JPH0121193Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil lock prevention device for an oil-cooled compressor, and more particularly to an oil lock prevention device for a vane rotary type compressor.

Conventionally, many engine-driven oil-cooled compressors of this type have used the internal pressure difference between the cylinder and the oil chamber to inject cooling oil into the air end of the cylinder from the oil reservoir at the bottom of the oil chamber. ing. However, in this type of engine, the compressed air in the oil chamber is released to the outside air by an automatic release valve that automatically opens immediately after the engine stops, but the pressure inside the oil chamber is at atmospheric pressure. It takes some time for the pressure to be reduced to atmospheric pressure, and while the pressure is being reduced to atmospheric pressure, the pressure inside the oil chamber is higher than that inside the machine's cylinder, so excess cooling oil is injected into the air end of the machine's cylinder. be done. The amount of cooling oil injected reaches more than half of the volume inside the cylinder of this machine. When the operation is stopped, the vane and the inner wall surface of the cylinder of the machine simply come into contact at a position between the intake stroke and the compression stroke in the cylinder of the machine. Therefore, the remaining cooling oil in the cylinder of this machine between the intake stroke and the compression stroke passes through the vane and the inner wall of the cylinder of this machine, and then is extracted into the oil chamber via the air pipe. However, even with this, some cooling oil may remain between the intake stroke position and the compression stroke position in the cylinder of this machine, causing a so-called oil lock phenomenon that makes the rotor unable to rotate at the next startup. In order to solve this problem, it is known that an oil lock prevention device is provided between the intake stroke position and the compression stroke position of the cylinder of this machine, which is comprised of a valve mechanism for extracting the remaining cooling oil. However, even with the provision of the oil lock prevention device as described above, the oil lock phenomenon sometimes occurs. In other words, as is well known, between the position of the compression stroke of the cylinder of this machine and the position of the next intake stroke, not only the vanes but also the circumferential surface of the rotor are in contact with the wall surface of the cylinder of this machine.
The space between them is an extremely narrow gap. For this reason, the cooling oil that remains between the compression stroke position and the next intake stroke position, especially the cooling oil that remains in large amounts at the starting end where the next intake stroke takes place, is removed from the cylinder of this machine as described above. Since it cannot pass between the rotor and the circumferential surface of the rotor, it is not extracted and remains in the cylinder of the machine at the starting end where the intake stroke is performed. In this way, the cooling oil remaining at the start of the intake stroke of the cylinder of this machine causes
An oil lock phenomenon was to occur during the next start-up.

In order to solve this problem, there are conventionally known methods, namely, Utility Model Publication No. 31-6940 and Utility Model Publication No. 36-
There is an idea described in Publication No. 18975. In both designs, a blocking device equipped with a diaphragm is installed in the oil feed pipe installed between the oil chamber and the cylinder of the machine, and when the operation is stopped, the pressure inside the cylinder of the machine immediately becomes atmospheric pressure. The closing device closes due to the operation of the diaphragm and shuts off the cooling oil supplied from the oil chamber into the cylinder of the machine, thereby preventing the oil lock phenomenon from occurring at the next startup. However, when the configuration disclosed in Japanese Utility Model Publication No. 31-6940 is shown in FIG. 2, 101 is a cylinder, 102
is a rotor whose shaft 109 is rotationally driven by a motor M,
104 is a blade, 106 is an inlet, 108 is an air tank, and a gear pump 110 and a cooler 1 are connected to a pipe 114 provided between the air tank 108 and the cylinder 101.
13 is installed, and the gear pump 110 is attached to the rotor shaft 10.
9 sucks up the liquid 111 such as water or oil in the air tank 108 and transfers it to the cylinder 1 through the hole 112.
01, a diaphragm piston valve 115 as shown in FIG.
The piston 116 side is connected to a liquid passage such as water or oil, and the diaphragm 117 side is connected to a final compression chamber 121 in the cylinder 101 via a pipe 120. During normal operation of the compressor, the pressure in the final compressor chamber 121 rises to the same level as the pressure in the air tank 108, so the cylinder pressure acts on the lower side of the diaphragm 117 to adjust the adjustment pressure 11.
Since the piston valve 116 is opened against the force of 8 and liquid such as water or oil flows into the pipe 114, there is no problem. Next, if the motor is stopped with pressure built up in the air tank 108 due to operation of the unloader or unexpected power outage, the compressed air in the air tank 108 will not flow back because the blocking valve 107 is activated. Therefore, the inside of the cylinder 101 becomes atmospheric pressure, and the diaphragm 117 is pushed by the regulating spring 118 to push the piston valve 116 downward, thereby closing the water or oil liquid passage. In summary, this closure device has a diaphragm and a piston valve 115 attached to the pipe 114, and as shown in FIG. It is necessary to form a piping port for communication, an inlet port, and an exhaust port with the piping 114, and to make the piping 120 and 114 openable and closable with the piston 116. Therefore, compared to the case where the diaphragm valve 115 is not provided, this proposal increases the number of assembly parts related to the valve 115 and becomes complex, and the number of machining increases. This, together with the complicated structure, increased production costs accordingly.

Therefore, the present invention was developed in view of the above circumstances, and when the machine is stopped, the cooling oil remaining between the compression stroke position and the next intake stroke position of the cylinder of the machine is extracted, and the remaining cooling oil is removed during the next startup. To provide an oil lock prevention device for a compressor which can effectively prevent oil lock phenomenon from occurring at times, has an extremely simple structure, is extremely low in price, and has excellent durability.

In order to achieve the above object, the present invention provides a vane rotary type oil-cooled compressor with a wall portion located on the starting end side of the intake stroke in the cylinder of the machine;
An oil lock prevention device for the compressor is provided, which communicates with the upper wall of the oil chamber through an oil recovery cylinder, and includes a piston inside the oil recovery cylinder that is always urged toward the oil chamber by a spring member. This is a characteristic feature.

An embodiment of the device according to the present invention will be described below based on the drawings.

Prior to this explanation, in a conventionally known vane rotary type oil-cooled compressor, a cylinder 1 of this machine has a rotor 2 therein, and an intake port 20 is opened in a wall portion. It goes without saying that a capacity regulator and an air cleaner are connected to this intake port 20. The rotor 2 is adapted to rotate in the direction of arrow A around an eccentric shaft 5 when the engine is started, and has an appropriate number of fitting grooves 4 extending from its circumferential surface in the direction of the eccentric shaft 5. Vanes 3 that protrude and retract as they rotate are fitted into the fitting grooves 4 so that their tips abut against the inner wall surface of the cylinder 1 of the machine, and their protruding and retracting movements cause air to be sucked in from the intake port 20 and compressed. It's summery. Also, the inside of the air end of the cylinder 1 of this machine, that is, the final part of the compression stroke, and the inside of the oil chamber 7 are connected to the air supply pipe 6.
and oil chamber 7.
The lower oil reservoir is communicated with one or more appropriate positions within the cylinder 1 of this machine, such as at the initial stage of the compression stroke, through an oil feed pipe 8. In this case, it goes without saying that an oil cooler may be attached to the oil feed pipe 8, and oil may be supplied from the oil chamber 7 into the cylinder 1 of the machine via this oil cooler.
On the other hand, an oil separator 10 is attached inside the discharge port 21 of the oil chamber 7, and the compressed air from which the cooling oil 19 has been separated by the oil separator 10 passes through the service valve 11 for adjusting the air amount. It is designed to be supplied to an external load device via the external load device. Further, this discharge port 21 is provided with an automatic release valve 12 that automatically opens immediately after the engine stops to reduce the pressure inside the oil chamber 7 to atmospheric pressure.
is attached.

The present invention is based on the vane rotary type oil-cooled compressor mentioned above.
At the same time, a vent hole 22 is bored in the upper wall of the oil reservoir of the oil chamber 7, and this oil recovery port 1
4 and the vent 22 are sequentially connected through an oil recovery pipe 23, an oil recovery cylinder 13, and a vent pipe 24, and a piston 15 fitted with a seal ring 16 is inserted into the oil recovery cylinder 13. The outer circumferential surface of the piston 15 and the inner wall surface of the oil recovery cylinder 13 are slidably sealed with a seal ring 16, and a coil spring 17 that constantly urges the piston 15 in the direction of the oil chamber 7 is also provided inside. do. Further, a nozzle 18 is formed on the inner wall surface of the ventilation pipe 24 so as to narrow the pipe diameter.

In the oil lock prevention device for an engine-driven compressor configured as described above, when the engine is first started and the rotor 2 is rotated, air is taken in from the intake port 20 and compressed as the volume of the compression chamber decreases. After that, this compressed air is sent into the oil chamber 7 via the air supply pipe 6. This increases the pressure inside the oil chamber 7, making it possible to supply compressed air, and since the inside of the oil chamber 7 is at a higher pressure than the vicinity of the oil filler ports 9 and 9' in the cylinder 1 of this machine, there is a difference in pressure. Due to the pressure, oil is supplied from the oil reservoir at the bottom of the oil chamber 7 through the oil feed pipe 8 into the cylinder 1 of the machine, such as the compression chamber and the side surface of the rotor. This cooling oil 19 cools the compressed air and other parts in the cylinder 1 of this machine, and also lubricates and seals each sliding part. After fulfilling these functions, it is sent together with the compressed air through the air pipe 6. The cooling oil is collected in the oil chamber 7, and the mist cooling oil is transferred to the oil separator 10 in the oil chamber 7.
The oil is separated from the compressed air and stored in the lower part of the oil chamber 7, and the same circulation as described above is repeated again.

By the way, before the compressor is started, the internal pressure of the oil chamber 7 is the same as that of the cylinder 1 of the present invention, and the piston 15 is pressed toward the oil chamber 7 by the bias of the coil spring 17. When the compressor is started, the internal pressure of the oil chamber 7 increases as described above, and the pressure inside the oil chamber 7 becomes higher than that near the oil filler port 14, so the compressed air inside the oil chamber 7 passes through the nozzle 18 and is sent to the oil recovery cylinder. 13, and the piston 15 is pressed toward the cylinder 1 of the machine against the bias of the coil spring 17.
The movement of this piston 15 is regulated by the action of the nozzle 18, so it is slow. When the engine is stopped in such a state, the rotor 2 also stops, and the automatic release valve 12 automatically opens accordingly. At this time,
The internal pressure of the oil chamber 7 and the internal pressure of the cylinder 1 of this machine do not become the same pressure instantly, so while the internal pressure of the cylinder 1 of this machine is lower than the internal pressure of the oil chamber 7, the oil filler ports 9 and 9' are connected to the cylinder 1 of this machine. Cooling oil is injected into the tank. On the other hand, as the internal pressure of the oil chamber 7 decreases, the piston 15 also slides toward the oil chamber 7 due to the bias of the coil spring 17, and the action of the piston 15 causes the intake stroke of the cylinder 1 of the machine to be performed. The excess cooling oil 19 that has accumulated in the room, especially the starting end of the intake stroke, is sucked into the oil recovery cylinder 13, and the excess cooling oil 1 is removed from the room where the intake stroke is performed, that is, the starting end of the intake chamber.
Remove 9.

The present invention can similarly prevent oil lock in motor-driven compressors. However, in the case of motor drive, the compressed air in the oil chamber is not normally released into the atmosphere after the motor stops, but the oil lock phenomenon described above is the same as in the case of engine drive, and the technical idea of the present invention also applies to motor drive. It is similarly applicable. Also, when the compressor is started next time, the pressure inside the oil chamber increases and the piston 15 is gradually pushed up, causing the oil recovery cylinder 1 to rise.
The oil is discharged into the cylinder 1 of the machine from inside 3 and is used for lubrication, cooling, etc. in the same way as oil from the oil filler ports 9 and 9'.

As described above, according to the compressor oil lock prevention device according to the present invention, the piston is suctioned by using the internal pressure difference between the oil chamber and the cylinder of the machine immediately after the power source stops, and thereby, the piston is sucked immediately after the power source stops. Excessive cooling oil remaining at the start end of the intake stroke in the cylinder of this machine is sucked into the oil recovery cylinder and removed, so the next time the compressor is started, the oil lock generated by the excess cooling oil will be removed. This phenomenon can be effectively prevented, and it has various effects such as not only does it not require any power source to slide the piston, but also has an extremely simple structure and is inexpensive.

[Brief explanation of the drawing]

The first page is a cross-sectional view showing an embodiment of the compressor oil lock prevention device according to the present invention, FIG. 2, FIG. 3 are drawings of the conventional device, and FIG. FIG. 3 is a longitudinal sectional view of the diaphragm piston valve. 1... Machine cylinder, 7... Oil chamber,
13...oil recovery cylinder, 15...piston.

Claims (1)

[Scope of Claim for Utility Model Registration] In a vane rotary type oil-cooled compressor, the final part of the compression stroke in the cylinder 1 of this machine is communicated with an oil chamber 7 via an air pipe 6, and the lower part of the oil chamber 7 is connected to an oil pipe 8. It communicates with the oil filling ports 9 and 9' provided on the wall surface at the initial stage of the compression stroke in the cylinder 1 of this machine, and an oil separator 10 is provided inside the discharge port 21 provided on the upper wall surface of the oil chamber 7. An automatic release valve 12 is provided toward the outside of the outlet 21 that operates after the engine has stopped, and an oil recovery valve 12 is installed between the wall located on the start end side of the intake stroke in the cylinder 1 of this machine and the upper wall of the oil chamber 7. pipe 23, oil recovery cylinder 13 and vent pipe 2
4, and a piston 15 fitted with a seal 16 is installed inside the oil recovery cylinder 13 so as to be able to slide in a sealed state, and the piston 15 is always kept in a chamber on the side of the oil recovery pipe 23. This compressor is characterized in that a coil spring 17 is installed inside to bias the chamber 7, and the side chamber of the ventilation pipe 24 is configured to directly communicate with the ventilation pipe 24 in which a nozzle 18 is formed on the inner wall surface so as to narrow the pipe wall. Oil lock prevention device.