JPH0229013Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a buffer drive device for stopping a reciprocating object such as a reciprocating trolley at a moving end without impact, and in particular reduces costs by simplifying the device. This invention relates to a buffer drive device that enables

FIG. 1 shows a reciprocating type truck drive device as described above, in which a truck 1 travels along a travel locus 2 such as a rail, and reciprocates between a solid line position and a two-dot chain line position. Such a reciprocating trolley 1 is used for transporting workpieces and scraps on an assembly line, etc., and is also suitable for various transport devices.
By this, the cart 1 existing at one moving end is pushed away toward the other moving end, and by repeating this alternately, the cart 1 can travel back and forth. The cart 1 that has been traveling is usually configured to eventually collide with a stopper (not shown) at one end of its movement and come to a stop. If the truck 1 were to directly collide with a fixed stopper when stopped, the impact force would be large and the truck 1 and the stopper would be damaged prematurely. For this reason, conventionally, shock devices such as shock absorbers and shock dampers that act during exhaust are connected to the air supply/exhaust parts of the air cylinders 3a and 3b, and compressed air is supplied to the shock absorber side and the pressure source side of each air cylinder 3a and 3b. It was necessary to provide separate solenoid valves for switching, which caused an increase in costs.

Therefore, the purpose of the present invention is to eliminate the drawbacks such as the cost inherent in the conventional shock absorbers for reciprocating objects as described above, and the gist thereof is to In a device for alleviating the shock at the time of stopping at a moving end by a pair of fluid actuators provided at the moving end, a pipe line connecting each of the fluid actuators and a pressure source,
A one-way shuttle valve having a slidable valve body that selectively communicates between one of the discharge side port and the inlet side port and the outlet side port and is normally biased toward the side that closes the inlet side port. and connecting the fluid supply and discharge ports of each of the fluid actuators to the outlet port of the one-way shuttle valve,
and a reciprocating system in which the inlet port of each of the shuttle valves is connected to the pressure source or to a common switching valve that opens to atmospheric pressure, and the discharge port is opened via a pressure control means. The present invention provides a shock absorbing device for moving objects.

Next, embodiments embodying the present invention will be described in detail with reference to the accompanying drawings to provide an understanding of the present invention.

FIG. 1 is a pneumatic circuit diagram showing a shock absorbing device for a reciprocating object according to an embodiment of the present invention. In this embodiment, control using an air cylinder will be explained as in the conventional example, but the present invention uses a hydraulic cylinder operated not only by such a pneumatic circuit but also by a hydraulic circuit as an example of a fluid actuator. Good too.

In FIG. 1, the trolley 1 reciprocates on a travel trajectory 2 such as a rail as described above, is pushed off by a pair of air cylinders 3a and 3b provided at its moving end, and travels back and forth from the solid line position to the two-dot chain line position. . The air supply/exhaust ports 4a and 4b of each of the air cylinders 3a and 3b are connected to outlet ports 7a and 7b of quick exhaust type one-way shuttle valves 6a and 6b via pipes 5a and 5b, respectively. The one-way shuttle valves 6a and 6b are a type of three-port valve as shown in FIG. The structure is such that the valve body 10 slides, the port 8 or 9 on the side that pushes the valve body 10 and the outlet side port 7 communicate with each other, and the port on the side that loses the pressure is closed by the valve body 10. In order to provide directionality in the standby state, the valve body 10 is always moved in one direction (inlet side port 9
It has a built-in compression spring 11 that biases it toward the closing side).

Hereinafter, elements on the one-way shuttle valve 6a side will be described with a suffix a, and elements on the one-way shuttle valve 6b side will be described with a suffix b.

The inlet ports 9a and 9b of the one-way shuttle valves 6a and 6b are connected to conduits 12a and 12b, respectively.
A 4-port solenoid valve 13, which is a type of switching valve,
The discharge ports 8a and 8b of the one-way shuttle valves 6a and 6b are respectively open to atmospheric pressure via relief valves 14a and 14b having pilot ports, which are examples of pressure control means. .

Therefore, when the solenoid valve 13 is operated to the state shown in the first diagram, the compressed air flowing out from the pressure source 15 flows through the solenoid valve 1.
3 and then through the conduit 12a to the one-way shuttle valve 6.
Flows into the inlet port 9a of the valve a, and moves the valve body 10a in the direction of the discharge port 8a against the compression spring 11a. As a result, the valve body 10a closes the discharge side port 8a, and the compressed air that has flowed into the one-way shuttle valve 6a flows from the outlet side port 7a to the pipe line 5a.
The air flows into the air cylinder 3a through the air cylinder 3a, and advances the piston rod 16a of the air cylinder 3a. As a result, the truck 1 shown by the solid line moves in the direction of the opposing air cylinder 3b.

In this state, the piston rod 16b of the other air cylinder 3b is in the advanced state as shown by the broken line, so the traveling truck 1 comes into contact with the tip of the piston rod 16b, causing the piston rod 16b to retreat. Then, the pressure at the air supply/exhaust port 4b of the air cylinder 3b increases. At this point, the inlet port 9b on the one-way shuttle valve 6b side is open to atmospheric pressure via the solenoid valve 13 as shown in the figure, so the valve body 10b is pressed against the compression spring 11.
b to close the inlet side port 9b.
Therefore, the pressure increase at the air supply/exhaust port 4b of the air cylinder 3b passes through the conduit 5b to the one-way shuttle valve 6.
b is transmitted to the outlet side port 7b, and further supplied to the primary side of the relief valve 14b via the discharge side port 8b which is in communication with the outlet side port 7b, and the relief valve 14b is brought into communication due to the increase in pilot pressure. The compressed air discharged from the air cylinder 3b passes through the one-way shuttle valve 6b and is discharged into the atmosphere from the relief valve 14b.

Therefore, by appropriately adjusting the set pressure of the relief valve 14b, the amount of compressed air released from the relief valve 14b can be appropriately restricted, so that the retraction speed of the piston rod 16b of the air cylinder 3b is gradually reduced. This makes it possible to reduce the impact force when the truck 1 collides with the stopper. Such a buffering capacity is achieved by the relief valve 14b.
This is possible by adjusting the set pressure.

In order to move the truck 1, which is stopped at the position indicated by the two-dot chain line in FIG. is actuated rightward to apply pressure from the pressure source 15 to the inlet port 9b of the one-way shuttle valve 6b. As a result, the valve body 10b
moves in the direction of closing the discharge side port 8b, and the compressed air is prevented from flowing in the direction of the relief valve 14b, and the compressed air is moved in the direction of closing the discharge side port 8b.
The air is supplied from the air cylinder 3b to the piston rod 16b, which advances the truck 1 in the opposite direction. At this point, the inlet port 9a of the one-way shuttle valve 6a is open to atmospheric pressure, so the valve body 10a has moved to the position where it closes the inlet port 9a. When the traveling truck 1 comes into contact with the tip of the piston rod 16a of the air cylinder 3a and moves the piston rod 16a backward, the compressed air discharged from the air cylinder 3a is transferred to the outlet port 7a of the one-way shuttle valve 6a. The air is supplied to the relief valve 14a through the discharge port 8a, increasing its pilot pressure. Therefore, when the pressure at the air supply/exhaust port 4a of the air cylinder 3a exceeds the set pressure of the relief valve 14a, the relief valve 14a
is activated and compressed air is released into the atmosphere, which gradually absorbs energy and decelerates the trolley 1, alleviating the impact force when it stops.

In the above embodiment, a one-way shuttle valve using a compression spring 11 was used, but a one-way shuttle valve that does not use a spring can also produce the same effect.

Further, in the above embodiment, a cart moving device using an air cylinder as a drive source has been described, but the driving source may be a hydraulic cylinder. It can be applied to any case where an inertial impact occurs at the end.

As described above, the present invention provides a device for alleviating the shock at the stop of a reciprocating object at a moving end using a pair of fluid actuators provided at the moving end, in which a pipe connecting each of the fluid actuators and a pressure source is provided. A one-way valve having a slidable valve body that selectively communicates one of the discharge side port and the inlet side port with the outlet side port and is normally biased toward the side that closes the inlet side port. a shuttle valve is interposed, the fluid supply/discharge port of each of the fluid actuators is connected to the outlet side port of the one-way shuttle valve, and the inlet side port of each of the shuttle valves is connected to the pressure source, or This buffer drive device for a reciprocating object is connected to a common switching valve that opens to atmospheric pressure, and the discharge side port is opened via a pressure control means, so it is a fluid actuator for reciprocating operation. There is no need to use a shock absorber or other shock absorber for each fluid actuator, and the operating valve such as a solenoid valve for operating each fluid actuator can be omitted to just one, making a significant contribution to reducing the cost of the shock absorber. .

[Brief explanation of the drawing]

FIG. 1 is a pneumatic circuit diagram showing a shock absorber according to an embodiment of the present invention, and FIG. 2 is a side sectional view showing a schematic structure of a one-way shuttle valve that can be used in the same embodiment. Explanation of symbols, 1...Dolly, 3a, 3b...Air cylinder, 4a, 4b...Intake/exhaust port, 6a, 6b
... Shuttle valve, 7a, 7b ... Outlet side port,
8a, 8b...Discharge side port, 9a, 9b...Inlet side port, 13...Solenoid valve, 14a, 14b...
...Relief valve.

Claims (1)

[Scope of utility model registration request] In a device for alleviating the shock at the stop of a reciprocating object at a moving end using a pair of fluid actuators provided at the moving end, a discharge side port and an inlet are provided in a pipe line connecting each of the fluid actuators and a pressure source. A one-way shuttle valve having a slidable valve body that selectively communicates between one of the side ports and the outlet side port and is normally biased toward the side that closes the inlet side port is interposed, and each of the above Common switching that connects the fluid supply and discharge ports of the fluid actuator to the outlet ports of the one-way shuttle valves, and connects the inlet ports of each of the shuttle valves to the pressure source or opens to atmospheric pressure. A buffer drive device for a reciprocating object, characterized in that it is connected to a valve and the discharge side port is opened via pressure control means.