JP2590036B2 - Stud welding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stud welding machine which is provided with a latch mechanism for stopping a movable table holding a stud at a pulling start position, and which is used for rebar welding of a buried tunnel.

[0002]

2. Description of the Related Art A process in which a welding current is applied while an end protrusion of a stud is pressed against a base material to generate an arc only at the end protrusion of the stud, and the stud is retracted a predetermined distance from the base material by a lifting mechanism. In the stud welding method, a method of continuously generating an arc between the entire cross section of the stud tip and the base material and melting the stud and the base material, and pressing the melted stud against the molten pool of the base material, current is applied. The timing between the lifting of the stud and the lifting of the stud, the lifting amount of the stud, the pressing force and the pressing speed of the stud against the base material are important.

In a conventional stud welding machine in which the studs are pulled up by a magnet and the studs are pushed in by a spring, proper control of these is not easy.
The present inventors have developed a pneumatic cylinder drive type stud welding machine as disclosed in Japanese Patent Publication No. 3-72388.

In this stud welding machine, a moving table provided with a stud holding clamp is mounted on a base so as to be linearly movable.
A pneumatic cylinder that lifts and presses the stud against the base material by moving the carriage back and forth is provided between the base and the carriage, and the hook at the tip engages the receiving pin on the carriage to start lifting the carriage. The latch lever to be stopped is pivotally connected to the base with a transverse pivot.

In this stud welding machine, the lifting and pressing of the studs are performed by pushing and pulling of the pneumatic cylinder, so that not only a sufficiently strong force and a fast response speed can be obtained, but also the flow control valve of the pneumatic cylinder can be used freely. Although the speed can be adjusted, the workability is not good in this aspect because the engagement between the latch lever and the receiving pin is all performed manually.

For example, in the manufacture of the above-described submerged tunnel box, it is necessary to weld a large number of reinforcing bars to a steel shell. Therefore, in order to efficiently digest this enormous amount of work, four stud welding machines are required. The adoption of a large number of welding units, such as 10 stations, has been proposed, but improving the efficiency of the engagement operation between the latch lever and the receiving pin has been a major bottleneck. Also, if one of the many latch levers is forgotten to be engaged, the stud welding at that location will be defective. However, it is not easy to perform the inspection of the welding quality for a very large number of studs.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to automatically perform an engagement operation between a latch lever and a receiving pin to automatically complete a welding preparation, thereby improving workability of the entire stud welding. An object of the present invention is to provide a stud welding machine which can improve a large amount of welding work efficiently and properly.

[0008]

The stud welding machine according to the present invention will be described below with reference to the reference numerals in the accompanying drawings.
A moving table 2 provided with a stud holding clamp 1 is mounted on a base 3 so as to be able to move linearly, and a driving cylinder 6 for pulling up and pressing a stud 5 against a base material 4 by forward and backward movement of the moving table 2 is mounted on the base 3. And a latch lever 7 for engaging the receiving pin 9 on the movable table side with the tip hook portion 8 and stopping the movable table 2 at the pulling start position is pivotally attached to the base 3 with the transverse pivot 10. I do.

The transverse pivot 10 is eccentrically disposed ahead of the center of gravity G of the latch lever 7, and the eccentric load urges the latch lever 7 to rotate away from the receiving pin 9, thereby causing the latch lever 7 to receive the receiving pin. An operating cylinder 11 is provided on the base 3 for rotating in the direction of engagement with the base 9, and a spring means 12 for maintaining the engagement between the receiving pin 9 and the latch lever 7 by urging the moving base 2 forward. 3, the engagement between the latch lever 7 and the receiving pin 9 is released when the stud 5 is pulled up by the retreat operation of the movable base 2.

[0010]

In this stud welding machine, the state immediately before the start of operation preparation is as shown in FIG. 1, and the latch lever 7 is at a standby position where the tip hook 8 is disposed obliquely upward. In this state, when the driving cylinder 6 is operated and the movable table 2 is driven backward in a direction away from the base material 4 as shown in FIG. 2, the spring means 12 is elastically deformed between the base 3 and the movable table 2. . At the stage where the movable base 2 is retracted until the receiving pin 9 passes below the tip hook portion 8, the operating cylinder 6 is operated to press the latch lever 7 as shown in FIG. The main body is brought into contact with the receiving pin 9

In this state, when the driving cylinder 6 is stopped to be in a free state, the movable base 2 is driven forward by the elastic repulsive force of the spring means 12, and the receiving pin 9 moves along the main portion of the latch lever 7. After a slight forward movement, the engagement between the tip hook 8 of the latch lever 7 and the receiving pin 9 is established as shown in FIG. Since the engagement state between the latch lever 7 and the receiving pin 9 is maintained by the pressing force of the spring means 12 acting via the movable table 2, the movable table 2 is stopped and held at the stud pulling start position.

After the engagement between the latch lever 7 and the receiving pin 9 is established, the operation cylinder 11 is reversely operated as shown in FIG. 5 to stop pressing the latch lever 7. Through the above steps, the preparation for operation of the stud welding machine is completed, and the stud holding clamp 1 of the movable base 2 is loaded with the stud 5 such as a reinforcing bar.
Is pressed against the base material 4 such as a steel shell, and the stud 5 is fastened and fixed to the clamp 1.

After a predetermined time, the moving table 2 is driven backward by a predetermined distance in a direction away from the base material 4 by the operation of the driving cylinder 6, and the stud 5 is pulled up. The reciprocating operation of the movable base 2 causes the receiving pin 9 to move in a direction away from the tip hook 8 of the latch lever 7. In this manner, the transmission of the pressing force from the spring means 12 is interrupted at the moment when the receiving pin 9 is detached from the distal end hook portion 8, so that the latch lever 7 is actuated by the rotational moment due to the eccentric load, thereby causing the transverse pivot. The tilting rotation is made around the center 10 and the tip hook portion 8 returns to the standby position where the hook portion 8 comes obliquely upward.

During this time, a high current flows, an arc is continuously generated, and the tip of the stud 5 and the heat input point of the base material 4 are melted. After a predetermined time, the high current is cut off, and the movable base 2 is driven forward by a predetermined distance toward the base material 4 by the reverse operation of the driving cylinder 6, and the stud 5 is pushed into the base material 4, thereby completing the stud welding. .

[0015]

In the illustrated embodiment, the stud welding machine is of a horizontal type in which the stud 5 is loaded horizontally, the base 3 is arranged horizontally, and the front end rising portion 14 and the rear end rising portion 15 of the base 3 are provided. Between them, two horizontal guide shafts 16 are installed in parallel. On the lower surface of the moving base 2, legs 17, 1
The bearing block 18 through which each guide shaft 16 passes is fixed to each leg 17. The driving cylinder 6 is horizontally fixed to the rear end rising portion 15, and a guide shaft 16 is fixed.
The distal end of the piston rod 19 of the driving cylinder 6 is fixed to the rear leg 17.

The front surface 15a of the rear end rising portion 15 of the base 3
Is a stopper surface with which the rear surface 2a of the movable base 2 comes into contact when the stud 5 is raised, and limits the amount of the stud 5 raised. The operating cylinder 11 is the auxiliary arm 2
The piston rod 21 is horizontally fixed to the base 3 through the base 0 and is parallel to the guide shaft 16 and is disposed above the main portion of the latch lever 7. An arc shield 22 is fixed to the upper end of the front end rising portion 14 of the base 3, and a stud holding clamp 1 is fixed to an intermediate portion of the base 3 so as to be aligned with the arc shield 22.

The receiving pin 9 protrudes from the rear side surface of the movable base 2. The latch lever 7 is configured so that the rear portion has a larger cross-sectional shape than the front portion so that the weight of the portion behind the transverse pivot 10 is greater than the weight of the front portion, and the center of gravity G is located behind the transverse pivot 10. It is deviated. Latch lever 7
Another method of returning rotation due to the eccentric load of
An unbalanced weight made of a material having a large specific gravity can be embedded in the rear portion. The forward biasing spring means 12 of the movable base 2 is constituted by a compression coil spring, and its front and rear ends are respectively formed with a rear recess 23 of the movable base 2 and a rear end rising part 1 of the base 3.
5 is inserted into the front recess 24.

An electromagnet unit 2 is provided on the lower surface of the front end of the base 3.
The base 5 is fixed to the base material 4 made of a steel plate by the magnetic attraction force of the electromagnet unit 25. Driving cylinder 6 and operating cylinder 11
Are all composed of pneumatic cylinders, but can be replaced with hydraulic cylinders.

Driving cylinder 6 and operating cylinder 1
In one pneumatic circuit, an electromagnetic valve, a timer, and the like necessary for obtaining the above-described operation sequence and timing are incorporated.
In the illustrated embodiment, the stud 5 is lifted and pressed by the single drive cylinder 6 in the forward and reverse directions. However, the drive cylinder for lifting and the drive cylinder for pressing are different. Can be separately provided.

[0020]

As described above, in the stud welding machine of the present invention, the base 3 is equipped with the movable base 2 provided with the clamp 1 for holding the stud, and the movable base 2 is moved back and forth by the driving cylinder 6 so that the base is moved forward and backward. In the cylinder drive type stud welding machine, the stud 5 is lifted and pressed against the material 4, the tip hook portion 8 of the latch lever 7 is engaged with the receiving pin, and the movable base 3 is stopped at the pulling start position. The latch lever 7 is rotated by the operation cylinder 11 provided on the base 3 in a direction in which the latch lever 7 engages with the receiving pin 9, and the base 3 and the movable base 2 are moved.
The movable base 2 is urged forward by a spring means 12 provided therebetween to maintain the engagement between the catch lever 9 and the catch lever 9 when the stud 5 is pulled up. It releases the latch lever 7 to the standby position where the latch lever 7 is detached from the receiving pin 9 due to the eccentric load. By automatically engaging the latch lever 7 with the receiving pin 9, welding preparation is automatically performed. The workability of the entire stud welding is improved.

As described above, since the workability is improved by the automation, a large number of welding operations can be efficiently and appropriately performed, and a plurality of welding units arranged side by side can be easily assembled without worrying about welding failure due to forgetting to put on. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a stud welding machine according to one embodiment of the present invention, showing a state immediately before welding preparation is started.

FIG. 2 is a front view of the stud welding machine when a moving table is driven backward by a driving cylinder in an initial stage of welding preparation.

FIG. 3 is a front view of the stud welding machine when a latch lever is pressed and rotated by an operation cylinder in a next stage of welding preparation.

FIG. 4 is a front view of the stud welding machine when the driving cylinder is set free at the next stage of the welding preparation and the moving table is driven forward by the spring means.

FIG. 5 is a front view of the stud welding machine when the operation cylinder is returned to a standby position in a final stage of welding preparation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stud holding clamp 2 Moving stand 3 Base 4 Base material 5 Stud 6 Driving cylinder 7 Latch lever 8 Tip hook part 9 Receiving pin 10 Transverse pivot 11 Operation cylinder 12 Spring means 13 Stud tip projection 14 Base Front end rising portion 15 Rear end rising portion of base 16 Guide shaft 17 Leg 18 Bearing block 19 Piston rod of driving cylinder 20 Auxiliary arm 21 Piston rod of operating cylinder 22 Arc shield 23 Rear recess of moving table side 24 Base Side front recess 25 electromagnet unit

Claims (1)

(57) [Claims] 1. A moving table provided with a stud holding clamp is provided on a base so as to be linearly movable, and a driving cylinder for raising and pressing a stud against a base material by a forward and backward movement of the moving table is provided on the base and the moving table. Provided between them, the latch lever that engages the receiving pin on the moving table side with the tip hook portion and raises the moving table to stop at the start position is pivotally connected to the base with the transverse pivot, and the transverse pivot is moved from the center of gravity of the latch lever. An eccentric arrangement is also provided forward, and the eccentric load urges the latch lever to rotate away from the receiving pin, and provides an operating cylinder on the base that rotates the latch lever in the direction to engage with the receiving pin. A spring means is provided between the base and the movable base for urging the movable base forward to maintain the engagement between the latch pin and the latch lever, and when the stud is pulled up by the retreat operation of the movable base, the latch lever and the latch pin are connected. Disengage Stud welding machine.