JP2015036155A - Bar ring processing method and bar ring processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bar ring processing method and a bar ring processing device which can efficiently form a pair of bar ring-shaped parts, which extend outwards with each other, on a first wall part and a second wall part which are so disposed to face each other.SOLUTION: Provided is a bar ring processing device 50 for forming a pair of bar ring-shaped parts which extend outwards with each other on a first wall part and a second wall part which are so disposed to face each other. The bar ring processing device 50 is characterized in that a first forming part 65 corresponding to a first bar ring-shaped part is formed on one end side of an axis O1, a second forming part 65B corresponding to a second bar ring-shaped part is formed on the other end side of the axis O1, and the bar ring processing device is equipped with a middle punch 65 which can be moved in the axis O1 direction, a first punch 52P for moving the middle punch 65 to the first wall part side, and a second punch 51P for moving the middle punch 65 to the second wall part side.

Description

  The present invention relates to a burring method and a burring apparatus for processing a pair of burring-shaped portions extending outward from each other on a pair of opposed wall portions.

  As is well known, as a link structure member for connecting a plurality of objects, a link structure member in which a connecting portion is formed at an end or an intermediate position of the link structure member has been put to practical use. Is used for various applications.

  For example, various types of suspension devices for automobiles have been put into practical use. For example, suspension links such as a lower link, an upper link, and a lateral link are used in a five-link suspension (for example, a patent) Reference 1).

  In such a link structure member, for example, a suspension link as shown in FIG. 1 of Patent Document 1 is composed of a coupling portion 111 formed in a cylindrical shape and a wall portion formed in a U shape and opposed to each other. The coupling portion 112 is configured to be connected by the rod portion 113. The coupling portion 111 is connected to the axle by inserting a bush or the like into the hole and inserting a shaft member or the like into the inserted bush. The coupling portion 112 is connected to the vehicle body by a bolt inserted through the fastening hole.

  Some suspension links, such as lateral links, do not necessarily receive a large load from the vehicle body and can be thinned in strength, but when connecting the connecting portion to the rod portion by welding, In some cases, it is necessary to increase the thickness in order to obtain a sufficient strength in the welded portion, and as a result, there is a problem that the weight of the link structural member increases.

  On the other hand, for the purpose of reducing the weight of the link structural member, when integrally forming a joint having wall portions facing each other at the end of the metal tube, the thickness of the joint depends on the thickness of the metal tube to be molded. Therefore, it is necessary to stably hold the bush or the like within the thickness range of the opposing wall portion constituting the coupling portion, and it is not easy to stably hold the bush or the like. This is even more so when the end portion of the metal tube is expanded to form a bush holding portion into which a large bush can be inserted.

  Therefore, in the joint portion including the bush holding portion, in order to increase the holding area in the inner periphery of the bush holding hole by forming the rising wall portion in the peripheral portion of the bush holding hole formed in the opposing wall portion, A burring technique for forming a burring shape portion in a bush holding hole or the like is widely used (see, for example, Patent Document 2).

JP 2007-076547 A JP 2005-246474 A

  However, for example, in the case of using a burring apparatus as described in Patent Document 2, in order to form a pair of burring-shaped parts on opposing wall parts, burring was performed on one of the opposing wall parts. Later, it is necessary to perform burring on the other wall portion, and it is necessary to perform burring in two steps, so that there is a problem that work efficiency is lowered.

  Further, even if burring is performed in two steps, it is difficult to form a pair of burring shapes extending outward from each other on the opposing wall by the conventional burring method. When burring is performed before the wall is bent into a U shape, it is not easy to make the bush holding holes constituted by the burring shape portions important for fitting the bushes or the like coaxial. There wasn't.

  The present invention has been made in view of such circumstances, and a pair of burring-shaped portions that extend outward from each other are efficiently provided on the first wall portion and the second wall portion that are opposed to each other. An object of the present invention is to provide a burring method and a burring apparatus that can be formed into a single piece.

In order to solve the above problems, the present invention proposes the following means.
The invention according to claim 1 is a burring method for forming a pair of burring-shaped portions extending outward from each other on the first wall portion and the second wall portion arranged to face each other. A first burring shape portion extending outward from the first wall portion on one end side of an axis passing through the first wall portion and the second wall portion between the first wall portion and the second wall portion. A first punch corresponding to the second punching portion and a second molding portion corresponding to a second burring shape portion extending outward from the second wall portion at the other end of the axis. The intermediate punch is moved to the first wall portion side and protruded from the first wall portion to form the first burring shape portion, and the intermediate punch is moved to the second wall portion side. The second burring shape portion is formed by projecting from the second wall portion. Characterized in that it.

  The invention according to claim 2 is a burring apparatus for forming a pair of burring-shaped portions extending outward from each other on the first wall portion and the second wall portion arranged to face each other. The first wall portion can be disposed between the first wall portion and the second wall portion, and extends outwardly from the first wall portion to one end side of an axis passing through the first wall portion and the second wall portion. A first molding portion corresponding to the one burring shape portion is formed, and a second molding portion corresponding to the second burring shape portion extending outward from the second wall portion is formed at the other end of the axis. An intermediate punch that is movable in the axial direction, a first punch that moves the intermediate punch toward the first wall and protrudes from the first wall, and an intermediate punch that moves the second wall And a second punch that is moved to the portion side and protrudes from the second wall portion. To.

According to the burring method and the burring apparatus according to the present invention, the first burring shape portion extending outward from the first wall portion is formed between the first wall portion and the second wall portion. An intermediate punch in which a second forming portion for forming a forming portion and a second burring shape portion extending outward from the second wall portion is disposed, and the intermediate punch is moved to the first wall portion side The first burring shape portion is formed by projecting from the first wall portion, and after forming the first burring shape portion, the middle punch is moved to the second wall portion side to project from the second wall portion. A second burring shape is formed.
Therefore, it is possible to easily process the pair of burring-shaped portions extending outward from each other on the first wall portion and the second wall portion arranged to face each other.
Further, since the burring can be performed by the intermediate punch reciprocating once between the first wall portion side and the second wall portion side, the pair of burring shape portions can be efficiently processed.

  In this specification, the pair of burring-shaped portions extending outward from each other includes a burring-shaped portion having a wall portion extending from the first wall portion toward the opposite side of the second wall portion, It is comprised by the burring shape part which has a wall part extended toward the opposite side to a 1st wall part from two wall parts.

  Invention of Claim 3 is a burring processing apparatus of Claim 2, Comprising: The intermediate punch return mechanism which returns the said intermediate punch to the intermediate position of the said 1st wall part and the said 2nd wall part is provided. It is characterized by.

  According to the burring apparatus according to the present invention, the intermediate punch is provided with the intermediate punch returning mechanism that returns the intermediate punch to the intermediate position between the first wall portion and the second wall portion. It is possible to return to a position that does not interfere with the first burring shape portion and the second burring shape portion, and the product after burring processing is smoothly taken out, and the efficiency between the opposing wall portions of the intermediate product to be burring processed An intermediate punch can be arranged.

  Invention of Claim 4 is a burring apparatus of Claim 2 or 3, Comprising: At the front-end | tip of a said 1st shaping | molding part, the punch which punches the hole before a burring process in the said 1st wall part Is formed.

  According to the burring apparatus according to the present invention, the punching punch for punching the hole before burring is formed in the first wall at the tip of the first molding part. Since only the hole on the wall side needs to be processed, productivity in the entire manufacturing process can be improved.

  According to the burring method and the burring apparatus according to the present invention, a pair of burring-shaped portions that extend outward from each other are efficiently formed on the first wall portion and the second wall portion that are opposed to each other. be able to.

It is a figure which shows an example of the lateral link shape | molded by applying the burring method which concerns on one Embodiment of this invention. It is a front view which shows schematic structure of the lateral link to which the burring processing method which concerns on one Embodiment of this invention is applied. It is a figure which shows the cross section of the bush holding wall part to which the burring processing method of the lateral link which concerns on one Embodiment of this invention is applied, and is the figure which looked at the longitudinal direction of the rod part shown in FIG. It is a figure which shows an example of the flowchart which manufactures a lateral link by integrally forming a bush holding part in the edge part of the steel pipe which applies the burring process which concerns on one Embodiment of this invention. It is a figure explaining the manufacturing process which manufactures a lateral link by integrally forming a bush holding part in the end of a steel pipe concerning one embodiment of the present invention, and when forming a bush holding part, it is a steel pipe by pre-forming. It is a figure which shows the state which expanded the surrounding wall part. It is a figure explaining the manufacturing process which manufactures a lateral link by integrally forming a bush holding part in the end of a steel pipe concerning one embodiment of the present invention, and when forming a bush holding part, to a preformed steel pipe It is a figure which shows the state which shape | molded the slit. It is a figure explaining the manufacturing process which manufactures a lateral link by integrally forming a bush holding part in the end of a steel pipe concerning one embodiment of the present invention, and is a preformed slit when forming a bush holding part It is a figure which shows the state which set the attached steel pipe to the press die. It is a figure explaining the manufacturing process which manufactures a lateral link by integrally forming a bush holding part in the end of a steel pipe concerning one embodiment of the present invention, and was inserted in a die when forming a bush holding part It is a figure which shows the state which a punch advances with respect to the steel pipe with a slit. It is a figure explaining the manufacturing process which manufactures a lateral link by integrally forming a bush holding part in the end of a steel pipe concerning one embodiment of the present invention, and when forming a bush holding part, a punch is to an advance end. It is a figure which advances and shows the state by which the bush holding part before trimming was shape | molded by plastic deformation. It is a figure which shows an example of schematic structure of the burring processing apparatus which concerns on one Embodiment of this invention. It is a figure explaining the burring process which concerns on one Embodiment of this invention, and is a figure which shows the state which set the bush holding wall part before the burring process after trimming to the burring apparatus. It is a figure explaining the burring process which concerns on one Embodiment of this invention, and is a figure which shows the state which shape | molds a 1st burring shape part by moving an upper punch and projecting a middle punch from a 1st wall part. It is a figure explaining the burring process which concerns on one Embodiment of this invention, and is a figure which shows the state which shape | molds a 2nd burring shape part by moving a lower punch and projecting a middle punch from a 2nd wall part. It is a figure explaining the burring process which concerns on one Embodiment of this invention, and is a figure which shows the state which the 1st press member and the 2nd press member retracted, and the bush holding | maintenance part was made possible to take out from a burring apparatus.

Hereinafter, a burring apparatus and a burring method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7D.
FIG. 1 is a perspective view showing a schematic configuration of a lateral link (link structure member) in which a bush holding portion is formed by molding an end portion of a steel pipe (metal tube) according to an embodiment. Indicates a link. FIG. 2 is a front view showing an outline of the lateral link 1. FIG. 3 is a view showing a cross section of the bush holding portion of the lateral link according to the embodiment, and FIGS. 3 (A), (B), (C), and (D) are the bushes shown in FIG. This corresponds to AA, BB, CC, and DD views when the holding portion 20 is viewed in the longitudinal direction of the rod portion.

  As shown in FIGS. 1 and 2, the lateral link 1 includes a rod portion 10, a bush holding portion 20 connected to one end side of the rod portion 10, and a fastening portion 30 connected to the other end side of the rod portion 10. For example, the bush holding portion 20 can be connected to the axle by a shaft member or the like inserted through a bush (not shown), and the fastening portion 30 is connected to the vehicle body (not shown) by a bolt or the like. It is possible.

  The rod part 10 is constituted by a hollow steel pipe (metal pipe) whose cross section orthogonal to the longitudinal direction is a closed cross section, and both ends of the steel pipe are plastically deformed by press forming, whereby the bush holding part 20 and the fastening part are fastened. The part 30 is integrally formed with the rod part 10 and connected thereto. In this embodiment, the rod part 10 has a peripheral wall part with a circular cross section orthogonal to the longitudinal direction, for example.

  The bush holding portion 20 includes a tube expansion taper portion 11, a straight portion 12, a bush holding wall portion (opposing wall portion) 21, and a widening connection portion 22, and the bush holding wall portion 21 is interposed via the widening connection portion 22. The widened connecting portion 22 is connected to the bush holding wall portion 21 and the rod portion 10.

  The expanded pipe taper portion 11 is formed by forming a steel pipe made of a material, and has a taper that is expanded in a conical shape by plastic deformation from the proximal end side to the distal end side, for example, and the distal end side is opened larger than the inner diameter of the rod portion 10. And the surrounding wall part of the pipe expansion taper part 11 is formed more thinly than the steel pipe used as a material.

  The straight portion 12 is connected to the distal end side of the tube expansion taper portion 11 and is formed to have the same diameter and the same thickness as the opening side end portion of the tube expansion taper portion 11.

  The bush holding wall portion 21 is configured to have a pair of opposed wall portions having flat portions facing each other on the distal end side. In this embodiment, the distal end side is viewed from the proximal end side (rod portion 10 side). As shown in FIG. 3A, a flat portion is formed on the front end side of the bush holding wall portion 21 over the entire width.

A bush holding hole (attachment hole) 24 is formed at the center of the bush holding wall portion 21 in the width direction, and a burring-shaped portion 25 is formed at the peripheral edge of the bush holding hole 24.
In this embodiment, the burring shape portion 25 is configured to extend from the bush holding wall portions (first wall portion 211, second wall portion 212) 21 to the sides outward from each other, and the first wall portion 211. The rising length from the second wall portion 212 and the inner peripheral diameter are the same.

  A bush (not shown) is inserted into a bush holding surface 25A (see FIG. 3A) formed on the inner periphery of the burring portion 25 and the bush holding hole 24, and a shaft member or the like is inserted into the bush. Thereby, the bush holding | maintenance part 20 is connected with an axle shaft via a bush. Moreover, since the burring-shaped part 25 has an upright wall part and a large area of the inner peripheral surface of the bush holding hole 24 formed in the burring-shaped part 25 can be secured, the bushing etc. can be stably Can be held.

As shown in FIGS. 2 and 3B, the widened connection portion 22 has a pair of substantially channel-shaped wall portions in which bent portions where cross sections perpendicular to the rod portion 10 are close to each other are formed at both ends. The distal end side is connected to the bush holding wall portion 21 and the proximal end side is connected to the distal end portion of the straight portion 12.
Further, the widened connecting portion 22 is formed so that a V-shaped gap is formed from the proximal end side to the distal end side when viewed from the front, and the bent portions at both ends are shortened so that the flat portion is gradually widened. It is plastically deformed.

As a result, the widened connection portion 22 is formed in a substantially channel shape in cross section, and is formed so as to gradually change the shape from the cross section channel shape to the flat portion while widening from the proximal end side toward the distal end side.
FIG. 3D shows a cross section of the bush holding portion 20 viewed from the rod portion 10 in the longitudinal direction of the rod portion 10.

  Further, the pair of wall portions constituting the bush holding wall portion 21 and the widened connection portion 22 have a length in a cross section orthogonal to the rod portion 10, and the straight portion 12 in which the steel pipe is expanded (the slit formed in the manufacturing process). It is the same length as the peripheral length of the peripheral wall portion (excluding the width).

  As shown in FIG. 2, the fastening part 30 includes a fastening wall part (opposing wall part) 31, a first separation connection part 32, and a second separation connection part 33, and the fastening wall part 31 is a first separation part. It is connected to the rod portion 10 via the connection portion 32 and the second separation connection portion 33, and the first separation connection portion 32 and the second separation connection portion 33 are connections for connecting the fastening wall portion 31 and the rod portion 10. It is a shape part.

  The fastening wall portion 31 has a pair of opposing wall portions having flat portions facing each other on the distal end side. For example, when the distal end side is viewed from the proximal end side (rod portion 10 side), the fastening wall portion 31 extends over the entire width. A flat portion is formed. An attachment hole 34 is formed at the center of the fastening wall portion 31 in the width direction.

The first separation connection portion 32 has, for example, a pair of channel-shaped wall portions having cross-sections orthogonal to the rod portion 10 and close to each other at both ends, and the fastening wall portion 31 is connected to the distal end side. At the same time, the second separation connecting portion 33 is connected to the proximal end side.
Further, the first separation connecting portion 32 is plastically deformed so that a V-shaped gap is formed from the base end side toward the tip end side, and the flat portion is gradually widened while the bent portions at both ends are reduced. Has been. A reinforcing bead that swells inward from the outside and extends in the longitudinal direction is formed on the center side in the width direction of the first separation connecting portion 32.

The second separation connection portion 33 has a pair of substantially channel-shaped wall portions in which a cross section perpendicular to the rod portion 10 is formed with bent portions that are close to each other at both ends, and the first separation connection portion 32 is on the tip side. Connected and connected to the rod portion 10 on the base end side, and bent portions having cross-sections formed at both ends are formed into a substantially channel shape, and the pair of wall portions are mutually connected from the base end side toward the tip end side. The distance is gradually separated and formed into a V shape in front view.
Further, at the center in the width direction of the second separation connecting portion 33, one reinforcing bead that swells outward from the inside and extends in the longitudinal direction is formed.

  As a result, the connection shape portion has a substantially channel shape in cross section, and the second separation connection portion 33 is connected to the first separation connection portion 32 while being separated from the proximal end side toward the distal end side, and the first separation connection portion. The connection portion 32 has a substantially channel shape in cross section, and the cross section from the proximal end side toward the distal end side gradually changes from the channel shape to the flat portion.

  The pair of wall portions constituting the fastening wall portion 31, the first separation connection portion 32, and the second separation connection portion 33 have a length in a cross section perpendicular to the rod portion 10, which is a steel pipe (a slit formed in the manufacturing process). Is the same length as the peripheral length of the peripheral wall portion.

  Next, a method for forming the bush holding portion 20 will be described with reference to FIGS. 4 and 5A to 5E. FIG. 4 is a diagram illustrating an example of a flowchart illustrating a manufacturing process of a lateral link that forms a lateral link by integrally forming a bush holding portion 20 at an end portion of a steel pipe to which burring processing according to an embodiment is applied, 5A to 5E are views for explaining a manufacturing process for integrally forming the bush holding portion 20 according to the embodiment.

(1) First, for example, a tube expansion punch (not shown) is inserted into the steel pipe 10M constituting the rod portion 10 to form a molding scheduled portion 20A for molding the bush holding portion 20 (S1).
As shown in FIG. 5A, the planned forming portion 20A includes a tube expanding taper portion 11 having a conical diameter expanded from the proximal end side to the distal end side of the steel tube 10M by a tube expanding punch or the like, a straight portion 12, and a bush holding portion. 20 to be formed, and the forming portion 20A has a longer circumference than the steel pipe 10M and is thinner than the steel pipe 10M.
(2) Next, two slits 210S extending in the longitudinal direction are formed in the steel pipe 10M, two wall portions 210A having the same circumferential length are provided, and the divided wall portion 20B corresponding to the bush holding portion 20 is provided. Form (S2).
In this embodiment, for example, as shown in FIG. 5B, by forming two slits 210S at a circumferential position symmetrical to the central axis of the forming wall portion 210, a pair of the same shape before press forming is opposed to each other. A wall portion 210A is formed.
(3) Next, the pre-press molding wall portion 210A is press-molded, and the pre-press molding wall portion 210A is plastically deformed into a bush holding wall portion 210C after press molding (S3).
The press molding is performed, for example, in the procedure as shown in FIGS. 5C to 5E.
1) First, as shown in FIG. 5C, it is set in the press die K1, and the punch K2 is advanced in the axial direction of the steel pipe 10M and inserted between the press-molding front wall portions 210A.
2) Next, by moving the punch K2 forward, as shown in FIG. 5D, the slit 210S is formed into a substantially V-shaped slit 210T, and the wall portion 210A is formed with bent portions at both ends in the width direction. As the side goes, the bent portion becomes shorter and plastically deforms into an intermediate shape wall portion 210B whose shape changes to a flat portion, thereby forming an intermediate wall portion 20C of the bush holding portion 20.
3) Next, as shown in FIG. 5E, the punch K2 is advanced to the forward end, the slit 210T is formed into the slit 210U, and the intermediate shape wall portion 210B is formed into the bush holding wall portion 210C after press molding, and the tip side is A pre-trimming bush holding portion 20D corresponding to the bush holding portion 20 spaced apart at substantially the same interval as the outer diameter of the expanded steel pipe 10M is formed.
(4) Next, the pre-trimming bush holding portion 20D is trimmed by a trimming press or the like to remove the excess of the outer shape and before burring before the burring processing 211H and 212H (see FIG. 6) are formed. The first and second wall portions 211A and 212A (see FIG. 6) are formed (S4).
(5) Next, the burring shape portion 25 is formed by burring the first burring scheduled portion 211P and the second burring scheduled portion 212P (S5).

  Next, a burring apparatus and a burring method according to an embodiment will be described with reference to FIGS. 6 and 7A to 7D. The code | symbol 50 shown in FIG. 6 has shown the burring processing apparatus.

  The burring apparatus 50 includes a first pressing member 51 that presses the first wall 211 side from the outside, a second pressing member 52 that presses the second wall 212 side from the outside, an intermediate pressing member 60, An intermediate punch 65, a lower punch (second punch) 51P, an upper punch (first punch) 52P, and an intermediate punch return mechanism are provided.

  The first pressing member 51, the second pressing member 52, the intermediate pressing member 60, the middle punch 65, the lower punch 51 </ b> P, and the upper punch 52 </ b> P are formed on the first wall portion 211 and the second wall portion 212 that are arranged to face each other. The burring-shaped portions 251 and 252 can move in the direction of the axis O1 passing through the centers of the bush holding holes 241 and 242. In this embodiment, the axis O1 is formed in the vertical direction, for example.

Here, the bush holding wall portion 21 includes a first bush holding wall portion 211 and a second bush holding wall portion 212.
A first burring shape portion 251 is formed in the first bush holding wall portion 211, and a bush holding hole 241 is formed in the first burring shape portion 251.
Further, the second burring shape portion 252 is formed in the second bush holding wall portion 212, and the bush holding hole 242 is formed in the second burring shape portion 252.

  Further, the first and second wall portions 211A and 212A before burring are the surplus outer shape of the untrimmed bush holding portion 20D by trimming or the like before being processed into the first and second wall portions 211 and 212. Are the portions corresponding to the first and second wall portions 211 and 212 (see FIG. 2) where the bush holding holes 211H and 212H are formed before burring, and the first and second burring scheduled portions 211P and 212P. The term “burring processing” refers to a portion that is positioned at the peripheral edge of the bush holding holes 211H and 212H before burring.

  The first pressing member 51 has a perforated flat plate shape in which a processing hole 51H corresponding to the first burring shape portion 251 (see FIG. 7B) is formed and a first pressing surface 51A is formed on the upper surface (surface on one end side). In this embodiment, it is arranged in the lower part of the burring apparatus 50, and can be moved forward and backward with respect to the first wall part 211A before burring by an actuator provided in a press apparatus (not shown), for example. It is said that.

  The processing hole 51H has an inner periphery formed corresponding to the outer periphery of the first burring shape portion 251, and backs up the outer periphery of the first burring shape portion 251 formed by lowering the middle punch 65. ing.

  The first pressing surface 51A is formed, for example, corresponding to the outer surface of the first wall 211, and the first pressing surface 51A comes into contact with and presses the first wall 211A before burring. When the burring shape portion 251 is formed, the first wall portion 211 is prevented from being deformed by the forming force of the intermediate punch 65.

  The second pressing member 52 has a perforated flat plate in which a processing hole 52H corresponding to the second burring shape portion 252 (see FIG. 7C) is formed and a second pressing surface 52A is formed on the lower surface (the surface on the other end side). In this embodiment, it is arranged in the upper part of the burring apparatus 50. For example, it is moved forward and backward with respect to the second wall part 212A before burring by an actuator provided in a press apparatus (not shown). It is possible.

  The processing hole 52H has an inner periphery formed corresponding to the outer periphery of the second burring shape portion 252, and backs up the outer periphery of the second burring shape portion 252 formed by raising the middle punch 65. ing.

  The second pressing surface 52A is formed, for example, corresponding to the outer surface of the second wall portion 212, and the second pressing surface 52A comes into contact with and presses the second wall portion 212A before burring. When the burring shape portion 252 is formed, the second wall portion 212 is prevented from being deformed by the forming force of the intermediate punch 65.

  The intermediate pressing member 60 has a cylindrical shape whose outer shape can be disposed between the first wall portion 211A and the second wall portion 212A before burring, and is on the first wall portion 211 side (lower side). A first support wall 61 is formed at the end and a second support wall 62 is formed at the end on the second wall 212 side (upper side).

The first support wall 61 has a first pressing surface 60A formed on the lower surface (one end side surface) and a hole 61H through which the first burring forming portion 65A of the intermediate punch 65 can pass on the inner peripheral side. Has been.
The second support wall portion 62 has a second pressing surface 60B formed on the upper surface (the surface on the other end side), and a hole through which the second burring forming portion 65B of the intermediate punch 65 can pass on the inner peripheral side. 62H is formed.

The space between the first support wall 61 and the second support wall 62 is a cylindrical recess 60C having an inner diameter slightly larger than the middle punch 65, with the diameter being increased from the hole 61H and the hole 62H around the axis O1. The middle punch 65 is movable in the direction of the axis O1.
The cylindrical recess 60C accommodates a first return spring 61S and a second return spring 62S, and can be expanded and contracted in the direction of the axis O1.

  In this embodiment, the intermediate punch 65 includes, for example, an intermediate punch body 66 formed in a cylindrical shape, and a spring support rib 67 formed in the circumferential direction at the center of the intermediate punch body 66 in the axis O1 direction. Yes.

A first burring forming portion 65A for forming the first burring shape portion 251 is formed at a lower portion (one end side) of the middle punch 65. The first burring forming portion 65A has an inner diameter of the first burring shape portion 251. A corresponding outer diameter is formed.
In addition, a second burring forming portion 65B for forming the second burring shape portion 252 is formed on the upper portion (the other end side) of the middle punch 65, and the second burring forming portion 65B is the second burring shape portion 252. The outer diameter corresponding to the inner diameter is formed.

A first return spring 61S is disposed around the middle punch main body 66 between the spring support rib 67 and the first support wall 61, and between the spring support rib 67 and the second support wall 62. In addition, a second return spring 62S is arranged.
The first return spring 61S is configured to bias the spring support rib 67 toward the second wall 212, and the second return spring 62S is configured to bias the spring support rib 67 toward the first wall 211. Has been.

In this embodiment, the spring support rib 67, the first support wall 61, the second support wall 62, the first return spring 61S, and the second return spring 62S return the intermediate punch 65 to the intermediate position in the direction of the axis O1. It constitutes a medium punch return mechanism.
In this embodiment, the intermediate punch 65 moved to the first wall portion 211A (first wall portion 211) side before burring or the second wall portion 212A (second wall portion 212) side before burring. It is configured to return to the center position (intermediate position) in the direction of the axis O1.

The lower punch (second punch) 51P is disposed below the middle punch 65 and in the machining hole 51H of the first pressing member 51. For example, the lower punch (second punch) 51P can be advanced and retracted in the direction of the axis O1 by an actuator provided in a press device (not shown). The intermediate punch 65 can be pressed upward in the direction of the axis O1.
Further, the lower punch 51P has an outer diameter smaller than the inner diameter of the bush holding hole 241 of the first burring shape portion 251, and passes through the bush holding hole 241 of the first burring shape portion 251 and moves the middle punch 65 upward. Can be pressed.

The upper punch (first punch) 52P is disposed in the processing hole 52H of the second pressing member 52 above the middle punch 65, and can be advanced and retracted in the direction of the axis O1 by an actuator provided in a press device (not shown), for example. The intermediate punch 65 can be pressed downward in the direction of the axis O1.
Further, the upper punch 52P has an outer diameter smaller than the inner diameter of the pre-burring hole 212H of the second burring scheduled portion 212P, and can pass through the pre-burring hole 212H and press the middle punch 65 downward. Has been.

  Note that the amount of advancement (stroke) of the upper punch 52P and the lower punch 51P after contacting the middle punch 65 is made different so that the first burring shape portion 251 and the rising wall portion of the second burring shape portion 252 It is good also as a structure from which height of differs.

  Next, an example of a burring method according to an embodiment will be described with reference to FIGS. 7A to 7D. 7A to 7D are views for explaining a burring method according to an embodiment.

(1) First, as shown in FIG. 7A, the first and second wall portions 211A and 212A before burring in which the outer shape and the bush holding holes 211H and 212H before burring are formed by trimming are moved in the direction of arrow F1. Then, the first pressing member 51 and the second pressing member 52 are moved in the directions of the arrows F2 and F3, respectively, to the first and second wall portions 211A and 212A before burring processing. Abut from one side and press.
(2) Next, as shown in FIG. 7B, the middle punch 65 is lowered by the upper punch 52P in the direction of the arrow F4, and the peripheral portion of the bush holding hole 211H before burring of the first burring scheduled portion 211P is The first burring shape portion 251 is formed by bending the second burring processing planned portion 212P (second wall portion 212) to the opposite side.
At this time, the middle punch 65 contracts the first return spring 61S, and the second return spring 62S extends.
(3) Next, as shown in FIG. 7C, the middle punch 65 is raised in the direction of the arrow F5 by the lower punch 51P, and the peripheral portion of the bushing hole 212H before burring formed in the second burring scheduled portion 212P The second burring shape portion 252 is formed by bending the first wall portion 211 to the opposite side.
At this time, the middle punch 65 contracts the second return spring 62S, and the first return spring 61S extends.
(4) Next, as shown in FIG. 7D, when the first wall portion 211 and the second wall portion 212 having the first burring shape portion 251 and the second burring shape portion 252 are formed, the first pressing member 51, The lower punch 51P is lowered in the arrow F6 direction, and the second pressing member 52 and the upper punch 52P are raised in the arrow F7 direction.
When the lower punch 51P is lowered, the middle punch 65 is urged toward the central portion in the direction of the axis O1 by the return spring 62, and returns to the central portion in the direction of the axis O1.
As a result, there is no interference between the first burring shape portion 251 and the first pressing member 51 and the lower punch 51P, and there is no interference between the second burring shape portion 252 and the middle punch 65, the second pressing member 52 and the upper punch 52P. Thus, the product subjected to burring can be taken out from the burring apparatus 50 by moving in the direction of arrow F8.

According to the burring apparatus 50 according to the embodiment, the first molding portion 65A and the second burring shape portion 252 for molding the first burring shape portion 251 are formed between the first wall portion and the second wall portion. The intermediate punch 65 formed with the second forming portion 65B is arranged, and the intermediate punch 65 is moved to the first wall portion 211 side so as to protrude from the first burring planned portion 211P. After forming the first burring shape portion 251, the second burring shape portion 252 is formed by moving the middle punch 65 to the second wall portion 212 side and projecting from the second wall portion burring scheduled portion 212. To do.
Accordingly, the intermediate punch 65 reciprocates once between the first wall portion 211 side and the second wall portion 212 side, whereby a pair of first and second wall portions 211 and 212 extend outward from each other. The burring shape part 25 can be shape | molded efficiently.

  Further, according to the burring apparatus 50 according to the embodiment, since the intermediate punch return mechanism is provided, the intermediate punch 65 is moved to the center of the first wall portion 211 and the second wall portion 212 after the burring processing is completed. The product after returning to the position can be smoothly taken out without interfering with the first burring shape portion 251 and the second burring shape portion 252.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.
For example, in the above-described embodiment, the case where the link structure member is the lateral link 1 has been described, but instead of the lateral link 1, the present invention is applied to other suspension links for automobiles, building structures, and mechanical structures. You may apply, when processing a burring-shaped part to the connection parts including the bush holding wall part of a link structure member.

Moreover, in the said embodiment, although the case where the 1st wall part 211 and the 2nd wall part 212 were the same shape was demonstrated, even if the 1st wall part 211 and the 2nd wall part 212 are made into the shape from which it differs. Good.
Moreover, in the said embodiment, although the 1st burring shape part 251 and the 2nd burring shape part 252 were made into the same internal diameter, and demonstrated having the standing wall part of the same length toward outward, The rising wall portions formed in the first burring shape portion 251 and the second burring shape portion 252 have different heights, or the bush holding holes 241 and 242 of the first burring shape portion 251 and the second burring shape portion 252 are provided. Different inner diameters may be used.

  Further, in the above embodiment, the burring apparatus 50 includes the spring support rib 67, the first support wall portion 61, the second support wall portion 62, the first return spring 61S, and the second return spring 62S. Although the case of having the punch return mechanism has been described, a configuration without the medium punch return mechanism may be provided, or a configuration with a medium punch return mechanism with a different configuration may be used.

  Moreover, in the said embodiment, although the center punch 65 in which the return mechanism returns to the center position in the direction of the axis O1 between the 1st wall part 211 and the 2nd wall part 212 was demonstrated as the intermediate position. The intermediate position is not limited to the center position of the first wall portion 211 and the second wall portion 212 in the direction of the axis O1, and can be arbitrarily set.

  Further, in the above embodiment, the steel pipe 10M is expanded and formed wider than the circumferential length of the steel pipe 10M, and the bush holding wall part 21 is separated from the rod part 10 at substantially equal intervals. Although the case where the shape portion is formed has been described, the bush holding wall portion 21 formed by the tube expansion may be spaced apart at a wider interval than the rod portion 10, or is applied to the fastening portion 30 or the like that is not tube expanded. You can also

  Further, in the above embodiment, the case where the circular bush holding hole is formed in the burring shape portion 25 has been described. For example, the hole formed in the burring shape portion 25 is a polygon such as a triangle or a rectangle. Needless to say, it is not limited to a regular polygon.

  In the above-described embodiment, the case where the axis O1 is formed in the vertical direction and the middle punch 65 advances and retracts in the vertical direction has been described. However, the axis O1 may be a direction that intersects the vertical direction.

  Further, in the burring apparatus 50, a punch before punching a hole before burring is formed on the tip side of the first forming portion 65A of the intermediate punch 65, and the bush before burring of the first burring scheduled portion 211P. The configuration may be such that the formation of the holding hole 211H is omitted.

  In the above embodiment, the first wall portion and the second wall portion have the same shape and the same thickness. However, the first wall portion and the second wall portion may have different shapes and thicknesses. The burring hole shape and the burring shape portion of the two wall portions may be different shapes.

  Moreover, in the said embodiment, although the case where burring was carried out to the bush holding wall part integrally formed in the edge part of a steel pipe was demonstrated, the bush connected by the welding etc. to the edge part of the rod part which comprises a link structure member The holding wall portion may be subjected to burring, or the bush holding wall portion connected to the intermediate position of the rod portion by welding or the like may be subjected to burring processing.

  Further, instead of the steel pipe, for example, a pipe material made of other materials such as plastically deformable magnesium (including an alloy), aluminum (including an alloy), or the like may be used.

  According to the burring method and the burring apparatus according to the present invention, a pair of burring-shaped portions that extend outward from each other are efficiently formed on the first wall portion and the second wall portion that are opposed to each other. Can be used industrially.

O1 Axis 1 Lateral link (link structure member)
10 Rod part 11 Tube expansion part 20 Bush holding part (mounting part)
21 Bush holding wall (opposite wall)
24 Bushing holding hole (mounting hole)
25 Burring shape section 50 Burring processing equipment 51P Lower punch (second punch)
52P Upper punch (first punch)
60 Intermediate pressing member 61 First support wall (return mechanism)
61S 1st return spring (return mechanism)
62 Second support wall (return mechanism)
62S Second return spring (return mechanism)
65 Medium punch 67 Spring support rib 67 (return mechanism)
65A First burring molding part (first molding part)
65B Second burring molding part (second molding part)
211 1st wall part (bush holding wall part)
212 Second wall (bush holding wall)
211A First wall portion 212A before burring processing Second wall portion 211P before burring processing First burring processing planned portion 212P Second burring processing planned portion 211H Bushing holding hole 212H before burring processing Bushing holding hole 241 before burring processing Bushing holding hole (First wall)
242 Bushing holding hole (second wall)
251 Burring shape part (1st wall part)
252 Burring shape part (second wall part)

Claims (4)

A burring method for forming a pair of burring-shaped portions extending outward from each other on a first wall portion and a second wall portion arranged to face each other,
A first burring extending outward from the first wall portion between the first wall portion and the second wall portion on one end side of an axis passing through the first wall portion and the second wall portion. A first molding portion corresponding to the shape portion is formed, and a second molding portion corresponding to a second burring shape portion extending outward from the second wall portion is formed on the other end side of the axis. Place the punch inside
The first burring shape portion is formed by moving the middle punch toward the first wall portion and projecting from the first wall portion,
A burring method characterized in that the second burring shape portion is formed by moving the middle punch toward the second wall portion and projecting from the second wall portion. A burring apparatus for forming a pair of burring-shaped portions extending outward from each other on a first wall portion and a second wall portion arranged to face each other,
It can be arranged between the first wall portion and the second wall portion, and extends outward from the first wall portion on one end side of an axis passing through the first wall portion and the second wall portion. A first molding portion corresponding to the first burring shape portion to be formed and a second molding corresponding to the second burring shape portion extending outward from the second wall portion on the other end side of the axis. A medium punch in which a portion is formed and movable in the axial direction;
A first punch that moves the middle punch toward the first wall and protrudes from the first wall;
A second punch for moving the middle punch toward the second wall and projecting from the second wall;
A burring apparatus characterized by comprising: The burring apparatus according to claim 2,
A burring processing apparatus comprising an intermediate punch return mechanism for returning the intermediate punch to an intermediate position between the first wall portion and the second wall portion. A burring apparatus according to claim 2 or 3,
A piercing punch for punching a hole before burring in the first wall is formed at the tip of the first molding part.

Images