JPH0687681U - Air compressor - Google Patents

Abstract

(57) [Summary] [Purpose] Compressed air is filled between the air compressor and the pneumatic equipment, and after the work is completed, the motor that drives the air compressor will stop when the manual switch is turned off and the air is returned. The compressed air remains as it is, and the durability of the sealing material or the like of pneumatic equipment is shortened. [Structure] A power source 1 drives a motor 7 via a manual switch 3 and a pressure switch 5 to drive an air compressor 8. As a result, the compressed air in the air tank 12 is kept within a certain range, and the three-way switching valve 15 is passed through the discharge pipe 14.
Compressed air is supplied to a pneumatic cylinder 16 which is controlled by. A solenoid valve 25 that is electrically closed and is wired and operates from the secondary side of the manual switch 3 is connected to the air tank 12. When the manual switch 3 is turned off after the work is completed, the solenoid valve 2
5 opens and the compressed air pressure in the air tank 12 drops,
The O-ring 19 and the like of the pneumatic cylinder 16 do not receive the compressed air pressure during the night rest, and the durability increases.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an air compressor, and more particularly to an air compressor in a state where pneumatic equipment is connected.

[0002]

[Prior art]

 FIG. 3 is a flow sheet of a conventional example. The power source 1 is connected to the primary side electrode 3a of the manual switch 3 by the wiring 2, and the secondary side terminal 3b of the manual switch 3 is connected to the primary side electrode 5a of the pressure switch 5 via the wiring 4. The secondary terminal 5 b of the pressure switch 5 is wired to the motor 7.

The output shaft of the motor 7 and the input shaft of the air compressor 8 are connected by a belt device 9. The air compressor 8 is configured to compress the air sucked from the air intake hole (suction port) 11 and discharge it into the air tank 12. The pressure switch 5 is opened when the upper limit pressure of the compressed air in the air tank 12 is detected, and closed when the lower limit pressure is detected. Therefore, when the compressed air pressure in the air tank 12 is below the lower limit, the manual switch 3 is turned on, and the electric power from the power source 1 is supplied to the motor 7 through the wiring 2, the manual switch 3, the wiring 4, the pressure switch 5 and the wiring 6. Then, the motor 7 rotates and the air compressor 8 is operated via the belt device 9, and the atmosphere is sucked and compressed from the air intake hole 11 and discharged to the air tank 12. The compressed air pressure in the air tank 12 thus continues to rise, and when the upper limit pressure is detected by the pressure switch 5, the pressure switch 5 is opened and the motor 7 is cut off. The compressed air in the air tank 12 is consumed by pneumatic equipment as described later, and the compressed air pressure in the air tank 12 decreases, so when the lower limit pressure is reached, the air compressor 8 operates again as described above. .

The air compressor 8 used here is of any type, but is a positive displacement compressor in which compressed air in the air tank does not flow back to the air intake hole 11 when the air compressor 8 is stopped. A check valve for preventing backflow of compressed air from the tank 12 to the air compressor 8 is provided.

A discharge pipe 14 for sending compressed air from the air tank 12 to a device using compressed air is arranged, and a spring offset type pneumatic cylinder 16 is connected to a terminal of the discharge pipe 14 via a three-way switching valve 15. Although not shown in the drawing, an aftercooler, an air dryer, a mist filter and the like are appropriately inserted in the discharge pipe 14. In this example, the stop valve 17 is provided.

In the above description, in the pneumatic cylinder 16, the piston 18 is vertically movably fitted into the cylinder tube 16d via an O-ring 19 that seals between the inner wall of the cylinder tube 16d and the piston rod of the piston 18. 18a projects to the outside of the cylinder tube 16d, and its tip is connected to the working machine. The cylinder chamber 16a on one side of the piston 18 of the cylinder tube 16d is connected to the three-way switching valve 15 by a pipe 21, and the cylinder chamber 16b on the other side is compressed between the piston 18 and the end wall of the cylinder tube 16d. The coil spring 22 is contracted. The cylinder chamber 16b communicates with the atmosphere through intake and exhaust holes 16c.

The three-way switching valve 15 is a solenoid valve or a manual valve and is provided with a port P connected to the discharge pipe 14, a port A connected to the pipe 21 and a port B connected to the atmosphere. A valve position that closes and communicates between ports P and A to send compressed air to the pneumatic cylinder 16, and a valve that closes port P and connects ports A and B to allow compressed air in the pneumatic cylinder 16 to escape to the atmosphere. The position and position can be taken.

The pipe 23 from the drain hole 12 a provided in the lower portion of the air tank 12 is designed to drain the drain through a drain drain valve 24.

The stop valve 17 is normally open at all times, and when compressed air is stored in the air tank 12 by the operation of the air compressor 8, the three-way switching valve 15 is switched to switch the port as described above. When B is closed and ports P and A are communicated with each other, compressed air is sent into the cylinder chamber 16a of the pneumatic cylinder 16, and the piston 18 becomes a load applied to the compression coil spring 22 and the piston rod 18a by the pressure of the compressed air. When the pressure rises, the three-way switching valve 15 is switched to close the port P and the port A and the port B are communicated with each other, the compressed air in the cylinder chamber 16a is released into the atmosphere through the pipe 21, the port A and the port B. Therefore, the piston 18 descends due to the spring force of the compression coil spring 22. If the three-way switching valve 15 is not operated, the piston 18 remains stopped at the lower limit position or the upper limit position, and the compressed air is not consumed because the port P or the port B of the three-way switching valve 15 is closed.

[0010]

[Problems to be solved by the device]

 After finishing the work, the worker turns off the manual switch 3 and returns. Since there is a sealed state between the air compressor 8 and the pneumatic cylinder 16, pressure remains applied. Therefore, when the port B of the three-way switching valve 15 is closed and the ports P and A are communicated with each other, the piston 18 of the pneumatic cylinder 16 is stopped at the upper limit position with the compression coil spring 22 compressed. The O-ring 19 remains pressurized with compressed air pressure. The compressed air pressure is still applied to the air tank 12, the discharge pipe 14, the three-way switching valve 15, the stop valve 17, the pipe 23, the drain valve 24, and the like. Therefore, even though the air compressor is not used, each member disposed on the compressed air discharge side is pressurized with compressed air. Regarding the time of pressurization, when the operating time of the air compressor per day was 8 hours, the rest time of the day was 16 hours, and the pressure was applied during the rest time of the night. The O-ring 19 of the pneumatic cylinder 16 has a short life due to the above reasons.

In a reciprocating air compressor equipped with a piston and an intake / exhaust valve, the intake valve is closed and the exhaust valve is opened during normal stop, so compressed air pressure is applied to the piston and the crank bottoms out. It is at the point position. On the other hand, at the first start of the morning, each member is cooled, and the lubricating oil is low in temperature, so the load applied to the motor 7 is large, so when the air compressor 8 is driven, the breaker blows or the fuse blows. There is also a drawback.

The above-described pneumatic cylinder 16 is an example, and similar problems also exist with various pneumatic devices. The joint portion of each member on the discharge side of the air compression device also has a long non-operating compressed air pressure. is recieving. Therefore, there is a disadvantage that the creep load is constantly applied to the component member to which the compressed air pressure is applied.

It is an object of the present invention to provide an air compression device that can extend the life of pneumatic equipment.

[0014]

[Means for Solving the Problems]

 A first aspect of the present invention relates to an air compressor provided with a pneumatic device for supplying compressed air to a drive motor of an air compressor from a power source through a manual switch and using compressed air in a discharge pipe. Between the discharge side and the pneumatic equipment that uses compressed air, the member in which compressed air is present and the atmosphere are connected via a solenoid valve that is closed, and the solenoid valve is connected to the secondary side of the manual switch. The air compression device is characterized in that it is connected to an electric circuit that turns on and off only when the manual switch is opened and closed.

In a second aspect of the present invention, the discharge pressure of the air compressor is controlled by a pressure switch, and the pressure switch detects an upper limit pressure of an air tank that stores compressed air discharged by the air compressor. The air compression device according to the first invention is characterized in that it is opened and the lower limit pressure is detected to be closed.

In a third aspect of the present invention, the discharge pressure of the air compressor uses the upper limit pressure of an air tank that stores compressed air discharged from the air compressor to bring the air compressor into a non-compressed state, and the lower limit pressure. The air compression device according to the first aspect, wherein the air compression device is brought into a compressed state by using the.

A fourth invention of the present invention is the air compressor according to any one of the first to third inventions, characterized in that the solenoid valve is arranged so as to communicate with a drain hole of an air tank. Is.

[0018]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

Example 1 FIG. 1 is a flow sheet of Example 1. In FIG. 1, the same components as those in FIG. 3 of the conventional example are denoted by the same reference numerals and the description thereof will be omitted.

A solenoid valve 25 for energization is attached to the pipe 23 from the drain hole 12 a, and an electric circuit is energized only when the manual switch 3 is opened / closed on the secondary side of the manual switch 3. The wiring 10 is connected to the solenoid valve 25 from the wiring 4 between the side terminal 3b and the primary side electrode 5a of the pressure switch 5.

Next, the operation will be described. When the port B of the three-way switching valve 15 is closed and the ports P and A are in communication with each other and the manual switch 3 is turned off, the solenoid valve 25 is cut off, the solenoid valve 25 is opened, and the air tank is closed. The compressed air in 12 is discharged into the atmosphere through the drain hole 12a, the pipe 23, and the solenoid valve 25, and the air pressure in the air tank 12 is lowered, so that the compressed air in the cylinder chamber 16a of the pneumatic cylinder 16 is compressed. Is also returned to the air tank 12 through the pipe 21, the three-way switching valve 15 and the pipe 14 with the lowering of the piston 18 due to the spring force of the compression coil spring 22, and is discharged into the atmosphere through the drain hole 12a, the pipe 23 and the solenoid valve 25. It As a result, the air pressure in each member provided on the discharge side of the air compressor 8 becomes atmospheric pressure, and is not pressurized until the operation starts the next day after the work is completed. Therefore, for example, the O-ring 19 is not always pressed, so that the durability is increased and the compression coil spring 22 is also in an expanded state, so that the O-ring 19 can be used with a large stress against the creep limit. Also, the durability of the joint of each pipe is increased.

Since the compressed air pressure in the air tank 12 drops to atmospheric pressure as described above, when the manual switch 3 is turned on the next morning in the morning, when the motor 7 is driven via the pressure switch 5, each of the air compressors 8 is driven. Even if the friction of the sliding portion is large due to the low temperature, the motor 7 is started in the state where the compressed air load (the difference between the intake pressure and the discharge pressure) is small, so the breaker does not come off and the fuse does not blow.

Example 2 FIG. 2 is a flow sheet of an example. The difference from the first embodiment is that the member in which compressed air exists between the discharge side of the air compressor 8 and the pneumatic cylinder 16, which is a pneumatic device that uses compressed air, is an air tank in the first embodiment. In Example 2, the discharge pipe 14 was used. That is, a pipe 26 branched from the discharge pipe 14 is connected to the atmosphere via a solenoid valve 25 that is closed by energization, and the wiring 10 is a secondary side of the manual switch 3 and is energized / disconnected only by opening / closing the manual switch 3. The wiring 4 which is an electric circuit is connected to the solenoid valve 25.

Also in this embodiment, when the manual switch 3 is turned off at the end of the work, the compressed air in the air tank 12, the discharge pipe 14, the three-way switching valve 15, the pipe 21, and the pneumatic cylinder 16 is discharged through the solenoid valve 25. .

Although the embodiment uses the pressure switch to control the compressed air pressure, the pilot valve is operated by the compressed air pressure to open the intake valve of the air compressor. In the case of the above, the solenoid valve may be controlled by wiring similar to the above, which is led from the wiring between the secondary side terminal of the manual switch and the motor.

Although only the contact portion of the manual switch is shown in the embodiment, it includes a direct input or a manual input to operate a switch through a relay.

[0027]

[Effect of device]

 A first aspect of the present invention is to provide an electric power to a motor of an air compressor through a manual switch to drive the air compressor by the motor to provide a pneumatic device on a discharge side with a manual switch. The piping between the solenoid valve for energization wired from the secondary side and the member on the discharge side where compressed air exists, and the compressed air that is blocked on the discharge side when the manual switch is turned off through this solenoid valve is released. However, it has the effect of extending the life of pneumatic equipment.

The second aspect of the present invention is suitable when the first aspect is applied to a pressure switch type air compression device.

The third aspect of the present invention is suitable when the second aspect is applied to an unloader type air compression device.

In a fourth aspect of the present invention, in any one of the first to third aspects, since the solenoid valve is communicated with the drain hole of the air tank, the solenoid valve can be easily attached.

[Brief description of drawings]

FIG. 1 is a flow sheet of Example 1 of the present invention.

FIG. 2 is a flow sheet of Example 2 of the present invention.

FIG. 3 is a flow sheet of a conventional example.

[Explanation of symbols]

 1 Power Supply 2 Wiring 3 Manual Switch 4 Wiring 5 Pressure Switch 6 Wiring 7 Motor 8 Compressor 15 Three-way Switching Valve 16 Pneumatic Cylinder 25 Solenoid Valve 26 Piping

Claims (4)

[Scope of utility model registration request] 1. An air compression device equipped with pneumatic equipment for supplying compressed air to a drive motor of an air compressor from a power source through a manual switch and using compressed air in a discharge pipe, wherein compressed air is supplied from a discharge side of the air compressor. A pneumatic valve is used to communicate with the atmosphere in which compressed air is present and the atmosphere through a solenoid valve that is closed, and the solenoid valve is energized only when the manual switch on the secondary side of the manual switch is opened or closed. An air compression device characterized by being connected to an electric circuit that is cut off. 2. The discharge pressure of the air compressor is controlled by a pressure switch, and the pressure switch detects the upper limit pressure of an air tank that stores compressed air discharged by the air compressor and opens it, and detects the lower limit pressure. The air compressor according to claim 1, wherein the air compressor is closed. 3. The discharge pressure of the air compressor uses an upper limit pressure of an air tank for storing compressed air discharged from the air compressor to bring the air compressor into a non-compressed state and a lower limit pressure to bring it into a compressed state. The air compression device according to claim 1, wherein 4. The electromagnetic valve is arranged so as to communicate with a drain hole of an air tank.
The air compression device according to any one of 1.