CN115046039A - Safety valve - Google Patents

Abstract

The invention provides a safety valve which can rapidly reduce the fluid pressure of a main flow path. A safety valve (1) having: a housing (4); a valve seat (5) provided in the housing (4); a valve element (6) which is housed in the housing (4) so as to be capable of reciprocating, and which is seated on the valve seat (5) or separated from the valve seat (5) in accordance with the fluid pressure of the main flow path (2); and an urging member (8) that urges the valve element (6) toward the valve seat (5), wherein the safety valve (1) has: a throttle section (75) that throttles the fluid that has passed between the housing (4) and the valve body (6) and flows toward the discharge flow path (3); and a partition space (S2) which is partitioned on the back surface side of the valve body (6) and communicates with the discharge flow path (3).

Description

safety valve

technical field

The present invention relates to a safety valve for venting excess internal pressure.

Background technique

A safety valve is provided in piping or fluid equipment, and the safety valve opens when the pressure of the internal fluid abnormally increases due to some influence, discharges the internal fluid, and closes the valve as the pressure decreases.

For example, the safety valve disclosed in Patent Document 1 includes a case that communicates with a main flow path and a discharge flow path that are arranged to face linearly, a valve seat that is provided in the case, and a valve body that A reciprocating manner is accommodated in the housing; and a spring biases the valve body in the valve closing direction. Normally, the valve is closed by the urging force of the spring, and the main flow path and the discharge flow path are in a non-communication state. Then, when the fluid pressure in the main passage becomes a predetermined value or more, the valve body moves against the force of the spring, and leaves the valve seat to open the valve, and part of the fluid in the main passage is released to the discharge passage, and the fluid in the main passage is released. The pressure is maintained below a certain level.

Patent Document 1: Japanese Patent Application Laid-Open No. 2014-145478 (Page 5, Figure 1)

In the safety valve of Patent Document 1, since the main flow path and the discharge flow path are arranged to face each other in a straight line, when the valve is opened, the fluid in the main flow path flows in the valve opening direction of the valve body, so that the flow of the fluid to the valve body is avoided. Movement in the valve opening direction has an effect. However, since the safety valve like Patent Document 1 has a valve opening corresponding to the fluid pressure in the main flow, there is a possibility that the valve opening is not fully opened and the fluid pressure in the main flow cannot be released immediately.

SUMMARY OF THE INVENTION

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

In order to solve the above-mentioned problems, the safety valve of the present invention has a housing, a valve seat provided in the housing, and a valve body which is reciprocally accommodated in the housing and is reciprocated in accordance with the fluid pressure in the main passage. seated on the valve seat or separated from the valve seat; and an urging member that urges the valve core toward the valve seat, wherein the safety valve has a throttle portion that allows the valve body to pass through the casing The fluid between the valve body and the valve body is throttled to flow toward the discharge flow path; and a partition space is partitioned on the back side of the valve body and communicates with the discharge flow path.

Therefore, when the valve is opened, in addition to the pressure of the fluid in the main passage acting on the valve body in the valve opening direction, the Venturi effect of the throttle portion acts, so that the fluid in the divided space is discharged to the discharge passage, thereby Since the valve body is pulled in the valve-opening direction, the valve body can be largely moved in the valve-opening direction, and the fluid pressure in the main flow path can be quickly reduced. In addition, when the valve is closed, since it takes time for the fluid to be introduced from the discharge flow path to the partitioned space, there is a so-called damping effect, and the valve body is smoothly and slowly seated on the valve seat.

The divided space and the discharge flow path may be communicated with each other through a communication path extending in the reciprocating motion direction of the valve body.

Accordingly, since the communication passage extends in the reciprocating direction of the valve body, the fluid in the divided space can be smoothly discharged to the discharge passage through the communication passage by the movement of the valve body in the valve opening direction.

The relief valve may include a passage member separate from the housing, the communication passage may be provided in the center of the passage member, and the throttle portion may be provided on the outer periphery of the passage member.

Thereby, since the communication passage and the throttle portion can be integrally formed with respect to the passage member, the communication passage and the throttle portion can be easily manufactured with high accuracy.

The discharge passage side of the throttle portion may be inclined toward the center of the passage member.

As a result, the flow of the fluid passing through the throttle portion can be guided to the vicinity of the opening of the communication passage, so that the fluid in the partitioned space can be easily drawn into the discharge passage.

The passage member may guide the valve body.

Thereby, the flow path can be formed to be large between the valve body and the case.

The partition space may be formed by the passage member and the valve body.

Thereby, the divided space can be constituted by the passage member.

Description of drawings

FIG. 1 is a cross-sectional view showing a safety valve in a valve-closed state according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view of a portion where the guide member is cut at a position partially different from that in FIG. 1 .

FIG. 3 is a cross-sectional view showing the safety valve in an open state.

FIG. 4 is an explanatory diagram schematically showing the pressure distribution of the fluid flowing around the throttle portion.

5 is a cross-sectional view of a safety valve showing a valve-open state according to Embodiment 2 of the present invention.

Label description

1: Safety valve; 2: Main flow path; 3: Discharge flow path; 4: Housing; 5: Valve seat; 6: Valve core; 7: Passage member; 8: Spring (Forcing member); 10: Safety valve; 71: communication passage; 72: shaft portion; 75: throttle portion; 600: valve core; 700: passage member; S1: internal space; S2: divided space.

Detailed ways

Hereinafter, the form for implementing the safety valve of this invention is demonstrated based on an Example. In addition, although this Example demonstrated the safety valve assembled in the warm water toilet seat apparatus as an example, it can also apply to other uses.

[Example 1]

The safety valve of Embodiment 1 will be described with reference to FIGS. 1 to 4 . Hereinafter, the left and right sides viewed from the front side of FIG. 1 will be described as the left and right sides of the safety valve. In detail, the right side of the drawing on which the main flow passage 2 of the warm water toilet seat apparatus is arranged is taken as the right side of the safety valve 1 , and the left side of the drawing on which the discharge flow passage 3 is arranged is taken as the left side of the safety valve 1 . .

The safety valve 1 of the present invention is installed in, for example, a water supply pipe of a warm water toilet seat apparatus, and 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 adjusted so that the fluid pressure of the water supply pipe is always constant. Protect the water supply piping or equipment connected to it below the specified pressure.

As shown in FIG. 1 , the safety valve 1 mainly includes a housing 4 that constitutes a part of the main flow passage 2 and the discharge flow passage 3 described later; a valve seat 5 that is provided in the housing 4; and a valve body 6 that can It is accommodated in the inner space S1 of the casing 4 in a way of reciprocating left and right; a passage member 7 is fixed to the casing 4 and has a communication passage 71 to be described later; Valve seat 5 exerts force.

The housing 4 includes a first housing 41 on the side of the main flow passage 2 where the valve seat 5 is formed, and a second housing 42 on the side of the discharge flow passage 3 where the passage member 7 is arranged. On the left side of the first case 41 is formed a stepped concave portion 41a recessed toward the right side. The large-diameter portion of the left end of the concave portion 41a can be screwed and fixed to the large-diameter portion of the second case 42. The middle-diameter portion of the second case 42 is partially disposed with a filler 9 to be described later interposed therebetween, and the smallest-diameter portion 41b at the right end is formed to extend to the right. In addition, you may fix the large diameter part of the 2nd case 42 to the large diameter part of the recessed part 41a by caulking.

On the right side of the first housing 41 is formed a through hole extending through the left and right sides, the right part of the through hole becomes the first flow path 21 , and the left part becomes the flow path 23 . In addition, a second flow path 22 branching upward is formed at a connecting portion of the first flow path 21 and the flow path 23 . The first flow path 21 is connected to the fluid pipe on the upstream side of the water supply piping, and the second flow path 22 is connected to the fluid pipe on the downstream side of the water supply piping. 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 .

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

The second case 42 has a stepped through hole extending in the left-right direction, and the diameter of the right portion 42 a of the through hole is larger than the diameter of the left portion 31 . The part 31 on the left side 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 . In addition, below, the site|part 42a on the right side of a through-hole is called the large diameter part 42a, and the site|part 31 on the left side is called the 3rd flow path 31. FIG.

The inner space S1 of the case 4 is composed of the smallest diameter portion 41b of the recess 41a of the first case 41 , the large diameter portion 42a of the second case 42 , and the first case 41 and the second case 42 divided by the packing 9 . The gap is formed, and communicates with the main flow channel 2 and the discharge flow channel 3 .

The valve body 6 mainly includes a movable member 61 that is relatively movable in the axial direction with respect to the housing 4 (specifically, relatively movable in the axial direction with respect to the shaft portion 72 of the passage member 7 ), and a right end fixed to the movable member 61 . part of the sealing member 62 is constituted. Further, the sealing member 62 is formed of an elastic member such as rubber or synthetic resin.

The movable member 61 has a bottom wall portion 61a extending in the radial direction at the right end, a cylindrical outer cylindrical portion 61b extending leftward from the outer edge of the bottom wall portion 61a, and a bottom wall portion 61a extending leftward from the center of the bottom wall portion 61a. The cylindrical inner cylinder part 61c. The shaft portion 72 of the passage member 7 is inserted into the inner cylindrical portion 61c so as to be relatively slidable in the axial direction. In the valve body 6 , on the back side (ie, the left side) of the sealing member 62 that is substantially in contact with or separated from the valve seat 5 , the bottom wall portion 61 a and the inner cylindrical portion 61 c of the movable member 61 and the shaft of the passage member 7 are formed by The portion 72 is formed with a divided space S2 separated from the inner space S1.

In addition, the right end portion of the spring 8 is externally fitted to the inner cylindrical portion 61 c, and the left end portion of the spring 8 is externally fitted to the shaft portion 72 of the passage member 7 . In addition, the right end portion of the spring 8 is in contact with the left surface of the bottom wall portion 61a. Moreover, the protrusion part 61d which protrudes to the right side is formed in the right surface of the bottom wall part 61a, and the sealing member 62 is being fixed so that the protrusion part 61d may be covered.

Next, the structure of the passage member 7 will be described based on FIGS. 1 and 2 . In addition, in order to explain the structure of the passage member 7 in an easy-to-understand manner, FIG. 2 shows a state in which the passage member 7 is cut at a position partially different from that in FIG. 1 .

As shown in FIGS. 1 and 2 , the passage member 7 includes 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 cylindrical portion 61c. Moreover, the outer peripheral surface of the left end part of the base part 73 becomes the tapered part 73a whose front end tapers toward the left side.

In addition, a communication passage 71 extending in the left-right direction through the base portion 73 and the shaft portion 72 is formed in the center of the passage member 7 , and the communication passage 71 communicates the partitioned space S2 with the third flow passage 31 . In addition, the "center of the passage member 7" referred to here does not necessarily mean the mathematical radial center of the passage member 7, but refers to a position inward of the outer periphery of the bulging portion 74 in the passage member 7.

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 evenly arranged in the circumferential direction with notches cut out from the outer diameter side so as to penetrate in the left-right direction. part 74a. In addition, the left end portion of the spring 8 is in contact with the right surface of the bulging portion 74 .

The right end portion of the tapered portion 73 a is formed to be positioned on the right side of the left end surface of the bulging portion 74 . That is, the throttle 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 throttle portion 75 communicates the internal space S1 and the third flow path 31. The cross-sectional area of the narrowed portion 75 is formed to be smaller than the cross-sectional areas of the internal space S1 and the third flow passage 31 serving as flow paths on the upstream and downstream sides of the narrowed portion 75 . In addition, the throttle portions 75 are equally arranged around the communication passage 71 . In addition, the number of the throttle portions 75 can be freely changed, and may be an even number or an odd number, but it is preferable to arrange them equally.

As shown in FIGS. 1 and 2 , in the normal state of the safety valve 1, the valve body 6 is urged by the spring 8 and the sealing member 62 is pressed against the valve seat 5 to close the valve, and the fluid flowing through the water supply piping forms the main passage from the The first flow path 21 of 2 flows into the second flow path 22 . In addition, in the valve-closed state of the safety valve 1 , air exists in the inner space S1 , the partitioned space S2 , and the third flow path 31 of the casing 4 . Hereinafter, for convenience of description, the fluid flowing in the water supply pipe will be described as water, and the fluid in the internal space S1 , the partitioned space S2 , and the third flow path 31 will be described as air.

In addition, as shown in FIG. 3 , when the water pressure of the main passage 2 rises for some reason and exceeds a predetermined value, the valve body 6 overcomes the urging force of the spring 8 due to the water pressure of the main passage 2 . Moving to the left, safety valve 1 opens. As a result, the water in the main passage 2 passes through the inner space S1 of the casing 4 (specifically, a flow passage passing through the gap between the inner peripheral surface of the casing 4 and the outer peripheral surface of the valve body 6 in the inner space S1 ), Then, it is discharged to the third flow path 31 through the notch portion 74 a and the throttle portion 75 . In addition, in the fully open state of the safety valve 1, the left end surface of the valve body 6 abuts on the right surface of the bulging portion 74 of the passage member 7, and the movement of the valve body 6 in the valve opening direction is restricted.

Since the main flow path 2 and the discharge flow path 3 are linearly opposed to each other in the left-right direction, the water in the main flow path 2 flows in the valve opening direction of the valve body 6 in the internal space S1, and the loss due to the flow of water is small, It has no effect on the movement of the valve core 6 in the valve opening direction.

In addition, when the safety valve 1 is opened, the air in the inner space S1 is pushed out by the water pressure of the main passage 2 , and the air is discharged to the third passage 31 through the throttle portion 75 . When the air passes through the throttle 75 with a small cross-sectional area, the flow velocity increases, and when it flows into the third flow path 31 with a large cross-sectional area, the area where the fluid flows and the surrounding area are relatively negative pressure. , the air in the relatively high-pressure partitioned space S2 is discharged to the third flow path 31 through the communication path 71 , whereby the valve body 6 is pulled in the valve opening direction. As a result, in the initial valve opening of the safety valve 1, in addition to the water pressure in the main passage 2, the negative pressure generated in the throttle portion 75 is used to move the valve body 6 in the valve opening direction largely, and the valve opening degree can be increased. In order to fully open, the fluid pressure of the main flow path 2 is rapidly reduced.

Next, the pressure distribution of the fluid (ie, air or water) flowing around the throttle portion 75 will be described. As shown in FIG. 4 , the fluid pressure P1 ′ in the vicinity of the upstream of the throttle portion 75 is higher than the fluid pressure P1 of the fluid flowing in the interior 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' in the downstream vicinity of the throttle portion 75 is lower than the fluid pressure P2 (P2>P2'). In addition, the fluid pressure gradually increases as it goes to a position further downstream than the downstream vicinity of the throttle portion 75 , and stabilizes at a fluid pressure lower than the fluid pressure P1 .

In this way, the left end of the communication passage 71 is disposed near the downstream of the throttle portion 75 where the negative pressure is the highest, that is, the absolute pressure is the lowest (fluid pressure P2 ′).

In addition, when the safety valve 1 is closed, it takes time for the fluid to be introduced from the discharge flow path 3 to the partitioned space S2 , so there is a so-called damping effect, and the valve body 6 is smoothly and slowly seated on the valve seat 5 .

In addition, since the communication passage 71 that communicates the divided space S2 and the discharge flow passage 3 extends in the reciprocating direction of the valve body 6 , when the valve body 6 moves in the valve opening direction, the air in the divided space S2 can pass through the communication passage 71 It is smoothly discharged to the discharge flow path 3 .

Further, a communication passage 71 is provided in the center of the passage member 7 which is separate from the casing 4 , and around the communication passage 71 , a tapered portion 73 a and a cutout portion 74 a constituting the throttle portion 75 are equally arranged. As a result, the communication passage 71 , the tapered portion 73 a , and the cutout portion 74 a can be integrally formed with respect to the passage member 7 , so that the communication passage 71 and the throttle portion 75 can be easily manufactured with high accuracy. In addition, since the throttle portions 75 are equally arranged, the fluid can flow in a balanced manner.

In addition, the tapered portion 73 a constituting the throttle portion 75 is inclined so that the front end tapers toward the left end portion of the communication passage 71 , that is, the end portion of the communication passage 71 on the side of the discharge flow passage 3 . The fluid is guided to the vicinity of the opening at the left end of the communication passage 71 (specifically, to a region slightly to the left of the opening of the left end of the communication passage 71 in the third flow passage 31 ), and the air in the divided space S2 is easily drawn into the third flow passage 31 . 3 flow path 31.

In addition, the passage member 7 guides the valve body 6 . Specifically, the inner cylindrical portion 61c of the valve body 6 is inserted into the shaft portion 72 of the passage member 7 so as to be relatively slidable in the axial direction, and the valve body 6 can be stably slid by the relative sliding of the shaft portion 72 and the inner cylindrical portion 61c. Reciprocating motion. In this way, since the valve body 6 is guided by the passage member 7, the flow path can be formed to be large between the valve body 6 and the case 4, and the flow of the fluid can be smoothed and the flow rate can be increased.

In addition, since the inner cylindrical portion 61c of the valve body 6 is opened toward the direction of fluid flow (ie, the discharge flow path 3 side), the fluid does not easily enter the partitioned space S2 by detouring from the gap between the inner cylindrical portion 61c and the shaft portion 72. The state of the fluid pressure in the partitioned space S2 is maintained.

In addition, since the divided space S2 is formed by the passage member 7 and the valve body 6, and the divided space S2 can be constituted by the passage member 7, it is not necessary to prepare new parts for forming the divided space S2, and the number of parts can be reduced and the structure can be simplified.

In addition, the communication passage 71 is gradually narrowed from the left end portion toward the right end portion. As a result, a throttle portion is formed in the communication passage 71 at a position close to the partitioned space S2. Therefore, when the valve body 6 is moved to the left due to the water pressure when the valve is opened, it is pushed from the partitioned space S2 to the connection. The air in the passage 71 becomes relatively negative pressure on the left end side of the communication passage 71 due to the Venturi effect, so that the fluid in the partitioned space S2 can be easily drawn into the discharge passage 3 efficiently.

In addition, the passage member 7 functions as a spring holder. Thereby, by adjusting the position of the passage member 7 which is separate from the case 4 with respect to the case 4, the spring 8 can be appropriately arranged, so that the assembly of the safety valve 1 is simplified.

In addition, since the left end portion of the spring 8 abuts on the right surface of the bulging portion 74 of the passage member 7 , and the spring 8 is separated and arranged at the upstream side of the throttle portion 75 , the throttle portion 75 is prevented from being clogged by the spring 8 . , the flow of the fluid toward the throttle portion 75 is not hindered.

In addition, the passage member 7 functions as a movement restriction portion of the valve body 6 in the valve opening direction. Thereby, since it is not necessary to provide the movement restricting part in the casing 4, the structure of the casing 4 can be simplified.

In addition, the left end surface of the valve body 6 is in contact with the right surface of the bulging portion 74 of the passage member 7, and the movement of the valve body 6 in the valve opening direction is restricted. That is, the movement of the valve body 6 in the valve opening direction is restricted to a position separated from the throttle portion 75 on the upstream side, so that the throttle portion 75 is prevented from being blocked by the valve body 6 and the fluid flowing toward the throttle portion 75 is not blocked. flow.

[Example 2]

Next, the safety valve of the second embodiment will be described with reference to FIG. 5 . In addition, about the same structure as the above-mentioned embodiment, the repeated structure description is abbreviate|omitted.

As shown in FIG. 5 , the safety valve 10 of the second embodiment has the same structure as that of the above-described first embodiment except for the structures of the valve body 600 and the passage member 700 . The side wall portion 610b of the movable member 610 of the valve body 600 extends leftward from the outer edge of the bottom wall portion 610a at the right end, and the movable member 610 of the valve body 600 has a recessed portion 611 that opens on the left side.

The passage member 700 has an annular plate portion 760 radially outwardly protruding from the right end of the base portion 730 and a cylindrical portion 770 extending rightward from the outer edge of the annular plate portion 760, and the shaft portion 72 of the first embodiment is not provided. . In the passage member 700 , the annular plate portion 760 and the cylindrical portion 770 form a concave portion 780 open on the right side.

The valve body 600 is inserted into the cylindrical portion 770 of the passage member 700 so as to be relatively slidable in the left-right direction. Between the valve body 600 and the passage member 700 , a partitioned space S2 is formed by the recessed portion 611 and the recessed portion 780 . In addition, although not shown here, it is preferable to arrange|position a ring member which allows relative sliding and prevents fluid from entering between the outer peripheral surface of the side wall part 610b and the inner peripheral surface of the cylindrical part 770.

In this way, since the valve body 600 is guided by the cylindrical portion 770 of the passage member 700 , the reciprocating motion of the valve body 600 is stabilized, and a large flow path can be secured between the outer peripheral surface of the cylindrical portion 770 and the inner peripheral surface of the housing 4 .

In addition, since the passage member 700 is fitted on the outer peripheral surface of the valve body 600 , the fluid pressure of the fluid flowing in the internal space S1 bypasses the back side of the valve body 600 and does not act on the movement of the valve body 600 toward the valve seat 5 . Therefore, it is easy to move the valve body 600 in the valve opening direction.

The embodiments of the present invention have been described above with reference to the drawings, but the specific configuration is not limited to these embodiments, and changes or additions within the scope of the gist of the present invention are also included in the present invention.

For example, in the above-mentioned Embodiments 1 and 2, the communication path is exemplified to extend in the left-right direction, but the communication path may extend in a curved or meandering manner.

In addition, in the above-mentioned Embodiments 1 and 2, the communication passage has a tapered shape whose tip is tapered toward the divided space side, but the communication passage may extend in the left-right direction so as to have a constant cross-section.

In addition, in the above-mentioned Embodiments 1 and 2, the communication passage is exemplified in the case where the passage member is provided, but it may be provided in the casing. In addition, a plurality of communication paths may be provided.

In addition, in the above-mentioned Embodiments 1 and 2, the mode in which the throttle portion is formed between the passage member and the casing is exemplified, but it may be provided in either the passage member or the casing. In addition, the throttling parts may be arranged unequally. For example, at least one throttle portion may be provided.

In addition, in the above-mentioned Embodiments 1 and 2, the mode in which the discharge flow path side of the throttle portion is inclined toward the center of the passage member is exemplified. The sides may be linear in the left-right direction, or may be inclined toward the outer diameter direction.

In addition, in the above-mentioned Embodiments 1 and 2, the embodiment in which the partition space is formed by the valve body and the passage member is exemplified, but a separate partition member may be prepared, and the valve body and the partition member may form the partition space.

In addition, in the above-mentioned Embodiments 1 and 2, the mode in which the passage member is used as the spring holder of the biasing member is exemplified, but the case may be the spring holder.

In addition, in the above-mentioned Embodiments 1 and 2, the case where the passage member serves as the movement restriction portion in the valve opening direction of the valve body is exemplified, but the housing may serve as the movement restriction portion in the valve opening direction.

In addition, in the above-mentioned Embodiments 1 and 2, a coil spring-shaped spring was exemplified as the urging member, but it can be freely changed as long as it can urge the valve body toward the valve seat.

In addition, in the above-mentioned Embodiments 1 and 2, the case in which a part of the main flow passage and the discharge flow passage is constituted by the case is exemplified, but the main flow passage may not be provided in the case as long as the case communicates with the main flow passage and the discharge flow passage. and part of the discharge flow path.

Claims (6)

1. A safety valve having: case; a valve seat, which is arranged on the housing; a valve core, which is accommodated in the housing in a reciprocating manner, and is seated on the valve seat or separated from the valve seat according to the fluid pressure of the main flow path; and an urging member that urges the valve core toward the valve seat, in, The safety valve has: a throttle portion that throttles the fluid passing between the housing and the valve core to flow toward the discharge flow path; and A partition space is partitioned on the back side of the valve body, and communicates with the discharge flow path. 2. The safety valve of claim 1, wherein, The divided space and the discharge flow path communicate with each other through a communication path extending in the reciprocation direction of the valve body. 3. The safety valve of claim 2, wherein, The relief valve includes a passage member separate from the housing, the communication passage is provided in the center of the passage member, and the throttle portion is provided on the outer periphery of the passage member. 4. The safety valve of claim 3, wherein, The discharge flow passage side of the throttle portion is inclined toward the center of the passage member. 5. The safety valve according to claim 3 or 4, wherein, The passage member guides the valve body. 6. The safety valve according to any one of claims 3 to 5, wherein, The divided space is formed by the passage member and the valve body.

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