JPS64256Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a device that synchronizes a moving workpiece and a machine body in an assembly line, a processing line, etc. with each other.

(Prior Art) Conventionally, as a device capable of tightening a plurality of parts to be tightened with one device on an assembly line, a multi-axis nut runner 5 having a plurality of sockets 4 is known as shown in FIG. This nut runner 5 is suspended from an I-shaped beam 3 on the ceiling so that it can travel in the same direction as the moving direction of the workpieces 2 transferred by the assembly conveyor 1. In addition,
18 is a cylinder for raising and lowering the nut runner 5, and 19 is a balancer provided on the I-shaped beam 3 for returning to its original position.

When tightening the workpiece 2 using this nut runner 5, it is done as follows. That is, while the workpiece 2 is being transferred by the assembly conveyor 1, the worker manually moves the nut runner 5 from the original position to the tightening position directly above the workpiece 2 and positions it. After lowering the nut runner 5 using the cylinder 18 and aligning the socket 4 so that it fits into the portion of the workpiece 2 to be tightened, the operator issues a start command to start tightening. After the tightening is completed, the nut runner 5 is freely raised by the lifting cylinder 18, and then the nut runner 5 is pulled by the harness 19 and returned to its original position.

(Problems to be Solved by the Invention) In this way, in the conventional technology, the nut runner 5 has to be manually moved and positioned to the tightening position of the workpiece 2, so the positioning work is very troublesome and the productivity is low. It is becoming.

Therefore, a method that could be considered is to synchronize the nut runner with the movement of the workpiece by placing equipment, such as a pilot bar, synchronizing rod, and actuator, on the floor opposite to the worker on the assembly line. The installation space required is large and the equipment cost is very high.
The current situation is that it has not been put into practical use. For these reasons, the development of a synchronization device with high synchronization accuracy, a simple structure, and a small installation space has become a major challenge for those skilled in the art, but the reality is that such a practical synchronization device has not yet been provided. It is in.

The present invention has been made in view of the above circumstances, and aims to provide a synchronizing device with a simple structure and a small installation space.

(Means for Solving the Problems) The technical means of the present invention is characterized by rotating a rotating member integrally having a contactor that comes into contact with the work in a machine body that can move in the same direction as the work. The machine body is provided with a limit switch that is operated by the rotation of the rotating member,
A fluid pressure circuit connected to a drive cylinder for moving the machine body is configured to connect a fluid pressure supply source and a fluid pressure supply source between the head side chamber of the drive cylinder and the fluid pressure supply source and between the rod of the drive cylinder based on a signal from the limit switch. The drive cylinder includes an electromagnetic valve that communicates between the side chamber and the discharge port side, and a mechanical servo valve that is operated by rotation of the rotating member and controls the amount of fluid discharged from the rod side chamber of the drive cylinder. A fixed stopper is provided opposite the end face of the piston rod of the cylinder to restrict movement of the piston rod. In the present invention, the moving speed of the drive cylinder, that is, the moving speed of the machine body, is set to be slightly higher than the moving speed of the workpiece.

(Operation) The operation of the synchronization device having the above configuration will be explained. A workpiece is transferred by a conveyor or the like, and when the workpiece comes into contact with a contact of a rotating member, the rotating member rotates, thereby operating a limit switch and a mechanical servo valve. The operation of the limit switch activates the electromagnetic valve, and fluid pressure is supplied to the head side chamber of the drive cylinder, while the rod side chamber of the drive cylinder is switched to the discharge port side, and the drive cylinder becomes ready for operation.

On the other hand, mechanical servo valves increase the amount of fluid discharged from the rod side chamber of the drive cylinder as the rotation angle of the rotating member increases, thereby changing the moving speed of the machine body from zero to slightly higher than the moving speed of the workpiece. The machine has the function of increasing the speed steplessly up to a maximum speed of 100 mph, and when the mechanical servo valve operates, the rod side chamber of the drive cylinder is opened wide, and the machine body moves in the same direction as the workpiece at a speed that exceeds the moving speed of the workpiece. Move with. As a result of the movement, the contact and the rotating member are gradually rotated in the opposite direction and actuated in the direction in which the mechanical servo valve is turned off. As a result, the speed of the machine body decreases, so that the workpiece pushes the mechanical servo valve again via the contact and the rotating member, which acts to increase the moving speed of the machine body. In other words, the mechanical servo valve functions to control the movement speed of the machine body, and the machine body moves while increasing and decreasing the speed to match the movement speed of the workpiece.
Synchronization with the work will be performed.

(Embodiment) An embodiment of the present invention will be explained below with reference to FIGS. 1 to 3. 1 is to move a workpiece 2 having a plurality of parts to be tightened on the upper surface to the right in FIG. 1. The assembly conveyor 3 is an I-shaped beam extending parallel to the assembly conveyor 1 in the ceiling above the assembly conveyor 1, and the I-shaped beam 3 is equipped with a polyaxial nut runner having a plurality of sockets 4 on the lower surface side. (Machine body) 5 is suspended. Natsutranna 5
is adapted to be moved in the same direction as the transfer direction of the workpiece 2 by a drive cylinder 6 connected thereto, and movement of the piston rod 7 of the drive cylinder 6 to the left in FIG. 3 is regulated by a fixed stopper 8 fixedly installed so as to face the end surface of the piston rod 7. In this embodiment, the piston rod 7 can move toward and away from the fixed stopper 8, but if necessary, a flange 7a may be attached to the piston rod 7 to prevent the piston rod 7 from being separated by more than a predetermined distance from the fixed stopper 8, as shown in FIG. In addition, a holding member 8a for holding the flange portion 7a may be fixed to the fixed stopper 8. It should be noted that it is also possible in terms of design for the fixed stopper 8 and the piston rod 7 to be made into an integral structure by welding or the like.

Reference numeral 9 denotes a plate cam (rotating member) that is rotatably attached to a suitable position on the nut runner 5. The plate cam 9 has a contact 10 extending downward.
The lower end portion of is adapted to come into contact with the forward end surface of the workpiece 2 . Therefore, the plate cam 9 can rotate in the direction of arrow A in the figure as the contactor 10 is displaced and swung by a minute angle due to the advance of the workpiece 2. A limit switch 11 is attached to the nut runner 5 at a location corresponding to the plate cam 9 so as to be turned on when the plate cam 9 rotates in the direction of arrow A.

Reference numeral 12 in FIG. 3 is an air source as a fluid pressure supply source for the drive cylinder 6, and an electromagnetic solenoid valve 13 is located between the air source 12 and the drive cylinder 6.
is provided. This solenoid valve 13
is switched to the forward position in response to an ON signal from the limit switch 11, and switched to the backward position in response to a tightening completion signal (not shown) and a retreat signal from the rising end of the nut runner 5. When the solenoid valve 13 is switched to the forward position, the head side chamber of the drive cylinder 6 communicates with the air source 12, and the rod side chamber opens to the atmosphere (corresponding to the muffler 14 here).
Then, communication becomes possible via a mechanical servo valve 17, which will be described later. Conversely, when the solenoid valve 13 is switched to the retracted position, the head side chamber communicates with the discharge port, and the rod side chamber communicates with the check valve 17.
It becomes possible to communicate with the air source 12 via a.

Reference numerals 15 and 16 indicate hydroconverters (air-hydraulic pressure transmitters) disposed between the solenoid valve 13 and the head side chamber and rod side chamber of the drive cylinder 6, respectively.
As shown in the figure, it is installed at the top of the drive cylinder 6. Therefore, the hydroconverter 15,
A hydraulic circuit is formed in a circuit closer to the drive cylinder 6 than the hydroconverters 15 and 16, and an air circuit is formed in a circuit closer to the air source 12 than the hydroconverters 15 and 16. The reason why the air pressure is changed to hydraulic pressure by the hydroconverters 15 and 16 is to improve the responsiveness of the operation of the drive cylinder 6 and prevent pulsation by utilizing the incompressibility of the hydraulic oil.

A mechanical servo valve 17 is provided in the circuit between the hydroconverter 16 and the rod side chamber of the drive cylinder 6, and the mechanical servo valve 17 operates to switch the limit switch 11 by rotating the plate cam 9 in the direction of arrow A in FIG. It is starting to operate with a slight delay. When the mechanical servo valve 17 is operated and switched to the on position, the rod side chamber of the drive cylinder 6 communicates with the hydro converter 16.
In addition, 18 is a lifting cylinder for raising and lowering the nut runner 5, and 19 is a balancer for returning the nut runner 5 to the original position shown in FIG. 1, which is provided on the I-shaped beam 3.
In FIG. 3, 20 and 21 are filters, 22 is a pressure reducing valve, and 23 is a pressure gauge. Although the solenoid valve 13 is disposed on the floor side of the assembly line like the air source 12, it can also be disposed at an appropriate position on the nut runner 5 or the I-shaped beam 3.

Next, the operation of the simple synchronization device according to this embodiment will be explained in detail. Note that the drive cylinder 6
The forward speed of the assembly conveyor 1 is set to be slightly higher than the transfer speed of the workpiece 2.
It is configured to be changeable depending on the conveyance speed of the workpieces 2 and the number of works 2.

As shown in FIG. 1, when the workpiece 2 is transferred to the right in the figure by the assembly conveyor 1 and moved to a predetermined position, the upper end surface of the workpiece 2 in the advancing direction comes into contact with the lower end portion of the contactor 10. After contact, work 2
As the cam plate 9 moves forward, the cam plate 9 rotates in the direction of arrow A in FIG. 1 via the contact 10. By rotating the cam plate 9 in the direction of arrow A, the limit switch 11 is first turned on. When the limit switch 11 is turned on, the solenoid valve 1 is turned on as described above.
3, the solenoid valve 13 is switched from the neutral position to the forward position. With the solenoid valve 13 switched to the forward position,
The air source 12 communicates with the hydroconverter 15, where air pressure is applied, and the air source 12 is connected to the drive cylinder 6 via a hydraulic circuit.
The inside of the head side chamber becomes pressurized.

After that, when the cam plate 9 further rotates in the direction of arrow A due to the forward movement of the workpiece 2, the mechanical servo valve 17 is operated and switched to the on position, and the drive cylinder 6 is turned on.
The rod side chamber communicates with the hydro converter 16 and is in an open state. When the rod side chamber is opened, the tip end surface of the piston rod 7 is pressed against the fixed stopper 8 by the pressure inside the head side chamber.
Next, with the piston rod 7 pressed against the fixed stopper 8, the cylinder body 6 of the drive cylinder 6 is
Only a starts to move together with the workpiece 2. In other words, the nut runner 5 moves forward in the same direction as the moving direction of the workpiece 2.

Then, when the forward speed of the nut runner 5 gradually increases and exceeds the forward speed of the workpiece 2,
Since the workpiece 2 moves away from the contact 10, the cam plate 9 gradually rotates in the direction of arrow B in FIG. 1 via the contact 10. As the cam plate 9 rotates in the direction of arrow B and the mechanical servo valve 17 switches to the OFF position, the function of the mechanical servo valve 17 described above reduces the amount of oil discharged from the rod side chamber of the drive cylinder 6. As a result, the forward speed of the cylinder body 6a, that is, the nut runner 5, decreases and attempts to stop. When the forward speed of the nut runner 5 becomes smaller than that of the workpiece 2 and decreases to a certain speed (including the case of zero speed), the workpiece 2 is moved again via the contactor 10, as described above. The rotation of the cam plate 9 in the direction of arrow A is increased, the mechanical servo valve 17 is switched to the full flow direction, and the forward speed of the nut runner 5 increases again to exceed the forward speed of the workpiece 2.

As described above, the flow rate is frequently increased/decreased by the mechanical servo valve 17 while the head side chamber of the drive cylinder 6 is kept in a pressurized state, thereby accelerating and decelerating the nut runner 5 several times in a very short period of time. is repeated, whereby the forward speed of the nut runner 5 is completely synchronized with the forward speed of the workpiece 2. Therefore, Natsutranna 5 and Work 2
By achieving speed synchronization with the nut runner 5, the nut runner 5 is automatically positioned at a tightening position corresponding to the workpiece 2.

Here, the synchronization accuracy of the nut runner 5 will be described. With the head side chamber of the drive cylinder 6 pressurized with hydraulic oil, the mechanical servo valve 17
Since the drive cylinder 6 operates simultaneously with the operation of
Coupled with the fact that the hydraulic oil is incompressible, the responsiveness is high and errors in synchronization accuracy of the nut runner 5 can be suppressed as much as possible.

When the nut runner 5 is automatically positioned at the tightening position, the nut runner 5 is lowered by the lifting cylinder 18 as shown by the imaginary line in FIG. Fit and tightening begins. When the tightening of the part to be tightened is completed, a tightening completion signal is issued, the lifting cylinder 18 raises the nut runner 5, a retreat signal is given to the solenoid valve 13, and the balancer 19 raises the nut runner 5 in the same manner as before. It will return to the original position shown in FIG.

In this way, the nut runner 5 moves in synchronization with the work 2 and moves while maintaining the tightening position according to the work 2, so the nut runner 5 can be moved by hand.
Productivity is improved by eliminating the hassle of moving.
Moreover, the drive cylinder 6 as an actuator
is connected to the nut runner 5, and the hydro converters 15, 16 and mechanical servo valve 17 are incorporated into the nut runner 5, and are arranged in a large space on the ceiling, so that effective work space on the assembly line can be secured and the tightening Work efficiency also improves.
In this embodiment, the piston rod 7 is configured to be able to move toward and away from the fixed stopper 8, so that the operator can manually move the nut runner 5 as in the prior art if necessary.

Although the embodiments have been described above, the present invention also includes the following configurations.

In the embodiment, the mechanical servo valve is operated with a delay in the operation of the limit switch due to the rotation of the rotating member, but the order in which the limit switch and mechanical servo valve operate is not particularly limited.

Although a cam member is used as the rotating member in the embodiment, a rotating lever or the like may also be used.

In the embodiment, the case where the machine body is a nut runner has been described, but the synchronizing device of the present invention is not limited to nut runners, but can be widely applied to processing machines such as welding machines, painting machines, and cutting machines.

In the embodiment, the fluid pressure circuit is configured by combining an air circuit and a hydraulic circuit, but it can also be configured by using only an air circuit or only a hydraulic circuit.

(Effects of the invention) As described above, according to the invention, the drive cylinder and mechanical servo valve are configured to move in synchronization with the movement of the workpiece together with the moving machine body. Therefore, it is possible to obtain a practical synchronizing device with a simple structure without reducing the work space as in the conventional case. Additionally, as the workpiece moves, the machine body synchronizes by increasing or decreasing the moving speed to match the moving speed of the workpiece, and if the workpiece stops, the machine body also stops, so not only can high synchronization accuracy be expected. Therefore, reliable synchronous control can be performed at all times regardless of the speed of movement of the workpiece.

[Brief description of the drawings]

FIG. 1 is an overall front view showing an embodiment of the present invention;
Figure 2 is an enlarged partial sectional view showing an example of the structure of the joint between the piston rod and the fixed stopper in Figure 1;
This figure is a hydraulic and pneumatic circuit diagram relating to the synchronizer shown in FIG. 1, and FIG. 4 is an overall front view showing a conventional nut runner. 2... Work, 5... Nut runner (machine body), 6... Drive cylinder, 7... Piston rod, 8... Fixed stopper, 9... Plate cam (rotating member), 10... Contact, 11... ...Limit switch, 12...Air source, 13...Solenoid valve, 15, 16...Hydro converter, 17...
...Mechanical servo valve.

Claims (1)

[Scope of utility model registration request] A drive cylinder is connected to the machine body to move the machine body in the same direction as the workpiece at a speed slightly higher than the workpiece's moving speed, and a rotating member having a contact that comes into contact with the workpiece is connected to the workpiece. A limit switch is provided in the machine body so as to be rotatable in the moving direction and in the counter-moving direction, and a limit switch operated by the rotation of the rotating member is disposed at a location of the machine body corresponding to the rotating member, and In a fluid pressure circuit that operates a cylinder, communication is established between the head side chamber of the drive cylinder and its fluid pressure supply source and between the rod side chamber of the drive cylinder and the discharge port side based on a signal from the limit switch. A fixed stopper for regulating the movement of the piston rod of the driving cylinder is incorporated, and a mechanical servo valve is actuated by the rotation of the rotating member to control the amount of fluid discharged from the rod side chamber of the driving cylinder. , a simple synchronizer characterized in that it is provided corresponding to the end face of the piston rod.