JPH08215859A - Seam welding equipment - Google Patents

Abstract

PURPOSE: To weld by seam welding a tube for a pouring spout onto the body of a fuel tank, without using any special parts for securing sealing performance and regardless of the size or shape of the fuel tank, surely, quickly and with a satisfactory sealing result secured. CONSTITUTION: In a pair of electrodes holding a part in between in which a flange-shaped plate 21 on the side of a tube 20 for a pouring spout is superposed on the oppositely facing body part 22b of a fuel tank, one is structured to be a cylindrical fixed electrode 18 provided with a flat face 18a that is in contact with the inner face of the body part 22b of the fuel tank. The other is structured to be a roller electrode 16, which is in contact with the outer face of the flange-shaped plate 21 on the tube 20 side and which, while pressurizing the flange-shaped plate 21 pressed against the outer face of the body part 22b of the fuel tank, rotates around the cylindrical axial center (a) of the fixed electrode 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seam welding apparatus used for manufacturing a fuel tank for an automobile, for example, a seam welding for welding a tube constituting a fuel tank inlet to a fuel tank main body. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, projection welding or spot welding means and bolt tightening means have been used together to fix an oil inlet tube to a fuel tank body. That is, FIG. 5 is a cross-sectional view of an essential part showing a conventional tube fixing structure. In FIG. 5, reference numeral 50 denotes a fuel tank body, and a hole 51 is formed at a position corresponding to an oil filling port, and a peripheral portion of the hole 51 is formed. Annular protrusion 50 by burring
a is formed. Reference numeral 52 denotes an oil filler tube, one end portion 52a of which is passed through the hole 51 and the fuel tank main body 50.
A flange-shaped plate portion 53 facing the annular protrusion 50a and the fuel tank main body portion 50b on the outer periphery thereof is fixed to the outer peripheral surface of the tube 52 outside the hole 51 by welding. There is. As shown in FIG. 6, bolt-through holes 53a are formed in the flange-shaped plate portion 53 at appropriate intervals in the circumferential direction.

Reference numeral 54 denotes a metal-made thick annular member which is superposed on the outer peripheral portion 50b of the annular protruding portion 50a of the fuel tank main body 50. The annular member 54 has a portion facing the bolt insertion hole 53a. Female screw hole 54
The annular member 54 is projection-welded or spot-welded P to the outer peripheral portion 50b of the fuel tank main body 50 at the portion between the female screw holes 54a adjacent to each other. A packing 55 is sandwiched between the flange-shaped plate portion 53 on the side of the tube 52 and the annular protrusion 50a and the annular member 54 on the side of the fuel tank main body 50, and the flange 55 is tightened to tighten the packing 55. Bolt insertion hole 5 of the plate member 53
The tube 52 is attached to the fuel tank body 50 by screwing a bolt 56 from the female screw hole 3a into the female screw hole 54a.
It was fixed in a sealed state.

[0004]

In the conventional tube fixing structure having the above-mentioned structure, the sealing performance cannot be obtained by only projection welding or spot welding.
Since packing 55 and bolts 56 are used together to secure the sealing performance because there is a risk of fuel leakage and the like, a very large number of parts and a great deal of work are required, resulting in extremely high productivity. Not only bad, but also expensive to make. Furthermore, in order to cope with the deterioration of the packing 55 with time,
There is an inconvenience that the bolts 56 need to be tightened and the packing 55 itself needs to be replaced.

In order to eliminate the above-mentioned inconvenience, it is conceivable to seam-weld the tube-side flange-shaped plate portion to the fuel tank body. In this case, since the sealability is excellent, parts such as packing and bolts for securing the sealability are unnecessary, but when attempting seam welding using a conventional general seam welding device, the fuel tank main body is It is necessary to swivel with respect to the pair of roller electrodes, which not only enlarges the size of the seam welding apparatus as a whole, but also
It is very difficult to have versatility so that it can be applied to fuel tanks of various sizes and shapes, and multiple types of seam welding equipment of different shapes and sizes must be prepared, which is a great economic The physical burden is imposed. Therefore, conventionally, as this type of tube fixing means,
As shown in FIG. 5, it has been common to employ a combined structure of projection welding or spot welding means and bolt tightening means.

The present invention has been made in view of the above-mentioned circumstances, and does not use any special parts for ensuring the sealing property, and the fuel inlet tube is used for the fuel inlet regardless of the size and shape of the fuel tank. It is an object of the present invention to provide a seam welding device that can be securely and quickly fixed in a state where a good sealing property is secured.

[0007]

In order to achieve the above object, the seam welding apparatus according to the present invention is provided with the above-mentioned hole of an oil filler tube having one end inserted into the tank body through a hole formed in the fuel tank body. A flanged plate portion on the tube side, which is a seam welding device for welding a flange-shaped plate portion fixed to an outer peripheral surface on the outer side and a fuel tank main body portion facing the plate portion in an overlapping state. Of the pair of electrodes sandwiching the overlapping portion with the fuel tank main body portion facing this, one electrode is configured as a cylindrical fixed electrode having a flat surface that abuts the inner surface of the fuel tank main body portion, The other electrode is a roller electrode that revolves around the cylinder axis of the cylindrical fixed electrode while pressing the tube-side flange plate against the outer surface of the fuel tank body. It is characterized in that there.

[0008]

According to the present invention, the flange-like plate portion on the side of the tube for the fuel injection port and the fuel tank main body portion facing this are overlapped, and the inner surface of the fuel tank main body portion is abutted against the flat surface of the cylindrical fixed electrode. While being in contact with each other, the overlapping portion is set in a sandwiched state between the pair of electrodes so that the roller electrode is brought into contact with the flange-shaped plate portion on the tube side.
In this state, while pressing the flange-shaped plate portion against the outer surface of the fuel tank main body portion via the roller electrode,
By revolving the roller electrode around the cylinder axis of the cylindrical fixed electrode, the fuel tank main body is not swung, and along with the revolution of the roller electrode, the flange-shaped plate portion is formed continuously in the circumferential direction. It is possible to perform seam welding (electrical resistance welding) in a gas-tight and water-tight state with the fuel tank main body portion facing this.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall side view of an inlet seam welding apparatus according to an embodiment of the present invention, and FIG. 2 is an enlarged side view of the electrode seam welding apparatus and its surroundings. In each of these drawings, reference numeral 1 is a box-shaped device body that incorporates a welding transformer 2, a motor (not shown), and the like. Reference numeral 3 denotes an octagonal lifting guide having an octagonal hole fixed to the upper part of the apparatus main body 1 through a bracket 4, and an octagonal rod 6 which is vertically movable by an air cylinder 5 is provided in the hole of the guide 3. A vertically rotating shaft 9 is supported in a gear box 7 fixed to the lower end of the rod 6 through a tapered roller bearing 8 so as to be inserted and supported. The vertical rotating shaft 9 is interlockingly connected to the motor via bevel gears 10, 10, a horizontal rotating shaft 11, and a lateral shaft 13 with a universal joint 12.

Reference numeral 14 denotes a cantilever-shaped swivel arm which is fixed to the lower end of the vertical rotating shaft 9 and projects to one side. Rotate together. An electrode head 15 is fixedly connected to the lower surface of the other end of the swivel arm 14, and one end of the electrode head 15 is a roller electrode 1 which is one of a pair of electrodes.
6 is rotatably supported around an axis b of a horizontal electrode shaft (not shown) in the head 15, whereby the roller electrode 16 rotates with the rotation shaft 8 and the swivel arm 14 and the electrode head 15. It is configured to be able to revolve around the vertical axis a of the rotary shaft 9 while rotating on its axis.

Reference numeral 17 denotes an electrode support base fixed to the lower part of the apparatus main body 1. On the upper surface of the electrode support base 17, at a position on the extension line of the vertical axis a of the rotary shaft 9 in the vertical direction, The upper end is formed on the horizontal flat surface 18a, and the cylindrical electrode 18 which is the other of the pair of electrodes is fixed. The roller electrode 16 and the tubular fixed electrode 18 cause the flange-shaped plate portion 21 on the fuel injection tube 20 side and the tube insertion hole 22a of the fuel tank body 22 facing the flange-shaped plate portion 21.
A pair of electrodes sandwiching the overlapping portion with the surrounding main body portion 22b from above and below is formed.
8, the flat surface 18a at the upper end abuts the inner surface of the fuel tank body portion 22b, and the roller electrode 16 is connected to the tube 20.
Side flange-shaped plate portion 21 is brought into contact with the upper surface thereof to press the flange-shaped plate portion 21 against the outer surface of the fuel tank body portion 22b while pressurizing it, that is, the cylindrical axis of the cylindrical fixed electrode 18, that is, the vertical axis a. It is configured to revolve around.

As shown in FIG. 2, the cylindrical fixed electrode 18 has an insulating plate 23 on the upper surface of the electrode supporting base 17.
Is electrically connected to the secondary side of the welding transformer 2 by a fixed conductor 24 extended to the welding transformer 2, while the roller electrode 16 is made of a U-shaped flexible conductor 25. A fixed conductor 27 fixedly supported on the gear box 7 via an insulating plate 26, a spectacle-shaped split conductor 28, and one of the split conductors 28 fitted and fixed to the lower end of the rotating shaft 9 by external fitting. The silver rotary sliding conductor 30 slidably contacting the hole 29A so as to be relatively rotatable, and the swivel arm 14 described above.
Also, it is electrically connected to the secondary side of the welding transformer 2 through a horizontal electrode shaft (not shown) in the electrode head 15.

FIGS. 3 and 4 show a concrete structure of a conducting portion from the fixed conductor 27 to the revolving arm 14 in the conducting path for conducting the roller electrode 16 to the secondary side of the welding transformer 2. As is clear from these figures, the spectacle-shaped split conductor 28 has two horizontal
It is composed of two half-divided conductor pieces 28A, 28B that are divided and have semicircular cutouts on both sides in the width direction, and are formed by semicircular cutouts on both sides in the width direction of these half-divided conductor pieces 28A, 28B. Of the circular holes 29A and 29B, the silver rotary sliding conductor 30 is slidably contacted with one hole 29A and the other hole 29B is formed at the end of the fixed conductor 27. The respective cylindrical conductor portions 27a are fitted in such a state that they cannot rotate relative to each other, and then the two half conductor pieces 28A and 28B are fastened to each other at their widthwise central portions via bolts 32 containing springs 31. As a result, the cylindrical conductor portion 27a of the fixed conductor 27 is formed.
To the turning arm 14 through the half conductor pieces 28A and 28B and the rotary sliding conductor 30.

Next, the operation of seam welding the flange-shaped plate portion 21 on the fuel filler tube 20 side to the fuel tank main body 22 using the inlet seam welding device configured as described above will be described. In the state where the roller electrode 16 is raised by the contraction operation of the air cylinder 3, the fuel tank main body portion of the fuel tank body portion 22b facing the flange-shaped plate portion 21 on the oil injection tube 20 side that is overlapped with each other The inner surface of 22b is brought into contact with the flat surface 18a of the cylindrical fixed electrode 18. At this time, the fuel tank body 22 is positioned by an appropriate supporting member 33 as shown in FIG. 1, for example.

Next, when the octagonal rod 6 is lowered along with the extension operation of the air cylinder 3, the roller electrode 16 is passed through the gear box 7, the swing arm 14 and the electrode head 15 which are fixed to the lower end of the rod 6. As shown in FIG. 2, the flange-shaped plate portion 21 on the tube 20 side is brought into contact with the overlapped portion to form a pair of electrodes 18, 1.
It is set in a sandwiched state between the six.

When a motor (not shown) is driven in this state, the rotational force is transmitted to the vertical rotary shaft 9 via the horizontal shaft 13 with the universal joint 12, the horizontal rotary shaft 11, and the bevel gears 10, 10. As a result, the rotary shaft 9 rotates around the axis a in the direction of arrow c in FIG. 2, and with this rotation, the roller electrode 16 along with the revolving arm 14 and the electrode head 15 causes the flange-shaped plate portion 21 to move to the fuel tank. The shaft core a is pressed against the outer surface of the main body portion 22b while being pressed.
It will revolve around its own axis. At this time, since a current is supplied between the electrodes 16 and 18 via the welding transformer 2, the flange-shaped plate portion 21 and the flange-shaped plate portion 21 are continuously formed in the circumferential direction as the roller electrode 16 revolves. The tube 20 is fixed to the fuel tank main body 22 by seam welding (electrical resistance welding) in an airtight and watertight state with the opposing fuel tank main body portion 22b. When one seam welding is completed, the rotary shaft 9 is reversely rotated in synchronism with the upward movement by the air cylinder 3 so that the roller electrode 16 together with the revolving arm 14 and the electrode head 15 is shown by a solid line in FIG. Return to position.

As described above, it is not necessary to rotate the fuel tank main body 22 and the tube 20 with respect to the pair of electrodes 16 and 18, and the roller electrode 16 is fixed and set.
Since the predetermined seam welding can be performed by the revolution of the side, the electrodes 16, 18 can be downsized while the overall size of the device is reduced.
It is possible to provide versatility such that it can be applied to fuel tanks of various sizes and shapes simply by exchanging.
Further, it is possible to omit the use of components such as packing and bolts for ensuring the sealing property, and it is possible to improve the productivity and reduce the manufacturing cost.

When the structure as shown in FIGS. 3 and 4 is adopted as the conduction path from the welding transformer 2 to the roller electrode 16, the structure around the rotation axis is simple and the appearance is simple. In addition, although it is possible to configure it into a well-assembled one, a flexible covered electric wire may be used in addition to this.

[0019]

As described above, according to the present invention, one electrode of a pair of electrodes is a fixed electrode, and
Since the other electrode is a roller electrode that revolves around the axis of the fixed electrode while pressing the tube-side flange-shaped plate portion against the outer surface of the fuel tank main body portion,
There is no need to rotate the fuel tank body, and with the roller electrode revolved while it is fixedly set, the flange plate and the fuel tank body that faces the flange plate are sequentially seam welded in a continuous line in the circumferential direction. can do. Therefore, while aiming at downsizing of the entire device, it is possible to have versatility such that it can be applied to fuel tanks of various sizes and shapes simply by exchanging the electrodes, and at the same time, the tube-side flange-shaped plate portion and Improve productivity and reduce manufacturing costs by omitting components such as packings and tightening bolts to secure the sealing performance between the opposing fuel tank body and eliminating assembly work for those components. Can be planned. Even so, it is possible to fix the tube to the fuel tank main body in a state where a very excellent sealing property is secured by seam welding.

[Brief description of drawings]

FIG. 1 is an overall side view of an inlet seam welding apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged side view around the electrode head of the above seam welding device.

FIG. 3 is an enlarged vertical cross-sectional view of a main part showing a specific structure of a conductive part from a fixed conductor to a swivel arm in a conductive path that conducts a roller electrode to a secondary side of a welding transformer.

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a cross-sectional view of an essential part showing a conventional tube fixing structure.

FIG. 6 is a plan view of a flange-shaped plate portion.

[Explanation of symbols]

 16 Roller Electrode 18 Cylindrical Fixed Electrode 20 Tube for Oil Filling Port 21 Flange Plate 22 Fuel Tank Main Body 22a Tube Insertion Hole 22b Tank Main Body Faces Flange Plate a Rotating Shaft Core

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiji Takamoto 4-3-1, Nishimikuni, Yodogawa-ku, Osaka City, Osaka Prefecture Osaka Electric Co., Ltd.

Claims (1)

[Claims] 1. A flange-shaped plate portion fixed to an outer peripheral surface outside the hole of a fuel injection tube having one end inserted into the tank body through a hole formed in the fuel tank body, and a fuel facing the plate portion. A seam welding device for welding a tank main body portion in an overlapped state, of a pair of electrodes sandwiching an overlapped portion of the tube-side flange-shaped plate portion and a fuel tank main body portion facing the flange-shaped plate portion, One electrode is configured as a cylindrical fixed electrode having a flat surface that abuts the inner surface of the fuel tank body portion, and the other electrode has the tube-side flange-shaped plate portion on the outer surface of the fuel tank body portion. A seam welding device comprising a roller electrode that revolves around a cylinder axis of the cylindrical fixed electrode while being pressed and pressed.