JPS62263831A - Progressive punching method and die - Google Patents

Abstract

PURPOSE:To reduce a die cost, etc., by forming respectively the projecting part or recessed part in the shape about equal to the punching shape on a pair of cutting tools, embossing the punching shape of the majority as well and punching the part not embossed yet. CONSTITUTION:The cutting tools 3, 3' for engraving, a punch 8 and die 12 are respectively arranged on the upper die and lower die 1, 2. In this case the dimension of the width and length of the cutting tool 5 is set slightly smaller than the width and length of the punching shape and the upper end opening dimension of the cutting tool 5' is slightly set smaller than the width and length of the punching shape as well. In the 1st stage, the engraving is performed on the front and back of a blank (m) by the engraving parts 4, 4' of the cutting tools 3, 3', the majority zone is pressed in the 2nd stage and unshearing zone is sheared by the punch 8 and die 12 in the 3rd stage. In this way, the man-hour is reduced and due to the reduction and miniaturization in the number of die parts and of the die, the die cost is reduced and the production efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a punching method and a structure of a progressive die that can be effectively used in conjunction with progressive punching.

[Problems to be solved by the prior art and the invention] Punching using a progressive die can significantly improve the mass productivity of products compared to a single die, but it is usually a punching die that uses a punching die, a punching die, or a cut-off die. Because multiple shearing dies are combined, it has a complicated structure. Conventionally, cutting tools with long cutting edges that are formed and assembled with high precision are dispersed in multiple punching processes, and the material is They were successively punched into a predetermined shape.

However, since the cutting edge of the cutting tool is long and a high degree of dimensional accuracy is required between the cutting edge and the goo to be combined with it,
It is extremely difficult to ensure the strength of the cutting tool, process it with high precision, and assemble it so that a predetermined clearance is set between the rear upper mold and the lower mold. Furthermore, there is a problem in that the clearance is enlarged due to wear due to use, which reduces the life of the mold and the quality of the product. In addition, due to the strength of the lower die, it is not possible to punch out the entire finished shape of the product in just one process, so the cutting tools must be distributed over multiple processes as described above. When the individual cutting tools and molds for each process are assembled, cumulative errors occur in the progressive mold as a whole, making it difficult to ensure the quality of the mold, and even causing the mold itself to become larger. There is an inconvenience in that a great deal of time and expense are required for its production.

In view of these circumstances, the present invention provides a mold that is simple, easy, inexpensive, and maintains accuracy, and also provides products of extremely high quality using this mold. The purpose of the present invention is to provide a progressive punching method that can be used for many years.

[Means and effects for solving the problem] In the punching process according to the present invention, at least one of the front and back surfaces of the material is first engraved along the punched shape, and then a convex shape that is equal to the punched shape is carved. Most of the engraved part is embossed and cut by a pair of cutting tools each having a part or a recess, and finally, the unembossed part is cut by a punching tool. Therefore, the dimensional accuracy of the punched shape can be determined by the stamp made on the material, and the amount of clearance required between the upper die and the lower die can be relaxed.

This simplifies the manufacture and assembly of mold parts to ensure the specified dimensional accuracy of the product, and furthermore, the clearance can be increased, so that the I'i'i between the cutting tool and the material during processing can be increased. The life of parts such as cutters can be improved by reducing frictional contact. Furthermore, by making a stamp in advance, the material is sheared along the stamp, thereby preventing the occurrence of burrs, etc., and as a result, the quality of the product can be improved.

〔Example〕

Figures 1 to 6 show an example of the punching method of the present invention and a mold used to carry out the method, and in the figures, 1.2 shows the material m being fed between these. The upper and lower dies 3 and 3', which are configured to be sequentially transferred by the device and to position the material m at a predetermined position, are used to form a stamping part by electrical discharge machining or the like along the punched shape of the material m. 4 and 4' are formed, and the positions of the stamping parts 4 and 4' on the front side in the direction of transport of the material m and the mutual positions of the upper mold 1 and the lower mold 2 are aligned and screwed onto these molds 1 and 2, respectively. 5□ 5' is a stamping tool; 6 is a cutting tool 5 which has been etched by etching, electric discharge machining, etc. in accordance with each punched shape, and at least the dimensions of its lower end surface are shown in FIG. As shown, the width W1 is the width W of the punched shape.
40 to 100 μm smaller than 0 and its length Ll
7 is a convex portion set to be smaller than the length Lo of the punched shape, and 7 is a cutter 5' that is etched corresponding to each convex portion 6, and the width W of the upper end opening is as shown in FIG. , is about 40 to 100 μm larger than the width W0 of the punched shape, and its length Lx is the length Lo of the punched shape
80 mm smaller than the length Ll of the convex portion 6.
A recess is set to be larger by ~200 μm, 8 is a punch screwed onto the upper mold l whose cross-sectional shape is set to be approximately 40-100 μm smaller than the punched shape, and 9 slides vertically on the upper mold l. A temporary presser 12 is attached to the tip of the screw 10 that is securely fitted, is pressed downward by the elasticity of a spring 11, and slightly protrudes from the punch 8 in the normal state.
is a goo that is set approximately 20 to 40 μm smaller than the punched part of the punched shape, and the upper die 3 and the lower die 3'
, the embossing cutter 5.5', the punch 8, and the die 12 are paired to form a first step, a second step, and a third step, respectively.

Next, to explain the punching processing method using such a mold, biloft holes (not shown) are arranged on both sides of the strip-shaped material m along the transfer direction on the mold. A biloft hole is formed in which the material m can be successively engaged in each step, and as the material m is transferred through the mold, it is reliably positioned at a position corresponding to each step by a pilot pin. First, in the first step, the stamping parts 4.4' of the stamping cutters 3, 3' are used to stamp m1 with a V-shaped cross section, for example, on both the front and back sides of the material m along the punched shape. m,' are engraved. In this case, the cross-sectional shape, depth, etc. of the markings m, . Thereafter, as the upper die l rises, the material m is lifted from the lower die 2 and is transferred by a predetermined pitch to be stamped r.
The part formed with n, 9m, ' is the die extrusion tool 5
, 5'. In this second step, the punching area defined by the markings m,,,' is pressed by the corresponding convex part 6 of the upper mold 1, so that the punching area defined by the markings m,,,,' is approximately Lt along the longitudinal direction, which is the majority of the area.
(See FIG. 5) The extending portion is pushed into the recess 7 of the embossing cutter 5' as shown in FIG. 312I and FIG. In this case, the embossing depth d of the recess 7 is preferably about 80 to 100% of the thickness of the material m, so that at least the length 1 of the protrusion 6 of the portion pushed into the recess 7 is (see FIG. 3), and the portion of the punched shape that is not pushed into the recess 7, that is, the U-shape at both ends of the punched shape shown by diagonal lines in FIG. The area engraved is not sheared and is pressed as it is with the upper surface of the embossing cutter 5' (see FIG. 4).

The embossed material m is further transferred to the third process, where it is punched 8 and die 1 in the same manner as in the previous and second processes.
2. In this third step, as shown in FIG. 6, the punch 8 presses the punch 8 from above, including the part that was not sheared in the second step, so that the unsheared area, ie, the unembossed area, is pressed from above by the punch 8. The parts are sheared and further pushed into the die 12 by lowering the punch 8. Thus die 1
The material m pushed into the die 2 is discharged to the outside of the mold as a punching waste m', but at this time, the punching waste m' is inserted into the die 1 whose width is slightly narrower than that of the die 1.
2 with a moderate pressing force, and the punched scrap m
Since `` is curved to follow the concave portion 7 in the second step, appropriate elastic deformation is brought about in this clamping portion.

Therefore, when the punch 8 moves upward after the blank m is punched out, the occurrence of so-called punching scraps, in which punching scraps are raised together with the punch, can be prevented.

Furthermore, regarding this lifting of punched scraps, since the center part of the lower end surface of the punch 8 is hollowed out, the punch 8 and punched scraps are
The contact area with ' can be made small, which further promotes the effect of preventing removal of scraps.

According to the punching method of the present invention, first, the punching shape, that is, the product accuracy can be determined by the stamping process using the stamping cutters 3 and 3', so the clearance accuracy between the upper die and the lower die and the accuracy of the product can be determined. Problems such as cumulative errors in the mold as a whole are resolved, and sufficient product accuracy is ensured through this stamping stage.Also, although it is a progressive mold, the stamping, embossing, and punching processes can be Since a predetermined punching shape can be completely processed by providing only one process for each process, the number of processes is reduced to a fraction of that of conventional molds, reducing the number of parts in the mold and reducing the number of parts. Miniaturization can be achieved. Furthermore, since a stamp is made in advance along the punching shape and the material is sheared based on the groove of the stamp, so-called burrs and cracks do not occur on the sheared surface, and it is easy to use in the next process of embossing and punching. The dimensional accuracy of each cutting tool is reduced by about an order of magnitude compared to the conventional case, and this does not affect the dimensional accuracy of the product itself. The clearance of the punch 8 can be selected to be relatively large, so that when punching the material m with the punch 8, the punch 8 and the material m are punched without frictional contact, so that the life of cutting tools such as the punch 8 can be improved. In addition, since materials with relatively low wear resistance can be used as the material for the cutting tool, it is possible to improve the workability of the edges.

Incidentally, each of the steps of stamping, embossing, and punching in the above embodiments may be composed of two or more steps depending on the shape of the punch. For example, both the front and back sides of the material may be stamped in separate steps. You can also do it.

〔Effect of the invention〕

As described above, according to the punching method of the present invention, production efficiency is improved by reducing the number of processing steps, and the structure of the mold used is reduced, as well as the cost and labor of manufacturing it. The life of the mold can be increased. Additionally, there are various benefits, such as improved product quality.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the method of the present invention and the structure of a mold that can be applied thereto, Fig. 2 is a cross-sectional view of the stamping tool showing the stamping process, and Figs. 3 and 4 are the stamping tool. 5 is a plan view showing the relationship between the embossing cutter and the punching shape, and FIG. 6 is a sectional view showing the punching process. 1... Upper die, 2... Lower die, 3.3'... Cutting tool for marking, 4.4゛... Stamping section, 5.5'...
Embossing cutter, 6...convex portion, 7...concave portion, 8.
...Punch, 12...Die. Figure 5 Figure 16

Claims (1)

[Claims] Most of the stamped shape is formed by a pair of cutting tools that form a stamp on at least one side of the material along the punched shape, and each of which has a protrusion or a recess formed in a shape substantially equal to the punched shape. A punching method in which the parts of the punched shape that are not embossed are punched out.