阅读说明：本技术 具有欠压保护和超温超流切断功能的燃气安全阀及其方法 (Gas safety valve with under-pressure protection and over-temperature and over-flow cut-off functions and method thereof ) 是由 金志江 李文庆 钱锦远 于 2020-07-14 设计创作，主要内容包括：本发明公开了一种具有欠压保护和超温超流切断功能的燃气安全阀,其包括阀体、欠压保护装置和超温超流切断装置,欠压保护装置包括阀塞盖、阀杆、第一弹簧和支板,阀塞盖和支板均为将阀体内部径向封闭的板状结构,阀杆上套设有第一弹簧；超温超流切断装置由前到后依次设有支架、控制板和导磁套,支架上连接有能轴向伸缩的第二弹簧,第二弹簧后方连接有导杆；超温超流切断装置后方设有阀塞,在阀体外部套设有能沿阀体轴向移动的活动套,活动套上固定有磁环,导磁套能随着磁环沿导杆移动。本发明的燃气安全阀使用范围广泛,同时设有欠压保护装置和超温超流切断装置,无需额外的动力,在不同的故障发生时,便可自行启动,整个过程无需人为操作。(The invention discloses a gas safety valve with under-voltage protection and over-temperature and over-current cutting-off functions, which comprises a valve body, an under-voltage protection device and an over-temperature and over-current cutting-off device, wherein the under-voltage protection device comprises a valve plug cover, a valve rod, a first spring and a support plate, the valve plug cover and the support plate are both of plate-shaped structures for radially sealing the inside of the valve body, and the valve rod is sleeved with the first spring; the overtemperature and superflow cut-off device is sequentially provided with a bracket, a control plate and a magnetic sleeve from front to back, the bracket is connected with a second spring capable of axially stretching, and the rear part of the second spring is connected with a guide rod; the valve plug is arranged behind the over-temperature and over-current cut-off device, a movable sleeve capable of moving along the axial direction of the valve body is sleeved outside the valve body, a magnetic ring is fixed on the movable sleeve, and the magnetic sleeve can move along a guide rod along with the magnetic ring. The gas safety valve has wide application range, is provided with the under-voltage protection device and the over-temperature and over-flow cut-off device at the same time, does not need additional power, can be automatically started when different faults occur, and does not need manual operation in the whole process.)

1. A gas safety valve with under-pressure protection and overtemperature and overtlow cut-off functions is characterized by comprising a valve body (1), an under-pressure protection device and an overtemperature and overtlow cut-off device, wherein the valve body (1) is of a hollow cylindrical structure, the under-pressure protection device is positioned in front of the interior of the valve body (1), and the overtemperature and overtlow cut-off device is positioned behind the interior of the valve body (1);

the under-voltage protection device comprises a valve plug cover (2), a valve rod (4), a first spring (3) and a support plate (5), wherein the support plate (5) is arranged behind the valve plug cover (2); the valve plug cover (2) and the support plate (5) are both plate-shaped structures which radially seal the interior of the valve body (1), and are respectively fixedly connected with the inner wall of the valve body (1), and the joint has air tightness; the valve plug cover (2) is provided with a first through center hole along the axial direction, and the support plate (5) is provided with a second through center hole and a first vent hole along the axial direction; the front end of the valve rod (4) is attached and fixed with the valve plug cover (2) and completely covers the first central hole, the rear end of the valve rod penetrates through the second central hole, the valve rod (4) can axially move in the second central hole, and the valve rod (4) and the second central hole are airtight; a first spring (3) is sleeved on the valve rod (4), one end of the first spring (3) is fixedly connected with the front end of the valve rod (4), the other end of the first spring is fixedly connected with the support plate (5), and the first spring (3) is always in a compressed state;

the overtemperature and superflow cutting device is sequentially provided with a bracket (7), a control plate (9) and a magnetic sleeve (11) from front to back, the bracket (7) is fixedly connected with the inner wall of the valve body (1), the control plate (9) and the magnetic sleeve (11) are both of plate-shaped structures which radially seal the inside of the valve body (1) and can axially move along the inner wall of the valve body (1), the control plate (9) is provided with a third central hole and a second vent hole which are communicated along the axial direction, and the magnetic sleeve (11) is provided with a fourth central hole and a third vent hole which are communicated along the axial direction; the bracket (7) is connected with a second spring (8) capable of axially stretching, and a guide rod (10) is connected behind the second spring (8); one end of the guide rod (10) is fixedly connected with the second spring (8), the other end of the guide rod penetrates through the third central hole and the fourth central hole, and the air tightness is formed between the guide rod (10) and the third central hole and between the guide rod and the fourth central hole; the control plate (9) is fixedly connected with the guide rod (10), and the magnetic conduction sleeve (11) can axially slide along the guide rod (10);

a valve plug (15) is arranged behind the over-temperature and over-flow cutting device; the valve plug (15) seals the inner part of the valve body (1) in the radial direction, the valve plug is fixedly connected with the inner wall of the valve body (1), the connection part is airtight, a through fifth central hole is formed in the valve plug (15) in the axial direction, and the guide rod (10) can completely seal the fifth central hole;

the valve comprises a valve body (1), wherein a movable sleeve (14) capable of moving along the axial direction of the valve body (1) is sleeved outside the valve body (1), a magnetic ring (13) is fixed on the movable sleeve (14), and the magnetic sleeve (11) can move along a guide rod (10) along with the magnetic ring (13).

2. The gas safety valve of claim 1, wherein there are a plurality of the first vent hole, the second vent hole, and the third vent hole.

3. A gas safety valve according to claim 1, wherein the front end of the valve stem (4) is provided with a boss.

4. Gas safety valve according to claim 1, characterized in that the support (7) comprises a circular frame and several spokes, each passing through the centre of the circular frame.

5. The gas safety valve according to claim 1, characterized in that the flux sleeve (11) is made of a material having magnetic properties.

6. Gas safety valve according to claim 1, characterized in that the second spring (8) is made of a material that loses its elasticity by heat energy.

7. Gas safety valve according to claim 6, characterized in that the second spring (8) is of rubber material.

8. The gas safety valve according to claim 1, characterized in that a third spring (12) is further arranged between the movable sleeve (14) and the valve body (1), one end of the third spring (12) is fixed on the valve body (1), and the other end of the third spring is fixed with the magnetic ring (13); the third spring (12) is used for driving the movable sleeve (14) to reset.

9. The gas safety valve of claim 1, wherein the first, second, third, fourth and fifth central bores are all at the same horizontal level.

10. A gas supply control method using the gas safety valve according to any one of claims 1 to 9, characterized by comprising:

1) when the valve body is in a normal gas supply range, the valve rod (4) is pushed to move backwards under the action of gas pressure, the first central hole is opened, the first spring (3) is gradually compressed, when the elasticity and the gas pressure of the first spring (3) are the same, the position of the valve rod (4) is stable, and gas passes through the first central hole, the first vent hole, the bracket (7), the second vent hole, the third vent hole and the fifth central hole in sequence and is finally discharged from the gas outlet of the valve body (1); because the area of the second vent hole is smaller than the air passing area of the bracket (7), the air pushes the control plate (9) and the guide rod (10) to synchronously move backwards, the second spring (8) is gradually stretched, when the stretching force of the second spring (8) is the same as the air pressure, the position of the guide rod (10) is stable, and a gap is reserved between the guide rod (10) and the fifth central hole;

2) when the gas pressure is lower than the normal gas supply range, the gas pressure on the valve rod (4) is reduced, the valve rod (4) moves forwards under the elastic force of the first spring (3), the first central hole is completely closed, and a gas passage is cut off;

3) when the gas supply range is higher than the normal gas supply range, the gas pressure on the control plate (9) is increased, the guide rod (10) moves backwards under the action of the gas pressure, the fifth central hole is completely closed, and a gas passage is cut off; when the gas pressure returns to normal, the movable sleeve (14) is pushed forwards, the magnetic conduction sleeve (11) pushes the control plate (9) forwards through the magnetic force of the magnetic ring (13), and the guide rod (10) is driven to move forwards to leave the fifth central hole;

4) when a fire disaster occurs, the second spring (8) is heated and loses elasticity, the action of the gas pressure on the control plate (9) is greater than the elasticity of the second spring (8), the guide rod (10) is driven to move backwards, the fifth central hole is completely closed, and a gas passage is cut off.

Technical Field

The invention belongs to the field of gas appliances, and particularly relates to a gas safety valve with under-voltage protection and over-temperature and over-flow cutting-off functions and a method thereof.

Background

The gas safety self-closing valve is a passive novel safety device which is installed at the tail end of an indoor low-pressure gas pipeline, is connected with a burner through a hose (or can be connected by a metal corrugated pipe), and when the system pressure exceeds a specified value, a gas safety valve can sense the gas pressure, automatically closes and can be manually reset. The gas safety valve can ensure that the safety problem can not occur in the use process of a user, and plays a role of 'fuse'. At present, the common gas valve can be worn to different degrees in a long-term use process, so that the gas safety valve is not closed tightly, gas leakage accidents are caused, and the use safety of a user is influenced. Therefore, the innovative structural design is carried out on the gas safety valve, the long-term reliable operation of the gas safety valve is ensured, and the novel gas safety valve has very important significance for ensuring the safe operation of the whole natural gas pipeline system and the use safety of users.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings in the prior art and provides a gas safety valve with functions of under-pressure protection and over-temperature and over-flow cut-off and a method thereof. The innovative structure of the invention has safe and stable operation, long-term reliability and important significance for ensuring the use safety of users and the safe use of natural gas energy.

In order to achieve the purpose, the invention adopts the following technical scheme:

a gas safety valve with under-pressure protection and overtemperature flow cut-off functions comprises a valve body, an under-pressure protection device and an overtemperature and overtemperature flow cut-off device, wherein the valve body is of a hollow cylindrical structure, the under-pressure protection device is positioned in front of the interior of the valve body, and the overtemperature and overtemperature flow cut-off device is positioned behind the interior of the valve body;

the under-voltage protection device comprises a valve plug cover, a valve rod, a first spring and a support plate, wherein the support plate is arranged behind the valve plug cover; the valve plug cover and the support plate are both of plate-shaped structures which radially seal the interior of the valve body, and are respectively fixedly connected with the inner wall of the valve body, and the joint has air tightness; the valve plug cover is provided with a first through center hole along the axial direction, and the support plate is provided with a second through center hole and a first vent hole along the axial direction; the front end of the valve rod is fixedly attached to the valve plug cover and completely covers the first central hole, the rear end of the valve rod penetrates through the second central hole, the valve rod can axially move in the second central hole, and air tightness exists between the valve rod and the second central hole; the valve rod is sleeved with a first spring, one end of the first spring is fixedly connected with the front end of the valve rod, the other end of the first spring is fixedly connected with the support plate, and the first spring is always in a compressed state;

the overtemperature and superflow cut-off device is sequentially provided with a bracket, a control plate and a magnetic sleeve from front to back, the bracket is fixedly connected with the inner wall of the valve body, the control plate and the magnetic sleeve are both of plate-shaped structures which radially seal the interior of the valve body and can axially move along the inner wall of the valve body, the control plate is provided with a third central hole and a second vent hole which are communicated along the axial direction, and the magnetic sleeve is provided with a fourth central hole and a third vent hole which are communicated along the axial direction; the bracket is connected with a second spring capable of axially stretching, and a guide rod is connected behind the second spring; one end of the guide rod is fixedly connected with the second spring, the other end of the guide rod penetrates through the third central hole and the fourth central hole, and the air tightness is formed among the guide rod, the third central hole and the fourth central hole; the control plate is fixedly connected with the guide rod, and the magnetic conduction sleeve can axially slide along the guide rod;

a valve plug is arranged behind the over-temperature and over-flow cut-off device; the valve plug seals the interior of the valve body in the radial direction, the valve plug is fixedly connected with the inner wall of the valve body, the joint of the valve plug and the inner wall of the valve body is airtight, a through fifth central hole is formed in the valve plug in the axial direction, and the guide rod can completely seal the fifth central hole;

the valve body is sleeved with a movable sleeve capable of moving along the axial direction of the valve body, a magnetic ring is fixed on the movable sleeve, and the magnetic sleeve can move along the guide rod along with the magnetic ring.

Preferably, the first vent hole, the second vent hole and the third vent hole are all plural.

Preferably, the front end of the valve rod is provided with a boss.

Preferably, the support comprises a circular frame and a plurality of spokes, and the spokes all pass through the circle center of the circular frame.

Preferably, the magnetic conductive sleeve is made of a magnetic material.

Preferably, the second spring is made of a material which loses elasticity by heat energy.

Further, the second spring is made of rubber materials.

Preferably, a third spring is further arranged between the movable sleeve and the valve body, one end of the third spring is fixed on the valve body, and the other end of the third spring is fixed on the magnetic ring; and the third spring is used for driving the movable sleeve to reset.

Preferably, the first center hole, the second center hole, the third center hole, the fourth center hole and the fifth center hole are all located at the same horizontal position.

Another object of the present invention is to provide a gas supply control method using any one of the above gas safety valves, specifically as follows:

1) when the valve body is in a normal gas supply range, the valve rod is pushed to move backwards under the action of gas pressure, the first central hole is opened, the first spring is gradually compressed, when the elasticity of the first spring is the same as the gas pressure, the position of the valve rod is stable, gas passes through the first central hole, the first vent hole, the support, the second vent hole, the third vent hole and the fifth central hole in sequence, and finally is discharged from the gas outlet of the valve body; because the area of the second vent hole is smaller than the gas passing area of the bracket, the gas pushes the control plate and the guide rod to synchronously move backwards, the second spring is gradually stretched, when the stretching force of the second spring is the same as the gas pressure, the position of the guide rod is stable, and a gap is reserved between the guide rod and the fifth central hole;

2) when the pressure is lower than the normal gas supply range, the gas pressure on the valve rod is reduced, the valve rod moves forwards under the elastic force of the first spring, the first central hole is completely closed, and a gas passage is cut off;

3) when the gas supply range is higher than the normal gas supply range, the gas pressure on the control plate is increased, the guide rod moves backwards under the action of the gas pressure, the fifth central hole is completely closed, and a gas passage is cut off; when the gas pressure returns to normal, the movable sleeve is pushed forwards, the magnetic conduction sleeve pushes the control plate forwards through the magnetic force of the magnetic ring, and the guide rod is driven to move forwards to leave the fifth central hole;

4) when a fire disaster occurs, the second spring loses elasticity after being heated, the action of the gas pressure on the control plate is greater than the elasticity of the second spring, the guide rod is driven to move backwards, the fifth central hole is completely sealed, and a gas passage is cut off.

Compared with the prior art, the technical scheme of the invention has the following advantages:

1) the gas safety valve is suitable for the cut-off protection of various gas appliances in kitchens such as families, groups, units, hotels and the like, and has wide application range; the under-voltage protection device and the over-temperature and over-current cut-off device are arranged at the same time, extra power is not needed, the device can be started automatically when different faults occur, and manual operation is not needed in the whole process;

2) the gas safety valve has an overtemperature cutoff function, and can be automatically closed when the temperature of the valve body is increased due to fire or other faults of a user house, so that secondary disasters caused by gas leakage are prevented;

3) the gas safety valve is safe and reliable in operation, the whole valve body structure can still keep good stability in long-time operation, and the service life is long.

4) The gas safety valve can be arranged at the tail end of a low-pressure gas pipeline and is connected with a burner through a hose (or can be connected with a metal corrugated pipe), and when the natural gas pipeline is abnormally boosted or abnormally underpressurized, the gas safety self-closing valve can be automatically closed; when the temperature of the gas safety valve is abnormally increased due to fire, the gas safety valve can be automatically closed, and the use safety of a user is guaranteed.

Drawings

FIG. 1 is a schematic diagram of the apparatus of the present invention;

FIG. 2 is a schematic structural diagram of the under-voltage protection device shown in FIG. 1;

FIG. 3 is a schematic view of the structure of the superflow cutoff device of FIG. 1;

FIG. 4 is a schematic diagram of the structure of the flow sheet of FIG. 3;

FIG. 5 is a schematic structural view of the second bracket of FIG. 3;

fig. 6 is a schematic structural view of the flux sleeve of fig. 3.

In the figure: 1. a valve body; 2. a plug cover; 3. a first spring; 4. a valve stem; 5. a support plate; 6. a valve plug sleeve; 7. a support; 8. a second spring; 9. a control panel; 10. a guide bar; 11. a flux sleeve; 12. a third spring; 13. a magnetic ring; 14. a movable sleeve; 15. a valve plug.

Detailed Description

The invention will be further elucidated and described with reference to the drawings and the detailed description. The technical features of the embodiments of the present invention can be combined correspondingly without mutual conflict.

For convenience of description, in the present application, along the gas flow direction, the gas inlet direction is the front, and the gas outlet direction is the rear.

As shown in fig. 1, the gas safety valve with under-pressure protection and overtemperature cutoff functions comprises a valve body 1, an under-pressure protection device and an overtemperature and overtemperature cutoff device, wherein the valve body 1 is of a hollow tubular structure, the under-pressure protection device is located in front of the interior of the valve body 1, and the overtemperature and overtemperature cutoff device is located behind the interior of the valve body 1. The following describes each apparatus in detail:

as shown in fig. 2, the undervoltage protection device includes a plug cap 2, a valve rod 4, a first spring 3 and a support plate 5, and the support plate 5 is disposed behind the plug cap 2. The valve plug cover 2 and the support plate 5 are both of a plate-shaped structure and completely seal the section inside the valve body 1, the valve plug cover 2 and the support plate 5 are respectively fixedly connected with the inner wall of the valve body 1, and the joint has air tightness. The valve plug cover 2 is provided with a first through center hole along the axial direction, and the support plate 5 is provided with a second through center hole and a plurality of first vent holes along the axial direction. The front end of the valve rod 4 is attached and fixed to the valve plug cover 2, the front end of the valve rod 4 can completely cover the first central hole, a boss structure is arranged at the front end of the valve rod 4 to completely cover the first central hole, and the cross sectional area of the front end of the valve rod 4 is large. The rear end of the valve rod 4 penetrates through the second central hole, the valve rod 4 can move back and forth in the second central hole along the axial direction, air tightness exists between the valve rod 4 and the second central hole, and air can only penetrate through the support plate 5 through the first vent hole. The outside cover of valve rod 4 is equipped with first spring 3, and the one end of first spring 3 and the front end fixed connection of valve rod 4, the other end and the extension board 5 fixed connection of first spring 3, first spring 3 are in compression state all the time, have certain pretightning force, can be with valve rod 4 pressfitting on first centre bore.

In practical application, in order to facilitate the installation and the disassembly, the under-voltage protection device can further comprise a valve plug sleeve (6), the valve plug sleeve (6) is of a hollow cylindrical structure, and the outer diameter of the valve plug sleeve (6) is the same as the inner diameter of the valve body 1, namely, the valve plug sleeve is attached to the inner wall of the valve body 1. The valve plug sleeve (6) is arranged behind the valve plug cover 2 and is fixedly connected with the valve plug cover 2. The valve rod 4, the first spring 3 and the support plate 5 of the undervoltage protection device are arranged in the hollow interior of the valve plug sleeve (6) according to the original position and the matching relation. Due to the fact that the valve plug sleeve (6) is arranged, the overall installation and the disassembly of the undervoltage protection device can be more convenient.

As shown in fig. 3, the over-temperature and over-current cutoff device is sequentially provided with a bracket 7, a control plate 9 and a magnetic sleeve 11 from front to back, wherein the bracket 7 is fixedly connected with the inner wall of the valve body 1, and the control plate 9 and the magnetic sleeve 11 are both of plate-shaped structures and can completely seal the cross section inside the valve body 1. As shown in fig. 5, the support 7 includes a circular frame and a plurality of spokes, and the spokes all pass through the center of the circular frame to maintain the stable structure of the support 7. The control plate 9 and the magnetic conductive sleeve 11 can axially move along the inner wall of the valve body 1, the control plate 9 is provided with a third through hole and a plurality of second through holes which are communicated along the axial direction, and the magnetic conductive sleeve 11 is provided with a fourth through hole and a plurality of third through holes which are communicated along the axial direction. As shown in fig. 4, six second ventilation holes in an annular array may be formed in the control plate 9, and the six second ventilation holes are uniformly distributed on the control plate 9 to facilitate the passage of gas. As shown in fig. 6, three third ventilation holes may be formed in the flux sleeve 11, and the three third ventilation holes are uniformly distributed on the flux sleeve 11 to facilitate the passage of gas. The bracket 7 is connected with a second spring 8 capable of axially stretching, a guide rod 10 is connected behind the second spring 8, and the second spring 8 is made of a material which can lose elasticity when heated, preferably a rubber material. One end of the guide rod 10 is fixedly connected with the second spring 8, the other end of the guide rod penetrates through the third central hole and the fourth central hole simultaneously, and the air tightness is formed between the guide rod 10 and the third central hole and between the guide rod 10 and the fourth central hole. That is, the gas can only pass through the control plate 9 and the flux sleeve 11 through the second vent hole and the third vent hole, respectively. The control plate 9 is fixedly connected with the guide rod 10, and the control plate and the guide rod move simultaneously without allowing relative movement. The magnetic sleeve 11 can axially slide along the guide rod 10 and does not influence the air tightness. The magnetic sleeve 11 is made of magnetic material.

The rear of the over-temperature and over-flow cut-off device is also provided with a valve plug 15, the valve plug 15 is fixed at the outlet end of the valve body 1, and the position of the valve plug is closer to the outlet end than the over-flow cut-off device. The valve plug 15 completely seals the cross section of the inner part of the valve body 1, the valve plug 15 is fixedly connected with the inner wall of the valve body 1, and the joint of the valve plug 15 and the inner wall of the valve body 1 has air tightness. The valve plug 15 is provided with a through fifth central hole along the axial direction, and the guide rod 10 can completely seal the fifth central hole, so that gas cannot pass through the fifth central hole.

The outside of the valve body 1 is sleeved with a movable sleeve 14 capable of moving along the axial direction of the valve body 1, a magnetic ring 13 is fixed on the movable sleeve 14, and the magnetic conductive sleeve 11 can move along the guide rod 10 along with the magnetic ring 13. In practical application, a third spring 12 can be arranged between the movable sleeve 14 and the valve body 1, one end of the third spring 12 is fixed on the valve body 1, and the other end is fixed with a magnetic ring 13; the third spring 12 is used for driving the movable sleeve 14 to reset. In order to make the valve body structure more beautiful and better in sealing performance, the first center hole, the second center hole, the third center hole, the fourth center hole and the fifth center hole of the gas safety valve are all in the same horizontal position.

The gas supply control method of the gas safety valve in use comprises the following steps:

1) when the valve rod is in a normal air supply range, the valve rod 4 is pushed to move backwards under the action of gas pressure, the first central hole is opened, the first spring 3 is gradually compressed, when the elasticity of the first spring 3 is the same as the gas pressure, the position of the valve rod 4 is stable, gas sequentially passes through the first central hole, the first vent hole, the support 7, the second vent hole, the third vent hole and the fifth central hole, and finally is discharged from the air outlet of the valve body 1. Because the area of the second vent hole is smaller than the air passing area of the bracket 7, the air pushes the control plate 9 and the guide rod 10 to synchronously move backwards, the second spring 8 is gradually stretched, when the stretching force of the second spring 8 is the same as the air pressure, the position of the guide rod 10 is stable, and a gap is reserved between the guide rod 10 and the fifth central hole.

Specifically, when the normal air feed state, because the effect of gas pressure, gas can push away valve rod 4 for valve rod 4 can move along the axial direction of gas safety valve body 1, and the axial motion of valve rod 4 is just supported in the effect of extension board 5. The first spring 3 is gradually compressed as the valve rod 4 moves axially. The supporting force provided by the first spring 3 is larger and larger, and the valve rod 4 stops moving until the acting force of the first spring 3 on the valve rod 4 is equal to the acting force of gas on the valve rod 4. At the moment, the first central hole on the valve plug cover 2 can be normally communicated with gas, and the gas passes through the second vent holes of the bracket 7 and the control plate 9 in sequence after passing through the first central hole of the valve plug cover 2. Because the control plate 9 is provided with the second vent hole, but the area ratio of the second vent hole is relatively small, the gas pushes the control plate 9 to move towards the gas outlet of the gas safety valve body 1. The second spring 8 will be gradually stretched until the support force due to the stretching and the force of the gas are equal, and the guide rod 10 will not move. In this state, the guide rod 10 and the valve plug 15 are not yet in contact with each other, and the fifth center hole of the valve plug 15 is not yet blocked. The gas passes through the third through hole of the magnetic sleeve 11, the fifth central hole of the valve plug 15 and the gas outlet of the gas safety valve body 1 in sequence and reaches the gas appliance, so that the normal use requirement of a user is met.

2) When the air supply range is lower than the normal air supply range, the air pressure on the valve rod 4 is reduced, the valve rod 4 moves forwards under the elastic force of the first spring 3, the first central hole is completely closed, and an air passage is cut off.

Specifically, when a problem occurs in the gas line, such as digging up the gas line for road construction, insufficient supply pressure of the gas may be caused. At the moment, the under-pressure protection device of the gas safety valve can automatically work to automatically cut off the gas supply, so that the safety of a user is ensured to the maximum extent. The motion process of the undervoltage protection device is as follows: when the gas changed into the insufficient state of air feed pressure by normal air feed state, the effort at valve rod 4 both ends can change, and the effort of gas can reduce, and first spring 3 is greater than the effort of gas to valve rod 4 to the effort of valve rod 4. The valve rod 4 can move towards the air inlet end of the gas safety valve body 1 under the action of the combination force of the two until the valve rod 4 can press the first central hole of the valve plug cover 2 under the action of the first spring 3. At the moment, gas can not pass through the gas safety valve, and the valve is closed when the pressure is reduced, so that the safety of a user is protected to the maximum extent.

3) When the gas supply range is higher than the normal gas supply range, the gas pressure on the control plate 9 is increased, the guide rod 10 moves backward under the action of the gas pressure, the fifth central hole is completely closed, and the gas passage is cut off. When the gas pressure returns to normal, the movable sleeve 14 is pushed forward, the magnetic conductive sleeve 11 pushes the control plate 9 forward through the magnetic force of the magnetic ring 13, and the guide rod 10 is driven to move forward to leave the fifth central hole.

Specifically, when the pressure of the fuel gas is too high, the overtemperature and overtlow cut-off device of the fuel gas safety valve can automatically work to automatically cut off the fuel gas supply, so that the danger is prevented. The motion process of the over-temperature and over-current cutting device is as follows: when the gas pressure is abnormally increased from the normal gas supply to the gas supply, the pressure acting on both ends of the control plate 9 is changed at this time. The force of the gas on the control plate 9 will be greater than the pull of the second spring 8 on the guide rod 10. The guide rod 10 and the control plate 9 fixed on the guide rod 10 move axially along the direction of the gas outlet end of the gas safety valve body 1. At this time, the guide rod 10 presses the fifth center hole of the valve cover 15 to cut off the gas passage. Under the effect of the continuous gas pressure, the guide rod 10 can continuously compress the fifth central hole of the valve plug 15, so that the closed state of the gas passage is kept for a long time, and potential danger brought to a user by the abnormal rising of the gas supply pressure is prevented.

When the gas pressure returns to normal, the user can manually move the movable sleeve 14 at the moment, and push the movable sleeve to move along the direction of the gas inlet end of the gas safety valve body 1. Because the movable sleeve 14 is fixedly connected with the magnetic ring 13, the magnetic ring 13 also moves along the direction of the gas inlet end of the gas safety valve body along with the movement of the movable sleeve 14. Under the action of magnetic force, along with the movement of the magnetic ring 13, the magnetic conductive sleeve 11 in the gas safety valve body also can move towards the air inlet end of the gas safety valve body 1, and at the moment, because the magnetic conductive sleeve 11 can freely move on the guide rod 10, when the magnetic conductive sleeve 11 moves, the guide rod 10 and the control plate 9 do not move. Until the magnetic sleeve 11 contacts the control plate 9 in the process of moving to the air inlet end. At this time, the magnetic sleeve 11 will push the control plate 9 to move toward the air inlet end. Due to the fixed connection between the control plate 9 and the guide bar 10, the guide bar 10 will also move to the right. When a user looses his hand, the movable sleeve 14 and the magnetic ring 13 will return to the original position along the direction of the valve body air outlet end under the action of the third spring 12, and at this time, the magnetic sleeve 11 will also move along the direction of the valve body air outlet end under the action of the magnetic force of the magnetic ring 13 until the original position is returned. The gas safety valve can return to the initial state through the operation of pushing the movable sleeve 14 by the user.

4) When a fire occurs, the second spring 8 loses elasticity due to heating, the action of the gas pressure on the control plate 9 is greater than the elasticity of the second spring 8, the guide rod 10 is driven to move backwards, the fifth central hole is completely sealed, and a gas passage is cut off.

Specifically, when a fire disaster occurs in a user house, the overtemperature and overtlow cut-off device of the gas safety valve also automatically works at the moment, and the gas safety valve starts the automatic cut-off device to automatically cut off the gas supply, so that the occurrence of a secondary disaster is prevented. The motion process of the over-temperature and over-current cutting device is as follows: when the temperature of the gas valve rises under normal work, the rubber spring 8 of the gas safety valve under normal work can be softened due to high temperature and lose elasticity. At this time, the acting force of the two ends of the guide rod 10 changes, the elastic force of the second spring 8 is reduced, and the guide rod 10 tightly presses the fifth central hole of the valve plug 15 under the pushing force of the gas. The passage of the gas will be closed at this time so that no gas escapes from the outlet of the gas safety valve. The overtemperature cutoff function has important significance for preventing secondary disasters.

The above-described embodiments are merely preferred embodiments of the present invention, which should not be construed as limiting the invention. Various changes and modifications may be made by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present invention. Therefore, the technical scheme obtained by adopting the mode of equivalent replacement or equivalent transformation is within the protection scope of the invention.