JP2013217463A - Air spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air spring capable of suppressing degradation in durability of a stopper and sinking amount of a vehicle body while maintaining good cushioning property at the time of deflation.SOLUTION: An air spring 1 includes an outer cylinder 11, a lower face plate 12, a diaphragm 13, an external stopper 14, a rubber support plate 15, a built-in stopper 16, and a limiting metal fitting 17. At the limiting metal fitting 17, a bent part 17a is formed to protrude in such a manner as approaches a second opposing surface 12a side. On the second opposing surface 12a, seal part 22b is formed which opposes the bent part 17a in a direction perpendicular to a main load direction at the time of deflation. The bent part 17a and the seal part 22b are formed in such a manner as a bent surface 17b and a seal inner wall surface 12c follow each other in the main load direction at the time of deflation.

Description

  The present invention relates to an air spring, and more particularly to an air spring capable of suppressing a decrease in the amount of vehicle body sinking and a durability of a stopper while maintaining good cushioning during deflation. It is.

  In a railway vehicle or the like, an air spring is disposed between the vehicle main body and the carriage in order to reduce the impact and vibration applied to the vehicle body when the vehicle is traveling. Referring to FIGS. 19 and 20, as the air spring, an outer cylinder 110, a lower surface plate 120 disposed below the outer tube 110, and a rubber-made material disposed so as to connect the outer cylinder 110 and the lower surface plate 120. A bolsterless air spring 100 mainly including a diaphragm 130, a laminated rubber 140 positioned below the lower surface plate 120, and a laminated rubber lower plate 150 positioned below the laminated rubber 140 is well known. In addition to the laminated rubber 140, an air spring further provided with a built-in stopper that can be elastically deformed has been proposed in order to ensure good cushioning in the vertical direction during deflation and to cope with displacement in the horizontal direction. (For example, refer to Patent Documents 1 and 2).

JP 2009-156330 A JP 2003-254378 A

  In the air springs of Patent Documents 1 and 2, since the horizontal displacement during deflation is relieved by the shearing deformation of the built-in stopper, there is a problem that the durability of the built-in stopper is lowered when the displacement is large. Further, as the built-in stopper, one having a relatively small spring constant is used in order to ensure good cushioning properties. Therefore, there is a problem that the amount of settlement of the vehicle body becomes large while good cushioning properties in the vertical direction during deflation are ensured.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an air spring capable of suppressing the amount of settlement of the vehicle body and the durability of the stopper during deflation.

  The air spring of the present invention connects a first support member, a second support member arranged at an interval in the main load direction when viewed from the first support member, and the first support member and the second support member. The closed space is formed by this, and the elastically deformable diaphragm and the first support member side as viewed from the second support member are arranged on the opposite side, and the elastically deformable first stopper and the first stopper are viewed. A third support member disposed on the side opposite to the second support member side, a first facing surface that is a surface facing the second support member of the first support member, and a first support member of the second support member Arranged on the second stopper support surface, which is one of the second opposing surface that is the surface to be contacted or the third opposing surface that is the surface that is the surface of the third support member that is opposed to the first support member, and is elastically deformable. On the opposite side of the second stopper and the second stopper support surface when viewed from the second stopper And a fourth support member which is location. The fourth support member is formed with a first displacement limiting portion protruding so as to approach the second stopper support surface side. A second displacement limiting portion is formed on the first facing surface or the second facing surface so as to protrude in a direction along the main load direction and to face the first displacement limiting portion in a direction perpendicular to the main load direction during deflation. Yes. The first displacement restricting portion and the second displacement restricting portion are mainly composed of a surface facing the second displacement restricting portion of the first displacement restricting portion and a surface facing the first displacement restricting portion of the second displacement restricting portion at the time of deflation. They are formed along each other in the load direction.

  In the air spring of the present invention, the fourth support member is formed with a first displacement limiting portion protruding so as to approach the second stopper support surface side. Therefore, the distance between the fourth support member and the second stopper support surface is smaller than that of the air spring in which the first displacement limiting portion is not formed. Thereby, when the 2nd stopper arrange | positioned on a 2nd stopper support surface is compressed at the time of deflation, it becomes easy to contact | abut the 4th support member and the structural member arrange | positioned at the 2nd stopper support surface side. As a result, the amount of compression of the second stopper during deflation is reduced. Further, in the air spring of the present invention, the second displacement limiting portion facing the first displacement limiting portion in the direction perpendicular to the main load direction at the time of deflation is formed on the first facing surface or the second facing surface. Therefore, during deflation, the displacement of the fourth support member in the direction perpendicular to the main load direction is limited. Thereby, the displacement in the direction perpendicular to the main load direction of the second stopper in which the fourth support member is disposed is limited, and as a result, it is possible to suppress a decrease in durability of the second stopper. Thus, according to the air spring of the present invention, it is possible to provide an air spring that can suppress the amount of settlement of the vehicle body and the durability of the stopper during deflation.

  In the air spring, the first displacement limiting unit and the second displacement limiting unit are opposed to the surface of the first displacement limiting unit that faces the second displacement limiting unit and the first displacement limiting unit of the second displacement limiting unit during deflation. You may form so that a surface may mutually contact. Thereby, the displacement in the direction perpendicular to the main load direction of the second stopper can be more effectively limited. As a result, it is possible to more effectively limit the reduction in the durability of the stopper.

  In the air spring, the first displacement restricting portion and the second displacement restricting portion may be formed spaced apart from each other in a direction perpendicular to the main load direction during deflation. Thereby, while restricting the displacement of the second stopper in the direction perpendicular to the main load direction, the external force applied from the direction can be easily reduced. That is, a minute external force applied from the direction can be reduced by the displacement of the second stopper, and as a result, the riding comfort of the vehicle can be improved.

In the air spring, the distance between the first displacement limiting portion and the second displacement limiting portion is d, the spring constant of the second stopper is K, and the side opposite to the side of the fourth support member disposed on the second stopper. If static friction coefficient mu _s of the sliding surface is a surface on the _side, a vertical efficacy in the contact surface between the sliding surface and the first supporting surface or the second supporting surface has a F _z, the relationship Kd ≧ μ _s F _z May be satisfied. Thus, when an external force is applied from a direction perpendicular to the main load direction, the first support member and the fourth support member or the second support member are brought into contact before the first displacement limiter and the second displacement limiter come into contact with each other. And a fourth support member can be slid. As a result, the riding comfort of the vehicle can be further improved.

In the air spring, _μs which is a static friction coefficient of the sliding surface may be 0.4 or less. Thereby, slip is generated between the first support member and the fourth support member or the second support member and the fourth support member while suppressing the contact between the first displacement limiter and the second displacement limiter. It becomes easier.

  As is apparent from the above description, according to the air spring of the present invention, it is possible to reduce the amount of car body sinking while maintaining good cushioning during deflation, and to suppress the durability of the stopper. An air spring can be provided.

It is a schematic sectional drawing which shows the structure of an air spring. It is a schematic sectional drawing for demonstrating operation | movement of an air spring. It is a schematic sectional drawing for demonstrating operation | movement of an air spring. It is a schematic sectional drawing for demonstrating operation | movement of an air spring. It is a schematic sectional drawing which shows the structure of an external stopper. It is a schematic sectional drawing which shows partially the structure of an external stopper. It is a schematic sectional drawing which expands and shows the structure of an air spring. 6 is a schematic cross-sectional view showing a structure of an air spring according to Embodiment 2. FIG. FIG. 10 is a schematic cross-sectional view for explaining the operation of the air spring of the second embodiment. FIG. 10 is a schematic cross-sectional view for explaining the operation of the air spring of the second embodiment. FIG. 10 is a schematic cross-sectional view for explaining the operation of the air spring of the second embodiment. FIG. 10 is a schematic cross-sectional view for explaining the operation of the air spring of the second embodiment. FIG. 10 is a schematic cross-sectional view for explaining the operation of the air spring of the second embodiment. FIG. 10 is a schematic cross-sectional view for explaining the operation of the air spring of the second embodiment. FIG. 10 is a schematic cross-sectional view for explaining the operation of the air spring of the second embodiment. FIG. 10 is a schematic cross-sectional view for explaining the operation of the air spring of the second embodiment. It is a schematic sectional drawing which shows the structure of an air spring. It is a schematic sectional drawing which shows the structure of an air spring. It is a schematic sectional drawing which shows the structure of the conventional air spring. It is a schematic sectional drawing which shows the structure of the conventional air spring.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
First, Embodiment 1 which is one embodiment of the present invention will be described. First, the structure of the air spring of this embodiment will be described. Referring to FIG. 1, an air spring 1 according to the present embodiment includes an outer cylinder 11 as a first support member, a bottom plate 12 as a second support member, a diaphragm 13, and an external stopper as a first stopper. 14, a rubber lower plate 15 as a third support member, a built-in stopper 16 as a second stopper, and a restricting bracket 17 as a fourth support member.

  In a region including the axis (center axis) P of the outer cylinder 11, a vehicle body side spigot 11 a that protrudes along the axis P to the side opposite to the lower surface plate 12 side is formed. An O-ring 11b is attached to the outer periphery of the vehicle body side spigot 11a. The outer cylinder 11 is connected to the vehicle body side (not shown) via the vehicle body side spigot 11a.

  The lower surface plate 12 is arranged at an interval in the main load direction as viewed from the outer cylinder 11 so as to share the axis P with the outer cylinder 11. A seal portion 12b as a second displacement limiting portion that protrudes in the direction along the main load direction is formed on the outer side of the limit metal fitting 17 on the second facing surface 12a that is a surface facing the outer cylinder 11 of the lower surface plate 12. Has been.

  The diaphragm 13 forms a closed space by connecting the outer cylinder 11 and the lower surface plate 12. Specifically, both ends of the diaphragm 13 are supported by the outer cylinder 11 and the lower surface plate 12, respectively. Thereby, the diaphragm 13, the outer cylinder 11, and the lower surface plate 12 form a closed space S. The diaphragm 13 is made of, for example, rubber and can be elastically deformed.

  The external stopper 14 is disposed on the side opposite to the outer cylinder 11 side when viewed from the lower surface plate 12. The external stopper 14 has a plurality of hard layers 14a made of metal and a plurality of elastic layers 14b made of rubber, and has a structure in which the hard layers 14a and the elastic layers 14b are alternately stacked in the main load direction. The external stopper 14 can be elastically deformed by having a plurality of elastic layers 14b. A hollow portion is formed in a region including the axis P of the external stopper 14.

  The rubber lower plate 15 is disposed on the side opposite to the lower surface plate 12 when viewed from the external stopper 14 so as to share the axis P together with the outer cylinder 11 and the lower surface plate 12. In the vicinity of the axis P of the rubber lower plate 15, a cart side spigot 15 a is formed along the axis P so as to protrude on the opposite side to the external stopper 14 side. In other words, a truck-side spigot 15 a is attached to the rubber lower plate 15 as a small-diameter portion that protrudes with the axis P as the central axis. An O-ring 15b is attached to the outer periphery of the truck-side spigot 15a. The rubber lower plate 15 is connected to a cart (not shown) through a cart side spigot 15a. The air spring 1 supports the vehicle body (not shown) with respect to the carriage (not shown) on the support surface 15c of the rubber lower plate 15.

  The built-in stopper 16 is disposed on the second facing surface 12 a that faces the outer cylinder 11 of the lower surface plate 12. The built-in stopper 16 has a cylindrical shape centered on the axis P, for example, and has a hollow portion in a region including the axis P. The built-in stopper 16 is made of, for example, a massive rubber and can be elastically deformed. The spring constant of the built-in stopper 16 is not particularly limited, and may be larger or smaller than the spring constant of the external stopper 14.

  The restriction metal 17 is disposed on the side opposite to the second facing surface 12a when viewed from the built-in stopper 16. A bent portion 17a as a first displacement limiting portion protruding so as to approach the second facing surface 12a side is formed in a region including the end portion of the limiting metal member 17. The bent portion 17a is formed to face the seal portion 12b formed on the lower surface plate 12 during deflation in a direction perpendicular to the main load direction.

  The bent portion 17a and the seal portion 12b are composed of a bent surface 17b that is a surface facing the seal portion 12b of the bent portion 17a and a seal inner wall surface 12c that is a surface facing the bent portion 17a of the seal portion 12b during deflation. They are formed along each other in the direction. More specifically, the bent portion 17a and the seal portion 12b are formed such that the bent surface 17b and the seal inner wall surface 12c are parallel to each other during deflation. In the air spring 1 of the present embodiment, the bent portion 17a and the seal portion 12b are formed such that the bent surface 17b and the seal inner wall surface 12c are in contact with each other during deflation.

  Next, the operation of the air spring 1 of the present embodiment will be described. Referring to FIG. 2, in an inflated state in which a predetermined pressure is maintained in a closed space S formed inside diaphragm 13, the impact and vibration applied from the carriage (not shown) side when the vehicle travels are 13 is relaxed by elastic deformation. On the other hand, referring to FIG. 3, in a state where the pressure in the closed space S is lowered, for example, in a deflated state that is a puncture state, the outer cylinder 11 is lowered to the lower surface plate 12 side. Will be in contact. As the outer cylinder 11 is further lowered, the built-in stopper 16 disposed in contact with the restricting metal member 17 is compressed in the main load direction as shown in FIG. Then, when the bent portion 17a of the restricting bracket 17 contacts the lower surface plate 12, the lowering of the outer cylinder 11 stops. Further, at the time of the deflation, when a vibration or impact is applied from a direction perpendicular to the main load direction and the restricting bracket 17 is to be displaced in the direction, the bent surface 17b and the inner wall surface 12c of the seal come into contact with each other. Is limited.

  As described above, in the air spring 1 of the present embodiment, the built-in stopper 16 that is elastically deformable separately from the external stopper 14 is disposed on the second facing surface 12 a of the lower surface plate 12. Therefore, the internal stopper 16 is compressed when the outer cylinder 11 descends to the lower surface plate 12 side during deflation, and as a result, good cushioning properties in the vertical direction during deflation are ensured. Further, in the air spring 1, a bent portion 17 a that protrudes so as to approach the second facing surface 12 a side is formed in a region including the end portion of the restricting metal fitting 17. Therefore, the distance between the limit metal fitting 17 and the second facing surface 12a is smaller than that of an air spring in which the bent portion 17a is not formed. Thereby, when the built-in stopper 16 disposed on the second facing surface 12a is compressed during deflation, the restricting metal member 17 and the second facing surface 12a are more likely to come into contact with each other. As a result, the compression amount of the built-in stopper 16 at the time of deflation is reduced, and the amount of settlement of the vehicle body is suppressed. In the air spring 1, a seal portion 12 b is formed on the second facing surface 12 a outside the restricting metal member 17 so as to face the bent portion 17 a in the direction perpendicular to the main load direction during deflation. For this reason, when the restricting bracket 17 is to be displaced in a direction perpendicular to the main load direction, the displacement is limited by the contact between the bent portion 17a and the seal portion 12b. Thereby, the displacement in the said direction of the internal stopper 16 is restrict | limited, As a result, the fall of durability of the internal stopper 16 can be suppressed. As described above, the air spring 1 according to the present embodiment is an air spring capable of suppressing the amount of settlement of the vehicle body and a decrease in the durability of the stopper while maintaining good cushioning during deflation.

  In the air spring 1, the bent portion 17a and the seal portion 12b are formed such that the bent surface 17b and the seal inner wall surface 12c are in contact with each other. Thereby, the displacement of the built-in stopper 16 in the direction perpendicular to the main load direction can be more effectively limited. More specifically, the deformation of the built-in stopper 16 in this direction can be restricted. As a result, the deterioration of the durability of the built-in stopper 16 can be more effectively limited.

  Thus, when the bent surface 17b and the seal inner wall surface 12c are brought into contact with each other, the displacement of the built-in stopper 16 in the direction perpendicular to the main load direction can be effectively limited, while the outer cylinder 11 and If the slidability with respect to the restricting bracket 17 is poor (the frictional resistance is large), the impact and vibration applied from the direction are not sufficiently mitigated, and the derailment coefficient of the vehicle may increase. In this case, as shown in FIG. 1, a sliding member 11d made of a low friction material is provided on the first facing surface 11c facing the lower surface plate 12 of the outer cylinder 11 and the surface 17c facing the outer cylinder 11 of the restricting bracket 17. 17d may be arranged respectively. Thereby, the impact and vibration applied from the direction perpendicular to the main load direction can be effectively mitigated by the slip generated between the outer cylinder 11 and the restricting bracket 17.

  In the air spring 1, a sliding member (not shown) made of a low friction material may be disposed on at least one of the bent surface 17b and the seal inner wall surface 12c. As a result, when the built-in stopper 16 is compressed during deflation and the restricting bracket 17 is lowered toward the lower surface plate 12, the frictional resistance between the bent portion 17a of the restricting bracket 17 and the seal portion 12b is reduced. As a result, the lowering operation of the limit fitting 17 during deflation becomes smooth, and the built-in stopper 16 can be compressed more easily.

  Moreover, in the air spring 1, although it is easy to form the seal part 12b on the 2nd opposing surface 12a outside a limit metal fitting 17, it is not restricted to this. That is, the seal portion 12b only needs to be formed so as to face the bent portion 17a of the limit fitting 17 in a direction perpendicular to the main load direction and to be exposed when viewed in plan from above the limit fitting 17. For example, the seal portion 12 b may be formed on the second opposing surface 12 a that is the center portion of the lower surface plate 12 and that is on the inner side of the restriction bracket 17.

  In the air spring 1, the external stopper 14 may have a structure in which a plurality of hard layers 14 a and elastic layers 14 b are alternately stacked in the main load direction, but is not limited thereto. That is, the external stopper 14 is only required to be elastically deformable. As shown in FIG. 5, for example, a conical surface centered on the axis P is formed on the outer periphery of the stopper support member 14c having a hollow portion in the region including the axis P. You may have the structure where the elastic layer 14b which consists of the block-shaped rubber | gum which has is arrange | positioned. Further, as shown in FIG. 6, the stopper support member 14c has a structure in which a plurality of hard layers 14a and elastic layers 14b are alternately stacked so as to form a conical surface with the axis P as the center. May be. Further, the external stopper 14 does not have the laminated structure as described above, and may be a massive rubber.

  Further, in the air spring 1, the built-in stopper 16 may be a lump rubber, but is not limited thereto. That is, the built-in stopper 16 is only required to be elastically deformable, and may have a structure in which a plurality of hard layers and elastic layers are alternately stacked in the main load direction, similarly to the external stopper 14. In addition, it has a structure in which a plurality of hard layers and elastic layers are alternately stacked on the outer peripheral portion of the stopper support member having a hollow portion in the region including the axis P so as to form a conical surface with the axis P as the center. May be.

  Moreover, in the air spring 1, as shown in FIG. 7, the restricting metal fitting 17 may be arranged so that the built-in stopper 16 is maintained in a pre-compressed state. Thereby, the compression amount of the built-in stopper 16 at the time of deflation is further reduced, and as a result, the sinking amount of the vehicle body can be more effectively suppressed.

(Embodiment 2)
Next, Embodiment 2 which is another embodiment of the present invention will be described. First, the structure of the air spring 2 of the present embodiment will be described. The air spring 2 of the present embodiment basically has the same configuration as that of the air spring 1 of the first embodiment and has the same effects. However, the air spring 2 according to the present embodiment is different from the air spring 1 according to the first embodiment in the positional relationship between the restriction fitting and the seal portion.

Referring to FIG. 8, in the air spring 2, the bent portion 27 a and the seal portion 22 b of the limit metal fitting 27 are formed at a distance d from each other in a direction perpendicular to the main load direction. Further, in the air spring 2, the spring constant of the built-in stopper 26 is K, and the static friction coefficient of the sliding surface of the sliding member 27d disposed on the surface 27c opposite to the side of the limiting bracket 27 disposed on the built-in stopper 26 is provided. the mu _s, if the normal force at the contact surface between the sliding member 27d and the sliding member 21d disposed on first opposing face 21c and the F _z, the relationship Kd ≧ μ _s F _z is may be filled In addition, the relationship of Kd <μ _s F _z may be satisfied. The normal force _Fz is appropriately selected depending on the design of the entire vehicle.

Next, the operation of the air spring 2 of the present embodiment will be described. First, the operation of the air spring 2 when the relationship of Kd ≧ μ _s F _z is satisfied will be described. Referring to FIG. 9, first, the deflated state in which the pressure in the diaphragm 23 is reduced is reached, and the sliding member 21 d arranged in the outer cylinder 21 and the sliding member 27 d arranged in the restricting metal fitting 27 come into contact with each other. . Next, referring to FIG. 10, a load (including impact and vibration) is applied from the direction perpendicular to the main load direction during vehicle travel, and the built-in stopper 26 is displaced in that direction. Here, the elastic force Kd of the built-in stopper 26 when the built-in stopper 26 is displaced by the distance d is equal to or greater than the maximum static friction force μ _s F _z applied to the outer cylinder 21. Therefore, the force applied to the outer cylinder 21 as the reaction force of the elastic force Kd of the built-in stopper 26 is maximum before the built-in stopper 26 is displaced by the distance d, that is, before the bent portion 27a of the limit metal fitting 27 contacts the seal portion 22b. The static friction force μ _s F _z or more, and as a result, slip occurs between the outer cylinder 21 and the limit fitting 27. 11 and 12, the outer cylinder 21 slides on the limit fitting 27 while receiving the dynamic friction force μ _d F _z (μ _d : dynamic friction coefficient on the sliding surface of the sliding member 27d). Thus, when the air spring 2 satisfies the relationship of Kd ≧ μ _s F _z , even if a load is applied to the air spring 2 from a direction perpendicular to the main load direction, Therefore, the occurrence of an impact due to the collision between the limit metal fitting 27 and the seal portion 22b is suppressed.

Next, the action of the air spring 2 when the relationship of Kd <μ _s F _z is satisfied will be described. Referring to FIG. 13, first, as in the case described above, the deflated state in which the pressure in the diaphragm 23 is reduced is established, and the sliding member 21d and the sliding member 27d are in contact with each other. Next, referring to FIG. 14, when a load is applied to the air spring 2 from a direction perpendicular to the main load direction, the built-in stopper 26 is displaced in that direction. Here, the elastic force Kd of the built-in stopper 26 when the built-in stopper 26 is displaced by the distance d is smaller than the maximum static friction force μ _s F _z applied to the outer cylinder 21. Therefore, the force applied to the outer cylinder 21 as the reaction force of the elastic force Kd of the built-in stopper 26 is maximum before the built-in stopper 26 is displaced by the distance d, that is, before the bent portion 27a of the limit metal fitting 27 contacts the seal portion 22b. It becomes smaller than the static friction force μ _s F _z . As a result, as shown in FIG. 15, before the slip between the outer cylinder 21 and the limit fitting 27 occurs, the bent portion 27a of the limit fitting 27 comes into contact with the seal portion 22b. Then, as shown in FIG. 16, by further applying a load from a direction perpendicular to the main load direction, the outer cylinder 21 slides on the limit metal fitting 27 while the displacement of the built-in stopper 26 in the direction is limited. .

  As described above, in the air spring 2 according to the present embodiment, the bent portion 27a and the seal portion 22b of the limit metal fitting 27 are formed at intervals from each other in the direction perpendicular to the main load direction. Thereby, the load applied from the direction can be easily reduced while restricting the displacement of the built-in stopper 26 in the direction. That is, a minute load applied from the direction can be relaxed by the displacement of the built-in stopper 26, and as a result, the riding comfort of the vehicle can be improved. For example, when the load applied in the direction is very small, such as when the vehicle travels in a straight line, the built-in stopper 26 is displaced to reduce the load. When an excessive load is applied in the direction such as when the vehicle is traveling on a curve, the displacement of the built-in stopper 26 is limited to a certain amount, and the load is caused by the slip generated between the outer cylinder 21 and the limit metal fitting 27. Is alleviated.

Further, when the air spring 2 satisfies the relationship of Kd ≧ μ _s F _z , slipping between the outer cylinder 21 and the limit fitting 27 occurs without the limit fitting 27 and the seal portion 22b coming into contact with each other, and thereby The load is relaxed. Thereby, when a load is applied from a direction perpendicular to the main load direction, it is possible to cause a slip between the outer cylinder 11 and the limit fitting 17 before the bent portion 27a and the seal portion 12b come into contact with each other. As a result, the riding comfort of the vehicle can be further improved.

In the air spring 2, the static friction coefficient μ _s is preferably 0.4 or less, and more preferably 0.2 or less. Thereby, it becomes easier for the air spring 2 to satisfy the relationship of Kd ≧ μ _s F _z . As a result, it becomes easier to cause the slip between the outer cylinder 21 and the limit fitting 27 while suppressing the contact between the limit fitting 27 and the seal portion 22b.

  In the air spring 2, the distance d between the bent portion 27 a and the seal portion 22 b is preferably ½ or less of the height of the built-in stopper 26. As described above, the distance d between the bent portion 27a and the seal portion 22b, that is, the distance that the built-in stopper 26 can be displaced in the direction perpendicular to the main load direction, suppresses a decrease in durability of the built-in stopper 26. It can be within a possible range.

In the air spring 2, an elastic member such as rubber may be disposed on at least one of the bent surface 27b and the seal inner wall surface 22c. Thus, when the air spring 2 satisfies the relationship Kd <μ _s F _z , when a load is applied from a direction perpendicular to the main load direction and the bent portion 27a and the seal portion 22b collide, the impact due to the collision is caused. Can be relaxed by the elastic member.

  Further, in the air spring 2, when the frictional resistance between the bent portion 27a and the second opposing surface 22a of the lower surface plate 22 is sufficiently larger than the frictional resistance between the sliding members 21d and 27d, the frictional resistance is concerned. Thus, the displacement of the built-in stopper 26 in the direction perpendicular to the main load direction can be limited.

  In the air springs 1 and 2 according to the first and second embodiments, the built-in stoppers 16 and 26 are provided on the second facing surfaces 12a and 22a, which are the surfaces facing the outer cylinders 11 and 21 of the bottom plates 12 and 22, respectively. Although only the case where it arrange | positions was demonstrated, the air spring of this invention is not restricted to this. That is, referring to FIG. 17, in the air spring of the present invention, the built-in stopper 36 is disposed on the first facing surface 31 c that is the surface facing the lower surface plate 32 of the outer cylinder 31, and is outside the restricting bracket 37. The air spring 3 in which the seal portion 31e protruding in the direction along the main load direction is formed on the first facing surface 31c may be used. As shown in FIG. 17, in the air spring 3, the seal portion 31e faces the bent portion 37a in the direction perpendicular to the main load direction during deflation. Referring to FIG. 18, the air spring of the present invention is an air spring 4 in which a built-in stopper 46 is disposed on a third facing surface 45 c that is a surface facing the outer cylinder 41 of the rubber lower surface plate 45. Also good. As shown in FIG. 18, the built-in stopper 46 is disposed so as to be positioned above the lower surface plate 42 in the main load direction. Thereby, the built-in stopper 46 of the air spring 4 can function for improving the cushioning property in the vertical direction during deflation, as is the case with the built-in stoppers 16, 26, and 36 of the air springs 1, 2, and 3. . As described above, the air springs 3 and 4 have the same effects as the air springs 1 and 2, although the structure of the air springs 3 and 4 is different from the air springs 1 and 2 of the first and second embodiments in the arrangement of the built-in stopper.

  The embodiment disclosed this time is to be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The air spring of the present invention can be particularly advantageously applied to an air spring that is required to suppress the amount of settlement of the vehicle body and a decrease in the durability of the stopper while maintaining good cushioning during deflation.

  1, 2, 3, 4 Air spring, 11, 21, 31, 41 Outer cylinder, 11a Car body side spigot, 11b, 15b O-ring, 11c, 21c, 31c First facing surface, 11d, 17d, 21d, 27d Sliding member , 12, 22, 32, 42 Lower surface plate, 12a, 22a Second facing surface, 12b, 22b, 31e Seal portion, 12c, 22c Seal inner wall surface, 13, 23 Diaphragm, 14 External stopper, 14a Hard layer, 14b Elastic layer , 14c Stopper support member, 15, 45 Rubber lower plate, 15a Bogie side spigot, 15c Support surface, 16, 26, 36, 46 Built-in stopper, 17, 27, 37 Restriction bracket, 17a, 27a, 37a Bending portion, 17b, 27b Bending surface, 17c, 27c surface, 45c Third opposing surface.

In the air spring, the distance between the first displacement limiting portion and the second displacement limiting portion is d, the spring constant of the second stopper is K, and the side opposite to the side of the fourth support member disposed on the second stopper. static friction coefficient mu _s of the slip plane that put the sliding member disposed on the side surface, vertical in the contact surface between the sliding member, the sliding member disposed on the first opposing face and the second opposing face When the drag force is F _z , the relationship of Kd ≧ μ _s F _z may be satisfied. Thus, when an external force is applied from a direction perpendicular to the main load direction, the first support member and the fourth support member or the second support member are brought into contact before the first displacement limiter and the second displacement limiter come into contact with each other. And a fourth support member can be slid. As a result, the riding comfort of the vehicle can be further improved.

Claims (5)

A first support member;
A second support member disposed at an interval in the main load direction as viewed from the first support member;
A diaphragm that is elastically deformable by forming a closed space by connecting the first support member and the second support member;
A first stopper disposed on the opposite side of the first support member as viewed from the second support member and elastically deformable;
A third support member disposed on the side opposite to the second support member side as viewed from the first stopper;
A first facing surface that is a surface facing the second supporting member of the first supporting member, a second facing surface that is a surface facing the first supporting member of the second supporting member, or the third supporting member. A second stopper that is arranged on a second stopper support surface that is one of the third opposing surfaces that are the surfaces facing the first support member, and is elastically deformable,
A fourth support member disposed on the side opposite to the second stopper support surface side when viewed from the second stopper;
The fourth support member is formed with a first displacement limiting portion protruding so as to approach the second stopper support surface side,
A second displacement limit projecting in a direction along the main load direction on the first facing surface or the second facing surface and facing the first displacement limiting portion in a direction perpendicular to the main load direction during deflation. Part is formed,
The first displacement limiting portion and the second displacement limiting portion are opposed to the surface of the first displacement limiting portion that faces the second displacement limiting portion and the first displacement limiting portion of the second displacement limiting portion during deflation. The air springs are formed so as to be along each other in the main load direction.   The first displacement limiting portion and the second displacement limiting portion are opposed to the surface of the first displacement limiting portion that faces the second displacement limiting portion and the first displacement limiting portion of the second displacement limiting portion during deflation. The air spring according to claim 1, wherein the air springs are formed so as to contact each other.   2. The air spring according to claim 1, wherein the first displacement limiting portion and the second displacement limiting portion are formed to be spaced from each other in a direction perpendicular to the main load direction during deflation. The distance between the first displacement limiting portion and the second displacement limiting portion is d, the spring constant of the second stopper is K, and the side opposite to the side of the fourth support member disposed on the second stopper. Assuming that the coefficient of static friction of the sliding surface, which is the side surface, is μ _s , and the vertical effect at the contact surface between the sliding surface and the first support surface or the second support surface is F _z , Kd ≧ μ _s F _z The air spring according to claim 3, wherein the relationship is satisfied. The air spring according to claim 4, wherein a static friction coefficient μ _s of the sliding surface is 0.4 or less.

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