JP6994699B2 - Airless wheels - Google Patents

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, rubble, etc. are scattered, because iron scraps, rubble, etc. damage the pneumatic tires.
In the Great East Japan Earthquake, tire punctures occurred frequently while emergency vehicles were driving on roads 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 patch is disclosed (Patent Document 1).
In such an invention, since it is not a pneumatic tire, a flat tire can be avoided.

JP-A-2017-185925

However, at sites such as sediment-related disasters, the tires of emergency vehicles may slip on soft ground roads containing sand and mud, and the running performance of the tires may be lost. In addition, emergency vehicles may travel on ordinary asphalt roads.
Therefore, as a tire for an emergency vehicle, it can run on a road containing rubble without puncture, and on soft ground containing sand and mud, and has good running performance even on a road surface such as a normal asphalt road. Tires are needed.

On a road surface such as a normal asphalt road, a tire with high rigidity can obtain stable running performance, but on soft ground containing sand, mud, etc., it is presumed that the tire with high rigidity tends to slip.
On the other hand, on such soft ground, it is presumed that tires with low rigidity, high deformability, and a larger contact area than usual are more effective, but with such low rigidity tires, ordinary asphalt roads are presumed to be effective. The running performance on the road surface like this will deteriorate.

In the invention described in Patent Document 1 described above, the rigidity of the tire cannot be changed each time according to the condition of the road surface even if the component of the special rubber or the like is adjusted. There was a problem that things became difficult.

It is an object of the present invention to provide an airless wheel which suppresses the occurrence of slip even on soft ground without puncturing and has excellent running performance even on a road surface such as a normal asphalt road.

The airless wheel according to the present invention is characterized by the following points. That is, the hub 30 attached to the axle 20 of the vehicle, the tubular rim 50 fixed around the hub 30, and a plurality of openings formed at intervals in the circumferential direction on the peripheral surface of the rim 50. A portion 60, a plurality of grounding members 70 movably projecting from the opening 60 in the radial direction of the rim 50 and grounding to a grounding surface, and an urging force for urging the grounding member 70 to the outside of the rim 50 in the radial direction. It is characterized by having a member 90 and an urging force changing means 100 for changing the magnitude of the urging force of the urging member 90.

According to the present invention, a cylindrical rim 50 is fixed around a hub 30 attached to an axle 20 of a vehicle. A plurality of openings 60 are formed on the peripheral surface of the rim 50 at intervals in the circumferential direction, and a plurality of grounding members 70 that are in contact with the grounding surface project from the openings 60.
When the rim 50 rotates with the hub 30, the ground contact member 70 touches the ground plane and kicks the ground plane to move the vehicle forward or backward.
Further, the urging force changing means 100 can change the magnitude of the urging force of the urging member 90 that urges the grounding member 70 radially outward of the rim 50 according to the state of the ground contact surface. For this reason, when traveling on a hard ground contact surface such as an asphalt road, the urging force of the urging member 90 is increased to maintain running stability as a highly rigid grounding member 70, and the vehicle travels on soft ground such as sand and mud. At that time, the urging force of the urging member 90 is reduced to increase the grounding area as the grounding member 70 having low rigidity, and the occurrence of slip is suppressed.

Further, the urging 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 material as the urging member 90, and the extrusion block 110 and the extrusion. The block 110 is provided with a moving means 200 for moving the block 110 in the radial direction of the rim 50.

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

Further, the moving means 200 is provided around the hub 30, and a regulation guide in which a radial groove (specifically, a radial groove 242) with which one end of the extrusion block 110 in the axle 20 direction is engaged is formed. The extrusion guide member is arranged facing the regulation guide member 240 and has a spiral groove (specifically, a spiral groove 232) in which the other end of the extrusion block 110 in the axle 20 direction is engaged. It is characterized by having 230 and a drive mechanism 220 for rotating the extrusion guide member 230 in the forward and reverse directions.

In the present invention, one end of the extrusion block 110 in the axle 20 direction engages with the radial groove of the regulation guide member 240, and the other end of the extrusion block 110 in the axle 20 direction is in the spiral groove of the extrusion guide member 230. Engaged.
The drive mechanism 220 rotates the extrusion guide member 230 forward or reverse depending on the state of the ground plane. Here, one end of the extrusion block 110 in the axle 20 direction is restricted from rotating by the regulation guide member 240. As a result, 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 contact member 70.
As described above, with the simple structure, 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.

It is an embodiment of the present invention, and is a partial external perspective view showing an airless wheel. It is an embodiment of the present invention and is a partial vertical sectional view of an airless wheel. It is explanatory drawing of the state which removed the ground contact member, the rim, and the urging member from the airless wheel which concerns on embodiment of this invention. In order to deepen the understanding of the present invention, a state in which the urging force is changed by a simple model is shown, and (A) is a conceptual diagram showing a case where the rigidity is low, and (B) is a conceptual diagram showing a case where the rigidity is high. In order to deepen the understanding of the present invention, it is explanatory drawing by the simple model of the extrusion guide member, the regulation guide member, and the extrusion block. It is an external view which shows the running state in a step by using the airless wheel which concerns on embodiment of this invention. It is explanatory drawing which shows the moving state of the ground contact member in the traveling state in a step by using the airless wheel which concerns on embodiment of this invention. In order to deepen the understanding of the present invention, a state in which the urging force is changed by a simple model is shown, and (A) is an explanatory diagram 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 running state of a rigid body surface is shown by a simple model having different rigidity, (A) is a wheel with high rigidity, and (B) is an external perspective view with a wheel with low rigidity. In order to deepen the understanding of the present invention, a running state on a sand slope by a simple model having different rigidity is shown. FIG. Is. The traveling state on a rigid body surface is shown using the airless wheel according to the embodiment of the present invention, (A) is an explanatory view of a state of high rigidity, and (B) is an explanatory view of a state of low rigidity. It is explanatory drawing which shows the slip ratio at the time of running on the ground covered with the sand of different inclination angles in the state of different rigidity by using the airless wheel which concerns on embodiment of this invention. It is explanatory drawing which shows the state of the sandy ground after movement in the running state in the sandy 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 has a cylindrical hub 30 to which the axle 20 of the vehicle is attached, a regular octagonal disc 40 fixed to both ends of the hub 30, and a hub by being fixed to the outer edge of the disc 40. It is equipped with a cylindrical rim 50 fixed around it.

The rim 50 is provided with a plurality of openings 60 penetrating the front and back at equal intervals over the entire circumference of the rim 50. A part of the square plate-shaped grounding member 70 movably protrudes outward from each opening 60 in the radial direction and is in contact with the grounding surface.
At the end of the grounding member 70 on the hub 30 side, a flange portion 80 (see the simplified model in FIG. 5), which is one size larger than the dimension of the opening 60 and abuts on the edge of the opening 60 on the hub 30 side, is provided. It is provided.
The flange portion 80 abuts on the edge of the opening 60 of the rim 50 so that the grounding member 70 does not come off the opening 60 to the outside.

FIG. 2 is a partial vertical sectional view of the airless tire 10.
On the hub 30 side of the grounding member 70, a spring is provided as an urging member 90 that abuts on the end surface of the grounding member 70 on the hub 30 side and applies an urging force that presses the grounding member 70 radially outward of the rim 50. Has been done.
The airless tire 10 according to the present embodiment includes 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. There are 300 tires.

The urging 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 for supporting the spring material as the urging member 90 and the extrusion block 110 having the diameter of the rim 50. It is equipped with a transportation means 200 for moving in a direction.
The extrusion block 110 is located between the hub 30 and the rim 50, and sandwiches the urging member 90 between the grounding member 70 and the ground member 70.
The moving means 200 is capable of moving the extrusion block 110 to the rim 50 side or the hub 30 side in order to change the length of the urging member 90.
The moving means 200 is provided around the hub 30 and is arranged face-to-face with the regulation guide member 240 and the regulation guide member 240 having a radial radial groove 242 in which one end of the extrusion block 110 in the axle 20 direction is engaged. The extrusion block 110 has an extrusion guide member 230 having a spiral groove with which the other end in the axle 20 direction is engaged, and a drive mechanism 220 for rotating the extrusion guide member 230 in the forward and reverse directions.

On the side surface of the extrusion block 110 on the extrusion guide member 230 side, a columnar engaging portion 120 slidably engaged with the spiral groove 232 is provided (see the simplified model in FIG. 5).
A protrusion 130 slidably engaged with the radial groove 242 is provided on the side surface of the extrusion block 110 on the regulation guide member 240 side (see the simplified model in FIG. 5).
On the outer surface of the extrusion block 110 on the rim 50 side, a spring fixing portion 112 for fixing the end portion of the spring, which is the urging member 90, on the hub 30 side is provided.

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 and a right disk fixed to the right end side of the hub 30 when viewed from the front of FIG. Has 42 and.

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 portion protruding on the outer peripheral edge of the side surface of the extrusion guide member 230 on the drive motor side. An external gear 224 that meshes with the internal gear 226 and a drive gear 222 that meshes with the external gear 224 and is provided on the drive shaft of the drive motor are provided.
The airless tire 10 according to the present embodiment is a rotating body 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 electric power and an electric signal (control signal) through a brush through an annular electric circuit arranged concentrically with respect to the airless tire 10 which is a rotating body.

FIG. 3 shows the airless tire 10 from which the rim 50, the ground contact member 70, and the urging member 90 have been removed.
The extrusion block 110 is sandwiched between the extrusion guide member 230 and the regulation guide member 240. The extrusion blocks 110 are formed around the hub 30 radially at the same angular interval, one by one corresponding to the grounding member 70.
A spring fixing portion 112 for fixing the end portion of the urging member 90 on the hub 30 side is provided on the outer surface of the extrusion block 110 on the rim 50 side. The spring fixing portion 112 has a cylindrical shape as a whole, and two spring fixing portions 112 project to the grounding member 70 side with respect to one extrusion block 110.

The drive unit 210 is provided with two motors at intervals of 180 degrees. The number is not particularly limited to two, and three may be provided at 120-degree intervals, four may be provided at 90-degree intervals, and five or more may be provided at equal-angle intervals. May be good. The above arrangement is arranged at equal angles as described above in consideration of the balance of rotation, but is not particularly limited to the arrangement at equal intervals, and the number may be only one.

FIG. 4 shows a state in which the urging force is changed by a simple model in order to deepen the understanding of the relationship between the grounding member 70, the urging member 90, and the extrusion block 110 of the present embodiment.
When a force F is applied to the grounding member 70 from the left view of FIG. 4 (A), the force F is received by the urging member 90, and the relationship between the force F and the amount of deformation of the spring as the urging member 90 is shown in FIG. 4 (A). A) The relationship is proportional as shown in the graph on the right.

When the extrusion block 110 is moved upward by a distance of x1 from FIG. 4 (A) as shown in FIG. 4 (B), the relationship between the force F and the amount of deformation of the spring is the graph on the right of FIG. 4 (B). It will start from point B, which is shrunk by x1. That is, when the extrusion block 110 is moved in the direction of shortening the length of the spring as the urging member 90, the ground contact member 70 is not pushed against the rim 50 until the force F1, and the rigidity becomes high.
As a result, the rigidity can be changed depending on the position of the extrusion block 110.

FIG. 5 is an explanatory diagram based on a simplified model for deepening the understanding of the mechanisms of the extrusion guide member 230, the regulation guide member 240, and the extrusion block 110 of the present embodiment.
The regulation 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 regulation guide member 240 side, a square plate-shaped protrusion 130 having a width slidably engaged with the width of the radial groove 242 is formed.
The radial groove 242 and the protrusion 130 have a role of keeping the extrusion block 110 movable in the radial direction of the hub 30 and restricting the movement of the hub 30 in the circumferential direction.

The extrusion guide member 230 is formed with a spiral groove 232. On the surface of the extrusion block 110 on the extrusion guide member 230 side, three engagement portions 120 having a width that allows them to 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 extrusion guide member 230 is rotated in a state where the movement in the circumferential direction is restricted, the spiral groove 232 and the engaging portion 120 extrude based on the movement of the engaging portion 120 sliding in the rotating spiral groove 232. The block 110 can be moved in the radial direction of the hub 30.
In this simple model, the diameters of the central axes of the extrusion guide member 230 and the regulation guide member 240 are formed to be smaller than the actual diameter in order to make the mechanism easier to understand, and the spiral groove 232 and the radial groove are formed over substantially the front surface of the side surface. Although 242 is formed, in the one according to the present embodiment, there is a large hole in the center of the extrusion guide member 230 and the regulation guide member 240 for the hub to enter, and the whole is formed in a ring shape (annular ring shape). There is.

FIG. 6 is an external view showing a state in which an obstacle 610 is placed and run in order to show a running state on a step in the airless tire 10 according to the present embodiment. A dustproof cover 14 is placed around the airless tire 10.
The airless tire 10 according to the present embodiment can run without any trouble in overcoming the obstacle 610 regardless of whether the rigidity is high or low. It is formed.
Specifically, as shown in FIG. 7A, in a state of high rigidity, the amount of deformation of the grounding member 70 due to the force of pushing the grounding member 70 (the amount of movement pushed to the hub 30 side) can be shortened. The obstacle 610 can be overcome only by applying a force to one grounding member 70 (and its urging member 90).

On the other hand, as shown in FIG. 7B, when the rigidity is low, the deformation amount (movement amount pushed toward the hub 30 side) of the grounding member 70 is larger than that in the case of FIG. 7A due to the pushing force of the grounding member 70. Since it becomes long, a force is applied not only to one grounding member 70 but also to the grounding members 70 on both sides thereof, and the load is supported by a total of three grounding members 70. In this way, even when the rigidity is low, the urging member 90 corresponding to the plurality of grounding members 70 functions, so that even when the rigidity is low, it is possible to cope with it.

In the present embodiment, by having the above-mentioned configuration, the following actions and effects are exhibited.
According to this 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 peripheral surface of the rim 50 at intervals in the circumferential direction, and a plurality of grounding members 70 that are in contact with the grounding surface project from the openings 60.
When the rim 50 rotates with the hub 30, the ground contact member 70 touches the ground plane and kicks the ground plane to move the vehicle forward or backward.
Further, the urging force changing means 100 can change the magnitude of the urging force of the urging member 90 that urges the grounding member 70 radially outward of the rim 50 according to the state of the ground contact surface. For this reason, when traveling on a hard ground contact surface such as an asphalt road, the urging force of the urging member 90 is increased to maintain running stability as a highly rigid grounding member 70, and the vehicle travels on soft ground such as sand and mud. At that time, the urging force of the urging member 90 is reduced to increase the grounding area as the grounding member 70 having low rigidity, and the occurrence of slip is suppressed.

A more specific explanation will be given.
According to the present embodiment, since the tire is an airless tire 10 instead of a normal pneumatic tire, it does not puncture and become inoperable even when traveling on rough terrain including rubble and rocks.
Further, according to the present embodiment, the urging force changing means 100 changes the urging force of the urging member 90 under the control of the control means 300. When the urging force changing means 100 increases the urging force of the urging member 90, the distance (deformation amount) that 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 increased. The tire can be shortened and have high rigidity.

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

As a result, when traveling on a road surface as a rigid surface such as a normal asphalt road, the tire is controlled to have high rigidity, and when traveling on soft ground containing sand, mud, etc., the tire has low rigidity. It becomes possible to control.
As a result, the airless tire according to the present embodiment can suppress the occurrence of slip even on soft ground without puncturing, and can 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 extrusion block 110 that supports the spring material in the radial direction of the rim 50, so that the expansion / 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 in the radial direction of the hub 30 between the hub 30 and the rim 50, the moving means 200 moves the extrusion block 110 to the rim 50 side or the hub 30. By moving it to the side, the length of the urging member 90 sandwiched between the extrusion block 110 and the grounding member 70 can be changed. Thereby, the urging force of the urging member 90 can be changed.

In the present embodiment, one end of the extrusion block 110 in the axle 20 direction engages with the radial groove 242 of the regulation guide member 240, and the other end of the extrusion block 110 in the axle 20 direction is the spiral of the extrusion guide member 230. Engages in a spiral groove 232.
The drive mechanism 220 rotates the extrusion guide member 230 forward or reverse depending on the state of the ground plane. Here, the rotation of one end of the extrusion block 110 in the axle 20 direction is restricted by the regulation guide member 240. As a result, 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 contact member 70.
A more specific explanation will be given.

In the present embodiment, the rotational driving force of the drive unit 210 is transmitted to the extrusion guide member 230 via 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 surface also rotates integrally. The extrusion block 110 is kept movable in the radial direction of the hub 30, and the 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 extruded block 110 does not move in the circumferential direction of the hub 30. The extrusion block 110 can be moved in the radial direction of 30.

Further, by changing the rotation direction of the extrusion guide member 230, the extrusion block 110 can be changed to either the outer direction or the inner direction in the radial direction. As a result, the length of the urging member 90 sandwiched between the extrusion block 110 and the ground contact member 70 can be freely changed, and as a result, the rigidity of the airless tire 10 according to the present embodiment can be changed. Can be changed.

In this embodiment, the protrusion 130 of the extrusion block 110 is engaged with the radial groove 242 of the regulation guide member 240 that rotates integrally with the hub 30. Since the radial groove 242 extends radially in the radial direction of the hub 30, the extrusion block 110 is restricted from moving in the circumferential direction of the hub 30 and is maintained in the radial direction of the hub 30. Can be done.
As described above, with the simple structure, the rotational force of the drive mechanism 220 with respect to the extrusion block 110 can be changed to the radial movement force of the rim 50.
By further subdividing the grounding member 70, the load can be dispersed as much as possible, and the slip ratio can be further reduced.

(Example 1)
FIG. 8 shows the position of the extrusion block 110 of the airless tire 10 and the deformed state of the ground contact member 70 according to the present embodiment, using a simple model, the low rigidity state of FIG. 8A and FIG. 8B. It is explanatory drawing which shows the state of high rigidity of).
As shown in FIG. 8, a simplified model of the structure of the airless tire 10 according to the present embodiment is created, a grounding member 70 having a flange portion 80, a rim 50 having an opening 60, a disk 40, an extrusion block 110, and an extrusion. A structure corresponding to the spring as the urging member 90 sandwiched between the block 110 and the grounding member 70 was created. With this simple model, the extrusion block 110 is grounded to the grounding member 70 from the position of the extrusion block 110 in FIG. 8 (A) and the case of FIG. The amount of deformation (sinking) of the grounding member 70 when a load of 7.5 kg is applied to the grounding member 70 in the case of FIG. 8B corresponding to the state of high rigidity in which the urging force is increased by 10 mm closer to the side. Amount) is shown in the bar graph of FIG. In the low rigidity state of FIG. 8A, when a load of 7.5 kg is applied to the grounding member 70, the deformation amount of the grounding member 70 of 10.8 mm is obtained. On the other hand, in the high rigidity state of FIG. 8B in which the extrusion block 110 is brought closer to the grounding member 70 by 10 mm to increase the urging force, when a load of 7.5 kg is applied to the grounding member 70, the deformation is 1.4 mm. It becomes the quantity. Under this condition, in the case of high rigidity, the amount of deformation was reduced by about 87% as compared with the case of low rigidity.

(Example 2)
FIG. 9 shows a running state of a rigid body surface by a simple model having different rigidity in order to understand the airless tire 10 according to the present embodiment.
FIG. 9A shows a rigid tire 500 having high rigidity, which is made of a thick resin that is hard to be deformed and has a structure in which the entire tire is hard to be deformed.
Specifically, the rigid body circle portion 510 corresponding to the hub 30, the rigid body outer circle portion 520 corresponding to the grounding member 70, and the rigid body spokes that substantially fix the distance between the rigid body circle portion 510 and the rigid body outer circle portion 520. It is equipped with a part 530.

FIG. 9B shows a flexible tire 501 having low rigidity, which is made of a thin metal plate that is easily deformed and has a structure in which the entire tire is easily deformed.
Specifically, it is easy to be sandwiched between the flexible inner circle portion 511 corresponding to the hub 30, the flexible outer circle portion 521 corresponding to the grounding member 70, and the flexible inner circle portion 511 and the flexible outer circle portion 521. It is equipped with a deformable cylindrical flexible cylindrical portion 531.

The thickness of the case where the rigid tire 500, which is a tire having high rigidity as shown in FIG. 9A, is used, and the case where the flexible tire 501, which is a tire having low rigidity as shown in FIG. 9B, is used. The running performance was investigated on the rigid surface of the acrylic plate.
In the rigid body tire 500 and the flexible tire 501, a drive motor as a drive device having the same performance is attached to the central axis of the rigid body circle 510 and the flexible inner circle 511, and the history of the rotation angle is measured on the rotation axis. A possible rotary encoder is installed.

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

Further, in order to compare the rolling resistances of the rigid tire 500 and the flexible tire 501, the current value flowing through the drive motor as the drive unit 210 directly connected to the rotation axis of each tire was recorded, and the average value was calculated. ..
As a result, the rigid tire 500 of FIG. 9 (A) has 772.8 mA, the flexible tire 501 of FIG. 9 (B) has 886.3 mA, and the rolling resistance is higher than that of the flexible tire 501 of FIG. 9 (B). The rigid tire 500 of (A) was smaller.
That is, when the ground is a rigid surface, the rigid tire 500 of FIG. 9A has a smaller rolling resistance, and the running performance is better than that of the flexible tire 501 of FIG. 9B.

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

As a result of similarly calculating the slip ratio described with reference to FIG. 9 and calculating the average value, the average slip ratio when the rigid tire 500 of FIG. 10 (A) is used is 0.29, and FIG. 10 (B). The average slip ratio when the flexible tire 501 of) was used was 0.06.
The flexible tire 501 of FIG. 10 (B) had a smaller slip ratio than the rigid tire 500 of FIG. 10 (A), and the running performance was better.
Comparing the appearance shapes of the tires in the running test, as shown in FIGS. 10 (A) and 10 (B), the rigid tire 500 of FIG. 10 (A) has smaller deformation, and the flexible tire 501 of FIG. 10 (B) has a smaller deformation. The deformation in the vicinity of the contact patch became large, and the flexible tire 501 became larger when the contact area was compared.

As shown in FIGS. 10 (A) and 10 (B), in the rigid tire 500 of FIG. 10 (A), slipping is likely to occur due to the concentration of the load in a small area, and in the flexible tire 501 of FIG. 10 (B), FIG. Since the ground contact area is larger than 10 (A), the load is distributed and slipping is less likely to occur.

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

It should be noted that this numerical value of 10 mm is an example and is not limited to this, and it is sufficient to provide a difference in the position of the extrusion block 110 to some extent so that a difference in the urging force of the urging member 90 occurs. Is.
A thick acrylic plate is used as the rigid body surface, but the material is not particularly limited to this, and a wood plate, another resin plate, a metal plate, or the like may be used.

In each of the airless tires 10 of FIGS. 11A and 11B, the rotation 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 the same as in the first embodiment. And the current value of the drive motor that rotates the axle 20 was measured, and the test was performed three times to calculate the average value.
As a result, the slip ratio is 0.03 in the high rigidity state of FIG. 11 (A) and 0.03 in the low rigidity state of FIG. 11 (B), which are the same numerical values, and the difference between the two is I couldn't see it.

On the other hand, the current value of the drive motor that applies the rotational driving force to the rotating 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 low rigidity state of FIG. 11 (B). The high rigidity state of FIG. 11 (A) had a smaller average current value and a smaller rolling resistance than the low rigidity state of FIG. 11 (B).

That is, although there is no difference in the slip ratio, the one with high rigidity is the one in which the drive motor that applies the rotational driving force of the airless tire 10 is not loaded, and the one with high rigidity on the ground of the rigid body surface. However, the running performance was good.

FIG. 12 shows the slip ratio when the airless tire 10 according to the present embodiment is actually run on the ground covered with sand having different inclination angles in a state of different rigidity.
When the ground condition is covered with sand and the horizontal inclination angle is 0 degrees, the running performance is investigated at 0 degrees, 5 degrees, 10 degrees, and 15 degrees in the same manner as in FIG. 11, and the slip ratio. Was calculated.

As a result, as shown in the graph showing the relationship between the tilt angle and the slip ratio in FIG. 12, in the horizontal state where the tilt angle is 0 degrees, there was no difference between the high rigidity state and the low rigidity state, but the tilt was not observed. As the angle increases to 5 degrees, 10 degrees, and 15 degrees, the slip ratio becomes larger in the high rigidity state, and at the inclination angle of 15 degrees, the slip ratio becomes 0.29 in the high rigidity state, and the rigidity becomes higher. In the low state, the slip ratio was 0.24, and the largest difference occurred.
That is, in the case where sand is spread as the ground, the slip ratio is smaller in the low-rigidity state than in the high-rigidity state, and a good difference in performance is observed.

FIG. 13 shows the appearance state of the sandy ground on the ground after the running test at the inclination angle of 15 degrees of FIG.
In the case of FIG. 15 (A) in the state of low rigidity, no trace of the collapse of the sand on the ground after the running test is seen, and the trace of the grounding member 70 remains clearly, whereas the state of high rigidity remains. In the case of FIG. 15B, the result was that a number of traces of collapse of the sand on the ground after the running test were observed.
In the low-rigidity state, it was possible to run without slipping due to the increase in the ground contact area, whereas in the high-rigidity state, it slipped on the surface of the sand and scraped out. As a result, it is presumed that the slip ratio could be reduced in the state of low rigidity.
From the results of the above examples, it was possible to show the effectiveness of the airless tire 10 on a road surface such as an asphalt road as a rigid body surface or on soft ground due to sandy ground.

10 Airless wheels (airless tires)
14 Dustproof cover 20 Axles
30 hub 40 disc
41 Left disc 42 Right disc
50 rim 60 opening
70 Grounding member 80 Collar
90 Bounce member 100 Basis force changing means
110 Extrusion block 112 Spring fixing part
120 Engagement part 130 Protruding part
200 means of transportation 210 drive unit
220 Drive mechanism 222 Drive gear
224 External gear 226 Internal gear
230 Extrusion guide member 232 Spiral groove
240 Regulatory 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 body spokes 531 Flexible cylindrical parts
610 Obstacles

Claims (2)

With a hub attached to the axle of the vehicle,
A cylindrical rim fixed around the hub,
A plurality of openings formed on the peripheral surface of the rim at intervals in the circumferential direction, and
A plurality of grounding members that movably project from the opening in the radial direction of the rim and ground to the grounding surface.
An urging member that urges the grounding member to the outside in the radial direction of the rim, and
The urging force changing means for changing the magnitude of the urging force of the urging member,
Have,
The means for changing the force is
An extrusion block provided on the inner peripheral portion of the rim so as to be movable in the radial direction of the rim and supporting the spring material as the urging member, and
A moving means for moving the extrusion block in the radial direction of the rim,
Airless wheels equipped with . The means of transportation is
A regulatory guide member provided around the hub and having a radial groove with which one end of the extrusion block in the axial direction engages.
An extrusion guide member which is arranged face-to-face with the regulation guide member and has a spiral groove in which the other end in the axle direction of the extrusion block is engaged.
A drive mechanism for rotating the extrusion guide member in the forward and reverse directions and
The airless wheel according to claim 1 .

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