JP5852497B2 - Hollow member for reinforcement and manufacturing method thereof - Google Patents

Description

  The present invention relates to a reinforcing hollow member used for a door beam of an automobile and a method for manufacturing the same.

  A technique of attaching a bracket to a reinforcing hollow member in advance and fixing the reinforcing hollow member to the target member by tightening a bolt and a nut through the bracket when fixing the reinforcing hollow member to the target member (such as an automobile door panel). (Bracket system) is known (see Patent Document 1). However, the bracket system has a disadvantage in terms of cost because the number of parts is increased and the number of manufacturing steps is increased because the bracket needs to be processed. Further, when the reinforcing hollow member is fixed to the target member, it is necessary to tighten the bolt while supporting the nut on the bracket with a tool or the like, and there is a problem that workability is poor.

  Thus, techniques such as Patent Documents 2 and 3 are known as methods in which brackets are omitted. In Patent Document 2, a hole in which a bolt can be loosely fitted is formed in one flange of a reinforcing hollow member, a nut is disposed in a portion facing the hole of the flange, and the bolt and nut are tightened via the target member. Shown to do. Patent Document 3 discloses that the end portion in the longitudinal direction of the reinforcing hollow member is crushed and bolted into a hole formed in the end portion.

JP-A-5-254344 JP 2001-301462 A JP-A-9-58386

  According to Patent Documents 2 and 3, by omitting the bracket, the problem of the number of parts for the bracket is reduced, but as with Patent Document 1, a bolt / nut tightening structure is adopted. Depending on the number of parts for the number of nuts, cost and weight are required. In terms of work, the number of bolts and nuts required for tightening work is complicated. Furthermore, since it is necessary to secure a working space for tightening the bolts and nuts, there is a problem in that it is difficult to secure the fixing strength of the reinforcing hollow member with respect to the target member due to restrictions on the arrangement interval of the nuts. In particular, Patent Document 2 is disadvantageous in terms of fixing strength because it is fixed to the target member via a single flange.

  An object of the present invention is to provide a reinforcing hollow that can reliably secure the fixing strength to the target member and can easily perform the fixing operation to the target member while reducing the number of parts and reducing the cost and weight. It is providing a member and its manufacturing method.

In order to achieve the above object, according to a first aspect of the present invention, a reinforcing hollow member fixed to the target member to reinforce the target member is a hollow main body made of metal, the target member A crushing portion formed by crushing a pair of opposing walls constituting the main body at a portion fixed to the main body, a head, and a shaft extending from the head The shaft portion penetrates the crushing portion, and the peripheral portion of the shaft portion in the crushing portion is plastically flowed to be caulked and fastened to the crushing portion, and the welding current is passed from the head to the tip of the shaft portion. the shaft tip is provided and a plurality of rivets that are spot welded to said subject member, the portion in contact with at least said body in said rivet, characterized in that the insulating layer is formed by, for reinforcement Sky member is provided.

According to a second aspect of the present invention, there is provided a method of manufacturing a reinforcing hollow member having a hollow main body made of metal and fixed to the target member in order to reinforce the target member, the target member of the main body the portion to be fixed to, by crushing a pair of walls facing each other forming the body, possess a pinch forming step of forming a pinch, a shaft portion extending from the head and the head The shaft portion of a plurality of rivets having an insulating layer formed in a portion in contact with the main body is penetrated through the crushing portion, and the peripheral portion of the shaft portion in the crushing portion is plastically flowed to cause the rivet to A caulking step for caulking and fastening to a crushing portion, and a welding step for spot welding the shaft portion tip to the target member by flowing a welding current from the head portion of the rivet to the shaft portion tip. Special The method of reinforcing a hollow member.

According to the first and second aspects, the bracket can be omitted, and it is not necessary to employ a bolt / nut tightening structure. Can be reduced. In addition, it is not necessary to secure a working space for tightening the bolts and nuts, and there is no restriction on the arrangement interval of the rivets, so it is easy to ensure the fixing strength of the reinforcing hollow member to the target member. In addition, since the crushing portion is formed by crushing a pair of walls facing each other, the fixing strength is improved as compared with the configuration in which the object member is fixed via one flange as in Patent Document 2. Can be made. Further, it is not necessary to tighten bolts and nuts, and the fixing operation can be easily performed. As described above, according to the first and second aspects, it is possible to reliably secure the fixing strength to the target member while suppressing the number of parts and reducing the cost and weight, and to easily fix the target member. Can be done. In addition, when a plurality of rivets are provided in the crushing portion, when welding one rivet to the target member and then welding a rivet arranged adjacent to the rivet to the target member, the welding current is applied to the rivet that has already been welded. Easy to flow toward. Therefore, welding is not performed appropriately, and the fixing strength of the reinforcing hollow member with respect to the target member can be reduced. On the other hand, according to the above configuration, the presence of the insulating layer prevents the welding current from flowing toward the already welded rivet. Thereby, said problem can be reduced.

  In the second aspect, the crushing portion forming step and the caulking step may be simultaneously performed by press working. According to this structure, simplification of a manufacturing process is implement | achieved by performing formation of a crushing part, and caulking fastening of a rivet simultaneously.

  In the first aspect, the main body includes a pair of flanges facing each other and a pair of webs facing each other and connecting the pair of flanges, respectively, and configured by the pair of flanges and the pair of webs It may have a B-shaped cross section, and the crushing part may be formed by crushing the pair of webs. In the second aspect, the main body includes a pair of flanges facing each other and a pair of webs facing each other and connecting the pair of flanges, respectively, and includes the pair of flanges and the pair of webs. The crushing part may be formed by crushing the pair of webs in the crushing part forming step. According to these configurations, the absorbing power of the load in the direction orthogonal to the flange (impact force generated at the time of a collision when the reinforcing hollow member is used as a door beam of an automobile) is improved.

  In the first and second aspects, the thickness of the flange may be larger than the thickness of the web. According to this structure, the strength of a crushing part improves because a thick flange overlaps in a crushing part. Further, since the web is thin, the crushing portion can be easily formed.

  In the first aspect, the plurality of rivets may be caulked and fastened to the crushing portion while being separated from each other. In the second aspect, in the caulking step, the plurality of rivets may be caulked and fastened while being separated from each other in the crushing portion. According to these structures, the load concerning each rivet can be reduced by providing a several rivet in a crushing part. As a result, the fixing strength of the reinforcing hollow member to the target member can be improved.

  In the first and second aspects, the main body may be made of an aluminum alloy, and the rivet may be made of steel. According to this configuration, it is possible to reduce the weight of the reinforcing hollow member by configuring the main body with a relatively lightweight aluminum alloy. Further, when the main body is made of an aluminum alloy and the target member is made of steel, when both are joined by welding, a highly brittle Al-Fe intermetallic compound is generated at the interface between the two, and the fixing strength is reduced. Problems can arise. However, according to the above configuration, the rivet made of steel and the target member are both spot-welded, so that an intermetallic compound is not generated at the interface between the main body and the target member, and the fixing hollow member has a fixed strength with respect to the target member. It can be surely secured.

  While suppressing the number of parts and reducing the cost and weight, it is possible to reliably secure the fixing strength to the target member and to easily perform the fixing operation to the target member.

It is the schematic which shows the example which used the hollow member for reinforcement which concerns on one Embodiment of this invention as a door beam of a motor vehicle. (A) is a perspective view which shows the longitudinal direction edge part of the hollow member for reinforcement which concerns on one Embodiment of this invention. (B) is sectional drawing which followed the IIB-IIB line | wire shown to Fig.2 (a). It is sectional drawing along the III-III line shown to Fig.2 (a) which shows the process of spot-welding each rivet to an object member. It is a flowchart which shows the manufacturing method of the hollow member for reinforcement which concerns on one Embodiment of this invention. It is sectional drawing corresponding to FIG.2 (b) which shows the condition when a press work is performed in steps.

  Hereinafter, preferred embodiments of the present invention will be described.

  The reinforcing hollow member 1 according to an embodiment of the present invention can be used as a door beam of an automobile, for example, as shown in FIG. In FIG. 1, a reinforcing hollow member 1 is disposed between an inner panel and an outer panel of an automobile door, and is fixed to the inner panel (target member). In this example, the reinforcing hollow member 1 has a function of reinforcing a door of an automobile and protecting a passenger of the automobile by absorbing an impact caused by a collision from a side surface of the door.

  As shown in FIG. 2, the reinforcing hollow member 1 includes a hollow main body 2 elongated in one direction and end portions in the longitudinal direction of the main body 2 (hereinafter referred to as “longitudinal end portions”). 2, only one end portion is shown in FIG. 2, but the other end portion has the same configuration.) And a rivet 3 that is caulked and fastened. The main body 2 is made of an extruded material of an aluminum alloy, and the rivet 3 is made of steel. The target member to which the reinforcing hollow member 1 is fixed may be made of any material, but is preferably made of steel in the same manner as the rivet 3 from the viewpoint of suppressing the formation of intermetallic compounds.

  The main body 2 includes a pair of flanges 2a facing each other and a pair of webs 2b facing each other and connecting the pair of flanges 2a, respectively, and a rectangular shape formed by the pair of flanges 2a and the pair of webs 2b. Having a cross section. The thickness of the flange 2a is larger than the thickness of the web 2b.

  Each end of the main body 2 is a portion fixed to a target member (a door panel in the example of FIG. 1). Each end portion of the main body 2 is provided with a crushing portion 2x formed by crushing a pair of webs 2b. Each of the crushing portions 2x is firmly caulked and fastened so that the two rivets 3 are not removed.

  Each rivet 3 has a head portion 3a and a shaft portion 3b extending from the head portion 3a. Each rivet 3 is caulked and fastened to the crushing portion 2x by the shaft portion 3b penetrating the crushing portion 2x and the peripheral portion of the shaft portion 3b in each flange 2a of the crushing portion 2x plastically flows. The two rivets 3 provided in each crushing portion 2x are arranged at the center in the width direction of the main body 2 while being separated from each other in the longitudinal direction of the main body 2.

  As shown in FIG. 3, the reinforcing hollow member 1 is fixed to the target member 10 by spot welding the tip of the shaft portion 3 b of each rivet 3. An insulating layer 3x is formed on a portion (the bottom surface of the head portion 3a and the peripheral surface of the shaft portion 3b) in contact with the main body 2 in the rivet 3 arranged at a position closest to the end portion of the main body 2. Accordingly, when spot welding is performed by sequentially arranging the electrodes 50a, 50b on the upper and lower sides for each rivet 3, one rivet 3 (on the right side in FIG. 3) is first welded to the target member 10 and then the rivet 3 is attached. When the adjacent rivet 3 (left side in FIG. 3) is welded to the target member 10, the welding current flows toward the already welded rivet 3 (right side in FIG. 3) as indicated by an arrow 50Y. Is prevented. At this time, due to the presence of the insulating layer 3x, the welding current appropriately flows from the head 3a of the left rivet 3 in FIG. 3 through the shaft 3b toward the tip of the shaft 3b as indicated by an arrow 50X. .

  In order to prevent the rivet 3 from melting and flowing out during spot welding, the longitudinal direction of the main body 2 from the axial center of the rivet 3 arranged at the position closest to the end of the main body 2 to the edge of the end of the main body 2 It is preferable to secure a distance D (see FIGS. 2A and 3) about 2.5 times the diameter of the shaft portion 3b.

  Next, a method for manufacturing the reinforcing hollow member 1 will be described.

  In order to manufacture the reinforcing hollow member 1, first, components (the main body 2 and the four rivets 3) are prepared (S1 in FIG. 4). At this time, the main body 2 has not yet been provided with the crushing portion 2x at each end portion, and has a constant cross section (a cross section having a square shape as shown in FIG. 5A) over the entire longitudinal direction.

  After S1, in two of the four rivets 3 prepared in S1, the insulating layer 3x is formed on the bottom surface of the head 3a and the peripheral surface of the shaft portion 3b (S2: insulating layer forming step). In S2, the insulating layer 3x may be formed by applying an insulating paint to each surface of the rivet 3 (for example, Geomet (registered trademark) treatment or Disco (registered trademark) treatment may be employed). ).

  After S2, as shown to Fig.5 (a), the main body 2 and the rivet 3 are arrange | positioned between metal mold | die 60a, 60b (S3). At this time, the two rivets 3 on which the insulating layer 3x is formed in S2 are arranged at positions closest to the respective end portions of the main body 2, and the two rivets 3 on which the insulating layer 3x is not formed are disposed on the respective end portions of the main body 2. Place it in the second closest position. Each rivet 3 is disposed such that the head 3a is placed on the lower mold 60b and the shaft 3b protrudes upward. A hole 60x having a diameter that is slightly larger than the diameter of the shaft portion 3b is formed in the upper mold 60a. The main body 2 and the rivet 3 are arranged so that the hole 60x and the shaft portion 3b are aligned, and the tip of the shaft portion 3b is positioned at the center in the width direction of the lower flange 2a.

  After S3, press working is performed (S4: crushing portion forming step + caulking step). In S4, the crushing part 2x is formed in each edge part of the main body 2 by press work, and the rivet 3 is caulked and fastened to each crushing part 2x. Specifically, as shown in FIGS. 5B and 5C, the upper mold 60a is lowered while the lower mold 60b is stationary. Then, the tip of the shaft portion 3b presses the central portion in the width direction of the lower flange 2a from below, the corresponding portion of the lower flange 2a rises, and the pair of webs 2b bend outward (see FIG. 5 (b)). The pair of webs 2b are further bent outward, and the shaft portion 3b penetrates the center in the width direction of the lower flange 2a, and further penetrates the center in the width direction of the upper flange 2a (FIG. 5C). reference). In this way, at each end of the main body 2, the pair of webs 2b are crushed to form a crushed portion 2x. At the same time, the shaft portion 3b of each rivet 3 penetrates the crushed portion 2x, and the crushed portion 2x Two flanges 2 are caulked and fastened to the crushing portion 2x by plastic flow of the peripheral portion of the shaft portion 3b in each flange 2a. The pair of webs 2b may be bent inward.

  Through the above steps, the reinforcing hollow member 1 is completed.

  As described above, according to the reinforcing hollow member 1 and the manufacturing method thereof according to the present embodiment, the bracket can be omitted, and it is not necessary to adopt a tightening structure with bolts and nuts. The number of parts corresponding to the number is unnecessary, and the cost and weight can be reduced. Further, it is not necessary to secure a working space for tightening the bolts and nuts, and there is no restriction on the arrangement interval of the rivets 3, so that it is easy to secure the fixing strength of the reinforcing hollow member 1 to the target member 10. And since the crushing part 2x is formed by crushing a pair of wall (web 2b) which mutually opposes, compared with the structure which fixes to an object member via one flange like patent document 2. , The fixing strength can be improved. Further, it is not necessary to tighten bolts and nuts, and the fixing operation can be easily performed. As described above, according to the present embodiment, it is possible to reliably secure the fixing strength to the target member while suppressing the number of parts and reducing the cost and weight, and to easily perform the fixing operation on the target member. it can.

  According to the manufacturing method of this embodiment, simplification of a manufacturing process is implement | achieved by performing simultaneously formation of the crushing part 2x and caulking fastening of the rivet 3 by S4.

  The main body 2 has a square-shaped cross section constituted by a pair of flanges 2a and a pair of webs 2b, and the crushing portion 2x is formed by crushing the pair of webs 2b. Thereby, the absorption power of the load in the direction perpendicular to the flange 2a (impact force generated at the time of a collision when the reinforcing hollow member 1 is used as an automobile door beam) is improved.

  Moreover, the thickness of the flange 2a is larger than the thickness of the web 2b. In this case, the strength of the crushing portion 2x is improved by overlapping the thick flange 2a in the crushing portion 2x. Moreover, since the web 2b is thin, formation of the crushing part 2x can be performed easily.

  A plurality of rivets 3 are provided in the crushing portion 2x. Thereby, the load concerning each rivet 3 can be reduced. As a result, the fixing strength with respect to the object member 10 of the reinforcing hollow member 1 can be improved.

  An insulating layer 3x is formed on a portion (the bottom surface of the head portion 3a and the peripheral surface of the shaft portion 3b) in contact with the main body 2 in the rivet 3 disposed at a position closest to the end of the main body 2. In the case where a plurality of rivets 3 are provided in the crushing portion 2x, when welding one rivet 3 to the target member 10 and then welding the rivet 3 disposed adjacent to the rivet 3 to the target member 10, the welding current is already present. It tends to flow toward the welded rivet 3 (see arrow 50Y in FIG. 3). Therefore, welding is not performed appropriately, and the fixing strength of the reinforcing hollow member 1 with respect to the target member 10 can be reduced. On the other hand, according to the above configuration, due to the presence of the insulating layer 3x, the welding current flows properly as indicated by the arrow 50X in FIG. 3, and the welding current is prevented from flowing toward the already welded rivet 3. . Thereby, said problem can be reduced.

  The main body 2 is made of an aluminum alloy, and the rivet 3 is made of steel. According to this structure, weight reduction of the reinforcing hollow member 1 can be achieved by configuring the main body 2 with a relatively light aluminum alloy. In addition, when the main body 2 is made of an aluminum alloy and the target member 10 is made of steel, when both are joined by welding, a highly brittle Al—Fe intermetallic compound is generated at the interface between the two, and the fixing strength is reduced. Problems may occur. However, according to the above configuration, an intermetallic compound is not generated at the interface between the main body 2 and the target member 10 by spot welding the rivet 3 and the target member 10 both made of steel, and the target of the reinforcing hollow member 1 The fixing strength with respect to the member 10 can be reliably ensured.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments and examples, and various design changes can be made as long as they are described in the claims. is there.

  The reinforcing hollow member according to the present invention can be applied to other than the door beam.

  The number of rivets provided in the crushing part may be an arbitrary number of 1 or more. The arrangement of the rivets is also arbitrary. For example, the plurality of rivets may be arranged along one or a plurality of rows extending in the longitudinal direction of the main body, or may be arranged randomly.

  In the main body, the thickness of the flange may be the same as or smaller than the thickness of the web.

  The shape of the main body only needs to be hollow, and is not limited to one having a cross section as in the above-described embodiment. For example, the main body may be a square tube having a square or rectangular cross section, a circular tube having a circular cross section, or the like.

  The material of the main body is not limited to the aluminum alloy, and may be any metal material other than the aluminum alloy (for example, steel). The material of the rivet is not limited to steel and is arbitrary.

  The position of the crushing part in the main body is not limited to both ends in the longitudinal direction. For example, the crushing portion may be provided only at one end in the longitudinal direction of the main body at the center in the longitudinal direction of the main body.

  The insulating layer may be formed on at least a portion of the rivet that is in contact with the main body. For example, in the above-described embodiment, an insulating layer is formed on one of the two rivets provided in each crushing portion (two rivets in total), but two rivets are focused on only one crushing portion. An insulating layer may be formed on one of them (only one rivet). Alternatively, an insulating layer may be formed on all rivets. Further, in one rivet, an insulating layer may be formed on a portion other than the portion in contact with the main body (for example, the upper surface of the head 3a).

  The formation of the insulating layer is not limited to the Geomet (registered trademark) treatment or the Disco (registered trademark) treatment, and any other method (for example, a method of performing chromate treatment after galvanization) may be employed.

  The crushing portion forming step and the caulking step may be performed separately instead of simultaneously.

DESCRIPTION OF SYMBOLS 1 Hollow member for reinforcement 2 Main body 2a Flange 2b Web (wall)
2x Crushing part (part fixed to the target member)
3 Rivet 3a Head 3b Shaft 3x Insulating layer 10 Target member

Claims (11)

In the reinforcing hollow member fixed to the target member to reinforce the target member,
A hollow main body made of metal, the main body provided with a crushing portion formed by crushing a pair of opposing walls constituting the main body in a portion fixed to the target member,
It has a head part and a shaft part extending from the head part, the shaft part penetrates the crushing part, and the peripheral part of the shaft part in the crushing part is plastically flowed and is caulked and fastened to the crushing part. A plurality of rivets in which the shaft tip is spot-welded to the target member by a welding current flowing from the head to the shaft tip ,
Equipped with a,
A reinforcing hollow member, wherein an insulating layer is formed on at least a portion of the rivet that contacts the main body . The main body includes a pair of flanges facing each other and a pair of webs facing each other and connecting the pair of flanges, respectively, and a rectangular cross section formed by the pair of flanges and the pair of webs Have
The reinforcing hollow member according to claim 1, wherein the crushing portion is formed by crushing the pair of webs.   The hollow member for reinforcement according to claim 2, wherein a thickness of the flange is larger than a thickness of the web.   The reinforcing hollow member according to any one of claims 1 to 3, wherein the plurality of rivets are caulked and fastened to the crushing portion while being separated from each other. The reinforcing hollow member according to any one of claims 1 to 4 , wherein the main body is made of an aluminum alloy, and the rivet is made of steel. A method of manufacturing a reinforcing hollow member that has a hollow main body made of metal and is fixed to the target member in order to reinforce the target member,
A crushing part forming step of forming a crushing part by crushing a pair of walls that constitute the main body on a portion fixed to the target member of the main body,
Have a shank extending from the head and the head, the shaft portion of the plurality of rivets insulating layer is formed on the portion in contact with the body is passed through the pinch, the in the pinch A caulking step in which the rivet is caulked and fastened to the crushing portion by plastic flow of a peripheral portion of the shaft portion ;
A welding step of spot welding the shaft tip to the target member by passing a welding current from the head of the rivet to the tip of the shaft;
A method for producing a reinforcing hollow member. The manufacturing method according to claim 6 , wherein the crushing portion forming step and the caulking step are simultaneously performed by press working. The main body includes a pair of flanges facing each other and a pair of webs facing each other and connecting the pair of flanges, respectively, and a rectangular cross section formed by the pair of flanges and the pair of webs Have
The manufacturing method according to claim 6 or 7 , wherein in the crushing part forming step, the crushing part is formed by crushing the pair of webs. The manufacturing method according to claim 8 , wherein a thickness of the flange is larger than a thickness of the web. The manufacturing method according to any one of claims 6 to 9 , wherein in the caulking step, the plurality of rivets are caulked and fastened to the crushing portion while being separated from each other. The manufacturing method according to any one of claims 6 to 10 , wherein the main body is made of an aluminum alloy, and the rivet is made of steel.

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