JPH0763846B2 - Roll spot welder - Google Patents

Description

Description: TECHNICAL FIELD The present invention sandwiches a welding line of a welded portion with a pair of electrodes, and performs roll spot welding while energizing and pressing along the welding line of the welded object. The present invention relates to improvement of a roll spot welding machine.

(Prior Art) As a conventional roll spot welding machine, for example, JP-A-63
There is one disclosed in Japanese Patent No. 123574, and this roll spot welding machine will be described.

That is, by moving one electrode of a pair of electrodes provided to face each other in the direction of sandwiching the object to be welded,
The other electrode is moved by utilizing the reaction force with the object to be welded, and the electrodes are welded while being pressed and sandwiched by both electrodes with a uniform force from both sides.

In a specific structure, an electrode head that rotatably supports one electrode is connected to a piston rod of a cylinder to move the electrode head, and a guide rod provided separately guides this movement. The upper and lower surfaces of the electrode head that rotatably supports the other electrode (the upper and lower surfaces of the electrode head parallel to the pair of electrodes) are located between the pair of electrode frames, and the electrode frame is slidable. There is.

(Problem to be Solved by the Invention) In the above-described conventional roll spot welding machine, since one electrode on the side moved by the cylinder is not guided by the electrode frame, the movement of one electrode At this time, it is necessary to widen the mutual electrodes so that one electrode and the electrode frame do not interfere with each other.

Therefore, the distance between the center of one of the electrodes and the outer surface of the electrode frame becomes wider, and, for example, when the pair of electrodes is guided along the welding line by the robot hand, the outer surface of the electrode frame contacts the obstacle. However, there is a problem in that the moving range of the pair of electrodes is narrowed and a large work space is required.

Further, since the movement of one electrode is not guided by the electrode frame as described above, another guide device for guiding one electrode is required, which causes a problem that the structure becomes complicated.

Furthermore, since the upper and lower surfaces of the electrode head are located between the pair of electrode frames, it is not possible to secure a sufficient distance between the surface of the electrode frame and the pair of electrodes. The position cannot be deeper than the edge of the workpiece. For this reason, there is a problem that the position of the welding line is limited and the welding may become difficult.

The present invention has been made in order to solve the above-mentioned conventional problems, and avoids interference between one electrode and a bracket made of a plate body, eliminating the need for a wide working space for welding, and making the structure An object of the present invention is to provide a roll spot welding machine that is simple and that facilitates welding by eliminating the restriction on the position of the welding line.

(Means for Solving the Problems) As means for solving the above problems, the present invention attaches a roll spot welding machine main body equipped with a pair of electrodes to a movable arm of a robot, and covers the pair of electrodes between the electrodes. In a roll spot welding machine that sandwiches a welded portion and energizes and pressurizes the pair of electrodes while guiding the pair of electrodes along the welding line of the work piece by the movable arm, relative to the movable arm. A bracket composed of facing plate bodies is provided so as to be movable up and down, and vertically between the plate bodies of the bracket,
A pair of electrode heads having electrodes orthogonal to each other are provided on the plate body, one electrode head is provided so as to be vertically movable along a side surface of the plate body of the bracket, and the other electrode head is provided on the plate body of the bracket. The pressure cylinder is rotatably provided above the bracket, and the piston rod of the pressure cylinder and the one electrode head are connected to each other.

(Operation) Since the present invention is configured as described above, it has the following operations. That is, a bracket composed of plate members facing each other on the movable arm is provided so as to be vertically movable, and a pair of electrode heads provided with electrodes orthogonal to the plate members are provided above and below between the plate members of the bracket, A sufficient distance is provided between the bracket made of a plate and the pair of electrodes to eliminate the restriction on the position of the welding line.

Further, one electrode head is provided so as to be movable up and down along the side surface of the plate body of the bracket to narrow the mutual width of the pair of brackets, and an electrode head having one electrode is provided for the plate body. Have them guide you along the sides.

Further, a bracket composed of a plate body facing the movable arm is provided so as to be movable up and down, the other electrode head is fixed between the plate bodies of the bracket, and a pressure cylinder is rotatably mounted on the upper part of the bracket. When the welding target is welded by connecting the piston rod of this pressurizing cylinder to one of the electrode heads, the welding line is reliably held at the correct position by utilizing the reaction force.

(Embodiment) Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

In the figure, 50 is a roll spot welding machine main body, 2,
Reference numeral 3 denotes a pair of electrodes provided on the roll spot welder main body 50. Reference numeral 4 is an electrode head, and 5 is a power supply shaft. The power supply shaft 5 is rotatably fitted to the electrode head 4,
One electrode 2 of the pair of electrodes 2 and 3 is attached to the tip portion thereof.

A power supply block 6 for supplying a welding current is connected to the power supply shaft 5, and a welding transformer (not shown) is connected to the power supply block 6 via a secondary cable.

Reference numeral 7 is an electrode head, and 8 is a feeding shaft. The power supply shaft 8 is rotatably fitted to the electrode head 7, and the other electrode 3 of the pair of electrodes 2 and 3 is attached to the tip portion thereof.

A power supply block 9 for supplying a welding current is connected to the power supply shaft 8, and a welding transformer (not shown) is connected to the power supply block 9 via a secondary cable.

As shown in FIG. 2, reference numerals 10 and 11 are brackets made of plates disposed on both sides of the electrode heads 4 and 7, and 12 and 13 are electrode heads 4.
Guide rails arranged on both sides of the guide rail. Guide rail 1
2, 13 are attached to bases 14, 15 fixed to brackets 10, 11.

Reference numerals 16 and 17 denote bearings slidably fitted to the guide rails 12 and 13, and the bearings 16 and 17 are fixed to both side surfaces of the electrode head 4, respectively.

As a result, the electrode head 4 slides vertically on the guide rails 12 and 13. That is, a pair of electrode heads 4 and 7 having electrodes orthogonal to the plate body are arranged above and below between the plate bodies of the bracket, and one electrode head 4 is attached to the bracket 1
It is designed to move up and down along the side surface of the 0, 11 plate. The electrode head 7 is fixedly supported on the lower ends of the brackets 10 and 11.

A pressure cylinder 18 is provided above one electrode head 4, and a knuckle 19 is attached to a piston rod 18a of the pressure cylinder 18.

A cylinder mounting plate 20 is fixed to the portion of the pressure cylinder 18 on the piston rod 18a side.
A hole 20a through which the piston rod 18a of the pressurizing cylinder 18 passes is bored in the central portion of 20.

In addition, hinges 21 and 22 are provided on both sides of the hole 20a of the cylinder mounting plate 20.
Is provided with these hinges 21, 22 and bracket
The hinges 23, 24 provided at appropriate places on the upper portions of the 10, 10 are rotatably connected by hinge pins 25, 26.

Reference numeral 27 denotes a link fixed to the electrode head 4, and a long hole 28 is formed on the side surface of the link 27 so that the electrode head 4 can move, which is orthogonal to the moving direction (vertical direction in FIG. 4).

Then, one side of the link 29 is rotatably connected to the link 27 by a pin 33 inserted into the elongated hole 28. Link 29
Has a base end rotatably connected by a pin 30 to links 31 and 32 provided at appropriate positions of the brackets 10 and 11. The other side of the link 29 is rotatably connected to the knuckle 19 mounted on the piston rod 18a by a pin 34.

As a result, the pressure cylinder 18 is rotatably connected to the brackets 10 and 11, and the piston rod of the pressure cylinder 18 is connected.
18a is connected to one electrode head 4.

Further, mounting plates 35 and 36 (see FIG. 3) are fixed to the brackets 10 and 11 made of plate bodies on the side opposite to the electrodes 2 and 3,
A slide substrate 51, which is a sliding body, is attached to the attachment plates 35 and 36. In addition, the slide board 51 has bearings 55, 5
6, the bearings 55 and 56 are slidably fitted to the pair of guide rails 53 and 54 which are guide members fixed to the base 52.

Therefore, the slide board 51 includes a pair of guide rails 53,
It slides on the electrode 54 in parallel with the sliding direction of the electrode head 4 (that is, in the vertical direction). As a result, the brackets 10 and 11 made of plates also move in the vertical direction.

In addition, as shown in FIGS. 1 and 2, a slide substrate
A stopper 57 made of a rod member is fixed to the surface of the slide substrate 51 between the bearing 55 and the bearing 56 fixed to the 51. The tip portion 57a of the stopper 57 is inserted into a stopper hole 58 formed in a substantially central portion of the base 52.

The tip end 57a of the stopper 57 is pressed against the stopper surface 58a inside the stopper hole 58 by a lock cylinder described later to be locked, and the swing of the slide substrate 51 is suppressed.

Since the stopper 57 for locking the slide substrate 51 is provided on the slide substrate 51 in this manner, when the roll spot welding machine main body 50 is moved to a predetermined position by the robot arm 37, high speed movement is possible and productivity is improved. Has the effect of being able to.

The length of the stopper hole 58, into which the tip portion 57a of the stopper 57 is inserted, in the sliding direction of the slide substrate 51 corresponds to the maximum wear amount of the pair of electrodes 2, 3, that is, the pair of electrodes 2, 3.
The maximum amount of wear is set to at least a longer length. Therefore, the sliding amount of the slide substrate 51 is
Suppressed by the length of 58.

Reference numeral 59 denotes a lock cylinder fixed to the upper part of the base, which moves the stopper 57 via the slide substrate 51. The pusher 6 is attached to the piston rod 59a of the lock cylinder 59.
0 is installed.

Reference numeral 61 is a robot mounting plate fixed to the base 52, and the roll spot welding machine main body 50 is a movable arm of a robot (not shown), that is, a robot arm 37 via the robot mounting plate 61.
Installed on.

The operation of the roll spot welding machine configured as described above will be described.

Before welding, the body 50 of the roll spot welder is a robot arm
It is attached to 37 and waiting in its original position. At this time, the lock cylinder 59 operates, the piston rod 59a of the lock cylinder 59 extends, and the pusher 60 causes the stopper 57 to move to the first position.
In the figure, push down to the tip 57a of the stopper 57.
Is pushed down to the stopper surface 58a of the stopper hole 58 (the lower surface of the stopper hole 58 in FIG. 1). That is, the slide substrate 51 is locked by this.

In this state, when the object to be welded (not shown) is positioned at a predetermined position, the pair of electrodes 2 and 3 provided on the main body 50 of the roll spot welder causes the robot arm 37 to set the welding start point of the object to be welded. It can be moved to the position where it can be clamped.

During this time, since the slide substrate 51 is locked, the roll spot welder main body 50 can move to the object to be welded (not shown) without swinging.

When the pair of electrodes 2, 3 moves to a position where the welding start point of the object to be welded can be clamped, the lock cylinder 59 operates again,
The piston rod 59a of the lock cylinder 59 is shortened to unlock the slide board 51, and the pressure cylinder
The piston rod 18a of 18 extends.

When the piston rod 18a of the pressurizing cylinder 18 extends, the pressurizing force of the pressurizing cylinder 18 is knuckle 19, link 29, link
27, the electrode head 4 is moved in the direction of the electrode head 7 along the guide rails 12 and 13, and the welding start point of the object to be welded is held by the pair of electrodes 2 and 3 with a considerable pressing force.

When the pair of electrodes 2 and 3 sandwich the welding start point of the object to be welded, first, one electrode 2 of the pair of electrodes 2 and 3 contacts the welding start point of the object to be welded, and then the other Since it moves toward the electrode 3, the reaction force, that is, back pressure is generated at this time, and the back pressure is transmitted to the slide substrate 51 via the brackets 10 and 11. When the back pressure is transmitted to the slide board 51, the slide board 51 moves upward in FIG.

When the slide substrate 51 moves upward, the other electrode 3 also moves upward, and holds the welding start point of the object to be welded together with the one electrode 2. This back pressure acts until the electrode pressure of one electrode 2 and the electrode pressure of the other electrode 3 become equal. That is, the welding line of the object to be welded is always reliably sandwiched by the pair of electrodes 2 and 3 with a constant electrode pressing force.

Then, when the welding start point of the object to be welded is sandwiched by the pair of electrodes 2 and 3, the pair of electrodes 2 and 3 is energized, and the roll spot welder main body 1 is guided along the welding line of the object to be welded. Robot arm 37 being taught to
Is guided along the welding line of the object to be welded, and the desired roll spot welding is performed.

That is, the pair of electrodes 2 and 3 perform roll spot welding along the welding line of the object to be welded while rotating by the electrode pressing force to the object to be welded and the driving force of the robot arm 37.

In this manner, the welding line of the welding object is roll spot welded, and when the welding of all the desired welding lines of the welding object is completed, the pressurizing cylinder 18 operates again, and the piston rod 18a of the pressurizing cylinder 18 is operated. To shorten. As a result, the electrode head 4 moves in a direction away from the electrode head 7, the clamp of the welding line of the workpiece by the pair of electrodes 2 and 3 is released, and the lock cylinder 59 also operates and the piston of the lock cylinder 59 moves. The rod 59a is extended, the stopper 57 is pushed down by the pusher 60, and the tip 57a of the stopper 57 is inserted into the stopper hole 5.
It is pressed against the stopper surface 58a of 8 to lock the slide substrate 51.

When the slide substrate 51 is locked, the robot arm 37 returns the roll spot welding machine main body 50 to the original position, and one cycle of roll spot welding is completed.

(Effect of the invention) As described in detail above, according to the present invention, a bracket composed of plate members opposed to a movable arm is provided so as to be movable up and down, and a bracket orthogonal to the plate members is provided above and below the plate members. Since the pair of electrode heads provided with the electrodes thus formed are provided so that the bracket formed of the plate body and the pair of electrodes are sufficiently separated from each other, the position of the welding line can be set deep. With this, the position of the welding line is not limited, and the welding can be easily performed.

Further, one electrode head is provided so as to be movable up and down along the side surface of the plate body of the bracket to narrow the mutual width of the pair of brackets, and an electrode head having one electrode is provided for the plate body. Since it is possible to guide along the side surface, a special guide device is not required and the structure of the welder body can be simplified. Further, since the guide device is not required, the distance between the center of one electrode and the outer surface of the bracket can be narrowed. As a result, the range of guiding the pair of electrodes can be widened, and sufficient work can be performed in a narrow space.

Further, a bracket composed of plate bodies opposed to the movable arm is provided so as to be movable up and down, the other electrode head is fixed between the plate bodies of the bracket, and a pressure cylinder is rotatably provided above the bracket, When welding the object to be welded by connecting the piston rod of the pressurizing cylinder and one of the electrode heads, the welding line can be reliably clamped by utilizing the reaction force.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is a front view of a roll spot welding machine main body with one bracket removed, FIG. 2 is a left side view of that of FIG. 1, and FIG. 3 is III of FIG. FIG. 50 …… Roll spot welder main body 2 …… One electrode 3 …… Other electrode 18 …… Cylinder 18a …… Piston rod 37 …… Robot arm (movable arm) 51 …… Slide substrate (sliding body) 53, 54 ...... Guide rail (guide member)

Front Page Continuation (72) Inventor Masafumi Matsuo 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd. (72) Inventor Hidenori Makihara 5-16 Hosoya-cho, Toyota-shi, Aichi Kito Kogyo Co., Ltd. (72 ) Inventor Fumio Matsumoto 5-16 Hosoya-cho, Toyota City, Aichi Prefecture Kito Kogyo Co., Ltd. (72) Inventor Takayuki Yamamoto 5-16 Hosoya-cho Toyota City, Aichi Kito Kogyo Co., Ltd. (56) References Special Kai 63-123574 (JP, A)

Claims (1)

[Claims] 1. A roll spot welding machine main body having a pair of electrodes is attached to a movable arm of a robot, a welded portion is sandwiched between the pair of electrodes, and the pair of electrodes is covered by the movable arm. In a roll spot welding machine for conducting a roll spot welding by energizing and pressurizing while guiding along a welding line of a welded object, a bracket made of plate bodies opposed to the movable arm is provided so as to be movable up and down, and a plate of the bracket. Up and down between the body,
A pair of electrode heads having electrodes orthogonal to each other are provided on the plate body, one electrode head is provided so as to be vertically movable along a side surface of the plate body of the bracket, and the other electrode head is provided on the plate body of the bracket. A roll spot welding machine, characterized in that a pressure cylinder is rotatably provided above the bracket, and a piston rod of the pressure cylinder and the one electrode head are connected to each other.