Safety valve

Abstract

The present invention provides a safety valve that can rapidly reduce the fluid pressure in the main flow path. A safety valve (1) includes: a housing (4); a valve seat (5) provided in the housing (4); a valve element (6) received in the housing (4) so as to be reciprocable, and seated on or separated from the valve seat (5) according to the fluid pressure in the main flow path (2); and a biasing member (8) that biases the valve element (6) toward the valve seat (5). The safety valve (1) further includes: a throttling portion (75) that throttles the fluid passing between the housing (4) and the valve element (6) and causes it to flow toward the discharge flow path (3); and a partitioned space (S2) that is partitioned on the back side of the valve element (6) and communicates with the discharge flow path (3).

Description

Technical Field

[0001] The present invention relates to a safety valve for discharging excessive internal pressure. Background Art

[0002] A safety valve is provided in a pipe or a fluid device. The safety valve opens when the pressure of the internal fluid abnormally increases due to some influence, discharges the internal fluid, and closes as the pressure decreases.

[0003] For example, the safety valve disclosed in Patent Document 1 has: a housing configured to communicate between a main flow path and a discharge flow path that are linearly opposed; a valve seat provided in the housing; a valve element housed in the housing so as to be reciprocable; and a spring that biases the valve element in the valve closing direction. In a normal state, the valve is closed by the action of the spring, and the main flow path and the discharge flow path are in a non-communicating state. And, when the fluid pressure in the main flow path becomes a specified value or more, the valve element moves against the action of the spring, moves away from the valve seat and opens, discharges a part of the fluid in the main flow path to the discharge flow path, and maintains the fluid pressure in the main flow path below a certain level.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-145478 (page 5, Figure 1)

[0005] In the safety valve of Patent Document 1, since the main flow path and the discharge flow path are linearly opposed, when the valve opens, the fluid in the main flow path flows in the valve opening direction of the valve element, so that the influence of the fluid flow on the movement of the valve element in the valve opening direction is avoided. However, the safety valve as in Patent Document 1 has a valve opening degree corresponding to the fluid pressure in the main flow path, so the valve opening degree may not be fully open, and the fluid pressure in the main flow path cannot be immediately discharged. Summary of the Invention

[0006] The present invention has been made in view of such problems, and an object thereof is to provide a safety valve capable of rapidly reducing the fluid pressure in the main flow path.

[0007] To solve the above problems, the safety valve of the present invention has: a housing; a valve seat provided in the housing; a valve element housed in the housing so as to be reciprocable, and seated on the valve seat or separated from the valve seat according to the fluid pressure in the main flow path; and a biasing member that biases the valve element toward the valve seat, wherein the safety valve has: a throttle portion that throttles the fluid passing between the housing and the valve element and flows toward the discharge flow path; and a partitioned space that is partitioned on the back side of the valve element and communicates with the discharge flow path.

[0008] Thus, when the valve is opened, in addition to the fluid pressure in the main flow path acting on the valve element in the opening direction, due to the Venturi effect of the throttle portion, the fluid in the partition space is discharged into the discharge flow path, whereby the valve element is pulled in the opening direction. Therefore, the valve element can be moved significantly in the opening direction, and the fluid pressure in the main flow path can be rapidly reduced. Further, when the valve is closed, since it takes time for the fluid to be introduced from the discharge flow path into the partition space, there is a so-called damping effect, and the valve element smoothly and slowly seats on the valve seat.

[0009] Alternatively, the partition space and the discharge flow path may be connected by a communication path extending along the reciprocating movement direction of the valve element.

[0010] Thus, since the communication path extends along the reciprocating movement direction of the valve element, when the valve element moves in the opening direction, the fluid in the partition space can be smoothly discharged into the discharge flow path through the communication path.

[0011] Alternatively, the safety valve may include a passage member separate from the housing, the communication path may be provided at the center of the passage member, and the throttle portion may be provided on the outer periphery of the passage member.

[0012] Thus, the communication path and the throttle portion can be integrally formed with respect to the passage member, and thus it is easy to manufacture the communication path and the throttle portion with high precision.

[0013] Alternatively, the discharge flow path side of the throttle portion may be inclined toward the center of the passage member.

[0014] Thus, the flow of the fluid that has passed through the throttle portion can be guided toward the vicinity of the opening of the communication path, and thus it is easy to introduce the fluid in the partition space into the discharge flow path.

[0015] Alternatively, the passage member may guide the valve element.

[0016] Thus, a larger flow path can be formed between the valve element and the housing.

[0017] Alternatively, the partition space may be formed by the passage member and the valve element.

[0018] Thus, the partition space can be constituted by the passage member. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a cross-sectional view of a safety valve showing a valve-closed state of Embodiment 1 of the present invention.

[0020] Figure 2 is a cross-sectional view taken at a position where the guiding member is cut at a part different from Figure 1 in part.

[0021] Figure 3It is a cross-sectional view of a safety valve showing the open valve state.

[0022] Figure 4 It is an explanatory diagram schematically showing the pressure distribution of the fluid flowing around the throttle portion.

[0023] Figure 5 It is a cross-sectional view of a safety valve showing the open valve state of Example 2 of the present invention.

[0024] Reference numeral description

[0025] 1: Safety valve; 2: Main flow path; 3: Discharge flow path; 4: Housing; 5: Valve seat; 6: Valve element; 7: Passage member; 8: Spring (biasing member); 10: Safety valve; 71: Communication path; 72: Shaft portion; 75: Throttle portion; 600: Valve element; 700: Passage member; S1: Internal space; S2: Partitioned space. Detailed implementation mode

[0026] Hereinafter, a method for implementing the safety valve of the present invention will be described based on the embodiments. In addition, although this embodiment is described by taking the safety valve assembled in the warm water cleaning toilet seat device as an example, it can also be applied to other uses.

[0027]

Embodiment 1

[0028] Refer to Figures 1 to 4 The safety valve of Embodiment 1 will be described. Hereinafter, the left and right sides observed from the front side of Figure 1 will be described as the left and right sides of the safety valve. Specifically, the right side of the paper surface on which the main flow path 2 of the warm water cleaning toilet seat device is arranged will be described as the right side of the safety valve 1, and the left side of the paper surface on which the discharge flow path 3 is arranged will be described as the left side of the safety valve 1.

[0029] The safety valve 1 of the present invention is, for example, assembled in the water supply pipe of the warm water cleaning toilet seat device. When the fluid pressure in the water supply pipe abnormally increases due to some influence, the fluid is discharged to the outside of the water supply pipe, and the fluid pressure of the water supply pipe is adjusted to always be below a specified pressure, protecting the water supply pipe or the equipment connected thereto.

[0030] As Figure 1 shown, the safety valve 1 mainly includes: a housing 4 that constitutes a part of the main flow path 2 and the discharge flow path 3 described later; a valve seat 5 provided on the housing 4; a valve element 6 housed in the internal space S1 of the housing 4 so as to be able to reciprocate left and right; a passage member 7 fixed to the housing 4 and having a communication path 71 described later; and a spring 8 as a biasing member that biases the valve element 6 toward the valve seat 5.

[0031] The housing 4 has a first housing 41 on the side of the main flow path 2 where a valve seat 5 is formed, and a second housing 42 on the side of the discharge flow path 3 where the passage member 7 is arranged. A stepped recess 41a recessed to the right is formed on the left side of the first housing 41. The large-diameter portion at the left end of the recess 41a can be screwed and fixed to the large-diameter portion of the second housing 42. The medium-diameter portion of the second housing 42 is arranged with a packing 9 to be described later at a slightly smaller-diameter portion, and the smallest-diameter portion 41b at the right end extends to the right. Alternatively, the large-diameter portion of the second housing 42 can be fixed to the large-diameter portion of the recess 41a by caulking.

[0032] A through hole extending through in the left-right direction is formed on the right side of the first housing 41. The right-side portion of the through hole becomes the first flow path 21, and the left-side portion becomes the flow path 23. In addition, a second flow path 22 branching upward is formed at the connection portion between the first flow path 21 and the flow path 23. The first flow path 21 is connected to the upstream fluid pipe in the water supply pipe, and the second flow path 22 is connected to the downstream fluid pipe in the water supply pipe. That is, the first flow path 21, the second flow path 22, and the flow path 23 constitute a part of the main flow path 2.

[0033] In addition, the bottom provided at the right end of the smallest-diameter portion 41b of the recess 41a has a portion protruding in a cylindrical shape to the left from the radial center of the bottom. The left end of the cylindrical portion becomes the valve seat 5, and the hollow portion of the cylindrical portion becomes the flow path 23 communicating with the first flow path 21 and the second flow path 22.

[0034] The second housing 42 has a stepped through hole extending in the left-right direction. The diameter of the right-side portion 42a of the through hole is larger than the diameter of the left-side portion 31. The left-side portion 31 of the through hole is connected to a drain pipe communicating with the outside of the water supply pipe and constitutes a part of the discharge flow path 3. Hereinafter, the right-side portion 42a of the through hole is referred to as the large-diameter portion 42a, and the left-side portion 31 is referred to as the third flow path 31.

[0035] The internal space S1 of the housing 4 is composed of the smallest-diameter portion 41b of the recess 41a of the first housing 41, the large-diameter portion 42a of the second housing 42, and the gap between the first housing 41 and the second housing 42 divided by the packing 9, and is communicated with the main flow path 2 and the discharge flow path 3.

[0036] The valve element 6 mainly includes a movable member 61 that can move relative to the housing 4 in the axial direction (specifically, can move relative to the shaft portion 72 of the passage member 7 in the axial direction), and a sealing member 62 fixed to the right end portion of the movable member 61. In addition, the sealing member 62 is composed of an elastic member such as rubber or synthetic resin.

[0037] The movable member 61 has a radially extending bottom wall portion 61a at its right end, a cylindrical outer cylinder portion 61b extending leftward from the outer edge of the bottom wall portion 61a, and a cylindrical inner cylinder portion 61c extending leftward from the center of the bottom wall portion 61a. The shaft portion 72 of the passage member 7 is inserted into the inner cylinder portion 61c so as to be axially slidable relative to it. In the valve element 6, on the back side (i.e., the left side) of the sealing member 62 that substantially contacts or separates from the valve seat 5, a partition space S2 separated from the internal space S1 is formed by the bottom wall portion 61a and the inner cylinder portion 61c of the movable member 61 and the shaft portion 72 of the passage member 7.

[0038] In addition, the right end portion of the spring 8 is externally fitted to the inner cylinder portion 61c, and the left end portion of the spring 8 is externally fitted to the shaft portion 72 of the passage member 7. Further, the right end portion of the spring 8 abuts against the left surface of the bottom wall portion 61a. In addition, a protruding portion 61d protruding to the right is formed on the right surface of the bottom wall portion 61a, and the sealing member 62 is fixed so as to cover the protruding portion 61d.

[0039] Next, based on Figure 1 and Figure 2 the structure of the passage member 7 will be described. In addition, in order to easily understand the structure of the passage member 7, Figure 2 a state in which the passage member 7 is cut at a position different from the position of Figure 1 in part is shown.

[0040] As Figure 1 and Figure 2 shown, the passage member 7 has a base portion 73, a small-diameter shaft portion 72 extending rightward from the base portion 73, and a bulging portion 74 protruding annularly toward the outer diameter of the base portion 73. The left end portion of the base portion 73 extends into the third flow path 31, and the shaft portion 72 at the right end portion of the base portion 73 extends into the inner cylinder portion 61c. In addition, the outer peripheral surface of the left end portion of the base portion 73 is a tapered portion 73a whose front end tapers toward the left.

[0041] In addition, a communication path 71 extending through the base portion 73 and the shaft portion 72 in the left-right direction is formed in the center of the passage member 7, and the communication path 71 connects the partition space S2 and the third flow path 31. Here, the "center of the passage member 7" does not need to be the mathematical radial center of the passage member 7, but refers to a position inside the passage member 7 closer to the inner side than the outer periphery of the bulging portion 74.

[0042] In addition, the left end surface of the bulging portion 74 is fixed to the bottom of the large-diameter portion 42a of the second housing 42, and the bulging portion 74 is provided with cutout portions 74a that are equally arranged in the circumferential direction and cut from the outer diameter side so as to penetrate in the left-right direction. In addition, the left end portion of the spring 8 abuts against the right surface of the bulging portion 74.

[0043] The right end portion of the conical portion 73a is formed to be located on the right side of the left end surface of the bulging portion 74. That is, a throttling portion 75 is formed by the left end portion of the cutout portion 74a of the passage member 7 and the inner peripheral surface of the housing 4, and the internal space S1 and the third flow path 31 are communicated through the throttling portion 75. The cross-sectional area of the throttling portion 75 is formed to be smaller than the cross-sectional areas of the internal space S1 and the third flow path 31, which are the flow paths on the upstream side and the downstream side of the throttling portion 75. In addition, the throttling portions 75 are evenly arranged around the communication path 71. In addition, the number of the throttling portions 75 can be freely changed, and can be an even number or an odd number, but it is preferably evenly arranged.

[0044] As Figure 1 and Figure 2 shown, in normal times, since the valve element 6 is urged by the spring 8 and the sealing member 62 is pressed against the valve seat 5, the safety valve 1 is closed, and the fluid flowing in the water supply pipe flows from the first flow path 21 constituting the main flow path 2 to the second flow path 22. In addition, in the closed state of the safety valve 1, air exists in the internal space S1, the partition space S2, and the third flow path 31 of the housing 4. Hereinafter, for the sake of convenience of explanation, the fluid flowing in the water supply pipe is regarded as water, and the fluids in the internal space S1, the partition space S2, and the third flow path 31 are regarded as air for explanation.

[0045] In addition, as Figure 3 shown, when the water pressure of the main flow path 2 rises due to some reason and exceeds the specified value, due to the water pressure of the main flow path 2, the valve element 6 moves to the left against the acting force of the spring 8, and the safety valve 1 opens. Thereby, the water in the main flow path 2 passes through the internal space S1 of the housing 4 (specifically, the flow path through the gap between the inner peripheral surface of the housing 4 and the outer peripheral surface of the valve element 6 in the internal space S1), and then is discharged to the third flow path 31 through the cutout portion 74a and the throttling portion 75. In addition, in the fully open state of the safety valve 1, the left end surface of the valve element 6 abuts against the right surface of the bulging portion 74 of the passage member 7, and the movement of the valve element 6 in the opening direction is restricted.

[0046] Since the main flow path 2 and the discharge flow path 3 are arranged in a straight line and opposed to each other in the left-right direction, the water in the main flow path 2 flows in the internal space S1 in the opening direction of the valve element 6, and the loss caused by the water flow is small, which has no influence on the movement of the valve element 6 in the opening direction.

[0047] In addition, when the safety valve 1 opens, due to the water pressure in the main flow path 2, the air in the internal space S1 is pushed out, and this air is discharged to the third flow path 31 through the throttle portion 75. When this air passes through the throttle portion 75 with a small cross-sectional area, its flow velocity increases. When it flows into the third flow path 31 with a large cross-sectional area, the area where the fluid flows and the area around it relatively become a negative pressure. Due to this negative pressure, the air in the partition space S2 with a relatively high pressure is discharged to the third flow path 31 through the communication path 71, and thus the valve element 6 is pulled in the opening direction. Thereby, in the initial stage of opening of the safety valve 1, in addition to the water pressure in the main flow path 2, the negative pressure generated in the throttle portion 75 is also utilized to greatly move the valve element 6 in the opening direction, enabling the valve opening to be fully open and rapidly reducing the fluid pressure in the main flow path 2.

[0048] Next, the pressure distribution of the fluid (i.e., air or water) flowing around the throttle portion 75 will be described. As Figure 4 shown, the fluid pressure P1' near the upstream of the throttle portion 75 is higher than the fluid pressure P1 of the fluid flowing in the internal space S1 (P1' > P1). In addition, the fluid pressure P2 immediately behind the throttle portion 75 is lower than the fluid pressure P1 (P1 > P2). In addition, the fluid pressure P2' near the downstream of the throttle portion 75 is even lower than the fluid pressure P2 (P2 > P2'). In addition, as the position moves further downstream than the position near the downstream of the throttle portion 75, the fluid pressure gradually increases and stabilizes at a fluid pressure lower than the fluid pressure P1.

[0049] In this way, the left end portion of the communication path 71 is arranged near the downstream of the throttle portion 75 where the negative pressure is the largest, that is, the absolute pressure is the lowest (the fluid pressure P2'), so it is easy to introduce the air in the partition space S2 into the third flow path 31.

[0050] In addition, when the safety valve 1 closes, since it takes time for the fluid to be introduced from the discharge flow path 3 into the partition space S2, there is a so-called damping effect, and the valve element 6 smoothly and slowly seats on the valve seat 5.

[0051] In addition, since the communication path 71 connecting the partition space S2 and the discharge flow path 3 extends along the reciprocating movement direction of the valve element 6, when the valve element 6 moves in the opening direction, the air in the partition space S2 can be smoothly discharged to the discharge flow path 3 through the communication path 71.

[0052] In addition, a communication path 71 is provided at the center of the passage member 7 separated from the housing 4, and the conical portion 73a and the notch portion 74a constituting the throttle portion 75 are evenly arranged around the communication path 71. Thereby, the communication path 71, the conical portion 73a, and the notch portion 74a can be integrally formed for the passage member 7, so it is easy to manufacture the communication path 71 and the throttle portion 75 with high precision. In addition, since the throttle portions 75 are evenly arranged, the fluid can flow evenly.

[0053] In addition, the conical portion 73a forming the throttle portion 75 is inclined such that the front end tapers toward the left end portion of the communication path 71, i.e., the end portion on the discharge flow path 3 side of the communication path 71. Therefore, the fluid that has passed through the throttle portion 75 can be guided to the vicinity of the opening at the left end of the communication path 71 (specifically, guided to a region slightly to the left of the opening at the left end of the communication path 71 in the third flow path 31), and it is easy to introduce the air in the partition space S2 into the third flow path 31.

[0054] In addition, the passage member 7 guides the valve element 6. Specifically, the inner cylinder portion 61c of the valve element 6 is inserted into the shaft portion 72 of the passage member 7 so as to be able to slide relative to the axial direction. By the relative sliding of the shaft portion 72 and the inner cylinder portion 61c, the valve element 6 can reciprocate stably. In this way, since the valve element 6 is guided by the passage member 7, a larger flow path can be formed between the valve element 6 and the housing 4, and the flow of the fluid can be made smooth and the flow rate can be increased.

[0055] In addition, since the inner cylinder portion 61c of the valve element 6 opens toward the direction of fluid flow (i.e., the discharge flow path 3 side), the fluid is not easily detoured from the gap between the inner cylinder portion 61c and the shaft portion 72 into the partition space S2, and the state of low fluid pressure in the partition space S2 can be maintained.

[0056] In addition, the partition space S2 is formed by the passage member 7 and the valve element 6, and the passage member 7 can be used to form the partition space S2. Therefore, it is not necessary to newly prepare a component for forming the partition space S2, and the number of components can be reduced and the structure can be simplified.

[0057] In addition, the communication path 71 gradually tapers from the left end portion toward the right end portion. As a result, a throttle portion is formed at a position of the communication path 71 close to the partition space S2. Therefore, when the valve element 6 moves to the left due to water pressure during valve opening, the air pushed from the partition space S2 to the communication path 71 becomes relatively negative pressure on the left end side of the communication path 71 due to the Venturi effect, and it is easy to effectively introduce the fluid in the partition space S2 toward the discharge flow path 3.

[0058] In addition, the passage member 7 functions as a spring seat. As a result, by adjusting the position of the passage member 7 separated from the housing 4 relative to the housing 4, the spring 8 can be appropriately arranged, so the assembly of the safety valve 1 is simple.

[0059] In addition, since the left end portion of the spring 8 abuts against the right surface of the bulging portion 74 of the passage member 7 and the spring 8 is separately arranged at a position upstream of the throttle portion 75, the throttle portion 75 is prevented from being blocked by the spring 8, and the flow of the fluid flowing toward the throttle portion 75 is not hindered.

[0060] In addition, the passage member 7 functions as a movement restricting portion for the valve element 6 in the valve opening direction. As a result, it is not necessary to provide a movement restricting portion in the housing 4, and thus the structure of the housing 4 can be simplified.

[0061] In addition, it is a structure in which the left end surface of the valve element 6 abuts against the right surface of the bulging portion 74 of the passage member 7, and the movement of the valve element 6 in the valve opening direction is restricted. That is, the movement of the valve element 6 in the valve opening direction is restricted to a position separated from the throttle portion 75 toward the upstream side, so that the throttle portion 75 is prevented from being blocked by the valve element 6, and the flow of the fluid flowing toward the throttle portion 75 is not hindered.

[0062]

Embodiment 2

[0063] Next, Figure 5 the safety valve of Embodiment 2 will be described. In addition, for the same structures as those in the above embodiments, the repeated structural descriptions are omitted.

[0064] As Figure 5 shown, the safety valve 10 of the present Embodiment 2 has the same structure as that of the above Embodiment 1 except for the structures of the valve element 600 and the passage member 700. The side wall portion 610b of the movable member 610 of the valve element 600 extends from the outer edge of the bottom wall portion 610a at the right end toward the left side, and a recess 611 that opens to the left is formed inside the movable member 610 of the valve element 600.

[0065] The passage member 700 has an annular plate portion 760 that projects outward in diameter from the right end of the base portion 730 and a cylindrical portion 770 that extends from the outer edge of the annular plate portion 760 toward the right side, and the shaft portion 72 of the above Embodiment 1 is not provided. In this passage member 700, a recess 780 that opens to the right is formed by the annular plate portion 760 and the cylindrical portion 770.

[0066] The valve element 600 is inserted and disposed in the cylindrical portion 770 of the passage member 700 so as to be relatively slidable in the left - right direction. Between the valve element 600 and the passage member 700, a partition space S2 is formed by the recess 611 and the recess 780. In addition, although not shown here, preferably, a ring member that allows relative sliding and suppresses the entry of fluid is disposed between the outer peripheral surface of the side wall portion 610b and the inner peripheral surface of the cylindrical portion 770.

[0067] In this way, the valve element 600 is guided by the cylindrical portion 770 of the passage member 700, so that the reciprocating movement of the valve element 600 is stable, and a large flow path can be ensured between the outer peripheral surface of the cylindrical portion 770 and the inner peripheral surface of the housing 4.

[0068] In addition, since the passage component 700 is externally fitted to the outer peripheral surface of the valve element 600, the fluid pressure of the fluid flowing in the internal space S1 is detoured to the back side of the valve element 600 and does not act in the direction of moving the valve element 600 toward the valve seat 5. Therefore, it is easy to move the valve element 600 in the valve opening direction.

[0069] As described above, the embodiments of the present invention have been described with reference to the drawings. However, the specific structure is not limited to these embodiments, and changes or additions within the scope not departing from the gist of the present invention are also included in the present invention.

[0070] For example, in the above-described Embodiments 1 and 2, the way in which the communication path extends in the left-right direction is illustrated. However, the communication path may also extend in a curved or serpentine manner.

[0071] In addition, in the above-described Embodiments 1 and 2, the communication path has a tapered shape that tapers toward the partition space side at the front end. However, the communication path may also extend in a manner with a constant cross-section in the left-right direction.

[0072] In addition, in the above-described Embodiments 1 and 2, the way in which the communication path is provided in the passage component is illustrated. However, it may also be provided in the housing. In addition, a plurality of communication paths may be provided.

[0073] In addition, in the above-described Embodiments 1 and 2, the way in which the throttle portion is formed between the passage component and the housing is illustrated. However, it may be provided in either the passage component or the housing. In addition, the throttle portions may be unevenly arranged. For example, at least one throttle portion may be provided.

[0074] In addition, in the above-described Embodiments 1 and 2, the way in which the discharge flow path side of the throttle portion is inclined toward the center of the passage component is illustrated. However, as long as negative pressure acts on the communication path, for example, the discharge flow path side of the throttle portion may also be linear in the left-right direction, or may be inclined toward the outer diameter direction.

[0075] In addition, in the above-described Embodiments 1 and 2, the way in which the partition space is formed by the valve element and the passage component is illustrated. However, a partition component may be separately prepared, and the partition space may be formed by the valve element and the partition component.

[0076] In addition, in the above-described Embodiments 1 and 2, the way in which the passage component serves as the spring seat of the biasing member is illustrated. However, the housing may also serve as the spring seat.

[0077] In addition, in the above-described Embodiments 1 and 2, the way in which the passage component serves as the movement restricting portion for the valve element in the valve opening direction is illustrated. However, the housing may also serve as the movement restricting portion in the valve opening direction.

[0078] In addition, in the above-described Embodiments 1 and 2, as the biasing member, a helical spring-shaped spring is illustrated. However, as long as it can bias the valve element toward the valve seat, it can be freely changed.

[0079] In addition, in the above-described Embodiments 1 and 2, the manner in which the housing forms a part of the main flow path and the discharge flow path is illustrated. However, as long as the housing communicates with the main flow path and the discharge flow path, it is also possible not to provide a part of the main flow path and the discharge flow path in the housing.

Claims

1. A safety valve having: a housing; a valve seat provided in the housing; a valve element received in the housing so as to be reciprocable, and seated on or separated from the valve seat according to the fluid pressure in the main flow path; and a biasing member that biases the valve element toward the valve seat, wherein the safety valve has: a throttling portion that throttles the fluid passing between the housing and the valve element and causes it to flow toward the discharge flow path; and a partitioned space that is partitioned on the back side of the valve element and communicates with the discharge flow path, the partitioned space and the discharge flow path communicate through a communication path extending in the reciprocating movement direction of the valve element, the safety valve has a passage member separate from the housing, and the communication path is provided at the center of the passage member.

2. The safety valve according to claim 1, wherein the throttling portion is provided on the outer periphery of the passage member.

3. The safety valve according to claim 2, wherein the discharge flow path side of the throttling portion is inclined toward the center of the passage member.

4. The safety valve according to claim 2, wherein the passage member guides the valve element.

5. The safety valve according to any one of claims 2 to 4, wherein the partitioned space is formed by the passage member and the valve element.

Images