JP4414011B2 - Manufacturing method of metal pipe having large and small diameter parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a method of manufacturing a metal tube having a large and small diameter portion, in particular, from a tubular metal material having an inner diameter equal to the inner diameter over the entire length, an inner diameter and an outer diameter larger than those of the tubular metal material, Manufactures a metal tube comprising a small-diameter portion whose inner and outer diameters are smaller than those of the tubular metal material, a tapered portion in which a large-diameter end is connected to the large-diameter portion, and a small-diameter end is connected to the small-diameter portion. On how to do. This type of metal tube is used in four-wheel buggies and motorcycle swing arms.
[0002]
[Prior art]
Conventionally, when this type of metal pipe is manufactured, the first process is performed using a first processing machine, the second process is performed using a second processing machine, and the diameter is expanded using a third process. Employs a method of performing ironing using a third processing machine (see, for example, Japanese Patent Application Laid-Open No. 59-144541).
[0003]
[Problems to be solved by the invention]
However, according to the conventional method, since three dedicated processing machines are required, the equipment cost becomes high. The workpiece is transferred between the first and second processing machines and between the second and third processing machines. There is a problem in that the production efficiency is poor because the two transfer operations are necessary, and there is a large occupation space such as a space for installing three dedicated processing machines and a space for transferring the workpiece twice.
[0004]
[Means for Solving the Problems]
An object of the present invention is to provide a method of manufacturing a metal tube having the large and small diameter portions, which can reduce equipment costs, improve production efficiency, reduce an occupied space, and the like.
[0005]
In order to achieve the above object, according to the present invention, the inner diameter and the outer diameter are larger than those of the tubular metal material, and the inner diameter and the outer diameter are larger than those of the tubular metal material. A method of manufacturing a metal tube comprising a smaller diameter portion than those of the tubular metal material, a tapered portion in which a large diameter end is connected to the large diameter portion, and a small diameter end is connected to the small diameter portion. ,
In order to install the tubular metal material on the first processing machine and produce an intermediate body from the tubular metal material, by drawing to the range from one end of the tubular metal material to the axially intermediate portion, Forming a small-diameter region having an outer diameter smaller than those of the tubular metal material and a tapered region in which a small-diameter end is connected to the small-diameter region, and forming the inner and outer diameters of those in the tubular metal material. A first step of leaving the large-diameter region connected to the large-diameter end of the tapered region, and the intermediate body is installed in a second processing machine to expand the diameter to the large-diameter region. Using the second step of forming the large-diameter portion and the tapered portion by performing processing, and subsequently forming the small-diameter portion by ironing the small-diameter region ,
The second processing machine includes a first die connected to the support plate via a gas cushion, a die for diameter expansion and ironing processing fixed on a base, a support plate capable of moving up and down relative to the die. A first punch for diameter expansion supported on the lower end of the rod of the second, and a second punch for ironing fixed to the support plate via a second rod that slidably penetrates the hollow portion of the first punch. In the second step, the small-diameter region of the intermediate body transferred from the first processing machine is fitted into the equal-diameter hole portion in the die hole of the die, and the tapered region is The support plate is lowered while being fitted in the tapered hole at the upper end of the die hole. As the lowering of the support plate, first, the first punch is inserted into the large-diameter region of the intermediate body to expand into the large-diameter region. The large diameter part and taper part are formed by diameter processing. Then, the second punch is lowered with respect to the first punch while the taper portion is clamped between the first punch and the taper hole portion at the upper end of the die hole, and the small diameter region of the intermediate body is ironed. A method of manufacturing a metal tube having large and small diameter portions is provided.
[0006]
As mentioned above, if two dedicated processing machines are used and the intermediate material, which is a workpiece, is transferred once, the equipment cost is reduced, the production efficiency is improved, and the occupied space is reduced compared to the conventional method. Can be achieved.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, (a), the tubular metal raw material 1 is comprised from high-tensile steel, and has the same inner and outer diameters d ₁ and D ₁ over its entire length. A metal tube 2 shown in FIG. 1 (d) is manufactured from a tubular metal material 1 through a primary intermediate body 6 in FIG. 1 (b) and a secondary intermediate body 10 in FIG. 1 (c). , the outer diameter d _2, D ₂ is the large-diameter portion 3 is larger than those d _1, D ₁ of the tubular metal blank 1, among them d ₁ of the outer diameter d _3, D ₃ tubular metal blank 1, D ₁ A smaller diameter portion 4, and a tapered portion 5 having a large diameter end connected to the large diameter portion 3 and a small diameter end connected to the small diameter portion 4. In FIG. 1, (b), the primary intermediate body 6 has a small-diameter region 7 whose inner and outer diameters d ₄ and D ₄ are smaller than those d ₁ and D _{1 of the} tubular metal material 1, and a small diameter in the small-diameter region 7. The taper region 8 provided with continuous ends, the inner and outer diameters d ₁ and D ₁ are the same as those d ₁ and D _{1 of the} tubular metal material 1, and the large diameter end of the tapered region 8 is provided continuously. It consists of a radial region 9. In FIG. 1C, the secondary intermediate 10 includes a large-diameter portion 11 having the same shape as the large-diameter portion 3 of the metal tube 2, a tapered portion 12 having substantially the same shape as the tapered portion 5 of the metal tube 2, 1 It has a small-diameter region 13 having the same shape as the small-diameter region 7 of the next intermediate 6.
[0008]
2 and 3 show a process of manufacturing the primary intermediate 6 from the tubular metal material 1 using the first processing machine 14, and FIGS. 4 to 6 show the primary processing using the second processing machine 15. The process of manufacturing the metal pipe 2 from the intermediate body 6 through the secondary intermediate body 10 is shown.
[0009]
In the first processing machine 14 of FIG. 2, a drawing die 17 is installed on a base 16, and a flat plate-like pressing member 18 is arranged above the drawing die 17. The pressure member 18 is attached to a lifting member of the press machine. The die 17 has an upward die hole 19, and the die hole 19 opens on the upper surface of the die 17 and has a shallow large-diameter hole portion 20 having an inner diameter substantially equal to the outer diameter D ₁ of the tubular metal material 1, A shallow tapered hole portion 21 having a large diameter end connected to the annular lower end of the large diameter hole portion 20 and having an inner peripheral surface shape substantially the same as the outer peripheral surface shape of the tapered portion 5 of the metal tube 2 on the small diameter end side; An annular upper end is connected to the small-diameter end of the hole 21, and a deep small-diameter hole 22 having an inner diameter substantially equal to the outer diameter D ₃ of the small-diameter part 4 of the metal tube 2 is provided. The pressurizing member 18 has a mandrel 23 that hangs down from its lower surface, and the mandrel 23 limits the amount of inward bulging of the inner peripheral surface of the small diameter region 7 in the primary intermediate body 6.
[0010]
In manufacturing the primary intermediate 6, the following means is adopted.
[0011]
(A) As shown in FIG. 2, the lower end portion of the tubular metal material 1 is fitted into the large-diameter hole portion 20 of the die hole 19 in the first processing machine 14, and the tubular metal material 1 is erected on the die 17. .
[0012]
(B) The pressure member 18 is lowered and the mandrel 23 is loosely inserted into the tubular metal material 1, and then the lower surface of the pressure member 18 is brought into contact with the upper end surface of the tubular metal material 1 to pressurize the material 1.
[0013]
(C) By introducing the lower end portion side of the tubular metal material 1 through the tapered hole portion 21 into the small diameter hole portion 22, the range from one end portion of the tubular metal material 1 to the axially intermediate portion, in the embodiment, the lower end portion To approximately the length position of about two-thirds, the drawing process is performed. As a result, as shown in FIG. 3, the primary intermediate 6 is obtained. In the primary intermediate 6, the small-diameter region 7 and the tapered region 8 are formed by drawing, and the large-diameter portion 9 is left as an unprocessed portion. In this case, the inner peripheral surface of the small diameter region 7 may or may not contact the outer peripheral surface of the mandrel 23.
[0014]
In the second processing machine 15 of FIG. 4, a diameter expansion and ironing die 25 is installed on a base 24, and a pressure member 26 is disposed above the die 25. The die 25 has an upward die hole 27, and the die hole 27 has a large diameter end opened on the upper surface of the die 25 and has a shallow inner peripheral surface shape substantially the same as the outer peripheral surface shape of the tapered portion 5 of the metal tube 2. The tapered hole portion 28 has an annular upper end connected to the small diameter end of the tapered hole portion 28, and a deep isometric hole portion 29 having an inner diameter substantially equal to the outer diameter D ₃ of the small diameter portion 4 of the metal tube 2.
[0015]
The pressurizing member 26 has a support plate 30 attached to an elevating member of a press machine, and a plurality of gas cushions 31 are installed on the upper surface of the support plate 30. A plurality of rods 32 having upper ends connected to the gas cushions 31 slidably pass through the support plate 30 and extend downward, and a first punch 33 for expanding the diameter is provided at the lower ends of the rods 32. It is supported via the support flange portion 34.
[0016]
The first punch 33 is connected to the lower surface of the support flange portion 34 and has an equal diameter processing portion 35 having an outer diameter substantially the same as the inner diameter d ₂ of the large diameter portion 3 of the metal tube 2, and the same diameter. A large-diameter end is connected to the annular lower end of the shaping portion 35, and a tapered machining portion 36 having an outer circumferential shape substantially the same as the inner circumferential shape of the tapered portion 5 of the metal tube 2 is provided. The first punch 33 has a shallow large-diameter concave portion 37 that opens to the small-diameter end of the tapered processing portion 36, and a deep small-diameter hole portion 38 that communicates with the large-diameter concave portion 37 and opens on the upper surface of the support flange portion 34. . The upper end of the rod part 40 of the second punch 39 for ironing is attached to the center of the lower surface of the support plate 30, and the rod part 40 penetrates the small diameter hole 38 of the first punch 33 slidably. A plug-shaped processed portion 41 is connected to the lower end of the rod portion 40. The plug-shaped processed portion 41 is connected to a tapered guide portion 42 with a small-diameter end facing downward, and a large-diameter end of the guide portion 42, An equal-diameter portion 43 that is larger than the inner diameter d ₄ of the small-diameter region 13 of the primary intermediate body 10 and substantially equal to the inner diameter d ₃ of the small-diameter portion 4 of the metal tube 2, and the large-diameter end at the equal-diameter portion 43 And a base end portion 44 having small diameter ends connected to the rod portion 40 respectively. During the diameter expansion processing, the equal diameter portion 43 of the plug-shaped processing portion 41 is accommodated in the large diameter concave portion 37 of the first punch 33, and the guide portion 42 protrudes from the large diameter concave portion 37.
[0017]
When manufacturing the metal pipe 2 from the primary intermediate body 6, the following means are adopted.
[0018]
(A) As shown in FIG. 4, the small-diameter region 7 of the primary intermediate 6 transferred from the first processing machine 14 is fitted into the equal-diameter hole portion 29 of the die hole 27 in the second processing machine 15, The tapered region 8 is fitted into the tapered hole portion 28 of the die hole 27.
[0019]
(B) As shown in FIG. 5, the entire pressure member 26 is lowered to obtain the secondary intermediate 10 from the primary intermediate 6. That is, by inserting the isometric processing portion 35 of the first punch 33 into the large-diameter region 9 of the primary intermediate 6 and subjecting the large-diameter region 9 to diameter expansion processing, the large-diameter portion of the metal tube 2 is obtained. 3 and taper portion 12 corresponding to 3 and taper portion 5 are formed. In this case, the taper portion 12 is clamped by the cooperation of the taper hole portion 28 of the die hole 27 and the taper-shaped processed portion 36 of the first punch 33, and the molding is clearly performed. The small diameter region 7 of the primary intermediate 6 is left as an unprocessed small diameter region 13.
[0020]
(C) In the state where the taper portion 12 is clamped by the first punch 33 and the die 25 as shown in FIG. 5, the support plate 30 and the second punch 39 of the pressing member 26 are lowered as shown in FIG. Then, the plug-shaped processed portion 41 is inserted into the small-diameter region 13 of the secondary intermediate body 10, and the small-diameter region 13 is ironed over the entire length thereof in cooperation with the equal-diameter portion 43 and the equal-diameter hole portion 29. To form the small diameter portion 4 of the metal tube 2.
[0021]
【The invention's effect】
According to the present invention, in manufacturing a metal tube composed of a large diameter portion, a tapered portion, and a small diameter portion, as described above, two dedicated processing machines are used, and the intermediate that is the workpiece is transferred by 1 unit. Therefore, compared to the conventional method, the equipment cost can be reduced, the production efficiency can be improved, and the occupied space can be reduced.
[Brief description of the drawings]
1A is a sectional view of a tubular metal material, FIG. 1B is a sectional view of a primary intermediate, FIG. 1C is a sectional view of a secondary intermediate, and FIG. 1D is a sectional view of a metal tube. .
FIG. 2 is a cross-sectional view before processing in the first processing machine.
FIG. 3 is a cross-sectional view at the end of processing in the first processing machine.
FIG. 4 is a cross-sectional view before processing in the second processing machine.
FIG. 5 is a cross-sectional view of the second processing machine at the end of the first stage processing.
FIG. 6 is a cross-sectional view of the second processing machine at the end of the second stage of processing.
[Explanation of symbols]
1 the tubular metal blank 2 metal pipe 3 large diameter portion 4 small diameter portion 5 tapered portion 6 primary intermediate 7 diameter region 8 tapered region 9 large diameter region 14 first machine 15 and the second processing machine D _1, D _2, D ₃ , D ₄ outer diameter d ₁ , d ₂ , d ₃ , d ₄ inner diameter

Claims (1)

From the tubular metal material (1) having the same outer diameter (d ₁ , D ₁ ) over the entire length, the inner and outer diameters (d ₂ , D ₂ ) are those of the tubular metal material (1) (d ₁ , D _A large diameter portion (3) larger than ₁ ), and a small diameter portion (4) whose inner and outer diameters (d ₃ , D ₃ ) are smaller than those (d ₁ , D ₁ ) of the tubular metal material (1); A method of manufacturing a metal pipe (2) comprising a tapered portion (5) having a large diameter end connected to the large diameter portion (3) and a small diameter end connected to the small diameter portion (4). ,
In order to manufacture the intermediate body (6) from the tubular metal material (1) by installing the tubular metal material (1) on the first processing machine (14), an axis line is formed from one end of the tubular metal material (1). By drawing the range up to the middle part in the direction, the inner and outer diameters (d ₄ , D ₄ ) are smaller than those (d ₁ , D ₁ ) of the tubular metal material (1) (7). And a tapered region (8) in which a small-diameter end is connected to the small-diameter region (7), respectively, and the inner and outer diameters (d ₁ , D ₁ ) are those of the tubular metal material (1) in the unprocessed portion. A first step of leaving a large diameter region (9) that is the same as (d ₁ , D ₁ ) and is connected to the large diameter end of the tapered region (8);
The intermediate body (6) is installed in the second processing machine (15), and the large-diameter region (9) is subjected to diameter expansion processing, whereby the large-diameter portion (3) and the tapered portion (5) are formed. A second step of molding and subsequently ironing the small diameter region (7) to form the small diameter portion (4) ,
The second processing machine (15) includes a die (25) for diameter expansion and ironing that is fixed on a base (24), and a support plate (30) that can be raised and lowered with respect to the die (25). The first punch (33) for diameter expansion supported on the lower end of the first rod (32) connected to the support plate (30) via the gas cushion (31), and the first punch (33 ) And a second punch for ironing (39) fixed to the support plate (30) through a second rod (40) that slidably penetrates the hollow portion of
In the second step, the small-diameter region (7) of the intermediate body (6) transferred from the first processing machine (14) is replaced with an equal-diameter hole portion in the die hole (27) of the die (25). (29) and the taper region (8) is fitted in the taper hole (28) at the upper end of the die hole (27), and the support plate (30) is lowered. The first punch (33) is inserted into the large-diameter region (9) of the intermediate body (6), and the large-diameter region (9) is subjected to diameter expansion processing, whereby the large-diameter portion (3) and the taper are formed. The second punch (39) is formed while the tapered portion (5) is clamped by the first punch (33) and the tapered hole portion (28) at the upper end of the die hole (27). ) Is lowered with respect to the first punch (33) to reduce the small diameter region (7) of the intermediate body (6). Large, characterized in that so as to ironing, method for producing a metal tube having a small diameter portion.

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