JPH0347682A - Feeding device for resistance welding gun - Google Patents

Abstract

PURPOSE:To smooth feeding of a resistance welding gun by supporting a swinging frame to support the welding gun freely swingably by a fixed frame and providing an actuator to rotate the swinging frame by a specified angle. CONSTITUTION:A first connecting terminal 38 at the fixed frame 12 side connected with a feeding cable and a second connecting terminal 42 provided at the swinging frame 16 side are constituted attachably and detachably by driving a cylinder 26 for driving. By this method, current capacity is increased and the feeding cable is made thick and as a result, even if flexibility is lowered and weight is increased, a retreating action of the welding gun from a work is not hindered and smoothness is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply device for a resistance welding gun mounted on a spot welding robot or the like.

[Prior Art] Generally, a larger welding current is required to join steel plates that have been subjected to anti-corrosion treatment by resistance welding, so the cross-sectional area of the power supply cable connected to the welding gun must be increased. Must be.

On the other hand, there are disadvantages in that the weight of the power supply cable increases and its flexibility is impaired, which impedes the operation of the welding gun.

In order to overcome such inconveniences and to make the welding operation smoother, particularly for so-called equalized type welding guns that involve oscillating motion for each welding shot, the present applicant has developed the following:
A patent application has been filed for a power supply device for a resistance welding gun configured to connect the terminal on the welding gun side and the terminal on the power supply cable side when the welding gun is at the welding point position (Japanese Patent Application No. 153873/1983).
No. 63-15387).

[Problems to be Solved by the Invention] However, the deterioration of the flexibility of the power supply cable and the deterioration of the operating conditions of the welding gun due to the increase in its weight make it difficult to operate the welding gun not only during welding but also when changing workpieces. This also becomes apparent when the work is evacuated from the work.

The present invention has been made in view of the above, and provides a power supply device for a resistance welding gun that allows smooth operation when the welding gun retreats from a welding work position to a retreat position without being affected by a power supply cable. With the goal.

[Means for Solving the Problems] In order to solve the above problems, a power supply device for a resistance welding gun of the present invention includes: a swinging frame on which a welding gun is supported; and a rocking frame that swingably supports the swinging frame. a first connection terminal provided on the fixed frame side and connected to a power supply cable on the power source side; and a second connection provided on the swing frame side and detachable from the first connection terminal. The apparatus is characterized in that it includes a terminal, a conductive member wired from the second connection terminal to the welding gun, and an actuator that rotates the swing frame by a certain angle.

Further, the power supply device for a resistance welding gun of the present invention includes a swinging frame on which the welding gun is supported, a fixed frame that swingably supports the swinging frame, and a power supply device provided on the fixed frame side and connected to the power supply side. a first connection terminal connected to a cable; a second connection terminal provided on the swing frame side and detachable from the first connection terminal; and a conductive wire wired from the second connection terminal to the welding gun. a first actuator for rotating the swing frame by a certain angle; and a second connection by displacing the first connection terminal when the swing frame is positioned at a predetermined position under the driving action of the first actuator. It is characterized by comprising a second actuator that is connected to the terminal.

[Function] When the welding gun is in the welding work position, the first connection terminal connected to the power supply cable on the power source side is connected to the second connection terminal provided on the swing frame, so that the welding gun When a current is supplied to the swing frame and the welding gun is moved away from the welding position by rotating the swing frame, the connection state between the first connection terminal and the second connection terminal is released.

[Example] Next, an example of a power supply device for a resistance welding gun according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the configuration of a power supply device 10 according to this embodiment. In the figure, a swing frame 16 to which two welding guns are attached is swingably supported via a shaft portion 14 on a fixed frame 12 fixed on a machine stand (not shown). The swing frame 16 includes a pair of swing support plates 18a and 18b fixed to the shaft portion 14, and an arm portion 20 fixed to the upper end of the swing support plates 18a and 18b.
A pair of welding guns 22. are attached to both ends of the arm portion 20.
24 is attached. The configuration of this welding gun 22, 24 will be described later.

Here, as shown in FIG. 2, which is a side view of the power supply device 10, the power supply device 10 functions as an actuator for rotating the swing frame 16, on which the welding gun 22, 24 is supported, by a predetermined angle. The tip of the piston rod 26a of the swing cylinder 26 is connected to the lower end of the swing support plates 18a, 18b of the swing frame 16 via a pin 28.

Next, in the power supply device 10, the welding gun 22.24
The power supply line arranged to supply welding current to the welding current will be explained.

First, the power supply cable 30 extending from a power supply (not shown) is connected to a pair of first brackets 34 attached to the tip of a support member 32 fixed to the side surface of the fixed frame 12 and extending in the horizontal direction.
via a connector 37 to terminals 36 and 36 of. The first terminal 36.36 includes a pair of first
connection terminals 38.38 are attached. On the other hand,
On the swing frame 16 side, the first connection terminal 38.38 and a pair of detachable second connection terminals 42.42 are attached to a second terminal 40.40.

Here, the first connection terminal 38.38 and the second connection terminal 42.
Details of 42 are shown in FIG. The first connection terminal 38 is a so-called tulip-shaped contact, which is a conductive segment made of a good conductor such as copper and having a lock-shaped tip.
4a to 44f are arranged in two rows facing each other, and curved leaf springs 46a to 46f are held by a bundle 45 on the back side thereof.
The structure is such that the distance between the conductive segments H4a to 44c and 44d to 44f is narrowed. On the other hand, the second connection terminal 42 has a wedge shape and is held between the conductive segments 44a to 44f when inserted between them.
Thereby, a connection state with the first connection terminal 38 is obtained.

Next, in the swing frame 16, a conductive member is wired to flow a current from the second connection terminal 42 to the welding gun 22.24. That is, the second terminals 4o, 40 are connected to a pair of first conductor plates 48a, 48b, respectively, and the first conductor plates 48a, 48b are flexible conductive members, in this case, a pair of ounces 50a, 50b. is connected to one end of the Further, the other ends of the ounces 50a, 50b are connected to one end of a pair of second conductor plates 52a, 52b with an insulating material interposed therebetween, and the other ends are connected to the pair of ounces 54a, 54b.
It is connected to a pair of third conductor plates 56a and 56b via 4b.

Here, the welding gun 22 is electrically connected to the second conductor plates 52a, 52b, and the welding gun 24 is electrically connected to the third conductor plates 56a, 56b.

Next, the construction of the welding guns 22, 24 is shown in FIG. In this case, the welding guns 22, 24 are of identical construction.

First, the fixed gun arm 62 is attached to the bracket 60, and the electrode 64 is attached to the tip thereof.

On the other hand, in the movable gun arm 66 that is paired with the fixed gun arm 62 and has the electrode 65 attached thereto, a pin 70 is formed on the bracket 60 and projects from a lever portion 68 at the tail end of the movable gun arm 66 . A connecting member 80 is connected to the lever part 68 via a pin 74 and extends from a piston rod 78 of a cylinder 76 that engages with the three-shaped cam groove 72 and drives the movable gun arm 66 to open and close. . Note that reference numeral 81 indicates a flexible conductive member that connects the second conductor plate 52a and the movable gun arm 66.

Next, the cylinder 76 is engaged with the lower end side of the bracket 60 by means of pins 82a and 82b, and the support member 8
The guide rod 86 is displaceably engaged with a guide rod 86 installed between an upper frame 84a and a lower frame 84b formed above and below the frame 4, via a sliding portion 88. The sliding portion 88 and the upper frame 84 of the support body 84
A coil spring 90 is interposed between the coil spring 9o and the coil spring 9o, and the entire welding gun 22 is urged downward by the elastic force of the coil spring 9o.

Here, the operation of such welding gun 22 will be schematically explained. In the figure, the piston 76a of the cylinder 76 is
When displaced in the direction of arrow A, the movable gun arm 66 is guided along the cam groove 72 in which the pins 70, 74 engage.
rotates in the closing direction relative to the fixed gun arm 62.

On the other hand, when the piston 76a of the cylinder 76 is displaced in the direction of the arrow B in the figure, contrary to the above, the stepped portion 78a formed at the end of the piston rod 78 is supported during its stroke. It abuts against the upper end of the body 84. Then, in the process of the piston 76a being displaced to the stroke end, the entire welding gun 22 is displaced downward, and the movable gun arm 66 is rotated in the opening direction from the fixed gun arm 62.

The power supply device for a resistance welding gun according to this embodiment is basically constructed as described above, and its operation and effects will be explained next.

First, as shown in FIGS. 1 and 3, during welding work, in order to apply welding current to the welding guns 22 and 24, the first connection terminal 38 provided on the fixed frame 12 side and the swing frame are connected. 16
The electrode 64 of the fixed gun arm 62 and the electrode 65 of the movable gun arm 66 are connected to the second connecting terminal 42 provided on the side, so that in each of the welding guns 22 and 24, the electrode 64 of the fixed gun arm 62 and the electrode 65 of the movable gun arm 66 are connected to each other.
A predetermined voltage is applied between them. Therefore, the picture electrode 64.
When the workpiece is pressurized between 65 and 65, the welding current is applied,
The Joule heat generated at this time welds the workpiece.

After continuing the welding work as described above, the welding gun 22.
24, the power supply device 10 operates as follows.

That is, as shown in FIG.
The piston rod 26a of No. 6 moves forward, and this piston rod 26a connects to the swing support plates 18a, 18b via the pin 28.
, the entire swing frame 16 rotates about the shaft portion 14 in the direction of arrow C. Therefore, the second connection terminal 42 that is integral with the swing frame 16 is detached from the first connection terminal 38 on the fixed frame 12 side.

As a result, the welding gun 22 supported by the swing frame 16
．． 24 retreats to the retracted position indicated by the two-dot chain line.

On the other hand, when the welding gun 22.24 is returned to the welding work position after completing the various operations associated with replacing the workpiece, the piston rod 26a of the swinging cylinder 26 is moved back by an operation opposite to that described above. , while the swing frame 16 rotates in the direction of the arrow, the second connection terminal 42 connects to the first connection terminal 38.
inserted for.

In this way, the operation of shifting the welding guns 22, 24 from the welding work position is carried out smoothly without being hindered by the power supply cable 30.

The embodiments described above are configured so that the connection terminals can be attached and detached when the swing frame 16 is rotated. Next, another embodiment will be described based on FIG. 5. here,
Components that are the same as those in the first embodiment are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In this second embodiment, the first connecting terminal 38 is configured to be movable upwardly and downwardly by a cylinder on the fixed frame 12 side with respect to the second connecting terminal 42 fixed to the swinging frame 16.

That is, a mounting member 104 supported vertically displaceably through a buffer spring 102 engages with the guide rod 100, and in this case, a pin member 106 fixed to the guide rod 100 is bored into the mounting member 104. long hole 108
Since the mounting member 104 is loosely fitted into the elongated hole 108, the mounting member 104 is configured to be able to be displaced by the length of the elongated hole 108 in the longitudinal direction. A cylinder 110 is fixed to the mounting member 104, and the cylinder 1
The ten piston rods 110a are connected to the lower end of the case 112 in which the first connection terminal 38 is held. A guide portion 114 is fixed to the side surface of the case 112 and is slidably fitted to the tip of the guide rod 100.

Next, the first connection terminal 38 is connected to the power supply cable 30 as follows.
connected to. That is, the power supply cable 30 is connected to the first fixed conductive plates 116a, 116b, and the first fixed conductive plates 116a, 116b are connected to one end of the flexible ounces 120a, 120b via the connection part 118, The other end side of these ounces 120a and 120b is the connection part 1
22 to second fixed conductive plates 124a and 124b connected to the first connection terminal 38.

Therefore, in the second embodiment as described above, the piston rod 110a of the cylinder 110 moves forward during welding work, and the first connecting terminal 38 is connected to the second connecting terminal 42. on the other hand,
When the welding guns 22, 24 retreat to the retracted position, the piston rod 110a retreats and the first connection terminal 38 separates, so that the swing frame 16 can smoothly rotate as described in the first embodiment. It will be done.

[Effects of the Invention] As described above, according to the present invention, the connecting terminal on the fixed frame side that is connected to the power supply cable and the connecting terminal on the swinging frame side that supports the welding gun are connected and detached by actuator drive. ing. For this reason, even if the power supply cable becomes thicker to increase the current capacity, resulting in decreased flexibility and increased weight, the movement of retracting the welding gun from the workpiece will not be hindered and its smoothness will be improved. This has the effect of ensuring that

[Brief explanation of drawings]

FIG. 1 is a perspective view of a power supply device for a resistance welding gun according to the present invention, FIG. 2 is a side view of the power supply device in FIG. 1, and FIG. 3 is an enlarged sectional view of a connection terminal provided in the power supply device. , FIG. 4 is a partially cutaway side view of a welding gun to which the power supply device is applied, and FIG. 5 is a configuration explanatory diagram of a connection terminal attachment/detachment mechanism according to another embodiment.

Claims (4)

[Claims] (1) A swinging frame that supports a welding gun, a fixed frame that swingably supports the swinging frame, and a first connection terminal provided on the fixed frame side and connected to a power supply cable on the power source side. a second connection terminal provided on the swing frame side and detachable from the first connection terminal; a conductive member wired from the second connection terminal to the welding gun; A power supply device for a resistance welding gun, characterized by comprising an actuator for rotation. (2) In the power supply device according to claim 1, the first connection terminal and the second connection terminal are fixed to the swing frame and the fixed frame, respectively, so that the first connection terminal and the second connection terminal can be attached and detached by the rotational movement of the swing frame. Characteristic power supply device for resistance welding guns. (3) A swinging frame that supports a welding gun, a fixed frame that swingably supports the swinging frame, and a first connection terminal provided on the fixed frame side and connected to a power supply cable on the power source side. a second connection terminal provided on the swing frame side and detachable from the first connection terminal; a conductive member wired from the second connection terminal to the welding gun; a first actuator that rotates the swing frame; and a second actuator that displaces the first connection terminal and connects it to the second connection terminal when the swing frame is positioned at a predetermined position under the driving action of the first actuator. A power supply device for a resistance welding gun, comprising: (4) The device according to claim 3, wherein the second actuator is a cylinder, and the cylinder is attached to a vertically displaceable attachment member, and the attachment member is configured to adjust the displacement of a pin member provided on the guide rod. A power supply device for a resistance welding gun, characterized in that its operation is regulated within a range.