Sealing device and hydrogen storage device

Abstract

The present invention discloses a sealing device, which relates to the technical field of hydrogen energy utilization. The sealing device includes a sealing ring, a pressing ring and a driving device. The sealing ring is used to be sleeved in a first groove on the circumferential direction of the cover body. The pressing ring is used to be placed below the cover body. The output member of the driving device passes through the cover body and is connected to the pressing ring, and can drive the pressing ring to move axially along the cover body to squeeze the sealing ring, so that the sealing ring deforms to close the gap between the tank body and the cover body. The present invention also discloses a hydrogen storage device, which includes a tank body, a cover body and the sealing device. The cover body can be fixedly connected to the opening of the tank body. Therefore, the sealing device and the hydrogen storage device can enable the sealing ring to still fully deform and expand under the conditions of insufficient pressure and low temperature in the hydrogen storage device, effectively ensuring the sealing performance at the connection position between the tank body and the cover body and avoiding hydrogen leakage.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen energy utilization, and particularly to a sealing device and a hydrogen storage device. Background Art

[0002] Hydrogen energy has the advantages of high calorific value, environmental friendliness, recyclability, etc. As an ideal energy source, hydrogen energy has a very broad development prospect. In the development and use of hydrogen energy, the storage link of hydrogen energy is its core part. Many countries have made a lot of explorations on the development of hydrogen storage technologies, hoping to find and develop safe, cheap and effective hydrogen storage methods.

[0003] New energy vehicles often use hydrogen as one of the power sources, and hydrogen storage devices are often placed in new energy vehicles to provide hydrogen. Currently, the end of a hydrogen storage device is usually provided with an interface, and an end cover is provided at the interface. On the one hand, the end cover can be connected to the hydrogen storage device to seal its tank body, and on the other hand, a hydrogen delivery pipeline can be connected to the end cover for discharging or inputting hydrogen.

[0004] In the prior art, a sealing ring is provided between the end cover and the tank body. The air pressure of hydrogen is used to squeeze the sealing ring, so that the sealing ring deforms and closely fits between the end cover and the tank body to achieve the effect of preventing the leakage of a high-pressure hydrogen storage tank. However, in the above method, at low temperatures, the deformability of the sealing ring is poor and it is prone to insufficient deformation. Moreover, as the hydrogen storage device is used, the internal pressure of the hydrogen storage device is insufficient, which is also likely to cause the sealing ring to be insufficiently deformed and unfolded, resulting in a poor sealing performance at the connection position between the tank body and the cover of the hydrogen storage device and the problem of hydrogen leakage. Summary of the Invention

[0005] The purpose of the present invention is to provide a sealing device and a hydrogen storage device to solve the problems existing in the above prior art, so that the sealing ring can still be fully deformed and unfolded under the conditions of insufficient pressure and low temperature in the hydrogen storage device, effectively ensuring the sealing performance at the connection position between the tank body and the cover and avoiding hydrogen leakage.

[0006] To achieve the above purpose, the present invention provides the following solution:

[0007] The present invention provides a sealing device, including a sealing ring, a pressing ring and a driving device. The sealing ring is used to be sleeved in a first groove on the circumferential direction of a cover body. The pressing ring is used to be placed below the cover body. The output member of the driving device passes through the cover body and is connected to the pressing ring, and can drive the pressing ring to move axially along the cover body to squeeze the sealing ring, so that the sealing ring deforms to seal the gap between the tank body and the cover body.

[0008] In some embodiments, the driving device includes a rod body which is used to pass through the cover body and is axially fixed to the cover body. One end of the rod body extending into the can body can be threadedly connected to the pressing ring. The pressing ring is used to be slidably connected to the can body in a direction parallel to the axial direction of the cover body. Rotating the rod body can drive the pressing ring to approach and squeeze the sealing ring.

[0009] In some embodiments, a clutch device is further included. The clutch device has a first state and a second state. In the first state, the clutch device can connect the rod body and the cover body so that the rotation of the rod body can drive the rotation of the cover body. In the second state, the clutch device can disconnect the rod body from the cover body. Rotating the rod body can change the clutch device from the first state to the second state and threadedly connect the rod body and the pressing ring.

[0010] In some embodiments, the clutch device includes a first fixing block, a second fixing block, an insertion rod and an ejecting member. The first fixing block is used to be fixedly connected to the outer wall of the rod body. A first slot is provided in the first fixing block. The second fixing block is used to be fixed on the cover body. A second slot is provided in the second fixing block. The ejecting member is used to be fixed on the inner wall of the can body and can pass through the pressing ring and extend into the second slot. The insertion rod is movably arranged in the first slot. An elastic element is arranged in the first slot. Two ends of the elastic element respectively abut against the inner wall of the first slot and the insertion rod. The insertion rod can be inserted into the second slot under the elastic force of the elastic element so that the clutch device is in the first state. The rotation of the cover body can drive the second fixing block to approach the ejecting member in the axial direction of the cover body and eject the insertion rod out of the second slot so that the clutch device is in the second state.

[0011] In some embodiments, the lower surface of the insertion rod is an inclined surface. In the direction away from the rod body, the distance from the inclined surface to the upper end surface of the cover body gradually decreases.

[0012] In some embodiments, at least one guiding plate is fixedly arranged on the side wall of the second fixing block. The guiding plate has a guiding inclined surface. The end surface of the second slot has a limiting member which is used to limit the complete detachment of the insertion rod from the second slot. When the insertion rod abuts against the ejecting member, the length of the insertion rod extending out of the limiting member is a first length. When the rod body drives the insertion rod to rotate circumferentially away from the second fixing block and the guiding plate, the length of the insertion rod extending out of the limiting member is a second length. When one end of the insertion rod away from the first fixing block is squeezed by the guiding inclined surface, the insertion rod can change from the second length to the first length.

[0013] The present invention also provides a hydrogen storage device, which includes a tank body, a cover body, and the sealing device described in any one of the above. The cover body can be fixedly connected to the opening of the tank body.

[0014] In some embodiments, the first groove has an inclined surface, and in the direction away from the upper end surface of the cover body, the distance from the inclined surface to the inner wall of the tank body gradually increases.

[0015] In some embodiments, a first through groove is further formed on the cover body. The first through groove is arc-shaped and communicates the space inside the tank body with the first groove. The pressing ring can extend from the space inside the tank body into the first groove through the first through groove to squeeze the sealing ring.

[0016] In some embodiments, a first accommodation cavity is provided inside the cover body. The first accommodation cavity communicates with the outside. A ratchet wheel and a plurality of pawls are arranged in the first accommodation cavity. The pawls can be inserted into the ratchet wheel. The ratchet wheel is coaxially arranged and fixedly connected with the rod body. The pawls are rotatably connected to the cover body. When the rod body rotates in the first direction, the ratchet wheel disengages from the engagement with the pawls. When the rod body rotates in the second direction, the ratchet wheel maintains the engagement with each pawl, so that the rod body drives the cover body to rotate synchronously and the cover body can be screwed out of the tank body. The first direction is opposite to the second direction.

[0017] The present invention has achieved the following technical effects compared with the prior art:

[0018] The present invention provides a sealing device and a hydrogen storage device. By arranging a sealing ring, a pressing ring, and a driving device in the hydrogen storage device, the sealing ring is sleeved in the first groove on the circumferential direction of the cover body, the pressing ring is arranged below the cover body, and the driving device passes through the cover body and is connected to the pressing ring, and can drive the pressing ring to axially move along the cover body to squeeze the sealing ring, so that the sealing ring deforms to seal the gap between the tank body and the cover body. Therefore, the sealing device and the hydrogen storage device can enable the sealing ring to be fully deformed and unfolded under the conditions of insufficient pressure and low temperature in the hydrogen storage device, effectively ensuring the sealing performance at the connection position between the tank body and the cover body and avoiding hydrogen leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 It is a cross-sectional view of the hydrogen storage device in an embodiment of the present invention;

[0021] Figure 2 Schematic structural diagram of a hydrogen storage device in an embodiment of the present invention;

[0022] Figure 3 is Figure 1 Partial enlarged schematic view of the hydrogen storage device at position A in

[0023] Figure 4 Schematic structural diagram of the cover body of the hydrogen storage device in an embodiment of the present invention;

[0024] Figure 5 is Figure 1 Partial enlarged schematic view of the hydrogen storage device at position B in

[0025] Figure 6 Schematic structural diagram of the pressing ring of the hydrogen storage device in an embodiment of the present invention;

[0026] Figure 7 Schematic structural diagram of the guide plate of the hydrogen storage device in an embodiment of the present invention.

[0027] Figure 8 Cross-sectional view of the ratchet of the hydrogen storage device in an embodiment of the present invention.

[0028] Wherein: 1 - tank body; 14 - ejecting member; 2 - cover body; 22 - first groove; 223 - inclined surface; 24 - first through groove; 27 - driving device; 271 - rod body; 272 - first fixing block; 273 - first slot; 2732 - inserting rod; 2733 - elastic element; 2734 - inclined surface; 28 - first accommodating cavity; 281 - ratchet; 282 - pawl; 29 - second fixing block; 291 - second slot; 292 - guide plate; 293 - guiding inclined surface; 3 - sealing ring; 4 - pressing ring; 432 - thread; 433 - square groove. Specific embodiments

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] Embodiment 1

[0031] A sealing device provided in this embodiment, as shown in Figure 1-3As shown in the figure, it includes a sealing ring 3, a retaining ring 4 and a driving device 27. The sealing ring 3 is used to be sleeved in the first groove 22 on the circumference of the cover body 2. The retaining ring 4 is used to be placed under the cover body 2. The output member of the driving device 27 passes through the cover body 2 and is connected to the retaining ring 4, and can drive the retaining ring 4 to move axially along the cover body 2 to squeeze the sealing ring 3, so that the sealing ring 3 deforms to close the gap between the tank body 1 and the cover body 2. In this application, by arranging the sealing ring 3, the retaining ring 4 and the driving device 27 in the hydrogen storage device, the sealing ring 3 is sleeved in the first groove 22 on the circumference of the cover body 2, the retaining ring 4 is arranged under the cover body 2, the driving device 27 passes through the cover body 2 and is connected to the retaining ring 4, and can drive the retaining ring 4 to move axially along the cover body 2 to squeeze the sealing ring 3, so that the sealing ring 3 deforms to close the gap between the tank body 1 and the cover body 2. Therefore, this sealing device and the hydrogen storage device can enable the sealing ring 3 to be fully deformed and unfolded under the conditions of insufficient pressure and low temperature in the hydrogen storage device, effectively ensuring the sealing performance at the connection position between the tank body 1 and the cover body 2, and avoiding hydrogen leakage.

[0032] In some embodiments of this embodiment, such as Figure 6 As shown in the figure, the driving device 27 includes a rod body 271. The rod body 271 is used to pass through the cover body 2 and is axially fixed to the cover body 2. One end of the rod body 271 extending into the tank body 1 can be threadedly connected to the retaining ring 4. The retaining ring 4 is used to be slidably connected in the tank body 1 along a direction parallel to the axis of the cover body 2. Rotating the rod body 271 can drive the retaining ring 4 to approach and squeeze the sealing ring 3. Through the threaded connection between the rod body 271 and the retaining ring 4 and the sliding connection between the retaining ring 4 and the tank body 1, the squeezing of the sealing ring 3 by the retaining ring 4 is a controllable and stable process. This structure can precisely adjust the pressure of the retaining ring 4 on the sealing ring 3. During the operation of the device, when affected by external factors such as vibration and temperature change, this pressing structure can ensure that the sealing ring 3 always maintains a good sealing state and will not lose the sealing effect due to slight displacement or deformation, thereby improving the reliability of the seal.

[0033] In some embodiments of this embodiment, such as Figure 5As shown, the sealing device further includes a clutch device, which has a first state and a second state. In the first state, the clutch device can connect the rod body 271 and the cover body 2, so that the rotation of the rod body 271 can drive the rotation of the cover body 2. In the second state, the clutch device can disconnect the rod body 271 from the cover body 2. Rotating the rod body 271 can change the clutch device from the first state to the second state and thread-connect the rod body 271 with the retaining ring 4. The clutch device having two states realizes the versatility of the sealing device. On the one hand, the clutch device, as an integral rotating part, is used for the rotation operation of the cover body 2. On the other hand, during the operation of the device, if hydrogen leakage is found, by rotating the rod body 271, the clutch device is switched to the second state, so that the retaining ring 4 squeezes the sealing ring 3 to seal the leakage point, without the need for complex disassembly or adjustment of the entire device, greatly improving the practicability and adaptability of the sealing device.

[0034] In some embodiments of this embodiment, the clutch device includes a first fixing block 272, a second fixing block 29, a plug rod 2732 and an ejecting member 14. The first fixing block 272 is used for fixedly connecting with the outer wall of the rod body 271. A first slot 273 is arranged in the first fixing block 272. The second fixing block 29 is used for being fixed on the cover body 2. A second slot 291 is arranged in the second fixing block 29. The ejecting member 14 is used for being fixed on the inner wall of the tank body 1 and can pass through the retaining ring 4 and extend into the second slot 291. The plug rod 2732 is movably arranged in the first slot 273. An elastic element 2733 is arranged in the first slot 273. Two ends of the elastic element 2733 respectively abut against the inner wall of the first slot 273 and the plug rod 2732. The plug rod 2732 can be inserted into the second slot 291 under the elastic force of the elastic element 2733 to make the clutch device in the first state. The rotation of the cover body 2 can drive the second fixing block 29 to approach the ejecting member 14 in the axial direction of the cover body 2 and push the plug rod 2732 out of the second slot 291 to make the clutch device in the second state. When the cover body 2 rotates, the ejecting member 14 approaches the second fixing block 29 in the axial direction. Using this relative movement, the plug rod 2732 is pushed out of the second slot 291 to realize the switching from the first state to the second state. The whole process is based on the interaction between mechanical components, without the need for complex electronic control or additional power sources, reducing the risk of the clutch device failing due to electronic component failures or power supply problems and improving the reliability of state switching.

[0035] In some embodiments of this embodiment, the lower surface of the insertion rod 2732 is an inclined surface 2734. In the direction away from the rod body 271, the distance from the inclined surface 2734 to the upper end surface of the cover body 2 gradually decreases. The lower surface of the insertion rod 2732 being an inclined surface 2734 enables the insertion rod 2732 to gradually and smoothly disengage from the second slot 291 during the process of being pushed out. This gradual disengagement method can reduce the impact force and frictional force between components, thereby reducing the possibility of damage to the insertion rod 2732 and the slot due to sudden strong friction or collision, and improving the smoothness and reliability of the state switching of the clutch device.

[0036] In some embodiments of this embodiment, as Figure 7 shown, at least one guide plate 292 is fixedly arranged on the side wall of the second fixing block 29. The guide plate 292 has a guide inclined surface 293. The end surface of the second slot 291 has a limiting member for restricting the insertion rod 2732 from completely disengaging from the second slot 291. When the insertion rod 2732 abuts against the pushing member 14, the length of the insertion rod 2732 extending out of the limiting member is the first length. When the rod body 271 drives the insertion rod 2732 to rotate circumferentially away from the second fixing block 29 and the guide plate 292, the length of the insertion rod 2732 extending out of the limiting member is the second length. When the end of the insertion rod 2732 away from the first fixing block 272 is squeezed by the guide inclined surface 293, the insertion rod 2732 can change from the second length to the first length. When the rod body 271 moves downward and rotates along the axis direction of the cover body 2, the insertion rod 2732 is squeezed by the guide inclined surface 293 and retracts. This mechanical squeezing method can ensure that the insertion rod 2732 stably disengages from the second slot 291, enabling the clutch device to enter the second state. This squeezing method through the guide inclined surface 293 is more reliable and can effectively avoid the situation of jamming or incomplete disengagement of the insertion rod 2732 during the disengagement process, thereby achieving precise switching of the state of the clutch device.

[0037] Embodiment Two

[0038] This embodiment also provides a hydrogen storage device, which includes a tank body 1, a cover body 2, and the sealing device of the first embodiment. The cover body 2 can be fixedly connected to the opening of the tank body 1. By providing a sealing ring 3, a pressing ring 4, and a driving device 27 in the hydrogen storage device, the sealing ring 3 is sleeved in the first groove 22 on the circumferential direction of the cover body 2. The pressing ring 4 is arranged below the cover body 2. The driving device 27 passes through the cover body 2 and is connected to the pressing ring 4, and can drive the pressing ring 4 to move axially along the cover body 2 to squeeze the sealing ring 3, so that the sealing ring 3 deforms to close the gap between the tank body 1 and the cover body 2. Therefore, this sealing device and the hydrogen storage device can enable the sealing ring 3 to still fully deform and expand under the conditions of insufficient pressure and low temperature in the hydrogen storage device, effectively ensuring the sealing performance at the connection position between the tank body 1 and the cover body 2, and avoiding hydrogen leakage. Specifically, the tank body 1 is vertically arranged, and an opening is provided at the upper end of the tank body 1. A connecting pipe is fixed to the opening. The cover body 2 is cylindrical. The cover body 2 can be inserted into the connecting pipe along the axis direction of the connecting pipe and is fixed to the connecting pipe. A connecting sleeve is fixed to the outer circumference of the cover body 2. An installation groove is provided at the upper end of the connecting pipe. The connecting sleeve is threadedly connected to the installation groove, so as to connect the cover body 2 and the tank body 1. The cover body 2 and the tank body 1 are connected by threads. This connection method is convenient for the installation and disassembly between the cover body 2 and the tank body 1. During the tightening process, the mutual engagement between the threads can make the cover body 2 and the tank body 1 fit tightly, and can effectively prevent hydrogen leakage.

[0039] In some embodiments of this embodiment, the first groove 22 has an inclined surface 223. In the direction away from the upper end surface of the cover body 2, the distance from the inclined surface 223 to the inner wall of the tank body 1 gradually increases. The first groove 22 with a gradually decreasing radial dimension can enable the sealing ring 3 to seal the gap between the cover body 2 and the tank body 1 with a small amount of deformation during the upward movement due to extrusion. Under the conditions of insufficient pressure and low temperature in the hydrogen storage device, the sealing ring 3 can still fully deform and expand, effectively ensuring the sealing performance at the connection position between the tank body 1 and the cover body 2, and avoiding hydrogen leakage.

[0040] In some embodiments of this embodiment, as Figure 4 shown, a first through groove 24 is further provided on the cover body 2. The first through groove 24 is arc-shaped and communicates the space inside the tank body 1 with the first groove 22. The pressing ring 4 can extend from the space inside the tank body 1 into the first groove 22 through the first through groove 24 to squeeze the sealing ring 3. The first through groove 24 can enable the pressing ring 4 to reach the first groove 22 from the inside of the tank body 1, so as to apply pressure to the sealing ring 3, ensuring that the pressing ring 4 can accurately apply pressure on the sealing ring 3 through the first through groove 24, effectively increasing the compression degree of the sealing ring 3, and further improving the sealing effect.

[0041] In some embodiments of this embodiment, as Figure 8As shown, the cover body 2 has a first accommodation cavity 28 which communicates with the outside. A ratchet wheel 281 and a pawl 282 are arranged in the first accommodation cavity 28. The pawl 282 can be inserted into the ratchet wheel 281. The ratchet wheel 281 is coaxially arranged and fixedly connected with the rod body 271. The pawl 282 is rotatably connected with the cover body 2. When the rod body 271 rotates in the first direction, the ratchet wheel 281 disengages from the pawl 282. When the rod body 271 rotates in the second direction, the ratchet wheel 281 remains engaged with each pawl 282, so that the rod body 271 drives the cover body 2 to rotate synchronously, and the cover body 2 can be screwed out from the tank body 1. The first direction is opposite to the second direction. When internal maintenance of the sealing device is required, such as replacing the sealing ring 3 or inspecting other components, by controlling the engagement and disengagement of the ratchet wheel 281 and the pawl 282, the cover body 2 can be conveniently unscrewed, enabling maintenance personnel to easily open the sealing device and perform necessary repair and maintenance work, which facilitates the disassembly and maintenance operations of the hydrogen storage device.

[0042] In the present invention, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A sealing device, comprising a sealing ring, characterized in that: The invention also includes a pressure ring and a driving device, wherein the sealing ring is used to be sleeved in a first groove on the circumference of the cover body, the pressure ring is used to be placed under the cover body, the output member of the driving device passes through the cover body and is connected to the pressure ring, and can drive the pressure ring to move along the axial direction of the cover body to squeeze the sealing ring, so that the sealing ring is deformed to close the gap between the tank body and the cover body; the driving device includes a rod body, the rod body is used to pass through the cover body and be axially fixed to the cover body, one end of the rod body extending into the tank body can be threadedly connected with the pressure ring, the pressure ring is used to be slidably connected to the tank body along a direction parallel to the axial direction of the cover body, and rotating the rod body can drive the pressure ring to approach and squeeze the sealing ring; the invention also includes a clutch device, the clutch device has a first state and a second state, the clutch device in the first state can connect the rod body and the cover body so that the rotation of the rod body can drive the cover body to rotate, and the clutch device in the second state can disconnect the rod body from the cover body, and rotating the The rod body can change the clutch device from the first state to the second state and make the rod body threadedly connected to the pressure ring; the clutch device includes a first fixed block, a second fixed block, an insertion rod and a push-out piece, the first fixed block is used to be fixedly connected to the outer wall of the rod body, a first slot is arranged in the first fixed block, the second fixed block is used to be fixed on the cover body, a second slot is arranged in the second fixed block, the push-out piece is used to be fixed on the inner wall of the tank body and can pass through the pressure ring and extend into the second slot, the insertion rod can be movably arranged in the first slot, an elastic element is arranged in the first slot, the two ends of the elastic element are respectively abutted against the inner wall of the first slot and the insertion rod, the insertion rod can be inserted into the second slot under the elastic force of the elastic element so that the clutch device is in the first state, and the rotation of the cover body can drive the second fixed block to approach the push-out piece in the axial direction of the cover body and push the insertion rod out of the second slot so that the clutch device is in the second state.

2. The sealing device according to claim 1, characterized in that: The lower surface of the insertion rod is in the form of an inclined surface, and in the direction away from the rod body, the distance from the inclined surface to the upper end surface of the cover body gradually decreases.

3. The sealing device according to claim 1, characterized in that: At least one guide plate is fixedly arranged on the side wall of the second fixed block, and the guide plate has a guiding inclined surface. The end surface of the second slot is provided with a limiting piece, and the limiting piece is used to limit the insertion rod from completely disengaging from the second slot. When the insertion rod abuts against the abutting piece, the length of the insertion rod extending out of the limiting piece is a first length. When the rod body drives the insertion rod to rotate until it circumferentially disengages from the second fixed block and the guide plate, the length of the insertion rod extending out of the limiting piece is a second length. When the end of the insertion rod away from the first fixed block is squeezed by the guiding inclined surface, the insertion rod can change from the second length to the first length.

4. A hydrogen storage device, characterized in that: It comprises a tank body, a cover body and the sealing device according to any one of claims 1 to 3, wherein the cover body can be fixedly connected to the opening of the tank body.

5. The hydrogen storage device according to claim 4, characterized in that: The first groove has an inclined surface, and the distance from the inclined surface to the inner wall of the tank body gradually increases in a direction away from the upper end surface of the cover body.

6. The hydrogen storage device according to claim 4, characterized in that: The cover body is also provided with a first through groove which is arc-shaped and connects the space in the tank body with the first groove. The pressure ring can extend from the space in the tank body through the first through groove into the first groove to squeeze the sealing ring.

7. The hydrogen storage device according to claim 4, characterized in that: The cover body is provided with a first accommodating cavity, which is communicated with the outside. A ratchet and a pawl are arranged in the first accommodating cavity, and the pawl can be inserted into the ratchet. The ratchet is coaxially arranged and fixedly connected with the rod body, and the pawl is rotatably connected with the cover body. When the rod body rotates along a first direction, the ratchet disengages from the engagement with the pawl. When the rod body rotates along a second direction, the ratchet maintains the engagement with each of the pawls, so that the rod body drives the cover body to rotate synchronously and the cover body can be screwed out of the tank body. The first direction is opposite to the second direction.

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