JPH0631489A - Positioning jig for welding - Google Patents

Abstract

PURPOSE:To improve the precision for positioning and to improve the efficiency of manufacture by adopting plural numbers of rack and pinion mechanism for deciding the center of a steel tube. CONSTITUTION:Restricting arms 6 to restrict an inner wall 7a of a steel tube 7 at three places of the circumference are provided movable to the radius direction inside a lower jig 2 positioning an inserted subject 8. When a central gear 3 is rotated and controlled, a pinion gear 4 is rotated, and the restricting arms 6 are pushed with a rack gear 5 to the steel tube inner wall 7a in being uniform in three directions. This positioning jig for welding can improve the precision for positioning the parts and can do a holding process until fixing of welding after welding while moving the parts by providing the restricting arm 6 being expandably controlled with a rack and pinion mechanism inside the lower jig 2 when the inserted subject 8 is welded to the steel tube 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig capable of positioning a steel pipe and an insert such as a bearing when they are welded and moving the welded parts while holding the parts. Is.

[0002]

2. Description of the Related Art Positioning for welding an insert to a steel pipe largely depends on the accuracy of each component. Fig. 2 shows the schematic structure of a conventional welding jig of this type.
FIG. 3B is a perspective view of the lower jig, and FIG. 6B is a vertical cross-sectional view showing a usage state of the upper and lower jigs. In the figure, 1 is an upper jig, 2 is a lower jig, 7 is a steel pipe to be welded, 8 is an insert inserted between the upper and lower jigs, and 9 is a welded portion. The work procedure is given below.

(1) The steel pipe 7 is erected on the lower jig 2.

(2) Insert the insert 8 into the steel pipe 7.

(3) Insert the upper jig 1 from above and hold down the insert 8.

(4) Weld the welding portion.

(5) When the welding work is completed, the unit is removed from the jig and moved to the next step.

[0008]

In the structure of the conventional jig, the position of the insert 8 is determined by the upper and lower jigs 1 and 2, but the inner wall 7a of the steel pipe 7 is of the insert 8. It is premised that the center of the insert 8 and the center of the steel pipe 7 are coincident with each other because it is supposed to come into contact with the outer wall 8a and is restrained only by the interference, and it depends on the accuracy of the parts. For this reason, welding is always performed in a state in which there is a possibility of positional deviation of the component tolerance.

Further, the conventional jig is of a stationary type, and the movement of the unit after welding cannot be restrained. As a result, it was necessary to hold it on the jig until the fixing of the welded portion was completed, which was inefficient.

The present invention solves the above two problems of the prior art, and an object thereof is to improve the positioning accuracy and the manufacturing efficiency.

[0011]

In order to achieve this object, a jig (lower jig) of the present invention comprises a rack and pinion mechanism which can be controlled by a central gear, and a constraint which expands and contracts by the rack and pinion mechanism. Have arms.

[0012]

According to the present invention, the lower jig internally has a plurality of rack and pinion mechanisms controlled by the central gear, and by controlling the central gear, the restraining arm for positioning is expanded and contracted. Determine the center of the steel pipe. The verticality of the steel pipe is also determined at the same time. Next, the insert is pressed against the lower jig by the upper jig. At this time, the center and horizontal of the insert are determined.
Through these processes, the positions of the steel pipe, the jig, and the insert are accurately determined.

Further, even after the upper jig is removed after welding, the lower jig can be moved together with the parts by stretching the inner wall of the steel pipe, and the position does not shift during the movement.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of one embodiment of the present invention.
[Fig. 3] is a vertical cross-sectional view of the upper and lower jigs in use, (b) is a plan view of the positioning rack and pinion mechanism portion of (a), and (c) is a perspective view of (b). In the figure, 3 is a central gear, 4 is a rack gear, 5 is a pinion gear, and 6 is a restraining arm. The rack and pinion mechanism is composed of a rack gear 4 and a pinion gear 5, and has three sets in the case of this embodiment. By controlling the rotation of the central gear 3 (arrow direction), the rack gear 4 rotates, and the pinion gear 5 expands and contracts (arrow direction). As a result, the restraining arm 6 uniformly pushes the inner wall 7a of the steel pipe 7 in the three directions to determine the center of the steel pipe. It is possible to solve the conventional problem that the center of the parts varies due to the accuracy of individual parts.

The center of the insert 8 is determined by a positioning pin (not shown). Horizontalness is determined by pressing the upper jig 1 against the lower jig 2, which is the same as the conventional method.
By using the jig of the present invention, it is possible to position the component more accurately than in the past.

Conventionally, the movement of the parts after welding is carried out after being removed from the jig, so that it is necessary to wait until the welded parts are fixed. However, in the jig of the present invention, since it is stretched by the inner wall of the steel pipe as described above, it is possible to move together with the steel pipe and the insert while restraining the positional relationship between them. As a result, it is possible to save the holding time after welding until sticking and improve the manufacturing efficiency.

[0017]

As described above, in the welding positioning jig of the present invention, when the insert is welded to the steel pipe, the lower jig is equipped with the restraining arm that can be expanded and contracted by the rack and pinion mechanism. This enables the positioning accuracy of parts to be improved and the holding process from welding to sticking can be performed while moving the parts. Therefore, it is possible to improve the manufacturing efficiency by omitting the holding time required in the past. A jig can be realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a welding positioning jig according to an embodiment of the present invention.

FIG. 2 is a schematic view of the configuration of a conventional positioning jig.

[Explanation of Codes] 1 ... Upper jig, 2 ... Lower jig, 3 ... Central gear, 4 ... Rack gear, 5 ... Pinion gear, 6 ... Restraining arm.

Claims (1)

[Claims] 1. A jig for positioning a component during welding, comprising a rack and pinion mechanism that can be controlled by a central gear in a lower jig for positioning and holding the component, and the rack and pinion mechanism expands and contracts. Positioning jig for welding, characterized in that the arm determines the center and vertical position of the welding member.