JP6145445B2 - Gate valve - Google Patents

Description

  The present invention relates to a gate valve, and more particularly to a gate valve for semiconductor manufacturing.

  Since gate valves for semiconductor manufacturing are at a lower temperature than the semiconductor processing chamber, products generated in the process may adhere to the valve body surface and the inside of the gate valve, and a heater is used to prevent this. Installed.

  Patent Document 1 describes a structure in which a heater for heating a valve body is installed in a heater housing portion of a valve body support member.

  Patent Document 2 describes a structure in which a flat and wide shallow dovetail having an outline of a pattern circulating around a channel opening is provided, and a heater is continuously circulated in the dovetail. It is described that the heater is provided so as to be surrounded by the bellows.

JP 2009-204137 A Japanese Patent Laid-Open No. 10-132095

  Various heaters and heater arrangement structures have been proposed for preventing products generated during the process from adhering to the valve body surface and the inside of the gate valve. The heater described in Patent Document 1 is housed in a heater housing portion formed in a rectangular groove according to the shape of the valve body. A planar heater is used as the heater and is pressed and supported by a lid, and a solution for the problem derived from expansion caused by heating of the heater is not sufficient. In Patent Document 2, a flat and wide shallow dovetail groove is formed, and sheathed heaters are continuously circulated and disposed therein, and similarly to Patent Document 1, the problem is caused by expansion due to heating of the heater. The solution about is not enough.

  In view of this point, the present invention achieves a problem derived from expansion due to the sheath heater being pressed and supported by the groove structure which is a heater housing portion, and heating the sheath heater, for example, uniformizing the heating state of the entire valve. It prevents the product from adhering, eliminates the problems derived from the expansion of the heater, extends the life of the heater, and solves these problems by devising the groove structure that is the heater storage part. An object of the present invention is to provide a structure that can be made inexpensive without requiring processing.

The present invention comprises a valve plate disposed opposite to a valve seat, a stem connected to the valve plate, for opening and closing the valve plate, and a drive device for driving the valve plate with respect to the valve seat. In a gate valve in which a heater base is provided integrally or separately, a groove is provided in the heater base, and a sheathed heater is provided in the groove.
The groove has a constant groove width and has a number of corrugations in which crests and troughs are alternately formed regularly and uniformly, and is wound from the longitudinal end to the longitudinal end on the valve plate side surface of the heater base. The sheathed heater is formed so that the distance between one crest of the groove and the trough on the opposite side of the groove in both cross sections perpendicular to the longitudinal direction is equal to or less than the diameter of the sheathed heater. The gate valve is provided in such a manner that the gate valve is disposed in contact with the groove in a state in which the pressing force from the wave-shaped peak and trough acts.

According to the present invention, in the gate valve described above, the heater base is formed separately from the stem and disposed between the valve plate and the stem, and a groove is provided on a side surface of the valve plate of the separate heater base. A gate valve is provided.
The present invention provides a gate valve characterized in that, in the gate valve described above, a heater base is formed integrally with a stem, and a groove is provided on a side surface of the stem opposite to the valve plate.
According to the present invention, in the gate valve described above, the groove is formed by being wound twice or more on the surface of the heater base or stem, and the contact of the sheathed heater with the groove is formed substantially over the entire groove length. A gate valve is provided.
According to the present invention, in the gate valve described above, the groove is formed by being wound once on the surface of the heater base or stem, and the contact of the sheathed heater with the groove is formed substantially over the entire groove length. A gate valve is provided.

  In the present invention, as described above, in the sheathed heater, the distance between the one crest portion of the groove and the trough portion on the opposite side in both perpendicular cross-sectional directions is equal to or smaller than the diameter of the sheathed heater, Since each of the sheathed heaters is arranged in contact with the corrugated peaks and valleys in a state in which a pressing force is applied directly from each corrugated peak, Wave-shaped peaks and valleys can be directly pressed and supported rather than fixed, and problems derived from expansion caused by heating of the heater, for example, heating of the entire valve can be effectively achieved to achieve uniformity. This prevents the product from adhering, disperses and accumulates the linear expansion derived from the expansion of the heater, and extends the life of the sheathed heater. Ingenuity of a certain groove itself Since the resolution I, it is possible to provide an inexpensive By now, the structure without requiring any special processing to the sheath heater.

The front view which shows the form of the gate valve 100 which is an Example of this invention. Sectional drawing which expands and shows the AA cross section of FIG. The figure which shows the whole form of the groove | channel formed in the heater base. The figure which shows the one part detail of FIG. The figure which shows the form which has arrange | positioned the sheathed heater 31 to the groove | channel 10. FIG. Sectional drawing of the longitudinal direction of a sheathed heater. BB sectional drawing of FIG. The figure which shows the heater base shape used as a present Example, and a comparative product heater base shape. The figure which shows the shape of the heater base of another example. The figure which shows the location of the measurement point of a heater base with which it used for the evaluation test.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a front view showing a configuration of a gate valve 100 according to an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view taken along the line AA of FIG. In FIG. 1, the configuration of the groove 10 forming the center of the present embodiment is shown by a solid line, but this is shown by a solid line for understanding the present embodiment, and the actual configuration is as shown in FIG. is there. In the embodiment, the right side of the drawing is called the valve seat side, and the opposite side is called the back side. In the present invention, a sheathed heater is used. As is well known, a sheathed heater is a heater embedded in a sheathed tube via an electrical insulator, and the sheathed heater is electrically connected to the sheathed tube or its equivalent. This refers to a heater embedded through an insulator, which acts as a heater for heating and is sometimes called a heater.

  1 and 2, a gate valve 100 includes a valve plate 4 that is a valve body disposed to face the valve seat 1, an O-ring 5 that is disposed on a valve seat side surface of the valve plate 4, and a valve plate 4. The heater base 6 disposed on the back side, the stem 7 disposed on the back side of the heater base 6, the groove 10 formed on the valve seat side surface of the heater base 7, the heater base 6 and the valve plate 4 And a heater cover 8 that closes the opening of the groove 10 and a heater 9 disposed in the groove 10. As described above, the valve plate is arranged to face the valve seat, the stem is connected to the valve plate and opens and closes the valve plate, and the drive device that drives the valve plate with respect to the valve seat. A heater base is provided integrally or as a separate body, and a groove is provided in the heater base, and a gate valve 100 in which a sheathed heater is disposed in the groove is formed.

  An opening 3 communicating with a processing chamber (not shown) is formed in the valve seat 2, and the valve seat 2 is closed and opened by a valve plate 4.

  The valve plate 4 is fixed to the stem 7 by the bolt 11 together with the heater base 6, and the stem 7 is connected to the drive unit 12. The drive unit 12 includes a drive source (not shown), and can drive the valve plate 4 in the vertical direction and the swing direction. Various operation methods have been proposed and disclosed for the drive form of the valve plate 4 by the drive unit 12.

  In FIG. 1, the combined structure of the heater base 6 and the stem 7 is formed in two places on the left and right. The combined structure of the heater base 6 and the stem 7 may be formed at one place or at a plurality of places.

  In this example, the heater base 6 is configured as a separate body from the valve plate 4 and is integrated by a bolt 11. However, a groove 10 is formed in the stem itself, and a sheathed heater 31 (see FIG. 5) is embedded in the groove. The heater cover 8 can be closed. In this case, the heater base portion where the groove is provided is formed in the stem 7. The stem is integrated with the heater base. The integrated stem is fixed to the valve plate 4 by bolts 13. When the heater base is integrally manufactured on the stem, a groove can be formed on the side surface opposite to the valve plate 4. A groove cover is attached to the groove.

  The sheathed heater 31 is disposed in the pipe 15 provided in the stem 7, is connected to a power source (not shown) arranged outside the drive unit 12, and is temperature-controlled by a control device (not shown). The temperature of the valve plate 4 is controlled.

  FIG. 3 shows an overall configuration of the groove 10 formed in the heater base 6.

  In FIG. 3, the groove 10 has a large number of corrugations in which crests 21 and troughs 22 are alternately formed in a regular and uniform manner with a constant groove width, from the longitudinal end 23 on the valve gate side surface of the heater base 6. It is formed by being wound around the longitudinal end 24. Moreover, it forms over the upper-lower-end part. The peak portion 21 indicates a groove portion that rises upward as shown in the figure, and the valley portion 22 indicates a portion that is recessed downward as shown in the drawing. The longitudinal side end 23 indicates the left end of the heater base 6, and the longitudinal end 24 indicates the right end of the heater base 6. In the figure, the upper and lower end portions are referred to as upper and lower end portions. These crests and troughs can be processed by controlled machining, and grooves can be easily formed. Therefore, the shape of the peak portion and the valley portion is not limited to the structure described in FIG. 3, and it is easy to make each apex portion and bottom point portion partially linear or on an arc.

  In the case of this example, it is wound twice from the longitudinal end to the longitudinal end. Between each wound groove | channel, the wall 25 which divides these two grooves is formed. Reference numerals 26 and 27 denote bolt holes.

  FIG. 4 shows a partial detail of FIG. When the bulge on the upper side surface of one groove 10 is a ridge portion 21A, the depression is a valley portion 22A, the bulge on the lower side surface is a ridge portion 21B, and the depression is a valley portion 22B, the groove 10 is as described above. The groove width is constant, and a large number of wave shapes are formed in which peaks 21 and valleys 22 are alternately formed regularly and uniformly.

  The bottom point of the upper valley portion 22A does not extend beyond the apex of the lower mountain portion 21B. On both longitudinal sections, the distance between the bottom point and the apex is determined depending on the structural properties of the sheathed heater such as the thickness of the sheathed heater (see FIG. 5) to be inserted, that is, the diameter.

  At the lower end of the heater base 6, a heater groove 14 for introducing and deriving a heater is formed, and a groove 30 for installing a T / C for controlling a thermocouple for temperature measurement is formed. A mounting screw 29 for attaching the control T / C is provided in the groove 30.

  FIG. 5 shows a form in which the sheathed heater 31 is disposed in the groove 10. Here, the heater 9 shown in FIG. 1 is shown as a sheathed heater 31 in this example.

  6 shows a cross section in the longitudinal direction of the sheathed heater 31, and FIG. 7 shows a BB cross section of FIG. In these drawings, the sheathed heater 31 is configured by arranging a heater wire 62 through an electrical insulator 63 in an outer casing 61, and has elasticity as a whole. The configuration of the sheathed heater may be another configuration.

  In FIG. 5, in the sheathed heater 31, the distance between one crest portion 21B of the groove and the trough portion 22A on the opposite side in both perpendicular cross sections with respect to the longitudinal direction is equal to or less than the diameter of the sheathed heater. It is arranged in a straight line. The corrugated peaks are arranged in contact with each corrugated peak in a state in which a pressing force is elastically applied from each corrugated peak. The contact arrangement is important, and the elasticity of the sheathed heater is not lost even after the contact arrangement. Since the sheathed heater 31 to be disposed is arranged in a straight line, it is not necessary to perform any processing during the placement, and the sheathed heater is placed in the groove 10 by the worker without changing the material and in the straight shape. It is forcibly arranged using the elasticity it has. An instrument may be used and arranged. For example, the distance between the crests and crests, the crevice and crevice distances, crest and crevice distances, amplitude, groove width, and the width of the groove on one side of the groove opposite to the crest 21B. The interval between the valley portions 22A and the thickness of the sheathed heater 31 are set. In this way, the longitudinal interval is set. The sheathed heater 31 arranged linearly in the wave-shaped groove contacts these portions in a state where a pressing force is applied from the wave-shaped peak and valley. The contact state forms a fixed contact using elasticity, and the sheathed heater 31 is fixed in contact with the groove 10 without providing any mechanical fixing means. The feature of this contact fixation is that the pressed points are uniformly formed with a constant interval, and are formed at an extremely short interval. As a result, when the sheathed heater 31 is about to expand by heating, the expansion becomes local due to the formation of the large number of short interval pressing and fixing means, and is not accumulated or accumulated. Thus, it is possible to avoid the heater disconnection failure derived by avoiding the accumulation. As in this example, by using a linear sheathed heater as it is, the influence depending on the skill of the heater bending worker can be reduced, and the heater life can be easily extended. become.

  In the end portion of the heater base, the groove 10 has an arc shape instead of a corrugated shape. The arc-shaped groove 10A has a larger curvature state of the inner diameter than the outer diameter, and the groove width is larger than the groove width in the central portion of the heater base. The sheathed heater 31 is disposed along the inner wall of the groove at this end portion, and makes it easy to absorb expansion of the sheathed heater 31 due to heating. By adopting the above-described contact fixing form between the groove and the sheathed heater 31, the groove width can be made to be equal to or slightly wider than the groove width in the central portion.

  The sheathed heater introduction portion 31A is guided from the inside of the heater winding 14 and is disposed from the groove on the lowermost side of the outer winding, wound inside the groove 10 from the outer periphery, switched to the inner periphery, and the end point of winding of the groove 10 In the vicinity of 31, the arrangement in the groove is completed. In this example, the groove 10 is formed by being wound twice on the valve gate side surface side of the heater base 6, and the contact of the sheathed heater 31 with the groove 10 is formed substantially over the entire groove length. The groove 10 may be wound two or more times. The number of windings is determined by temperature setting and heater characteristics. In any case, it is inevitable that inflection points are formed due to the arrangement of the sheathed heaters, but the problem due to the formation of these inflection points is solved.

  FIG. 8 shows a heater base shape and a comparative heater base shape according to this embodiment.

  8A shows a comparative heater base shape, and FIG. 6B9 shows the heater base shape of this example. The shape of the comparative linear groove is indicated by 10M, and the shape of the corrugated sheathed heater is indicated by 31M. As can be seen from the shape of FIG. 8 (A), the thermal expansion of the corrugated sheathed heater 31A is accumulated, or at the circumferential portion of the end portion, or where the expansion is accumulated, or the portion where the expansion is concentrated and strongly contacts the groove outer wall. Stress concentration is derived in the sheathed heater at a location where the bending change on the wiring is large, for example, at a bending change location from the outer periphery to the inner periphery. In contrast, in the present embodiment, since the mounting configuration of the sheathed heater 31 restrains thermal expansion as described above, stress concentration at these locations can be avoided, and the lifetime of the sheathed heater can be avoided. Can be lengthened. That is, according to the present embodiment, the displacement due to heating of the sheathed heater can be reduced, local stress concentration can be avoided, and the lifetime of the sheathed heater can be extended.

  If the installation is as shown in the comparison product, the installation of the sheathed heater will depend on the work skill of the assembly worker, and the sheathed heater will be installed. Is likely to occur. According to the present embodiment, there is no individual difference, the mounting state is uniform, and even if a plurality of winding structures are adopted, stress concentration can be avoided at a place where the bending change on the sheathed heater wiring is large. it can. In addition, since the sheath heater can be bent and contacted with the groove uniformly, it is possible to achieve heat transfer as designed, and there is an effect that the heating state of the entire valve body is uniform. Uniformity of the warmed state is effective in preventing local adhesion of the product.

  FIG. 9 shows an example in which the groove 10 is formed by being wound once around the valve gate side surface of the heater base 6, and the contact of the sheathed heater 31 with the groove 10 is formed substantially over the entire groove length. . As shown in FIG. 8A, the shape of the groove is indicated by 11A, and the shape of the sheathed heater is indicated by 31A. These comparison results are the same as described for FIG.

  The result of having confirmed and examined about the influence by the form by a present Example on the temperature distribution of the valve body surface is demonstrated.

  FIG. 10 is a diagram showing locations of measurement points on the heater base used in this evaluation test.

・ Test valve: Twin roll cam gate valve ・ Heater base: Comparative product shown in FIGS. 8 and 9 and heater base shape of this example ・ Pressure: Vacuum ・ Temperature control temperature: Set temperature 120 ° C.
・ Temperature measurement: By a thermocouple built into the heater base.

・ Control method: ON-OFF control (118 ℃ -ON, 120 ℃ -OFF control)
Measurement location: valve body surface, summary of 10 location test results shown in FIG. As for the variation of the valve body surface temperature at the temperature control temperature (120 ° C.), the average value of (maximum value-minimum value at 10 measurement points) is the average of three examples shown in FIGS. The measurement results were as follows.

Example 1 ... 6.6 ° C
Example 2 ... 8.6 ° C
Example 3 ... 7.8 ° C
Average value: 7.8 ° C
From the above results, the average value of the variation in the valve body surface temperature measured three by three with the comparative product and the heater base of this example was improved by 1 to 2 ° C. Thus, the test results showed improvement in the temperature distribution state. It was assessed that there were at least no major differences. As described above, it was determined that the influence on the temperature distribution on the surface of the valve element may be better, but not worse, as compared with the comparative product.

  As described above, in this embodiment, as described above, in the sheathed heater, the distance between the one ridge portion of the groove and the opposite ridge portion in both the perpendicular cross-sectional directions is set to be equal to or less than the diameter of the sheath heater. It is linearly arranged in a groove of a shape, and is characterized by a structure in which the corrugated peaks and troughs are arranged in contact with each corrugated peak in a state where a pressing force acts elastically. Therefore, the linear sheathed heater can be elastically pressed and supported by the corrugated peaks and valleys instead of being fixed, and problems derived from expansion caused by heating of the sheathed heater, for example, heating of the entire valve surface Uniformity is achieved to prevent product adhesion, linear expansion derived from the expansion of the heater is not dispersed and accumulated, the heater life can be extended, and these solutions can be stored in the heater. Part Because it is solved by the ingenuity of itself, it is possible to provide an inexpensive By now, the structure without requiring any special processing to the sheath heater.

  2 ... valve seat, 4 ... valve plate (valve element), 5 ... O-ring, 6 ... heater base, 7 ... stem, 8 ... heater cover, 9 ... heater, 10 ... groove, 12 ... drive part, 14 ... heater groove , 21, 21A, 21B ... mountain, 22, 22A, 22B ... valley, 25 ... wall, 31 ... sheath heater, 100 ... gate valve.

Claims (5)

It consists of a valve plate arranged opposite to the valve seat, a stem connected to the valve plate, for opening and closing the valve plate, and a drive unit for driving the valve plate with respect to the valve seat. In a gate valve in which a heater base is provided as a separate body, a groove is provided in the stem or the heater base, and a sheathed heater is provided in the groove,
The groove has a constant groove width, and has a number of corrugations in which crests and troughs are alternately formed regularly and uniformly, and is wound from the longitudinal end to the longitudinal end on the valve gate side surface of the heater base. The sheathed heater is formed so that the distance between one crest of the groove and the trough on the opposite side of the groove in both cross sections perpendicular to the longitudinal direction is equal to or less than the diameter of the sheathed heater. The gate valve is disposed in contact with the groove in a state where the pressing force from the wave-shaped peak and valley is applied.   2. The gate valve according to claim 1, wherein the heater base is formed separately from the stem and disposed between the valve plate and the stem, and a groove is provided on a side surface of the valve plate of the separate heater base. A gate valve characterized by that. 2. The gate valve according to claim 1, wherein the heater base is formed integrally with the stem, and the groove is provided on the side surface of the stem opposite to the valve plate.   3. The gate valve according to claim 1, wherein the groove is formed by being wound twice or more on the surface of the heater base or stem, and the contact of the sheathed heater with the groove substantially extends over the entire groove length. A gate valve characterized by being formed.   3. The gate valve according to claim 1, wherein the groove is formed by being wound once on the surface of the heater base or the stem, and the contact of the sheathed heater with the groove substantially extends over the entire groove length. A gate valve characterized by being formed.

Images