JP2005052853A - Method for manufacturing metallic rolled pipe product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a metallic wound pipe product by which productivity is improved because the metallic wound pipe product can be manufactured in a small number of processes and the occupied space of a manufacturing device is reduced. <P>SOLUTION: A base stock 32 consisting of a flat metal plate is made into a primary bent article 40 having rising parts 36 in a part of one end side and a part of the other end side. Next, by clamping an outside die 44 consisting of an upper die 50 having a forming surface 54 and a lower die 52 having a forming surface 56, the rolled pipe product 22 is made. At this time, a relatively displaceable core bar 46 is beforehand inserted into the inside space of the primary bent article 40 and by pressing the primary bent article 40 with the outside die 44 and the core bar 46 from the inner peripheral side and the outer peripheral side at the same time accompanying the movement of the core bar 46 when clamping the outside die 44, the primary bent article is bent and deformed along each forming surface 54, 56, 42. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a metal-wrapped pipe product that can be applied to, for example, manufacturing a pipe fitting for an engine mount of an automobile.

2. Description of the Related Art Conventionally, as a kind of automobile engine mount, a mounting bracket has a cylindrical pipe fitting (rolled pipe product), and a mount body is press-fitted and held in the pipe fitting. ing.
As a method of manufacturing the pipe fitting, a method as shown in FIGS. 8 and 9 is performed.

In FIG. 8I, reference numeral 200 denotes a material made of a metal flat plate material obtained by punching.
In this manufacturing method, as shown in (II), both ends of the material 200 are bent in the primary bending process and bent with a curvature close to that of the final pipe fitting (rolled pipe product) 224 (see FIG. 9). A primary bent product 204 having an end bent portion 202 is provided.
Further, a secondary bending step is performed on the primary bent product 204, and a substantially W-shaped secondary bending having a pair of arc-shaped portions 206 and a protruding portion 207 that curves and protrudes on the same side as the pair of arc-shaped portions 206. This is a processed product 208.

  Then, the secondary bent product 208 is placed on the lower mold 212 which is one of the split molds of the outer mold 210 having the split mold structure shown in FIG. 9 in the next tertiary bending process shown in (III). In this state, the cored bar 214 having a circumferential surface is pushed downward, and the middle half of the secondary bent product 208 is inserted into the semicircular concave molding surface 216 of the lower mold 212 and the cored bar 214. Bending into a semicircular shape along the molding surface of the outer peripheral surface.

At this time, the other part of the secondary bent product 208 is substantially wound around the outer peripheral surface of the part exposed from the lower mold 212 of the cored bar 214. In this way, a third-order bent product 218 is obtained.
Here, the third-order bent product 218 has a shape having a gap S between end portions close to each other.

Therefore, in order to eliminate the gap S by setting each end portion to the butted state, the following fourth bending process is performed.
Specifically, as shown in FIG. 9 (IV), the upper mold 220 having the semicircular concave molding surface 222 which is the other divided mold of the outer mold 210 is moved relative to the lower mold 212 to clamp the mold. Then, the upper half of the third bent product 218 is bent and deformed along the molding surface 222 of the upper mold 220.
As a result, a cylindrical pipe fitting 224 made of a wound pipe whose both ends are abutted is obtained.

However, in this manufacturing method, four bending steps are required until the final cylindrical pipe fitting 224 is obtained from the flat plate material 200, and there is a problem that the number of steps is large and the production efficiency is poor.
Moreover, since there are many processes, the space for implementing each process occupies a large space as a whole.

  Furthermore, after opening the clamped upper and lower molds and removing the product, each end of the pipe fitting 224 is slightly opened by a springback or the like, and a slight gap is formed there. Along with this, the roundness is lowered, and the shape and dimensional accuracy are also deteriorated.

  The above is an example in the case of pipe fittings for automobile engine mounts, but this type of manufacturing method is also known as a manufacturing method for various other types of wound pipe products.

For example, Patent Document 1 below discloses a similar manufacturing method as a method for manufacturing a lock holder of a steering lock mechanism.
In the manufacturing method of Patent Document 1, the primary bending step of FIG. 8, that is, the step of using both end portions of the material made of a flat plate as the end bending portions 202 is omitted, and the material is bent into a cylindrical shape in three steps as a whole. Processing.

On the other hand, Patent Documents 2 and 3 listed below disclose manufacturing methods in which bending is performed without using a cored bar.
In this manufacturing method, both ends of a flat plate-like material are bent into a curved shape by a primary bending process to form an end bent portion, and then the whole is bent into a U-shape by secondary bending, and The U-shaped processed product is bent into a cylindrical shape in the final tertiary bending process.
Also in the manufacturing methods of Patent Document 2 and Patent Document 3, the bending process is performed three times.

  As described above, the conventional manufacturing method requires many bending steps in order to obtain the final wound pipe product from the raw material, and this causes the above-described problems.

Japanese Patent Laid-Open No. 10-244318 JP-A-9-168824 JP-A-9-234511

  The present invention is based on the above circumstances, and can manufacture a metal wound pipe product with a small number of steps, thereby improving the production efficiency and reducing the space occupied by the manufacturing apparatus. It was made for the purpose of providing the manufacturing method of a pipe product.

  Thus, the method for producing a metal-wound pipe product of the present invention is a method for producing a metal-wound pipe product by bending a metal flat plate into a pipe shape, and (a) using the metal flat plate as a raw material. A primary bending step of bending the one end portion and the other end portion of the material into a rising shape on the same side; and (b) a concave molding surface corresponding to the outer peripheral surface shape of the wound pipe product. The outer mold having a split mold structure composed of a plurality of divided molds is clamped, and the primary bent product obtained in the primary bending step is bent into a wound pipe shape. A core metal having an outer peripheral molding surface corresponding to the inner peripheral surface shape of the core and capable of relative displacement with respect to the outer mold is compatible with the primary bending product having a shape different from the molding surface of the core metal. It is inserted into the inner space surrounded by the up part and the remaining intermediate part, and the core metal moves when the outer mold is clamped Accordingly, the primary bent product is simultaneously clamped from the inner peripheral side and the outer peripheral side by the outer mold and the core metal, and is pressed and deformed along the respective molding surfaces. And a secondary bending step of working together to be bent into a wound pipe shape.

  According to a second aspect of the present invention, in the first aspect, the wound pipe product has a cylindrical shape as a whole, and the molding surface of the outer mold and the cored bar has a shape corresponding to the outer peripheral surface and inner peripheral surface of the cylinder. It is characterized by.

  According to a third aspect of the present invention, in any one of the first and second aspects, the rising shape of the rising portion is a shape that rises substantially perpendicularly from the intermediate portion therebetween in the primary bending step. To do.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, in the primary bending step, a protrusion that curves to the same side as the rising portion is formed in the intermediate portion, and in the secondary bending step, The projecting portion is pressed toward the outer mold from the inner circumference side to the outer mold by the mandrel with the movement of the mandrel, and thus the projecting section and its peripheral part are pressed between the outer mold and the core metal. While pressing and deforming into a shape along the molding surface, along with the deformation, the end portions of the compatible ascending portion are bent and deformed along the molding surface of the outer mold and the core metal, and the approach direction along the molding surface The end portions are brought into contact with each other.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the outer mold has an upper and lower split mold structure, and the primary bent product is set in a lower mold that is one split mold. In this state, the upper mold, which is the other divided mold, is clamped, and at that time, the upper mold is bent and deformed along its own molding surface and the molding surface of the core metal, and The upper die is formed with a female fitting surface having an inclined shape that opens in a C shape following the molding surface, while the lower die is fitted to the female fitting surface in a clamped state. A male fitting surface is formed in advance, and the female fitting surface is used as a guide surface for moving and guiding the rising portion toward the molding surface of the upper mold when clamping.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the wound pipe product is a wound pipe product for automobile engine mount.

Effects and effects of the invention

As described above, according to the present invention, the one end side portion and the other end side portion of the flat plate-like material are bent into a rising shape on the same side in the primary bending step, and the secondary bending step includes 1 The second bending product is simultaneously sandwiched between the inner peripheral side and the outer peripheral side by the core metal and the outer mold of the split mold structure, and the first bending processed product is the outer peripheral surface of the core metal and the inner peripheral surface of the outer mold, That is, it is pressed and deformed along the molding surface, and is bent into a wound pipe shape at once in a state of being wound around a core metal. According to the present invention, a wound pipe product is manufactured with a small number of steps. The production efficiency of such a wound pipe product can be increased, and the manufacturing cost of the wound pipe product can be reduced.
Further, since the total number of processes is reduced, the total space including the space occupied by each process can be reduced.

The present invention can be suitably applied particularly to the manufacture of a cylindrical pipe product (Claim 2).
Further, in the primary bending step, the rising shape of the rising portion can be a shape that rises at a substantially right angle from an intermediate portion therebetween (claim 3).

  Next, according to a fourth aspect of the present invention, a protruding portion is formed in the intermediate portion in the primary bending step, and the protruding portion is moved from the inner peripheral side by the core metal with the movement of the core metal in the secondary bending step. The outer part is pressed toward the outer mold, and the protruding part and its peripheral part are pressed and deformed into a shape along the molding surface of the outer mold and the core metal, and each end of the compatible ascending part is accompanied with the deformation. The parts are moved relative to each other in the approaching direction while being bent and deformed along the molding surfaces of the outer mold and the cored bar, so that the ends are brought into abutment with each other.

In the quaternary bending process shown in FIG. 9 (IV) described above, during the clamping operation of the upper mold 220, each end of the tertiary bending product 218 wound around the cored bar 214 is simply in the butting direction. For this reason, there is a problem that each end portion is slightly opened by a spring back or the like after the mold opening and demolding. Forcibly and finally, the end parts of the rising parts of the metal plate move relative to each other in the approaching direction along the molding surface of the outer mold and the metal core, that is, along the cavity formed between the outer mold and the metal core. In particular, since both end portions are bent and deformed until they are strongly abutted with each other, it is possible to solve the problem that each end portion opens and a gap is formed after mold opening and demolding.
As a result, the shape and dimensional accuracy of the wound pipe product can be increased. In particular, in the case of a cylindrical wound pipe product, the roundness can be increased as compared with the conventional one.

  Next, according to the fifth aspect of the present invention, the female fitting surface formed on the upper die, which is one of the split dies, is used as a guide surface for moving and guiding the pair of rising portions toward the molding surface of the upper die. In this way, even if the shape of the rising part of the primary bending product is slightly deviated from the set shape, the rising part is guided to the molding surface of the upper mold without any trouble during mold clamping. Can bend and deform well.

  The present invention is particularly suitable for application to the manufacture of a wound pipe product for automobile engine mounts (Claim 6).

Next, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, reference numeral 10 denotes an automobile engine mount having a mounting bracket 12 and a mount body 14.
The mount main body 14 has a cylindrical outer tube fitting 16, a cylindrical inner tube fitting 18, and a rubber elastic body 20 that connects them, and the whole is integrally vulcanized and bonded. Yes.

As shown in FIG. 2, the mounting bracket 12 includes a cylindrical pipe fitting (rolled pipe product) 22, a pair of attachment bolts 24, and a support portion 26 that supports the pipe fitting 22.
The support portion 26 includes a base portion 28 formed by bending a metal plate material into a U shape, and a plate-like connection portion 30 that connects the base portion 28, and the pipe fitting 22 is connected to the support portion 26. Are integrated by welding.

The mounting bracket 12 press-fits the mount main body 14, specifically, the outer cylinder fitting 16 into the pipe fitting 22, and holds it in a fitted state.
As shown also in FIG. 3, in this example, the pipe fitting 22 of the mounting bracket 12 is formed by winding a metal flat plate member into a cylindrical shape with both end portions butted.

4 to 7 specifically show the manufacturing method of this embodiment of the pipe fitting 22 made of this wound pipe.
In this embodiment, first, as shown in FIG. 4I, a material 32 made of a metal flat plate is prepared by punching a plate.

  Then, the material 32 is subjected to primary bending according to the process shown in FIG. 5 (primary bending process), and rises at a substantially right angle from the intermediate portion 36 to one end side and the other end side shown in FIG. A substantially W-shaped primary bent product 40 having a pair of rising portions 34 and a protruding portion 38 that curves and protrudes on the same side as the rising portion 34 at the intermediate portion 36 is provided.

As shown in FIG. 5, in this primary bending process, a processing die having a male die 42 and a female die 43 is used, and the male die 42 is placed on the female die 43 with the material 32 set on the female die 43. The material 32 is bent into a substantially W shape as shown in FIG.
The primary bending product 40 obtained here has a shape in which the pair of rising portions 34 rises substantially parallel to each other in the pushing direction of the male mold 42 and substantially perpendicular to the intermediate portion 36.

  In FIG. 5 (III), W represents a width dimension between the outer surfaces of the pair of rising portions 34. The width dimension W is substantially equal to the outer diameter of the pipe fitting 22.

  Next, the primary bending product 40 obtained in this way is subjected to secondary bending, which is the final bending process, as shown in FIG. 4 (III) (secondary bending process). The final cylindrical and wound pipe-shaped pipe fitting 22 is manufactured at once from the processed product 40.

In this secondary bending process, the primary bending product 40 is bent using the outer mold 44 and the cored bar 46 having upper and lower split mold structures.
Here, the metal core 46 has the same outer diameter as the inner diameter of the pipe fitting 22, and the entire outer peripheral surface thereof is a molding surface 48 having a shape corresponding to the inner peripheral surface of the pipe fitting 22.

On the other hand, the outer mold 44 has an upper and lower divided structure of an upper mold (divided mold) 50 and a lower mold (divided mold) 52.
The upper mold 50 and the lower mold 52 have concave and semicircular molding surfaces 54 and 56 corresponding to the outer peripheral surface of the pipe fitting 22, respectively.
Further, the upper mold 50 is provided with an inclined female fitting surface 58 that opens in the shape of a letter C following the molding surface 54.
Correspondingly, the lower mold 52 is provided with a male fitting surface 60 having the same inclined shape and fitted to the female fitting surface 58 of the upper mold 50 in a clamped state.

The cored bar 46 is provided with a shaft portion 62 as shown in FIG. 6 (B), and can be moved in and out in the left-right direction as a whole in FIG. 6 (B).
The cored bar 46 is supported in a floating state in which it can be moved in the vertical direction by a spring (not shown).

In the secondary bending process, as shown in FIGS. 4 (III) and 6 (A), first, the primary processed product 40 is set on the lower mold 52.
At this time, the lower part of the primary bent product 40 is partially fitted into the recess of the lower mold 52.
Along with the setting of the primary bent product 40 to the lower mold 52, the metal core 46 is axially disposed in the inner space surrounded by the pair of rising portions 34 and the intermediate portion 36 in the primary bent product 40. insert.

Next, as shown in FIG. 7, the upper mold 50 is moved downward in the figure to cause the outer mold 44 to perform a mold clamping operation. That is, the upper mold 50 and the lower mold 52 are closed in the vertical direction.
As a result, the primary bent product 40 is simultaneously clamped from the inner peripheral side and the outer peripheral side by the core metal 46 and the outer die 44, that is, the upper die 50 and the lower die 52, as shown in FIG. 4 (III). As shown in FIG. 3, the metal pipe 46 is bent (pressed) along the molding surface 48 of the metal core 46 and the molding surfaces 54, 56 of the outer die 44, and is molded (bent) into the cylindrical pipe fitting 22 shown in FIG. The

In this secondary bending step, the cored bar 46 in a floating state is forcibly lowered downward together with the upper die 50 by the downward pressing force as the upper die 50 is lowered as shown in FIG.
At this time, in the primary bent product 40, the upward protruding portion 38 in the drawing in the intermediate portion 36 is pressed downward by the cored bar 46, and the protruding portion 38 and its peripheral portion are formed in a semicircular shape in the lower die 52. The surface 56 and the metal core 46 are bent and deformed along the lower half of the forming surface 48, whereby the lower half of the primary bent product 40 is formed into a semicircular shape.

  On the other hand, the pair of rising portions 34 in the primary bent product 40 is forcibly pushed upward in the drawing along with the deformation of the protruding portion 38 into the semicircular shape, and the semicircular molding surface 54 and the upper die 50 Along the upper half of the molding surface 48 of the core metal 46, the respective end portions move relative to each other while bending and deforming on the molding surfaces 54 and 48, and finally the end portions are clamped. In this manner, the butt-up state is brought into strong contact with each other.

When the secondary bending process as described above is performed, the upper mold 50 is moved upward in the drawing to open the outer mold 44, and the secondary bent product, that is, the pipe fitting 22 is further removed from the outer mold 44. Is removed from the cored bar 46.
Here, the cylindrical and wound pipe-shaped pipe fitting 22 shown in FIG. 2 is obtained.

According to the manufacturing method of the present example as described above, the pipe fitting 22 can be produced with a small number of steps, and the production efficiency of the pipe fitting 22 can be increased, and the manufacturing cost of the pipe fitting 22 can be reduced. it can.
Further, since the total number of steps is reduced, the total space including the space for performing each step can be reduced.

In this example, the protruding portion 38 is formed in the intermediate portion 36 in the primary bending process, and the protruding portion 38 and its peripheral portion are pressed by the core metal 46 in the secondary bending process, so that the outer mold 44 and the core metal 46 are pressed. The die is pressed and deformed into a shape along the molding surfaces 54, 56, and 48, and each end portion of the compatible ascending portion 34 is relatively moved along the molding surfaces 54, 56, and 48, so as to be in a butted state. It is possible to solve the problem that each end is opened by springback or the like after opening and demolding.
Thereby, the shape and dimensional accuracy of the pipe fitting 22 can be increased, and the roundness thereof can be increased as compared with the conventional case.

  In this example, the female fitting surface 58 formed on the upper die 50 also serves as a guide surface for moving and guiding the rising portion 34 to the molding surface 54 of the upper die 50, so that the rising portion 34 of the primary bent product 40 is Even when the shape deviates slightly from the set shape, the rising portion 34 can be guided to the molding surface 54 of the upper die 50 without hindrance at the time of clamping and can be bent and deformed satisfactorily.

Although the embodiment of the present invention has been described above, this is merely an example.
For example, the present invention can be applied as a manufacturing method of the outer tube fitting 16 or the like in the mount main body 14 of FIG. 1 depending on circumstances, and the wound pipe product has an elliptical shape or an axial pipe end surface that is uneven or corrugated. It does not matter. Furthermore, the present invention can be applied as a method for manufacturing a metal wound pipe product for various uses other than engine mounts, and the present invention is implemented in variously modified forms without departing from the gist thereof. Is possible.

It is a figure which shows the engine mount for motor vehicles containing the pipe metal fitting which is an application object of this invention. It is a figure which shows the attachment bracket of FIG. It is a figure which shows the shape of the pipe metal fitting of FIG.1 and FIG.2 in a single-piece | unit state. It is explanatory drawing which shows the manufacturing method of embodiment of this invention to process order. It is explanatory drawing which shows a part of process in FIG. 4 in more detail. FIG. 5 is an explanatory diagram showing another part of the process in FIG. 4 in more detail. It is explanatory drawing which shows the advantage of this embodiment with the effect | action. It is explanatory drawing which shows the manufacturing method of the conventional pipe metal fitting in order of a process. It is explanatory drawing of the process following FIG.

Explanation of symbols

10 Engine mount 22 Pipe fittings (rolled pipe products)
32 Material 34 Rising part 36 Intermediate part 38 Projection part 40 Primary bending product 44 Outer mold 46 Core metal 48, 54, 56 Molding surface 50 Upper mold (split mold)
52 Lower mold (split type)
58 Female mating surface 60 Male mating surface

Claims (6)

A method of manufacturing a metal wound pipe product by bending a metal flat plate into a pipe shape,
(A) a primary bending step in which the metal flat plate material is used as a raw material, and one end side portion and the other end side portion of the raw material are bent into a rising shape on the same side;
(B) A primary obtained by the primary bending step by clamping an outer mold having a split mold structure composed of a plurality of divided molds, which has a concave molding surface corresponding to the outer peripheral surface shape of the wound pipe product. The bent product is bent into a wound pipe shape, and at this time, a core metal having an outer peripheral molding surface corresponding to the inner peripheral surface shape of the wound pipe product and being relatively displaceable with respect to the outer mold, The core metal is inserted into an inner space surrounded by an upward portion and the remaining intermediate portion of the first bent product having a shape different from the molding surface of the core metal, and the core metal is clamped when the outer die is clamped. The primary bent product is simultaneously clamped from the inner peripheral side and the outer peripheral side with the outer mold and the core metal with movement, and is pressed and deformed along the respective molding surfaces, and the outer mold and the core metal And a secondary bending process that works together to be bent into a wound pipe shape,
A method for manufacturing a metal-wound pipe product, comprising:   In Claim 1, The said wound pipe product has comprised the cylindrical shape as a whole, The shaping | molding surface of the said outer mold | type and a metal core has comprised the shape corresponding to the outer peripheral surface of a cylinder, and an internal peripheral surface, It is characterized by the above-mentioned. Manufacturing method for metal wound pipe products.   3. The metal wound pipe product according to claim 1, wherein the rising shape of the rising portion in the primary bending step is a shape rising substantially perpendicularly from the intermediate portion between them. Method.   4. The method according to claim 1, wherein a protrusion that curves to the same side as the rising portion is formed in the intermediate portion in the primary bending step, and the protrusion is connected to the metal core in the secondary bending step. With the movement of the metal core, the metal core is pressed from the inner peripheral side toward the outer mold to the outer peripheral side, so that the projecting part and its peripheral part are shaped along the molding surface of the outer mold and the metal core. While being deformed by pressing, each end of the compatible ascending portion is bent and deformed along the molding surface of the outer mold and the core metal along with the deformation, and relatively moved in the approaching direction along the molding surface. A method of manufacturing a metal-wound pipe product, characterized in that the ends are brought into a butted state.   5. The split mold structure according to claim 1, wherein the outer mold has an upper and lower split mold structure, and the first bent product is set in a lower mold which is one split mold. The upper die is clamped, and at that time, the upper die is bent and deformed along its own molding surface and the molding surface of the core metal, and the upper die is molded. An inclined female fitting surface that opens in a U-shape is formed following the surface, while a male fitting surface that fits the female fitting surface in a clamped state is formed on the lower mold. A method for manufacturing a metal-wound pipe product, wherein the female fitting surface is used as a guide surface for moving and guiding the rising portion toward the molding surface of the upper mold when clamping.   6. The method of manufacturing a metal wound pipe product according to claim 1, wherein the wound pipe product is a wound pipe product for an engine mount of an automobile.

Images