JP3165107B2 - Spot welding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spot welding machine for performing spot welding on a work (workpiece).

[0002]

2. Description of the Related Art In a conventional spot welding machine 101, as shown in FIG.
A transformer 107 is provided below the column 105. One end of a secondary cable 109 for energization is connected to a booth bar 111 of the transformer 107.
Connected through. The cable 109 extends upward from a support arm 113 provided at the upper part of the column 105, and the cable 109 is suspended from the upper part.
5 are connected to the welding gun 117. This cable 109 is adapted to be moved left and right and up and down. In addition, the other electrode 121 is provided on the upper surface of the work table 119 provided integrally with the base 103.
Is provided. This electrode 121 has a booth bar 12
3 and connected to the transformer 107.

As another spot welding machine 101, FIG.
Are known. 6, the same components as those in FIG. 5 are denoted by the same reference numerals, and duplicate description will be omitted.

[0006] In FIG. 6, a cable 109 is connected to the booth bar 111 via copper booth bars 125 and 127.

[0005]

In the conventional spot welding machine 101 shown in FIG. 5 described above, the welding gun unit 115,
Since the support arm 113 is raised and lowered, and considering the handling of the support arm 113 when turning, the cable 109 must be pulled out from the upper end of the column 105 as shown in FIG. Would. The output current of the spot welding machine 101 is such that the longer the cable 109, in other words, the longer the energizing path, the greater the electrical resistance and the lower the output.

On the other hand, the spot welding machine 101 shown in FIG.
Then, by using copper booth bars 125 and 127 having a smaller resistance than the cable 109 and shortening the current supply path by raising and lowering only the welding gun unit for raising and lowering the welding gun 117, the output can be prevented from being reduced. However, the copper booth bars 125 and 127 are much heavier than the cable 109. For this reason, since the copper booth bars 125 and 127 are disposed on the support arm 113, a load is generated when the support arm 113 is turned, and the handling performance of the welding gun 117 is reduced.

Further, in the conventional spot welding machine 101 shown in FIGS.
When a large current of 000 amperes flows, a magnetic field is generated around the cable 109 and the booth bar 125 (111) as shown in FIG. As shown in (1), the electromagnetic force F is generated around the cable 109 due to Fleming's left hand rule, and the cable 109 may be hit and hit by an operator, which is dangerous for the operator.

Further, when the cable is partially fixed, there is a problem that work is restricted and work efficiency is reduced.

As a method of shortening the power supply path, a method in which the cable 109 is taken out from under the work table 119 and connected to the welding gun 117 can be considered. It is not a good method.

[0010] An object of the present invention is to shorten the current supply path as much as possible so that the output current does not decrease, and even when a large current flows through the cable, the cable is not exposed and the maneuvering of the welding gun is improved, so that the operator can be provided with a good operation. An object of the present invention is to provide a spot welding machine that does not cause danger and does not reduce work efficiency.

[0011]

According to a first aspect of the present invention, there is provided a spot welding machine according to the first aspect of the present invention. the in the spot welding machine having the configuration vertically support posts having vertically movably supports the horizontal portion of the cable by a support member which is vertically to the support arm
With the vertical part of the cable between the support posts
And provided on the opposite side of the column and movable in a direction intersecting the support column and in front of the cable.
Serial cable pressing member for urging the vertical portion to the support column direction is provided, when energizing the cable and is characterized by comprising providing a fixing device for fixing the cable pressing member.

Accordingly, the support arm is moved horizontally, and the welding gun is moved up and down with respect to the support column, so that the welding gun is positioned with respect to the workpiece.

When a current is applied when spot welding is performed on the work with a welding gun, the cable pressing member is fixed by a fixing device, the movement of the cable is regulated by the cable pressing member, and the movement amount of the cable is minimized. Therefore, the safety of workers is ensured. When the power is not supplied, the cable pressing member is released from the fixing device, and is freely moved right and left and up and down, so that the handling of the welding gun is improved.

According to a second aspect of the present invention, in the spot welder of the first aspect, the length of the cable is shorter than a length obtained by adding a length of the support column to a total length of a support arm. It is a feature.

Therefore, the length of the cable, that is, the current path is shorter than in the conventional case, and the output current is not reduced, so that the cost is reduced and the operator can easily operate the spot gun.

According to a third aspect of the present invention, in the spot welder of the first or second aspect, the cable pressing member is a flexible member.

Therefore, since the cable pressing member is a flexible member, the cable is held without being damaged and can be moved freely.

[0018]

[0019]

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Referring to FIGS. 1 and 2, as the spot welding machine 1, a flat bed 3 is mounted on a floor surface with anchor bolts or the like. On this bed 3, a column 5 extending in the vertical direction is erected. On the lower left side of the column 5, a work table 7 for mounting and fixing the work W is provided.

A hollow revolving shaft 11 is rotatably supported on the left side wall of the upper part of the column 5 in FIG. One end of a support arm 13 extending in the horizontal direction is mounted on the turning shaft 11.
A guide rail 15 is provided on a lower surface of the support arm 13 in the longitudinal direction. A plurality of sliders 17 are slidably provided on the guide rail 15, and a moving frame 19 is integrated with the sliders 17.

The moving frame 19 has a driving motor 21
And a pipe 23 is provided to hang down. For example, a gun support tube 25 as an example of a support column is mounted on the outer periphery of the pipe 23 so as to extend in the vertical direction. A pressurizing cylinder 27 and a rotating shaft 29 are provided below the gun support cylinder 25 in this order.
Below the pressurizing cylinder 27, a pressurizing rod 31 extends downward through the inside of the rotating shaft 29, and a welding gun 33 is provided at the tip of the pressurizing rod 31.
An electrode (welding tip) 35 is detachably attached to the tip of the welding gun 33.

A ball screw (not shown) extending in the vertical direction is provided in the pipe 23, and the upper portion of the ball screw is connected to the drive motor 21 via drive transmission means. A nut member is screwed into the ball screw, and a gun support tube 25 is provided on the nut member.

The rotary shaft 29 is provided with a bracket 37, and the bracket 37 is connected to the welding gun 33 by pins 39. Moreover, the welding gun 33 is rotated around the pin 39 as a fulcrum. A handle 45 provided with an energizing switch 43 is provided via a bracket 41 at a rear portion (left portion in FIG. 1) of the welding gun 33.

With the above configuration, the support arm 13 is pivoted in the horizontal direction with the pivot 11 as a fulcrum, and the moving frame 19 is guided by the guide rail 15 and moved in the longitudinal direction of the support arm 13. When the drive motor 21 is driven, a ball screw (not shown) is rotated, and the gun support cylinder 25 is moved up and down via a nut member. Will also be moved up and down. Further, when the operator grips and operates the handle 45, the welding gun 33 is rotated in the vertical direction with the pin 39 as a fulcrum, and when the pressing cylinder 27 is operated, the pressing rod 31 is pressed.
, The electrode 35 of the welding gun 33 is pressurized.

The upper surface of the work table 7 has the electrode 3
5 and the other electrode 47 is connected to a transformer 53 provided in the column 5 via copper booth bars 49 and 51. One end of a cable 55 is connected to the welding gun 33 having the electrode 35, and the other end of the cable 55 is connected to an upper end of a booth bar 59 via a joint 57. The booth bar 59 extends in the vertical direction, and the other end (lower end) of the booth bar 59 is connected to the upper end of another booth bar 61 and the lower end of the booth bar 61 is connected to the transformer 53 via the booth bar 63. ing.

With the above configuration, the operator operates the welding gun 33 by grasping the handle 45, and turns on the energizing switch 43 with, for example, a plurality of SPCC, 1 mm thick workpieces between the electrodes 35 and 47. Then, a current flows and the work is spot-welded.

One end of a rope 65 as an example of a cable pressing member is connected to the middle (vertical portion) of the cable 55, and the rope 65 is connected to the rope 65 as shown in FIG. A weight 69 is connected to the other end of the rope 65 through a pair of upper and lower guides 67 for holding. The weight 69 is for applying tension to the rope 65. The guide 67 has a curved surface 71 for improving the durability of the rope 65. The horizontal portion of the rope 65 is suspended from the support arm 13 by a suspension member 73.

As shown in FIG. 2, the upper guide 67 has an air cylinder 75 as an example of a fixing device.
And a knob 79 made of resin is attached to a distal end (lower end) of a piston rod 77 mounted on the air cylinder 75. When the piston rod 77 is lowered by operating the air cylinder 75, the rope 65 is fixed by the knob 79 and the lower guide 67.

With the above configuration, as described above, the welding gun 33 having the electrode 35 can be freely moved up and down, left and right, and is positioned with respect to the work. The cable 65 is suspended from the support arm 13 by a suspension member 73 as an example of a support member.
However, this does not hinder the movement of the welding gun 33. Therefore, the operator can freely position the welding gun 33.

When the positioning of the welding gun 33 is completed, the operator presses the power switch 43 to energize. At this time, a magnetic field is generated around the cable 55, the cable 55 that are less constrained, receives a force by the generated magnetic field is about to be moved. When the magnitude of the current exceeds about 13,000 A, for example, the movement becomes remarkable. The cable 55 has a large weight, for example, 10 k
g. The worker is very likely to be hit directly by the cable 55 when energized.

Therefore, by restricting the cable 55 with the rope 65 as a rope pressing member at the time of energization, the movement of the cable 55 can be restricted, and safety for the worker can be ensured.

Specifically, the air cylinder 75 is actuated at the same time when the power switch 43 is pressed, and the knob 79 is pushed downward, and the rope 65 is pressed against the lower guide 67 so that the rope 65 does not move. Power supply is started in this state. The cable 55 tries to move under the influence of the magnetic field,
Since the movement is restricted by the rope 65, the movement amount is minimized. At the same time as the energization is completed, the piston rod 77 contracts, the knob 79 retracts, the rope 65 becomes free, and the cable 55 becomes free. As described above, the movement of the cable 55 can be restricted only when power is supplied, and the safety of the worker can be ensured without any hindrance when the worker performs normal work. Further, work can be performed without lowering work efficiency.

The length of the cable 55, that is, the current path is made shorter than the length obtained by adding the length of the gun support tube 25 to the total length of the support arm 13, so that the output current is not reduced and the cost is reduced. In addition, the operation of the welding gun 33 can be facilitated.

The rope 65 does not expand and contract, for example, nylon,
By using a flexible member such as cotton, the cable 55 can be held without any trouble and can be freely moved.

FIG. 3 shows another embodiment.
In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

In FIG. 3, a rope 65 is connected to the cable 55.
Is connected, and the other end of the rope 65 is wound around a mainspring 81 as a winding device provided on the gun support tube 25. Further, the gun support cylinder 25 is provided with a guide 67, an air cylinder 75, a piston rod 77 and a knob 79.

With the above structure, when the air cylinder 75 is operated when the cable 55 is moved to the left and right with respect to the gun support cylinder 25 and positioned, the piston rod 7 is moved.
The knob 79 descends via the knob 7 and the knob 79 and the guide 6
7, the rope 65 is held. In this state, electricity is supplied and the workpiece is welded. For example, when the cable 55 is moved to the right in FIG.
When the user operates the knob 5, the knob 79 moves up via the piston rod 77, and the rope 65 is in a free state. When the cable 55 moves to the left in FIG. 3, it is pulled out from the mainspring 81 by a necessary amount.

Therefore, in the case of this example, the same effect as in the above-described example can be obtained.

FIG. 4 shows another embodiment.
In FIG. 4, cylindrical members 83 and 85 are mounted on the cable 55 and the gun support cylinder 25, respectively.
The cylindrical member 83 and the cylindrical member 85 are connected by a connecting member 87.

Therefore, the cable 55 and the gun support cylinder 2
5 is always held and moved at a constant interval, and positioning is performed. Therefore, the same effect as in the above-described example can be obtained, and workability can be improved as compared with the related art.

The present invention is not limited to the above-described embodiment, but can be embodied in other forms by making appropriate changes.

[0044]

As will be understood from the above description of the embodiment of the invention, according to the first aspect of the present invention, the support arm is moved horizontally and the welding gun is moved up and down with respect to the support column. Then, the welding gun is positioned with respect to the workpiece.

When a spot welding process is performed on the work with a welding gun, when a current is applied, the cable pressing member is fixed by the fixing device, and the movement of the cable is regulated by the cable pressing member, thereby minimizing the movement amount of the cable. And the safety of workers can be ensured. When the power is not supplied, the cable pressing member is released from the fixing device and can be freely moved right and left and up and down, so that the handling of the welding gun is improved. In addition, work can be performed without lowering work efficiency.

According to the second aspect of the present invention, the length of the cable, that is, the current path can be made shorter than in the prior art, the output current is not reduced, the cost can be reduced, and the spot gun can be operated. Can be easily operated by the user.

According to the third aspect of the present invention, since the cable pressing member is a flexible member, the cable can be held without being damaged and can be moved freely.

[0048]

[Brief description of the drawings]

FIG. 1 is a side view of a spot welding machine according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a part viewed from an arrow II in FIG.

FIG. 3 is a side view of another embodiment for holding a cable.

FIG. 4 is a side view of another embodiment for holding a cable.

FIG. 5 is a side view of a conventional spot welding machine.

FIG. 6 is a side view of another conventional spot welding machine.

FIG. 7 is a plan view of a cable and a booth bar in a conventional spot welding machine.

FIG. 8 is an explanatory diagram when a magnetic field is generated in a conventional cable.

[Explanation of symbols]

 Reference Signs List 1 spot welding machine 5 column 13 support arm 19 moving frame 23 pipe 25 gun support tube (support column) 33 welding gun 35, 47 electrode 43 energizing switch 45 handle 53 transformer 55 cable 65 rope (cable pressing member) 73 suspension member ( Supporting member) 75 Air cylinder (fixing device) 79 Knob

Claims (3)

(57) [Claims] 1. A spot welding machine having a structure in which a supporting column provided with a welding gun movably up and down is vertically suspended on a supporting arm movably supported on an upright column. The horizontal portion of the cable is supported and provided by a supporting member vertically suspended at the vertical portion of the cable.
Are arranged on the opposite side of the column with the support column therebetween.
Provided with Te, when the cable pressing member for urging said vertical portion of the movable and the cable in a direction crossing the support column to the support column direction provided, energizing the cable, fixing the cable pressing member A spot welding machine, comprising: 2. The spot welding machine according to claim 1, wherein a length of the cable is shorter than a length obtained by adding a length of the support column to a total length of a support arm. 3. The spot welding machine according to claim 1, wherein the cable pressing member is a flexible member.