JP2665240B2 - Centering method of electrode in spot welding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an electrode (an upper electrode,
Lower electrode).

(Prior Art) A conventional spot welding machine is provided with an upper electrode and a lower electrode opposed vertically, and the upper electrode and the lower electrode are provided so as to be adjustable in the vertical direction and the front-rear direction (horizontal direction). Things.

Therefore, in order to weld appropriate positions of the stacked metal plates, the upper electrode and the lower electrode are centered by appropriately adjusting the positions of the upper electrode and the lower electrode in the front-rear direction and the vertical direction. Then, a current was appropriately applied to the upper electrode and the lower electrode, and an appropriate pressure was applied to the upper electrode to spot-weld an appropriate position of the stacked metal plates.

(Problems to be Solved by the Invention) It is not easy to accurately center the upper electrode and the lower electrode by adjusting the positions of the upper electrode and the lower electrode in the front-rear direction. Therefore, the core of the upper electrode may not be aligned with the core of the lower electrode, and if spot welding is performed in such a case, the strength and quality of the welded portion of the metal plate may be extremely deteriorated. is there.

[Structure of the Invention] (Means for Solving the Problems) As described above, in order to solve the conventional problems, in the present invention, the upper part of the frame can be moved vertically by the operation of the pressurizing cylinder device. A vertical moving body is provided, an upper arm is provided on the vertical moving body so as to be movable and fixed in a horizontal direction, and an upper electrode gripping device for gripping the upper electrode is provided at a tip end of the upper arm. The lower arm is horizontally movable and fixed at the lower portion of the frame, and the tip of the lower arm is spot-welded to the metal plate superposed in cooperation with the upper electrode. Providing a lower electrode gripping device for gripping the lower electrode, in a spot welding machine configured to be able to adjust the gripping position of the lower electrode in the vertical direction, a method of centering the electrode, comprising the following steps: And it said that there were pictures.

(I) moving the upper arm in the horizontal direction so that the tip of the upper electrode is located above the welded portion of the metal plate, and fixing the upper arm so as to be immovable in the horizontal direction; i) after the step is completed, the gripping position of the upper electrode is adjusted in the vertical direction, and the tip of the upper electrode is inserted into the hollow centering member; and (iii) after the step (ii) is completed. Moving the lower arm in the horizontal direction, inserting the tip of the lower electrode into the centering member, fixing the lower arm immovably in the horizontal direction, and adjusting the gripping position of the lower electrode in the vertical direction. The process of letting go.

(Operation) The upper arm is moved in the horizontal direction so that the tip of the upper electrode is located above the portion to be welded on the metal plate, and is fixed immovably in the horizontal direction. Next, the holding position of the upper electrode is adjusted in the vertical direction, and the tip of the upper electrode is inserted into the hollow centering member. Then, the lower arm is moved in the horizontal direction, the tip of the lower electrode is inserted into the centering member, the lower arm is immovably fixed in the horizontal direction, and the gripping position of the lower electrode is adjusted in the vertical direction. . As described above, the centering of the upper electrode and the lower electrode can be performed.

After the centering of the upper electrode and the lower electrode, the vertical moving body is moved upward by the operation of the pressurizing cylinder device, and the tip of the upper electrode is detached from the centering member, and the centering member is removed. Remove from the tip of the lower electrode. or,
In the case of performing spot welding, a current is applied to the upper electrode and the lower electrode, and the welded portion of the superposed metal plates is pressed by the upper electrode by the operation of the pressing cylinder device.

(Embodiment) With reference to FIG.
And a substantially C-shaped frame 9 composed of an upper frame 5 and a lower frame 7 extending in the front-rear direction (left-right direction in FIG. 1) at the upper and lower portions of the column 3.

An upper holder 11 is provided at an appropriate position in the front of the upper frame 5.
Are provided so as to be movable up and down. That is, the upper frame 5
The guide member 13 (not shown) provided at an appropriate position is provided with a vertically extending guide bar 13 movably up and down, and the lower end of the guide bar 13 is provided at an appropriate position of the upper holder 11 as a vertically movable body. It is connected to the position.

In order to move the upper holder 11 in the vertical direction, a pressurizing cylinder device 15 is provided at an appropriate position at the front of the upper frame 5.
The distal end of a piston rod 17 that can freely project downward from the pressurizing cylinder device 15 is connected to the upper holder 11.

With the above configuration, the upper holder 11 moves up and down via the guide bar 13 by appropriately operating the pressurizing cylinder device 15.

The upper holder 11 is provided with an upper arm 19 that is movable in a horizontal front-rear direction. The upper arm 19 cannot rotate around the axis of the upper arm 19.

More specifically, referring to FIG. 2, a through hole 21 is formed in the upper holder 11, and key grooves 23 and 25 are formed in the inside of the through hole 21 and the upper arm 19, respectively. . A detent key 27 is provided in engagement with these key grooves 23 and 25. At an appropriate position of the upper holder 21, a positioning bolt 29 is screwed and provided.

With the above configuration, the upper arm 19 can be moved in the front-rear direction (the left-right direction in FIG. 2) guided by the upper holder 11 without rotating about the axis of the upper arm 19. Therefore, after the upper arm 19 is located at an appropriate position in the front-rear direction, by appropriately operating the positioning bolt 29, the lower end of the positioning bolt 29 presses the appropriate position of the upper arm 19, and Is positioned.

On the front side of the upper arm 19, a collet chuck device (upper electrode gripping device) 33 for gripping the upper electrode 31 whose position is adjustable in the vertical direction is provided.

More specifically, referring to FIG. 3, a collet body 35 in a collet chuck device 33 is provided on the front side (left side in FIG. 3) of the upper arm 19, and a taper formed in the collet body 35 is provided. Collet in hole 37
39 are provided in engagement. The collet 39 is a hollow cylinder
By making a plurality of cuts into 41 to form a nail part 43,
A tapered portion 43a is formed outside the pawl portion 43 to engage with the tapered hole 37.

With the above configuration, the collet 39 is engaged with the tapered hole 37 of the collet body 35, and the collet 39 moves downward,
The claws 43 of the collet 39 open. As the collet 39 moves upward, the claws 43 of the collet 39 close. Therefore, by opening and closing the claw portion 43 of the collet 39, the upper electrode 31 located at an appropriate upper and lower position can be gripped, and the gripping state can be released.

In order to move the collet 39 up and down, the collet chuck device 33 is provided with a clamping cylinder device 45.

More specifically, the collet body 35 is provided with a cylinder 47 of the clamping cylinder device 45, and a piston 49 that can move up and down is provided in the cylinder 47.
The upper electrode 31 penetrates through a through hole 49a formed in the piston 49, and the lower part of the piston 49 is screwed to the upper part of the collet 39. The piston 49 is a cylinder
The first and second hydraulic chambers 51 and 53 are formed by being located in the inside 47.

With the above configuration, by appropriately supplying pressure oil to the first hydraulic chamber 51, the piston 49 and the collet 39 move downward, and the pawl portion 43 of the collet 39 opens. Also, by appropriately supplying pressure oil into the second hydraulic chamber 53, the piston 4
9. The collet 39 moves upward, and the claws 43 of the collet 39 close. Therefore, by appropriately operating the clamping cylinder device 45, the upper electrode 31 positioned at an appropriate position in the vertical direction can be gripped or the gripping state can be released.

Referring to FIG. 1 again, a lower electrode 57 is provided at an appropriate position at the front of the lower frame 7 via a link mechanism 55 so that the position of the lower electrode 57 can be adjusted horizontally in the front-back direction.

More specifically, a support bracket 59 is provided at an appropriate position at the front of the lower frame 7. One end of a first lower arm 61 of a link mechanism 55 that can swing (an example of movement) in a horizontal front-rear direction is attached to the support bracket 59 by a hinge pin 63.
Are connected via. The other end of the first lower arm 61 is connected via a hinge pin 67 to one end of a second lower arm 65 that is swingable in the horizontal front-rear direction.

With the above configuration, the first lower arm 61 and the second lower arm
The lower electrode 57 moves in the front-rear direction while swinging 65 in the front-rear direction around the hinge pins 63, 67, respectively. Therefore, even when there is an obstacle in front of the lower electrode 57, the lower electrode 57 can move in the front-rear direction while avoiding the obstacle.

In order to make the first lower arm 61 and the second lower arm 65 not swing in the front-rear direction, respectively,
9. Brake cylinder devices 69 and 71 are provided at appropriate positions of the first lower arm 61, respectively.

The other end of the second lower arm 65 is provided with a collet chuck device (lower electrode grip device) 73 for gripping the lower electrode 57 whose position can be adjusted in the vertical direction. A clamping cylinder device 75 for vertically moving a collet chuck (not shown) in the collet chuck device 73 is provided. The collet chuck device 73 and the clamping cylinder device 75 are
Collet chuck device 33, cylinder device for clamping
Since the configuration is the same as that of 45, details of the configuration are omitted.

A transformer (not shown) is provided at an appropriate position of the column 3 in order to allow a current to flow through the upper electrode 31 and the lower electrode 57. Copper plates 77 and 79 provided in the transformer are respectively provided with the upper electrode 31. , And is electrically connected to the lower electrode 57.

The operation of the present embodiment will be described based on the configuration as described above.

The upper electrode 31 is moved in the front-rear direction so that the upper electrode 31 is located above a predetermined position on the metal plate, and the positioning bolt 29 is appropriately operated when the upper electrode 31 is located at an appropriate position. The electrode 31 is positioned at an appropriate position in the front-back direction. Then, by appropriately operating the clamping cylinder device 45 to hold an appropriate position of the upper electrode 21, the upper electrode
Position 31 at an appropriate position in the vertical direction.

Next, the first lower arm 61 and the second lower arm 65 are made to be swingable in the front-rear direction by operating the brake cylinder devices 69 and 71 as appropriate. Then, as shown in FIG. 4, the tip 31a of the upper electrode 31 is inserted into the hollow centering member 81, and the lower electrode 57 is moved to an appropriate position in the front-rear direction. 57 a is inserted into the centering member 81.

Then, by appropriately operating the brake cylinder devices 69 and 71 to make the first lower arm 61 and the second lower arm 65 unswingable, the lower electrode 57 is positioned at an appropriate position in the front-rear direction. Can be done. Also, by appropriately operating the clamping cylinder device 75,
The lower electrode 57 can be positioned at an appropriate position in the vertical direction.

Finally, the pressurizing cylinder device 15 is appropriately operated to press the appropriate position of the stacked metal plates by the upper electrode 31, and the transformer is appropriately operated to flow current to the upper electrode 31 and the lower electrode 57. Thereby, spot welding of the superposed metal plates can be performed.

The configuration of the invention of this embodiment is summarized as follows.

That is, the upper frame 5 is provided with an upper holder 11 which can be moved in the vertical direction by the operation of the pressurizing cylinder device 15, and the upper arm 19 is provided on the upper holder 11 so as to be movable and fixed in the horizontal direction. A collet chuck device 33 for gripping the upper electrode 31 is provided at the distal end so that the gripping position of the upper electrode 31 can be adjusted in the vertical direction, and the lower arms 61 and 65 are swung (moved) in the lower frame 7 in the horizontal direction. A collet chuck device 73 for holding a lower electrode 57 for performing spot welding on a metal plate superposed in cooperation with the upper electrode 31 is provided at the distal end of the lower arm 61, 65. A centering method for the electrodes 31, 57 in the spot welding machine 1 configured so that the gripping position of the electrode 57 can be adjusted in the vertical direction, the method including the following steps.

(I) moving the upper arm 19 horizontally so that the tip 31a of the upper electrode 31 is located above the welded portion of the metal plate, and fixing the upper arm 19 so as to be immovable in the horizontal direction; After the step (i) is completed, the gripping position of the upper electrode 31 is adjusted in the vertical direction, and the tip 31a of the upper electrode 31 is inserted into the hollow centering member 81; (iii) the step (ii) ) After the process is completed, the lower arm 61,
65 is swung in the horizontal direction, the tip 51a of the lower electrode 57 is inserted into the centering member 81, the lower arms 61, 65 are fixed so that they cannot swing in the horizontal direction, and the grip position of the lower electrode 57 is raised and lowered. The process of adjusting the position in the direction.

Therefore, according to the invention of the present embodiment, the tip 31a of the upper electrode 31 is inserted into the hollow centering member 81, so that the lower electrode 5
By inserting the tip of 7 into the centering member 81,
The core of the upper electrode 31 and the core of the lower electrode 57 can be accurately aligned, and when spot welding is performed on the welded portion of the metal plate overlapped by the cooperation of the upper electrode 31 and the lower electrode 57, the The strength and quality of the welded portion of the metal plate can be improved.

[Effects of the Invention] As described above, according to the present invention, the tip of the upper electrode is inserted into the hollow centering member, and the tip of the lower electrode is inserted into the centering member. When the spot welding is performed on the superposed metal plates by the cooperation of the upper and lower electrodes, the strength and quality of the welded portions of the superposed metal plates can be reduced. Can be improved.

[Brief description of the drawings]

The drawings illustrate an embodiment of the present invention, and FIG. 1 is a right side view of a schematic spot welding machine. FIG. 2 is an enlarged view of an arrow view in FIG. FIG. 3 is an enlarged sectional view of a collet chuck device and a cylinder device for clamping. FIG. 4 is a diagram for explaining the function of centering the upper electrode and the lower electrode. 1 spot welding machine 31 upper electrode 57 lower electrode 55 link mechanism

Claims (1)

(57) [Claims] An up-down moving body is provided at the upper part of a frame, which is movable up and down by the operation of a pressurizing cylinder device. An upper arm is provided on the up-and-down moving body so as to be movable and fixed in a horizontal direction. An upper electrode gripping device for gripping the upper electrode is provided at a tip portion, and a gripping position of the upper electrode is configured to be vertically adjustable. A lower arm is provided at a lower portion of the frame so as to be movable and fixed in a horizontal direction. At the tip of the arm, a lower electrode gripping device for gripping a lower electrode for performing spot welding on a metal plate superposed in cooperation with the upper electrode is provided, and a gripping position of the lower electrode can be adjusted in a vertical direction. A method for centering an electrode in a spot welding machine, comprising the following steps. (I) moving the upper arm in the horizontal direction so that the tip end of the electrode is located above the welded portion of the metal plate, and fixing the upper arm so as to be immovable in the horizontal direction; i) after the step is completed, the gripping position of the upper electrode is adjusted in the vertical direction, and the tip of the upper electrode is inserted into the hollow centering member; and (iii) after the step (ii) is completed. Moving the lower arm in the horizontal direction, inserting the tip of the lower electrode into the centering member, fixing the lower arm immovably in the horizontal direction, and adjusting the gripping position of the lower electrode in the vertical direction. The process of letting go.