JP4127125B2 - Manufacturing method of vehicle frame structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a vehicle frame structure, in particular, to a method of manufacturing a suitable vehicle frame structure to be formed by welded together by combining cylindrical workpiece of aluminum or an aluminum alloy.
[0002]
[Prior art]
Conventionally, there has been proposed a vehicle frame structure formed by combining and joining hollow extruded profiles of aluminum or aluminum alloy (hereinafter simply referred to as aluminum) (see Patent Document 1).
[0003]
This is intended for a subframe of an automobile, and is a cross member of an aluminum hollow extruded member that includes a reinforcing partition wall that extends in the extrusion direction and is integrally formed on a peripheral wall portion to partition the hollow portion, and an aluminum hollow extruded member. The side members are arranged substantially at right angles to each other, and a part of the peripheral wall portion at the end of the side member is joined to the outer surface of the peripheral wall portion connected to the reinforcing partition wall portion of the cross member by MIG welding or the like along the connecting portion. Thus, the connection strength between the cross member and the side member is increased.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-337722
[Problems to be solved by the invention]
By the way, as in the conventional example described above, when welding an aluminum material having both high thermal conductivity and linear expansion coefficient and difficult to locally heat by MIG welding, which has a large amount of heat input to the object to be welded, the amount of strain is grasped and It is difficult to control the deformation by putting a probable amount, and there is a possibility that the shape accuracy after welding may be lowered, and a welding method that can effectively suppress this distortion deformation is required.
[0006]
The present invention has been made in view of the above problems, and an object thereof is to provide a method of manufacturing a vehicle frame structure which high shape accuracy can be obtained while maintaining the weld quality.
[0007]
[Means for Solving the Problems]
In the present invention, both ends of the cross member are positioned by penetrating through holes provided in the peripheral edge portions of the pair of side members, and the edge of the through hole of the side member is placed in a state where cooling water is circulated in the cross member. The cross member peripheral part was welded.
[0008]
【The invention's effect】
Therefore, in the present invention, both ends of the cross member are positioned through the through holes provided in the peripheral edge portions of the pair of side members, and the through holes of the side members are formed in a state in which cooling water is circulated in the cross member. Since the edge and the peripheral edge of the cross member are welded together, distortion deformation due to welding can be effectively suppressed, and high shape accuracy can be obtained while maintaining welding quality.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a method of manufacturing a vehicle frame structure of the present invention will be described with reference to one embodiment. 1 to 3 show an embodiment of a method for manufacturing a vehicle frame structure to which the present invention is applied. FIG. 1 is a perspective view showing the entire vehicle frame structure, and FIG. 2 is a cross-sectional view showing details of the welded joint portion. FIG. 3 is a schematic view showing a method for manufacturing a vehicle frame structure.
[0010]
FIG. 1 shows a vehicle frame structure 1 applied to, for example, a skeleton structure of a floor portion of a vehicle body, and includes a pair of left and right side members 2A and 2B and a plurality of cross members 3 that connect the side members 2A and 2B. In addition, both end portions of the plurality of cross members 3 are integrally formed on the side members 2A and 2B by MIG welding.
[0011]
The side members 2A and 2B are made of an aluminum hollow extruded section having a box-shaped cross section, and include, for example, an upper wall portion 5, a lower wall portion 6, and left and right wall portions 7 and 8, as shown in FIG. Manufactured from aluminum hollow extruded profile. The left and right wall portions 7 and 8 of the pair of left and right side members 2A and 2B have the same shape as the cross-sectional shape of the cross member 3, and through holes 9 into which the ends of the cross member 3 can be inserted are opened. Prepare.
[0012]
The cross member 3 is made of an aluminum hollow extruded member having a box-shaped cross section. For example, the cross member 3 is made of an aluminum hollow extruded member having a peripheral wall portion 3B composed of upper and lower front and rear wall portions. The total length of the cross member 3 is longer than the interval between the left and right wall portions 8 on the inner sides of the side members 2A and 2B facing each other, and shorter than the interval between the left and right wall portions 7 on the outer side. ing. Both end portions 3A of the cross member 3 are inserted into the through holes 9 of the left and right wall portions 8 inside the side members 2A and 2B, and the edges of the through holes 9 and the peripheral wall portions 3B of the cross member 3 are bonded by MIG welding 4. They are joined together.
[0013]
In the cavities of the side members 2A, 2B and the cross member 3 formed of hollow extruded sections, urethane foam 10 injected from through holes 9 opened in the left and right wall portions 7 outside the side members 2A, 2B. Filled with foam. The strength of each member is improved by the foamed urethane 10, and the rigidity of the entire body frame 1 is increased.
[0014]
A method of welding the body frame 1 will be described below with reference to FIG. In FIG. 3, the side members 2A and 2B are clamped at predetermined positions by a jig (not shown), and the cross member 3 is inserted into the through holes 9 provided in the left and right wall portions 8 inside the side members 2A and 2B. In this state, it is clamped at a predetermined position by a jig (not shown).
[0015]
A water passage jig 11 having a hollow hole 12 is inserted into the through hole 9 opened in the left and right wall portions 7 on the outer side of the side members 2A and 2B, and the front end of the water passage jig 11 is a hollow extrusion of the cross member 3. It fits into the end opening of the profile. A heat-resistant seal 13 is provided at the tip of the water flow jig 11, and abuts against the end of the cross member 3 through the seal 13 and fits into the opening so that the water flow jig 11 and the cross at both ends are crossed. The hollow portion of the member 3 forms a space that is watertight with respect to the outside.
[0016]
The hollow holes 12 of the water passing jigs 11 at both ends are connected to a cooling water circulation device 15 via a pipe line 14 so that hot water or normal cooling water circulated by the cooling water circulation device 15 flows through the cross member 3. is doing. The cooling water circulation device 15 includes a pump 17 controlled by the welding machine controller 16, a tank 18, and a supply valve 19 and a discharge valve 20 for supplying and discharging hot water or cooling water to the tank 18, and circulating hot water or cooling water. The temperature is controlled.
[0017]
In the above welding apparatus, as a preparation state for starting welding, hot water (40 ° C. to 50 ° C.) is supplied into the tank 18, and hot water is circulated in the cavity of the cross member 3 by the pump 17. The temperature of the side members 2A and 2B that are in contact with 3 through the through hole 9 is raised. The weldability at the start of welding is stabilized by the temperature rise between the weld members.
[0018]
Next, welding between the peripheral wall 3B of the cross member 3 and the edge of the through hole 9 of the side members 2A and 2B is started. Since welding heat is generated when welding is started, normal cooling water is supplied into the tank 18 by the welding machine controller 16, and the cooling water is circulated in the cavity of the cross member 3 by the pump 17. Suppresses the temperature rise of the welding member. The cross member 3 and the side members 2A, 2B are prevented from being deformed because the temperature rise is suppressed by the cooling water during welding.
[0019]
When the welding is completed, the side members 2A, 2B and the cross member 3 are formed on the integrated body frame 1. The water passing jig 11 is removed, the inside of the cavity of the cross member 3 is dried, and the cavities of the cross member 3 and the side members 2A, 2B are inserted through the through holes 9 in the outer left and right wall portions 7 where the side members 2A, 2B are opened. The portion is filled with foamed urethane 10 and foamed. The foamed urethane foam 10 increases the strength of each member integrated as the vehicle body frame 1 and improves the rigidity of the vehicle body frame 1.
[0020]
In the present embodiment, the following effects can be achieved.
[0021]
(A) Both ends of the cross member 3 are positioned through the through holes 9 provided in the peripheral edge portions of the pair of side members 2A and 2B, and the side member 2A is in a state where cooling water is circulated in the cross member 3. Since the edge of the 2B through hole 9 and the peripheral edge 3B of the cross member 3 are welded together, distortion deformation due to welding can be effectively suppressed, and high shape accuracy can be obtained while maintaining welding quality.
[0022]
(A) Both ends of the cross member 3 are allowed to pass through only one side of the through holes 9 provided in the left and right wall portions 7 and 8 of the pair of side members 2A and 2B. Positioned in a state of being accommodated in the shape of 2B, and the edge of the through hole 9 of the side member 2A, 2B and the peripheral edge 3B of the cross member 3 are welded and joined with cooling water flowing through the cross member 3 Therefore, the urethane foam 10 is filled into the hollow portions of the cross member 3 and the side members 2A, 2B from the through holes 9 of the outer left and right wall portions 7 where the side members 2A, 2B are opened, and the vehicle frame is formed. The strength of each member integrated as 1 can be increased, and the rigidity of the vehicle frame 1 can be improved. Of course, the resin may be separately filled in the cavity of the cross member 3 of the vehicle frame 1 and the cavities of the side members 2A and 2B to be foamed.
[0023]
(C) The temperature of the cross member 3 and the side members 2A and 2B that are in contact with the cross member 3 through the through-holes 9 is raised as the cooling water by adjusting the temperature until the start of welding. The weldability at the start of welding can be stabilized by the temperature rise between them.
[0024]
In the above-described embodiment, both ends of the cross member 3 penetrate only the through holes 9 provided in the left and right wall portions 8 of the pair of side members 2A and 2B, and both end portions of the cross member 3 are the side members 2A, Although description has been given of positioning in the state of being accommodated in the shape of 2B, although not shown, both ends of the cross member penetrate through through holes provided in both the left and right wall portions of the pair of side members and are welded. In this case, the resin is separately filled in the cavity of the cross member and the cavity of the side member to be foamed.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an entire vehicle frame structure according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing details of a weld joint.
FIG. 3 is a schematic view showing a method for manufacturing a vehicle frame structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle frame 2A, 2B Side member 3 Cross member 4 Welding part 7, 8 Right-and-left wall part 9 Through hole 10 Resin, such as urethane foam 11 Water flow jig 15 Cooling water circulation device

Claims (4)

In the manufacturing method of the vehicle frame structure formed by welding and joining both end portions of a plurality of cross members made of hollow extruded shapes to a pair of side members made of hollow extruded shapes,
Position both ends of the cross member through the through holes provided in the peripheral edge of the pair of side members,
A method for manufacturing a vehicle frame structure, wherein the edge of the through hole of the side member and the peripheral edge of the cross member are welded together in a state where cooling water is circulated in the cross member. Both ends of the cross member are positioned in a state where both ends of the cross member are accommodated in the shape of the side member by penetrating only one side of the through holes provided in the left and right wall portions of the shape of the pair of side members. And
2. The method of manufacturing a vehicle frame structure according to claim 1, wherein the edge of the through hole of the side member and the peripheral edge of the cross member are welded together in a state where the cooling water is circulated in the cross member.   The method for manufacturing a vehicle frame structure according to claim 1 or 2, wherein the cooling water is warm water adjusted to start of welding.   2. A vehicle frame formed by welding a cross member made of a hollow extruded shape member and a side member, and at least a cavity in the cross member is filled with resin and foamed. The manufacturing method of the vehicle frame structure as described in any one of Claim 3.

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