JP4989382B2 - Axle spring for vehicle - Google Patents

Description

  The present invention relates to a shaft spring device used for railway vehicles, trucks, industrial vehicles, and the like, and more specifically, a plurality of elastic layers between a main shaft and an outer cylinder having the same or substantially the same axis. The present invention relates to a shaft spring device in which an elastic portion of a laminated rubber structure is provided in which a hard rubber partition and a hard partition wall are alternately laminated in the inner and outer directions concentrically or substantially concentrically with the shaft center.

  For example, in a railway vehicle, this type of shaft spring device is interposed between the carriage frame and the axle side member in order to absorb and relieve the snake behavior and the impact during vertical movement. That is, as shown in FIG. 5 of Patent Document 1, the shaft spring device as an example of the shaft box support device is made of a plurality of intermediate rigid cylinders and rubber between the main shaft and the outer cylinder arranged around the spindle. A plurality of elastic layers are concentric and are alternately laminated in the radial direction to constitute an axial spring device.

  Here, as shown in FIG. 3, the conventional general shaft spring A is a means for suspending and supporting an axle box 27 that supports the axle 26 of the wheel 25 on the carriage frame 28 in a railway carriage (an example of a mounting target) 29. A plurality of intermediate cylinders 32 and 33 and a plurality of rubber layers 34 are concentrically disposed between the main shaft 30 and the outer cylinder 31 disposed around the main shaft 30 and are alternately laminated in the radial direction to provide a shaft spring. Part 35 is configured. Reference numeral 37 denotes a stopper flange integrated with the main shaft 30.

  The main shaft 30 is made of metal and is formed in a conical cylinder shape. A cylindrical support shaft portion 38 is formed at the lower end of the main shaft 30 to be fixed to the car box 27 of the axle 26. The plurality of intermediate cylinders 32 and 33 and the outer cylinder 31 arranged around the main shaft 30 are made of metal like the main shaft 30 and are formed in a conical cylinder shape. In such a state, the position is shifted in the direction of the axis Q of the main shaft 30 so as to become an upper position toward the outside. The rubber layer 34 is interposed between the main shaft 30, the intermediate cylinders 32 and 33, and the outer cylinder 31, and is vulcanized and integrated with these.

  By the way, as a tendency of this type of shaft spring device, in order to increase the ride comfort when the weight of the vehicle body is small, such as when the vehicle is empty, and the difficulty of wheel load slipping during curving, etc. In many cases, soft rubber is used as the elastic layer constituting the, and the overall spring constant is set low. However, if the overall spring constant is set low, for example, when a large body weight exceeding the capacity is loaded, the elastic layer may be greatly bent and the ride comfort may deteriorate, or cracks and creep may occur in the elastic layer. There is a tendency that the durability of the shaft spring device and the feeling of riding tend to be adversely affected.

  Therefore, if the spring constant is set high in order to improve ride comfort under heavy loads, such as capacity, and avoid cracks and creep in the elastic layer, it will now follow the curve when the vehicle weight is small, such as when the vehicle is empty. Sexuality and ride comfort deteriorate. In addition, from the viewpoint of recent wheel load management, it may be difficult to adopt the new vehicle from the viewpoint of easy removal of the wheel load if the spring constant at each load is constant and troublesome adjustment of the wheel load. .

In order to solve the above problem, as shown in FIG. 1 of Patent Document 1, an auxiliary spring is provided on the upper portion of the main shaft, and the auxiliary spring does not act in a low load range (when the vehicle is empty). Also disclosed is a shaft spring device having a non-linear spring characteristic in which an auxiliary spring cooperates with a plurality of elastic layers to exhibit a spring action in a high load range where the vehicle body weight becomes the same. Further, as shown in FIG. 2 of Patent Document 2, when the diameter of the flange of the main shaft is increased and the innermost hard partition wall (intermediate cylinder) is extended downward and the elastic portion is bent to some extent, the flange and the innermost side are bent. As a structure (so-called metal touch structure) in which the hard partition wall comes into contact, a device for producing a non-linear characteristic has been tried.
Japanese Patent Laid-Open No. 2003-40107 JP 2006-57746 A

  However, since the means shown in FIG. 1 of Patent Document 1 requires an auxiliary spring separately from the elastic layer, it is accompanied by an increase in the number of parts, and in order to fix the auxiliary spring to the upper part of the main shaft. Therefore, it is expected that an appropriate fixing means that does not fall off must be used, and that fixing work is difficult. In the means for causing the components shown in Patent Document 2 to interfere with each other, the problem of noise at the time of interference remains, and wear and fatigue are involved, and it seems difficult to obtain stable characteristics over a long period of time.

  In view of the above circumstances, the object of the present invention may be to increase the number of parts, such as non-linear characteristics that can exhibit good riding comfort and vibration reduction action regardless of various changes in sprung weight. An object of the present invention is to provide an improved shaft spring for a vehicle that can be obtained as much as possible without causing a noise or premature wear and having excellent durability.

In the invention according to claim 1, a plurality of elastic layers 4 and hard partition walls 5 are concentric with the shaft center P or between the main shaft 1 and the outer cylinder 2 having the same or substantially the same shaft center P. In the vehicular shaft spring in which the elastic part 3 of the laminated rubber structure is alternately laminated in the radially inner and outer directions in a substantially concentric state,
One end of the outer cylinder 2 in the axial center P direction is closed, and a sealed chamber 7 is formed at a portion surrounded by the closed portion 6, the main shaft 1, and the elastic portion 3 , and is suspended in the sealed chamber 7. It is characterized by being equipped with a fluid cushion mechanism 9 that encloses a fluid 8 for use.

  The invention according to claim 2 is the vehicle shaft spring according to claim 1, wherein the fluid 8 is air.

  According to a third aspect of the present invention, in the vehicular shaft spring according to the first or second aspect, a predetermined amount of an incompressible member 12 is provided in the sealed chamber 7.

  The invention according to claim 4 is the vehicle shaft spring according to any one of claims 1 to 3, wherein each of the outer peripheral surface 1a of the main shaft 1, the elastic portion 3, and the inner peripheral surface 2a of the outer cylinder. The cross-sectional views in the direction along the axis P are formed in a C-shape aligned in the same direction, and the elastic part 3 is in the direction along the axis P with respect to the main shaft 1. It is arranged close to the small diameter side, and the outer cylinder 2 is configured in a conical laminated rubber structure that is arranged close to the small diameter side with respect to the elastic part 3 in the direction along the axis P. It is characterized by.

  According to a fifth aspect of the present invention, in the vehicle shaft spring according to any one of the first to fourth aspects, the main shaft 1 is formed in a cylindrical shape having a hollow portion 1e, and the main shaft 1 is sealed. A plug 10 for closing the hollow portion 1e is provided at the chamber side end.

  According to the first aspect of the present invention, as will be described in detail in the section of the embodiment, the linear spring characteristic by the shaft spring and the nonlinear spring characteristic by the fluid cushion mechanism are combined, that is, the nonlinear spring characteristic. Can be obtained. Since the fluid cushion mechanism has a general configuration in which a suspension fluid is sealed in a sealed chamber, there is no collision between components such as a metal touch, which is advantageous in terms of noise and durability, and the fluid cushion. Since most of the mechanism is formed by a component of a shaft spring, it is possible to reduce the number of dedicated additional parts and the like and it is economical. As a result, the non-linear characteristics that can provide good riding comfort and vibration reduction regardless of various changes in the sprung weight, without causing an increase in the number of parts, as well as noise and early wear. It is possible to provide an improved vehicle shaft spring that can be obtained while having no fear and excellent durability. Further, if air is selected as the fluid as in the second aspect, a reasonable advantage that a clear non-linear characteristic is exhibited can be added with an inexpensive configuration.

  According to the invention of claim 3, since the volume (volume) of the sealed chamber can be reduced by disposing an incompressible member in the sealed chamber, conditions such as a required spring constant, initial load, or maximum load are required. Accordingly, an appropriate amount of an incompressible member can be inserted and adjusted so that desired spring characteristics can be exhibited, and thus there is an advantage that the usability is improved.

  According to the invention of claim 4, any of the effects of the structures of claims 1 to 3 is exhibited in the shaft spring having the conical laminated rubber structure. For example, when applied to a railway vehicle, the ride comfort It is possible to provide a vehicular shaft spring that can provide advantages such as improvement of the curve and improvement of curve passing ability.

  According to the invention of claim 5, the current vehicle in which the hollow cylindrical main shaft is adopted as the external communication structure so as not to be affected by the change in the internal volume of the shaft spring accompanying the expansion and contraction of the elastic portion. Even if it is a shaft spring for a use, there exists an effect which becomes rich in the versatility that a nonlinear spring characteristic can be acquired only by adding the plug which obstruct | occludes the one end.

  Hereinafter, an embodiment of a shaft spring for a vehicle according to the present invention will be described with reference to the drawings as for a rail vehicle used in a rail car. 1 is a sectional view showing the structure of a vehicle shaft spring according to the present invention, FIG. 2 is a view showing a spring characteristic graph of the shaft spring of FIG. 1, and FIG. 3 is a partially cutaway view showing a conventional rail vehicle shaft spring. It is a side view.

[Example 1]
As illustrated in FIG. 1, the vehicle shaft spring A according to the first embodiment includes three layers (a main layer 1 and an outer cylinder 2 having a vertical axis P that is the same (or substantially the same) as the main shaft 1). A laminated rubber structure in which a plurality of examples) of elastic layers 4 and two layers (a plurality of examples) of hard partition walls 5 are alternately laminated in the inner and outer directions in a concentric state (or almost concentric state) with the longitudinal axis P. The shaft spring portion a is formed by interposing the elastic portion 3 and the fluid cushion mechanism 9 is formed integrally with the upper portion of the shaft spring portion a.

  The main shaft 1 is made of metal and is formed in an upper conical outer peripheral surface 1a, a stopper flange 1b, a lower end opening 1c, a screw portion 1d (a lower end opening portion 1c for fixing to an axle case. And a cylindrical member having a hollow portion 1e. The outer cylinder 2 is formed in a conical cylinder having a C-shaped cross section having a conical inner peripheral surface 2a having a downwardly expanding shape and a fitting inner peripheral surface 2b inside the upper end. The outer cylinder 2 is arranged closer to the upper side than the upper side (conical outer peripheral surface 1a side) with respect to the main shaft 1 (closer to the smaller diameter side with respect to the main shaft 1 in the direction along the axis P). .

  The elastic portion 3 is composed of inner and outer three rubber layers (an example of an elastic layer) 4A, 4B and 4C centered on the longitudinal axis P, and inner and outer hard partition walls 5A and 5B. It is equipped over the main shaft 1 and the outer cylinder 2 in a state of being interposed between 1a and the conical inner peripheral surface 2a. Each hard partition 5 is formed from a metal plate such as a steel plate, reinforced plastic, or the like. Each rubber layer 4 and each hard partition wall 5 are each formed in a tapered cylindrical shape in which the cross-sectional view shape in the direction along the longitudinal axis P is a C shape.

  In other words, the shaft spring portion a has a letter C in which the cross-sectional shapes in the direction along the longitudinal axis P of each of the outer peripheral surface 1a, the elastic portion 3, and the outer cylinder inner peripheral surface 2a of the main shaft 1 are aligned in the same direction. In the direction along the longitudinal axis P, the elastic portion 3 is arranged closer to the smaller diameter side with respect to the main shaft 1 and the outer cylinder 2 is elastic in the direction along the longitudinal axis P. The conical laminated rubber structure is arranged close to the small diameter side of the portion 3.

  The fluid cushion mechanism 9 closes one end of the outer cylinder 2 in the direction of the longitudinal axis P to form a sealed chamber 7 between the closed portion 6 and the main shaft 1, and a fluid for suspension in the sealed chamber 7. 8 is enclosed. More specifically, the upper end of the main shaft 1 is equipped with a plug 10 for closing the hollow portion 1e, and the upper end of the outer cylinder 2 is closed with an O-ring 11 for closing the upper end of the outer cylinder. A disc lid 6 is provided as a closure. Therefore, a sealed chamber 7 is formed at a portion surrounded by the disc lid 6, the elastic portion 3, and the stopper 10. By enclosing air (an example of fluid) 8 in the sealed chamber 7, the fluid cushion mechanism An air cushion mechanism 9 as an example is configured.

  In order to adjust (increase / decrease adjustment) the volume of the sealed chamber 7, as shown in FIG. 1, an internal volume adjusting body made of incompressible liquid or solid (fine particles) such as water, antifreeze, sand, etc. An example of an incompressible member) 12 may be enclosed in the sealed chamber 7 in advance. By adjusting the volume of the sealed chamber 7, the initial load and nonlinear characteristics (described later) of the air cushion mechanism 9 can be adjusted.

  The spring characteristic (suspension characteristic) by the shaft spring part a is equivalent to that by the conventional shaft spring, and as shown by the line X indicated by the broken line in FIG. A linear characteristic (or h substantially linear characteristic) is obtained in which the reaction load, which is a force for the elastic part 3 to lift the outer cylinder 2, increases in proportion. In other words, the spring constant is constant regardless of the downward movement amount of the outer cylinder 2. However, some nonlinear characteristics (the amount of downward movement of the outer cylinder 2 increases depending on the inclination angle with respect to the vertical axis P that forms a letter C, and the specifications such as the height position of the outer cylinder 2 with respect to the main shaft 1. (The characteristic that the spring constant slightly increases with the time).

  Since the spring characteristic (suspension characteristic) of the air cushion mechanism 9 is a general air suspension, the downward movement amount of the outer cylinder 2 is increased as indicated by a dashed line Y in FIG. Along with this, it exhibits a clear non-linear characteristic in which the increasing rate of the reaction load increases. That is, the spring constant increases as the amount of downward movement of the outer cylinder 2 increases. Therefore, the relationship graph between the downward movement of the outer cylinder 2 as the vehicle shaft spring A and the reaction force load is a combination of the line X and the line Y as shown by the solid line Z in FIG. It is to show.

As described above, according to the vehicle shaft spring A according to the first embodiment of the present invention, the following 1. to 3. The effect of can be obtained.
1. Non-linear characteristics: By reducing (crushing) the air volume (volume) of the sealed chamber (air chamber) 7 by deformation due to a load, the pressure increases and a non-linear spring characteristic can be obtained.
2. Adjustment of the air volume: By sealing a predetermined amount of a non-compressible liquid or solid whose shape can be freely changed, that is, an incompressible member, into the sealed chamber (air chamber) 7, the volume of the sealed chamber can be adjusted, Non-linear characteristics and initial load settings can be adjusted.
3. Stability: The air cushion mechanism 9 can be realized by only adjusting the volume of the sealed chamber 7 by adding the stopper 10, the incompressible member 12, and the O-ring 11, that is, non-linear characteristics can be realized. Accordingly, compared with the conventional means for obtaining the nonlinear characteristics, the secular change is small and the initial performance is easily maintained.

  The disc lid 6 is also provided in a conventional shaft spring, and an O-ring 11 that seals the disc lid 6 and the outer cylinder 2 is added to form a sealed chamber 7. Since there is no need for the incompressible member 12, the minimum additional parts based on the current model using the conventional hollow main shaft 1 are the stopper 10 and the O-ring 11. Further, in a configuration having the main shaft 1 having a solid cross section without a hole due to a new design or the like, a vehicle shaft spring having a non-linear characteristic equipped with a fluid cushion mechanism 9 by adding only the O-ring 11 is economical. There is an advantage that can be built. Since the thickness of the disc lid 6 and the amount of the incompressible member 12 can be variably set, the lower end line of the disc lid 6 and the upper end line of the incompressible member 12 are imaginary lines in FIG. It is drawn.

[Another Example]
The fluid sealed in the sealed chamber 7 may be other than air (eg, inert gas such as nitrogen gas, compressible liquid). Further, the closing portion 6 may be a disc lid formed integrally with the outer cylinder 2. As the posture of the vehicle shaft spring A, a vertically inverted one with respect to FIG. 1 or a horizontally oriented posture having a left-right axis P can be used.

Sectional drawing which shows the structure of the shaft spring by Example 1 The figure which shows the relationship graph of the outer cylinder descent | fall movement amount and reaction force load of the shaft spring for vehicles of FIG. Side view of a partially cut-out showing a conventional shaft spring installed on a railway carriage

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main shaft 1a Outer peripheral surface of main shaft 1e Hollow part 2 Outer cylinder 2a Outer cylinder inner peripheral surface 3 Elastic part 4 Elastic layer 5 Hard partition 6 Closed part 7 Sealed chamber 8 Fluid (air)
9 Fluid Cushion Mechanism 10 Plug 12 Incompressible Member A Vehicle Shaft Spring P Shaft Center

Claims (5)

Laminated rubber in which a plurality of elastic layers and hard partition walls are alternately laminated in the inner and outer directions concentrically or substantially concentrically with the shaft center between the main shaft and the outer cylinder having the same or substantially the same shaft center. A vehicle shaft spring having an elastic part of the structure interposed therein,
Closing one end of the outer cylinder in the axial direction to form a sealed chamber at a portion surrounded by the closed portion, the main shaft, and the elastic portion , and enclosing a suspension fluid in the sealed chamber A shaft spring for a vehicle equipped with a fluid cushion mechanism.
  The shaft spring for a vehicle according to claim 1, wherein the fluid is air.   The axle spring for vehicles according to claim 1 or 2 by which a predetermined amount of incompressible members are arranged in said sealed room.   The outer peripheral surface of the main shaft, the elastic part, and the outer cylinder inner peripheral surface are formed in a C shape in which the cross-sectional shapes in the direction along the axial center are aligned in the same direction, and the elastic part Is arranged close to the small diameter side with respect to the main shaft in the direction along the axis, and is arranged close to the small diameter side with respect to the elastic portion in the direction along the axis. The shaft spring for vehicles as described in any one of Claims 1-3 comprised by the cone laminated rubber structure made.   The vehicle according to any one of claims 1 to 4, wherein the main shaft is formed in a cylindrical shape having a hollow portion, and a plug that closes the hollow portion is provided at the sealed chamber side end of the main shaft. Shaft spring.

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