Movable pathway

Abstract

To provide a movable passage in which a sealing member for sealing a gap between an outer passage and an inner passage can be hardly worn.SOLUTION: In an elongated state where an overhanging amount L1 of a tip passage 30 (an inner passage) with respect to a fixed passage 20 (an outer passage) is increased, a gap between an inner peripheral surface of the fixed passage 20 and an outer peripheral surface of the tip passage 30 is sealed by expanding a sealing member 50 by a supply / discharge part 70. The sealing state between the fixed passage 20 and the tip passage 30 is released by contracting the expanded sealing member 50 by the supply / discharge part 70. By releasing the sealing state with the sealing member 50 when the tip passage 30 is longitudinally moved with respect to the fixed passage 20, it is possible to prevent the fixed passage 20 or the tip passage 30 and the sealing member 50 from rubbing against each other, thereby inhibiting wear of the sealing member 50.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a movable passage in which an inner passage is inserted into an outer passage, and particularly to a movable passage capable of making a seal member that seals between the outer passage and the inner passage less prone to wear. [Background Art]

[0002] For example, some movable passages installed on station platforms are expandable and contractible by changing the amount of protrusion of a cylindrical inner passage in the front-rear direction relative to a cylindrical outer passage (Patent Document 1). This movable passage is brought into an extended state by protruding the inner passage in the front-rear direction relative to the outer passage, and is brought into a shortened state by retracting the inner passage into the outer passage. The extended movable passage is connected to the entrance / exit of a vehicle stopped at the platform, and passengers get on and off between the platform and the vehicle through the movable passage. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 04-325365 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Outside the extended movable passage connecting a stopped vehicle and a platform, atmospheric pressure may change due to factors such as another vehicle passing through the station. Therefore, in order to suppress the propagation of this atmospheric pressure change from the outside to the inside of the movable passage, it is conceivable to seal between the outer passage and the inner passage. In addition, for example, movable passages connecting buildings are similarly required to seal between the outer passage and the inner passage to ensure airtightness.

[0005] However, if the seal member is sandwiched in the radial direction between the inner peripheral surface of the outer passage and the outer peripheral surface of the inner passage, the seal member will rub when changing the amount of protrusion of the inner passage relative to the outer passage, which may make the seal member more prone to wear.

[0006] The present invention was made to solve the above-mentioned problems, and aims to provide a movable passage that can reduce wear on the sealing member that seals the space between the outer passage and the inner passage. [Means for solving the problem]

[0007] To achieve this objective, the movable passage of the present invention is a movable passage that expands and contracts in the front-rear direction by switching between an extended state and a shortened state which is shortened relative to the extended state, comprising: a cylindrical outer passage extending in the front-rear direction; a cylindrical inner passage inserted inside the outer passage and moving relative to the outer passage in the front-rear direction; a drive mechanism that switches from the shortened state to the extended state by increasing the amount of protrusion of the inner passage relative to the outer passage due to the relative movement; an annular sealing member disposed around the entire circumference between the outer circumferential surface of the inner passage and the inner circumferential surface of the outer passage and which is expandable or contractible at least in the radial direction; a supply unit that expands the sealing member by supplying fluid to the sealing member; and a discharge unit that contracts the sealing member by discharging fluid from the sealing member, wherein in the extended state, the space between the outer circumferential surface of the inner passage and the inner circumferential surface of the outer passage is sealed by the sealing member expanded by the supply unit, and the seal between the inner passage and the outer passage is released by contracting the expanding sealing member by the discharge unit. [Effects of the Invention]

[0008] According to the movable passage described in claim 1, a cylindrical inner passage is inserted inside a cylindrical outer passage extending in the front-rear direction, and the movable passage is switched from a shortened state to an extended state by increasing the amount of extension of the inner passage in the front-rear direction relative to the outer passage by a drive mechanism. An annular sealing member is arranged around the entire circumference between the outer circumferential surface of the inner passage and the inner circumferential surface of the outer passage. In the extended state, fluid is supplied to the sealing member by a supply unit, causing the sealing member to expand radially, thereby sealing the space between the outer circumferential surface of the inner passage and the inner circumferential surface of the outer passage.

[0009] The discharge section discharges fluid from the sealing member, causing the expanding sealing member to contract, thereby releasing the seal between the inner passage and the outer passage. By releasing the seal provided by the sealing member when the inner passage is moved in the front-to-back direction relative to the outer passage, friction between the outer passage, the inner passage, and the sealing member can be reduced, thereby suppressing wear of the sealing member.

[0010] Examples of "discharge sections" include pumps that forcibly discharge fluids and valves that release fluids to the atmosphere to allow them to be discharged naturally.

[0011] Inside The side passage has a contact portion in which the outer circumferential surface of the position sealed by the sealing member in the extended state is positioned radially outward relative to the outer circumferential surface in the front-rear direction. This makes it easier to radially separate the outer circumferential surface of the inner passage in the front-rear direction of the contact portion, where it is not sealed by the sealing member, from the inner circumferential surface of the outer passage. Therefore, the area requiring high machining precision on the inner circumferential surface of the outer passage to prevent contact between the outer passage and the inner passage can be limited to a small area such as the outer circumferential surface of the contact portion, making it easier to manufacture the inner passage.

[0012] Claim 2 The movable passage described herein provides the following effects in addition to those of the movable passage described in claim 1. The movable passage connects the first part and the second part in the extended state. The drive mechanism adjusts the amount of extension in the extended state according to the distance from the first part to the second part. This allows the length of the movable passage in the extended state connecting the first part and the second part to be adjusted by adjusting the amount of extension of the inner passage relative to the outer passage when the distance in the front-rear direction from the first part to the second part changes. Furthermore, since the sealing member is positioned between the outer circumferential surface of the inner passage and the inner circumferential surface of the outer passage, it can seal the space between them even if the relative positions of the inner passage and the outer passage shift according to the amount of extension in the extended state.

[0013] Claim 3The movable passage described herein provides the following effects in addition to those of the movable passage described in claim 1. The movable passage connects the first part and the second part in the extended state and is fixed to the first part. A sealing member is attached to the outer passage fixed to this first part, and when the sealing member expands, it makes close contact with the inner passage. This eliminates the need for a mechanism to move at least a part of the supply section for supplying fluid into the inside of the sealing member together with the inner passage when the extension amount is changed by the drive mechanism, thus simplifying the supply section. Furthermore, compared to the case where a part of the supply section is moved together with the inner passage by the drive mechanism, the force required to move the inner passage can be reduced, thus allowing the drive mechanism to be miniaturized.

[0014] Claim 4 According to the described movable passage, claims 1 to 3 In addition to the effects of the movable passage described in any of the above, the following effects are achieved: When the discharge section deflates the expanding seal member, it discharges the fluid so that the fluid pressure inside the seal member becomes lower than atmospheric pressure. This makes it easier to separate the expanding seal member from the area where it is in close contact with the surrounding material compared to the case where the discharge section simply opens the inside of the seal member to atmospheric pressure. As a result, friction between the outer passage or inner passage and the seal member can be reduced, and wear of the seal member can be further suppressed. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view of a movable passage in one embodiment. [Figure 2] This is a cross-sectional view of a movable passageway. [Figure 3] This is a partially enlarged cross-sectional view of the movable passageway, specifically section III in Figure 2. [Figure 4] (a) is a partially enlarged cross-sectional view of the movable passage showing the state in which the sealing member has been expanded from the state in Figure 3, and (b) is a partially enlarged cross-sectional view of the movable passage showing the state in which the sealing member has been contracted from the state in Figure 4(a). [Modes for carrying out the invention]

[0016] Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. First, the overall configuration of the movable passage 10 according to one embodiment will be described with reference to FIG. 1. FIG. 1 is a perspective view of the movable passage 10. In FIG. 1, a state where the movable passage 10 is extended to its maximum length is illustrated, and a part of the movable passage 10 (for example, a ceiling 24 connecting the upper ends of side walls 22) is omitted for schematic illustration.

[0017] In addition, the arrow F-B in each drawing including FIG. 1 indicates the expansion and contraction direction of the movable passage 10, the arrow F side is the front side in the expansion and contraction direction, and the arrow B side is the rear side in the expansion and contraction direction. Further, the arrow L-R indicates a horizontal direction perpendicular to the expansion and contraction direction of the movable passage 10, and the arrow U-D indicates the vertical direction of the movable passage 10 perpendicular to the expansion and contraction direction and the horizontal direction. In the following description, the expansion and contraction direction of the movable passage 10 is simply referred to as the "front-rear direction" for description.

[0018] As shown in FIG. 1, the movable passage 10 is a movable passage including: a fixed passage 20 fixed to a station platform 2; a tip passage 30 projecting forward (in the direction of arrow F) from the fixed passage 20; and a drive mechanism 40 that changes the forward-rear projection amount L1 of the tip passage 30 relative to the fixed passage 20.

[0019] By increasing the projection amount L1 via the drive mechanism 40, the movable passage 10 is brought into an extended state, and the tip portion 34 of the tip passage 30 is connected to the entrance / exit of the vehicle 4 (see FIG. 2) stopped in front of the platform 2. This allows passengers to get on and off between the platform 2 and the vehicle 4 through the extended movable passage 10.

[0020] On the other hand, the shortened state is a state where the movable passage 10 is shortened toward the platform 2 side such that the projection amount L1 is minimized by the drive mechanism 40. When the vehicle 4 travels in front of the platform 2, the movable passage 10 is in the shortened state.

[0021] A partition wall 21 is formed in the fixed passageway 20, extending in the left-right direction (arrows LR direction), and this partition wall 21 separates the platform 2 side from the vehicle 4 running path side. The partition wall 21 constitutes the front end of the fixed passageway 20, and a roughly rectangular opening 21a is formed therein. The front passageway 30 extends forward from this opening 21a.

[0022] The side walls 22 extending from the rear surface of the partition wall 21 toward the rear are provided in pairs on either side of the opening 21a. Rails 23 extending in the front-rear direction are fixed to the inner surface (the wall surface facing the end passage 30) of each of these pair of side walls 22.

[0023] The upper ends of a pair of side walls 22 are connected by a ceiling 24 (see Figure 2), and the ceiling 24, the pair of side walls 22, and the platform 2 form a fixed passageway 20 in a rectangular cylindrical shape extending in the front-to-back direction. The lower part of the fixed passageway 20 is not limited to the platform 2, but may be made up of a separate member fixed on the platform 2.

[0024] The tip passage 30 is a passage that is inserted into the opening 21a of the fixed passage 20. The tip passage 30 is formed in a rectangular cylindrical shape with openings on both the front and rear sides, by a floor portion 31 that constitutes the lower surface, a pair of wall portions 32 that constitute the left and right sides respectively, and a top portion 33 that constitutes the upper surface.

[0025] The drive mechanism 40 is an air cylinder that extends and retracts by extending and retracting a piston rod 42 relative to a cylinder 41. With its extension and retraction direction oriented in the front-rear direction, the cylinder 41 is attached to the partition wall 21 of the fixed passage 20 while penetrating the partition wall 21, and the tip of the piston rod 42 is attached near the tip 34 of the tip passage 30. The drive mechanism 40 is arranged symmetrically on both the left and right sides of the movable passage 10.

[0026] Next, with reference to Figures 2 and 3, the various parts of the movable passage 10 will be described in more detail. Figure 2 is a cross-sectional view of the movable passage 10. Figure 3 is a partially enlarged cross-sectional view of part III of Figure 2 of the movable passage 10. In Figures 2 and 3, the cross-section is shown in a plane perpendicular to the left-right direction of Figure 1, and is cut approximately at the center of the movable passage 10 in the left-right direction. The figures also show the state in which the overhang amount L1 of the tip passage 30 relative to the fixed passage 20 is maximized. Furthermore, in Figures 2 and 3, the state in which the internal cavity 56 of the sealing member 50 is equal to atmospheric pressure is shown.

[0027] As shown in Figures 2 and 3, the rear end 35 of the front passage 30 extends radially outward in a flange-like manner relative to the floor 31, wall 32, and ceiling 33. The upper parts of both the left and right edges of this rear end 35 are slidably engaged with the rails 23 of the side wall 22. This guides the movement of the front passage 30 in the front-rear direction relative to the fixed passage 20.

[0028] An annular contact portion 36 protrudes from the front of the rear end portion 35, extending around the entire circumference of the front passage 30. The lower part of the contact portion 36 overlaps with and integrates with the floor portion 31 of the front passage 30, while the upper and side portions of the contact portion 36 are positioned radially separated from the top portion 33 and the wall portion 32. Furthermore, in the extended state of the movable passage 10, the contact portion 36 and the edge of the opening 21a of the partition wall 21 are separated radially around the entire circumference by a certain distance and contour and face each other.

[0029] An annular sealing member 50 is positioned around the entire circumference between the outer circumferential surface of the contact portion 36 (the outer circumferential surface of the tip passage 30) and the edge of the opening 21a (the inner circumferential surface of the fixed passage 20). The sealing member 50 is a so-called inflatable seal and is made of an elastic material such as rubber that can expand or contract at least in the radial direction. The sealing member 50 protrudes radially (up and down and left and right) inward from the entire circumference of the edge of the opening 21a.

[0030] The sealing member 50 comprises a bottom portion 51 that is in close contact with the edge of the opening 21a, a pressing portion 52 that faces the contact portion 36 and is radially opposite to the bottom portion 51, and a pair of side portions 53 that connect the pressing portion 52 and the bottom portion 51 in the radial direction and face each other in the front-rear direction. The sealing member 50 is formed hollow, having a cavity 56 surrounded by the bottom portion 51, the pressing portion 52, and the pair of side portions 53.

[0031] The bottom portion 51 is a plate-like part and is positioned in the front-rear direction by fitting it into a groove 21b provided on the edge of the opening 21a. This groove 21b is formed by recessing a part of the edge of the opening 21a in a stepped manner. However, the groove 21b may also be formed between liners by fixing liners separated in the front-rear direction to the edges of the opening 21a, or the groove 21b may be formed by combining a step and liners.

[0032] The bottom portion 51 protrudes outward in the front-rear direction from a pair of side portions 53. This protruding portion of the bottom portion 51 is sandwiched between a fixing plate 60 fixed to the edge of the opening 21a and the bottom of the groove 21b, thereby fixing the bottom portion 51 to the edge of the opening 21a.

[0033] The pair of side portions 53 are formed in a cross-section in which the radial central portions are bent toward each other. The pressing portion 52 is formed in a plate shape with both edges in the front-rear direction connected to the side portions 53, and a plurality of protrusions 54 project toward the contact portion 36.

[0034] A restricting wall 61 rises vertically from the edge of the fixing plate 60 on the side of the sealing member 50, which is positioned on both the front and rear sides of the sealing member 50. The radially inner tip of this restricting wall 61 is not in contact with the contact portion 36 and is at the same height as the tip of the projection 54 when the cavity 56 (inside) of the sealing member 50 is at the same pressure as atmospheric pressure.

[0035] As shown in Figures 1 and 3, a supply / discharge section 70 for supplying or discharging air to or from the cavity 56 of the sealing member 50 is provided in the fixed passage 20. The supply / discharge section 70 comprises a pipe 71, a pump 72, a tank 73, and a valve 74.

[0036] The pipe 71 is routed inside the partition wall 21 to which the sealing member 50 is attached, along the sealing member 50. A branch pipe 71a that branches off from this pipe 71 penetrates the wall surface of the partition wall 21 on the opening 21a side and the bottom 51 of the sealing member 50, and communicates with the cavity 56 of the sealing member 50. The branch pipe 71a is connected to multiple locations around the sealing member 50.

[0037] The piping 71 that extends outward from the partition wall 21 is connected to a tank 73 fixed to the home 2 via a valve 74. The air inside the tank 73 is pressurized or depressurized by supplying and discharging air using a pump 72. The valve 74 is a three-way valve that opens and closes the connection between the piping 71 and the tank 73, and also allows the inside of the piping 71 to be released to the atmosphere.

[0038] Since the sealing member 50 is attached to the fixed passage 20, the air supply and discharge section 70 for supplying and discharging air from the cavity 56 of the sealing member 50 can be located in the fixed passage 20 or the home 2. Therefore, when the extension amount L1 is changed by the drive mechanism 40, a mechanism for moving at least a part of the air supply and discharge section 70 together with the tip passage 30 is unnecessary, and the air supply and discharge section 70 can be simplified. Furthermore, compared to the case where a part of the air supply and discharge section 70 is moved together with the tip passage 30 by the drive mechanism 40, the force required by the drive mechanism 40 to move the tip passage 30 can be reduced, so the drive mechanism 40 can be made smaller.

[0039] Next, referring to Figures 4(a) and 4(b) in addition to Figure 3, the operation of the sealing member 50 when the movable passage 10 is expanded and contracted will be explained. Figure 4(a) is a partially enlarged cross-sectional view of the movable passage 10 showing the state in which the sealing member 50 has been expanded from the state in Figure 3. Figure 4(b) is a partially enlarged cross-sectional view of the movable passage 10 showing the state in which the sealing member 50 has been contracted from the state in Figure 4(a). In Figures 4(a) and 4(b), a portion of the piping 71 on the valve 74 side, the pump 72, the tank 73, and the valve 74 are schematically shown.

[0040] First, in the shortened state where the extension L1 of the end passage 30 relative to the fixed passage 20 is minimized and the movable passage 10 is shortened toward the platform 2 side, the valve 74 opens the piping 71 to atmospheric pressure, and the cavity 56 of the piping 71 and the sealing member 50 is at the same pressure as atmospheric pressure. Furthermore, the valve 74 blocks the space between the piping 71 and the tank 73. In this state, the pump 72 is operated to compress the air inside the tank 73.

[0041] Next, when the train 4 stops in front of platform 2, the drive mechanism 40 increases the extension amount L1, connecting the end passage 30 to the train 4 and extending the movable passage 10. Note that the distance from platform 2 to train 4 in the longitudinal direction (the width direction of train 4) may vary depending on the shape of platform 2 and the width of train 4. Also, due to the influence of the air spring (not shown) of train 4, train 4 may swing in the width direction (the longitudinal direction of the movable passage 10) even when stopped.

[0042] By adjusting the extension amount L1 by the drive mechanism 40 according to the distance from platform 2 to vehicle 4, the length in the longitudinal direction of the extended movable passageway 10 connecting platform 2 and vehicle 4 can be adjusted. For example, the extension amount L1 may be increased, and a sensor may detect when the end passageway 30 comes into contact with vehicle 4, at which point the change in extension amount L1 may be stopped. Alternatively, the distance in the longitudinal direction (width direction of vehicle 4) from platform 2 to vehicle 4 may be detected by a sensor installed on a track (not shown), and the extension amount L1 may be determined according to the detection result.

[0043] In the entire range where the distance from platform 2 to vehicle 4 can vary (the entire range where the overhang amount L1 can vary), the dimensions in the front-rear direction from the rear end 35 to the front end of the contact portion 36 of the front passage 30 are set so that the sealing member 50 attached to the edge of the opening 21a of the partition wall 21 faces radially with the contact portion 36 of the front passage 30.

[0044] When the seal member 50 and the contact portion 36 are facing each other in the extended state, the valve 74 connects the piping 71 and the tank 73. As a result, as shown in Figure 4(a), compressed air in the tank 73 is sent from the piping 71 and the branch pipe 71a into the cavity 56 of the seal member 50, causing the seal member 50 to expand. Once the expansion of the seal member 50 is complete, the valve 74 is closed to block the connection between the piping 71 and the tank 73.

[0045] When the sealing member 50 expands due to the supply and discharge section 70, the pressing section 52 is pressed against the outer circumferential surface of the contact section 36, creating a tight seal. As a result, the space between the fixed passage 20 and the tip passage 30 is sealed all around by the sealing member 50.

[0046] Here, outside the extended movable passageway 10 connecting platform 2 and train car 4, the air pressure may change due to other trains passing through the station, etc. The sealing member 50 can suppress the propagation of this air pressure change from the outside to the inside of the movable passageway 10 through the fixed passageway 20 and the end passageway 30.

[0047] Furthermore, in order to minimize the impact of this pressure change on passengers, passengers are permitted to pass through the movable passageway 10 only after the expansion of the sealing member 50 is complete. Compared to supplying air directly from the pump 72 to the cavity 56 of the sealing member 50, supplying pre-compressed air from the tank 73 to the cavity 56 allows the sealing member 50 to expand more quickly, thereby shortening the time from when the vehicle 4 stops until passengers are permitted to pass through the movable passageway 10.

[0048] Furthermore, since the branch pipe 71a is connected to multiple locations around the sealing member 50, the sealing member 50 can be inflated more quickly, and the time from when the vehicle 4 stops until permission to pass through the movable passage 10 can be shortened. In addition, although the pressing portion 52 comes into contact with the contact portion 36 due to the rapid inflation, the impact at the time of contact can be mitigated by the multiple protrusions 54 (see Figure 3) provided on the pressing portion 52, thereby reducing the collision noise.

[0049] Furthermore, when sealing by sandwiching a sealing member between the fixed passage 20 and the tip passage 30 in the front-rear direction, if the amount L1 of the tip passage 30 overhanging the fixed passage 20 relative to the fixed passage 20 (the relative position between the fixed passage 20 and the tip passage 30) is not extended to its maximum extent in the extended state, there is a risk that the sealing member cannot be sandwiched.

[0050] In contrast, the sealing member 50 seals the space between the inner circumferential surface of the radially overlapping fixed passage 20 (the edge of the opening 21a) and the outer circumferential surface of the tip passage 30 (the outer circumferential surface of the contact portion 36) in the radial direction. Therefore, even if the relative positions of the fixed passage 20 and the tip passage 30 are misaligned, it is easy to seal the space between them. In particular, the dimensions of the contact portion 36 in the front-rear direction are set so that the sealing member 50 faces the contact portion 36 over the entire range in which the overhang amount L1 in the extended state can change, so the space between the fixed passage 20 and the tip passage 30 can be reliably sealed regardless of the overhang amount L1.

[0051] Furthermore, the outer circumferential surface of the contact portion 36 sealed by the sealing member 50 is positioned radially outward relative to the outer circumferential surface of the tip passage 30 ahead of that portion. Similarly, the edge of the opening 21a is positioned radially inward relative to the inner circumferential surface of the fixed passage 20 behind that portion. As a result, the inner circumferential surface of the fixed passage 20 and the outer circumferential surface of the tip passage 30 in the positions not sealed by the sealing member 50 can be easily separated radially from each other. Therefore, the areas requiring high machining precision for radially opposing surfaces in order to prevent contact between the fixed passage 20 and the tip passage 30 can be limited to a small area such as the outer circumferential surface of the contact portion 36 and the edge of the opening 21a, making it easier to manufacture the fixed passage 20 and the tip passage 30.

[0052] In the pre-expansion state shown in Figure 3, the pair of side portions 53 of the sealing member 50 are bent toward each other in the radial central portion. However, during expansion, as shown in Figure 4(a), the side portions 53 straighten radially so that this bend opens. This makes it easier to expand the sealing member 50 radially and easier to separate the sealing member 50 from the contact portion 36 before expansion. As a result, the dimensional accuracy required between the outer circumferential surface of the contact portion 36 and the edge of the opening 21a, which is necessary to prevent the sealing member 50 from contacting the contact portion 36 when not expanding, can be reduced, making it easier to manufacture the fixed passage 20 and the tip passage 30.

[0053] Furthermore, the regulating walls 61 on both the front and rear sides of the sealing member 50 restrict the expansion direction of the sealing member 50 in the radial direction. This allows the sealing member 50 to be pressed against the contact portion 36 with greater force without dispersing the expansion direction of the sealing member 50. This improves the sealing performance of the sealing member 50.

[0054] Next, as shown in Figure 4(b), when switching the extended movable passage 10 to a shortened state in order to launch the vehicle 4, first, the air in the cavity 56 of the expanding sealing member 50 is discharged by the supply and discharge section 70. This causes the sealing member 50 to contract and move away from the contact section 36, releasing the seal between the fixed passage 20 and the tip passage 30. After that, the drive mechanism 40 moves the tip passage 30 backward relative to the fixed passage 20, reducing the extension amount L1 to the minimum and shortening the movable passage 10.

[0055] When the overhang amount L1 is reduced, the seal provided by the sealing member 50 is released, making it less likely for the contact portion 36 and the sealing member 50 to rub against each other. In addition, when the overhang amount L1 is increased again, the seal provided by the sealing member 50 is released, making it less likely for the contact portion 36 and the sealing member 50 to rub against each other. As a result, wear of the sealing member 50 can be suppressed.

[0056] While the sealing member 50 is expanding, the connection between the piping 71 and the tank 73 is blocked by the valve 74, and the air inside the tank 73 is depressurized in advance by the pump 72. From this state, the connection between the piping 71 and the tank 73 is restored by the valve 74, allowing the air in the cavity 56 of the sealing member 50 to be quickly discharged through the piping 71 into the tank 73, thereby allowing the expanding sealing member 50 to deflate quickly.

[0057] Furthermore, since the branch pipe 71a is connected to multiple points around the sealing member 50, the sealing member 50 can be retracted more quickly. As a result, the time required to switch the movable passage 10 to the shortened state and depart the vehicle 4 can be reduced.

[0058] When the sealing member 50 contracts, the cavity 56 is not opened to atmospheric pressure but rather depressurized, and air is discharged so that the pressure in the cavity 56 becomes lower than atmospheric pressure. This makes it easier to separate the sealing member 50, which has become tightly adhered due to expansion, from the area where it is in contact, compared to the case where only the valve 74 opens the cavity 56 of the pipe 71 and the sealing member 50 to atmospheric pressure. As a result, friction between the sealing member 50 and the contact portion 36 can be reduced, and wear of the sealing member 50 can be further suppressed.

[0059] Furthermore, by keeping the cavity 56 of the sealing member 50 under reduced pressure relative to atmospheric pressure until the movable passage 10 is in its shortened state, friction between the tip passage 30 and the sealing member 50 can be made less likely. After the movable passage 10 is in its shortened state, the movement of the tip passage 30 relative to the fixed passage 20 is complete, so the valve 74 is opened to atmospheric pressure in the piping 71 and the cavity 56 of the sealing member 50. This reduces the time required to expand the sealing member 50 next compared to when the cavity 56 of the sealing member 50 is kept under reduced pressure.

[0060] Although the present invention has been described above based on embodiments, it can be easily inferred that the present invention is not limited in any way to the above embodiments, and that various improvements and modifications are possible without departing from the spirit of the present invention.

[0061] In the above embodiment, the case in which the drive mechanism 40 that changes the amount L1 of the forward extension of the tip passage 30 relative to the fixed passage 20 is an air cylinder was described, but it is not necessarily limited to this. For example, the drive mechanism 40 may be made up of a hydraulic cylinder, an electric cylinder, etc., not just an air cylinder. Furthermore, the drive mechanism 40 may be made up of other known actuators, such as a mechanism that converts rotational motion into linear motion to change the extension amount L1. In addition, the case in which the extension amount L1 in the extended state is adjustable by the drive mechanism 40 is not limited to the case in which the extension amount L1 in the extended state is fixed to a predetermined amount such as the maximum.

[0062] The relative sizes of these passages can be changed so that the fixed passage 20 is inserted inside the tip passage 30. Even in this case, the amount L1 of the tip passage 30 protruding from the fixed passage 20 refers to the distance from the front end of the fixed passage 20 to the front end of the tip passage 30. Note that changing the amount L1 of the tip passage 30 protruding forward from the fixed passage 20 is equivalent to changing the amount of the fixed passage 20 protruding backward from the tip passage 30.

[0063] In the above embodiment, a movable passage 10 that can be extended and retracted in one stage by having a nested structure between a fixed passage 20 and a tip passage 30 has been described, but it is not necessarily limited to this. For example, by providing one or more cylindrical intermediate passages between the fixed passage 20 and the tip passage 30 in a nested structure, the extension and retraction of the movable passage 10 may be made in two or more stages. The drive mechanism 40 that extends and retracts each passage (changes the amount of extension between the passages) is not limited to an air cylinder and may be changed as appropriate as described above. In addition, the amount of extension between the passages may be fixed in the extended state or made adjustable.

[0064] In the above embodiment, the case in which the sealing member 50 is attached to the fixed passage 20 has been described, but it is not necessarily limited to this. For example, the sealing member 50 may be attached to the tip passage 30 (contact portion 36). Also, if the movable passage 10 extends and retracts at multiple locations, the sealing member 50 may be provided at least one of these locations, and the spaces between the other passages may be sealed by a different sealing mechanism.

[0065] In the above embodiment, the case in which air in the cavity 56 of the sealing member 50 is supplied and discharged by the supply and discharge section 70 was described, but it is not necessarily limited to this. For example, a supply section for supplying air to the cavity 56 and a discharge section for discharging air from the cavity 56 may be provided separately. Furthermore, it is not limited to supplying and discharging air by the supply and discharge section 70 (supply section and discharge section), but fluids such as gases or liquids other than air may also be supplied and discharged.

[0066] The supply and discharge section 70 (discharge section) may not only be used to release the seal by reducing the pressure of the cavity 56 relative to atmospheric pressure using a pump 72 or the like, but may also be used without a pump 72 or the like, by opening the cavity 56 of the expanding sealing member 50 to atmospheric pressure and allowing the fluid to be discharged naturally by the restoring force of the rubber. Alternatively, the tank 73 may be omitted from the supply and discharge section 70, and the fluid may be supplied and discharged directly to the cavity 56 by the pump 72.

[0067] In the above embodiment, the case was described in which the outer circumferential surface of the contact portion 36 sealed by the sealing member 50 is positioned radially outward with respect to the outer circumferential surface of the tip passage 30 forward of that portion. However, the embodiment is not necessarily limited to this. For example, the contact portion 36 may be omitted, and the sealing member 50 may be placed in close contact with the outer circumferential surface of the tip passage 30, which is substantially flat in the front-rear direction.

[0068] Furthermore, the contact portion 36 is not limited to the case where it protrudes forward from the rear end portion 35; the contact portion 36 may also be formed by extending a part of the outer circumferential surface of the front-rear direction of the front-end passage 30 radially. In addition, when the fixed passage 20 is inserted inside the front-end passage 30, the contact portion 36 into which the sealing member 50 makes close contact may be formed on the fixed passage 20 by positioning a part of the outer circumferential surface of the fixed passage 20 radially outward with respect to its front-rear direction.

[0069] In the above embodiment, the case in which the sealing member 50 is formed hollow has been described, but it is not necessarily limited to this. For example, the bottom portion 51 may be omitted and the bottom surface of the sealing member 50 may be open, and a cavity 56 may be formed between the fixed passage 20 (edge ​​of the opening 21a) or the tip passage 30 (contact portion 36).

[0070] In the above embodiment, the movable passageway 10 was described as connecting the platform 2 and the vehicle 4, but it is not necessarily limited to this. For example, the movable passageway 10 can connect the first part and the second part and be fixed to the first part. Examples of the first part and the second part include buildings, automobiles, aircraft, ships, and the ground. The first part and the second part may also be of the same type. [Explanation of symbols]

[0071] 2 Home (Part 1) 4 Vehicles (Part 2) 10 Movable aisle 20 Fixed passage (outside passage) 30 Tip passage (inner passage) 36 Contact part 40 Drive mechanism 50 sealing member 70 Supply and discharge section (supply section and discharge section) L1 overhang amount

Claims

1. A movable passage that extends and retracts in the front-to-back direction by switching between an extended state and a shortened state which is a shortened state relative to the extended state, A cylindrical outer passage extending in the front-to-back direction, A cylindrical inner passage is inserted inside the outer passage and moves relative to the outer passage in the front-rear direction, A drive mechanism that switches from the shortened state to the extended state by increasing the amount of the inner passage overhanging the outer passage through the relative movement, An annular sealing member is disposed around the entire circumference between the outer circumferential surface of the inner passage and the inner circumferential surface of the outer passage, and is expandable or contractible at least in the radial direction. A supply unit that expands the sealing member by supplying fluid to the sealing member, The system includes a discharge section that causes the sealing member to contract by discharging fluid from the sealing member, In the extended state, the seal member expanded by the supply unit seals the space between the outer circumferential surface of the inner passage and the inner circumferential surface of the outer passage, and the seal between the inner passage and the outer passage is released by contracting the expanding seal member by the discharge unit. The movable passage is characterized in that the inner passage has a contact portion in which the outer circumferential surface of the position sealed by the sealing member in the extended state is positioned radially outward with respect to the outer circumferential surface in the front-rear direction.

2. The aforementioned movable passage connects the first part and the second part in the extended state. The movable passage according to claim 1, characterized in that the amount of extension in the extended state is adjusted according to the distance from the first part to the second part of the drive mechanism.

3. The aforementioned movable passage connects the first part and the second part in the extended state and is fixed to the first part. The outer passage is fixed to the first part, The movable passage according to claim 1, wherein the sealing member is attached to the outer passage and adheres tightly to the inner passage when it expands.

4. The movable passage according to any one of claims 1 to 3, characterized in that the discharge section discharges fluid such that when the seal member is contracted during expansion, the fluid pressure inside the seal member becomes lower than atmospheric pressure.

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