JP2736395B2 - Wheel force measuring device and structure stress measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for measuring a wheel acting force for detecting a road friction force, a vertical drag, a road friction coefficient and the like acting on wheels of a vehicle. And the like can serve as a control input signal of an anti-lock brake device (ABS) for preventing the wheels from locking when the vehicle is suddenly braked or a traction control device for preventing the wheels from slipping excessively during acceleration.

[0002]

2. Description of the Related Art For example, in a conventional anti-lock brake device (ABS) installed in an automobile, a method of automatically controlling braking so that a slip ratio calculated based on a vehicle body speed and a wheel speed falls within a certain range is generally used. (For example, JP-B-59-30585, JP-A-60-6013).
See No. 54 publication. ). The relationship between the road surface friction coefficient and the slip ratio can vary depending on the road surface conditions. for that reason,
In the above conventional method, the braking force may not be maximum depending on the road surface condition, and in this case, the minimum braking distance cannot be obtained. Also, since the vehicle speed is an estimated value from the wheel speed, there is a problem in accuracy in controlling the slip ratio. In order to accurately grasp the vehicle speed, complicated devices such as a ground speed sensor (for example, JP-A-63-64861) and a vehicle deceleration sensor (for example, JP-A-63-170157) are required. .

Further, an ABS incorporating a road surface friction force or a road surface friction coefficient as a measured value is disclosed in, for example,
No. 25169 proposes this. In the device described in the publication, the torque (tire torque) of the road surface frictional force acting on the wheels is calculated from the wheel angular acceleration and the brake fluid pressure, and the tire torque during the increase of the brake fluid pressure is calculated. Is used as a material for determining the state immediately before locking of the wheels. However, in this device, the tire torque is calculated indirectly from the wheel angular acceleration and the brake fluid pressure, and the calculated value is calculated due to the existence of uncertain constants such as the wheel inertia rate and the braking efficiency of the brake. Has a problem with accuracy. As a solution to this, an ABS that directly measures the road surface friction force or the road surface friction coefficient has been proposed by the applicant of the present application (for example, Japanese Patent Application No. 2-24819).
issue).

[0004] In a traction control device for a vehicle, the conventional device detects wheel slip during acceleration by measuring the wheel speed in the same manner as ABS. Also in this case, there is a problem similar to that of the ABS in which the control is performed based on the wheel speed.

[0005]

SUMMARY OF THE INVENTION A novel ABS using, as control input information, a road friction force which can vary depending on the road surface condition during traveling or a wheel acting force such as a road friction coefficient.
Alternatively, in order to put the traction control device into practical use, it is required to measure these wheel acting forces accurately and simply.

Accordingly, an object of the present invention is to provide a wheel acting force measuring device which meets the above-mentioned demand.

[0007]

DISCLOSURE OF THE INVENTION In order to solve the above-mentioned problems, the present invention takes the following technical means.

According to a first aspect of the present invention, there is provided a wheel acting force measuring device, wherein a stress detecting sensor having a strain gauge is buried and fixed at or near an axle of a vehicle, and a horizontal shear stress acting on the axle is fixed. Or a wheel acting force measuring device configured to detect a shear force in a vertical direction, wherein the stress detection sensor is configured to eliminate or reduce an influence of an axle torque acting on the axle, and the strain gauge is configured to be It is arranged so as to be located on or near the stress center axis near the axle or near the axle, and the detection output of the stress detection sensor is processed by a signal processing circuit.

The stress center line is a line connecting the areas where the influence of the distortion due to the torsion torque acting on the axle is least, and in the case of a simple circular axis, coincides with the center axis. When a braking force is applied to the wheels, the road surface frictional force that the tires receive from the road surface in the vehicle longitudinal direction acts equivalently as a stress that tends to shear the axle extending in the vehicle width direction in the vehicle longitudinal direction. At the same time, the normal force that the tire receives from the road surface due to the weight of the vehicle acts as a stress that tends to shear the axle up and down. In the present invention, basically, a stress detection sensor capable of measuring the horizontal shear strain generated on the axle by the road surface friction force or a stress detection sensor capable of measuring the vertical shear strain generated on the axle by the vertical drag. , On the center axis of the axle stress. As a result of disposing the stress sensors in this manner, the crosstalk component due to the torsional torque acting on the axle during braking is appropriately removed or reduced from the output of each of the stress detection sensors.

[0010] In a preferred embodiment, the stress detection sensor is embedded and fixed in a hole provided in the axle or in the vicinity of the axle, and the stress detection sensor is connected to the inner wall surface in the hole. It is buried and fixed, or buried and fixed in the hole via an isolating material. In this case, the separating material fills a gap between the stress detection sensor and the inner wall surface of the hole, and joins the stress detection sensor and the inner wall surface. In some cases, the plurality of holes are provided on the axle of the vehicle or in the vicinity of the axle. , For example, a horizontal shear stress corresponding to the road surface frictional force and a vertical shear stress corresponding to the vertical drag are taken out. Then, by processing the respective detection signals relating to the horizontal shear stress corresponding to the road surface friction force and the vertical shear stress corresponding to the vertical reaction force by the signal processing circuit, the road surface friction coefficient is extracted. be able to.

In a preferred embodiment, the signal processing circuit is embedded in the axle or in the vicinity of the axle together with the stress detection sensor. This increases the S / N ratio of the output signal of the sensor.

In a preferred embodiment, the stress detection sensor has a structure in which a strain gauge is integrated on or near the surface of the substrate. The method of integrating the strain gauge with the substrate in this way includes a method of attaching the strain gauge to the surface of the substrate, a method of embedding the strain gauge near the surface of the substrate, and a method of integrating the strain gauge with the surface of the semiconductor substrate. It is possible to consider a method of building it into the product.

In a preferred embodiment, a stress detection sensor buried and fixed such that a strain gauge is located on or near the center of stress of the axle or the vicinity of the axle is provided near the axle of the vehicle or in the vicinity of the axle. A sub-stress detection sensor for detecting brake torque is provided in the vicinity of the main stress detection sensor as a sensor, and these stress detection signals are processed by a signal processing circuit. The configuration is such that a stress signal such as torque is removed or reduced. The basic concept of the present invention is to dispose the stress detection sensor on the central axis of the stress. However, there is a case where a torsional torque component caused by the braking force is mixed into each sensor output. In this case, the target acting force can be measured more accurately by separately detecting the brake torque and removing it from the output of the main stress detection sensor.

According to a second aspect of the present invention, there is provided a wheel acting force measuring device, wherein a hole is provided at or near an axle,
A wheel acting force measuring device configured to embed and fix a stress detection sensor having a strain gauge in the hole and to detect a force acting on the axle, wherein the stress detection sensor includes a strain gauge on a surface of a base. Affixed or embedded with a strain gauge near the surface of the substrate, embedded and fixed in the hole via an isolating material, and the detection output of the stress detection sensor is processed by a signal processing circuit. It is characterized by:

According to this aspect, the stress detection sensor includes:
For example, by using a simple method in which a strain gauge is integrated with a base in advance and the stress detection sensor is mounted in a hole provided in the axle or in the vicinity of the axle. The stress detection sensor, more specifically, a strain gauge integrated with the base can be arranged by selecting an appropriate position such as the above.

[0016] Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the drawings.

[0017]

FIG. 1, FIG. 2 and FIG. 3 show an embodiment in which a wheel acting force measuring apparatus of the present invention is configured to measure a road surface friction coefficient.

FIG. 1 shows a mounting state of a stress selection sensor, FIG. 2 shows a stress detection sensor, and FIG. 3 shows a signal processing circuit. As shown in FIG. 1, in this embodiment, a stress detection sensor is mounted on an axle or near an axle of a non-driven wheel having a strut-type suspension structure often used in passenger cars.

A hole 2 is formed from the upper surface to the lower surface of the axle 1 (knuckle in this example) so that the central axis extends in a direction 11 perpendicular to the road surface and intersects the axle center line (stress center line). . The diameter of the hole 2 is, for example, about 5 to 10 mm. Here, the center line (stress center line) of the axle is
The axle 1 is generated by the road surface frictional force, the normal force, and the lateral force (side force) acting on the wheel rotating about the spindle.
The center line of the bending deformation occurring on the axle 1 (the line on which neither tensile strain nor compressive strain is generated due to the bending deformation) or the center line of the torsional deformation generated on the axle 1 by the brake torque at the time of the brake operation (on that line, (A line that does not cause shear strain). These approximately coincide with the centerline of the spindle (centerline 5 of the axle).

A stress detecting sensor 3 is inserted into the hole 2. As shown in FIG. 2, the stress detection sensor 3 includes a rectangular parallelepiped base body 20 made of a plastic such as epoxy resin or a metal material, and a strain measuring unit attached thereto. As the strain measuring means, for example, a metal resistance wire strain gauge can be used. In the figure, the strain gauges 21 to 24 and 31 to 34 are indicated by line segments on each surface of the base 20.

The strain gauges 21 to 24 and 31 to 34
Affixing to the surface of the base 20 using, for example, an adhesive,
Alternatively, it is attached to the base 20 by being embedded near the surface of the base 20 or the like. Strain gauges 21 to 24 and 31
Desirably, each of .about.34 is mounted at a 45.degree. Angle to the y-axis. The stress detection sensor 3 thus formed is inserted into the hole 2 and installed on the center line of the axle (center line 5 of the axle). X, y, z
The axes are the traveling direction 9 of the wheel, the axle direction 10 and the vertical direction 1 respectively.
Match with 1. The upper surface (one surface whose normal direction is the z-axis direction) of the stress detection sensor 3 is located above the center line of the axle, and the lower surface thereof (the other surface whose normal direction is the z direction). ) Is located below the center line of the axle, and the magnitude of the tensile or compressive strain caused by the bending deformation caused by the road surface friction force acting on the wheels and the normal force and the lateral force is the same at each bottom surface. It is desirable that the position be Similarly, the front surface (one surface whose normal direction is the x-axis direction) and the rear surface (the other surface whose normal direction is the x direction) of the stress detection sensor 3 sandwich the center line of the axle therebetween. And it is desirable that the strain caused by the bending deformation or the torsional deformation be the same on each surface.

The hole 2 is preferably made of a filler (separation material).
4 filled. The filler 4 is desirably made of a material such as an epoxy resin equivalent to the base of the stress detection sensor 3. The filler 4 sufficiently fills the periphery of the stress detection sensor 3 and replaces the stress detection sensor 3. It is firmly fixed in the hole 2. Thereby, the strain gauges 21 to 2
4 and 31 to 34 are effectively embedded and fixed in the holes 2 at predetermined positions and in predetermined directions.

As in the signal processing circuit of FIG. 3, a set of strain gauges 21, 22, 23, and 24 of the stress detection sensor 3;
A set of strain gauges 31, 32, 33, and 34 is assembled into bridges, and each bridge is connected to a DC power source 42 via an electric signal line 8.
Circuit 41 and DC power supply 4
5 and an amplifier 46.

The upper surface and the lower surface of the stress detection sensor 3 are subjected to shear strain in the upper and lower surfaces of the stress detection sensor 3 due to the road surface frictional force acting on the wheels. The strain gauges 21 to 24 sense this shear strain. The amplifier circuit 41 outputs a voltage signal proportional to the shear strain, that is, proportional to the road surface frictional force. In addition to the strain gauges 21 to 24 being assembled in a bridge, the shear strain is sensed in the vicinity of the center line of the axle. Therefore, the crosstalk to the output signal due to the bending deformation and the torsional deformation is caused. Can be suppressed as low as possible. That is, with this configuration, a wheel acting force measuring device capable of accurately measuring the road surface friction force is realized.

Similarly, along with the normal force acting on the wheels, the front and rear surfaces of the stress detection sensor 3
Shear strain occurs in those planes. Strain gauges 31-34
Senses this shear strain. The amplifier circuit 44 outputs a voltage signal proportional to the shear strain, that is, proportional to the normal force. In addition to the strain gauges 31 to 34 being assembled in a bridge, since the shear strain is sensed near the center line of the axle, the crosstalk to the output signal due to the bending deformation and the torsional deformation is caused. Can be suppressed as low as possible. That is, with this configuration, a wheel acting force measuring device that accurately measures the normal force is realized. Then, the arithmetic circuit 47 calculates the quotient of the road surface frictional force and the normal force to obtain the road surface friction coefficient.

In this embodiment, since the periphery of the stress detection sensor 3 in the hole 2 is filled with a synthetic resin such as an epoxy resin or another material, the strain gauges 21 to 24 and 31 to 34 are provided. Can be effectively protected from the outside world.

In order to measure only one of the road surface frictional force and the normal force, the stress detection sensor 3 shown in FIG. 4 can be used instead of the stress detection sensor 3 shown in FIG. It is desirable that each of the strain gauges 21 to 24 be attached at an angle of 45 ° with respect to the y-axis. For the purpose of measuring the road surface frictional force, it is preferable that the x, y, and z axes in FIG. 4 coincide with the vertical direction 11, the traveling direction 9 of the wheel, and the axle direction 10, respectively. For the purpose of measuring the vertical drag, the x, y, and z axes in FIG. The relationship between the mounting position and the center line is the same as in the case of the stress detection sensor shown in FIG. In this case, the strain gauges 21 to 24 are connected to the signal processing circuit shown in FIG. That is, the amplifier 41
Connected to. The amplifier circuit 41 outputs a signal corresponding to the road surface frictional force or the vertical drag.

Lateral force (side force) as wheel acting force
Is measured using the stress detection sensor shown in FIG. 6 and each of the strain gauges 21 to 24 is set as shown in FIG.
Mounting along the axis or z-axis, x,
The directions of y and z are respectively defined as the traveling direction 9 of the wheel, the axle direction 10,
The connection is made in the vertical direction 11 and the connection is made in the same manner as the signal processing circuit shown in FIG. Thereby, a wheel acting force measuring device for measuring the lateral force acting on the wheel can be configured.

Another embodiment of the stress detecting sensor is shown in FIGS. In these embodiments, the stress detection sensor is configured by attaching gauges 21 to 24 for strain measurement to a flat plate portion 52 formed on one end surface of a rod-shaped structure 51. Also in this case, a metal resistance wire strain gauge is suitably used as the gauge. Even if the rod-shaped structure 51 is made of plastic or the like, the axle 1 in which the sensor is embedded is used.
The same material may be used. Strain gauges 21, 22, 2
Both axes 3 and 24 are at 45 ° to the central axis 50
The axle 1 has a hole 2
Fixedly mounted inside. That is, it is attached and fixed by hammering, bonding, brazing, welding, shrink fitting or the like. Since the stress detection sensor according to this embodiment has the rod-shaped structure, there is an advantage that the position and the direction of the strain gauge can be easily set as desired when the stress detection sensor is embedded and fixed in the hole 2. In particular, in the configuration shown in FIG. 8, the width of the flat plate portion 52 is smaller than the diameter of the rod-shaped structure 51. Therefore, this stress detection sensor 3
When the flat plate portion 52 is embedded and fixed in the hole 2, it is possible to prevent the flat plate portion 52 from being deformed by twisting or the like due to rotation or the like, thereby giving extra strain or damaging the flat plate portion 52.

FIG. 9 is an enlarged view of the hole 2 provided in the axle. In this embodiment, two stress detection sensors 3 shown in FIG. 4 are used. One stress detection sensor 3 is disposed on the center axis of the axle. X,
It is placed so that the y and z directions are the vertical direction 11, the traveling direction 9 of the wheels, and the axle direction 10, respectively. By connecting the sets of strain gauges 21 to 24 and 21 to 24 of each stress detection sensor 3 in the same manner as the signal processing circuit shown in FIG. 3, the driving torque or the brake acting on the wheels together with the road surface frictional force. Brake torque when the device operates can be output. If the arithmetic circuit 47 calculates the sum of the output signals of the two amplifier circuits 41 and 44, the road surface frictional force is obtained, and if the difference is calculated, the above torque is obtained.

FIG. 10 shows another embodiment for measuring the road surface frictional force, in which an amplifying circuit 41 is embedded in a hole 2 together with a stress detection sensor 3 arranged on the center axis of an axle. . Embedding the amplifier circuit 41 in the hole 2 can be realized by current circuit integration technology. By arranging the amplifier circuit 41 near the stress detection sensor 3, an output signal with less noise can be obtained through the signal line 53.

FIG. 11 shows a horizontal axle with holes,
As in the case of (1), the amplification circuit 41 is embedded in the hole together with the stress detection sensor 3.

FIG. 12 shows a device for measuring driving torque or braking torque acting on wheels together with road surface frictional force using two stress detecting sensors 3. An example in which the processing circuit 54 is embedded in a hole together with the stress detection sensor 3 is shown. Reference numeral 55 denotes an output signal line of the signal processing circuit 54. In addition, by using a semiconductor strain gauge, it is also possible to integrate the stress detection sensor, the amplifier circuit, and the arithmetic circuit and bury it in the hole.

FIG. 12 shows an example in which the hole 2 for inserting the stress detection sensor 3 is provided along the vertical direction 11, but the direction of the hole 2 may be arbitrary, for example, the traveling direction of the wheel. 9 may be provided along the horizontal direction. FIG. 13 shows a configuration provided along the axle direction 10.
Further, the position of the hole is not limited to the position of the knuckle as in the case of FIG.
In the embodiment shown in FIG. 13, the same type of stress sensor shown in FIG. 7 or FIG. 8 has an advantage that it can be used both as a road surface frictional force detecting device and a vertical drag detecting device simply by changing the orientation of the sensor. Have.

FIG. 14 shows still another embodiment of the wheel acting force measuring device. Also in this embodiment, as an example, an axle of a non-drive wheel of an automobile having a strut type suspension structure often used in a passenger car,
A metal resistance wire strain gauge as a stress detection sensor is attached as specified. This embodiment is configured to measure the road surface frictional force as the wheel acting force.

A hole 2 is provided from the upper surface and the lower surface of the axle (knuckle in this example) so that their central axes are aligned with each other along a direction 11 perpendicular to the road surface and intersect with the center line of the axle. . The diameter of the hole 2 is, for example, 5 to 10 mm.
Degree is fine. It is desirable that the bottom surface of each hole 2 is as close as possible to the center line of the axle. For example, the distance between the bottom surfaces near the center line of the axle may be about 1 mm. The hole 2 provided from the upper surface is located above the center line of the axle, and the hole 2 provided from below is located below the center line of the axle. A position where the magnitude of the tensile or compressive strain due to bending deformation caused by bending becomes the same at each bottom surface, or a position where the magnitude of the shear strain due to torsional deformation caused by brake torque at the time of brake operation becomes the same at each bottom surface It is desirable that

A metal resistance wire strain gauge is attached to each of the bottom surfaces in the following manner. Four strain gauges are prepared, and two strain gauges are attached to each bottom face. All strain gauges are attached so that their axes are at 45 ° to the central axis direction 10 of the spindle. And these strain gauges 21 to
24 is assembled in a bridge circuit as shown in the signal processing circuit of FIG.

A shear strain is generated at each of the bottom surfaces of the above holes due to the road surface frictional force acting on the wheels. These strain gauges sense this shear strain. The amplifier circuit 41 outputs a voltage signal proportional to the shear strain, that is, proportional to the road surface frictional force. Since the hole 2 is drilled and the above-mentioned shear strain is sensed near the center line of the axle, crosstalk to the output signal due to the above-mentioned bending deformation and torsion deformation is combined with the fact that the bridge is assembled. It can be suppressed as low as possible. That is, an accurate road surface friction force measuring device is realized. By filling the hole 2 with a synthetic resin such as an epoxy resin or other materials, the strain gauges 21 to 24 can be protected from the outside.

FIG. 15 shows still another embodiment of the wheel acting force. In this embodiment, the normal reaction is measured as the wheel acting force. Also in the present embodiment, as an example, a metal resistance wire strain gauge is attached as a strain measurement gauge to an axle of a non-driven wheel of an automobile having a strut type suspension structure. As shown in the figure,
From both sides of the axle 1 (knuckle in this example), the respective central axes are aligned with each other along the traveling direction 9 of the wheels,
Moreover, it is desirable that a hole be provided so as to cross the center line of the axle. The diameter of the hole may be, for example, about 5 to 10 mm, similarly to the above-described road surface friction force measuring device. The bottom surface of each hole is preferably provided near the center line of the axle. For example, the distance between the bottom surfaces near the center line of the axle may be about 1 mm. The hole provided from the front side and the center line of the axle are located forward, and the hole provided from the back side is located behind the center line of the axle. The position where the magnitude of the tensile or compressive strain caused by the bending deformation caused by the normal force is the same on each bottom surface, or the magnitude of the shear strain caused by the torsional deformation caused by the brake torque when the brake is applied is the same on each bottom surface It is desirable that it is a holding position.

A metal resistance wire strain gauge is attached to each of the above bottom surfaces in the following manner. Four strain gauges are prepared, and two strain gauges are attached to each bottom face. Each strain gauge is attached so that its axis is at 45 ° to the direction 11 perpendicular to the road surface. And these sets of strain gauges 21 to 2
4 is assembled into a bridge as shown in the signal processing circuit of FIG.
Connected to amplifier circuit 41. Due to the normal force acting on the wheels from the road surface, in-plane shear strain occurs at each of the bottom surfaces of the holes. These strain gauges sense this shear strain. The amplification circuit 41 outputs a voltage signal proportional to the shear strain, that is, proportional to the normal force. Since the hole 2 is formed and the shear strain is sensed near the center line of the axle, crosstalk to an output signal due to bending deformation and torsion deformation can be suppressed as low as possible. That is, an accurate vertical drag measuring device is realized. Further, by filling the hole 2 with a synthetic resin such as an epoxy resin or other materials, the strain gauge can be protected from the outside.

The road surface friction force measuring device shown in FIG.
By combining with the vertical drag measuring device shown in (1), a wheel acting force measuring device for measuring a road surface friction coefficient can be constituted. For the same reason as described above for the case of configuring the road friction force measuring device and the case of configuring the vertical drag measuring device, the wheel acting force measuring device has high accuracy in which the crosstalk is suppressed as low as possible. .

[Brief description of the drawings]

FIG. 1 is a partially transparent perspective view showing an embodiment of a wheel acting force measuring device according to the present invention.

FIG. 2 is a partially transparent perspective view showing an example of a stress detection sensor used in the wheel acting force measuring device of the present invention.

FIG. 3 is an explanatory diagram of an example of a signal processing circuit of the wheel acting force measuring device according to the present invention.

FIG. 4 is a partially transparent perspective view showing another example of the stress detection sensor used in the wheel acting force measuring device of the present invention.

FIG. 5 is an explanatory diagram of another example of the signal processing circuit of the wheel acting force measuring device of the present invention.

FIG. 6 is a partially transparent perspective view showing still another example of the stress detection sensor used in the wheel acting force measuring device of the present invention.

FIG. 7 is a partially transparent perspective view showing another embodiment of the wheel acting force measuring device of the present invention.

FIG. 8 is a partially transparent perspective view showing still another embodiment of the wheel acting force measuring device of the present invention.

FIG. 9 is a perspective view showing an embodiment in which a plurality of stress detection sensors are used so that a braking torque or a driving torque other than a road surface friction force can be measured as a wheel acting force.

FIG. 10 is a perspective view showing an embodiment in which a signal processing circuit and a stress detection sensor are embedded in the same hole in a case where a road surface friction force is measured as a wheel acting force.

FIG. 11 is a perspective view of an embodiment in which a signal processing circuit and a stress detection sensor are embedded in the same hole in a case where a road surface friction force is measured as a wheel acting force, and the hole is provided horizontally. It is.

FIG. 12 shows a configuration in which a plurality of stress detection sensors are used so that a brake torque or a driving torque can be measured in addition to a road surface friction force as a wheel acting force; FIG. 3 is a perspective view showing the embodiment in which the implant is performed.

FIG. 13 is a partially transparent perspective view showing another example of the hole in which the stress detection sensor is embedded and fixed in the wheel acting force measuring device of the present invention.

FIG. 14 is a partially transparent perspective view showing another embodiment of an installation state of a stress detection sensor in a device configured to measure a road surface friction force as a wheel acting force.

FIG. 15 is a partially transparent perspective view showing another embodiment of a state where a stress detection sensor is installed in a device for measuring a normal force as a wheel acting force.

[Explanation of symbols]

 Reference Signs List 1 axle 2 hole 3 stress detection sensor 4 filler (separation material) 5 center axis of axle 7 wheel 8 electric signal line of stress detection sensor 9 wheel traveling direction 10 axle direction 11 vertical direction 21 to 24 strain gauge 31 to 34 strain Gauge 41 Amplifier circuit 43 Amplifier 44 Amplifier circuit 46 Amplifier 47 Operation circuit

Claims (15)

(57) [Claims] 1. A wheel acting force configured to embed and fix a stress detection sensor provided with a strain gauge on or near an axle of a vehicle to detect a horizontal shear stress or a vertical shear stress acting on the axle. In the measurement and detection device, the stress detection sensor is arranged such that the strain gauge is located on or near a stress center axis near the axle or the axle so as to eliminate or reduce the influence of the shaft torque acting on the axle. A wheel processing force measurement device, wherein the detection output of the stress detection sensor is processed by a signal processing circuit. 2. The wheel acting force measuring device according to claim 1, wherein the stress detection sensor is embedded and fixed in an axle or a hole provided near the axle. 3. The wheel force measuring device according to claim 2, wherein the stress detection sensor is embedded and fixed in the hole so as to be joined to an inner wall surface thereof. 4. The stress detection sensor is embedded and fixed in the hole via an isolating material, and the isolating material fills a gap between the stress detection sensor and an inner wall surface of the hole,
Joining the stress detection sensor and the inner wall surface,
The wheel acting force measuring device according to claim 2. 5. A plurality of said holes are provided at or near an axle of a vehicle, and said stress detection sensors are embedded and fixed in each of said holes, and a signal processing circuit processes a signal of each stress detection sensor. 5. A method according to claim 2, wherein a specific stress is taken out.
The wheel force measuring device according to any one of the above. 6. The stress detection sensor includes a sensor for detecting a horizontal shear stress acting on an axle and a sensor for detecting a vertical shear stress acting on an axle. The wheel acting force measuring device according to any one of claims 1 to 5, wherein the detected signal is processed by the signal processing circuit to extract a road surface friction coefficient. 7. The wheel acting force measuring device according to claim 1, wherein said signal processing circuit is embedded in an axle or in the vicinity of an axle together with said stress detection sensor. 8. The wheel acting force measuring device according to claim 1, wherein the stress detecting sensor has a structure in which a strain gauge is integrated on or near the surface of the base. 9. The wheel acting force measuring device according to claim 8, wherein the substrate has a cubic shape, and a strain gauge is integrated with a surface of the substrate to constitute the stress detection sensor. 10. The wheel operation according to claim 8, wherein the substrate has a rod shape, and a strain gauge is integrated with a flat plate provided at one end thereof to constitute the stress detection sensor. Force measuring device. 11. The wheel acting force measurement according to claim 8, wherein the substrate is a semiconductor substrate made of ceramic or silicon, and a strain gauge is integrated with the semiconductor substrate to constitute the stress detection sensor. apparatus. 12. A strain gauge in the stress detection sensor, wherein the strain gauge is disposed so as to intersect at about 45 ° with a stress center line of the axle and / or a line perpendicular to the stress center line. Item 12. The wheel force measuring device according to any one of Items 1 to 11. 13. A main stress detection sensor, wherein a stress detection sensor buried and fixed such that a strain gauge is located on or near a stress center line near the axle or near the axle is provided as a main stress detection sensor. A sub-stress detection sensor for detecting brake torque is provided near the detection sensor, and a stress signal such as a brake torque is obtained from an output signal of the main stress detection sensor by processing these stress detection signals by a signal processing circuit. A wheel acting force measuring device characterized in that it is eliminated or reduced. 14. A wheel acting force measuring device comprising a hole provided in an axle or in the vicinity of an axle, a stress detection sensor having a strain gauge embedded therein and fixed in the hole, and configured to detect a force acting on the axle. The stress detection sensor may be formed by attaching a strain gauge to the surface of the base or embedding the strain gauge near the surface of the base, and may be embedded and fixed in the hole via an isolating material. A wheel acting force measuring device, wherein a detection output of a sensor is processed by a signal processing circuit. 15. The signal processing circuit according to claim 1, wherein the signal processing circuit includes a bridge circuit of the stress detection sensor, an amplification circuit in addition to the bridge circuit, or an arithmetic circuit in addition thereto. 15. The wheel acting force measuring device according to any one of 1 to 14.