Pressure reduction valve

Abstract

To provide a pressure reduction valve capable of suppressing unfastening of a pressure reduction mechanism part relative to a base part.SOLUTION: A pressure reduction valve comprises: a base part 2; a pressure reduction mechanism part 3 which is attachable to and detachable from the base part 2; a seal member 36 which is interposed between the base part 2 and the pressure reduction mechanism part 3; and a pin 4 which prevents the pressure reduction mechanism part 3 from coming off from the base part 2. Screwing is performed by a combination of a female screw of the base part 2 and a male screw 311 of the pressure reduction mechanism part 3. The male screw 311 is formed in an outer periphery of an expansion portion 31, which is formed while being expanded to a radially outer side, in an insertion portion 30 which is positioned radially inside of the base part 2 in the pressure reduction mechanism part 3. When an arrangement direction of the base part 2 and the pressure reduction mechanism part 3 is defined as a reference, the seal member 36, the expansion portion 31 and the pin 4 are positioned successively from the side of the base part 2. In the pin 4, a central portion 41C which extends over the base part 2 and the pressure reduction mechanism part 3 abuts on a region radially inside of a root of the male screw 311 on a face of the expansion portion 31 on the side of the pressure reduction mechanism part 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pressure reducing valve that is installed in a fluid path such as a water pipe and is capable of reducing the pressure of the fluid. [Background technology]

[0002] In pressure reducing valves, as described in Patent Document 1, for example, there is a configuration in which a pressure reducing mechanism section (referred to as a "valve mechanism unit" in Patent Document 1) incorporating a mechanism for reducing the pressure of a fluid is detachable from a base section (referred to as a "valve box" in Patent Document 1) connected to the primary and secondary fluid piping. This configuration allows for the continued use of the base section, which is relatively resistant to deterioration, and incorporates moving mechanisms such as a diaphragm, valve body, and spring, so that only the pressure reducing mechanism section, which is prone to functional degradation over time, can be replaced, making it more advantageous than a configuration in which the entire valve is integrated.

[0003] It is conceivable that the pressure reducing mechanism may be removed from the base or loosened relative to the base due to mischief or accidental operation, etc. In this case, the fluid may leak to the outside, so there is room for improvement in the structure of the pressure reducing valve.

[0004] Furthermore, in the configuration described in Patent Document 1, the pressure reducing mechanism is inserted into the base to form a single unit, but it is also possible to fix the two together by screwing them together, and in that case, as with the above, there is still room for improvement in the structure of the pressure reducing valve. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-205425 Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a pressure reducing valve having a screw-fastening structure that can prevent the pressure reducing mechanism from being loosened from the base. [Means for solving the problem]

[0007] The present invention provides a pressure reducing mechanism comprising: a base having an inlet and an outlet for a fluid, the inside and outside of which are separated by a partition; a pressure reducing mechanism that is detachably attached to the base and reduces the pressure of a fluid passing through the base when the pressure is higher than a set pressure; a seal member that is interposed in a liquid-tight state between the base and the pressure reducing mechanism; and a pin that engages across the base and the pressure reducing mechanism to prevent the pressure reducing mechanism from being detached from the base, wherein the base and the pressure reducing mechanism are threadedly connected by a combination of a female thread formed on the base and a male thread formed on the pressure reducing mechanism. The pressure reducing valve is configured to be coupled to the pressure reducing mechanism, and the male thread is formed on the outer periphery of a protrusion that protrudes radially outward at an insertion portion that is located radially inside the base when attached to the base of the pressure reducing mechanism, and based on the alignment direction of the base and the pressure reducing mechanism, the sealing member, the protrusion, and the pin are located in that order from the base side, and the central part of the part of the pin that extends between the base and the pressure reducing mechanism abuts against a region of the surface of the protrusion that is on the pressure reducing mechanism side that is radially inward than the valley of the male thread.

[0008] According to the above configuration, the sealing member is located closer to the base than the pin and the protruding portion, so water leakage from the pin portion does not occur and scale buildup on the female and male threads can be prevented.

[0009] In addition, the sealing member can be an O-ring made of rubber or soft resin, the pin can be positioned at two radial locations on either side of the radial center of the insertion portion, and the outer diameter of the O-ring and the radial outer dimensions of the pin at the two locations can be smaller than the root diameter of the male thread.

[0010] This configuration prevents the O-ring from getting caught on the female thread of the base and being damaged when the pressure reducing mechanism is attached to the base. Furthermore, if the male thread loosens relative to the female thread, the pins can be prevented from getting caught on the threads of each screw, which can cause damage to the pins or jamming. [Effects of the Invention]

[0011] The present invention can prevent the pressure reducing mechanism from being loosened from the base in a pressure reducing valve having a screw-fastening structure. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a partial cross-sectional front view of a pressure reducing valve according to an embodiment of the present invention. [Figure 2] FIG. 4 is a right side view of the pressure reducing valve. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. [Figure 4] FIG. 2 is an enlarged view of the area enclosed by IV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] First, one embodiment of the pressure reducing valve 1 according to the present invention will be described. For convenience, directions (up and down directions, etc.) described below are expressed using the illustrated directions, with the side shown in Fig. 1 being the front side. However, the pressure reducing valve 1 of this embodiment can also be used, for example, lying on its side at an angle of 90 degrees to the illustrated direction, and the directions can change depending on the installation situation. Therefore, the directions are not limited to those described below.

[0014] The pressure reducing valve 1 is installed in a pipe shaft of, for example, an apartment building, and is used to supply tap water at an appropriate pressure to each unit. The pressure reducing valve 1 of this embodiment is shown in Figs. 1 and 2, and mainly comprises a base 2, a pressure reducing mechanism 3, and a pin 4. The basic configuration of the pressure reducing valve 1 of this embodiment is the same as that of a conventional valve (for example, that described in Patent Document 1). Therefore, the basic configuration of the pressure reducing valve 1 will be described only briefly.

[0015] The base 2 has an inlet 21 and an outlet 22 for a fluid such as tap water, and is separated into an inside and an outside by a partition wall 23, through which the fluid flows. The inlet 21 and the outlet 22 are formed with piping threads or the like so that fluid piping (such as a water pipe) can be connected. The base 2 also has a cylindrical portion 24 that opens upward. A female thread 241 is formed around the entire inner periphery near the top end of this cylindrical portion 24. The portion protruding to the left from the base 2 in Figure 2 is a pressure gauge connection portion 25, which is used when measuring pressure.

[0016] The pressure reducing mechanism 3 is detachably attached to the base 2, and reduces the pressure of the fluid passing through the base 2 when the pressure is higher than the set pressure. The pressure reducing mechanism 3 is arranged so that a portion of it enters the internal space of the base 2 when attached. To attach it to the base 2, a male thread 311 that can be screwed into the female thread 241 of the base 2 is formed around the entire circumference.

[0017] Here, the insertion part 30 of the pressure reducing mechanism 3 is located on the radially inner side of the base part 2 when attached to the base part 2, and a protruding part 31 is formed to protrude radially outward. The protruding part 31 is formed in a flange shape around the entire circumference of the radially inner part of the insertion part 30. The upper surface of the protruding part 31 is a horizontal plane. The male thread 311 is formed on the curved surface on the outer periphery of the protruding part 31, from the upper end to the lower end, all around the circumference.

[0018] The pressure reducing mechanism 3 has a plurality of radially opening inlets 32 formed in a portion thereof that extends into the base 2. In this embodiment, four substantially rectangular inlets 32 are formed at equal intervals around the circumference. Fluid from the primary side passes through the inlets 32 from the outside to the inside, allowing the fluid to flow vertically within the pressure reducing mechanism 3. A flow path (not shown) is connected above the inlets 32, and this flow path faces a pressure reducing unit (not shown) equipped with a diaphragm supported by a spring. The pressure reducing unit includes a valve element 33 provided below the diaphragm or the like and exposed to the internal space of the base 2 through which the fluid passes from the primary side to the secondary side. When the diaphragm rises, the valve element 33 also rises, allowing the flow path above the valve element 33 (i.e., the cross-sectional area through which the fluid passes within the base 2) to be narrowed according to the pressure of the primary side fluid.

[0019] When the pressure of the fluid on the primary side is low enough that pressure reduction is not necessary (below the set pressure), all of the fluid that passes through the inlet 32 ​​flows downward toward the secondary side. On the other hand, when the pressure of the fluid on the primary side is high, part of the fluid that passes through the inlet 32 ​​flows upward and reaches the pressure reduction section (specifically, the underside of the diaphragm). In the pressure reduction section, the diaphragm rises according to the balance between the fluid pressure and the biasing force of the spring. This causes the valve element 33 to rise compared to when the set pressure is reached, increasing pressure loss within the pressure reduction mechanism 3. As a result, the fluid flowing on the secondary side is reduced in pressure.

[0020] In the pressure reducing mechanism 3, a flange 34 is formed below the inlet 32, with a diameter larger than the vertical portion where the inlet 32 ​​is formed. The flange 34 is provided around the entire circumference. The projection dimension of the flange 34 from the base end is constant around the entire circumference. This flange 34 separates the primary side from the secondary side when the pressure reducing mechanism 3 is attached to the base 2. The upper surface of the flange 34 is horizontal. A lower seal member 35 made of an O-ring made of rubber or soft resin is provided on the outer periphery of the flange 34 to prevent fluid from flowing around the flange 34. This ensures a fluid path through the radially inner portion of the pressure reducing mechanism 3 where pressure reduction occurs.

[0021] In this embodiment, the base 2 and the pressure reducing mechanism 3 are threadedly coupled to each other by a combination of a female thread 241 and a male thread 311 formed at the respective coupling locations. The pressure reducing mechanism 3 can be threadedly coupled to and uncoupled from the base 2 by rotating the entire pressure reducing mechanism 3 around an axis in the vertical direction. To prevent fluid leakage from the threaded portion (between the female thread 241 and the male thread 311) for the threaded coupling, an upper seal member 36 composed of an O-ring made of rubber or soft resin is provided at the interface between the base 2 and the pressure reducing mechanism 3. At the joint between the base 2 and the pressure reducing mechanism 3, the seal members 35 and 36 provided on the pressure reducing mechanism 3 provide a seal by manually tightening the pressure reducing mechanism 3 to the required mounting position without using tools. The seal members 35 and 36 are interposed between the base 2 and the pressure reducing mechanism 3 in a liquid-tight manner. The sealing members 35 and 36 may be provided in the base 2 instead of the pressure reducing mechanism 3.

[0022] The pin 4 engages across the base 2 and the pressure reducing mechanism 3. This prevents the pressure reducing mechanism 3 from coming off the base 2. The base 2 is provided with a pin hole 26, into which the pin 4 is inserted. The pins 4 are located at two radial positions on either side of the radial center of the insertion portion 30.

[0023] The pin 4 of this embodiment has a configuration as shown in FIG. 3. The pin 4 is made of metal and is integrally formed by bending the pin 4. The pin 4 is formed of a linearly extending engagement portion 41 and a connecting portion 42 connecting one end of a pair of opposing, parallel engagement portions 41, 41, forming a U-shape in plan view. The pair of (two) engagement portions 41, 41, which are opposed to each other in the U-shape, are positioned so as to correspond to the two positions based on the insertion portion 30. When inserting the pin 4 into the pin hole 26, the end of the pair of engagement portions 41, 41, which is the open side of the U-shape and to which the connecting portion 42 is not connected (the upper end in FIG. 3), is inserted first. The connecting portion 42 is positioned so as to abut against the outer periphery of the base 2. As shown in FIG. 3, the connecting portion 42 is curved, for example, with a smaller curvature (larger radius of curvature) than the outer periphery of the base 2. The connecting portion 42 may be curved with a curvature that fits along the outer periphery of the base portion 2. The pin 4 is located above the upper seal member 36 (see FIG. 4), and water does not reach the position of the pin 4. Therefore, no seal is provided between the pin 4 and the pin hole 26 to make the space between them liquid-tight.

[0024] Next, the arrangement of the seal member and the pin 4 will be described. With respect to the alignment direction of the base 2 and the pressure reducing mechanism 3, the seal member, the protruding portion 31, and the pin 4 are positioned in this order from the base 2 side (bottom to top in the vertical direction). Furthermore, a central portion 41C of the engagement portion 41 of the pin 4, which is the portion that extends between the base 2 and the pressure reducing mechanism 3, abuts against a region of the surface of the protruding portion 31 facing the pressure reducing mechanism 3 that is radially inward of the root of the male thread 311. Because the pin 4 is positioned in this manner, the upper seal member 36 is positioned closer to the base 2 (lower) than the pin 4 and the protruding portion 31. Therefore, the upper seal member 36 blocks moisture, preventing water leakage from the pin 4 and preventing the buildup of scale on the female thread 241 and the male thread 311 due to water leakage.

[0025] Furthermore, the outer diameter of the upper seal member 36, which is an O-ring, and the outer dimensions of the pin 4 at two locations in the radial direction are set smaller than the root diameter of the male thread (see FIG. 4). This dimensional relationship prevents the upper seal member 36 from getting caught on the female thread of the base 2 and being damaged when the pressure reducing mechanism 3 is attached to the base 2. Furthermore, if the male thread becomes loose relative to the female thread, the pin 4 will get caught on the threads of the screws 241, 311, preventing the pin 4 from being damaged or jammed.

[0026] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0027] For example, in this embodiment, the fluid passed through the pressure reducing valve 1 is tap water, but the present invention is not limited to this and may be any of a variety of liquids.

[0028] In the above embodiment, the pin 4 was a single piece integrally formed from the engagement portion 41 and the connection portion 42, but this is not limited to this and the pin 4 may be made up of two separate rod-shaped bodies consisting only of the engagement portion 41.

[0029] The pin 4 may be provided with a retainer to prevent the pin 4 from easily coming out of the pin hole 26 when subjected to an external force. The retainer may be, for example, a stopper that engages with the pin 4 by recess-projection fitting or the like, or a friction member (such as a rubber ring) that is interposed between the pin 4 and the pin hole 26. Alternatively, a screw thread may be formed at the tip of the pin 4 (engagement portion 41) and a nut may be screwed onto the thread to prevent the pin 4 from coming out. [Explanation of symbols]

[0030] 1 Pressure reducing valve 2 base 21 Entrance 22 Exit 23 Bulkhead 24 Cylindrical part 241 Internal thread 25 Pressure gauge connection 26 pin holes 3 Pressure reducing mechanism 30 Insertion part 31 Overhang 311 Male thread 32 Inlet 33 Valve body 34 Tsuba 35 Lower seal material, O-ring 36 Seal member (upper seal member), O-ring 4-pin 41 Engagement portion 41C Center of engagement part 42 Connection

Claims

1. a base having an inlet and an outlet for a fluid, the inside and outside of which are separated by a partition wall; a pressure reducing mechanism that is detachably provided on the base and reduces the pressure of the fluid passing through the base when the pressure is higher than a set pressure; a seal member interposed in a liquid-tight state between the base portion and the pressure reducing mechanism portion; a pin that engages with the base and the pressure reducing mechanism to prevent the pressure reducing mechanism from being separated from the base, The base and the pressure reducing mechanism are configured to be threadedly coupled by a combination of a female thread formed on the base and a male thread formed on the pressure reducing mechanism, the male screw is formed on an outer periphery of a protruding portion formed to protrude radially outward in an insertion portion located radially inside the base when the pressure reducing mechanism is attached to the base, the sealing member, the protruding portion, and the pin are positioned in this order from the base side based on the arrangement direction of the base and the pressure reducing mechanism, A pressure reducing valve in which the central portion of the pin extending between the base and the pressure reducing mechanism abuts against an area of ​​the surface of the protrusion facing the pressure reducing mechanism that is radially inward of the root of the male thread.

2. the sealing member is an O-ring made of rubber or soft resin, The pins are located at two radial locations on either side of the radial center of the insertion portion, 2. The pressure reducing valve according to claim 1, wherein an outer diameter of the O-ring and outer dimensions of the pin in the radial direction at the two locations are smaller than a root diameter of the male thread.

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