Cleanliness monitoring device

Abstract

To reduce particles trapped within a line in a cleanliness monitoring device equipped with a switching valve in the line connected to a particle counter.SOLUTION: A cleanliness monitoring device comprises: a probe 14 which is installed inside a chamber; a first pipeline 16 one end of which is connected to the probe 14; a particle counter 18 which measures the number of fine particles; a second pipeline 20 one end of which is connected to the particle counter 18; a third pipeline 22 one end of which is connected to the chamber; and a switching valve 24 to which the other end of the first pipeline 16, the other end of the second pipeline 20, and the other end of the third pipeline 22 are connected. The switching valve 24 includes a fixed body 28 which has a sliding object surface 28A, and a sliding body 30 which has a sliding surface 30A. The other end of the first pipeline 16 is connected to one of the fixed body 28 and the sliding body 30, and the other end of the second pipeline 20 and the other end of the third pipeline 22 are connected to the other of the fixed body and the sliding body. The inner diameters d of the other end of the first pipeline 16 and the other end of the second pipeline 20 are the same and they are connected so as to face each other.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a cleanliness monitoring device used for monitoring the cleanliness inside a chamber. [Background technology]

[0002] There is known a cleanliness monitoring device that uses a particle counter to monitor the cleanliness inside a work room (chamber) such as an isolator, a safety cabinet, or a glove box during work or production (see Patent Document 1). In such a cleanliness monitoring device, a probe installed in the work room is connected to the particle counter via a pipe (tube), and air inside the work room is sucked in and introduced into the particle counter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-015431 A Summary of the Invention [Problem to be solved by the invention]

[0004] In isolators and safety cabinets, the inside of the chamber must be decontaminated after work or production, and the inside of the piping (tubes) connected to the chamber must also be decontaminated to reduce the risk of microbial contamination. At this time, it becomes necessary to switch the piping (tubes) from the suction line connected to the particle counter to, for example, a decontamination line leading to the work room. To switch between the suction line and the decontamination line, for example, a switching valve can be used. However, if there are steps or gaps in the switching valve or at the connection between the piping (tubes) and each line, some of the particles sucked in from the probe may be trapped in these steps or gaps, and the cleanliness level may not be measured correctly by the particle counter.

[0005] An object of the present invention is to reduce particles trapped in a line in a cleanliness monitoring device in which a switching valve is installed in the line connecting a probe to a particle counter. [Means for solving the problem]

[0006] The cleanliness monitoring device of the present invention for monitoring the cleanliness inside a chamber includes a probe installed in the chamber, a first pipeline having one end connected to the probe, a particle counter for measuring the number of fine particles, a second pipeline having one end connected to the particle counter, a third pipeline having one end connected to the chamber, a changeover valve to which the other end of the first pipeline, the other end of the second pipeline, and the other end of the third pipeline are connected, and a driving means for operating the changeover valve, wherein the changeover valve has a fixed body having a sliding surface and a sliding body having a sliding surface, the other end of the first pipeline is connected to one of the fixed body and the sliding body, and the other end of the second pipeline and the other end of the third pipeline are connected to the other, and the inner diameters of the other end of the first pipeline and the other end of the second pipeline are the same and are connected so as to face each other.

[0007] The cleanliness monitoring device according to a second aspect of the present invention is characterized in that, in the first aspect, the sliding body is a rotating body, and the pipelines are switched by rotating the rotating body with the driving means. Effect of the Invention

[0008] According to the present invention, in a cleanliness monitoring device in which a switching valve is installed in a line connected to a particle counter, it is possible to reduce particles trapped in the line. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic vertical sectional view showing the overall configuration of a cleanliness monitoring device according to a first embodiment of the present invention. [Diagram 2] FIG. 3( b ) is a cross-sectional view taken along the AOB in FIG. [Diagram 3]FIG. 2 is a plan view of the switching valve of the first embodiment as viewed from the side to which the first pipeline is connected. [Figure 4] FIG. 5(b) is a cross-sectional view of the COD of FIG. [Diagram 5] FIG. 11 is a plan view of the switching valve of the second embodiment as viewed from the side where the second and third pipelines are connected. [Figure 6] FIG. 8 is a cross-sectional view of FIG. 7 in a DE direction. [Figure 7] 7 is a view of the switching valve of FIG. 6 as seen from the sliding body side. [Figure 8] FIG. 11 is an enlarged vertical cross-sectional view of a connection portion between a first pipe line and a second pipe line in a switching valve according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a schematic vertical sectional view showing the overall configuration of a cleanliness monitoring device according to a first embodiment of the present invention.

[0011] The cleanliness monitoring device 10 of the first embodiment includes a probe 14 installed in a chamber 12, such as an isolator or a safety cabinet, a first pipeline 16 having one end connected to the probe 14, a particle counter 18 that measures the number of fine particles, a second pipeline 20 having one end connected to the particle counter 18, a third pipeline 22 having one end connected to the chamber 12, and a switching valve 24 to which the other end of the first pipeline 16, the other end of the second pipeline 20, and the other end of the third pipeline 22 are connected. Note that the upstream side of the first pipeline 16 includes a flexible portion.

[0012] The switching valve 24 is a valve that enables the line connected to the first line 16 to be switched between the second line 20 and the third line 22, and a pump 26 is provided in the middle of the third line 22 to circulate the air in the chamber 12 through the first line 16, the switching valve 24, and the third line 22 during decontamination.

[0013] Next, the configuration of the switching valve 24 of the first embodiment will be described with reference to Figures 2 and 3. Figure 2 is an AOB cross-sectional view of Figure 3(a), and Figure 3 is a plan view of the switching valve 24 seen from the side to which the first pipeline 16 is connected. Figure 3(a) shows a state during use of the isolator (safety cabinet), where the first pipeline 16 is placed at position A and connected to the second pipeline 20. Figure 3(b) shows a state during chamber decontamination, where the first pipeline 16 is placed at position B and connected to the third pipeline 22.

[0014] The switching valve 24 includes a fixed body 28 having a sliding surface 28A, and a sliding body 30 having a sliding surface 30A that comes into sliding contact with the sliding surface of the fixed body 28. The sliding body 30 is, for example, a disk-shaped rotating body whose center is integrally attached to a rotating shaft 32 that is pivoted to the fixed body 28. A first pipeline 16 is attached perpendicular to the sliding surface 30A (sliding surface 28A) at a position offset from the rotating shaft 32 in the sliding body 30. Meanwhile, a second pipeline 20 and a third pipeline 22 are attached perpendicular to the sliding surface 28A (sliding surface 30A) at two positions in the fixed body 28 that are offset from the rotating shaft 32 by the same distance as the first pipeline 16.

[0015] 3(a) and 3(b), in the fixed body 28 of the switching valve 24, the second pipeline 20 and the third pipeline 22 are disposed at positions offset by, for example, 90 degrees around the rotation axis O of the rotating shaft 32. The rotating shaft 32 penetrates the fixed body 28 and extends to the opposite side to the sliding body 30, and is connected to a rotary actuator (driving means) 36 via a joint 34. The rotary actuator 36 rotates the sliding body 30 through the rotating shaft 32 within a range of 90 degrees relative to the fixed body 28.

[0016] The switching valve 24 includes a locking mechanism for restricting the movable range of the rotating sliding body 30 and for accurately positioning the first pipeline 16 relative to the second pipeline 20 and the third pipeline 22. The locking mechanism of this embodiment is composed of locking portions 38A and 38B provided on the fixed body 28 and an engagement member 38 provided on the sliding body 30 which engages with the locking portions 38A and 38B.

[0017] For example, the outer periphery of the sliding body 30 is surrounded by an outer peripheral member 40 integrally attached around the sliding surface 28A of the fixed body 28, and the locking portions 38A and 38B are provided on the outer peripheral member 40. On the other hand, the locking member 38 is a member extending radially outward from the sliding body 30, and rotates integrally with the sliding body 30 relative to the fixed body 28. As shown in FIG. 3(a), in a state where the first pipeline 16 is accurately aligned with the second pipeline 20 (position A), one side surface (the side surface on the right side in FIG. 3) of the extension portion of the locking member 38 abuts against the locking portion 38A, and as shown in FIG. 3(b), in a state where the first pipeline 16 is accurately aligned with the third pipeline 22 (position B), the other side surface (the side surface on the left side in FIG. 3) of the extension portion of the locking member 38 abuts against the locking portion 38B.

[0018] As a result, the first pipeline 16 is moved between position A where it is connected to the second pipeline 20 and position B where it is connected to the third pipeline 22, and the movement of the first pipeline 16 is absorbed by the flexible portion on the upstream side.

[0019] Further, annular seal members 42A, 42B are provided on the sliding surface 28A so as to circumferentially surround the radially inner and outer sides of the second pipeline 20 and the third pipeline 22. The seal members 42A, 42B are pressed against the sliding surface 30A that is in close contact with the sliding surface 28A, and maintain the airtightness of the area defined between the seal members 42A and 42B.

[0020] 2 and 3(a), when the first pipeline 16 is disposed at position A (when connected to the second pipeline 20), the center line of the first pipeline 16 coincides with the center line of the second pipeline 20. The inner diameter d of the end of the first pipeline 16 connected to the sliding body 30 and the inner diameter d of the end of the second pipeline 20 connected to the fixed body 28 are equal, and when the first pipeline 16 is disposed at position A, both ends are disposed to face each other.

[0021] In the embodiment shown in Fig. 2, the end of the first pipe 16 is disposed at a position spaced a predetermined distance from the sliding surface 30A of the sliding body 30, and its tip surface abuts against the step portion 30B of the sliding body 30. A hole 30C having an inner diameter equal to the inner diameter d of the first and second pipes 16, 20 communicating with the sliding surface 30A is provided inside the step portion 30B. The end of the second pipe 20 is disposed at a position spaced a predetermined distance from the sliding surface 28A of the fixed body 28, and its tip surface abuts against the step portion 28B of the fixed body 28. A hole 28C having an inner diameter equal to the inner diameter d of the first and second pipes 16, 20 communicating with the sliding surface 28A is provided inside the step portion 28B. In addition, an elastic material or a clay-like material may be provided on the step 30B of the sliding body 30 and the step 28B of the fixed body 28, and the tip surfaces of the first and second pipelines 16, 20 may be abutted against this elastic material or clay-like material, thereby preventing gaps from occurring between the step and the tip surfaces.

[0022] As described above, according to the cleanliness monitoring device 10 of the first embodiment, when the first pipeline 16 is disposed at position A of the switching valve 24, the first pipeline 16 and the second pipeline 20 are connected via smooth cylindrical holes 28C, 30C without irregularities or steps formed in the fixed body 28 and the sliding body 30. As a result, particles sucked in from the probe 14 are introduced into the particle counter 18 without being trapped in the line, so that the cleanliness inside the chamber 12 can always be measured correctly.

[0023] Next, a cleanliness monitoring device of a second embodiment will be described with reference to Figures 4 to 7. In the changeover valve 24 of the cleanliness monitoring device 10 of the first embodiment, the first pipeline 16 is attached to the sliding body 30, and the second and third pipelines 20, 22 are attached to the fixed body 28. On the other hand, in the changeover valve 44 of the cleanliness monitoring device of the second embodiment, the second and third pipelines 20, 22 are attached to the sliding body 50, and the first pipeline 16 is attached to the fixed body 48. In the following description, the same reference numerals are used for configurations similar to those of the first embodiment, and description thereof will be omitted.

[0024] Fig. 4 corresponds to Fig. 2 of the first embodiment and is a COD cross-sectional view of Fig. 5(a). Fig. 5 corresponds to Fig. 3 of the first embodiment. That is, Fig. 5(a) shows a state in which the isolator (safety cabinet) is in use, and Fig. 5(b) shows a state during chamber decontamination.

[0025] In the second embodiment, the first pipeline 16 is attached perpendicularly to a sliding surface 48A of the fixed body 48 of the switching valve 44, and the second and third pipelines 20, 22 are attached perpendicularly to a sliding surface 50A of the sliding body 50. The sliding body 50 is attached integrally to a rotating shaft 32 pivoted on the fixed body 48, and is connected to a rotary actuator 36 via a joint 34. However, in the second embodiment, the rotating shaft 32 extends on the opposite side to the fixed body 48, and the rotary actuator 36 is also disposed on the opposite side to the fixed body 48.

[0026] As in the first embodiment, the sliding body 50 is a disk-shaped rotating body, and its outer periphery is surrounded by the outer peripheral member 40. The sliding body 50 is provided with an engagement member 38 extending outward from the outer periphery, and the sliding body 50 can be rotated within a range of 90 degrees as in the first embodiment by engaging with the locking portions 38A and 38B provided on the outer peripheral member 40. Therefore, the downstream sides of the second and third pipelines 20 and 22 attached to the sliding body 50 include flexible portions.

[0027] The second and third pipelines 20, 22 are attached at positions offset by the same distance from the rotating shaft 32 and at positions shifted by 90 degrees around the rotation axis O. The first pipeline 16 is disposed at position C in FIG. 5 on the fixed body 48. During cleanliness monitoring while the isolator (safety cabinet) is in use, the second pipeline 20 is disposed at position C as shown in FIG. 5(a) and connected to the first pipeline 16. At this time, the engaging member 38 engages with the locking portion 38A, and the sliding body 50 is positioned. On the other hand, during chamber decontamination, the third pipeline 22 is disposed at position C and connected to the first pipeline 16. At this time, the engaging member 38 engages with the locking portion 38B, and the sliding body 50 is positioned.

[0028] Figures 6 and 7 are diagrams for explaining the mounting structure of the rotary actuator 36 to the switching valve 44. Figure 6 is a cross-sectional view taken along line DE in Figure 7, and Figure 7 is a view seen from the side of the sliding body 50 in Figure 6. Note that each pipe line is omitted in Figure 6.

[0029] The rotary actuator 36 is supported by a support member 52 attached to the outer circumferential member 40. The support member 52 is a member having a U-shaped cross section, and the tip ends of its side walls 52A are attached to the outer circumferential surface of the outer circumferential member 40. The side walls 52A extend from the outer circumferential surface of the outer circumferential member 40 along the rotating shaft 32, and their base ends are connected by a bottom plate portion 52B. The rotary actuator 36 is attached to the bottom plate portion 52B.

[0030] 7, a state in which the second pipeline 20 is disposed at position C (on the first pipeline 16) and the third pipeline 22 is disposed at position D is shown by a solid line, and the second pipeline 20 disposed at position E is shown by a dashed line. As shown in Fig. 7, in the second embodiment, the movement range of the second pipeline 20 and the third pipeline 22 covers an angle of 180 degrees around the rotation axis O. Therefore, a notch 52C is formed in the bottom plate portion 52B of the support member 52 so as to surround the rotary actuator 36 by 180 degrees so that the second and third pipelines 20, 22 do not interfere with each other when moved.

[0031] 2 and 3(a), when the second pipeline 20 is disposed at position C (when connected to the first pipeline 16), the center line of the second pipeline 20 coincides with the center line of the first pipeline 16. The inner diameter d of the end of the second pipeline 20 connected to the sliding body 50 and the inner diameter d of the end of the first pipeline 16 connected to the fixed body 48 are equal, and when the second pipeline 20 is disposed at position C, both ends are disposed to face each other.

[0032] An end of the second pipeline 20 is disposed at a position spaced a predetermined distance from the sliding surface 50A of the sliding body 50, and its tip surface abuts against a step 50B of the sliding body 50. A hole 50C having an inner diameter equal to the inner diameter d of the first and second pipelines 16, 20 communicating with the sliding surface 50A is provided inside the step 50B. An end of the first pipeline 16 is disposed at a position spaced a predetermined distance from the sliding surface 48A of the fixed body 48, and its tip surface abuts against a step 48B of the fixed body 48. A hole 48C having an inner diameter equal to the inner diameter d of the first and second pipelines 16, 20 communicating with the sliding surface 48A is provided inside the step 48B.

[0033] As described above, in the cleanliness monitoring device of the second embodiment as well, when the second conduit 20 is disposed at position C of the switching valve 44, the second conduit 20 and the first conduit 16 are connected via smooth cylindrical holes 48C, 50C that are free of irregularities and steps and are formed in the fixed body 48 and the sliding body 50. This allows particles sucked in from the probe 14 to be introduced into the particle counter 18 without being trapped in the line, so that the cleanliness inside the chamber 12 can always be measured correctly.

[0034] Next, a switching valve 54 according to a third embodiment will be described with reference to FIG. 8. FIG. 8 is an enlarged vertical cross-sectional view of the switching valve 54 according to the third embodiment, focusing on the connection between the first pipeline 16 and the second pipeline 20. In the first and second embodiments, the ends of the first and second pipelines 16 and 20 are abutted against the step portions 28B, 30B, 48B, and 50B while maintaining the inner diameter d. However, in the third embodiment, the first and second pipelines 16 and 20 are fixed to the step portions 28B, 30B, 48B, and 50B using an insert 56. Note that the same reference numerals are used for the same configurations as those in the first and second embodiments, and the description thereof will be omitted.

[0035] 8, the insert 56 has a cylindrical shape with the same inner diameter d as the first and second pipelines 16, 20, and the outer periphery of the tip end is chamfered and sloped. On the other hand, a flange portion 56A is provided from the base end of the insert 56, extending outward by a length substantially the same as (slightly shorter than) the thickness of the first and second pipelines 16, 20.

[0036] The tip of the insert 56 is inserted until the tip faces of the first and second pipelines 16, 20 abut against the flange portion 56A, thereby expanding the diameters of the ends of the first and second pipelines 16, 20 into which the insert 56 is inserted. The first and second pipelines 16, 20 with the insert 56 attached are inserted into the fixed body 48 and the sliding body 50 until the flange portion 56A comes into close contact with the steps 28B, 30B, 48B, 50B.

[0037] The outer peripheral surfaces of the ends of the first and second pipelines 16, 20 into which the insert 56 is inserted are fitted snugly into the cylindrical surfaces surrounding the steps 28B, 30B, 48B, 50B, and the outer peripheral surfaces of the first and second pipelines 16, 20 expanded in diameter by the insert 56 are sandwiched and tightly attached between the cylindrical surfaces formed on the fixed body 48 and the sliding body 50 and the insert 56. This allows the first and second pipelines 16, 20 to be more securely and airtightly connected to the fixed body 48 and the sliding body 50. At this time, the first and second pipelines 16, 20, the insert 56, and the holes 28C, 30C, 48C, 50C are connected with a substantially constant inner diameter d, and no irregularities are formed at the joints.

[0038] As described above, the third embodiment also provides the same effects as the first and second embodiments.

[0039] In this embodiment, the second pipeline 20 and the first pipeline 16 are connected via cylindrical holes 28C, 30C, 48C, and 50C formed in the fixed bodies 28 and 48 and the sliding bodies 30 and 50, which have the same diameter as the inner diameters of the first and second pipelines 16 and 20. However, in the first and second embodiments, a configuration may be used in which the tip surfaces of the ends of the second pipeline 20 and the first pipeline 16 are directly abutted against each other and opposed to each other, without using the holes 28C, 30C, 48C, and 50C.

[0040] Furthermore, in the switching valve of this embodiment, the rotary actuator 36 is used as the driving means for rotating the rotating shaft 32. However, the driving means is not limited to this, and other driving means such as a servo motor can also be used.

[0041] In the changeover valve of this embodiment, a rotor is used as the sliding body, and the pipeline is switched by rotating the rotor relative to the fixed body with the driving means. However, the sliding body may be a sliding member that reciprocates on the fixed body, and the pipeline may be switched by moving the sliding body back and forth with the driving means such as a cylinder. [Explanation of symbols]

[0042] 10 Cleanliness monitoring device 12. Chamber 14 Probe 16 1st pipeline 18 Particle Counter 20 2nd pipeline 22 3rd pipeline 24, 44, 54 Switching valve 28, 48 Fixed body 28A, 48A sliding surface 30, 50 sliding body 30A, 50A sliding surface 36 Rotary actuator (drive means)

Claims

1. the apparatus comprises a probe disposed within a chamber, a first conduit having one end connected to the probe, a particle counter for measuring the number of fine particles, a second conduit having one end connected to the particle counter, a third conduit having one end connected to the chamber, a changeover valve to which the other end of the first conduit, the other end of the second conduit, and the other end of the third conduit are connected, and a drive means for operating the changeover valve; The switching valve has a fixed body having a sliding surface and a sliding body having a sliding surface, the other end of the first pipeline is connected to one of the fixed body and the sliding body, and the other end of the second pipeline and the other end of the third pipeline are connected to the other of the fixed body and the sliding body, a second end of the first pipe and a second end of the second pipe having the same inner diameter and connected to each other so as to face each other;

2. 2. The cleanliness monitoring device according to claim 1, wherein the sliding body is a rotating body, and the pipelines are switched by rotating the rotating body with the driving means.

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