JP2005199761A - Air spring for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress as much as possible a rolling-in phenomenon of a synthetic fiber net body contributing to reduction in frictional resistance and a spring constant in sliding contact with a sliding plate, and to surely and stably exhibit expected performance by interposition of the net body over a long period. <P>SOLUTION: Slits 6 are formed from an outer peripheral end 5e to a diameter inner direction in a plurality of parts spaced in a peripheral direction on an outer peripheral part of the doughnut-shaped synthetic fiber net body 5 interposed between the sliding plate attached to an upper surface rubber part brought into contact with a flexible member on an upper surface plate of an air spring and the flexible member, and having a property for reducing the frictional resistance during horizontal displacement. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air spring for a vehicle that is installed and used as a shock absorber for a railway vehicle in which a voltaless truck is mainly used.

  In this type of air spring, horizontal displacement in the left-right and front-rear directions acts on the flexible member, which is the main part of the air spring during meandering and turning during vehicle travel. In particular, in the case of a railcar voltaless carriage, the horizontal displacement is very large. At the time of such horizontal displacement, if the outer peripheral rubber layer portion of the flexible member and the rubber portion formed by vulcanization adhesion to the metal upper plate remain in contact, the sliding friction resistance between them is very large, As a result, the spring constant becomes large and the horizontal displacement behavior is poor, so that the cushioning performance inherent to the air spring is low. In addition, since the sliding frictional resistance is large, there is a difficulty that the rubber layer portion of the flexible member is worn and damaged early, or punctures and becomes unusable early.

  In order to eliminate such difficulties, conventionally, a sliding plate made of metal or synthetic resin is attached to the rubber portion of the upper surface plate that contacts the flexible member, and the sliding plate and the flexible member are interposed between the sliding plate and the flexible member. By interposing a donut-shaped synthetic fiber network 50 as shown in FIG. 4 and sliding between the sliding plate and the synthetic fiber network 50 during horizontal displacement, the frictional resistance and the spring constant are reduced. There has been known one that secures good buffering performance and prevents breakage due to wear of the flexible member to improve durability (for example, see Patent Documents 1 and 2).

JP 54-86073 A JP-A-55-76237

  However, in the conventional air spring as described above, when receiving a horizontal displacement force in the left-right direction and the front-rear direction, the synthetic fiber network 50 in a perfect circular donut shape as shown in FIG. As shown in FIG. 5A or 5C, the displacement direction is deformed into an ellipse having a major axis, and a tensile force acts in the major axis direction at the time of deformation. The mesh body part into which the diagonal line is inserted is easily folded into the radially inward side and is easily caught between the sliding plate and the flexible member. The effect, that is, the cushioning performance and the damage prevention performance of the flexible member are impaired, and further, the synthetic fiber network 50 itself is damaged, or the amount of entrainment is increased, so that the durability of the entire air spring is sufficient. I can't secure it There was a problem.

  The present invention has been made in view of the above circumstances, and suppresses the entrainment phenomenon of the synthetic fiber network as much as possible, and reliably and stably exhibits the expected performance due to the interposition of the network for a long period of time. An object of the present invention is to provide an air spring for a vehicle that can achieve improvement.

  To achieve the above object, the air spring for a vehicle according to the present invention is provided with a sliding plate made of metal or synthetic resin on the upper surface rubber portion that comes into contact with the flexible member by the upper surface plate of the air spring, In a vehicle air spring in which a donut-shaped synthetic fiber network is sandwiched between the sliding plate and the flexible member, an outer peripheral portion of the synthetic fiber network is spaced in the circumferential direction. It is characterized in that slits are formed at a plurality of locations from the outer peripheral edge toward the radially inner side.

  According to the present invention having the above-described features, when the donut-shaped synthetic fiber network is deformed in the displacement direction due to horizontal displacement in the left-right direction and the front-rear direction of the air spring accompanying meandering or turning during vehicle travel The tensile force acting in the major axis direction due to the deformation can be absorbed and reduced by the slit, so that the outer peripheral portion of the synthetic fiber network is folded inwardly between the sliding plate and the flexible member. Entrainment can be suppressed. Therefore, it is possible to suppress the entrainment phenomenon of the synthetic fiber network as much as possible, and to prevent damage to the synthetic fiber network itself, by simply making a simple improvement by forming a plurality of slits in the outer peripheral portion of the synthetic fiber network. Suppressing the bias and ensuring the expected performance due to the presence of the sliding plate and synthetic fiber network, that is, the cushioning performance by reducing the frictional resistance at the time of horizontal displacement and the damage prevention performance of the flexible member over a long period of time. The effect of being able to be exhibited and the durability of the entire air spring can be sufficiently improved.

  In the vehicle air spring according to the present invention described above, if the number of slits formed in the outer peripheral portion of the synthetic fiber network is excessively increased, the rigidity of the synthetic fiber network is reduced, and the sliding plate is displaced during horizontal displacement. The synthetic fiber network that is in sliding contact with the surface may be deformed or easily biased in the direction of displacement, and the inherent performance of reducing sliding friction resistance may be greatly impaired. As for the number of slits formed in the case, it is desirable that the number of slits is about 4 to 8 at regular intervals in the circumferential direction.

  In addition, as the length of each slit is increased with respect to the radial width of the synthetic fiber network, the tensile force is reduced and the above-described effect of suppressing the entrainment is increased. The synthetic fiber network may be broken at the slit forming portion at the time of sliding contact, and the performance may not be achieved originally, and considering that, the length of the slit is relative to the radial width of the synthetic fiber network. It is preferable that the length is 0.15 to 0.3.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of an entire vehicle air spring according to the present invention. In FIG. 1, reference numeral 1 denotes an upper surface plate made of a metal plate. The upper rubber portion 3 having a tapered slope 3a is vulcanized and bonded. Reference numeral 2 denotes a flexible member having a toroidal shape and having a reinforcing layer 2c in which a steel cord or a textile cord 2b is embedded as a reinforcing material (see FIG. 2). The bead portions 2a and 2a are fixed to the upper surface plate 1, the stopper receiving base 8, the lower surface plate 7 and the stopper 9 by a self-sealing method or a fastening method, respectively.

  As shown in FIG. 2, a sliding plate 4 made of metal or synthetic resin such as polyethylene or polypropylene is adhered to the tapered inclined surface 3a of the upper rubber portion 3 with an adhesive or vulcanized. As shown in the enlarged view of FIG. 3, a doughnut-shaped synthetic fiber is provided between the sliding plate 4 and the flexible member 2 as shown in an enlarged view in FIG. The net-like body 5 is sandwiched.

  The synthetic fiber network 5 is made of heat-treated polyamide fiber, polyester fiber, vinylon fiber, or the like with less fluff, and has such rigidity that it is not biased by friction with the sliding plate 4. In order to make it have a means, a thick fiber yarn with rigidity is used, or a means for giving rigidity by coating a resin is taken.

  In the vehicular air spring 10 having the basic configuration as described above, as shown in FIG. 3, the outer peripheral edge 5e of the synthetic fiber network 5 is provided at a plurality of locations at equal intervals in the circumferential direction. A slit 6 is formed from the inner side toward the inner side. The number of the slits 6 is suitably 4 to 8 (indicated by 8 in the drawing), and the slits 6 have a length L with respect to the width R in the radial direction of the synthetic fiber network 5, that is, L / R is suitably set in the range of 0.15 to 0.3.

  In the vehicular air spring 10 configured as described above, the donut-shaped synthetic fiber network 5 is displaced in the displacement direction by horizontal displacement of the air spring 10 in the left-right direction and the front-rear direction in accordance with meandering and turning during vehicle travel. When deformed, the tensile force acting in the major axis direction due to the deformation can be absorbed and reduced by the slit 6 so that the outer peripheral portion of the synthetic fiber network 5 can be reduced as shown in FIGS. Can be prevented from being folded inwardly between the sliding plate 4 and the flexible member 2. In addition, by setting the number and length L of the slits 6 to values in the above-described range, the synthetic fiber network 5 itself can be prevented from being deformed and broken, and also to break at the slit 6 forming portion. It is possible to reduce the frictional resistance at the time of horizontal displacement by the smooth sliding action between the sliding plate 4 and the synthetic fiber network 5 and to increase the desired buffering performance and the damage prevention performance of the flexible member 2. The durability of the air spring 10 as a whole can be improved by reliably and stably exerting it over a period of time.

  Incidentally, the present inventor uses a synthetic fiber network having a radial width R of 150 mm and a conventional product in which no slit is formed in the synthetic fiber network, and a length L = 40 mm on the outer peripheral portion of the synthetic fiber network 5 ( L / R≈0.267) The slits 6 having the length L = 30 mm (L / R = 0.2) and the example product 1 of the present invention in which eight slits 6 having the same interval in the circumferential direction were formed. Example product 2 of the present invention in which 6 pieces are formed at equal intervals in the direction, and Comparative product 1 in which 10 slits of length L = 40 mm (L / R≈0.267) are formed at equal intervals in the circumferential direction The comparative product 2 in which eight slits having a length L = 50 mm (L / R≈0.333) are formed at equal intervals in the circumferential direction is prepared and prepared. Perform endurance test by repeatedly applying the same horizontal displacement to each, entrainment or bias With measuring the horizontal displacement repeat count to shape or breakage occurs, and overall determination, as shown in Table 1 for the performance and durability of the entire air spring from the measurement result.

As is apparent from Table 1, in the conventional product, entanglement occurred in 1.2 × 10 ⁴ until the target durability count of 2.4 × 10 ⁵ was not reached. No entrainment occurred in Nos. 1 and 2 even at the target durability of 2.4 × 10 ⁵ . Further, in Comparative Example Product 1, the synthetic fiber network is biased and deformed at 2.0 × 10 ⁴ position until the target durability number of 2.4 × 10 ⁵ is not reached. In Comparative Example Product 2, While breakage occurred at the slit forming site at the 5.5 × 10 ⁴ position until the target durability count of 2.4 × 10 ⁵ was not reached, Examples 1 and 2 of the present invention had the target durability count of Even at 2.4 × 10 ⁵ , no biased deformation or breakage occurred. From these comprehensive judgments, the products 1 and 2 according to the present invention reach the target durability of the air spring, that is, the durability life, with respect to the cushioning performance by reducing the frictional resistance at the time of horizontal displacement and the damage prevention performance of the flexible member. It was confirmed that it can be maintained stably.

  In addition, in the comprehensive judgment in Table 1, ◯ means that there is no entrainment, bias deformation, and breakage, and that means that the expected performance can be maintained up to the durability life of the entire air spring, and Δ does not cause a decrease in performance due to entrainment. Meaning that partial deformation or fracture occurred before reaching the endurance life, and x means that the expected performance was lost early due to entrainment.

It is a longitudinal cross-sectional view of the whole air spring for vehicles which concerns on this invention. It is an enlarged vertical sectional view of the A section of FIG. It is an enlarged plan view which shows the half of the synthetic fiber network which is the principal part. It is an enlarged plan view which shows the half of the synthetic fiber net body in the conventional air spring for vehicles. (A) shows the state of a normal synthetic fiber network in which the vehicle air spring is not subjected to horizontal displacement force in the lateral direction and the longitudinal direction, and (b) and (c) are horizontal displacements in the lateral direction and the longitudinal direction. It is a schematic plan view which shows the deformation | transformation state of the synthetic fiber network when receiving force.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper surface board 2 Flexible member 3 Upper surface rubber part 4 Sliding board 5 Synthetic fiber network 6 Slit 10 Air spring L Length of slit R Radial width of synthetic fiber network

Claims (3)

A sliding plate made of metal or synthetic resin is attached to the upper rubber portion of the air spring that comes into contact with the flexible member, and a donut-shaped synthetic fiber is provided between the sliding plate and the flexible member. In the vehicle air spring in which the mesh body is sandwiched,
A vehicular air spring characterized in that slits are formed from the outer peripheral edge toward the radially inner side at a plurality of locations spaced in the circumferential direction on the outer peripheral portion of the synthetic fiber network. 2. The vehicle air spring according to claim 1, wherein four to eight slits are formed in the outer peripheral portion of the synthetic fiber network at equal intervals in the circumferential direction. The vehicular air spring according to claim 1 or 2, wherein the slit is formed with a length of 0.15 to 0.3 with respect to a radial width of the synthetic fiber network.

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