JP2021008829A - Vacuum generator - Google Patents

Abstract

To provide a vacuum generator by which desired exhaust performance can be stably obtained while improving productivity.SOLUTION: A valve part 30 of an opening/closing valve 12, a nozzle 32, a vacuum generation part 34 and a suction port 16 communicating with the vacuum generation part 34 are arranged in a flow passage 26 in an order of a flow direction of a working fluid, and the flow passage 26 has a first path 56 extending from an inlet 26a, and reaching the valve part 30, a second path 58 extending from the valve part 30, a third path 60 extending from the second path 58 in a direction intersecting with the second path 58, and a fourth path 62 extending from the third path 60 in a direction intersecting with the third path 60, and reaching the nozzle 32. The second path 58 includes a plurality of first branch paths 58a, and the valve part 30 has an inlet port 80 connected with the first path 56, and a plurality of outlet ports 82 connected with the plurality of first branch paths 58a, respectively.SELECTED DRAWING: Figure 4

Description

The present invention relates to a vacuum generator, and more particularly to a vacuum generator for evacuating process gas from a gas cylinder housed in a cylinder cabinet arranged in a semiconductor manufacturing apparatus.

Patent Document 1 discloses a vacuum exhaust device having a vacuum generating portion in a flow path of a working gas and capable of evacuating from a connecting pipe communicating with the vacuum generating portion. This device is, in other words, a vacuum generator, which includes a body, a check valve, a shutoff valve, a nozzle, and a connecting pipe. The working gas is an inert gas such as nitrogen gas. The body is formed with a flow path having an inlet and an outlet for working gas on the same side thereof. A check valve is provided at the inlet of the flow path to prevent backflow of working gas from downstream to upstream.

The shut-off valve is an on-off valve, which is provided downstream of the check valve and has a valve portion that shuts off or communicates with the flow path by opening and closing. On the other hand, the nozzle is provided at the outlet of the flow path and throttles the working gas after flowing through the shutoff valve to generate a negative pressure in the vacuum generating portion formed downstream of the nozzle. The connection pipe is a suction pipe that is communicated with the vacuum generating portion and connected to the gas cylinder to be exhausted, and sucks the process gas remaining in the gas cylinder by the negative pressure generated in the vacuum generating portion. The sucked process gas is exhausted from the outlet of the flow path together with the working gas, and the vacuum exhaust of the gas cylinder is performed in this way.

Japanese Patent No. 4444622

The nozzle narrows the cross-sectional area of the flow path in the throttle hole, accelerates the flowing working gas, and ejects it from the throttle hole as a high-speed jet stream. The drawing hole is formed by drilling a fine hole of, for example, about 0.75 mm in a metal member. Since the drill used has a small diameter, it is easily broken during drilling, and an expensive high-hardness drill is often used or replaced after drilling several times. Therefore, there is a problem that the productivity of the vacuum generator is lowered.

Further, depending on the required specifications of the vacuum generator, it may be desired to flow a large flow rate of working gas as compared with the conventional one to achieve a desired exhaust performance. However, if the diameter of the throttle hole is made too small, the flow rate of the working gas flowing through the nozzle is limited, and it takes a long time to evacuate the gas cylinder. Further, if the diameter of the throttle hole is made too small, if the working gas contains solid impurities, the throttle hole may be blocked by the impurities. In these cases, the desired exhaust performance of the vacuum generator may not be achieved.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a vacuum generator capable of stably achieving desired exhaust performance while improving productivity. is there.

The present invention can be realized as the following aspects.
The vacuum generator according to this embodiment communicates with the valve portion, the nozzle, the vacuum generating portion, and the vacuum generating portion of the on-off valve in the order of the flow direction of the working gas through the flow path of the working gas having the inlet and the outlet opened in the body. Equipped with a suction port, the working gas is supplied from the inlet and ejected from the nozzle to generate a negative pressure in the vacuum generating part, and the vacuum exhaust is made from the exhaust target connected to the vacuum generating part via the suction port toward the outlet. The flow path is a first path extending from the inlet to the valve portion, a second path extending from the valve portion, and a third path extending from the second path to the second path in a direction intersecting the second path. And a fourth road extending from the third road in a direction intersecting the third road to the nozzle, the second road includes a plurality of first branch roads, and the valve portion is connected to the first road. It has an inlet port and a plurality of exit ports to which a plurality of first branch paths are connected.

Further, in the vacuum generator described above according to this aspect, the inlet port is located at the center of the valve bottom wall of the valve portion in the radial direction, and the plurality of outlet ports are located around the inlet port of the valve bottom wall.
Further, in the vacuum generator described above according to this aspect, the third path includes a plurality of second branch paths to which a plurality of first branch paths are connected to each other.

Further, in the vacuum generator described above according to this aspect, the third path includes a combined flow path of a plurality of second branch paths.
Further, in the vacuum generator described above according to this aspect, the flow path cross-sectional area of the combined flow path of the third road is equal to or larger than the total flow path cross-sectional area of the flow path cross-sectional areas of the plurality of second branch roads.

Further, in the vacuum generator described above according to this aspect, the flow path cross-sectional area of the combined flow path of the third road is equal to or larger than the total flow path cross-sectional area of the flow path cross-sectional areas of the plurality of first branch paths.

According to the above-described aspect of the present invention, it is possible to provide a vacuum generator capable of stably achieving desired exhaust performance while improving productivity.

It is a front view of the vacuum generator which concerns on one Embodiment of this invention. It is a top view which looked at the vacuum generator from the direction A of FIG. It is a side view which looked at the vacuum generator from the B direction of FIG. It is sectional drawing including a part appearance of a vacuum generator. It is a flow chart which shows the flow path composition of a vacuum generator. FIG. 4 is a cross-sectional view clearly showing the positional relationship between the two first branch paths and the two exit ports. It is sectional drawing of the 1st member seen from the CC direction of FIG. It is a figure which showed the positional relationship between the two first branch roads and two exit ports seen from the CC direction of FIG. It is an enlarged view of the cross section of the nozzle of FIG. FIG. 5 is a cross-sectional view of a first member having two first branch paths according to a modified example of the present invention.

Hereinafter, the vacuum generator according to the embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a front view of the vacuum generator 1 (hereinafter, also referred to as VG1). The VG1 is, for example, an exhaust unit for evacuating the process gas remaining in a gas cylinder (cylinder, exhaust target) (not shown). One or more gas cylinders are housed in, for example, a cylinder cabinet arranged in a semiconductor manufacturing apparatus (not shown). The gas cylinder from which the residual process gas has been exhausted by the VG1 is replaced with a new gas cylinder filled with the process gas.

The VG1 has a rectangular parallelepiped body 2 made of metal, and an inlet port 4 and an outlet port 6 for working gas are provided so as to project from an access surface 2a formed on the same side of the body 2. Connecting nuts 8 and 10 are attached to the outer ends of the inlet and outlet ports 4 and 6, respectively. The working gas is an inert gas such as compressed nitrogen gas, which is supplied to the VG1 via a tube (not shown) connected to the nut 8 of the inlet port 4.

The working gas flowing through the VG1 and the process gas sucked from the gas cylinder are exhausted through a tube (not shown) connected to the nut 10 of the outlet port 6. Further, the actuator 14 of the on-off valve 12 is provided so as to project from the back surface 2b on the opposite side of the access surface 2a of the body 2.

FIG. 2 shows a plan view of VG1 viewed from the direction A of FIG. 1, and FIG. 3 shows a side view of VG1 viewed from the direction B of FIG. A suction port 16 is provided so as to project from the side surface 2c of the body 2 orthogonal to the access surface 2a and the back surface 2b. A nut 18 for connection is attached to the outer end of the suction port 16. A tube or the like (not shown) communicating with the gas cylinder is connected to the nut 18 of the suction port 16, and the process gas remaining in the gas cylinder is sucked through the suction port 16.

When viewed in FIGS. 1 and 3, the body 2 is vertically divided into a first member 20 on the inlet port 4 side and a second member 22 on the exit port 6 side. The first fastening surface 20a of the first member 20 and the second fastening surface 22a of the second member 22 are matched, and four bolts 24 with hexagonal holes are inserted from the second member 22 side to form the first member 20. By connecting with the second member 22, one rectangular parallelepiped body 2 is formed.

FIG. 4 shows a cross-sectional view including a partial appearance of the VG1. The body 2 is formed with a working gas flow path 26 in which the inlet 26a and the outlet 26b are open. The flow path 26 is provided with a check valve 28, a valve portion 30 of the on-off valve 12, a nozzle 32, a vacuum generating portion 34, and the like in the order of the flow direction of the working gas. The check valve 28 is accommodated in the check valve mounting hole 36 formed at the inlet 26a of the flow path 26 via the union body 38, and prevents the backflow of the working gas from the downstream to the upstream in the flow path 26. The union body 38 is attached to the check valve mounting hole 36 by screwing or the like. The inlet port 4 is connected to the outer end of the union body 38.

The on-off valve 12 includes an actuator 14 and a valve portion 30, and the valve portion 30 is provided downstream of the check valve 28 and is attached to a valve portion mounting hole 40 opened in the back surface 2b of the body 2 by screwing or the like. ing. The on-off valve 12 is, for example, a diaphragm-type shut-off valve that opens and closes the valve portion 30 by an air-driven actuator 14. The valve portion 30 includes a valve seat 42, a diaphragm 44, and the like, and the diaphragm 44 separates from and contacts the valve seat 42 by the operation of the actuator 14, thereby blocking or communicating with the flow path 26.

The nozzle 32 is housed in a nozzle mounting hole 46 formed at the outlet 26b of the flow path 26. A diffuser 48 is inserted on the downstream side of the nozzle 32 of the nozzle mounting hole 46, and the diffuser 48 is attached to the access surface 2a at the outlet 26b by fixing means such as screwing or welding.

The vacuum generating portion 34 is a space formed between the nozzle 32 of the nozzle mounting hole 46 and the diffuser 48. The nozzle 32, the vacuum generating unit 34, and the diffuser 48 form a so-called ejector 50, and the working gas is accelerated by flowing through the nozzle 32 having a narrow cross-sectional area of the flow path 26 to become a high-speed jet stream, and this high-speed jet stream becomes a vacuum. After being released once by the generating unit 34, it flows through the diffuser 48.

Since the suction port 16 is communicated with the vacuum generation unit 34, the process gas remaining in the gas cylinder is sucked through the suction port 16 by the negative pressure generated in the vacuum generation unit 34 due to the so-called ejector effect. The process gas sucked from the gas cylinder is exhausted from the outlet port 6 together with the working gas.

The first member 20 constituting the body 2 includes a working gas inlet 26a, an inlet port 4, a check valve 28, and an on-off valve 12, and constitutes a working gas supply section 52 in the VG1. On the other hand, the second member 22 constituting the body 2 includes an outlet 26b and an outlet port 6, an ejector 50 composed of a nozzle 32, a vacuum generating unit 34, and a diffuser 48, and a suction port 16, and is a process in the VG1. It constitutes a gas exhaust section 54.

The flow path 26 has a third path 60 extending from the first member 20 to the second member 22 between the valve portion 30 and the nozzle 32. Specifically, the flow path 26 has a first road 56 extending from the inlet 26a via the check valve 28 to the valve portion 30, a second road 58 extending from the valve portion 30, and a second road 58 to the second road. It has a third road 60 extending in a direction intersecting the 58, and a fourth road 62 extending from the third road 60 in a direction intersecting the third road 60 to reach the nozzle 32.

Further, in the flow path 26, the first curved road 64 that smoothly connects the second road 58 and the third road 60, and the second curved road 66 that smoothly connects the third road 60 and the fourth road 62. And are formed. More specifically, the first road 56 and the second road 58 are straight roads that are substantially parallel to each other, and the third road 60 is in a direction that intersects substantially vertically from the end of the second road 58 via the first curved road 64. It is a straight road that extends, and the fourth road 62 is a straight road that extends from the end of the third road 60 through the second curved road 66 in a direction that intersects substantially vertically.

The first road 56 is formed as a linear elongated hole together with the check valve mounting hole 36 and the valve portion mounting hole 40 by drilling the first member 20 of the body 2 from the access surface 2a or the back surface 2b side with a drill or the like. It is formed. The second path 58 is formed as a linear elongated hole together with the valve portion mounting hole 40 by drilling the first member 20 of the body 2 from the back surface 2b side with a drill or the like.

The fourth road 62 is formed as a linear elongated hole together with the nozzle mounting hole 46 by drilling the second member 22 of the body 2 from the side of the access surface 2a with a drill or the like. The third road 60 is formed by drilling the first member 20 and the second member 22 from the side of the first fastening surface 20a and the side of the second fastening surface 22a with a drill or the like. When the 20 and the second member 22 are combined, they are formed as continuous linear elongated holes.

An annular grooves 68 and 70 are formed around the openings of the third road 60 on the first and second fastening surfaces 20a and 22a, respectively. An annular gasket 72 is fitted into each of the annular grooves 68 and 70, the first and second fastening surfaces 20a and 22a are matched in this state, and the first and second members 20 and 22 are fastened with the respective bolts 24. As a result, the working gas flowing through the third road 60 does not leak from the minute gap between the first and second fastening surfaces 20a and 22a, and the third road 60 is airtightly formed.

The first curved road 64 is formed from the side of the first fastening surface 20a to the third road 60 after forming the third road 60, or from the side of the back surface 2b after forming the valve portion mounting hole 40 and the second road 58. A ball end mill or the like (not shown) having a hemispherical tip is inserted into the second path 58 and cut. As a result, the first curved road 64 is formed as a curved surface curve that is bent at a right angle, and the second road 58 and the third road 60 are smoothly continuous.

The second curved road 66 is formed from the side of the second fastening surface 22a to the third road 60 after forming the third road 60, or from the side of the access surface 2a after forming the nozzle mounting hole 46 and the fourth road 62. The above-mentioned ball end mill or the like is inserted into the fourth road 62 and cut. As a result, the second curved road 66 is formed as a curved surface curve that is bent at a right angle, and the third road 60 and the fourth road 62 are smoothly continuous. In this way, the flow path 26 of the present embodiment is formed in a stepped shape that is bent at right angles in two steps from the second road 58 to the fourth road 62 when viewed in FIG.

Hereinafter, the operation of the VG1 will be described with reference to the flow chart showing the flow path configuration of the VG1 shown in FIG. In the VG1 having the above-described configuration, when the compressed working gas is supplied from the inlet port 4 to the flow path 26 in the direction of the solid arrow, the working gas is opened through the first path 56 while being blocked from backflow by the check valve 28. It flows through the valve portion 30 of the valved on-off valve 12.

The working gas that has flowed through the valve portion 30 flows in the second path 58, the third path 60, and the fourth path 62 in this order, and further passes through the ejector 50 including the nozzle 32, the vacuum generating section 34, and the diffuser 48. At this time, due to the negative pressure generated in the vacuum generating portion 34, the process gas of the gas cylinder is sucked in the direction of the arrow in the broken line through the suction port 16, and the process gas is exhausted from the outlet port 6 together with the working gas.

Here, in the present embodiment, as shown in FIG. 4, the second road 58 is composed of two first branch roads 58a, and the first road 56 is connected to the valve bottom wall 30a of the valve portion 30. A port 80 and two outlet ports 82 to which the two first branch paths 58a are connected are formed. Note that FIG. 4 shows only a cross section of the two first branch paths 58a so that the two first branch paths 58a and the two outlet ports 82 are represented in order to explain the schematic configuration of the series of flow paths 26. Is shown with a cross section at an angle different from that of the other regions, and the cross section of one of the two first branch paths 58a is omitted in the middle.

FIG. 6 shows an actual cross-sectional view that clearly shows the positional relationship between the two first branch paths 58a and the two exit ports 82 in FIG. Further, FIG. 7 shows a cross-sectional view of the first member 20 as viewed from the CC direction of FIG. Further, FIG. 8 shows a diagram showing the positional relationship between the two first branch paths 58a and the two exit ports 82 as viewed from the CC direction of FIG.

As shown in FIG. 6, the inlet port 80 is located in the radial center of the valve bottom wall 30a, and the two outlet ports 82 are located around the inlet port 80 of the valve bottom wall 30a. Since the valve seat 42 and the diaphragm 44 are arranged at the center of the valve portion 30 in the radial direction, the two outlet ports 82 are formed around the inlet port 80 on the valve bottom wall 30a.

More specifically, the two outlet ports 82 are formed at line-symmetrical positions on both sides of the inlet port 80 in the radial direction. The working gas that has flowed into the valve portion 30 from the inlet port 80 is separated from the valve seat 42 by the diaphragm 44, and is discharged from the two outlet ports 82.

As described above, by providing the valve portion 30 with the two outlet ports 82 and forming the second path 58 from the two first branch paths 58a, the flow path cross-sectional area of the second path 58 of the present embodiment, that is, 2 The total flow path cross-sectional area S1 of the flow path cross-sectional area s1 of the first branch path 58a is double the flow path cross-sectional area S3 as compared with the case where only one second path 58 is provided in the conventional case. Will be done. That is, a working gas having twice the flow rate of the conventional one can be flowed through the second road 58.

The third road 60 is formed with two second branch roads 60a to which the two first branch roads 58a are connected to each other. Further, in the third road 60, a combined flow path 60b of two second branch roads 60a is formed. That is, in the case of the present embodiment, the third road 60 is composed of two second branch roads 60a and a combined flow path 60b. The merging flow path 60b is perforated with the same hole diameter from the first member 20 side to the second member 22 via the gasket 72, and communicates with the fourth path 62 as the third path 60.

The flow path cross-sectional area S of the combined flow path 60b of the third road 60 is equal to the total flow path cross-sectional area S2 of the flow path cross-sectional areas s2 of the two second branch paths 60a, and the flow of the two first branch paths 58a. It is equal to the total flow path cross-sectional area S1 of the road cross-sectional area s1. Hereinafter, in addition to the areas s1, s2, S1, S2, and S, the hole diameter of the first branch path 58a: d1, the hole diameter of the second branch path 60a: d2, and the hole diameter of the confluence 60b: d3. Numerical values are shown in Examples 1 and 2.

(Example 1)
-Hole diameter d1, d2: 3.8 mm
・ Channel cross-sectional area s1, s2: 11.3 mm2
-Total flow path cross-sectional area S1, S2, S: 22.6 mm2
・ Hole diameter d3: 5.38 mm

(Example 2)
-Hole diameter d1, d2: 4.4 mm
・ Channel cross-sectional area s1, s2: 15.2 mm2
-Total flow path cross-sectional area S1, S2, S: 30.4 mm2
-Hole diameter d3: 6.22 mm

In this way, the flow path cross-sectional area S of the combined flow path 60b is doubled as compared with the case where it is the same as the conventional flow path cross-sectional areas s1 and s2, and the third path 60 is operated at twice the flow rate of the conventional one. Gas can flow. When the flow path cross-sectional area S is not exactly equal to the total flow path cross-sectional area S2 and the total flow path cross-sectional area S1, the flow path cross-sectional areas S are the total flow path cross-sectional area S2 and the total flow path, respectively. It is preferably at least slightly larger than the cross-sectional area S1. Further, the hole diameter of the fourth road 62 in this case is substantially the same as the hole diameter d3 of the combined flow path 60b.

FIG. 9 shows an enlarged view of the cross section of the nozzle 32 of FIG. The nozzle 32 accelerates the working gas and ejects it from the throttle hole 32a. The minimum hole diameter d4 of the throttle hole 32a of the present embodiment is formed by drilling a metal first member 20 with a diameter larger than that of the conventional one with a drill or the like.

As described above, in the VG1 of the present embodiment, the second road 58 is composed of two first branch roads 58a, and the valve bottom wall 30a of the valve portion 30 is connected to the inlet port 80 to which the first road 56 is connected. Two outlet ports 82 are formed to which the two first branch paths are connected to each other. As a result, the second path 58 is simply composed of the two first branch paths 58a without requiring a significant change in the body 2, and a larger flow rate of working gas than before from the second path 58 toward the nozzle 32 is required. Can be shed.

Specifically, the flow path cross-sectional area S of the combined flow path 60b of the third road 60 is equal to the total flow path cross-sectional area S1 of the flow path cross-sectional areas s1 of the two first branch paths 58a. As a result, when the hole diameter d1 of the first branch path 58a is formed to be the same as the hole diameter of the conventional second path 58, the flow rate is double that of the conventional one from the second path 58 to the third path 60 and eventually to the nozzle 32. The working gas can flow. Therefore, the diameter of the throttle hole 32a of the nozzle 32 can be increased as compared with the conventional one while maintaining the same exhaust performance as the conventional one, so that the desired exhaust performance can be obtained while improving the productivity of the VG1. It can be realized stably.

Further, the inlet port 80 is located at the center of the valve bottom wall 30a in the radial direction, and the two outlet ports 82 are located around the inlet port 80 of the valve bottom wall 30a. In order to arrange the valve seat 42 and the diaphragm 44, the inlet port 80 is formed in the radial center of the valve bottom wall 30a, but two outlet ports 82 are formed around the inlet port 80 in the valve bottom wall 30a. Therefore, it is possible to stably realize the desired exhaust performance while improving the productivity of the VG1 without requiring a significant change in the valve portion 30.

Further, on the third road 60, two second branch roads 60a to which the two first branch roads 58a are connected are formed. As a result, only by configuring the third road 60 from the two second branch roads 60a, the working gas flowing from the two first branch roads 58a flows into the two second branch roads 60a, respectively, while the third road 60 A larger flow rate of working gas than before can flow toward the nozzle 32.

Specifically, the flow path cross-sectional area S of the combined flow path 60b of the third road 60 is equal to the total flow path cross-sectional area S2 of the flow path cross-sectional areas s2 of the two second branch paths 60a. As a result, when the hole diameter d2 of the second branch path 60a is formed to be the same as the hole diameter of the conventional third path 60, the flow rate is double that of the conventional one toward the third path 60 to the fourth path 62, and eventually the nozzle 32. The working gas can flow. Therefore, it is possible to stably realize the desired exhaust performance while improving the productivity of the VG1.

Further, in the third road 60, a combined flow path 60b of two second branch roads 60a is formed. As a result, a larger flow rate of working gas than before can flow from the third road 60 toward the nozzle 32 without requiring branching of the fourth road 62. Therefore, it is possible to stably realize the desired exhaust performance while improving the productivity of the VG1.

In particular, in the present embodiment, the combined flow path 60b is continuously formed from the first member 20 side to the second member 22 via the gasket 72, and is communicated with the fourth road 62 as the third road 60. Therefore, since only one gasket 72 needs to be provided as in the conventional case, the number of parts of the VG1 does not increase.

Further, the minimum hole diameter d4 of the throttle hole 32a of the nozzle 32 can be made larger than the conventional one. As a result, it is possible to flow a large flow rate of working gas through the VG1 as compared with the conventional one while maintaining the exhaust performance of the VG1 at the same level as the conventional one.

Further, the diameter of the drill used for drilling the throttle hole 32a can be increased as compared with the conventional one. Therefore, since the drill is less likely to break during drilling, it is not necessary to use an expensive high-hardness drill due to concern about breakage, and the number of times the drill is replaced is reduced, so that the productivity of VG1 can be improved. ..

Although the description of one embodiment of the present invention has been completed above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, the combined flow path 60b of the third road 60 may be formed not in the first member 20 but in the second member 22. In this case, as shown in the modified example of FIG. 10, two first branch paths 58a can be formed in the first member 20 as the second path 58 by drilling parallel to each other from the respective outlet ports 82. is there. In this case, although the processing of the first branch path 58a becomes easy, two annular grooves 68a are formed on the first fastening surface 20a of the first member 20, and two gaskets 72 are required.

Further, although not shown, the two first branch paths 58a communicate with the two second branch paths 60a formed on the second member 22 via the two gaskets 72. Further, the combined flow path 60b of the third road 60 is formed in the middle of the third road 60 or at the connection point with the fourth road 62 of the third road 60. Even in the case of this modification, at least the exhaust performance (suction performance) of the VG1 can be maintained at the same level as the conventional one, and a large flow rate of the working gas can be flowed through the VG1 as compared with the conventional one.

Further, the flow path 26 of the present embodiment is mainly composed of the first road 56 to the fourth road 62, both of which are straight roads, and further forms a first curved road 64 and a second curved road 66. However, the flow path 26 is not strictly limited to this configuration. Further, the flow path 26 may be provided with a bleed path (not shown) that allows the flow of working gas that bypasses the valve portion 30. Further, a form in which the check valve 28 is not provided in the VG1 is also allowed.

Further, in the case of the present embodiment, the body 2 is composed of the first member 20 and the second member 22, but the present invention can also be applied to the VG1 having an integral body that is not divided into two. Further, the first branch road 58a forming the second road 58 and the second branch road 60a forming the third road 60 are not limited to two, and three or more may be provided. In this case, a number of outlet ports 82 corresponding to the number of the second branch paths 60a are formed in the valve portion 30.

Further, the VG1 of the present embodiment can be applied not only to the vacuum exhaust of the gas cylinder housed in the cylinder cabinet arranged in the semiconductor manufacturing apparatus but also to the vacuum exhaust of various exhaust targets.

1 Vacuum generator 2 Body 12 On-off valve 16 Suction port 26 Flow path 26a Inlet 26b Outlet 30 Valve 32 Nozzle 32a Squeezing hole 34 Vacuum generating part 56 1st road 58 2nd road 58a 1st branch road 60 3rd road 60a 2nd Branch road 60b Combined flow path 62 4th road 80 Inlet port 82 Exit port

Claims (6)

The working gas flow path having inlets and outlets opened in the body is provided with a valve portion of an on-off valve, a nozzle, a vacuum generating portion, and a suction port communicating with the vacuum generating portion in the order of the flow direction of the working gas. A gas is supplied from the inlet and ejected from the nozzle to generate a negative pressure in the vacuum generating portion, and vacuum exhaust is directed from an exhaust target connected to the vacuum generating portion via the suction port toward the outlet. It is a vacuum generator that does
The flow path is
A first path extending from the inlet to the valve
The second path extending from the valve portion and
A third road extending from the second road in a direction intersecting the second road,
It has a fourth path extending from the third path in a direction intersecting the third path and reaching the nozzle.
The second road includes a plurality of first branch roads.
The valve portion
The entrance port to which the first road is connected and
A vacuum generator having a plurality of outlet ports to which the plurality of first branch paths are connected to each other. The vacuum generator according to claim 1, wherein the inlet port is located at the radial center of the valve bottom wall of the valve portion, and the plurality of outlet ports are located around the inlet port of the valve bottom wall. The vacuum generator according to claim 1 or 2, wherein the third road includes a plurality of second branch roads to which the plurality of first branch roads are connected to each other. The vacuum generator according to claim 3, wherein the third path includes a plurality of combined flow paths of the second branch paths. The vacuum generator according to claim 4, wherein the flow path cross-sectional area of the combined flow path has a total flow path cross-sectional area or more of the flow path cross-sectional areas of the plurality of second branch paths. The vacuum generator according to claim 4 or 5, wherein the flow path cross-sectional area of the combined flow path has a total flow path cross-sectional area or more of the flow path cross-sectional areas of the plurality of first branch paths.

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