JPH06339789A - Joining structure for car frame - Google Patents

Abstract

PURPOSE:To provide a joining structure for a car frame, in which the fitness of a gusset, etc., can be executed and the weld strength can be kept without removing weld bead produced at the weld part. CONSTITUTION:In a structure including a first square pipe 11 forming the vehicle frame, a second square pipe 12 having the end surface butting against the side surface of the first square pipe and cross section almost equal to the first square pipe and the weld bead 14 formed at the butt part 13 between the side surface of the first pipe 11 and the end surface of the second square pipe 12, the end surface of the second square pipe 12 has a narrow width part narrower than the width size of the side surface of the first square pipe 11 to form a step at the butt part 13. Then the weld bead 14 is positioned in a step and on crossing lines between respective extended upper surfaces of the pipes 11, 12 and between respective extended lower surfaces of the pipes 11, 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure for a vehicle frame which constitutes a frame in a vehicle such as a bus or a truck.

[0002]

2. Description of the Related Art A vehicle frame receives a vertical load in a stationary state in order to support and connect various devices and loads and to transmit the loads to front wheels and rear wheels. Further, as the vehicle travels, vertical inertial loads are applied, and front, rear, left and right horizontal loads are applied during turning, starting and braking. Further, if the vehicle travels on a rough road, a torsional load is applied to the frame. In addition to the static load described above, a dynamic load acts on the frame during traveling.

Due to these loads, a shearing force, a bending moment, and a torsion moment are generated, and the frame is deformed, so that stress concentration is likely to occur locally at the joint portion of the members constituting the frame.

Therefore, the frame is required to have a strength capable of withstanding the static load and the dynamic load, but the frame has a complicated structure, the wall thickness of the frame constituting member is increased, and the cross-sectional area is increased. It means that the body weight increases,
It also causes an increase in material costs. Therefore, the conventional configuration is as shown in FIG.

That is, 1 is a ladder-shaped frame of a bus, which is a pair of side members 2 and 2 and a plurality of cross members 3 connecting the side members 2 and 2 ...
It consists of and. The side member 2 and the cross member 3 are made of a square pipe made of steel, and as shown in FIG. 5, the end surface of the cross member 3 made of a square pipe is butted against the side surface of the side member 2 made of a square pipe. The butt portions 4 are joined by welding.

However, when the end surface of the cross member 3 is butted against the side surface of the side member 2 and the butted portion 4 is welded, a weld bead 5 is generated. Therefore, when the panel or the gusset 6 is attached to the welded portion as shown in FIG. 6, the weld bead 5 is removed by welding finishing and the gusset 6 is attached as a flat surface.

[0007]

However, as described above, when the weld bead 5 is removed by welding finishing in order to attach the gusset 6 to the welded portion of the side member 2 and the cross member 3, the welding strength is increased. Is reduced, and there is a risk of fracture when stress concentration occurs in the joint during traveling, and a post-processing step such as welding finishing is required.

The present invention has been made in view of the above circumstances, and the purpose thereof is to be able to attach a gusset or the like without removing the welding bead generated in the welded portion and maintain the welding strength. An object is to provide a joint structure for a vehicle frame.

[0009]

In order to achieve the above-mentioned object, the present invention has a first square pipe forming a frame of a vehicle and an end face that abuts a side surface of the first square pipe. At the same time, it is formed at a second square pipe having a cross section substantially equal to that of the first square pipe, and at a butting portion of the side surface of the first square pipe and the end surface of the second square pipe. A welded bead, the end surface of the second square pipe forms a narrow portion narrower than a width dimension of a side surface of the first square pipe, and a step is formed in the abutting portion. Together with the welding bead in the step, in an extension line connecting the upper surfaces of the first and second rectangular pipes, and in an extension line connecting the lower surfaces of the first and second rectangular pipes, respectively. It has been made to exist. The welding bead is settled in the step space formed between the first and second square pipes.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 3, 11 is a first square pipe that constitutes a side member of a vehicle body frame such as a bus, and 12 is a second square pipe that also constitutes a cross member. The first and second square pipes 11 and 12 have substantially the same cross-sectional area, and the abutting portion 13 of the second square pipe 12 is narrower than the width dimension of the side surface of the first square pipe 11. ing.

Then, by welding the abutting portion 13 of the second square pipe 12 in contact with the side surface of the first square pipe 11, the second square pipe 12 is welded to the second square pipe 11 by welding. The square pipe 12 is connected. A weld bead 14 is generated at the abutting portion 13 by this welding, and the weld bead 14 is contained in the step space formed at the abutting portion 13 of the first square pipe 11 and the second square pipe 12,
The square pipe 11 does not project to the upper surface side. Therefore, the panel or gusset 15 can be attached without removing the welding bead 14, that is, without lowering the welding strength.

[0012]

As described above, according to the present invention, the end portion of the second square pipe that abuts the side surface of the first square pipe is made narrower than the side surface of the first square pipe. As a result, a gusset or the like can be attached without removing the welding bead generated in the welded portion, the welding strength can be maintained, and post-welding processing becomes unnecessary.

[Brief description of drawings]

FIG. 1 is a perspective view of a connected state of a square pipe showing an embodiment of the present invention.

FIG. 2 is a side view of a connected state of the square pipe of the embodiment.

FIG. 3 is a side view showing a state in which the gusset of the embodiment is attached.

FIG. 4 is a plan view of a frame of a general bus.

FIG. 5 is a side view of a connected state of a conventional square pipe.

FIG. 6 is a side view showing a state in which a gusset is also attached.

[Explanation of symbols]

11 ... 1st square pipe, 12 ... 2nd square pipe, 13 ...
Butt, 14 ... Weld bead.

Claims (1)

[Claims] 1. A second square pipe having a first square pipe forming a frame of a vehicle, an end face that abuts a side surface of the first square pipe, and a cross section substantially equivalent to the first square pipe.
A square pipe, and a weld bead formed at the abutting portion of the side surface of the first square pipe and the end surface of the second square pipe, wherein The end face forms a narrow width portion narrower than the width dimension of the side surface of the first square pipe to form a step in the butting portion, and the welding bead is in the step, and A joint structure for a vehicle frame, characterized in that it is present in an extension line connecting the upper surfaces of the two double-angled pipes and in an extension line connecting the lower surfaces of the first and second double-angled pipes.