JP4419115B2 - Air spring for bolsterless bogie of railway vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air spring for a bolsterrel carriage of a railway vehicle, and more particularly to an air spring that can reduce deformation and wear of a rubber member that constitutes the air spring, thereby extending the service life.
[0002]
[Prior art]
Conventionally, air springs for railway vehicles have good ride comfort due to good vibration insulation and soft spring coefficient, and the height adjustment mechanism of the leveling valve allows the height of the vehicle to be increased. Since it has an advantage that a soft spring coefficient can be obtained without greatly changing the value, it is widely used.
[0003]
Here, the bolsterless bogie used for the railway vehicle rotates around the vertical axis of the bogie center with respect to the vehicle body during so-called bogies when passing through a curve. At this time, at the positions of the air springs at the left and right ends of the carriage, the front and rear displacement proportional to the span and rotation angle of the left and right air springs and the rotational displacement around the vertical axis are received.
[0004]
The air spring absorbs vibrations, and suppresses transmission of vibrations from the upstream side (trolley frame side) to the downstream side (vehicle body side). A rubber part (diaphragm) that can seal air under a variable displacement is provided. Due to the deformation, the rubber part causes a contact phenomenon with other parts.
[0005]
For example, when the bogie is bogie while passing through a curve, the air spring for the bolsterless bogie is displaced by about 150 mm in the horizontal direction at the upper portion (vehicle body side) and the lower portion (bogie frame side). Such displacement is absorbed by the deflection of the diaphragm constituting the air spring, but the diaphragm is deformed not only based on the longitudinal displacement but also based on the rotational displacement when the bogie is bogie.
[0006]
As described above, the diaphragm is made of a rubber material, and in an expanded state with an internal pressure, the diaphragm is in contact with the outer cylinder constituting the air spring and the rubber seat of the inner cylinder. Therefore, if the body is deformed by about 150 mm in the front-rear direction and is further twisted around the vertical axis by the bogie angle, there is a problem that wrinkles are generated in the diaphragm or the contact pressure at the contact portion increases.
[0007]
In particular, in a bolsterless bogie, since the air spring must allow large horizontal displacement and bogie angle (bogie rotation angle) when the bogie bogies, large deformation of the diaphragm occurs, The diaphragm may excessively contact the outer cylinder or the inner cylinder constituting the air spring, and wear may occur.
[0008]
Further, the work in a state in which such a frictional force is generated reduces the wear resistance, or the rubber melts and accelerates the wear of the rubber. These are factors that shorten the life of diaphragms and rubber members.
[0009]
[Problems to be solved by the invention]
The present invention was made to solve the problems of the prior art, and relaxed the contact conditions between the diaphragm constituting the air spring for a bolsterless bogie of a railway vehicle and the rubber member of the outer cylinder and the inner cylinder, An object of the present invention is to provide an air spring that can reduce the amount of wear of rubber and thereby extend the wear life of a diaphragm or a rubber member.
[0010]
[Means for Solving the Problems]
The inventors have intensively studied to achieve the above object, and devised the present invention by conducting a detailed study on the contact portion between the diaphragm and the rubber member of the inner cylinder or the outer cylinder. .
[0011]
That is, the present invention provides an air spring for a bolsterless bogie of a railway vehicle comprising a diaphragm and a rubber seat that contacts the diaphragm and supports the diaphragm, wherein the rubber seat includes a rubber member that contacts the diaphragm, A backing metal that supports a rubber member, and the rubber member is formed with a substantially constant thickness at a portion that contacts the diaphragm, and the backing metal is formed with the diaphragm of the rubber member. A support surface that supports the rubber member is formed so as to be substantially perpendicular to a perpendicular to the contact surface, and the rubber seat has a corner portion that contacts the diaphragm, and in a longitudinal section of the corner portion , bolus railcar radius of curvature of the contact portion between the diaphragm of the rubber member, characterized in that it is formed at least twice the thickness of the diaphragm It is to provide an air spring-less carriage.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a longitudinal sectional view showing a schematic configuration of an air spring according to an embodiment of the present invention. As shown in FIG. 1, the air spring 1 according to the present embodiment includes a diaphragm 2, and an inner cylinder 3 and an outer cylinder 4 that support the diaphragm 2. Here, the inner cylinder 3 includes a shear pack 5 and a rubber seat 6 that contacts the diaphragm 2 and supports the diaphragm 2. The rubber seat 6 includes a rubber member 7 that contacts the diaphragm 2 and a backing metal 8 that supports the rubber member 7. Further, a rubber member 7 is also provided inside the outer cylinder 4 that contacts the diaphragm 2, and is configured to perform the same function as the rubber seat 6.
[0015]
As shown in FIG. 8, the air spring 1 having such a configuration is mounted between the vehicle body 10 and the carriage 11 in use, and supports the vehicle body 10 in a state where the diaphragm 2 is expanded by the height adjusting mechanism 9.
[0016]
Hereinafter, the shape of the rubber seat 6 which is a feature of the air spring 1 according to the present embodiment will be described in detail.
[0017]
In general, rubber materials exhibit properties close to those of non-compressed materials, and the Poisson's ratio is also close to 0.5. It is known that when a compression or tension load is applied, the rubber material does not change in volume.
[0018]
That is, assuming that the strains in the x, y, and z axis directions are ε _x , ε _y , and ε _z ,
ε _x + ε _y + ε _z = 0 (1)
It can be expressed as. This means that the contact load is compressed and contracted in the direction in which the load is applied, but the elongation occurs in the direction perpendicular to the load direction.
[0019]
For example, when compressed in the x direction, that is, ε _x <0 (2)
In order to satisfy the above equation (1), ε _y + ε _z > 0 (3) inevitably.
And extend in the y and z directions.
[0020]
Here, if the extension in the vertical direction is constrained and does not extend freely,
ε _y + ε _z = 0 (4)
If it is, above to satisfy the equation (1) ε _x = 0 ··· (5)
This means that the compression is not easy and exhibits extremely hard physical properties in the load direction.
[0021]
If such a phenomenon occurs in the contact surface between the rubbers, it can be said that the contact pressure distribution in the region within the surface is concentrated and an increase in the maximum value of the contact surface pressure is easily induced.
[0022]
The shape of the rubber seat 6 according to the present embodiment has been devised based on the above-described concept, and the backing metal 8 supports a load in the compression direction and has a direction perpendicular to the load direction. The shape is such that the elongation of the rubber member 7 is not restricted.
[0023]
That is, the angle α formed by the perpendicular Φ of the contact surface μ of the rubber member 7 with the diaphragm 2 and the support surface γ supporting the rubber member 7 of the backing metal 8 is vertical. .
[0024]
In other words, first, define the perpendicular Φ as in the following equation (6),
Contact surface μ⊥ (vertical) perpendicular Φ of rubber member 7 (6)
Next, the angle α formed by the contact surface μ and the perpendicular Φ is always perpendicular on the support surface γ, that is,
α = 90 ° (7)
The shape of the support surface γ of the backing metal 8 is determined so as to always satisfy the relational expression.
[0025]
Here, as for the rubber seat 6 which concerns on this embodiment, the thickness of the part which contacts the diaphragm 2 of the rubber members 7 is formed substantially constant. This is because if the thickness of the rubber member 7 is changed, the deformation of the rubber member 7 is not uniform, and strain concentration and deformation restraint are likely to occur, which is avoided. As described above, the shape of the support surface γ of the backing metal 8 according to the present embodiment is determined under the incidental condition that the thickness of the rubber member 7 is constant.
[0026]
For example, as shown in FIG. 2, in the portion where the contact surface μ of the rubber member 7 is formed in an arc shape, the support surface γ of the backing metal 8 is concentric with the arc and the rubber member A shape having a radius of curvature smaller by the thickness of 7 is determined. Further, in the portion where the contact surface μ of the rubber member is formed on a straight line, the support surface γ of the backing metal 8 is also a straight line parallel to the contact surface μ, and the restriction of the rubber member 7 is minimized as a whole. It is supposed to be a shape that becomes
[0027]
Here, as shown in FIG. 1 described above, the diaphragm 2 is in contact with the inner cylinder 3 or the outer cylinder 4 and depends on the running state of the vehicle (straight line, curve) and vibration (rolling, left-right movement, etc.). Thus, the range of contact and the size and distribution of contact pressure are changing. Such contact is an important element for generating a restoring force for vertical displacement and a restoring force for left and right vibrations and for normally supporting the posture of the vehicle body. However, excessive contact surface pressure is caused by the diaphragm 2 and the inner cylinder 3. Or since the abrasion of the rubber | gum which comprises the outer cylinder 4 is accelerated | stimulated, the one where a contact surface pressure is lower is preferable.
[0028]
Therefore, in the air spring 1 according to the present embodiment, focusing on the longitudinal section of the rubber seat 6 that contacts the diaphragm 2, a numerical analysis method by a computer that can simulate the internal pressure of the air spring 1 and the displacement during bogies is a finite method. An analysis method based on the element method (FEM) was developed, and parametric analysis was performed to change the radius of curvature R of the corner portion of the rubber seat 6 , and favorable conditions that can reduce the contact surface pressure were calculated. In this analysis, as described above, the perpendicular Φ of the contact surface μ of the rubber member 7 with the diaphragm 2 and the support surface γ supporting the rubber member 7 of the backing metal 8 are formed. The condition was that the angle α was vertical. Further, in such analysis, the influence of the air pressure inside the diaphragm 2 and the bogie displacement that occurs when the vehicle bends the curve (displacement in which the upper body side of the air spring 1 and the lower carriage frame side shift in the horizontal direction). The change in contact surface pressure was also grasped.
[0029]
As an example of the analysis result, an example in which the contact surface pressure distribution along the corner portion of the diaphragm 2 and the rubber seat 6 is analyzed is shown in FIG. In FIG. 3, (a) shows an example of an analysis result at the time of internal pressure load, and (b) shows an example of an analysis result at the time of bogie displacement load (in addition to the internal pressure load of (a), a load due to bogie displacement). FIG. 4 shows a plot of the maximum contact surface pressure when the radius of curvature R of the corner portion is changed parametrically.
[0030]
As shown in FIG. 4, by increasing the radius of curvature R, the maximum contact surface pressure is reduced. In particular, by making the radius of curvature R more than twice the wall thickness t of the diaphragm 2, the absolute value of the maximum contact surface pressure can be lowered, the wear resistance performance of rubber can be maintained, and a longer life can be expected. I understood.
[0031]
As described above, it has been found that by limiting the shape parameters of the contact surface shape of the rubber seat 6 , the contact surface pressure is averaged and the maximum contact surface pressure can be reduced. The lower the contact surface pressure, the smaller the frictional force generated in the direction perpendicular to the contact surface pressure, that is, along the surface of the diaphragm 2, which is effective in reducing wear of the diaphragm 2 and the rubber seat 6 .
[0032]
Further, the rubber seat 6 according to the present embodiment shown in FIG. 5 (R / t = 4 in FIG. 5A, R / t = 2 in FIG. 5B) and the comparative product shown in FIG. The result of comparing the contact surface pressure is shown in FIG. Here, the comparative product shown in FIG. 6 is such that the support surface 14 of the backing metal 8 that supports the rubber member 7 is not perpendicular to the perpendicular 13 of the contact surface 12 of the rubber member 7 with the diaphragm 2. It is formed so as to include (about 45 ° to 90 °) (R / t = 3.3). As shown in FIG. 7, it was found that the rubber seat 6 according to the present embodiment is more uniform than the comparative product in terms of wear because the contact surface pressure distribution is equalized and the maximum value is reduced.
[0033]
In the present embodiment, the rubber seat 6 of the inner cylinder 3 has been mainly described. However, the present invention is not limited to this, and the same applies to the outer cylinder 4 and a rubber member provided inside thereof. Is possible. In addition, although the description has been made assuming that the support surface of the backing metal 8 that supports the rubber member 7 is perpendicular to the perpendicular of the contact surface 12 of the rubber member 7 with the diaphragm 2, the present invention is not necessarily completely It does not need to be vertical, and includes what can be regarded as vertical within the range of design error.
[0034]
【The invention's effect】
As described above, according to the air spring for a bolsterless bogie of a railway vehicle according to the present invention, the contact condition between the diaphragm constituting the air spring and the rubber member of the outer cylinder or the inner cylinder is alleviated, and the rubber wear This has an excellent effect of reducing the amount and extending the wear life of the diaphragm and the rubber member.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of an air spring according to an embodiment of the present invention.
FIG. 2 is an enlarged longitudinal sectional view showing a rubber seat shown in FIG.
FIGS. 3A and 3B are examples of analysis results of contact surface pressure distribution along the corners of the diaphragm and the rubber seat shown in FIG. 1, wherein FIG. 3A is an internal pressure load, and FIG. 3B is a bogie displacement load. Examples of analysis results are shown below.
4 shows the maximum value of the contact surface pressure when the radius of curvature R of the corner portion of the rubber seat shown in FIG. 1 is changed.
FIG. 5 is a longitudinal sectional view showing a design example of a rubber seat according to the present invention.
FIG. 6 is a longitudinal sectional view showing a design example of a rubber seat of a comparative example.
FIG. 7 is a result of comparing the maximum contact surface pressure of the rubber seat according to the present invention and the rubber seat of the comparative example.
FIG. 8 is a schematic configuration diagram showing a state in which an air spring according to the present invention is mounted on a vehicle.

Claims (1)

In an air spring for a bolsterless carriage of a railway vehicle comprising a diaphragm and a rubber seat that contacts the diaphragm and supports the diaphragm,
The rubber seat includes a rubber member that contacts the diaphragm, and a backing metal that supports the rubber member,
The rubber member is formed so that the thickness of the portion in contact with the diaphragm is substantially constant,
The backing metal is formed such that a support surface for supporting the rubber member is substantially perpendicular to a perpendicular to a contact surface of the rubber member with the diaphragm ,
The rubber seat has a corner portion that comes into contact with the diaphragm, and in the longitudinal section of the corner portion, the radius of curvature of the contact portion of the rubber member with the diaphragm is more than twice the wall thickness of the diaphragm. bolsterless air spring bogie, characterized in that it is formed.

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