JP2007148465A - Pressure reducing valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain the miniaturization of a product and the higher accuracy of product characteristics by reducing sliding resistance generated accompanied by the reciprocation of a pressure control shaft. <P>SOLUTION: The pressure reducing valve 1 used for water supply piping comprises the pressure control shaft 16 which reciprocates by being connected with a pressure control diaphragm 14 operating for determining an equilibrium point between outflow secondary pressure P<SB>2</SB>and the spring force of a pressure control spring 15 arranged so as to cope with the secondary pressure, thereby approaching and separating a valve element 20 to and from a valve seat 21 in which the secondary pressure P<SB>2</SB>acts on the shaft 16 as back pressure. The shaft 16 is slidably supported by a holder 22, and the holder 22 is retained by a valve case 2 in a floating state. An inside seal 32 provided between the shaft 16 and the holder 22 for preventing the inflow primary pressure P<SB>1</SB>to a back pressure chamber 26 is fitted to a mounting groove 33 formed on the inner circumferential surface of the holder 11 while closely contacting with the outer circumferential surface of the shaft 16 so as to be slidable. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pressure reducing valve which is a kind of valve device, and more particularly to a pressure reducing valve suitable for use in a water supply pipe. The pressure reducing valve of the present invention is used for, for example, a water supply pipe in a warm water washing toilet seat device.

  Strainers, check valves, pressure reducing valves, water stop valves, heat exchangers, flow control valves, nozzles, etc. are arranged in order from the upstream side of the water supply piping in the warm water washing toilet seat device. It has a function of adjusting the outlet secondary pressure so that the supply water pressure supplied to the downstream water stop valve is always constant.

  FIG. 3 shows an example of a pressure reducing valve 51 according to a conventional example.

The pressure reducing valve 51 is first closed the outflow side secondary pressure P ₂ and the pressure regulating diaphragm 53 to operate seeking equilibrium between the spring force of the arranged pressure regulating spring 52 to counteract this of the pressure reducing valve 51 A pressure adjusting shaft 54 is connected to the free end of the pressure adjusting diaphragm 53. The pressure adjusting shaft 54 reciprocates in the axial direction (vertical direction in the figure) in accordance with the operation of the pressure adjusting diaphragm 53, and the valve body portion 55 integrally provided on the outer peripheral surface thereof approaches the valve seat portion 56. The opening area of the valve hole 57 is increased or decreased by separating. Therefore, for example, when the secondary pressure P ₂ increases, the floating end of the pressure adjusting diaphragm 53 rises due to the balance with the pressure adjusting spring 52, and the pressure adjusting shaft 54 rises accordingly. close to the valve seat portion 56, are reduced in opening area of the valve hole 57, the flow rate is throttled by the secondary pressure P ₂ is reduced.

Further, in the pressure reducing valve 51, the secondary pressure P ₂ so that it can be easily operated even pressure regulating diaphragm 53 at a low pressure level, also introduced into the back pressure chamber 58 provided in FIG vertical side of the pressure regulating shaft 54 It is comprised so that. The back pressure chamber 58 is provided between a lower end shaft portion 54a of the pressure adjusting shaft 54 and a lid member 59 provided integrally with a cylindrical bearing portion 60 that slidably supports the lower end shaft portion 54a. .

Further, an inner seal 61 is provided between the lower end shaft portion 54 a of the pressure adjusting shaft 54 and the cylindrical bearing 60 so that the inflow side primary pressure P ₁ does not flow into the back pressure chamber 58. The O-ring 63 is mounted in an annular mounting groove 62 provided on the outer peripheral surface of the pressure adjusting shaft 54, and the O-ring 63 is slidably brought into close contact with the inner peripheral surface of the cylindrical bearing portion 60. Yes.

The lid member 59 is fixed to the valve case 65 using a required number of assembly bolts 64, but the cylindrical bearing portion 60 and the valve case 65 prevent the primary pressure P ₁ from flowing out of the pressure reducing valve 51. An outer seal 66 is provided between the O-ring 68 and an O-ring 68 mounted in an annular mounting groove 67 provided on the outer peripheral surface of the cylindrical bearing portion 60. The structure is configured to be in close contact with the inner surface of the case 65.

  By the way, these kinds of pressure reducing valves 51 have recently been required to have high precision of product characteristics as well as downsizing of products. However, since the component tolerance does not decrease even when the product is downsized, generally, when the product is downsized, the product characteristics tend to deteriorate, and thus downsizing of the product is difficult.

In this regard, in order to improve the product characteristics while reducing the size of the product, it is effective to reduce the sliding resistance of the inner seal 61, but the conventional technique has the following disadvantages, Therefore, it is considered difficult to reduce the sliding resistance.
(A) Since the mounting groove 62 for mounting the O-ring 63 is provided on the outer peripheral surface of the pressure adjusting shaft 54, the pressure adjusting shaft 54 is formed to have a large diameter to ensure the necessary strength. Yes. When the diameter of the pressure adjusting shaft 54 is large, a large diameter is used for the O-ring 63 attached to the pressure adjusting shaft 54. Since the large O-ring 63 has a large sliding diameter, the sliding resistance is large. .
(B) The O-ring 63 mounted in the mounting groove 62 is a type of seal (so-called squeeze packing) that involves volume compression with respect to its elastic deformation, and this type of seal has a large sliding resistance due to the volume compression.
(C) The lid member 59 provided with the cylindrical bearing portion 60 that slidably supports the pressure adjusting shaft 54 is completely fixed to the valve case 65 by the assembly bolt 64. Therefore, even if a misalignment occurs between the pressure adjusting shaft 54 and the cylindrical bearing portion 60 that supports the pressure adjusting shaft 54, the misalignment is fixed as it is. It becomes a factor to increase greatly.

Further, according to the above prior art, since the O-ring 63 is mounted on the pressure adjusting shaft 54 that operates according to pressure fluctuation, the inner peripheral surface of the lid member 59 (the inner diameter portion of the cylindrical bearing portion 60) and The primary pressure P ₁ is affected by the difference in diameter of the outer diameter portion of the pressure adjusting shaft 54 (the primary pressure P ₁ acts on the pressure adjusting shaft 54 via the O-ring 63). Therefore, the pressure regulation balance may become uneven due to fluctuations in the primary pressure P ₁ (the primary pressure P ₁ acts on the pressure regulation shaft 54 via the O-ring 63, and the pressure regulation operation of the pressure regulation shaft 54 is performed. The operation of the pressure adjusting shaft 54 may become unstable.

JP-A-61-229037 (FIG. 1)

  In view of the above points, the present invention can reduce the sliding resistance caused by the reciprocating motion of the pressure regulating shaft, which is a constituent element of the pressure reducing valve, thereby reducing the size of the product and increasing the accuracy of the product characteristics. It aims at providing the pressure-reduction valve which can implement | achieve. It is another object of the present invention to provide a pressure reducing valve that can stabilize the operation of the pressure adjusting shaft without the primary pressure affecting the pressure adjusting operation of the pressure adjusting shaft via the inner seal.

  In order to achieve the above object, a pressure reducing valve according to claim 1 of the present invention is a pressure reducing valve used in a water supply pipe, and includes a secondary pressure on the outflow side of the pressure reducing valve and a pressure adjusting spring arranged to counter this. A pressure adjusting shaft that is connected to a pressure adjusting diaphragm that operates to obtain an equilibrium point with a spring force and reciprocates to move the valve body portion toward and away from the valve seat portion; In the pressure reducing valve in which the secondary pressure acts as a back pressure, the pressure adjusting shaft is slidably supported by a holder, and the holder is held in a valve case in a floating state, and the inlet side primary pressure of the pressure reducing valve An inner seal provided between the pressure adjusting shaft and the holder is attached to a mounting groove provided on the inner peripheral surface of the holder so that the inner pressure surface of the pressure adjusting shaft is slidable on the outer peripheral surface of the pressure adjusting shaft. Wherein the contact.

  The pressure reducing valve according to claim 2 of the present invention is the pressure reducing valve according to claim 1 described above, wherein the holder is held in the valve case via an outer seal disposed on the outer peripheral side thereof. It is hold | maintained at the said valve case, It is characterized by the above-mentioned.

  Further, the pressure reducing valve according to claim 3 of the present invention is characterized in that, in the pressure reducing valve according to claim 1 or 2, the lip packing arranged with the seal lip toward the primary pressure side is used as the inner seal. .

  In the pressure reducing valve according to the first aspect of the present invention having the above-described configuration, first, an inner seal provided between the pressure adjusting shaft and the holder so that the primary pressure on the inflow side of the pressure reducing valve does not flow into the back pressure chamber is provided on the holder. A mounting groove for mounting an inner seal on the outer peripheral surface of the pressure adjusting shaft because it is mounted in a mounting groove provided on the inner peripheral surface and is slidably in close contact with the outer peripheral surface of the pressure adjusting shaft. There is no need to provide. Therefore, since the diameter dimension of the pressure adjusting shaft can be reduced as compared with the conventional one, it is possible to use the inner seal having a small diameter dimension, thereby reducing the sliding resistance.

  In addition to the pressure reducing valve according to the first aspect, the pressure regulating shaft is slidably supported by the holder and the holder is held in the valve case in a floating state. When the misalignment occurs between the pressure shaft and the holder, the misalignment can be absorbed by the holder following the pressure adjusting shaft. Therefore, even if a misalignment occurs between the pressure adjusting shaft and the holder, this can be eliminated, and it is possible to suppress a significant increase in sliding resistance.

  In order to hold the holder in the valve case in a floating state as described above, it is preferable to hold the holder on the valve case via an outer seal disposed on the outer peripheral side thereof. With this, the holder can operate following the inclination and eccentricity of the pressure adjusting shaft.

  In addition, since the inner seal (O-ring) is not attached to the pressure adjusting shaft as in the prior art, but the inner seal is attached to the holder side that supports the pressure adjusting shaft, the primary pressure passes through the inner seal. Does not act on the pressure regulating shaft. Therefore, it is possible to prevent the primary pressure from affecting the pressure adjusting operation of the pressure adjusting shaft.

  Furthermore, in the pressure reducing valve according to claim 3 of the present invention, since the lip packing in which the seal lip is disposed toward the primary pressure side is used as the inner seal, the sliding resistance of the seal itself is reduced. It is possible to make it. That is, the lip packing is in close contact with the mating surface by the elastic spring of the seal lip, and is not due to volume compression like the squeeze packing such as the O-ring in the prior art, so the generated sliding resistance is In contrast, it becomes much smaller. Therefore, also from this point, the sliding resistance can be reduced.

  The present invention has the following effects.

  That is, in the pressure reducing valve according to claim 1 or 2 of the present invention, the sliding resistance generated is reduced by reducing the diameter of the pressure adjusting shaft and the inner seal based on the above configuration and the follow-up operation of the holder, and the sliding resistance is reduced. If it is done, it will become possible to achieve high accuracy of the product. Therefore, as the intended purpose of the present invention, it is possible to reduce the sliding resistance caused by the reciprocating motion of the pressure regulating shaft that is a component of the pressure reducing valve, thereby reducing the size of the product and increasing the accuracy of the product characteristics. A pressure reducing valve to be realized can be provided.

  In addition, when the inner seal is attached to the pressure adjusting shaft as in the past, the primary pressure acts on the pressure adjusting shaft via the inner seal, so that the smooth operation of the pressure adjusting shaft is hindered and the product characteristics are affected. However, according to the present invention, since the inner seal is mounted on the holder side, the primary pressure does not act on the pressure adjusting shaft via the inner seal. Therefore, the primary pressure does not hinder the smooth operation of the pressure adjusting shaft, and the product characteristics can be stabilized.

  In addition to this, in the pressure reducing valve according to claim 3 of the present invention, since the sliding resistance is reduced even in the structure of the seal itself made of the lip packing, the sliding resistance can be further reduced. it can.

  The lip packing has a so-called self-pressurizing function in which the close contact force of the seal lip increases or decreases in accordance with the pressure difference between the front pressure acting on the front surface and the back pressure acting on the back surface. Therefore, when the pressure difference between the primary pressure and the secondary pressure is large, the seal lip is in close contact, and when the pressure difference is small, the seal lip is weak and in close contact. The close force is unlikely to occur. Therefore, from this point, the sliding resistance can be further reduced.

  In addition, it is possible to eliminate the influence of the primary pressure by using an inner-diameter seal using a seal lip (lip packing) instead of an outer-diameter seal such as an O-ring in the prior art, thus improving pressure regulation performance. Can be made.

  The present invention includes the following embodiments.

Constitution···
(A) The valve case slidably supports the floating member, and the floating member further slidably supports the shaft.
(B) An annular groove is dug into the floating member to be inserted into the shaft, and no groove is dug into the outer surface of the shaft.
(C) The valve case and the floating member are sealed with an O-ring, but the tension is small enough to be slidable.

effect···
(D) Since the groove is not dug into the outer surface of the shaft, the shaft can be made smaller in diameter and the sliding resistance can be reduced.
(E) Although the floating member is affected by the pressure difference between the primary pressure side and the secondary pressure side on the annular groove, it is separated from the shaft and is not directly affected by the shaft, and is not easily affected by misalignment or the like.
(F) The Y packing is mounted so that the lip side receives the primary pressure side (high pressure). Since the Y-packing opens in the radial direction with the primary pressure and seals, when the pressure difference between the primary pressure side and the secondary pressure side is small, the seal pressing force is reduced and it becomes easy to perform fine pressure adjustment.
(G) By adopting the above structure, it is possible to achieve downsizing and obtain highly accurate pressure reducing valve characteristics.

Other embodiments ...
(H) Since the structure slides with the outer diameter of the shaft, it is possible to reduce the outer diameter of the shaft and the reaction force due to the primary pressure is not applied at all.
(I) Since the seal part is floated only by holding by the O-ring, adverse effects such as a coaxial shift are difficult to occur.
(J) The sliding resistance can be further reduced by using a Y seal for the shaft seal.

  Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a sectional view of a pressure reducing valve (diaphragm type pressure reducing valve) 1 according to an embodiment of the present invention. The pressure reducing valve 1 according to this embodiment is used for a water supply pipe in a warm water washing toilet seat device, and the outlet side secondary pressure P is always constant so that the water supply pressure supplied to the water stop valve disposed downstream thereof is constant. ₂ has a function of adjusting ₂ and is configured as follows.

  That is, first, the valve case 2 of the pressure reducing valve 1 is provided by watertightly combining the body 3, the cover 4 and the output block 5, and the pressure adjusting diaphragm 14 and the pressure adjusting diaphragm 14 are provided inside the valve case 2. Actuating components such as a pressure spring 15 and a pressure adjusting shaft 16 are incorporated. The body 3 is provided with an inflow-side primary port 6, and the output block 5 is provided with an outflow-side secondary port 7. Both ports 6, 7 are provided in the body 3. The flow path 8, the valve chamber 9, the valve hole 10 and the diaphragm chamber 11, and the flow paths 12 and 13 provided in the body 3 and the output block 5 are communicated.

In the diaphragm chamber 11, a pressure adjusting diaphragm 14 is installed between the body 3 and the cover 4. The pressure regulating diaphragm 14 is in its floating end axially (FIG seeking equilibrium between the spring force of the arranged pressure regulating spring 15 to counteract this and secondary pressure P ₂ of the pressure reducing valve 1 The pressure adjusting shaft (also referred to as a shaft) 16 and a diaphragm retainer (also referred to as a plate) 17 and a spring retainer (also referred to as a nut) 18 are arranged at the free end of the pressure adjusting diaphragm 14. Are connected. The pressure adjusting spring 15 is elastically interposed between the pressure adjusting screw 19 screwed into the cover 4 and the spring retainer 17, and the spring force can be adjusted by adjusting the screwing amount of the pressure adjusting screw 19. It is said that.

  The pressure adjusting shaft 16 reciprocates in the axial direction in accordance with the operation of the pressure adjusting diaphragm 14, and a valve seat portion in which a conical surface valve body portion 20 provided integrally with the outer peripheral surface thereof is provided in the body 3. The opening area of the valve hole 10 is increased / decreased by approaching and moving away from the valve 21, and the lower end shaft portion 16 a is slidably supported by a holder (also referred to as a floating member) 22.

  That is, a holder chamber 23 is provided in the body 3 so as to communicate with the valve chamber 9. A holder 22 is inserted into the holder chamber 23 together with a stopper 24, and this holder 22 is connected to the lower end of the pressure adjusting shaft 16. The shaft portion 16a is slidably supported. The holder 22 is prevented from being detached from the holder chamber 23 by a spacer 25 disposed below the holder 22, and the spacer 25 is disposed in the output block 5.

Further, the pressure adjusting shaft 16 is configured such that the secondary pressure P ₂ acts as a back pressure. For this reason, a back pressure chamber 26 is provided below the pressure adjusting shaft 16 and the pressure adjusting shaft 16 and the holder 22. It is provided so as to be surrounded by. Further, each communication hole 27 is provided in the spacer 25 and the holder 22 so as to supply the back-pressure chamber 26 to the secondary pressure _{P 2.}

  The holder 22 is formed in a cylindrical shape with a bottom and is inserted into the holder chamber 23, and is held in the body 3 so as to be swingable in a so-called floating state in the holder chamber 23. Further, the holder 22 is swingable with respect to the body 3 by being held on the body 3 via an outer seal 29 disposed on the outer peripheral side thereof, and the outer seal 29 is formed on the outer peripheral surface of the holder 22. A squeeze packing such as an O-ring 31 mounted in an annular mounting groove 30 is provided. The holder 22 is set to have an outer diameter dimension smaller than the inner diameter dimension of the holder chamber 23 to set a play gap (not shown) in the radial direction, and the axial length is set to the stopper 24 and the spacer 25. It is formed to be smaller than the axial distance between them, and axial play gaps (not shown) are set together, and can swing with respect to the body 3 within the range of these play gaps.

Furthermore, the inner seal 32 is provided between the pressure adjusting shaft 16 and the holder 22 so as not to primary pressure P ₁ of the valve chamber 9 side flows into the back pressure chamber 26, the inner seal 32, the holder 22 is constituted by a lip packing such as a Y packing 34 mounted in an annular mounting groove 33 provided on the inner peripheral surface of the belt 22. The Y packing 34 has an outer peripheral side seal lip 34a that is in close contact with the bottom surface of the mounting groove 33, and an inner peripheral side seal lip 34b that is slidably in close contact with the outer peripheral surface of the pressure adjusting shaft 16. lip 34a, 34b of the primary pressure _{P 1} side (in the figure above) is placed toward the.

Pressure reducing valve 1 configured as described above, there is the water pressure supplied to the water stop valve disposed on the downstream side as described above always adjust the secondary pressure P ₂ of the outflow to be constant side , for example 2 when primary pressure P ₂ increases, the pressure regulating loose ends of equilibrium by regulating pressure diaphragm 14 with spring 15 is increased, since the pressure regulating shaft 16 is increased along with this, the valve body 20 is a valve close to the seat 21, are reduced in opening area of the valve hole 10, the flow rate is throttled by the secondary pressure P ₂ is reduced. On the contrary in this state, 2 the primary pressure P ₂ decreases, regulating the floating end portion of the pressure regulating diaphragm 14 by equilibrium lowered the pressure spring 15, since the pressure regulating shaft 16 is lowered along with this, the valve body portion 20 is away from the valve seat portion 21, is enlarged opening area of the valve hole 10, the flow rate is increased secondary pressure P ₂ is boosted. Therefore, always it has been possible to a constant secondary pressure P ₂ by such pressure regulating function.

  Further, the pressure reducing valve 1 is characterized in that the following effects can be obtained by the above configuration.

First in the pressure reducing valve 1 of the above configuration, the inner seal 32 of the primary pressure P ₁ the pressure reducing valve 1 is provided between the pressure adjusting shaft 16 and the holder 22 so as not to flow into the back pressure chamber 26, the inner periphery of the holder 22 In order to mount the inner seal 32 on the outer peripheral surface of the pressure adjusting shaft 16, the mounting groove 33 provided on the surface is slidably in close contact with the outer peripheral surface of the pressure adjusting shaft 16. No mounting groove is provided. Therefore, since the diameter dimension of the pressure adjusting shaft 16 can be reduced as compared with the conventional one, it is possible to use the inner seal 32 having a smaller diameter dimension, thereby reducing the sliding resistance.

  Further, since the pressure adjusting shaft 16 is supported by the holder 22 and the holder 22 is swingably held by the output block 5 of the valve case 2, the pressure adjusting shaft 16 is interposed between the pressure adjusting shaft 16 and the holder 22. When misalignment occurs, the holder 22 swings to absorb this misalignment. Therefore, even if a misalignment occurs between the pressure adjusting shaft 16 and the holder 22, this can be eliminated, and it is possible to suppress a significant increase in sliding resistance.

  Therefore, since the sliding resistance is reduced by reducing the diameter of the pressure adjusting shaft 16 and the inner seal 32 and swinging the holder 22 in this way, the sliding resistance of the pressure adjusting shaft 16 is as intended. Therefore, it is possible to provide the pressure reducing valve 1 that realizes miniaturization of the product and high accuracy of product characteristics.

Further, when the inner seal 61 is mounted on the pressure adjusting shaft 54 as in the above-described prior art, the primary pressure P ₁ acts on the pressure adjusting shaft 54 via the inner seal 61 (primary pressure P). ₁ tends to push down the shaft 54 via the inner seal 61), the smooth operation of the pressure regulating shaft 54 is impeded, and the product characteristics are affected (the hysteresis that occurs in the flow rate characteristics and pressure characteristics of the pressure reducing valve). However, according to the pressure reducing valve 1, since the inner seal 32 is mounted on the holder 22, the primary pressure P ₁ is applied to the pressure adjusting shaft 16 via the inner seal 32. It does not act (the primary pressure P ₁ acting on the inner seal 32 attempts to push the holder 22 down and not the shaft 16). Therefore, 1 to never primary pressure P ₁ inhibits smooth operation of the pressure regulating shaft 16, the flow characteristics and pressure characteristics of the can to stabilize the operating characteristics of the product (pressure reducing valve, is generated hysteresis Smaller).

Further, as the inner seal 32, the seal lip 34a, for Y packing 34 disposed 34b toward the primary pressure P ₁ side is used, and can be even with the seal 32 itself to reduce the sliding resistance Has been. That is, the Y packing 34 is in close contact with the mating surface by the elastic springs of the seal lips 34a and 34b, and is not due to volume compression like the squeeze packing of the O-ring 63 or the like in the above prior art. The dynamic resistance is much smaller than the squeeze packing. In general, the sliding resistance of the Y packing is about 1/3 that of the O-ring. Therefore, also from this point, sliding resistance can be reduced.

The Y packing 34 has a so-called self-pressurizing function in which the close force of the seal lips 34a and 34b increases or decreases in accordance with the pressure difference between the front pressure acting on the pressure receiving surface (front surface) and the back pressure acting on the back surface. have. Therefore, the primary pressure _{P 1} and the secondary pressure _{P 2} of the seal lip 34a when a large pressure difference, 34b are closely strong, sealing lip 34a when the pressure difference is small, closely force such that 34b is closely weak Therefore, it is difficult to generate a close force larger than necessary. Therefore, from this point, the sliding resistance can be further reduced.

  In the above embodiment, the valve case 2 is composed of a combination of the body 3, the cover 4, and the output block 5. However, as shown in FIG. 2, the body 3, the cover 4, and the lid member (base plate). In this case, the secondary port 7 is provided in the body 3 together with the primary port 6.

Sectional drawing of the pressure reducing valve which concerns on the Example of this invention Sectional drawing of the pressure reducing valve which concerns on the other Example of this invention. Sectional view of a pressure reducing valve according to a conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure reducing valve 2 Valve case 3 Body 4 Cover 5 Output block 6 Primary side port 7 Secondary side port 8, 12, 13 Flow path 9 Valve chamber 10 Valve hole 11 Diaphragm chamber 14 Pressure adjusting diaphragm 15 Pressure adjusting spring 16 Pressure adjusting Shaft 16a Lower end shaft portion 17 Diaphragm retainer 18 Spring retainer 19 Pressure adjusting screw 20 Valve body portion 21 Valve seat portion 22 Holder 23 Holder chamber 24 Stopper 25 Spacer 26 Back pressure chamber 27, 28 Communication hole 29 Outer seal 30, 33 Mounting groove 31 O-ring (squeeze packing)
32 Inner seal 34 Y packing (lip packing)
34a, 34b Seal lip

Claims (3)

A pressure reducing valve (1) used in a water supply pipe, which is a balance between the secondary pressure (P ₂ ) on the outflow side of the pressure reducing valve (1) and the spring force of a pressure regulating spring (15) arranged so as to oppose it. A pressure regulating shaft (16) that is connected to a pressure regulating diaphragm (14) that operates to obtain a point and reciprocates to move the valve body portion (20) toward and away from the valve seat portion (21); In the pressure reducing valve (1) in which the secondary pressure (P ₂ ) acts as a back pressure on the pressure adjusting shaft (16),
The pressure regulating shaft (16) is slidably supported by a holder (22) and the holder (22) is held in a valve case (2) in a floating state.
An inner seal (32) provided between the pressure adjusting shaft (16) and the holder (22) so that the inflow side primary pressure (P ₁ ) of the pressure reducing valve (1) does not flow into the back pressure chamber (26), A pressure reducing valve mounted in a mounting groove (33) provided on an inner peripheral surface of the holder (22) and slidably in close contact with an outer peripheral surface of the pressure adjusting shaft (16). The pressure reducing valve of claim 1,
The holder (22) is held by the valve case (2) in a floating state by being held by the valve case (2) via an outer seal (29) disposed on the outer peripheral side thereof. Pressure reducing valve. The pressure reducing valve according to claim 1 or 2,
A pressure reducing valve using a lip packing (34) arranged with the seal lips (34a) (34b) facing the primary pressure (P ₁ ) as the inner seal (32).

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