JP2016182863A - Wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel which achieves high travelling performance even when used in a vehicle which travels on soft ground and achieves excellent shock absorption performance against an impact from the outside.SOLUTION: A wheel 10 is attached to an axle of a vehicle and includes: a hub 1 having a cylindrical member into which the axle is inserted; a ground member 2 provided at a radial outer side of the wheel relative to the hub; and elastic members 5 and shock absorbing members 6 which are provided between the hub and the ground member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wheel.

  The surfaces of celestial bodies such as the Moon and Mars are rough terrain where there are rocks and gravel. Above all, the lunar surface is a soft ground with thick sand called regolith. When the vehicle travels on soft ground, the ground is destroyed by the rotation of the wheels. As the destruction of the ground progresses, the wheels may sink into the ground and cause a stack.

  Non-Patent Document 1 discloses an elastic wheel using the elastic characteristics of a metal material as a technique for suppressing the breakage of soft ground and maintaining the running performance of the vehicle.

Kojiro Iizuka, 2 others, “Examination of wheel shape of lunar surface exploration wheel type robot for running on soft ground considering elastic characteristics”, Transactions of the Japan Society of Mechanical Engineers (C), December 25, 2008, 74th Volume 748, p. 2962-2967

  The elastic wheel of Non-Patent Document 1 exhibits excellent running performance against soft ground with a high slope. However, since the elastic wheel uses a metal spring, there is a problem that when the external impact is applied, vibration is generated by the metal spring and the posture of the vehicle becomes unstable. Further, there is a problem that the metal spring is plastically deformed by an external impact, and the vehicle cannot run.

  The present invention has been made in view of the above problems, and provides a wheel that exhibits good high running performance even when used in a vehicle running on soft ground, and exhibits excellent shock absorption with respect to external impact. The purpose is to provide.

  (1) The present invention is a wheel attached to an axle of a vehicle, the hub having a cylindrical member into which the axle is inserted, a grounding member provided on the outer side in the radial direction of the wheel with respect to the hub, A wheel comprising an elastic member and an impact absorbing member provided between the hub and the grounding member.

  (2) In the wheel of the present invention, preferably, the elastic member includes a cylindrical metal spring, and the metal spring is fixed to the hub.

(3) In the wheel of the present invention, preferably, the impact absorbing member includes particles.
(4) In the wheel of the present invention, preferably, the impact absorbing member further includes a particle holder that encloses the particles therein.

(5) Preferably in the wheel of this invention, the said grounding member contains a two-dimensional fiber.
(6) In the wheel of the present invention, preferably, the wheel includes a boundary member provided along a circumferential direction of the wheel between the hub and the grounding member, and the diameter of the wheel of the boundary member The elastic member is provided on the inner side in the direction, and the shock absorbing member is provided on the outer side in the radial direction of the wheel of the boundary member.

  ADVANTAGE OF THE INVENTION According to this invention, even if it uses for the vehicle which drive | works a soft ground, the wheel which shows favorable driving | running | working performance and shows the outstanding impact absorption with respect to the impact from the outside can be provided.

2 is a schematic perspective view showing an internal structure of a wheel in the first embodiment. FIG. It is a figure which shows 1 process of the manufacturing process of the wheel shown in FIG. It is a figure which shows 1 process of the manufacturing process of the wheel shown in FIG. It is a figure which shows 1 process of the manufacturing process of the wheel shown in FIG. It is a figure which shows 1 process of the manufacturing process of the wheel shown in FIG. FIG. 6 is a schematic perspective view showing a modification of the wheel according to the first embodiment. FIG. 6 is a schematic perspective view showing a modification of the wheel according to the first embodiment. FIG. 6 is a schematic perspective view showing a modification of the wheel according to the first embodiment. It is a figure which shows an example of the positional relationship of a hub and an elastic member. It is a figure which shows an example of the external shape of particle | grains. It is a figure which shows an example of the external shape of particle | grains. It is a figure which shows an example of the external shape of particle | grains. It is a figure which shows an example of the external shape of particle | grains. It is a figure which shows an example of the positional relationship of a hub and an elastic member. FIG. 6 is a schematic diagram showing an internal structure of a wheel in a second embodiment. It is a schematic diagram of the traveling test machine used in the examples. It is a graph which shows the result of an impact absorption test.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
The structure of the wheel in Embodiment 1 is demonstrated using FIGS.

  The wheel in Embodiment 1 is a wheel which can be used suitably for the vehicle which drive | works a soft ground, for example.

  As shown in FIG. 1, a wheel 10 according to the present embodiment is provided on the outer side in the radial direction of the wheel 10 with respect to the hub 1 made of a cylindrical member into which an axle of a vehicle body is inserted, and the hub 1. A grounding member 2 and an elastic member 5 and an impact absorbing member 6 provided between the hub 1 and the grounding member 2 are provided.

  The hub 1 and the grounding member 2 are provided point-symmetrically around the common axis O with the common axis O as the center. The common axis O is parallel to the axle, and hereinafter, the direction along the common axis O is referred to as the wheel width direction, the direction orthogonal to the common axis O is referred to as the wheel radial direction, and the direction around the common axis O is defined as the direction around the common axis O. It is called the wheel circumferential direction.

  The elastic member 5 is fixed to the outer surface of the hub 1. A space surrounded by the outer surface of the hub 1, the outer surface of the elastic member 5, and the inner surface of the grounding member 2 is filled with an impact absorbing member 6.

  The diameter of the wheel 10 is preferably 10 mm or more and 5000 mm or less. If the wheel diameter is less than 10 mm, it is difficult to produce the wheel. On the other hand, when the diameter of the wheel exceeds 5000 mm, the frictional force between the wheel and the ground increases due to the increase in the wheel weight and the contact area due to the wheel deformation, and the rotational power for driving the wheel becomes enormous.

  The width of the wheel is preferably 10 mm or more and 3000 mm or less. If the wheel width is less than 10 mm, it is difficult to produce the wheel. On the other hand, when the width of the wheel exceeds 3000 mm, the frictional force between the wheel and the ground increases due to an increase in the wheel weight and an increase in the contact area due to the deformation of the wheel, and the rotational power for driving the wheel becomes enormous.

  The weight of the wheel is preferably 0.1 g or more and 30000 g or less. If the weight of the wheel is less than 0.1 g, the wheel part cannot be configured. On the other hand, if the weight of the wheel exceeds 30000 g, the frictional force between the wheel and the ground increases due to the increase in the wheel weight and the contact area due to the wheel deformation, and the rotational power for driving the wheel becomes enormous.

  Next, each member which comprises the wheel in this Embodiment is demonstrated, showing the manufacturing process of a wheel.

  2-5 is a figure which shows 1 process of the manufacturing method of the wheel in one embodiment of this invention, respectively.

  As shown in FIG. 2, the hub 1 is prepared. The hub 1 has a cylindrical shape, and a front end portion of a vehicle axle is inserted therein. The hub 1 is made of a metal material such as an aluminum alloy. The size of the hub 1 is not particularly limited as long as it can be used for a normal vehicle.

  On the outer surface of the hub 1, circular grooves 1a for inserting a fixing member for fixing the elastic member 5 to the hub 1 are formed at six locations. The number, position, and size of the grooves 1 a are not particularly limited as long as the elastic member 5 can be fixed to the hub 1.

  Next, as shown in FIG. 3, a donut-shaped bag-like shape having an opening including a hub cover 4 covering the outer surface of the hub 1, a grounding member 2, and a side member 3 on the outer side in the wheel radial direction of the hub 1. A member (hereinafter also referred to as an outer shape member) is disposed. The outer shape member constitutes the outer shape of the wheel. As the outer member, for example, a two-dimensional fiber, a rubber plate, a film material, a mesh material, a fabric, or a fiber made of a composite configuration thereof can be used. Among these, two-dimensional fibers are preferable because they are easily deformed and can be flexibly deformed with respect to the ground. Two-dimensional fibers are preferable because cracks are difficult to propagate when screws, nails, metal pieces, or the like are stuck in the wheel. As the two-dimensional fiber, a high-strength fiber such as a urethane-coated fabric is preferable.

  Next, as shown in FIG. 4, the elastic member 5 is fixed to the hub 1. A groove 5 a corresponding to the groove 1 a of the hub 1 is formed in the elastic member 5. The groove 1a of the hub 1 and the groove 5a of the elastic member 5 are overlapped, and a fixing member made of a bolt is inserted so as to pass through both grooves, thereby fixing the elastic member 5 to the hub 1.

  The elastic member 5 is not particularly limited as long as it is a material that can be deformed by an external stress and can return to its original shape after the stress is removed. For example, a metal spring, an elastic plate made of a composite material, a shape memory alloy, a magnet, or the like can be used. Among these, a cylindrical metal spring is preferable because a wheel exhibiting good running performance can be obtained for a soft ground with a high slope.

  In FIG. 4, three elastic members 5 are arranged on the outer surface of the hub 1 at equal intervals. The number of elastic members 5 is not particularly limited as long as the wheels can have sufficient elasticity. For example, as shown in FIG. 6, six elastic members 5 can be arranged.

  In FIG. 4, the wheel width direction length of the hub 1 is substantially the same as the wheel width direction length of the elastic member 5, and the axial direction of the hub 1 and the axial direction of the elastic member 5 are substantially parallel. The location of the elastic member 5 with respect to the hub 1 is not particularly limited as long as the wheel can have sufficient elasticity. For example, as shown in FIG. 9, a plurality of elastic members 5 having a length in the wheel width direction shorter than the length in the wheel width direction of the hub 1 (in FIG. 9, the length of the elastic member 5 in the wheel width direction is the hub width). 1/3 of the length in the wheel width direction of 1). The elastic member 5 can also be fixed to the hub 1 at a position shifted in the wheel circumferential direction so that at least a part of each elastic member 5 overlaps when viewed from the side member. Further, as shown in FIG. 14, the elastic member 25 made of an arc-shaped metal spring can be arranged so as to span between the flanges 7 provided at both ends of the hub 1 in the wheel axial direction.

  Next, as shown in FIG. 1, the shock absorbing member 6 is disposed in a space surrounded by the outer surface of the hub 1, the outer surface of the elastic member 5, and the inner surface of the grounding member 2. The location of the impact absorbing member 6 is not particularly limited as long as it is a space between the hub 1 and the grounding member 2. For example, the shock absorbing member 6 can be disposed in a space surrounded by the inner surface of the elastic member 2.

  The shock absorbing member 6 is not particularly limited as long as it is a material that can dissipate stress from the outside to suppress the shock and impart flexibility to the wheel. For example, bead-like particles, gel, liquid, gas, etc. can be used. Among them, the bead-like particles are preferable because they are a collection of rigid bodies and can be deformed flexibly and are easy to handle.

  The shape of each particle constituting the shock absorbing member is not particularly limited. For example, the particle shape may be a spherical shape as shown in FIG. 10, an ellipsoidal shape as shown in FIG. 11, a polyhedral shape as shown in FIG. 12, or a complex solid shape as shown in FIG. be able to.

  The size of the particles is not particularly limited as long as it can be deformed as an aggregate. For example, the equivalent circle diameter of each particle (the diameter of a circle having the same area as the projected area of the particle) should be 0.01 mm or more and 1000 mm or less for wheels having any diameter (from small vehicles to large special wheels). It is preferable from a viewpoint that it can respond.

  The material of the particles is not particularly limited as long as it can be deformed as an aggregate. For example, a rigid body such as a solid or a crystal that hardly deforms due to external stress, or an elastic body that deforms due to external stress can be used.

  The weight of the particles is not particularly limited as long as it can be deformed as an aggregate. For example, it is preferable that the weight of each particle is 1 mg or more and 1000 g or less from the viewpoint of being able to cope with wheels having any diameter (from small vehicles to large special wheels).

  As shown in FIG. 1, the particles may be disposed directly in the space between the hub 1 and the grounding member 2 as particles. In addition, as shown in FIG. 7, the particles may be disposed in a space between the hub 1 and the grounding member 2 after being encapsulated in the deformable particle holder 15. Further, as shown in FIG. 8, both particles that are directly arranged as particles and those that are enclosed in a deformable particle holder 15 may be used at the same time. As the deformable particle holder, for example, a two-dimensional fiber, a rubber plate, a film material, a mesh material, a cloth, or a bag made of these composite structures can be used.

  When gel, liquid, or gas is used as the impact absorbing member 6, it is preferable to use these materials by sealing them in a deformable impermeable sealed container. As the deformable impermeable sealed container, for example, a bag in which a rubber material, a film material or the like is sewn can be used.

  Next, as shown in FIG. 5, the side member 3 was arranged so as to close the opening of the bag-like outer member, and the outer member and the side member 3 were sewn together. The wheel of Embodiment 1 can be obtained through the above steps.

[Embodiment 2]
The structure of the wheel in Embodiment 2 is demonstrated using FIG. FIG. 15 is a schematic diagram showing the internal structure of the wheel in the second embodiment.

  As shown in FIG. 15, the wheel 40 of the present embodiment includes a hub 1 made of a cylindrical member into which an axle of a vehicle body is inserted, and a grounding provided on the outer side in the radial direction of the wheel with respect to the hub 1. A boundary member 8 provided along the circumferential direction of the wheel is included between the member 2 and the hub 1 and the grounding member 2. An elastic member 5 is provided inside the boundary member 8 in the radial direction of the wheel, and an impact absorbing member 6 is provided outside the boundary member 8 in the radial direction of the wheel.

  The elastic member 5 is fixed to the outer surface of the hub 1. The boundary member 8 is fixed to the outer surface of the elastic member 5. A space surrounded by the outer surface of the boundary member 8 and the inner surface of the grounding member 2 is filled with the shock absorbing member 6. A side member (not shown) is disposed on the side surface of the wheel 40.

  The hub 1, the grounding member 2, the hub cover 4, the elastic member 5, and the impact absorbing member 6 can have the same configuration as in the first embodiment.

  The boundary member 8 is not particularly limited as long as it is a material that can distinguish the region where the elastic member 5 is disposed from the region where the shock absorbing member 6 is disposed. As the boundary member 8, for example, a two-dimensional fiber, a rubber plate, a film material, a mesh material, a fabric, a fiber made of a composite configuration of these, or a metal plate can be used.

  The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

[Production of wheel]
Example 1
In Example 1, a wheel having the internal structure shown in FIG. 1 was produced.

  First, as shown in FIG. 2, a cylindrical member made of an aluminum alloy and having an outer diameter of 80 mm, an inner diameter of 70 mm, and a length of 150 mm was prepared as the hub 1. As an outer diameter member, a donut-shaped bag having an opening made of a urethane-coated cloth of cotton was prepared. The outer diameter member had an outer diameter in the wheel radial direction of 199 mm, an inner diameter of 81 mm, and a width in the wheel width direction of 99 mm. As shown in FIG. 3, the outer diameter member was disposed so as to cover the outer surface of the hub 1.

  Next, as the elastic member 5, three metal springs made of a cylindrical member made of an aluminum alloy and having an outer diameter of 60 mm, a length of 100 mm, and a thickness of 0.1 mm were prepared. As shown in FIG. 4, the elastic member 5 is fixed to the hub 1 with bolts so that the axial direction of the hub 1 and the axial direction of the elastic member 5 are parallel to the outer surface of the hub 1. The three elastic members were arranged at equal intervals in the circumferential direction of the hub 1.

  Next, 500 particle holders made of a cube-shaped cloth bag having a side of about 5 cm were prepared. 300 g of bead-like particles made of polypropylene (equivalent circle diameter of 0.5 mm to 1.5 mm, weight of each particle of 0.5 g to 1.5 g) were sealed in the bag, and the bag was closed. As shown in FIG. 7, the shock absorbing member 15 made of a beaded bag is disposed in a space surrounded by the hub 1, the elastic member 5, and the grounding member 2.

  Next, as shown in FIG. 5, the side member 3 made of cotton urethane-coated fabric was placed on the side surface of the wheel and stitched with the outer shape member to obtain the wheel of Example 1.

(Comparative Example 1)
As Comparative Example 1, a so-called elastic wheel having the same hub 1, grounding member 2, elastic member 5, and side member 3 as in Example 1 and including no shock absorbing member was produced.

[Running test]
(Running test machine)
Using the traveling test machine 16 shown in FIG. The traveling test machine 16 includes a tire weight adjusting balancer 17, a carriage 18, a parallel link 19, a rotating shaft 22, a ground 21, and a horizontal rail 23. The wheel 10 is attached to the rotating shaft 22.

  The rotating shaft 22 is connected to the carriage 18 through the parallel link 19. The carriage 18 can actively move on the horizontal rail 23 by the movement of the wheel 10 attached to the rotating shaft 22. There is a fulcrum of the parallel link 19 at the center of the carriage 18, and the rotation shaft 22 and the tire weight adjusting balancer 17 are arranged symmetrically with the fulcrum as the center of rotation. Therefore, the load applied to the wheel 10 can be adjusted by adjusting the weight of the tire weight adjusting balancer 17. Further, since the rotation center of the parallel link 19 is a bearing, it can actively rotate with respect to the vertical movement of the wheel 10.

(measuring device)
The movement of the wheel when the wheel of Example 1 and Comparative Example 1 is mounted on the traveling test machine 16 and traveled is measured using a three-dimensional measuring device (T10 manufactured by Viscon). The three-dimensional measuring apparatus reflects light emitted from a camera to a reflective marker installed on a measurement target (wheel), captures the reflected light using a plurality of cameras, and detects the coordinates of the reflective marker. In this embodiment, a reflection marker is arranged at the center of the wheel, and the measurement is performed with the wheel traveling direction as the X axis and the wheel settling direction as the Y axis.

(Measurement condition)
The influence of the slope of the ground on the moving speed of the wheel was measured. The measurement conditions were as follows.

Load applied to wheels (total weight of parallel link 19 and rotating shaft 22): 5000 g
Angular velocity: 5.72deg / sec
Inclination: 0 °, 5 °, 10 °, 15 °
Ground: Soft ground (silica sand)

(Measurement result)
The measurement results are shown in Table 1.

走行試験結果より、実施例１の車輪は、傾斜度が大きくなるにしたがって、移動速度が若干低下するものの、傾斜度が０°から１５°の範囲において、良好な走行性能を維持できることが確認された。特に傾斜度が０°の場合は、実施例１の車輪の移動速度は、弾性車輪である比較例１の車輪の移動速度と非常に近く、良好な移動速度であった。

From the running test results, it was confirmed that the wheel of Example 1 can maintain good running performance in the range of 0 ° to 15 °, although the moving speed slightly decreases as the inclination increases. It was. In particular, when the inclination was 0 °, the moving speed of the wheel of Example 1 was very close to the moving speed of the wheel of Comparative Example 1, which is an elastic wheel, and was a favorable moving speed.

[Shock absorption test]
(Test method)
Setting is made so that a load of 5 kg is applied to the wheel, and vibration of the wheel when the wheel is dropped from a height of 500 mm is measured using a three-dimensional measuring device (T10 manufactured by Viscon).

(Measurement result)
The measurement results are shown in FIG.

  As shown in FIG. 17, the wheel of Example 1 took about 0.6 seconds from when the wheel contacted the ground until the vibration converged. The wheel of Comparative Example 1 took about 2.2 seconds from when the wheel contacted the ground until the vibration converged. Therefore, it was confirmed that the wheel of Example 1 was very excellent in shock absorption performance compared with the wheel of Comparative Example 1.

  The wheel of the present invention is particularly beneficial when used on a vehicle traveling on the surface of a celestial body.

DESCRIPTION OF SYMBOLS 1 Hub 2 Grounding member 3 Side member 4 Hub cover 5,25 Elastic member 6,26,36,46 Shock absorbing member 7 Flange 8 Boundary member 10,20,30,40 Wheel 15 Particle holder 16 Running test machine 17 Tire weight adjustment Balancer 18 Carriage 19 Parallel link 21 Ground 22 Rotating shaft 23 Horizontal rail

Claims (6)

Wheels mounted on the axle of the vehicle,
A hub having a cylindrical member into which the axle is inserted;
A grounding member provided on the outer side in the radial direction of the wheel with respect to the hub;
An elastic member and an impact absorbing member provided between the hub and the ground member;
Wheel. The elastic member includes a cylindrical metal spring,
The metal spring is fixed to the hub;
The wheel according to claim 1. The shock absorbing member includes particles,
The wheel according to claim 1 or claim 2. The impact absorbing member further includes a particle holder that encloses the particles therein.
The wheel according to claim 3. The grounding member includes a two-dimensional fiber;
The wheel according to any one of claims 1 to 4. The wheel includes a boundary member provided along a circumferential direction of the wheel between the hub and the grounding member,
The elastic member is provided on the radially inner side of the wheel of the boundary member,
The shock absorbing member is provided on the outer side in the radial direction of the wheel of the boundary member,
The wheel according to any one of claims 1 to 5.

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