JP2006226778A - Ground pressure distribution measuring device of tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately measure tire ground pressure distribution under various conditions in high speed rotation or the like. <P>SOLUTION: This measuring device comprises a drum retaining section 15 for retaining a drum 11 rotatably about the axial center P1, and a tire retaining section 17 for supporting a test tire 16 rotatably about the axial center P2 while radially pressing the test tire 16 to the inner peripheral surface 12a (or outer peripheral surface) of a drum body 12. A plurality of micro pressure sensors 25 are buried on the inner peripheral surface 12a side (or outer peripheral surface side) of the drum body 12 with which the test tire 16 comes into contact, and the test tire 16 is rolled on the micro pressure sensors 25 to measure the tire ground pressure distribution at any rotation speed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a contact pressure distribution measuring apparatus for tires of automobiles and the like, and more specifically, to measure a contact pressure distribution by bringing a test tire into contact with an inner peripheral surface or an outer peripheral surface of a rotating drum of the measuring apparatus.

  As a conventional method for measuring the contact pressure distribution of a tire, a pressure mat and a pressure sensor are arranged on the table of the measuring device, and the test tire is grounded on the table to measure the contact pressure distribution, and the pressure mat on the actual road surface. There is a method of measuring by passing an actual vehicle on the surface.

As an example of the pressure mat, as shown in FIG. 9, there is a sheet body 1 in which a back surface of a base 1a having a uniform thickness is a flat surface 1b and elastic protrusions 1c are regularly distributed on the surface (Japanese Patent Laid-Open No. Hei. No. 3-226636).
Specifically, the sheet body 1 is disposed with the elastic protrusions 1c in contact with the grounding body 2 made of a transparent body, and the tire 3 is pressed against the grounding body 2 from the flat surface 1b side of the sheet body 1. The deformation state of the elastic protrusion 1c is observed through the grounding body 2 and the pressure distribution is measured.

  As a method of measuring the contact pressure distribution on the table using the pressure sensor, a film-like sensor sheet in which the sensors are arranged in a grid is laid on the table, and the rotating body is rolled on the sheet. As shown in FIG. 10, a measuring plate 7 incorporating a pressure sensor 8 is attached to a traveling flat plate 6 on which the rotating body 5 travels, and the position of the pressure sensor 8 and the measuring point 9 of the rotating body 5 are There is a method of measuring by rotating the rotating body 5 on the measurement plate 7 after adjusting so as to match (refer to Japanese Patent Laid-Open No. 3-78636).

However, the measurement on the table of the measuring device can set the moving speed of the rotating body only to an extremely low speed of about 2 km / h, and therefore cannot measure the contact pressure distribution at an arbitrary speed, particularly at a high speed.
Also, when measuring by running an actual vehicle on the sensor embedded in the actual road, the traveling speed is limited to about 100 km / h, and it is impossible to measure at ultra high speed from 100 km / h to 300 km / h. It is. Therefore, there is a problem that not only tire data cannot be acquired during high-speed driving, but also various phenomena that can occur during high-speed driving of an automobile such as a standing wave phenomenon and a hydroplaning phenomenon cannot be verified.

JP-A-3-226636 JP-A-3-78636

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to measure a tire contact pressure distribution during high-speed running with a test and measurement device.
Another object of the present invention is to make it possible to test and measure the contact pressure distribution of a tire under various conditions such as running on a wet road, braking, and cornering with high accuracy.

In order to solve the above problems, the present invention comprises a drum having a cylindrical shape and a smooth surface, and drum holding means for holding the drum so as to be rotatable around a horizontal axis.
Tire holding means for supporting the test tire so as to be rotatable about a horizontal axis while bringing the outer peripheral surface of the test tire into contact with the inner peripheral surface or the outer peripheral surface of the drum with a required load;
Rotation driving means for rotating the drum and / or the tire holding means;
A plurality of ultra-small pressure sensors embedded on the outer peripheral surface side or the inner peripheral surface side of the drum with which the test tire contacts at least on the same axis;
Contact pressure distribution measurement of a tire, wherein the contact pressure distribution of the tire is measured by detecting the contact pressure of the test tire rolling on the inner or outer peripheral surface of the drum with the pressure sensor. The device is provided.

The ultra-small pressure sensor used in the present invention described above refers to a width of an exposed surface for detecting a load load of about 2 mm or less, preferably about 1 mm or less.
As described above, the measuring device of the present invention is a drum type, and an ultra-small pressure sensor is embedded in the inner peripheral surface of the drum or the outer peripheral surface of the drum, and a test tire is rolled on the ultra-small pressure sensor. The tire contact pressure is detected by the pressure sensor.
According to this method, by increasing the rotational speed of the drum or the test tire, it is possible to measure the contact pressure distribution of the tire during high-speed / ultra-high speed running. Therefore, it becomes possible to verify various phenomena such as a standing wave phenomenon that could not be verified at low speed rotation as in the prior art. Moreover, since the change in the contact pressure corresponding to the speed change can be quantitatively examined, the difference in the contact pressure based on the difference in tire specifications can be verified.

Furthermore, compared to actual vehicle tests, conditions such as speed and entry angle can be adjusted accurately, and the contact pressure distribution during high-speed rotation and changes in the pressure distribution within a very short time before exiting from the contact state, etc. Can also be analyzed.
Thus, since various tire data with high accuracy and effectiveness assuming various conditions of the tire can be acquired, it is possible to make a significant contribution to improving tire performance.

The tire contact pressure distribution measuring device of the present invention includes the following types.
In the first type, the rotation driving means is connected to the drum holding means to rotate the drum, while the tire holding section rotatably holds the test tire freely and rotates the tire on the drum to be rotated. The type to be made.
The second type is a type in which the tire holding portion is provided with a rotation driving means for rotating the tire, while the drum is rotatably held freely and the drum is rotated with respect to the actual rotation of the tire.
The third type is a type that has both a tire holding part and a drive part that rotationally drives both the drum and can measure the contact pressure at the time of tire slip by changing the rotational speed of the drum and the rotational speed of the test tire. It is said.

It is preferable that the first type drum among the types is provided with the rotation driving means for rotating the drum at a predetermined rotation speed, and the test tire is driven to rotate by rotation of the drum.
In other words, by rotating the drum side, the test tire brought into contact with the required load can be easily driven and driven to rotate along the drum surface, but the test tire side is driven to rotate and the drum side is driven. It is not easy to do so, and the rotational driving force of the test tire must be set large, and the contact load of the test tire on the drum side must be increased and the rotational driving force of the test tire must be set large.

Furthermore, an axis angle adjusting means for making the axis of the test tire parallel or inclined with respect to the axis of the drum and / or a load load adjusting means for the drum of the test tire may be provided.
When the axis of the test tire is tilted with respect to the drum axis by the axis angle adjusting means, it is possible to assume the cornering of the tire, and in that case, the contact load on the drum of the test tire is measured in the test tire axial direction. By making the difference, it is possible to accurately approximate the behavior of the tire during cornering.

The drum is closed at one end of a cylindrical drum body and provided with a tire insertion opening at the other end, and the test tire is inserted into the drum through the opening. The test tire is preferably contacted with the required load.
When the inside drum type is used in this way, a thin water film is stretched in the drum, so that the contact pressure distribution assuming the running on a wet road surface can be measured, so that the hydroplaning phenomenon can be verified. Similarly, by icing the drum inner peripheral surface, the contact pressure distribution on the icing road surface can be measured.

It is preferable that the width of the drum in the axial direction is larger than the width of the test tire in the axial direction, and the pressure sensors are arranged side by side over the entire width of the drum.
With this configuration, it is possible to accurately grasp the contact pressure distribution of the entire width of the tire at the time of one passage.
More preferably, the micro pressure sensors are embedded not only in a single line in the axial direction but also in a plurality of lines in the circumferential direction of the drum, and the sensors are embedded in a wider range than the ground contact length of the tire. As a result, it is possible to measure the pressure distribution of the entire contact surface, and further, the pressure distribution of the entire contact surface corresponding to the contact shape, and the tire performance can be analyzed in more detail.

The interval between adjacent micro pressure sensors is preferably not less than half the width of the sensor and not more than the width of the sensor. This is because the sensors interfere with each other when they are closer than half the width of the sensor, and the accuracy of data decreases when they are separated from the width of the sensors.
For example, when the width of the pressure sensor is 0.8 mm, the width between the sensors is in the range of 0.4 mm to 0.8 mm. Especially when the width is 0.4 mm, many sensors can be arranged, and more accurate pressure distribution is measured. it can.

As the micro pressure sensor, a commercially available optical fiber micro pressure sensor can be suitably used.
Optical fiber ultra-compact pressure sensor, which is an optical sensor, is not affected by EMI / RFI, has excellent safety at high temperatures up to 350 ° C, and transmits detection signals to the connected measuring means with high accuracy. There are advantages such as being able to.

  As described above, according to the present invention, it is possible to acquire and analyze a variety of tire data with high accuracy assuming various conditions such as when traveling at high speed or traveling on a wet road surface. In particular, it is possible to verify various phenomena such as standing wave phenomenon and hydroplaning phenomenon that can occur during ultra-high speed driving, and differences in phenomena due to tire specifications. As a result, it can contribute to the design of the tire and can greatly contribute to the improvement of the tire performance.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show an inside drum type tire ground pressure distribution measuring apparatus 10 according to a first embodiment of the present invention.

  The measuring device 10 includes a cylindrical drum 11, a drum holding means 15 that rotatably holds the drum 11 around a horizontal axis P1, a rotation driving device 18 attached to the drum holding means 15, Test tire holding means (hereinafter referred to as tire holding means) that supports the test tire 16 so as to be rotatable about the horizontal axis P2 while bringing the outer peripheral surface of the test tire 16 into contact with the inner peripheral surface of the drum 11 with a required load. 17). The tire holding means 17 is not provided with a rotational drive device, and the test tire 16 is configured to be driven and rotated by the drum 11 that is rotationally driven.

The drum 11 is made of steel, and includes a drum main body 12 having a smooth inner peripheral surface, a disk-shaped back wall 13 that closes one end surface of the drum main body 12, and an opening 14 on the other end surface. An inner flange portion 14 a is provided along the periphery of the opening 14.
The drum holding means 15 is provided behind the back wall 13 of the drum 11, and the tip of a support rod 52 that is rotatably supported on a base 50 via a bearing 51 is fixed to the back wall 13. Support. The other end of the support rod 52 is connected to the output shaft of the motor 18 of the rotational drive means mounted on the base 50, and the rotational speed of the drum 11 can be adjusted by adjusting the rotational speed of the motor 18.

  The tire holding means 17 is provided on the opening side of the drum body 12, and is provided with a support leg 20 slidably provided on the base 19 so as to be slidable in the front-rear direction indicated by arrows, and a lifting cylinder 40 is provided on the support leg 20. And a tire support shaft 22 connected to the lower side of the support arm 21 in the horizontal direction. The tire support shaft 22 supports the test tire 16 arranged in the vertical direction, and the test tire 16 is arranged in the drum body 12 so as to be rotatable in the vertical direction. The test tire 16 is brought into pressure contact with the inner peripheral surface 12a of the drum body 12, and the load to be applied is adjusted by moving the support arm 21 up and down by the lifting cylinder 40. The test tire 16 is a tire with a wheel rim and filled with a required air pressure, and the support shaft 22 is inserted into a shaft hole of the wheel rim.

  As shown in FIG. 2, the width W1 of the drum body 12 in the direction of the axis P1 is larger than the width W2 of the test tire 16 in the direction of the axis P2. On the inner peripheral surface 12a side of the drum body 12, a large number of ultra-small pressure sensors 25 are embedded in a straight line in the direction of the axis P1 with an interval L1 over the entire width W1. Also in the circumferential direction, a plurality of rows are embedded at intervals L1 over the required length L2.

In the present embodiment, the optical fiber microminiature sensor shown in FIG. 3 is used as the microminiature pressure sensor 25. Each pressure sensor 25 is connected to the tip of a cable 27. As shown in FIG. 4, the sensor 25 has a rectangular parallelepiped shape, the contact surface 25 a exposed to the inner peripheral surface of the drum body 12 is a square, and the embedded portion 25 b in the drum body 12 is elongated.
In this embodiment, the exposed surface has a square shape of 0.8 mm square and a depth of 10 mm.

Specifically, a plurality of cable holes 22 are provided in the thickness direction of the drum body 12, cables 27 connected to the pressure sensors 25 are inserted into the cable holes 22, and all the cables 27 are connected to the outer periphery of the drum body 12. Derived to the side and connected to the measuring device 100 that measures the ground pressure distribution by the detection signal from the sensor.
The pressure sensor 25 is arranged so that the contact surface 25 a forms a flat surface that is continuous with the surface of the inner peripheral surface 12 a of the drum body 12. The periphery of the pressure sensor 25 arranged in this way is fixed by a resin 23 filled in a recess 12b formed in advance in the drum body 12.

The interval L1 between the embedded pressure sensors 25 is 0.5 mm in this embodiment. Further, the length L2 in the drum circumferential direction of the embedded region of the pressure sensor 25 is set to be longer than the contact length of the test tire 16.
The cable 27 is provided with a measuring means (computer) 55 that receives a detection signal from the pressure sensor 25 and measures the contact pressure distribution of the test tire based on the detection signal, and the measurement means 55 includes a measurement result display means 56. It is attached.

When measuring the contact pressure distribution of the test tire in the tire contact pressure distribution measuring apparatus 10 having the above configuration, first, the test tire 16 is held by the tire holding means 17 and inserted into the drum through the opening 14 of the drum 11. Next, the test tire 16 is brought into contact with the inner peripheral surface of the tire body 12 with a required load by the lifting cylinder 40.
In this state, the motor 18 is rotationally driven at a required rotational speed to rotate the drum 11.
The test tire 16 elastically brought into contact with the inner peripheral surface by the rotation of the drum 11 follows the reverse rotation direction, and the rotation speed of the drum 11 and the rotation speed of the test tire 16 are in a proportional relationship. Therefore, when the drum 11 is rotated at a high speed, the test tire 16 is also rotated at a high speed, and a state of traveling at a high speed on the road surface can be assumed.

Thus, the contact pressure distribution can be measured with high accuracy by the pressure sensor 25 while rotating the test tire 16 at an arbitrary speed. In other words, the electrical resistance of the pressure sensor 25 changes with the load applied, and the pressure distribution and magnitude can be measured by the measuring means 55.
Accordingly, it is possible to measure the tire contact pressure distribution during high-speed rotation or ultra-high-speed rotation, and thus various phenomena such as a standing wave phenomenon can be verified.

In particular, in this embodiment, since the contact surface 25a of the ultra-compact pressure sensor 25 is embedded in a wide range so as to contact the entire ground contact surface of the test tire 16, detailed data analysis is possible.
Further, since the interval L1 between the adjacent contact surfaces 25a is set to 0.5 mm which is not more than the width 0.8 mm of the contact surface 25a and the width is not less than 0.4 mm, the pressure sensor portions 25 may interfere with each other. In addition, since the data is arranged densely, the data accuracy can be maintained at a high level.

  Further, since the drum 11 is provided with the back wall 13 and the inner flange portion 14a, water can be accumulated in the drum 11 to form a thin water film. Therefore, it is possible to measure the contact pressure distribution during high-speed traveling on a wet road surface, and to verify the hydroplaning phenomenon. Furthermore, if an icing part is provided on the inner peripheral surface of the drum 11, the contact pressure distribution of the tire at the icing part can also be measured.

  5 and 6 show a drum-type tire contact pressure distribution measuring apparatus 30 according to a second embodiment of the present invention.

  The drum-type tire contact pressure distribution measuring device 30 includes a drum holding portion 35 that holds a cylindrical drum 31 having a smooth surface rotatably around an axis P3, and a test tire 36 that is rotatable around an axis P4. And a tire holding portion 37 for holding the tire, and the contact pressure distribution is measured by rolling the test tire 36 so as to be in contact with the outer peripheral surface 31 a of the drum 31.

  Specifically, the drum holder 35 is equipped with a rotation drive device 38 having a rotation speed control means for the drum 31, but the tire holder 37 is not provided with a rotation drive device, and the test tire 36 is rotated by the rotation of the drum 31.

  The tire holding portion 37 is supported on the base 39 via a cylinder 40 ′ that raises and lowers the test tire 36 in the contact / separation direction with respect to the outer peripheral surface 31 a of the drum 31. The cylinder 40 'allows the test tire 36 to be pressed and brought into contact with the outer peripheral surface 31a of the drum 31 in the radial direction to apply a load, and the load to be applied can be adjusted.

  As shown in FIG. 6, the width W3 of the drum 31 in the direction of the axis P3 is larger than the width W4 of the test tire 36 in the direction of the axis P4. On the outer peripheral surface 31a side of the drum 31, a large number of ultra-small pressure sensors 25 are embedded in a line in the direction of the axis P3 over the entire width W3. Since this ultra-small pressure sensor 25 is the same as the pressure sensor 25 of the first embodiment, the same reference numerals are given and description thereof is omitted.

  Specifically, the contact surface 25a of the pressure sensor 25 is embedded on the outer peripheral surface 31a side of the drum 31 in a row at intervals of 0.5 mm while being exposed so that the outer peripheral surface 31a is flat. The periphery of the pressure sensor 25 arranged in this manner is hardened with a resin 43 filled in a recess 31b formed in advance in the drum 31. The cable 27 of each pressure sensor 25 is led out to the inner peripheral side of the drum 31 and connected to a data reading device (not shown).

  In the present embodiment, the micro pressure sensors 25 are arranged only in a row in the width W3 direction of the drum 31. However, since the drum 31 is wider than the test tire 36, the contact pressure of the entire width of the tire at the time of one pass. The distribution can be measured accurately.

FIG. 7 shows the third embodiment, which is different from the first embodiment in that drive means for rotating the test tire 16 at an arbitrary rotational speed is provided on the tire holding means 17 side. Other configurations are the same, and a motor for rotating the drum 11 is provided.
That is, a motor 60 is attached to the support arm 21, and the support shaft 22 is rotationally driven by the motor 60 at a required rotational speed.
Thus, by rotating both the drum 11 and the test tire 16 and making the rotation speed different, the tire can be slipped, and the contact pressure distribution of the tire at the time of the slip is also measured. Can do.

FIG. 8 shows the fourth embodiment. The difference from the first embodiment is that the axis of the tire is inclined in the horizontal direction with respect to the axis of the drum so that the test tire can be brought into contact with the drum. Means are provided to measure the ground pressure distribution in a state where the tire does not travel linearly but is inclined with respect to the traveling direction and has a slip angle.
Specifically, the upper and lower sandwiching plate portions 21a and 21b are projected from the support arm 21, inserted between the sandwiching plate portions 21a on the proximal end side of the support shaft 22, and the upper and lower sandwiching plate portions 21a and 21b. It is supported by a pin 49 with the support shaft 22 sandwiched therebetween. The pin 49 is fixed to the support shaft 22 and is rotatably passed through the upper and lower sandwiching plate portions 21a and 21b. By rotating the rotation operation plate 49a provided at one end of the pin 49, the support shaft is interposed via the pin 49. 22, the test tire 16 held by the support shaft 22 is rotated so that the axis P5 can be inclined with respect to the axis P6 of the drum 11 at an arbitrary angle.
In this way, the tire contact pressure distribution during cornering can be measured by inclining the axis of the test tire with respect to the axis of the drum 11 and adjusting the slip angle.

Further, when the tire axis is tilted in the vertical direction with respect to the tire axis and the drum axis arranged in the horizontal direction by the axis angle adjusting means, the camber angle of the test tire with respect to the drum is adjusted. The ground pressure distribution can be measured.
It is also possible to measure the ground pressure distribution while simultaneously adjusting the slip angle and the camber angle.

1 is a front view of a tire ground pressure distribution measuring apparatus according to a first embodiment of the present invention. It is a principal part schematic perspective view of the tire ground-pressure distribution measuring apparatus shown in FIG. It is a top view of the microminiature pressure sensor shown in FIG. FIG. 3 is an enlarged perspective view of a main part of the drum body shown in FIG. 2. It is a top view of the tire ground pressure distribution measuring apparatus concerning a second embodiment of the present invention. It is a principal part schematic perspective view of the tire ground-pressure distribution measuring apparatus shown in FIG. It is a principal part enlarged front view which shows 3rd Embodiment. (A) is a principal part enlarged front view which shows 4th Embodiment, (B) is sectional drawing of (A). It is a figure which shows a prior art example. It is a figure of another prior art example.

Explanation of symbols

10, 30 Tire contact pressure distribution measuring device 11, 31 Drum 12 Drum body 15, 35 Drum holder 16, 36 Test tire 17, 37 Tire holder 25 Ultra-compact pressure sensor 25a Contact surface

Claims (8)

A drum having a cylindrical shape and a smooth surface;
Drum holding means for holding the drum rotatably about a horizontal axis;
Tire holding means for supporting the test tire rotatably around an axis in the horizontal direction while contacting the outer peripheral surface of the test tire with a required load with respect to the inner peripheral surface or the outer peripheral surface of the drum;
Rotation driving means for rotating the drum and / or the tire holding means;
A plurality of ultra-small pressure sensors embedded on the outer peripheral surface side or the inner peripheral surface side of the drum with which the test tire contacts at least on the same axis;
Contact pressure distribution measurement of a tire, wherein the contact pressure distribution of the tire is measured by detecting the contact pressure of the test tire rolling on the inner or outer peripheral surface of the drum with the pressure sensor. apparatus.   The tire ground contact pressure distribution measuring device according to claim 1, wherein the drum holding means includes the rotation driving means for rotating the drum at a predetermined rotation speed, and the test tire is driven to rotate by rotation of the drum.   The tire contact pressure distribution measuring device according to claim 1, further comprising a load load adjusting unit for a drum of the test tire.   The tire ground contact pressure distribution measuring device according to any one of claims 1 to 3, further comprising: an axis angle adjusting means for making the axis of the test tire parallel or inclined with respect to the axis of the drum.   The drum is closed at one end of a cylindrical drum body and provided with a tire insertion opening at the other end, and the test tire is inserted into the drum through the opening. The tire ground contact pressure distribution measuring device according to any one of claims 1 to 4, wherein the test tire is configured to contact with a required load.   The width of the drum in the axial direction is larger than the width of the test tire in the axial direction, and the pressure sensors are arranged side by side across the entire width of the drum. The tire contact pressure distribution measuring device according to any one of the preceding claims.   The tire contact pressure distribution measuring apparatus according to claim 6, wherein an interval between the adjacent pressure sensors is not less than half of the sensor width and not more than the sensor width.   The tire pressure contact pressure distribution measuring device according to any one of claims 1 to 7, wherein the pressure sensor is an optical fiber microminiature pressure sensor.

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