JP2019101946A - Pressure reduction valve - Google Patents

Abstract

To provide a pressure reduction valve comprising: a pressure reduction valve mechanism including a valve body having a water stop function that variably adjusts a passage area of a boundary between a primary passage and a secondary passage; and a vent valve mechanism that opens/closes according to internal pressure of the secondary passage, the pressure reduction valve being designed not to pose problems for the water stop function of the pressure reduction valve mechanism and a water stop function of the vent valve function.SOLUTION: A pressure reduction valve comprises: a pressure reduction valve mechanism comprising a valve body having a water stop function that variably adjusts a passage area of a boundary between a primary passage and a secondary passage: and a vent valve mechanism that opens/closes according to internal pressure of the secondary passage. The valve body of the pressure reduction valve mechanism is guided in a center axial direction of the pressure reduction valve mechanism and at two points separate in the center axial direction of the pressure reduction valve mechanism. A valve seat or a valve body of the vent valve mechanism is guided in a center axial direction of the vent valve mechanism and at two points separate in the center axial direction of the vent valve mechanism.SELECTED DRAWING: Figure 1

Description

The present invention provides a pressure reducing valve mechanism including a valve body having a water blocking function that variably adjusts the flow passage area at the boundary between the primary passage and the secondary passage, and a relief valve that opens and closes according to the internal pressure of the secondary passage. The present invention relates to a pressure reducing valve including a valve mechanism.

The pressure reducing valve includes a pressure reducing valve mechanism having a water stopping function for variably adjusting the flow passage area at the boundary between the primary side passage and the secondary side passage, and a relief valve mechanism opening and closing according to the internal pressure of the secondary side passage. The mechanism and the relief valve mechanism are pressure reducing valves which are lift valve mechanisms sharing a central axis, and the body, a cylinder formed by a part of the body, a piston head reciprocating in the cylinder, and a piston head A seal member for sealing the sliding contact between the cylinder and the inner circumferential surface of the cylinder, a piston rod extending from one end of the piston head and projecting from one end of the cylinder to the secondary passage outside the cylinder, and one end of the cylinder A first valve seat to be formed, a first valve body fixed to one end of the piston rod projecting out of the cylinder and facing the first valve seat, and an opening formed in a portion of the cylinder peripheral wall facing the piston rod , It is formed by a first spring that urges the stone head in the valve closing direction, a cylinder whose one end faces the other end of the piston head, a diaphragm whose center is fixed to the cylinder, and a part of the body A diaphragm case that faces the diaphragm and forms a pressure sensing chamber communicating with the secondary side passage in cooperation with the diaphragm, the cylinder, and the piston head, a second spring that presses the diaphragm toward the pressure sensing chamber, and a second spring And a spring case which accommodates the other end of the cylinder and holds the peripheral portion of the diaphragm in cooperation with the diaphragm case, and a second valve seat or second valve disposed at the one end of the cylinder A body, and a second valve seat or second valve seat that engages with the other end of the piston head and faces the second valve seat or second valve body disposed at the one end of the cylinder, The first valve body and the first valve seat are valve bodies of the pressure reducing valve mechanism Forming a valve seat, a pressure reducing valve forming the valve seat and the valve body of the second valve seat and the second valve body and is relief valve mechanism is disclosed in Patent Document 1.
The pressure reducing valve of Patent Document 1 has an advantage that the pressure reducing valve mechanism and the relief valve mechanism can be integrated.

JP, 2013-196399, A

In the pressure reducing valve disclosed in Patent Document 1, the first valve body is guided in the central axis direction of the pressure reducing valve mechanism only at the sliding contact portion between the piston head and the cylinder. There is a problem that the first valve body is easily inclined to the closing surface of the pressure reducing valve mechanism, which may cause the smooth movement of the pressure reducing valve mechanism and the water stopping function. In addition, since the second valve seat or the second valve body disposed at the one end of the cylindrical body is not guided in the central axis direction of the relief valve mechanism, it is easily affected by component accuracy and assembly accuracy. There is a problem that the valve seat or the second valve body tilts with respect to the closing surface of the relief valve mechanism, and the smooth movement of the relief valve mechanism and the water stopping function may be disturbed.
The present invention has been made in view of the above problems, and a pressure reducing valve mechanism having a water blocking function for variably adjusting the flow passage area of the boundary between the primary passage and the secondary passage, and the internal pressure of the secondary passage. The pressure reducing valve mechanism and the pressure relief valve mechanism are pressure reducing valves that are lift valve mechanisms that share a central axis, and the body and a cylinder formed by a part of the body A piston head reciprocatively sliding in the cylinder, a seal member for sealing a sliding contact portion between the piston head and the inner circumferential surface of the cylinder, and one end of the piston head to extend from one end of the cylinder to the secondary side outside the cylinder A piston rod protruding into the passage, a first valve seat formed by the one end of the cylinder, a first valve body fixed to the one end of the piston rod projecting out of the cylinder and facing the first valve seat, the cylinder Pisce of the peripheral wall An opening formed at a portion facing the rod, a first spring urging the piston head in the valve closing direction, a cylinder whose one end portion opposes the other end of the piston head, and a center portion of the cylinder The diaphragm is formed by a fixed diaphragm, a diaphragm case formed by a part of the body and facing the diaphragm, forming a pressure sensing chamber communicating with the diaphragm, cylinder and piston head and communicating with the secondary side passage, and A second spring pressing to the side, a second spring and a spring case accommodating the other end of the cylinder and holding the peripheral edge of the diaphragm in cooperation with the diaphragm case, the one end of the cylinder A second valve seat or second valve body disposed, and a second valve seat or second valve body engaged with the other end of the piston head and disposed at the one end of the cylinder 2 valve body or 2nd valve seat The first valve body and the first valve seat form the valve body and the valve seat of the pressure reducing valve mechanism, and the second valve seat and the second valve body form the valve seat and the valve body of the relief valve mechanism An object of the present invention is to provide a pressure reducing valve which does not disturb the water stopping function of the pressure reducing valve mechanism and the water stopping function of the relief valve mechanism.

In order to solve the above problems, in the present invention, the pressure reducing valve mechanism having a water stop function for variably adjusting the flow passage area at the boundary between the primary passage and the secondary passage, and the internal pressure of the secondary passage. The pressure reducing valve mechanism and the pressure relief valve mechanism are pressure reducing valves that are lift valve mechanisms that share a central axis, the body and a cylinder formed by a part of the body, A piston head reciprocatively sliding in the cylinder, a seal member for sealing a sliding contact portion between the piston head and the cylinder inner circumferential surface, and one end of the piston head extending from one end of the cylinder to the secondary side passage outside the cylinder A piston rod projecting to the end, a first valve seat formed by the one end of the cylinder, a first valve body fixed to the one end of the piston rod projecting to the outside of the cylinder and facing the first valve seat, a cylinder peripheral wall Pis of An opening formed at a portion facing the rod, a first spring urging the piston head in the valve closing direction, a cylinder whose one end portion opposes the other end of the piston head, and a center portion of the cylinder The diaphragm is formed by a fixed diaphragm, a diaphragm case formed by a part of the body and facing the diaphragm, forming a pressure sensing chamber communicating with the diaphragm, cylinder and piston head and communicating with the secondary side passage, and A second spring pressing to the side, a second spring and a spring case accommodating the other end of the cylinder and holding the peripheral edge of the diaphragm in cooperation with the diaphragm case, the one end of the cylinder A second valve seat or second valve body disposed, and a second valve seat or second valve body engaged with the other end of the piston head and disposed at the one end of the cylinder 2 valve body or 2nd valve seat The first valve body and the first valve seat form the valve body and the valve seat of the pressure reducing valve mechanism, and the second valve seat and the second valve body form the valve seat and the valve body of the relief valve mechanism. The first valve body of the pressure reducing valve mechanism is guided in the central axial direction of the pressure reducing valve mechanism at two places separated in the central axial direction of the pressure reducing valve mechanism, and a second valve seat disposed at the one end of the cylinder. Alternatively, the pressure reducing valve is characterized in that the second valve body is guided at two points spaced apart in the central axis direction of the relief valve mechanism in the central axis direction of the relief valve mechanism.
In the pressure reducing valve according to the present invention, the first valve body of the pressure reducing valve mechanism is guided in the central axial direction of the pressure reducing valve mechanism at two points separated in the central axial direction of the pressure reducing valve mechanism. It is not affected by the accuracy, does not tilt against the closing surface of the pressure reducing valve mechanism, and does not affect the smooth movement or water blocking function of the pressure reducing valve mechanism. The second valve seat or the second valve body disposed at one end of the cylindrical body is guided in the central axis direction of the relief valve mechanism at two places separated in the central axis direction of the relief valve mechanism, so the part accuracy And is not susceptible to assembly accuracy and does not tilt against the closing surface of the relief valve mechanism. Therefore, the second valve body or the second valve seat engaged with the other end of the piston head can be guided in the central axis direction of the relief valve mechanism at two points separated in the central axis direction of the relief valve mechanism. If fixed to the other end, the second valve body or second valve seat engaged with the other end of the piston head is also less affected by component accuracy and assembly accuracy, and does not tilt relative to the closing surface of the relief valve mechanism , Do not disturb the smooth movement of the relief valve mechanism and the water stop function.

In a preferred aspect of the present invention, the second valve body or second valve seat is released between the second valve body or second valve seat engaged with the other end of the piston head and the other end of the piston head A third spring is provided for urging the valve mechanism in the valve closing direction, and a stopper for restricting the movement of the second valve body or the second valve seat in the valve closing direction of the relief valve mechanism is provided at the other end of the piston head. The second valve body or the second valve seat is guided in the central axial direction of the relief valve mechanism at two points separated in the central axial direction of the relief valve mechanism.
By setting the spring constant of the third spring to a small value, it is possible to prevent the performance deterioration of the sealing material constituting the second valve body or the second valve seat with time. By disposing the stopper, the relief valve mechanism can be reliably opened. Between the second valve body or second valve seat engaged with the other end of the piston head and the other end of the piston head, the second valve body or second valve seat toward the valve closing direction of the relief valve mechanism When the third spring to be biased is disposed, if the second valve body or the second valve seat is guided in the central axis direction of the relief valve mechanism at two points separated in the central axis direction of the relief valve mechanism The second valve body or the second valve seat is not inclined to the closing surface of the relief valve mechanism, and the smooth movement of the relief valve mechanism and the water stopping function are not disturbed.
In a preferred embodiment of the invention, a slight play is provided in the guide of the second valve body or the second valve seat which engages with the other end of the piston head.
Even if the second valve seat or the second valve body is slightly inclined to the closing surface of the relief valve mechanism due to the influence of the part accuracy or the assembly accuracy, the second valve seat or the second valve body engages with the other end of the piston head If a slight play is provided in the guide of the valve body or the second valve seat, the second valve body or the second valve seat can tilt following the second valve seat or the second valve body, and the second valve It can be in close contact with the seat or the second valve body.
In a preferred embodiment of the present invention, the second valve body or second valve seat engaged with the other end of the piston head is attached to the other end of the piston head by a push and twist bayonet type connection mechanism.
By means of a push and twist bayonet type connection mechanism, the second valve body or the second valve seat can be easily attached to the other end of the piston head.
In a preferred embodiment of the present invention, the second valve body or second valve seat engaged with the other end of the piston head is fixed to the other end of the piston head.
The other end of the piston head guided in the central axial direction of the relief valve mechanism at two points spaced apart from the second valve body or the second valve seat engaged with the other end of the piston head in the central axial direction of the relief valve mechanism If the second valve body or the second valve seat is also fixed to the second portion, the second valve body or the second valve seat is also guided in the central axis direction of the relief valve mechanism at two points separated in the central axis direction of the relief valve mechanism. Do not lean against.

FIG. 6 is a cross-sectional view of the pressure reducing valve according to the embodiment of the present invention when the pressure reducing valve mechanism is open and when the relief valve mechanism is closed. (A) is a whole sectional view, (b) is a partially enlarged view of (a). FIG. 6 is a cross-sectional view of the pressure reducing valve according to the embodiment of the present invention when the pressure reducing valve mechanism is closed and when the relief valve mechanism is closed. (A) is a whole sectional view, (b) is a partially enlarged view of (a). FIG. 6 is a cross-sectional view of the pressure reducing valve according to the embodiment of the present invention when the pressure reducing valve mechanism is closed and when the relief valve mechanism is opened. (A) is a whole sectional view, (b) is a partially enlarged view of (a). It is a block diagram of the 2nd valve body which is a component of the relief valve mechanism engaged with the piston head of the pressure-reduction valve which concerns on the Example of this invention. (A) is a top view, (b) is a bb sectional view of (a), (c) is a c-c arrow view of (a), (d) is a view of (a) It is a dd arrow line view, (e) is an ee cross-sectional view of (c). It is a block diagram of the piston head of the pressure-reduction valve which concerns on the Example of this invention. (A) is an end view of the side on which the constituent members of the relief valve mechanism are engaged, (b) is a bb arrow view of (a), (c) is a c-c cross section of (a) It is a figure, (d) is a dd sectional view of (a), (e) is an e-e sectional view of (a). It is a figure which shows the assembly | attachment procedure to the piston head of the 2nd valve body which comprises the relief valve mechanism of the pressure-reduction valve which concerns on the Example of this invention.

A pressure reducing valve according to an embodiment of the present invention will be described.
As shown in FIG. 1, the pressure reducing valve 1 includes a body 2. The body 2 has a primary side passage 2a and a secondary side passage 2b formed therein, and has a cylinder 2c and a diaphragm case 2d.
The pressure reducing valve 1 includes a piston head 3 slidingly reciprocated in a cylinder 2c, an O-ring 4 sealing a sliding contact portion between the piston head 3 and the inner peripheral surface of the cylinder 2c, and a cylinder extending from one end of the piston head 3 A piston rod 5 protruding from one end of 2c to the secondary passage 2b outside the cylinder 2c, a first valve seat 6 formed by the one end of the cylinder 2c, and one end protruding out of the cylinder 2c of the piston rod 5 A first valve body 7 fixed to the first valve seat 6 and facing the first valve seat 6, a first spring 8 engaging the first valve body 7 to bias the piston head 3 in the valve closing direction, and two of the body 2 A spring retainer 9 for the first spring 8 which is watertightly screwed and fixed to a portion forming the next side passage 2b and accommodates the first spring 8 and accommodates the first valve body 7 in a reciprocally slidable manner, and a cylinder 2c Shaped at the part facing piston rod 5 of the peripheral wall The opening 10, the cylinder 11 whose one end faces the other end of the piston head 3, the diaphragm 12 whose center is fixed near the one end of the cylinder 11 and a part of the body 2 The above-described diaphragm case 2d, which forms the pressure sensing chamber 13 facing the diaphragm 12, communicates with the secondary side passage 2b in cooperation with the diaphragm 12, the cylinder 2c and the piston head 3, and the diaphragm 12 A spring case for accommodating the second spring 14 pressing to the 13 side, the second spring 14 and the longitudinally central portion and the other end portion of the cylinder 11 and sandwiching the peripheral portion of the diaphragm 12 in cooperation with the diaphragm case 2d A second valve seat 16 disposed at the one end of the cylindrical body 11 and a second spring 16 engaged with the other end of the piston head 3 via the third spring 17 so as to face the second valve seat 16 Disc 18 , And a. The spring constant of the third spring 17 is set to a small value.

The cylinder 11 includes a first portion 11a having one end portion disposed in the pressure sensing chamber 13, and a second portion 11b disposed in the spring case 15 and fixedly coupled to the first portion 11a. There is. The first portion 11 a and the second portion 11 b cooperate to hold the central portion of the diaphragm 12. As described above, the second valve seat 16 is disposed at one end portion of the first portion 11a disposed in the pressure sensing chamber 13, and the one end portion is externally fitted to the cylinder 2c so as to be reciprocatively slidable. A plurality of openings 11a 'are formed in the fitting portion. The end of the second portion 11b closer to the first portion 11a forms a spring retainer for the second spring 14, and the end separated from the first portion 11a is reciprocably slidably fitted in the cylindrical portion 15a of the spring case doing.
A drainage cylinder 19 extends from the spring case 15.

A pressure reducing valve mechanism α is formed by the cylinder 2c, the piston head 3, the first valve seat 6, the first valve body 7, the first spring 8, the diaphragm 12, the second spring 14 and the like. The pressure reducing valve mechanism α is a lift valve mechanism having a central axis X, that is, a shutoff mechanism having a closing member in which at least one component opens and closes along the central axis X perpendicular to the closing surface. The first valve body 7 opens and closes along the central axis X perpendicular to the closing surface. The first valve body 7 has two parts, a sliding contact portion between the piston head 3 and the inner peripheral surface of the cylinder 2c spaced apart from each other in the central axis X direction, and a sliding contact portion between the first valve body 7 and the spring retainer 9 At the central axis X direction.
A relief valve mechanism β is formed by the cylindrical body 11, the diaphragm 12, the second spring 14, the second valve seat 16, the third spring 17, and the second valve body 18. The relief valve mechanism β is a lift valve mechanism that shares the central axis X with the pressure reducing valve mechanism α. The second valve seat 16 and the second valve body 18 open and close vertically to the closing surface along the central axis X. The second valve seat 16 includes a sliding contact portion between the second cylindrical body portion 11b and the spring case cylindrical portion 15a, which are spaced apart from each other in the central axis X direction, and a sliding contact portion between the first cylindrical body portion 11a and the cylinder 2c. It is guided in the central axis X direction at two places.

As shown in FIG. 4, the second valve body 18 has a bottomed cylindrical case 18 a and a seal member 18 b fitted and fixed to the case 18 a. An annular bulging portion 18c in the radial direction is formed on the outer peripheral side surface of the open end of the case 18a. A pair of arms 18 d extend radially outward from the outer peripheral side surface of the case 18 a at an interval of 180 degrees in the circumferential direction. An annular groove 18e for accommodating one end of the third spring 17 is formed in the bottom wall of the case 18a.
As shown in FIG. 5, the other end of the piston head 3 has a large diameter recess 3a for accommodating the second valve body 18 and a small diameter for accommodating the other end of the third spring 17 continuously to the large diameter recess 3a. A recess 3 b is formed. The large-diameter concave portions 3a, the first longitudinal groove 3a ₁ of the pair extending on opposite sides between the central axis X from the other end of the piston head 3, a circumferential groove 3a ₂ extending from the terminal end of the longitudinal groove 3a ₁ a second longitudinal grooves 3a ₃ of the pair extending toward sandwiched between the central axis X in the course of the circumferential grooves 3a ₂ from opposing circumferential groove 3a ₂ to the other end of the piston head 3 is formed. The second longitudinal grooves 3a ₃ terminates without reaching the other end of the piston head 3. Some of the circumferential groove 3a ₂ forms a slit through the wall of the large diameter recess 3a.
A third spring 17 having an arm 18d of the second valve body 18 and one end engaged with the second valve body 18 and the other end engaged with the small diameter recess 3b of the piston head 3; The longitudinal groove 3a ₁ , the circumferential groove 3a ₂ , and the second longitudinal groove 3a ₃ constitute a bayonet type connection mechanism that pushes and twists between the second valve body 18 and the other end of the piston head 3.
When attaching the second valve body 18 to the other end of the piston head 3, as shown in FIG. 6A, the third spring 17 is inserted into the small diameter recess 3b, and the pair of arm portions 18d is formed as a pair of first directly facing the longitudinal groove 3a _1, while sliding the annular swelling portion 18c to the peripheral side surface of the large-diameter portion 3a, the second valve body 18 is inserted into the large diameter recess 3a, the annular groove 18e third spring 17 The second valve body 18 is further pushed into the large diameter recess 3a while pressing the third spring 17 and the pushing is stopped when the arm 18d abuts on one side wall of the circumferential groove 3a ₂ as shown in FIG. as shown in b), to rotate the second valve body 18 to stop the axis X around the circumferential groove 3a ₂ twisted. During rotation, the second valve body 18 receives the biasing force of the third spring 17, the arm portion 18d is pressed against the other side wall of the circumferential groove 3a _2. The second valve body 18 continues to rotate, and as shown in FIG. 6C, when the arm portion 18 d reaches the rotational position facing the second longitudinal groove 3 a ₃ , the second spring receives the urging force of the third spring 17. the valve body 18, as shown in FIG. 6 (d), while engaging the arm portion 18d to the second longitudinal grooves 3a _3, moves toward the other end of the piston head 3, the arm portion 18d and the second longitudinal It abuts on the end of the groove 3a ₃ and stops. The second valve body 18 is attached to the other end of the piston head 3 in the above procedure. The second valve body 18 attached to the other end of the piston head 3 has a sliding contact portion between the annular bulging portion 18c and the circumferential side surface of the large diameter recess 3a, spaced from each other in the central axis X direction, and an arm It is guided in the central axis X direction at two points of the engagement portion between the portion 18 d and the second vertical groove 3 a ₃ .

The operation of the pressure reducing valve 1 will be described.
When the water discharger (not shown) connected to the secondary side passage 2b via a pipe (not shown) is closed and the water flow in the pipe is stopped, as shown in FIG. The pressure reducing valve mechanism α is closed by coming into contact with the 1 valve seat 6. Also in the relief valve mechanism β, as long as the internal pressure of the secondary side passage 2b (hereinafter referred to as the secondary pressure) does not reach the valve opening pressure, the seal member 18b of the second valve body 18 receiving the biasing force of the third spring 17 It abuts on the second valve seat 16 to close the valve. When the seal member 18b of the second valve body 18 abuts on the second valve seat 16 and the relief valve mechanism β is closed, the arm 18d of the second valve body 18 extends the second longitudinal groove 3a ₃ It is not in contact with the end of the second longitudinal groove 3a _{3 on} the way.
Since the secondary side passage 2 b and the pressure sensing chamber 13 communicate with each other, a secondary pressure is applied to the diaphragm 12. The primary pressure is not transmitted to the pressure sensing chamber 13 and is not applied to the diaphragm 12 as the O-ring 4 seals the sliding contact portion between the piston head 3 and the cylinder 2 c.
When the water discharging device is opened, the secondary pressure is reduced, and the biasing force in the valve closing direction due to the secondary pressure applied to the diaphragm 12 is reduced, and as shown in FIG. Away from the first valve seat 6, the pressure reducing valve mechanism α opens. When the tap water flows through the annular gap formed between the first valve body 7 and the first valve seat 6, a pressure loss occurs and the tap water is depressurized.
If the secondary pressure rises for some reason during operation of the pressure reducing valve mechanism α, the diaphragm 12 is elastically deformed in a direction away from the first valve seat 6 against the biasing force of the second spring 14 and fixed to the diaphragm 12 The moved cylinder 11 moves in a direction to move away from the piston head 3, and the piston head 3 which receives the biasing force of the first spring 8 moves the first valve body 7 following the cylinder 11, The valve body 7 approaches the first valve seat 6. As a result, the annular gap between the first valve seat 7 and the first valve body 6 is narrowed, and the pressure loss when tap water passes through the annular gap is increased. As a result, the secondary pressure drops. Therefore, the secondary pressure is maintained at a predetermined value by the pressure reducing valve mechanism α.
During the operation of the pressure reducing valve mechanism α, the contact state between the second valve seat 16 and the seal member 18b of the second valve body 18 receiving the biasing force of the third spring 17 is maintained, and the relief valve mechanism β is closed. ing.

When the secondary pressure rises to the valve closing pressure of the pressure reducing valve mechanism α during operation of the pressure reducing valve mechanism α, the first valve body 7 abuts on the first valve seat 6, and the pressure reducing valve mechanism α closes the valve of FIG. It will be in the state.
When the secondary pressure further increases beyond the valve closing pressure of the pressure reducing valve mechanism α, the diaphragm 12 is further elastically deformed in the direction away from the first valve seat 6, and the cylinder 11 moves in the direction further away from the piston head 3 . When the cylinder 11 moves in a direction to move further away from the piston head 3, the second valve 18 receiving the biasing force of the third spring 17 maintains the contact with the second valve seat 16 and moves the cylinder 11. However, when the secondary pressure reaches the valve opening pressure of the relief valve mechanism β, the arm 18d abuts on the end of the second longitudinal groove 3a ₃ and the relief valve mechanism β of the second valve body 18 is closed. Movement in the valve direction is restricted.
When the secondary pressure rises above the valve opening pressure of the relief valve mechanism β, as shown in FIG. 3, from the piston head 3 following the further elastic deformation of the diaphragm 12 in the direction away from the first valve seat 6 The second valve seat 16 which moves in the direction away from the seal member 18b of the second valve body 18 whose movement in the valve closing direction of the relief valve mechanism β is restricted by the end of the second longitudinal groove 3a ₃ releases the relief valve The mechanism β is opened, and the pressure sensing chamber 13 and hence the secondary side passage 2b is formed in the first portion 11a of the cylindrical member 11, the second valve seat 16 and the second valve body 18 It communicates with the external environment through the gap between the two, the central hole of the first portion 11a and the second portion 11b of the cylindrical member 11, the internal space of the spring case 15, and the drainage cylinder 19. As a result, as shown by a large number of arrows in FIG. 3B, the water in the pressure sensing chamber 13 and hence in the secondary side passage 2b flows into the internal space of the spring case 15, and the external environment via the drainage cylinder 19 And the secondary pressure is reduced to prevent damage to the water-surrounding equipment connected to the secondary passage 2b.

In the pressure reducing valve 1, the first valve body 7 of the pressure reducing valve mechanism α includes a sliding contact portion between the piston head 3 and the inner peripheral surface of the cylinder 2 c spaced apart from each other in the central axis X direction, and the first valve body 7. The second valve seat 16 of the relief valve mechanism β is guided in two directions of the sliding contact portion with the spring retainer 9 in the central axis X direction, and the second valve seat 16 of the relief valve mechanism β is spaced apart from each other in the central axis X direction The second valve body 18 of the relief valve mechanism β is guided in the central axis X direction at two points, a sliding contact portion with the spring case cylindrical portion 15a and a sliding contact portion with the cylinder first portion 11a and the cylinder 2c. The sliding contact portion between the annular bulging portion 18c and the circumferential side surface of the large diameter recess 3a and the engaging portion between the arm portion 18d and the second longitudinal groove 3a ₃ which are spaced apart from each other in the central axis X direction. Since it is guided in the direction of extension of the central axis X, it is not easily affected by component accuracy and assembly accuracy, and the first valve body 7 is depressurized. The second valve seat 16 and the second valve body 18 do not tilt relative to the closing surface of the relief valve mechanism β, and the smooth movement and the water blocking function of the pressure reducing valve mechanism α There is no hindrance to the smooth movement and the water stop function of the valve mechanism β. Since there is a slight play in the engagement portion between the arm 18 d and the second longitudinal groove 3 a ₃ , the second valve body 18 can be slightly inclined to the closing surface of the relief valve mechanism β. Therefore, the second valve body 18 follows the second valve seat 16 even if the second valve seat 16 is slightly inclined with respect to the closing surface of the relief valve mechanism β under the influence of component accuracy and assembly accuracy. Thus, it is possible to face the second valve seat 16 and to be in close contact therewith.
In the pressure reducing valve 1, since the spring constant of the third spring 17 is set to a small value, a large surface pressure is not generated at the contact portion of the seal member 18 b of the second valve body 18 with the second valve seat 16. It is possible to prevent the performance deterioration of the sealing material 18b with time. Having arranged the second longitudinal grooves 3a ₃ which functions as a stopper of the second valve body 18, to ensure the relief valve mechanism β can be opened.
The guides of the first valve body 7, the second valve seat 16, and the second valve body 18 at two locations are a smooth movement and a sliding resistance of the first valve body 7, the second valve seat 16, and the second valve body 18. From the viewpoint of reduction, it is desirable to separate as much as possible in the central axis X direction.
In the pressure reducing valve 1, since the bayonet type connection mechanism for pressing and twisting is disposed, the second valve body 18 can be easily attached to the other end of the piston head 3.

Instead of sliding fitting the first valve body 7 directly to the spring retainer 9, the valve shaft extended from the first valve body 7 may be slidably fitted to the cylindrical portion extending from the bottom wall of the spring retainer 9. Alternatively, the first valve body 7 may be guided in the direction of the central axis X in any other configuration.
Instead of the second valve seat 16, an annular second valve body is disposed at one end of the cylinder 11, and instead of the second valve body 18, an annular second valve seat is disposed at the other end of the piston head 3. You may set it.
In addition to the annular bulging portion 18c in the radial direction formed on the outer peripheral side surface of the open end in the bottomed cylindrical case 18a, the annular bulging portion in the radial direction is also formed on the outer peripheral side surface of the bottom portion It may be in sliding contact with the circumferential side surface of the diameter recess 3a. The guide in the direction of the central axis X of the second valve body 18 is more reliable.
The second valve body 18 may be fixed to the other end of the piston head 3. Since the piston head 3 is guided in the central axis X direction at two places separated from each other, the second valve body 18 fixed to the other end of the piston head 3 is also guided in the central axis X direction at two places separated from each other It will be done. Therefore, the second valve body 18 is not easily affected by component accuracy and assembly accuracy, does not tilt relative to the closing surface of the relief valve mechanism β, and does not affect smooth movement or water stop function of the relief valve mechanism β .

The present invention is widely applicable to a pressure reducing valve provided with a relief valve mechanism.

Reference Signs List 1 pressure reducing valve 2 body 2a primary side passage 2b secondary side passage 2c cylinder 2d diaphragm case 3 piston head 6 first valve seat 7 first valve body 8 first spring 11 first spring 11 cylinder 12 diaphragm 13 pressure sensing chamber 14 second spring 15 Spring case 16 second valve seat 17 second valve body 19 drain cylinder α pressure reducing valve mechanism β relief valve mechanism

Claims (5)

The pressure reducing valve includes a pressure reducing valve mechanism having a water stopping function for variably adjusting the flow passage area at the boundary between the primary side passage and the secondary side passage, and a relief valve mechanism opening and closing according to the internal pressure of the secondary side passage. The mechanism and the relief valve mechanism are pressure reducing valves which are lift valve mechanisms sharing a central axis, and the body, a cylinder formed by a part of the body, a piston head reciprocating in the cylinder, and a piston head A seal member for sealing the sliding contact between the cylinder and the inner circumferential surface of the cylinder, a piston rod extending from one end of the piston head and projecting from one end of the cylinder to the secondary passage outside the cylinder, and one end of the cylinder A first valve seat to be formed, a first valve body fixed to one end of the piston rod projecting out of the cylinder and facing the first valve seat, and an opening formed in a portion of the cylinder peripheral wall facing the piston rod , It is formed by a first spring that urges the stone head in the valve closing direction, a cylinder whose one end faces the other end of the piston head, a diaphragm whose center is fixed to the cylinder, and a part of the body A diaphragm case that faces the diaphragm and forms a pressure sensing chamber communicating with the secondary side passage in cooperation with the diaphragm, the cylinder, and the piston head, a second spring that presses the diaphragm toward the pressure sensing chamber, and a second spring And a spring case which accommodates the other end of the cylinder and holds the peripheral portion of the diaphragm in cooperation with the diaphragm case, and a second valve seat or second valve disposed at the one end of the cylinder A body, and a second valve seat or second valve seat that engages with the other end of the piston head and faces the second valve seat or second valve body disposed at the one end of the cylinder, The first valve body and the first valve seat are valve bodies of the pressure reducing valve mechanism The second valve seat and the second valve body form the valve seat and the valve body of the relief valve mechanism, and the first valve body of the pressure reducing valve mechanism is separated in the central axis direction of the pressure reducing valve mechanism. The two valve seats are guided in the central axial direction of the pressure reducing valve mechanism at two locations, and the second valve seat or second valve body disposed at the one end of the cylinder escapes at two locations separated in the central axial direction of the relief valve mechanism A pressure reducing valve characterized in that it is guided in the central axis direction of a valve mechanism. Attach the second valve body or second valve seat between the second valve body or second valve seat engaged with the other end of the piston head and the other end of the piston head in the valve closing direction of the relief valve mechanism A third spring for biasing is disposed, and a stopper for regulating the movement of the second valve body or the second valve seat in the closing direction of the relief valve mechanism is disposed at the other end of the piston head, the second valve The pressure reducing valve according to claim 1, wherein the body or the second valve seat is guided in the central axis direction of the relief valve mechanism at two points separated in the central axis direction of the relief valve mechanism. 3. The pressure reducing valve according to claim 2, wherein a slight play is provided to a guide of the second valve body or the second valve seat engaged with the other end of the piston head. The second valve body or the second valve seat engaged with the other end of the piston head is attached to the other end of the piston head by a bayonet type connection mechanism which pushes and twists. The pressure reducing valve as described in 3. The pressure reducing valve according to claim 1, wherein a second valve body or a second valve seat engaged with the other end of the piston head is fixed to the other end of the piston head.

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