JP2004255405A - Method for manufacturing flanged cylindrical member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a flanged cylindrical member by which shock lines formed in a flange part is reduced while cutting manufacturing cost. <P>SOLUTION: After a forming stage for forming the flanged cylindrical member having the flange part by applying a plurality of drawing works to a material to be formed, the shock lines formed at the flange part 1a in the forming stage are reduced by pressing the flange part with press dies ( a punch 3 and a die 2 ). At this time, the dies with a plurality of grooves 4 formed in a concentric circular and serrated shape on the surfaces which are brought into contact with the flange part is used as the press die which are used. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a flanged tubular member obtained by a drawing method, and more particularly to a method for manufacturing a flanged cylindrical member capable of improving a shock line formed on a flange portion after drawing.
[0002]
[Prior art]
In the method of manufacturing a flanged tubular member, in which a plurality of drawing processes are sequentially performed to gradually reduce the diameter of the tubular portion, bending back to the flange portion of the flanged tubular member is repeatedly performed. Therefore, as shown in FIG. 8A, the wrinkles are formed concentrically on the surface of the flange due to the reduced thickness and bending habit. Such a wrinkle is called a “shock line”, and the flatness of the surface of the flange portion is deteriorated by the shock line. For this reason, if the flange portion is an attachment portion between members, the seating between the members will be poor, and if the flange portion is an end surface of an airtight container or the like, the sealing property will be reduced. Therefore, a technique for preventing such a shock line is disclosed in, for example, the following patent document.
[0003]
[Patent Document 1]
Japanese Patent No. 2762634 [0004]
[Problems to be solved by the invention]
Apart from the method of preventing the shock line from being drawn as described above, there is also a method of improving the shock line formed on the flange. For example, there is a method of improving the shock line by applying a high surface pressure equivalent to forging to the flange portion to crush unevenness formed in the flange portion. However, according to this method, the surface area is large in spite of the thickness of the flange, so that it is in a restrained state, and the constituent material of the flange hardly flows. It is necessary to increase the applied surface pressure, and large-scale equipment such as a large-capacity press device capable of applying a high surface pressure is required. Also, the central part of the flange has a large constraint coefficient and the constituent material is less likely to flow, whereas the outer peripheral part of the flange is easier for the constituent material to flow. 8B is deformed in the compression direction, and as a result, as shown in FIG. Therefore, in order to prevent this, a high-rigidity press die (die or punch) that is not easily deformed even at a high surface pressure is required. As a result, the equipment cost and the die cost increase, and the manufacturing cost increases.
[0005]
On the other hand, there is also a method of performing rotation processing such as spinning processing and removing a shock line by this rotation processing. However, since rotation processing such as spinning processing is required, the processing time is significantly increased (10 to 50 times), so that productivity is poor. Further, there is a problem that a machine such as a spinning machine is required, and equipment costs are increased, so that manufacturing costs are increased.
[0006]
The present invention has been made in view of the above-described problems, and has a flanged cylinder that can improve a shock line formed in a flange while reducing manufacturing costs and improving productivity. An object of the present invention is to provide a method for manufacturing a shaped member.
[0007]
[Means for Solving the Problems and Functions / Effects]
In order to solve the above-mentioned problems, a method of manufacturing a flanged member according to the present invention is directed to a shock-improving shock line formed on a flange portion of a flanged cylindrical member by pressing the flange portion with a press die. A line improving step, wherein in the shock line improving step, as the press die, a plurality of grooves are formed concentrically on a surface abutting on the flange portion, and a plurality of grooves are formed in a cross section including an axis of the press die. Characterized in that a groove having a saw-tooth shape in cross section is used.
[0008]
According to the shock line improving process as described above, the flange is formed by the groove formed in the press die when the flange is pressed by the press die at a surface pressure equal to the tensile strength of the flange. The constituent material is guided to the groove, and the thicker portion of the flange portion flows to the thinner portion. In addition, since a shock line is formed concentrically on the flange portion, a plurality of concentrically formed press dies and a saw-tooth-shaped cross-section shape allows the constituent material of the flange portion to be a material for the flange portion. The fluid flows preferentially in the radial direction, and the thickness of the flange in the radial direction is uneven, so that the thickness of the flange is likely to be uniform. Therefore, a shock line and a bending habit can be improved. As described above, the shock line formed in the flange portion in the step of forming the flange portion is improved by the shock line improving step according to the present invention, so that a flanged cylindrical member having a good flatness of the flange portion can be manufactured. Can be.
[0009]
Furthermore, in the press mold used in the present invention, when the flange is brought into contact with the flange, the contact area with the flange is reduced by an amount corresponding to the formation of the groove, and is smaller than that without the groove. The constituent material of the flange can be caused to flow with a relatively small surface pressure (surface pressure equivalent to the tensile strength of the flange). Therefore, there is no need to use a large-capacity large-sized press die, so that manufacturing costs can be reduced. Further, since the surface pressure acting on the flange portion can be reduced, it is possible to prevent the shape of the flange portion from becoming a medium-thickness shape in which the thickness of the outer peripheral portion is small without using a high-rigidity press die. .
[0010]
Further, it is preferable that the shape of the sawtooth groove is set so that the constituent material of the flange flows preferentially outward in the radial direction. Thereby, the constituent material of the flange portion flows preferentially outward in the radial direction, so that the shock line can be improved and a decrease in the thickness of the outer peripheral portion of the flange portion can be more effectively suppressed. .
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1, the method for manufacturing a flanged tubular member in the present embodiment includes a forming step A1 of forming a flanged tubular member by performing a plurality of drawing processes on a material to be molded, and a forming step A1. And a shock line improving step A2 for improving a shock line formed in the portion. Further, the forming step A1 includes a pre-drawing step A11 of drawing a workpiece (a plate-shaped member in the present embodiment) to form a tubular portion of a flanged tubular member, and a pre-drawing step A11. And a next drawing step A12 of forming a flange portion while reducing the diameter of the cylindrical portion. Further, the shock line improving step A2 can be performed by pressing the collar portion with a press die, and a first shock line improving step A21 of pressing with a first press die and a second shock line of pressing with a second press die. And a line improvement step A22. Further, in the present embodiment, the finishing step A3 is performed after the shock line improving step.
[0012]
Hereinafter, these steps will be described in detail. FIG. 2 shows a molding step of molding a flanged tubular member. First, the pre-drawing step A2 is performed on the plate-shaped molding material W shown in FIG. As a result, a cup-shaped tubular portion W1 is formed on the workpiece W, and a flange portion W2 is formed (FIG. 2B). Next, the flange portion W2 is formed while reducing the diameter of the cylindrical portion W1 formed as described above (FIGS. 2C to 2E). At this time, a flange portion W2 is formed in FIG. 2 (c), and a shoulder portion W3 formed between the flange portion W2 and the cylindrical portion W1 is bent back as the diameter of the cylindrical portion W1 is reduced. The portion that was the shoulder W3 becomes a part of the flange W2. Then, when the diameter of the cylindrical portion W1 is reduced to a desired diameter (FIG. 2D), a through hole is formed in the bottom of the cylindrical portion W1, and a flange portion 1a as shown in FIG. And the flanged tubular member 1 having the tubular portion 1b can be formed.
[0013]
In the above-described forming process, since the drawing is performed a plurality of times, a shock line resulting from the plurality of times of the drawing is generated in the flange portion 1a of the flanged tubular member 1. Further, in FIG. 2, the next drawing step of forming the flange portion 1a while reducing the diameter of the cylindrical portion 1b is performed only about two or three times, but the cylindrical portion 1b having a small diameter is actually formed. Since it is difficult to reduce the diameter of the cylindrical portion 1b all at once, the diameter of the cylindrical portion 1b is reduced a plurality of times and the shoulder portion W3 is bent back, so that a large number of concentric shock lines are formed. Will be formed.
[0014]
When such a shock line is formed in the flange portion 1a, when the flanged cylindrical member 1 is attached to another member, the seating as an attachment surface is poor, or the flange portion 1a is airtight. When used as an end face of a container or the like, the sealing property is reduced. Therefore, it is necessary to improve the shock line formed on the flange 1a in the molding process.
[0015]
FIG. 3 shows in detail a surface portion of the press-type used in the shock line improvement step, which comes into contact with the flange portion 1a of the flanged tubular member 1. As shown in FIG. As shown in FIG. 3, in the present embodiment, a press die for pressing the flange 1 a is constituted by a punch 3 and a die 2. A plurality of saw-tooth-shaped grooves 4 are formed on the surfaces of the press 3 and the die 2 that come into contact with the flange 1a. The plurality of grooves 4 are formed concentrically and continuously at a predetermined pitch x around the axis O of the press die (the punch 3 and the die 2). The pitch amount x of the groove portion 4 is set to a suitable value according to the plate thickness of the flange portion 1a of the flanged tubular member 1 where the shock line is formed. More specifically, the pitch x of the groove 4 is preferably set to be 1 to 3 times the plate thickness of the flange 1a. Further, the grooves formed in the punch 3 and the die 2 are formed by aligning the positions of the punch 3 and the die 2.
[0016]
The surfaces of the punch 3 and the die 2 that come into contact with the flange portion 1a are formed so that the central portion of the punch 3 and the die 2 is slightly raised from the outer peripheral portion. More specifically, the surface of the punch 3 and the die 2 that comes into contact with the flange 1a is tapered as a whole at a predetermined angle θ with the center of the press die (the punch 3 and the die 2) as a fulcrum. θ can be set, for example, in the range of 0 to 0.5 °.
[0017]
Further, the vicinity of the groove 4 is shown in detail in FIG. As shown in FIG. 4, in a cross section including the axis O of the press die (the die 2 in FIG. 4), the groove 4 is formed in a saw-tooth shape, and the groove 4 extends from the deepest part 4 a of the groove 4 to the axis O of the die 2. The side surface 4b (referred to as the axial side surface 4b) of the groove 4 formed toward the outer periphery of the die 2 is formed from the deepest portion 4a of the groove 4 toward the outer periphery of the die 2 (the outer side surface 4c). Also has a gentle shape. That is, the radial length of the axial side surface 4b is longer than the radial length of the outer peripheral side surface 4c. Further, the axial side surface 4b has a round shape convex toward the surface side of the die 2, and the outer peripheral side surface 4c has a round shape convex toward the inside of the die 2. . Further, the depth of each groove 4 is set to 0.05 to 0.2 mm. The shape of the axial side surface 4b and the outer peripheral side surface 4c may be simply tapered. However, in order to effectively flow the constituent material of the flange portion 1a of the flanged tubular member 1, the groove portion 4 is required. It is more desirable to make the shape of both side surfaces 4b and 4c into a round shape.
[0018]
Hereinafter, a shock line improving process for improving a shock line generated in the flange portion 1a of the flanged tubular member 1 by the punch 3 and the die 2 shown in FIGS. 3 and 4 will be described in detail with reference to FIGS. I do. First, the cylindrical portion 1b of the flanged tubular member 1 is inserted into the opening 2a formed in the die 2, and the flange 1a is arranged such that the back surface of the flange portion 1a contacts the surface of the die 2. Then, in this state, the punch 3 is brought into contact with the surface of the flange 1a on the side not in contact with the die 2, and the flange 1a is pressed by the die 2 and the punch 3 to press the flange 1a. At this time, the pressure applied to the flange 1a is sufficient if the surface pressure is equal to the tensile strength of the flange 1a.
[0019]
As a result, as shown in detail in FIG. 6, the side surfaces 4b and 4c of the groove 4 hold down the large irregularities of the shock line, and the material of the surface of the flange 1a flows from the portion where the plate thickness is reduced to the portion where the thickness is not so. Thus, the shock line can be improved. In addition, the constituent material of the flange portion 1a is pressed down by the axial side surface 4b of the groove portion 4 in particular, so that the material flows preferentially in the radial outer peripheral direction of the flange portion 1a. This is because the axial side surface 4b is formed to be longer in the radial direction than the outer peripheral side surface 4c, so that there are many constituent materials of the flange portion 1a pressed down on the axial side surface 4b of the groove portion 4. Further, in the present embodiment, since the axial side surface 4b of the groove portion 4 has a convex shape toward the surface side of the die 2, the constituent material of the flange portion 1a can more easily flow to the outer peripheral portion side.
[0020]
As described above, in the present embodiment, since the large unevenness of the shock line is pressed down preferentially on the radially outer peripheral side of the flange 1a by the side surface 4b of the groove 4, a plurality of shocks formed concentrically on the flange 1a. The line can be effectively leveled in the radial direction of the flange portion 1a, and the thickness of the outer peripheral portion of the flange portion 1a can be prevented from being reduced. Further, since the groove 4 is formed in the die 2 and the punch 3, the contact area of the press die (the die 2 and the punch 3) in contact with the flange 1 a of the flanged tubular member 1 is reduced by a flat surface press. Less than the mold, and the constraint coefficient is smaller. For this reason, even if the pressure applied to the press die (the punch 3 and the die 2) is small, the constituent material of the flange portion 1a can be pressed by the side surface 4b of the groove portion 4, so that the flange portion 1a is shocked with a surface pressure equal to the tensile strength. The line can be improved, and it is not necessary to use a large-capacity press device with a large press load, and the manufacturing cost can be reduced.
[0021]
Further, the above-described shock line improving step can be performed a plurality of times. In this case, the shock line improvement step described above can be set as the first shock line improvement step, and the second shock line improvement step can be performed subsequent to the first shock line improvement step. In the second shock line improvement step, the press die (punch 3 and die 2) used in the first shock line improvement step is used as a first press die, and a second press die different from the first press die is used. It can be carried out. As the second press die, a punch 3 'and a die 2' as shown in FIG. 7 can be used, and a groove 4 'formed on the surface of the flanged tubular member 1 which comes into contact with the flange 1a. It is preferable to use one having a different form from the first press die (the punch 3 and the die 2). Specifically, the position of the deepest portion 4'a of the groove 4 'formed in the second press die (punch 3' and die 2 ') is formed in the first press die (punch 3 and die 2). A groove which is shifted in the radial direction from the position of the deepest part 4'a of the groove 4 'can be used. More specifically, the deepest portion 4′a of the groove portion 4 ′ of the second press die is the same as the deepest portion 4a of the groove portion 4 of the first press die, and is １ ／ to 倍 times the pitch amount x of the groove portion 4. It is better to stagger. In particular, the deepest portion 4'a of the groove portion 4 'of the second press die is closer to the outer peripheral side than the deepest portion 4'a of the groove portion 4' of the first press die, from 1/3 to 1/3 of the pitch amount x of the groove portion 4. It is better to shift about / 2 times. The shape of the groove 4 'formed on the second press die (punch 3' and die 2 ') has the same shape as the groove 4 formed on the first press die (punch 3 and die 2). And the pitch amounts x and x 'are set to the same value.
[0022]
In the above second shock line improving step, the groove 4 ′ formed in the second press die (punch 3 ′ and die 2 ′) is formed by the groove formed in the first press die (punch 3 and die 2). 4 has the same shape and the same pitch amount as the groove portion 4, but the groove portion 4 ′ formed in the second press die is different from the groove portion 4 formed in the first press die in shape and pitch amount. You may make it employ | adopt. For example, the pitch amount x 'of the groove portion 4' of the second press die can be set to a value different from the pitch amount x of the groove portion 4 of the first press die.
[0023]
As described above, the position of the deepest portion 4a of the groove portion 4 of the second press die is shifted from the position of the deepest portion 4a of the groove portion 4 of the first press die, and the first shock line improving step and the second shock line improving step are continued. By doing so, the surface of the flange portion 1a can be made flatter than after the first shock line improvement step. Further, by shifting the groove portion 4 of the second press die toward the outer peripheral portion side of the flange portion 1a by about 1/3 to 1/2 times the pitch amount x of the groove portion 4, the second shock line improving step allows Since the constituent material of the portion 1a gradually moves to the outer peripheral side, the thinning of the outer peripheral portion of the flange portion 1a can be further suppressed.
[0024]
After the shock line generated in the flange portion 1a is improved by the above-described shock line improvement process, minute unevenness remaining in the flange portion 1a is improved by a finishing process. This finishing step can be performed by using a press die (punch and die) having a flat surface in contact with the flange portion 1a and pressing the flange portion 1a with the press die. At this time, when the flange 1a is pressed, the pressing surface pressure applied to the press die is sufficient to be equal to the tensile strength of the flange 1a. Thereby, fine irregularities on the surface of the flange 1a can be improved, and the surface of the flange 1a can be further flattened.
[0025]
【The invention's effect】
As described above, according to the method of the present invention, even if the flange is pressed with a relatively small surface pressure (surface pressure equivalent to the tensile strength of the flange), the thickness of the flanged tubular member is reduced. In addition, the constituent material of the flange portion can be made to flow, and a shock line such as a reduction in plate thickness and a bending habit formed on the flange portion by a plurality of drawing processes can be improved. Therefore, in order to improve the shock line, it is not necessary to use a large-capacity (equivalent to forging in the conventional method) press apparatus having a relatively large surface pressure, and as a result, it is possible to reduce equipment costs and reduce manufacturing costs. To contribute.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a flow of each step of a method for manufacturing a flanged tubular member of the present invention.
FIG. 2 is a diagram illustrating a molding step of the present invention.
FIG. 3 is a schematic view of a press die used in a shock line improvement process.
FIG. 4 is an enlarged view showing the shape of a groove formed on the surface of the press die.
FIG. 5 is a diagram illustrating a shock line improvement step.
FIG. 6 is a view for explaining how a press die improves a shock line of a flange portion.
FIG. 7 is a diagram illustrating a second shock line improvement step.
FIG. 8 is a view showing a problem of a flanged tubular member obtained by a conventional method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Flanged cylindrical member 1a Flanged part 1b Cylindrical part 2, 2 'Dice (press type)
3, 3 'punch (press type)
4, 4 'groove portion 4a, 4'a Deepest portion 4b of groove portion, 4'b Axial side surface 4c of groove portion, 4'c Outer peripheral side surface of groove portion

Claims (1)

A shock line improving step of improving the shock line formed on the flange portion of the flanged cylindrical member by pressing the flange portion with a press die,
In the shock line improving step, as the press die, a plurality of grooves are formed concentrically on a surface that comes into contact with the flange, and in a cross section including an axis of the press die, a cross-sectional shape of the plurality of grooves is A method for producing a flanged tubular member, characterized by using a saw-toothed member.

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