JP2019089475A - Airless wheel - Google Patents

Abstract

To provide an airless wheel which is not punctured, of which occurrence of slippage is suppressed on even a soft ground, and which is excellent in road holding performance on even a road surface such as a normal asphalt road.SOLUTION: This airless wheel has: a hub 30 which is fitted to an axle of a vehicle; a cylindrical rim 50 which is fixed around the hub 30; plural openings which are so formed on a peripheral surface of the rim 50 as to be spaced from one another in a circumferential direction; plural grounding components 70 which so project as to be movable in a radial direction of the rim 50 from the openings and ground onto a grounding surface; an energization component 90 which energizes the grounding component 70 to a radial direction outer side of the rim 50; energization force changing means 100 which changes a magnitude of energization force of the energization component 90.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an airless wheel.

Pneumatic tires used on ordinary asphalt roads are prone to punctures when traveling on rough terrain where iron scraps, rocks, debris, etc. are scattered, because iron scraps, debris, etc. damage the pneumatic tires.
In the Great East Japan Earthquake, there were frequent tire punctures when the emergency vehicle was traveling on the road including rubble after the earthquake.
As a technique for preventing such a puncture, there is an airless tire, and for example, a technique of using a special rubber for a tread ring having a contact surface is disclosed (Patent Document 1).
In such an invention, since it is not a pneumatic tire, puncture can be avoided.

JP, 2017-185925, A

However, at a site such as a landslide disaster, a tire of an emergency vehicle may slip on a road that has become soft ground containing sand and mud, and the travelability of the tire may be lost. In addition, emergency vehicles may travel on ordinary asphalt roads.
Therefore, as a tire for emergency vehicles, it is possible to run on a soft ground including sand and mud without being punctured even on a road including rubble etc. Furthermore, the running performance is good even on a road surface such as a normal asphalt road You will need a tire.

A tire with high rigidity can obtain stable running performance on a road surface such as an ordinary asphalt road, but on soft ground including sand, mud and the like, it is presumed that the tire with high rigidity slips easily.
On the other hand, in such soft ground, a tire with low rigidity, high deformability and high contact area may be considered to be more effective, but with such low rigidity tires, ordinary asphalt road The driving performance on a road surface like this will fall.

  In the invention described in Patent Document 1 mentioned above, the rigidity of the tire can not be changed each time according to the condition of the road surface even if the component etc. of the special rubber is adjusted, so it corresponds to all the cases as described above. There was a problem that things became difficult.

  An object of the present invention is to provide an airless wheel having excellent running performance on a road surface such as a normal asphalt road while suppressing the occurrence of a slip on a soft ground without puncture.

  The airless wheel according to the present invention is characterized by the following points. That is, a hub 30 attached to an axle 20 of a vehicle, a cylindrical rim 50 fixed around the hub 30, and a plurality of openings formed in the circumferential surface of the rim 50 at intervals in the circumferential direction A portion 60, a plurality of grounding members 70 movably protruding in the radial direction of the rim 50 from the opening 60 and contacting the ground surface, and urging the grounding member 70 radially outward of the rim 50 A member 90 and biasing means 100 for varying the magnitude of the biasing force of the biasing member 90 are provided.

According to the present invention, a tubular rim 50 is fixed around the hub 30 attached to the axle 20 of the vehicle. A plurality of openings 60 are formed on the circumferential surface of the rim 50 at intervals in the circumferential direction, and a plurality of ground members 70 that are grounded from the openings 60 project to the ground surface.
When the rim 50 rotates with the hub 30, the ground contact member 70 comes in contact with the ground contact surface and kicks the ground contact surface to advance or reverse the vehicle.
Further, the biasing force of the biasing member 90 that biases the grounding member 70 radially outward of the rim 50 can be changed according to the state of the ground contact surface. Therefore, when traveling on a hard ground such as an asphalt road, the biasing force of the biasing member 90 is increased to maintain running stability as a highly rigid ground contact member 70 and travel on a soft ground such as sand or mud. When doing this, the biasing force of the biasing member 90 is reduced to increase the contact area as a low rigidity grounding member 70, thereby suppressing the occurrence of slip.

  Further, the biasing force changing means 100 is provided on the inner peripheral portion of the rim 50 so as to be movable in the radial direction of the rim 50, and the extrusion block 110 supporting a spring material as the biasing member 90; And moving means (200) for moving the block (110) in the radial direction of the rim (50).

  In the present invention, when the moving means 200 moves the push block 110 supporting the spring material in the radial direction of the rim 50, the expansion and contraction stroke of the spring material changes, and the rigidity of the grounding member 70 can be easily changed.

  Furthermore, the moving means 200 is provided around the hub 30, and a restriction guide in which a radial groove (specifically, a radial groove 242) is formed in which one end of the extrusion block 110 in the axle 20 direction engages. An extrusion guide member in which a spiral groove (specifically, a spiral groove 232) is disposed facing the member 240 and the regulation guide member 240 and engaged with the other end of the extrusion block 110 in the axle 20 direction. And 230, and a drive mechanism 220 for rotating the push-out guide member 230 forward and reverse.

In the present invention, one end of the extrusion block 110 in the direction of the axle 20 engages with the radial groove of the restriction guide member 240, and the other end of the extrusion block 110 in the direction of the axle 20 is in the spiral groove of the extrusion guide member 230. It is engaged.
The drive mechanism 220 rotates the push-out guide member 230 forward or reverse according to the state of the ground contact surface. Here, the rotation of the one end of the extrusion block 110 in the direction of the axle shaft 20 is restricted by the restriction guide member 240. Thus, the other end of the extrusion block 110 is guided by the spiral groove formed in the extrusion guide member 230, and moves in the radial direction of the rim 50 to change the rigidity of the ground member 70.
Thus, the rotational force of the drive mechanism 220 can be changed to the radial movement force of the rim 50 with respect to the extrusion block 110 by the simple structure.

It is an embodiment of the present invention, and is a partial external appearance perspective view showing an airless wheel. It is an embodiment of the present invention, and is a partial longitudinal section of an airless wheel. It is an explanatory view in the state where a grounding member, a rim, and an energizing member were removed from an airless wheel concerning an embodiment of the invention. In order to deepen understanding of the present invention, it shows a change state of biasing force by a simple model, and (A) is a conceptual view showing a case where rigidity is low and (B) a case where rigidity is high. In order to deepen understanding of the present invention, it is an explanatory view by a simple model of an extrusion guide member, a regulation guide member, and an extrusion block. It is an external view which shows the traveling state in a level | step difference using the airless wheel which concerns on embodiment of this invention. It is explanatory drawing which shows the movement state of the grounding member in the driving | running | working state in a level | step difference using the airless wheel which concerns on embodiment of this invention. In order to deepen the understanding of the present invention, the modified state of the biasing force by a simple model is shown, and (A) is an explanatory view showing a case where the rigidity is low and (B) a case where the rigidity is high. In order to deepen the understanding of the present invention, a traveling state of a rigid surface according to a simplified model with different rigidity is shown. (A) is a wheel with high rigidity, (B) is an external perspective view with a wheel with low rigidity. In order to deepen the understanding of the present invention, the running condition on a sand slope is shown by a simple model with different rigidity, and (A) is a wheel with high rigidity, (B) is an appearance perspective view showing a wheel with low rigidity. It is. It is an explanatory view of a traveling state on a rigid surface using an airless wheel according to an embodiment of the present invention, in which (A) is a state of high rigidity, and (B) is a state of low rigidity. It is explanatory drawing which shows the slip ratio at the time of making the ground which spread the sand in which inclination angles differ in a state of different rigidity using the airless wheel which concerns on embodiment of this invention. It is explanatory drawing which shows the state of the sand ground after the movement in the driving | running state in a sand ground using the airless wheel which concerns on embodiment of this invention.

FIG. 1 is an external perspective view of an airless tire 10 as an airless wheel according to the present embodiment.
The airless tire 10 includes a cylindrical hub 30 to which a vehicle axle 20 is attached, a regular octagonal disk 40 fixed to both ends of the hub 30, and a hub 40 fixed to the outer edge of the disk 40. And a cylindrical rim 50 fixed to the periphery.

The rim 50 is provided with a plurality of openings 60 penetrating to the front and back, at equal intervals all around the rim 50. A part of the square plate-like grounding member 70 movably protrudes from the openings 60 radially outward of the rim 50 and is grounded to the grounding surface.
At the end of the ground member 70 on the hub 30 side, there is a flange 80 (see a simplified model in FIG. 5) which is a size larger than the dimension of the opening 60 and abuts on the edge of the opening 60 on the hub 30 side. It is provided.
When the flange 80 abuts on the edge of the opening 60 of the rim 50, the grounding member 70 is formed so as not to come off the opening 60.

FIG. 2 is a partial longitudinal sectional view of the airless tire 10.
A spring as an urging member 90 is provided on the hub 30 side of the ground contact member 70 to apply an urging force to abut the end surface of the ground contact member 70 on the hub 30 side to press the ground contact member 70 radially outward of the rim 50. It is done.
In the airless tire 10 according to the present embodiment, an urging force changing means 100 for changing the magnitude of the urging force of the urging member 90 and a control means for controlling the change of the urging force by the urging force changing means 100. And 300 are provided.

The biasing force changing means 100 is provided on the inner peripheral portion of the rim 50 so as to be movable in the radial direction of the rim 50, and supports the spring block as the biasing member 90. And moving means 200 for moving in the direction.
The extrusion block 110 is located between the hub 30 and the rim 50 and sandwiches the biasing member 90 with the grounding member 70.
The moving means 200 is capable of moving the push block 110 toward the rim 50 or the hub 30 in order to change the length of the biasing member 90.
The moving means 200 is provided around the hub 30 and disposed so as to face the restriction guide member 240 in which the radial radial groove 242 is formed to engage with one end of the extrusion block 110 in the axle 20 direction. The push-out guide member 230 is formed with a spiral groove in which the other end of the push-out block 110 in the direction of the axle shaft 20 engages, and a drive mechanism 220 for rotating the push-out guide member 230 forward and reverse.

A cylindrical engaging portion 120 slidably engageable with the spiral groove 232 is provided on the side surface of the extrusion block 110 on the extrusion guide member 230 side (see a simplified model in FIG. 5).
A protrusion 130 slidably engageable with the radial groove 242 is provided on a side surface of the extrusion block 110 on the regulation guide member 240 side (see a simplified model in FIG. 5).
A spring fixing portion 112 is provided on the outer surface of the push block 110 on the rim 50 side to fix an end portion of the spring as the biasing member 90 on the hub 30 side.

  Here, the disk 40 connecting the hub 30 and the rim 50 is a left disk 41 fixed to the left end side of the hub 30 viewed from the front of FIG. 2 and a right disk fixed to the right end side of the hub 30 And 42.

The drive mechanism 220 includes a drive unit 210 having a drive motor fixed to the left disk 41, and an internal gear 226 provided inside the circumference of a projecting portion of the outer peripheral edge of the side of the drive guide on the drive motor side. And an external gear 224 meshing with the internal gear 226, and a drive gear 222 meshing with the external gear 224 and provided on the drive shaft of the drive motor.
The airless tire 10 according to the present embodiment is a rotary electric transmission mechanism for transmitting electric power to the drive motor of the airless tire 10 and a control signal for controlling the drive of the drive motor from the control means 300 inside the vehicle. It has a slip ring 400 as a part.
The slip ring 400 is for transmitting an electric power and an electric signal (control signal) via a brush through an annular electric path arranged concentrically with the airless tire 10 which is a rotating body.

FIG. 3 shows the airless tire 10 with the rim 50, the ground contact member 70 and the biasing member 90 removed.
The extrusion block 110 is sandwiched and mixed between the extrusion guide member 230 and the restriction guide member 240. The extrusion blocks 110 are formed radially around the hub 30 at the same angular intervals, corresponding to the ground members 70 one by one.
A spring fixing portion 112 for fixing an end of the biasing member 90 on the hub 30 side is provided on the outer surface of the extrusion block 110 on the rim 50 side. The overall shape of the spring fixing portion 112 is cylindrical, and two spring fixing portions 112 protrude toward the grounding member 70 with respect to one extrusion block 110.

  The driving unit 210 is provided with two motors at an interval of 180 degrees. The number is not particularly limited to two, and three may be provided at intervals of 120 degrees, four at 90 degrees, or five or more at equiangular intervals. It is also good. The arrangement described above is arranged equiangularly as described above in consideration of the balance of rotation, but it is not particularly limited to the arrangement at equal intervals, and the number may be only one.

FIG. 4 shows how the biasing force is changed by a simple model in order to further understand the relationship between the ground contact member 70, the biasing member 90, and the push block 110 according to the present embodiment.
When force F is applied to the grounding member 70 from the left view of FIG. 4A, the relationship between the force F and the amount of deformation of the spring as the biasing member 90 is received as shown in FIG. The relationship is proportional as shown in the graph on the right of A).

As shown in FIG. 4B, when the extrusion block 110 is moved upward by a distance of x1 from that of FIG. 4A, the relationship between the force F and the amount of deformation of the spring is a graph of the right figure of FIG. It will start from the point B which is reduced by x1. That is, when the push block 110 is moved in the direction in which the length of the spring as the biasing member 90 is reduced, the ground contact member 70 is not pushed into the rim 50 until the force F1, and the rigidity becomes high.
As a result, the rigidity can be varied by the position of the extrusion block 110.

FIG. 5 is an explanatory view using a simplified model for better understanding of the mechanisms of the extrusion guide member 230, the regulation guide member 240, and the extrusion block 110 according to the present embodiment.
The restriction guide member 240 is formed with radial grooves 242 extending radially in the radial direction. On the surface of the extrusion block 110 on the restriction guide member 240 side, a square plate-like protrusion 130 having a width that can be slidably engaged with the width of the radial groove 242 is formed.
The radial grooves 242 and the protrusions 130 maintain the push block 110 movably in the radial direction of the hub 30 and have a role in regulating the movement of the hub 30 in the circumferential direction.

In the extrusion guide member 230, a spiral groove 232 in a spiral shape is formed. On the surface of the extrusion block 110 on the extrusion guide member 230 side, three engagement portions 120 having a width that can be slidably engaged with the spiral groove 232 are provided. The number is not limited to three, and may be one, two or four or more.
When the push-out guide member 230 is rotated in a state in which the movement in the circumferential direction is restricted, the spiral groove 232 and the engaging portion 120 push out based on the movement of the engaging portion 120 sliding in the rotating spiral groove 232. The block 110 can be moved radially of the hub 30.
In this simple model, in order to make the mechanism easy to understand, the diameters of the central axes of the extrusion guide member 230 and the restriction guide member 240 are formed smaller than in actuality, and the spiral groove 232 or radial groove Although 242 is formed, in the embodiment according to the present embodiment, a large hole into which the hub is inserted is provided at the center of the extrusion guide member 230 and the restriction guide member 240, and the whole is formed in a ring shape (ring shape) There is.

FIG. 6 is an external view of the airless tire 10 according to the present embodiment, in which an obstacle 610 is placed to travel in order to show a traveling state at a level difference. A dustproof cover 14 is placed around the airless tire 10.
In the airless tire 10 according to the present embodiment, it is possible to travel without any problems occurring in overcoming the obstacle 610 in either the high rigidity state or the low rigidity state. It is formed.
Specifically, as shown in FIG. 7A, in a state of high rigidity, it is possible to shorten the amount of deformation of the ground contact member 70 (the amount of movement pushed into the hub 30 side) by the force pushing the ground contact member 70. The obstacle 610 can be overcome only by applying a force to one grounding member 70 (and its biasing member 90).

  On the other hand, in the low rigidity state as shown in FIG. 7B, the amount of deformation of the ground contact member 70 (the amount of movement pushed into the hub 30 side) is greater than in the case of FIG. Because of the lengthening, in addition to one grounding member 70, a force is applied to the grounding members 70 on both sides thereof, and a load is supported by a total of three grounding members 70. As described above, even in the case where the rigidity is low, the biasing member 90 corresponding to the plurality of ground members 70 functions so that it is possible to cope with the case where the rigidity is low.

In the present embodiment, by having the above-described configuration, the following actions and effects are achieved.
According to the present embodiment, a cylindrical rim 50 is fixed around the hub 30 attached to the axle 20 of the vehicle. A plurality of openings 60 are formed on the circumferential surface of the rim 50 at intervals in the circumferential direction, and a plurality of ground members 70 that are grounded from the openings 60 project to the ground surface.
When the rim 50 rotates with the hub 30, the ground contact member 70 comes in contact with the ground contact surface and kicks the ground contact surface to advance or reverse the vehicle.
Further, the biasing force of the biasing member 90 that biases the grounding member 70 radially outward of the rim 50 can be changed according to the state of the ground contact surface. Therefore, when traveling on a hard ground such as an asphalt road, the biasing force of the biasing member 90 is increased to maintain running stability as a highly rigid ground contact member 70 and travel on a soft ground such as sand or mud. When doing this, the biasing force of the biasing member 90 is reduced to increase the contact area as a low rigidity grounding member 70, thereby suppressing the occurrence of slip.

A more specific description will be given.
According to the present embodiment, since the tire is not the normal pneumatic tire but the airless tire 10, the vehicle will not be punctured and unable to travel even when traveling on rough terrain including rubble, rocks and the like.
Further, according to the present embodiment, under the control of the control means 300, the biasing force changing means 100 changes the biasing force of the biasing member 90. When the biasing force changing means 100 strengthens the biasing force of the biasing member 90, the distance (deformation amount) by which the grounding member 70 is pushed from the opening 60 of the rim 50 toward the hub 30 by the force applied to the grounding member 70 from the grounding surface is The tire can be short and stiff.

Conversely, if the biasing force of the biasing member 90 is weakened, the distance (deformation amount) by which the grounding member 70 is pushed from the opening 60 of the rim 50 to the hub 30 becomes longer even if the same force as described above is applied to the grounding member 70. It can be a tire with low rigidity.
That is, by the control of the control means 300, the rigidity of the tire can be freely adjusted.

Thus, when traveling on a road surface as a rigid surface such as a normal asphalt road, the tire is controlled to a tire with high rigidity, and when traveling on a soft ground containing sand, mud, etc., a tire with low rigidity is used. It becomes possible to control.
As a result, the airless tire according to the present embodiment can suppress the occurrence of slips even on soft ground without puncture and can be made to have excellent running performance even on a road surface such as a normal asphalt road.

In the present embodiment, the moving means 200 moves the push-out block 110 supporting the spring material in the radial direction of the rim 50, so that the expansion and contraction stroke of the spring material changes, and the rigidity of the grounding member 70 can be easily changed.
That is, in the present embodiment, in a state where the extrusion block 110 is movably restricted between the hub 30 and the rim 50 in the radial direction of the hub 30, the moving means 200 moves the extrusion block 110 toward the rim 50 side or the hub 30. By moving it to the side, the length of the biasing member 90 sandwiched between the extrusion block 110 and the grounding member 70 can be changed. Thereby, the biasing force of the biasing member 90 can be changed.

In the present embodiment, one end of the extrusion block 110 in the direction of the axle 20 engages with the radial radial groove 242 of the restriction guide member 240, and the other end of the extrusion block 110 in the direction of the axle 20 is the spiral of the extrusion guide member 230. In the form of a spiral groove 232.
The drive mechanism 220 rotates the push-out guide member 230 forward or reverse according to the state of the ground contact surface. Here, the rotation of the one end portion of the extrusion block 110 in the direction of the axle shaft 20 is restricted by the restriction guide member 240. Thus, the other end of the extrusion block 110 is guided by the spiral groove formed in the extrusion guide member 230, and moves in the radial direction of the rim 50 to change the rigidity of the ground member 70.
A more specific description will be given.

  In the present embodiment, the rotational drive force of the drive unit 210 is transmitted to the extrusion guide member 230 through the drive gear 222, the external gear 224, the internal gear 226, and the like to rotate the extrusion guide member 230. When the extrusion guide member 230 rotates, the spiral groove 232 on the side also rotates together. The push block 110 is movably maintained in the radial direction of the hub 30 and its movement in the circumferential direction is restricted. In addition to this, the engaging portion 120 slidably engaged with the spiral groove 232 slides along the spiral groove 232 so that the extrusion block 110 is not moved in the circumferential direction of the hub 30. The push block 110 can be moved in the radial direction of 30.

  Furthermore, by changing the rotation direction of the extrusion guide member 230, it is possible to change the extrusion block 110 to either the radially outward direction or the inward direction. This makes it possible to freely change the length of the biasing member 90 sandwiched between the extrusion block 110 and the grounding member 70, and as a result, the rigidity of the airless tire 10 according to the present embodiment. Can be changed.

In the present embodiment, the projecting portion 130 of the extrusion block 110 is engaged with the radial groove 242 of the restriction guide member 240 that rotates integrally with the hub 30. The radial grooves 242 radially extend in the radial direction of the hub 30, and therefore restrict the movement of the extrusion block 110 in the circumferential direction of the hub 30 and maintain the radial movement of the hub 30. Can.
Thus, the rotational force of the drive mechanism 220 with respect to the extrusion block 110 can be changed to the moving force in the radial direction of the rim 50 with a simple structure.
The load can be dispersed as much as possible by further dividing the grounding member 70, and it is possible to further reduce the slip ratio.

Example 1
FIG. 8 shows the position of the extrusion block 110 of the airless tire 10 according to the present embodiment and the deformed state of the ground contact member 70 using the simplified model in the state of low rigidity in FIG. State of high rigidity).
As shown in FIG. 8, a simplified model of the structure of the airless tire 10 according to the present embodiment is created, and a grounding member 70 having a ridge 80, a rim 50 having an opening 60, a disc 40, an extruded block 110, and extrusion A spring corresponding to the biasing member 90 sandwiched between the block 110 and the grounding member 70 was prepared. With this simple model, the extrusion block 110 is set at a predetermined position, and the extrusion block 110 is grounded from the position of the extrusion block 110 of FIG. 8A corresponding to the state of low rigidity and the position of the extrusion block 110 of FIG. In the case of FIG. 8 (B) corresponding to the high rigidity state where the biasing force is increased by 10 mm closer to the side, the amount of deformation of the ground contact member 70 when a load of 7.5 kg is applied to the ground contact member 70 (sinking Amount) is shown in the bar graph of FIG. In the state of low rigidity in FIG. 8A, when a load of 7.5 kg is applied to the ground contact member 70, the amount of deformation of the ground contact member 70 is 10.8 mm. On the other hand, in the state of high rigidity shown in FIG. 8B in which the pushing force is increased by moving the extrusion block 110 closer to the grounding member 70 by 10 mm, a load of 7.5 kg is applied to the grounding member 70 to deform 1.4 mm. Amount. Under this condition, in the case of the high rigidity state, a reduction of about 87% in amount of deformation was observed as compared to the low state.

(Example 2)
FIG. 9 shows a traveling state of a rigid surface according to a simplified model having different rigidity in order to understand the airless tire 10 according to the present embodiment.
FIG. 9A shows a rigid rigid tire 500, which is made of a resin of a thick plate which is hard to deform, and has a structure in which the entire tire is not easily deformed.
Specifically, a rigid body circular portion 510 corresponding to the hub 30, a rigid body outer circular portion 520 corresponding to the grounding member 70, and a rigid body spoke for substantially fixing the distance between the rigid body inner circular portion 510 and the rigid body outer circle portion 520 And a unit 530.

FIG. 9 (B) shows a flexible tire 501 with low rigidity, which is a thin sheet metal plate that is easily deformed, and has a structure in which the entire tire is easily deformed.
Specifically, the flexible inner circular portion 511 corresponding to the hub 30, the flexible outer circular portion 521 corresponding to the grounding member 70, and the flexible inner circular portion 511 and the flexible outer circular portion 521 are easily mixed. And a cylindrical flexible cylindrical portion 531 that can be deformed.

As shown in FIG. 9A, the thickness is different between the case where the rigid tire 500 having high rigidity is used and the case where the flexible tire 501 having low rigidity is used as shown in FIG. 9B. The running performance was investigated on the rigid surface of the plate acrylic plate.
In the rigid tire 500 and the flexible tire 501, drive motors as driving devices with the same performance are attached to the central axes of the rigid inner circle portion 510 and the flexible inner circle portion 511, and the history of rotation angle is measured on the rotation axis Possible rotary encoders are attached.

From the stopped state, it is driven to rotate for a predetermined time, and the distance that each tire actually moved and the theoretical distance calculated from the measurement results of the rotation angle from the rotary encoder are calculated, and based on these values Slip rate is calculated.
The slip ratio in the case of driving is calculated by ((tire speed-vehicle speed) / tire speed).
As a result, in the rigid tire 500 of FIG. 9 (A), the slip ratio is 0.01, and in the flexible tire 501 of FIG. 9 (B), the slip ratio is 0.01. There was no difference in slip ratio with 501.

In addition, in order to compare the rolling resistance of the rigid tire 500 and the flexible tire 501, the current value flowing to the drive motor as the drive unit 210 directly connected to the rotary shaft of each tire was recorded, and the average value was calculated. .
As a result, it becomes 772.8 mA in the rigid tire 500 of FIG. 9 (A), it becomes 886.3 mA in the flexible tire 501 of FIG. 9 (B), and the rolling resistance is more than that of the flexible tire 501 of FIG. 9 (B). The rigid tire 500 of (A) is smaller.
That is, when the ground is a rigid surface, the rolling resistance of the rigid tire 500 of FIG. 9 (A) is smaller, and the running performance is better than that of the flexible tire 501 of FIG. 9 (B).

  Next, as shown in FIGS. 10A and 10B, the same rigid tire 500 and the flexible tire 501 as those described in FIG. 9 which is a simplified model of the airless tire 10 according to the present embodiment are used. And, the comparison of the running performance on the slope which was spread with sand having an inclination angle of about 15 degrees was performed three times each.

As a result of similarly calculating the slip ratio described in FIG. 9 described above and calculating the average value thereof, the average slip ratio in the case of using the rigid tire 500 of FIG. The average slip ratio was 0.06 when using the flexible tire 501).
The slip ratio of the flexible tire 501 of FIG. 10 (B) is smaller than that of the rigid tire 500 of FIG. 10 (A), and the running performance is improved.
When the external shape of each tire in the running test is compared, as shown in FIGS. 10A and 10B, the rigid tire 500 in FIG. 10A has smaller deformation, and the flexible tire 501 in FIG. 10B. In this case, the deformation in the vicinity of the ground contact surface is large, and the soft tire 501 is larger when the ground contact area is compared.

  As shown in FIGS. 10 (A) and 10 (B), in the rigid tire 500 of FIG. 10 (A), the load is concentrated on a small area so that it becomes easy to slip, and in the flexible tire 501 of FIG. 10 (B) By the contact area being larger than 10 (A), the load is dispersed and it becomes difficult to slip.

(Example 3)
By changing the position of the extrusion block 110 using the airless tire 10 according to the present embodiment, the running performance in the state of high rigidity in FIG. 11 (A) and the state of low rigidity in FIG. 11 (B) Surveyed.
The extruded block 110 of FIG. 11 (A) has a difference of about 10 mm between the position of the extruded block 110 in the state of high rigidity in FIG. 11 (A) and the state of low rigidity in FIG. 11 (B). Is adjusted so as to be closer to the rim 50 than in FIG. 11 (B).

The numerical value 10 mm is an example, and the present invention is not limited to this, and a difference may be provided to the position of the extrusion block 110 to some extent so that a difference in the biasing force of the biasing member 90 is generated. It is.
In addition, although a thick acrylic plate was used as the rigid surface, the material is not particularly limited thereto, and a wood board, another resin board, a metal board or the like may be used.

In each airless tire 10 of FIGS. 11 (A) and 11 (B), the rotational shaft of the drive motor (using a different one from the drive unit 210) is directly connected to the axle 20 for a predetermined time, and the slip ratio is And the electric current value of the drive motor which rotates the axle shaft 20 was measured, the test was done 3 times, and the average value was computed.
As a result, the slip ratio is 0.03 in the state of high rigidity in FIG. 11 (A), and is 0.03 in the state of low rigidity in FIG. 11 (B). I could not see it.

  On the other hand, the current value of the drive motor for applying the rotational drive force to the rotary shaft in each state was measured three times in the same manner as in the first embodiment, and the average was calculated. The average current value was 599 mA, and the average current value was 632 mA in the state of low rigidity in FIG. The state of high rigidity in FIG. 11A has a smaller average current value and lower rolling resistance than the state of low rigidity in FIG. 11B.

  That is, although there is no difference in the slip ratio, in the state of high rigidity, no load is applied to the drive motor for applying the rotational driving force of the airless tire 10, and on the ground of the rigid surface, the state of high rigidity However, the driving performance was good.

FIG. 12 shows the slip ratio when actually traveling the ground in which sand with different inclination angles is spread in a state of different rigidity using the airless tire 10 according to the present embodiment.
In a state where the ground is covered with sand, when the inclination angle of the ground is 0 degree, the traveling performance is examined at 0 degree, 5 degrees, 10 degrees, 15 degrees in the same manner as in FIG. Was calculated.

As a result, as shown in the graph showing the relationship between the inclination angle and the slip ratio in FIG. 12, in the horizontal state where the inclination angle is 0 degree, the difference between the high rigidity state and the low rigidity state was not found. As the angle increases to 5 degrees, 10 degrees, and 15 degrees, the slip ratio increases in the high rigidity state, and at an inclination angle of 15 degrees, the slip ratio is 0.29 in the high rigidity state, and the rigidity is The slip ratio was 0.24 in the low state of, and the largest difference occurred.
That is, in the case where the ground was sand-packed, the slip ratio became smaller in the low rigidity state than in the high rigidity state, and a good performance difference was observed.

FIG. 13 shows the appearance of the sand on the ground after the running test at the inclination angle of 15 degrees in FIG.
In the case of FIG. 15 (A) in the state of low rigidity, no sign of collapse of the sand on the ground after the running test is found and the mark of the ground contact member 70 clearly remains, while the state of high rigidity In the case of FIG. 15 (B), it was a result that several marks where the sand on the ground after the running test was broken were seen.
In the low rigidity state, it was possible to travel without slippage due to the increase in the contact area, while in the high rigidity state, it slipped and scraped off the surface of the sand. As a result, it is inferred that the low rigidity state could reduce the slip ratio.
From the results of the above example, it was possible to show the effectiveness of the airless tire 10 in a road surface such as an asphalt road as a rigid surface and in a soft ground by sand.

10 Airless wheels (airless tires)
14 Dustproof cover 20 axles
30 hubs 40 disks
41 left disc 42 right disc
50 rims 60 openings
70 grounding member 80 buttocks
90 biasing member 100 biasing means
110 extruded block 112 spring fixing portion
120 engaging portion 130 projecting portion
200 moving means 210 drive unit
220 Drive Mechanism 222 Drive Gear
224 external gear 226 internal gear
230 Extrusion guide member 232 Spiral groove
240 Regulating guide member 242 Radial groove
300 control means 400 slip ring
500 rigid tire 501 flexible tire
510 Rigid inner circle 511 Flexible inner circle
520 Rigid outer circle 521 Flexible outer circle
530 Rigid spokes 531 Flexible cylinder
610 Obstacle

Claims (3)

A hub attached to the axle of the vehicle,
A tubular rim fixed around the hub;
A plurality of openings formed circumferentially spaced on the circumferential surface of the rim;
A plurality of grounding members that movably protrude from the opening in the radial direction of the rim and are grounded to the ground surface;
A biasing member for biasing the ground contact member radially outward of the rim;
Biasing force changing means for changing the magnitude of the biasing force of the biasing member;
With airless wheels. The biasing force changing means is
An extrusion block which is provided on the inner peripheral portion of the rim so as to be movable in the radial direction of the rim and supports a spring material as the biasing member;
Moving means for moving the extrusion block in the radial direction of the rim;
The airless wheel according to claim 1, comprising: The moving means is
A restriction guide member provided around the hub, and formed with a radial groove engaged with one end of the extrusion block in the axle direction;
An extrusion guide member disposed facing the restriction guide member, and formed with a spiral groove engaged with the other end of the extrusion block in the axle direction;
A drive mechanism for rotating the extrusion guide member forward and reverse;
The airless wheel according to claim 2, comprising: