Air spring diaphragm and method for mounting the air spring diaphragm

Abstract

To provide an air spring diaphragm which can suppress the generation of winkles, can make appearance favorable, and can suppress an increase of a material cost, man-hours and weight, and an attachment method of the air spring diaphragm.SOLUTION: In an air spring diaphragm 23 composed of an elastic material having an annular upper bead part 35 fittable to an upper face plate 20 fixed to a vehicle body side, an annular lower bead part 36 fittable to a laminated rubber upper plate 21 fixed to a bogie side, and a cylindrical main body part 39 interposed between the upper bead part 35 and the lower bead part 36, the main body part 39 is composed of a main material layer formed of a material having flexibility, and a reinforcing layer embedded into the main material layer in a state of extending along a circumferential direction of the main body part 39, and a cord joint 54 obtained by superimposing end parts of the reinforcing layer in the circumferential direction of the main body part 39 by a prescribed length is arranged in a position intersecting with a winkle generation position 55 in which winkles are liable to be generated when the upper face plate 20 is displaced in a fore-and-aft (left-and-right) direction with respect to the laminated rubber upper plate 21.SELECTED DRAWING: Figure 12

Description

Technical Field

[0004] , , , , , , , , , , , , , , , , , , ,

[0005]

[0001] The present invention relates to a diaphragm for an air spring and a method for attaching the diaphragm for an air spring.

Background Art

[0002] For example, as disclosed in Patent Documents 1 to 3, an air spring for a railway vehicle includes an upper surface plate on the vehicle body side, a lower surface plate on the bogie side, and an annular diaphragm disposed across the upper surface plate and the lower surface plate. In many cases, an elastic body such as laminated rubber is provided on the lower side of the diaphragm.

[0003] Currently newly manufactured railway vehicle bogies are mainly of a bolsterless structure. Therefore, an air spring for a railway vehicle is mainly required for a bolsterless bogie. An air spring for a bogie with a bolster bears (absorbs) displacements in the vertical and lateral directions. In contrast, an air spring for a bolsterless bogie bears, in addition to the burden of the above displacements, the longitudinal displacement associated with bogie rotation. Therefore, in fact, higher strength and higher rigidity have been required for diaphragms for bolsterless bogies.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] The diaphragm is subjected not only to vertical loads but also to longitudinal displacements associated with the rotation of the bogie, which can sometimes cause wrinkles. Relative rotation between the bolsterless bogie and the railway vehicle during curved travel is absorbed by the torsional deformation and shear displacement of the diaphragm, causing folds to form on the diaphragm surface with use. Repeated folding leaves traces of these folds, i.e., wrinkles. Repeated folding can lead to the progression of cracks or delamination between materials.

[0006] An effective way to prevent wrinkle formation is to increase the rigidity of the diaphragm, and one way to do this is to increase the number of reinforcing layers, i.e., the number of plies (layers). However, increasing the number of plies increases material costs and manufacturing time, and the increased weight is a drawback.

[0007] The object of the present invention is to provide an air spring diaphragm and a method for mounting an air spring diaphragm that can suppress the occurrence of wrinkles, improve appearance, and reduce increases in material costs, manufacturing time, and weight. [Means for solving the problem]

[0008] The air spring diaphragm according to the present invention is made of an elastic material and has an annular upper bead portion that can be fitted to an upper plate fixed to the vehicle body, an annular lower bead portion that can be fitted to a lower plate fixed to the bogie, and a cylindrical main body portion interposed between the upper bead portion and the lower bead portion. The main body portion consists of a main material layer made of a flexible material and a reinforcing layer embedded in the main material layer in a state that extends along the circumferential direction of the main body portion, and a cord joint, which is the circumferential end of the reinforcing layer of the main body portion, is provided at a position that intersects with the wrinkle generation position that occurs when the upper plate is displaced forward or backward in the direction of travel relative to the lower plate.

[0009] The mounting method according to the present invention is a mounting method for attaching an air spring diaphragm to a bogie provided under the vehicle body, wherein the air spring diaphragm is attached to the bogie such that the mark indicating the position of the cord joint aligns with a specific position where wrinkles may occur when the upper plate is displaced forward or backward in the direction of travel relative to the lower plate. [Effects of the Invention]

[0010] According to the present invention, a joint formed by overlapping the circumferential ends of the main body of the reinforcing layer by a predetermined length is provided at a position that intersects with the wrinkle generation location that occurs when the upper plate is displaced forward or backward in the direction of travel relative to the lower plate. As a result, the generation of wrinkles can be suppressed, the appearance of the diaphragm can be improved, and the increase in material costs, manufacturing man-hours, and weight of the diaphragm can be suppressed. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view showing a bogie for a railway vehicle using an air spring, which is one embodiment of this invention. [Figure 2] This is a cross-sectional view showing an air spring for railway vehicles. [Figure 3] This is a side view showing a diaphragm used in an air spring, with a cross-sectional view showing the area to the right of the center line. [Figure 4] This is a cross-sectional view showing the upper bead portion of the diaphragm. [Figure 5] This is a cross-sectional view showing the lower bead portion of the diaphragm. [Figure 6] This is a cross-sectional view of the main part of the diaphragm, showing a portion of it broken open. [Figure 7] This is a magnified view of the key area, showing the angle at which the gaps in the grid created by the intersection of the first layer's 1-ply cord and the second layer's 2-ply cord become smaller. [Figure 8] This is a magnified view of the key area, showing the angle at which the gaps in the grid created by the intersection of the first layer's 1-ply cord and the second layer's 2-ply cord become larger. [Figure 9]An example showing the positions of the inner rubber joint, outer rubber joint, 2-ply joint, and 1-ply joint, which is a plan view of the diaphragm seen from above. [Figure 10] Another example showing the positions of the inner rubber joint, outer rubber joint, 2-ply joint, and 1-ply joint, which is a plan view of the diaphragm seen from above. [Figure 11] Another example showing the positions of the inner rubber joint, outer rubber joint, 3 / 4-ply joint, and 1 / 2-ply joint, which is a plan view of the diaphragm seen from above. [Figure 12] A side view showing a diaphragm provided with a ply joint intersecting the wrinkle generation position. [Figure 13] A side view showing a diaphragm provided with a cross ply joint intersecting the wrinkle generation position. [Figure 14] A process diagram showing the manufacturing process of an air spring for railway vehicles. [Figure 15] A reference diagram showing the wrinkle generation positions occurring in the first and second diaphragms provided on the first car body and the third and fourth diaphragms provided on the second car body, respectively, of a vehicle traveling on a curve. [Figure 16] A side view of an air spring showing the wrinkle generation position where wrinkles occur when the upper panel is displaced forward in the traveling direction with respect to the lower panel. [Figure 17] A side view of an air spring showing the wrinkle generation position where wrinkles occur when the upper panel is displaced backward in the traveling direction with respect to the lower panel.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, a diaphragm for an air spring, which is an embodiment of this invention, will be described with reference to the drawings. Hereinafter, basically, the diaphragm for an air spring is abbreviated as "diaphragm", and the air spring for railway vehicles is abbreviated as "air spring", respectively. Note that the diaphragm for an air spring of this invention is not limited to railway vehicles, and may be used for, for example, automobiles or the like.

[0013] Fig. 1 shows a schematic view of a bogie 10 that constitutes a railway vehicle. The bogie 10 is, for example, a bolsterless bogie, and a car body is installed on the bogie 10. Air springs 11 and 12 are installed between the bogie 10 and the car body. In Fig. 1, the car body is omitted to prevent complication of the drawing.

[0014] The bogie 10 is a running device that integrally houses a wheel set (wheel and axle), a bearing, a journal box, a driving device, a basic braking device, etc., and is attached under the car body. The components that make up the bogie 10 include a wheel set, a bogie frame (the largest structural member of the bogie) 13, a primary spring (such as a coil spring that connects the wheel set and the bogie frame 13) as a suspension, a secondary spring (connects the bogie frame 13 and the car body, mainly including air springs 11 and 12, etc.), a main electric motor as a running device, a gear device, a braking device, etc.

[0015] The bogie frame 13 is composed of side beams 14 and 15 and cross beams 16 and 17 that are main strength members. The side beams 14 and 15 are arranged on both sides in the traveling direction of the bogie frame 13, and they are welded together by the cross beams 16 and 17, and have a structure that is approximately H-shaped when viewed from above. The cross beams 16 and 17 protrude from the left and right side beams 14 and 15. The air springs 11 and 12 are respectively installed on the protruding parts of the cross beams 16 and 17. That is, the air springs 11 and 12 are respectively arranged approximately at the center of the left and right side beams 14 and 15.

[0016] Note that the bogie 10 includes a bogie type that supports one car body with two bogies 10 and a connecting bogie that arranges a bogie between car bodies. Hereinafter, the air springs 11 and 12 attached to the bogie will be described. Note that the air spring of this invention may be attached to a connecting bogie. Also, both the air spring 11 and the air spring 12 have the same configuration.

[0017] As shown in Figure 2, the air spring 11 comprises an upper plate 20, a lower plate (hereinafter referred to as the laminated rubber upper plate) 21, a diaphragm 23 sandwiched between the upper plate 20 and the laminated rubber upper plate 21, and laminated rubber 24 attached to the lower surface of the laminated rubber upper plate 21.

[0018] The top plate 20 is attached to the vehicle body. The laminated rubber top plate 21 is attached to the bogie. The diaphragm 23 has openings at the top and bottom, and is cylindrical in shape, with the central part in the direction of the central axis 25 bulging radially outward more than both ends.

[0019] The center of the top plate 20 has a first air supply pipe 26 protruding upward, which communicates with the internal space of the diaphragm 23. The first air supply pipe 26 is connected to a vehicle height adjustment valve (not shown) for adjusting the height of the vehicle body. On the lower side of the top plate 20, a rubber elastic member 27 is fixed to its periphery, and an upper connecting member 28, which is concentric with the top plate 20, is fixed inside the elastic member 27. An upper sliding plate 29 is laminated on the lower surface of the upper connecting member 28. The upper opening of the diaphragm 23 is closed by the top plate 20, the upper connecting member 28, etc.

[0020] The laminated rubber upper plate 21 is a rigid, annular structure concentric with the upper plate 20, and is made of a steel plate such as stainless steel. A lower connecting member (hereinafter referred to as a bead sheet) 31, which is concentric with the laminated rubber upper plate 21 and faces the upper connecting member 28, is fixed to the upper surface of the laminated rubber upper plate 21 by bolts 32. An air vent 33 communicating with the internal space of the diaphragm 23 is formed in the center of the bead sheet 31. A lower sliding plate 34 is laminated on the upper surface of the bead sheet 31.

[0021] The diaphragm 23 is a rubber elastic membrane formed in the shape of a tire. The upper bead portion 35, which is the upper opening edge, is held down by the top plate 20 and the upper connecting member 28, while the lower bead portion 36, which is the lower opening edge, is held down by the laminated rubber top plate 21 and the bead sheet 31. As a result, the diaphragm 23 is held between the top plate 20 and the laminated rubber top plate 21, preventing air from leaking out of the internal space.

[0022] As shown in Figure 3, the diaphragm 23 is an annular (tubular) membrane made of an elastic material having an upper bead portion 35, a lower bead portion 36, and a main body portion 39 interposed between the upper bead portion 35 and the lower bead portion 36. The main body portion 39 consists of a main material layer 43 (see Figures 4 and 5) made of a flexible material and a reinforcing layer 46 embedded in the main material layer 43 (see Figures 4 and 5) in a state that extends along the circumferential direction of the main body portion 39 (circumferential direction of the main body portion). Note that Figure 3 shows the form of the diaphragm 23 in its product state as a component before it is assembled as an air spring 11.

[0023] As shown in Figure 4, the upper bead portion 35 is fitted onto the upper bead wire 37, which is a ring-shaped fitting. In other words, the upper bead portion 35 is held in an annular opening shape that can be fitted onto the upper plate 20 (see Figure 2) which is fixed to the vehicle body.

[0024] As shown in Figure 5, the lower bead portion 36 is fitted onto the lower bead wire 38, which is a ring-shaped fitting. In other words, the lower bead portion 36 is held in an annular opening shape that can be fitted onto the laminated rubber upper plate 21 (see Figure 2) which is fixed to the trolley side.

[0025] As shown in Figure 6, the diaphragm 23 is manufactured with a three-layer structure consisting of an inner rubber layer 40, an outer rubber layer 41, and an intermediate reinforcing layer 46. The inner rubber layer 40 and the outer rubber layer 41 constitute the main material layer 43 and are rubber layers with excellent flexibility, weather resistance, aging resistance, and airtightness.

[0026] The reinforcing layer 46 consists of a first reinforcing layer 44 and a second reinforcing layer 45 positioned on the radially outer side of the first reinforcing layer 44, and is a strong reinforcing material for reinforcing the diaphragm 23. When the second reinforcing layer 45 is placed over the first reinforcing layer 44, it is sometimes called a two-ply structure. Ply indicates the number of layers of the reinforcing layer 46. However, the configuration of the plies that create the diaphragm 23 is an even number of layers, as an odd number of layers would not allow the diaphragm 23 to function. The reinforcing layer 46 may also have a laminated structure of four or more layers. The first reinforcing layer 44 and the second reinforcing layer 45 consist of a sheet formed by weaving together a fibrous core material (referred to as tire cord), such as nylon cord, and covered with an elastic material such as rubber. The tire cord of the first reinforcing layer 44 and the tire cord of the second reinforcing layer 45 are arranged, for example, diagonally to each other. The first reinforcing layer 44 and the second reinforcing layer 45 are provided to extend along the circumferential direction of the main body 39. The circumferential ends of the main body portion 39 of the first reinforcing layer 44 are overlapped to form a cord joint (connection) of the first reinforcing layer 44. The cord joint formed in the first reinforcing layer 44 is called a 1-ply joint. The circumferential ends of the main body portion 39 of the second reinforcing layer 45 are overlapped to form a cord joint of the second reinforcing layer 45. The cord joint formed in the second reinforcing layer 45 is called a 2-ply joint. The cord joints, which are the circumferential ends of the main body portion 39 of the reinforcing layer 46, are not only more rigid than the outer layer rubber 41 and the inner layer rubber 40, but also more rigid than the main material layers 43 other than the joints. The joint portion is indicated as a cord joint (connection).

[0027] The upper end of the reinforcing layer 46 is wrapped around the upper bead wire 37. While Figure 6 illustrates the upper end of the reinforcing layer 46, the lower end of the reinforcing layer 46 is wrapped around the lower bead wire 38 (see Figure 5). The reinforcing layer 46 is not limited to nylon; it can be made from materials such as polyester, aramid, or rayon.

[0028] An important characteristic related to ride comfort for the air spring 11 is the "spring constant," which represents the load required to displace the air spring 11 in the vertical, longitudinal, and lateral directions. Among the components that make up the air spring 11, the spring constant is provided by the combination of the laminated rubber 24 and the diaphragm 23. Here, the vertical direction is the direction perpendicular to the rail when the air spring is viewed from the side. The longitudinal direction is the direction parallel to the rail when the air spring is viewed from above. The lateral direction is the direction perpendicular to the rail when the air spring is viewed from above.

[0029] The diaphragm 23 is a composite material in which a reinforcing layer 46, having an arrangement angle during molding, is embedded in a curved main material layer 43, consisting of a first reinforcing layer 44 and a second reinforcing layer 45. The reinforcing layer 46 has more than 100 times the rigidity of the rubber (main material layer 43) that forms the inner and outer rubber layers 40 and 41, and greatly affects the spring constant of the air spring 11.

[0030] In order to set a predetermined spring constant, the second reinforcing layer 45 is molded to a specific alignment angle relative to the first reinforcing layer 44. As shown in Figures 7 and 8, the first reinforcing layer 44 and the second reinforcing layer 45 are stacked alternately with an angle of code angle θ1 or code angle θ2 relative to the vertical when viewed through the two layers from the circumferential direction.

[0031] For example, as shown in Figure 7, when angle θ1 is smaller than angle θ2, the area of ​​the grid generated by the intersection of the first reinforcing layer 44 and the second reinforcing layer 45 becomes larger than the grid shown in Figure 8, and the spring becomes softer.

[0032] Conversely, as shown in Figure 8, when angle θ2 is greater than angle θ1, the area of ​​the grid becomes smaller than that of the grid shown in Figure 7, increasing the rolling resistance and thus making the spring stiffer. Angles θ1 and θ2 are the angles between the vertical line and the second reinforcing layer 45, and are half the chord angle when viewing the second reinforcing layer 45 and the first reinforcing layer 44 from the circumferential direction. The diaphragm 23 becomes softer as its spring constant (strength of repulsive force) decreases, and stiffer as its spring constant increases.

[0033] The reinforcing layer 46 is molded by being wrapped around the drum during manufacturing. As a result, a joint (seam) is created at least one location on the outer circumference of the diaphragm 23. Joints also occur in the inner rubber layer 40 and the outer rubber layer 41. In other words, if the reinforcing layer 46 is made of two plies, four types of joints will be created: an inner rubber joint, an outer rubber joint, a one-ply joint, and a two-ply joint. The inner rubber joint is formed by overlapping the circumferential ends of the main body portion 39 of the inner rubber layer 40. The outer rubber joint is formed by overlapping the circumferential ends of the main body portion 39 of the outer rubber layer 41.

[0034] As shown in Figure 9, when viewing the diaphragm 23 from above, the joints can be positioned as follows: an inner layer rubber joint 47 at a position to the left (0 degrees) from the central axis 25 of the diaphragm 23; an outer layer rubber joint 48 at a position to the right (180 degrees) from the central axis 25; a two-ply joint 49 at a position above (90 degrees) from the central axis 25; and a one-ply joint 50 at a position below (270 degrees) from the central axis 25. In other words, joints are provided at four division positions in all directions from the central axis 25 of the diaphragm 23. The inner layer rubber joint 47 and the outer layer rubber joint 48 are provided at positions opposite the central axis 25. Note that in Figure 9, the direction of travel is to the left (0 degrees) from the central axis 25 of the diaphragm 23.

[0035] Furthermore, as shown in Figure 10, when viewing the diaphragm 23 from above, an inner layer rubber joint 47 can be positioned to the left (0 degrees) from the central axis 25 of the diaphragm 23, an outer layer rubber joint 48 can be positioned diagonally upward to the right (135 degrees) from the central axis 25, and a cord joint consisting of a 1-ply joint 50 and a 2-ply joint 49 can be positioned diagonally downward to the right (225 degrees) from the central axis 25. Note that in Figure 10, the direction of travel is to the left (0 degrees) from the central axis 25 of the diaphragm 23.

[0036] Furthermore, when the reinforcing layer 46 is constructed with 4 plies, for example, as shown in Figure 11, when viewing the diaphragm 23 from above, an inner layer rubber joint 47 can be positioned to the left (0 degrees) from the central axis 25 of the diaphragm 23, an outer layer rubber joint 48 can be positioned to the right (180 degrees) from the central axis 25, a first cord joint (3 / 4 ply joint) 51 consisting of a 3 ply joint and a 4 ply joint can be positioned above (90 degrees) from the central axis 25, and a second cord joint (1 / 2 ply joint) 52 consisting of a 1 ply joint and a 2 ply joint can be positioned below (270 degrees) from the central axis 25. Note that in Figure 11, the direction of travel is to the left (0 degrees) from the central axis 25 of the diaphragm 23.

[0037] As shown in Figure 12, the cord joint 54 can be positioned along diagonal directions other than the horizontal direction when viewing the diaphragm 23 from the side. For example, the cord joint 54 can be positioned so as to extend approximately linearly from the upper left to the lower right of the side of the diaphragm 23. Although not shown, the cord joint 54 can also be positioned in the opposite direction, approximately linearly from the upper right to the lower left. The cord joint 54 is positioned to intersect with wrinkle occurrence locations 55 where wrinkles may occur. The cord joint 54 includes at least a single-ply joint 50 and a two-ply joint 49.

[0038] Alternatively, as shown in Figure 13, for example, two cord joints 54 may be arranged in an overlapping manner, crossing each other. One cord joint 54 is positioned so as to extend approximately linearly from the upper left to the lower right of the side surface of the diaphragm 23. The other cord joint 54 is positioned so as to extend approximately linearly from the upper right to the lower left of the side surface of the diaphragm 23. In this case, it is desirable to provide a cross-ply joint 56, formed by crossing the two cord joints 54, at a position that intersects with respect to the wrinkle formation position 55. Here, it is sufficient for the cross-ply joint 56 to partially intersect with respect to the wrinkle formation position 55.

[0039] As shown in Figure 14, the manufacturing process of the diaphragm 23 includes a cutting process 58, a molding process 59, a vulcanization process 60, and an assembly process 61. The reinforcing fiber rubber, such as the inner layer rubber 40, outer layer rubber 41, first reinforcing layer 44, and second reinforcing layer 45, which are cut in the cutting process 58, are supplied to the molding process 59. In the molding process 59, the reinforcing fiber rubber is fitted into a mold and molded while being pressurized with high-temperature, high-pressure gas. The molded diaphragm 23 is supplied to the vulcanization process 60.

[0040] In detail, during molding process 59, a cylindrical drum is used to form an unvulcanized rubber molded body by wrapping reinforcing fiber rubber (two or four layers of tire cord) and inner and outer rubber layers 40 and 41 around its outer surface in a cylindrical shape. At both ends of the unvulcanized rubber molded body, the wrapped inner and outer rubber layers 40 and 41 are folded back using the upper bead wire 37 and lower bead wire 38 to complete the unvulcanized rubber molded body.

[0041] At this time, the cylindrical molded body that has been wrapped has a smaller diameter at both ends in the vertical (height) direction than at the center, so after molding is complete, the cylindrical drum is disassembled and the molded body is removed. The removed unvulcanized rubber molded body is then inserted into the product mold in the vulcanization process 60, an airbag is placed inside, and high-pressure air is supplied to the airbag to pressurize it from the inside and vulcanize it to create the diaphragm 23. The finished diaphragm 23 is sent to the assembly process 61, where it is assembled into an air spring.

[0042] When a railway vehicle is traveling on a curve, a load is applied to the diaphragm 23 in the lateral (travel) direction, which may cause wrinkles to form on its sides. As shown in Figure 15, beneath the vehicle body 63, there are two bogies 10 equipped with wheels, one at the front and one at the rear in the direction of travel. The first bogie 10a is located at the front in the direction of travel, and the second bogie 10b is located at the rear in the direction of travel. Each bogie 10a and 10b is equipped with two diaphragms 23, so there are a total of four diaphragms (1st to 4th diaphragms 23a, 23b, 23c, and 23d). Each diaphragm 23a to 23d has a mark indicating the position of the code joint 54 at a predetermined position in the circumferential direction when viewed from above, and is attached to the bogie 10 so that the mark aligns with a specific position in the circumferential direction. In other words, the position of the joint can be determined from the position of the mark. The specific location is a position where wrinkles may occur when the top plate 20a is displaced forward or backward in the direction of travel relative to the laminated rubber top plate 21a.

[0043] As the car body 63 approaches a curve, the bogie 10 automatically changes direction to follow the curve and proceeds along the curved track. While the car body 63 is traveling along the curve, the first bogie 10a rotates by an angle of plus θ3 relative to the car body 63, and the second bogie 10b rotates by an angle of minus θ4. At this time, the first to fourth diaphragms 23a to 23d are subjected to loads that displace them in the left-right direction.

[0044] For example, in the first diaphragm 23a located on the left side in the direction of travel of the first bogie 10a, the top plate 20a is displaced forward (left side) in the direction of travel relative to the laminated rubber top plate 21a. At this time, when the first diaphragm 23a is viewed from above, a wrinkle may occur at a specific position (referred to as the first position) indicated by reference numeral 65 on the circular contour of the first diaphragm 23a. The first position 65 is visible from the inside 67 of the inner rail 66.

[0045] Furthermore, in the second diaphragm 23b located on the right side in the direction of travel of the first bogie 10a, the top plate 20b is displaced to the rear (right) side in the direction of travel relative to the laminated rubber top plate 21b. At this time, wrinkles may occur at a specific position (referred to as the second position) indicated by reference numeral 68 on the circular contour of the second diaphragm 23b. The second position 68 is visible from the outside 70 of the outer rail 69.

[0046] In the third diaphragm 23c of the second bogie 10b, located on the left side in the direction of travel, the top plate 20c is displaced to the rear (right) side in the direction of travel relative to the laminated rubber top plate 21c. At this time, wrinkles may occur at a specific position indicated by reference numeral 71 (referred to as the third position). The third position 71 is visible from the inside 67 of the inner rail 66.

[0047] Then, in the fourth diaphragm 23d located on the right side in the direction of travel of the second bogie 10b, the top plate 20d is displaced forward (left side) in the direction of travel relative to the laminated rubber top plate 21d. At this time, wrinkles may occur at a specific position indicated by reference numeral 73 (referred to as the fourth position). The fourth position 73 is visible from the outside 70 of the outer rail 69.

[0048] As described above, the specific position is where wrinkles may occur when the top plate 20 is displaced forward or backward in the direction of travel relative to the laminated rubber top plate 21. For this reason, when attaching the diaphragm 23 to the bogie 10 located under the vehicle body 63, the mark indicating the position of the cord joint 54 can be aligned with the specific position, thereby positioning the cord joint 54 at a location that intersects with the wrinkle occurrence position.

[0049] Wrinkles may occur in a roughly linear fashion from the upper left to the lower right, as shown in Figure 16, when the top plate 20 is displaced forward (left) in the direction of travel relative to the laminated rubber top plate 21. In Figure 16, the location where wrinkles occur is shown as the first wrinkle location 75. The first wrinkle location 75 appears on the left side of the main body 39 when the diaphragm 23 is viewed from the side. The first wrinkle location 75 shown in Figure 16 is likely to occur on the side of the first diaphragm 23a when viewed from the inside 67 of the inner rail 66 shown in Figure 15, and on the side of the fourth diaphragm 23d when viewed from the outside 70 of the outer rail 69.

[0050] Furthermore, wrinkles may occur in a nearly linear fashion from the upper right to the lower left, as shown in Figure 17, when the top plate 20 is displaced to the rear (right) side in the direction of travel relative to the laminated rubber top plate 21. In Figure 17, the location where wrinkles occur is shown as the second wrinkle location 76. The second wrinkle location 76 appears on the right side of the main body 39 when the diaphragm 23 is viewed from the side. The second wrinkle location 76 shown in Figure 17 is likely to occur on the side of the second diaphragm 23b when viewed from the outside 70 of the outer rail 69 shown in Figure 15, and on the side of the third diaphragm 23c when viewed from the inside 67 of the inner rail 66.

[0051] Therefore, it is preferable to provide the cord joint 54 so as to intersect with one of the wrinkle occurrence positions 75, 76 on the side surface of the diaphragm 23. Furthermore, it is preferable to provide the cord joint 54 in the range of angles within which it intersects with one of the wrinkle occurrence positions 75, 76, from the angle that forms a vertical line when viewed from the side surface of the diaphragm 23 to the angle that is just before the horizontal line. The most rigid and effective configuration is achieved when the cord joint 54 intersects with one of the wrinkle occurrence positions 75, 76 at approximately 90 degrees. Furthermore, if there is a risk of wrinkles occurring at two locations indicated by wrinkle occurrence positions 75, 76 on one side surface in the circumferential direction of the diaphragm 23, the wrinkle occurrence positions 75, 76 may appear in a V-shape with the central axis 25 of the diaphragm 23 as the pivot point. For this reason, it is preferable to provide two cord joints 54 in a roughly V-shape with the central axis 25 of the diaphragm 23 as the pivot point, intersecting with a part of each of the wrinkle occurrence positions 75, 76.

[0052] Furthermore, it is preferable to provide a cross-ply joint 56 at a position that intersects with the wrinkle formation positions 75 and 76. Preferably, the cross-ply joint 56 partially intersects with the wrinkle formation positions 75 and 76.

[0053] The air spring 11 using the diaphragm 23 described above is explained as being installed on the bolsterless bogie 10 shown in Figure 1, but this invention is not limited to this, and may be installed on, for example, a direct mount bogie having a bolster.

[0054] Furthermore, although the air spring 11 described above is as shown in Figure 2, this invention is not limited to this, and may also include air springs applied to railway vehicle suspension systems that have a different structure, mainly due to the laminated rubber 24, or diaphragms used in such air springs. In other words, the air spring may be configured to have a laminated rubber with a conical stopper structure. [Explanation of Symbols]

[0055] 10... Dolly 11, 12... Air spring 13... Bogie frame 20…Top plate 21…Bottom panel (laminated rubber top plate) 23... Diaphragm 24…Laminated rubber 25…Central axis 35... Upper bead section 36...Lower bead section 37… Upper bead wire 38... Lower bead wire 39...Main body 40...Inner layer rubber 41…Outer layer rubber 43…Main material layer 44…First reinforcement layer 45…Second reinforcement layer 46…Reinforcement 47…Inner layer rubber joint 48…Outer layer rubber joint 49…2-ply joint 50…1-ply joint 54... Code joint 55…Wrinkle formation location 56…Cross ply joint 65...First position (Wrinkle formation location) 66...Inner rail 67... Inside the inner rail 68...Second position (Wrinkle formation location) 69... External rail 70...Outside of the outer rail 71...3rd place value (Wrinkle occurrence location) 73...4th position (Wrinkle formation location) 75…First wrinkle formation location 76...Second wrinkle formation location

Claims

1. An air spring diaphragm made of an elastic material having an annular upper bead portion that can be fitted to an upper plate fixed to the vehicle body, an annular lower bead portion that can be fitted to a lower plate fixed to the bogie, and a cylindrical main body portion interposed between the upper bead portion and the lower bead portion, The main body consists of a main material layer made of a flexible material and a reinforcing layer embedded in the main material layer in a manner that extends along the circumferential direction of the main body. An air spring diaphragm in which the cord joint, which is the circumferential end of the reinforcing layer of the main body, is provided at a position that intersects with the wrinkle generation position that occurs when the upper plate is displaced forward or backward in the direction of travel relative to the lower plate.

2. The wrinkle formation location is, When the upper plate is displaced forward in the direction of travel relative to the lower plate, a first wrinkle formation position occurs linearly from the upper left to the lower right when the diaphragm is viewed from the left side in the direction of travel, The diaphragm for an air spring according to claim 1, which includes a second wrinkle generation position that occurs linearly from the upper right to the lower left when the upper plate is displaced to the rear in the direction of travel relative to the lower plate, when the diaphragm is viewed from the left side in the direction of travel.

3. The air spring diaphragm according to claim 2, wherein the cord joint is provided intersecting the wrinkle-generating position at a 90-degree angle.

4. The first wrinkle formation position appears to the left of the central axis of the main body when the diaphragm is viewed from the left side in the direction of travel. The air spring diaphragm according to claim 2, wherein the second wrinkle formation position appears to the right of the central axis of the main body when the diaphragm is viewed from the left side in the direction of travel.

5. The reinforcing layer comprises a first reinforcing layer and a second reinforcing layer disposed radially outward of the first reinforcing layer. The cord joint includes a one-ply joint which is the circumferential end of the first reinforcing layer to the main body and a two-ply joint which is the circumferential end of the second reinforcing layer to the main body. The diaphragm for an air spring according to claim 1, wherein a cross-ply joint formed by the intersection of the one-ply joint and the two-ply joint is provided at a position intersecting the wrinkle generation position.

6. The air spring diaphragm according to claim 5, wherein the cross-ply joint partially intersects with respect to the wrinkle generation position.

7. A mounting method for attaching an air spring diaphragm to a bogie located beneath the vehicle body, A mounting method for the air spring diaphragm according to any one of claims 1 to 6, wherein the mark indicating the position of the cord joint aligns with a specific position where wrinkles may occur when the upper plate is displaced forward or backward in the direction of travel relative to the lower plate.

Images