JPS6182936A - Method for improving accuracy of sheared cross section in press work - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to press working using a precision mold, and particularly to an improvement in a working method for improving the precision of the sheared surface of a workpiece.

Recently, reflecting the industry's needs for high quality and low cost,
For example, molding of hammer members of stamping type printers, etc., which conventionally relied on cutting and polishing, is increasingly performed exclusively by press working.

However, when a material of a certain thickness is punched out by press working, a fractured surface is formed in a part of the sheared surface.

Since the fractured surface has a rough surface structure and poor dimensional accuracy, the above-mentioned cutting and polishing processes are required again, and the loss time increases.

For this reason, there is a strong demand for the development of a method for improving the precision of the sheared surface of press work, which can guarantee sufficiently high precision even with press work alone.

[Conventional technology]

FIG. 2 is a diagram for explaining the conventional method of press secondary processing, (al is a plan view of the main part showing a workpiece placed on a die and a guide for positioning the workpiece, (b
1 is a side cross-sectional view of the main part showing the state of the chips generated by the pre-pressing process (shearing process), (C1 is the post-pressing process (finishing process) and the chips and sheared surfaces interfere with each other due to this process. Main part side sectional view showing the condition, fd
) respectively show perspective views of essential parts showing the state of the sheared surface of the workpiece after processing.

As shown in each figure above, the press processing machine consists of a pair of punches (
Consisting of a male die) 6 and a die (female die) 7, the workpiece is positioned by a die (male die) 6 and a die (female die) 7.
It has a structure in which it is finished into a predetermined shape and size by shearing.

The knockout 8 and the restoring pin 9 are attached to the press processing machine, and in the first stage process, they descend in the direction of the arrow B in response to the movement of the punch 〇, and in the second stage process, they rise in the direction of the arrow B to remove the processed material. Processed? This is a member that functions to return IJl to its original position.

The processing method using the press processing machine will be explained below in accordance with the process order.

The same figure (al shows a state in which the workpiece 1 placed on the die 7 has its both ends positioned by the both-end guides 5. At this time, the workpiece 1 is placed on the die hole 7'' with reference to is positioned.

Next, as shown in FIG. fbl, the punch 6 descends in the direction of the arrow, and the chip 4 is cut off from the sheared surface 2 of the workpiece 1 by press shearing formed by the punch 6 and the die 7. The workpiece 1 is then finished into a predetermined shape and size.

In this processing step, the chip 4 is strongly pressed toward the guide 5 at both ends, so that it comes into close contact with the inner surface of the guide 5 at both ends.

Next, in the same figure (C1, the punch 6 that has finished the previous step (shearing) moves in the direction of arrow B, and the workpiece l is also knocked out 8.
．． It is shown that it has been pushed up by the restoring pin 9 and has returned to its pre-processing position. At this time, only the sheared surface 2 of the workpiece 1 that comes into pressure contact with the tip 4 that is in close contact with the guides 5 at both ends is the tip 4.
The surface is "squeezed" and has a partially finished surface.

However, during the above process, the chips 4 in the portion not restrained by the guide 5, that is, the unrestricted zone 13, are scattered outward at this point, so that they do not have any effect on the shear surface 2 of the unworked object in the later pressing process. become.

Therefore, the fractured surface 3 formed in the pre-pressing process remains as it is.

The same figure (dl is a diagram showing the state of the machined surface of the workpiece 1 completed by the above-mentioned processing, and as mentioned above, in the sheared surface 2 of the workpiece, i[i
7, that is, the fractured surface 3 of the rough structure remains in the formed state except for the "squeezed" part by the chip 4.

Since the fracture surface 3 is rough and structurally fragile,
Surface finishing is required through post-processing such as cutting and polishing.

[The problem that the invention attempts to solve]

The present invention solves the above problems, namely, the pre-pressing process (shearing process).
By adding -11, the fracture surface formed by the old folded surface C is pushed to the original folded surface C and the shear cross-sectional area direction of the sheared ball is 1, one method. This was done in order to provide the following.

[Means for solving problems]

The above problem is solved by a method for improving the precision of a sheared surface that is configured to perform, by secondary press processing, finishing the dimensions of a workpiece cut out in the primary press processing and shaping the sheared surface. A guide for positioning the workpiece is formed so as to restrain the entire circumference of the sheared surface of the workpiece, and is cut from the workpiece before the secondary press processing and tightly adheres to the entire inner circumference of the guide. This depth can be solved by a method for improving the degree of shearing area of the press work, which is configured to come into pressure contact with the shear surface of the workpiece in a subsequent stage of the secondary press work.

[Effect]

The present invention replaces the conventional positioning guide that restrains only a part of the workpiece with a full-circumference guide formed to restrain the entire machining surface of the workpiece. The annular chip cut from the workpiece during machining is drawn so that it adheres to the inner circumference of the all-around guide, and a "shaped hole" is formed by the all-around guide and the annular chip.
i'? Sign or Z).

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram for explaining the method for improving the degree of shearing area in press working according to the present invention, in which (a) shows an annular chip formed on the outer periphery of the shearing surface of the object with a full circumference guide and an extraction force I+-m. Main part plan view shown (ill is a perspective view of the annular chip, fc)
is a perspective view of the workpiece after machining is completed;

Note that the same reference numerals indicate the same objects throughout the figures.

As shown in the figure, in the shear surface accuracy improvement method of the present invention, the guide for positioning the workpiece 1 is composed of a circumferential guide 10 that restrains the entire machining surface of the workpiece. The chip cut out from 1 ml of the workpiece during the process becomes an annular chip 14 that is tightly attached to the inner periphery of the guide hole 11 of the full-circumference guide "10".

Therefore, the workpiece 1 returning to the original position -1 in the subsequent press step is forced to be press-fitted into the shaping hole 12 constituted by the circumferential guide 10 and the annular tip 14.

While the workpiece 1 passes through the shaping hole 12, the sheared surface 2 is squeezed by the annular tip 14, and the sheared surface 2 is automatically finished.

The figure (bl) shows a state in which the fracture surface 3 shown in FIG. 2 (dl) disappears and becomes a shaped shear surface 2 by means of the present invention.

[Effects of the Invention] As explained in detail above, the method for improving shear plane accuracy in press working according to the present invention improves the shape of the guide for positioning the workpiece from the conventional partial guide type to the full circumference guide type. This has a great effect in that the rough fractured surface formed on the sheared surface can be automatically and accurately finished.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the method for improving the precision of a shearing surface in press working according to the present invention, (al is a principal part plane showing the entire circumference guide and the annular chip formed on the outer periphery of the shearing surface of the workpiece. In the figure, fbl is a perspective view of the annular tip, (C1 is a perspective view of the workpiece after processing is completed, Figure 2 is a diagram for explaining the conventional method of press secondary processing, and fat is a perspective view of the annular chip. A plan view of the main parts showing the mounted workpiece and the kite for positioning the workpiece, fbl is approximately (
The state of the h5f nap produced by the shearing process is not shown in Figure 111;
(finishing process) and this process - J-Measurement surface diagram that does not show the state of interference between the knob and the sheared surface or the table, +dl indicates the state of the sheared surface of the workpiece after machining. FIG. Figure [E] l is the workpiece, 2 is the shear surface, 3 is the fracture surface, 4
is a chip, 5 is a guard on both ends, 6 is a bunch, 7 is a die, 7 is a die hole, 8 is a knockout, 9 is a restoring pin,
10 is a full circumference kite, II is a guide hole, 12 is a shaping a, I
:t is II' I Marichunon, 14L;! The cyclic ten and zo are shown respectively. Figure 1 (CI+

Claims (1)

[Claims] A shear surface accuracy improvement method configured to perform, by press secondary processing, dimension finishing and shear surface shaping of a workpiece that has been cut out in the press primary processing, the method comprising: A guide for positioning an object is formed so as to restrain the entire circumference of the sheared surface of the workpiece, and a chip is cut from the workpiece in a pre-stage of press secondary processing and tightly adheres to the entire inner circumference of the guide, A method for improving the precision of a sheared surface in press working, characterized in that the method is configured to come into pressure contact with the sheared surface of the workpiece in a subsequent stage of secondary press working.