JPH0347637A - Method for pressing sheet metal in preventing burrs from occurring - Google Patents

Abstract

PURPOSE:To prevent burrs from occurring by providing a groove in advance along a shearing position of a part of a sheet metal which makes a product and comes in contact with a die. CONSTITUTION:When a material 13 to be worked is sheared by a press, a groove 14 is set in advance at a schedule place to be sheared of the material 13 to be worked to restrain burrs from occurring. Further, when an NC turret press, special dies for marking the groove on the lower surface of the sheet metal and an ordinary blanking die are used, burring as well as shearing can be substantially carried out at the same time. A set-up for flexible and quick burring can be carried out in accordance with a working shape, further, a very versatile burring method capable of removing burrs out of an intermediate part of the sheet metal such as a notch, a hole, etc., and a part of a comparatively complicated shape is given. Consequently, it is possible to give such a method that manual operation is eliminated and scraps by burring is prevented fully from occurring.

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a burr-preventing sheet metal press working method, and in particular,
The present invention relates to a burr-preventing sheet metal press processing method that is highly effective when applied to a C-turret punch press for sheet metal processing.

[Prior art and its problems]

Shear processing using a press is a processing method that uses a die and a punch to cause shear deformation to the workpiece and separate it, but in normal sheet metal press processing, the occurrence of burrs cannot be avoided. Figure 6(a) shows who 6
1 and a shear burr 63 formed as a sharp blade-like edge in the extension of the fracture surface 62 on the opposite side. When such a sheet metal 60 is used as a part of the structural material of an electronic device, the burr 63 may damage the electrical wiring coating, or
It may also injure the hands of workers during the manufacturing process or maintenance work. Therefore, sheet metal manufacturers use various methods to prevent burrs, and how to select a burr suppression/burr removal method in relation to manufacturing costs has become a very big problem.

Various deburring methods have been known for a long time.
March 20, 1985) Industrial Technology Service Center P,
It is introduced in detail in 261-319. However, for example, sheet metal used in electronic measuring instruments, etc.
Manual deburring with tools is the most practical way to deburr a wide variety of parts with relatively complex shapes and holes. For example, a "scraper" 65 as shown in FIG. 6(b), a "file" 66 as shown in FIG. 6(C), etc. are used.

However, such manual work is time-consuming, poses safety concerns for the workers, and has the drawbacks of uneven finish. Furthermore, when the file 66 is used to remove scratches from the aluminum plate, it has the disadvantage of causing clogging.

Furthermore, a belt sander 68 schematically shown in FIG. 6(d)
, and other methods using rotary mechanical tools.

However, mechanical tools have the disadvantage that they can only deburr relatively large parts such as straight parts of the workpiece, and notches cannot be used to deburr holes.
The drawback was that the abrasive material also caused clogging.

Further, chemical methods such as dissolution may be considered, but there is a risk that areas other than the burrs will be eroded, the finish may not be uniform, and it is relatively time consuming.

Furthermore, special pressing methods have been proposed that suppress burrs during press processing or perform processing and deburring at the same time, but these have the drawback of requiring special processing equipment and increasing costs. .

[Problem that the invention seeks to solve]

The present invention has been made in order to eliminate the drawbacks of the prior art described above, and its purpose is to pre-groove the shearing area of the workpiece when shearing the workpiece using a press. By providing this, it is possible to suppress the occurrence of burrs and to take effective measures against burrs with a small investment. Another purpose is to use an NC turret press, a special mold for stamping grooves on the underside of the sheet metal, and a regular punching mold.
This makes it possible to perform deburring virtually simultaneously with the shearing process, and also enables flexible and quick deburring setups depending on the processed shape. To provide a highly versatile deburring method capable of deburring relatively complex shapes.

It also eliminates independent manual work and contributes to reducing the risk to workers. Another object is to eliminate the need for measures for conveying and removing chips by providing a method that does not generate any chips during deburring.

[Means for solving problems]

In short, the present invention is characterized in that, in shearing a sheet metal using a die, grooves are provided in advance along the shearing position on the surface of the sheet metal that is to be made into a product, which is in contact with the die. be. In particular, when providing the grooves, press working can be used, and some or all of the working can be performed using an NC turret punch press.

〔Example] Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

First, the present invention will be explained in detail with reference to FIG. First, as shown in Figure (a), a metal plate (sheet metal) 13 is pressed using a mold 11 having a protrusion with a V-shaped cross section and a mold 12 to form a groove 14 as shown in the box. Here, the sheet metal 13 is an aluminum plate with a thickness of 1.6 m.

Next, as shown in Figure (C), the cutting mold 15 and I6
The sheet metal 13 is positioned so that the center of the clearance coincides with the valley of the groove 14. At this time, the left part 13A placed on the mold 15 is the part to be made into a product. Next, as shown in Figure (d), cutting is performed. During cutting, stress is concentrated at the valley portion of the groove 14, and it is thought that the breakage occurs from there. Figure (e) shows the sheet metal 13A after cutting. Its edges are pre-chamfered,
From the surface 13a of the sheet metal 13, the sagging portion 13b, the sheared surface 1
3c, the fracture surface 13d, the inner surface 14a of the groove 14, and the back surface 13e of the sheet metal 13, no burrs are generated at all. Therefore, there is no need to perform deburring.

As shown in Figure (b), the angle θ of the V-groove is 75° instead of 90°. This has the effect of preventing the occurrence of subsequent burrs. The optimum angle is not limited to this value, and may vary depending on the material, dimensions, groove shape, etc., so it may be determined by experiment at the time of implementation.

There is a possibility that a small burr may be generated at the boundary between the inner surface 14a of the groove 14 and the fracture surface 13d, but even if it occurs, it will be extremely small and negligible. Also, mold 1
The positional relationship between 5 and 16 and the sheet metal 13 is not limited to the above-mentioned position, but may be shifted to a more suitable position to prevent burrs from forming near the valleys of the grooves 14.

Various types of press machines and molds can be used to carry out the present invention. For example, the present invention can be applied to progressive molds for power press parts by cutting after forming grooves.

Further, in the above explanation, the groove 14 is provided only on one side of the sheet metal,
Although only one side is chamfered, it is also possible to provide chamfers 84 on both sides and chamfer both the front and back sides.

Next, the application of the present invention to the NC press machine 2 as briefly shown in FIG. 2 will be explained. The NC press 2 has a plurality of molds (not shown) mounted on upper and lower turrets 21 and 22, and selects a mold by rotating the turret under the control of an NC controller. The sheet metal material is positioned in the XY force direction by the movement of the carriage 24, and the process continues until the machining of -1 sheet metal is completed.
It can be processed continuously.

FIG. 3 shows an example of a mold used when the NC press 2 is used. The lower mold 3A includes a base portion 31, a projection portion 32, and a contact portion 33. The protrusion 32 serves as a substantial mold for forming the groove, and has a shape such that a chevron-shaped protrusion 32b is integrally formed on the top of a rectangular parallelepiped 32a. Fixed. The contact part 33 has a hole 33a into which the protrusion 32 is inserted, is attached to the base part 31 so as to be movable in the direction along the central axis of the mold 3, and is biased upward by elastic force. There is. The protrusion 32b of the protrusion 32 is normally drawn into the hole 33a as shown in FIG.
When the contact surface 33c is pushed downward, as shown in Figure (d),
protrude from

The upper die 3B is a cylindrical die in which the punching surface 34a is substantially flat, and the end portion 34b is rounded.

Next, a case will be described in which the present invention is implemented using the NC press 2 and the molds 3A and 3B. As shown in Figure 4(a),
The lower mold 3A is used by being attached to the lower turret disk 40A, and the upper mold 3B is partially attached to the turret disk 40B.

During pressing, the sheet metal 41 is sandwiched between the punch surface 34a of the upper mold and the contact surface 33c of the lower mold, as shown in FIG. 3(b).

At this time, the protrusion 32b bites into the lower side of the metal sheet, and due to the resulting plastic deformation, a contour corresponding to the protrusion 32b is formed on the lower surface of the sheet metal 41. While repeating such a punching process, the sheet metal 41 is continuously moved to perform a so-called additional punch.
) A groove 44 is formed as shown in FIG.

FIG. 4(C) shows a part of the back surface of the sheet metal 41 held by the NC press, and then, by punching, the inner part of the groove to be made into a product is punched out.

Overtaking will be explained with reference to FIG. As shown in Figure (a), the sheet metal 4 is
1, and then lower the punch 52 as shown in Figure (b) to perform a six-opening. Further, in Figure 0 (C), where pressing is repeated while continuously moving the sheet metal 41, the locations where holes are to be made are indicated by broken lines. Finished product 41a
Since the back side of the end face is chamfered in advance with the groove 44 and the other side is "sloped", there is no need to perform further deburring.

In this way, in the embodiment using the NC press, it is sufficient to provide grooves in advance by additional punching in accordance with the locations to be treated, so there is a high degree of freedom in implementation, and setup can be made relatively easily.

Furthermore, since it can be applied to manufacturing processes using computer-aided design and manufacturing systems, it has the potential to dramatically improve overall manufacturing efficiency.

Furthermore, in the above embodiments, the protrusions provided on the lower die are illustrated as being linear, but the protrusions are not limited to this, and may be of various shapes, including curves such as circular arcs. Needless to say, it can be done. moreover,
In addition to being used for overtaking, a specially designed mold can also be used to machine a groove that corresponds to the press shape of the mold designed for single hole drilling.

Further, in the above embodiment, the groove 44 is described as being provided on the lower surface of the sheet metal 41, but it is needless to say that the groove 44 is not limited to this and may be provided on the upper surface.

〔effect〕

Since the present invention has the above-described structure and operation, when a workpiece is sheared by a press, the occurrence of burrs can be prevented by providing grooves in advance at the location where the workpiece is to be sheared. The effect is that effective burr countermeasures can be taken with a small investment. Also,
This can be carried out using an NC talent press, a special mold for stamping grooves on the underside of the sheet metal, and a regular punching mold, so deburring can be done virtually at the same time as the shearing process. Furthermore, it is possible to flexibly and quickly set up deburring according to the processing shape, and it is highly versatile as it can deburr the middle part of sheet metal such as cutouts and holes, and relatively complex shapes. This has the effect of providing a deburring method. Moreover, this has the effect that independent manual work can be omitted and the danger to the worker is reduced. Another object is that since no chips are generated during deburring, it is possible to eliminate the need for measures to transport and remove chips.

[Brief explanation of drawings]

1 to 5 relate to embodiments of the present invention, FIG. 1 is a diagram showing a sheet metal and a mold showing a basic embodiment of the present invention, and FIG. 2 is a perspective view schematically showing an NC press device. Figure 3 is a diagram showing a mold for carrying out the present invention using the NC press machine shown in Figure 2, and Figure 4 is a diagram for explaining the additional punching process for forming grooves in a sheet metal using the mold shown in Figure 3. Figures 5 and 5 are diagrams for explaining the overtaking process for further cutting the sheet metal shown in Figure 4, and Figure 6 is a diagram for explaining the prior art. 13.41: Sheet metal, 15.16, 51, 52: Mold, 13A, 41a: Sheet metal for product, 14.41a:
groove.

Claims (1)

[Scope of Claims] 1. In the shearing process of a sheet metal using a die, the method includes the step of forming a groove in advance along the shearing position on the surface of the sheet metal that is to be made into a product, which is in contact with the die. Features a burr-preventing sheet metal press processing method. 2. The burr-preventing sheet metal press processing method according to claim 1, wherein the step of providing the groove is a stamping step using a press. 3. The burr-preventing sheet metal press working method according to claim 2, wherein part or all of the stamping process and the shearing process are performed by additional stamping process. 4. The stamping process and the shearing process are performed using a device that continuously presses one sheet metal by numerically controlling the selection of a plurality of molds, the positioning of the workpiece relative to the molds, and the processing procedure. 4. The burr-preventing sheet metal press working method according to claim 3.