JP2016151291A - Safety valve - Google Patents

Abstract

An on-off valve operation of a safety valve is appropriately controlled. A safety valve 2 suitable for being attached to a pressure vessel 1 includes a main body 3, a relief passage 5, a valve body 12 movable between a shut-off position and an open position, and the valve body in a shut-off position. A holding member 13, a heat-shrinkable heat receiving member 4, and a buffer member 16, which are movable between a holding position for holding and an allowable position for allowing the valve body to move to the open position, are provided. One end of the heat receiving member is connected to the holding member and contracts when receiving heat to move the holding member from the holding position to the allowable position. The buffer member allows the holding member to move from the holding position to the allowable position due to thermal contraction of the heat receiving member, and prevents the holding member from moving from the holding position to the allowable position due to an external force acting on the heat receiving member. [Selection] Figure 2

Description

  The present invention relates to a safety valve.

  A safety valve suitable for being attached to a pressure vessel, a main body, an escape passage formed in the main body, an inlet suitable for communicating with the inside of the pressure vessel, and communicating with the outside of the pressure vessel An escape passage having an outlet suitable for being opened; a valve body movable between a blocking position for blocking the escape passage; an open position for opening the escape passage; and a receiving hole formed in the main body; A holding member housed in the accommodation hole so as to be movable between a holding position for holding the valve body in the shut-off position and an allowable position for allowing the valve body to move to the open position, and a holding position for the holding member A heat-shrinkable heat-receiving member extending from the main body and having one end connected to the holding member and the other end fixed to a stationary member outside the main body and receiving heat Shrink to move the holding member from the holding position to the allowable position. That, the safety valve is known which includes a heat-receiving member, (for example, see Patent Document 1). In Patent Document 1, the heat receiving member is attached to the surface of the pressure vessel. Therefore, when the temperature of the pressure vessel rises, the heat receiving member receives heat and contracts, and the force in the direction toward the allowable position acts on the holding member by the heat receiving member. As a result, the holding member is moved to the allowable position, and the valve body is moved to the open position by the internal pressure of the pressure vessel. Therefore, the safety valve is opened, and the fluid in the pressure vessel is released out of the pressure vessel. For this reason, it is prevented that the temperature of a pressure vessel rises too much and a pressure vessel bursts.

International Publication No. 2010/132997

  However, since the heat receiving member extends outside the main body of the safety valve, some external force may act on the heat receiving member. In this case, although the temperature of the pressure vessel is low, the holding member may be moved to the allowable position by this external force, and the safety valve may open. That is, the safety valve may malfunction.

  According to the present invention, there is provided a safety valve suitable for being attached to a pressure vessel, and a main body, an escape passage formed in the main body, and an inlet suitable for communicating with the inside of the pressure vessel. A relief passage having an outlet suitable for communicating with the outside of the pressure vessel; a valve body movable between a blocking position for blocking the relief passage; and an open position for opening the relief passage; A holding hole formed in the main body, a holding position in which the valve body is held in the blocking position, and an allowable position in which the valve body is allowed to move to the open position. A holding member that is movably accommodated, a biasing member that biases the holding member toward the holding position, and a heat-shrinkable heat receiving member that extends from the main body, one end connected to the holding member The other end is a stationary member outside the main body. The heat receiving member, which is fixed and contracts when receiving heat, resists the urging force of the urging member and moves the holding member from the holding position to the allowable position, and the holding member and the inner surface of the receiving hole. A buffer member disposed between the heat receiving member and the heat receiving member, wherein the heat receiving member allows the holding member to move from the holding position to the permissible position, and the external force acting on the heat receiving member causes the holding member to A safety valve is provided that includes a buffer member that prevents movement from a holding position to the allowed position.

  The on-off valve operation of the safety valve can be appropriately controlled.

It is the schematic which shows a pressure vessel and a safety valve. It is a schematic sectional drawing of the safety valve which shows the case where a holding member exists in a holding position and a valve body exists in the interruption | blocking position. It is a schematic sectional drawing of the safety valve which shows the case where a holding member exists in a permission position, and a valve body exists in an open position. It is a schematic sectional drawing of the safety valve which shows the case where external force acts on a heat receiving member.

  Referring to FIG. 1, reference numeral 1 denotes a pressure vessel, and 2 denotes a safety valve suitable for being attached to the opening of the pressure vessel 1. A gas or liquid is accommodated in the pressure vessel 1 under pressure. The pressure vessel 1 is constituted by, for example, a hydrogen gas tank of an electric vehicle fuel cell system, and hydrogen gas is accommodated in the pressure vessel 1 under pressure. The safety valve 2 includes a main body 3 and a heat receiving member 4 extending from the main body 3 to the outside.

  2 and 3, an escape passage 5 is formed in the main body 3. In the embodiment according to the invention, the escape passage 5 has an inlet-side passage portion 6 and an outlet-side passage portion 7 connected to each other. In the embodiment according to the present invention, the inlet-side passage portion 6 and the outlet-side passage portion 7 are orthogonal to each other, so that the escape passage 5 is L-shaped. An inlet 6 a communicated with the inside of the pressure vessel 1 through the opening of the pressure vessel 1 is formed at one end of the inlet side passage portion 6. On the other hand, an outlet 7 a communicating with the outside of the pressure vessel 1, for example, the atmosphere, is formed at one end of the outlet side passage portion 7.

  An accommodation hole 8 is formed in the main body 3. In the embodiment according to the present invention, the accommodation hole 8 communicates with the escape passage 5 through the communication hole 9 at one end and communicates with the outside of the main body 3 through the opening 10 at the other end. In the embodiment according to the present invention, a lid is attached to the other end of the accommodation hole 8, and an opening 10 is provided in this lid. The communication hole 9 is aligned with the outlet side passage portion 7. A receiving hole 11 is formed in the main body 3 so as to be aligned with the inlet side passage portion 6 and communicated with the escape passage 5.

  A valve body 12 is disposed in the escape passage 5. The valve body 12 is movable between a blocking position for blocking the escape passage 5 and an open position for opening the release passage 5. A holding member 13 is disposed in the accommodation hole 8. The holding member 13 is movable between a holding position that holds the valve body 12 in the blocking position and an allowable position that allows the valve body 12 to move to the open position. Further, a spherical engagement member 14 is disposed in the communication hole 9. The engagement member 14 is movable between an intrusion position that has entered the escape passage 5 on the downstream side of the shut-off position of the valve body 12 and an exit position that has exited from the escape passage 5.

  That is, as shown in FIG. 2, when the holding member 13 is in the holding position, a part of the holding member 13 has entered the communication hole 9 and is in contact with the engaging member 14. As a result, the engaging member 14 is held at the intrusion position. The valve body 12 is urged by the fluid in the pressure vessel 1 in the valve opening direction, that is, toward the receiving hole 11. For this reason, the valve body 12 engages with the engaging member 14 and is held at the blocking position. That is, the safety valve 2 is closed.

  On the other hand, as shown in FIG. 3, when the holding member 13 is in the allowable position, the holding member 13 is retracted from the communication hole 9. As a result, the engaging member 14 can be moved to the retracted position by being pushed by the valve body 12. Therefore, the valve body 12 can move to the open position in the receiving hole 11. That is, the safety valve 2 can be opened.

  A biasing member 15 that biases the holding member 13 toward the holding position is disposed between the holding member 13 and the inner surface of the receiving hole 8, particularly the inner surface of the lid portion in which the opening 10 is formed. In an embodiment according to the invention, the biasing member 15 is formed from a compression spring.

  Further, a buffer member 16 is disposed between the holding member 13 and the inner surface of the accommodation hole 8, particularly the inner surface of the lid portion in which the opening 10 is formed. The buffer member 16 has a characteristic that when the increasing speed of the compressive force in the longitudinal direction acting on the buffer member 16 is large, it is difficult to compress in the longitudinal direction when the increasing speed of the compressive force is small. When a force from the holding position (FIG. 2) toward the allowable position (FIG. 3) acts on the holding member 13, a longitudinal compressive force acts on the buffer member 16. When the increasing speed of the force acting on the holding member 13 is small, the buffer member 16 is easily compressed in the longitudinal direction, so that the holding member 13 can move to the allowable position. On the other hand, when the increasing speed of the force acting on the holding member 13 is large, the buffer member 16 is hardly compressed in the longitudinal direction, and thus the holding member 13 is maintained in the holding position. In an embodiment according to the present invention, the cushioning member 16 is formed from a dilatant fluid housed in a deformable container. The dilatant fluid is formed from, for example, a mixture of silicone oil and boric acid, or a mixture of silicone resin and silica. In another embodiment (not shown), the buffer member 16 is formed of a damper using oil or air as a working fluid.

  On the other hand, the heat receiving member 4 has a linear shape extending through the opening 10, one end is connected to the holding member 13, and the other end is fixed to the stationary member 20 outside the main body 3. In the embodiment according to the present invention, the stationary member 20 is fixed to the main body 3 by a rigid tubular support member 21. In another embodiment, not shown, the stationary member 20 is formed from the outer surface of the pressure vessel 1 or the vehicle frame. That is, the other end of the heat receiving member 4 is fixed to the outer surface of the pressure vessel 1 or the vehicle frame.

  The heat receiving member 4 has heat shrinkability. In the embodiment according to the present invention, the heat receiving member 4 is formed of a shape memory alloy. That is, the heat receiving member 4 is extended more than the memory shape at room temperature. Next, when the heat receiving member 4 receives heat and the temperature of the heat receiving member 4 becomes higher than a predetermined shape recovery temperature (for example, 110 ° C.), the heat receiving member 4 returns to the memory shape, that is, contracts. In another embodiment (not shown), the heat receiving member 4 is formed from a heat-shrinkable resin.

  The heat receiving member 4 is attached to the holding member 13 and the stationary member 20 in a state where the heat receiving member 4 is extended from the memory shape at room temperature. In this case, almost no tension is applied to the heat receiving member 4. As a result, the holding member 13 is held in the holding position by the urging member 15, and thus the safety valve 2 is maintained in the closed state.

  In the embodiment according to the present invention, the heat receiving member 4 is disposed along the surface of the pressure vessel 1 as shown in FIG. Therefore, for example, when the temperature of the pressure vessel 1 increases due to a vehicle fire or the like and the temperature of the heat receiving member 4 becomes higher than the shape recovery temperature, the heat receiving member 4 contracts. As a result, a force from the holding position toward the allowable position acts on the holding member 13 by the heat receiving member 4. In this case, the increasing speed of the force acting on the holding member 13 is relatively small. Therefore, the holding member 13 is moved to the permissible position by the heat receiving member 4 against the urging force of the urging member 15. As a result, the safety valve 2 is opened and the hydrogen gas in the pressure vessel 1 is released to the outside.

  On the other hand, an external force may act on the heat receiving member 4 due to, for example, a vehicle collision. FIG. 4 shows a case where the support member 21 is detached from the main body 3 due to a large external force acting on the heat receiving member 4. Also in this case, the force from the holding position toward the allowable position acts on the holding member 13 by the heat receiving member 4. However, in this case, the increasing speed of the force acting on the holding member 13 is relatively large. Therefore, the holding member 13 is maintained at the holding position by the buffer member 16. As a result, the safety valve 2 is kept closed. That is, the malfunction of the safety valve 2 is prevented. In the example shown in FIG. 4, the heat receiving member 4 is detached from the holding member 13.

  That is, the buffer member 16 allows the holding member 13 to move from the holding position to the allowable position due to thermal contraction of the heat receiving member 4, and the holding member 13 moves from the holding position to the allowable position due to external force acting on the heat receiving member 4. It means that they are prevented from doing.

  In another embodiment not shown, the engaging member 14 is omitted. In this case, when the holding member 13 is in the holding position, the holding member 13 escapes into the passage 5 and engages with the valve body 12, thereby holding the valve body 12 in the blocking position. On the other hand, when the holding member 13 is moved to the permissible position, the holding member 13 is released from the passage 5 and separated from the valve body 12, thereby allowing the valve body 12 to move to the open position.

DESCRIPTION OF SYMBOLS 1 Pressure vessel 2 Safety valve 3 Main body 4 Heat receiving member 5 Escape passage 6a Inlet 7a Outlet 8 Accommodating hole 12 Valve body 13 Holding member 15 Energizing member 16 Buffer member

Claims (3)

A safety valve suitable for being attached to a pressure vessel,
The body,
An escape passage formed in the body, the relief passage having an inlet suitable for communicating with the interior of the pressure vessel and an outlet suitable for communicating with the exterior of the pressure vessel;
A valve body movable between a blocking position for blocking the escape passage and an open position for opening the escape passage;
An accommodation hole formed in the body;
A holding member housed in the housing hole so as to be movable between a holding position for holding the valve body in the blocking position and an allowable position for allowing the valve body to move to the open position;
A biasing member that biases the holding member toward the holding position;
A heat-shrinkable heat-receiving member extending from the main body, one end of which is connected to the holding member and the other end is fixed to a stationary member outside the main body, and contracts when receiving heat to attach the biasing member. A heat receiving member that moves the holding member from the holding position to the allowable position against a force;
A cushioning member disposed between the holding member and the inner surface of the receiving hole, wherein the holding member is allowed to move from the holding position to the allowable position due to thermal contraction of the heat receiving member; A buffer member that prevents the holding member from moving from the holding position to the permissible position by an external force acting on the member;
With safety valve.   The safety valve according to claim 1, wherein the heat receiving member is made of a shape memory alloy.   The safety valve according to claim 1 or 2, further comprising a tubular support member that fixes the stationary member to the main body, wherein the heat receiving member is accommodated in the support member.

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