Seal structure and seal-up ring

Abstract

To provide a sealing structure and seal-up ring that can ensure sealing performance even when the O-ring deteriorates due to external environmental influences. [Solution] The seal structure 1 comprises a fitting 3 through which gas flows, a ring-shaped groove 21 provided on the outer circumference 25 of the fitting 3 along the circumferential direction of the fitting 3, an inlet pipe 5 provided around the outer circumference 25 of the fitting 3 through which gas flows toward the fitting 3, and O-rings 27 and 29 provided in the groove 21 in the axial direction of the fitting 3 when compressed, which contact the inner circumference 24 of the inlet pipe 5 with the repulsive force against compression to prevent gas from leaking to the outside from between the outer circumference 25 of the fitting 3 and the inner circumference 24 of the inlet pipe 5. The seal structure 1 further comprises a ring-shaped seal-up ring 31 provided between the O-rings 27 and 29 in the groove 21 and which can slide within the groove 21 in the axial direction of the fitting 3 due to the pressure of the gas.

Description

Technical Field

[0001] The present invention relates to a sealing structure and a sealing up-ring.

Background Art

[0002] In a high-pressure hose connected to a gas container through which gas flows in, when the high-pressure hose is pulled due to the gas container tipping over or the like and a tension greater than a certain level is generated, there is a device equipped with a gas release prevention mechanism that blocks the flow path between the gas container and the high-pressure hose so that gas is not released to the outside. For example, Patent Document 1 discloses a structure as a gas release prevention mechanism, which includes a tubular nipple body and a tubular slide body that is slidably attached inside the tube of the nipple body. In a state where a tension greater than a certain level is not applied to the high-pressure hose, the inside of the tube of the nipple body and the inside of the tube of the slide body are in communication, and gas flows between the inside of the tube of the nipple body and the inside of the slide tube. On the other hand, when a tension greater than a certain level is applied to the high-pressure hose, the slide body slides due to the tension, and the inside of the tube of the nipple body and the inside of the tube of the slide body become non-communicating, and gas stops flowing. In this structure, two O-rings are fitted between the nipple body and the slide body so that gas does not leak from the gap between the inner peripheral wall surface of the nipple body and the outer peripheral wall surface of the slide body, and the gap is sealed by the repulsive force of the fitted O-rings (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since O-rings like the one in Patent Document 1 are usually made of rubber, when immersed in gas, additives in the rubber may leach out, reducing the mass and potentially decreasing the wire diameter, weakening the repulsive force, and thus reducing the sealing performance. Furthermore, even in low-temperature environments, the hardness of the O-ring may increase, weakening the repulsive force and potentially reducing the sealing performance. Thus, with the configuration in Patent Document 1, there was a possibility that the sealing performance would decrease if the O-ring deteriorated due to the influence of the external environment.

[0005] The present invention was made to solve these problems, and its objective is to provide a sealing structure and a seal-up ring that can ensure sealing performance even when the O-ring deteriorates due to the influence of the external environment. [Means for solving the problem]

[0006] The seal structure of the present invention comprises an inner cylinder through which a fluid flows, an annular groove provided on the outer circumference of the inner cylinder along the circumferential direction of the inner cylinder, an outer cylinder having a portion provided around the outer circumference of the inner cylinder and through which the fluid flows toward the inner cylinder, and two O-rings provided in the groove in a compressed state, aligned in the axial direction of the inner cylinder, and contacting the inner circumference of the outer cylinder by the repulsive force against compression to prevent the fluid from leaking to the outside from between the outer circumference of the inner cylinder and the inner circumference of the outer cylinder, wherein the seal structure comprises a ring-shaped seal-up ring provided between the two O-rings in the groove and capable of sliding within the groove in the axial direction of the inner cylinder by the pressure of the fluid.

[0007] The seal-up ring of the present invention is a ring-shaped member provided between the two O-rings in the groove of a seal structure comprising: an inner cylinder through which a fluid flows; an annular groove provided on the outer circumference of the inner cylinder along the circumferential direction of the inner cylinder; an outer cylinder having a portion provided around the outer circumference of the inner cylinder, through which the fluid flows toward the inner cylinder; and two O-rings provided in the groove in the axial direction of the inner cylinder when compressed, which contact the inner circumference of the outer cylinder due to the repulsive force against compression, thereby preventing the fluid from leaking to the outside from between the outer circumference of the inner cylinder and the inner circumference of the outer cylinder. The seal-up ring is provided between the two O-rings in the groove and is a ring-shaped member that can slide within the groove in the axial direction of the inner cylinder due to the pressure of the fluid. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a sealing structure and a seal-up ring that can ensure sealing performance even when the O-ring deteriorates due to the influence of the external environment. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view showing a high-pressure hose equipped with a sealing structure having a seal-up ring according to an embodiment of the present invention. [Figure 2] Figure 1 is an enlarged view of the fitting and inlet pipe, where (a) shows the state in which gas is flowing between the fitting and the inlet pipe, and (b) shows the state in which a tension greater than or equal to a predetermined value is applied to the hose from the state shown in (a). [Figure 3] This is an enlarged view of the vicinity of the O-ring in Figure 2(a). [Figure 4] Figure 2(a) is an enlarged cross-sectional view of the seal-up ring. [Figure 5] The images show enlarged cross-sectional views corresponding to Figure 3, where (a) shows the O-ring contracted from the state shown in Figure 3, and (b) and (c) show the state in which the seal-up ring is pressing against the O-ring. [Modes for carrying out the invention]

[0010] The present invention will be described below in accordance with preferred embodiments. It should be noted that the present invention is not limited to the embodiments shown below, and can be modified as appropriate without departing from the spirit of the invention. Furthermore, in the embodiments shown below, some illustrations and descriptions of certain components are omitted. It goes without saying that, regarding the details of the omitted technologies, publicly known or well-known technologies are applied as appropriate, to the extent that they do not contradict the content described below.

[0011] First, with reference to Figures 1 and 2, the configuration of a high-pressure hose equipped with a seal structure having a seal-up ring according to this embodiment will be described. Figure 1 is an axial cross-sectional view showing a high-pressure hose equipped with a seal structure having a seal-up ring according to an embodiment of the present invention. Figure 2 is an enlarged view of the joint and inlet pipe in Figure 1, where (a) shows a state in which gas is flowing between the joint and the inlet pipe, and (b) shows a state in which a tension of a predetermined value or more is applied to the hose from the state shown in (a).

[0012] The high-pressure hose 100 shown in Figure 1 is a gas-release prevention type high-pressure hose and comprises a fitting 3 (inner cylinder), a hose 13, a fastener 11, an inlet pipe 5 (outer cylinder), a handle 7, and an end nut 9. The fitting 3 is a cylindrical member through which gas flows as a fluid and is connected to the hose 13. The inside of the fitting 3 is the fitting-side flow path 3a through which the gas flows. One end 41 of the fitting 3 is open, and the outer circumference near the end 41 has a corrugated axial cross-sectional shape and constitutes a connection part 12 that is inserted into the pipe of the hose 13. The other end 43 of the fitting 3 is closed, but as shown in Figure 2(a), there are communication holes 23a and 23b near the other end 43 that connect the outer circumference of the fitting-side flow path 3a (the inner circumference of the fitting 3) and the outer circumference of the fitting 3 in the radial direction of the fitting 3, and these are provided as gas flow paths. Furthermore, a C-ring 15 is fitted around the outer circumference of the fitting 3 along the circumferential direction. The hose 13 is a pipe through which gas flows, and is made of a flexible material. The connecting portion 12 of the fitting 3 is inserted into one end, and a connecting fitting (not shown) is provided at the other end for connection to other equipment such as a regulator (not shown). The fastener 11 is a fastener that prevents the hose 13 from coming out of the fitting 3. It covers the outer circumference of the portion of the hose 13 into which the fitting 3 is inserted, and fastens the hose 13 toward the fitting 3.

[0013] The inlet pipe 5 is a cylindrical member through which gas flows toward the fitting 3, and is connected to a gas container (not shown), such as an LP gas cylinder. As shown in Figure 2(a), the hollow section 6 inside the inlet pipe 5 is the passage through which the gas flows. The hollow section 6 has an opposing section 6a, an enlarged diameter section 6b, a central section 6c, and a connecting section 6d. The opposing section 6a is one end of the hollow section 6 and is the part that connects to the fitting 3, and has a diameter slightly larger than the outer diameter of the fitting 3. The enlarged diameter section 6b is the part connected to the upstream end of the opposing section 6a and has a larger diameter than the opposing section 6a. The central section 6c is the part connected to the upstream end of the enlarged diameter section 6b. The connecting section 6d is the other end of the hollow section 6 and is connected to the upstream end of the central section 6c, and is connected to a gas container, etc. The handle 7 shown in Figure 1 is the part that workers or others use to hold when connecting the high-pressure hose 100 to a gas container, and is an annular member provided around the outer circumference of the inlet pipe 5. The end nut 9 is a nut that holds the fitting 3, and is provided around the outer circumference of the fitting 3 and the inlet pipe 5, and screws into the inlet pipe 5, and holds the fitting 3 by contacting the outer circumference of the C ring 15.

[0014] As shown in Figure 2(a), the high-pressure hose 100 has a tip portion 5a (part) of the inlet pipe 5, which is the portion where the opposing portion 6a is provided, located around the outer circumference of the fitting 3, and the fitting 3 is movable in a direction C parallel to the axial direction relative to the inlet pipe 5. In this configuration, when the high-pressure hose 100 is in normal use with gas flowing through it, the axial position of the fitting 3 relative to the inlet pipe 5 is maintained such that the communication holes 23a and 23b are exposed within the enlarged diameter portion 6b. In this state, the gas supplied from the gas container to the high-pressure hose 100 flows from the connection portion 6d through the central portion 6c to the enlarged diameter portion 6b, as shown by arrow A. The gas that has flowed into the enlarged diameter portion 6b then flows into the hose 13 (see Figure 1) via the communication holes 23a and 23b and the fitting-side flow path 3a, as shown by arrow B. The gas that has flowed into the hose 13 is supplied to downstream gas equipment (not shown) via regulators, gas meters, etc. (not shown). In this way, the high-pressure hose 100, when in normal use, can supply gas from the upstream gas container to the downstream side via the inlet pipe 5 and fitting 3.

[0015] On the other hand, if the gas container tips over and a tension exceeding a predetermined value is applied to the hose 13, the tension causes the joint 3 to move in the direction of C relative to the inlet pipe 5. As shown in Figure 2(b), when the joint 3 moves to a position where the communication holes 23a and 23b face the inner circumference 24 of the tip 5a, the inner circumference 24 of the tip 5a closes the communication holes 23a and 23b. In this state, gas cannot flow between the enlarged diameter portion 6b and the communication holes 23a and 23b, so gas cannot flow between the joint 3 and the inlet pipe 5. In this way, the high-pressure hose 100 stops gas flowing when a tension exceeding a predetermined value is applied to the hose 13. Therefore, even if the gas container tips over and the hose 13 is pulled, it is possible to prevent gas from being released from the high-pressure hose 100. The "predetermined value" of the tension that causes the joint 3 to move, that is, the operating force of the gas release prevention mechanism, can be adjusted, for example, by reducing the outer diameter of the C-ring 15. The reason is that when fitting 3 moves, it is necessary to deform the outer diameter of C-ring 15 to a smaller size. This concludes the explanation of the configuration of the high-pressure hose 100.

[0016] Next, the configuration of the seal structure having a seal-up ring according to this embodiment will be described with reference to Figures 2 to 5. Figure 3 is an enlarged view of the vicinity of the O-ring in Figure 2(a). Figure 4 is an enlarged cross-sectional view of the seal-up ring in Figure 2(a). Figure 5 is an enlarged cross-sectional view corresponding to Figure 3, where (a) shows the case when the O-ring has contracted from the state in Figure 3, and (b) and (c) show the state when the seal-up ring is pressing against the O-ring.

[0017] As shown in Figures 2(a) and 2(b), the high-pressure hose 100 has a structure in which the fitting 3 is movable relative to the inlet pipe 5 in the direction C. Therefore, it is equipped with a sealing structure 1 which is a structure that seals to prevent gas leakage from between the outer circumference 25 of the fitting 3 and the inner circumference 24 of the tip portion 5a of the inlet pipe 5, as shown in Figure 3. As shown in Figure 3, the sealing structure 1 comprises the fitting 3, the groove portion 21, the inlet pipe 5, O-rings 27 and 29, and the seal-up ring 31.

[0018] The fitting 3 is an inner cylinder through which gas flows. The groove 21 is an annular groove provided on the outer circumference 25 of the fitting 3, along the circumferential direction of the fitting 3. The inlet pipe 5 is an outer cylinder with a tip 5a, which is the part provided around the outer circumference 25 of the fitting 3, through which gas flows toward the fitting 3. The O-rings 27 and 29 are sealing members that prevent fluids such as gas from leaking from the fitting 3 to the outside of the inlet pipe 5 through the gap between the outer circumference 25 of the fitting 3 and the inner circumference 24 of the tip 5a of the inlet pipe 5, and are made of an elastic material such as rubber. The wire diameter of the O-rings 27 and 29 is thicker than the radial distance H1 between the bottom 21a of the groove 21 and the inner circumference 24 of the tip 5a of the inlet pipe 5. Therefore, the O-rings 27 and 29 are provided in the groove 21 in a compressed state so that the radial thickness of the fitting 3 and the inlet pipe 5 is approximately the same as the radial distance H1. The O-rings 27 and 29 provided in the groove 21 attempt to return to their original shape in response to compression, but because their wire diameter is greater than the radial distance H1, they cannot return to their original shape. Therefore, the O-rings 27 and 29, due to their repulsive force against compression, come into contact with the inner circumference 24 of the tip 5a of the inlet pipe 5, pressing the inner circumference 24 in the direction of F1, and come into contact with the bottom 21a of the groove 21, pressing the bottom 21a in the direction of F2. As a result, the O-rings 27 and 29 seal the space between the outer circumference 25 of the joint 3 and the inner circumference 24 of the tip 5a of the inlet pipe 5, preventing gas from leaking to the outside.

[0019] The O-rings 27 and 29 are provided in the groove 21, side by side in the axial direction of the joint 3. Figure 3 shows an example in which O-ring 27 is provided on the upstream side in the direction of gas flow, and O-ring 29 is provided on the downstream side in the direction of gas flow. By arranging the two O-rings 27 and 29 side by side in the direction of gas flow in this way, there are two sealing points, thus improving the sealing performance. Furthermore, even if one of the O-rings 27 or 29 cannot seal the space between the outer circumference 25 of the joint 3 and the inner circumference 24 of the tip 5a of the inlet pipe 5, the sealing performance can be ensured if the other can seal, thus providing redundancy in the sealing performance. Here, sealing performance refers to the ability to prevent gas from leaking to the outside from the space between the outer circumference 25 of the joint 3 and the inner circumference 24 of the tip 5a of the inlet pipe 5. The same applies to the following explanation.

[0020] The seal-up ring 31 is a component for ensuring the sealing performance of the sealing structure 1 when the O-rings 27, 29, especially the O-ring 27, deteriorate. It is a ring-shaped component provided around the outer circumference of the groove portion 21 and between the O-ring 27 and the O-ring 29. Different from the O-rings 27, 29, the seal-up ring 31 does not have the function of sealing between the outer circumference 25 of the joint 3 and the inner circumference 24 of the tip portion 5a of the inlet pipe 5, and can slide axially (in the direction of G) within the groove portion 21 under the pressure of the fluid. Specifically, the inner diameter D1 of the seal-up ring 31 shown in FIG. 4 is slightly larger than the outer diameter of the bottom 21a of the groove. Also, the radial thickness D2 of the seal-up ring 31 is smaller than the radial distance H1 between the bottom 21a of the groove portion 21 shown in FIG. 3 and the inner circumference 24 of the tip portion 5a of the inlet pipe 5. Therefore, the seal-up ring 31 can move axially with respect to the joint 3 which is the inner cylinder.

[0021] For example, assume that the O-ring 27 is immersed in the gas flowing through the high-pressure hose 100 and deteriorates, the additives in the rubber flow out and the mass decreases and shrinks, so that the wire diameter becomes thinner, and as shown in FIG. 5(a), the radial thickness T of the joint 3 becomes smaller than the radial distance H1. In this case, the O-ring 27 cannot contact the inner circumference 24 of the tip portion 5a of the inlet pipe 5, so the sealing performance is lost. When the O-ring 27 loses the sealing performance, the O-ring 29 is also immersed in the gas, so it may deteriorate, the additives in the rubber flow out, the mass decreases and shrinks, and the wire diameter becomes thinner, and there is a possibility of losing the sealing performance. Also, when the hardness of the O-rings 27, 29 increases in a low-temperature environment and the repulsive force against press-fitting becomes weak, they may also deteriorate and there is a possibility of losing the sealing performance.

[0022] If the O-ring 27 deteriorates and loses its sealing ability, the gas flowing through the high-pressure hose 100 flows between the O-ring 27 and the inlet pipe 5, pressing the seal-up ring 31 in the direction G, parallel to the axial direction of the joint 3, as shown by the white arrow in Figure 5(b). Since the seal-up ring 31 can move in the axial direction of the joint 3, when pressed by the gas, it moves in the direction G due to the gas pressure, pressing the O-ring 29 in the axial direction of the joint 3. The pressed O-ring 29 is compressed in the axial direction of the joint 3, increasing its compression ratio and increasing its repulsive force. Due to this repulsive force, the O-ring 29 comes into contact with the inner circumference 24 of the tip 5a of the inlet pipe 5, pressing in the direction J, as shown in Figure 5(c), and further comes into contact with the downstream wall surface 21b of the groove 21, pressing in the direction K. As a result, the O-ring 29 seals the space between the outer circumference 25 of the fitting 3 and the inner circumference 24 of the tip 5a of the inlet pipe 5, preventing gas from leaking to the outside. Note that the direction of G is the direction in which the gas flows from upstream to downstream in the high-pressure hose 100.

[0023] In this seal structure 1, when the O-ring 27 deteriorates, the seal-up ring 31 is pressed by the fluid and slides, pressing against the downstream O-ring 29 to increase the compression ratio, and pressing against the inlet pipe 5 and the wall surface 21b of the groove 21 to ensure sealing performance. Therefore, sealing performance can be ensured even if the O-rings 27 and 29 deteriorate.

[0024] Furthermore, in seal structure 1, a seal-up ring 31 is provided between O-ring 27 and O-ring 29. Therefore, when the sealing performance of O-ring 27 is ensured, O-ring 27 prevents fluid from flowing towards the seal-up ring 31. Thus, as long as O-ring 27 does not deteriorate, the seal-up ring 31 does not press against O-ring 29, which is advantageous because there is no risk of the seal-up ring 31 constantly pressing against O-ring 29 and accelerating its deterioration.

[0025] The material of the seal-up ring 31 is preferably one that does not damage the inner circumference 24 of the tip portion 5a, which is the sealing surface, and is preferably made of resin. The shape of the seal-up ring 31 is not particularly limited as long as it can be pressed by the fluid to press the downstream O-ring 29 and increase the compression ratio, but as shown in Figures 3 and 4, it is preferable that the cross-sectional shape horizontal in the axial direction is trapezoidal. Specifically, it is preferable that the lower base 31a of the trapezoid of the seal-up ring 31 is in contact with the bottom 21a of the groove portion 21, and the trapezoidal side 31b facing the downstream O-ring 29 is inclined from the upper end 21c of the groove portion 21 toward the bottom 21a, approaching the downstream O-ring 29. In this configuration, as shown in Figure 5(c), the downstream tip of the side 31b of the seal-up ring 31 is pressed against the O-ring 29 so that it bites into the gap 29a between the O-ring 29 and the bottom 21a of the groove 21, thereby pressing against the inner circumference 24 of the inlet pipe 5 and the wall surface 21b of the groove 21. As a result, it becomes less likely for a gap to form between the downstream O-ring 29 and the wall surface 21b of the groove 21 and the inner circumference 24 of the inlet pipe 5, thus ensuring a more reliable seal. The above is a description of the configuration of the seal structure 1 having the seal-up ring 31 according to this embodiment.

[0026] As described above, the seal structure 1 according to this embodiment comprises a joint 3, a groove 21, an inlet pipe 5, O-rings 27 and 29 provided in the groove 21, and a seal-up ring 31 provided between the O-rings 27 and 29 in the groove 21 and slidable within the groove 21. In this configuration, when the O-ring 27 deteriorates, the seal-up ring 31 is pressed by the fluid and slides, pressing the downstream O-ring 29 to increase the compression ratio, thereby pressing the inner circumference 24 of the inlet pipe 5 and the wall surface 21b of the groove 21 to ensure sealing performance. Therefore, the seal structure 1 can ensure sealing performance even when the O-rings 27 and 29 deteriorate.

[0027] Furthermore, the seal-up ring 31 of the seal structure 1 according to this embodiment has a trapezoidal cross-sectional shape, with the lower base 31a of the trapezoid in contact with the bottom 21a of the groove 21, and the side 31b facing the O-ring 29 inclined toward the O-ring 29 from the upper end 21c of the groove 21 toward the bottom 21a. In this configuration, the downstream tip of the inclined side 31b of the seal-up ring 31 presses the O-ring 29 so as to bite into the gap 29a between the O-ring 29 and the bottom 21a of the groove 21, thereby pressing the inner circumference 24 of the inlet pipe 5 and the wall surface 21b of the groove 21. As a result, it becomes less likely for a gap to form between the downstream O-ring 29 and the wall surface 21b of the groove 21 and the inner circumference 24 of the inlet pipe 5, and a more reliable seal can be achieved.

[0028] Although the present invention has been described above based on embodiments, the present invention is not limited to the above embodiments, and modifications may be made without departing from the spirit of the invention, and other technologies may be combined as appropriate to the extent possible. Furthermore, publicly known or well-known technologies may be combined as appropriate to the extent possible.

[0029] For example, in the embodiment described above, the seal structure 1 is provided on the high-pressure hose 100. However, the seal structure 1 can also be provided on other parts or devices besides the high-pressure hose 100, as long as it is necessary to prevent gas from leaking to the outside from between the outer circumference of the inner cylinder and the inner circumference of the outer cylinder. [Explanation of symbols]

[0030] 1: Seal structure 3: Fitting (inner cylinder) 5: Inlet pipe (outer cylinder) 5a:Tip (part) 21: Groove 21a: bottom 21c: Upper end 24: Inner circumference 25: Perimeter 27, 29: O-ring 31: Seal-up ring 31a: Bottom bottom 31b: edge

Claims

1. A seal structure comprising: an inner cylinder through which a fluid flows; an annular groove provided on the outer circumference of the inner cylinder along the circumferential direction of the inner cylinder; an outer cylinder having a portion provided around the outer circumference of the inner cylinder, through which the fluid flows toward the inner cylinder; and two O-rings provided in the groove in a compressed state, aligned in the axial direction of the inner cylinder, which contact the inner circumference of the outer cylinder due to the repulsive force against compression, thereby preventing the fluid from leaking to the outside from between the outer circumference of the inner cylinder and the inner circumference of the outer cylinder, A seal structure characterized by comprising a ring-shaped seal-up ring provided between the two O-rings in the groove, which is capable of sliding within the groove in the axial direction of the inner cylinder by the pressure of the fluid.

2. The aforementioned seal-up ring is The cross-sectional shape horizontal in the axial direction is trapezoidal, the lower base of the trapezoid is in contact with the bottom of the groove, and the side of the trapezoid facing the downstream O-ring in the direction of fluid flow is inclined from the upper end of the groove toward the bottom toward the downstream O-ring. The seal structure according to claim 1, characterized in that

3. A seal structure comprising: an inner cylinder through which fluid flows; an annular groove provided on the outer circumference of the inner cylinder along the circumferential direction of the inner cylinder; an outer cylinder having a portion provided around the outer circumference of the inner cylinder, through which the fluid flows toward the inner cylinder; and two O-rings provided in the groove in the axial direction of the inner cylinder when compressed, which contact the inner circumference of the outer cylinder due to the repulsive force against compression, thereby preventing the fluid from leaking to the outside from between the outer circumference of the inner cylinder and the inner circumference of the outer cylinder; wherein a ring-shaped member is provided between the two O-rings in the groove and is capable of sliding within the groove in the axial direction of the inner cylinder due to the pressure of the fluid. A seal-up ring characterized by the following features.

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