JP2015064641A - Pressure-reducing valve having dirt entry removal mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily remove a state that a minute foreign matter enters between a valve body and a valve seat, to return to a normal state.SOLUTION: In a pressure-reducing valve in which a valve body 6 detachable to a valve seat 5 provided on a secondary opening part end surface 3a of a valve port 3 and a drive unit 7 connected to the valve body 6 to control an aperture of the valve body 6 according to pressure fluctuation of a secondary side flow path 2 are included in a valve box 4 provided to communicate a primary side flow path 1 with the secondary side flow path 2 via the valve port 3, a throttle valve 9 that is able to throttle a flow rate from the primary side to the secondary side is provided in the primary side flow path 1.

Description

  The present invention relates to a pressure reducing valve having a dust biting release mechanism that prevents biting of foreign matters (hereinafter also referred to as dust) such as iron powder, sand, and scale between a valve body and a valve seat.

  In Patent Document 1, a primary side flow path and a secondary side flow path communicating with each of an inlet and an outlet established on the valve box side are partitioned by a partition wall inside the valve box, and the primary side flow path and The secondary side passage is communicated with the valve port established in the partition wall, and can be freely attached to and detached from a valve seat protruding from the end surface of the secondary side opening of the valve port at one end of the valve rod inserted through the valve port. A disc valve (hereinafter simply referred to as a valve body) is connected, and a diaphragm that senses and displaces a pressure variation in the secondary flow path is connected to the other end of the valve stem, and the diaphragm is opened. There is disclosed a pressure reducing valve that is urged by an adjusting spring in the direction, the strainer mesh provided on the inlet side is 0.4 mm, and the gap between the valve stem and the valve port is 0.5 mm or less.

  In the pressure reducing valve, the gap between the valve stem and the valve port is set to a narrow interval of 0.5 mm to reduce the water supply pressure (primary pressure) and reduce the pressure that presses the diaphragm in the valve closing direction. In the stable state where the water was passed through the secondary side, the opening of the valve body (distance between the valve body and the valve seat) was made larger than the gap (0.5 mm) between the valve stem and the valve port, and passed through the strainer and the gap. This prevents dust from being caught between the valve body and the valve seat.

JP 2002-132351 A (FIGS. 1 and 2)

However, when the primary pressure is high, the opening of the valve element may stabilize at a very narrow interval of about 0.2 mm. In such a case, the water flow may be more stable than the gap between the valve stem and the valve port. Since the opening degree of the valve body is narrower, there has been a problem that fine foreign matter that has passed through the gap between the valve stem and the valve port is caught between the valve body and the valve seat.
In view of this, the present invention provides a pressure reducing valve having a dust biting release mechanism that easily releases such a state and restores it to a normal state even if minute foreign matter is caught between the valve body and the valve seat. The purpose is that.

In view of the above problems, a pressure reducing valve having a dust biting release mechanism according to the present invention is provided in a valve box provided so as to communicate a primary side flow path and a secondary side flow path via a valve opening. Depressurization provided with a valve body detachably attached to a valve seat provided on the end face of the opening, and a drive unit connected to the valve body so as to control the opening degree of the valve body according to the pressure fluctuation of the secondary side flow path In the valve, a throttle valve capable of restricting a flow rate from the primary side to the secondary side is provided in the primary side flow path.
As a specific example, the throttle valve is a plug that can be freely attached to and detached from a seat ring provided in the primary flow path, and the primary side and the secondary side in which the primary flow path is partitioned in a watertight manner by closing the plug. It is characterized by comprising an orifice drilled in a spindle to which a plug is fixed so as to communicate with each other.
Further, the valve body is formed in a taper shape that is gradually reduced in diameter toward the valve seat, and has a contact protrusion that can be in close contact with the valve seat when the valve is closed at a midway position of the taper. The surface facing the valve seat is formed flat, and an annular protrusion-like contact portion that can be in close contact with the valve seat when the valve is closed is formed on the facing surface, and the surface facing the valve seat is closed. It is formed in a flat shape having a contact portion that can be brought into close contact with the valve seat at the time of the valve, and a cylindrical slide portion that can slidably contact the inner wall of the valve port is provided at the center of the contact portion. The part has a concavo-convex line parallel to the axis line in the circumferential direction, and the ridge slides on the inner wall of the valve port except when the valve element is fully open. Set so that the space between the tip of the ridge and the valve seat is larger than the space between the ridges, or slides in a watertight manner on the inner wall of the valve port formed with the valve seat Even if the valve body is formed so that it can be inserted into and removed from the valve port, and the valve body is detached from the valve port when the valve is opened. good.
Further, the valve body may be formed of self-lubricating rubber, or one or both of the valve seat and the valve body may be coated with a fluororesin.

In short, the present invention can be attached to and detached from a valve seat provided on the end face of the secondary opening of the valve port in a valve box provided so that the primary channel and the secondary channel communicate with each other via the valve port. In a pressure reducing valve including a valve body and a drive unit connected to the valve body so as to control the opening degree of the valve body in accordance with pressure fluctuations in the secondary side flow path, the primary side flow path from the primary side Since a throttle valve that can throttle the flow rate to the secondary side is provided, if the throttle valve functions, the flow rate to the secondary side decreases, so the secondary side pressure decreases and the valve element opens fully. Can do.
As a result, the fine foreign matter staying around the valve body and the valve seat through the strainer can be caused to flow down to the downstream side, and the foreign matter can be prevented from being caught between the valve body and the valve seat. .

The throttle valve is a plug that can be freely attached to and detached from a seat ring provided in the primary side flow path, and a plug that communicates with the primary side and the secondary side in which the primary side flow path is partitioned in a watertight manner by closing the plug. Since it is composed of an orifice drilled in a fixed spindle, in a normal state where the plug is detached from the seat ring, the primary flow path is in a normal communication state, so the pressure reducing valve performs its original function, and if necessary The spindle is seated on the seat ring and closed to close the primary flow path in a watertight manner on the primary side and the secondary side. From the primary side to the secondary side by the orifice provided in the spindle As described above, the valve body can be fully opened, and fine foreign matter that passes through the strainer and stays around the valve body and the valve seat can flow down to the downstream side. , Valve body It is possible to prevent the foreign matter is caught between the seats Prefecture.
Therefore, according to the present invention, the foreign matter can be prevented from being caught by adjusting the flow rate of the primary flow path with a simple operation of moving the spindle back and forth.
In addition, since the throttle valve having a simple structure and a small number of parts can be incorporated into the pressure reducing valve as described above, it is not necessary to increase the size of the pressure reducing valve itself, and the required cost can be suppressed.

  The valve body is formed in a tapered shape that gradually decreases in diameter toward the valve seat, and has a contact portion that can be brought into close contact with the valve seat when the valve is closed at a midway position of the taper. Even when the water flow is stable at an extremely narrow interval of about 0.2 mm, the valve body is inclined and the downstream side of the contact portion with the valve seat is wider than the conventional disc valve. Fine foreign matter that passes through the strainer and approaches the valve disc and the valve seat is easy to flow without resistance, and the frequency of biting between the valve disc and the valve seat is drastically reduced compared to the conventional disc valve. Even when the valve is fully opened by functioning the valve, foreign matter can be swept away to the downstream side of the valve body without difficulty, and foreign matter can be prevented from being caught between the valve body and the valve seat.

  The valve body has a flat surface facing the valve seat, and an annular protrusion-like projecting portion that can be in close contact with the valve seat when the valve is closed is formed on the facing surface. Even when the water flow is stable at an extremely narrow interval of about 0.2 mm, the contact projection that is seated on the valve seat protrudes from the flat surface facing the valve seat, and the downstream side of the contact projection is a conventional disc. Since the space is larger than the valve, fine foreign matter that passes through the strainer and approaches the valve disc and the valve seat can easily flow without resistance, and the frequency of biting between the valve disc and the valve seat is set to the conventional disc valve. Compared to the above, it is possible to prevent foreign matter from getting caught between the valve body and the valve seat without any difficulty even when the throttle valve is operated as described above and the valve body is fully opened. .

  The valve body is formed in a flat shape having a contact portion that can be brought into close contact with the valve seat when the valve seat is closed, and a cylindrical shape that can slidably contact the inner wall of the valve port at the center of the contact portion. The sliding part is set so that the ridge is parallel to the axis line in the circumferential direction, and the ridge is in sliding contact with the inner wall of the valve port except when the valve body is fully opened. Therefore, in normal valve opening, water is allowed to pass through the groove of the sliding part in the valve port of the valve body, and foreign matter larger than the cross-sectional area of the groove is not allowed to flow down to the secondary side. When the valve is fully opened by functioning the throttle valve as described above, the uneven streak is pulled out from the valve mouth, and the distance between the concave streak and the valve seat By setting the interval to be large, foreign matter staying upstream of the valve body is swept away to the downstream side of the valve body, and foreign matter is caught between the valve body and the valve seat. It can be stopped.

  The valve body is formed in the shape of a piston that can be slidably contacted in a watertight manner with the inner wall of the valve port that forms the valve seat, and is shorter than the axial length of the valve port and is detachable from the valve port. Since the valve body is sometimes set off from the valve opening, even when the valve opening is about 0.2 mm and the water flow is stabilized at a very narrow interval, the valve body is separated from the valve opening by a small interval. Because the space on the downstream side of the valve body is wider than the conventional disc valve, fine foreign matter that passes through the strainer and approaches the valve body and the valve seat easily flows without resistance, and between the valve body and the valve seat. The frequency of biting is drastically reduced compared to the conventional disc valve, and even when the throttle valve is operated and the valve body is fully opened as described above, foreign matter staying upstream of the valve body is also downstream of the valve body. The foreign matter between the valve body and the valve seat can be prevented from being caught.

  Since the valve body is made of self-lubricating rubber, fine foreign matter that flows down to the valve body through the strainer slides on the surface of the valve body and does not stay between the valve body and the valve seat. Since the fluid flows down to the secondary flow path, no foreign matter is caught between the valve body and the valve seat.

  Since one or both of the valve seat and the valve body is coated with fluororesin, fine foreign matter that flows through the strainer to the valve seat and the valve body slides on the valve seat and the valve body surface, and between the valve body and the valve seat. Since it does not stay and flows down to the secondary side flow path during the opening of the valve, the practical effect such as that foreign matter is not caught between the valve body and the valve seat is significant.

It is a center longitudinal cross-sectional view which shows the valve closing state of the pressure reducing valve which has the dust biting cancellation | release mechanism based on this invention. It is a center longitudinal cross-sectional view which shows a valve open state same as the above. It is a center longitudinal cross-sectional view which shows the fully open state of the valve body which functioned the throttle valve same as the above. It is a principal part expanded sectional view which is a 1st modification of a valve body and shows a valve closing state. It is a principal part expanded sectional view which shows a valve open state same as the above. It is a principal part expanded sectional view which shows the fully open state of the valve body which functioned the throttle valve same as the above. It is a principal part expanded sectional view which is a 2nd modification of a valve body and shows a valve closing state. It is a principal part expanded sectional view which shows a valve open state same as the above. It is a principal part expanded sectional view which shows the fully open state of the valve body which functioned the throttle valve same as the above. It is a 3rd modification of a valve body, and is a principal part expanded sectional view which shows a valve closing state. It is a principal part expanded sectional view which shows a valve open state same as the above. It is a principal part expanded sectional view which shows the fully open state of the valve body which functioned the throttle valve same as the above. It is AA sectional drawing of FIG. It is a 4th modification of a valve body, and is a principal part expanded sectional view which shows a valve closing state. It is a principal part expanded sectional view which shows a valve open state same as the above. It is a principal part expanded sectional view which shows the fully open state of the valve body which functioned the throttle valve same as the above.

An embodiment of the present invention will be described below with reference to the drawings.
The pressure reducing valve having a dust biting release mechanism according to the present invention opens and closes the valve port 3 in a valve box 4 provided so as to communicate the primary side channel 1 and the secondary side channel 2 via the valve port 3. Therefore, the valve body 6 detachably attached to the valve seat 5 provided on the secondary opening end face 3a of the valve port 3 and the opening degree of the valve body 6 are controlled in accordance with the pressure fluctuation in the secondary flow path 2. And a drive unit 7 connected to the valve body 6, and a pressure detection chamber 8 of the drive unit 7 provided in communication with the secondary side channel 2 to detect the pressure of the secondary side channel 2. Further, a direct-acting pressure reducing valve, which is provided with a throttle valve 9 capable of restricting the flow rate from the primary side to the secondary side in the primary flow path 1 by manual operation from the outside of the valve box 4.

The valve box 4 has an inlet 10 and an outlet 11 on the left and right sides thereof, and a primary channel 1 and a secondary channel 2 that communicate with the inlet 10 and the outlet 11, respectively.
The primary flow path 1 is composed of a straight flow path 1a coaxial with the secondary flow path 2 on the right side of the valve box 4, and a right-angle flow path 1b bent upwardly from the straight flow path 1a. Yes.

  In the center of the valve box 4 is provided a partition wall 12 in which a primary channel 1 and a secondary channel 2 are vertically divided, and a valve port 3 is opened in the partition 12 so that both channels 1 and 2 communicate with each other. Thus, the flow paths 1 and 2 of the inlet 10 and the outlet 11 are formed in an S shape.

  The upper part of the valve box 4 is formed by joining a circular dish-shaped recess 13 formed by surrounding a flange 13a and a hat-shaped bonnet 14 formed by surrounding a flange 14a at the lower opening end via a diaphragm 15, respectively. The flanges 13a and 14a are fastened with bolts and nuts (not shown), an adjustment spring 16 is disposed in the upper space (inside the bonnet 14) partitioned by the diaphragm 15, and the lower (inside the recess 13) is disposed in the pressure detection chamber 8. The drive part 7 is comprised.

The adjustment spring 16 is composed of a compression coil spring, and is compressed and interposed between a diaphragm retainer and a spring receiver 17 combined with the upper surface of the diaphragm 15 and an adjustment screw 18 screwed from the upper end opening of the bonnet 14. .
Then, the adjustment screw 18 is moved up and down to adjust the elastic force of the adjustment spring 16, and the displacement of the diaphragm 15 below is adjusted.
The upper end of the bonnet 14 is covered with a cap 19.

  The pressure detection chamber 8 (recess 13) is provided with a circular opening at the center of the lower part (corresponding to the corresponding part of the valve port 3 above the valve box 4) and communicates with the primary flow path 1, and the opening A cylindrical portion 20 having a predetermined length is provided continuously downward.

  The lower peripheral wall of the cylindrical portion 20 is suspended so as to be continuous with the partition wall 12 between the primary side flow path 1 and the secondary side flow path 2, and one of the portions facing the primary side flow path 1 on the lower peripheral wall. The part is opened so as to communicate with the primary side flow path 1, and the adjacent part between the lower part of the pressure detection chamber 8 and the cylindrical part 20 corresponding to the secondary side flow path 2 in the partition wall 12 is opened to the secondary side. The flow path 2 and the pressure detection chamber 8 are communicated.

  In addition, a valve rod 21 inserted through the tubular portion 20 and the valve port 3 is suspended from the center of the diaphragm 15, and a disc-shaped valve body 6 for opening and closing the valve port 3 is formed at the lower end of the valve rod 21. The valve body 3 and the drive unit 7 are connected to each other.

The valve body 6 is detachably provided on a valve seat 5 projecting in an annular shape on the end surface 3a of the secondary opening of the valve port 3 so as to receive the primary pressure in the valve opening direction. The degree of opening is controlled by.
The valve body 6 has a disc-like shape in which a valve portion 6a made of a synthetic rubber is formed in a disc shape, and only the upper side is opened except for a surface (upper surface in the drawing) facing the valve seat 5. The valve body cover 6b is loaded, and the shape of the valve portion 6a is maintained.

The valve portion 6a of the valve body 6 is made of self-lubricating rubber such as fluoro rubber (FKM), or the surface thereof is coated with fluororesin to reduce the frictional resistance of the surface facing the valve seat 5. doing. The surface of the valve seat 5 may be coated with a fluororesin.
In this way, by making the surfaces of the valve body 6 and the valve seat 5 easy to slip, fine foreign matter does not always stay between the valve body 6 and the valve seat 5, and the secondary-side flow path 5 during valve opening. It is made to flow down.

  A piston 22 that slides on the inner wall of the tubular portion 20 is provided outwardly in the middle of the valve stem 21, and an O-ring 23 is provided around the piston 22 so that the primary side flow path 1 and the pressure are increased. The detection chamber 8 is partitioned in a watertight manner.

The effective pressure receiving area of the piston 22 is set slightly larger than the effective pressure receiving area on the primary side of the valve body 6.
The diaphragm receiver 24 formed of a nut joined to the lower surface of the diaphragm 15 is formed to have a diameter larger than that of the cylindrical portion 20, and the diaphragm receiver 24 is disposed at the upper open end of the cylindrical portion 20 with the diaphragm 15 displaced to the lowest limit. The lift of the valve body 6 in this state is regulated.

  The pressure reducing valve thus piped is directed upward (valve closing direction) to the diaphragm 15 by the secondary side pressure in the pressure detection chamber 8 communicating with the secondary side flow path 2 and downward (opened) by the adjustment spring 16. When the force in the valve direction is balanced, the opening degree of the valve body 3 is controlled, and the secondary pressure is maintained at a constant pressure lower than the primary pressure, as shown in FIG.

  The throttle valve 9 includes a plug 9a that can be attached to and detached from a seat ring 25a, which will be described later, provided in the primary channel 1 and a primary side that separates the primary channel 1 in a watertight manner by closing the plug 9a. It is mainly composed of an orifice 9c drilled in a spindle 9b to which a plug 9a is fixed so as to communicate with the next side.

Hereinafter, the throttle valve 9 will be described in detail.
A screw hole 26 coaxial with the straight flow path 1a is formed at the closed end of the straight flow path 1a facing the outlet 11 via the partition wall 12.
The screw hole 26 closes and fixes the proximal end opening of the cylindrical strainer 25 coaxially lying on the straight flow path 1a, and at the same time the proximal end of the spindle 9b that passes through the axial center of the strainer 25 so as to freely advance and retract. A strainer cap 27 having a side screwed in a watertight manner is screwed in a watertight manner, and the strainer cap 27 is detachably attached to the valve box 4.
Further, the opening 25a at the front end of the strainer 25 is inserted in a watertight manner into a receiving port 28 of the strainer 25 provided downstream of the linear flow path 1a, thereby forming a seat ring 25a in which the plug 9a is detachable. In a normal state in which the plug 9a is detached from the seat ring 25a, the primary flow path 1 is in a normal communication state, so that the flowing water passes through the strainer 25 in the straight flow path 1a from the inlet 10 through the right angle flow path 1b. And flow downstream.

  In the spindle 9b, a frustoconical plug 9a having a diameter gradually reduced toward the seat ring 25a is fixed to the distal end of the strainer 25 protruding outward (downstream) from the distal end opening (sheet ring) 25a. The base end projecting outward from the strainer cap 27 is formed with a knob 9d which is formed to have a diameter larger than the spindle screw hole provided in the strainer cap 27 and is advanced and retracted while rotating the spindle 9b.

  In the normal state of FIGS. 1 and 2 in which only the knob 9d protrudes from the strainer cap 27, the spindle 9b is pushed into the valve box 4 and the plug 9a is detached from the seat ring 25a so that the primary channel 1 (straight line) The flow path 1a) is in a communicating state, and the pressure reducing valve performs the original function of maintaining the secondary pressure at a certain pressure lower than the primary pressure as described above.

  Further, when the spindle 9b is pulled out from the strainer cap 27 (valve box 4) while manually rotating the knob 9d in the normal state, the plug 9a is closed by being seated on the seat ring 25a, and the straight flow path is closed. 1a is partitioned in a watertight manner on the primary and secondary sides.

As a result, a linear flow path is formed only by the orifice 9c, which is composed of an elongated hole formed in a predetermined length from the distal end of the shaft center of the spindle 9b to the proximal end and a diameter hole that is orthogonal to the elongated hole and communicates with the strainer 25 1a communicates and can reduce the flow from the primary side to the secondary side.
A retaining ring 29 is provided at an appropriate position of the spindle 9a so as to come into contact with the inner end surface of the strainer cap 27 that closes and fixes the proximal end opening of the strainer 25 when the distal end opening 25a is closed by the plug 9a.

As described above, when the throttle valve 9 is operated to reduce the flow rate from the primary side to the secondary side, the flow rate to the secondary side decreases, so the secondary side pressure decreases and the valve body 6 is fully opened. be able to.
As a result, fine foreign matter that has passed through the strainer 25 and stays around the valve body 6 and the valve seat 5 is allowed to flow down to the secondary side, and the foreign matter is caught between the valve body 6 and the valve seat 5. To prevent it.

  At this time, the valve portion 6a of the valve body 6 is formed of self-lubricating rubber, or the surface of the valve body 6 is coated with a fluororesin, or the surface of the valve seat 5 is coated with a fluororesin, whereby the valve body 6 and the valve body 6a. The frictional resistance of the surface of the seat 5 is reduced, and fine foreign matters that flow down to the valve body 6 and the valve seat 5 through the strainer 25 slide on the surface and do not stay between the valve body 6 and the valve seat 5. During the opening of the valve, it flows down to the secondary side flow path 2, so that no foreign matter is caught between the valve body 6 and the valve seat 5.

Next, four modifications of the valve body 6 will be described with reference to the drawings.
Each valve body 6 to be described below is incorporated in the pressure reducing valve, and the other components are the same as described above. Therefore, the same or corresponding parts are denoted by the same reference numerals, and the description thereof is omitted. To do.

First, the valve body 6 of the first modified example shown in FIGS. 4 to 6 is formed in a tapered shape in which the valve portion 6a is gradually reduced in diameter toward the valve seat 5, and the valve body 6a in the middle of the taper is shown in FIG. And a contact protrusion 30 that can be brought into close contact with the valve seat 5 when the valve is closed.
The valve portion 6a is made of self-lubricating rubber as described above, or has a fluororesin coating on the surface.

By forming the valve body 6 as described above, even when the opening of the valve body 6 is stable at a very narrow interval as shown in FIG. Since the space X is wider on the downstream side than the conventional disc valve, the fine foreign matter that passes through the strainer 25 and approaches the valve body 6 and the valve seat 5 flows without resistance. It is easy to reduce the frequency of biting between the valve body 6 and the valve seat 5 as compared with the conventional disc valve.
Further, when the throttle valve 9 is made to function as described above and the valve body 6 is fully opened as shown in FIG. 6, foreign matter is easily swept down to the downstream side of the valve body 6, and the valve body 6 and the valve seat 5 are Prevents biting of foreign objects.

In the valve body 6 of the second modified example shown in FIGS. 7 to 9, the valve portion 6 a is formed in a flat disk shape on the surface facing the valve seat 5, and on the surface facing the valve 6 a An annular protrusion-like contact portion 30 that can be brought into close contact with the valve seat 5 when the valve is closed as shown in FIG.
The valve portion 6a is made of self-lubricating rubber as described above, or has a fluororesin coating on the surface.

By forming the valve body 6 as described above, even when the opening degree of the valve body 6 is stable at a very narrow interval as shown in FIG. Protrudes from the flat facing surface with the valve seat 5, and the space X is wider on the downstream side than the contact portion 30 compared to the conventional disc valve, so that it passes through the strainer and approaches the valve body 6 and the valve seat 5 finely. Therefore, the frequency of biting between the valve element 6 and the valve seat 5 can be drastically reduced as compared with the conventional disc valve.
Further, even when the throttle valve 9 is made to function as described above and the valve body 6 is fully opened as shown in FIG. 9, foreign matter is swept away to the downstream side of the valve body 6 without difficulty, and between the valve body 6 and the valve seat 5. Prevents biting of foreign objects.

In the valve body 6 of the third modified example shown in FIGS. 10 to 13, the valve portion 6a has a contact protrusion 30 that can be in close contact with the valve seat 5 when the valve seat 6 is closed as shown in FIG. And a cylindrical sliding portion 31 capable of slidingly contacting the inner wall of the valve port 3 is provided at the center of the contact projection 30.
The sliding portion 31 is provided with concave and convex strips 31a and 31b having a triangular cross section that is shorter than the axial length of the valve port 3 and parallel to the axial line in the circumferential direction (see FIG. 13).
The valve portion 6a is made of self-lubricating rubber as described above, or has a fluororesin coating on the surface.

When the valve element 6 is not fully opened, the ridges 31b are set so as to slidably contact the inner wall of the valve port 3. Thus, in the normal valve opening state shown in FIG. Water is passed through the groove 31a of the moving part 31, and the foreign material larger than the cross-sectional area of the groove 31a does not flow down to the secondary side, and the frequency of biting between the valve body 6 and the valve seat 5 can be drastically reduced.
Further, when the throttle valve 9 is operated as described above and the valve body 6 is fully opened as shown in FIG. 12, the ridges 31a and 31b are pulled out from the valve port 3, and the ridge 31a (between the tips of the ridges 31b). By setting the distance S between the tips of the ridges 31a and 31b and the valve seat 5 to be larger than the distance d, the foreign matter staying upstream of the valve body 6 is moved to the downstream side of the valve body 6. The foreign matter between the valve body 6 and the valve seat 5 is prevented from being caught.

In the valve body 6 of the fourth modification shown in FIGS. 14 to 16, the valve portion 6 a is formed in a piston (column) shape that can be slidably contacted with the inner wall of the valve port 3 formed with the valve seat 5 in a watertight manner. At the same time, it is shorter than the axial length of the valve port 3 and can be inserted into and removed from the valve port 3.
The valve portion 6a is made of self-lubricating rubber as described above, or has a fluororesin coating on the surface.

Further, the secondary opening end face 3a of the valve port 3 is formed in a flat annular shape, and the secondary opening end face 3a is formed in a disc shape when the valve is closed as shown in FIG. It is made to contact.
Then, by setting the valve body 6 so that the valve body 6 is detached from the valve port 3 when the valve is opened, even if the opening of the valve body 6 is stabilized at a very narrow interval as shown in FIG. Since the space X is wider on the downstream side of the valve body 6 that is separated from the valve port 3 by a narrow interval than the conventional disc valve, the fine foreign matter that passes through the strainer 25 and approaches the valve body 6 and the valve seat 5. Is easy to flow without resistance, and the frequency of biting between the valve body 6 and the valve seat 5 can be drastically reduced as compared with the conventional disc valve.
Further, when the throttle valve 9 is made to function as described above and the valve body 6 is fully opened as shown in FIG. 16, the foreign matter staying upstream of the valve body 6 is also transferred to the downstream side of the valve body 6. The foreign matter between the valve body 6 and the valve seat 5 is prevented from being caught.

1 Primary side flow path 2 Secondary side flow path 3 Valve port
3a End face of secondary side opening 4 Valve box 5 Valve seat 6 Valve body 7 Drive unit 9 Throttle valve
9a plug
9b spindle
9c orifice
25a Seat ring
30 Touching part
31 Sliding part
31a concave
31b ridges

Claims (8)

  A valve body provided so that the primary side flow path and the secondary side flow path communicate with each other via the valve port, a valve body that can be attached to and detached from a valve seat provided on the end surface of the secondary side opening of the valve port; In a pressure reducing valve provided with a drive unit linked to the valve body so as to control the opening degree of the valve body in accordance with the pressure fluctuation of the secondary side flow path, from the primary side to the secondary side in the primary side flow path A pressure reducing valve having a dust biting release mechanism, characterized in that a throttle valve capable of reducing the flow rate is provided.   The throttle valve is a plug that can be freely attached to and detached from a seat ring provided in the primary side flow path, and a plug that communicates with the primary side and the secondary side in which the primary side flow path is partitioned in a watertight manner by closing the plug. 2. The pressure reducing valve having a dust biting release mechanism according to claim 1, wherein the pressure reducing valve comprises an orifice drilled in a fixed spindle.   The valve body is formed in a tapered shape having a diameter gradually reduced toward the valve seat, and has a contact portion that can be brought into close contact with the valve seat when the valve is closed at a midway position of the taper. Alternatively, a pressure reducing valve having the dust biting release mechanism described in 2.   The valve body is formed with a flat surface facing the valve seat, and an annular protrusion-shaped projecting portion capable of being in close contact with the valve seat when the valve is closed is formed on the facing surface. A pressure reducing valve having the dust biting release mechanism according to 1 or 2.   The valve body is formed in a flat shape having a contact portion that can be brought into close contact with the valve seat when the valve seat is closed, and a cylindrical shape that can slidably contact the inner wall of the valve port at the center of the contact portion. The sliding portion is provided with an uneven strip that is parallel to the axis line in the circumferential direction, and the protruding strip slides against the inner wall of the valve port when the valve body is not fully opened. 3. The dust bite according to claim 1 or 2, wherein the ridge is pulled out from the valve port when fully open, and the distance between the tip of the ridge and the valve seat is larger than the interval between the grooves. A pressure reducing valve having a release mechanism.   The valve body is formed in the shape of a piston that can be slidably contacted in a watertight manner with the inner wall of the valve port that forms the valve seat, and is shorter than the axial length of the valve port and is detachable from the valve port. 3. The pressure reducing valve having a dust biting release mechanism according to claim 1 or 2, wherein the valve body is sometimes set so as to be detached from the valve port.   7. The pressure reducing valve having a dust biting release mechanism according to claim 1, wherein the valve body is made of self-lubricating rubber.   7. A pressure reducing valve having a dust biting release mechanism according to claim 1, wherein one or both of the valve seat and the valve body is coated with a fluororesin.

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