JPH0367881B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Object of the Invention [Field of Industrial Application] This invention relates to a spiked tire used when a vehicle runs on an icy and snowy road.

[Prior Art] It has been known to use spiked tires in which a plurality of spikes protrude from the tread of the tire in order to prevent the tire from slipping when a vehicle runs on an icy or snowy road. There is.

Conventional spike tires have a structure in which spikes are driven into a snow tire and protrude approximately 1.5 to 2.0 mm from the tire surface. A tip made of cemented carbide or the like is usually attached to the tip of the spike for wear resistance.

Conventional spiked tires have this structure, so on roads free of ice and snow, the spikes scrape the road surface and scatter as dust into the atmosphere, causing pollution problems. As a countermeasure, current measures include reducing the protrusion of the spikes to 1.0 to 1.5 mm, or increasing the number of spikes to 154 mm.
Efforts have been made to reduce the number of tires per tire from 122 tires per tire, but this does not essentially solve the pollution problem, and on the other hand, it does not improve the performance of tires on icy and snowy roads. It is considered to be a safety problem as it may cause a drop in the temperature. In addition, in recent years, it has been considered to insert and remove spikes depending on the road surface situation, but the spike pins that have been considered have extremely complex structures and require some type of actuator (for example, a pneumatic actuator) to insert and remove the spike pins. , electric actuator), the size is large and the price is high, so it has not been put into practical use.

Because of these factors, it is possible to maintain tire performance on icy and snowy roads without scraping the road surface, and therefore, when used on non-icy and snowy roads, without impairing running stability on icy and snowy roads. There is a need for the development of a spiked tire that can prevent the occurrence of pollution, is compact in size, inexpensive, and operates reliably.

The applicant of the present invention previously proposed such a spike pin for spiked tires in Patent Application No. 168663 of 1985 (Japanese Unexamined Patent Publication No. 63-25109, Japanese Patent Publication No. 3-33522).

As shown in FIG.
06; a cup 102 is rotatably held within the cup 102 while being guided by the guide surface 106, and a portion of the cup 102 is
A spiked ball 107 comprising a ball 103 exposed from the opening of the ball 103 and a spike tip 104 attached to and projected from the exposed portion of the ball 103.
It is.

This spike ball 107 is driven into the tire 110, and the spiked tire 10 as shown in FIG.
1, the spiked tire 101 is on the road surface 108
is an icy and snowy road surface, the tread 1 of the tire 110
12 slides on the road surface 108 in the sliding direction 116, a force F in the opposite direction to the sliding direction 116 acts on the top 111 of the spiked ball 107, and a rotational moment acts on the spiked ball 107, as shown in FIG. , the spike ball 107 is on the guide surface 106
As the spike tip 104 rotates, the edge 104a of the spike tip 104 touches the spike ball 10.
7 and bites into the road surface 108. In this state, the bottom surface 113 of the ball 103 is connected to the cup 102.
When the ball 103 comes into contact with the bottom surface 114 of the tire, the rotation of the ball 103 is stopped, and the braking force G from the road surface 108 applied to the edge 104a is transmitted to the tire 110, thereby stopping the sliding between the tread surface 112 and the road surface 108. Furthermore, when the road surface 108 is an ice-free road surface, the spike tips 104 touch the edge 115 of the tire.
is pushed back to the original position, and the tread 112 and road surface 1
There is no slippage between ball 103 and ball 08.
The structure is such that the spike tip 104 does not rotate, so the spike tip 104 does not protrude, and the road surface 108 is not damaged.

The spike tire 101 configured in this way is
The structure is simple, and the spike tips act reliably to stop slipping only when there is slippage between the tire tread and the road surface and there is a need to prevent slipping, regardless of the environmental temperature. No necessary road scraping problems arise.

[Problems to be Solved by the Invention] However, on the other hand, in the spike tire 101 configured in this way, the spike balls 107
A moderate clearance is required between the cup 102 and the ball 103, and a high degree of machining accuracy is required.
There is a tendency for costs to be high, and a solution to this problem is desired.

This invention was made in view of the above circumstances, and it is possible to make spikes protrude from the tire surface only when slippage occurs depending on the road surface condition, thereby preventing scraping of the road surface. This significantly reduces the amount of pollution that occurs on non-icy roads without degrading the tire's performance on icy and snowy roads, thus preventing the generation of pollution when used on non-icy and snowy roads without impairing driving stability on icy and snowy roads. More importantly, it is an object of the present invention to provide a spiked tire which is particularly simple in structure, reliable in operation, and inexpensive.

(B) Structure of the Invention [Means for Solving the Problem] Corresponding to this object, the spiked tire of the present invention is a spiked tire that is provided with spikes fitted into holes opened in the tread of the tire, which The hole has a small diameter part whose inner diameter is reduced by an annular protrusion projecting inwardly from the side surface in the middle part in the depth direction, and the spike has a constriction in the center part in the axial direction with a smaller outer diameter than both ends. and an edge portion projecting radially from one end with respect to the shaft, and the tire has the constricted portion of the spike fitted into the small diameter portion of the hole, and An end of the spike is exposed to the outside, and at least a portion of the axial end surface of the other end holds the spike in a state separated from the bottom of the hole.

Hereinafter, details of the present invention will be explained with reference to the drawings showing one embodiment.

In FIG. 1, FIG. 2, FIG. 7, and FIG. 8, 1 is a spiked tire. A spiked tire 1 is formed by fitting a large number of spikes 3 into a tire 2.

The tire 2 is made of an elastic material such as rubber, and has a tread 4 formed with a large number of holes 5 opening therein.

As shown in FIG. 5, the hole 5 is formed with the radial direction 6 of the tire 2 as the axis 9, and the depth from the tread surface 4 in the direction of the axis 9 is H. The inner diameter of the hole 5 is not constant, and the upper space 7 extends from the depth O to H ₁ from the tread surface.
In this case, R is almost constant at ₁ , but the depth from the tread is H ₁
A portion H ₂ from 2 to 3 is a small diameter portion 8 where the inner diameter is suddenly reduced, and the wall surface of the hole 5 in this portion forms an annular protrusion 11 that protrudes inward from the side surface 12. The annular protrusion 11 has an upper
Both the lower surfaces are planes perpendicular to the axis 9, but the tip 11
The corners of b are rounded so as to smoothly transition from the upper surface to the lower surface, and the vertical cross section is formed into a semicircular arc shape that protrudes inwardly from both sides with the axis 9 in between.

In the part from depth H ₂ to H, the diameter is from R ₁ to O
The bottom surface 13 of the hole 5 has a hemispherical shape, and this portion of the hole 5 forms a lower space 14.
The depth H-H ₂ of the lower space 14 is the depth of the upper space 7
H is greater than ₁ .

As shown in detail in FIGS. 3 and 4, the spike 3 is integrally molded of cemented carbide metal, and is symmetrical about its axis 15 and rotated around the axis 15 by a pair of right-angled hyperbolas centered at a point O. The obtained side surface 16 has a rotational hyperboloid shape, and the minimum outer diameter r ₂ of the axially central constriction 17 is approximately equal to R ₂ . One end surface 18 in the axis 15 direction includes an annular surface 18a that extends inward perpendicularly to the axis 15 from one end 16a of the side surface 16, and an annular surface 18.
and a top surface 18b which forms the remaining inner part of , and has a partially spherical shape with the point O as the center and which is convex to the outside. The side surface 16 and the annular surface 18 cooperate to form the end 16
An edge portion 21 having a point a is formed, and thus the edge portion 21 projects radially outward from the top surface 18b with respect to the shaft 15. The distance from point O to end 16a is greater than the distance from point O to top surface 18b.

The other end surface 22 in the direction of the axis 15 is connected to the other end 16b of the side surface 16 with rounded corners, and has a partially spherical shape convex outward about point O.

The spike 3 is held by the tire 2 with the shaft 15 aligned with the axis 9 of the hole 5 and the constricted portion 17 fitted into the small diameter portion 8 of the hole 5. The center part 18c is almost flush with the tread 4 of the tire 2, and the other top surface 22
A predetermined gap 20 is provided between the hole 5 and the bottom surface 13 of the hole 5.

[Action/Effect] Next, the spike tire 1 configured as described above
The operation will be explained with reference to FIGS. 6 and 7.

When a vehicle runs on a road surface, the spiked tire 1 is connected to the tread surface 4 of the tire 2 and the spikes 3.
The center portion 18c of the top surface 18b is in contact with the road surface 23.

When the road surface 23 is an icy and snowy road surface, if the tread surface 4 of the tire 2 slides in the direction 30 with respect to the road surface 23,
A force F in a direction 31 opposite to the sliding direction 30 acts on the center portion 18c of the top surface 18b of the spike 3.

Since the spike 3 is held in close contact with the annular protrusion 11 made of an elastic body at the constriction 17, a rotational moment acts on the spike 3 and the annular protrusion 1
1 is deformed, allowing the spike 3 to tilt with respect to the axis 9 of the hole 5, and as a result, the tip 16a of the edge 21 undergoes rotational displacement, protrudes outside the tread 4, and comes into contact with the road surface 23. Hit it and eat it. In this state,
The spike 3 receives a braking force G in the direction of stopping slippage from the road surface 23 at a portion 16c on the side surface 16 side of the edge portion 21, and this braking force G causes a portion 16d on the side surface 16 on the opposite side with respect to the shaft 15 to move into the upper space. 7
Press the upper surface of the annular protrusion 11 within the portion 16
When the other end 16e on the same side as c and the shaft 15 is pressed against the lower surface of the annular protrusion 11 within the lower space 14, the force is transmitted to the tire 2, and the sliding on the tread surface 4 of the tire 2 is stopped. Along with this, the forces F and G cease to act, so the annular protrusion 11 returns to its original shape due to its elasticity, and the friction with the bottom surface 13 is eliminated by the gap 20 between the end surface 22 of the spike 3. Spike 3 also returns to its original position naturally, and the vehicle continues to drive during this time.

On the other hand, when the road surface 23 is an ice-free road surface, the tires do not slip, so the state shown in FIG. The protrusion 11 exerts a cushioning effect, and there is a gap 20 between the end surface 22 of the spike 3 and the bottom surface 13 of the hole 5 of the tire 2, so that the spike 3 is displaced inward in the radial direction 6 of the tire 2. , the spikes 3 do not damage the road surface.

As is clear from the above explanation, according to the present invention, it is possible to make the spikes protrude from the tire surface only when slipping occurs depending on the road surface conditions, thereby significantly reducing road surface scraping. Moreover, it is possible to prevent the generation of pollution when used on non-icy and snowy roads without reducing the performance of the tire on icy and snowy roads, and therefore without impairing running stability on icy and snowy roads. It is possible, and more importantly, to obtain a spiked tire which is particularly simple in construction, reliable in operation and inexpensive.

[Other Examples] In the spiked tire 1 of the above-described embodiment, the spikes 3 were integrally formed of cemented carbide, but as shown in the spike 3a shown in FIG. 8, only the edge portion 21a is made of carbide. It may be made of metal to save material.

In addition, as shown in FIGS. 9 and 10, the top surface 1
Instead of a smooth partial spherical surface, the spike 3b may have a concentric uneven surface 28 to make it difficult to slip on an icy and snowy road surface.

Further, as in the spiked tire 1d shown in FIG. 11, the bottom surface 13d of the hole 5d may be configured such that a portion thereof comes into contact with the end surface 22 of the spike 3.
In this case, since a portion of the end surface 22 when the edge 21 protrudes outside the tread surface 4 comes into contact with the bottom surface 13d, a strong anti-slip force is obtained and a non-slip surface that does not prevent the edge from returning to the original position is obtained. A contact portion remains with respect to the bottom surface 13d.

Furthermore, forming a plurality of slits 24 on the wall surface of the hole 5d as shown in FIG. 12 to create a cushioning effect is also effective in preventing damage to the road surface.

In addition, as shown in FIG. 13, in order to prevent unnecessary operation on an ice-free road surface, a spiked tire is equipped with a support ring 25 made of shape memory metal that goes around the annular protrusion 11e of the tire 2e. It may be set as 1e. The support ring 25 hardens into an annular shape as shown in FIG. 14 in a high temperature range, which is the environmental temperature of an ice-free road surface, to prevent the spike from tilting, and softens in a low temperature range, which is the environmental temperature of an ice-and-snow road surface. The transformation point is set so as not to prevent the spike 3 from deforming and inclining according to external force.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional partial view showing a spiked tire according to an embodiment of the present invention, FIG. 2 is a partial plan view of the spiked tire shown in FIG. 1, and FIG. 3 is a spike of the spiked tire shown in FIG. 1. A front view showing
Figure 4 is a vertical cross-sectional view showing the spikes of the spiked tire shown in Figure 1, Figure 5 is a vertical cross-sectional view showing the spike attachment holes of the spiked tire shown in Figure 1, and Figure 6 is shown in Figure 5. A plan view of the hole, FIG. 7a is a vertical cross-sectional explanatory view showing the relationship between the road surface and the spiked tire when slipping occurs, FIG. 7b is a vertical cross-sectional view showing the spiked tire during anti-slip action, and FIG. 9 is a longitudinal sectional view showing another spike of a spiked tire according to another embodiment of the present invention, FIG. 9 is a longitudinal sectional view showing another spike, FIG. 10 is a plan view of the spike shown in FIG. 9, and FIG. FIG. 12 is a vertical cross-sectional partial view showing a spiked tire according to still another embodiment of the present invention.
FIG. 13 is a partial plan view showing another embodiment of a hole in a spiked tire; FIG.
FIG. 14 is a plan view showing the support ring of the spiked tire shown in FIG. 13, FIG. 15 is a half-sectional front view showing the spike ball of the conventional spiked tire, and FIG.
Figure 6 is an explanatory diagram showing a state in which the spiked tire with the spiked ball buried therein shown in Figure 15 is slipping, and Figure 17 is an explanatory diagram showing the state in which the spiked ball shown in Figure 15 is in the process of preventing slipping. be. 1...Spike tires, 2...Tires, 3...
Spike, 4...Tread, 5...Hole, 6...Radial direction, 7...Upper space, 8...Small diameter portion, 9...Axis,
11...Annular protrusion, 11a...Socket part, 11b
... Tip, 12 ... Side, 13 ... Bottom, 14
... Lower space, 15 ... Axis, 16 ... Side, 16
a... end, 17... constriction, 18... end surface, 1
8a... Annular surface, 18b... Top surface, 20... Gap, 21... Edge portion, 22... End surface, 23...
Road surface, 24...Slit, 25...Support ring, 30
...Sliding direction, 31...Direction, 100...Top end,
101...Spike tire, 102...Cup,
103...ball, 104...spike tip,
104a...Edge, 106...Guidance surface, 107
...Spike ball, 108... Road surface, 110...
... Tire, 111 ... Top, 112 ... Tread, 1
13...bottom surface, 114...bottom surface, 115...edge, 116...direction.

Claims (1)

[Claims] 1. A spiked tire equipped with a spike fitted into a hole opened in the tread of the tire, wherein the hole has a small inner diameter reduced by an annular protrusion projecting inward from the side surface at the middle part in the depth direction. The spike has a constricted portion having an outer diameter smaller than both ends in the axial center thereof, and has an edge portion projecting radially from one end with respect to the shaft, and the tire has The constricted portion of the spike is fitted into the small diameter portion of the hole, the one end is exposed to the outside, and at least a portion of the axial end surface of the other end is separated from the bottom of the hole. A spiked tire, characterized in that the spike is held in a state in which the spike is held in a state in which the spike is held in a state where