JP2008119734A - Method for upsetting cylindrical base stock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for upsetting a cylindrical base stock by which a core metal for preventing a buckling of the cylindrical base stock can easily be inserted and arranged into the hollow part of the cylindrical base stock. <P>SOLUTION: A first restricting part 41 of the core metal 40 is made of a rigidity material and a second restricting part 42 of the core metal 40 is made of a rubber elastic material. The diameter of the second restricting part 42 is set at smaller than the inner diameter of non-working scheduled part 3 of the base stock 1. The core metal 40 is inserted and arranged into the hollow part of a working scheduled part 2 and the non-working scheduled part 3 in the base stock 1. Successively, the inner peripheral surface 3a of the non-working scheduled part 3 of the base stock 1 is restricted with the peripheral surface of the restricting part 42 of the core metal 40 by pressure-compressing the second restricting part 42 of the core metal 40 in the axial direction. In this state, the working scheduled part 2 of the base stock 1 is bulged to the outside so that the thickness in the formed recessed part 12 is increased, by moving a guide 20 in the reverse direction to the moving direction of a punch 30 while pressurizing the working-scheduled part 3 of the base stock 1 with the punch 30 in the axial direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tubular material upsetting method and a cylindrical material upsetting apparatus that bulges a predetermined portion of a cylindrical material outwardly so that the wall thickness increases.

  In general, the upsetting process is to increase the diameter of the planned processing portion of the material by pressing the planned processing portion of the rod-shaped material in the axial direction. In this upsetting process, if the planned processing portion of the material is buckled during processing, the resulting product (that is, the upsetting product) becomes a defective shape (wrinkles, fogging, etc.), and the value as a product is impaired. Therefore, conventionally, the following upsetting method is known in order to prevent the planned processing portion of the material from buckling.

  That is, the material is fixed to the fixed die, and the material processing scheduled portion is inserted into the insertion hole provided in the guide, thereby holding the material processing scheduled portion in a buckling-prevented state. Next, processing the material exposed between the tip of the guide and the fixed die by moving the guide in the direction opposite to the direction of punch movement while pressing the planned processing portion of the material with the punch in its axial direction This is a method of expanding the diameter of the planned portion (see, for example, Patent Documents 1-3).

  The upsetting method described above is applied when processing a solid rod-shaped material.

  Further, when the material is not solid but cylindrical, the present applicant has proposed the following upsetting method.

  That is, by inserting and arranging a mandrel in the hollow portion of the cylindrical material to be processed and the non-processed portion, the inner peripheral surface of the material to be processed and the non-processed portion is constrained by the peripheral surface of the mandrel. . Further, the non-scheduled part of the material is disposed in the restraining hole provided in the restraining die, so that the outer peripheral surface of the non-scheduled part of the material is restrained by the peripheral surface of the restraining hole. In addition, the planned processing portion of the material is disposed in a molding recess provided at the end of the constraining die. Furthermore, by arranging the planned processing portion of the material in the insertion hole provided in the guide, the outer peripheral surface of the planned processing portion of the material is restrained by the peripheral surface of the insertion hole. Next, while pressing the portion to be processed of the material in the axial direction with the punch, the guide is moved in the direction opposite to the moving direction of the punch so that the portion to be processed of the material is increased in thickness in the molding recess. (See, for example, Patent Document 4).

This upsetting method has an advantage that a part of the material can be prevented from buckling inward during processing by the mandrel, and thus a high-quality cylindrical upsetting product can be manufactured.
JP-A-48-62646 Japanese Patent Laid-Open No. 9-253782 JP 2003-290862 A International Publication No. 2006/080503 Pamphlet

  However, the above-described method for upsetting a cylindrical material has the following difficulties.

  In other words, the diameter of the mandrel extends over the entire length of the mandrel and the non-machined part of the material so that the mandrel can constrain the inner peripheral surface of the material planned to be processed and non-processed parts on its peripheral surface. It is set to be approximately equal to the inner diameter of the planned portion. Therefore, when the mandrel is inserted and arranged in the hollow portion of the material, a very large frictional force acts on the peripheral surface of the mandrel from the inner peripheral surface of the material, and as a result, the mandrel is inserted into the hollow portion of the material. It was difficult. In particular, when the length of the material is long, it is very difficult to insert the mandrel. Further, after the processing, it is difficult to extract the mandrel from the hollow portion of the material (that is, the upsetting product).

  The present invention has been made in view of the above-described technical background, and an object thereof is to easily insert and dispose a mandrel for preventing buckling of the tubular material into the hollow portion of the tubular material. An object of the present invention is to provide a tubular material upsetting method and a cylindrical material upsetting apparatus that can be suitably used for the upsetting method.

  The present invention provides the following means.

[1] The mandrel is inserted and arranged in the hollow portion of the cylindrical material to be processed and the non-processed portion, thereby restraining the inner peripheral surface of the material to be processed and the non-processed portion with the peripheral surface of the mandrel. And
The non-scheduled part of the material is placed in the restraint hole provided in the restraining die, thereby restraining the outer peripheral surface of the non-scheduled part of the material with the peripheral surface of the restraint hole,
And, while arranging the processing planned portion of the material in the molding recess provided at the end of the constraint die,
By placing the planned processing portion of the material in the insertion hole provided in the guide, the outer peripheral surface of the planned processing portion of the material is restrained by the peripheral surface of the insertion hole,
Next, while pressing the portion to be processed of the material in the axial direction with the punch, the guide is moved in the direction opposite to the moving direction of the punch so that the portion to be processed of the material is increased in thickness in the molding recess. In the upsetting processing method of the cylindrical material to bulge outward,
The mandrel includes a first restraining portion made of a rigid body that restrains the inner peripheral surface of the material planned processing portion and a rubber elastic body that restrains at least a portion near the processing target portion on the inner peripheral surface of the non-processed portion of the raw material A second restraining portion made of
The first constraining portion of the mandrel can be inserted and arranged in conformity with the hollow portion of the planned processing portion of the material,
The diameter of the second restraining portion of the mandrel is set smaller than the inner diameter of the non-processed portion of the material,
By constraining the inner peripheral surface of the planned processing portion of the material with the peripheral surface of the first constraining portion of the core metal by inserting and placing the mandrel in the hollow portion of the planned processing portion and the non-processing planned portion of the material,
By compressing and compressing the second constraining portion of the mandrel in the axial direction, at least the portion near the planned processing portion on the inner peripheral surface of the non-working planned portion of the material is constrained by the peripheral surface of the second constraining portion of the mandrel. And
In this state, the upsetting process for the cylindrical material is characterized in that the upsetting process is performed.

[2] The second constraining portion of the mandrel restrains only the vicinity of the planned processing portion on the inner peripheral surface of the non-processing planned portion of the material,
A second constraining portion of the mandrel is disposed in the hollow portion of the non-scheduled part of the material on the receiving member that receives the end of the material on the opposite side of the non-scheduled part of the material in the axial direction of the material. Receiving projections are provided integrally in the axial direction,
2. The method for upsetting a cylindrical material according to item 1, wherein the diameter of the receiving projection of the receiving member is set smaller than the inner diameter of the non-processed portion of the material.

[3] The mandrel is separable into the first restraining part and the second restraining part,
On the end face of the first restraining portion of the mandrel, a substantially spherical connecting projection is integrally projected,
A connection recess corresponding to the connection protrusion is provided on the end face of the second restraining portion of the mandrel,
The upsetting process of the cylindrical material according to the preceding item 1 or 2, wherein the first protrusion and the second lock of the mandrel are detachably connected to each other by fitting the connection protrusion into the connection recess. Method.

[4] A mandrel disposed within the hollow portion of the planned processing portion and the non-processing planned portion of the cylindrical material, and restraining the inner peripheral surface of the processing planned portion and the non-processing planned portion of the material;
A restraint die that has a restraint hole and restrains the outer peripheral surface of the non-processed portion of the material disposed in the restraint hole with the peripheral surface of the restraint hole,
A molding recess provided at the end of the constraining die;
A guide that has an insertion hole and restrains the outer peripheral surface of the processing planned portion of the material disposed in the insertion hole with the peripheral surface of the insertion hole;
A punch that pressurizes the planned processing portion of the material in its axial direction,
While pressing the planned processing part of the material with its punch in the axial direction, the guide is moved in the opposite direction to the punch moving method, so that the planned processing part of the material increases outside in the molding recess. In the upsetting apparatus for cylindrical materials configured to bulge into
The mandrel includes a first restraining portion made of a rigid body that restrains the inner peripheral surface of the material planned processing portion and a rubber elastic body that restrains at least a portion near the processing target portion on the inner peripheral surface of the non-processed portion of the raw material A second restraining portion made of
The first constraining portion of the mandrel can be inserted and arranged in conformity with the hollow portion of the planned processing portion of the material,
The diameter of the second restraining portion of the mandrel is set smaller than the inner diameter of the non-processed portion of the material,
An upsetting apparatus for a cylindrical material, comprising: a mandrel pressurizing unit that pressurizes and compresses the second restraining portion of the mandrel in the axial direction thereof.

[5] The second constraining portion of the mandrel restrains only the vicinity of the planned processing portion on the inner peripheral surface of the non-processing planned portion of the material,
A second constraining portion of the mandrel is disposed in the hollow portion of the non-scheduled part of the material on the receiving member that receives the end of the material on the opposite side of the non-scheduled part of the material in the axial direction of the material. Receiving projections are provided integrally in the axial direction,
The cylindrical material upsetting apparatus according to the preceding item 4, wherein the diameter of the receiving projection of the receiving member is set smaller than the inner diameter of the non-processed portion of the material.

[6] The mandrel is separable into the first restraining part and the second restraining part,
On the end face of the first restraining portion of the mandrel, a substantially spherical connecting projection is integrally projected,
A connection recess corresponding to the connection protrusion is provided on the end face of the second restraining portion of the mandrel,
The upsetting process of the cylindrical material according to 4 or 5 above, wherein the first protruding portion and the second holding portion of the mandrel are detachably connected to each other by fitting the connecting protrusion into the connecting recess. apparatus.

  The present invention has the following effects.

  In the invention of [1], since the diameter of the second restraining portion of the mandrel is set smaller than the inner diameter of the non-processed portion of the material, the mandrel can be easily inserted into the hollow portion of the material. . Furthermore, by compressing and compressing the second constraining portion of the mandrel in the axial direction, at least a portion in the vicinity of the planned processing portion on the inner peripheral surface of the non-processed portion of the material is the peripheral surface of the second constraining portion of the core Therefore, the second constraining portion of the mandrel can prevent a problem that the non-processed portion of the material buckles inward during processing. In addition, the first restraining portion of the mandrel can prevent a problem that the planned processing portion of the material buckles inward during processing. As a result, a high-quality cylindrical upsetting product can be manufactured. Moreover, since the diameter of the second restraining portion of the mandrel is reduced by releasing the pressurization of the second restraining portion of the mandrel after the processing, the mandrel can be easily removed from within the hollow portion of the material (that is, the upsetting product). Can be extracted.

  In the invention of [2], since the second constraining portion of the mandrel constrains only a portion in the vicinity of the planned processing portion on the inner peripheral surface of the non-working planned portion of the material, The load required for pressure compression can be reduced, and further, the amount of misalignment of the mandrel accompanying the pressure compression of the second restraining portion of the mandrel can be reduced as much as possible.

  Moreover, the receiving member that receives the end of the material opposite to the non-processed portion with respect to the non-processed portion in the axial direction of the material is disposed in the hollow portion of the non-processed portion of the material, and the second core A receiving projection that receives the restraining portion in the axial direction is integrally provided. Thereby, the length of the mandrel can be shortened. Therefore, the mandrel can be more easily inserted and arranged in the hollow part of the material, and the mandrel can be further easily extracted from the hollow part of the material (that is, the upsetting product) after processing.

  Furthermore, the diameter of the receiving protrusion of the receiving member is set smaller than the inner diameter of the non-processed portion of the material. Therefore, the receiving protrusion of the receiving member can be easily inserted and disposed in the hollow portion of the non-processed portion of the material.

  In the invention of [3], since the first constraining portion and the second constraining portion of the mandrel are separably connected to each other, the characteristics (eg, elastic characteristics) of the second constraining portion of the mandrel are repeatedly used. In the case of deterioration, the second restraining portion can be separated from the first restraining portion of the mandrel. Thereby, a 2nd restraint part can be exchanged for a new thing.

  Further, the connecting protrusion of the first restraining portion of the mandrel is substantially spherical, and the connecting recess of the second restraining portion of the mandrel has a shape corresponding to the connecting protrusion, so that the second restraining portion of the mandrel is When the pressure compression is performed in the axial direction, the outer peripheral portion of the connection concave portion of the second restraining portion is reliably compressed and compressed. Therefore, the inner peripheral surface of the non-processed portion of the material can be reliably restrained by the peripheral surface of the second restraining portion.

  In the inventions [4] to [6], it is possible to provide a tubular material upsetting apparatus suitably used in the tubular material upsetting method of the present invention.

  Several preferred embodiments of the present invention will now be described with reference to the drawings.

  In FIG. 1, (10A) is an upsetting apparatus according to the first embodiment of the present invention, and (1) is a cylindrical material.

  In FIG. 5, (5) is a cylindrical upsetting product manufactured by the upsetting apparatus (10A) of the first embodiment. This upsetting product (5) is provided with a screw hole as a preform for manufacturing a shaft portion of an arm for a vehicle (automobile, railway vehicle, etc.) or at the end of a cylindrical shaft portion, for example. It is used as a preform for manufacturing a member to be manufactured.

  As shown in FIG. 1, the material (1) has a straight cylindrical shape, and more specifically, a straight round pipe shape, and is made of, for example, aluminum (including an alloy thereof, the same applies hereinafter). The cross-sectional shape of the material (1) is annular. Further, the inner diameter, outer diameter, and thickness of the material (1) are all set to be constant in the axial direction of the material (1). The material (1) is made of an extruded material, for example.

  In the present invention, the material of the material (1) is not limited to aluminum, and may be a metal other than aluminum (eg, brass, copper, stainless steel) or plastic.

  The planned processing portion (2) of the material (1) is located on one side of both axial sides of the material (1), that is, the one side in the axial direction of the material (1) is the processing planned portion ( It corresponds to 2). On the other hand, the non-processed portion (3) of the material (1) is located on the other side portion in the axial direction of the material (1), that is, the other side portion in the axial direction of the material (1) is the non-processed portion ( It corresponds to 3). That is, the part other than the planned processing portion (2) of the material (1) is the non-processing planned portion (3). The planned processing portion (2) and the non-processing planned portion (3) of the material (1) are arranged adjacent to each other in the axial direction of the material (1). Then, when the planned processing portion (2) of the material (1) is thickened to the design shape, as shown in FIG. 5, the bulging portion (7) bulging outward so as to increase the wall thickness. Is formed.

  The shaft part (6) of the upsetting product (5) is composed of a non-scheduled part (3) of the material (1). Moreover, the bulging part (7) bulged outside so that thickness may increase is formed in the edge part of an upsetting product (5) over the perimeter. The bulging portion (7) is formed by upsetting the planned processing portion (2) of the material (1). In this upsetting product (5), for example, another member (for example, a bush holding member) is joined and integrated by friction stir welding, or a screw hole is formed at the end thereof. is there.

  The upsetting apparatus (10A) is for bulging the planned processing part (2) of the material (1) outward so that the thickness increases. As shown in FIG. 1, the upsetting apparatus (10A) includes a mandrel (40), a mandrel pressurizing means (50), a constraining die (10), a molding recess (12), and a receiving member. (15), a guide (20), a punch (30), a guide driving means (52), and a punch driving means (54).

  The mandrel (40) is a straight bar having a circular cross section. The mandrel (40) is inserted and arranged in the hollow portion of the material (1) to be processed (2) and the non-processed portion (3), and the material (1) is scheduled to be processed (2) and not to be processed. The inner peripheral surfaces (2a) and (3a) of the portion (3) are restrained in a buckling-prevented state by the peripheral surface of the mandrel (40). The configuration of the mandrel (40) will be described in detail below.

  The mandrel (40) includes a first restraining portion (41) for restraining the inner peripheral surface (2a) of the planned processing portion (2) of the material (1), and a non-processing planned portion (3) of the material (1). A second restraining portion (42) for restraining the inner peripheral surface (3a). The first restraining part (41) and the second restraining part (42) of the mandrel (40) are arranged adjacent to each other in the axial direction of the mandrel (40).

  The length of the first restraining portion (41) of the mandrel (40) is set to be approximately equal to or longer than the length of the planned processing portion (2) of the material (1). Further, the length of the second restraining portion (42) of the mandrel (40) is set substantially equal to the length of the non-processed portion (3) of the material (1).

  More specifically, in the first embodiment, the first restraining portion (41) of the mandrel (40) is the processing planned portion (in the inner peripheral surface (2a) of the processing planned portion (2) of the material (1) ( 2) to restrain the entire surface in the axial direction. The second restraining portion (42) of the mandrel (40) restrains the entire surface in the axial direction of the non-scheduled portion (3) on the inner peripheral surface (3a) of the unscheduled portion (3) of the material (1). Is.

  The first restraining portion (41) of the mandrel (40) is a straight rod and is made of a rigid body. As the rigid body, for example, cold mold steel or high-speed tool steel is used. However, in the present invention, the material of the first restraining portion (41) is not limited to the above.

  The second restraining portion (42) of the mandrel (40) has a straight rod shape and is made of a rubber elastic body. As the rubber elastic body, for example, fluorine rubber, silicone rubber, and nitrile rubber are used. However, in the present invention, the material of the second restraining portion (42) is not limited to the above.

  The diameter of the first restraining portion (41) of the mandrel (40) is set to be approximately equal to the inner diameter of the planned processing portion (2) of the material (1), that is, the first restraining portion of the mandrel (40). (41) can be inserted and arranged to fit snugly into the hollow portion of the planned processing portion (2) of the material (1). Therefore, in the state where the first restraining portion (41) of the mandrel (40) is inserted and arranged in the hollow portion of the planned processing portion (2) of the raw material (1), the inner portion of the planned processing portion (2) of the raw material (1) The entire circumferential surface (substantially the entire surface) of the circumferential surface of the first restraining portion (41) abuts on the circumferential surface (2a) in contact with the inner circumferential surface of the planned processing portion (2) of the material (1). The first restraining portion (41) is configured so that (2a) is restrained in a buckling-preventing state on the peripheral surface of the first restraining portion (41).

  The diameter of the second restraining portion (42) of the mandrel (40) is set smaller than the inner diameter of the non-processed portion (3) of the material (1). Therefore, in a state where the second restraining portion (42) of the mandrel (40) is inserted and arranged in the hollow portion of the non-processed portion (3) of the material (1), the non-processed portion (3) of the material (1). The second restraining portion (42) is configured such that the peripheral surface of the second restraining portion (42) does not come into contact with the inner circumferential surface (3a).

  The diameter of the second restraining portion (42) of the mandrel (40) will be described in detail below.

  The diameter of the second constraining part (42) is set to be less than 1 time with respect to the inner diameter of the non-processed part (3) of the material (1), particularly 0.998 times or less (more preferably 0.985). The following is desirable. By doing so, when the mandrel (40) is inserted and arranged in the hollow part of the material (1), the peripheral surface of the second restraining part (42) of the mandrel (40) is not scheduled to be processed of the material (1). The inner peripheral surface (3a) of the part (3) can be reliably prevented from coming into contact, and therefore the mandrel (40) can be reliably and easily inserted into the blank (1).

  Furthermore, the diameter of the second restraining portion (42) is desirably 0.8 times or more (more desirably 0.950 times or more) with respect to the inner diameter of the non-processed portion (3) of the material (1). . By doing so, the load required to pressurize and compress the second restraining portion (42) of the mandrel (40) can be reliably reduced, and further, the second restraining portion ( 42) The amount of displacement of the mandrel (40) due to pressure compression can be reduced as much as possible.

  Further, the mandrel (40) is separable into a first restraining portion (41) and a second restraining portion (42), and the first restraining portion (41) and the second restraining portion (42). Are connected as follows.

  In other words, a spherical connecting projection (41a) protrudes and is integrally formed at the center of the end face of the first restraining portion (41). On the other hand, the connection recessed part (42a) corresponding to the connection protrusion (41a) is formed in the center part of the end surface of the 2nd restraint part (42). The shape of this connection recessed part (42a) is a shape corresponding to a connection protrusion (41a), ie, it is spherical. And a 1st restraint part (41) and a 2nd restraint part (42) are mutually connected by forcibly fitting a connection protrusion (41a) in a connection recessed part (42a). Furthermore, the first restraining portion (41) and the second restraining portion (42) are separated by forcibly pulling out the connecting protrusion (41a) from the inside of the connecting recess (42a). In this way, the core (40) has the first restraining part (41) and the second restraining part (42) connected to each other in a separable manner.

  The mandrel pressurizing means (50) is for pressurizing and compressing the second restraining portion (42) of the mandrel (40) in its axial direction. The mandrel pressurizing means (50) has a fluid pressure cylinder (eg, hydraulic cylinder, gas cylinder) as its pressurizing drive source. And the 1st restraint part (41) of the mandrel (40) is connected to the front-end | tip part of the expansion-contraction rod (50a) of a fluid pressure cylinder.

  The restraining die (10) has a restraining hole (11) having a circular cross section extending in the axial direction. The non-processed scheduled portion (3) of the material (1) is inserted and disposed in the restraining hole (11). The restraint hole (11) is provided through the restraint die (10) in the axial direction. This constraining die (10) constrains the outer peripheral surface of the non-processed portion (3) of the material (1) inserted and disposed in the constraining hole (11) in a buckling-prevented state by the peripheral surface of the constraining hole (11). To do. Therefore, the diameter of the constraining hole (11) is set to a size that allows the non-processed portion (3) of the material (1) to be inserted into the constraining hole (11).

  In addition, the constraining die (10) is divided into a plurality of (for example, two) parts by a dividing surface that vertically cuts the constraining hole (11).

  The molding recess (12) is provided continuously to the restraining hole (11) at one axial end of the restraining die (10). More specifically, the molding recess (12) is an annular recess formed adjacent to one end in the axial direction of the peripheral surface of the restraining hole (11) of the restraining die (10). (12a) is the bottom of the molding recess (12).

  The receiving member (15) is made of a rigid body, and the end (1a) opposite to the non-processed portion (2) of the material (1) is opposite to the non-processed portion (2) of the material (1). It is received in the axial direction. The receiving member (15) is disposed on the other axial end side of the constraining die (10). The receiving member (15) closes the other end opening of the restraining hole (11) of the restraining die (10).

  The guide (20) has an insertion hole (21) having a circular cross section extending in the axial direction. A processing scheduled portion (2) of the material (1) is inserted and disposed in the insertion hole (21). This insertion hole (21) restrains the outer peripheral surface of the planned processing portion (2) of the material (1) inserted and disposed in the insertion hole (21) in a buckling-prevented state by the peripheral surface of the insertion hole (21). In addition, the processing scheduled portion (2) of the material (1) is held so as to be movable in the axial direction. The insertion hole (21) is provided through the guide (20) in the axial direction. (20a) is the tip of the guide (20).

  The guide (20) is movable in the direction (25) opposite to the movement direction (35) of the punch (30) (see FIG. 3).

  The punch (30) is for pressurizing the planned processing portion (2) of the material (1) in the axial direction thereof. The tip of the punch (30) is formed in a cross-sectional shape corresponding to the cross-sectional shape of the axial end of the material (1) (ie, the planned processing portion (2)), that is, the tip of the punch (30). The cross-sectional shape is an annular shape.

  The punch (30) is inserted and arranged in the insertion hole (21) of the guide (20) so as to be movable in the axial direction.

  Further, a hollow portion (32) extending in the axial direction is formed inside the punch (30). The fluid pressure cylinder of the mandrel pressurizing means (50) is disposed in the cavity (32) in a non-fixed state with respect to the punch (30).

  The punch drive means (54) moves the punch (30) in the axial direction of the material (1), and applies a pressing force to the punch (30) to press the planned processing portion (2) of the material (1). Is to do. The punch driving means (54) is connected to the punch (30), and applies a driving force to the punch (30) by fluid pressure (hydraulic pressure, gas pressure) or the like. The punch driving means (54) has a control unit for controlling the moving speed of the punch (30), that is, the pressing speed.

  The guide drive means (52) moves the guide (20) in the direction (25) opposite to the moving direction (35) of the punch (30) (that is, the pressing direction of the material processing scheduled portion (2) by the punch (30)). (Refer to FIG. 3). The guide driving means (52) is connected to the guide (20), and applies a driving force to the guide (20) by fluid pressure (hydraulic pressure, gas pressure), an electric motor, a spring or the like. The guide driving means (52) has a control unit that controls the moving speed of the guide (20).

  Next, the upsetting method using the upsetting apparatus (10A) of the first embodiment will be described below.

  First, as shown in FIG. 1, the non-processed portion (3) of the material (1) is inserted and disposed in the restraining hole (11) of the restraining die (10). Thereby, the process scheduled part (2) of a raw material (1) is arrange | positioned in the shaping | molding recessed part (12) of a constraining die (10). Further, in this state, the outer peripheral surface of the non-processed portion (3) of the material (1) is in contact with the peripheral surface of the restraining hole (11) over the entire length of the non-processed portion (3). The entire outer peripheral surface of the non-processed portion (3) of the material (1) is constrained in a buckling-prevented state by the peripheral surface of the constraining hole (11). Further, the end (1a) on the opposite side of the non-processed portion (2) with respect to the non-processed portion (3) of the material (1) is brought into contact with the receiving member (15). The portion (1a) is received by the receiving member (15) in a movement-blocking state in the axial direction of the material (1).

  Next, the mandrel (40) is inserted and disposed in the hollow portion of the planned processing portion (2) and the non-processing planned portion (3) of the material (1). As a result, the inner peripheral surface (2a) of the planned processing portion (2) of the material (1) extends around the entire length of the planned processing portion (2) around the first restraining portion (41) of the mandrel (40). The entire surface of the inner peripheral surface (2a) of the planned processing portion (2) of the material (1) is thereby prevented from buckling by the peripheral surface of the first restraining portion (41) of the mandrel (40). Restrained by On the other hand, the entire inner peripheral surface (3a) of the non-processed portion (3) of the material (1) is not in contact with the peripheral surface of the second restraining portion (42) of the mandrel (40). It is not restrained by the peripheral surface of the 2nd restraint part (42) of a mandrel (40). Further, the distal end portion of the second restraining portion (42) of the mandrel (40) abuts on the receiving member (15), so that the distal end portion is axially directed to the mandrel (40) by the receiving member (15). The movement has been blocked.

  Furthermore, the processing planned portion (2) of the material (1) is inserted and arranged in the insertion hole (21) of the guide (20). As a result, the outer peripheral surface of the planned processing portion (2) of the material (1) is restrained in a buckling-prevented state by the peripheral surface of the insertion hole (21) of the guide (20).

  Furthermore, an initial clearance X is provided between the tip (20a) of the guide (20) and the bottom (12a) of the molding recess (12). The interval between the initial clearances X is the tip (20a) of the guide (20) in a state before the movement of the punch (30) (that is, pressurization of the material processing scheduled portion (2) by the punch (30)) is started. And the bottom portion (12a) of the molding recess (12), the material (1) is set to be less than the buckling limit length in the cross-sectional area of the exposed portion of the planned processing portion (2). In the present invention, the buckling limit length refers to the buckling limit length in the punch pressing force.

  Next, as shown in FIG. 2, the second restraining part (42) of the mandrel (40) is compressed in the axial direction by the mandrel pressurizing means (50). Then, the diameter of the second restraining portion (42) is increased, whereby the entire inner peripheral surface (3a) of the non-processed portion (3) of the material (1) is covered with the peripheral surface of the second restraining portion (42). Restrain the buckling prevention state. In this state, the inner peripheral surface (3a) of the non-processed portion (3) of the material (1) contacts the peripheral surface of the second restraining portion (42) over the entire length of the non-processed portion (3). ing. Since the second restraining portion (42) is made of a rubber elastic body, a very large frictional force acts on the peripheral surface of the second restraining portion (42). Therefore, the inner peripheral surface (3a) of the non-processed portion (3) of the material (1) can be reliably restrained by the peripheral surface of the second restraining portion (42). This state is maintained.

  Next, as shown in FIG. 3, the punch (30) is moved by the punch driving means (54), and the processing target portion (2) of the material (1) is pressed in the axial direction by the punch (30), and the guide The guide (20) is moved in the direction (25) opposite to the moving direction (35) of the punch (30) by the driving means (52). Thus, the exposed portion of the planned processing portion (2) of the material (1) exposed between the distal end portion (20a) of the guide (20) and the bottom portion (12a) of the forming recess (12) is formed into the forming recess (12 ) Slowly bulge outward so that the wall thickness increases.

  Here, it is desirable to provide a time lag between the start of movement of the punch (30) and the start of movement of the guide (20). That is, when pressurization of the processing portion (2) of the material (1) by the punch (30) is started, the position of the guide (20) is first fixed to the initial position, and then the punch (30). Is moved, and the planned processing part (2) of the material (1) is pressurized in the axial direction by the punch (30). Then, after the time lag elapses, the guide (20) is moved in the direction opposite to the moving direction (35) of the punch (30) while the punch (30) is continuously pressed against the processing scheduled portion (2) of the material (1). Move to (25). At this time, the moving speed of the guide (20) is such that the material (1) to be processed (2) exposed between the tip (20a) of the guide (20) and the bottom (12a) of the molding recess (12). It is controlled by the control unit of the guide driving means (52) so as to be less than the buckling limit length in the cross-sectional area of the exposed portion.

  With the movement of the punch (30) and the guide (20), the planned processing portion (2) of the material (1) gradually bulges outward so that the thickness increases in the molding recess (12), and the processing is scheduled. The material of the part (2) is press-fitted into the molding recess (12) and is filled.

  And as shown in FIG. 4, when all the materials of the processing plan part (2) of a raw material (1) are press-fitted and filled in the shaping | molding recessed part (12), ie, the processing planned part ( When the entire thickness of 2) is increased, the movement of the punch (30) and the guide (20) is stopped. At this time, the processing target portion (2) of the material (1) is bulged into the design shape, that is, the bulging portion (outwardly bulged so as to increase the wall thickness at the end of the material (1)). 7) is formed.

  With the above procedure, the process of increasing the thickness of the planned processing portion (2) of the material (1) is completed.

  Next, the pressurization of the second restraining portion (42) of the mandrel (40) by the mandrel pressurizing means (50) is released. As a result, the diameter of the second constraint (42) decreases and returns to its original size.

  Next, the mandrel (40) is pulled out from the hollow portion of the material (1) (that is, the upsetting product (5)) together with the punch (30) and the guide (20). Further, the material (1) is taken out from the restraining hole (11) of the restraining die (10). Thereby, the upsetting product (5) shown in FIG. 5 is obtained.

  In addition, in the said 1st Embodiment, the stop position with respect to the shaping | molding recessed part (12) bottom part (12a) of the front-end | tip part of a punch (30), and the shaping | molding recessed part (12) bottom part (12a) of the front-end | tip part (20a) of a guide (20). ) Matches the stop position. However, in the present invention, both stop positions do not necessarily coincide.

  Thus, the upsetting method of the first embodiment has the following advantages.

  That is, since the diameter of the second restraining portion (42) of the mandrel (40) is set smaller than the inner diameter of the non-processed portion (3) of the material (1), the mandrel (40) is made of the material ( It can be easily inserted into the hollow part of 1). Furthermore, by compressing and compressing the second restraining portion (42) of the mandrel (40) in the axial direction, the inner peripheral surface (3a) of the non-processed portion (3) of the raw material (1) 40) is restrained by the peripheral surface of the second restraining portion (42), so that the non-working scheduled portion (3) of the material (1) is buckled inward during processing. 42). Moreover, the malfunction which the process scheduled part (2) of a raw material (1) buckles inside at the time of a process can be blocked | prevented by the 1st restraint part (41) of a mandrel (40). As a result, a high-quality cylindrical upsetting product (5) can be manufactured. Moreover, since the diameter of the 2nd restraint part (42) of a mandrel (40) reduces by cancelling | releasing the pressurization of the 2nd restraint part (42) of a mandrel (40) after a process, a mandrel (40 ) Can be easily extracted from the hollow portion of the material (1) (that is, the upsetting product (5)).

  Moreover, since the 1st restraint part (41) of the mandrel (40) and the 2nd restraint part (42) are connected so that isolation | separation is mutually possible, the characteristic of the 2nd restraint part (42) of a mandrel (40) When (example: elastic property) deteriorates due to repeated use, the second restraining portion (42) can be separated from the first restraining portion (41) of the mandrel (40). Thereby, a 2nd restraint part (42) can be exchanged for a new thing.

  Furthermore, the connection protrusion (41a) of the first restraining portion (41) of the mandrel (40) is spherical, and the connection recess (42a) of the second restraining portion (42) of the mandrel (40) is the connection protrusion. When the second constraining part (42) of the mandrel (40) is pressed and compressed in the axial direction, the shape corresponding to the part (41a), that is, a spherical shape, the connecting concave part (42a) of the second constraining part (42) The outer peripheral portion is also reliably compressed and compressed. Therefore, the inner peripheral surface (3a) of the non-processed portion (3) of the material (1) can be reliably restrained by the peripheral surface of the second restraining portion (42).

  Here, in the first embodiment, at the time of upsetting, the guide (20) is moved by the driving force of the guide driving means (52). However, in the present invention, the guide (20) is not necessarily driven as such. It does not need to be moved by force. That is, in the present invention, the guide (20) may be moved by a pushing-back force acting on the guide (20) by press-fitting the material (1) into the molding recess (12) of the material (1) to be processed. good. In this case, the guide (20) can be moved without necessarily using the guide driving means (52), and thus the upsetting apparatus (10A) can be simplified.

  6-9 is a figure explaining the upsetting apparatus (10B) and upsetting method which concern on 2nd Embodiment of this invention. In these drawings, the same reference numerals are given to the same elements as those of the upsetting apparatus (10A) of the first embodiment.

  A cylindrical upsetting product (5) manufactured by the upsetting apparatus (10B) of the second embodiment is the same as that of the first embodiment shown in FIG.

  The configuration of the upsetting apparatus (10B) of the second embodiment will be described below with a focus on differences from the configuration of the upsetting apparatus (10A) of the first embodiment.

  As shown in FIG. 6, in the upsetting apparatus (10B) of the second embodiment, the second restraining portion (42) made of a rubber elastic body of the mandrel (40) is not scheduled to be processed of the material (1). Only the vicinity portion (3b) of the planned processing portion (2) on the inner peripheral surface (3a) of the portion (3) is constrained. Therefore, the length of the second restraining portion (42), that is, the necessary fixed length (frictional force) is determined by appropriately adjusting the deformation resistance, but in the case of aluminum material, it is 5 to 50 mm, preferably 20 About 30 mm. The total length of the mandrel (40) is shorter than the total length of the mandrel of the first embodiment.

  The receiving member (15) is integrally formed with a receiving projection (16) that receives the second restraining portion (42) of the mandrel (40) in the axial direction. This receiving protrusion (16) is made of a rigid body like the receiving member (15), and is disposed in the hollow portion of the non-processed portion (3) of the material (1). In addition, the diameter of the receiving projection (16) is set smaller than the inner diameter of the non-processed portion (3) of the material (1). More specifically, the diameter of the core (40) in the uncompressed state is set. 2 It is set equal to the diameter of the restraint part (42).

  Other configurations of the upsetting apparatus (10B) of the second embodiment are the same as the configurations of the upsetting apparatus (10A) of the first embodiment.

  The upsetting method using the upsetting apparatus (10B) of the second embodiment is substantially the same as the upsetting method of the first embodiment, and will be briefly described below.

  First, as shown in FIG. 6, the non-processed portion (3) of the material (1) is inserted and disposed in the restraining hole (11) of the restraining die (10). Thereby, the process scheduled part (2) of a raw material (1) is arrange | positioned in the shaping | molding recessed part (12) of a constraining die (10). Further, the end (1a) on the opposite side of the non-processed portion (2) with respect to the non-processed portion (3) of the material (1) is brought into contact with the receiving member (15). The portion (1a) is received by the receiving member (15) in a movement-blocking state in the axial direction of the material (1). Further, the receiving projection (16) of the receiving member (15) is inserted and arranged in the hollow portion of the non-processed portion (3) from the opening (1a) of the material (1). In this state, the inner peripheral surface (3a) of the non-processed portion (3) of the material (1) is not in contact with the peripheral surface of the receiving projection (16).

  Next, the mandrel (40) is inserted and disposed in the hollow portion of the planned processing portion (2) and the non-processing planned portion (3) of the material (1). As a result, the entire inner peripheral surface (2a) of the planned processing portion (2) of the material (1) is constrained in a buckling-prevented state by the peripheral surface of the first constraining portion (41) of the mandrel (40). On the other hand, a portion (3b) in the vicinity of the planned processing portion (2) on the inner peripheral surface (3a) of the non-processing planned portion (3) of the material (1) is the second constraining portion (42) of the mandrel (40). It is not in contact with the peripheral surface, that is, not constrained by the peripheral surface of the second restraining portion (42) of the mandrel (1). Further, the distal end portion of the second restraining portion (42) of the mandrel (40) abuts on the distal end of the receiving projection (16) of the receiving member (15), whereby the distal end portion receives the receiving projection (16). ) In the axial direction of the mandrel (40).

  Furthermore, the processing planned portion (2) of the material (1) is inserted and arranged in the insertion hole (21) of the guide (20). As a result, the outer peripheral surface of the planned processing portion (2) of the material (1) is restrained in a buckling-prevented state by the peripheral surface of the insertion hole (21) of the guide (20).

  Furthermore, an initial clearance X is provided between the tip (20a) of the guide (20) and the bottom (12a) of the molding recess (12).

  Next, as shown in FIG. 7, the second restraining portion (42) of the mandrel (40) is pressurized and compressed in the axial direction by the mandrel pressurizing means (50). Then, the diameter of the 2nd restraint part (42) increases, Thereby, the vicinity part (3b) of the process scheduled part (2) in the internal peripheral surface (3a) of the non-processed scheduled part (3) of a raw material (1). Restraining to the buckling prevention state on the peripheral surface of the second restraining portion (42). Since the second restraining portion (42) is made of a rubber elastic body, a very large frictional force acts on the peripheral surface of the second restraining portion (42). Therefore, the vicinity part (3b) of the planned processing part (2) on the inner peripheral surface (3a) of the non-processed part (3) of the material (1) is reliably restrained by the peripheral surface of the second restraining part (42). be able to. This state is maintained.

  Next, as shown in FIG. 8, as in the upsetting method of the first embodiment, the punch (30) is moved by the punch driving means (54), and the planned processing portion (2) of the material (1) is moved. The guide (20) is moved in the direction (25) opposite to the movement direction (35) of the punch (30) by the guide driving means (52) while being pressed by the punch (30) in the axial direction. Thus, the exposed portion of the planned processing portion (2) of the material (1) exposed between the distal end portion (20a) of the guide (20) and the bottom portion (12a) of the forming recess (12) is formed into the forming recess (12 ) Slowly bulge outward so that the wall thickness increases.

  And as shown in FIG. 9, when all the materials of the process planned part (2) of a raw material (1) are press-fitted and filled in the shaping | molding recessed part (12), ie, the process planned part ( When the entire thickness of 2) is increased, the movement of the punch (30) and the guide (20) is stopped.

  With the above procedure, the process of increasing the thickness of the planned processing portion (2) of the material (1) is completed.

  Next, the pressurization of the second restraining portion (42) of the mandrel (40) by the mandrel pressurizing means (50) is released. Thereby, the diameter of a 2nd restraint part (42) reduces and it returns to the original magnitude | size.

  Next, the mandrel (40) is pulled out from the hollow portion of the material (1) (that is, the upsetting product (5)) together with the punch (30) and the guide (20). Further, the material (1) is taken out from the restraining hole (11) of the restraining die (10). Thereby, the upsetting product (5) shown in FIG. 5 is obtained.

  Thus, the upsetting method of the second embodiment has the following advantages in addition to the advantages of the upsetting method of the first embodiment.

  That is, the second restraining portion (42) of the mandrel (40) is only the portion (3b) in the vicinity of the planned processing portion (2) on the inner peripheral surface (3a) of the non-processing planned portion (3) of the material (1). Therefore, the load required to pressurize and compress the second restraining portion (42) of the mandrel (40) can be reduced. Therefore, as the mandrel pressurizing means (50), one having a low pressurizing ability can be used, so that an inexpensive upsetting apparatus (10B) can be provided and the downsetting apparatus (10B) can be downsized. Can be planned. Furthermore, it is possible to reduce as much as possible the amount of displacement of the mandrel (40) due to pressure compression of the second restraining portion (42) of the mandrel (40).

  And the receiving member (15) which receives the edge part (1a) on the opposite side to a process planned part (2) with respect to the non-processed part (3) of a raw material (1) in the axial direction of a material (1), A receiving protrusion (16) that is disposed in the hollow portion of the non-processed portion (3) of the material (1) and receives the second restraining portion (42) of the mandrel (40) in the axial direction is integrally formed. Yes. Thereby, the length of the mandrel (40) can be shortened. Therefore, the mandrel (40) can be more easily inserted and arranged in the hollow portion of the material (1), and the mandrel (40) can be inserted into the material (1) after processing (that is, the upsetting product (5)). It can be more easily extracted from the hollow portion.

  Further, the diameter of the receiving projection (16) of the receiving member (15) is set smaller than the inner diameter of the non-processed portion (3) of the material (1). Therefore, the receiving protrusion (16) of the receiving member (15) can be easily inserted and arranged in the hollow portion of the non-processed scheduled portion (3) of the material (1).

  As mentioned above, although several embodiment of this invention was described, this invention is not limited to what was shown to the said embodiment.

  For example, the upsetting method and the upsetting apparatus according to the present invention produce a preform for producing a shaft portion of a vehicle arm or a member provided with a screw hole at an end portion of a cylindrical shaft portion. It is not limited to what is applied in order to manufacture the preform for performing, It can apply in order to manufacture the preform for various products.

  Moreover, in the said embodiment, although the process planned part (2) of a raw material (1) is located in the axial direction one side part of a raw material (1), in this invention, the process planned part (2) of a raw material (1). May be located in the middle in the axial direction of the material (1). Furthermore, in the present invention, the planned processing portions (2) of the material (1) are respectively positioned on both sides in the axial direction of the material (1), and both of the planned processing portions may be processed simultaneously.

  Moreover, in this invention, you may process in the state which heated the process scheduled part (2) of the raw material (1) to predetermined temperature, and you may process it without heating.

  In the present invention, the constraining die (10) and the guide (20) may be divided into a plurality of pieces.

  In the present invention, the material (1) may be cylindrical or rectangular.

  INDUSTRIAL APPLICABILITY The present invention can be used for a tubular material upsetting method and a cylindrical material upsetting apparatus that bulges a processing target portion of a cylindrical material outwardly so that the thickness increases.

FIG. 1 is a cross-sectional view of the upsetting apparatus before the cylindrical material upsetting apparatus according to the first embodiment of the present invention processes a scheduled portion of the cylindrical material. FIG. 2 is a cross-sectional view of the upsetting apparatus in a state where the second restraining portion of the mandrel of the upsetting apparatus is compressed and compressed. FIG. 3 is a cross-sectional view of the upsetting apparatus in a state where the planned processing portion of the material is being processed by the upsetting apparatus. FIG. 4 is a cross-sectional view of the upsetting apparatus after the planned processing portion of the material is processed by the upsetting apparatus. FIG. 5 is a perspective view of an upsetting product manufactured by the upsetting apparatus. FIG. 6 is a cross-sectional view of the upsetting apparatus in a state before processing the scheduled portion of the cylindrical material by the upsetting apparatus for the cylindrical material according to the second embodiment of the present invention. FIG. 7 is a cross-sectional view of the upsetting apparatus in a state where the second restraining portion of the mandrel of the upsetting apparatus is compressed and compressed. FIG. 8 is a cross-sectional view of the upsetting apparatus in a state where the planned processing portion of the material is being processed by the upsetting apparatus. FIG. 9 is a cross-sectional view of the upsetting apparatus after the planned processing portion of the material has been processed by the upsetting apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Material 2 ... Planned process part 2a ... Inner peripheral surface 3 of a planned process part ... Non-processed planned part 3a ... Inner peripheral surface 5 of a non-processed planned part ... Upset product 7 ... Swelling part 10A, 10B ... Upset Processing device 10 ... restraining die 11 ... restraining hole 12 ... molding recess 15 ... receiving member 16 ... receiving protrusion 20 ... guide 21 ... insertion hole 25 ... guide moving direction 30 ... punch 35 ... punch moving direction 40 ... metal core 41 ... 1st restraint part 41a ... Connection protrusion 42 ... 2nd restraint part 42a ... Connection recessed part 50 ... Mandrel pressurizing means 52 ... Guide drive means 54 ... Punch drive means

Claims (6)

By constraining the inner peripheral surface of the material planned processing portion and the non-processing planned portion with the peripheral surface of the mandrel by inserting and arranging the mandrel in the hollow portion of the cylindrical material processing planned portion and the non-processing planned portion,
The non-scheduled part of the material is placed in the restraint hole provided in the restraining die, thereby restraining the outer peripheral surface of the non-scheduled part of the material with the peripheral surface of the restraint hole,
And, while arranging the processing planned portion of the material in the molding recess provided at the end of the constraint die,
By placing the planned processing portion of the material in the insertion hole provided in the guide, the outer peripheral surface of the planned processing portion of the material is restrained by the peripheral surface of the insertion hole,
Next, while pressing the portion to be processed of the material in the axial direction with the punch, the guide is moved in the direction opposite to the moving direction of the punch so that the portion to be processed of the material is increased in thickness in the molding recess. In the upsetting processing method of the cylindrical material to bulge outward,
The mandrel includes a first restraining portion made of a rigid body that restrains the inner peripheral surface of the material planned processing portion and a rubber elastic body that restrains at least a portion near the processing target portion on the inner peripheral surface of the non-processed portion of the raw material A second restraining portion made of
The first constraining portion of the mandrel can be inserted and arranged in conformity with the hollow portion of the planned processing portion of the material,
The diameter of the second restraining portion of the mandrel is set smaller than the inner diameter of the non-processed portion of the material,
By constraining the inner peripheral surface of the planned processing portion of the material with the peripheral surface of the first constraining portion of the core metal by inserting and placing the mandrel in the hollow portion of the planned processing portion and the non-processing planned portion of the material,
By compressing and compressing the second constraining portion of the mandrel in the axial direction, at least the portion near the planned processing portion on the inner peripheral surface of the non-working planned portion of the material is constrained by the peripheral surface of the second constraining portion of the mandrel. And
In this state, the upsetting process for the cylindrical material is characterized in that the upsetting process is performed. The second constraining part of the mandrel restrains only the vicinity of the planned processing part on the inner peripheral surface of the non-scheduled part of the material,
A second constraining portion of the mandrel is disposed in the hollow portion of the non-scheduled part of the material on the receiving member that receives the end of the material on the opposite side of the non-scheduled part of the material in the axial direction of the material. Receiving projections are provided integrally in the axial direction,
The tubular material upsetting method according to claim 1, wherein the diameter of the receiving projection of the receiving member is set smaller than the inner diameter of the non-processed portion of the material. The mandrel is separable into a first restraining part and a second restraining part,
On the end face of the first restraining portion of the mandrel, a substantially spherical connecting projection is integrally projected,
A connection recess corresponding to the connection protrusion is provided on the end face of the second restraining portion of the mandrel,
The upsetting of the cylindrical material according to claim 1 or 2, wherein the first projecting portion and the second restraining portion of the mandrel are separably connected to each other by fitting the connecting protrusion into the connecting recess. Processing method. A mandrel that is disposed in the hollow portion of the processing planned portion and the non-processing planned portion of the tubular material, and restrains the inner peripheral surface of the processing planned portion and the non-processing planned portion of the material;
A restraint die that has a restraint hole and restrains the outer peripheral surface of the non-processed portion of the material disposed in the restraint hole with the peripheral surface of the restraint hole,
A molding recess provided at the end of the constraining die;
A guide that has an insertion hole and restrains the outer peripheral surface of the processing planned portion of the material disposed in the insertion hole with the peripheral surface of the insertion hole;
A punch that pressurizes the planned processing portion of the material in its axial direction,
While pressing the planned processing part of the material with its punch in the axial direction, the guide is moved in the opposite direction to the punch moving method, so that the planned processing part of the material increases outside in the molding recess. In the upsetting apparatus for cylindrical materials configured to bulge into
The mandrel includes a first restraining portion made of a rigid body that restrains the inner peripheral surface of the material planned processing portion and a rubber elastic body that restrains at least a portion near the processing target portion on the inner peripheral surface of the non-processed portion of the raw material A second restraining portion made of
The first constraining portion of the mandrel can be inserted and arranged in conformity with the hollow portion of the planned processing portion of the material,
The diameter of the second restraining portion of the mandrel is set smaller than the inner diameter of the non-processed portion of the material,
An upsetting apparatus for a cylindrical material, comprising: a mandrel pressurizing unit that pressurizes and compresses the second restraining portion of the mandrel in the axial direction thereof. The second constraining part of the mandrel restrains only the vicinity of the planned processing part on the inner peripheral surface of the non-scheduled part of the material,
A second constraining portion of the mandrel is disposed in the hollow portion of the non-scheduled part of the material on the receiving member that receives the end of the material on the opposite side of the non-scheduled part of the material in the axial direction of the material. Receiving projections are provided integrally in the axial direction,
The tubular material upsetting apparatus according to claim 4, wherein the diameter of the receiving projection of the receiving member is set smaller than the inner diameter of the non-processed portion of the material. The mandrel is separable into a first restraining part and a second restraining part,
On the end face of the first restraining portion of the mandrel, a substantially spherical connecting projection is integrally projected,
A connection recess corresponding to the connection protrusion is provided on the end face of the second restraining portion of the mandrel,
The tubular material upsetting according to claim 4 or 5, wherein the first protrusion and the second lock of the mandrel are detachably connected to each other by fitting the connection protrusion into the connection recess. Processing equipment.

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