GB2445820A - Vehicle tyre warming and/or cooling device - Google Patents

Abstract

The device is for mounting on a racing motorcycle during use of the tyre 44 and comprises at least one intake conduit 30, 130 and at least one outlet conduit 18, 118 directed at the tyre. The or each intake conduit 30, 130 is adapted for connection to a source of air at a chosen temperature, which may be above ambient in order to warm the tyre 44, or at or below ambient in order to cool the tyre. The device has a valve to selectively allow or restrict the flow of air from the outlet conduit. The device can have two outlet conduits 18, 118 directed at different parts of the tyre 44, so that selected parts of the tyre can be warmed/cooled as desired. The valve can be a pivoting pendulum plate 20, 120 which selectively blocks one of two outlet conduits 18, 118 directed to either tyre side and acts due to motorcycle tilting during cornering.

Description

TYRE WARMER AND/OR COOLER

FIELD OF THE INVENTION

This invention relates to a lyre warmer and/or cooler, in particular to a lyre warmer and/or cooler for the tyres of racing motorcycles.

BACKGROUND OF THE INVENTION

The grip offered by a vehicle tyre upon a road surface is known to increase if the temperature of the tyre is above ambient. For this reason, the tyres of racing vehicles are often warmed prior to use, and it is known for an insulating cover to be placed around part or all of a tyre, the insulating cover having an electrical heating element therein, which heating element warms the tyre. Most tyre warmers of this type are designed to warm the tyres to around 76-80 C.

Tyre warmers of this type can only be used on a vehicle's tyres whilst the vehicle is stationary, and in most cases raised so that the lyres are clear of the ground.

This is often sufficient, however, since once a race is underway acceleration, braking and cornering of the vehicle generate heat which can maintain an elevated tyre temperature. Thus, whilst the passing air flow acts to cool the lyre towards ambient temperature, that cooling is typically less significant that the friction-induced heating, and the lyre maintains an elevated temperature during a race.

Motorcycles suffer a particular problem in this regard, however, in that different parts of the lyre surface engage the road as the motorcycle passes around a circuit. Specifically, the two sides of the tyres are used at different corners, i.e. only the left-hand side of the lyre will experience friction and therefore the induction of heat on a left-hand bend, and vice versa, and only the centre of the lyre will experience the induction of heat during straight-line acceleration and braking. Since rubber is an effective heat insulator, any heat generated in one part of the tyre will be conducted only slowly throughout the remainder of the tyre.

Most racing circuits have more corners in one direction that the other, and it is known for a racing lyre of a motorcycle to have different temperatures between its two sides throughout a circuit, and therefore the level of grip which is available on left-hand bends differs from that available on right-hand bends. This difference is usually small but can be sufficient to cause the rider either to exceed the limit of grip, or to use less grip than is available, on a particular corner, the former resulting in a crash, the latter in a slower lap time than is possible.

It is not always the case that a lyre must be warmed to reach its maximum grip, and it is known for the grip to be reduced when the lyre exceeds its optimum temperature. The optimum temperature vanes according to the make-up of the lyre. With wet-weather tyres for example, it is known for the tyres to overheat and lose grip (and in extreme cases also break down) when the temperature of the lyre rises too high, as might occur if the track dries out and the lyre loses the benefit of cooling water on the track.

SUMMARY OF THE INVENTION

The present invention seeks to provide a device which according to a first aspect can act to maintain an elevated temperature in a chosen part of the lyre by providing selective heating to that part of the lyre, and according to a second aspect can act to reduce the temperature in a chosen part of the lyre.

According to the invention therefore, there is provided a device for warming and/or cooling a vehicle lyre comprising at least one intake conduit and at least one outlet conduit, the intake conduit(s) being adapted for connection to a source of air at a chosen temperature, the device having a valve to selectively allow or restrict the flow of air from the outlet conduit.

Preferably, the device is adapted for mounting to a motorcycle so that the chosen parts of a tyre of the motorcycle can be warmed and/or cooled as desired during use of the motorcycle, for example during a race.

According to the first aspect the intake conduit is adapted for connection to a source of air at a temperature above ambient, and according to the second aspect the intake conduit is adapted for connection to a source of air at a temperature at or below ambient. Thus, the term "chosen temperature" does not imply a defined temperature but merely a suitable temperature range, the invention being effective in its first aspect whenever the chosen temperature is above the temperature of the tyre for example.

Preferably, there are two outlet conduits and the valve comprises a plate, flap or the like which can selectively open one of the outlet conduits and close the other of the outlet conduits. Desirably, the valve moves (preferably pivots) between a first position in which one of the outlet conduits is open and the other outlet conduit is closed; a second position in which said one of the outlet conduits is closed and said other outlet conduit is open; and a third position in which neither outlet conduit is open. Preferably, the valve moves under the influence of gravity.

In certain embodiments the invention may operate only according to the first aspect, i.e. the device operates only to warm a chosen part of the vehicle tyre. In such embodiments only one intake conduit is required, connected to a source of "warm" air. In other embodiments the invention may operate only according to the second aspect, and in such embodiments only one intake conduit is required, connected to a source of "cool" air. In yet other embodiments the invention can operate according to both aspects, i.e. the device can act to warm chosen parts of the tyre and to cool chosen parts of the tyre, the chosen parts either being warmed and cooled at the same time so that the chosen parts are different, or else the chosen parts are the same and the warming and cooling occur at different times according to changing requirements.

Preferably, the outlet conduit(s) have an adjustable orifice, so that the position and direction of the outgoing air can be adjusted as desired.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention will now be described in more detail, by way of example, with reference to the accompanying schematic drawings, in which: Fig. 1 shows a front view of an embodiment of the device employing both aspects of the invention; Fig.2 shows a side-sectional view of part of the embodiment of Fig. 1; and Fig.3 shows a top-sectional view of part of the embodiment of Figs. I and 2.

DETAILED DESCRIPTION

The device 10 shown in Figs. 1-3 comprises a first housing 12 (which embodies the invention according to the first aspect) and a second housing 14 (which embodies the invention according to the second aspect). It will be understood from the following description that the housing 12 or the housing 14 could be used independently of each other if desired, the device 10 is shown comprising both housings for ease of understanding.

Considering initially the first housing 12, this comprises a generally closed chamber which has a first outlet conduit 16 and a second outlet conduit 18 fitted thereto (only the extreme ends of the conduits 16,18 which are in connection with the housing 12 are seen in Fig.1). Within the housing 12 is located a generally triangular plate 20 which is mounted upon a pivot 22. The plate 20 is therefore able to pivot within the housing 12 as indicated by the arrows in Fig.1.

As seen from Figs. 2 and 3, the plate 20 lies close to the front wall 24 of the housing 12, to which the outlet conduits 16, 18 are connected, and in the position shown in Figs. 1-3 the plate 20 covers and closes off the outlet conduits 16 and 18. It will be understood that it is not necessary for the plate 20 to seal the outlet s conduits 16,18, and in fact some clearance between the plate 20 and the front waIl 24 is preferred to allow substantially free pivoting of the plate, notwithstanding that this will permit a small flow of air from the housing into the outlet conduits 16 and 18.

It will be understood that as the plate 20 pivots clockwise to its extreme position (which extreme position in this embodiment is provided by the edge 26 of the plate engaging the wall of the housing 12), the outlet conduit 16 is opened and the outlet conduit 18 remains closed, and vice versa as the plate pivots anti-clockwise.

In this preferred embodiment, the housing 12 also has two inlet conduits 30, 32 (though only the inlet conduit 30 is visible in Fig.2, the inlet conduit 32 being hidden behind the inlet conduit 30 in this view). It will be understood that the inlet conduits 30, 32 of the housing 12 are similar to (and are preferably identical to) the inlet conduits 130, 132 of the second housing 14 shown in Fig.3.

As is shown in Fig.3, the inlet conduits 130,132 each contain a fan 40 or the like to force air under pressure into the housing 14. Also, the inlet conduit 132 contains an electrical heating element 42 to heat (or further heat) the air entering the housing through that inlet conduit. The arrangement is similar (or perhaps identical) for the intake conduits 30, 32 of the housing 12.

Accordingly, the inlet conduits 32 and 132 are intended to allow warmed air (i.e. air at a temperature above ambient, and ideally also above that of the chosen part of the tyre) to enter the housings 12, 14 respectively, whilst the inlet conduits 30, are intended to allow cool air (i.e. air at or below ambient) to enter the housings 12, 14 respectively.

In other embodiments the housing 12 has only a warm air inlet conduit, and the housing 14 only a cool air conduit, but it is preferred that both housings have two inlet conduits to cover all situations as explained below.

It is expected that the invention will find its greatest utility according to its first aspect. In embodiments according to that aspect only a single housing 12 is required, and that housing needs only a warm air inlet conduit 32, and the following three paragraphs assumes that is the case for simplicity.

If as is intended the housing 12 is fitted adjacent to the tyre of a motorcycle, with the front wall 24 rearmost of the motorcycle (so that the view of Fig.1 is towards the front of the motorcycle) it will be understood that as the motorcycle leans into a left-hand bend, gravity will act to pivot the plate 20 in a clockwise direction relative to the housing 12.. During such leaning, the left hand side L of the tyre 44 is will experience friction-induced heating, whilst the right hand side R will experience no such heating, but will instead experience cooling caused by the flow of ambient air therepast. Accordingly, whilst the motorcycle undertakes a left-hand bend the right side R of the tyre 44 will normally undergo a fall in temperature (from an elevated temperature towards ambient).

As is apparent from Figs. 2 and 3, the outlet conduits all terminate close to the tyre 44, and the outlet conduit 16 in particular terminates close to the right side R of the tyre 44. During the taking of a left-hand bend as described above, warm air flows into the housing 12 through the inlet conduit 32 and out of the housing 12 through the outlet conduit 16. This warmed air leaves the outlet conduit close to the surface of the right side R of the tyre 44 and acts to warm the tyre, or at least to help maintain an elevated temperature in the right side R of the tyre 44 in opposition to the cooling effect of the passing ambient air flow.

When the motorcycle is undertaking a right-hand bend on the other hand, the plate 20 pivots anti-clockwise and the warm air is directed through the outlet conduit 18 towards the left-hand side I of the tyre 44.

In its simplest form according to the first aspect therefore, the present invention provides a device which can automatically divert warm air towards the side of the tyre which is not experiencing friction-induced heating. Some race circuits with for example mostly left-hand bends can have a considerable distance between right-hand bends, and during the time taken between those right-hand bends the right hand side of the lyre can cool sufficiently to require the rider to adopt a more cautious approach and a slower speed around the right-hand bends than would be the case with a warmer right side of the lyre. The present invention can assist in keeping the right hand side of the lyre at a more elevated temperature between the right-hand bends so that the rider can adopt a more aggressive approach and take the corner at a higher speed.

As above indicated, it is not only necessary to warm a racing lyre to achieve its optimum performance; it is sometimes necessary to cool the lyre also (or rather to maintain the lyre at a temperature close to ambient). This is most commonly required when a motorcycle is fitted with wet-weather tyres whilst the track is dry (this may occur on a drying track after a wet start, or in the mistaken expectation that rain would fall. According to its second aspect, the present invention provides a device which an act to cool a lyre, by forcing cooled or ambient air across the lyre.

The second housing 14 of Figs. 1-3 achieves this aspect. Like the first housing 12 the second housing 14 has two outlet conduits 116, 118, each of which terminates adjacent to a respective side of the lyre 44. Also like the first housing 12, the second housing 14 has two inlets 130, 132 as show in Fig.3. However, to provide the second aspect of the invention the second housing 14 requires only a cool air inlet conduit 130.

The housing 14 contains a pivoting plate 120. Unlike the plate 20, however, the plate 120 has a central opening 46 (shown in dotted outline). It will be understood that as the plate 120 pivots clockwise to its extreme position (which extreme position in this embodiment is provided by the edge 126 of the plate engaging the

R

wall of the housing 14), the outlet conduit 118 is opened and the outlet conduit 116 remains closed, and vice versa as the plate pivots anti-clockwise.

If as is intended the housing 14 is fitted adjacent to the tyre of a motorcycle, with s the front wall 124 rearrnost of the motorcycle (so that the view of Fig. I is towards the front of the motorcycle) it will be understood that as the motorcycle leans into a left-hand bend, gravity will act to pivot the plate 120 in a clockwise direction relative to the housing 14. During such leaning, the left hand side L of the lyre 44 will experience friction-induced heating, which may cause the temperature of the side L to exceed the optimum temperature for maximum grip, or even to exceed its working limit. During this movement, cool air flows into the housing 14 through the inlet conduit 130 and out of the housing 14 through the outlet conduit 118.

This cool air leaves the outlet conduit 118 close to the surface of the left side L of the lyre 44 and acts to cool that side of the lyre, in addition to the cooling effect of the passing ambient air flow.

Alternatively, it would of course be possible to use a plate 20 such as that of housing 12 in the housing 14, with the outlet conduits 130, 132 crossed, but the use of the plate design as shown is preferred.

In order to cool the lyre 44, it is not necessary that the air is cooled below ambient though this is within the scope of the present invention. Instead, it is believed that the increase in substantially ambient air flow across the lyre which the present invention as above described can provide will be of benefit in reducing the temperature of a chosen part of the lyre towards ambient Accordingly, it will be understood that the invention according to its first aspect can be achieved with a single housing 12 and a single (warm) air intake 32, whilst the second aspect can be achieved with a single housing 14 and a single (cool or ambient) air intake 130. Nevertheless, as above described the present invention can also comprise a first housing 12 and a second hosing 14, each housing having two air intakes, so as to achieve optimum performance in changing conditions.

By providing two housings with the different plate arrangements described, and providing two air intakes to each housing, it can be arranged that either side of the lyre 44 can be warmed or cooled, when the motorcycle is undertaking a right-hand or a left-hand bend.

Thus, it may be desirable for both sides of the lyre to be heated dunng an early part of a race, in which case air is delivered into both housings 12, 14 from the warm air intake conduit 32, 132. During the middle of a race the invention may be operated in its first aspect to keep the acoIdfl side of the lyre at an elevated temperature, and towards the end of a race both sides of the lyre may be cooled to prevent the lyre from overheating.

Clearly, if the track has more bends in one direction than the other, it may be necessary to cool one side of the lyre and warm the other side during the race.

The requirements upon the invention for a particular lyre at a particular track can be determined by calculation or by experiment. The device can be fitted with a controller to open and close either the warm air intake conduit or the cool air intake conduit as desired, and the controller can control the temperature of the air entering each of the housings 12, 14 according to a predetermined timing sequence for the various stages of a race, or according to measurements or estimates of lyre temperature obtained during the race.

The device can be fitted to both the rear lyre and/or the front lyre of a motorcycle, as desired. The warm air can be generated by the heating element and/or by other means, for example by convection from the exhaust pipe, the radiator and/or the engine directly, or the warm "air" may comprise or include exhaust gases.

It will be understood that the drawings are schematic, in particular in relation to the outlet conduits. In practice, the outlet conduits would be of a size and shape to maximise air flow therethrough, and may therefore incorporate shallow bends and larger cross-sections than drawn. ln addition, the outlet conduits may include an adjustable outlet nozzle whereby the position and direction of the outflowing air in relation to the tyre can be adjusted.

It will be appreciated from Fig.1 that the angle through which the housing 12 must be tilted to fully open the respective outlet conduits 16, 18 is around 300, and the angle through which the housing 112 must be tilted to fully open the respective conduits 116, 118 is somewhat less than this. The angular tilt required is a function of the dimensions of the components of the device, and can be set as required. In any event, however, the angular tilt required must be less than the angle through which a motorcycle leans in a corner (which for a racing motorcycle is well in excess of 450).

The invention is not limited to racing motorcycles, and can be fitted to all motorcycles. The invention is not likely to have any measurable effect for most road-going motorcycles in everyday use, however, though a rider may benefit from the invention when using a motorcycle on a track day.

The invention is described primarily for use in warming or cooling one or other side of the tyre, but it is also expected to have utility to warm or cool the centre of the tyre, which part of the tyre is used for straight-line acceleration and braking.

The housings, plates and/or the outlet conduits can be suitably modified to allow for the selective warming and/or cooling also of the central part of the lyre if desired.

Claims (15)

II CLAIMS

1. A device for warming and/or cooling a vehicle tyre during use of the tyre, the device comprising at least one intake conduit and at least one outlet conduit, each intake conduit being adapted for connection to a source of air at a chosen temperature, the device having a valve to selectively allow or restrict the flow of air from the outlet conduit.

2. The device according to Claim I adapted for mounting to a motorcycle.

3. The device according to Claim I in which there are two outlet conduits.

4. The device according to Claim 3 in which the valve can move between a first position in which one of the outlet conduits is open and the other outlet conduit is closed, and a second position in which said one of the outlet conduits is closed and said other outlet conduit is open,

5. The device according to Claim 4 in which the valve has a third position in which neither outlet conduit is open.

6. The device according to any one of Claims 1-5 in which the valve is a pivoting plate.

7. The device according to Claim 6 in which the pivoting plate has an opening which can expose an outlet conduit.

8. The device according to any one of Claims 1-7 in which the valve acts automatically.

9. The device according to any one of Claim 8 in which the valve acts under the influence of gravity.

10. The device according to any one of Claims 1-9 in which the outlet conduit(s) have an adjustable outlet orifice.

11. The device according to any one of Claims 1-10 in which the intake conduit(s) include means to force air into the device.

12. A motorcycle fitted with a device according to any one of Claims 1-11, with the outlet conduit(s) having their outlet orifice(s) adjacent to a tyre of the motorcycle.

13. The motorcycle according to Claim 12 in which there are two outlet conduits, one of the conduits having its outlet orifice located adjacent to the right-hand side of the tyre, the other of the outlet conduits having its outlet orifice located adjacent to the left-hand side of the tyre.

14. The motorcycle according to Claim 13 in which the intake conduit is connected to a source of air at above ambient temperature.

15. A device for warming and/or cooling a vehicle tyre during use of the tyre, the device being constructed or arranged substantially as described in relation to Figs. 1-3 of the accompanying drawings.

15. The motorcycle according to Claim 13 in which the device has a heater for heating air to above ambient temperature.

16. A method of warming and/or cooling a motorcycle tyre during use, comprising the steps of: {i} mounting a device according to any one of Claims 1-11 to the motorcycle, with the outlet conduit(s) adjacent to the lyre; {ii} connecting the intake conduit to a source of air at above ambient temperature; (iii) operating the valve to selectively allow or restrict the flow of air from the outlet conduit, whereby to selectively deliver or not deliver air at above ambient temperature along the outlet conduit and across the lyre.