GB2540984A

GB2540984A - Tyre profile control

Info

Publication number: GB2540984A
Application number: GB1513715.1A
Authority: GB
Inventors: Bradley Stuart
Original assignee: Energy Technologies Institute LLP
Current assignee: Energy Technologies Institute LLP
Priority date: 2015-08-03
Filing date: 2015-08-03
Publication date: 2017-02-08
Also published as: GB201513715D0

Abstract

A tyre containing means for changing the tyre profile, the tyre comprising a first sidewall; a second sidewall wherein the first sidewall and the second sidewall are opposite sides of the tyre; a crown portion and the means for changing the tyre profile; characterised in that the means comprises one or more components, adapted to be electrically actuated, acting on parts of the tyre. The one or more components may be made from an electrically activated material, an electroactive polymer, and electro-magnetic material or magneto-rheological materials. The application also relates to a tyre profile control system and a voltage regulator and voltage supply for the control system.

Description

Tyre Profile Control

Summary of the Invention [0001] The invention relates to a tyre profile control system.

Background [0002] A factor affecting tyre performance is the tyre profile. A tyre that has a large contact area with a road surface will have more grip and a larger rolling resistance. A larger rolling resistance increases traction and braking performance. A large contact area is suited for roads with corners, turns and where the road surface conditions are poor. Poor road surface conditions include, for example, wet roads and roads made from dirt and gravel. A tyre that has a small contact area with the road surface will have a smaller rolling resistance. A smaller rolling resistance reduces friction with the road surface which, in turn, reduces the required power. Consequently, less fuel is needed and overall emissions are reduced. Additionally, less friction with the road surface creates less noise pollution and a better driving experience. A small contact area is suited for straight roads with good road surface conditions, for example, a motorway. Some vehicles are required to cross between different surfaces or operate in different conditions multiple times a day and require tyres that are optimal for all possibilities.

[0003] Tyre profile control systems are known in the art. Tyre profile control systems aim to solve problems associated with the need for different tyre profiles for different weather conditions, whilst travelling on different road surfaces and/or operating changeable loads. For example, US 2013/0153082 discloses a variable friction tyre. The variable friction tyre has a primary inflatable tube that is encapsulated by a tyre wall portion and a secondary inflatable tube that is disposed between a portion of tread and the primary inflatable tube. The secondary inflatable tube is selectively inflated or deflated in order to vary the amount of the tread portion in contact with the ground.

[0004] Using a pneumatic method for controlling the tyre, as disclosed in the above example, is disadvantageous. The time the time necessary for the air pressure to increase or decrease in the secondary inflatable tube is relatively slow and so is not useful when a quick response time is needed, for example, whilst emergency braking. Additionally, storing air at a high pressure has the potential to be very dangerous in the event the tyre fails.

[0005] The invention aims at addressing the above shortcomings.

Summary [0006] The invention relates to a tyre profile control system where the means for changing the profile tyre comprises applying a voltage across one or components situated in the vehicle tyre.

[0007] The profile of the tyre is controlled by applying a voltage to a component that is located within the structure of a tyre. When a voltage is applied to the component, the dimensions of the component change. Consequently, the profile of the tyre is modified. The change in tyre profile effects the contact area between the tyre and the road surface. The tyre profile control system enables the contact area of the tyre between the tyre and the road surface to be controlled. Preferably, the component is made from an electroactive polymer.

[0008] Electroactive polymers have a quick rise time, allowing the dimensions to change quickly. In addition, electroactive polymers are easily moulded and can be easily joined to the tyre.

[0009] Controlling the tyre profile allows the tyre to adapt to different conditions advantageously optimising the rolling resistance of the tyre. Lowering the rolling resistance of the tyre lowers the fuel consumption by 5%, thereby, lowering C02 emissions. Increasing the rolling resistance of the tyre increases traction and improves braking performance. Improving braking performance has a number of advantages including improved safety for drivers, passengers, other road users and pedestrians.

[0010] Altering the tyre profile allows for the temperature of the tyre to be optimised for the conditions. Tyre temperature control allows the tyre to be cooler and therefore decrease tyre wear and increase the life of the tyre. Tyre temperature control further allows for the tyre to be hotter and therefore increasing grip and improving traction and braking performance. Decreasing the contact area of the tyre also decreases the noise generated by the vehicle. Thereby lowering noise pollution and increasing user experience.

[0011] Using the tyre profile control system described herein is advantageous over the prior art because response time to change the tyre profile is decreased. A more responsive tyre profile control system enabled the rolling resistance of the tyre to be optimized more quickly. In addition, embodiments of the disclosed invention eliminate the need for different pressures in the same tyre. The high pressure secondary inflatable tube can be dangerous should it fail.

[0012] Additionally, the component may have a means for generating one or more signals that can be used as a sensor to sense tyre deformation and road surface conditions. The sensed tyre deformation and road surface conditions can then be used to regulate the voltage applied to the component. By so doing, the component acts as both an actuator for altering the tyre profile and a sensor for determining conditions. Using sensors to determine tyre deformation and road conditions allows for the tyre profile to be self-regulated and changed automatically, minimizing manual input and therefore reducing user error.

Brief description of the drawings [0013] The accompanying drawings illustrate embodiments of the invention, and, together with the general description given above and the detailed description given below, serve to explain features of the invention.

[0014] Figure 1 illustrates a system for tyre profile control.

[0015] Figure 2 illustrates a bowed tyre configuration.

[0016] Figure 3 illustrates a tyre with a flattened tyre configuration.

Detailed description [0017] Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. References made to particular examples and implementations are for illustrative purposes, and are not intended to limit the scope of the invention or the claims.

[0018] Figure 1 shows a tyre profile control system. The tyre profile control system 100 comprises a tyre 102 and a voltage application system 104. The tyre 102 comprises a first sidewall 106, a second sidewall 108, a crown 110 and a tread portion 112. A component 114 with means for changing the tyre profile is situated within the tyre 102. The voltage application system 104 comprises a voltage supply 116 and a voltage regulator 118. The voltage supply 116 is connected to the component 114. The voltage regulator 118 may be connected the component 114. The tyre 102 is the same as a standard tyre, however it has the component 114 with means for changing the tyre profile situated within the crown 110. In a preferred embodiment the component 114 is an electroactive polymer and is joined to the first sidewall 106 and the second sidewall 108.

[0019] The component 114 acts an electro-mechanical actuator. Component 114 receives a voltage which causes component 114 to change dimension. The change in dimension, in turn, causes the tyre profile change.

[0020] In a preferred embodiment, the component 114 acts on the first sidewall 106 and the second sidewall 108, causing the crown 110 to bow. Consequently, the contact area of the tyre with the road surface is reduced. In order to increase rolling resistance, the voltage is no longer applied to the component 114. Consequently, the force acting on the first sidewall 106 and the second sidewall 108 is reduced causing the crown to flatten. Thus, the contact area of the tyre with the road surface is increased.

[0021] The voltage application system 104 comprises the voltage supply 116. The voltage supply supplies a voltage across the component 114. In an example the voltage applied is at least 2000 volts. The voltage supply 116 may generate a voltage by a slip ring or a reluctance machine. The slip ring or the reluctance machine can be combined with a brake disc or antilock braking system already part of a vehicle.

[0022] The voltage application system 104 further comprises a voltage regulator 118. The voltage regulator 118 provides a regulator signal to the voltage supply 116. The regulator signal is adjusted depending on the required traction needed by the tyre 102. By so doing, regulates the amount of voltage applied to the component 114 and consequently controls the contact area of the tyre 102 and the road surface. The voltage regulator 118 receives information regarding the road surface conditions from one or more sensors. The one or more sensors may be detecting road surface conditions, weather conditions or vehicle loads.

[0023] In a preferred embodiment, the sensor may be the component 114. As the component 114 changes dimensions due to the applied voltage, it also produces a back electromotive force 120. The produced back electromotive force 120 can be used to determine road conditions and tyre deformation.

[0024] Figure 2 illustrates a tyre profile with a small contact area 200 . The tyre profile with a small contact area 200 comprises the tyre 102, the component 114, as previously described with reference to figure 1, and a contact area 202. In an embodiment, when a voltage is applied to the component 144 the change in dimension causes the tyre 102 to bow. Thus, reducing the contact area 202.

[0025] Figure 3 illustrates a tyre profile with a large contact area 300. The tyre profile with a large contact area 300 comprises the tyre 102, the component 114, as previously described with reference to figure 1, and a contact area 302. In an embodiment, when a voltage is no longer applied to the component 114 the change in dimension causes the tyre 102 to flatten. Thus, increasing the contact area 302.

Alternative Embodiments [0026] In an alternative embodiment, the component 114 acts directly on the crown 110 of the tyre 102. The component changes dimension and pushes or pulls the internal surface of the crown. Thus, changing the tyre profile.

[0027] In another embodiment, the component 114 acts on a first shoulder 122 and a second shoulder 124 of the tyre 102. As the component changes dimension the shoulders are pulled toward or pushed away from each either causing the tyre to bow and flatten, respectively.

[0028] In another alternative embodiment, the component 114 is a plurality of discrete components. The plurality of discrete components may be located circumferentially around the perimeter of the tyre.

[0029] In another embodiment the sensor may be one or more sensors operable to sense road conditions, tyre deformation, weather conditions, operating loads and/or any other feature that can affect tyre performance.

[0030] With reference to figure 2, in an alternative embodiment a lack of applied voltage to the component 114 causes its dimensions to change. Thus, reducing the contact area 202.

[0031] With reference to figure 3, in an alternative embodiment applying a voltage to the component 114 causes its dimensions to change. Thus, increasing the contact area 302.

[0032] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any combination.

[0033] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations.

Claims

1. A tyre comprising: a first sidewall; a second sidewall wherein the first sidewall and the second sidewall are opposite sides of a tyre; a crown portion; and means for changing the tyre profile; Characterised in that the means comprises one or more components, adapted to be electrically actuated, acting on parts of the tyre.

2. A tyre according to claim 1, wherein the one or more components are made from an electrically activated material.

3. A tyre according to claim 1, wherein the one or more components are made from an electroactive polymer.

4. A tyre according to claim 1, wherein the one or more components are made from electro-magnetic materials, magneto-rheological materials.

5. A tyre according to any one of claims 1 to 4, wherein the one or more components are connected to the first sidewall and the second sidewall.

6. A tyre according to any one of claims 1 to 4, wherein the one or more components are located circumferentially around the perimeter of the tyre.

7. A tyre according to any one of claims 1 to 6 further comprising: a crown wherein the crown encases the one or more components.

8. A tyre profile control system comprising: a tyre according to any of one of claims 1 to 7; a voltage application system operable to apply a voltage to one or more components wherein the one or more components changes shape depending on the applied voltage;

9. A tyre profile control system according to claim 8, further comprising: the voltage application system comprising a voltage regulator and a voltage supply wherein the voltage regulator is arranged to send a voltage regulation signal to the voltage supply.

10. A voltage regulator according to claim 9, comprising: one or more sensors operable to sense tyre deformation and road conditions.

11. A voltage regulator according to claim 10, wherein the sensor comprises the one or more components adapted to generate a back-electromotive force.

12. A voltage supply according to claim 9, wherein the voltage supply is arranged to provide a voltage to the one or more components.

13. A voltage supply according to claims 11 and 12, wherein the voltage supplied to the one more components is proportional to the back-electromotive force.

14. A voltage supply according to claim 13, wherein the voltage supply comprises a voltage generator wherein the voltage generator is adapted to generate a voltage from an ABS voltage generator circuit or a brake disc voltage generator circuit.

15. A voltage supply according to claim 12, wherein the voltage supply is operable to supply at least 2000 volts.