JP2555469Y2 - Air compressor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air compressor, and more particularly, to an air compressor with a pneumatic device connected thereto.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional flow sheet. The power supply 1 is connected to the primary electrode 3a of the manual switch 3 by the wiring 2 and the secondary terminal 3b of the manual switch 3 is connected to the primary electrode 5a of the pressure switch 5 via the wiring 4.
A secondary terminal 5 b of the pressure switch 5 is connected to a motor 7 by a wire 6.

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 compresses the air sucked from an air intake hole (suction port) 11 and discharges the compressed air into an air tank 12. The pressure switch 5 opens when the upper limit pressure of the compressed air in the air tank 12 is detected, and closes when the lower limit pressure is detected. Therefore, when the compressed air pressure in the air tank 12 is lower than the lower limit, the manual switch 3 is turned on, and the power from the power supply 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. And the motor 7
Rotates, and the air compressor 8 is operated via the belt device 9 to suck and compress the atmosphere from the air intake hole 11 and discharge the air to the air tank 12. The compressed air pressure in the air tank 12 thus continues to rise, and the upper limit pressure is set by the pressure switch 5.
Is detected, the pressure switch 5 is opened and the motor 7 is turned off. The compressed air in the air tank 12 is consumed by the pneumatic device as described later, and the compressed air pressure in the air tank 12 decreases. Therefore, when the pressure reaches the lower limit, 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 the compressed air in the air tank does not flow back to the air intake hole 11 when the air compressor 8 is stopped.
If necessary, a check valve is provided to prevent the compressed air from the air tank 12 from flowing back to the air compressor 8.

[0005] pneumatic cylinder 16 of the spring offset type through the discharge pipe 14 is disposed is the three-way switching valve 15 to the terminal sending the compressed air to the compressed air used equipment from the air tank 12 is connected. Although not shown, an aftercooler, an air dryer, a mist filter, and the like are appropriately provided in the discharge pipe 14. In this example, a stop valve 17 is provided.

In the above description, the pneumatic cylinder 16 is fitted into the cylinder tube 16d via an O-ring 19 for sealing the inner wall of the cylinder tube 16d so as to be movable up and down.
a protrudes out of the cylinder tube 16d, and connects its tip to the working machine. Piston 1 of cylinder tube 16d
8 is connected to the three-way switching valve 15 by a pipe 21 and the other one of the cylinder chambers 16a.
In b, a compression coil spring 22 is contracted between the piston 18 and the end wall of the cylinder tube 16d. The cylinder chamber 16b communicates with the atmosphere through an intake / exhaust hole 16c.

The three-way switching valve 15 is a solenoid valve or a manual valve, and has a port P connected to the discharge pipe 14, a port A connected to the pipe 21, and a port B communicating with the atmosphere. A valve position for closing and communicating compressed air to the pneumatic cylinder 16 by communicating between the ports P and A, and a valve for closing the port P and communicating the ports A and B to release the compressed air in the pneumatic cylinder 16 to the atmosphere The position can be taken.

A pipe 23 from a drain hole 12 a provided at a lower portion of the air tank 12 drains a drain through a drain valve 24.

The stop valve 17 is normally open at all times.
When compressed air is stored in the air tank 12 by the operation of the air compressor 8, the three-way switching valve 1
5, when the port B is closed and the ports P and A are communicated with each other, the compressed air is sent to the cylinder chamber 16a of the pneumatic cylinder 16, and the piston 18 is moved by the pressure of the compressed air to the compression coil spring 22 and the piston rod 18a. When the pressure rises against the applied load, the three-way switching valve 15 is switched to close the port P, and the port A and the port B communicate with each other, the compressed air in the cylinder chamber 16a flows into the atmosphere through the pipe 21, the port A, and the port B. The compression coil spring 22
The piston 18 is lowered by the spring force of. If the three-way switching valve 15 is not operated, the piston 18 remains stopped at the lower limit or the upper limit position, and the port P of the three-way switching valve 15
Alternatively, the compressed air is not consumed because the port B is closed.

[0010]

After the work is completed, the operator turns off the manual switch 3 and returns. Since the space between the air compressor 8 and the pneumatic cylinder 16 is in a sealed state, the pressure is still applied. Therefore, in a state where the port B of the three-way switching valve 15 is closed and the ports P and A are in communication, the piston 18 of the pneumatic cylinder 16 stops at the ascending limit position with the compression coil spring 22 compressed, and O Ring 19 remains pressurized with compressed air pressure. Of course, air tank 12, discharge pipe 14, three-way switching valve 15, stop valve 1
7, the compressed air pressure is still applied to the pipe 23, the drain valve 24, and the like. For this reason, although the air compressor is not used, each member disposed on the compressed air discharge side is pressurized with compressed air unnecessarily. Regarding the pressurizing time, if the daily operating time of the air compressor is 8 hours, the daily downtime is 16 hours, and the pressure was applied even during the nighttime downtime. The O-ring 19 of the pneumatic cylinder 16 has a short life for such a reason.

In a reciprocating air compressor having a piston and an intake / exhaust valve, since the intake valve is closed and the exhaust valve is open at the time of a normal stop, the compressed air pressure is applied to the piston, and the crank is dead. It is at the point position. On the other hand, at the start of the first morning, each member is cooled, and the load applied to the motor 7 is large due to the low temperature of the lubricating oil. Therefore, when the air compressor 8 is driven, the breaker is cut off or the fuse is blown. There are drawbacks.

The above-described pneumatic cylinder 16 is an example,
Similar problems also occur in various types of pneumatic devices, and the joints of the respective members on the discharge side of the air compression device also receive a long non-operating compressed air pressure. Therefore, there is also an inconvenience that a creep load always acts on the component to which the compressed air pressure is applied.

An object of the present invention is to provide an air compressor that can extend the life of a pneumatic device.

[0014]

According to the present invention, there is provided an air compressor having a pneumatic device which is supplied with power from a power supply via a switch to a drive motor of an air compressor, and which stops at an end of the discharge pipe in a state of closing the discharge pipe. In the compressor, stop the air compressor.
When stopped, it communicates with a pneumatic device that uses compressed air to communicate between the member where compressed air is present and the atmosphere via a solenoid valve that is energized and closed, and according to the opening and closing of the switch on the secondary side of the switch. An air compression device characterized by being connected to an electric circuit that turns off only electricity.

[0015]

[0016]

[0017]

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 in FIG. 3 of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

An electric circuit that is energized and closed is attached to the pipe 23 through the drain hole 12a, and an electric circuit is energized on the secondary side of the manual switch 3 only in accordance with the opening and closing of the manual switch 3. In this example, the secondary side of the manual switch 3 The wiring 10 is connected to the solenoid valve 25 from the wiring 4 between the terminal 3 b and the primary electrode 5 a of the pressure switch 5.

Next, the operation will be described. In a state where the port B of the three-way switching valve 15 is closed and the ports P and A are in communication,
When the work is completed and the manual switch 3 is turned off, the solenoid valve 2
5 is cut off, the electromagnetic valve 25 is opened, and the compressed air in the air tank 12 is discharged into the atmosphere through the drain hole 12a, the pipe 23, and the electromagnetic valve 25, and the air pressure in the air tank 12 is reduced. The compressed air in the cylinder chamber 16a of the pneumatic cylinder 16 returns 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,
It is released to the atmosphere through the drain hole 12a, the pipe 23, and the solenoid valve 25. As a result, the air pressure in each member provided on the discharge side of the air compressor 8 becomes the atmospheric pressure, and is not pressurized after the operation is completed until the start of operation on the next day. Accordingly, for example, the O-ring 19 is not always pressurized, so that the durability is increased, and the compression coil spring 22 is also in the 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 portion of each pipe increases.

As described above, the compressed air pressure in the air tank 12 is reduced to the atmospheric pressure.
When the motor 7 is driven via the pressure switch 5 when the pressure is turned on, the compressed air load (difference between the intake pressure and the discharge pressure) even if the friction of each sliding portion of the air compressor 8 is large due to the low temperature.
Is small, the motor 7 is started, so that the breaker does not come off or the fuse does not blow.

Example 2 FIG. 2 is a flow sheet of an example. The difference between the first embodiment and the first embodiment is that the member in which the compressed air is present between the discharge side of the air compressor 8 and the pneumatic cylinder 16 which is the pneumatic device using the compressed air is the air tank in the first embodiment. Example 2
Is a discharge pipe 14. That is, the pipe 26 branched from the discharge pipe 14 is communicated with the atmosphere via the solenoid valve 25 which is closed and energized, and the wiring 10 is energized / disconnected only on the secondary side of the manual switch 3 by opening and closing the manual switch 3. The wiring 4 serving as an electric circuit and the solenoid valve 25 are connected.

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. .

In this embodiment, a pressure switch is used to control the compressed air pressure. The unloader-type compressed air pressure adjustment that operates the pilot valve by the compressed air pressure and opens the intake valve of the air compressor is used. What is performed is the same as above, and the solenoid valve may be controlled by the wiring led from the wiring between the secondary terminal of the manual switch and the motor.

In the embodiment, only the contact portion of the manual switch is shown, but it includes a direct input or manual input and an operation of the switch via a relay.

[0027]

According to the present invention, there is provided an air compressor having a pneumatic device which is supplied with power from a power source via a switch to a drive motor of an air compressor and stops at an end of the discharge pipe in a state of closing the discharge pipe. When the air compressor is stopped, it communicates with a pneumatic device that uses compressed air to communicate between the member where compressed air is present and the atmosphere via a solenoid valve that is energized and closed, and connects the solenoid valve to the secondary side of the switch. Connected to pneumatic equipment by connecting to an electric circuit that turns off and on only when the switch is opened and closed
Then, the compressed air that is blocked on the upstream side of the pneumatic device is released, and the life of the pneumatic device and the like is extended.

[0028]

[0029]

[0030]

[Brief description of the drawings]

FIG. 1 is a flow sheet according to a first embodiment of the present invention.

FIG. 2 is a flow sheet according to a second embodiment 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 (1)

(57) [Scope of request for utility model registration] 1. An air compressor having a pneumatic device that is supplied with power from a power supply via a switch to a drive motor of an air compressor and stops at an end of the discharge pipe in an operation state of closing the discharge pipe. When the equipment is stopped, the air flows through a member that has compressed air and the atmosphere through a pneumatic device that uses compressed air through an electromagnetic valve that is energized and closed, and opens and closes the switch on the secondary side of the switch. An air compressor characterized in that it is connected to an electric circuit that turns off and on only in accordance with the following.