JPH0327247B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a filtration device that recovers and filters lubricating oil supplied to rotating or sliding parts of various mechanical systems so that it can be reused.

[Conventional technology]

Lubricating systems for rotating or sliding parts of injection molding machines and various general machine tools include those that confine lubricating oil in a closed space and those that continuously lubricate lubricating oil. In particular, the latter lubrication system is generally adopted for machines that require precision. In mechanical systems that require a large amount of lubricating oil, it is widely practiced to provide a cycle in which the lubricating oil is injected into operating parts and then collected and filtered.

For example, toggle lubricating oil for injection molding machines and disposable lubricating oil for machining centers, mechanical presses, etc. are collected in an oil pan provided in a lubricating section and then sent to a recovery filtration device. This recovery filtration device mainly includes a tank connected to an oil pan by a pipe, and has a conduit with a filter between the clean oil tank and the tank. The clean oil tank stores reusable lubricating oil that has been purified by a filter and supplies lubricating oil to lubricated parts of the machine by pumping up.

[Problem that the invention seeks to solve]

Pumps are often used as the main means for sending lubricating oil to the pipe line arranged from the recovery filtration device to the clean oil tank.

In addition, with conventional methods, the recovered lubricating oil contains a considerable amount of water, so one example of an attempt to actively remove this water in the recovery filtration device is a method that uses an oil-water separator in combination. has been adopted. However, even with such a separator, complete separation of oil and water is still insufficient.

Therefore, an object of the present invention is to make it possible to completely remove moisture without impairing the original function of the oil cleaner.

[Means for solving problems]

In order to achieve the above object, the present invention is a recovery filtration device that collects lubricating oil supplied from a lubricant to a lubricated part of equipment into a recovery tank, and circulates it from the recovery tank to the lubricant via a filter. An air supply system is provided for pressurizing air into the space above the surface of the lubricating oil stored from the upper side of the recovery tank.

In addition, by providing a system in the recovery tank that detects the lubricating oil and water levels and sends signals to the solenoid valve, the lubricating oil can be continuously circulated including the recovery tank, and water can be used as a drain. It can also be removed from the system.

〔Example〕

Hereinafter, features of the present invention will be specifically explained with reference to embodiments shown in the drawings.

FIG. 1 is a schematic diagram showing a lubricating oil circulation system equipped with a recovery filtration device of the present invention, and this example shows a lubrication system for a toggle type injection molding machine.

In the lubricating oil circulation system, the lubricating oil circulates in the order of the oil supply device 1 storing clean lubricant oil, the toggle sliding part 2, the oil pan 3, and the recovery filtration device 4, and then returns to the oil supply device 1.
It constitutes a circuit that returns to .

The oil supply device 1 is provided with a float switch 1a for detecting overflow and lower limit amount inside,
The piping 1b provided between the toggle sliding portion 2 and the toggle sliding portion 2 is equipped with a pump 1c for supplying lubricating oil.
Further, the oil pan 3 is installed in the injection molding machine and is arranged to receive lubricating oil applied to the toggle sliding part 2 and to collect cooling water 2b that flows in when replacing the mold 2a. . Water such as lubricating oil and cooling water 2b may be separated by specific gravity difference to allow the water to settle at the bottom of the oil pan 3 and be discharged through the drain 3a.

The recovery filtration device 4 mainly includes a recovery tank 5,
A lubricating oil supply and discharge system is attached to this. A recovery pipe 6 is connected between the recovery tank 5 and the oil pan 3, and a supply pipe 7 is connected to the oil supply device 1 to form a circulation circuit for lubricating oil from the oil pan 3 to the oil supply device 1. . The recovery pipe 6 includes a strainer 6a, an inlet solenoid valve 6b, and a check valve 6c for preventing backflow of lubricating oil from the recovery tank 5 toward the oil pan 3 in the order of flow.

The supply pipe 7 has a lower end opening located at a level in the middle of the recovery tank 5, and supplies lubricating oil from the upper end of the oil supply device 1. A cleaner 7a is provided in the middle of the pipe to clean the collected lubricating oil. This cleaner 7a has a built-in paper roll filter used in general industrial machinery, and has the function of removing foreign matter, moisture, etc. contained in lubricating oil. In addition, the collection pipe 6 has its strainer 6a.
A bypass pipe 8 branched from a downstream position is installed.

Furthermore, a drain pipe 9 is provided on the bottom side of the recovery tank 5 for discharging mixed water. A drain electromagnetic valve 9a is incorporated in the conduit of this drain pipe 9, and a drain receiver 9b is provided at the end of the pipe.

The lubricating oil is supplied from the recovery tank 5 to the oil supply device 1 by supplying compressed air to the recovery tank 5 from the outside. In other words, pressure is applied to the surface of the stored lubricating oil, and the lubricating oil is pushed out by this pressure, and a compressed air supply system is provided outside the recovery tank 5. This compressed air supply system is composed of an air supply pipe 11 connected to a compressed air supply source 10 such as a compressor, and a flow path to the supply source 10 and a silencer 12 is switched in the middle of the pipe. An electromagnetic switching valve 11a is provided. The air supply pipe 11 is inserted from the upper end of the recovery tank 5, and the opening at the lower end is kept at a level that will not be immersed in the oil surface. Further, the muffler 12 has a structure in which it communicates with the recovery tank 5 through the switching valve 11a and opens to the atmosphere. Note that 11b is a pressure gauge that displays the air pressure within the air supply pipe 11.

Furthermore, four float switches are arranged in the recovery tank 5 to operate in response to changes in the oil level. In other words, a drain float switch 13 for opening and closing the drain solenoid valve 9a, a water emergency switch 14 for the inlet solenoid valve 6b,
An air supply float switch 15a for opening and closing the electromagnetic switching valve 11a and an air stop float switch 15b are provided at appropriate levels. These various float switches 13 to 15b are arranged in order from the lowest level to the top in the recovery tank 5, and the lower drain and water emergency float switches 13 and 14 respond to changes in the level of water settling at the bottom. It operates accordingly. In addition, upper air supply and stop float switches 15a and 15b
operates in response to changes in oil level.

In the above circuit configuration, cleaned lubricating oil is supplied from the oil supply device 1 to the toggle sliding part 2 by the pump 1c to lubricate the mechanical part, and then dripped into the oil pan 3. At this time, if there is an abnormally large amount of water precipitated in the oil pan 3, it can be disposed of outside the circuit via the drain 3a. In addition, the lubricating oil in the oil pan 3 is transferred from the recovery pipe 6 to the recovery tank 5.
As the oil level rises, the air inside is released from the muffler 12, which is open to the atmosphere.

After the lubricating oil is recovered, when the oil level rises and reaches the air supply float switch 15a, this is activated and the air supply pipe 11 communicates with the compressed air supply source 10. Then, air is sent into the recovery tank 5 to push down the oil level, and the lubricating oil is force-fed from the supply pipe 7 to the oil supply device 1. At this time, since the lubricating oil passes through the cleaner 7a, foreign matter, moisture, etc. are removed, and the purified lubricating oil can be sent to the oil supply device 1.

During the process of sending lubricating oil by air, when the oil level drops to the level of the air stop float switch 15b, the electromagnetic switching valve 11a closes the air supply pipe 11.
the flow path is switched to the muffler 12 side. Due to this operation, the supply of lubricating oil to the oil supply device 1 is stopped, and the inside of the recovery tank 5 is opened to the atmosphere.

On the other hand, even while the lubricating oil is being supplied to the oil supply device 1, the lubricating oil from which relatively large foreign objects (about 100 meshes per element) have been removed is flowing from the oil pan 3 by the strainer 6a. Therefore, by inflowing from the oil pan 3 and supplying compressed air to the oil supply device 1 so that the oil level does not drop to the air stop float switch 15b, a circulation system that can continuously purify the lubricating oil can be created. It becomes possible.

Furthermore, the lubricating oil containing water in the recovery tank 5 settles to the bottom due to the principle of oil-water specific gravity separation. Then, when the level of the water settling at the bottom reaches the drain float switch 13, control is performed to open the drain solenoid valve 9a. By this control, the precipitated water is sequentially discharged to the drain receiver 9b.

Further, when the amount of inflow from the oil pan 3 is greater than the amount supplied to the oil supply device 1, the water level reaches a level above the drain float switch 13. To deal with this, the level of the water emergence float switch 14 is set to a position lower than the lower end of the supply pipe 7, and the inlet solenoid valve 6b is controlled to be closed before water flows into the supply pipe 7. Through this control, the level of inflow water is regulated and water is discharged from the open drain electromagnetic valve 9a.

This kind of control detects both water and oil levels using a float switch and opens and closes the necessary valves at the appropriate time, so the lubricating oil can be continuously circulated and the water can be quickly discharged from the system. The result is a reusable lubricating oil from which water has been completely removed.

〔Effect of the invention〕

As explained above, in the recovery filtration device of the present invention, purified lubricating oil is forced out and supplied to the oil supply device from the outside by pressurizing air, and the respective levels of water and lubricating oil in the recovery tank are adjusted. It detects and controls various solenoid valves necessary for air injection and water discharge. Therefore, relatively expensive and complicated mechanical pumps and motors are not required to feed lubricating oil to the oil supply device, and emulsions that tend to occur due to the operation of these devices can be extruded effectively using air. is prevented. Also,
Silent operation is possible, and since there is no temperature rise, the degree of viscosity deterioration can be reduced. Furthermore, since no accessory parts such as an oil/water separator are required, an inexpensive and compact lubricating oil recovery and filtration device can be provided.

[Brief explanation of drawings]

FIG. 1 shows a lubricating oil circulation system equipped with a recovery filtration device of the present invention. 1: Oil supply device, 2: Toggle sliding part, 3: Oil pan, 4: Recovery filtration device, 5: Recovery tank, 6: Recovery pipe, 7: Supply pipe, 8: Bypass pipe, 9: Drain pipe, 10: Supply source, 11: Air supply pipe, 12: Silencer, 13: Drain float switch, 14:
Float switch for water emergencies, 15a:
Air supply float switch, 15b: Air stop float switch.

Claims (1)

[Scope of Claims] 1. A recovery filtration device in which lubricating oil supplied from an oil supply device to a lubricated part of equipment is collected in a recovery tank and circulated from the recovery tank to the oil supply device via a filter, A lubricating oil recovery and filtration device characterized by being provided with an air supply system that presses air into the space above the oil surface of the lubricating oil stored from the upper side. 2 A float switch is provided in the recovery tank that operates by detecting the level of lubricating oil and the level of water precipitated at the bottom, and opens and closes the air passage of the air supply system in response to signals from these float switches. 2. The lubricating oil recovery and filtration device according to claim 1, further comprising a solenoid valve for recovering lubricating oil from a lubricated part and a solenoid valve for discharging water as a drain.