spot welding gun pressurizing device

Abstract

(1) Minimize the amount of design work required. (2) By enabling parts processing from individual manufacturing to mass production, costs will be significantly reduced. (3) Stabilize the quality of the pressurizing device that constitutes the welding mechanism. [Solution] A spot welding gun pressurizing device having electrodes on a movable arm and applying pressure to electrodes on a fixed arm, characterized in that the drive motor is positioned parallel to the ball screw shaft, the torque is transmitted to the ball screw shaft by a toothed belt and pulley, the overall length is significantly reduced, and the position of the drive motor can be changed vertically, horizontally, and forward and backward.

Description

[Technical Field]

[0001] The present invention relates to a pressurizing device for a spot welding gun, wherein in order to minimize the size of the pressurizing device for the spot welding gun as much as possible, the overall length is shortened, and the drive motor can be rearranged in up-down, left-right and front-rear directions. [Background Art]

[0002] As conventional techniques using belt drive in a pressurizing device for a spot welding gun, those described in Japanese Patent No. 2844412 and Japanese Patent Application Laid-Open No. 07-080651 (Japanese Patent No. 2721951) can be cited. Both of these are pressurizing devices for C-type spot welding guns and cannot be used for X-type spot welding guns. Although there is a description that the position of the drive motor can be changed to any position on the circumference centered on the ball screw, there is no description of a specific method for doing so. In Japanese Patent Application Laid-Open No. 07-080651 (Japanese Patent No. 2721951), there is a description that the mounting position of the drive motor can be changed to either one of the two surfaces of the base. However, it can be understood from the drawings that the position cannot be changed unless components are replaced. In another conventional technique disclosed in Japanese Patent Application Laid-Open No. 2004-160466, even if the main body of the pressurizing device is short, the drive motor is directly connected to the rear of the main body of the pressurizing device, resulting in an increased overall length. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent No. 2844412 [Patent Document 2] Japanese Patent Application Laid-Open No. 07-080651 (Japanese Patent No. 2721951) [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-160466 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Previously, because the pressure device of the spot welding gun was long and the position of the drive motor was fixed, the spot welding gun body had to be redesigned individually depending on the interference specification range of the pressure device to fit within the interference specification range specified for each customer. Consequently, a significant amount of design time was spent on each welding gun, which was a major cause of delays in drawing releases and delivery deadlines. The manufacturing and assembly of parts had to be done on an individual basis, which contributed to increased costs.

[0005] Therefore, the welding gun pressurizing device of this invention solves the following problems. (1) Avoid spending time on design work. (2) Parts processing enables mass production and significantly reduces costs. [Means for solving the problem]

[0006] In other words, this invention relates to a spot welding gun pressurizing device having an electrode provided on the movable arm side, and pressurizing the movable arm against an electrode provided on the fixed arm side, wherein the drive motor is arranged parallel to the ball screw shaft, and the drive torque is transmitted to the ball screw shaft by a toothed belt and pulley, and the piston rod housing the ball screw nut and ball screw shaft is housed inside the shaft for the ball screw shaft support bearing, the end of the ball screw shaft is fixed to the shaft for the ball screw shaft support bearing, and furthermore the toothed belt pulley houses the shaft for the ball screw shaft support bearing and is fixed to the shaft for the ball screw shaft support bearing.

[0007] vinegar In the pressurizing device of a pot welding gun, the entire pressurizing device or the pulley case is rotated at 90° intervals or 180° intervals around the center of the ball screw shaft. ni This device is characterized by its ability to change the position of the motor.

[0008] Furthermore, in the pressurizing device of the spot welding gun, the drive motor is positioned 180° in the tooth width direction of the toothed belt. Move it to a different position Another feature is that the drive motor's position can be changed.

[0009] Furthermore, a key feature of the spot welding gun's pressurizing device is that the entire pressurizing device can be used interchangeably for both C-type and X-type spot welding guns. [Effects of the Invention]

[0010] As a result of the above configuration, the present invention can achieve the following effects. (1) To address various interference ranges, the pressurizing devices for spot welding guns, which have been manufactured in many varieties until now, can now be shared regardless of whether they are for C-type or X-type spot welding guns, and have been standardized into several types corresponding to different strokes. (2) Compared to before, the design man-hours were almost eliminated, and parts processing became possible through mass production, resulting in a significant reduction in costs. Parts inventory was also minimized, and standard procedures were established for assembly and inspection work. [Brief explanation of the drawing]

[0011] [Figure 1] This invention outlines the pressurizing device for a spot welding gun, with (a) to (c) showing that the entire pressurizing device has four mounting surfaces to the welding gun body at 90° intervals. (a) is a schematic top view, (b) is a schematic front cross-sectional view, and (c) is a cross-sectional view AA of (a). [Figure 2] (d) is a schematic top view, and (e) is a schematic front view of the drive motor rotated 180 degrees vertically with respect to the center of the ball screw shaft 21 and positioned below. Note that in Figures 2(d) to 3(g), the pulley case 30 is a separate part from the pressurizing device body. [Figure 3] (f) is a cross-sectional view of BB in Figure 2(e), and (g) is a cross-sectional view of CC in (f). [Figure 4]It is a schematic front view of Fig. 1(b). [Figure 5] It is a schematic front view of Fig. 2(e). [Figure 6] It is a schematic left side view of Fig. 5. [Figure 7] Fig. 5 is a schematic front view showing a state where the drive motor is rotated 180 degrees in the vertical direction about the center of the ball screw shaft 21 and placed at an upper position. [Figure 8] It is a schematic left side view of Fig. 7. [Figure 9] It is a schematic front view showing a state where the drive motor M is arranged by rotating 180° in the left-right direction about the center of the ball screw shaft 21 with respect to Fig. 7. [Figure 10] It is a schematic right side view of Fig. 9. MODE FOR CARRYING OUT THE INVENTION

[0012] Hereinafter, the pressurizing device for a spot welding gun of the present invention will be described more specifically based on the drawings. First, Fig. 1 shows an outline of the pressurizing device for a spot welding gun according to the present invention, wherein (a) is a schematic top view of a state where the pressurizing device has four mounting surfaces to the welding gun main body at every 90°, and the drive motor M is arranged on the rear surface of the pulley case 30, (b) is a schematic front sectional view thereof, and (c) is an A-A sectional view of (a). In Fig. 1(b), X-type bearings 12 and 13 for spot welding guns are attached to the upper surface and the lower surface of the pressurizing device main body. These bearings are attached as swing trunnion bearings for the pressurizing device only in the case of an X-type spot welding gun, are removed in the case of a C-type spot welding gun, and are assembled to the welding gun main body using the mounting tapped holes 19 for the C-type spot welding gun. Further, the bearing 17 is arranged at the tip end of the piston rod 22 of the X-type spot welding gun bearing 12. In Fig. 1(b), reference numeral 1 denotes an electrode provided on the movable arm 2 side, and the movable arm 2 is configured to perform a pressurizing operation against the electrode 3 provided on the fixed arm 4 side. Next, FIG. 1(c) is a cross-sectional view taken along line A-A of FIG. 1(a). The X-type bearings 12 and 13 for the spot welding gun are assembled on the left and right surfaces of the pressurizing device main body, but can be re-assembled on the upper and lower surfaces. In this case, the muffler cylinder 14 and the PT elbow 15 will be relocated to the left and right surfaces. Further, by re-assembling the X-type bearings 12 and 13 for the spot welding gun on the upper and lower surfaces of the pressurizing device main body, the position of the drive motor M can be indexed by 90° when the pressurizing device is assembled to the welding gun main body. Here, "indexing" means "to rearrange the position to each predetermined angle." Therefore, "index" means "position change to each predetermined angle." It means "e" (the same applies below).

[0013] Next, FIG. 2(d) is a schematic top view of FIG. 2(e), and FIG. 2(e) is a schematic front cross-sectional view of FIG. 2(d). In FIGS. 2(d) and 2(e), the pulley case 30 is a separate component from the pressurizing device main body, is spigot-fitted to the pressurizing device main body, and is fastened by bolts, so that the pulley case 30 can be indexed at every 90° for reassembly. That is, in the pressurizing device main body 11, the ball screw shaft 21 is screwed with the ball screw nut 29 inside the piston rod 22. The ball screw shaft 21 is fitted and fixed to the shaft 16 for the ball screw shaft support bearing, and the piston rod 22 is arranged in the pressurizing device main body 11 by the X-type bearings 12, 13 for the spot welding gun and the packing case 24. Reference numeral 23 denotes a bearing, which is mounted on the shaft 16 for the ball screw shaft support bearing and rotatably holds the ball screw shaft 21. Then, the ball screw shaft 21 is rotated by a toothed belt 28 stretched between a pulley 25 mounted on the shaft 16 for the ball screw shaft support bearing and a pulley 26 mounted on the motor rotating shaft 27 of the drive motor M, so that the piston rod 22 is advanced and retracted relative to the ball screw shaft 21 of the pressurizing device in FIG. 2(e). FIG. 4 is a schematic front view of FIG. 1(b), and FIG. 5 is a schematic front view of FIG. 2(e).

[0014] Next, in Figure 3(f), which is a cross-sectional view of BB in Figure 2(e), and in Figure 3(g), which is a cross-sectional view of CC in Figure 3(f), the pulley case fastening bolts 31 for attaching the pulley case 30 to the pressurizing device body and the motor mounting plate fastening bolts 32 for fixing the motor mounting plate 18 are shown. Since the pitch spacing of the four bolts of the pulley case fastening bolts 31 is the same both left and right, and up and down, the pulley case 30 can be mounted indexed at 90° intervals.

[0015] And a common feature of the present invention is, a) In order to shorten the overall length, the piston rod 22, which houses the ball screw nut 29 and the ball screw shaft 21, is housed inside the shaft 16 for the ball screw shaft support bearing, the end of the ball screw shaft 21 is fixed to the shaft 16 for the ball screw shaft support bearing, and the toothed belt pulley 25 houses the aforementioned 16 and is fixed to the aforementioned 16. b) Since the entire pressurizing device can be assembled to the welding gun body by indexing it at 90° or 180° intervals with respect to the center of the ball screw shaft 21, the drive motor M can also be indexed at 90° or 180° intervals. c) Furthermore, since the center of the dimension obtained by adding the thickness of the pulley case cover 20 to the thickness of the front and rear surfaces of the pulley case 30 coincides with the center of the belt tooth width, the front and rear surfaces of the pulley case 30, i.e., the tooth width direction of the toothed belt 28, can be indexed by 180°, making it possible to reposition the drive motor M, replace or adjust parts and bolts as needed.

[0016] In other words, in Figure 2(b), the ball screw shaft 21 is screwed with a ball screw nut 29 inside the piston rod 22 within the pressurizing device body 11. The ball screw shaft 21 is fitted and fixed to the shaft 16 for the ball screw shaft support bearing, and the piston rod 22 is located inside the pressurizing device body 11 via X-type spot welding gun bearings 12, 13 and a packing case 24. Then, a toothed belt 28 stretched between a pulley 25 attached to the shaft 16 for supporting the ball screw shaft bearing and a pulley 26 attached to the motor rotation shaft 27 of the drive motor M rotates the ball screw shaft 21, causing the piston rod 22 to move back and forth relative to the ball screw shaft 21 of the pressurizing device.

[0017] Figures 4 through 10 below show that the welding gun body of the spot welding gun's pressurizing device has two mounting surfaces at 180° intervals. Specifically, Figure 4 is a schematic front view of Figure 1(b), and Figure 5 is a schematic front view of Figure 2(e), showing that the mounting surface of the welding gun body of the pressurizing device body 11 of the spot welding gun is indexed at 180° intervals. Figure 6 is a schematic left side view of Figure 5, where 12 and 13 are X-type spot welding gun bearings formed on the upper and lower surfaces of the pressurizing device body 11, respectively, 14 is a sound-dampening tube, and 15 is a PT elbow. Next, Figure 7 shows the state in Figure 5 where the pressurizing device body 11 and the drive motor M are indexed 180° vertically, and Figure 8 is a schematic left side view thereof.

[0018] Finally, Figure 9 shows yet another overview of the pressurizing device for the spot welding gun of this invention, a schematic front view showing the drive motor M mounted on top and rotated 180 degrees symmetrically, and Figure 10 is a schematic right side view thereof. [Industrial applicability]

[0019] As a result of the above configuration, the present invention can also exhibit the following advantages in addition to the effects described above. (1) For various interference ranges, the pressurizing devices, of which we have manufactured many types in the past, can now avoid interference ranges simply by rearranging them. (2) Compared to before, the design man-hours were almost zero, and parts processing could be done in mass production, resulting in a significant reduction in costs. (3) Parts inventory has been minimized, standard procedures have been established for assembly and inspection work, and the quality of the spot welding gun pressure device has also stabilized. (4) To address various interference ranges, we were able to standardize the spot welding guns, which we had previously manufactured in many different types, into just a few types. (5) Compared to before, the design man-hours were almost zero, and parts processing could be done in mass production instead of individual processing, resulting in a significant reduction in costs. (6) Parts inventory has been minimized, and standard procedures have been established for assembly and inspection work. (7) The quality of the pressure device for the spot welding gun has also stabilized. [Explanation of Symbols]

[0020] M Drive Motor 1 electrode 2 Movable arms 3 electrodes 4 Fixed Arms 11 Pressurizing device body 12,13 X-type spot welding gun bearings 14 Silencer tube 15 PT Elbow 16. Shaft for ball screw shaft support bearing 17 bearings 18 Motor mounting plate 19 C-type spot welding gun mounting tapped holes 20 Pulley Case Cover 21 Ball screw shaft 22 Piston Rod 23 bearings 24 Packing Case 25, 26 Pulley 27 Motor Rotation Shaft 28 Toothed belt 29 Ball screw nut 30 Pulley Case 31 Pulley case tightening bolts 32 bearings

Claims

1. A spot welding gun pressurizing device having an electrode provided on the movable arm side, and pressurizing the movable arm against an electrode provided on the fixed arm side, wherein the drive motor is arranged parallel to the ball screw shaft, and the drive torque is transmitted to the ball screw shaft by a toothed belt and pulley, and the piston rod housing the ball screw nut and ball screw shaft is housed inside the shaft for the ball screw shaft support bearing, the end of the ball screw shaft is fixed to the shaft for the ball screw shaft support bearing, and the toothed belt pulley houses the shaft for the ball screw shaft support bearing and is fixed to the shaft for the ball screw shaft support bearing.

2. The spot welding gun pressurizing device according to Claim 1, characterized in that the entire pressurizing device or the pulley case can be rotated at intervals of 90° or 180° around the center of the ball screw shaft as the rotational center, thereby allowing the drive motor to be repositioned.

3. The spot welding gun pressurizing device according to claim 1, characterized in that the drive motor is repositioned by rotating it 180° in the tooth width direction of the toothed belt, thereby enabling the drive motor to be repositioned.

4. The spot welding gun pressurizing device according to any one of claims 1 to 3, characterized in that the entire pressurizing device can be used for both a C-type spot welding gun and an X-type spot welding gun.

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