JPH0329486B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of pressing a bottomed tube made of a thin plate constituting a bearing box or the like for pivotally supporting a bearing.

Conventionally, ironing using a press machine was used as a processing method for finishing the inner diameter of bearing boxes, etc. that hold bearings press-fitted in, but this method suffers from variations in the thickness of the thin plate material (usually around 10% of the thickness of steel plates) and problems with ductility. Variations in the accuracy of one finish occur due to variations. 2. Burning of processing tools. 3 tools damaged. 4. Lack of pressure and energy in press machine. There were other problems. As a countermeasure for this, increasing the number of press processing steps, cutting processing,
It was customary to perform a grinding process to ensure accuracy.

The present invention eliminates the need for the above-mentioned conventional work, absorbs variations in wall thickness due to variations in thickness and ductility of the thin plate material, and ensures the required accuracy.

An embodiment of the present invention will be described below with reference to the accompanying drawings. Figure 1 shows a bearing box that supports bearings.A shaft 3 that engages bearings 2 held in two thin plate bearing boxes 1 is connected to a V-pulley 5 driven by a V-belt 4. It has the function of being attached to one side and transmitting power to other equipment through the other shaft end 6. The outer diameter of such a bearing 2 and the bearing box 1
The dimensional accuracy of the mating part is usually φ50 when made of steel plate.
In this case, a finished dimensional accuracy of approximately 20 μM is required.

In order to ensure such dimensional accuracy, at least one ring-shaped recess 7 is provided on the inner wall surface of the cylindrical body 8 of the bearing box 1, and during ironing, excess material due to changes in plate thickness is removed from this ring-shaped recess 7. They are collected in the recess 7 to ensure the accuracy of the inner diameter of the bearing box 1. Recess 7
is preferably formed in two stages, one at the approximate center of the depth of the barrel portion 8 and the other near the bottom.

Next, the processing sequence of the cylinder body will be explained with reference to FIG. The thin plate 10 shown in FIG. 3A is molded into cap-shaped parts 11 and 12 as shown in FIGS. Processed in the 3rd process of the next process
A ring-shaped recess 7 is formed in the side wall 17 of the bearing part 8 by the molding shown in FIG. 3D, and finished molding is performed as shown in FIG. 3E.

Finish forming of the bearing portion 8 will be described in detail with reference to FIG. FIG. 4A shows a state in which the bearing part 8 is inserted into the die 19, and the ironing punch 20 is made Δt larger on one side than the inner diameter of the bearing part 9, and ironing is performed. During machining, while machining the dimension 21 as shown in FIG. 4B, the first ring-shaped recess 7 absorbs the amount of variation in thickness that is thicker than the initial setting. Similarly, as shown in FIG. 4C, the dimension 22 is also absorbed by the second ring-shaped recess 23.

As described above, the press working method of the present invention allows press working to ensure finishing accuracy without being affected by variations in the thickness and ductility of the thin plate material by absorbing excess thickness using the ring-shaped recess in the cylinder body. This prevents seizure with the processing tool, prevents damage to the processing tool, and eliminates pressure and energy shortages in the press machine.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of a bearing box formed by a press working method according to an embodiment of the present invention, Fig. 2 is a detailed sectional view of the bearing part, and Figs. 3 A to E are process diagrams showing the press working order. , FIGS. 4A to 4C are process diagrams showing the finishing process. 1...Bearing box, 2...Bearing, 3...Shaft, 7...
Recessed portion, 8...Cylinder body.

Claims (1)

[Scope of Claims] 1. At least one ring-shaped recess is formed on the inner wall surface of the cylinder body of a cylinder with a bottom made of a thin plate in a pre-pressing process, and the excess thickness of the thin plate is pressed out with a punch in the final inner diameter finishing process of the press. , a method for pressing a thin plate bottomed tube in which the excess thickness is absorbed by the ring-shaped recess. 2. The method for press working of a thin plate bottomed cylinder according to claim 1, wherein the ring-shaped recess is formed in the inner wall surface of the cylinder body at approximately the center of the depth of the cylinder and near the bottom.