TWI541439B - Oil diffusion pump and vacuum film forming device - Google Patents

Description

Oil diffusion pump and vacuum film forming device

The present invention relates to an oil diffusion pump connected to a vacuum chamber constituting various vacuum film forming apparatuses such as a steaming device or a sputtering device, and as a vacuum pump suitable for vacuuming the chamber, the present invention also has A vacuum membrane device in which the oil diffusion pump is assembled.

In various vacuum film forming apparatuses such as a vapor deposition apparatus or a sputtering apparatus, an oil diffusion pump can be used for the vacuum pump used in the exhaust apparatus to evacuate the inside of the vacuum chamber constituting the apparatus. In the conventional oil diffusion pump, an oil-diffusing pump uses an electric heater having a heating wire as a heating source of the working oil contained in the boiler (Patent Document 1).

[Advanced technical literature]

Patent Document 1: JP-A-2007-23778

When the heating wire is used as the heating source of the working oil, there is an advantage that the device can be formed inexpensively, but there are factors that cause various problems such as, for example, the heating wire is broken to cause the heating function to disappear, and the heating wire is poorly insulated. Leakage occurs, and the terminal block is in poor contact due to high temperature. Further, in the case of using a heating wire, since there is a high temperature close to red heat, it is necessary to carefully select a place to be installed, and thus there is a problem that the degree of freedom in selecting a place to be installed is limited.

As a heating wire for the action oil heating source, considering the energy efficiency There will be a lot of heat conduction losses. As a result, there are problems such as the following.

(1) Waste of electricity

(2) The rising speed of heating is slow (long startup time)

(3) Poor thermal responsiveness and maintainability

(4) The material of the heating object (heated body) must be selected from materials that can withstand high temperatures for a long time.

(5) It also heats the periphery of the object to be heated without contributing to the heating of the oil with the object to be heated.

According to an aspect of the present invention, an oil diffusion pump and a vacuum film forming apparatus using the pump as an exhaust device are provided. The oil diffusion pump has an oil vapor generator capable of solving the problem that occurs when the heating wire is used as a heating source for the operating oil, and has fewer failures and is more energy-efficient during operation.

The oil diffusion pump of the present invention is a vacuum pump in which an oil vapor generator is disposed in a jet flow device inside the casing, and the oil vapor generator operates to vaporize the action oil into oil vapor, and the oil vapor is from the oil vapor. The jet flow device is ejected to perform an exhaust operation of the suction gas. The oil vapor generator comprises: a container, the wall surface extending in a rising direction, the lower end of the tubular member formed of the heated material is closed, the inside is used for storing oil; and the induction coil is wound around the tubular member through the insulating material; And a power supply device that applies low frequency alternating current to the induction coil. By operating the power supply device, low frequency alternating current is applied to the coil to heat the tubular member itself, and the oil in the container is vaporized.

In the present invention, the wall surface of the tubular member of the oil vapor generator extends in the rising direction, and two of the hollow portions that are annular in the circumferential direction The sides respectively form a cylindrical inner wall and an outer wall to form a double structure, and the induction coil can be wound around the atmospheric side of the inner wall through the insulating material. In the present invention, the induction coil of the oil vapor generator is composed of an insulated and heat-resistant electric wire.

The vacuum film forming apparatus of the present invention includes an exhaust device that evacuates a vacuum chamber, and the oil diffusing pump of the present invention can be used as the exhaust device.

The oil vapor generator assembled in the oil diffusion pump of the present invention is wound around the tubular member (which eventually becomes a heat generating body) made of a material to be heated by an induction coil through an insulating material, and is applied as an operating oil heating source. Low frequency alternating current is applied to the coil to heat the barrel member itself, and the heat of action is vaporized by this heat.

That is, according to the oil vapor generator assembled in the oil diffusion pump of the present invention, the coil is not heated, but low frequency alternating current is applied to the coil, and a magnetic flux that is locked up and down is generated in the rising direction of the tubular member, whereby the magnetic flux is An induced current is generated in the tubular member, that is, an eddy current is generated, thereby generating Joule heat (low frequency induction heating). This heat is used to heat the tubular member itself (the tubular member itself is heated), thereby heating the working oil. Therefore, the heating function is basically not lost due to the disconnection. Since all of the current is consumed as the tubular member itself as a heating element, leakage does not occur due to insulation failure. Instead of heating the coil and applying low-frequency alternating current to the coil to heat the tubular member itself, the coil itself does not become a heating element, and the contact failure of the terminal block does not occur at a high temperature. Further, from the viewpoint of the property of locally heating the hydraulic oil source, there is an advantage that the degree of freedom of selection of the arrangement place of the coil is increased.

The oil diffusion pump of the present invention is assembled with the oil vapor generation of the present invention Therefore, it is possible to consume the entire current applied to the coil of the oil vapor generator on the tubular member as the heat generating body. As a result, there are a plurality of advantages, for example, it is possible to improve the heat responsiveness of the heating element, to improve the energy efficiency, and to consume less energy, and to shorten the heating temperature rise time of the working oil (the startup time is shortened).

In the oil vapor generator of the present invention, the heat generating body wound around the induction coil, that is, the upper end in the rising direction of the tubular member is exposed from the oil surface of the moving oil to be contacted, so that the oil vapor rising from the oil surface is in contact with The upper portion of the inner wall of the tubular member exposed from the oil surface is further heated to generate sufficiently heated oil vapor. As a result, in the oil diffusion pump to which such an oil vapor generator is attached, the heating rate of the hydraulic oil can be increased in a shorter time, which is extremely advantageous from the viewpoint of energy efficiency.

1‧‧‧Vacuum film forming device

8‧‧‧Action oil

10‧‧‧(vacuum) chamber

21‧‧‧ pipeline

23‧‧‧Attraction line

25‧‧‧Differential pipeline

26‧‧‧pipe

27‧‧‧pipe

28‧‧‧pipes

29‧‧‧pipe

31‧‧‧Main exhaust valve

33‧‧‧Leak valve

35‧‧‧Rough exhaust valve

37‧‧‧Auxiliary valve

39‧‧‧Leak valve

50‧‧‧Oil diffusion pump

51‧‧‧Shell

53‧‧‧Spray device

53a‧‧‧Nozzles

55‧‧‧Inhalation Department

57‧‧‧Exhaust Department

59‧‧‧ oil storage tank

60‧‧‧ Rotary pump (oil rotary vacuum pump)

70‧‧‧Oil vapour generator

71‧‧‧Frame (cylinder)

71a‧‧‧ Hollow

71b‧‧‧ frame wall

71c‧‧‧ frame outer wall

71d‧‧‧The upper wall of the frame

72‧‧‧Under the cover

73‧‧‧Insulation materials

74‧‧‧heating body

75‧‧‧Induction coil

76‧‧‧heating components

77‧‧‧pipe

78‧‧‧ iron core

79‧‧‧ rim

L‧‧‧ oil noodles

U‧‧‧Upper

Fig. 1 is a schematic structural view of a vacuum film forming apparatus according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view showing an example of an oil diffusion pump used in the vacuum film forming apparatus of Fig. 1 .

Fig. 3 is a schematic structural cross-sectional view showing an example of a main part of an oil vapor generator used in the oil diffusion pump of Fig. 2.

Fig. 4 is a cross-sectional view taken along line IV-IV of Fig. 3.

Fig. 5 is a partial cross-sectional view of the oil vapor generator used in the oil diffusion pump, which corresponds to the other aspects of Fig. 3.

Fig. 6 is a partial cross-sectional view of the oil vapor generator used in the oil diffusion pump, which corresponds to the other aspects of Fig. 3.

Fig. 7 is a view showing another example of the configuration of the oil vapor generator incorporated in the oil diffusion pump of this example.

Fig. 8 is a view showing another example of the configuration of the oil vapor generator incorporated in the oil diffusion pump of this example.

Hereinafter, an example of the present invention will be described based on the drawings. As shown in Fig. 1, the vacuum film forming apparatus 1 of the present embodiment has a vacuum chamber (vacuum container) 10 as a main body of the apparatus, and various equipments necessary for film formation (film formation) are disposed inside, for example: A film formation source (not shown) such as an evaporation source or a sputtering source, or a substrate holder or the like that holds a substrate to be processed. The chamber 10 is connected to the downstream side of the line 21. A pressure gauge (not shown) is also connected to the chamber 10 to detect the air pressure (vacuum degree) in the chamber 10.

The upstream side of the line 21 is connected to the downstream side of the suction line 23 through the main exhaust valve 31. An intake portion 55 of an oil diffusion pump (oil diffusion vacuum pump) 50 is connected to the upstream side of the suction line 23. The downstream side of the branch line 25 is connected to the middle of the line 21. A downstream side of the line 26 is connected to the branch line 25, and a leak valve 33 is connected to the upstream side of the line 26.

The upstream side of the branch line 25 is connected to the downstream side of the line 27 through the coarse exhaust valve 35. A rotary pump (oil rotary vacuum pump) 60 is connected to the upstream side of the line 27. The downstream side of the line 28 is connected to the middle of the line 27. The upstream side of the line 28 is connected to the exhaust portion 57 of the oil diffusion pump 50 through the auxiliary valve 37. The line 27 is also connected to the downstream side of the line 29 at the connection of the line 28, and a leak valve 39 is provided on the upstream side of the line 29. A vacuum gauge (not shown) is connected to the pipe 28 for detecting the air pressure (vacuum degree) in the oil diffusion pump 50.

The vacuum film forming apparatus 1 of the present example has a control device (not shown) that controls the operation of the device 1 in addition to the above configuration. The control device provided in this example includes a main control circuit (not shown) including a processing circuit such as a CPU (Central Processing Unit), a memory element (memory) built in the control circuit, and control of the operation of the rotary pump 60. The rotary pump control circuit (not shown) and the oil diffusion pump control circuit (not shown) that controls the operation of the oil diffusion pump 50.

The main control circuit is connected to a vacuum gauge drive circuit (not shown) and is connected to a vacuum gauge connected to the line 21. The main control circuit is connected to the respective valves (main exhaust valve 31, leak valve 33, 39, rough exhaust valve 35, auxiliary valve 37) which are opened and closed in accordance with the predetermined program command of the main control circuit. Since the oil diffusion pump 50 is connected to the rotary pump 60, the gas discharged from the oil diffusion pump 50 through the auxiliary valve 37 can be sucked by the rotary pump 60 and discharged through a path not shown.

The rotary pump 60 of this example is used to complete the auxiliary pump, and the back pressure of the oil diffusion pump 50P used as the main pump is maintained below the critical value, so the rotary pump 60 is also used as the coarse exhaust. The pump is used. The rotary pump 60 can be constituted, for example, by an oil rotary pump such as a rotary airfoil. The rotary airfoil oil rotary pump has a rotating rotor in the cylinder. The cylinders have mutually independent open and exhaust ports. The rotor is fitted with a movable valve, and the outer edge of the valve is pressed against the inner wall of the cylinder by the centrifugal force of the rotor. As a result, when the rotor rotates, the volume of the rotor, the valve, and the inner wall of the cylinder is changed, thereby becoming a mechanism for sending out the gas.

As shown in Fig. 2, the oil diffusion pump 50 of this example has a cylindrical container (housing) 51 whose bottom is closed. An oil vapor generator 70 is disposed at the bottom of the casing 51, and the hydraulic oil is heated to be vaporized. A jet flow device 53 is disposed in the casing 51, and the steam of the working oil 8 (see FIG. 3) heated by the oil vapor generator 70 is sucked therein. The oil vapor that has risen after the injection is ejected in the exhaust direction through the nozzle 53a. The upper end of the casing 51 is provided with an intake portion 55, and the side surface of the casing 51 is provided with an exhaust portion 57.

Next, the operation of the oil diffusion pump 50 will be described. When the main exhaust valve 31 is opened and the oil vapor generator 70 is operated, the hydraulic oil 8 is heated by the oil vapor generator 70 to around 230 ° C to be vaporized (oil vapor), and is ejected from the nozzle 53a into the side wall of the casing 51. surface. By this injection, the suction gas (the air in the chamber 10) sucked by the intake unit 55 is sprayed in the traveling direction of the jet flow, and is discharged from the exhaust portion 57. Thereby, the inside of the chamber 10 is evacuated. The small circle in Fig. 2 schematically shows the state of the oil vapor after the oil vaporization. In order to prevent the hydraulic oil 8 from entering the chamber 10, the oil vapor is ejected from the nozzle 53a, and the suction portion 55 is opened.

Further, since the casing 51 is cooled by the water-cooling pipe 58, the oil vapor of the hydraulic oil 8 adhering to the inner wall of the casing 51 is cooled and condensed, and is returned to the sump 59 below the casing 51, and then by the oil vapor generator 70. Heating and re-vaporizing to form a cyclical mechanism.

As shown in the third and fourth figures, the oil vapor generator 70 of the present example is disposed at the bottom of the casing 51 of the oil diffusion pump 50 shown in Fig. 2, and has a cylindrical casing (cylinder member) 71. It is made of a material to be heated and is used as a part of a vacuum container. As the material to be heated, at least one of stainless steel, carbon steel, and a rolled steel for general structure defined by JIS-G3101 can be used.

For the stainless steel, for example, all kinds of SUS such as SUS304, SUS303, SUS302, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, SUS430F, and SUS302 can be used. The carbon steel contains high carbon steel such as low carbon steel such as mild steel material and low carbon steel such as hard steel material. The rolled steel for general construction includes SS330, SS400, SS490, SS540.

Among them, it is preferable to form a frame 71 by applying a plating treatment to a ferromagnetic material having a low electrical resistance such as a soft steel material or the like having an impedance ratio of about 10 × 10 ^-8 Ωm to about 20 × 10 ^-8 Ωm. When the frame 71 is formed of a ferromagnetic material (soft steel or the like) having a low electrical impedance, the amount of eddy current generated on the induction coil 75 is increased due to the low electrical impedance, and as a result, the frame body 71 itself is self-heated. The amount becomes large, and higher heating efficiency can be expected. It is also a good choice to form the frame 71 with the general steel SS400. In addition to these, the frame 71 may be formed by bonding a stainless steel sheet to the atmosphere-side surface of the material to be heated to form a stainless steel-coated steel sheet.

The frame body 71 extends in the rising direction (up-and-down direction), and the cylindrical inner wall 71b and the outer frame wall 71c which are arranged concentrically are formed on both sides of the annular hollow portion 71a in the circumferential direction, forming a double structure. However, the upper surfaces of the inner and outer outer walls 71b and 71c are closed by the annular frame upper wall 71d, and the lower surfaces of the inner and outer outer walls 71b and 71c are annularly opened. The lower surface of the casing 71 (the inner wall 71b of the casing) is closed by the lower cover 72. In this example, the area surrounded by the inner wall 71b and the lower cover 72 constitutes an oil sump 59 (see FIG. 2), and the hydraulic oil 8 is filled and stored therein. For example, when the inner wall 71b and the outer wall 71c of the frame are formed at a height of 120 mm, when the operation of the oil vapor generator 70 is stopped, the hydraulic oil 8 is filled so that the height of the oil surface L is about 30 mm. In this case, when the oil vapor generator 70 starts to operate, the oil level L of the hydraulic oil 8 is lowered to, for example, about 10 mm. In this example, it is preferable that the inner wall 71b of the frame and the outer wall 71c of the frame are formed in a range of 5 mm to 12 mm in thickness. In particular, in the case of low-frequency induction heating, it is advantageous that the thickness of the inner wall 71b of the heating element is thicker from the viewpoint of current permeation (for example, 8 mm to 10 mm). about).

The periphery of the inner wall 71b of the casing (the side of the hollow portion 71a, on the atmospheric side in this example) is wound around the induction coil 75 through the insulating material 73. The insulating material 73 can be formed, for example, of a polyimide film having a thickness of about 10 μm to 180 μm.

The wire constituting the induction coil 75 is a heat-resistant electric wire having a low electrical resistance and an insulating material having a high heat-resistant temperature. Such a wire is, for example, an oxidized alumite wire or the like. The diameter of the wires constituting the induction coil 75 can be selected from the range of 2 mm to 4 mm. The number of turns of the induction coil 75 can be selected from 7 to 14 turns.

Further, the induction coil 75 is connected to a power supply device (not shown) for applying a current of the induction coil 75 (a low-frequency alternating current of several tens of Hz to several hundred Hz) and a control device (control device) for the power supply.

In order to maintain the vacuum, the frame 71 requires strength (thickness). Therefore, when a high frequency is used, there are the following problems: (1) The skin 71 of the heat generating body (especially the inner wall 71b of the frame) is likely to have a skin effect. The skin effect refers to the inner wall 71b of the frame which has a certain thickness by focusing on the conductor, and it is found that the temperature rise is not easily transmitted to the inside as compared with the case where the temperature of the skin near the outer side is increased. When such a skin effect is found, the heating efficiency of the working oil is deteriorated. (2) Not only the heating efficiency of the operating oil is deteriorated, but also the long-term running oil diffusion pump is accompanied by an increase in the temperature of the induction coil 75 itself.

When the high frequency is used, there are the following problems: (3) In order to generate a high frequency, an expensive inverter is required, and as a result, the cost of the device may increase. (4) In the case where a plurality of heating blocks are provided, the induced current interference or the generation of high-frequency noise for each of the heating blocks may also affect a plurality of machines.

In this case, in order not to cause these problems, the low frequency current is used. The current applied to the induction coil 75 for the power supply device.

Next, the operation of the oil vapor generator 70 will be described. The power supply device operates, and the induction coil 75 is applied with, for example, an alternating current of a voltage of 200 V (rms), a current of 12 A (rms), a frequency of 50 Hz or 60 Hz, and a magnetic flux that is locked up and down in the rising direction of the casing 71 (the inner wall 71b of the casing). Thereby, the magnetic flux generates an eddy current in the casing 71 (the inner wall 71b of the casing) to generate Joule heat (low frequency induction heating). By using this heat, the casing 71 (the inner wall 71b) itself is heated, and the hydraulic oil 8 stored in the casing 71 (the area surrounded by the inner wall 71b and the lower cover 72) is directly heated. When the oil vapor rising from the oil surface in the casing 71 comes into contact with the upper portion of the inner wall 71b of the casing which is exposed from the oil surface and becomes hot, it is further heated to become a sufficiently heated high-temperature oil vapor and rise to the jet flow. Inside the device 53, it is ejected from the nozzle 53a.

As described above, since the casing 51 of the oil diffusion pump 50 is cooled by the water-cooling pipe 58, the oil vapor of the hydraulic oil 8 adhering to the inner wall of the casing 51 is cooled and condensed, and is returned to the oil reservoir 59 below the casing 51. The oil reservoir 59 communicates with the lower cover 72 with respect to the region surrounded by the inner wall 71b and the lower portion 72. Therefore, the hydraulic oil 8 that has been condensed and returned is reheated and vaporized by the oil vapor generator 70, and circulated.

In the oil vapor generator 70 of the present embodiment, the induction coil 75 is wound around the insulating frame 75 around the cylindrical casing 71 (in the inner wall 71b of the present example) made of a material such as mild steel or SS400. The heating source of the oil 8 heats the inner wall 71b of the casing by applying a low-frequency current to the induction coil 75, and the operating oil 8 is vaporized by this heat. Since the induction coil 75 is not heated, there is no problem of disconnection, and the heating function does not disappear due to disconnection. In addition, there is no leakage due to poor insulation. Moreover, since the induction coil 75 is not heated, the induction coil 75 itself does not become a heating element, and the contact of the terminal block due to high temperature does not occur. bad. Since the oil vapor generator 70 of this example is mounted with the oil vapor generator 70 of this example, the entire current of the induction coil 75 flowing through the oil vapor generator 70 can be consumed in the casing 71 (in the inner wall 71b of this example). ) itself. As a result, the heat responsiveness of the casing 71 as the heating element can be improved, the energy efficiency is high, the energy consumption is small, and the heating temperature rise time of the hydraulic oil 8 can be shortened (the startup time of the pump 50 can be shortened). ). In the oil vapor generator 70 of the present example, the heat generating body that surrounds the induction coil 75, that is, the upper end U of the casing 71 (the inside of the casing 71b) in the rising direction is exposed from the oil surface L of the moving oil to be contacted, The oil vapor rising from the oil surface L comes into contact with the upper portion of the inner wall 71b of the casing exposed from the oil surface L, whereby it is further heated to generate sufficiently heated oil vapor. As a result, in the oil diffusion pump 50 to which the oil vapor generator 70 of this example is attached, the heating rate of the hydraulic oil 8 can be increased in a shorter time, which is extremely advantageous from the viewpoint of energy efficiency.

The above examples are examples for making the invention easier to understand, and are not intended to limit the invention. Therefore, each element disclosed in the above embodiments includes all design changes or equivalents within the technical scope of the present invention.

For example, in the above-described example, the induction coil 75 is wound around the inner wall 71b (the atmosphere side) formed of the mild steel material or the SS400 through the insulating material 73. However, the present invention is not limited to this form, and for example, the following can also be used. The structure (see Fig. 5) is used to realize the effect of this example.

The tubular heat generating body 74 is disposed to extend on the inner wall surface (the vacuum side in contact with the hydraulic oil 8) of the inner wall 71b of the casing. The upper end U of such a heating element 74 is preferably exposed from the oil surface L of the stored hydraulic oil 8. The heating element 74 is formed of a steel material (stainless steel, carbon steel, rolled steel for general structure, stainless steel coated steel sheet, or the like) of the above-described example.

At least a member existing between the heating element 74 and the induction coil 75 is formed of a material having a heat resistance, a high electrical insulating property, and a heat insulating property (stainless steel) (in this example, at least the inner wall 71b of the casing) may be a frame. Body 71)). The heat of the heating element 74 can be used to heat the working oil more efficiently. Further, it is preferable that the member (inside wall 71b) is tightly joined to the heat generating body 74. Thereby, heat conduction can be made more efficient and the working oil can be heated efficiently.

A heat radiating member 76 formed of a material having heat resistance, high electrical insulating properties, and high thermal conductivity (for example, aluminum nitride) is disposed around the induction coil 75. The coil temperature is placed on the outer wall (the outer wall 71c of the frame, etc.) to efficiently dissipate heat and lower the coil temperature. A core 78 of a magnetic sheet material is disposed around the heat radiating member 76. Improve the power factor of the pump and improve the efficiency of power use. The rim 79 is disposed such that it supports the induction coil 75 or the core 78 from the atmosphere side (from the lower side of the paper in Fig. 5) for fixing the induction coil 75 or the core 78 to the pump.

Alternatively, the effect of this example can be achieved by, for example, the structure shown below (see Fig. 6). The inner wall 71b itself can be constituted by the tubular heat generating body 74. At this time, the insulating material 73 (for example, a polyimide film having a thickness of about 10 μm to 180 μm or the like) is interposed between the induction coil 75 and the heating element 74. The other parts are the same as the frame of Figure 5.

In the frame of the third embodiment, the rim 79 shown in FIGS. 5 and 6 is omitted. However, the frame of the third embodiment can be supported from the atmosphere side by using the same rim.

In the above example, the single oil diffusion pump is provided with one oil vapor generator 70. However, the present invention is not limited to this example, and in particular, when reviewing the enlargement of the oil diffusion pump, for example, as shown in Figs. A plurality of oil vapor generators 70 of this example may be disposed at the bottom of the housing 51.

Next, examples (embodiments) and comparative examples of the present invention will be described. [Examples] In the present example, an oil diffusion pump 50 (Fig. 2) in which one oil vapor generator 70 (Fig. 3) was assembled as an operating oil heating source was prepared and evaluated under the following conditions.

(Oil diffusion pump 50) Diameter of exhaust port: 250mm, exhaust speed: 2900L/sec, arrival pressure in vacuum chamber: 6.7×10 ^-6 Pa (Pascal), power required: 0.7KW, operating oil: LION S, 1L.

(Oil vapour generator 70) The height of the inner wall 71b and the outer wall 71c of the frame is 120 mm, and the height L of the oil surface L of the hydraulic oil is 30 mm (at the time of stopping) and 10 mm (during operation).

[Comparative Example] In this example, an oil diffusion pump of a conventional structure was prepared, and an electric heater using a heating wire (nickel wire) as a heating oil source was placed at the bottom of the pump, and evaluated under the following conditions.

(Conventional oil diffusion pump) the diameter of the exhaust outlet: 250mm, exhaust velocity 2900L / sec, reaches the pressure in the vacuum chamber: 6.7 × 10 ^-6 Pa (pascal) or less, require electrical power: 2.0KW (200V) , action oil: LION S, 1L.

[Evaluation] The oil diffusion pump of each example was used to detect the running electric power. Specifically, the power supply to the nickel wire (comparative example) and the induction coil (invention) is detected by a hook gauge electric power meter, and the electric power (electrical power at startup, electric power during operation) is calculated from voltage, current, and power factor. The ratio of the examples to the comparative examples was calculated (for the conventional ratio). As a result, the operating electric power of the embodiment was reduced by 40% from the conventional ratio at the time of starting, and the conventional ratio was reduced by 65% during the operation, and it was found that the power consumption can be greatly reduced at the time of startup and operation.

For each example, the oil diffusion pump detects the temperature (side, bottom). As a result, the side temperature (atmospheric side) of the examples was 170 °C. This is 26% less than the comparative example (230 ° C). Therefore, it has been confirmed that it is possible to concentrate heating on the inner cylinder of the boiler, contributing to the reduction of power consumption. On the other hand, the bottom surface temperature of the Example was 120 ° C, which was found to be able to greatly suppress heat loss as compared with the comparative example (red hot state) in which the red hot heating block was exposed and was extremely high. Moreover, it can be understood that a good level can be achieved without considering the ground damage.

8‧‧‧Action oil

51‧‧‧Shell

59‧‧‧ oil storage tank

70‧‧‧Oil vapour generator

71‧‧‧Frame (cylinder)

71a‧‧‧ Hollow

71b‧‧‧ frame wall

71c‧‧‧ frame outer wall

71d‧‧‧The upper wall of the frame

72‧‧‧Under the cover

73‧‧‧Insulation materials

75‧‧‧Induction coil

77‧‧‧pipe

L‧‧‧ oil noodles

U‧‧‧Upper

Claims (4)

An oil diffusion pump is provided with an oil vapor generator in a jet flow device inside a casing, and the oil vapor generator operates to vaporize the hydraulic oil into oil vapor, and the oil vapor is ejected from the jet flow device for suction. a gas exhausting operation, the oil vapor generator comprising: a container, the wall surface extending in a rising direction, the lower end of the tubular member formed of the heated material is closed, the inside is used for storing oil; and the induction coil is wound around the insulating material a periphery of the tubular member; a power supply device that applies a low-frequency alternating current of several tens Hz to several hundreds Hz to the induction coil; a wall surface of the tubular member extends in a rising direction, and a hollow portion that is annular in a circumferential direction The two sides respectively form a cylindrical inner wall and an outer wall to form a double structure, and the induction coil is wound around the atmospheric side of the inner wall through the insulating material; wherein the tubular member is heated by operating the power supply device By itself, the oil in the container is vaporized. An oil diffusion pump is provided with an oil vapor generator in a jet flow device inside a casing, and the oil vapor generator operates to vaporize the hydraulic oil into oil vapor, and the oil vapor is ejected from the jet flow device for suction. An exhausting action of the gas, the oil vapor generator comprising: a container, the wall surface extending in a rising direction, closing a lower end of the tubular member formed of the heated material, and storing the inside for storing oil; and an induction coil wound around the tubular member Surrounding; power supply device, applying low frequency alternating current of several tens Hz to hundreds of Hz to the induction a coil; the wall surface of the tubular member extends in a rising direction, and a cylindrical inner wall and an outer wall are respectively formed on both sides of the hollow portion that is annular in the circumferential direction, forming a double structure, which is composed of a material to be heated The tubular heat generating body is disposed to extend along an inner wall surface of the vacuum side of the inner wall, and the induction coil is wound around an atmosphere side of the inner wall; wherein the heating element is heated by operating the power supply device, The oil in the container is vaporized. The oil diffusion pump according to claim 1 or 2, wherein the induction coil is composed of an insulated and heat-resistant electric wire. A vacuum film forming apparatus comprising an exhaust device for evacuating a vacuum chamber, the exhaust device using the oil diffusion pump according to any one of claims 1 to 3.