Slide valve

Abstract

A slide valve (3) arranged to overlap a first chamber wall (2a) and a second chamber wall (2b) of a chamber (1), which are connected perpendicularly to each other, and which opens and closes an opening (6) formed in the first chamber wall (2a) with a valve plate (8), wherein the slide valve (3) comprises a valve plate housing frame (4) with a first frame wall (4a) which is pressed against the first chamber wall (2a) and a second frame wall (4b) which is pressed against the second chamber wall (2b), a connecting opening (6a) formed in the first frame wall (4a) such that it is in contact with the opening (6), a valve plate (8) which is slidable in the valve plate housing frame (4) and thereby opens and closes the connecting opening (6a), an actuating mechanism section (10) which triggers the opening and closing of the valve plate (8), and a fastening device (5, 5A,5B) for fastening the valve plate housing frame (4) to the first chamber wall (2a) or the second chamber wall (2b), wherein the fastening device (5, 5A, 5B) comprises a fastening screw (18, 33) screwed into a threaded hole (15, 31) formed perpendicularly in the first chamber wall (2a) or the second chamber wall (2b), and a screw insertion opening (17, 32) formed perpendicularly in the first frame wall (4a) or the second frame wall (4b) of the valve plate housing frame (4) corresponding to one chamber wall (2a, 2b) and through which the fastening screw (18, 33) passes, wherein a cam mechanism (19, 34) generates a thrust force in a direction perpendicular to the screw axis (L2) of the fastening screw (18, 33) in the valve plate housing frame (4) when the fastening screw (18, 33) is tightened to secure one frame wall (4a, 4b) against and to one chamber wall (2a,2b) to press and fasten, is formed at the fastening screw (18, 33) and in the screw insertion opening (17, 32), and wherein the other frame wall (4b, 4a) of the valve plate housing frame (4) is pressed against the other chamber wall (2b, 2a) of the chamber (1) by the thrust force.

Description

Technical field The present invention relates to a slide valve that is attached to a chamber wall of a vacuum chamber in a semiconductor manufacturing device and that opens and closes an opening formed in the chamber wall with a valve plate. State of the art In a semiconductor manufacturing setup, a slide valve is used to open and close an opening connected to a vacuum chamber. Such a setup is very expensive, and high precision is required during operation. Therefore, regular maintenance is essential. Maintenance involves various tasks, such as removing the slide valve from the vacuum chamber and replacing a damaged valve plate or sealing elements, among other things. The part of the vacuum chamber to which a slide valve is attached, and its surrounding components, have a complex design.Therefore, more recently a slide valve with a design as described in the Japanese patent JP H04-210391A has been used, in which the removal and reattachment of the slide valve, the replacement of a valve plate and the like can be carried out as easily and quickly as possible. This known slide valve is designed such that a closure assembly is formed by integrating a valve plate (closing plate), which opens and closes the opening (through-port), a valve plate housing frame (housing-like element) which accommodates the valve plate, a valve stem (piston rod) connected to the valve plate, and an actuating mechanism section (cylinder unit) which triggers the opening and closing of the valve plate via the valve stem. The closure assembly is detachably attached to the vacuum chamber by fixing the valve plate housing frame to a side wall of the chamber via a fastening screw. The opening connected to the valve plate housing frame is opened and closed by the valve plate. During maintenance, the valve plate and sealing elements can therefore be easily replaced by removing the entire closure assembly from the vacuum chamber. US 5,909,867 A discloses a slide valve that spans mutually perpendicular walls of a chamber and opens and closes an opening in the first chamber wall with a valve plate. The slide valve has a housing frame with a first frame wall, which is attached to the chamber by a mounting screw. The mounting screw is screwed into an angled mounting hole in the first frame wall and the chamber wall behind it. JP 2013 - 36 506 A discloses a slide valve with a chamber and a housing frame arranged therein. The first frame wall of the housing frame is connected to the first chamber wall by means of four fastening screws. The fastening screws are arranged perpendicular to the first frame wall and the first chamber wall and exert a thrust force parallel to the screw axis. Further valve assemblies are known from EP 2 740 979 A1 and US 4 573 616 A. Furthermore, fastening devices are disclosed in US 4 781 503 A, US 4 867 428 A, US 2 283 494 A and JP 2004 - 360 919 A. Summary of the invention In the known slide valve, attaching the valve plate housing frame to a chamber side wall using a fastening screw requires bringing two mutually perpendicular, connected surfaces of the valve plate housing frame into contact with two mutually perpendicular side walls of the chamber. For this reason, the screw mounting holes in the slide valve are designed at a 45° angle relative to both the connected surface and the side wall. The fastening screw is screwed into the angled mounting hole, thereby bringing the two connected surfaces of the valve plate housing frame into contact with the two side walls of the chamber. However, such a method, in which the valve plate housing frame is fixed to a side wall of the chamber using angled mounting holes, is cumbersome insofar as it is difficult to ensure the exact position when machining the mounting holes. A multi-functional machining center must be used, and the workpieces must be fixed at an angle. This results in poor machinability and high costs. It is therefore an object of the present invention to propose a slide valve whose valve plate housing frame can be connected to a side wall of a chamber without using an angled fastening screw, wherein two connected, mutually perpendicular surfaces of the valve plate housing frame are in contact with two mutually perpendicular side walls of the chamber. The slide valve should have a simple and clear design. This problem is essentially solved by the invention through the features of claim 1. Advantageous embodiments of the invention are the subject of the dependent claims. To solve the problem described above, according to one embodiment of the present invention, a slide valve is provided which is arranged such that it overlaps a first chamber wall and a second chamber wall which are connected perpendicularly to each other and which closes an opening formed in the first chamber wall with a valve plate, wherein the slide valve has a valve plate housing frame with a first frame wall which is pressed against the first chamber wall and a second frame wall which is pressed against the second chamber wall, wherein a connecting opening formed in the first frame wall is connected to the opening, a valve plate which is slidable in the valve plate housing frame and thereby opens and closes the connecting opening, and an actuating mechanism section which causes the valve plate to open and close.and a fastening device for fixing the valve plate housing frame to the first chamber wall or the second chamber wall, the fastening device comprising a fastening screw which is screwed into a threaded opening which is formed perpendicularly in the first chamber wall or the second chamber wall, and a screw insertion opening which is formed perpendicularly in the first frame wall or the second frame wall of the valve plate housing frame and which faces one chamber wall and through which the fastening screw is passed, a cam mechanism which, when the fastening screw is tightened, generates a thrust force in a direction perpendicular to the axis of the fastening screw in the valve plate housing frame in order to press one frame wall against one chamber wall and fix it there, and which is formed on the fastening screw and in the screw insertion opening,and wherein the other frame wall of the valve plate housing frame is pressed against the other chamber wall of the chamber by the thrust force. According to a particular embodiment of the present invention, the cam mechanism has a cam surface, which is a uniformly inclined surface on the fastening screw, and a cam receiving surface, which is a uniformly inclined surface in the screw insertion opening. The inclination direction and angle of the cam surface and the inclination direction and angle of the cam receiving surface are each the same. In this case, the cam surface is preferably formed on a cam element that is integrally formed with or separate from the fastening screw, while the cam receiving surface is formed on the inner surface of the screw insertion opening. Preferably, the cam element is designed separately from the fastening screw and can be attached to the fastening screw in such a way that the cam element is rotatable about the axis of the fastening screw, but is prevented from moving in the axial direction. According to a particular embodiment of the present invention, both the cam surface and the cam receiving surface are flat. In this case, the cam element is preferably not circular in the front view, the cam surface can be formed on the outer surface of the cam element, the screw insertion opening can have a cam element insertion section in which the cam element is not rotatably inserted, and the cam receiving surface can be formed on the inner surface of the cam element receiving section. According to another preferred embodiment of the present invention, both the cam surface and the cam receiving surface have a conical surface shape, and the outer diameter of the largest part of the conical surface forming the cam surface is smaller than the inner diameter of the smallest part of the conical surface forming the cam receiving surface. In this case, the cam element is preferably cylindrical, the conical cam surface can be formed on the cam element, the screw insertion opening can have a small diameter hole section and a large diameter hole section, which are circular and have different diameters, and the conical cam receiving surface can be formed between the small diameter hole section and the large diameter hole section. According to the present invention, the valve plate housing frame can be attached to the chamber wall of the chamber by means of a combination of a fastening screw which is attached in a perpendicular direction to a frame wall of a valve plate housing frame and a chamber wall of a chamber, and a cam mechanism, wherein two frame walls of the valve plate housing frame perpendicular to each other are pressed against two chamber walls of the chamber perpendicular to each other. Further objectives, features, and possible applications of the present invention will also become apparent from the following description of exemplary embodiments and the drawing. All features described or illustrated, individually or in any combination, constitute the subject matter of the invention, irrespective of their compilation in the claims or their cross-reference. Brief description of the drawings Fig. 1 is a partial section showing a first embodiment of the present invention and depicting a state in which a first frame wall of a valve plate housing frame of a slide valve is connected to a first chamber wall of a chamber via fastening devices. Fig. 2 is a right-hand view of Fig. 1. Fig. 3A is an enlarged detail of Fig. 1, and Fig. 3B is a right-hand view of Fig. 3A. Fig. 4A is a section in a preliminary state before tightening the fastening screw in Fig. 3A, and Fig. 4B is a right-hand view of Fig. 4A. Fig. 5A is a section depicting a state in which the fastening screw has been tightened from the preliminary state according to Fig. 4A to an intermediate fastening position, and Fig. 5B is a right-hand view of Fig. 5A.Figure 6 is a partial section showing a second embodiment of the present invention and depicting a state in which a second frame wall of a valve plate housing frame of a slide valve is connected to a second chamber wall of a chamber via fastening devices. Figure 7 is a right-hand view of Figure 6. Figure 8A is an enlarged detail of Figure 6, and Figure 8B is a top view of Figure 8A. Figure 9A is a section in a preliminary state before tightening the fastening screw in Figure 8A, and Figure 9B is a top view of Figure 9A. Figure 10A is a section showing a state in which the fastening screw has been tightened from the preliminary state according to Figure 9A to an intermediate fastening position, and Figure 10B is a top view of Figure 10A.Figure 11 shows a modification of a fastening device as a third embodiment of the present invention and is a partial section showing a state in which a first frame wall of a valve plate housing frame of a slide valve is fixed to a first chamber wall of a chamber via the fastening device. Figure 12 is a partial section of a preliminary state before the fastening screw in Figure 11 is tightened. Figure 13 is a partial section showing a state in which the fastening screw has been tightened to an intermediate fastening position, starting from the preliminary state according to Figure 12. Figure 14 is a section showing a further modification of the fastening device of the third embodiment. Description of embodiments Figures 1 and 2 show a first embodiment of a slide valve according to the present invention. In the figures, reference numeral 1 denotes a vacuum chamber, hereinafter referred to simply as a "chamber", for processing a semiconductor; reference numeral 2 denotes a chamber wall surrounding the chamber 1; reference numeral 3 denotes a slide valve attached to the chamber wall 2 of the chamber 1, with a valve plate housing frame 4 arranged between them; and reference numeral 5 denotes fastening devices for fixing the valve plate housing frame 4 to the chamber wall 2. Chamber 1 is a rectangular, cuboid chamber surrounded by chamber wall 2. It has a longitudinal and a transverse direction and is used for various processing steps on the semiconductor while evacuated. Chamber wall 2 comprises a first chamber wall 2a, located at one longitudinal end of chamber 1, which has a horizontally elongated opening 6 for inserting and removing the semiconductor into and from chamber 1. A second chamber wall (bottom wall) 2b is connected perpendicularly to the lower end of the first chamber wall 2a and has a valve insertion opening 7 into which a part of the slide valve 3 is inserted. A third chamber wall (top wall) 2c, opposite the second chamber wall 2b, forms a lid that can be opened and closed.When the third chamber wall 2c is open, the slide valve 3 is inserted into chamber 1, and the slide valve 3 is fixed to the first chamber wall 2a with the fastening devices 5, with the valve plate housing frame 4 positioned between them. The slide valve 3 comprises the valve plate housing frame 4, a connecting opening 6a formed in a first frame wall 4a of the valve plate housing frame 4 such that it communicates with the opening 6, a valve plate 8 which is displaced within the valve plate housing frame 4, opens and closes the connecting opening 6a and thereby opens and closes the opening 6, an actuating mechanism section 10 which triggers the opening and closing of the valve plate 8 via a valve stem 9, and the fastening devices 5 which fix the valve plate housing frame 4 to the chamber wall 2 of the chamber 1. The valve plate housing frame 4, the valve plate 8, the valve stem 9, and the actuating mechanism section 10 are integrally assembled into a single structure. The valve plate housing frame 4 comprises the first frame wall 4a, which is arranged parallel to the first chamber wall 2a of chamber 1, and a second frame wall 4b, which is connected perpendicularly to the first frame wall 4a. When the valve plate housing frame 4 is attached to the chamber wall 2a of chamber 1, the first frame wall 4a is pressed against the inner surface of the first chamber wall 2a of chamber 1, with a first sealing element 11a surrounding the opening 6 positioned between them. The second frame wall 4b is pressed against the inner surface of the second chamber wall 2b of chamber 1, with a second sealing element 11b surrounding the valve insertion opening 7 positioned between them. The first sealing element 11a is attached to the first frame wall 4a, and the second sealing element 11b is attached to the second frame wall 4b. The second frame wall 4b of the valve plate housing frame 4 is connected to the upper end of the actuating mechanism section 10 via a connecting device (not shown). A shaft opening 12 in the second frame 4b, through which the valve stem 9 passes, is connected to the chamber 1 and is closed off from the environment by a bellows or the like in the actuating mechanism section 10. As can be seen from Figs. 3A, 3B, 4A and 4B, the fastening devices 5 each comprise a threaded hole 15 and a guide hole 16, which are formed in the first chamber wall 2a of the chamber 1 perpendicular to the chamber wall 2a, a screw insertion opening 17, which is formed in the first frame wall 4a of the valve plate housing frame 4 perpendicular to the frame wall 4a, a fastening screw 18, which is screwed through the screw insertion opening 17 into the threaded hole 15, and a cam mechanism 19, which consists of a cam surface 20 and a cam receiving surface 21, which are formed on the fastening screw 18 and in the screw insertion opening 17. Several fastening devices 5 are provided at positions away from the connecting opening 6a of the first frame wall 4a, i.e. at positions near the second frame wall 4b. The screw insertion opening 17 has an elongated, slot-like shape and extends in the vertical direction of the first frame wall 4a. A rectangular cam element insertion section 22 at one end of the screw insertion opening 17 opens into the chamber 1. Therefore, the cam element insertion section 22 forms part of the screw insertion opening 17. For the sake of simplicity, however, in the following description the elongated part will be referred to as the "screw insertion opening 17" and the rectangular part as the "cam element insertion section 22". The cam receiving surface 21, which is a planar inclined surface, is formed on one of the four inner side faces of the cam element insertion section 22 that is closest to the second frame wall 4b. The cam receiving surface 21 is uniformly inclined so that it gradually approaches the second frame wall 4b as it extends to the open end of the cam element insertion section 22. The angle formed between the cam receiving surface 21 and an insertion opening axis L1, i.e., the central axis of the screw insertion opening 17, is preferably 45° or less and particularly about 20 to 30°. In the example shown, the angle is 25°. The fastening screw 18 comprises, in order from the distal end to the proximal end along the screw axis L2, i.e. its central axis, a threaded section 18a on which an external thread is formed, a cylindrical section 18b on which no external thread is formed, and a circular screw head 18c on which an Allen key hole 18d is formed for rotary actuation. A cam element 23, which is rectangular in front view, is attached to the cylindrical section 18b and is rotatable about the screw axis L2, its movement in the direction of the screw axis L2 being limited by a locking ring 24. The cam surface 20, which is in contact with the cam receiving surface 21, is formed on one of the four outer side surfaces of the cam element 23, which faces the cam receiving surface 21 of the cam element insertion section 22. This cam surface 20 is a flat, inclined surface that is uniformly inclined in the same direction as the cam receiving surface 21, i.e., such that it gradually approaches the screw axis L2 as it progresses towards the distal end of the fastening screw 18.The angle formed between the cam surface 20 and the screw axis L2 is the same as the angle formed between the cam receiving surface 21 and the insertion opening axis L1 and is 25° in the example shown. Thanks to the cam mechanism 19, formed by the cam surface 20 and the cam receiving surface 21, when the fastening screw 18 is tightened to fix the first frame wall 4a and the first chamber wall 2a, a thrust force is generated in a direction perpendicular to the screw axis L2 of the fastening screw 18 in the valve plate housing frame 4, and the second frame wall 4b of the valve plate housing frame 4 is pressed against the second chamber wall 2d of the chamber 1 by the thrust force. The process for attaching the slide valve 3 to the chamber wall 2 of the chamber 1 with the fastening devices 5 is carried out as follows. Figures 4A and 4B show a preliminary state before the valve plate housing frame 4 of the slide valve 3, which is housed in chamber 1, is fixed to the first chamber wall 2a of chamber 1 by the fastening device 5. This preliminary state is one in which part of the distal end of the threaded section 18a of the fastening screw 18 is screwed into the threaded hole 15, the distal end of the cylindrical section 18b is inserted into the guide hole 16, and the fastening screw 18 is thus provisionally and stably attached to the first chamber wall 2a but not yet tightened. At this time, the first sealing element 11a and the second sealing element 11b are not yet compressed. Therefore, the wall surfaces 4c of the first frame wall 4a and the second frame wall 4b of the valve plate housing frame 4 are not in contact with the inner surfaces of the first chamber wall 2a and the second chamber wall 2b of chamber 1.The cam surface 20 of the cam element 23 is in contact with the cam receiving surface 21 of the cam element insertion section 22 at a position near the open end of the cam element insertion section 22, and the cylindrical section 18b of the fastening screw 18 is arranged near the first opening end 17a, which is one of the two ends in the longitudinal axis direction of the screw insertion opening 17 that is closer to the second frame wall 4b. As the fastening screw 18 is tightened further from the preliminary state shown in Fig. 4A, the fastening screw 18 moves forward, rotating as the cam element 23 moves forward without rotating within the cam element insertion section 22. As shown in Figs. 5A and 5B, the fastening screw 18 reaches an intermediate fastening position where a pressing surface 23a at the distal end of the cam element 23 is in contact with a pressed surface 22a at the bottom of the cam element insertion section 22. At this time, the cam surface 20 of the cam element 23 presses the cam receiving surface 21, sliding along the cam receiving surface 21. Therefore, a vertical force component acts in a direction perpendicular to the screw axis L2 as a shear force on the valve plate housing frame 4.This thrust force presses the valve plate housing frame 4 against the second chamber wall 2b of the housing 1, and the second frame wall 4b is pressed against the second chamber wall 2b, compressing the second sealing element 11b. At this time, the wall surface 4c of the second frame wall 4b may be in contact with the inner surface of the second chamber wall 2b, but preferably it is separated from the second chamber wall 2b, with a narrow gap between it and the inner surface. Due to the movement of the valve plate housing frame 4, the cylindrical section 18b of the fastening screw 18 is arranged near a second opening end 17b opposite the first opening end 17a of the screw insertion opening 17. A force component in a direction parallel to the screw axis L2 also acts on the valve plate housing frame 4. This parallel force component also presses the valve plate housing frame 4 towards the first chamber wall 2a. This parallel force component is smaller than the vertical force component, so the valve plate housing frame 4 is displaced slightly towards the first chamber wall 2a, thereby slightly compressing the first sealing element 11a. Next, when the fastening screw 18 is turned further from the intermediate fastening position shown in Fig. 5A and tightened to a final fastening position shown in Figs. 3A and 3B, the valve plate housing frame 4 is moved towards the first chamber wall 2a of chamber 1, and the first frame wall 4a is pressed against the first chamber wall 2a, compressing the first sealing element 11a. Simultaneously, the second frame wall 4b is pressed against the second chamber wall 2b, compressing the second sealing element 11b, and is moved along the second chamber wall 2b, remaining in this position. Therefore, the second sealing element 11b is preferably subjected to a non-stick treatment to prevent it from adhering to the second chamber wall 2b and generating dust (abrasion). The wall surface 4c of the first frame wall 4a can be in contact with the inner surface of the first chamber wall 2a or spaced apart from the inner surface of the first chamber wall 2a, maintaining a small gap between them. To prevent the first frame wall 4a from being displaced by the pressing force when the connecting opening 6a is closed by the valve plate 8, the first frame wall 4a is preferably in contact with the first chamber wall 2a. To minimize dust generation through metal-on-metal contact in this case, preferably only parts of the wall surface 4c of the first frame wall 4a are in contact with the first chamber wall 2a, while the remaining part of the wall surface is recessed and therefore not in contact with the first chamber wall 2a.In this case, the wall surface parts that come into contact with the first chamber wall 2a are preferably a part of the upper end of the first frame wall 4a, which lies on the outside of the first sealing element 11a, as well as parts around the screw insertion openings 17. By tightening the fastening screws 18 of all fastening devices 5, the fastening of the valve plate housing frame 4 to the chamber wall 2 of the chamber 1, i.e. the fastening of the slide valve 3 to the chamber 1, is thus completed. The removal of the slide valve 3 from chamber 1 for maintenance purposes or the like can be carried out in the reverse order of the fastening procedure described above. Since in this case the cam element 23, which is attached to the fastening screw 18, is locked to the fastening screw 18 by the locking ring 24, when the fastening screw 18 is removed, the cam element 23 is removed together with the fastening screw 18 from the cam element insertion section 22. Figures 6 and 7 show a second embodiment of the present invention. The second embodiment differs from the first embodiment in that a second frame wall 4b of a valve plate housing frame 4 is attached to a second chamber wall 2b of a chamber 1 by means of several fastening devices 5A. For this purpose, in the illustrated example, a fastening device 5A is provided on each outer side in the longitudinal direction of a valve insertion opening 7 formed in the second chamber wall 2b. As can be seen from Figures 8A, 8B, 9A and 9B, the fastening devices 5A have essentially the same structure as the fastening devices 5 of the first embodiment. This means that the fastening devices 5A each have a threaded hole 15 and a guide hole 16 formed in the second chamber wall 2b of the chamber 1 perpendicular to the chamber wall 2b, a screw insertion opening 17 formed in the second frame wall 4b of a valve plate housing frame 4 perpendicular to the frame wall 4b, a fastening screw 18 which is screwed into the fastening hole 15 through the screw insertion opening 17, and a cam mechanism 19 formed on the fastening screw 18 and in the screw insertion opening 17. The cam mechanism 19 is formed by a cam surface 20, which is formed on an outer side surface of a cam element 23 that is attached to the fastening screw 18, and a cam receiving surface 21, which is formed on an inner side surface of the cam element insertion section 22 in the screw insertion opening 17. The cam surface 20 and the cam receiving surface 21 are formed on side surfaces of the cam element 23 and the cam element insertion section 22 that are closest to the first frame wall 4a. In the second embodiment, the process for attaching the second frame wall 4b of the valve plate housing frame 4 to the second chamber wall 2b of the chamber 1 with the fastening devices 5A is essentially the same as in the case of the first embodiment. This means that, starting from the preliminary state shown in Figs. 9A and 9B, the fastening screw 18 is screwed into an intermediate fastening position where the pressing surface 23a of the cam element 23 is in contact with the pressed surface 22a on the bottom of the cam element insertion section 22 (see Figs. 10A and 10B). This causes the cam surface 20 of the cam mechanism 19 to press the cam receiving surface 21, thus displacing the valve plate housing frame 4 towards the first chamber wall 2a of chamber 1. Consequently, the first frame wall 4a is pressed against the first chamber wall 2a, compressing the first sealing element 11a. Next, the fastening screw 18 is screwed further from the intermediate fastening position shown in Figures 10A and 10B and tightened to a final fastening position shown in Figures 8A and 8B. This moves the valve plate housing frame 4 towards the second chamber wall 2b of chamber 1, and the second frame wall 4b is pressed against the second chamber wall 2b, compressing the second sealing element 11b. At the same time, the first frame wall 4a, pressed against the first chamber wall 2a, is moved along the first chamber wall 2a and remains in this position. By tightening the fastening screws 18 of the two fastening devices 5A, the fastening of the valve plate housing frame 4 to the chamber wall 2 of the chamber 1, i.e. the attachment of the slide valve 3 to the chamber 1, is thus completed. In order to reduce the contact area with the first chamber wall 2a in the second embodiment, the first frame wall 4a of the valve plate housing frame 4 is designed such that a part surrounding the first sealing element 11a is in contact with the first chamber wall 2a, while the other part is not in contact with the first chamber wall 2a. Figures 11, 12 to 13 show a modification of a fastening device as a third embodiment of the present invention. The fastening device 5B differs from the fastening devices 5 and 5A of the first and second embodiments in that the inclined surfaces forming a cam surface 35 and a cam receiving surface 36 of a cam mechanism 34 have conical surfaces. The design of the fastening device 5B according to the third embodiment, in a case where, as in the first embodiment shown in Figures 1 and 2, a first frame wall 4a of a valve plate housing frame 4 is fixed to a first chamber wall 2a of a chamber 1 via the fastening device 5B, is described below. In this case, reference is made to Figures 1 and 2, if necessary, for the construction of the components other than the fastening device 5B, such as the construction of the chamber 1 and the valve plate housing frame 4, which are not described in Figures 11, 12 to 13. The fastening device 5B has a threaded hole 31 formed in the first chamber wall 2a of the chamber 1 perpendicular to the chamber wall 2a, a screw insertion opening 32 formed in the first frame wall 4a of the valve plate housing frame 4 perpendicular to the frame wall 4a, a fastening screw 33 which is passed through the screw insertion opening 32 and screwed into the threaded hole 31, and a cam mechanism 34 formed on the fastening screw 33 and in the screw insertion opening 32. The screw insertion opening 32 is a circular hole and, in sequence from the distal end to the proximal end of the screw insertion opening 32 along the axis L1 of the insertion opening, comprises a small-diameter hole section 32a, a large-diameter hole section 32b (which has a larger diameter than the small-diameter hole section), and a screw head insertion section 32c (which has a larger diameter than the large-diameter hole section 32b). The cam receiving surface 36, which has a conical surface, is formed between the small-diameter hole section 32a and the large-diameter hole section 32b. A seating section 32d, with which the screw head 33c of the fastening screw 33 comes into contact, is formed at the bottom of the screw head insertion section 32c. The fastening screw 33 comprises, in order from distal end to proximal end along the screw axis L2, a threaded section 33a with an external thread, a cylindrical section 33b without an external thread, and the circular threaded head 33c with a hexagonal hole (Allen key socket). Within the cylindrical section 33b, a large-diameter section 33b1 is formed on the proximal side (side of the screw head 33c), and a small-diameter section 33b2 is formed on the distal side (side of the threaded section 33a), both with different outer diameters. The cam surface 35, with a conical surface, is formed between the large-diameter section 33b1 and the small-diameter section 33b2. The outer diameter of the large-diameter section 33b1 of the fastening screw 33 is smaller than the inner diameter of the large-diameter hole section 32b of the screw insertion opening 32 and is slightly smaller than the inner diameter of the small-diameter hole section 32a, so that the large-diameter section 33b1 fits snugly into the small-diameter hole section 32a without rattling. Therefore, the outer diameter of the largest part of the conical surface forming the cam surface 35 is smaller than the inner diameter of the smallest part of the conical surface forming the cam receiving surface 36. The process for attaching the first frame wall 4a of the valve plate housing frame 4 to the first chamber wall 2a of the chamber 1 with the fastening device 5B of the third embodiment, which has the structure described above, is essentially the same as in the first embodiment. This means that Fig. 12 shows a preliminary state in which part of the distal end of the threaded section 33a of the fastening screw 33 is screwed into the threaded hole 31 of the screw insertion opening 32 and provisionally secured. In this preliminary state, the large-diameter section 33b1 of the fastening screw 33 is inserted into the large-diameter hole section 32b of the screw insertion opening 32, and part of the cam surface 35 is in contact with part of the cam receiving surface 36, but is not yet firmly pressed against the cam receiving surface 36. Therefore, the first frame wall 4a and the second frame wall 4b of the valve plate housing frame 4 are not in contact with the first chamber wall 2a and the second chamber wall 2b of chamber 1. Therefore, the insertion opening axis L1 of the screw insertion opening 32 and the screw axis L2 of the fastening screw 33 are not aligned. When the fastening screw 33 is screwed in from the preliminary state shown in Fig. 12 to an intermediate fastening position in which the screw head 33c comes into contact with the seat section 32d of the screw head insertion section 32c (see Fig. 13), a portion of the cam surface 35 with the conical surface comes into contact with a portion of the cam receiving surface 36, which also has a conical surface, and presses against the cam receiving surface 36, sliding along it. The large-diameter section 33b1 is inserted into the small-diameter hole section 32a. Therefore, the valve plate housing frame 4 is pressed by a thrust force in a direction perpendicular to the insertion opening axis L1 towards the second chamber wall 2b, and the second frame wall 4b is pressed against the second chamber wall 2b.The insertion opening axis L1 of the screw insertion opening 32 and the screw axis L2 of the fastening screw 33 are now aligned with each other. Next, when the fastening screw 33 is tightened to a fastening end position shown in Fig. 11, the valve plate housing frame 4 is moved to the first chamber wall 2a of the chamber 1, the first frame wall 4a is pressed against the first chamber wall 2a and the fastening of the valve plate housing frame 4 is completed. As with the fastening device 5A according to the second embodiment, as shown in Fig. 6 and Fig. 7, the fastening device 5B according to the third embodiment can also be used when the second frame wall 4b of the valve plate housing frame 4 is attached to the second chamber wall 2b of the chamber 1. In the fastening device 5B according to the third embodiment, a cam surface 35 is formed directly on the cylindrical section 33b of the fastening screw 33. As shown in Fig. 14, the cam surface 35 can also be formed by attaching a cylindrical cam element 37 to the cylindrical section 33b and shaping a portion, for example the distal end of the cam element 37, into a conical surface shape. In this case, the cam element 37 can be fixed to the fastening screw 33 or rotatable relative to it. If the cam element 37 is rotatable, it is preferably attached to the fastening screw 33 in such a way that its movement in the direction of the screw axis L2 is restricted, in order to prevent the cam element 37 from remaining in the screw insertion opening 32 when the fastening screw 33 is removed from the screw insertion opening 32. It can be said that in the fastening device 5B according to the third embodiment, the cylindrical section 33b of the fastening screw 33 is formed integrally with the cam element 37. In the illustrated embodiments, the angle formed between the cam surface 20, 35 and the screw axis L2, and the angle formed between the cam receiving surface 21, 36 and the insertion opening axis L1, are each less than 45° (for example, 25°), although the angles can also be 45°. By setting the cam surfaces 20, 35 and the cam receiving surfaces 21, 36 to 45°, when the fastening screw 18, 33 is tightened and the cam surface 20, 35 presses against the cam receiving surface 21, 36, equal shear forces can be generated that act on the cam receiving surface 21, 36, i.e., on the valve plate housing frame 4, both in a direction perpendicular to the screw axis L2 and in a direction parallel to the screw axis L2.This allows the valve plate housing frame 4 to be moved so that both the first frame wall 4a and the second frame wall 4b simultaneously approach the first chamber wall 2b and the second chamber wall 2b of chamber 1, respectively. This allows the attachment of the valve plate housing frame 4 to the chamber wall 2 of chamber 1 to be carried out simply and uniformly. Reference symbol list 1 Chamber 2 Chamber wall 2a First chamber wall 2b Second chamber wall 3 Slide valve 4 Valve plate housing frame 5, 5A, 5B Mounting device 6 Opening 6a Connecting opening 7 Valve insertion opening 8 Valve plate 10 Actuating mechanism section 11a First sealing element 11b Second sealing element 15 Threaded hole 17 Screw insertion opening 18 Mounting screw 18a Threaded section 18b Cylindrical section 18c Screw head 19 Cam mechanism 20 Cam surface 21 Cam receiving surface 22 Cam element insertion section 23 Cam element 31 Threaded hole 32 Screw insertion opening 32a Small diameter hole section 32b Large diameter hole section 33 Mounting screw 33a Threaded section 33b Cylindrical section 33b1 Large diameter section 33b2 Small diameter section 33c Screw head 34 Cam mechanism 35 Cam surface 36 Cam mounting surface 37 Cam element

Claims

A slide valve (3) arranged to overlap a first chamber wall (2a) and a second chamber wall (2b) of a chamber (1), which are connected perpendicularly to each other, and which opens and closes an opening (6) formed in the first chamber wall (2a) with a valve plate (8), wherein the slide valve (3) comprises a valve plate housing frame (4) with a first frame wall (4a) which is pressed against the first chamber wall (2a) and a second frame wall (4b) which is pressed against the second chamber wall (2b), a connecting opening (6a) formed in the first frame wall (4a) such that it is in contact with the opening (6), a valve plate (8) which is slidable in the valve plate housing frame (4) and thereby opens and closes the connecting opening (6a), an actuating mechanism section (10) which triggers the opening and closing of the valve plate (8), and a fastening device (5, 5A,5B) for fastening the valve plate housing frame (4) to the first chamber wall (2a) or the second chamber wall (2b), wherein the fastening device (5, 5A, 5B) comprises a fastening screw (18, 33) screwed into a threaded hole (15, 31) formed perpendicularly in the first chamber wall (2a) or the second chamber wall (2b), and a screw insertion opening (17, 32) formed perpendicularly in the first frame wall (4a) or the second frame wall (4b) of the valve plate housing frame (4) corresponding to one chamber wall (2a, 2b) and through which the fastening screw (18, 33) passes, wherein a cam mechanism (19, 34) generates a thrust force in a direction perpendicular to the screw axis (L2) of the fastening screw (18, 33) in the valve plate housing frame (4) when the fastening screw (18, 33) is tightened to secure one frame wall (4a, 4b) against and to one chamber wall (2a,2b) to press and fasten, is formed at the fastening screw (18, 33) and in the screw insertion opening (17, 32), and wherein the other frame wall (4b, 4a) of the valve plate housing frame (4) is pressed against the other chamber wall (2b, 2a) of the chamber (1) by the thrust force. The slide valve according to claim 1, characterized in that the cam mechanism (19, 34) has a cam surface (20, 35) which is a uniformly inclined surface formed on the fastening screw (18, 33), and a cam receiving surface (21, 36) which is a uniformly inclined surface formed in the screw insertion opening (17, 32), and that the inclination direction and inclination angle of the cam surface (20, 35) and the inclination direction and inclination angle of the cam receiving surface (21, 36) are each the same. The slide valve according to claim 1, characterized in that the cam mechanism (19, 34) has a cam surface (20, 35) formed on a cam element (23, 37) which is integrally formed with the fastening screw (18, 33), and that a cam receiving surface (21, 36) is formed on the inner surface of the screw insertion opening (17, 32). The slide valve according to claim 1, characterized in that the cam mechanism (19, 34) has a cam surface (20, 35) formed on a cam element (23, 37) which is provided separately from the fastening screw (18, 33), and that a cam receiving surface (21, 36) is formed on the inner surface of the screw insertion opening (17, 32). The slide valve according to claim 4, characterized in that the cam element (23) is attached to the fastening screw (18) by a locking ring (24), so that the cam element (23) is rotatable relative to the fastening screw (18) about the screw axis (L2) of the fastening screw (18) but is prevented from moving in the direction of the screw axis (L2). The slide valve according to one of claims 2 to 5, characterized in that both the cam surface (20) and the cam receiving surface (21) are designed as smooth surfaces. The slide valve according to claims 5 and 6, characterized in that the cam element (23) is not circular in the front view, that the cam surface (20) is formed on the outer surface of the cam element (23), that the screw insertion opening (17) has a cam element insertion section (22) in which the cam element (23) is not rotatably inserted, and that the cam receiving surface (21) is formed on the inner surface of the cam element insertion section (22). The slide valve according to one of claims 2 to 5, characterized in that the cam surface (35) and the cam receiving surface (36) each have conical surfaces and that the outer diameter of the largest part of the conical surface forming the cam surface (35) is smaller than the inner diameter of the smallest part of the conical surface forming the cam receiving surface (36), wherein an insertion opening axis (L1) of the screw insertion opening (32) is not aligned with the screw axis (L2), and wherein the thrust force is generated by the contact of a part of the cam surface (35) with a part of the cam receiving surface (36). The slide valve according to claims 3 to 5 and 8, characterized in that the cam element (37) is cylindrical, that the conical cam surface (35) is formed on the cam element (37), that the screw insertion opening (32) has a small diameter hole section (32a) and a large diameter hole section (32b), each of which is circular and has different diameters, and that the conical cam receiving surface (36) is formed between the small diameter hole section (32a) and the large diameter hole section (32b).

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