JPH045481A - Multiple stage compressor - Google Patents

Abstract

PURPOSE:To keep operation efficiency good, and prevent lubrication oil from being emulsified by setting a low pressure side compression part at a non- compression operation condition for a predetermined period after starting. CONSTITUTION:A crank case 2 forming part of a compressor main body 1 is connected with a low pressure side compression part first cylinder 3 and a high pressure side compression part second cylinder 4. A control circuit 35 executes a program stored preliminarily based on detection data of a pressure switch 34 and a time limiting signal from a time limiting device 33 to put a three-way electromagnetic valve 27 and a two-way electromagnetic valve 29 on/off for actuating a low pressure unloader device 19 and a high pressure unloader device 20, so operation of the compressor main body 1 is controlled. The cylinder 3 is set at a non-compression operation condition for a predetermined period after starting because the low pressure unloader device 19 is released. Generation of a large temperature difference is prevented between the compressor main body 1 and compression gas at the time of starting to restrict generation of drain, thereby lubrication oil can be prevented from being emulsified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multi-stage pressure m machine used for obtaining high-pressure compressed gas.

(Prior Art) In recent years, compressed gas used as a power source for machines, etc., is increasingly required to be of high pressure. To deal with this, multi-stage compressors have traditionally been used. As an example of this multi-stage compressor, the compressor body is provided with a low-pressure side compression section and a high-pressure side compression section in which compression members such as pistons are slidably housed with lubricating oil, and the low-pressure side compression section is provided with a low-pressure side compression section. A low-pressure side unrotor device that maintains the suction valve in an open state is manually operable, and a tank is connected to the high-pressure side compression section and a high-pressure side unrotor device is also provided. After the gas is compressed to an intermediate pressure, it is compressed to a high pressure in the high-pressure side compression section and stored in a tank, so that the high-pressure compressed gas can be supplied to various machines. In addition, when the internal pressure of the tank reaches the maximum pressure, this multistage compressor rotates the drive means such as a motor and operates each unloader device to perform non-compression operation, and when the internal pressure of the tank reaches the minimum pressure, each The operation of the unloader device is stopped and compression operation is performed again to maintain the internal pressure of the tank constant.

By the way, in general, when a multi-stage compressor performs gas compression and then stops operation and then performs recompression operation, water vapor in the gas or condensed water may enter the lubricating oil due to the temperature difference between the compressor body and the compressed gas. The lubricant may become emulsified if mixed together. Therefore, in order to avoid this, conventionally, for example, before starting recompression operation after stopping compression operation, the low pressure side unloader device is operated manually in advance to put the low pressure side compression section into a non-compression operation state, and then the high pressure side Gas is compressed only in the compression section, and once the compressor body has warmed up to a certain extent, the operation of the low-pressure side unloader device is stopped and both the low-pressure side compression section and the high-pressure side compression section perform compression operation to emulsify the lubricating oil. I was trying to prevent this from happening.

(Problem to be solved by the invention) However, in the conventional multi-stage pressure N machine described above, the lubricating oil emulsification prevention is performed by manually operating the low-pressure side unloader device each time, which makes the work complicated. there were. Furthermore, when the low-pressure side unrotor device is operated to compress gas only using the high-pressure side compression section, the amount of compressed gas obtained is a fraction of that when compressing gas using the low-pressure side compression section and the high-pressure side compression section. In the multi-stage compressor mentioned above, the operation of the low-pressure side unrotor device is manually stopped. If the unit is activated, it is easy to continue operation with the low-overload unloader device activated, and in such a case, a large amount of energy is required to obtain the specified amount of compressed gas, which may deteriorate operational efficiency. There was.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a multistage compressor that can prevent emulsification of lubricating oil while maintaining good operating efficiency.

(Means for Solving the Problems) In order to achieve the above object, the first invention sets the low-pressure side compression section to a non-compression operation state when starting the compressor main body, and sets the high-pressure side compression section to a pressure M The present invention is characterized in that a control means is provided for setting the low-pressure side compression section to the compression operation state after a predetermined period of time has elapsed.

In order to achieve the above object, the second invention sets the low-pressure side compression section to a non-compression operation state and the high-pressure side compression section to a compression operation state when starting the compressor main body, and sets the compressor main body or The present invention is characterized in that a control means is provided for setting the low-pressure side compression section to a compression operation state after the temperature of the compressed gas reaches a predetermined temperature.

(Function) Since the first invention is configured as described above, when the internal pressure of the tank reaches the minimum pressure after the compression operation is performed, the control means sets the low-pressure side compression part to the non-compression operation state to increase the pressure. The gas is compressed only in the side compression section, and a large temperature difference between the compressor body and the generated compressed gas is suppressed, so that no tren is generated and the lubricating oil is prevented from emulsifying. In addition, since the non-compressing operation of the low pressure side compression section is stopped by the control means without relying on human hands after a predetermined period of time has elapsed,
Air compression can be performed using the low-pressure side compression section and high-pressure side compression section without any complicated work, and air compression using the low-pressure side compression section and high-pressure side compression section can be resumed without manual operation, preventing forgetting operations. This reduces energy loss.

The second invention is configured as described above, and when the internal pressure of the tank or the minimum pressure is reached after compression operation is performed, the control means sets the low pressure side compression section to a non-compression operation state and performs high pressure side compression. Since the gas is compressed only in the compressor section, a large temperature difference between the compressor body and the generated compressed gas can be suppressed, and the generation of a tren can be prevented, and lubricating oil can be prevented from emulsifying. In addition, when the temperature of the compressor body or the compressed gas reaches a predetermined temperature, the control means or non-compressing operation of the low pressure side compression section is stopped without relying on human hands, so low pressure side compression can be performed without any complicated work. By allowing air compression to be performed by the low pressure side compression part and the high pressure side compression part, and by restarting the air compression by the low pressure side compression part and the high pressure side compression part without manual operation, it is possible to prevent forgetting operations, etc., and to suppress energy loss.

(Example) A multi-stage air compressor which is a first example of the present invention will be described below with reference to FIGS. 1 to 3.

In the figure, a first cylinder 3 of a low-pressure side compression section and a second cylinder 4 of a high-pressure side compression section are connected to a crankcase 2 forming a part of a compressor body 1. ′! Pistons 5 and 6 installed in the cylinder 3 and second cylinder 4 of s1, respectively, are connected to a crankshaft (not shown) driven by a motor 9 via connecting rods 7.8, and each cylinder head 10. 11 has a suction chamber 12.13 and a discharge chamber 14. Is is provided. Discharge chamber on low pressure side] 4
and the high-pressure side suction chamber] 3 are connected to each other through an intermediate pipe 16, and the high-pressure side discharge chamber 15 is connected to a tank 18 through a conduit I7, and the air sucked from the low-pressure side suction chamber 12 is connected to the first The cylinder 3 is compressed to an intermediate pressure, and then sent from the discharge chamber 14 through the intermediate pipe 16 to the suction chamber 13 on the high pressure side, and the second cylinder 4 is further compressed to a high pressure and sent to the tank 18 via the conduit 17. stored.

A low pressure unrotor device 19 and a high pressure unrotor device 20 are provided in the low pressure side suction chamber 12 and the high pressure side suction chamber 13, respectively.
Or is provided. The low-pressure unloader device 19 and the high-pressure unrotor device 20 are provided with an unloader piston 23.24 that is urged upward by an unrotor spring 21.22, and its tip end faces each of the low-pressure side and high-pressure side suction valves 25.26. It is being Low pressure side unloader piston 2
3 is a conduit 28 connected to a three-way solenoid valve 27 connected to the tank 18.
When the compressed air from the tank 18 is received upwardly, the suction valve 25 can be pressed and opened, and the high-pressure side unloader piston 24 is connected to the conduit 28 through a three-way solenoid valve 29. When compressed air from the tank 18 is received upward through a three-way solenoid valve 29 and a three-way solenoid valve 27 connected to the conduit 3o, the suction valve 26 can be pressed to open.

Further, 31 is an electromagnetic switch provided on the power supply side of the motor 9, and this electromagnetic switch 31 is turned on and off by a switch 32. On the downstream side of the electromagnetic switch 3J, a time limit device 33 is provided that measures the closing time of the three-way electromagnetic valve 29 and outputs a time signal indicating this when a predetermined period of time has elapsed. Note that the predetermined time is the first cylinder 3
When compression operation is performed only with the second cylinder 4 after the compression operation of the second cylinder 4 is stopped, the compressor main body 1 warms up from the time of the compression operation of the second cylinder 4. The time is roughly set so that the lubricating oil reaches a temperature at which it does not emulsify.

The tank 18 is also provided with a pressure switch 34 that detects the internal pressure of the tank 18, and is connected to the pressure switch 34, the three-way solenoid valve 27, the three-way solenoid valve 29, and the timer 33, and is connected to the control circuit 35. It is provided.

The control circuit 35 is constituted by a microcomputer, and executes a flocram which is stored in advance based on the detection data of the pressure switch 34 and the time limit signal from the time limit device 33, and controls the three-way solenoid valve 27 and the three-way solenoid valve 29. Controls the operation of this compressor by turning it on and off. The details of this control will be explained based on the flowchart shown in FIG.

When the switch 32 is turned on, the electromagnetic switch 31 is turned on and the motor 9 is started, and compression operation is performed until the internal pressure P of the tank 18 reaches the maximum pressure (Sterab Sl (hereinafter referred to as STELAB SL)).
It's called SL. The same applies hereinafter), S2), when the internal pressure P reaches the maximum pressure, the three-way solenoid valve 27 is turned on)) The low pressure unloader device 19 and the high pressure unrotor device 120 are operated to maintain each suction valve 25, 26 in the open state. internal pressure P
The unloader is operated (S3, S4, S5, S6) until the restart pressure (minimum pressure) is reached, and when the internal pressure P or the restart pressure is reached, the three-way solenoid valve 27 is turned off (closed).
Once the unload operation is canceled (S7), the three-way solenoid valve 29 is turned on (closed) and the three-way solenoid valve 27 is turned on (opened) to start (restart) the second cylinder 4, and (
S8, S9) Make the first cylinder 3 perform unloading operation while causing the second cylinder 4 to perform compression operation (s io)
. At this time, measurement by the timer 33 is started at the same time as the processing in S8, and when this measurement time reaches a preset time, a timer signal sent from the timer 33 is input to turn the three-way solenoid valve 27 and the three-way solenoid valve 29 on. Turn it off (S11.
S12.513) Compression operation (funnel operation) is performed until the internal pressure P of the tank 18 reaches the maximum pressure (S14.51
5) When the internal pressure P of the tank 18 reaches the maximum pressure, the process returns to 85 for processing. In addition, if it is determined that the measurement time has not reached the preset time and no time limit signal has been input in Sll processing, it will be determined whether the internal pressure P or the maximum pressure has been reached (516), and the internal pressure P or the maximum pressure will be determined. If the internal pressure P has not reached the maximum pressure, the process returns to S10, and when the internal pressure P reaches the maximum pressure, the three-way solenoid valve 29 is turned off (S17).
Return to step 5 and perform the process. In this embodiment, the control circuit 35 that performs such control and the time limit device 33 constitute a control means.

The operation of the air compressor configured as above will be explained.

When the switch 32 is turned on, the electromagnetic switch 31 is turned on, and the motor 9 is started, compression operation is performed until the internal pressure P of the tank 18 reaches the maximum pressure, and when the internal pressure P reaches the maximum pressure, the three-way solenoid valve 27 is turned on and the unrotor device 1
9.20 is operated, the suction valves 25 and 26 are kept open, and both the first cylinder 3 and the second cylinder 4 are operated in an unloaded state. When the internal pressure P of the tank 18 reaches the restart pressure, the three-way solenoid valve 27 is turned off and the first cylinder 3
Then, the second cylinder 4 is set to the compression operation state, the three-way solenoid valve 29 is turned on (closed), and the three-way solenoid valve 27 is turned on (opened), and the suction valve 2 of the first cylinder 3 is turned on (opened).
The first cylinder 3 is set to the unload operation (non-compression operation) by pressing 5 to open it, and the second cylinder 4 compresses the air, and the heat generated by compression causes the compressor body 1 to be activated. Compressed air is stored in a tank 18 while being heated.

At this time, when the three-way solenoid valve 29 is turned on (closed), the timer 33 starts measuring time and outputs a timer signal to the control circuit 35 when a predetermined period of time has elapsed. When the control circuit 35 receives the time limit signal, it turns off (closes) the three-way solenoid valve 27, releases the non-compression operating state of the first cylinder 3, and compresses air in the compression sections on the low-pressure side and the high-pressure side.

After the compression operation is stopped in this way, when the internal pressure P of the tank 18 reaches the restart pressure, the first cylinder 3 is put into a non-compression operation state, and the second cylinder 4 performs a compression operation, and the temperature of the compressor main body l increases. When the predetermined time required for the temperature to reach a temperature that does not emulsify the lubricating oil has elapsed, the operation of the low-overload unloader device is stopped under the control of the control circuit 35, and the first cylinder 3 and the second cylinder 4 are operated for compression. The temperature difference between the compressor main body 1 side and the generated compressed air can be suppressed to a small level, thereby preventing the generation of drainage and preventing the lubricating oil from being emulsified. Furthermore, after the low-pressure side unloader device is activated to prevent the lubricating oil from becoming emulsified, the control circuit 35 or the low-pressure side unloader device is stopped from operating, so that the first cylinder 3 can be operated without relying on human hands. Then, air compression using the second cylinder 4 is restarted, and a predetermined amount of compressed air can be obtained with less energy than when compressing air only using the second cylinder 4 due to forgetting to operate the conventional multi-stage compressor. Operation efficiency can be improved.

In this embodiment, the timer M33 is provided, but the control circuit 35 may have a timer function and the timer may execute the function of the timer 33.

Next, a second embodiment will be described based on FIGS. 4 and 5. Compared to the first embodiment, this control circuit 3 omits the timer 33 and provides a temperature sensor 36 on the outer wall of the intermediate pipe 16, and performs SKI processing instead of Sll.
The difference is that 7 is replaced with a control circuit 35,
Other members used are those shown in the first embodiment.

These same members are indicated by the same reference numerals, and only some of these drawings and explanations will be omitted.

The temperature switch 32 outputs a temperature detection signal to the control circuit 37 when the intermediate pipe 16 reaches a predetermined temperature.

The predetermined temperature is a temperature at which the lubricating oil does not become emulsified even when the compression operation of the cylinder 3 and the second cylinder 4 of the second section 1 is performed after the compression operation of the first cylinder 3 and the second cylinder 4 is stopped. This is roughly set. When the control circuit 37 inputs a temperature detection signal from the temperature switch 32 due to the temperature of the intermediate pipe 16 reaching a predetermined temperature in the determination process of S21, the control circuit 37 advances the process to 312 and executes the process, and no temperature detection signal is input. During this period, the process advances to S16 and is executed.

This multistage air compressor performs a compression operation, and after the internal pressure P reaches the maximum pressure and both the first cylinder 3 and the second cylinder 4 are unloaded, the internal pressure P of the tank 18 becomes the restart pressure. When the three-way solenoid valve 27 is turned off, both the first cylinder 3 and the second cylinder 4 are set to the compression operation state, and at the same time, the three-way solenoid valve 29 is turned on (closed) and the three-way solenoid valve 27 is turned off. Turn on (open) the first
The suction valve 25 of the cylinder 3 is pressed to open, the first cylinder 3 is set to an unload operation (non-compression operation), and the second cylinder 4 performs a compression operation. This compression operation warms the intermediate pipe 16, and when the temperature reaches that temperature or a predetermined temperature, the temperature switch 32 outputs a temperature detection signal. Then, the control circuit 37 turns off (closes) the three-way solenoid valve 27 to release the non-compression operating state of the first cylinder 3 and compress the air in the first cylinder 3 and the second cylinder 4.

Similarly to the first embodiment, the multi-stage air compressor of the second embodiment also has a main body 1 of the compressor warmed up, and the control circuit 37 controls the operation of the low-pressure side unrotor device to stop the first cylinder. 3 and the second cylinder 4 perform compression operation, the temperature difference between the compressor main body L side and the generated compressed air is suppressed to a small level, eliminating the generation of tren and preventing the lubricating oil from becoming emulsified. . Furthermore, after the low-pressure side unrotor device is activated to prevent the lubricating oil from becoming emulsified, the control circuit 37 or the low-pressure side unrotor device can be stopped to operate without relying on human hands. Air compression can be performed using the second cylinder 3 and the second cylinder 4, and a predetermined amount of compressed air can be obtained with less energy than when air is compressed using only the second cylinder 4.

In addition, in the second embodiment, the temperature switch 32 is connected to the intermediate pipe 1.
The temperature switch 32 may be installed inside the cylinder G to measure the temperature of the compressed air, or it may be installed inside the cylinder 4 on the high pressure side as shown in FIG.
It may be installed on the outer wall of the

Furthermore, in each of the above embodiments, the first cylinder 3 is set to a non-compression operating state and the second cylinder 4 is set to a compression operating state at step 86 in FIG. 3, that is, at the restart stage. Alternatively, the above-mentioned settings may be made at the Sl stage, that is, at the initial startup.

Further, in each of the above embodiments, the case of a multi-stage air compressor that compresses air has been described, but the present invention may be a multi-stage compressor that compresses other gases.

Further, although each of the above embodiments has been described as an example of a two-stage compressor, the present invention is not limited thereto, and may be a compressor with three or more stages.

(Effects of the Invention) As explained above, the present invention, after compression operation is performed, when the internal pressure of the tank or the minimum pressure is reached, the low-pressure side compression section is temporarily set to the non-compression operation state, and the high-pressure side compression section is turned off. By compressing the gas, there is no longer a large temperature difference between the compressor body and the compressed gas, suppressing the generation of tren and preventing emulsification of lubricating oil, and control after taking measures to prevent lubricating oil emulsification. Since the non-compression operation of the low-pressure side compression section is canceled by the means, air compression can be performed by the low-pressure side compression section and the high-pressure side compression section without complicated work, and air can be compressed by the low-pressure side compression section and the high-pressure side compression section. Compression is restarted in a timely manner, and specific energy loss is suppressed due to air compression using only the high-pressure side compression section, thereby maintaining good operating efficiency.

[Brief explanation of drawings]

Fig. 1 is a piping system diagram schematically showing a multistage compressor according to the first embodiment of the present invention, Fig. 2 is a sectional view showing an unloader device of the compressor, and Fig. 3 is a control of the compressor. Flowchart showing the processing contents of the circuit. Fig. 4 is a piping system diagram schematically showing the multistage compressor of the second embodiment. Fig. 5 is a flowchart showing the main part of the processing contents of the control circuit of the same compressor. , FIG. 6 is a piping system diagram showing a modification of the mounting of the temperature switch in the second embodiment. l... Compressor main body, 3... First cylinder, 4...
- Second cylinder, 18...tank, 33... time limit device, 35... control circuit. --(V'')Gubewa 00-F) rwa Figure 3 Figure Figure S12

Claims (2)

[Claims] (1) When starting up the compressor main body, the low-pressure side compression section is set to non-compression operation, the high-pressure side compression section is set to compression operation, and after a predetermined period of time, the low-pressure side compression section is set to compression operation. A multistage compressor characterized by being provided with a control means. (2) When the compressor main body is started, the low pressure side compression section is set to non-compression operation state, and the high pressure side compression section is set to compression operation state, and after the temperature of the compressor main body or compressed gas reaches a predetermined temperature. A multi-stage compressor characterized by comprising a control means for setting a low-pressure side compression section to a compression operation state.