JP2003001490A - Butt welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a butt welding method with which axial precision between two parts is improved and bending of the parts with welded heat shrinkage can be restrained. SOLUTION: A jig 2 used for the butt welding is provided with a V arm 4 having a V-shaped supporting surface 4a, and an axial adjustment of the V arm 4 to a center part 3, is beforehand performed to secure the axial precision of this V arm 4. In this way, the axes of the parts 1 can be held by being matched with the centers of the center parts 3 by pushing the parts 1 laid on the supporting surface 4a of the V arms 4 with flat pushers 5. Thereafter, the end surfaces of both parts 1 are butted to each other in the axial direction and the joining parts of both the parts 1 are irradiated with welding energy. At that time, since the heat shrinkage at the welding time can be cancelled by irradiating with the welding energy from the opposite peripheral parts of (e.g. at 180 deg. angle), the bending of the parts 1 can be restrained and the precision between the parts after welding can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butt welding method for axially butting and welding two parts having circular outer peripheral surfaces.

[0002]

2. Description of the Related Art In recent years, with the miniaturization and high precision of products,
It is required to reduce the diameter of element parts used in products and to weld parts with high precision. As an example of welding these parts together, there is a method shown in FIG. 7, for example. This is because when the pipe guide 100 and the pipe connector 110 as shown in FIG. 8 are welded, the convex portion 111 provided at the end of the pipe connector 110 is fitted and assembled to the cylindrical pipe guide 100. This is a method of welding the contact surface of. However, in this method, since the precision of the fitting parts and the precision of the combination when the two parts are fitted to each other by concavity and convexity are accumulated,
There was a phenomenon that the positional accuracy between the two parts deteriorates.

On the other hand, there is a butt welding method shown in FIG. This is applied when the two parts cannot be combined by concave and convex fitting because the pipe connector 110 does not have a convex part. Specifically, each collet
This is a method in which the end faces of the pipe guide 100 and the pipe connector 110 held by 120 and 130 are axially butted against each other, and the abutting faces of the two are irradiated with welding energy such as laser light to perform welding.

[0004]

However, in the conventional butt welding method, when the components held by the collets 120 and 130 are centered, the components are grasped from the change in the outer diameter of the grasped portion on the outer peripheral surface of the components. Since the reproducibility of accuracy is remarkably reduced, there is a problem in that the centering accuracy varies and a misalignment occurs between the two parts (see FIG. 10). Also, FIG.
As shown in 0, bending occurs between both parts due to heat shrinkage during welding, and thus it was difficult to maintain welding accuracy. The present invention has been made based on the above circumstances,
It is an object of the present invention to provide a butt welding method capable of improving accuracy between two parts and improving accuracy between parts after welding by suppressing bending of a part due to heat shrinkage of welding.

[0005]

(Invention of Claim 1) Two parts having a circular outer peripheral surface are held by a set of jigs so that their end faces are axially butted against each other, and welding energy is applied to both parts. A butt welding method of irradiating and welding a jointed part of the jig, wherein the jig is a V arm that forms a V-shaped support surface,
A flat presser that moves in opposition to the support surface is provided, and the V-arm and the flat presser support the circular outer peripheral surface of the component at three points in the circumferential direction, thereby centering the component. By supporting the component at three points by the V-arm and the flat presser, an appropriate grasping contact surface can be maintained without being affected by the outer diameter of the grasping portion of the component, and the reproducibility of the centering accuracy can be improved.

(Invention of Claim 2) In the butt welding method described in Claim 1, the axial center between both V arms is adjusted for one set of jigs. As a result, misalignment between the two parts can be suppressed, and desired welding accuracy can be maintained.

(Invention of claim 3) In the butt welding method according to claim 1 or 2, the welding energy is applied to the joined parts of the two parts from the direction equally divided in the circumferential direction. According to this method, thermal contraction during welding can be canceled each other and bending of the parts can be suppressed, so that the accuracy between the parts after welding can be improved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall view showing a butt welding method. In the present embodiment, when two pieces 1 are butt-welded, a set of jigs 2 described below is used. The two parts 1 are, for example, a pipe guide 1A and a pipe connector 1B, which are components of an injector for injecting fuel into an internal combustion engine (a cross-sectional shape is shown in FIG. 2).
And both are provided in a cylindrical shape having the same outer diameter.

As shown in FIG. 3, the set of jigs 2 (2A, 2B) respectively comprises a center 3, a V arm 4, and a flat presser 5.
Etc. The center 3 supports the component 1 from the axial direction, has a conical tip shape, and is rotatably supported on the side surface of the base 6 (see FIG. A). V
The arm 4 has a V-shape (120 mm) that supports the outer peripheral surface of the component 1.
The support surface 4a is provided to be adjustable in vertical position with respect to the base 6, and is fixed by tightening a fixing screw (not shown) (see FIG. B). The flat presser 5 is supported by a lateral arm 7 fixed to the upper side surface of the base 6, is provided so as to be movable in the vertical direction with respect to the lateral arm 7, and is biased downward by a spring 8.

In this set of jigs 2, the axial center of the V arm 4 with respect to the center 3 is adjusted in advance in order to secure the axial center accuracy between both V arms 4. A method of adjusting the axial center will be described with reference to FIG. A centering master 9 having the same outer diameter as the two parts 1 is held by both centers 3 (see FIG. A). After loosening the fixing screw, the V-arm 4 is moved upward so that the support surface 4a (V-shaped surface) of the V-arm 4 is aligned with the alignment master 9
(See Figure b). Tighten the fixing screw to fix the position of the V arm 4 with respect to the base 6. By the above operation, the axial center accuracy between both V arms 4 is secured.

Next, a method for butt-welding two parts 1 using the jig 2 will be described. a) Place the component 1 on the support surface 4a of the V-arm 4 (see FIG. 5).
(See (a)). b) The outer peripheral surface of the component 1 is pressed by the flat presser 5 so that the axis 1a of the component 1 coincides with the center of the center 3 (referred to as the virtual axis 3a) (see FIG. 5B). By this work, the grasping force evenly divided into 120 degrees is directed from the three directions to the virtual axis 3a, whereby the centripetality of the component 1 is improved.

C) The two parts 1A and 1B are held by the respective jigs 2A and 2B (see FIG. 6A). d) Move the jig 2B in the direction of the arrow in the figure
The end faces of A and 1B are butted against each other in the axial direction (Fig. 6).
(See (b)). e) As shown in FIG. 1, while rotating both components 1, the welding energy (for example, laser light) is irradiated to the jointed portions of both components 1. At this time, the welding energy is applied to the jointed portions of both components 1 from the direction equally divided in the circumferential direction (for example, the direction facing each other by 180 degrees).

(Effects of Embodiment) In the butt welding described above, the component 1 having a circular outer peripheral surface is supported by the V-arm 4 and the flat presser 5 from three directions equally divided into 120 degrees. An appropriate grasping contact surface can be maintained without being affected by the outer diameter of the grasping portion 1 and the reproducibility of the centering accuracy can be improved. Further, since the welding energy is applied to the jointed portions of the two components 1A and 1B from the direction equally divided in the circumferential direction, the heat shrinkage during welding can be canceled each other. As a result, the bending of the component 1 can be suppressed,
The accuracy between parts after welding can be improved.

[Brief description of drawings]

FIG. 1 is an overall view showing a butt welding method.

FIG. 2 is a sectional view of a component.

FIG. 3 is an explanatory diagram of a jig.

FIG. 4 is a view showing an axial center adjustment of a V arm.

FIG. 5 is a drawing showing a procedure for aligning parts.

FIG. 6 is a diagram showing a step of butting parts held by a jig.

FIG. 7 is a sectional view showing an example of a conventional welding method.

8 is a cross-sectional view of a component used in the welding method shown in FIG.

FIG. 9 is a cross-sectional view showing a conventional butt welding method.

FIG. 10 is a cross-sectional view showing a problem of butt welding.

[Explanation of symbols]

1 part 2 jigs 4 V arm 4a V arm support surface 5 flat press

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshiaki Kondo             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO

Claims (3)

[Claims] 1. A projection for welding two parts having circular outer peripheral surfaces held by a set of jigs so that their end surfaces are butted against each other in the axial direction, and welding energy is applied to the joined parts of both parts for welding. The welding method, wherein the jig includes a V arm that forms a V-shaped support surface, and a flat presser that faces the support surface and is movable. A butt welding method characterized in that the circular outer peripheral surface of a component is supported at three points in the circumferential direction to center the component. 2. The butt welding method according to claim 1, wherein the jigs of the pair are adjusted in axial center between both V arms. 3. The butt welding method according to claim 1 or 2, wherein welding energy is applied to the jointed portions of the two parts from directions equally divided in the circumferential direction. Lamination welding method.