JPH10339737A - Car speed detector and production articles therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a car speed detector which can stably detect car speed without exerting any adverse influence upon the traveling of car. SOLUTION: Concerning the car speed detector for finding car speed by detecting the rotating number of the tire of traveling vehicle, this device is provided with a plural number of magnetic field generating means 2 arranged around the outer periphery of tire 1 or at point symmetric positions near the outer periphery, and a magnetic field detecting means 3 for detecting the change of magnetic field caused by the rotation of tire. Besides, the car speed can be semipermanently detected without especially requiring maintenance after attachment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle speed detecting device used for a sensor of a car navigation system and the like, which determines a traveling speed of a vehicle relative to the ground, and a manufacturing product thereof.
In particular, while enabling stable detection of vehicle speed,
The device can be easily manufactured.

[0002]

2. Description of the Related Art A vehicle speed can be calculated by measuring the number of revolutions of tires of a running vehicle.

A conventional vehicle speed detecting device comprises a magnetic field generating means which rotates integrally with a tire, and a magnetic field detecting means for detecting a magnetic field of the magnetic field generating means, and the magnetic field detecting means is mounted at a position near a tire of a vehicle body. Can be

As shown in FIG. 8A, the magnetic field generating means is formed by using a permanent magnet or the like to magnetize a part of the steel portion inside the tire 81 to the N-pole and the other part to the S-pole. Actually, an S pole and an N pole are formed on the inner peripheral side of the tire, respectively. Or, as shown in FIG. Is done.

When the tire 81 having these magnetic field generating means rotates, a magnetic field leaking from the tire 81 changes a surrounding magnetic field. This change in the strength of the magnetic field is detected by the magnetic field detecting means 83.
, The number of rotations of the tire can be measured.
Therefore, if the diameter of the tire 81 is determined in advance by any method, the vehicle speed can be determined.

In the configuration shown in FIG. 8A, a special thing is not attached to the tire, so that a change in the magnetic field can be detected and the vehicle speed can be obtained without breaking the rotational balance of the tire.

On the other hand, in the configuration shown in FIG. 8B, the magnetic field of the magnetic field generating means 82 using a permanent magnet or the like is maintained semi-permanently. Can be detected.

[0008]

However, in the conventional vehicle speed detecting device, in the case of the structure shown in FIG. 8A, the steel of the tire is only temporarily magnetized. In response to changes in the surrounding magnetic field,
There is a problem that the strength of the magnetic field is weakened or disturbed, and it is necessary to re-magnetize the magnetic field from outside using a permanent magnet or the like in order to restore the original strength.

Further, this configuration cannot be adopted when the tire does not contain a magnetizable metal such as steel.

On the other hand, in the configuration shown in FIG. 8B, since the magnetic field generating means is attached to the outer peripheral side surface of the tire, the balance during rotation of the tire is disturbed, which may adversely affect the running characteristics of the vehicle. .

The present invention has been made to solve the conventional problems, and provides a vehicle speed detecting device capable of detecting the vehicle speed stably without adversely affecting the running of the vehicle. The purpose of the present invention is to provide convenient manufacturing supplies for the manufacture of products.

[0012]

Therefore, in the vehicle speed detecting device of the present invention, a plurality of magnetic field generating means using permanent magnets or the like are arranged so as not to lose the rotational balance of the tire, or a thin film or paint having a light weight can be used. Is used to form a magnetic field generating means.

Therefore, it is possible to semi-permanently detect a change in the magnetic field without disturbing the balance during rotation of the tire.

Further, the thin film or the magnetic paint of the present invention contains a magnetic powder and has good adhesion to tire rubber.

Therefore, the magnetic field generating means can be easily formed by bonding the thin film to a tire or applying a magnetic paint to the tire.

Further, the paint container of the present invention has a configuration in which a magnet is arranged at the paint outlet and the magnetic powder is magnetized in a certain direction only by applying the magnetic paint.

Therefore, the magnetic field generating means can be formed very easily.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a vehicle speed detecting device for detecting a rotational speed of a tire of a traveling vehicle to obtain a vehicle speed. Even number of arranged magnetic field generating means and a magnetic field detecting means for detecting a change in the magnetic field generated by the rotation of the tire are provided, without breaking the rotational balance of the tire, and particularly for maintenance after mounting. The vehicle speed can be detected semi-permanently without need.

According to a second aspect of the present invention, there is provided a vehicle speed detecting apparatus for detecting a rotational speed of a tire of a traveling vehicle to obtain a vehicle speed, wherein an outer circumferential distance of the tire is maintained at an equal interval at or near the outer circumference of the tire. A plurality of magnetic field generating means arranged in
It is provided with a magnetic field detecting means for detecting a change in a magnetic field caused by the rotation of the tire. Even with this device, without breaking the rotational balance of the tire, and without special maintenance after mounting, semi-permanent Vehicle speed can be detected.

According to a third aspect of the present invention, there is provided a vehicle speed detecting apparatus for detecting a rotational speed of a tire of a traveling vehicle to determine a vehicle speed, wherein the magnetized magnetic field generating means is bonded to an outer periphery or a vicinity of the outer periphery of the tire. And a magnetic field detecting means for detecting a change in a magnetic field caused by the rotation of the tire, and the thin film is lightweight, so that the rotation balance of the tire is not adversely affected. A magnetic field generating means can be formed.

According to a fourth aspect of the present invention, there is provided a thin film containing a magnetic powder magnetized in a predetermined direction and having an adhesive for tire rubber coated on one surface thereof. The magnetic field generating means can be formed by a very simple operation of attaching this film to the outer peripheral side surface of the tire. Further, even if there is no metal such as steel in the tire, the magnetic field generating means can be formed.

According to a fifth aspect of the present invention, there is provided a vehicle speed detecting device for detecting a rotational speed of a tire of a traveling vehicle to obtain a vehicle speed, wherein the constant value is applied to the outer periphery of the tire or in the vicinity of the outer periphery to constitute a magnetic field generating means. It is provided with a paint layer containing magnetic material powder magnetized in the direction, and a magnetic field detecting means for detecting a change in a magnetic field generated by rotation of the tire.Because the paint layer is lightweight, the rotation balance of the tire is improved. It is possible to form a magnetic field generating means that does not have an adverse effect.

According to a sixth aspect of the present invention, there is provided a magnetic paint containing a synthetic rubber-based material as a main component which contains a magnetic substance powder, adheres well to tire rubber, and solidifies when exposed to air. It is intended to be used for forming a magnetic field generating means of a vehicle speed detecting device, and this coating material is applied to a tire, and then the magnetic powder is magnetized in a certain direction, so that the magnetic field generating means can be easily formed. it can. Further, even if there is no metal such as steel in the tire, the magnetic field generating means can be formed.

According to a seventh aspect of the present invention, the paint container for storing the magnetic paint according to the sixth aspect is provided with an injection port for injecting the magnetic paint little by little, and the injection port is included in the magnetic paint to be injected. A permanent magnet or magnetized ferromagnetic metal that magnetizes the magnetic powder in a certain direction is provided. Just by applying the magnetic paint contained in this container, the magnetic powder in the magnetic paint is turned in a certain direction. And can be magnetized.

According to an eighth aspect of the present invention, the magnetic field detecting means is attached to the outside of the vehicle body so as to detect the magnetic field obliquely with respect to the outer peripheral surface of the tire. By providing the means, the magnetic field can be detected without a magnetic shield made of a metal such as a tire house interposed, so that a change in the strength of the magnetic field can be detected with high accuracy.

According to a ninth aspect of the present invention, there is provided a vehicle speed detecting device for detecting a rotational speed of a tire of a traveling vehicle to determine a vehicle speed, wherein a magnetic field generating means disposed on or near the outer periphery of the tire is provided by a rotation of the tire. It is provided with a magnetic field detecting means for detecting a change in the generated magnetic field, and a magnetic field reproducing means provided on the vehicle body for re-magnetizing the magnetic field generating means.If the magnetic field of the magnetic field generating means is weakened, or the tire steel , The desired magnetic field can be reproduced and the vehicle speed detecting operation can be performed semi-permanently.

According to a tenth aspect of the present invention, there is provided a vehicle speed detecting device for detecting a rotation of a tire of a traveling vehicle to obtain a vehicle speed, wherein an optical ground speed detecting means for optically detecting a speed of an outer peripheral surface of the tire is provided. The vehicle speed can be detected without providing any special means to the tires only by providing the optical ground speed detecting means. Further, this optical ground speed detecting means does not receive a fatal stain for detection.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) As shown in FIGS. 1 (a) (front view) and 1 (b) (side view), a vehicle speed detecting device according to a first embodiment has an outer peripheral side surface of a tire 1. A magnetic field generating means 2 is provided at a point symmetrical position of the section, and a magnetic field detecting means 3 for detecting a change in magnetic field strength.

The magnetic field generating means 2 is made of a member whose magnetization is maintained semi-permanently, such as a permanent magnet, and each magnetic field generating means 2 has the same mass. In FIG. 1, the two magnetic field generating means 2 are attached to positions just symmetric with respect to the center when the tire 1 is regarded as a circle, but the number of the magnetic field generating means 2 is further increased. You may. Even in that case, each magnetic field generating means 2 is arranged so as to form a pair at a point-symmetric position with respect to the center of the tire 1.

In this device, when the tire 1 rotates, the surrounding magnetic field changes due to the magnetic field leaking from the magnetic field generating means 2, and the change in the strength of the magnetic field is detected by the magnetic field detecting means 3. Then, when the number of changes in the magnetic field corresponding to the number of the magnetic field generating means 2 arranged on the circumference of the tire 1 is detected, the rotation number of the tire 1 is counted up by one. In this way, the change in the magnetic field is detected by the magnetic field detecting means 3 so that the rotation speed of the tire is measured, and the vehicle speed is determined.

In this device, even when the tire rotates, the magnetic field generating means 2 is balanced, so that there is no problem in the balance during rotation.

As described above, in this vehicle speed detecting device, it is possible to detect the vehicle speed without breaking the rotational balance of the tire, and to use a semi-permanently magnetized magnetic field generating means. The vehicle speed can be detected semi-permanently without maintenance after installation.

The magnetic field generating means 2 may be arranged at equal intervals around the tire so that the distances from the adjacent magnetic field generating means on the tire circumference are all equal. Even in this case, the rotational balance of the tire does not collapse. In this arrangement, the number of the magnetic field generating means can be odd.

(Second Embodiment) In the second embodiment,
A description will be given of a thin film containing a magnetic material, which is used as a magnetic field generating means of a vehicle speed detecting device. As shown in FIG. 2, this thin film contains a magnetic material magnetized in the central portion 5 and is adhered to the outer peripheral side surface of the tire to form a magnetic field generating means.

The material of the thin film 4 is desirably very light, has moderate flexibility, has relatively large tensile strength and impact strength, and has little change due to temperature and humidity or change with time. For example, cellulose acetate or Polyethylene terephthalate, vinyl chloride resin or the like is used.

The material of the thin film 4 is mixed with a magnetic powder to form the thin film 4. In FIG. 2, the portion 5 containing the magnetic material and the portion not containing the magnetic material are divided, but of course, all the portions of the thin film may contain the magnetic material.

After being formed as a film, a certain strong static magnetic field is applied to the thin film 4 to magnetize the magnetic material contained in the film in a certain direction. Make a magnet.

Next, an adhesive for tire rubber is applied to the side of the thin film 4 to be adhered to the tire, and the upper part is covered with a release paper and stored. When used as a magnetic field generating means, the release paper of the thin film 4 is peeled off and adhered to the vicinity of the tire outer peripheral side surface.

[0040] Even if this thin film is attached to the tire, the effect on the rotational balance of the tire can be neglected because only a slight increase in mass is involved. Therefore,
When the magnetic field generating means is formed of this thin film, it is not always necessary to provide a position for balancing the tire as in the first embodiment.

With this thin film, the magnetic field generating means can be formed by a very simple operation of sticking to the outer peripheral side surface of the tire. Further, even if there is no metal such as steel in the tire, the magnetic field generating means can be provided at an arbitrary place of the tire.

The adhesive may be applied to the bonding surface when the thin film is bonded to a tire.

(Third Embodiment) In the third embodiment,
The magnetic paint for forming the magnetic field generating means of the vehicle speed detecting device will be described.

The magnetic paint is contained in a paint container 7 as shown in FIG.
It is applied to a predetermined position of the tire 1 and solidified.

The magnetic paint is made of an organic paint mixed with a magnetic powder, and is made of a synthetic rubber paint that adheres well to tire rubber and solidifies when exposed to air.

When the magnetic field generating means is formed, the paint 5 is injected from the paint container 6 and applied directly to the tire 1 as shown in FIG. The applied paint 6 solidifies immediately.
Thereafter, the magnetic powder in the paint 6 is magnetized in a certain direction by using, for example, a permanent magnet or the like, and used as a magnetic field generating means.

The magnetic field generation means formed of this magnetic paint
Since the mass is negligible, there is no effect on the rotational balance of the tire. Further, the magnetic field generating means can be formed by a very simple operation of merely applying a paint to the outer peripheral side surface of the tire. Further, even if there is no metal such as steel in the tire, it is possible to provide a magnetic field generating means at an arbitrary position on the tire.

(Fourth Embodiment) In the fourth embodiment,
A paint container for storing a magnetic paint according to the third embodiment will be described.

This paint container is shown in FIG.
As shown in FIG. 4B (cross-sectional view), if the tube has a tube shape and the belly of the tube is pushed out, the paint inside is injected little by little to the outside.

A permanent magnet or a magnetized ferromagnetic metal is disposed at the injection port of the paint container, and when the paint is injected, the magnetic powder in the paint passing through the injection port may be a permanent magnet or a strong magnet. It is magnetized by the strong magnetism of the magnetic metal, and the direction of the magnetism becomes uniform. Therefore, when applying the magnetic paint to the tire using the paint container 7, a special magnetizing tool is not required, and the paint exerts the function of the magnetic field generating means only by applying.

As described above, the paint container has a function of storing the magnetic paint and magnetizing the magnetic paint ejected little by little. Therefore, if the magnetic paint stored in this container is injected little by little and applied to the tire, the magnetic field generating means can be easily formed.

(Fifth Embodiment) In the fifth embodiment,
The arrangement of the magnetic field detecting means in the vehicle speed detecting device will be described.

In the conventional vehicle speed detecting device, the magnetic field detecting means is mounted inside the vehicle body. However, in the device of this embodiment, as shown in FIG. Attached so that the effect of the magnetic field by the magnetic field generating means can be directly sensed.

More specifically, the magnetic field detecting means 3 is mounted at a position where the tire 1 is viewed from the outside, and the magnetic field generating means provided on the ground contact surface or the side surface of the tire 1 generates a magnetic field caused by rotation with the tire. Is observed from the oblique direction of the tire contact surface.

This position is set in the trunk by the magnetic field detecting means 3.
It is less susceptible to the shielding effect of the metal plate of the tire house as compared with the case where the vehicle is placed. Therefore, the magnetic field detecting means 3 can detect a change in the strength of the magnetic field with very good S / N.

(Sixth Embodiment) In the sixth embodiment,
A vehicle speed detecting device that can easily reproduce the magnetic field of the magnetic field generating means will be described.

As shown in FIG. 6, the apparatus has a magnetic field reproducing means 9 for generating a strong magnetic field and re-magnetizing the magnetic field generating means 2, and this magnetic field reproducing means 9 is attached to the vehicle body. ing. Other configurations are the same as those of the first embodiment (FIG. 1).

It is desirable that the strength of the magnetic field of the magnetic field generating means 2 does not change semi-permanently, but it is inevitably weakened due to the deterioration over time and the surrounding environment. As a result, it becomes difficult for the magnetic field detecting means 3 to detect a change in the magnetic field, and as a result, the vehicle speed cannot be detected.

In this device, when the intensity of the magnetic field generated from the magnetic field generating means 2 is weakened, the magnetic field reproducing means 9
However, the intensity of the magnetic field of the magnetic field generating means 2 is increased. For example, when the fluctuation of the magnetic field detected by the magnetic field detecting means 3 falls below a specified level, the magnetic field reproducing means 9 is activated. Then, when the magnetic field generating means 2 comes close to the magnetic field reproducing means 9 with the rotation of the tire 1, the magnetic field reproducing means 9 generates a strong magnetic field and remagnetizes the magnetic field generating means 2.

The magnetic field reproducing means 9 includes the magnetic field generating means 2
It is appropriate to use an electromagnet or the like that can temporally control the generated magnetic field so that only the location can be magnetized.

As described above, the vehicle speed detecting device can restore the strength of the magnetic field again when the magnetic field of the magnetic field generating means is weakened, thereby continuing the vehicle speed detecting operation semi-permanently. Becomes possible.

This apparatus can reproduce the magnetic field of the steel, which has been reduced with time, even if the magnetic field generating means is formed by magnetizing the steel of the tire.

(Seventh Embodiment) In the seventh embodiment,
A vehicle speed detection device that optically detects the speed of a tire surface will be described.

As shown in FIG. 7, this apparatus comprises an optical ground speed detecting means 10 for detecting the speed of the tire surface of a running vehicle.
It has.

The optical ground speed detecting means 10 generally receives the reflected light from the ground or the road surface by two light receiving means separated by a certain distance, and obtains a time difference from the frequency analysis of the differential output. To find the speed. For example, the optical ground speed can be detected using a sensor or the like introduced in “Speed Measurement Using Spatial Filter” (Measurement and Control, Vol. 7, No. 11, Tadashi Naito, Akira Kobayashi, etc.).

However, if the optical ground speed detecting means 10 is installed so as to detect information from the road surface, the speed is greatly affected by mud and dirt repelled from the ground because of the optical nature. Detection becomes impossible.

Therefore, in this apparatus, as shown in FIG. 7, a part of the ground contact surface of the tire 1 of the vehicle is observed from above the vehicle by the optical ground speed detecting means 10 as shown in FIG. The vehicle speed is determined by measuring tire movement.

More specifically, the optical ground speed detecting means 10 detects the flow of unevenness on the ground contact surface on the tire. Since the speed of the tire contact surface is equal to the speed of the vehicle, the vehicle speed can be obtained based on the measurement result of the optical ground speed detecting means 10.

In this vehicle speed detecting device, unlike the device using magnetism, there is no need to generate a magnetic field, and the vehicle speed can be measured only by attaching an optical ground speed detecting means. In addition, since the optical ground speed detecting means 10 can be attached far away from the road surface and does not have to be directed to the road surface, mud and dirt from the road surface can be avoided.

As described above, the vehicle speed detecting device can detect the vehicle speed without providing the tire with any special means such as the magnetic field generating means and without receiving fatal dirt.

[0071]

As is apparent from the above description, the vehicle speed detecting device of the present invention semi-permanently detects the vehicle speed without losing the rotational balance of the tire and without requiring any special maintenance after mounting. can do.

Further, an apparatus in which a magnetic field generating means is formed by a magnetic film or a magnetic paint has an effect that manufacture is easy.

Further, in a device in which the magnetic field detecting means is attached to the outside of the body of the car, a change in the magnetic field due to the rotation of the tire can be detected with high accuracy.

Further, in the apparatus provided with the magnetic field reproducing means, even if the magnetic field of the magnetic field generating means is weakened, the magnetic field can be reproduced and the vehicle speed detection can be continued semipermanently.

In an apparatus provided with an optical ground speed detecting means, the vehicle speed can be detected only by attaching the means, and no other special means is required.

By using the magnetic film and the magnetic paint of the present invention, the magnetic field generating means of the vehicle speed detecting device which does not break the rotational balance of the tire can be easily formed.

The paint container of the present invention can simplify the operation of forming the magnetic field generating means using the magnetic paint.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a vehicle speed detection device according to a first embodiment of the present invention;

FIG. 2 is an explanatory diagram of a magnetic field generation unit according to a second embodiment of the present invention;

FIG. 3 is an explanatory diagram of a magnetic field generating unit according to a third embodiment of the present invention;

FIG. 4 is an external view (a) and a sectional view (b) of a paint container according to a fourth embodiment of the present invention;

FIG. 5 is an explanatory diagram of a magnetic field detection unit according to a fifth embodiment of the present invention;

FIG. 6 is an explanatory diagram of a vehicle speed detection device according to a sixth embodiment of the present invention;

FIG. 7 is an explanatory diagram of a vehicle speed detection device according to a seventh embodiment of the present invention;

FIG. 8 is an explanatory diagram of a conventional vehicle speed detection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tire 2 Magnetic field generating means 3 Magnetic field detecting means 4 Thin film 5 Part containing magnetic material 6 Paint 7 Paint container 8 Car body 9 Magnetic field reproducing means 10 Optical ground speed detecting means 81 Tire 82 Magnetic field generating means 83 Magnetic field detecting means

Claims (10)

[Claims] 1. A vehicle speed detecting device for detecting a rotational speed of a tire of a running vehicle to determine a vehicle speed, comprising: an even number of magnetic field generating means arranged at a point symmetrical position on or near the outer periphery of the tire; And a magnetic field detecting means for detecting a change in a magnetic field caused by the vehicle speed. 2. A vehicle speed detecting device for detecting a rotational speed of a tire of a traveling vehicle to determine a vehicle speed, comprising: a plurality of tires arranged at an outer periphery of the tire or in the vicinity of the outer periphery at equal intervals on the periphery. A vehicle speed detecting device comprising: a magnetic field generating means; and a magnetic field detecting means for detecting a change in a magnetic field caused by rotation of a tire. 3. A vehicle speed detecting device for detecting a rotational speed of a tire of a traveling vehicle to obtain a vehicle speed, comprising a magnetized magnetic powder which is adhered to the outer periphery of the tire or in the vicinity of the outer periphery and constitutes a magnetic field generating means. A vehicle speed detecting device comprising: a thin film; and a magnetic field detecting means for detecting a change in a magnetic field caused by rotation of a tire. 4. A thin film for forming a magnetic field generating means of the vehicle speed detecting device according to claim 3, wherein the thin film contains a magnetic material powder magnetized in a certain direction, and has an adhesive for tire rubber on one surface. A thin film characterized by being coated. 5. A vehicle speed detecting device for detecting a rotational speed of a tire of a traveling vehicle to determine a vehicle speed, wherein a magnetic material magnetized in a fixed direction, which is applied to the outer periphery of the tire or in the vicinity of the outer periphery to constitute a magnetic field generating means. A vehicle speed detecting device comprising: a paint layer containing powder; and a magnetic field detecting means for detecting a change in a magnetic field caused by rotation of a tire. 6. A magnetic paint for forming a magnetic field generating means of the vehicle speed detecting device according to claim 5, which contains a magnetic powder, adheres well to tire rubber, and solidifies when exposed to air. A magnetic paint comprising a rubber-based material as a main component. 7. A paint container for storing the magnetic paint according to claim 6, further comprising an ejection port for injecting the magnetic paint little by little, wherein the ejection port includes a magnetic substance contained in the magnetic paint to be ejected. A paint container in which a permanent magnet or a magnetized ferromagnetic metal that magnetizes powder in a certain direction is arranged. 8. The apparatus according to claim 1, wherein the magnetic field detecting means is attached to an outer side of a vehicle body and detects a magnetic field obliquely with respect to an outer peripheral surface of the tire. Vehicle speed detection device. 9. A vehicle speed detecting device for detecting a rotational speed of a tire of a traveling vehicle to obtain a vehicle speed, wherein a magnetic field generating means arranged at or near the outer periphery of the tire detects a change in a magnetic field caused by rotation of the tire. A vehicle speed detecting device comprising: a magnetic field detecting means; and a magnetic field reproducing means provided on a vehicle body for re-magnetizing the magnetic field generating means. 10. A vehicle speed detecting device for detecting a rotation of a tire of a traveling vehicle to obtain a vehicle speed, comprising an optical ground speed detecting means for optically detecting a speed of an outer peripheral surface of the tire. Detection device.