation of drawings]

FIGS. 1 and 2 are drawings for explaining the conventional problems, and FIGS. 3 to 6 are drawings for explaining the present invention. 10... Workpiece, 20... Press table, 30... Upper ram of press, 40...
... Sizing core, 50 ... Punch, 6
0... Frame, γ0... Stripper plate, 80... Cylinder, 90...
...Tilt cam.

Claims (1)

[Claims for Utility Model Registration] The sizing core 40 is set up on the table 20 of the press, and the workpiece 10 fitted and placed on the guide portion at the tip of the sizing core is pushed down by the punch 50 provided on the upper ram of the press. A sizing device for sintered mechanical parts, characterized in that the device has the following configuration. (a) A stripper plate 70 is supported below the punch 50 via a frame 60 extending downward from the upper ram 30 so as to be able to reciprocate horizontally and in the -horizontal direction. (b) The stripper plate 70 has a Daruma-shaped (or convex-shaped) hole that has a large diameter portion 71 through which the workpiece 10 can pass and a small diameter portion 72 through which the workpiece 10 cannot pass. It is provided to match the direction. (c) The distance between the punch 50 and the stripper plate 10 is set larger than the height of the workpiece 10.