JP4567398B2 - Chemical valve - Google Patents

Description

  The present invention relates to a chemical valve for supplying or blocking chemical liquid.

  Conventionally, products such as semiconductors and liquid crystal displays are manufactured by subjecting a substrate to a series of processes such as cleaning, resist coating, exposure, development, etching, formation of an interlayer insulating film, and heat treatment. These various processes are performed in a substrate processing apparatus incorporating a plurality of processing units such as a coating processing unit and a heat treatment unit. A series of substrate processing proceeds by transferring a substrate between a plurality of processing units in a predetermined order by a transfer robot in the substrate processing apparatus, and processing each substrate in each processing unit. Among the processing units, for example, a coating processing unit that forms a thin film by applying a predetermined amount of chemical liquid to a semiconductor wafer includes a chemical valve that starts or stops the discharge of the chemical liquid. FIG. 7 is a cross-sectional view of the chemical valve 100 of the first conventional example. FIG. 8 is a cross-sectional view of a chemical valve 200 of the second conventional example.

  The chemical valve 100 shown in FIG. 7 includes an open / close chamber 102 connected to the primary channel 101a, an auxiliary chamber 103 connected to the secondary channel 101b, and a connecting pipe 104 that connects the open / close chamber 102 and the auxiliary chamber 103. Are provided on the same axis. The open / close chamber 102 is partitioned into a piston chamber and a working chamber by a partition wall 105, and a piston 106 slidably loaded in the piston chamber protrudes toward the working chamber side and is fixed to the control side diaphragm 107. The piston 106 moves up and down by a differential pressure between the elastic pressure of the spring 108 acting on the upper end surface and the pressure of compressed air supplied from the air supply / exhaust port 109 to the lower end surface, and a valve provided at the opening of the connection pipe 104. The control side diaphragm 107 is brought into contact with or separated from the seat 110. On the other hand, the peripheral portion of the compensation side diaphragm 112 is fixed to the auxiliary chamber 103, and the control side diaphragm 107 and the compensation side diaphragm 112 are connected via a connecting rod 111 that penetrates the connecting pipe 104. The compensation-side diaphragm 112 has the same shape as the control-side diaphragm 107, and is fixed to the auxiliary chamber 103 so that the thin-film portion 112a is curved upward like the thin-film portion 107a of the control-side diaphragm 107 (for example, patent Reference 1).

In such a chemical valve 100, since the control side diaphragm 107 and the compensation side diaphragm 112 mounted in the same direction are displaced synchronously, theoretically, the volume change of the open / close chamber 102 is compensated by the volume change of the auxiliary chamber 103, The volume of the entire valve is considered to be constant.
However, when the actual chemical solution valve 100 supplies the chemical solution, the compensation side diaphragm 112 deforms the thin film portion 112a downward by the fluid pressure. Therefore, in the chemical valve 100, the thin film portion 112a of the compensation side diaphragm 112 cannot be flexibly deflected and it is substantially difficult to compensate the volume change by the compensation side diaphragm 112.

  In this regard, in the chemical valve 200 of FIG. 8, the control-side diaphragm 201 and the compensation-side diaphragm 202 are attached in opposite directions and connected by a connecting rod 203, and the thin film portions 201a and 202a are respectively bent in the direction in which fluid pressure acts. Yes. Therefore, when the chemical valve 200 supplies operating air from the air supply / exhaust port 204 and raises the piston 205 against the spring 206, the control-side diaphragm 201 and the compensation-side diaphragm 202 make the thin film portions 201a and 202a flexible. When the control air diaphragm 201 and the compensation side diaphragm 202 are lowered by the elastic force of the spring 206 when the operating air is exhausted from the air supply / exhaust port 204 and is lowered by the elastic force of the spring 206, the control side diaphragm 201 and the compensation side diaphragm 202 are opened. 201a and 202a are integrally lowered while being flexibly bent and closed (see, for example, Patent Document 2).

JP 2003-185053 A JP 2003-278927 A

  However, in the chemical valve 200, since the control side diaphragm 201 and the compensation side diaphragm 202 move up and down while bending the thin film portions 201a and 202a that are curved in an arc shape, the valve chamber 207 that houses the control side diaphragm 201 and the compensation side diaphragm. The volume change of the compensation chamber 208 that accommodates 202 was unstable, and the volume change of the secondary side flow path varied. FIG. 9 is a diagram showing the relationship between the volume change generated in the secondary side flow path of the chemical valve 200 and the stroke.

  In the valve chamber 207, as shown in the graph LC1 in FIG. 9A, the volume increases in a parabolic manner as the stroke increases, whereas in the compensation chamber 211, as shown in the graph LC2 in FIG. 9B. As the stroke increases, the volume decreases parabolically. As a result, as shown in the graph LC3 of FIG. 9C, in the entire chemical valve 200, the volume change amount does not become zero and the volume changes except for a predetermined stroke (here, 0 mm, 1 mm). I was sorry. This is because the chemical solution is pushed out by the displacement of the control side diaphragm 201 or the compensation side diaphragm 202 just before the chemical valve 200 blocks the chemical solution, causing dripping, or the chemical solution from the tip of the discharge nozzle (not shown). Too much inhalation causes a decrease in the next chemical discharge amount, which is not preferable. In particular, there is a problem because, for example, in the semiconductor manufacturing process, fine processing is advanced and there is a high demand for uniform discharge amount of the chemical solution.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a chemical valve that can make the volume change generated in the secondary flow path constant.

The chemical valve according to the present invention has the following configuration.
In the chemical liquid valve for controlling the supply or interruption of drug solution, a valve chamber communicating with the input port, the compensation chamber communicating with the output port, is formed a communication hole communicating with the compensating chamber and the valve chamber body When the control side bellows valve body housed in said valve chamber, provided in said body, a valve seat the control side bellows valve body abuts or away, without the control side bellows valve body and the same shape, a compensation side bellows valve body housed in the compensation chamber, coupled to said control-side bellows valve body and the compensation side bellows valve body relative to said compensating side bellows valve body and the control side bellows valve body and connecting means for stretching and possess the, by the expansion and contraction operation of the control side bellows valve body and the compensating side bellows valve body by said connecting means, when the volume of the compensation chamber and the valve chamber is changed at the same time, The volume of the valve chamber increases. Indicates that the absolute value of the sum of the reduced valve chamber volume change amount and the compensation chamber volume change amount in which the compensation chamber volume has decreased or increased is constant at zero, the stroke of the control side bellows valve element An absolute value of the sum of the change amount of the valve chamber volume in which the volume of the valve chamber is increased or decreased and the change amount of the compensation chamber volume in which the volume of the compensation chamber is reduced or increased, The constant zero is characterized by adjusting by the stroke adjusting means .

That is, the chemical valve having the above-described configuration includes the volume of the valve chamber housing the control side bellows valve body and the compensation side bellows when the control side bellows valve body and the compensation side bellows valve body are relatively expanded and contracted by the connecting means. The volume of the compensation chamber that houses the valve element is relatively increased or decreased in proportion to the stroke. Since the control side bellows valve body and the compensation side bellows valve body have the same shape, the volume of the valve chamber and the compensation chamber increase or decrease with the same inclination. Volume change is constant.
Therefore, according to the chemical valve of the present invention, since the total volume change of the entire valve is constant, the volume change generated in the secondary side flow path can be made constant.

  In addition, for example, the tilt of the volume change of the valve chamber or the compensation chamber is deviated from the design value due to tolerance when processing the control side bellows valve body or the compensation side bellows valve body, and the total volume change of the entire valve varies. Even so, the stroke of the control side bellows valve element can be adjusted by the stroke adjusting means to reduce the variation in the total volume change of the entire valve.

(First Reference Example )
Next, a first reference example of the chemical valve according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the valve unit 1 </ b> A, in which the chemical valve 2 </ b> A is in a closed state. FIG. 2 is a cross-sectional view of the valve unit 1A and shows the chemical valve 2A in the valve open state.
The valve unit 1A is provided with a chemical liquid valve 2A and a suck back valve 3 arranged in parallel to the body 4 to control the start or stop of the chemical liquid discharge. In the body 4, the input port 5 communicates with the output port 11 through the first flow path 6, the attachment port 7, the communication hole 8, the auxiliary port 9, and the second flow path 10.

  The chemical valve 2A is an air operated on-off valve, and is configured to interlock the control side bellows valve body 20 and the compensation side bellows valve body 21. In the chemical valve 2A, a cover 23 is attached to a cylindrical cylinder 22 whose one end is closed to form a piston chamber 24. The piston chamber 24 is slidably loaded into the piston chamber 24, and the piston chamber 24 is moved to the upper chamber 24a. And the lower chamber 24b. The elastic force of the spring 26 contracted in the upper chamber 24a acts downward on the piston 25 in the figure. On the other hand, the upper chamber 24 a is opened to the atmosphere via the air supply / exhaust port 27, and the lower chamber 24 b communicates with the operation port 28. Therefore, an upward force in the figure can be applied to the piston 25 by supplying operation air from the operation port 28 to the lower chamber 24b, and the operation air in the lower chamber 24b is discharged from the operation port 28. As a result, the upward force in the figure can be released.

  A control-side bellows valve body 20 is held between the body 4 and the cylinder 22. The control-side bellows valve body 20 is formed by connecting a fixed portion 20a and a cylindrical portion 20c with a bellows portion 20b. The cylindrical portion 20c is inserted into the attachment port 7 so that the fixed portion 20a is interposed between the body 4 and the cylinder 22. It is pinched. For this reason, the opening of the attachment port 7 is blocked by the fixed portion 20 a of the control side bellows valve body 20, thereby forming the valve chamber 30. A sliding shaft 29 fixed to the piston 25 passes through the closed end surface of the cylinder 22 from the piston chamber 24 and is inserted into the control side bellows valve body 20. The lower end portion of the sliding shaft 29 is locked to the cylindrical portion 20 c and transmits the elastic force of the spring 26 to the control bellows valve body 20.

  In the body 4, a communication hole 8 and an auxiliary port 9 are formed on the same axis as the attachment port 7, and a valve seat 31 is provided using a step between the attachment port 7 and the communication hole 8. The control-side bellows valve body 20 has a recess formed inside the sealing surface where the cylindrical portion 20c seals to the valve seat 31, and the recess is penetrated from the auxiliary port 9 to the mounting port 7 through the communication hole 8. The tip of the connecting rod 32 is in contact.

  The compensation side bellows valve body 21 is formed by connecting a fixed portion 21a and a cylindrical portion 21c with a bellows portion 21b. The compensation side bellows valve body 21 is attached in the opposite direction to the control side bellows valve body 20, and is connected to a connecting rod by a recess formed in the cylindrical portion 21c. 32 receives the rear end. The columnar support member 33 holds the fixed portion 21 a of the compensation side bellows valve body 21 between itself and the body 4, and forms a compensation chamber 34 between the auxiliary port 9 and the compensation side bellows valve body 21. . The support member 33 is loaded such that the spring receiver 35 inserts the leg portion 35a from the fixing portion 21a of the compensating bellows valve body 21 into the bellows portion 21b and abuts against the valve body portion 21c. A lid 36 is attached to the support member 33 so as to compress and hold the compensation side spring 37 with the spring receiver 35. Therefore, the elastic pressure of the compensation spring 37 is constantly acting on the compensation bellows valve body 21 upward in the figure via the spring receiver 35.

  Here, the reason for providing the compensation side spring 37 is to sandwich and hold the connecting rod 32 in order to reduce the number of parts and the number of assembly steps. Therefore, the compensation side spring 37 is set to have a smaller elastic pressure than the spring 26, and the chemical valve 2A is of a normally closed type. Further, the tip end portion of the connecting rod 32 and the cylindrical portion 20 c of the control side bellows valve body 20 abut on a hemispherical surface, and the sealing force of the control side bellows valve body 20 is uniform in the circumferential direction with respect to the valve seat 31. To act on.

  The control-side bellows valve body 20 and the compensation-side bellows valve body 21 are integrally moved in the vertical direction in the figure via the connecting rod 32 to relatively expand and contract the bellows portions 20b and 21b. Are substantially the same shape. For the control side bellows valve body 20 and the compensation side bellows valve body 21, in order to ensure relative expansion and contraction more surely, the ones having the closest expansion / contraction degree are selected from the molded products of the bellows valve body. It is desirable to use.

  On the other hand, the suck back valve 3 is attached to a stepped portion formed by cutting out the body 4. A suck-back chamber 41 is opened in the stepped portion. In the body 4, a step for mounting the outer edge portion of the diaphragm 42 is formed around the opening forming the suck back chamber 41, and the cylinder 43 holds the diaphragm 42 between the body 4 and the body 4 via the diaphragm holder 44. is doing. A piston 45 is slidably loaded in the cylinder 43, and a diaphragm 42 is screwed to the lower end portion of the piston 45. A spring 46 is contracted between the diaphragm holder 44 and the piston 45 to push the piston 45 upward. The piston 45 abuts against the positioning shaft 47 and is restricted from moving upward. The positioning shaft 47 is screwed into a nut 48 that is non-rotatably attached to the cylinder 43, and a handle 49 is fixed to the upper end portion. The cylinder 43 has an operation port 43a. If operation air is supplied from the operation port 43a, a downward force acts on the piston 45, and if operation air is discharged from the operation port 43a, the downward force is released. The

  In addition, the valve unit 1A is a member (apparatus 4, body 22, cylinder 23, cover 23, support member 33, lid 36, cylinder 43, net 48, positioning shaft 27, handle 49, etc.) in view of corrosion resistance and the like. ) And members constituting the liquid contact surface (body 4, control side bellows valve body 20, compensation side bellows valve body 21, connecting rod 32, diaphragm 42, etc.) and members constituting the driving means (piston 25, sliding shaft 29). , Spring receivers 35, etc.) are formed of resin.

  Such a valve unit 1A is incorporated into, for example, a coating processing unit of a semiconductor manufacturing apparatus. That is, in the valve unit 1A, the input port 5 is connected to an upstream flow path (not shown) via a joint 12, while the output port 11 is connected to a downstream flow path (not shown) via a joint 13 to discharge (not shown). Communicates with the nozzle. When the application processing unit does not discharge the chemical liquid, the operation air is not supplied to the operation port 28 of the chemical liquid valve 2A and the operation port 43a of the suck back valve 3 as shown in FIG. Therefore, in the chemical liquid valve 2A, the piston 25 is pushed down by the elastic force of the spring 26, the control side bellows valve body 20 is pressed against the valve seat 31, and the chemical liquid valve 2A is closed. In the suck back valve 3, the piston 45 is abutted against the positioning shaft 47, and the diaphragm 42 stops at a predetermined position.

Thereafter, when the coating processing unit discharges the chemical solution, as shown in FIG. 2, the operation air is supplied to the operation port 28 of the chemical solution valve 2A and the operation port 43a of the suck back valve 3. When the pressure in the lower chamber 24 b overcomes the elastic pressure of the spring 26, the chemical liquid valve 2 </ b> A moves the piston 25 upward to separate the control side bellows valve body 20 from the valve seat 31, and the chemical liquid is first supplied from the input port 5. The output is output from the output port 11 through the flow path 6, the valve chamber 30, the communication hole 8, the compensation chamber 34, and the second flow path 10. And a chemical | medical solution begins to be discharged to the semiconductor wafer which is not illustrated from the discharge nozzle which is not illustrated. At the same time, the suck back valve 3 pushes down the piston 45 against the spring 46 and lowers the diaphragm 42 to reduce the volume of the suck back chamber 41.

  Thereafter, when the application processing unit stops the discharge of the chemical solution, the supply of the operation air to the operation port 28 of the chemical solution valve 2A and the operation port 43a of the suck back valve 3 is stopped as shown in FIG. The chemical liquid valve 2A pushes down the piston 25 by the elastic force of the spring 26, presses the control side bellows valve body 20 against the valve seat 31, and closes the chemical liquid supply. At the same time, the suck back valve 3 pushes up the piston 45 by the elastic force of the spring 46 to raise the diaphragm 42 and increase the volume of the suck back chamber 41. Then, a predetermined amount of the chemical solution is sucked back from the tip of the discharge nozzle (not shown) due to the expansion of the volume of the suck back chamber 41.

Here, the inventors tested the relationship between the volume change generated in the secondary flow path of the chemical valve 2A and the stroke. The test results are shown in FIG.
In this experiment, the volume change of the valve chamber 30, the compensation chamber 34, and the entire valve was measured by changing the stroke. As a measuring method of the volume change, for example, an L-shaped pipe is connected to the input port 5 of the valve unit 1A, and the fluid flows from the input port 5 to the output port 11, and then the outlet of the valve chamber 30 and the compensation chamber 34 The chemical liquid valve 2A is operated as an on-off valve while sequentially sealing the outlet and the outlet of the output port 11, and the change in the liquid level of the L-shaped pipe is measured. Further, for example, the pressure change at the input port 5 and the pressure at the outlet of the valve chamber 30, the outlet of the compensation chamber 34, and the outlet of the output port 11 are measured, and the volume change is measured by converting the pressure change into a volume change. May be.

  As a result, as shown in the graph LA1 in FIG. 3A, it has been found that the volume of the valve chamber 30 increases in proportion to the stroke. That is, in the chemical valve 2A, when the piston 25 rises, the cylindrical portion 20c of the control side bellows valve body 20 is pushed up by the elastic force of the compensation side spring 37 via the connecting rod 32, the compensation side bellows valve body 21, and the spring receiver 35. And rises while being pressed against the lower end of the sliding shaft 29. At this time, the bellows part 20b is compressed in proportion to the rising amount of the cylindrical part 20c, and the volume of the control side bellows valve body 20 is reduced. Therefore, the volume of the valve chamber 30 increases as the stroke of the control side bellows valve element 20 increases. Further, when the piston 25 is lowered, the chemical valve 2A is lowered by the cylindrical portion 20c of the control side bellows valve body 20 being pushed down by the sliding shaft 29. At this time, the bellows portion 20b extends in proportion to the descending amount of the cylindrical portion 20c, and the volume of the control side bellows valve body 20 increases. Therefore, the volume of the valve chamber 30 decreases as the stroke of the control side bellows valve element 20 decreases.

  On the other hand, as shown in the graph LA2 of FIG. 3B, it has been found that the volume of the compensation chamber 34 decreases in proportion to the stroke. That is, when the piston 25 is lifted, the chemical valve 2A is lifted by the cylindrical portion 20c of the compensation-side bellows valve body 21 being pushed up by the elastic pressure of the compensation-side spring 37 via the spring receiver 35. At this time, the bellows portion 21b extends in proportion to the rising amount of the cylindrical portion 21c, and the volume of the compensation side bellows valve body 21 increases. Therefore, the volume of the compensation chamber 34 decreases as the stroke of the control side bellows valve element 20 increases. Further, when the piston 25 is lowered, the chemical valve 2 </ b> A is lowered by the cylindrical portion 21 c of the compensation side bellows valve body 21 being pushed down via the connecting rod 32, the control side bellows valve body 20, and the sliding shaft 29. At this time, the bellows portion 21b is compressed in proportion to the descending amount of the cylindrical portion 21c, and the volume of the compensation side bellows valve body 21 is reduced. Therefore, the volume of the compensation chamber 34 increases as the stroke of the control side bellows valve element 20 decreases.

  Then, as shown in a graph LA3 in FIG. 3C, it has been found that the volume change amount is zero and constant throughout the chemical valve 2A. This is because the control-side bellows valve body 20 and the compensation-side bellows valve body 21 have the same shape, so that the control-side bellows valve body 20 and the compensation-side bellows valve body 21 are relatively expanded and contracted to provide the valve chamber 30 and the compensation chamber 34. As shown in graph LA1 in FIG. 3A and graph LA2 in FIG. 3B, the volume of valve chamber 30 and the volume of compensation chamber 34 increase and decrease at the same rate of change. In total, it is considered that the total volume change of the entire valve becomes zero and constant as shown in the graph LA3 in FIG.

  Therefore, in the valve unit 1A, if the displacement amount of the diaphragm 42 of the suck back valve 3 is adjusted, the chemical solution is sucked back by an arbitrary amount from the tip of the discharge nozzle (not shown), and the dripping of the chemical solution from the discharge nozzle is prevented. The next chemical discharge amount can be stabilized.

Therefore, according to the chemical valve 2A of the present reference example , the supply or blocking of the chemical liquid is controlled. The valve chamber 30 communicates with the input port 5, the compensation chamber 34 communicates with the output port 11, and the valve chamber. 30 and the compensation hole 34 are formed in the body 4, the control-side bellows valve body 20 accommodated in the valve chamber 30, and the control-side bellows valve body 20. Compensating side bellows valve body 21, control side bellows valve body 20, compensation side bellows valve body 21, which has the same shape as the valve seat 31 that contacts or separates from the control side bellows valve body 20 and is accommodated in the compensation chamber 34. And a connecting rod 32 that relatively expands and contracts the control-side bellows valve body 20 and the compensation-side bellows valve body 21, and the total volume change of the entire valve is constant. Constant volume change in the secondary channel Rukoto can.

(First Embodiment)
Next, a first embodiment of a chemical valve according to the present invention will be described with reference to the drawings. FIG. 4 is a cross-sectional view of the valve unit 1B.
The chemical valve 2B of the present embodiment differs from the chemical valve 2A of the first reference example in that it has a stroke adjusting mechanism 51. Therefore, here, the difference from the chemical valve 2A of the first reference example will be described in detail, and the common points will be denoted by the same reference numerals as the chemical valve 2A in the drawings, and description thereof will be omitted as appropriate.

  The valve unit 1B includes a chemical valve 2B and a suck back valve 3, and the chemical valve 2B includes a stroke adjustment mechanism 51. The stroke adjusting mechanism 51 is provided with a convex portion 23 a that engages with a nut 52 and stops rotation on the cover 23. A cylindrical guide 23b is formed on the cover 23 coaxially with the convex portion 23a, and a sliding shaft 53 that is screwed onto the nut 52 is airtightly loaded therein. A handle 54 is fixed to the upper end portion of the sliding shaft 53 with a set screw. The stroke adjusting mechanism 51 is formed of a resin molded product from the viewpoint of corrosion resistance and the like.

  In the chemical valve 2B, when the handle 54 is rotated in a predetermined direction with respect to the nut 52 engaged with the convex portion 23a of the cover 23, the sliding shaft 53 is lowered, while the handle 54 is rotated in a direction opposite to the predetermined direction. As a result, the sliding shaft 53 rises, and therefore the sliding shaft 53 can be arbitrarily positioned by adjusting the rotation amount of the handle 54. When operating air is supplied, the chemical valve 2B rises until the piston 25 hits the sliding shaft 53, and lifts the control side bellows valve body 20 by a predetermined amount to open the valve. When the operation air is discharged, the chemical liquid valve 2B pushes down the piston 25 by the elastic pressure of the control side spring 26 and presses the control side bellows valve body 20 against the valve seat 31 with a predetermined sealing force. Therefore, the stroke of the control side bellows valve body 20 is determined by the position of the sliding shaft 53.

  By the way, also in the chemical valve 2B, the compensation side bellows valve body 21 expands and contracts relative to the control side bellows valve body 20, and the volume change of the valve chamber 30 is compensated by the volume change of the compensation chamber 34. However, it is also conceivable that the volume change rate of the control side bellows valve body 20 and the compensation side bellows valve body 21 varies due to tolerances during processing. In this case, for example, if the volume change rate of the valve chamber 30 is larger than the volume change rate of the compensation chamber 34, the volume change amount increases according to the stroke as shown in LB3A of FIG. If the volume change rate is smaller than the volume change rate of the compensation chamber 34, as shown by LB3B in FIG. 5, there is a possibility that the total volume change of the entire valve decreases according to the stroke. Therefore, when such a problem occurs, if the stroke of the control side bellows valve element 20 is reduced by using the stroke adjusting mechanism 51, the variation in volume change of the entire valve is reduced, and the secondary side flow path is reduced. The volume change that occurs can be reduced. In addition, since the chemical | medical solution valve 2B comprises a valve part by the control side bellows valve body 20 and the compensation side bellows valve body 21, compared with a diaphragm valve body, it is easy to adjust a volume change.

  Therefore, according to the chemical valve 2B of the present embodiment, the control side bellows valve body 20 or the compensation side bellows valve body 21 is provided with the stroke adjusting mechanism 51 that adjusts the stroke of the control side bellows valve body 20. Even if the volume change of the valve chamber 30 or the compensation chamber 34 deviates from the design value due to tolerance when machining, and the total volume change of the entire valve varies, the stroke of the control side bellows valve element 20 is adjusted by the stroke adjustment mechanism 51. The variation in the total volume change of the entire valve can be reduced.

( Second reference example )
Next, a second reference example of the chemical valve according to the present invention will be described with reference to the drawings. FIG. 6 is a cross-sectional view of the valve unit 1C.
The chemical valve 2C of this reference example is different from the chemical valves 2A and 2B of the first reference example and the first embodiment in that it is a diaphragm valve. Therefore, here, the points different from the first reference example and the chemical valves 2A, 2B of the first embodiment will be described in detail, and the common points are given the same reference numerals as the chemical valves 2A, 2B in the drawings, Description is omitted as appropriate.

  The chemical liquid valve 2C is juxtaposed with the body 4 together with the suck back valve 3, and constitutes a valve unit 1C. The chemical liquid valve 2 </ b> C controls the chemical liquid using the control side diaphragm valve body 61 and the compensation side diaphragm valve body 62 which are cheaper than the bellows valve body.

  In the chemical valve 2C, a piston 63 is slidably loaded in a piston chamber 24 formed between a cylinder 22 and a cover 23, and the piston chamber 24 is partitioned into an upper chamber 24a and a lower chamber 24b in an airtight manner. . The piston 63 has a leg portion 64 protruding from the cylinder 22 toward the body 4 and screwed into the control side diaphragm valve body 61. The control side diaphragm valve body 61 is formed by injection molding a resin such as PTFE, and the peripheral edge portion 61a and the cylindrical portion 61c are connected by a thin film portion 61b. The control-side diaphragm valve body 61 is configured such that a peripheral edge portion 61 a is sandwiched between the cylinder 22 and the body 4, and the cylindrical portion 61 c is brought into contact with or separated from the valve seat 31 as the piston 63 moves up and down.

  On the other hand, the compensation side diaphragm valve body 62 is formed by injection molding a resin such as PTFE in the same shape as the control side diaphragm valve body 61, and the peripheral edge portion 62a and the cylindrical portion 62c are connected by a thin film portion 62b. The compensation-side diaphragm valve element 62 is disposed so as to be opposite to the control-side diaphragm valve element 61, and the peripheral edge 62 a is sandwiched between the body 4 and the support member 33. The compensation-side diaphragm valve body 62 engages with a spring receiver 35 that is slidably loaded on the support member 33, and the elastic pressure of the compensation-side spring 37 that is contracted between the spring receiver 35 and the lid 36 is always constant. It works upward. The compensation side spring 37 is set to have a smaller elastic force than the spring 26, and the connecting rod 32 is sandwiched between the cylindrical portion 61 c of the control side diaphragm valve body 61 and the cylindrical portion 62 c of the compensation side diaphragm valve body 62. Is held by.

  In such a chemical valve 2C, the control diaphragm valve body 61 and the compensating diaphragm valve body 62 open and close while deforming the thin film portions 61b and 62b. Therefore, when supplying the chemical liquid, the volume of the valve chamber 30 is large. 9A, the volume of the compensation chamber 34 increases as shown in FIG. 9B, and the volume of the compensation chamber 34 decreases as shown in FIG. 9B. On the other hand, when the supply of the chemical solution is stopped, the volume of the valve chamber 30 increases in a parabolic shape. The volume of the compensation chamber 34 increases parabolically.

  The chemical valve 2C uses the control-side diaphragm valve body 61 and the compensation-side diaphragm 62 having the same shape, but the shapes of the thin film portions 61b and 62b are slightly different depending on the dimensional accuracy, the mounting position, etc., and the control-side diaphragm valve Since the thin film portion 61b of the body 61 and the thin film portion 62b of the compensation side diaphragm valve body 62 are bent in opposite directions, the thin film portions 61b and 62b are not deformed in the same manner when the valve is opened and closed. Therefore, in the chemical valve 2C, the volumes of the valve chamber 30 and the compensation chamber 34 do not increase or decrease correspondingly, the volume of the entire valve changes in a parabolic shape, and the volume change of the secondary side flow path becomes unstable.

For this reason, the chemical valve 2C is provided with a stroke adjustment mechanism 51 similar to that of the first embodiment. When the lower chamber 24 b is pressurized, the chemical valve 2 </ b> C rises until the piston 63 hits the sliding shaft 53, thereby separating the control-side diaphragm valve body 30 from the valve seat 31 by a predetermined amount. Since the slide shaft 53 moves forward and backward in the cylinder 22 by rotating the handle 54, the stroke of the control-side diaphragm valve body 30 can be arbitrarily adjusted by adjusting the position of the slide shaft 53.

Therefore, the chemical valve 2C of the present reference example can be obtained by adjusting the stroke of the control side diaphragm valve element 61 to the stroke St (see FIG. 9) in which the volume change of the entire valve is zero using the stroke adjusting mechanism 51. The overall volume change becomes zero and constant, and the volume change generated in the secondary flow path can be made constant. Moreover, the chemical liquid valve 2C, by using the control-side diaphragm valve element 61 of the compensating side diaphragm valve element 62, the chemical liquid valve 2 A of the first reference example of using compensation side bellows valve body 21 and the control side bellows valve body 20 Material costs can be reduced and costs can be reduced.

  Although the embodiments of the present invention have been described, the present invention is not limited to the above-described embodiments, and various applications are possible.

(1) For example, in the above embodiment, the control-side bellows valve body 20 and the compensation-side bellows valve body 21 are coaxially arranged so as to operate integrally in the vertical direction. 20 and the compensation side bellows valve body 21 may be attached to the body 4 side by side, and the control side bellows valve body 20 and the compensation side bellows valve body 21 may be connected by connecting means having a seesaw mechanism. Also in this case, if the control-side bellows valve body 20 and the compensation-side bellows valve body 21 are relatively expanded and contracted by the seesaw mechanism to increase or decrease the volumes of the valve chamber 30 and the compensation chamber 34, the total volume change of the entire valve is constant. become.

(2) For example, an anti-rotation mechanism may be provided on the handle 54 of the first embodiment to prevent the handle 54 from being erroneously rotated after the slide shaft 53 is positioned.

It is sectional drawing of a valve unit concerning 1st reference example of this invention, Comprising: A chemical | medical solution valve shows a valve closed state. Similarly, it is sectional drawing of a valve unit, Comprising: A valve open state is shown. Similarly, it is a figure which shows the relationship between the volume change which arises in the secondary side flow path of a valve, and a stroke, (a) is a figure which shows the volume change of a valve chamber, (b) shows the volume change of a compensation chamber. (C) is a figure which shows the volume variation | change_quantity of the whole valve | bulb. 1 is a cross-sectional view of a valve unit according to a first embodiment of the present invention. Similarly, it is a figure which shows the relationship between the volume change produced in the secondary side flow path of a valve, and a stroke, and is a figure which shows the volume change amount of the whole valve | bulb. It is sectional drawing of the valve unit concerning the 2nd reference example of this invention. It is sectional drawing of the chemical | medical solution valve of a 1st prior art example. It is sectional drawing of the chemical | medical solution valve of a 2nd prior art example. It is a figure which shows the relationship between the volume change produced in the secondary side flow path of the chemical | medical solution valve of a 2nd prior art example, and a stroke, (a) is a figure which shows the volume change of a valve chamber, (b) is a figure of a compensation chamber. It is a figure which shows a volume change, (c) is a figure which shows the volume change amount of the whole valve | bulb.

Explanation of symbols

2A, 2B Chemical liquid valve 5 Input port 8 Communication hole 11 Output port 30 Valve chamber 34 Compensation chamber 20 Control side bellows valve body 21 Compensation side bellows valve body 32 Connecting rod 51 Stroke adjustment mechanism 61 Control side diaphragm valve body 62 Compensation side diaphragm valve body

Claims (1)

In the chemical valve that controls the supply or shutoff of the chemical,
A body formed with a valve chamber communicating with the input port, a compensation chamber communicating with the output port, and a communication hole communicating with the valve chamber and the compensation chamber;
A control side bellows valve body housed in the valve chamber;
A valve seat provided on the body, on which the control side bellows valve body abuts or separates;
Compensating side bellows valve body having the same shape as the control side bellows valve body, and being accommodated in the compensation chamber;
Connecting to the control-side bellows valve body and the compensation-side bellows valve body, and relatively extending and contracting the control-side bellows valve body and the compensation-side bellows valve body;
A valve in which the volume of the valve chamber is increased or decreased when the volumes of the valve chamber and the compensation chamber change simultaneously due to the expansion and contraction of the control side bellows valve body and the compensation side bellows valve body by the connecting means. The absolute value of the sum of the chamber volume change amount and the compensation chamber volume change amount in which the volume of the compensation chamber is reduced or increased is constant at zero ;
Having stroke adjusting means for adjusting the stroke of the control side bellows valve element;
To make the absolute value of the sum of the valve chamber volume change amount in which the volume of the valve chamber is increased or decreased and the compensation chamber volume change amount in which the volume of the compensation chamber is reduced or increased constant at zero is the stroke Adjusting with an adjustment means, The chemical | medical solution valve characterized by the above-mentioned.

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