JP2007090421A - Burring die and working method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a burring die and its working method by which the height of the burring and the thickness of a plate are made to be freely variable in accordance with the objective burring shape. <P>SOLUTION: This burring method is characterized in that, after applying drawing to the material W to be worked by inserting the punch 4 into the forming open part 3 where is formed on dies 2, 12 and shearing work is applied to a material W with shearing parts 6 formed on the dies 2, 12 by further forcedly pressing the same punch 4 in dies 2, 12 and, after adjusting the height position in the axial direction of the shearing parts 6 of the dies 2, 12, drawing work and shearing work are performed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a burring die for forming a cylindrical protruding portion on a workpiece, and a machining method thereof.

  Generally, in the burring method, after preparing a pilot hole in a workpiece, the peripheral portion of the hole is pushed out to form a cylindrical protruding portion. However, in this case, since the pilot hole machining and the burring process are separate processes, the work efficiency is lowered. In addition, there is a possibility that distortion occurs around the hole when the pilot hole is processed. Therefore, recently, for example, as disclosed in Patent Document 1 below, a method has been proposed in which drilling and burring are performed in one step using a die and punch having a specific shape.

In forming the opening for molding, the die used in this burring method forms a large-diameter portion and a small-diameter portion by inserting a counterbore in the mouth portion, and the punch is formed with the small-diameter portion of the die. A projection having a small diameter is formed on the lower surface of the tip portion with substantially the same diameter. Then, after the workpiece is formed into a shape along the large diameter portion of the die opening by pushing the punch into the die opening, the punch is further pushed into the die opening, and the punch shoulder and the die small diameter are formed. The workpiece is sheared at the corners of the part to perform drilling.
JP 7-116745 A (see summary and FIGS. 1 and 2)

  However, since the dies and punches used in this burring method have a specific shape, the height of the burring portion is determined by the depth of the large diameter portion of the die, and burring processing with various heights is performed. I can't. Regarding workpieces, those having a predetermined plate thickness can be burring, but those having various plate thicknesses cannot be processed. For this reason, when processing burrings having different heights or different thicknesses, there is a problem in that a number of dies and punches each having a desired burring shape must be prepared.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a burring processing mold and a processing method thereof in which the height and thickness of the burring can be changed according to the target burring shape. And

  The invention described in claim 1 includes a die having an opening for molding, and a punch for pressing a work piece placed on the die into the opening to perform a drawing process, and further including the punch. A burring die that pushes into the die and shears the workpiece at the shearing portion of the die, wherein the shearing portion of the die is configured such that the height position in the axial direction changes. It is a burring type.

  According to a fifth aspect of the present invention, after a punch is inserted into a molding opening formed in the die and the workpiece is drawn, the punch is further pushed into the die and the shear formed in the die. A burring method in which a shearing process is performed on the workpiece at a part, wherein the drawing part and the shearing process are performed after adjusting the axial position of the shearing part of the die. It is a processing method.

  In the inventions of claims 1 and 5, since the height position in the axial direction of the shearing portion is variable, if the height position of the shearing portion is changed according to the target burring shape, the same mold is used. Work materials with different burring heights and plate thicknesses can be formed. Since it is not necessary to prepare various dies and punches, it is extremely advantageous in terms of manufacturing cost and work efficiency.

  Next, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
1 is a cross-sectional view showing a state before burring of a burring die according to a first embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of the main part of FIG. 1, and FIG. 3 is a burring of the burring die FIG. 4 is a cross-sectional view showing a state after drilling of the burring die.

  As shown in FIG. 1, the burring die 1 includes a die 2 having a molding opening 3 and a punch 4 that is pushed into the opening 3. The die 2 is placed on a bed or bolster (not shown), and the punch 4 is configured to approach and separate from the die 2 by a predetermined driving means.

  The punch 4 is a rod-shaped body that advances and retreats with respect to the die 2 and is formed in an arc shape so that the corner portion of the tip can be drawn smoothly. The die 2 has a drawing unit 5 that cooperates with the punch 4 and performs drawing processing on the workpiece W made of a plate material, and a shearing unit 6 that performs shearing processing.

  The narrowed portion 5 is an edge portion of the opening 3 and is formed in an arc shape so that the workpiece W can easily enter. In this embodiment, the shearing portion 6 is separate from the main body 2 a of the die 2. Thus, the cylindrical member 7 is provided so as to be slidable in the opening 3, and shearing is performed at the upper edge corner of the cylindrical member 7.

  Since the protrusion length (hereinafter referred to as burring height) in the burring process is determined by the length L from the upper surface 2b of the die 2 to the upper surface 7a of the cylindrical member 7, if this length L is constant, various Cannot be formed with a burring height of.

  For this reason, in this embodiment, the die 2 is a so-called split type constituted by a main body 2a and a cylindrical member 7 that is separate from the main body 2a, and the axial height of the cylindrical member 7 is set high. It can be adjusted by the height adjusting means 8.

  The height adjusting means 8 may be anything as long as it moves the cylindrical member 7 in the axial direction. In the present embodiment, the height adjusting means 8 is provided on the outer peripheral surface of the cylindrical member 7. Rack 9, a pinion 10 meshing with the rack 9, and a drive source (not shown) such as a motor or hydraulic means for driving the pinion 10.

  When such a burring die 1 is used to perform drawing and shearing on the workpiece W, it must be dimensionally restricted so that a product with excellent appearance and accuracy can be obtained. Is preferred.

  Specifically, as shown in FIG. 2, the width m of the space S between the inner peripheral surface 5 a of the narrowed portion 5 and the outer peripheral surface 4 a of the punch 4 is slightly larger than the thickness t of the workpiece W. is doing. According to experiments, it has been found that the width of the space S is preferably such that a clearance of 5 to 20% with respect to the thickness t of the workpiece W is generated.

On the other hand, in the shearing portion 6, it is preferable that the upper end surface 7 a of the cylindrical member 7 and the upper surface 2 a of the die 2 are parallel, and the inner diameter D 1 of the cylindrical member 7 is slightly larger than the outer diameter D 2 of the punch 4. According to experiments, the degree of clearance of 5 to 10% is preferable. The curvature radius of the front end corner of the punch 4, depending on the thickness t and the strength of the workpiece W, in the case of steel sheets for automobiles, it is preferably set to about 16～20Mm.

  Next, a processing method using a burring processing mold will be described.

  First, the pinion 10 of the height adjusting means 8 is driven, and the length L from the upper surface 2b of the die 2 to the upper end surface 7a of the tubular member 7 is the axial direction of the punch 4 so that the desired burring height is obtained. The height position of the upper end surface 7a of the cylindrical member 7 is determined.

  Then, the workpiece W is placed on the upper surface of the die 2. In this state, the punch 4 is lowered and pushed into the opening 3 of the die 2, and a drawing process is applied to a part of the workpiece W. As shown in FIG. 3, the workpiece W enters the opening 3 along the arcuate corners of the die 2, and is formed into a cross-sectional inverted hat shape along the narrowed portion 5 of the die 2. Further, when the punch 4 is lowered, as shown in FIG. 4, the bottom portion of the workpiece W formed in a cross-sectional inverted hat shape is sheared by the shoulder portion of the cylindrical member 7 of the die 2 and the lower end of the punch 4. The

  When another burring height is formed on the workpiece W, the pinion 10 of the height adjusting means 8 is driven again, and the length from the upper surface 2b of the die 2 to the upper end surface 7a of the tubular member 7 is determined. The position of the cylindrical member 7 is determined so that L becomes another burring height. Similarly, when the punch 4 is lowered, the workpiece W is subjected to burring and shearing, and the workpiece W having another burring height is obtained.

  As described above, in this embodiment, the same die 2 and punch 4 are used, and the cylindrical member 7 can be formed to have different burring heights only by changing the position.

<Second Embodiment>
FIG. 5 is a sectional view showing a state before burring of a burring mold according to a second embodiment of the present invention, FIG. 6 is an enlarged sectional view of a main part of FIG. 5, and FIG. FIG. 8 is a cross-sectional view showing a state after burring of the burring type, and FIG. 9 is a cross-sectional view showing a state after drilling of the burring type. In addition, the same code | symbol is used for the member which is common in the member shown to FIGS. 1-4, and description is abbreviate | omitted.

  As shown in FIGS. 5 to 7, the burring die 11 according to the present embodiment is a split die in which a die 12 is formed by a plurality of layers of cylindrical members 13 arranged concentrically. The vertical height is adjusted by the height adjusting means 15.

  The height adjusting means 15 may be anything as long as the height can be adjusted sequentially from the innermost cylindrical member 13, for example, the first cylindrical member 13 that supports the entire cylindrical member 13 from below. You may comprise by the thing which has the support plate 16 and the 2nd support plate 17 which supports the cylindrical member 13 from which the support by the 1st support plate 16 was removed.

  In this way, the cylindrical member 13 whose height is sequentially adjusted by moving the first support plate 16 in the radial direction is determined, and the length L from the upper end surface 13b to the upper surface 12a of the die 12 is The desired burring height can be set to a predetermined length L by adjusting the height of the second support plate 17.

  When the height is adjusted sequentially from the innermost layer among the plurality of cylindrical members 13 in this way, the width m of the space S between the inner peripheral surface 5a of the throttle portion 5 and the outer peripheral surface 4a of the punch 4 is increased. The workpiece W having a thickness t corresponding to the width m can be formed. In addition, it is the same as that of embodiment mentioned above to make clearance generate to some extent.

  Next, a processing method using a burring processing mold will be described.

  First, the first support plate 16 is moved back and forth in the radial direction according to the thickness t of the workpiece W, and the cylindrical member 13 whose height is adjusted is dropped onto the second support plate 17. Then, the second support plate 17 is moved up and down in the vertical direction so that the cylindrical member 13 on the second support plate 17 corresponds to the desired burring height, and the height position is determined.

  As shown in FIG. 5, the workpiece W is placed on the upper surface of the die 12, and in this state, the punch 4 is lowered, pushed into the opening 3 of the die 12, and narrowed down to a part of the workpiece W. Add processing. As shown in FIG. 7, the workpiece W enters the opening 3 along the arcuate corners of the die 12, and is formed into a cross-sectional inverted hat shape along the narrowed portion 5 of the die 12. When the punch 4 is further lowered, the bottom of the workpiece W is sheared by the shoulder portion of the cylindrical member 13 of the die 12 and the lower end of the punch 4 as shown in FIG.

  When another burring height is formed on the workpiece W, the second support plate 17 of the adjusting means 15 is driven again, and the length from the upper surface 12b of the die 12 to the upper end surface 13a of the tubular member 13 is increased. The position of the cylindrical member 13 is determined so that the length L becomes another burring height. Similarly, when the punch 4 is lowered, the workpiece W is subjected to burring and shearing, so that the burring height can be increased.

  FIG. 10 is a cross-sectional view showing a state in which workpieces having different plate thicknesses are formed by the burring die according to the second embodiment.

   Next, when forming the workpiece W having a plate thickness t1 different from the plate thickness t described above, the space corresponding to the plate thickness t1 is driven by driving the first support plate 16 of the height adjusting means 15. The cylindrical member 13 having a predetermined number of layers is dropped on the second support plate 17 so that the width m of the part S is obtained. Similarly, when the punch 4 is lowered, the workpiece W enters the space S and can be subjected to burring, and when the punch 4 is further lowered, a shearing process is performed in the same manner as described above. Even workpieces W having different thicknesses can be molded.

  As described above, in this embodiment, the same die 12 and punch 4 are used, and the number of layers and the height position of the cylindrical member 13 are changed, so that the workpieces W having different burring heights and plate thicknesses t can be obtained. Burring and shearing can be performed.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. For example, in the above-described embodiment, the punch and the die have a cylindrical shape, but the present invention is not limited to this, and can be applied to a rectangular tube shape or a polygonal tube shape. Further, the height adjusting means 8 and 15 are not limited to those described above, and may be those using electrical means or the like, and various changes can be used.

It is sectional drawing which shows the state before the burring process of the burring process type | mold which concerns on the 1st Embodiment of this invention. It is a principal part expanded sectional view of FIG. It is sectional drawing which shows the state after the burring process of the burring process type | mold. It is sectional drawing which shows the state after drilling of the burring type. It is sectional drawing which shows the state before burring process of the burring process type | mold which concerns on the 2nd Embodiment of this invention. It is a principal part expanded sectional view of FIG. It is a perspective view of a burring type. It is sectional drawing which shows the state after the burring process of the burring process type | mold. It is sectional drawing which shows the state after drilling of the burring type. It is sectional drawing which shows the state which shape | molds the to-be-processed material from which board thickness differs by the burring type | mold which concerns on 2nd Embodiment.

Explanation of symbols

1,11 ... Burring type,
2,12 ... Die,
2a ... Die body,
3 ... opening,
4 ... Punch,
5 ... Drawing part,
6 ... shearing part,
7, 13 ... cylindrical member,
8, 15 ... Height adjustment means,
W: Work material.

Claims (7)

A die having an opening for molding, and a punch for pressing and drawing a workpiece placed on the die into the opening, and further pushing the punch into the die and a shearing portion of the die A burring mold that shears the workpiece.
The burring die according to claim 1, wherein the shearing portion of the die is configured such that the height position in the axial direction changes. The burring die according to claim 1, wherein the die is configured such that the thickness of the shearing portion is changed. The die is constituted by a main body and a cylindrical member provided in the opening, and the cylindrical member is provided with a height adjusting means for changing the height position in the axial direction. Item 3. A burring die according to item 1 or 2. 2. The die according to claim 1, wherein the die is formed of a plurality of layers of concentrically arranged cylindrical members, and height adjusting means for changing the height position sequentially from the innermost cylindrical member. 2. A burring mold according to 2. After a punch is inserted into the molding opening formed in the die and the workpiece is drawn, the punch is further pushed into the die and the workpiece is sheared into the workpiece by the shearing portion formed in the die. A burring method for applying
A burring method comprising: adjusting the height position of the shearing portion of the die in the axial direction, and then performing the drawing and shearing. The die is composed of a main body and a cylindrical member surrounding the opening, and after the height position in the axial direction of the cylindrical member is changed by a height adjusting means, the drawing and shearing are performed. The burring method according to claim 5, wherein: The die is composed of a plurality of layers of concentrically arranged tubular members, the thickness of the shearing portion is adjusted by selecting the number of layers of the tubular members, and then the drawing and shearing are performed. The burring method according to claim 5, wherein:

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