JP3782191B2 - Spot welder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spot welder that performs spot welding on a workpiece.
[0002]
[Prior art]
As a conventional spot welder, an upright support frame is provided, and an arm member that can pivot in the horizontal direction about a pivot axis is provided on the upper portion of the support frame. This arm member is provided with a moving frame that can move in the longitudinal direction of the arm member, and this moving frame is provided with a gun support cylinder that can be moved up and down and extended in the vertical direction.
[0003]
A welding gun is provided below the gun support tube. An electrode is provided at the tip of the welding gun, and a grip is provided at the rear of the welding gun.
[0004]
With the above configuration, when spot welding is performed on a work placed on a work table attached to the support frame, for example, the arm member is swiveled with the swivel axis as a fulcrum and moved with respect to the support frame. The gun support cylinder is moved in the longitudinal direction of the arm member through the frame, and the gun support cylinder is moved in the vertical direction.
[0005]
Next, the operator grips the grip provided at the rear part of the welding gun, positions the electrode provided at the tip of the welding gun at the desired position of the workpiece and energizes the workpiece, thereby spot welding at the desired position of the workpiece. Processing is performed.
[0006]
[Problems to be solved by the invention]
By the way, in the conventional spot welder described above, the welding gun is provided so as to be able to swing with respect to the gun support cylinder with a hinge pin as a fulcrum, so that the electrode provided at the welding gun tip at the tip of the welding gun After positioning the electrode, the welding gun is swung to press the electrode at the welding point.
[0007]
For this reason, there is a problem that the welding pressure is changed and the welding point is shifted due to the length of the electrode, so that welding with good quality cannot be obtained.
[0008]
An object of the present invention is to provide a spot welder in which when welding is performed at an welding point with an electrode, a constant pressure is applied and pressure is applied to obtain a good quality weld.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a spot welder of the present invention according to claim 1 is provided with an arm member capable of turning in a horizontal direction on a support frame, and a movable frame horizontally movable along the arm member is provided on the arm member. A gun support cylinder is provided on the moving frame so as to be movable up and down, and a barrel of a welding gun provided with a detachable electrode at the front end and an operation grip at the rear end is attached to a lower frame of the lower part of the gun support cylinder. In the spot welder provided so as to be swingable in the vertical direction with respect to the fulcrum, the moving frame is provided with a vertically moving air cylinder for vertically moving the gun support cylinder, and the vertically moving air cylinder is provided below the vertically moving air cylinder. A pressure air cylinder that is coaxial with the cylinder and is provided with a brake clutch on the lower frame below the gun support cylinder. A rod is provided coaxially with the air cylinder for pressurization, a rod is inserted through the axis of the brake clutch so as to be movable in the vertical direction, and a connecting rod connected via a pin is provided at the lower portion of the rod. A rod is connected to the operation grip side from the hinge pin of the welding gun so as to be swingable in the vertical direction, and the brake air cylinder is connected to the pressurization air cylinder so as to be movable up and down. When positioning the tip of the welding point at the welding point, the brake clutch of the brake air cylinder is turned off to allow the rod to move up and down, thereby allowing the welding gun to swing up and down. After positioning the tip at the welding point, turn on the brake clutch to regulate the vertical movement of the rod Further, the vertical swing of the welding gun is fixed, and the welding gun is linearly lowered by the pressurizing air cylinder to linearly pressurize the electrode through the welding gun. Is a summary .
[0010]
Therefore, when spot welding is performed on a work placed on a work table attached to the support frame, for example, the arm member is swung with the swiveling axis as a fulcrum with respect to the support frame and the moving frame is moved with respect to the arm member. The arm member is moved in the longitudinal direction. Further, the gun support cylinder is moved up and down by the vertical movement device with respect to the moving frame. Next, with the welding gun held by the operator and the brake device turned off, the electrode provided at the tip of the welding gun is positioned at a desired position on the workpiece, and the pressure device is turned on with the brake device turned on. Then, the electrode is linearly pressurized through a welding gun and energized, whereby spot welding is performed at a desired position of the workpiece.
[0011]
Thus, since the electrode is linearly pressed to the welding point of the workpiece, spot welding is always performed with a constant applied pressure regardless of the length of the electrode, so there is little deviation of the welding point. Good quality welding is obtained.
[0013]
In addition, since the air cylinder for vertical movement, the air cylinder for pressurization, and the air cylinder for brake are arranged in order on the gun support cylinder from the top and are composed of small air cylinders, the gun support cylinder is made compact. It moves with a small stroke to save energy.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0015]
Referring to FIGS. 1 and 2, as spot welder 1, a flat bed 3 is attached on a floor surface with an anchor bolt or the like. On the bed 3, a support frame (column) 5 extending in the vertical direction is erected. A work table 7 on which the work W is placed and fixed is attached to the lower side of the support frame 5 with a bolt or the like in FIG.
[0016]
A hollow turning shaft 10 is rotatably supported on the right side wall of FIG. 1 above the support frame 5 via a bearing 9. A conductive rod 11 such as copper is mounted in the hollow portion of the turning shaft 10. One end of an arm member 13 extending in the horizontal direction is attached to the pivot shaft 10. A guide rail 15 is provided on the lower surface of the arm member 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 slider 17.
[0017]
A bracket 21 is integrally attached to the moving frame 19 as shown in FIG. A guide member 23 is attached to the lower portion of the bracket 21. A guide rod 25 and a gun support cylinder 27 extending in the vertical direction are mounted on the guide member 23 so as to be movable in the vertical direction.
[0018]
In the gun support cylinder 27, a vertical movement device 29, a pressurization device 31, and a brake device 33 are sequentially arranged from the top to the bottom. A welding gun 39 is swingably provided on the lower frame 35 of the gun support cylinder 27 with a hinge pin 37 as a fulcrum. An electrode (tip) 41 is detachably mounted on the front end (left end in FIG. 1) of the welding gun 39, and a grip 43 is provided on the rear end (right side in FIG. 1).
[0019]
A power feeding joint device 45 is provided below the conductive rod 11 mounted on the pivot shaft 10, and the power feeding joint device 45 is free from contact with the conductive rod 11 when the pivot shaft 10 turns. In addition, at the time of energization, it is in contact with the conductive rod 11 and energized. The power supply joint device 45 is connected to a power source (not shown) via a bus bar 47 made of, for example, copper. On the other hand, one end of a bus bar 49 made of, for example, copper or the like is connected to the upper portion of the conductive rod 11, and the other end of the bus bar 49 is connected to the arm member 13, and further connected to the welding gun 39 via a cable or the like. Has been.
[0020]
As shown in FIG. 3, the vertical movement device 29 includes a vertical movement air cylinder 51, and the tip (upper end) of a piston rod 53 attached to the vertical movement air cylinder 51 is the moving frame 19. It is fixed with a nut 55. In addition, the left end of the plate 57 integrated with the upper surface of the vertically moving air cylinder 53 in FIG. 3 is fixed to the upper portion of the guide rod 25 with a nut 59.
[0021]
With the above configuration, when air is supplied to the air supply port 61 of the vertical movement air cylinder 51, the vertical movement air cylinder 51 is lowered with respect to the guide member 23, and when air is supplied to the air supply port 63, the guide member. 23 is raised. At this time, the guide rod 25 is lowered and raised with respect to the guide member 23, and the vertical movement cylinder 51 is smoothly lowered and raised.
[0022]
A pressurizing air cylinder 65 of the pressurizing device 31 is integrated with a lower portion of the vertical moving air cylinder 51. A piston rod 67 mounted on the pressurizing air cylinder 65 is fixed to an upper portion of a hollow cylindrical member 69 having an open lower portion provided in the pressurizing air cylinder 65.
[0023]
With the above configuration, when air is supplied to the air supply port 71 of the pressurizing air cylinder 65, the hollow cylindrical member 69 is lowered via the piston rod 67.
[0024]
A brake air cylinder 73 of the brake device 33 is provided in the lower portion of the hollow cylindrical member 69, and a brake clutch 75 is provided in the brake air cylinder 73. A rod 77 extending in the vertical direction and movable in the vertical direction is attached to the substantially central portion of the brake clutch 75.
[0025]
The lower frame 35 is attached to the lower part of the hollow cylindrical member 69. An upper portion of the rod 79 is connected to the lower portion of the movable rod 77 by a pin 81, and a lower end of the rod 79 is integrated with the welding gun 39.
[0026]
With the above configuration, when spot welding is performed on the work W placed on the work table 7 attached to the support frame 5, the center of the conductive rod 11 attached to the pivot shaft 10 with respect to the support frame 5 is a fulcrum. As shown in FIG. 2, the arm member 13 is rotated in the horizontal direction to the position indicated by a two-dot chain line in FIG.
[0027]
Further, the gun support cylinder 27 is lowered with respect to the moving frame 19 by the operation of the vertical movement air cylinder 51 of the vertical movement device, and the operator holds the grip 43 of the welding gun 39, and the brake air cylinder 73 of the brake device 33 is moved. In the state of being turned off, the electrode 41 provided at the tip of the welding gun 39 is positioned at a desired position of the workpiece W. In this state, the brake air cylinder 73 of the brake device 33 is turned on, and the pressurization air cylinder 65 of the pressurization device 31 is operated to pressurize the electrode 41 via the welding gun 39.
[0028]
In this pressurized state, spot welding is performed at a desired position of the workpiece W by energizing the electrode 41 from the power supply (not shown) through the bus bar 47, the power supply joint device 45, the bus bar 49, and the cable.
[0029]
Thus, since the electrode 41 is linearly pressurized to the welding point of the workpiece W, spot welding can always be performed with a constant pressure regardless of the length of the electrode 41. Good quality welding can be obtained with little deviation.
[0030]
The gun support cylinder 27 is configured by the vertical movement air cylinder 51 of the vertical movement device 29, the pressurization air cylinder 65 of the pressurization device 31, and the brake air cylinder 73 of the brake device 33 arranged in order from the upper side to the lower side. Therefore, the gun support cylinder 27 can be manufactured in a compact manner and can be moved with a small stroke to save energy.
[0031]
In addition, this invention is not limited to embodiment of invention mentioned above, It can implement in another aspect by making an appropriate change.
[0032]
【The invention's effect】
As can be understood from the embodiments of the invention as described above, according to the invention of claim 1, when spot welding is performed on a work placed on a work table attached to the support frame, for example, the support frame. The arm member is swung with the swivel axis as a fulcrum, and the moving frame is moved with respect to the arm member in the longitudinal direction of the arm member. Further, the gun support cylinder is moved up and down by the vertical movement device with respect to the moving frame. Next, with the welding gun held by the operator and the brake device turned off, the electrode provided at the tip of the welding gun is positioned at a desired position on the workpiece, and the pressure device is turned on with the brake device turned on. In this case, the electrode is set via a welding gun and energized to perform spot welding at a desired position on the workpiece.
[0033]
Thus, since the electrode is linearly pressed to the welding point of the workpiece, spot welding can always be performed with a constant pressure regardless of the length of the electrode, so there is little deviation of the welding point. A good quality weld can be obtained.
[Brief description of the drawings]
FIG. 1 is a side view of a spot welder according to an embodiment of the present invention.
FIG. 2 is a plan view of FIG.
FIG. 3 is an enlarged detail view of the portion indicated by the arrow III in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Spot welder 5 Support frame 7 Work table 10 Rotating shaft 11 Conductive rod 13 Arm member 19 Moving frame 21 Bracket 27 Gun support cylinder 29 Vertical movement device 31 Pressurization device 33 Brake device 39 Welding gun 41 Electrode 43 Grip 45 Feed joint device 51 Air cylinder for vertical movement 65 Air cylinder for pressurization 73 Air cylinder for brake

Claims (1)

The support frame is provided with an arm member that can pivot in the horizontal direction, the arm member is provided with a movable frame that can move horizontally along the arm member, and a gun support cylinder is provided on the movable frame so as to be movable up and down, and is attached to and detached from the tip. In a spot welding machine provided with an electrode capable of being operated and having a barrel of a welding gun provided with an operation grip at the rear end thereof provided on a lower frame of the lower part of the gun support cylinder so as to be swingable in a vertical direction with a hinge pin as a fulcrum. The moving frame is provided with a vertically moving air cylinder for moving the gun supporting cylinder up and down, and a pressurizing air cylinder coaxial with the vertically moving air cylinder is integrally provided at the lower part of the vertically moving air cylinder. A brake air cylinder having a brake clutch in the lower frame is provided coaxially with the pressurizing air cylinder, and the brake A rod that is inserted through the axis of the latch so as to be movable in the vertical direction is provided, a connecting rod that is connected to the lower portion of the rod through a pin is provided, and the connecting rod is closer to the operation grip side than the hinge pin in the welding gun. The brake air cylinder is provided so as to be swingable in the vertical direction. The brake air cylinder is connected to the pressurization air cylinder so as to be vertically movable. When the tip of the electrode is positioned at the welding point, the brake air cylinder is provided. After turning off the brake clutch of the air cylinder and allowing the rod to move up and down, the welding gun can swing up and down, and after the tip of the electrode is positioned at the welding point, the brake clutch is turned on. By restricting the vertical movement of the rod, the vertical swing of the welding gun is fixed, and the pressurizing air cylinder is fixed. Spot welding machine, characterized in that said linearly lowers the welding gun in the vertical direction gives the linear pressure to the electrode through the welding gun by.

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