High Pressure Tank

Abstract

To provide a technique that can prevent a seal from being damaged.SOLUTION: A high-pressure tank disclosed herein includes: a tank body having the inside space configured to contain a fluid; a cap located on the tank body and having a through hole that allows the inside space and the outside space of the tank body to communicate with each other; a valve body housed in the through hole and movable between an open position where the through hole is opened and a closed position where the through hole is closed along the axial direction of the through hole; and a ring-shaped seal located on the outer peripheral surface of the valve body, wherein the outer peripheral surface of the valve body includes, along the axial direction of the valve body, a groove portion where the seal is located, and a thick shaft portion adjoining the groove portion from the inside space side and having a larger diameter than the groove portion, and the length of the thick shaft portion is greater than the distance from a compression start position to the closed position, the compression start position meaning the position of the valve body where compression of the seal is started in a stroke in which the valve body moves from the open position to the closed position.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a high-pressure tank, and more particularly to a high-pressure tank in which a through-hole in a nozzle is closed by a valve body. [Background technology]

[0002] Patent Document 1 discloses a sealing structure including a tank body, a valve body, a nozzle, and a ring-shaped seal (e.g., an O-ring) that is accommodated in an accommodation area formed by the outer circumferential surface of the valve body and the inner circumferential surface of a through hole of the nozzle and seals the fluid. The through hole of the nozzle communicates the internal space of the tank body with the external space. The valve body moves along the axial direction of the through hole between an open position that opens the through hole of the nozzle and a closed position that closes the through hole. The valve body has, along the axial direction of the valve body, a groove portion in which a seal is arranged, and a thick shaft portion that is adjacent to the groove portion from the internal space side of the tank body and has a diameter larger than that of the groove portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-031830 A Summary of the Invention [Problem to be solved by the invention]

[0004] When the valve body moves from the open position to the closed position, the tip of the outer peripheral surface of the thick shaft portion comes into contact with the inner peripheral surface of the through hole, and the tip may damage the inner peripheral surface. The seal closes the through hole in a state where it is compressed between the groove portion of the valve body and the inner peripheral surface of the through hole. Therefore, if there is a scratch on the inner peripheral surface of the through hole, the seal is pressed strongly against the scratch. As a result, the seal may be damaged. This specification provides a technology that can prevent the seal from being damaged in a high-pressure tank in which the valve body closes the through hole of the nozzle. [Means for solving the problem]

[0005] The high-pressure tank disclosed in this specification includes a tank body having an internal space for accommodating a fluid, a cap provided in the tank body and having a through hole communicating the internal space with an external space of the tank body, a valve body accommodated in the through hole and movable along the axial direction of the through hole between an open position for opening the through hole and a closed position for closing the through hole, and a ring-shaped seal provided on an outer peripheral surface of the valve body. The outer peripheral surface of the valve body has, along the axial direction of the valve body, a groove portion in which the seal is disposed, and a thick shaft portion adjacent to the groove portion from the internal space side and having a larger diameter than the groove portion. When the position of the valve body when compression of the seal starts is defined as a compression start position during the course of movement of the valve body from the open position to the closed position, the length of the thick shaft portion is greater than the distance from the compression start position to the closed position. The length of the thick shaft portion here means the dimension from the proximal end of the thick shaft portion located proximal to the groove portion to the distal end of the thick shaft portion located distal to the groove portion.

[0006] When the valve body moves from the open position to the closed position, the ring-shaped seal is compressed between the inner peripheral surface of the through hole and the outer peripheral surface of the valve body. When the seal is compressed, a reaction force acts on the valve body from the seal over the entire circumference of the seal. Here, the frictional force generated between the outer peripheral surface of the seal and the inner peripheral surface of the through hole may be uneven along the circumferential direction of the seal. As a result, the seal is compressed at a certain portion in the circumferential direction of the seal and stretched at another portion. At the portion where the seal is compressed, the reaction force acting on the valve body from the seal is large. At the portion where the seal is stretched, the reaction force acting on the valve body from the seal is small. That is, the reaction force acting on the valve body from the seal may be uneven along the circumferential direction of the seal. When the reaction force of the seal becomes uneven, the valve body becomes eccentric with respect to the through hole. In this case, during the process in which the valve body moves further to the closed position, the distal end of the thick shaft portion may strongly contact the inner peripheral surface of the through hole, causing damage to the inner peripheral surface. In other words, the section in which the inner circumferential surface of the through hole may be damaged is the section through which the distal end of the thick shaft portion of the valve body passes while the valve body moves from the compression start position to the closed position.

[0007] Based on the above findings, in the technology disclosed in this specification, the length of the thick shaft portion is made longer than the distance from the compression start position to the closed position. With this configuration, the range in which the distal end of the thick shaft portion of the valve body moves and the range in which the seal moves do not overlap when the valve body moves from the compression start position to the closed position. Therefore, even if a scratch is formed on the inner circumferential surface of the through hole due to eccentricity of the valve body, it is possible to prevent the seal from coming into contact with the scratch. In other words, it is possible to prevent the seal from being damaged.

[0008] Details and further improvements of the technology disclosed in this specification are described in the following "Forms for Carrying Out the Invention". [Brief description of the drawings]

[0009] [Figure 1] 1 shows a cross-sectional view of a high-pressure tank 10 according to a first embodiment. [Diagram 2] 2 shows an enlarged view of the area within the dashed line II in FIG. [Diagram 3]1 shows an enlarged view similar to FIG. 2 of a high-pressure tank 10a according to a second embodiment. [Figure 4] A close-up view of a prior art high-pressure tank 100 is shown corresponding to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] In one embodiment of the present technology, the valve body may further include a second thick shaft portion adjacent to the groove portion from the external space side along the axial direction of the valve body and having the same diameter as the thick shaft portion. With this configuration, a step between the groove portion and the second thick shaft portion can prevent the seal compressed by the inner circumferential surface of the through hole from being pushed out toward the external space from the groove portion when the valve body moves from the compression start position to the closed position.

[0011] In one embodiment of the present technology, a distal end of the thick shaft portion located distal to the groove portion may be chamfered. With this configuration, when the valve body moves from the compression start position to the closed position, the chamfered surface interferes with the inner circumferential surface of the through hole. This makes it possible to prevent the inner circumferential surface of the through hole from being damaged.

[0012] In one embodiment of the present technology, the inner peripheral surface of the through hole may have, along the axial direction of the through hole, a first section having a first diameter and against which the seal abuts in the closed position, and a second section adjacent to the first section from the internal space side and having a diameter larger than the first diameter. In that case, when the valve body is in either the closed position or the compression start position, the distal end of the thick shaft portion located distal to the groove portion may face the second section of the through hole. According to this configuration, in the stroke in which the valve body is between the closed position and the compression start position, at least the distal end of the thick shaft portion of the valve body faces the second section having a diameter larger than the first diameter. As a result, in the stroke in which the valve body is between the closed position and the compression start position, the distance between the distal end of the thick shaft portion and the second section becomes large, so that it is possible to suppress contact between the distal end and the inner peripheral surface of the through hole. As a result, it is possible to suppress damage to the inner peripheral surface of the through hole.

[0013] In one embodiment of the present technology, an end of the first section located at the boundary between the first section and the second section may be chamfered. With this configuration, when the valve body moves between the compression start position and the closed position, the chamfered surface interferes with the outer circumferential surface of the thick shaft portion of the valve body. This makes it possible to prevent the outer circumferential surface of the thick shaft portion from being damaged.

[0014] (First embodiment) A high-pressure tank according to a first embodiment will be described with reference to the drawings. FIG. 1 shows a partial cross-sectional view of a high-pressure tank 10 according to a first embodiment. The high-pressure tank 10 includes a tank body 2, a nozzle 12, a valve body 13, and a seal 40. The high-pressure tank 10 is a tank that contains high-pressure hydrogen (i.e., a fluid), and is mounted, for example, on a fuel cell vehicle. The high-pressure tank 10 has a cylindrical shape that extends in the X-axis direction (i.e., the left-right direction on the paper surface of FIG. 1). FIG. 1 shows only one end of the high-pressure tank 10. In the following description, the tank body 2 side of the high-pressure tank 10 (i.e., the left side on the paper surface of FIG. 1) may be referred to as the "inside", and the opposite nozzle 12 side may be referred to as the "outside".

[0015] The tank body 2 includes a liner 4 and a reinforcing layer 6. The tank body 2 has a cylindrical shape extending in the X-axis direction (i.e., the left-right direction on the paper surface of FIG. 1). Both ends of the tank body 2 in the X-axis direction are bulged out like a dome. The liner 4 is a resin part that forms the internal space 3 that stores hydrogen. The reinforcing layer 6 is made of, for example, carbon fiber reinforced resin, and covers the liner 4 from the outside. This allows the tank body 2 to store high-pressure hydrogen in the internal space 3.

[0016] The nozzle 12 is provided at the end of the tank body 2 on the X-axis direction positive side (i.e., the right side of the paper in FIG. 1). The nozzle 12 includes a base portion 14 and a tubular portion 16. The X-axis direction positive side of the base portion 14 is covered by the liner 4 of the tank body 2. The tubular portion 16 protrudes outward from the reinforcing layer 6 of the tank body 2. The nozzle 12 has a through hole 20 that extends in the X-axis direction from the base portion 14 to the tubular portion 16. The through hole 20 communicates between the internal space 3 of the tank body 2 and the external space 5. The inner circumferential surface of the through hole 20 has a hole-side threaded section 21. The hole-side threaded section 21 is formed with a screw thread.

[0017] The valve body 13 is accommodated in the through hole 20. The valve body 13 includes a handle 8 and a valve rod 30. The outer circumferential surface of the valve rod 30 has a valve-side screw portion 31. The valve-side screw portion 31 is formed with a screw thread, which is screwed with the screw thread of the hole-side screw section 21. As a result, for example, when the handle 8 of the valve body 13 rotates in the direction of the arrow F1, the valve body 13 moves from the open position P1 toward the internal space 3. When the valve body 13 moves toward the internal space 3 and the end face 9 of the handle 8 on the internal space 3 side comes into contact with the end 18 of the tube part 16 of the nozzle 12 on the external space 5 side, the valve body 13 closes the through hole 20. On the other hand, when the handle 8 rotates in the opposite direction to the arrow F1, the valve body 13 moves from the closed position P2 where the through hole 20 is closed toward the open position P1. As a result, the through hole 20 is opened. In this manner, the valve body 13 moves along the direction of the axis A1 of the through hole 20 between the open position P1 and the closed position P2.

[0018] The seal 40 is an elastic ring-shaped member provided on the outer circumferential surface of the valve rod 30 of the valve body 13. The seal 40 is typically an O-ring made of silicone rubber. The seal 40 seals between the inner circumferential surface of the through hole 20 and the outer circumferential surface of the valve rod 30 by being compressed between the inner circumferential surface of the through hole 20 and the outer circumferential surface of the valve rod 30. The cross-sectional shape of the seal 40 is not limited to a circle. In a modified example, a square ring may be used for the seal 40 instead of the O-ring.

[0019] With reference to FIG. 2, the detailed structure of the through hole 20 of the cap 12 and the valve rod 30 of the valve body 13 will be described. FIG. 2 shows an enlarged view of the area surrounded by the dashed line II in FIG. 1. FIG. 2(A) shows the positional relationship between the through hole 20 and the valve rod 30 at the timing when the seal 40 of the valve body 13 starts to contact the inner circumferential surface of the through hole 20 during the process of the valve body 13 moving from the open position P1 to the closed position P2. That is, FIG. 2(A) shows the positional relationship between the through hole 20 and the valve rod 30 at the timing when the seal 40 starts to compress. In this specification, the position of the valve body 13 at which the seal 40 starts to compress during the process of the valve body 13 moving from the open position P1 to the closed position P2 is defined as the compression start position P3. That is, FIG. 2(A) shows the positional relationship between the through hole 20 and the valve rod 30 at the timing when the valve body 13 is located at the compression start position P3 during the process of the valve body 13 moving from the open position P1 to the closed position P2. On the other hand, Fig. 2(B) shows the positional relationship between the through hole 20 and the valve rod 30 at the timing when the valve disc 13 is located at the closed position P2. At the closed position P2 shown in Fig. 2(B), the seal 40 abuts against the seal compression section 25. Note that in Figs. 2(A) and 2(B), the axis A1 of the through hole 20 and the axis of the valve disc 13 are depicted as being coaxial.

[0020] The inner peripheral surface of the through hole 20 has, in addition to the hole-side threaded section 21, a large diameter section 22, a guide section 24, a first small diameter section 26, and a second small diameter section 28 along the direction of the axis A1. The large diameter section 22 is adjacent to the hole-side threaded section 21 from the internal space 3 side, and has approximately the same diameter as the hole-side threaded section 21. The guide section 24 is adjacent to the large diameter section 22 from the internal space 3 side, and has a curved surface that is inclined so as to approach the center of the through hole 20 toward the internal space 3 side. The first small diameter section 26 is adjacent to the guide section 24 from the internal space 3 side, and has a diameter D2 smaller than that of the large diameter section 22. The second small diameter section 28 is adjacent to the first small diameter section 26 from the internal space 3 side, and has the same diameter D2 as the first small diameter section 26.

[0021] The outer circumferential surface of the valve stem 30 of the valve body 13 has, in addition to the valve side thread portion 31, an outer thick shaft portion 32, a groove portion 34, an inner thick shaft portion 36, a chamfered portion 37, and a center shaft portion 38 along the direction of the axis A1. The outer thick shaft portion 32 is adjacent to the valve side thread portion 31 from the internal space 3 side and has a diameter D1 smaller than that of the valve side thread portion 31. The groove portion 34 is adjacent to the outer thick shaft portion 32 from the internal space 3 side and has a diameter smaller than the diameter D1 of the outer thick shaft portion 32. A seal 40 is disposed in the groove portion 34. The inner thick shaft portion 36 is adjacent to the groove portion 34 from the internal space 3 side and has a diameter D1 larger than that of the groove portion 34. The inner thick shaft portion 36 has a proximal end E1 located proximal to the groove portion 34 and a distal end E2 located distal to the groove portion 34. As shown in Figures 2(A) and 2(B), in this specification, the length L3 of the inner thick shaft portion 36 means the dimension from the proximal end E1 to the distal end E2.

[0022] The outer thick shaft portion 32 and the inner thick shaft portion 36 have the same diameter D1. Thus, the valve body 13 is adjacent to the groove portion 34 from the external space 5 side, and has the outer thick shaft portion 32 with the same diameter D1 as the inner thick shaft portion 36. That is, a step is formed at the boundary between the groove portion 34 and the outer thick shaft portion 32. This makes it possible to prevent the seal 40 compressed in the first small diameter section 26 of the through hole 20 from being pushed out of the groove portion 34 when the valve body 13 moves from the compression start position P3 toward the closing position P2. Similarly, the step at the boundary between the groove portion 34 and the inner thick shaft portion 36 makes it possible to prevent the seal 40 from being pushed out of the groove portion 34 when the valve body 13 moves from the closing position P2 toward the compression start position P3.

[0023] In addition, in this embodiment, when manufacturing the valve stem 30, the outer thick shaft portion 32 and the inner thick shaft portion 36 are processed simultaneously. This makes it possible to reduce the difference in outer diameter between the outer thick shaft portion 32 and the inner thick shaft portion 36, and also to reduce the deviation between the center of the outer thick shaft portion 32 and the center of the inner thick shaft portion 36.

[0024] In addition, the diameter D1 of the outer thick shaft portion 32 and the inner thick shaft portion 36 is set so that the gap between the outer peripheral surface of the outer thick shaft portion 32 and the inner thick shaft portion 36 and the inner peripheral surface of the first small diameter section 26 of the through hole 20 is minimized, taking into account the variation in the manufacturing process of the through hole 20 and the variation in the manufacturing process of the valve rod 30. This allows the seal 40 to approach the inner peripheral surface of the first small diameter section 26 without lowering the step between each of the thick shaft portions 32, 36 and the groove portion 34. This allows the seal 40 to reliably contact the inner peripheral surface of the first small diameter section 26. Furthermore, the amount by which the seal 40 protrudes from the outer peripheral surfaces of the outer thick shaft portion 32 and the inner thick shaft portion 36 can be reduced. Therefore, when the valve body 13 moves between the closed position P2 and the open position P1, the step between the groove portion 34 and the outer thick shaft portion 32 and the inner thick shaft portion 36 allows the seal 40 to be reliably accommodated in the groove portion 34.

[0025] As shown in the enlarged view at the top of FIG. 2(A), a chamfered portion 37 is formed at the distal end E2 of the inner thick shaft portion 36. The chamfered portion 37 is a so-called R chamfer. In a modified example, the chamfered portion 37 may be a C chamfer. The central shaft portion 38 is adjacent to the inner thick shaft portion 36 from the internal space 3 side and has a diameter smaller than the diameter D1 of the inner thick shaft portion 36. The central shaft portion 38 houses a temperature sensor and an introduction tube therein.

[0026] As shown by the arrow F2 in FIG. 2A, the valve body 13 moves further from the compression start position P3 toward the closed position P2. At this time, the outer peripheral surface of the seal 40 is compressed between the inner peripheral surface of the guide section 24. As a result, a reaction force acts on the valve rod 30 from the seal 40 over the entire circumference of the compressed seal 40. Here, the friction force generated between the outer peripheral surface of the seal 40, which rotates together with the valve rod 30 in the direction of the arrow F1, and the inner peripheral surface of the guide section 24 may be non-uniform along the circumferential direction of the seal 40. In addition, the seal 40 may have unavoidable manufacturing errors, such as the cross-sectional shape and the filling rate of the material. As a result, the seal 40 is compressed at some parts in the circumferential direction of the seal 40 and stretched at other parts. At the part where the seal 40 is compressed, the reaction force acting on the valve rod 30 from the seal 40 is large. At the part where the seal 40 is stretched, the reaction force acting on the valve rod 30 from the seal 40 is small. That is, the reaction force acting on the valve stem 30 from the seal 40 may be non-uniform along the circumferential direction of the seal 40. As a result, the valve stem 30 becomes eccentric with respect to the through hole 20.

[0027] Here, the prior art will be described with reference to FIG. 4. FIG. 4 shows an enlarged view of the high pressure tank 100 of the prior art, corresponding to FIG. 2. The high pressure tank 100 of the prior art has a cap 112 instead of the cap 12 of this embodiment. The high pressure tank 100 also has a valve stem 130 instead of the valve stem 30 of this embodiment, and a seal 140 instead of the seal 40. The cap 112 of the high pressure tank 100 has a through hole 120. The inner circumferential surface of the through hole 120 has a large diameter section 122, a guide section 124, and a first small diameter section 126 in addition to the hole side thread section 121. The hole side thread section 121 of the high pressure tank 100 of the prior art extends further inward than the hole side thread section 21 of the high pressure tank 10 of this embodiment. That is, in the high pressure tank 100 of the prior art, the valve stem 130 enters the inside of the through hole 120 more than in the high pressure tank 10 of this embodiment. Fig. 4(A) shows a conventional high-pressure tank 100 with the valve body positioned at the compression start position P3. Fig. 4(B) shows a conventional high-pressure tank 100 with the valve body positioned at the closed position P2.

[0028] The valve stem 130 of the high-pressure tank 100 has a valve-side threaded portion 131, an outer thick shaft portion 132, a groove portion 134, and an inner thin shaft portion 136. The outer thick shaft portion 132 has a diameter D1 smaller than that of the valve-side threaded portion 131. The groove portion 134 is adjacent to the outer thick shaft portion 132 from the inner space 3 side, and has a diameter smaller than the diameter D1 of the outer thick shaft portion 132. A seal 140 is disposed in the groove portion 134. As described above, when the valve stem 130 moves inward along the direction of the arrow F2, the step at the boundary between the groove portion 134 and the outer thick shaft portion 132 prevents the seal 140 from being pushed out of the groove portion 134.

[0029] 4, the inner end E10 of the outer thick shaft portion 132 is at a substantially right angle. This makes it possible to increase the flat area at the step at the boundary between the groove portion 134 and the outer thick shaft portion 132, compared to a configuration in which the inner end E10 of the outer thick shaft portion 132 is chamfered. This makes it possible to more reliably prevent the seal 140 from being pushed out of the groove portion 134.

[0030] In addition, the inner thin shaft portion 136 of the high pressure tank 100 is adjacent to the groove portion 134 from the inner space 3 side and has a diameter D4 smaller than that of the outer thick shaft portion 132. Therefore, the diameter D4 of the inner thin shaft portion 136 of the high pressure tank 100 is smaller than the diameter D1 of the inner thick shaft portion 36 of the high pressure tank 10 of the above-mentioned embodiment. As a result, the distance between the inner thin shaft portion 136 and the first small diameter section 126 is large. In the high pressure tank 100 of the conventional technology, for example, a gap of 1 mm or more is secured between the inner thin shaft portion 136 and the first small diameter section 126. As a result, even if the valve rod 130 is eccentric with respect to the through hole 120 when the inner thin shaft portion 136 passes through the first small diameter section 126, the tip of the inner thin shaft portion 136 is unlikely to interfere with the first small diameter section 126 of the through hole 120. Therefore, the high-pressure tank 100 of the conventional technology can prevent the inner circumferential surface of the first small diameter section 126 from being damaged.

[0031] However, if the diameter D4 of the inner thin shaft portion 136 is smaller than the diameter D1 of the outer thick shaft portion 132, a step occurs between the inner thin shaft portion 136 and the outer thick shaft portion 132. In other words, in the radial direction of the valve rod 130, the inner end E10 of the outer thick shaft portion 132 protrudes outward from the outer peripheral surface of the inner thin shaft portion 136. That is, the inner end E10 of the outer thick shaft portion 132 is closer to the inner peripheral surface of the first small diameter section 126 than the inner thin shaft portion 136. As described above, the inner end E10 of the outer thick shaft portion 132 is approximately at a right angle and is sharp. Therefore, when the valve rod 130 moves inward and becomes eccentric with respect to the through hole 120, as shown in FIG. 4(B), the inner end E10 of the outer thick shaft portion 132 damages the opposing section 127 that it has passed through, among the inner peripheral surface of the first small diameter section 126.

[0032] When the valve element of the high-pressure tank 100 of the conventional technology moves to the closed position P2, the high-pressure tank 100 is closed. As shown in FIG. 4(B), in the closed position P2, the seal 140 faces the seal compression section 125. The seal compression section 125 is located inside the facing section 127. That is, in the closed position P2, the seal 140 does not come into contact with the facing section 127. Therefore, any scratches made in the facing section 127 do not damage the seal 140.

[0033] However, for example, a case may be assumed in which the valve element of the high-pressure tank 100 of the conventional technology moves once to the compression start position P3 and then moves back to the closed position P2, or a case may be assumed in which the valve element of the high-pressure tank 100 of the conventional technology is replaced and a new valve element moves to the closed position P2. In these cases, the seal 140 is damaged when it passes through the opposing section 127 and moves to the seal compression section 125.

[0034] Conventionally, the eccentricity of the valve rod 130 was considered to be caused by the dimensional accuracy of each part, such as the variation in the manufacturing dimensions of the through hole 120, the variation in the manufacturing dimensions of the valve rod 130, or the variation in the manufacturing dimensions of the seal 140. However, the present inventors have investigated the relationship between the dimensional accuracy of each part and the occurrence of eccentricity of the valve rod 130. As a result, the present inventors have found that the main cause of the eccentricity of the valve rod 130 is not the dimensional accuracy of each part, but the change in the circumferential direction of the seal 140 caused by the friction force generated between the seal 140, which rotates together with the valve rod 130 in the direction of the arrow F1 (see FIG. 1), and the inner circumferential surface of the guide section 124. From this knowledge, the present inventors have considered that the occurrence of eccentricity of the valve rod 130 cannot be reduced to zero even if the dimensional accuracy of each of the above-mentioned parts is improved, and have sought a structure that can prevent the seal 140 from being damaged even if the valve rod 130 is eccentric.

[0035] Returning to FIG. 2(B), the structure of the high-pressure tank 10 of this embodiment will be described. When the valve rod 30 is eccentric with respect to the through hole 20, the chamfered portion 37 provided at the distal end E2 of the inner thick shaft portion 36 of the valve rod 30 on the inner space 3 side comes into contact with the second small diameter section 28 of the through hole 20. As a result, as shown in FIG. 2(B), the inner thick shaft portion 36 damages the opposing section 27 that faces the chamfered portion 37 among the inner circumferential surface of the second small diameter section 28. Similarly, when the valve body 13 moves from the closing position P2 to the compression start position P3, the chamfered portion 37 of the valve rod 30 comes into contact with the opposing section 27 of the through hole 20 and damages the opposing section 27. As shown in FIG. 2(B), the valve body 13 moves toward the inner space 3 by a distance L1 from the compression start position P3 to the closing position P2. Therefore, the length L2 of the facing section 27 where scratches occur is equal to the distance L1 from the compression start position P3 to the closing position P2.

[0036] As described with reference to FIG. 4, when the outer peripheral surface of the seal 40 is pressed against the scratch in the facing section 27, the seal 40 is damaged. As a result, the seal 40 may not be able to seal the through hole 20. In the high-pressure tank 10 of this embodiment, the length L3 of the inner thick shaft portion 36 is longer than the distance L1 from the compression start position P3 to the closing position P2. Therefore, in the high-pressure tank 10 of this embodiment, unlike the high-pressure tank 100 of the prior art, the seal compression section 25 is located outside the facing section 27. That is, the range in which the distal end E2 of the inner thick shaft portion 36 of the valve body 13 moves and the range in which the seal 40 moves do not overlap each other while the valve body 13 moves from the compression start position P3 to the closing position P2. Therefore, even if a scratch is formed in the facing section 27 on the inner peripheral surface of the through hole 20 due to eccentricity of the valve rod 30, the seal 40 can be prevented from coming into contact with the scratch. Therefore, the high-pressure tank 10 of this embodiment can suppress damage to the seal 40 caused by the scratch in the facing section 27.

[0037] Furthermore, in the high-pressure tank 10 of this embodiment, the distal end E2 of the inner thick shaft portion 36 is provided with a chamfered portion 37. Therefore, when the valve body 13 moves between the compression start position P3 and the closed position P2, the facing section 27 comes into contact with the chamfered portion 37. Therefore, compared to, for example, a configuration in which the non-chamfered distal end E2 and the facing section 27 come into contact with each other (see the valve rod 30a of the second embodiment), it is possible to suppress damage to the facing section 27.

[0038] (Second Example) A high-pressure tank 10a of the second embodiment will be described with reference to Fig. 3. The high-pressure tank 10a of the second embodiment has a through hole 20a instead of the through hole 20 of the first embodiment, and has a valve rod 30a instead of the valve rod 30 of the first embodiment. In other respects, the high-pressure tank 10a of the second embodiment has a similar structure to the high-pressure tank 10 of the first embodiment.

[0039] The through hole 20a of the high-pressure tank 10a of the second embodiment includes a chamfered section 27a and a second large diameter section 28a instead of the second small diameter section 28. The chamfered section 27a is provided at the end of the first small diameter section 26 located at the boundary between the first small diameter section 26 and the second large diameter section 28a. The chamfered section 27a is a so-called R chamfer. In a modified example, the chamfered section 27a may be a C chamfer. The second large diameter section 28a is adjacent to the first small diameter section 26 from the internal space 3 side and has a diameter D3 larger than the diameter D2 of the first small diameter section 26.

[0040] The valve stem 30a of the second embodiment differs from the valve stem 30 of the first embodiment in that it does not have a chamfered portion 37. Therefore, the distal end E2 of the inner thick shaft portion 36 forms a right angle.

[0041] Like the high-pressure tank 10 of the first embodiment, the high-pressure tank 10a of the second embodiment also has a length L3 of the inner thick shaft portion 36 (i.e., the dimension from the proximal end E1 to the distal end E2 of the inner thick shaft portion 36) longer than the distance L1 from the compression start position P3 to the closed position P2. Furthermore, the high-pressure tank 10a of the second embodiment includes, in addition to the first small diameter section 26 in which the seal compression section 25 with which the seal 40 abuts at the closed position P2 is provided, a second large diameter section 28a adjacent to the first small diameter section 26 from the internal space 3 side and having a diameter D3 larger than the diameter D2 of the first small diameter section 26. In the high-pressure tank 10a of this embodiment, the seal compression section 25 is located outside the second large diameter section 28a.

[0042] 3(A) and 3(B), even when the valve stem 30 of the valve body 13 is in either the closed position P2 or the compression start position P3, the distal end E2 of the inner thick shaft portion 36 of the valve body 13 faces the second large diameter section 28a. That is, the distal end E2 of the inner thick shaft portion 36 does not face the first small diameter section 26 from when the compression of the seal 40 starts until the valve body 13 moves to the closed position P2. Therefore, the distal end E2 of the inner thick shaft portion 36 can be prevented from damaging the first small diameter section 26 due to the reaction force of the seal 40. Furthermore, by increasing the distance between the distal end E2 of the inner thick shaft portion 36 and the second large diameter section 28a, the distal end E2 of the inner thick shaft portion 36 can be prevented from damaging the second large diameter section 28a.

[0043] As described above, the chamfered section 27a is formed at the end of the first small diameter section 26 on the side of the internal space 3. Therefore, compared to a configuration in which the end of the first small diameter section 26 on the side of the internal space 3 forms a right angle, it is possible to prevent the chamfered section 27a from damaging the outer circumferential surface of the inner thick shaft portion 36.

[0044] Although specific examples of the technology disclosed in this specification have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. Modifications of the above embodiments are listed below.

[0045] (Variation 1) The fluid contained in the internal space 3 of the high-pressure tank 10 is not limited to high-pressure hydrogen, but may be, for example, nitrogen gas, oxygen gas, liquid oxygen, or liquid nitrogen.

[0046] (Modification 2) The valve stem 30 of the valve body 13 of the first embodiment may not have the outer thick shaft portion 32. In a further modification, the inner thick shaft portion 36 and the outer thick shaft portion 32 may have different diameters.

[0047] (Modification 3) The valve stem 30 of the valve body 13 of the first embodiment does not have to have the central stem portion 38. In that case, the inner thick stem portion 36 may extend further toward the internal space 3.

[0048] (Modification 4) The valve stem 30 a of the valve body 13 of the second embodiment may have a chamfered portion 37 .

[0049] (Modification 5) The through hole 20a of the base 12 of the second embodiment does not have to have the chamfered section 27a.

[0050] The technical elements described in this specification or drawings have technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0051] 2: tank body, 3: internal space, 4: liner, 5: external space, 6: reinforcing layer, 8: handle, 9: end face, 10, 10a, 100: high pressure tank, 12, 112: nozzle, 13: valve body, 14: base portion, 16: cylinder portion, 18: end portion, 20, 20a, 120: through hole, 21: hole side screw section, 121, 22: large diameter section, 24, 124: guide section, 25, 125: seal compression section, 26, 126: first small diameter section, 27, 127: opposing section, 2 7a: chamfered section, 28: second small diameter section, 28a: second large diameter section, 30, 30a, 130: valve stem, 31: valve side screw portion, 131, 32, 132: outer thick shaft portion, 34, 134: groove portion, 36: inner thick shaft portion, 37: chamfered portion, 38: center shaft portion, 40, 140: seal, 136: inner thin shaft portion, A1: shaft, D1, D2, D3, D4: diameter, E1: proximal end, E2: distal end, P1: open position, P2: closed position, P3: compression start position

Claims

1. A high-pressure tank, A tank body having an internal space for containing a fluid; a nozzle provided on the tank body and having a through hole communicating the internal space with an external space of the tank body; a valve body that is accommodated in the through hole and that is movable along an axial direction of the through hole between an open position that opens the through hole and a closed position that closes the through hole; A ring-shaped seal provided on an outer circumferential surface of the valve body; Equipped with The outer circumferential surface of the valve body is, along the axial direction of the valve body, a groove portion in which the seal is disposed; a thick shaft portion adjacent to the groove portion from the internal space side and having a larger diameter than the groove portion; having When a position of the valve body when compression of the seal starts during a stroke of the valve body moving from the open position to the closed position is defined as a compression start position, a length of the thick shaft portion is greater than a distance from the compression start position to the closed position, an inner circumferential surface of the through hole has, along the axial direction of the through hole, a first section having a first diameter and against which the seal abuts in the closed position, and a second section adjacent to the first section from the internal space side and having a diameter larger than the first diameter; When the valve body is in either the closed position or the compression start position, a distal end of the thick shaft portion located distal to the groove portion faces the second section of the through hole. High pressure tank.

2. The outer circumferential surface of the valve body further includes a second thick shaft portion adjacent to the groove portion from the external space side along the axial direction of the valve body and having the same diameter as the thick shaft portion.

2. The high pressure tank according to claim 1.

3. The high pressure tank according to claim 1 , wherein a distal end of the thick shaft portion distal to the groove portion is chamfered.

4. 2. The high pressure tank according to claim 1, wherein an end of the first section located at the boundary between the first section and the second section is chamfered.

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