JPH0229438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a welding method for welding a lid to an open end of a cylinder.

For example, a lid is welded to the end of a cylinder of a shock absorber used in an automobile. When welding a lid to the end of this cylindrical body, it is necessary to center the cylindrical body and the lid. For this reason, in the past, the lid was formed into a cap shape, and the inner peripheral surface of the opening end of the cylinder or the inner peripheral surface of the lid was machined, and the lid or cylinder was fitted into this machined part. The cylindrical body and the lid body are welded together.

However, such conventional welding has the disadvantage that the cylinder or the lid must be machined one by one, which increases the number of man-hours and costs.

This invention was made in view of the above circumstances,
A cylinder is made by using a pressing and welding electrode that is movable up and down and has a recess in the center of the lower part, and a pair of clamping and welding electrodes that are positioned below the pressing and welding electrode and face each other so as to grip the cylinder. A welding method of welding a lid to the open end of the cylinder, the cylinder is positioned between the pair of clamping and welding electrodes, and then at least one of the pair of clamping and welding electrodes is brought close to the cylinder. By moving the cylinder in the direction, the cylinder is held between the other electrode and positioned so that the central axis of the cylinder substantially coincides with the central axis of the recess of the pressing and welding electrode, and the cylinder is shaped like a disk. The center of the flat part projects upward in a substantially spherical shape, and the lid body has a reference circular outer circumferential surface formed around the axis of the disk at the boundary between the flat part and the substantially spherical part. It is positioned between the cylinder and the pressing and welding electrode, and the pressing and welding electrode is lowered so that the inner peripheral edge of the recess and the reference circular outer peripheral surface portion of the lid located on the cylinder fit together. Then, with the cylinder and the lid body aligned, the lid body is pressed and welded to the upper open end of the cylinder by the pressing and welding electrode, and the cylinder and the lid body are aligned. The purpose of the present invention is to provide a welding method that enables accurate centering of the cylinder without machining and welds a lid to the open end of a cylinder, thereby reducing man-hours and reducing costs. do.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Reference numeral 1 in FIG. 1 is a base, and a fluid pressure cylinder device 3 is horizontally attached to a predetermined position of the base 1 via a bracket 2. As shown in FIG. A mounting member 4 is attached to the tip of the piston rod of this cylinder device 3.
is installed. Further, an L-shaped stopper 5 is disposed below the mounting member 4, and is mounted at a predetermined location on the base 1 so as to be movable and adjustable in the directions of arrows A and B in FIG. The mounting member 4
When moved in the direction of arrow A in FIG. 1, it comes into contact with a stopper 5 and is stopped at that position. Furthermore, a clamping and welding electrode 6 is attached to the mounting member 4. This clamping and welding electrode 6 is provided with a recess 8 having a circular arc surface having the same radius as the outer periphery of a cylinder (for example, the cylinder of a shock absorber) 7. Further, at a predetermined location on the base 1, a fluid pressure cylinder device 10 is horizontally attached via a bracket 9, facing the cylinder device 3. A mounting member 11 is attached to the tip of the piston rod of this cylinder device 10. A clamping and welding electrode 12 is attached to this attachment member 11. This clamping and welding electrode 12 has a recess 13 formed of an arcuate surface having the same radius as the outer circumference of the cylinder 7.
is provided. Thereby, the clamping and welding electrode 6 and the clamping and welding electrode 12 are opposed to each other to form a pair of welding electrodes. Further, a predetermined location above the intermediate portion between the clamping and welding electrode 6 and the clamping and welding electrode 12 (on the axis of the cylinder held by a pair of clamping and welding electrodes to be described later) is provided on the base 1. The fluid pressure cylinder device 1 is attached via the attached mounting plate 14.
5 is attached. This cylinder device 15
The piston rod extends downwardly through the mounting plate 14, and a mounting member 16 is attached to the distal end of the piston rod. A pressing and welding electrode 17 is attached to this attachment member 16. This pressing/welding electrode 17 is provided with a recess 20 having a circular inner circumferential surface having the same diameter as a reference circular outer circumferential surface 19 of a lid 18 to be described later. The disc-shaped lid body 18 is formed into a generally dish-shaped shape by press drawing, with the center of the flat part protruding upward in a generally spherical shape. At the time of this formation, the outer surface of the bottom part has a shape as shown in FIG. A reference circular outer circumferential surface 19 centered on the central axis of the lid body 18 is formed. Also at this time, lid body 1
The maximum diameter outer peripheral portion of the cylinder 8 is formed to have a diameter slightly smaller than the outer diameter of the cylinder 7. In addition, the lid body 18 is placed on the upper end of the cylinder 7 by manual operation or an appropriate mechanism (not shown), and the pressing and welding electrode 17 is lowered so that the reference circular outer circumferential surface 19 portion is placed on the inner circumference of the recess 20. It is designed to fit into the surface. Note that the effective pressure receiving area of the cylinder device 3 is larger than the effective pressure receiving area of the cylinder device 10. Furthermore, both cylinder devices 3 and 10 are configured to be operated by fluids having the same pressure.

When the lid 18 is welded to the open end of the cylinder 7, the cylinder 7 is erected on the base 1 and positioned between the clamping and welding electrodes 6 and 12. Further, the movement of the stopper 5 is adjusted in advance. That is, cylinder 7
is held between the holding and welding electrodes 6 and 12, and the central axis of the cylinder 7 is aligned with the central axis of the recess 20. In this state, the stopper 5 is brought into contact with the mounting member 4 and fixed to the base 1, and the position of the stopper 5 is set as the set position of the stopper 5 in this case. Then, when the cylinder devices 3 and 10 are operated in a state where the clamping and welding electrodes 6 and 12 and the pressing and welding electrode 17 are separated from the cylinder 7, one of the clamping and welding electrodes 6 is moved as shown in FIG. When the mounting member 4 moves in the direction of arrow A and comes into contact with the stopper 5, it is stopped at a predetermined position. Further, the other clamping/welding electrode 12 moves in the direction of arrow B in FIG. 1, contacts the cylinder 7, and further presses it. As a result, the cylinder 7 is held in a predetermined position by the holding and welding electrodes 6 and 12. That is, the cylinder 7 is held between the holding and welding electrodes 6 and 12, and the held cylinder 7 is further passed through the holding and welding electrode 12 by the cylinder device 10 in the direction indicated by the arrow B in FIG.
However, since the effective pressure receiving area of the cylinder device 3 is larger than the effective pressure receiving area of the cylinder device 10, the force with which the clamping and welding electrode 6 receives the cylinder 7 is due to the force of the clamping and welding electrode 12 holding the cylinder 7. The force is stronger than the pressing force, and therefore the clamping and welding electrode 6 remains at a predetermined position and does not move, so it is clamped at a predetermined position. Next, in this state, the lid body 1 is opened manually or by an appropriate mechanism (not shown).
8 is placed on the end of the cylinder 7. Next, when the cylinder device 15 is actuated, the pressing and welding electrode 17 gradually fits into the reference circular outer peripheral surface 19 of the lid body 18 as the pressing and welding electrode 17 descends, and the lid body 18 is moved by the pressing and welding electrode 17. It is pressed against the cylinder 7. As a result, the central axis of the lid 18 and the central axis of the cylinder 7 are aligned, and the two are centered. In this case, by fitting the reference circular outer peripheral surface 19 formed on the lid body 18 into the recess 20 formed at the lower part of the pressing and welding electrode 17, the positioning of the lid body 18 with respect to the cylinder 7 is ensured, and the cylinder Even if there is a slight misalignment between the pressing and welding electrode 17 and the lid body 18,
When the opening edge of the recess 20 is lowered, the lid 18
By being guided by the substantially spherical portion, positional deviation can be corrected, and accurate positioning, that is, accurate centering, can be performed. Therefore,
Even if there is a misalignment, there is no need for manual alignment, and centering can be automated.
Next, in this state, a pair of clamping and welding electrodes 6, 1
When a welding current is applied to 2 and the pressing/welding electrode 17, the lid 18 is welded to the cylinder 7 in a centered state. After that, the cylinder devices 3, 10, 15 are operated to clamp the clamping and welding electrodes 6, 1 from the cylinder 7.
2. Separate the pressing and welding electrode 17 and take out the cylinder 7.

In this way, the clamping and welding electrodes 6 and 12 are movable in the radial direction of the cylinder 7 to clamp and position the cylinder 7.
It is easy to install the cylinder 7 between the cylinders 12 and 12, and once the welding is finished, the cylinder 7 can be easily taken out by releasing the grip, improving work efficiency and being suitable for automation.

Note that when the effective pressure receiving area of the cylinder device 3 and the effective pressure receiving area of the cylinder device 10 are set to be the same effective pressure receiving area, it is necessary to introduce fluids having different pressures into these cylinder devices 3 and 10, respectively.

Further, in the above embodiment, the cylinder 7 has one type of outer diameter, but the cylinder 7 is not limited to this, and cylinders with various outer diameters can be used. In this case, since the mounting position of the stopper 5 can be adjusted, the outside diameter can be changed over a wide range, and the material used for the clamping and welding electrodes 6 and 12 can be saved. Further, it is preferable to investigate in advance the setting position of the stopper 5 with respect to the difference in the outer diameter of the cylinder and provide a position adjustment scale for the stopper 5.

Further, in the above embodiment, an L-shaped stopper is attached to the base 1, but the present invention is not limited to this. For example, a double rod-shaped cylinder device may be provided in place of the cylinder device 3, and the stopper of this cylinder device may be clamped. A screw may be provided on the outer circumferential surface of the piston rod on the side opposite to the dual-welding electrode 6, and a double nut may be screwed into this screw so as to be adjustable, so that this nut serves as the stopper 5. That is, the cylinder device 3 itself may be provided with a stopper mechanism.

As explained above, according to the present invention, at least one of the clamping and welding electrodes is movable in the radial direction of the cylinder to clamp and position the cylinder.
It is easy to install the cylinder between the clamping and welding electrodes, and when the clamping is released, it is also easy to take out the cylinder, improving workability and being suitable for automation.

Further, by fitting the recess formed in the lower part of the pressing and welding electrode to the reference circular outer peripheral surface formed on the lid, the lid can be reliably positioned with respect to the cylinder.

In particular, even if there is a slight misalignment between the pressing and welding electrode and the lid, the approximately spherical portion of the lid guides the lid to the opening edge of the recess of the pressing and welding electrode. By doing so, positional deviations can be corrected, accurate positioning, that is, accurate centering, and centering can be automated. Therefore, no man-hours are required, and costs can be reduced.

Further, the pair of clamping and welding electrodes are each operated by a fluid pressure cylinder device, and the effective pressure receiving area of one fluid pressure cylinder device is larger than the effective pressure receiving area of the other fluid pressure cylinder device, and the effective pressure receiving area of the one fluid pressure cylinder device is larger than the effective pressure receiving area of the other fluid pressure cylinder device. If the clamping and welding electrode operated by the fluid pressure cylinder device is provided with a stopper to stop it at a predetermined position, fluid of the same pressure can be used, and various types of electrodes related to the fluid pressure cylinder device can be used. Additional equipment can be largely omitted, and centering adjustment between the cylinder and the lid body is extremely easy.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway vertical cross-sectional view showing an embodiment of the present invention, FIG. 2 is a cross-sectional plan view taken along the line - in FIG. 1, and FIG. 3 is a vertical cross-sectional view of the lid. 3, 10, 15... Cylinder device, 5... Stopper, 6, 12... Clamping and welding electrode, 7...
Cylinder, 17... Electrode for pressing and welding, 18... Lid body, 19... Reference circular outer peripheral surface, 20... Recessed portion.

Claims (1)

[Scope of Claims] 1. A pressing and welding electrode that is movable up and down and having a concave portion in the center of its lower part, and a pair of clamping and welding electrodes located below the pressing and welding electrode and facing each other so as to clamp a cylinder. A welding method in which a lid is welded to the open end of a cylinder using a pair of clamping and welding electrodes, and after the cylinder is positioned between the pair of clamping and welding electrodes, at least one of the pair of clamping and welding electrodes is welded. By moving one electrode in a direction approaching the cylinder, the cylinder is sandwiched between it and the other electrode, and the cylinder is moved so that the central axis of the cylinder approximately coincides with the central axis of the recess of the pressing and welding electrode. , the center of the disc-shaped flat part protrudes upward in a substantially spherical shape, and the lid body has a reference circular outer circumferential surface formed around the axis of the disc at the boundary between the flat part and the approximately spherical part. is positioned between the upright cylinder and the pressing and welding electrode, and the pressing and welding electrode is lowered so that the inner peripheral edge of the recess and the reference circle of the lid located on the cylinder are aligned. In a state where the outer peripheral surface portions are fitted and the cylinder and the lid body are centered, the lid body is pressed and welded to the upper open end of the cylinder by the pressing and welding electrode. Welding method. 2 The pair of clamping and welding electrodes are each actuated by a fluid pressure cylinder device, and the effective pressure receiving area of one fluid pressure cylinder device is made larger than the effective pressure receiving area of the other fluid pressure cylinder device, and the one fluid 2. The welding method according to claim 1, wherein the clamping and welding electrode operated by the pressure cylinder device is stopped at a predetermined position by a stopper.