TW201910640A - Evacuation apparatus and method for cooling evacuation apparatus - Google Patents

Abstract

Disclosed are an evacuation apparatus and a method for cooling evacuation apparatus which are capable of promoting the cooling efficiency of evacuation apparatus. The evacuation apparatus includes an evacuation pump, a cooling mechanism and an air blower. The evacuation pump includes a pump main body, a driving part for driving the pump main body, and a control part for controlling the driving part. The cooling mechanism includes a cooling loop, a circulation pump for circulating cold medium in the cooling loop, and an air-cooling heat exchanger connected to the cooling loop and configured to cool the cold medium. The cooling mechanism is to cool the control part through the cold medium. The air blower is to blow outside air from the evacuation pump to the air-cooling heat exchanger, and is to air-cool the control part and the air-cooling heat exchanger through the outside air.

Description

 Vacuum exhaust device and cooling method of vacuum exhaust device  

The present invention relates to a vacuum exhaust device and a method of cooling a vacuum exhaust device.

In a vacuum pump such as a rotary pump, there is a type in which wind is taken in from the outside and the vacuum pump is forcibly cooled by air cooling (for example, refer to Patent Document 1). On the other hand, there is a circulation of the lubricating oil in a pipe, the lubricating oil is cooled by an air-cooled radiator connected to the pipe, and the vacuum pump is cooled by the cooled lubricating oil. Type (for example, refer to Patent Document 2).

 [Previous Technical Literature]    [Patent Literature]  

Patent Document 1: Japanese Laid-Open Patent Publication No. 2010-127118.

Patent Document 2: Japanese Laid-Open Patent Publication No. Hei 10-159780.

However, the greater the power required for the vacuum pump becomes, the greater the heat generated from the vacuum pump becomes. Thereby, the air-cooled cooling cannot correspond to an increase in the required power. On the other hand, in the method of cooling with lubricating oil, there is a case where the cooling performance is lowered when the lubricating oil is contaminated by the driving of the vacuum pump and deteriorates.

In view of the above circumstances, an object of the present invention is to provide a vacuum exhaust apparatus which improves cooling efficiency and a cooling method of a vacuum exhaust apparatus.

In order to achieve the above object, a vacuum exhaust apparatus according to an aspect of the present invention includes a vacuum pump, a cooling mechanism, and a blower. The vacuum pump includes a pump body, a drive unit that drives the pump body, and a control unit that controls the drive unit. The cooling mechanism includes a cooling circuit, a circulation pump that circulates the cooling medium in the cooling circuit, and an air-cooled heat exchanger that is connected to the cooling circuit and that can cool the cooling medium. The cooling mechanism cools the control unit by the cold medium. The blower is capable of blowing outside air from the vacuum pump toward the air-cooled heat exchanger. The air blower cools the control unit and the air-cooled heat exchanger by the outside air.

Thereby, the control unit can be cooled by the cold medium that has been cooled by the air-cooled heat exchanger, and further the outside air is blown from the vacuum pump toward the air-cooled heat exchanger, and the outside air collides with the air-cooling. The heat exchanger is exposed to the control unit before. As a result, the cooling efficiency of the vacuum exhaust device can be improved.

Further, the vacuum exhausting apparatus may further include: a casing for accommodating the vacuum pump and the cooling mechanism. In the air blower, the outside air is blown from the vacuum pump toward the air-cooling heat exchanger between the casing and the control unit.

Thereby, an air flow caused by the outside air is generated between the casing and the control unit, and the control unit is air-cooled efficiently.

In the above vacuum evacuation device, the control unit may be located between the air-cooled heat exchanger and the pump body.

Thereby, the external air sent by the blower collides with the control unit before hitting the air-cooled heat exchanger, and the cooling efficiency of the vacuum exhaust device can be improved.

In the above vacuum evacuation device, the air-cooling heat exchanger may be located between the blower and the control unit.

Thereby, the external air introduced by the blower collides with the air-cooled heat exchanger after colliding with the control portion. As a result, the air-cooled heat exchanger is air-cooled efficiently.

In the above vacuum evacuation device, the cooling mechanism may further cool the driving portion by the cold medium circulating through the cooling circuit. In the cooling circuit described above, the portion that cools the control portion is located upstream of the portion that cools the drive portion.

Thereby, the cold medium that has been cooled by the air-cooled heat exchanger cools the drive unit after cooling the control unit in advance. As a result, the cooling efficiency of the vacuum exhaust device can be improved.

Further, in the vacuum exhausting apparatus described above, the auxiliary pump may be further provided with a vacuum discharge port provided in the gas discharge port of the pump body.

Thereby, the gas discharge port provided to the pump body is evacuated by vacuum, and the load of the pump body can be reduced. As a result, the cooling efficiency of the vacuum exhaust device can be more improved.

In the above vacuum exhaust apparatus, the cooling circuit may include a differential pressure mechanism that is provided upstream of the portion that cools the control unit and that causes a difference in vapor pressure of the cold medium in the cooling circuit.

Thereby, a difference occurs in the boiling point of the cold medium upstream of the differential pressure mechanism and downstream, for example, the cold medium evaporates downstream of the differential pressure mechanism at a lower temperature than the upstream. As a result, heat is removed from the control portion by vaporization of the cold medium, and the cooling efficiency of the vacuum exhaust device can be further improved.

In order to achieve the above object, a method for cooling a vacuum exhaust device according to an aspect of the present invention includes the steps of: a vacuum pump having a pump body, a driving unit that drives the pump body, and a control unit that controls the driving unit; The air-cooled heat exchanger cools the cold medium cooled by the control unit. The outside air is blown from the vacuum pump toward the air-cooling heat exchanger, whereby the control unit and the air-cooled heat exchanger can be air-cooled by the outside air.

Thereby, the control unit can be cooled by the cold medium that has been cooled by the air-cooled heat exchanger, and further the outside air is blown from the vacuum pump toward the air-cooled heat exchanger, and the outside air collides with the air-cooled type. The heat exchanger is first exposed to the control section. As a result, the cooling efficiency of the vacuum exhaust device can be improved.

As described above, according to the present invention, it is possible to provide a vacuum exhausting device which improves cooling efficiency and a cooling method of the vacuum exhausting device.

1, 2, 3‧‧‧ vacuum exhaust

10‧‧‧Vacuum pump

11‧‧‧ pump body

12‧‧‧ Drive Department

13‧‧‧Control Department

13c‧‧‧shell

13h, 33h, 50h‧‧‧ openings

13s‧‧‧ circuit board

20‧‧‧Cooling mechanism

21‧‧‧cooling circuit

22‧‧‧Circulating pump

23‧‧‧Air-cooled heat exchanger

25‧‧‧Differential pressure mechanism

26‧‧‧ pressure gauge

27‧‧‧Accumulator

30‧‧‧Air blower

31‧‧‧moving impeller

32‧‧‧Rotary axis

33, 141‧‧ ‧ cover

40‧‧‧Power supply

50‧‧‧ frame

60‧‧‧Auxiliary pump mechanism

61‧‧‧Auxiliary pump

62, 63‧‧‧ piping

64‧‧‧ check valve

70‧‧‧Control device

90‧‧‧ caster mechanism

110‧‧‧ pump housing

111‧‧‧ suction pipe

112‧‧‧Exhaust pipe

113‧‧‧Intake chamber

114‧‧‧ suction port

115‧‧‧Exhaust chamber

116‧‧‧Exhaust port

121‧‧‧Motor housing

122‧‧‧Motor

122a‧‧‧Drive shaft

123a, 123b‧‧‧ timing gear

131, 132‧‧‧ spiral rotor

131s‧‧‧first tooth

132s‧‧‧second tooth

135, 136, 137, 138‧‧‧ shaft ends

140a, 140b, 150a, 150b‧‧‧ bearings

P, Q‧‧‧ part

T1‧‧‧ Temperature Sensor

Fig. 1 is a schematic block diagram of a vacuum exhausting apparatus of a first embodiment.

(a) of FIG. 2 is a schematic plan view of the components in the vacuum exhaust apparatus, and (b) of FIG. 2 is a schematic side view of the components of the vacuum exhaust apparatus.

Fig. 3 is a schematic cross-sectional view showing a main part of the inside of the vacuum pump.

Fig. 4 is a schematic side elevational view showing the components of the vacuum evacuation device of the second embodiment.

Fig. 5 is a schematic plan view showing the components of the vacuum evacuation device of the third embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In some cases, XYZ axis coordinates are introduced in each drawing.

 (First embodiment)  

Fig. 1 is a schematic block diagram of a vacuum exhausting apparatus of a first embodiment.

The vacuum exhaust system 1 includes a vacuum pump 10, a cooling mechanism 20, and a blower 30.

The vacuum pump 10 has a pump body 11, a drive unit 12, and a control unit 13. The pump body 11 is, for example, a body portion that evacuates a vacuum chamber. The drive unit 12 drives the pump body 11. The control unit 13 controls the drive unit 12.

The cooling mechanism 20 includes a cooling circuit 21, a circulation pump 22, and an air-cooling heat exchanger 23. The cooling mechanism 20 circulates the cold medium in the vacuum exhaust unit 1 and cools each of the pump body 11, the drive unit 12, and the control unit 13. The circulation pump 22 is disposed on the way of the cooling circuit 21, and circulates the cold medium in the cooling circuit 21. In the description of the direction of the flow of the cold medium in the cooling circuit 21, the direction of the inflow side of the cold medium is defined as "upstream" with respect to a certain portion, and the direction of outflow of the cold medium is defined as "downstream".

The air-cooled heat exchanger 23 is connected to the cooling circuit 21. For example, the air-cooled heat exchanger 23 is disposed on the way of the cooling circuit 21 and is disposed downstream of the circulation pump 22. For example, when the circulation pump 22 operates, the cold medium supplied from the circulation pump 22 flows into the air-cooled heat exchanger 23. The cold medium is cooled by the air-cooled heat exchanger 23, and the cold medium that has just been cooled by the air-cooled heat exchanger 23 flows into the cooling circuit 21 that is dragged around the control unit 13.

Thereby, in the drive unit 12 and the control unit 13, the control unit 13 is previously cooled by the cold medium, and then the drive unit 12 is cooled. That is, the cold medium heated by the driving unit 12 does not flow to the cooling circuit 21 that is dragged around the control unit 13, but the cold medium that has just been cooled by the air-cooled heat exchanger 23 flows into The cooling circuit 21 is dragged around the control unit 13. Thereby, the water cooling effect of the control unit 13 is improved. Then, the cold medium that has flowed out from the cooling circuit 21 that is dragged around the drive unit 12 is sucked by the circulation pump 22, and the circulation pump 22 supplies the cold medium to the air-cooled heat exchanger 23 again. This water cooling operation is repeated in the vacuum exhaust unit 1. In the present embodiment, the term "water-cooling" means cooling in addition to water, and cooling by a cooling liquid or a radiator liquid.

Further, since the cooling mechanism 20 is a circulation type cooling mechanism in the vacuum exhaust device 1, it is not necessary to supply the cold medium to the vacuum exhaust device 1 from outside the vacuum exhaust device 1. Therefore, the degree of freedom in providing the cooling mechanism 20 is improved.

Further, the vacuum exhaust device 1 of the present embodiment also has a gas cooling function.

For example, the blower 30 takes in outside air from the outside of the vacuum exhaust device 1 and blows outside air from the vacuum pump 10 toward the air-cooled heat exchanger 23. For example, the flow of outside air is schematically shown by an arrow A in the figure. The external air flows through the respective side faces of the pump body 11, the drive unit 12, and the control unit 13, and is blown to the front of the air-cooled heat exchanger 23. The outside air that has collided with the air-cooled heat exchanger 23 is sucked by the blower 30 provided on the side of the air-cooled heat exchanger 23, and is released to the outside of the vacuum exhaust unit 1 by the blower 30. Thereby, each of the pump body 11, the drive unit 12, the control unit 13, and the air-cooled heat exchanger 23 can be forcibly air-cooled by the outside air. This air cooling operation is repeated in the vacuum exhaust unit 1.

In the vacuum exhaust device 1, the outside air collides with the control portion 13 before it collides with the air-cooled heat exchanger 23. In other words, the external air that has been warmed up by the air-cooled heat exchanger 23 is discharged to the outside of the vacuum exhaust unit 1 by the blower 30, and is collided with the outside air before being heated by the air-cooled heat exchanger 23. Go to the control unit 13. Thereby, the air cooling effect of the control unit 13 is improved.

In the vacuum exhaust device 1, a temperature sensor T1 is attached to the control unit 13, and the measured value detected by the temperature sensor T1 is sent to the control unit 13. When the temperature of the control unit 13 is equal to or greater than the threshold value, the control unit 13 can suppress the operation of the drive unit 12 or stop the operation of the drive unit 12.

For example, the control unit 13 controls the switching speed of the transistor in the inverter control circuit of the control unit 13, the output of the circulation pump 22, and the output of the blower 30.

When the temperature of the control unit 13 exceeds a predetermined value, the control unit 13 increases the output of the blower 30, decelerates the switching speed of the inverter control circuit, or raises the output of the circulation pump 22, and the control unit 13 The temperature is controlled to be equal to or lower than a predetermined value.

In other words, the control unit 13 frequently operates during the operation of the vacuum exhaust device 1. Therefore, it is important to efficiently cool the heat emitted from the control unit 13. In the vacuum exhaust apparatus 1 of the present embodiment, even if the vacuum exhaust apparatus 1 is operated for a long period of time, the temperature of the control unit 13 can be controlled so that the temperature of the control unit 13 does not exceed 80 °C. It is needless to say that the pump body 11 and the drive unit 12 are set to be equal to or lower than a desired temperature.

Electric power is supplied from the outside of the vacuum exhaust apparatus 1 in each of the drive unit 12, the control unit 13, the circulation pump 22, and the blower 30. Further, the vacuum exhaust apparatus 1 may include a power source 40 as an auxiliary power source for supplying DC (direct current) power to the control unit 13, the circulation pump 22, and the blower 30.

(a) of FIG. 2 is a schematic plan view of the components in the vacuum exhaust apparatus, and (b) of FIG. 2 is a schematic side view of the components of the vacuum exhaust apparatus.

In the vacuum exhaust device 1, the vacuum pump 10 and the cooling mechanism 20 are housed in the casing 50. The shape of the frame 50 is, for example, a rectangular parallelepiped. The casing 50 has an opening 50h capable of taking in outside air. A caster mechanism 90 is provided below the casing 50.

In the vacuum exhaust device 1, the pump body 11, the drive unit 12, the control unit 13, the air-cooled heat exchanger 23, and the blower 30 are arranged in series in this order. In the present embodiment, the arrangement direction of these is taken as a series direction (Y-axis direction).

The pump body 11 is located at the forefront in the series direction. An intake pipe 111 and an exhaust pipe 112 are provided in the pump body 11. The intake pipe 111 is connected to an internal space of a vacuum tank (not shown), and the exhaust pipe 112 is connected to the atmosphere, an auxiliary pump (not shown), a device for treating the discharged gas, and the like.

The drive unit 12 is located between the pump body 11 and the air-cooled heat exchanger 23. The air-cooled heat exchanger 23 is located between the blower 30, the drive unit 12, and the control unit 13. The air-cooled heat exchanger 23 is, for example, a heat sink.

The control unit 13 is located between the air-cooled heat exchanger 23 and the pump body 11. The control unit 13 is adjacent to the drive unit 12 in a direction (X-axis direction) orthogonal to the series direction. The control unit 13 is attached to the drive unit 12. When the AC motor is used as the drive source of the drive unit 12, the control unit 13 has, for example, an inverter control circuit that controls the rotation speed of the AC motor.

In the inverter control circuit, since the switching operation of the switching element is frequently performed, there is a case where heat is generated at a high temperature. In the event that the temperature of the inverter control circuit has exceeded the threshold, the inverter control circuit will be damaged. Therefore, it is required to cool the control unit 13 efficiently in the vacuum exhaust apparatus.

The cooling mechanism 20 is located between the pump body 11 and the blower 30. The circulation pump 22 is arranged in parallel with the air-cooled heat exchanger 23 in the X-axis direction. The cooling circuit 21 is connected to the air-cooled heat exchanger 23. The cooling circuit 21 is dragged around the driving portion 12. The control unit 13 is cooled by being dragged around the cooling circuit 21 of the drive unit 12. However, in the cooling circuit 21, the portion P contributing to the cooling of the control portion 13 is located upstream of the portion Q of the cooling drive portion 12.

Thereby, the cold medium which has just been cooled by the air-cooled heat exchanger 23 flows into the portion P earlier than the portion Q. As a result, the drive unit 12 is efficiently cooled by water. Here, the cold medium is, for example, one of water, a coolant, a heat sink, and the like.

The blower 30 is located at the end of the series direction. The blower 30 has a rotary impeller 31, a rotating shaft 32, and a cover 33. An opening 33h for discharging outside air from the casing 50 is provided in the lid body 33.

When the blower 30 operates, the outside air is introduced into the casing 50 through the opening 50h, and the outside air flows between the casing 50 and the vacuum pump 10. The outside air is thereafter blown toward the air-cooled heat exchanger 23 and collides with the air-cooled heat exchanger 23. Then, the outside air in the casing 50 is released from the opening 33h by the movable impeller 31.

In the vacuum exhaust device 1, an air flow of external air from the vacuum pump 10 toward the air-cooling heat exchanger 23 is formed between the casing 50 and the control unit 13. When the vacuum pump 10 or the like is not housed in the housing 50, it is difficult to form an air flow that flows on the side surface of the control unit 13, and outside the control unit 13, the outside air is likely to stagnate near the control unit 13. . Thereby, the air cooling effect of the control unit 13 is reduced.

In the present embodiment, the vacuum pump 10 and the cooling mechanism 20 are housed by the housing 50, and the airflow forcibly flowing to the side surface of the control unit 13 is forcibly formed. As a result, the outside air around the control unit 13 is less likely to stagnate in the vicinity of the control unit 13, and the air cooling efficiency of the control unit 13 is improved.

As described above, in the vacuum exhaust apparatus 1, the control unit 13 is efficiently cooled by water from the side of the drive unit 12, and is also air-cooled efficiently from the side of the casing 50.

Further, even when the drive unit 12 and the control unit 13 are located at the forefront, and the drive unit 12, the control unit 13, the pump body 11, the air-cooling heat exchanger 23, and the blower 30 are arranged in series in this order, Since the control portion 13 is located upstream of the air flow in the series direction than the air-cooled heat exchanger 23, the same air-cooling effect can be obtained. This arrangement is also included in this embodiment.

In the case where the direction of the outside air flowing into the casing 50 is opposite to the direction A, that is, when the airflow is generated from the air-cooling heat exchanger 23 toward the vacuum pump 10, It is not preferable that the air-cooled heat exchanger 23 is air-cooled and the warmed outside air collides with the control unit 13.

Fig. 3 is a schematic cross-sectional view showing a main part of the inside of the vacuum pump. The arrangement of the cooling circuit 21 shown in FIG. 3 is an example, and is not limited to this example.

In Fig. 3, a twin-shaft type screw pump is shown as an example. The vacuum pump 10 of the present embodiment is not limited to a twin-shaft type screw pump, and may be a Roots type dry pump or a rotary pump.

In the vacuum pump 10, a pair of screw rotors 131, 132 are provided in a pump housing 110. The material of the pump casing 110 is, for example, cast iron. A heat sink (not shown) is provided on the outer circumference of the pump casing 110, for example, and the pump casing 110 is air-cooled by the outside air in the casing 50.

The pair of spiral rotors 131 and 132 are arranged side by side in the X-axis direction. The spiral rotor 131 has a spiral first tooth 131s, and the spiral rotor 132 has a spiral second tooth 132s that meshes with the first tooth 131s. The respective turn numbers of the first teeth 131s and the second teeth 132s are not limited to the illustrated number.

In the pump casing 110, each of the shaft end portion 135 of the spiral rotor 131 and the shaft end portion 137 of the spiral rotor 132 is inserted. A bearing 140a is disposed between the shaft end 135 and the pump casing 110. A bearing 140b is disposed between the shaft end 137 and the pump casing 110. The shaft end portion 135 is rotatably supported by the pump casing 110 via a bearing 140a, and the shaft end portion 137 is rotatably supported by the pump casing 110 via a bearing 140b. A cover body 141 covering the bearings 140a and 140b is airtightly fixed to the pump casing 110.

The shaft end portion 136 of the spiral rotor 131 opposite to the shaft end portion 135 and the shaft end portion 138 of the spiral rotor 132 opposite to the shaft end portion 137 are inserted into the pump casing 110 on the opposite side of the lid body 141. A bearing 150a is disposed between the shaft end portion 136 and the pump housing 110, and a bearing 150b is disposed between the shaft end portion 138 and the pump housing 110. The shaft end portion 136 is rotatably supported by the pump casing 110 via a bearing 150a, and the shaft end portion 138 is rotatably supported by the pump casing 110 via a bearing 150b.

The drive unit 12 has a motor housing 121, a motor 122, a timing gear 123a, and a timing gear 123b. The motor 122, the timing gear 123a, and the timing gear 123b are housed in the motor casing 121. The material of the motor casing 121 is, for example, an aluminum casting.

The motor 122 is constituted by, for example, an AC (alternating current) motor or the like. The drive shaft 122a of the motor 122 is coupled to the shaft end 138 of the helical rotor 132. The motor 122 rotates the helical rotor 132 by a predetermined number of revolutions. This number of rotations is controlled by the inverter control circuit of the control unit 13.

The timing gear 123a is attached to the shaft end portion 136 of the spiral rotor 131. The timing gear 123b is attached to the shaft end portion 138 of the spiral rotor 132. The timing gears 123a and 123b are connected in parallel to each other in the X-axis direction. Thereby, when the spiral rotor 132 rotates, the spiral rotor 131 rotates.

Here, on the side of the bearings 140a, 140b, the space defined by the pump casing 110, the first teeth 131s and the second teeth 132s is used as the suction chamber 113, and the sides of the bearings 150a, 150b are to be the pump casing 110, first. The space defined by the teeth 131s and the second teeth 132s serves as the exhaust chamber 115. The suction chamber 113 is connected to the intake pipe 111 via the intake port 114, and the exhaust chamber 115 is connected to the exhaust pipe 112 via the exhaust port 116.

Each of the spiral rotors 131, 132 is driven by the motor 122 to rotate in opposite directions to each other. Thereby, for example, the gas in the vacuum chamber is sucked from the suction port 114 and discharged from the exhaust port 116.

The control unit 13 has a circuit board 13s and a case 13c that protects the circuit board 13s. An opening 13h through which the outside air flowing into the casing 50 passes is provided in the casing 13c as needed. The circuit board 13s includes an inverter control circuit and the like. The motor casing 121 to be mounted on the circuit board 13s also serves as a heat sink of the circuit board 13s. Furthermore, the configuration of the control unit 13 is not limited to the illustrated example.

FIG. 3 shows an example of a flow path provided in the motor casing 121 as the cooling circuit 21. The cooling circuit 21 may be constituted by at least one of such a flow path, a cooling pipe provided outside the motor casing 121, and a joint connecting the cooling pipes to each other. The cooling pipe disposed outside the motor casing 121 may also be in contact with the motor casing 121 or away from the motor casing 121. Further cooling circuit 21 can also have a branched configuration.

As described above, in the present embodiment, the vacuum pump 10 is cooled by the cold medium that has cooled the control unit 13 by the air-cooling heat exchanger 23, and the vacuum pump 10 has the pump body 11 and the drive unit 12 that drives the pump body 11. And the control unit 13 that controls the drive unit 12. Further, by blowing outside air from the vacuum pump 10 toward the air-cooling heat exchanger 23, each of the air-cooling control unit 13 and the air-cooled heat exchanger 23 can be air-cooled by the outside air.

In the vacuum evacuation device 1, each of the drive unit 12 and the control unit 13 is water-cooled, and each of the pump body 11, the drive unit 12, the control unit 13, and the air-cooled heat exchanger 23 is forcibly air-cooled. In the vacuum evacuation device 1, since the temperature of the control unit 13 is controlled to be 80° C. or lower even if it is operated for a long period of time, the inverter control circuit of the control unit 13 spontaneously generates heat, and the inverter control is performed. The circuit is still set to be below 80 °C by water cooling and air cooling. Thereby, even if the vacuum exhaust apparatus 1 is operated for a long time, the inverter control circuit is not easily broken.

 [Second embodiment]  

Fig. 4 is a schematic side elevational view showing the components of the vacuum evacuation device of the second embodiment.

The vacuum exhaust unit 2 further includes an auxiliary pump mechanism 60 that vacuum-exhausts the exhaust pipe 112 provided in the pump body 11. The auxiliary pump mechanism 60 includes an auxiliary pump 61, a piping 62 disposed downstream of the auxiliary pump 61, a piping 63 disposed upstream of the auxiliary pump 61, and a check valve 64 being provided. In the middle of the exhaust pipe 112 between the pipe 62 and the pipe 63. The auxiliary pump mechanism 60 may also be disposed in the housing 50.

Thereby, the exhaust pipe 112 provided in the pump body 11 is evacuated, and the exhaust chamber 115 connected to the exhaust pipe 112 is evacuated by vacuum. For example, when the exhaust of the vacuum chamber by the pump body 11 is at the end stage, the amount of discharge from the vacuum chamber is reduced, and the flow rate of the gas flowing through the exhaust pipe 112 is reduced. The intake and exhaust of the auxiliary pump 61 are more advantageous than the amount of exhaust of the pump body 11, and even if the side of the pipe 63 becomes a negative pressure with respect to the side of the pipe 62, it flows through the pipe 62 by the presence of the check valve 64. The gas to the exhaust pipe 112 does not flow back into the pump body 11. Thereby, the auxiliary pump 61 is operated against the atmospheric pressure, and the pump body 11 does not become an operation in which the differential pressure is received between the intake chamber 113 and the exhaust chamber 115, but is substantially idling. Thereby, the load of the pump body 11 (the rotational load of the spiral rotors 131 and 132) is reduced, and heat generation from the pump body 11 can be suppressed. As a result, the cooling efficiency of the vacuum exhaust unit 1 can be more improved.

 [Third embodiment]  

Fig. 5 is a schematic plan view showing the components of the vacuum evacuation device of the third embodiment.

In the vacuum exhaust device 3, the cooling mechanism 20 further includes a differential pressure mechanism 25, a pressure gauge 26, and an accumulator 27. The differential pressure mechanism 25 is provided, for example, upstream of the portion P of the cooling circuit 21. By the circulation pump 22, a difference in pressure between the upstream of the differential pressure mechanism 25 and the downstream of the cooling circuit 21 can occur. In other words, the internal pressure difference of the cooling circuit 21 is generated on the supply side and the suction side of the circulation pump 22. The differential pressure mechanism 25 is, for example, an orifice. Further, the circulation pump 22 is a circulation pump of a gas-liquid mixing type.

For example, the pressure in the cooling circuit 21 downstream of the differential pressure mechanism 25 is set to be lower than the pressure in the cooling circuit 21 upstream of the differential pressure mechanism 25. For example, when the pressure in the cooling circuit 21 upstream of the differential pressure mechanism 25 is taken as a normal pressure (for example, 1 atmosphere), the pressure in the cooling circuit 21 downstream of the differential pressure mechanism 25 is set to be higher than normal pressure. Lower.

The pressure gauge 26 measures the pressure in the cooling circuit 21 (part Q) between the downstream of the differential pressure mechanism 25 and the circulation pump 22. The pressure value measured by the pressure gauge 26 is fed back to the output of the circulation pump 22. Thereby, for example, the pressure in the portion Q of the cooling circuit 21 is maintained constant.

The accumulator 27 is provided in a cooling circuit 21 between the upstream of the differential pressure mechanism 25 and the circulation pump 22. For example, the accumulator 27 is disposed between the air-cooled heat exchanger 23 and the circulation pump 22. The accumulator 27 is configured to reduce the pressure in the cooling circuit 21 when the pressure in the cooling circuit 21 between the upstream of the differential pressure mechanism 25 and the circulation pump 22 has become a predetermined value or more (for example, 1.1 or more). Leak valve.

For example, when the cold medium is water, the boiling point of the cold medium in the portion Q of the cooling circuit 21 is set to be 80% or less of the set temperature (for example, 80 ° C) of the control unit 13. For example, the boiling point of the cold medium in the portion Q of the cooling circuit 21 is set to be 64 ° C or lower. Further, the lower limit of the boiling point of the cold medium may be set to the dew point of the use environment. This is because when the temperature of the control unit 13 becomes a temperature lower than the dew point, the electronic circuit is condensed and a problem occurs. For example, by setting the lower limit of the boiling point of the cold medium to 40 ° C, it is possible to surely prevent the occurrence of condensation.

Thereby, even if the temperature of the cold medium in the portion Q of the cooling circuit 21 rises by the operation of the vacuum exhaust device 3, the cold medium temperature in the portion Q of the cooling circuit 21 has become a time point of 64 ° C, and the cold medium Part Q of the cooling circuit 21 is still vaporized. Thereby, the heat corresponding to the heat of vaporization of the cold medium is further removed from the driving unit 12 and the control unit 13, and the cooling efficiency of the vacuum exhausting device can be further improved. That is, even if the vacuum exhaust apparatus is operated for a long period of time, the control unit 13 can more reliably become the set temperature (for example, 80 ° C) or less.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can of course be applied. The various embodiments are not necessarily independent, but technically as complex as possible.

Claims (9)

 A vacuum exhausting device comprising: a vacuum pump having a pump body; a driving unit that drives the pump body; and a control unit that controls the driving unit; and a cooling mechanism that cools the control unit by a cold medium; And having: a cooling circuit; the circulation pump is configured to circulate the cooling medium in the cooling circuit; and the air-cooling heat exchanger is connected to the cooling circuit and capable of cooling the cold medium; and the blower is capable of external air The vacuum pump blows air toward the air-cooling heat exchanger, and air-cools the control unit and the air-cooled heat exchanger by the outside air.    The vacuum exhausting device according to claim 1, further comprising: a casing for accommodating the vacuum pump and the cooling mechanism; wherein the air blower is configured to move the outside air from the vacuum pump to the front between the casing and the control unit The air-cooled heat exchanger supplies air.    The vacuum exhaust device according to claim 1 or 2, wherein the control unit is located between the air-cooled heat exchanger and the pump body.    The vacuum exhaust apparatus according to claim 1 or 2, wherein the air-cooled heat exchanger is located between the blower and the control unit.    The vacuum exhausting device according to claim 1 or 2, wherein the cooling mechanism further cools the driving portion by the cold medium circulating in the cooling circuit; in the cooling circuit, a portion for cooling the control portion is located It is upstream further than the portion that cools the aforementioned driving portion.    The vacuum exhausting apparatus according to claim 1 or 2, further comprising: an auxiliary pump that evacuates a gas discharge port provided in the pump body.    The vacuum exhausting apparatus according to claim 5, wherein the cooling circuit has a differential pressure mechanism that is provided upstream of the portion that cools the control unit and that causes a vapor pressure of the cold medium to be poor in the cooling circuit. .    The vacuum exhaust apparatus according to claim 6, wherein the cooling circuit has a differential pressure mechanism that is provided upstream of the portion that cools the control unit and that causes a vapor pressure of the cold medium to be poor in the cooling circuit. .    A method for cooling a vacuum exhaust device for cooling a vacuum pump by a cold medium, wherein the vacuum pump has a pump body, a driving unit that drives the pump body, and a control unit that controls the driving unit, wherein the cold medium is a gas The cooling heat exchanger cools the control unit, and external air is blown from the vacuum pump toward the air-cooling heat exchanger, thereby cooling the control unit and the air-cooled heat exchanger with the outside air.