JPH0411406B2 - - Google Patents

Description

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

[Conventional technology]

2. Description of the Related 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 a snowy road or the like.

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 conditions, but the spike pins conventionally considered have extremely complex structures and require some kind of actuator (for example, It requires a pneumatic actuator, an electric actuator), is large in size and expensive, and has not been put into practical use.

For these reasons, it is desirable to develop spike tires that do not scrape the road surface and can maintain tire performance on icy and snowy roads, are compact in size, inexpensive, and operate quickly and reliably. It was rare.

[Problem that the invention seeks to solve]

The inventor of the present application previously proposed such a spiked tire in Patent Application No. 073141 of 1985 (Japanese Patent Application Laid-Open No. 62-227805). This proposed spiked tire uses a cushioning material whose hardness changes according to temperature changes to control the movement of the spike pins in and out, but the problem is that the response speed to temperature changes is slow. Therefore, it is desired to make the action of inserting and removing the spike even faster and more reliable.

This invention was made in view of the above circumstances, and it is possible to change the protrusion length of the spike from the tire surface depending on the road surface condition.
This greatly reduces road surface scraping, does not reduce tire performance on icy and snowy roads, and, importantly, has a particularly simple structure, quick and reliable operation, and is inexpensive. The purpose of this invention is to provide a low-cost spiked tire.

(B) Structure of the Invention [Means for Solving the Problem] Corresponding to this object, the spiked tire of the present invention has spike pins embedded in the tread of the tire, and has a structure that is less hard when the temperature is high. The spike pin is made of a particle-dispersed material in which particles made of a material that has a high hardness when the temperature is low is dispersed in a base material made of an elastic material, and is disposed between the base end of the spike pin in the central axis direction and the tire. a cushioning material provided therein; a bowl-shaped recess formed in a tread portion of the tire other than the portion where the spike pin is implanted;
The tire is characterized by comprising a communication hole passing through the tire and connecting the recess and the cushioning material, and a water-permeable filter made of an elastic porous material and disposed within the communication hole.

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

In Fig. 1, 1 is a spiked tire;
The spiked tire 1 includes spikes 4 embedded in the tread surface 3 of the tire 2.

The spike pin 4 is provided with a tip 5, which is implanted in the top 7 of the shank 6. The top 7 of the shank 6 and the tip 5 protrude outward from the tread 3 of the tire 2. The chip 5 is made of cemented carbide, and the shank 6 is made of metal.

A case 8 made of a shape memory alloy is fixed to the base end of the shank 6. The case 8 has an opening 10 at the bottom through which the central axis 9 of the shank 6 passes, and encloses a cylindrical cushioning material 11. Shank center axis 9
It is in contact with the cushioning material 11 from above and below. Therefore, the spike pin 4 consisting of the tip 5 and the shank 6, the case 8, the cushioning material 11, and the tire 2 are connected to the central axis 9.
The load in the direction of the central axis 9 acting on the chip 5 is transferred to the tire 2 through the cushioning material 11.
is transmitted to.

The cushioning material 11 is made of a material that hardens when the environmental temperature drops to the temperature when the vehicle is running on an icy and snowy road, and softens when the environmental temperature falls to the temperature when the vehicle is running on an ice-free road. The material for such a cushioning material 11 is a base material made of an elastic material such as rubber, and a material whose hardness changes with temperature changes, that is, a material whose hardness is high when the temperature is low and whose hardness is low when the temperature is high. and particles made of a material with high thermal conductivity and low specific heat. In this case, the temperature change transmitted to a part of the buffer material 11 is It is quickly transmitted throughout the body and can improve the responsiveness of the hardness change. For example, a suitable buffer material is one in which 20% of fine particles of polyvinyl acetate to which dimethyl phthalate is added as a softening agent are dispersed in rubber that is slightly softer than ordinary tire rubber. The hardness of this cushioning material changes approximately 4 times from 0℃ to 17℃.At 17℃, it is soft and weakens the protruding force of the spike pins, reducing damage to the road surface, and at 0℃, it becomes hard and reduces the protrusion force of the spike pins. Maintains ejection force and demonstrates the performance of spike pins on icy and snowy roads.
The dispersion material can be obtained by cooling and pulverizing particles or mixing them in the form of microcapsules.

Further, the case 8 is made of, for example, a unidirectional shape memory alloy and has an oblate spherical shape with an opening 10 at the bottom, and is soft at the environmental temperature when driving on an icy and snowy road, and has a shape that follows the shape of the hardened cushioning material 11. ,
As shown in FIG. 1, the chip 5 has a shape that allows the chip 5 to protrude outward from the tread surface 3 of the tire 2, and compresses the cushioning material 11, which is softened at the environmental temperature during driving on an ice-free road surface, in the direction 12 toward the inside of the tire 2. The chip 5 can be drawn inside the tread surface of the tire 2. A bowl-shaped recess 1 is formed in a portion 3b of the tread portion 3 of the tire 2 other than the portion 3a into which the spike pin 4 is implanted.
3 is recessed inward from the surface of the tread portion 3b, and the opening 1 of the case 8 is formed from the bottom of the recess 13.
A communication hole 14 reaching 0 is formed. The cross-sectional shape of the communication hole 14 is in the direction 12 as shown in FIG.
It has a flat elliptical shape with a small diameter, and the volume change when the tire rolls is large.

A method of forming such a circulation hole 14 inside the tire 2 is to vulcanize a plate spring having a predetermined shape with a flat cross section embedded and then pull it out, or A method such as embedding a rubber tube can be used.

A portion of the communication hole 14 near the recess 13 is filled with a water permeable filter 15 made of an elastic porous material. The porous material of the water-permeable filter 15 has a suitable pore size that prevents mud and sand from entering, for example, an average pore size of 8 μm to 60 μm.

[Action/Effect]

The spike tire 1 configured in this manner has a simple structure and is inexpensive.

When the road surface is ice-free and snow-free, the shape memory alloy is hardened and the softened cushioning material 11 is compressed in the direction 12, as shown in FIG. ) is more withdrawn.

When the driving road changes from this state to an icy and snowy road,
Due to the load applied to the tire tread surface 3, the ice and snow in contact with the tire tread surface 3 melts into ice water, which soaks the tip of the spike pin in the retracted state. On the other hand, this ice water enters the recess 13 in the portion 3b of the tire tread 3 under this load. At this time, the recess 1
3 is flattened by the load in the direction 12, and the recess 1
Since the flow hole 14 communicating with the opening 3 is also crushed by the load in the direction 12 and its volume is reduced, this low-temperature water quickly reaches the opening 10.

Moreover, when the tire rolls and the load applied to the portion 3b decreases, the volume of the recess 13 and the circulation hole 14 recovers, and the moment the portion 3b leaves the road surface, surrounding ice water is sucked into the recess 13. Extremely low temperature water is introduced into the flow hole 14 through the water-permeable filter and stored therein.

On the other hand, after the pin touches the ground, the circulation hole at the rear of the pin, which is further crushed by the rolling of the tire, drains cold water from the opening 10. In this way, the cross-sections of the circulation holes in front and behind the pin are sequentially crushed from the tip to the rear, so depending on the rolling of the tire, a pump is used to send cold water to the pin or to drain it. act. Although the diameter of the flow hole is not very large, as the number of tire rolls increases, the pumping action is repeated, making it possible to forcibly flow water that is difficult to flow.

In the opening 10, the cold water directly soaks a part of the cushioning material 11 and the case 8 surrounding it, and quickly transmits the low temperature to them. The low temperature is transmitted from above and below in the direction of the axis 9, and the shape memory alloy case 8 softens, and the cushioning material 1
1 is hardened, and the spike pin 4 protrudes from the portion 3a of the tire tread 3. This allows the low temperature to be transmitted directly to the cushioning material and the case 8 much more reliably and quickly than the transmission of low temperature from the tip side of the spike pin 4 alone, and the temperature response of the spike pin 4 is extremely good. It does not reduce the performance of the tire on the road surface.

[Brief explanation of drawings]

FIG. 1 is an explanatory longitudinal cross-sectional view taken along the line A-A in FIG. 2 showing a spiked tire according to an embodiment of the present invention, FIG. 2 is an explanatory plan view of the spiked tire shown in FIG. 1, and FIG. A cross-sectional view taken along line BB in FIG. 1 and FIG. 4 are explanatory longitudinal cross-sectional views showing the spiked tire in a state where the spike pins are retracted. 1...Spike tires, 2...Tires, 3...Treads,
3a, 3b...part, 4...spike pin, 5...chip, 6...shank, 7...top, 8...case, 10
...opening, 11...buffer material, 12...direction, 13...recess, 14...flow hole, 15...water-permeable filter.

Claims (1)

[Claims] 1 A particle dispersion system consisting of spike pins embedded in the tread of a tire and particles made of a material that has low hardness when the temperature is high and high hardness when the temperature is low, dispersed in a base material made of an elastic material. a cushioning material made of a material and disposed between the base end of the spike pin in the central axis direction and the tire;
A bowl-shaped recess formed in a tread portion of the tire other than the part where the spike pin is implanted, a communication hole passing through the tire and connecting the recess and the cushioning material, and an elastic porous material. and a water permeable filter arranged in the circulation hole.