JP3042961U - Main structure of X type spot gun - Google Patents

Abstract

(57) [PROBLEMS] To provide an X-type spot gun main shaft structure having a dramatically improved life by using an angular ball bearing or a tapered roller bearing as a bearing and preloading the bearing. SOLUTION: In an X-shaped spot gun in which at least one gun arm 1 of two gun arms having electrodes facing each other is rotatably pivoted, one of the gun arms is pivoted. In the vicinity of the part is branched into two forks 1a, 1b,
The other gun arm 4 is inserted between the forks near the pivot portion, and the gun arm between the forks is pivotally supported on the pivot portion by a hinge pin 6 via an angular ball bearing 21 or a tapered roller bearing. A main shaft structure of an X-shaped spot gun in which the bearing is preloaded between the two forks by mutually tightening the two forks.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an X-type spot gun in which at least one of two gun arms having electrodes facing each other is rotatably connected, and particularly to a main shaft structure thereof. is there.

[0002]

[Prior art]

 Conventionally, in an X-type spot gun having two gun arms pivotally rotatably provided with electrodes facing each other, one of the gun arms is bifurcated near the pivot part and the other gun arm is branched. -A thrust washer is inserted between the forks near the pivot, and the inner and / or outer sides of the forks are arranged on the same axis as the hinge pin to insulate the gun arms from each other. The thrust washer is provided on the sliding surface of the thrust washer by moving the thrust washer on the same axis as the hinge pin by providing a pressing means that directly or indirectly applies a biasing force from a direction intersecting the side surface of the thrust washer at a substantially right angle. The main shaft structure of an X-shaped spot gun which eliminates the generated gap is commonly known as disclosed in, for example, Japanese Unexamined Patent Publication No. 4-46882.

[0003]

[Problems to be solved by the device]

 By the way, the main shaft structure of the publicly known X-type spot gun is based on the assumption that a slide bearing is used and the thrust washer is worn, and when the thrust washer is worn, the pressing means as described above is used. It is necessary to move the thrust washer on the same axis as the hinge pin by using, and the work is troublesome, and no consideration is given to the abrasion of the insulating bush arranged on the outer periphery of the hinge pin. There's a problem.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to use an angular ball bearing or a tapered roller bearing as a bearing and preload the bearing. The main purpose is to provide a spindle structure for an X-type spot gun whose life is dramatically improved.

Further, by using a ring-shaped seal plate, the main shaft of an X-type spot gun in which the grease in the bearing can be retained and the spatter from the outside can be prevented to sufficiently protect the bearing. It is an attempt to provide a structure.

[0006]

[Means for Solving the Problems]

 To achieve the above object, the main structure of the X-shaped spot gun according to the present invention is such that one of the gun arms is bifurcated in the vicinity of the pivot portion and the other gun arm is in the vicinity of the pivot portion between the two forks. The gun arm between the two forks is pivotally supported by a hinge pin through an angular ball bearing or a tapered roller bearing in the pivot, and the bearing is preloaded between the forks by tightening the hinge pin and the fork together. It is characterized by being present.

Further, a ring-shaped insulating washer is arranged between the inner surface of the bifurcated portion and the side surface of the gun arm arranged between the bifurcated portions, and is fixed to the inner ring of the bearing in the space between the washer and the end surface of the bearing. It is characterized in that a seal plate having a ring shape and having a grease holding portion is arranged.

[0008]

[Embodiment of the invention]

 An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side view of a partial cross section of an X-shaped spot gun having a main shaft structure according to the present invention, and FIG. 2 is a detailed cross sectional view of the main shaft structure without equalization. In FIG. 1, 1 is a movable gun arm, an electrode 2 is attached to the tip of the arm 1, and a pin holding arm 3 is connected to the upper middle part of the arm 1. Has been done. Numeral 4 is a fixed gun arm, and an electrode 5 is attached to the tip of the arm 4 so as to face the electrode 2, and an intermediate portion of the arm 4 is fixed to the arm 1. The arm 1 is rotatable with respect to the arm 4 by being pivoted with a hinge pin 6 together with the lower rear end. Further, the drive portion main body 7 and the electric motor 8 are supported at the tip of the arm portion 41 extending from the pivot portion of the arm 4.

A holding member 9 extending rearward is fixed to the arm portion 41, and a connecting member 11 to a robot (not shown) is attached to the holding member 9 via a welding transformer 10. It is attached.

The output shaft 12 of the electric motor 8 is inserted into the drive unit main body 7, and a pinion gear 13 is attached to the output shaft 12. Further, a ball screw 14 is arranged in parallel with the output shaft 12 in the drive unit main body 7, and a gear 15 that meshes with the pinion gear 13 is attached to one end of the ball screw 14. The gears 13 and 15 form a speed reducer.

Reference numeral 16 is a ball nut that is screwed into the ball screw 14, and the ball nut 16 is integrated with the pressure rod 17 by bolting or the like, and its outer diameter is the pressure lock rod. It is substantially the same as the door 17 and constitutes a part of the pressure rod 17. The pressure rod 17 is arranged in the drive unit main body 7 so as to be non-rotatable and slidable.

A pin 18 is attached to the tip of the pressure rod 17, and a pin 19 is also attached to the pin holding arm 3 from the movable gun arm 1. A link 20 connects between the pins 18 and 19.

In the X-type electric gun configured as described above, the rotation of the output shaft 12 is reduced by the drive of the electric motor 8 through the pinion gear 13 and the gear 15 to rotate the ball flange 14. The rotation of the ball screw 14 causes the ball nut 16 to move forward and backward, so that the pressure rod 17 integrally formed with the ball screw 14 moves forward and backward. By moving the pressure rod 17 forward and backward, the movable gun arm 1 opens and closes with the hinge pin 6 as a fulcrum via the link 20 and the pin holding arm 3.

By the way, the movable gun arm 1 is branched into two forks 1a and 1b near its pivot, and the fixed gun arm 4 is inserted and arranged between the two forks 1a and 1b near its pivot. The frames 1 and 4 are pivotally supported by the hinge pin 6. That is, the forks 1a and 1b of the gun arm 1 are rotatable together with the hinge pin 6, and the hinge pin 6 is rotatable with respect to the fixed gun arm 4 via the angular ball bearings 21 and 21.

Reference numerals 22 and 22 are relatively hard insulating washers such as epoxy with glass. The insulating washers 22 have a slight gap with the fixed gun arm 4 on the opposite sides of the forks 1a and 1b. Are arranged. The inner surface of the insulating washer 22 is pressed against inner rings 24, 24 of the bearing 21 with a seal plate 23, 23 to be described later interposed therebetween. Reference numeral 25 is a spacer between the bearings 21 and 21, and 26 is an insulating bush arranged annularly on the outer periphery of the hinge pin 6.

The width of the inner ring 24 of the bearing 21 is formed slightly negative. A flange 6a is formed on one side of the hinge pin 6, and the inner surface of the flange 6a is fastened to the crotch portion 1b of the movable gun arm 1 by a plurality of bolts 27, 27 ... Further, on the other side of the hinge pin 6, a restraining plate 28 is disposed over the crotch portion 1a of the movable gun arm 1, and between the restraining plate 28 and the other side of the hinge pin 6 and between the restraining plate 28 and the movable gun arm 1 The crotch portions 1a are fastened with a plurality of bolts 29 and 30, respectively.

Reference numeral 31 is a grease supply pipe, and 32 is a shunt mounting surface mounted on the outer surface of the flange 6a.

In the main shaft structure of the X-shaped spot gun having the above-described structure, the bolts 29 and 30 are tightened into the hinge pin 6 and the crotch portion 1a of the movable gun arm 1, so that the pressing force is as shown by an arrow P. By acting, the minus of the width of the inner ring 24 of the bearing 21 is tightened, and the angular ball bearings 21 and 21 are preloaded between the two forks of the movable gun arm 1.

As described above, when the angular contact ball bearings 21 and 21 are preloaded between the two forks of the movable gun arm 1, the gun arm via the bearing 21 is operated during the operation of the X-shaped spot gun. Rattling between Nos. 1 and 4 can be completely eliminated, and rigidity can be sufficiently maintained, and life can be made semi-permanent if bearing capacity against welding pressure is sufficiently selected.

FIG. 3 is a detailed sectional view of the main shaft structure with the equalize. In FIG. 3, a gun arm 4 is inserted and arranged between the forked arms 1a and 1b of the gun arm 1, and these gun arms 1 and 4 are pivotally supported by a hinge pin 6, and the gun arms 4 and Since the basic structure such as the interposition of angular ball bearings 21 and 21 between the hinge pin 6 and the hinge pin 6 is substantially the same as that of the above-described embodiment, the same reference numerals are given to the drawings and the description thereof will be omitted. .

In order to make the gun arm 4 ecological, in this spindle structure, the cradle 51 connected to the robot (not shown) is arranged outside each of the forks 1a and 1b, and the hinge pin 6 is The holding plates 28, 28 are provided on both sides of the holding plate 28, and the cradle 51 is located on the outer periphery of each holding plate 28 via the bearings 52, 52. It is rotatable.

Also in the case of this embodiment, since the angular ball bearings 21 and 21 are preloaded between the two forks of the gun arm 1, the gun armature is inserted through the bearing 21 during operation of the X-shaped spot gun. There is no rattling between the frames 1 and 4, and the rigidity can be sufficiently maintained. If the bearing capacity against the pressure applied during welding is sufficiently selected, the life can be made semi-permanent.

As the seal plate 23, a ring-shaped one as shown in FIGS. 4 and 5 is used. The seal plate 23 is made of metal, plastic, or rubber, and has an annular recess 61 serving as a grease holding portion on the outer peripheral portion, and the inner peripheral portion 62 has an angular contact with the inner surface of the insulating washer 22. The ball bearing 21 is sandwiched between the inner ring 24 and the end surface of the inner ring 24. The tip of the outer periphery of the recess 61 is brought into contact with the end surface of the outer ring of the angular ball bearing 21.

As described above, the ring-shaped insulating washer 22 is arranged between the inner surfaces of the forked portions 1a and 1b and the side surface of the gun arm 4 arranged between the forked portions, and the washer 22 and the bearing end surface are separated from each other. When the ring-shaped seal plate 23 fixed to the inner ring 24 of the bearing is arranged in the space between them, the grease in the bearing 21 is reliably retained, and the insulating washer 22 and the gun armature are secured. The seal plate 23 prevents the invasion of spatter from the gap between the bearing 4 and the bearing 21 and does not affect the bearing 21.

In the above embodiments, the angular ball bearing 21 is used, but a tapered roller bearing may be used instead of the angular ball bearing. There is no substantial difference in the device.

[0026]

[Effect of the invention]

 As described above, the main structure of the X-shaped spot gun according to the present invention is such that one of the gun arms is bifurcated near the pivot and the other gun arm is inserted between the forks near the pivot. The gun arm between the two forks is pivotally supported by a hinge pin through an angular ball bearing or a tapered roller bearing in the pivot part, and the bearing is preloaded between the two forks by mutually tightening the hinge pin and the fork. Therefore, during operation of the X-type spot gun, there is no rattling between the gun arms via the bearings, core misalignment between the opposing electrodes is prevented, and sufficient rigidity can be maintained during welding. If the bearing capacity for the applied pressure is sufficiently selected, the spindle structure of the X-type spot gun with a semi-permanent life can be obtained.

Further, a ring-shaped insulating washer is arranged between the inner surface of the bifurcated portion and the side surface of the gun arm arranged between the bifurcated portions, and is fixed to the inner ring of the bearing in the space between the washer and the end surface of the bearing. If a ring-shaped seal plate with a grease holding part is arranged, the grease in the bearing can be held and spatter from the outside can be prevented, and the bearing can be protected sufficiently. It becomes the main shaft structure.

[Brief description of the drawings]

FIG. 1 is a side view of a partial cross section of an X-shaped spot gun having a spindle structure according to the present invention.

FIG. 2 is a detailed cross-sectional view of a main shaft structure without eco-rise.

FIG. 3 is a detailed cross-sectional view of a main shaft structure with an equalize.

FIG. 4 is a front view of a seal plate.

FIG. 5 is a sectional view taken along the line AA of FIG. 4;

[Explanation of symbols]

 1,4 Gun arm 1a, 1b Bifurcated branch arm 2,5 Electrode 6 Hinge pin 21 Angular ball bearing 22 Insulating washer 23 Seal plate 29, 30 Tightening bolt 61 Grease holding part

Claims (2)

[Utility model registration claims] 1. An X-shaped spot gun in which at least one of two gun arms having electrodes facing each other is pivotally pivoted so that one of the gun arms is pivoted. It is branched into two in the vicinity of the part, and the other gun
A cam is inserted between the forks near the pivot, and the gun arm between the forks is pivotally supported by a hinge pin in the pivot through an angular ball bearing or a tapered roller bearing, and the hinge pin and the fork are fastened to each other. A main shaft structure of an X-shaped spot gun, wherein the bearing is preloaded between the two forks. 2. A ring-shaped insulating washer is arranged between the inner surface of the bifurcated portion and the side surface of the gun arm arranged between the bifurcated portions, and is fixed to the inner ring of the bearing in the space between the washer and the end surface of the bearing. The main structure of the X-shaped spot gun according to claim 1, wherein a seal plate having a ring shape and having a grease holding portion is arranged.