JP2012178029A - Pressure reduction valve for liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a fluctuation range of a secondary side pressure of a pressure reduction valve for liquid.SOLUTION: The pressure reduction valve for liquid includes a drive shaft 26 for driving a valve body 23 in approaching/separating direction and a lever mechanism for driving the drive shaft corresponding to the movement of an operating rod. The lever mechanism includes: a first link mechanism provided with a lever 31 formed in an L shape, a lever pin 32 for supporting a bend part so as to swing the lever within a lever surface and a first engaging part (32) for freely slidably engaging one end of the lever with the operating rod, for converting the axial direction motion of the operating rod to the swing motion of the lever; and a second link mechanism provided with second engaging parts (36, 37) for engaging the other end of the lever with the drive shaft freely slidably in the longitudinal direction, for converting the swing motion of the lever to the axial direction motion of the drive shaft. A lever ratio K=A/B of an arm dimension A between the lever pin and an engaging pin and an arm dimension B between the lever pin and the axis of the operating rod is smaller than 1.

Description

  The present invention relates to a liquid pressure reducing valve, and more particularly, to a liquid pressure reducing valve suitable for adjusting a water supply pressure of a heat supply system such as a hot water supply system to a set water pressure.

  A heat supply system refers to a system that supplies water such as tap water by a heating source and supplies it as hot water supply or heating heat. For example, a heat supply system is known in which a solar heat collector, a gas water heater, a heat pump water heater, or the like is used alone as a heating source or an appropriate combination of these heating sources. In such a heat supply system, when a solar heat collector or a heat pump water heater is used as a heating source, water in a hot water tank is boiled using solar heat or midnight power in the daytime, for example, necessary for one day. The hot water is stored and operated. At the time of hot water supply, the hot water supplied from the hot water tank is mixed with the low temperature water to adjust the temperature to the set temperature, and then supplied to the kitchen, washroom, shower, bath, etc. In the case of a heater or the like, a heat exchanger is provided in the hot water tank, and heat is circulated between the heat exchanger and the heater to supply heat. In order to adjust the hot water supply temperature to the set temperature, a temperature adjustment valve that adjusts the mixing ratio of hot hot water and low temperature hot water is usually provided.

  However, if the pressure of tap water or the supply water pressure or the amount of water supplied to each part of the heat supply system fluctuates, the temperature adjustment operation becomes unstable. For this reason, hot water supply at a temperature higher than the set temperature may be performed, and the heat efficiency may be reduced. Therefore, it is desirable to provide a water pressure reducing valve in a water supply receiving line such as tap water to control the water supply pressure to a predetermined pressure.

  Conventionally, a pressure reducing valve for liquid such as water that is generally used is provided with a diaphragm in a partition wall of a pressure regulating chamber on which a secondary pressure acts, as described in Patent Documents 1 and 2, and the diaphragm There is known a pressure regulating mechanism in which a pressure regulating spring is pressed to the pressure regulating chamber side by a first pressure regulating spring. On the other hand, a pressure regulating valve provided with a valve body detachably connected to a valve seat having an opening communicated with the pressure regulating chamber is communicated with the inlet of the high-pressure liquid on the primary side, and the valve body is connected to the second pressure regulating valve. There is known a pressure reducing mechanism that is pressed against a valve seat by a spring. Then, the operating rod connected to the center of the diaphragm of the pressure regulating mechanism is directly connected to the drive shaft of the valve body, and the valve body is driven by the movement of the diaphragm displaced according to the secondary liquid pressure acting on the pressure regulating chamber. Thus, the opening degree of the pressure regulating valve is controlled, and the high-pressure liquid flowing in from the inflow port is reduced to a set pressure and sent out from the outflow port of the pressure regulating chamber to the supply place.

JP 2002-23856 A JP 2010-176229 A

  However, in the conventional pressure reducing valve for liquid, since the operating rod of the diaphragm and the drive shaft of the valve body of the pressure reducing valve are directly connected, the displacement amount (stroke) of the diaphragm and the valve body has the same relationship. As a result, the opening degree of the pressure regulating valve is adjusted in a one-to-one relationship according to the fluctuation range of the secondary side pressure in the pressure regulating chamber, so that the fluctuation range of the secondary side pressure is large and the pressure regulation accuracy is high. There is a problem of being bad.

  In particular, when applied to the water pressure reducing valve in the water supply system of the heat supply system, if the fluctuation range of the secondary side water supply pressure is large, the temperature adjustment of the temperature adjustment valve that adjusts the temperature by mixing hot water and water supply is stable. However, there is a problem that the hot water supply temperature becomes higher than the set temperature, and the heat efficiency is lowered.

  In addition, a water meter (water meter) that measures the amount of water supplied measures the amount of water supplied based on the number of rotations of the water turbine that rotates according to the flow rate of the water supply. There is a problem that the measured value of the water meter is not stable.

  The problem to be solved by the present invention is to suppress the fluctuation range of the secondary pressure of the liquid pressure reducing valve.

  In order to solve the above problems, a liquid pressure reducing valve according to the present invention includes a body having a pressure regulating chamber formed therein, a diaphragm constituting a part of a partition wall of the pressure regulating chamber, and a center of the diaphragm. An operating rod that is slidably supported, a valve seat having an opening provided in communication with the pressure regulating chamber, a valve body provided to face the valve seat, and a valve body connected to the valve body. A drive shaft that is supported slidably and drives in the direction away from the valve seat, a lever mechanism that drives the drive shaft according to the movement of the operating rod, and the valve seat in the pressure regulating chamber. And a liquid outlet connected to the pressure regulating chamber. The lever mechanism includes a lever formed in an L shape and the lever in the lever surface. A lever pin that movably supports the bending portion, and one end of the lever is slidably engaged with the operating rod. A first link mechanism that converts an axial movement of the operating rod into a swaying movement of the lever, and the other end of the lever is freely slidable in the longitudinal direction. And a second link mechanism that has a second engaging portion that engages with the shaft and converts the swinging motion of the lever into the axial motion of the drive shaft. The lever ratio K = A / B between the arm dimension A between the pin and the arm dimension B between the lever pin and the shaft of the operating rod is less than 1.

  According to the present invention, the valve body of the pressure regulating valve constituting the pressure reducing mechanism is driven via the lever mechanism in which the L-shaped lever is configured to be swingable around the lever pin on the operating rod of the diaphragm constituting the pressure regulating mechanism. Since the rod is connected and the lever ratio K of the L-shaped lever is less than 1, the displacement amount (stroke) of the valve body relative to the change in the displacement amount (stroke) of the diaphragm, that is, the opening amount of the pressure regulating valve (opening degree) ) Can be reduced. As a result, since the pressure in the pressure adjusting chamber can be finely controlled, the pressure fluctuation accuracy can be improved by suppressing the fluctuation range of the pressure on the secondary side. In the case of a water pressure reducing valve, the lever ratio K is preferably set to 1 / (1.3 to 1.5).

  In the above case, the first engaging portion is a rectangular insertion hole formed so as to intersect with the axis of the operating rod and into which one end of the lever is inserted. The inner surface with which the lever abuts is formed in an arc shape along the hole, and the second engagement portion includes an engagement pin 37 formed so as to intersect the axis of the drive shaft, and the other end of the lever And a long hole 36 formed along the longitudinal direction of the lever and into which the engagement pin is inserted.

  Furthermore, in any one of the liquid pressure reducing valves described above, the entire body including the body can be covered with a heat insulating material. According to this, it is possible to easily prevent the pressure reducing valve from freezing in winter.

  According to the present invention, since the fluctuation range of the secondary pressure of the liquid pressure reducing valve can be suppressed, the pressure adjustment accuracy can be improved.

It is a figure which shows the structure of the pressure reducing valve for water of one Example of this invention, (a) is a top view, (b) is sectional drawing seen from the front. It is a figure which shows the structure which covered the pressure reducing valve for water of FIG. 1 Example with the heat insulating material, and is sectional drawing which looked at the pressure reducing valve for water from the side surface. It is a figure which shows an example of the supporting member of a drive shaft. It is a figure which compares and shows the fluctuation range of the secondary side pressure of FIG. 1 Example, and the fluctuation range of the secondary side pressure of the conventional pressure reducing valve for liquids. It is a whole lineblock diagram showing an example of the heat supply system of the application object of the pressure reducing valve for water of the present invention.

  Embodiments of the liquid pressure reducing valve of the present invention will be described below with reference to the drawings.

  An overall configuration diagram of an example of a heat supply system to which the water pressure reducing valve of the present invention is applied will be described with reference to FIG. The heat supply system shown in the figure includes a solar heat collector 101 as a heating source, a hot water heater 102 using gas or petroleum as fuel, and a hot water storage tank 103. In the illustrated example, the heat collector 101 includes two heat collecting units 101a and 101b, and is connected to the heat exchanger 120 provided in the hot water storage tank 103 via the heat medium circulation paths 121a and 121b. The heat medium is circulated by a circulation pump 123 interposed in the medium circulation path 121 a to boil water in the hot water storage tank 103.

  On the other hand, water 105 such as water is supplied to the bottom of the hot water storage tank 103 through a water supply pipe 106, a water pressure reducing valve 107, and a water supply pipe 108. Hot water in the hot water storage tank 103 is pushed out by the water pressure of the water supply pipe 108, and hot water 111 is supplied from the hot water supply pipe 109 to a hot water supply place such as a kitchen via the electric three-way valve 110. A hot water supply pipe 112 branched from the hot water supply pipe 109 and a water supply pipe 114 branched from the water supply pipe 108 are connected to the temperature control valve 113, respectively. The temperature adjustment valve 113 mixes hot water with hot water to adjust the hot water temperature to a set temperature, and supplies it to the manual switching valve 116 via the hot water supply pipe 115. The manual switching valve 116 switches either water supply from the water supply pipe 106 or hot water supply from the hot water supply pipe 115 and supplies it to the water heater 102. Hot water heated by the water heater 102 is supplied to the hot water supply place 111 via the electric three-way valve 110. In addition, the code | symbol 117 in a figure is a relief valve which operate | moves when the hot water supply pressure exceeds a preset value.

  Here, with reference to FIGS. 1 and 2, a detailed configuration of the water pressure reducing valve 107 according to an embodiment of the present invention will be described. As shown in the sectional view of FIG. 1B, the water pressure reducing valve 107 of the present embodiment is configured to include a pressure adjusting mechanism, a pressure reducing mechanism, and a lever mechanism. The pressure regulating mechanism is formed to have a body 2 in which a pressure regulating chamber 1 is formed, and a cover body 3 provided by closing an opening formed in an upper partition wall in the figure of the body 2. A diaphragm 4 is provided at a joint portion between the body 2 and the cover body 3 as a part of the partition wall of the pressure regulating chamber 1. The body 2 and the cover body 3 are fastened by bolts 5. A diaphragm receiving plate 6 is laminated on the upper surface of the diaphragm 4, and a pressure adjusting spring 7 is provided in contact with the upper surface of the diaphragm receiving plate 6. The other end of the pressure adjusting spring 7 is in contact with a disk-shaped pressure adjusting plate 8 provided in the cylindrical portion of the cover body 3. One end of the pressure adjusting screw 9 is rotatably engaged with the center of the pressure adjusting plate 8, and the screw formed on the outer peripheral surface of the pressure adjusting screw 9 is formed on the insert nut 10 fixed to the top of the cover body 3. Are screwed together. Therefore, the pressure adjusting plate 8 is formed to be movable up and down in the cover body 3 by rotating the pressure adjusting screw 9. Further, the head of the operating rod 11 protrudes from the center of the diaphragm 4, and the diaphragm receiving plate 6 is sandwiched and fixed by the flange 11 a of the operating rod 11 and the nut 12. A leg portion of the operating rod 11 is provided to extend to the pressure regulating chamber 1, and a lower end thereof is slidably supported by a cylindrical support portion 13 provided upright on the bottom wall of the pressure regulating chamber 1. Yes. An opening 13 a that communicates with the pressure regulating chamber 1 is provided on the cylindrical wall at a position close to the bottom of the cylindrical support portion 13. Thereby, the operation rod 11 is smoothly slid to stabilize the operation of a lever mechanism described later.

  On the other hand, in the pressure reducing mechanism, the inlet 20 of the water supply is communicated with the pressure regulating chamber 1 via the pressure regulating valve 21, and the pressure regulating valve 21 contacts and separates from the cylindrical valve seat 22 having an opening communicated with the pressure regulating chamber 1. It has a rubber valve body 23 that can be provided. The valve body 23 is fixed to one end of the drive shaft 26 by a screw 25 with the valve cover 24 interposed therebetween. As shown in FIG. 3, the drive shaft 26 is slidably supported in the axial direction by a cylindrical support member 27 attached to the inner surface of the cylinder of the valve seat 22. That is, the support member 27 includes a cylindrical body 27a into which the drive shaft 26 is slidably inserted, a beam member 27b projecting radially at both ends of the cylindrical body 27a, and a cylinder of the valve seat 22 supported by the beam member 27b. It has a pair of cylindrical supports 27c attached to the inner surfaces of both ends. As a result, the drive shaft 26 is biased in the direction of the valve seat 22 by the high water supply pressure flowing into the inlet 20 acting on the valve cover 24. Further, a filter 29 is provided between the water supply inlet 20 and the pressure regulating valve 21 so as to cover the pressure regulating valve 21, thereby removing foreign matters contained in the water supply. The support member 27 is not limited to the structure illustrated in FIG. 3 as long as the drive shaft 26 can be slidably supported in the axial direction.

The lever mechanism includes a flat lever 31 formed in an L shape and a lever pin 32 that supports a bent portion of the lever 31. Thus, the lever 31 is supported around the lever pin 32 so as to be able to swing in the lever surface. One end of the lever 31 is inserted into a rectangular lever insertion hole 33 formed so as to intersect with the axis of the operating rod 11 (orthogonal in the illustrated example) (see FIG. 2). The rectangular lever insertion hole 33 has two insertion hole inner surfaces 33a and 33b (upper and lower inner surfaces in the figure) in the swing direction of the lever 31 so that the lever 31 can move smoothly. It is formed in an arc shape along. In the drawing of the lever 31, the upper and lower surfaces are in contact with each other so as to slide on the arc-shaped inner surface of the lever insertion hole 33. With this configuration, a first link mechanism that engages one end of the lever 31 and converts the axial movement of the operating rod 11 into the swaying movement of the lever 31 is formed.
On the other hand, an elongated hole 36 is formed at the other end of the lever 31 along the longitudinal direction of the lever 31, and the elongated hole 36 is planted on the outer surface of the drive shaft 26 of the pressure regulating valve 21 and engaged with the engaging pin 37. ing. As a result, a second link mechanism that converts the swaying motion of the lever 31 into the axial motion of the drive shaft 26 is formed. A dimension between the lever pin 32 and the engagement pin 37 is A, and a dimension between the lever pin 32 and the shaft center of the operating rod 11 is B. If the dimensional ratio of A / B is defined as lever ratio K = A / B, K <1 is set in the present invention. More specifically, the lever ratio K is preferably set to a range of 1 / (1.3 to 1.5).

  The pressure regulating chamber 1 of the water pressure reducing valve 107 configured as described above is communicated with the outlet 41 of the water supply via the check valve 40. The check valve 40 shuts off the water flow that flows into the pressure regulating chamber 1 from the outlet 41 side, and is not related to the features of the present invention, and therefore will not be described in detail. As shown in FIG. 2, the water pressure reducing valve 107 is a blow valve 42 that discharges water in the pressure regulating chamber 1 when an abnormal water pressure higher than a predetermined set pressure is applied in the pressure regulating chamber 1. Is provided.

  FIG. 2 is a cross-sectional view of the water pressure reducing valve 107 of the embodiment shown in FIG. 1 as covered by a heat insulating material cover 50 as viewed from the side. As illustrated, the heat insulating material cover 50 is divided into two upper and lower heat insulating material covers 50 a and 50 b so as to surround the body 2 and the cover body 3.

Next, the operation and effect of the characteristic part of the water pressure reducing valve of this embodiment will be described with reference to FIG. First, regarding the technical meaning of the lever ratio K, the basic principle of the liquid pressure reducing valve of the present invention will be described. The balance of pressure regulation of the liquid pressure reducing valve can be expressed by the following equation (1).
F1 = S × P ₂ + K × S ₀ × (P ₁ −P ₂ ) (1)
Here, the meanings of the symbols are as follows.
F1: Load [kgf] applied to the diaphragm 4 by the pressure regulating spring 7
S: Liquid pressure receiving area [cm ² ] of diaphragm 4
P ₂ : Secondary pressure [kgf / cm ² ]
K: Lever ratio S ₀ : Opening area of the valve seat 22 [cm ² ]
P ₁ : Secondary pressure [kgf / cm ² ]
That is, the expression (1) is based on the balance between the load of the pressure regulating spring 7 and the load obtained by applying the secondary pressure to the pressure receiving area of the diaphragm 4 (the opening amount of the pressure regulating valve 21 (opening diameter)). And opening).

In order to calculate the opening amount of the valve seat 22, a virtual orifice is assumed and a virtual orifice diameter D is calculated by the following equation (2). In equation (2), Qmax is the maximum flow rate of the liquid to be depressurized, (P ₁ -P ₂ ) is the pressure loss of the virtual orifice, and constant 0.009 is the structural time constant. The virtual orifice diameter D is a temporary setting of a precondition for calculating the diaphragm displacement amount H at the maximum flow rate.

On the other hand, the displacement amount H of the diaphragm 4, based on the virtual orifice diameter D, a relationship of BenzaHiraku diameter D ₀ and the following equation (3). Α in the equation is a displacement amount coefficient of the diaphragm 4, and is a coefficient for each flow rate in which the numerical value increases as the flow rate increases. As a result, the displacement amount for each flow rate of the diaphragm tends to increase in a quadratic curve.

As is clear from these equations (1) to (3), the valve seat opening diameter D ₀ is determined based on the displacement amount of the diaphragm 4. Then, the opening amount (opening diameter and opening degree) of the valve seat 22 of the pressure regulating valve 21 is determined by adjusting the correlation of the displacement amount of the diaphragm 4 with the lever ratio K so as to reduce the fluctuation range of the secondary pressure.

  As described above, according to the present embodiment, the pressure reducing mechanism is configured through the lever mechanism in which the L-shaped lever is configured to be swingable around the lever pin on the operating rod of the diaphragm constituting the pressure adjusting mechanism. Since the drive rod of the valve body of the pressure regulating valve is connected and the lever ratio K of the L-shaped lever is less than 1, the displacement amount (stroke) of the valve body with respect to the change in the displacement amount (stroke) of the diaphragm, that is, the adjustment The change in the opening amount of the pressure valve can be reduced. As a result, since the pressure in the pressure adjusting chamber can be finely controlled, the pressure fluctuation accuracy can be improved by suppressing the fluctuation range of the pressure on the secondary side.

  In particular, in the case of a water pressure reducing valve in which the lever ratio K is set to 1 / (1.3 to 1.5), the fluctuation range of the secondary water pressure with respect to the set pressure is ± 3 as shown by the curve I in FIG. %. On the other hand, in the case of a conventional liquid pressure reducing valve in which the valve body of the pressure regulating valve is directly driven by a diaphragm, a fluctuation range of ± 8% occurs as shown by a curve II in FIG. Thus, according to the present invention, the pressure fluctuation range on the secondary side of the pressure reducing valve for liquid can be greatly reduced, so that the pressure regulation accuracy can be improved.

  Moreover, according to the water pressure reducing valve in which the entire body including the heat insulating material is covered, it is possible to easily prevent freezing in winter.

DESCRIPTION OF SYMBOLS 1 Pressure regulation chamber 2 Body 3 Cover body 4 Diaphragm 6 Diaphragm receiving plate 7 Pressure regulation spring 8 Pressure regulation plate 9 Pressure regulation screw 11 Actuation rod 13 Support part 13a Opening 20 Inlet 21 Pressure regulation valve 22 Valve seat 23 Valve body 26 Drive shaft 27 Support member 29 Filter 31 Lever 32 Lever pin 33 Lever insertion hole 33a, b Insertion hole inner surface 36 Elongated hole 37 Pin 50 Thermal insulation cover

Claims (4)

  A body having a pressure regulating chamber formed therein, a diaphragm constituting a part of the partition wall of the pressure regulating chamber, an operating rod connected to the center of the diaphragm and supported to be freely slidable, and the pressure regulating chamber A valve seat having an opening provided in communication, a valve body provided to face the valve seat, and connected to the valve body so as to be slidably supported in a contact / separation direction with respect to the valve seat A drive shaft for driving, a lever mechanism for driving the drive shaft according to the movement of the operating rod, a liquid inflow port communicated with the pressure regulating chamber via the valve seat, and a pressure regulating chamber. The lever mechanism includes an L-shaped lever, a lever pin that supports the bent portion so that the lever can swing in the lever surface, and one end of the lever is the end of the lever. A first engaging portion that is slidably engaged with the operating rod, and applies the axial movement of the operating rod. A first link mechanism for converting the lever into a swaying motion, and a second engaging portion at which the other end of the lever slidably engages with the drive shaft in the longitudinal direction. And a second link mechanism for converting the movement into the axial movement of the drive shaft, between the arm dimension A between the lever pin and the engagement pin, and between the lever pin and the shaft of the operating rod. A pressure reducing valve for liquid having a lever ratio K = A / B with an arm dimension B of less than 1. The pressure reducing valve for liquid according to claim 1,
The first engagement portion is a rectangular insertion hole formed so as to intersect with the axis of the operating rod and into which one end of the lever is inserted. The insertion hole is an inner surface on which the lever abuts by a swinging motion. Is formed in an arc shape along the hole,
The second engagement portion includes an engagement pin formed to intersect the axis of the drive shaft, and a length at which the engagement pin is inserted at the other end of the lever along the longitudinal direction of the lever. A pressure reducing valve for liquid, comprising a hole. The pressure reducing valve for liquid according to claim 1 or 2,
The pressure reducing valve for liquid, wherein the lever ratio K is 1 / (1.3 to 1.5). The liquid pressure reducing valve according to any one of claims 1 to 3,
A pressure reducing valve for liquid, wherein the whole body including the body is covered with a heat insulating material.

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