JP2005066668A - Pipe-bracket joining structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To fit a bracket with high precision and ease by welding to a bent portion formed in a long pipe by plastic working. <P>SOLUTION: The invention relates to a pipe-bracket joining structure (upper frame)46 in which a first bent portion 63 is formed in a frame 61 made of a pipe by means of a bender and the bracket 54 for a stopper is joined to the first bent portion 63 or the vicinity of the first bent portion 63 by welding. The position of the cross section of the first bent portion 63 is determined so that the center of curvature C1 used in bending the frame 61 made of a pipe in consideration of the assumed cross section of the first bent portion 63 comes to a bottom. At the time of determining the position of the cross section of the first bent portion 63, weld beads 77 for fixing the bracket 54 for the stopper are placed at or near the center 87 of the crosswise outer circumferential portion at which the horizontal line passing through the center of the cross section intersects the outer circumferential face 86 of the frame made of a pipe. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pipe-bracket joint structure in which a bracket is attached to a bent portion obtained by forming a long pipe by plastic working.

  The pipe-bracket joint structure is obtained by welding a metal plate to a metal pipe, and is used in, for example, industrial machines and vehicles. Specifically, a steel pipe is bent or squeezed into a desired shape by plastic working, and then a plate bracket is fixed to the bending part or the squeezing part by welding.

As a conventional pipe-bracket joint structure, one used for a vehicle frame is known (for example, see Patent Document 1).
JP 2002-263837 A

FIGS. 11A and 11B are reprints of FIGS. 1 and 2 of Patent Document 1. FIG.
The pipe welding structure of Patent Document 1 is such that the pipe 1 is fixed to the vertical surfaces 5 and 6 of the bracket 4 by welding 14 and 15. The pipe 1 is formed by forming a concave-curved squashed 3 and has an advantage of improving the strength by the concave-curved squashed 3.

However, in the pipe welded structure of Patent Document 1, since the concave-curved crushing 3 is welded, care must be taken not to cause welding deformation or poor welding. The concave-shaped crush 3 is a plastically processed part, and the plastically processed part retains compressive force and tensile force, and is easily deformed by heat during welding and rapid cooling after welding. It is difficult to improve accuracy.
In addition, the plastic-processed part is not constant in the thickness of the pipe, the temperature difference of the pipe (base material) tends to increase, and it is difficult to weld.

  An object of the present invention is to attach a bracket accurately and easily to a bent portion formed by plastic working on a long pipe.

  The invention according to claim 1 is a pipe-bracket joint structure in which a bent portion is formed on a pipe frame by a bender method, and a bracket is joined to the bent portion or the vicinity of the bent portion by a welding method. If the cross-sectional orientation is determined so that the center of curvature used when bending the pipe frame is below, the horizontal line passing through the center of the cross section intersects the outer peripheral surface of the pipe frame. The welding bead which fixes a bracket to the part or its vicinity is arrange | positioned.

  In the invention according to claim 1, when the posture of the cross section is determined so that the center of curvature used when the pipe frame is bent assuming the cross section of the bent portion, the horizontal line passing through the center of the cross section is Welding beads that fix the brackets to the left and right outer periphery central parts that intersect the outer peripheral surface of the pipe frame or in the vicinity thereof are arranged, so the heat at the time of welding does not act directly on the welding residual stress that is generated in the bending part. The bending radius of the part can be substantially maintained. Therefore, there is an advantage that the accuracy of the pipe-bracket joint structure can be improved.

When the pipe is bent, the portion near the center of curvature increases in thickness and the portion far away becomes thinner, but the thickness does not change in the central portion of the outer periphery of the bent portion.
Since the welding bead is arranged at or near the center of the outer periphery of the bent portion, the thickness of the pipe frame is substantially constant. For example, it is not necessary to change the welding conditions during welding, and welding is easy.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a perspective view of a vehicle using a pipe-bracket joint structure of the present invention. A vehicle 11 includes a body 12, and the body 12 includes a front body 13 that forms a front, and a rear of the front body 13. An underbody 15 corresponding to the floor of the passenger compartment 14, a side body 16 that forms a side portion of the passenger compartment 14 in tandem with the underbody 15, doors 17 and 17 that are attached to the side body 16 so as to be openable and closable, and a front body 13 And a hood 18 attached to be openable and closable. 21 is a wind glass, 22 is an instrument panel, 23 is a headlamp, 24 is a bumper, and 25 is a front wheel.

  The front body 13 includes a side frame 31, a wheel house 32 attached to the side frame 31, a damper housing 33, a bulkhead 34 attached to the front side of the side frame 31 and the wheel house 32, and the side frame 31 as a dash of the underbody 15. And a side outrigger 36 integrally attached to the side sill 35 of the board 42 and the side body 16. Reference numeral 37 denotes a front fender, and 38 denotes an engine room.

  The underbody 15 includes a floor pan 41, a dashboard 42 that is attached to the front of the floor pan 41 and forms the front wall of the passenger compartment 14, and a wind that extends on the dashboard 42 and extends in the vehicle width direction (direction of arrow a). And a shield lower 43.

  FIG. 2 is a perspective view of a bulkhead using the pipe-bracket joint structure of the present invention. The bulkhead 34 is attached to the side frames 31, 31 and the wheel houses 32, 32. The bulkhead 34 has an upper frame 46, a lower frame 47, and upper and lower frames 46, 47 having a pipe-bracket joint structure. And side fixing plates 51 and 51 attached therebetween.

  Here, X in the upper right of the figure is an axis in the forward / reverse direction of the vehicle, Y is an axis perpendicular to the X axis and in the vehicle width direction, and Z is a vertical axis orthogonal to X and Y.

  The upper frame 46 is obtained by attaching a locking bracket 53, stopper brackets 54 and 55, side frame brackets 56 and 57, and wheelhouse brackets 58 and 59 to the pipe beam 52. Next, the upper frame 46 will be specifically described.

FIG. 3 is a front view of the pipe-bracket joint structure of the present invention.
As described above, the upper frame 46 having the pipe-bracket joint structure includes the pipe beam 52, the locking bracket 53, the stopper brackets 54 and 55, the side frame brackets 56 and 57, and the wheel house brackets 58 and 59. Consists of.

  The pipe beam 52 is formed by forming a bent portion in a pipe forming the pipe frame 61 by, for example, the bender method. Specifically, the first straight pipe portion 62 is formed in a substantially straight pipe state at the center. The first bent portions 63 and 64 are formed by the bending radius r1 in a manner connected to the straight pipe portion 62, the second straight pipe portions 65 and 66 are formed in a manner connected to the first bent portions 63 and 64, and the second straight pipe portion 65 is formed. , 66, the second bent portions 67, 68 are formed by the bending radius r2, and the third straight pipe portions 71, 72 are formed, connected to the second bent portions 67, 68. D indicates the outer diameter of the pipe frame 61 used for the pipe beam 52, C1 and C1 indicate the center of curvature of the first bent portions 63 and 64, and C2 and C2 indicate the center of curvature of the second bent portions 67 and 68, respectively.

The locking bracket 53 is a member for attaching a hood locking device (not shown) for locking the hood 18 (see FIG. 1), and the main body 73 fitted into the first straight pipe portion 62 has a U-shaped cross section. Molded. The main body 73 has mounting holes 74 for attaching the hood lock device.
The wheelhouse bracket 58 is a member attached to the wheelhouse 32 (see FIG. 2).
The wheelhouse bracket 59 is the same as the wheelhouse bracket 58.

FIG. 4 is a detailed view of part 4 of FIG. 3 and is a front view of the stopper bracket 54.
The stopper bracket 54 is a member that receives and holds the hood 18 (see FIG. 1). The stopper bracket 54 is a member in which the main body 76 that can be attached to the first bending portion 63 is formed, and the main body 76 is fixed by welding. Although welding conditions are arbitrary, for example, automatic welding (including semi-automatic) such as MIG was used, and the welding length was 15 mm. 77 (... indicates a plurality. The same applies hereinafter) indicates a bead.
The stopper bracket 55 (see FIG. 3) is the same as the stopper bracket 54, and a description thereof will be omitted.

FIG. 5 is a detailed view of part 5 of FIG. 3 and is a front view of the side frame bracket 56.
The side frame bracket 56 is a member that is fixed to the side frame 31 (see FIG. 2), and is a member formed with a main body 78 that can be attached to the second bending portion 67, and the main body 78 is fixed by welding. Although welding conditions are arbitrary, for example, automatic welding (including semi-automatic) such as MIG was used, and the welding length was 10 mm. 81 ... indicates a bead.
The side frame bracket 57 (see FIG. 3) is the same as the side frame bracket 56, and a description thereof will be omitted.

6 is a cross-sectional view taken along line 6-6 of FIG. 4 and shows welding of the stopper bracket 54 and the first bending portion 63. FIG.
The first bent portion 63 generates a neutral plane M, and the vertical plane M has a width W and a length the length of the pipe beam 52. When the stopper bracket 54 is welded to the first bending portion 63, the outer surface portions 83 and 83 that intersect the neutral surface M of the first bending portion 63 or the vicinity that intersects the neutral surface M is welded.

In other words, in the cross section of the first bent portion 63, the posture of the cross section of the first bent portion 63 is determined so that the curvature center point C1 used when bending the pipe frame 61 is downward (in the direction of the arrow b). At times, the horizontal line 85 passing through the center of the cross section intersects with the outer peripheral surface 86 of the pipe frame 61 on the left and right (left and right in the figure) outer peripheral central portions 87 and 87 or weld beads 77 and 77 for fixing the stopper bracket 54 to the vicinity thereof. Place. The outer peripheral central portion 87 is a portion corresponding to the outer surface portion 83. Reference numerals 88 and 88 denote ranges in the vicinity of the outer peripheral central portions 87 and 87, 91 denotes a side that receives compression when the pipe frame 61 is bent, and 92 denotes a side that receives tension when the pipe frame 61 is bent.
The welding performed on the first bending portion 64 (see FIG. 3) is the same as the welding performed on the first bending portion 63.

7 is a cross-sectional view taken along the line 7-7 in FIG. 5 and shows welding of the side frame bracket 56 and the second bent portion 67. FIG.
When the side frame bracket 56 is welded to the second bent portion 67, the outer surface portion 94 that intersects the neutral surface M of the second bent portion 67 or the vicinity that intersects the neutral surface M is welded.
In other words, in the cross section of the second bent portion 67, the posture of the cross section of the second bent portion 67 is determined so that the center of curvature C2 used when bending the pipe frame 61 is downward (in the direction of arrow c). In some cases, a weld bead 81 for fixing the side frame bracket 56 to the left and right (right and left in the drawing) outer peripheral central portions 96 and 96 where the horizontal line 95 passing through the center of the cross section intersects the outer peripheral surface 86 of the pipe frame 61 is provided. Deploy. The outer peripheral central portion 96 is a portion corresponding to the outer surface portion 94. Reference numerals 97 and 97 denote ranges in the vicinity of the outer peripheral central portions 96 and 96, 101 denotes a side that receives compression when the pipe frame 61 is bent, and 102 denotes a side that receives tension when the pipe frame 61 is bent. Here, the description has been made that the curvature center point C2 is at the bottom, but the curvature center point C2 may be at the top.
The welding performed on the second bending portion 68 (see FIG. 3) is the same as the welding performed on the second bending portion 67.

FIG. 8 is a perspective view of a stopper bracket having a pipe-bracket joint structure according to the present invention.
The main body 76 of the stopper bracket 54 includes front and rear welded ends 103 and 104 that are in contact with the first bent portion 63, a reference hole 106 that opens in the front surface 105 and also serves as an attachment hole, and a hood 18 (see FIG. 1). And an attaching portion 107 for attaching a contact member.
Here, the reference coordinates of the reference hole 106 of the stopper bracket 54 are X1, Y1, and Z1.

FIG. 9 is a perspective view of the side frame bracket of the pipe-bracket joint structure of the present invention.
The main body 78 of the side frame bracket 56 includes a welded end portion 108 that contacts the second bent portion 68, a reference hole 111 that opens in the front surface 109 and also serves as an attachment hole, and an attachment portion that is attached to the side frame 31 (see FIG. 2). 112.
Here, the reference coordinates of the reference hole 111 of the side frame bracket 56 are X2, Y2, and Z2.

Next, a manufacturing procedure of the upper frame 46 having a pipe-bracket joint structure will be briefly described.
FIG. 10 is an explanatory diagram of the manufacturing procedure of the pipe-bracket joint structure of the present invention.
First, a steel pipe having an outer diameter D to be a pipe frame 61 is prepared. At that time, the thickness t of the steel pipe is selected as a reference. Next, the steel pipe is plastically processed. In the case of bending by plastic working, a pipe beam 52 is obtained by inserting a core into a cut tube, setting it in a bender device, and completing bent portions such as a first bent portion 63 and a second bent portion 67. Subsequently, the bracket is welded as follows. The pipe beam 52 is set in a positioning device (not shown), and brackets such as a stopper bracket 54 and a side frame bracket 56 are also set. Subsequently, the positioning device can be arranged at a position where it can be welded to the first bending portion 63 by sending the stopper bracket 54 to the reference coordinates X1, Y1, Z1 based on preset conditions. By sending the bracket 56 to the reference coordinates X2, Y2, Z2, it can be arranged at a position where it can be welded to the second bending portion 67. Finally, MIG welding is performed as shown in FIGS. 6 and 7 and removed from the positioning device.

Next, the operation of the pipe-bracket joint structure of the present invention will be described.
As shown in FIG. 6, stopper brackets 54 and 55 (see FIG. 3) are fixed to the left and right (right and left in the figure) outer peripheral center portions 87 and 87 where the horizontal line 85 intersects the outer peripheral surface 86 of the pipe frame 61. By arranging the weld beads 77, 77, deformation after welding is suppressed. Specifically, the outer surface portions 83 and 83 that intersect the neutral surface M of the first bending portions 63 and 64 (see FIG. 3), or the vicinity that intersects the neutral surface M and the stopper brackets 54 and 55 (see FIG. 3). Since welding is performed, the outer surface portions 83 and 83 in which almost no bending stress (compressive stress or tensile stress) is generated are less likely to be affected by heat during welding, and accuracy can be improved.

  Further, the outer surface portions 83 and 83 that intersect with the neutral surface M of the first bent portions 63 and 64 (see FIG. 3) or the vicinity that intersects with the neutral surface M and the stopper brackets 54 and 55 (see FIG. 3) are welded. Therefore, the thickness of the pipe beam 52 is substantially constant. For example, it is not necessary to change welding conditions during welding, and welding is easy.

  As shown in FIG. 7, the side frame brackets 56 and 57 (see FIG. 3) are fixed to the left and right (left and right in the figure) outer periphery central portions 96 and 96 where the horizontal line 95 intersects the outer peripheral surface 86 of the pipe frame 61. By disposing the welding bead 81 to be deformed, deformation after welding is suppressed. Specifically, the outer surface portion 94 that intersects the neutral surface M of the second bent portions 67 and 68 (see FIG. 3) or the vicinity that intersects the neutral surface M and the side frame brackets 56 and 57 (see FIG. 3) are welded. Therefore, the outer surface portion 94 where almost no bending stress (compressive stress or tensile stress) is generated is less likely to behave due to heat during welding, and accuracy can be improved.

  Further, the outer surface portion 94 that intersects the neutral surface M of the second bent portions 67 and 68 (see FIG. 3) or the vicinity that intersects the neutral surface M and the side frame brackets 56 and 57 (see FIG. 3) are welded. Therefore, the thickness of the pipe beam 52 is substantially constant. For example, it is not necessary to change the welding conditions during welding, and welding is easy.

  Although the pipe-bracket joint structure of the present invention is applied to a four-wheeled vehicle in the embodiment, it can also be applied to a three-wheeled vehicle and can be applied to a general vehicle.

  The pipe-bracket joint structure of the present invention is suitable for a four-wheeled vehicle.

The perspective view of the vehicle using the pipe-bracket junction structure of this invention The perspective view of the bulkhead using the pipe-bracket junction structure of the present invention Front view of the pipe-bracket joint structure of the present invention Detailed view of part 4 of FIG. Detailed view of part 5 of FIG. 6-6 sectional view of FIG. Sectional view along line 7-7 in FIG. The perspective view of the bracket for stoppers of the pipe-bracket junction structure of the present invention The perspective view of the bracket for side frames of the pipe-bracket junction structure of this invention Manufacturing procedure explanatory diagram of the pipe-bracket joint structure of the present invention Fig. 1 and Fig. 2 reprint of Patent Document 1

Explanation of symbols

  46 ... Pipe-bracket joint structure (upper frame), 54, 55 ... Stopper bracket, 56, 57 ... Side frame bracket, 61 ... Pipe frame, 63, 64 ... First bending portion, 67, 68 ... Second Bending part, 77, 81 ... bead, 85, 95 ... horizontal line, 86 ... outer peripheral surface, 87, 96 ... outer peripheral central part, C1, C2 ... curvature center point.

Claims (1)

In a pipe-bracket joint structure in which a bent part is formed in a pipe frame by a bender method, and a bracket is joined by a welding method in the vicinity of the bent part or the bent part,
When the posture of the cross section is determined so that the center of curvature used when bending the pipe frame assuming the cross section of the bent portion is below,
A pipe-bracket joint structure characterized in that a weld bead for fixing a bracket is disposed at or near the left and right outer periphery central portions where a horizontal line passing through the center of the cross section intersects the outer peripheral surface of the pipe frame.

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