JPH0647456A - Method for press-blanking u shaped parts - Google Patents

Abstract

PURPOSE:To minimize blanking scrap by enhancing material utilizing ratio, and to efficient press blanking and improve the quality of parts by saving the cost of material, and unnecessitating the return blanking or the turning blanking. CONSTITUTION:Plural U shaped parts are pressed with blanking from a strip by a multi-stage type successive-feeding press device. At first, in the strip P, a pair of U shaped stators 1, 11 being a blank are arranged to be opposed with each other so that outer shape lines of both stators are overlapped by fitting one leg piece 11b of one stator 11 in a recessed part 1c of the other stator 1. In A process, pilot holes 2a, 2b are formed on the strip P. The pilot hole is set within partially blanking patterns 7, 8. In C process, a fine slit 4 having the prescribed length is formed on the overlapped outer shape lines of both stators 1, 11. In D-F processes, partial shapes 5, 6, 8 required for obtaining the part shape is pressed with blanking on the strip. In G process, one side stator 11 is dropped through with blanking, in H process, the partial shape 7 is pressed with blanking and the stator 1 is dropped through with blanking.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stamping method for stamping a U-shaped component such as a stator used in a two-pole stepping motor used in, for example, a quartz watch mechanical body.

[0002]

2. Description of the Related Art Conventionally, there are various blank arranging methods for punching, and in particular, the material utilization rate is increased to minimize the material cost.
For example, there is a lint-free method where adjacent blanks are cut off from one end, a staggered multi-row method in which blanks are arranged and punched in zigzag and multiple rows, a tilt method in which the blanks are arranged in an inclined manner, and a blank is saved. 180 ° rotated and lined up,
There are a rotating interleaved method of turning over and a method of alternately inverting and inverting the shape of blanks.

[0003]

The above-mentioned conventional arraying methods have their respective problems. For example, the scrapless method has poor product accuracy, and the staggered multi-row method is unsuitable for short scales. The mold becomes complicated, and there are many restrictions on the shape of the blank in the tilting method, and the applicable range is narrow. Further, the rotating alternate arrangement method and the inside-out alternate arrangement method require inversion and inside out, respectively, and are not efficient, and there is a problem that the burr and the direction of the droop are opposite and the quality of parts is deteriorated.

Therefore, an object of the present invention is to increase the material utilization rate to minimize the amount of scraps, to save the material cost, and to eliminate the need for reverse punching and inside out punching to improve the efficiency of press punching work and parts. Achieve an improvement in quality.

[0005]

In order to achieve the above object, the present invention provides a U-shaped part press-extracting method for punching a plurality of U-shaped parts from a band-shaped material by a multi-stage progressive press device, It consists of a combination of the following steps a to e. In the step a, one pair of blanks corresponding to the shape of the parts are mutually joined so that a part of the other blank is fitted in the recess of one blank and the outline of one blank overlaps the outline of the other blank. Place them face to face. In step b, a pilot hole is formed in the strip material.
In step c, a thin slit having a predetermined length is formed on the line where the outline of one blank overlaps the outline of the other blank. In the step d, the partial shape necessary for obtaining the shape of the component is removed from the band-shaped material. In the step e, one of the pair of blanks is removed, and then the other blank is removed.

If the above-mentioned pilot hole forming position is set within the pattern for partially removing the shape, unnecessary holes are not left in the U-shaped part.

When one of the pair of blanks is dropped and then the other blank is fed to the punching station for the other blank, it is effective to support the lower surface of the other blank by the supporting means for stable feeding. is there.

Before withdrawing one of the pair of blanks,
By completing all partial shape cuts for both blanks and pulling off one of the pair of blanks,
The other blank can also be removed at the same time, which is effective in reducing the number of steps.

[0009]

An embodiment of the present invention will be described with reference to the drawings. As an example of a blank corresponding to the shape of a part to be punched, the U-shaped stators 1 and 11 of a small motor are shown, and the leg portions 1b and 1 from the both ends of the base portions 1a and 11a.
b, 11b and 11b extend parallel to each other, and the gap between the two leg pieces is a recessed portion 1c, 11c equal to the width of the leg pieces. Notch 1d for positioning the rotor of the motor at the tips of both legs
And 1d, 11d and 11d are provided to form a magnetic pole portion. A pair of stators 1 and 11 having such a U-shape
By fitting one leg piece 11b of the other stator 11 into the recess 1c which is a gap between the leg pieces 1b of the one stator 1 and the leg pieces 1b of the other stator 1 and facing each other so that the outlines of both stators overlap. , Base 1a on the left side, base 11a
Is located on the right side. By arranging the blanks in this manner, it is possible to perform the punching with the least waste of the material from the strip-shaped material P having a width obtained by adding twice the width of the base portion to the length of the leg piece. As the strip material P, a magnetic material such as a silicon steel plate or permalloy is used.

As the pressing device, a multi-stage type progressive pressing device (not shown) is used, which is provided with a means for conveying the strip-shaped material P downward in FIG. A press device having a movable die is arranged.

As shown in FIG. 1, the strip-shaped material P is first in the first station A, and the pilot holes 2a and 2b are shown by hatching.
Is pulled out. The pilot hole is a guide hole used to convey the strip P downward, and is provided outside the shape of the U-shaped part, and is set in the patterns 7 and 8 for partial shape removal described later. And the pilot hole 2 on the right side of the strip P
a is located at a predetermined interval, and pilot holes 2b are located on the left side at a predetermined interval. In FIG. 1, the punched portion is shown by a solid line, and the pattern punched in a later step is shown by a two-dot chain line.

In the second station B, the pilot hole 2
Round holes 3 ... Are punched in the strip-shaped material P from which a and 2b have been punched out. The round holes 3 ... Are formed in the respective tip portions of the leg pieces 1b and 11b and are support holes for supporting the stator.

At the third station C, a hatched pattern 4a for forming a thin slit 4 having a predetermined length is punched on the line where the outlines of one stator 1 and the other stator 11 overlap. This is to minimize the shear stress when pulling out the stator at the end. If the shear stress is large, the material will be deformed and the accuracy of the parts will be deteriorated. Therefore, for parts that require particularly high accuracy, the pulling resistance should be reduced. Further, the position where the slit 4 is formed is determined by the cutout portion 1 for the rotor described later.
When removing d and 11d, a position that does not adversely affect the removal position accuracy is selected.

The fourth station D has three pairs as one station, and the cutouts 1d and 11 at positions separated by one pair.
The pattern 5 shown by the hatching for removing the partial shape for forming d is removed. Since the pattern 5 ... Is formed of the magnetic pole portion which is the heart of the stator, high accuracy is required.
Since the state of punching out the patterns 5 corresponds to punching around the entire circumference in the press, the pressing forces in the press die do not become unequal, and high position accuracy is possible. Furthermore, this is also to reduce the shear stress when the stator is finally pulled out.

The fifth station E has two pairs as one station, and the leg pieces 1b and 11b located on the opposite side of each pair.
Pattern 6 indicated by diagonal lines without a partial shape at the tip of
Is pulled out.

At the sixth station F, the pattern 8 for removing the partial shape between the base portions 11a and 11a of the adjacent stators 11 on one side of the strip P, for example, the right side, is pulled out. The pilot hole 2b extracted at the first station is located in the pattern 8 on the right side and is removed here, but the pattern 7 of the pilot hole 2a on the left side is not extracted yet, so the pilot hole on the left side is not extracted. The strip P is conveyed to the next station by 2a.

In the seventh station G, the base portion 11 is provided on the right side.
The remaining outline of the stator 11 where a is located is removed, and the stator 11 is received by a component receiver through a chute (not shown).

By removing the contour line of the stator 11, the contour line of the stator 1 in which the base portion 1a is located on the left side is also trimmed except the pattern 7 of the partial shape with the pilot hole 2a on the left side. Will be
Since the stators 1 ... Are continuous due to this pattern 7, they are conveyed to the next station through the pilot hole 2a on the left side. In this case, in the stator 1, the tip end of the leg piece 1b is a free end just like a cantilever, so that the support means 9 is provided as shown in FIG. 2 in order to stabilize the support state. . That is, a support 9a that is long in the carrying direction is provided so as to contact the lower surface of the stator 1 and cross substantially the center of the leg piece 1b. The support 9a is fixed to the upper end of a shaft 9b which penetrates the die 10 of the pressing device, and the lower end of the shaft 9b is received by a spring 9c. For this reason, the support 9a is always biased upward by a spring force, and can be moved up and down freely in accordance with the operation of punching.

At the eighth station H, the pattern 7 for removing the partial shape between the adjacent base portions 1a located on the left side is removed. As a result, the stator 1 is pulled out, and the stator 1 is received by the component receiver through a chute (not shown).

This completes the press removal of the stators 1 and 11.

The order of removing pilot holes, round holes, slits, partial shapes, outlines, etc. is not limited to the order of withdrawing at each station described above. Combinations are possible, and the number of pairs of stators at each station is not limited to this embodiment.

In the above example, by removing the pattern 7 located on the left side last, after removing one stator 11 of the pair of stators, the other stator 1 is removed. . However, the present invention is not limited to this, and by removing the pattern 7 located on the left side before the removal of one stator 11, the removal of one stator 11 and the removal of the other stator 1 at the same time. You may drop it.

The position of the pilot hole is not necessarily set in the pattern of partial shape removal, but can be set in an appropriate place.

[0024]

As described above, according to the method for punching out the U-shaped part of the present invention, the outlines of both blanks are overlapped by fitting a part of the other blank into the recess of the other blank. As a result, the material can be used without waste, the material utilization rate can be increased, the material cost can be reduced, and the cost of parts can be reduced. Pilot hole punching, thin slit punching, partial shape punching, blank punching out, etc. can be punched by the multi-stage sequential feed press device without the need to reverse or reverse the strip-shaped material, so processing is efficient. The quality can be made uniform because the removal direction is the same. Further, the slit stress and the partial shape can reduce the shear stress when the outline of the blank is finally removed, and the accuracy of the component can be improved.

By setting the formation position of the pilot hole in the pattern of partial shape removal, no useless hole is left in the part, and the waste of material when it is provided in another position outside the part is eliminated. it can.

By supporting by the supporting means, the other blank can be stably conveyed even after the one blank is pulled out.

By simultaneously withdrawing a pair of blanks, the number of steps can be reduced and the processing time can be shortened.

[Brief description of drawings]

FIG. 1 is a plan view for explaining an embodiment of the present invention and is for explaining a state in which a band-shaped material is processed in each step.

FIG. 2 is a cross-sectional view illustrating a supporting means.

[Explanation of symbols]

 P band-shaped material 1,11 blanks 1c, 11c recesses 2a, 2b pilot holes 4 slits 7, 8 pattern 9 support means

Claims (4)

[Claims] 1. A method of press-cutting a U-shaped part for punching a plurality of U-shaped parts from a band-shaped material by a multi-stage progressive press device, comprising a combination of the following steps a to e: Pressing method for U-shaped parts. a. One pair of blanks corresponding to the above-mentioned component shape are faced to each other so that a part of the other blank is fitted in the recess of one blank and the outline of one blank overlaps the outline of the other blank. Deploy. b. Pilot holes are formed in the strip. c. A thin slit having a predetermined length is formed on the line where the outline of one blank overlaps the outline of the other blank. d. The band-shaped material is subjected to partial shape cutting necessary for obtaining the shape of the component. e. One of the pair of blanks is withdrawn and then the other blank is withdrawn. 2. The press-punching method for a U-shaped part according to claim 1, wherein the formation position of the pilot hole is set within the pattern of the partial shape punching. 3. The support means according to claim 1, wherein when one of the pair of blanks is removed and then the other blank is sent to a removal station for the other blank, the lower surface of the other blank is supported. A method for punching out U-shaped parts, which is characterized by being supported by. 4. The method according to claim 1 or 2, wherein, before withdrawing one of the pair of blanks, all partial shape removal corresponding to both blanks is completed, and one of the pair of blanks is removed. A method of press-cutting a U-shaped part characterized in that the other blank is also removed at the same time by dropping it.