JPH10267149A - Valve and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of part items, improve the assembling workability, and reduce cost in a resin valve provided with a rotary member having a valve stem and a rotary valve part, and a valve body holding the rotary member so that it can be slidably and rotatably sealed. SOLUTION: The valve is provided with a rotary member 5 having a valve stem 51 and a rotary valve part 52, and a valve body 6 holding the rotary member 5 rotatably. The inner surface 65 of the valve body 6 and the outer surface 54 of the rotary member 5 are lapped one over the other so that they can be slidably sealed. With this valve, the rotary member 5 is set in a metal mold as a core, and molding resin is poured into a molding space around the core, and the valve body 6 is integrally injection-molded with synthetic resin. As material for the rotary member 5 and the valve body 6, PTFE or PFA can be suitably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a valve and a method for manufacturing the same.

[0002]

2. Description of the Related Art A rotary member having a valve stem and a rotary valve portion is slidably held by a valve body, and a communication passage provided in the rotary valve portion is provided in the valve body by rotation of the valve stem. A valve that is configured to be cut off and communicated with the entrance passage or the exit passage that is set is known as, for example, a rotary valve. The structure of a conventional valve of this kind is shown in FIG.

In the valve shown in FIG. 1, a rotary member 1 is formed by connecting two members, a valve rod 11 and a spherical rotary valve portion 12, and a communication passage 13 is formed in the rotary valve portion 12.
Are provided, and the valve stem 11 and the rotary valve portion 12 are both made of synthetic resin such as fluororesin. The valve body 2 is formed by joining two members of a main body 21 and a sub-body 22. For example, an inlet passage 23 is provided in the sub-body 22, and an outlet passage 24 is provided in the main body 21. I have. These main bodies 2
Both 1 and the sub-body 22 are made of synthetic resin such as fluorine resin. The valve body 2 and the rotary valve 12
, A valve seat 25 is provided, and a seal ring 26 is provided between the valve body 2 and the valve rod 11. The seal ring 26 is pressed against the seal seat 14 on the valve stem 11 side by a seal retainer 3 made of a synthetic resin such as a fluorine resin. Further, a seal ring 27 is provided between the main body 21 and the sub-body 22. The above-described valve seat 25, seal ring 26,
27 indicates that the inlet passage 23 and the outlet passage 24 are
It is necessary to prevent leakage of liquid when it is shut off by the flow path or when the inlet passage 23 and the outlet passage 24 communicate with each other through the communication passage 13. In FIG. 9, reference numeral 31 denotes an operating handle, 32 denotes a pressing ring for the seal holder 3, and 33 and 34 denote pressing rings for pipe holding.

[0004]

In the conventional valve shown in FIG. 9, the rotating member 1 and the valve body 2 are each formed of two members, and the valve seat 25 is provided to ensure the sealing performance. And seal rings 26 and 27
Are used. Therefore, in the conventional valve,
A large number of components are required, and the number of assembling steps is increased. In addition, a high level of assembling technology is required to secure the sealability, and there are many problems in terms of assembling workability and cost.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a valve having a small number of parts, excellent in productivity and economical efficiency, and a method of manufacturing the valve.

[0006]

According to the present invention, there is provided a valve comprising:
A rotary member having a valve stem and a rotary valve portion having a communication passage,
A valve body formed of a synthetic resin integrally molded body having an inlet passage and an outlet passage which hold the rotating member rotatably around its axis and which is cut off from the communication passage by rotation of the rotary valve portion. Wherein the inner surface of the valve body and the entire outer surface of the rotating member covered by the inner surface of the valve body overlap with each other in a slidable manner.

This valve can be easily and economically manufactured by the method for manufacturing a valve according to the method of the present invention. According to this manufacturing method, a rotary member having a valve stem and a rotary valve portion having a communication passage is set in a mold as a first core, and a second member for forming an inlet passage and an outlet passage is provided.
A core is set in the mold, and a molding resin is injected into a molding space around the first core and the second core, thereby holding the rotating member rotatably around its axis and The valve body having the inlet passage and the outlet passage, which is interrupted by the rotation of the rotary valve portion, is injection molded integrally with synthetic resin.

[0008] In the valve manufactured by the valve according to the present invention and the valve manufacturing method according to the method of the present invention, the valve body is formed of an integrally molded synthetic resin.
The valve body is composed of one part. Also, since the inner surface of the valve body and the outer surface of the rotating member covered by the valve body overlap in a slidable manner, the valve body is not used even though the valve seat and the seal ring described at the beginning are used. The sealing property is ensured by the overlapping portion between the inner surface of the rotary member and the outer surface of the rotating member.

In the valve according to the present invention and the method of manufacturing the valve according to the method of the present invention, the rotary member is formed of an integrally molded synthetic resin having the valve stem and the rotary valve portion having the communication passage. In this case, as in the case of the above-described valve body, the rotating member is formed of one component.

In the valve according to the present invention, an annular collar portion is provided at an axially intermediate portion of the valve stem of the rotating member,
It is possible to adopt a configuration in which an annular concave groove portion that holds the flange portion slidably and rotatably is provided on the inner surface of the valve body, and in such a case,
The overlapping area between the flange portion and the concave groove portion increases the area of the overlapping portion between the inner surface of the valve body and the outer surface of the rotating member, thereby improving the sealing performance. Also,
The flange and the concave groove engage with each other in the axial direction of the rotating member, thereby preventing the rotating member from being pulled out.

In the valve according to the present invention, the inner surface of the valve body and the outer surface of the rotary member overlapping the inner surface cooperate with each other to form an annular closed space. An inlet portion is provided, and an entirety of the peripheral wall surface of the sealed space is slidably adhered with an elastic annular sealing material housed and held in the sealed space.
Configuration can be adopted. By doing so, the sealing property between the rotating member and the valve body is further enhanced by the annular sealing material. Further, in the valve having the above-described configuration, in the method for manufacturing a valve according to the present invention, a semicircular groove-shaped recess may be provided on an outer surface of the rotating member set in the mold as the first core. In addition, it is possible to easily and economically make the recess by accommodating and holding the inner half of the annular sealing material having a circular cross section.

In the valve according to the present invention, the valve body includes a cylindrical portion for rotatably holding the valve stem of the rotating member, and a concave groove surrounding the valve stem is formed on an inner peripheral portion of an end surface of the cylindrical portion. An annular sealing material having elasticity is housed and held in the concave groove, and a cap body is attached to the cylindrical portion, and the cap body compresses the annular sealing material to remove the annular sealing material. It is possible to adopt a configuration in which a pressing portion that slidably adheres to the outer peripheral surface of the valve stem and the groove wall surface of the concave groove can be employed. The sealing performance between the valve body and the cylindrical portion is further enhanced.

In the method for manufacturing a valve according to the present invention,
If the melting point of the material forming the rotating member is equal to or higher than the melting point of the molding resin injected into the molding space, the valve body molded in the molding space becomes the first core. Or no possibility of fusing to the rotating member set in the mold. Therefore, a valve can be obtained immediately by molding the valve body, and in such a valve, the rotating member is rotatably held by the valve body, and the inner surface of the valve body and the outer surface of the rotating member can be hermetically slid. Will be overlapped. Here, as the material for forming the rotating member, ceramic or metal can be used in addition to synthetic resin.

In the method of manufacturing a valve according to the present invention, wherein an integral molded body of a synthetic resin is used for the rotating member set in a mold as a first core, the molding shrinkage of the synthetic resin forming the rotating member is performed. It is desirable that the molding resin injected into the molding space has a larger molding shrinkage ratio than the molding ratio. If the molding shrinkage of the synthetic resin forming the rotating member and the molding resin of the valve body is determined in such a relationship, the shrinkage after molding of the synthetic resin forming the valve body causes
The sealing performance at the overlapping portion between the inner surface of the valve body and the outer surface of the rotating member is further enhanced. Therefore, a valve made by this method exhibits high sealing performance. Note that the molding shrinkage of the synthetic resin or the molding resin refers to the shrinkage before and after molding due to curing after injection molding with the resin.

In the method of manufacturing a valve according to the present invention, in which an integrally molded synthetic resin is used for the rotating member set in a mold as a first core, the molding resin injected into the molding space is rotated by the rotation. It is possible to use the same synthetic resin as the synthetic resin forming the member.

In the method of manufacturing a valve according to the present invention, the rotating member is formed of a material selected from PTFE, ceramics and metal, and PFA, PP, PE, PPS, P
One kind of synthetic resin selected from EEK, PES, PA, and POM can be used. “PTFE” is a polytetrafluoroethylene resin, “PFA” is a perfluoroalkoxy fluororesin, “PP” is a polypropylene resin, “PE” is a polyethylene resin, “PPS” is a polyphenylsulfide resin, and “PEEK” is a polyether. Ether ketone resin, “PES” is a polyethersulfone resin, “PA” is a polyamide resin, and “POM” is an abbreviation for polyacetal resin. The above “ceramics” includes Al ₂ O ₃ and SiC.

[0017]

FIG. 1 is a longitudinal sectional view showing an embodiment of a valve according to the present invention. In this valve, the rotating member 5 includes a cylindrical valve stem 51 and a spherical rotating valve portion 5.
2 and a rotary valve portion 5
2 has a communication passage 53 orthogonal to the axis of the rotating member 5. In this rotating member 5, its outer surface 5
4 is formed by the outer peripheral surface 54a of the rotary valve portion 52 and the outer peripheral surface 54b of the valve rod 51. The valve body 6
A body body portion 61 holding the rotary valve portion 52;
A PFA including a cylindrical portion 62 protruding from the body main portion 61 and surrounding the valve stem 51, and sleeve portions 63 and 64 protruding forward and backward of the body main portion 61.
It is an integrally molded product of In this valve body 6, an inner surface 65 is formed by an inner peripheral surface 65 a of the body main body 61 and an inner peripheral surface 65 b of the cylindrical portion 62. Then, the inner peripheral surface 65a of the body main body 61 overlaps the outer surface 54a of the rotary valve portion 52, and the cylindrical portion 62
Of the valve stem 51 overlaps the outer peripheral surface 54b of the valve rod 51. In other words, the inner surface 6 of the valve body 6
5 is an inner surface 65 of the valve body 6 in the rotating member 5.
Overlying the outer surface 54 covered by the outer surface. In this case, the overlapping state is a state in which the rotating member 5 is capable of sealingly sliding with respect to the valve body 6. The rotating member 5 is rotatably held by a valve body 6 around its axis.

The body main body 61 is provided with an inlet passage 66 and an outlet passage 67.
67 is connected to the communication passage 5 by rotation of the rotary valve 52.
Communication is interrupted to 3.

The two sleeve portions 63 and 64 are respectively provided with pipe connecting members 71 and
72 are accommodated, and their pipe connection members 71,
72, the inlet passage 66 and the outlet passage 6 described above.
7 are provided with passages 73 and 74. The male screw 6 provided on the sleeves 63 and 64
Pressing rings 6 made of fluororesin for holding pipes 3a and 64a
8, 69 female screw portions 68a, 69a are screwed.

An operating handle 55 is attached to the upper end of the valve rod 51 of the rotating member 5, and when the handle 55 is rotated, the rotating member 5 rotates.

In the valve shown in FIG.
Is PTFE, and the valve body 6
Is PFA. For this reason, the melting point of the material forming the rotating member 5 depends on the valve body 6.
Is higher than the melting point of the synthetic resin forming Further, the molding shrinkage of the synthetic resin forming the valve body 6 is greater than the molding shrinkage of the synthetic resin forming the rotating member 5.

In this valve, the rotating member 5 and the valve body 6 used for the valve are not formed by combining several kinds of members, but are formed as one body. Therefore, this valve has one rotating member 5.
And one valve body 6. In addition, since the inner surface 65 of the valve body 6 and the outer surface 54 of the rotating member 5 overlap in a slidable manner, the sealing property of the overlapping portion is ensured without using a valve seat or a seal ring. .

The valve described with reference to FIG. 1 can be manufactured by a manufacturing method described below as an example. That is, as shown in FIG. 8, the rotating member 5 formed of an integrally molded body of PTFE is molded in advance, and the rotating member 5 is
As a core 110, an injection molding die 1 having a molding surface 101 on which the outer contour of the valve body 6 can be molded.
Set to 00. At the same time, a round rod-shaped second core 120 made of metal is inserted into a communication passage 53 provided in the rotary valve portion 52 of the rotary member 5 to allow the molding resin to enter the communication passage 53. The second core 120 is set in the mold 100 so that the second core 120 can form the inlet passage 73 and the outlet passage 74 of the valve body 6 with the second core 120. Further, metal third cores 130 and 140 having molding surfaces for molding the inner peripheral surfaces of the sleeve portions 63 and 64 are fitted to the second core 120 and set in the mold 100. I do.

In this manner, the rotating member 5 used as the first core 110 is kept at room temperature or preheated to the mold temperature, and the first core 110, the second core 120, and the third core Molding space S formed around 130
Then, PFA in a molten state, which is a molding resin for molding the valve body 6, is injected, and after a certain cooling time, the PFA is cured and removed from the mold 100. By doing so, the body main body 61, the cylindrical portion 62, and the sleeve portions 63 and 64 having the inlet passage 66 and the outlet passage 67 described in FIG. 1 are molded as a PFA integrally molded body.

By performing such a manufacturing method, the first core 1
PT, which is the material of the rotating member 5 used as 10
The melting point of FE is PFA which is a molding material of the valve body 6.
, The valve body 6 is molded without fusion during injection molding. Moreover, PTF
Since the molding shrinkage of PFA is larger than the molding shrinkage of E, after injection molding, the inner surface 65 of the valve body 6 molded with PFA is securely attached to the outer surface 54 of the rotating member 5 made of PTFE. Is in close contact with the
Inner surface 65 of valve body 6 and outer surface 54 of rotating member 5
It is useful to improve the sealing performance at the overlapping part with the slab.

In the method of manufacturing the valve described with reference to FIG. 1 and the valve described with reference to FIG.
TFE is used, and PFA is used as a molding material of the valve body 6.
However, it is also possible to use the same synthetic resin for the material of the rotating member 5 and the valve body 6, and if such the same material is used, the melting points of both the rotating member 5 and the valve body 6 become higher. Will be the same. Even when the melting point of the rotating member 5 and that of the valve body 6 are the same, when the valve body 6 is injection-molded, the molding material of the valve body 6 is applied to the rotating member 5 used as the first core 110. Fusing is unlikely to occur.
This is because both resins do not fuse even if the molten resin touches the cooled resin.

In the method of manufacturing the valve described with reference to FIG. 1 and the valve described with reference to FIG. 8, various materials can be selected as the material of the rotating member 5 and the material of the valve body 6. Specifically, in addition to the above-mentioned PTFE, ceramic or metal can be used as the material of the rotating member 5, and as the material of the valve body 6, in addition to the above-mentioned PFA, PP, PE, PPS, PEEK, PES, PA,
One kind of synthetic resin selected from POM can be used.

When a synthetic resin such as PTFE is used as the material of the rotating member 5, the maximum value of the surface roughness Rmax is used.
Has been confirmed to be able to secure a high degree of the above-mentioned sealing performance when processed to 6.3 μm or less. The rotating member 5
When ceramics or metals are used as the material of the above, if the maximum value Rmax of the surface roughness is processed to 2.3 μm or less, the above-mentioned high sealing performance can be secured, and the passage can be opened and closed for a long time. It has been confirmed that the wear of the inner surface 65 of the valve body 6 as the counterpart when the above is repeated is suppressed and the seal reliability is enhanced.

In the valve manufactured by using the valve manufacturing method according to the present invention, the inner surface 65 of the valve body 6 is formed.
Of the rotary member 5 at the overlapping portion between the valve body 6 and the outer surface 54 of the rotary member 5 depends on the magnitude of the holding force of the rotary member 5 by the valve body 6, and the magnitude of the holding force depends on the molding material of the valve body 6. It is related to shrinkage and tensile strength. That is, the valve body 6 formed of a synthetic resin having a large molding shrinkage ratio has a large holding force of the rotating member 5 even if the tensile strength is small, and conversely, a valve formed of a synthetic resin having a large tensile strength. The body 6 increases the holding force of the rotating member 5 even if the molding shrinkage is small. In the case of a valve used in a semiconductor manufacturing process, the molding material of the valve body 6 preferably has a shrinkage of 2% or more, particularly preferably 4% or more. Such a shrinkage is satisfied by using PFA for the molding material. Further, the tensile strength of the molding material of the valve body 6 is preferably 200 kg / cm ² or more, and particularly preferably 300 kg / cm ² or more.

Next, specific values of the molding shrinkage and the tensile strength of the synthetic resin that can be selected as the material of the valve body 6 will be described. Which material to choose depends on
It should be determined appropriately in consideration of the purpose, economy, and other conditions of the valve.

Shrinkage (%) Tensile strength (kg / cm ² ) PFA 3-5 300 PP 1-2400 PE 1-2 150 PPS 0.5-1900 PPS (with glass fiber) 0.2-0. 5 1300 PEEK 1900 PEEK (with glass fiber) 0.5 1700 PES 0.6 800 PES (with glass fiber) 0.2-0.5 1400 PA 1.5 700 POM 1.5 600

FIG. 1 illustrates a so-called ball valve in which the rotary valve portion 52 of the rotary member 5 is formed in a spherical shape, and FIG. 8 illustrates a method of manufacturing such a ball valve. The valve manufactured by adopting the valve manufacturing method according to the present invention is not limited to a ball valve.
For example, as shown in FIG.
2 may be formed in a columnar shape, or as shown in FIG. 3, the rotary valve portion 52 of the rotary member 5 may be formed in a truncated cone shape. In FIGS. 2 and 3, portions corresponding to the portions described in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted.

In the valve of the present invention and the valve manufactured by the method of manufacturing the valve of the present invention, as described above, the inner surface 65 of the valve body 6 and the outer surface 54 of the rotating member 5 overlap in a slidable manner. Thus, the sealing property of the overlapping portion is ensured. Next, measures for further improving the sealing property will be described.

In the countermeasure shown in FIG. 4, annular flanges 57, 57 are provided at two axially intermediate portions of the valve rod 51, and these flanges 57, 57 are provided on the inner surface 65 of the valve body 6. Annular concave grooves 60, 60 which are slidably held rotatably are provided. The same applies to the countermeasure shown in FIG. 5, which differs from the countermeasure shown in FIG.

If the measures shown in FIGS. 4 and 5 are taken,
Inner surface 65 of valve body 6 and outer surface 54 of rotating member 5
Since the area of the overlapping portion with that of FIG. 1 is larger than that in the case of FIG. 1, the sealing property is improved accordingly. In addition, by taking these measures, the flange portions 57, 57 and the concave groove portions 60, 60 are engaged in the axial direction of the rotating member 5, and the engagement causes the rotating member 5 to engage with the valve body 6. Has the advantage of being able to slide and rotate freely in a fixed position, and the rotation member 5 is prevented from coming off.

FIG. 6 shows another measure for improving the sealing performance. The countermeasure shown in the figure is to solve the problem of the inner surface 65 of the valve body 6 (specifically, the inner peripheral surface 65b of the cylindrical portion 62) and the outer surface 5 of the rotating member 5 overlapping the inner surface 65.
4 (specifically, the outer peripheral surface 54b of the valve rod 51) are provided with semicircular recesses 82 and 83 which cooperate with each other to form an annular closed space 81.
An annular seal member 84 made of an elastic rubber O-ring housed and held in the closed space 81 over the entire peripheral wall surface
Are slidably adhered to each other. The valve that takes such measures is the first core 110 described above.
The outer surface 5 of the rotating member 5 set in the mold 100
The semi-circular groove-shaped recessed portion 83 is formed in advance in FIG. 4 and the inner half of the annular sealing material 84 having a circular cross section is housed and held in the recessed portion 83, and the valve described with reference to FIG. It can be easily made by performing injection molding of the body 6. By adopting this manufacturing method, it is not necessary to incorporate the annular sealing material 84 into the rotating member 5 or the valve body 6 later.

When the annular sealing material 84 is housed and held in the closed space 81 as described above, the rotation member 5 and the valve body 6 are brought into close contact with the annular sealing material 84 and the closed space 81.
And the sealing property between them.

FIG. 7 shows another measure for improving the sealing performance. This valve body 6 holds the valve rod 51 of the rotating member 5 rotatably when the valve body 6 is injection-molded by employing the manufacturing method described with reference to FIG.
A groove 85 surrounding the valve rod 51 is formed in the inner peripheral portion of the end face of the cylindrical portion 62, and a male screw portion 86 is formed in the cylindrical portion 62. Then, in the valve obtained by molding the valve body 6, the concave groove 85 is formed.
An annular sealing material 87 made of a rubber O-ring or the like is accommodated therein, and the annular sealing material 87 is compressed by a pressing portion 89 of a cap body 88 which is screwed into the male screw portion 86 and mounted on the cylindrical portion 62, and is compressed. By its annular sealing material 8
7 is the outer peripheral surface 54b of the valve rod 51 and the groove wall surface 85a of the concave groove 85
And slidably adhered to them.

[0039]

As described above, in the valve of the present invention and the valve manufactured by the manufacturing method of the present invention, the valve body is formed of a single molded body of one synthetic resin. Since the sealing property is ensured by the overlap between the inner surface and the outer surface of the rotating member, the number of parts is reduced, and at the same time, the assembling workability and cost are greatly improved as compared with the conventional valve. Such a valve can be easily and inexpensively manufactured by the valve manufacturing method of the present invention.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a valve according to the present invention.

FIG. 2 is a longitudinal sectional view showing a main part of a valve employing a rotary valve section according to a modified example.

FIG. 3 is a longitudinal sectional view showing a main part of a valve employing a rotary valve according to another modification.

FIG. 4 is a partial longitudinal sectional view showing a first example of a measure for improving the sealing property.

FIG. 5 is a partial longitudinal sectional view showing a second example of a measure for improving the sealing property.

FIG. 6 is a partial longitudinal sectional view showing a third example of a measure for improving the sealing property.

FIG. 7 is a partial longitudinal sectional view showing a fourth example of a measure for improving the sealing property.

FIG. 8 is a longitudinal sectional view for explaining a method of manufacturing a valve according to the present invention.

FIG. 9 is a longitudinal sectional view of a conventional valve.

[Explanation of symbols]

 Reference Signs List 5 rotating member 6 valve body 51 valve stem 52 rotating valve portion 53 communication passage 54 outer surface of rotating member 54b outer peripheral surface of valve stem 57 flange 60 concave groove 62 cylindrical portion 65 inner surface of valve body 73 inlet passage 74 outlet passage 81 Sealed space 82, 83 Recessed portion 84 Annular sealing material 85 Recessed groove 85a Groove wall surface of concave groove 87 Annular sealing material 88 Cap body 89 Pressing portion 100 Mold 110 First core 120 Second core S Molding space

Claims (16)

[Claims] A rotary member having a valve stem and a rotary valve portion provided with a communication passage; holding the rotary member rotatably around its axis; and interrupting communication with the communication passage by rotation of the rotary valve portion. A valve body formed of an integral molded body of synthetic resin having an inlet passage and an outlet passage, wherein an inner surface of the valve body and an outer surface of the rotating member covered by the inner surface of the valve body are provided. A valve characterized in that it is entirely slidably overlapped with the whole. 2. The valve according to claim 1, wherein the rotary member is formed of an integrally molded synthetic resin having the valve stem and the rotary valve portion having the communication passage. 3. An annular groove portion is provided at an axially intermediate portion of the valve stem of the rotating member, and the annular groove portion slidably holds the flange portion on the inner surface of the valve body. The valve according to claim 1, wherein the valve is provided. 4. An inner surface of the valve body and an outer surface of the rotating member overlapping the inner surface are provided with recesses which cooperate with each other to form an annular closed space. The valve according to any one of claims 1 to 3, wherein an elastic annular sealing material housed and held in the closed space is slidably adhered to the entire peripheral wall surface of the closed space. . 5. The valve body includes a cylindrical portion rotatably holding the valve rod of the rotating member, and a concave groove surrounding the valve rod is provided on an inner peripheral portion of an end surface of the cylindrical portion. An annular sealing material having elasticity is accommodated and held, and a cap body is mounted on the cylindrical portion, and the cap body compresses the annular sealing material and compresses the annular sealing material with the outer peripheral surface of the valve stem. The valve according to any one of claims 1, 2, 3, and 5, further comprising a pressing portion that is slidably adhered to the groove wall surface of the concave groove. 6. The melting point of the material forming the rotating member is equal to or higher than the melting point of the synthetic resin forming the valve body.
A valve according to any one of claims 4 and 5. 7. The molding shrinkage of the synthetic resin forming the valve body is greater than the molding shrinkage of the synthetic resin forming the rotating member. A valve according to any one of claims 5 and 6. 8. The valve according to claim 2, wherein said rotating member and said valve body are formed of the same synthetic resin. 9. The rotating member is made of a material selected from PTFE, ceramics, and metal, and the valve body is made of PFA, PP, PE, PPS, PEEK,
8. The valve according to claim 1, wherein the valve is formed of one kind of synthetic resin selected from PES, PA, and POM. 10. A rotary member having a valve stem and a rotary valve portion having a communication passage is set in a mold as a first core, and a second core for forming an inlet passage and an outlet passage is provided in the mold. By setting in a mold and injecting molding resin into a molding space around the first core and the second core,
A valve body having the inlet passage and the outlet passage, which holds the rotating member rotatably around its axis and is cut off from the communication passage by rotation of the rotary valve portion, is integrally injection-molded with synthetic resin. A method for manufacturing a valve, comprising: 11. The method for manufacturing a valve according to claim 10, wherein the rotary member is formed of a synthetic resin integrally formed having the valve stem and the rotary valve portion having the communication passage. 12. A semicircular groove-shaped concave portion is provided on an outer surface of the rotating member set in the mold as the first core, and the concave portion has an inner peripheral surface of an annular sealing material having a circular cross section. The half of the side is held and held.
2. The method for manufacturing a valve according to 1. 13. The material for forming the rotating member, wherein the melting point of the material is equal to or higher than the melting point of the molding resin injected into the molding space.
The method for producing a valve according to any one of the above. 14. The molding resin according to claim 11, wherein said molding resin injected into said molding space has a molding shrinkage greater than that of said synthetic resin forming said rotating member. A method for manufacturing a valve according to the above. 15. The valve manufacturing method according to claim 11, wherein the molding resin injected into the molding space is the same synthetic resin as the synthetic resin forming the rotating member. . 16. The rotating member is formed of a material selected from PTFE, ceramics, and metal, and the molding resin injected into the space is PFA, PP, PE, PP
11. A synthetic resin selected from the group consisting of S, PEEK, PES, PA, and POM.
A method for manufacturing a valve according to any one of claims 14 and 15.