JP2006182087A - Method for temporary joining spacer constituting chassis frame and body mounting part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply and accurately make a body mounting part using a spacer by temporarily joining a pipe-like spacer at a round pipe end instead of spot-welding in a chassis frame with a round pipe structure. <P>SOLUTION: In this chassis frame 2, an upper nipping face 11 and a lower nipping face 12 opposed to each other at the length of a pipe-like spacer 13 shorter than inside diameter of a round pipe end 23 are formed at a round pipe end 23, and an upper insertion hole 111 and a lower insertion hole 121 are opened at a position relationship opposed to the upper nipping face 11 and the lower nipping face 12. A spacer 13 is interposed between the upper nipping face 11 and the lower nipping face 12 at a position relationship communicating with the upper insertion hole 111 and the lower insertion hole 121, and two or more caulking portions 112 meshed with an inner periphery or an outer periphery on an end face of the spacer 13 are formed on the upper nipping face 11 at a position relationship surrounding the upper insertion hole 111, so as to constitute the body mounting part 1 with the spacer 13 temporarily joined to the round pipe end 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a chassis frame having a round pipe structure in which a body attachment portion is constituted by a pipe-like spacer attached to an end portion of a round pipe, and a temporary fixing method of a spacer constituting the body attachment portion.

  The chassis frame is connected to the body and is used as a skeleton member of an automobile. For this reason, a body attachment part is comprised in the chassis frame. The body mounting portion only needs to be able to firmly fix the chassis frame to the body, and the structure is free. For example, Patent Document 1 presents a body attachment portion including a clamping surface formed by crushing the end portion of a round pipe that is a component of a round pipe structure chassis frame. The body mounting portion made of this clamping surface has the advantage that there is no problem of crushing the end of the round pipe by tightening bolts when connecting the body, and the connection relationship between the chassis frame and the body can be specified by the orientation of the clamping surface. .

  In addition, as disclosed in Patent Document 1, in a round pipe structure chassis frame, through holes are respectively provided on opposite surfaces of the round pipe end portions of the constituent elements, and pipe-like spacers are passed through the through holes and welded and fixed. Some body mounting portions were constructed (see Patent Document 1 and FIG. 6). As pointed out in Patent Document 1, the body mounting portion constituted by this spacer has a problem that it is difficult to make a hole in the exact position and direction in the round pipe, but the pipe-like spacer constitutes the bolt insertion hole. Therefore, since the bolt tightening only works for the compression of the spacer, there is an advantage that a strong connection between the chassis frame and the body can be realized.

Japanese Patent Laid-Open No. 10-324269

  The body mounting portion composed of the clamping surface proposed in Patent Document 1 has the advantage that the connection relationship between the chassis frame and the body can be specified by the orientation of the clamping surface without the problem of crushing the end of the round pipe. In addition, high dimensional accuracy is required. In addition, the body mounting portion obtained by crushing the end portion of the round pipe, which was strong against twisting as it is, has no possibility of crushing, and there is a possibility that the body mounting portion is bent due to twisting from the outside. In the case of a chassis frame having a round pipe structure, it is desirable that the body mounting portion can be configured as a round pipe if possible.

  When the body attachment portion is configured with a round pipe structure chassis frame using the round pipe as it is, it is necessary to attach a pipe-like spacer to prevent the end of the round pipe from being crushed. If the chassis frame can be fixed to the body, the spacer is no longer likely to fall off by tightening the bolt. For this reason, it is only necessary to be able to temporarily fix the spacer so that the spacer does not fall from a predetermined position until the chassis frame is fixed to the body. However, the conventional round pipe structure chassis frame that uses spacers for the body mounting part temporarily fixes the spacers by spot welding, which takes time for processing and the effects of heat (deterioration and deformation of members). And the like, and there is a possibility that the connection relationship between the chassis frame and the body is deviated as compared with the body mounting portion by the clamping surface.

  Therefore, in a round pipe structure chassis frame, instead of spot welding, a pipe-like spacer was temporarily fixed to the end of the round pipe, and studies were made to easily and accurately make a body mounting portion using the spacer.

  As a result of the study, we developed a chassis frame with a round pipe structure in which the body attachment part is configured by a pipe-like spacer attached to the end of the round pipe, and the length of the pipe-like spacer is shorter than the inner diameter of the round pipe end. A pair of opposing clamping surfaces are formed at the end of the round pipe, a pair of insertion holes are opened in a positional relationship facing each clamping surface, and a spacer is interposed between the clamping surfaces in a positional relationship communicating with the insertion hole. Then, by forming a caulking portion on the clamping surface that meshes with the inner peripheral edge or the outer peripheral edge of the end face of the spacer in a positional relationship surrounding the insertion hole, a chassis that constitutes a body attachment portion that temporarily fixes the spacer to the end of the round pipe. It is a frame. The caulking site may be a part caulking that partially meshes with the inner peripheral edge or the outer peripheral edge of the end face of the spacer, or an entire caulking that meshes with the entire circumference of the inner peripheral edge or the outer peripheral edge of the spacer end face.

  In the body attachment portion of the present invention, a spacer is interposed at the end of the round pipe, and the inner periphery or the outer periphery of the end surface of the spacer is caulked from the outer surface of the end of the round pipe, thereby temporarily attaching the spacer to the end of the round pipe. Stop and configure. Unlike conventional spot welding, the caulking realizes mechanical temporary fixing, so that the problem of the effect of heat at the end of the round pipe does not occur, and the body attachment portion can be made with high accuracy. As described above, if the chassis frame is fixed to the body, the spacer is tightened with bolts, and there is no possibility of displacement or dropout. Therefore, it is sufficient that the spacer can be temporarily fixed until the chassis frame is fixed to the body. Caulking that can prevent misalignment is sufficient.

  Here, when the caulking part is partial caulking, and there are two caulking parts, the position of the spacer is fixed by sandwiching the end face of the spacer with each caulking part facing the inner edge and the outer edge of the end face of the spacer. it can. However, when the end face of the spacer is sandwiched between the two caulking parts, there is a possibility that the spacer is displaced by swinging with the pair of caulking parts as an integral fixing part. Therefore, there are three or more caulking sites, and when both mesh only with the inner or outer peripheral edge of the spacer, the caulking sites are arranged at substantially equal intervals in the circumferential direction along the inner or outer peripheral edge. Good. In addition, when three or more caulking sites are separated into the inner peripheral edge or the outer peripheral edge of the end face of the spacer and mesh with each other, the caulking sites that are separated into the inner peripheral edge and the outer peripheral edge even if the caulking parts are close to each other are spacers. By sandwiching the end surfaces of the spacers alternately, it is possible to stabilize the prevention of the positional deviation of the spacers.

  The temporary fixing of the spacer by caulking according to the present invention is performed by sandwiching a pair of clamping surfaces formed at the end of the round pipe so as to reach the end surface of the pipe-shaped spacer, and the spacer is displaced with respect to the clamping surface where the caulking site is formed. It is realized by preventing. For this reason, it is necessary that there is a clamping surface addressed to at least the end face of the pipe. From this, it is good to use the pipe which has an internal diameter more than the magnitude | size of this insertion hole irrespective of the opening shape of an insertion hole. Here, “greater than the size of the insertion hole” means that the insertion hole has a maximum diagonal length when the insertion hole has a square cross section, and that the diameter is equal to or more than the diameter when the insertion hole has a circular cross section. A preferable spacer is a round pipe. In this case, the caulking part may be formed on the clamping surface at three or more caulking parts that mesh with the inner or outer peripheral edge of the end face of the spacer at substantially equal intervals in the circumferential direction.

  If the caulking part is formed on one of the clamping surfaces, it is possible to sufficiently prevent the spacer from being displaced.However, by providing the caulking part on each clamping surface where the spacer is sandwiched, the spacer can be more securely removed. Can be prevented. Further, since the caulking part is formed by denting or cutting the clamping surface, the influence of the strength reduction due to the formation of the caulking part is suppressed, and further, the part of the clamping surface that is clamped by reaching the end face of the spacer is formed. From the viewpoint of increasing the size, a caulking portion that engages with the outer peripheral edge of the end surface of the spacer is preferable to the inner peripheral edge of the end surface of the spacer that is close to the insertion hole.

  As long as the spacer is a pipe, it may be a round pipe, a square pipe, or other pipes having a polygonal cross section. For example, in the case of a spacer made of a square pipe, it is preferable to provide a caulking site for each surface. Further, the end face of the spacer may be a curved face as long as the holding face of the round pipe end portion can be formed in conformity with the end face while being basically a flat face. The opening shape of the insertion hole for the spacer may be any of a circular opening, a square opening, or a polygonal opening. For example, it is conceivable to use a pipe-shaped spacer that inscribes the insertion hole for the insertion hole that is a square opening. However, from the viewpoint of ease of processing and prevention of stress uneven distribution, the spacer is a round pipe having an inner diameter equal to or larger than the diameter of the insertion hole which is a circular opening, and the insertion hole and the spacer are concentrically positioned between the clamping surfaces. A configuration in which a spacer is interposed is preferable. In other words, the spacer of the round pipe is configured to be interposed between the clamping surfaces in which the circular opening insertion holes are opened. When three caulking sites are provided for the above-described configuration, it is preferable to provide one caulking site on the side opposite to the opening end of the round pipe end and two caulking sites remaining at 120 ° intervals from the caulking site.

  In order to manufacture the body attachment portion of the present invention, the spacer may be temporarily fixed according to the following procedure. That is, when the pipe-shaped spacer is temporarily fixed to the end of the round pipe in order to form the body mounting portion in the chassis frame of the round pipe structure, the length of the pipe-shaped spacer is shorter than the inner diameter of the end of the round pipe. A pair of sandwiching surfaces is formed, and a spacer is interposed between the sandwiching surfaces in a positional relationship communicating with the insertion hole with respect to the end of the round pipe having a pair of insertion holes opened in a positional relationship facing each clamping surface. Spacer insertion procedure, a caulking die with a length penetrating both insertion holes and protruding from the flat surface of the die body, and a clamping surface with one insertion hole opened on the die body. A spacer positioning procedure for bringing the flat surface into contact and inserting the protrusion from one insertion hole into the spacer and projecting from the other insertion hole, and a fitting hole to be externally fitted to the protrusion of the caulking die, A caulking punch is provided on the flat surface of the punch body to surround the mating hole. The caulking punch is inserted into the protrusion of the caulking die protruding from the other insertion hole. The spacer is rounded by a spacer temporary fixing procedure in which two or more caulking sites are formed in contact with the holding surface where the other insertion hole is opened and the inner edge or outer edge of the spacer is engaged by caulking protrusions. Temporarily fasten to the end of the pipe.

  The above procedure uses a pair of caulking dies and caulking punches to form a caulking site while positioning the spacer with respect to the insertion hole, and temporarily fixes the spacer to the end of the round pipe. The caulking die is a lower mold for forming the caulking site, and is a jig for positioning the spacer with respect to the insertion hole. The caulking punch is an upper die for forming the caulking site, and the caulking site is positioned with respect to the insertion hole via the caulking die by fitting the fitting hole to the projection portion of the caulking die. It is a jig.

  A specific spacer insertion procedure is to insert one insertion hole having an opening shape equal to the inner peripheral shape of the spacer cross section and the other insertion hole having an opening shape smaller than the inner peripheral shape of the spacer cross section. It is preferable that the center axes of the holes coincide with each other so that each hole is formed on each clamping surface formed at the end of the round pipe. One insertion hole having an opening shape equal to the inner peripheral shape of the cross-section of the spacer allows the projection of the caulking die inscribed in the spacer to be inserted into the spacer. On the other hand, the other insertion hole having an opening shape smaller than the inner peripheral shape of the cross section of the spacer forms an insertion hole through which the bolt is inserted while leaving a clamping surface pressed against the end surface of the spacer by forming a caulking portion. By aligning the central axes of the two insertion holes, the spacers can be positioned with respect to the two insertion holes via the protrusions of the caulking punch that are inserted into the two insertion holes.

  Next, the spacer positioning procedure includes a spacer inscribed portion having a cross-sectional shape equal to the inner peripheral shape of the cross-section of the spacer and an insertion hole projecting portion having a smaller cross-sectional shape than the inner peripheral shape of the spacer cross-section. An insertion hole protrusion is provided on the spacer inscribed portion to form a protrusion, and a caulking die that protrudes from the flat surface of the die body is used, and the protrusion of the caulking die is inserted into one insertion hole. Then, the spacer is inscribed in the spacer, and the spacer inscribed portion is inscribed in the spacer, and the insertion hole protruding portion is protruded from the other insertion hole in an internally fitted state so that the center axes of the both insertion holes and the spacer coincide with each other. The spacer inscribed portion is positioned according to one insertion hole, and further inserted into the spacer to be inscribed, thereby correcting the position of the spacer with respect to the one insertion hole. And the insertion hole protrusion part is positioned according to the other insertion hole, and ensures the positioning accuracy of the spacer inscribed part where the central axes coincide. Here, the insertion hole protruding portion can be made to protrude into the small other insertion hole described above in an internally fitted state by setting it to a cross-sectional shape smaller than the inner peripheral shape of the cross section of the spacer.

  And the spacer temporary fixing procedure uses a caulking punch in which two or more caulking sites are provided in the plane portion of the punch body in a positional relationship surrounding the fitting hole and at equal intervals in the circumferential direction surrounding the fitting hole, The planar portion of the die body is brought into contact with the holding surface where the other insertion hole is opened in a positional relationship in which the fitting hole is fitted to the projection portion of the caulking die protruding from the other insertion hole, and the end surface of the spacer is Two or more caulking portions that mesh with the inner peripheral edge or the outer peripheral edge are formed at equal intervals in the circumferential direction of the other insertion hole. The caulking punch is positioned by a caulking die, and the caulking die positions the spacer with respect to the insertion hole while being positioned with respect to the insertion hole, so that the caulking site formed by the caulking protrusion of the caulking punch is an insertion hole, And it can position with respect to a spacer, and can form two or more crimping site | parts which mesh | engage with the inner periphery or outer periphery of the end surface of a spacer correctly in a desired position.

  According to the present invention, it is possible to provide a body attachment portion in which a pipe-like spacer is temporarily fixed to a round pipe end portion by caulking in a round pipe structure chassis frame. This is the effect that the temporary fixing of the spacer by caulking is not affected by heat (deterioration or deformation of the member) unlike spot welding, and can be easily and accurately made by press molding. Further, when the spacer is caulked and fixed at the end of the round pipe, the end of the round pipe is obtained by using a caulking die having a projection inscribed in the spacer and a caulking punch fitted to the projection of the caulking die. It is also an effect that a body attaching portion in which a pipe-like spacer is temporarily fixed to the portion by caulking can be easily and accurately made.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a plan view of a round pipe structure chassis frame 2 having a body mounting portion 1 to which the present invention is applied, FIG. 2 is a partially enlarged perspective view showing the body mounting portion 1, and FIG. 3 shows another body mounting portion 1. FIG. 4 is a partially enlarged perspective view showing another example of the body mounting portion 1. FIGS. 5 to 7 are cross-sectional views showing the manufacturing process of the body mounting portion 1. FIG. FIG. 6 shows a spacer positioning procedure, and FIG. 7 shows a spacer temporary fixing procedure.

  As shown in FIG. 1, for example, the body mounting portion 1 of the present invention is an end portion of each of the members 21 and 22 of the chassis frame 2 in which side members 21 and cross members 22 made of round pipes are assembled in a cross-beam shape. A round pipe end 23 is formed. As shown in FIG. 2, the body mounting portion 1 includes a spacer 13 interposed between an upper clamping surface 11 and a lower clamping surface 12 formed in a round pipe end 23, and an upper insertion hole in the upper clamping surface 11. It is configured to be temporarily fixed by three caulking portions 112 which are partial caulking formed in a positional relationship surrounding 111.

  The upper clamping surface 11 and the lower clamping surface 12 of the round pipe end 23 are opposed to each other with a length L of a spacer 13 (see FIG. 5) made of a round pipe shorter than the inner diameter d of the round pipe end 23, They are formed in parallel. Each clamping surface 11, 12 opens an upper insertion hole 111 and a lower insertion hole 121 with a circular opening in an opposing positional relationship, and the upper clamping surface 11 in a positional relationship communicating with the upper insertion hole 111 and the lower insertion hole 121. In addition, a spacer 13 is interposed between the lower clamping surface 12. The surface shape of the upper clamping surface 11 or the lower clamping surface 12 and the normal direction of the upper insertion hole 111 or the lower insertion hole 121 determine the connection relationship (particularly the connection direction) between the body (not shown) and the chassis frame 2. Since the spacer 13 needs to be tightly sandwiched, it is desirable to form it accurately by press molding or the like.

  In this example, three caulking sites 112 that are partial caulking meshing with the outer peripheral edge of the end face of the spacer 13 are formed at equal intervals (120 degree intervals) in the circumferential direction in a positional relationship surrounding the upper insertion hole 111. From the viewpoint of preventing the displacement of the spacer 13, it is sufficient that the caulking portions 112 are formed at equal intervals. However, when the caulking portion 112 approaches the end surface 24 of the round pipe, the strength of the end portion 23 of the round pipe decreases. Therefore, as shown in this example, one caulking portion 112 is formed at a position farthest from the end face 24 of the round pipe, that is, at a point symmetrical position with respect to the end face 24 of the round pipe with the upper insertion hole 111 interposed therebetween. It is preferable to form two caulking portions 112 and 112 that remain at an interval of 120 degrees with respect to the portion 112.

  The caulking part may mesh with either the inner or outer peripheral edge of the spacer as long as the spacer can be fixed in position, and may be caulked not only on the partial caulking but also on the entire circumference. For example, as shown in FIG. 3, four caulking sites 113 meshing with the inner peripheral edge of the end surface of the spacer 13 are equally spaced in the circumferential direction (90 degree intervals) while being in a positional relationship surrounding the upper insertion hole 111 as in this example. May be formed. Also in this case, in order to suppress the strength reduction of the round pipe end 23, the caulking part 113 is formed at a position inclined 45 degrees from the point symmetry position with respect to the end face 24 of the round pipe across the upper insertion hole 111. The other caulking sites 113, 113, 113 are formed at intervals of 90 degrees from the center. The number of caulking sites by partial caulking may be larger, or caulking sites that engage with the inner and outer peripheral edges of the end face of the spacer may be formed. In addition, as shown in FIG. 4, a caulking portion 114 formed by caulking around the entire inner periphery of the end surface of the spacer 13 may be formed.

  The body mounting portion 1 of this example is manufactured according to the following procedure. First, in the spacer insertion procedure, as shown in FIG. 5, the flat and parallel upper and lower clamping surfaces 11 and 11 are opposed to each other with the length L of the round pipe-shaped spacer 13 shorter than the inner diameter d of the round pipe end 23. 12 is formed, and the upper insertion hole 111 and the lower insertion hole 121 are formed with respect to the round pipe end portion 23 in which the upper insertion hole 111 and the lower insertion hole 121 of the circular opening are opened in a positional relationship facing the holding surfaces 11 and 12, respectively. The spacer 13 is inserted between the upper clamping surface 11 and the lower clamping surface 12 so as to communicate with each other.

  In this example, the upper clamping surface 11 and the lower clamping surface 12 are formed in parallel with each other as a flat surface in accordance with the end surface of the flat spacer 13. Further, the upper insertion hole 111 is a circular opening equal to the inner peripheral shape of the cross section of the spacer 13, and the lower insertion hole 121 is a circular opening smaller than the inner peripheral shape of the cross section of the spacer 13, and the central axes C of both are made coincident. For forming the upper clamping surface 11 and the lower clamping surface 12 and opening the upper insertion hole 111 and the lower insertion hole 121, various conventionally known means can be used.

  For example, insert a core equal to the cross-sectional shape after formation from the end face of the round pipe, sandwich the round pipe end 23 between the upper mold and the lower mold forming the upper clamping surface 11 and the lower clamping surface 12, respectively, The insertion holes 111 and 123 can be formed by fitting the protrusions provided on the upper mold and the lower mold to the pair of upper and lower recesses provided. In this spacer insertion procedure, it is only necessary to insert the spacer 13 from the end face of the round pipe, and the upper insertion hole 111 and the lower insertion hole 121 do not need to be completely coincident with the central axis C. The positional relationship of the spacer 13 with respect to the upper insertion hole 111 and the lower insertion hole 121 is corrected by the following spacer positioning procedure.

  In the subsequent spacer positioning procedure, as shown in FIG. 6, a caulking die 3 having a length penetrating both insertion holes 111 and 121 and projecting the protruding portion 31 inscribed in the spacer 13 from the flat portion 321 of the die body 32 is formed. Then, the flat portion 321 of the die body 32 is brought into contact with the lower holding surface 12 having the lower insertion hole 121 opened, and the protrusion 31 is inserted into the spacer 13 from the lower insertion hole 121 and protruded from the upper insertion hole 111. The spacer 13 which has been displaced with respect to both the insertion holes 111 and 121 becomes a boundary between the spacer inscribed portion 311 and the insertion hole protruding portion 312 constituting the protruding portion 31 in the process of inserting the protruding portion 31 of the caulking die 3. The position is corrected by being pushed by the frustum side surface portion 313, and the spacer inscribed portion 311 is inscribed in the spacer 13, thereby being positioned with respect to the lower insertion hole 121 through the caulking die 3. In this example, since the upper insertion hole 111 and the lower insertion hole 121 are aligned with the central axis C, the positional relationship of the spacer 13 is also corrected with respect to the upper insertion hole 111.

  As shown in FIGS. 5 and 6, the caulking die 3 has a circular cross section equal to the inner peripheral shape of the cross section of the spacer 13 and is inserted into the spacer 13 from the lower insertion hole 121 and inscribed into the spacer inscribed portion 311. And a protrusion 31 formed of an insertion hole protruding portion 312 that protrudes from the upper insertion hole 111 and fits into the inner surface of the spacer 13 and protrudes from the flat portion 321 of the die body 32. Yes. In the caulking die 3 of this example, the upper edge of the insertion hole protrusion 312 that becomes the tip of the protrusion 31 is chamfered so that the protrusion 31 can be easily inserted from the lower insertion hole 121, and the position of the spacer 13 can be easily corrected. Therefore, a frustum side surface portion 313 serving as a boundary between the spacer inscribed portion 311 and the insertion hole protruding portion 312 is formed.

  Finally, in the spacer temporary fixing procedure, as shown in FIG. 7, the fitting hole 411 is externally fitted to the insertion hole protruding portion 312 of the caulking die 3, and the flat portion 412 of the punch body 41 of the caulking punch 4 is sandwiched upward. By contacting the surface 11, the three caulking portions 112 that are partial caulking meshed with the outer peripheral edge of the end surface of the spacer 13 by the three caulking projections 413 provided in a positional relationship surrounding the fitting hole 411 are raised. Form on the clamping surface 11 to complete the temporary fixing of the spacer 13. The caulking projection 413 is positioned with respect to the fitting hole 411, the fitting hole 411 is positioned by the insertion hole protruding portion 312 of the caulking die 3, the caulking die 3 is positioned by both the insertion holes 111 and 121, and the spacer 13 is positioned by the caulking die 3. The caulking portion 112 formed by the caulking projection 413 is positioned with respect to the upper insertion hole 111 and the spacer 13, and is positioned on the outer peripheral edge of the end surface of the spacer 13. It can be formed accurately with the meshing positional relationship.

  Further, the caulking die 3 and the caulking punch 4 of the present example press the upper clamping surface 11 and the lower clamping surface 12 with the spacer 13 interposed therebetween in the spacer temporary fixing procedure by the flat portions 321 and 412, respectively, to the end surface of the spacer 13. The upper clamping surface 11 and the lower clamping surface 12 are pressed together. The body mounting portion 1 of the present invention prevents the spacer 13 from being displaced by the caulking portion 112 and then clamps the spacer 13 between the upper clamping surface 11 and the lower clamping surface 12 so that there is no possibility of dropping off. The temporary fixing of the spacer 13 is realized. Here, the pressing of the upper clamping surface 11 and the lower clamping surface 12 by the flat portions 321 and 412 of the caulking die 3 and the caulking punch 4 bears the holding of the spacer 13 by the upper clamping surface 11 and the lower clamping surface 12. For this reason, in this example, as shown in FIG. 7, the fitting hole 411 of the caulking punch 4 is made deeper than the length in which the insertion hole protruding portion 312 of the caulking die 3 protrudes from the upper insertion hole 111. The upper clamping surface 11 and the lower clamping surface 12 can be pressed by the flat portions 321 and 412 of the die 3 and the caulking punch 4, respectively.

It is a top view of the chassis frame of the round pipe structure which has a body attaching part to which this invention is applied. It is a partial expansion perspective view showing a body attaching part. It is a partial expansion perspective view showing the body attachment part of another example. It is a partial expansion perspective view showing the body attachment part of another example. It is sectional drawing showing the spacer insertion procedure of the manufacturing process of a body attaching part. It is sectional drawing showing the spacer positioning procedure of the manufacturing process of a body attaching part. It is sectional drawing showing the spacer temporary fix | stop procedure of the manufacturing process of a body attaching part.

Explanation of symbols

1 Body mounting part
11 Upper clamping surface
111 Top insertion hole
112 Caulking site
12 Lower clamping surface
121 Bottom insertion hole
13 Spacer 2 Chassis frame
23 Round pipe end
24 End face of round pipe 3 Caulking dies
31 Protrusion
311 Spacer inscribed part
312 Insertion hole protrusion
313 frustum side
32 Dice body
321 Flat part 4 Caulking punch
41 Punch body
411 Mating hole
412 Plane section
413 Caulking projection

Claims (7)

In a round pipe structure chassis frame in which the body attachment part is configured by a pipe-like spacer attached to the end of the round pipe, the opposite clamping surface with the length of the pipe-like spacer shorter than the inner diameter of the end of the round pipe A position in which a pair of insertion holes are formed in a portion, a pair of insertion holes are opened in a positional relationship facing each clamping surface, a spacer is interposed between the clamping surfaces in a positional relationship communicating with the insertion hole, and the insertion holes are surrounded In this regard, a chassis frame is characterized in that a body attachment portion is provided in which the spacer is temporarily fixed to the end portion of the round pipe by forming a caulking portion that meshes with the inner peripheral edge or the outer peripheral edge of the end surface of the spacer. The spacer is a round pipe having an inner diameter that is equal to or larger than the size of the insertion hole, and two or more caulking sites that mesh with an inner peripheral edge or an outer peripheral edge of the end face of the spacer are formed on one or both of the clamping surfaces. Chassis frame. The spacer is a round pipe having an inner diameter equal to or larger than the diameter of the insertion hole which is a circular opening, and the spacer is interposed between the clamping surfaces in a positional relationship where the insertion hole and the spacer are concentric. The chassis frame described. When temporarily fixing the pipe-shaped spacer to the end of the round pipe to form the body mounting part in the chassis frame of the round pipe structure,
A pair of holding surfaces facing each other with a length of a pipe-like spacer shorter than the inner diameter of the end of the round pipe is formed, and the insertion of the insertion into the end of the round pipe having a pair of insertion holes opened in a positional relationship facing each holding surface. A spacer insertion procedure for interposing a spacer between the clamping surfaces in a positional relationship communicating with the hole;
A caulking die with a length penetrating both insertion holes and projecting from the flat surface of the die body with a protrusion inscribed in the spacer, and the flat surface portion of the die body is in contact with the clamping surface where one insertion hole is opened. And a spacer positioning procedure for inserting the protruding portion into the spacer from one insertion hole and projecting from the other insertion hole,
A caulking die protrusion that protrudes from the other insertion hole with a caulking punch provided on the flat portion of the punch body with a fitting hole that fits outside the caulking die protrusion and a caulking protrusion that surrounds the fitting hole. 2 or more in which the flat part of the die body is brought into contact with the holding surface where the other insertion hole is opened, and the inner peripheral edge or outer peripheral edge of the spacer end face is engaged by the caulking projection in a positional relationship in which the fitting hole is externally fitted to the part. With the spacer temporary fixing procedure for forming the caulking site,
A spacer temporary fixing method comprising temporarily fixing a spacer to a round pipe end. In the spacer insertion procedure, one insertion hole having an opening shape equal to the inner peripheral shape of the cross section of the spacer and the other insertion hole having an opening shape smaller than the inner peripheral shape of the spacer cross section are arranged at the center of both insertion holes. The spacer temporary fixing method according to claim 4, wherein the axial lines are matched to open each clamping surface formed at the end of the round pipe. The spacer positioning procedure consists of aligning the spacer inscribed portion with a cross-sectional shape equal to the inner peripheral shape of the spacer's cross-section and the insertion hole protruding portion having a smaller cross-sectional shape than the inner peripheral shape of the spacer's cross-section with their center axes aligned A protrusion is formed by providing an insertion hole protrusion on the spacer inscribed portion, and a caulking die that protrudes from the flat portion of the die body is used.
Insert the protrusion of the caulking die into the spacer from one insertion hole, incline the spacer inscribed portion into the spacer, and project the insertion hole protrusion from the other insertion hole in an internally fitted state. 6. The spacer temporary fixing method according to claim 4, wherein the central axis of the spacer coincides with the central axis. The spacer temporary fixing procedure uses a caulking punch in which two or more caulking sites are provided in a plane portion of the punch body in a positional relationship surrounding the fitting hole and at equal intervals in the circumferential direction surrounding the fitting hole,
The planar portion of the die body is brought into contact with the clamping surface where the other insertion hole is opened in a positional relationship of fitting the fitting hole to the projection portion of the caulking die protruding from the other insertion hole, and the end surface of the spacer is The spacer temporary fixing method according to claim 4, wherein two or more caulking portions meshing with the inner peripheral edge or the outer peripheral edge are formed at equal intervals in the circumferential direction of the other insertion hole.

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