JP4389244B2 - Vehicle contact surface frictional force improving device - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention improves the ground contact performance of a wheel on a wet road surface and secures motility such as braking, acceleration, and steering.
[0002]
[Prior art]
Conventionally, the coefficient of friction between the wheel and the road surface is greatly reduced on a wet road surface, and the braking, acceleration, and steering performance are greatly adversely affected.
Efforts are being made to improve drainage performance from the contact surface by devising tire tread patterns. In addition, a mechanism that adjusts the braking force of each wheel (ABS: Anti-Skid Brake System) or a mechanism that detects slip during acceleration and suppresses excessive torque to the wheel to prevent the wheels from locking due to sudden braking (traction) Control) has been devised and put to practical use.
However, even with these contrivances, on a wet road surface, the braking distance is significantly longer than on a dry road surface. In addition, safety and maneuverability such as the lateral flow of the vehicle body caused by wheel slip are greatly reduced on wet road surfaces. This is because the root cause that the road surface is wet is left unattended.
Spike tires are effective for preventing slippage on snow-capped surfaces and frozen surfaces, but in areas where the pavement surface is exposed or where the surface of the snow-capped surface or frozen surface is thin, the pavement surface under that layer is removed. hurt. In addition, there is a problem that the asphalt that has been cut off is scattered and becomes pollution. Therefore, at present, the general use of spike tires is limited.
[0003]
[Problems to be solved by the invention]
In the present invention, the ground contact force on the road surface is drained instantaneously and locally only when necessary , and is brought into a state close to a dry road surface to eliminate the cause of the wet road surface. Secure.
In addition, since high-pressure air or high-pressure steam is used for the snow-capped surface or the frozen surface, there is no effect even if it acts on the pavement surface.
[0004]
[Means for Solving the Problems]
The high-pressure air injection nozzle disposed immediately before the wheel contact surface blows away moisture on the road surface immediately before the contact with the wheel. On the snow-capped road surface, etc., by intermittently injecting, unevenness is created on the snow-capped surface to improve the frictional force. Further, compressed air is blown onto the tread surface of the tire to remove moisture and snow in the tread surface and tread groove.
On the snow-capped surface and the frozen surface, high-pressure steam is used instead of high-pressure air, or high-pressure steam is used in combination with high-pressure air.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the high-pressure air injection nozzle 1001 disposed immediately before the ground contact surface 1003 of the wheel 1002 blows away moisture on the road surface immediately before the ground contact. Immediately before the ground contact surface, it is in a dry state or a state close to it for a moment, and the wheel passes immediately after that.
As shown in FIG. 2, high-pressure air for injection is accumulated in a tank 2004 by a compressor 2003, and is injected from a nozzle when necessary, such as during braking. A method of always injecting during normal driving is also conceivable, but the compressor has a large capacity.
In an application such as a competition vehicle that uses only a limited time, a compressed air cylinder may be used instead of a compressor.
In order to drain the ground surface, it is conceivable to use a brush or a blade immediately before the ground surface, but it is expected that drainage will not be effectively performed on the water accumulated on the unevenness of the fine road surface. In addition, there is a risk of non-contact because there are dangerous side effects such as wear of brushes and blades, strong friction with the road surface when operating at high speed, affecting brake balance, and parts being torn and scattered. The ideal method is by compressed air where the water is drained.
[0006]
As shown in FIG. 2, when the injection unit 2005 is based on a wheel support portion (a brake attachment portion on the rear side of the wheel or a so-called unsprung portion such as a wheel side fulcrum of the suspension), the vertical movement of the wheel (suspension stroke) or steering is performed. Since it also moves with the wheel, it can always inject just before the grounding part. In this case, the compressor 2003 and the compressed air tank 2004 are on the vehicle body side, and are connected to the injection unit on the unsprung side by a flexible hose 2002 to send the compressed air to the injection unit. 2001 is a 5-port valve which opens the compressed air flow path when the injection unit is extended. In addition, after braking, the compressed air direction is switched to restore the extended injection unit. In the case where the suspension is very hard and the vehicle body hardly turns forward even when braking (the suspension stroke is small), or in the case of a rear wheel that does not change its direction during steering, the nozzle may be attached to the vehicle body side.
In the case of a passenger car, a sufficient braking effect can be obtained simply by attaching the nozzle to the front wheel. However, it is more effective to install the nozzle on wheels other than the front wheel for heavy vehicles and trailers with a long vehicle body.
In particular, heavy vehicles have large inertia, and the braking distance increases when the ground contact force on a wet road surface decreases. In addition, because of the large inertial mass, the energy to break in an accident is large. On the other hand, many of these heavy vehicles are equipped with air brakes and already have a compressor for this purpose. Therefore, it can be used for the purpose of the present invention.
[0007]
In order to effectively apply the pressure of compressed air to the road surface, the nozzle should be as close to the road surface as possible.
In competition vehicles running on limited, almost flat road surfaces, the nozzles may always be exposed just before the ground contact surface in rainy weather, but in normal use vehicles, if there are always nozzles on the road surface, There is a high possibility of damaging the nozzle by touching steps, slopes, or protrusions. Therefore, the nozzle is drawn to a sufficient height from the road surface that does not cause contact due to steps, slopes, protrusions, stone rollers, etc. that are expected in normal driving ( second position: FIG. 3b), and instantaneously only when necessary. nozzle is expanded at the position grazing the road surface (a first position: Figure 3a) it is practical (claim 1).
The nozzle descends to near the road surface but is not in contact with the road surface, so it is not affected by fine irregularities or undulations on the road surface.
[0008]
FIG. 4 shows an example of the mechanism of the injection unit that performs the expansion in this way.
At the time of deployment, compressed air flows from the port 4002 of the cylinder 4001, pushes the piston 4013, and the nozzle tube 4004 expands. Since there is a guide groove 4006 on the surface of the nozzle tube, the nozzle head 4005 rotates about 90 degrees near the end point of expansion and becomes parallel to the ground contact surface. At this position (first position) , high-pressure air in the cylinder 4001 flows into the nozzle pipe from the nozzle pipe port 4005 through the bypass flow path 4014 and is ejected from the nozzle 1001. That is, the bypass flow path 4014, the piston skirt 4007, the cylinder inner wall, and the nozzle pipe port 4008 form a slide valve for guiding compressed air to the nozzle pipe.
A series of these unfolding operations are performed in an instant. Moreover, the injection duration is several seconds required for normal stop.
After braking, compressed air flows from the port 4003, the nozzle head portion returns to the original rotational position, the piston contracts, and the nozzle tube is pulled back to the original position (second position) .
[0009]
In order to control the clearance while avoiding the collision between the undulating road surface and the nozzle when the nozzle is deployed at the first position , the nozzle support portion is provided with a spring for urging the nozzle in the road surface direction. In the state where the nozzle is deployed to the position, the gap between the nozzle and the road surface is created by the balance between the force to push the nozzle tip portion toward the road surface by the spring and the reaction force from the road surface caused by the jet air pressure of high pressure air or high pressure steam. Open control that keeps constant (Claim 2), or feedback control that detects the distance from the nozzle to the road surface by an air pressure sensor or an ultrasonic sensor and operates the means for moving the nozzle up and down to control the nozzle position (Claim) 3).
In particular, the spray nozzle can be configured as part of a pure fluid sensor. The proximity distance detection by the pure fluid sensor includes a back pressure type and an annular jet type. FIG. 5 shows an embodiment using the annular jet type.
When the injection target surface (road surface) 5008 is far away, the sensor tube 5001 has a negative pressure due to the entanglement phenomenon of the jet flow. However, when the injection target surface approaches, the sensor tube 5001 changes to a positive pressure. Positive pressure causes bellows 5002 to expand.
Since the injection unit can swing about the pivot 5003 and is attached to the unsprung support portion 5004, when the bellows expands, the injection unit is lifted upward and the nozzle moves away from the road surface.
That is, in this embodiment, the pressure of the sensor tube is a detection signal of the distance to the road surface, and the bellows that expands and contracts according to the detection level is a means for moving the nozzle up and down.
Further, the weak spring 5007 is a spring that biases the nozzle tip in the road surface direction, and generates a pressure for pressing the nozzle tip in the road surface direction. Since the injection force (reaction force of injection) works to push the nozzle up from the road surface, the spring 5007 receives a force in the compression direction and the repulsion force increases. In this way, the spring 5007 balances the force with which the nozzle moves away from the road surface (reaction force of injection) and the pressing pressure, and keeps the gap from the road surface of the nozzle constant.
Reference numeral 5005 denotes a sledge-shaped nozzle protector that protects the nozzle from the protrusion and, when riding on the protrusion, pushes up the injection unit against the repulsive force of the strong spring 5006 to separate the nozzle from the road surface. (The weak spring 5007 is fully contracted and the strong spring 5006 is activated).
In other words, with respect to the gentle undulation of the road surface, the distance from the road surface of the nozzle is appropriately followed by the balance between the reaction force of the injection and the pressure of the annular jet, and the balance of the repulsive force of the spring 5007 with these forces. For large and steep changes such as protrusions on the road surface, the height from the road surface is controlled so as to prevent the nozzle from colliding with the balance between the force that the protector 5005 pushes up and the repulsive force of the strong spring 5006.
As described above, the embodiment has been described in which only the mechanical means and the pneumatic means are used to protect the nozzle and keep the proper position against road surface undulation and protrusions.
Furthermore, the pressure of the annular jet is converted into an electric signal, or the distance from the nozzle to the road surface is detected using an ultrasonic sensor, an optical sensor, etc. , and the detection signal is accordingly applied to the electric signal provided on the nozzle support section. There is a method of controlling the nozzle position by moving the nozzle up and down by an actuator .
[0010]
As shown in FIG. 6, by adding a nozzle 6001 that blows high-pressure air to the tread surface of the tire, removing moisture and snow in the tread surface and the tread groove improves the frictional force between the tire and the road surface. . In particular, if the snow is clogged in the tread groove, the shearing force cannot be exerted, so it is effective to blow it off. In the case of compressed snow, it is more effective to use high-pressure steam instead of compressed air. Also, oil and the like attached to the tread surface can be removed.
[0011]
Next, the case where injection is performed intermittently will be described.
As shown in FIG. 7, the injection is intermittently performed on the snowy road. When jetting is performed, a depression 7001 is intermittently formed on the snow-capped surface. Accordingly, the pressure snow surface is uneven, and the corners of the depressions generate shearing force with the tire and are difficult to slip. Further, since the injection is intermittent, the consumption of compressed air can be suppressed.
In cold regions, using high-pressure steam instead of high-pressure air is effective not only for compressed snow but also for icing surfaces.
[0012]
FIG. 8 shows a case where high-pressure steam and high-pressure air are used in combination.
Reference numerals 1001 and 6001 denote high-pressure steam nozzles, and 8001 and 8002 denote high-pressure steam nozzles.
The high-pressure steam nozzle 8001 melts the pressure snow or icing road surface intermittently and intermittently forms grooves 7001. The high pressure air nozzle 1001 blows away the melted water. Reference numeral 2005 denotes a high-pressure air injection unit, and reference numeral 8003 denotes a high-pressure steam injection unit.
The high pressure steam nozzle 8002 melts and blows off the pressure snow that has entered the tread groove. Further, the groove 7001 is formed intermittently. The high-pressure air nozzle 6001 blows away the melted water from the tread surface and dries it. At this time, depending on the degree of dryness, when the residual moisture on the tread surface comes into contact with the ground, re-freezing occurs, and an adsorbing force is generated between the tread surface and the grounding surface, thereby increasing the grounding force.
[0013]
The primary need for this function is during sudden braking. If it does not operate during normal gentle braking operation, but only during certain sudden braking operations, the average amount of compressed air used is small and the compressor can be small. Further, since the injection time is several seconds, and sudden braking is rarely performed immediately, the storage tank for compressed air may have a capacity corresponding to one injection.
It is conceivable to use a panic brake detection function for detecting a sudden braking operation. The ABS has a function to detect panic brake operation. This is a function added in view of the case where drivers who are not accustomed to the operation of continuing to step on the brake in the event of an emergency cannot fully demonstrate the effect of the essential ABS. In this case, the full brake is automatically applied (the brake pedal force is maximized and the ABS control is applied). When the present invention is linked to this panic brake detection signal, a high braking effect is obtained together with the brake control by ABS, and the cause of operation as emergency braking is natural.
[0014]
The present invention may be further required even during sudden braking. That is, the function of the present invention is activated when a sudden acceleration operation is detected or when a slip is detected.
It is activated when a sudden acceleration or turning operation is detected, or when the vehicle acceleration in each direction exceeds a certain value.
Or linked to traction control. Traction control predicts or detects wheel slip due to excessive torque with respect to the road surface condition, and lowers engine output to an appropriate value or activates drive system control and brakes. If the signal that activates is also used as the activation signal of the present invention, slip prevention control in a natural situation becomes possible.
[0015]
【The invention's effect】
The present invention prevents the slipping of the wheel by removing the root cause of removing the wetness of the road surface, and because it uses compressed air, it can drain even if there are fine irregularities on the road surface, and it is non-contact As a result, there is no risk of influence on maneuverability or damage to members due to friction with the road surface. It can also be applied to road conditions such as snow pressure and freezing, and there is no impact on the road surface. It can be realized as a relatively simple, lightweight, inexpensive and highly reliable device.
Further, the present invention can be applied not only to automobiles such as passenger cars and heavy vehicles, but also to aircraft landing wheels, new traffic systems, and railway wheels.
[Brief description of the drawings]
FIG. 1 shows a basic configuration of the present invention.
FIG. 2 is an overall configuration of the present invention.
FIG. 3 shows how a mechanism that performs the functions of the present invention is deployed only when necessary.
FIG. 4 shows an embodiment of an injection unit that is deployed when necessary.
FIG. 5 shows an embodiment in which the nozzle position is controlled by air pressure and mechanical means.
FIG. 6 shows an embodiment in which injection is also performed on the tire tread surface.
FIG. 7 shows an embodiment in which intermittent injection is performed.
FIG. 8 shows an example in which high-pressure air and high-pressure steam are used in combination.
[Explanation of symbols]
1001 Injection nozzle 1002 Wheel 1003 Ground surface 2002 Flexible hose 2003 Compressor 2004 Compressed air tank 2005 Injection unit 4002 Expansion port 4003 Contraction port 4004 Nozzle pipe 4005 Nozzle head 4006 Guide groove 4007 Piston skirt 4008 Nozzle pipe port 4013 Piston 4014 Bypass flow path 5001 Sensor tube 5002 Bellows 5003 Pivot (Oscillation center of injection unit)
5004 Injection unit support 5005 Nozzle protector 5006 Strong spring 5007 Weak spring 5008 Injection target surface (road surface)
6001 Injection nozzle (for tread surface)
7001 Indentation (formed on the surface of snow or ice)
8001 High-pressure steam nozzle (for road surface)
8002 High-pressure steam nozzle (for tread surface)
High pressure steam injection unit

Claims (3)

In a vehicle that accelerates, brakes, and turns by frictional force between a road surface and a tread surface of a wheel, a tire is used to improve the frictional force between the two surfaces that generate the frictional force, that is, the road surface and the tread surface of the wheel. A nozzle that injects high-pressure air or high-pressure steam to the road surface immediately before the contact surface, that is, the road surface immediately before the ground contact surface, or to both the road surface immediately before the ground contact surface and the tread surface of the wheel, When a sudden braking operation is detected, a sudden acceleration operation is detected, or a slip is detected, it automatically and instantaneously expands to the first position that is very close to the road surface just before the wheel contact surface. a step of the road anticipated during normal traveling in addition to the above case, the inclination, the projection, the ground plane which is held in the second position in the height from sufficient road surface and the like can be avoided stone Friction force improvement equipment. The nozzle support portion includes a spring that biases the nozzle in the road surface direction, and in the state where the nozzle is deployed to the first position, the spring force that presses the nozzle in the road surface direction and the injection pressure of high-pressure air or high-pressure steam The contact surface frictional force improving device according to claim 1, wherein the nozzle is maintained at a constant height from the road surface at the first position by a balance with a reaction force from the road surface against the road surface. A sensor for detecting the distance between the position and the road surface of the nozzle, and means for lowering the nozzle by controlling the position from the road surface of the nozzle by operating the means for lowering the nozzle in response to the detection signal from the sensor The contact surface frictional force improving device according to claim 1, wherein the nozzle is maintained at a constant height from the road surface at the first position .

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