JPH03189216A - Tire temperature raising device - Google Patents

Abstract

PURPOSE:To have quick and stable temp. rise of a tire using a simple constitution through utilization of Joule's heat to be generated in a conductor, by embedding the conductor under the grounding surface of the tire, and by arranging a high frequency generating source in proximity to the grounding surface. CONSTITUTION:In a tire temp. rising device 11, a conductor 14 is embedded in a rubber member under the grounding surface 13a of a tire 13, and a high frequency generating source 10 is equipped in proximity to the grounding surface 13a. At the time of service, high frequency energy 10A is generated from the mentioned high frequency source 10 simultaneously with commencement of tire revolutions. This high frequency energy 10A is transmitted to the conductor 14 through the grounding surface 13a of the tire 13, and eddy current 14A is generated on the skin layer 14a of the conductor 14 by means of skin effect. Thereby Joule's heat is generated in the conductor 14 through utilization of this eddy current 14A and the resistance of the conductor 14, and the surface temp. of the tire 13 is raised.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tire temperature increasing device, and more particularly to a tire temperature increasing device that increases the temperature of a tire at the start of running.

(Prior art) In general, the surface temperature of the tire contact surface of a vehicle that has been stopped or parked for a long period of time before driving is approximately the same as the air temperature, and the surface temperature of the tire contact surface of a vehicle after driving for a long period of time is approximately the same as the air temperature. significantly lower than that of This difference in the surface temperature of the tire contact surface before and after driving is large, especially in winter, and causes a large difference in the running characteristics of the vehicle.

When the vehicle starts running and the tire surface temperature rises,
■The so-called grip force of the tires on the road surface increases, improving vehicle handling stability. In addition, (1) the rolling resistance of tires is reduced and fuel consumption is improved; That is, the ninth
As shown in the figure, the surface temperature of the tire contact patch increases with the passage of running time, but as the surface temperature increases, the rolling resistance (or rolling resistance coefficient) decreases.

Approximately 1 to 2 hours after the start of running, the surface temperature of the tire contact surface becomes saturated and remains almost constant, and the rolling resistance is significantly reduced.

Conventional tire temperature raising devices that actively raise the tire temperature using temperature raising devices include, for example, the Utility Model Application Publication No. 1-
There is one described in Japanese Patent No. 108804. As shown in FIGS. 10 to 12, a conductive rubber sheet 2 is specially attached to the inside of a tire 1, and electrodes 3 at both ends of the conductive rubber sheet 2 are connected to a battery 5 (not shown) via electric wires 6. This is a concatenation. Applying the voltage of the battery 5 to the conductive rubber sheet 2 causes the conductive rubber sheet 2 to generate heat,
The heat from the conductive rubber sheet 2 heats the tire from the inside and measures the temperature rise of the tire.

(Problem to be Solved by the Invention) However, in such conventional tire temperature increasing devices, heating elements are specially attached to the inside of the tire and these are connected to a power source, so there is no connection between the fixed side (vehicle body) and the heating element. The rotating side (tire) is connected via a slip ring 7 that rotates while in contact with the rotating side (tire). Therefore, there is a problem that the durability of the slip ring 7 decreases during use, causing poor contact and the like, resulting in poor reliability. Furthermore, since the slip ring 7 is interposed as an electrical connection function when installing and removing the tire 1, electrical opening and contact connection are required when installing and removing the tire 1. There is an issue of poor gender.

Therefore, the present invention has been made by focusing on such conventional problems, and improves reliability by making contactless without using slip rings, and also enables electrical disconnection, connection, and connection even when installing and removing tires. The purpose of the present invention is to provide a tire temperature increasing device that does not require a continuity test or the like and can greatly improve workability.

(Means for Solving the Problems) In order to achieve the above object, the tire temperature increasing device according to the present invention has the following features:
It is characterized in that a conductor is buried inside the tire tread and a high frequency generation source is placed close to the tire tread.

Further, it is preferable that the tire temperature increasing device includes a temperature sensor provided near the tire and a control means for controlling a high frequency current generated in a high frequency generation source based on a signal from the temperature sensor.

Here, the high frequency generation source may be a coil through which a high frequency current is passed from a high frequency current generation source, or may be one using a magnetron.

(Function) The tire temperature increasing device of the present invention has a conductor buried under the ground contact surface of the tire and a high frequency generation source placed close to the ground contact surface of the tire, so that high frequency energy is generated from the high frequency generation source. As a result, a large number of eddy currents I are generated in the skin layer of the conductor due to the skin effect. Due to this eddy current I and the resistance R of the conductor, Joule heat J is generated in the conductor as shown by the following formula J=I''H, and this heat is transferred to the rubber around the conductor.
Furthermore, it is transmitted to the rubber near the contact surface of the tire, increasing the temperature of this rubber, thereby increasing the surface temperature of the tire contact surface.

(Example) First, the basic concept of the present invention will be explained based on the drawings.

FIG. 1.2 is a schematic diagram showing the basic concept of the tire temperature increasing device according to the present invention.

In FIG. 1, reference numeral 11 denotes a tire temperature increasing device, and the tire temperature increasing device 11 has a conductor 14 buried in a rubber member under the ground contact surface 13a of the tire 13, and generates high frequency by approaching the ground contact surface 13a of the tire 13. A source 10 is placed.

In such a configuration, when the vehicle starts running and tires 1
When the switch is turned on at the same time as 3 starts rotating, high frequency energy is generated from the high frequency generation source IO. This high frequency energy 10A passes through the ground plane 13a of the tire 13 and is transmitted to the conductor 14 under the ground plane. Due to this high frequency energy of 10A, the second
As shown in the figure, an eddy current 14AI is generated due to the skin effect, and due to this eddy current 14AI and the resistance R of the conductor 14, Joule heat J (=I''R) is generated in the conductor 14, and the temperature of the conductor 14 is This Joule heat J is transmitted to the rubber inside the tire, raising the tire surface temperature Tt (hereinafter, all temperatures are expressed in degrees Celsius, and the symbol for degrees Celsius is omitted).

Embodiments of the present invention will be described below based on the drawings.

3 to 8 are diagrams showing an embodiment of the tire temperature increasing device according to the present invention, and the same components as in FIG. 1.2 are given the same reference numerals. This embodiment is an example in which a tire temperature increasing device 11 is applied to a tire 13 connected to an independent suspension mechanism 12 of a vehicle.

In FIGS. 3 to 5, a tire 13 is mounted on a rim 15 and attached to a hub 17 via a wheel 16. The hub 17 is the spindle 1 at the lower end of the independent suspension 12.
8 and a suspension lower arm 19
is connected to. An upper end portion of the independent suspension mechanism 12 is attached to a vehicle body 21 via a strut-up insulator 20. The independent suspension mechanism 12 includes a spring 22, a damper 23, and a strut 24 that holds the damper 23.
It has

In FIG. 5, the tire 13 consists of a pair of beads 26 fixed to the rim 15 and a rubber-coated steel cord, and a carcass 2 that extends between the beads 26 in a toroidal shape.
7, a multi-layer belt 29 made of a steel cord 28 which is a rubber-coated conductor arranged outside the crown portion of the carcass 27, and a covering rubber 30 that covers the outside of the belt 29 and the carcass 27. . 30A is a contact surface of the tire 13 that is in contact with the road surface. That is, tire 1
A steel cord 28 is buried under the ground plane 30A of No. 3.

32 is a coil, and the coil 32 is a high-frequency energy emitting part of a high-frequency generation source, and the coil 32 is a high-frequency energy emitting part of a high-frequency generation source, and the coil 32 is a high-frequency energy emission part of a high-frequency generation source, and
Approaching the upper side of 0A, the crown portion 13a of the tire 13
It is supported by a bracket 33 attached to the strut 24. 34 is a lead wire, and one end of the lead wire 34 is connected to the coil 32, and the other end is connected to a high frequency generator 35 (not shown) which is a high frequency generation source (indicated by reference numeral 35 in the overall block diagram of FIG. 7). ing. The high frequency generator 35, lead wire 34, and coil 32 constitute a high frequency generation source.

In FIG. 7, a high frequency generator 35 is connected to a battery 37 via a switch 36 that is linked to the ignition. A control means 40 is interposed between the coil 32 and the high frequency generator 35, and the control means 40 connects the high frequency generator 35 to the coil 32 through the lead wire 34 based on signals from the tire surface temperature sensor 41 and the vehicle speed sensor 42. It controls the high frequency current flowing through the The control means 40 has a control circuit 43 consisting of a microcomputer, and the control circuit 43 controls the tire 1 according to the flowchart shown in FIG.
Control the surface temperature of 3. The tire surface temperature sensor 41 is an infrared temperature sensor and is provided near the tire 13, and is capable of measuring the tire surface temperature without contact and transmitting a temperature signal S.

Next, the effect will be explained.

FIG. 8 is a flowchart showing a process that is repeatedly executed every predetermined calculation cycle in the control circuit 43 in the control means 40 of the tire temperature raising device of the present invention. Explain.

When the ignition key is turned on, the switch 36 is closed (ON) in conjunction with the ignition key, the high frequency generator 35 generates a high frequency current, and the control means 40
The control circuit 43 enters a standby state. First, the control circuit 43
The microcomputer within is initialized (step P
1).

Next, the control circuit 43 detects the surface temperature T of the tire 13 by the tire surface temperature sensor 41 and sends a temperature signal S.
1 is read (step P2). The vehicle speed sensor 42 detects the vehicle speed V and reads the transmitted vehicle speed signal S2 (step P3). In step P4, it is determined whether the surface temperature T of the tire 13 is equal to or higher than a predetermined temperature T0, and the predetermined temperature T is determined. If the speed is less than 1, it is determined whether the vehicle is in a stopped state based on the vehicle speed V already read in step P5. When the vehicle is not stopped,
In step P6, the high frequency current of the high frequency generator 35 is energized (ON) L to the coil 32, and the process returns to step P2.

When a high-frequency current is applied to the coil 32, a high-frequency magnetic flux is generated in the coil 32 so as to penetrate the crank part of the tire 13, as shown by arrow A in FIG.
The skin layer 28a of the steel cord 28 under the ground plane 30A of
Then, an eddy current I45 as shown in FIG. 6 is generated. Joule heat (J=I''R) is generated in the steel cord 28 due to this eddy current 145 and the electric resistance R of the steel cord 28, and the temperature of the steel cord 28 increases.The heat of the steel cord 28 is transferred to the surrounding rubber. Then, the tire tire 3 is warmed, and the surface temperature of the tire increases.

In step P2, the temperature signal S transmitted by the tire surface temperature sensor 41 is read again, and in step P3, the vehicle speed signal S2 transmitted by the vehicle speed sensor 42 is read again. In step P4, it is determined whether the surface temperature T of the tire 13 is equal to or higher than a predetermined temperature To. If it is less than the predetermined temperature T0, it is determined in step P whether the vehicle is in a stopped state. If the vehicle is in a stopped state, the power supply from the high frequency generator 35 to the coil 32 is stopped (OFF) in step P7. If the vehicle is not in a stopped state, the high frequency current from the high frequency generator 35 is applied to the coil 32 in step P6, and the process returns to step P. Such repetition is continued until the surface temperature T of the tire 13 reaches the predetermined temperature T0. In step P4, the surface temperature T becomes the predetermined temperature T.

When this happens, the current supply from the high frequency generator 35 to the coil 32 is stopped (OFF) in step P7.

Here, when the outside temperature is 20°C, set the tire surface temperature to 60°C.
Assuming that the temperature is maintained at °C, the high-frequency current 1', [
The field strength H and the Joule heat J generated in the steel cord 28 are determined as follows.

I r, frequency 14.5 earth, current 2.53 AH; 1
5.9 Oersted J, 2,230 J/S However, the above value assumes that the number of turns per unit length of the coil 32 is 1.
, 000 turns/m.

According to such a configuration, after the vehicle starts running, a high frequency current is applied to the coil disposed close to the ground plane 30A of the tire 13, and the skin layer 28a of the steel cord 28 under the ground plane 30A of the tire 13 is heated. Since the eddy current 45 is generated through the magnetic flux and the tire surface temperature is warmed up to the predetermined temperature T0, the tire 13 does not need to break in, and the contact surface 3 of the tire 13 is immediately heated after the start of running.
The surface temperature T of 0A rises to a predetermined temperature T0. Therefore, the grip performance and rolling resistance of the tire can be optimized quickly and almost simultaneously after the start of driving.

In addition, since the tire contact surface is heated electrically and without contact, reliability can be greatly improved, and there is no need for electrical opening, connection, or continuity tests when installing or removing tires. , work efficiency can be greatly improved. Also, the tires are not special; conventional tires with steel belts can be used.

(Effects) As explained above, according to the present invention, a conductor is buried under the ground contact surface of a tire, and a high frequency generation source is placed close to the ground contact surface of the tire, thereby generating Joule heat generated within the conductor. By rapidly raising the temperature of the contact surface of the tire, the running characteristics of the vehicle are improved quickly after the start of driving.

In addition, since this temperature rise is done without using a slip ring and without contact, reliability can be greatly improved, and there is no need for electrical openings, connections, or continuity tests when installing or removing tires. can significantly improve performance.

[Brief explanation of drawings]

1.2 are diagrams showing the basic concept of the present invention, FIG. 1 is a schematic diagram showing its basic configuration, and FIG. 2 is a conceptual diagram showing its main parts. 3 to 8 are diagrams showing one embodiment of the tire temperature increasing device according to the present invention, FIG. 3 is a front view of the main part including a partial cross section when the tire is mounted on a vehicle, and FIG. Third
FIG. 5 is an enlarged sectional view of its main parts, FIG. 6 is a conceptual diagram showing its operation, FIG. 7 is its overall schematic diagram, and FIG. 8 is its control circuit program. It is a flowchart which shows. FIG. 9 is a graph showing the relationship between the running time of the vehicle, the surface temperature of the ground contact surface of the tire, and the rolling resistance. Figures 10 to 12 are diagrams showing a conventional tire temperature increasing device. Figure 10 is a schematic diagram of the main part including a partial cross section, Figure 11 is a sectional view of the main part, and Figure 12 is the main part. It is a front view. 11... Tire temperature increasing device, 13... Tire, 28... Steel cord (conductor), 32...
. . . Coil (high frequency generation source), 35 . . . High frequency generator (high frequency generation source), 40 . . . Control means, 41 . . . Tire surface temperature sensor (temperature sensor )
, 42... Vehicle speed sensor, 43... Control circuit (control means).

Claims (2)

[Claims] (1) A tire temperature increasing device characterized in that a conductor is buried inside the tire contact surface and a high frequency generation source is placed close to the tire contact surface. (2) A temperature sensor is provided near the tire, and control means is provided for controlling a high frequency current generated in a high frequency generation source based on a signal from the temperature sensor.
Tire heating device described.