JP2011203124A - Tire shape measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire shape measuring device for accurately measuring the deformation state of a block of a tread part when the tire is actually in a rolling state on a road surface.SOLUTION: A camera unit 13 is attached to the axle of a wheel while the wheel is rolled via a coupling means 17 having a cloth roller ring (bearing), and a block section of the tire 11 constituting the wheel is imaged. A laser displacement gauge 21 measures the distance to the road surface. A linear actuator 22 keeps the distance between the camera unit 13 and the road surface constant by using the measurement result of the laser displacement gauge 21.

Description

  The present invention relates to a tire shape measuring device, and more particularly, to a tire shape measuring device that measures a deformation state of a block of a tire tread portion during tire rolling.

It is extremely important in the development of tires to know the strain distribution, strain speed, slip speed, etc. of the tire by measuring the shape of the tire tread portion during rolling of the tire. Conventionally, a tire tread measuring device that reproduces the state of the tire contact surface during rolling of the tire and images the contact surface of the tread and analyzes the behavior of the tread upon contact from the imaged result to evaluate the performance of the tire. Is known (see Patent Document 1).
"Tire tread measuring device" is provided on the opposite side of the tire with the grounding plate having transparency and the grounding plate sandwiched by the tire, and irradiates the tire tread with the laser beam through the grounding plate. At the same time, an image of the tire tread is taken, and thereby three-dimensional data representing the deformed shape of the tread portion and tread groove of the tire tread in the ground deformation state is acquired.

JP 2009-139268 A

However, in the conventional “treading surface measuring device”, the measurement is performed by creating a state in which the tire rolls on the road surface in a laboratory equipped with the measuring device. It is difficult to accurately grasp the phenomenon that occurs in tires that are rolling on the road surface, and it is possible to accurately measure the deformation shape of the block in the tire tread when the tire is in a rolling state. could not.
The present invention has been made in view of such problems, and an object of the present invention is to accurately measure the deformation state of a tire block when the tire is actually in a rolling state on the road surface. It is providing the tire shape measuring device which can do.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a tire shape measuring apparatus for measuring a shape of a tire block, wherein the wheel is configured to be rollable and attached to an axle of the wheel, and the tire block portion constituting the wheel. An image pickup means for picking up images is provided.

  According to a second aspect of the present invention, there is provided a tire shape measuring apparatus for measuring a shape of a tire block, wherein the wheel is rollable and attached to an axle of the wheel, and an imaging means for imaging a tire block portion constituting the wheel. And a road surface distance measuring means for measuring a distance from the road surface, and a position changing means for keeping the distance between the imaging means and the road surface constant by using a result of the road surface distance measuring means.

  According to a third aspect of the present invention, there is provided a tire shape measuring apparatus for measuring a shape of a tire block, wherein the wheel is made rollable and attached to an axle of the wheel, and the tire block portion constituting the wheel is imaged first. Using the results of the imaging means, the second imaging means attached to the vehicle body and imaging the block portion of the tire, the road surface distance measuring means for measuring the distance to the road surface, and the road surface distance measuring means, Position changing means for keeping the distance between the second imaging means and the road surface constant is provided.

  According to a fourth aspect of the present invention, there is provided a tire shape measuring apparatus for measuring a shape of a tire block, wherein the wheel is made rollable and attached to an axle of the wheel, and the tire block portion constituting the wheel is imaged first. The distance between the first imaging means and the road surface is kept constant by using the results of the first imaging means, the first road surface distance measuring means for measuring the distance from the road surface, and the first road surface distance measuring means. A first position changing means; a second imaging means attached to the vehicle body for imaging the block portion of the tire; a second road surface distance measuring means for measuring a distance from the road surface; and the second road surface distance. And a second position changing means for keeping the distance between the second imaging means and the road surface constant, using the result of the measuring means.

According to the first invention, since the imaging means is attached to the axle, it is possible to accurately measure the deformation state of the tire block when the tire is actually in a rolling state on the road surface.
According to the second invention, the road surface distance measuring means and the position changing means are attached to the imaging means, the ground height is measured by the road surface distance measuring means, the measured ground height is input to the position changing means, and the imaging means is always used. Since it is controlled so as to be in a fixed position, even if there is deformation in the tire, the imaging means can always shoot the same part of the tire, and therefore the deformation state of the tire block can be accurately measured. .
According to the third and fourth inventions, the imaging means is attached to the vehicle body via the position changing means, and the tire block portion is photographed with two imaging means, thereby measuring the deformation state of the tire block more accurately. can do.

It is explanatory drawing which shows typically the structure of the tire shape measuring apparatus which concerns on 1st Example of this invention. It is explanatory drawing which expands and shows the structure of the tire shape measuring apparatus which concerns on a 1st Example. It is explanatory drawing of the camera unit which image | photographs a tire. It is explanatory drawing of a tire rolling state. It is explanatory drawing of a picked-up image. It is explanatory drawing which shows the structure of the tire shape measuring apparatus which concerns on a 2nd Example. It is explanatory drawing when the tire shape measuring apparatus which concerns on a 2nd Example is seen from the vehicle front. It is a flowchart explaining the operation | movement when controlling a linear actuator.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram schematically showing the configuration of a tire shape measuring apparatus according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram showing an enlarged configuration of the tire shape measuring apparatus according to the first embodiment. FIG. 3 is an explanatory diagram of a camera unit that photographs a tire, FIG. 4 is an explanatory diagram of a tire rolling state, and FIG. 5 is an explanatory diagram of a captured image.

  As shown in FIG. 1 and FIG. 2, the tire shape measuring device photographs a block of the tire 11 constituting the wheel W in a vehicle C that travels when the wheel W rolls on the road surface R. A camera unit 13 (imaging means) that images the road surface R together with the side block of the camera, a holding member 14 that positions the camera unit 13 on the side of the tire 11, and a camera unit 13 that is input from the camera unit 13. Based on the image data of the image, there is a measuring device 15 that measures the strain distribution, strain speed, slip speed, etc. of the tire when the tire 11 rolls on the road surface R.

  As shown in FIG. 3, the camera unit 13 includes two high-speed cameras 18 and two lighting equipments 19. When the vehicle W travels on the road surface R of the wheel W when the vehicle C travels, The tire shoulder surface, i.e., the outer surface 16a of at least one block 16 located on the outermost periphery of the tread, can be photographed together with the road surface R as the same screen. As described above, the wheel W is separated from the side of the outer surface and close to the road surface R, and the camera lens faces the outer surface 16a and the road surface R.

The high-speed camera 18 is, for example, a camera that can shoot several hundred to tens of thousands of high-speed images per second. Under the camera arrangement conditions, the high-speed camera 18 has shooting conditions necessary for obtaining image data to be output to the measuring device 15. In order to ensure, select the lens to be used by calculating the required depth of field. The illuminating equipment 19 is for illuminating the outer surface 16a of the block 16 and the road surface R to which the camera lens is directed to ensure brightness necessary for photographing.
When two high-speed cameras 18 are used, panorama shooting and panorama synthesis can be performed to obtain a high-resolution shooting that provides twice the resolution. However, if the necessary shooting conditions can be ensured, 1 You may shoot with a high-speed camera. The lighting equipment 19 may be omitted or may be one as long as the necessary brightness can be secured.

The holding member 14 is attached to the axle of the wheel W, and includes a first holding unit 14a that connects the camera unit 13, a second holding unit 14b that connects the first holding unit 14a and the wheel Ww of the wheel W, and a wheel. It has the 3rd holding part 14c which connects the axle of W and the 1st holding part 14a.
The third holding portion 14c has one end fixed to the axle of the wheel W to prevent the camera unit 13 itself from rotating, and is provided with a linear bush 20 at the other end of the third holding portion 14c. The 1st holding | maintenance part 14a is connected with the 3rd holding | maintenance part 14c via the linear bush 20, and can adjust an up-down position. The second holding portion 14b has one end attached to the first holding portion 14a and the other end attached to a connecting means 17 having a cross roller ring (bearing). The connecting means 17 rotates the wheel W. The wheel W is made movable and is attached to the wheel Ww of the wheel W, that is, the axle.

  Thus, since the holding member 14 is attached to the axle, the camera unit 13 can be positioned in an optimum direction corresponding to the turning displacement of the wheel W during the steering of the wheel W. Therefore, the vehicle C is traveling by the high-speed camera 18 disposed and held on the side of the wheel W with the shooting direction facing the outer surface 16a of the block 16 via the holding member 14 attached to the axle of the wheel W. When the wheel W rolls, as shown in FIG. 4, by constantly photographing the road surface contact state of the block 16 of the tire 11 in contact with the road surface R, for example, as shown in FIG. 5, the tire 11 is deformed. In addition, it is possible to observe the actual tire rolling state at a fixed point with a highly accurate measurement image that allows image analysis without being out of focus.

  When the high-speed camera is attached to the vehicle body, the high-speed camera cannot always photograph the same part of the tire during steering or braking. In the first embodiment, since the high-speed camera is attached to the axle via a bearing, the high-speed camera can photograph the same part of the tire even during steering or braking. In the first embodiment, since the high-speed camera is attached to the axle, it is not necessary to consider the displacement of the suspension.

  FIG. 6 is an explanatory view showing the configuration of the tire shape measuring apparatus according to the second embodiment, and FIG. 7 is an explanatory view when the tire shape measuring apparatus according to the second embodiment is viewed from the front of the vehicle. is there. In the second embodiment, the laser displacement meter 21 that measures the distance between the camera unit 13 (imaging means) and the road surface R is connected to the second holding portion 14b ′ that connects the first holding portion 14a and the wheel Ww of the wheel W. (Road surface distance measuring means) and the measurement data of the distance between the camera and the road surface obtained by the laser displacement meter 21, when the vehicle C travels, the camera unit 13 has a certain distance from the road surface R and has an optimum height. The holding linear actuator 22 (position changing means) is provided. The second holding portion 14b ′ having one end attached to the first holding portion 14a is attached to the connecting means 17 having a cross roller ring (bearing) via the linear actuator 22, and the connecting means 17 The wheel W is made rollable and is attached to the wheel Ww of the wheel W by the wheel nut 23, that is, the axle of the wheel W. The laser displacement meter 21 and the linear actuator 22 are connected to the measuring device 15 by a connection line (not shown), and the measuring device 15 controls the linear actuator 22 based on a signal from the laser displacement meter 21. A sequencer (software) is stored. Since other configurations are the same as those of the first embodiment, description of other configurations is omitted.

  FIG. 8 is a flowchart for explaining the operation when the linear actuator is controlled so that the camera unit has a certain distance from the road surface and has an optimum height. First, the height of the camera unit 13 is adjusted so that the high-speed camera 18 can photograph the outer surface 16a of one block 16 located on the outermost periphery of the tread as the same screen together with the road surface R (step S11). At this time, the height is measured by the laser displacement meter 21, and 0 point is set in the laser displacement meter 21 (step S12). Next, a filter is set in the sequencer so that the linear actuator 22 does not operate following the small unevenness of the road surface during rolling (step S13). When the laser displacement meter 21 measures the height from the road surface (step S14), the sequencer calculates the amount of change (difference) in height (step S15), and the change is not a small height change due to small unevenness on the road surface. If there is a large change in height, such as during braking, a command for position change is sent to the linear actuator 22 (step S16), and the linear actuator 22 operates based on the position change to optimize the camera unit 13. The height is adjusted (step S17).

  In the first embodiment, when the tire is deformed and the photographing position changes, the high-speed camera cannot always photograph the same part of the tire. In the second embodiment, a laser displacement meter and an actuator are attached to the camera unit, the actuator is attached to the axle via a bearing, the ground height is measured with the laser displacement meter, and the measured ground height is input to the actuator. Since the high-speed camera is controlled so as to be always at a fixed position, the high-speed camera can always photograph the same portion of the tire even if the tire is deformed.

  In the second embodiment, the camera unit is attached to the wheel axle via the actuator, but the camera unit may be attached to the vehicle body via the actuator. In other words, a camera unit is attached to one end of a linear actuator equipped with a laser displacement meter, the other end of the linear actuator is fixed to the vehicle body, the ground height is measured with a laser displacement meter, and the measured ground height is input to the linear actuator. Thus, the camera unit may be controlled so as to be always at a fixed position. Further, a mode in which such a camera unit is attached to the vehicle body via an actuator and a mode of the first embodiment or the second embodiment described above are combined to photograph the block portion of the tire with two camera units. You may do it. By photographing the tire block with two camera units, the deformation state of the tire block can be measured more accurately.

DESCRIPTION OF SYMBOLS 11 Tire 13 Camera unit 14 Holding member 14a 1st holding | maintenance part 14b 2nd holding | maintenance part 14c 3rd holding | maintenance part 15 Measuring apparatus 16 Block 16a Outer side surface 17 Connection means 18 High-speed camera 19 Illumination equipment 20 Linear bush 21 Laser displacement meter 22 Linear Actuator 23 Wheel nut C Vehicle R Road surface W Wheel Ww Wheel

Claims (4)

In a tire shape measuring device that measures the shape of a tire block,
A tire shape measuring apparatus comprising: an imaging unit configured to image a block portion of a tire constituting the wheel, the wheel being configured to be rollable and attached to an axle of the wheel. In a tire shape measuring device that measures the shape of a tire block,
An imaging means for imaging a block portion of a tire that is mounted on a wheel axle so that the wheel can roll, and that constitutes the wheel;
Road surface distance measuring means for measuring the distance to the road surface;
Using the result of the road surface distance measuring means, a position changing means for keeping the distance between the imaging means and the road surface constant,
A tire shape measuring device comprising: In a tire shape measuring device that measures the shape of a tire block,
A first imaging means for allowing the wheel to roll and attached to an axle of the wheel, and imaging a block portion of a tire constituting the wheel;
A second imaging means attached to the vehicle body for imaging the block of the tire;
Road surface distance measuring means for measuring the distance to the road surface;
Using the result of the road surface distance measuring means, a position changing means for keeping the distance between the second imaging means and the road surface constant;
A tire shape measuring device comprising: In a tire shape measuring device that measures the shape of a tire block,
A first imaging means for allowing the wheel to roll and attached to an axle of the wheel, and imaging a block portion of a tire constituting the wheel;
First road surface distance measuring means for measuring a distance from the road surface;
Using the result of the first road surface distance measuring means, a first position changing means for keeping the distance between the first imaging means and the road surface constant;
A second imaging means attached to the vehicle body for imaging the block of the tire;
Second road surface distance measuring means for measuring the distance to the road surface;
Using the result of the second road surface distance measuring means, a second position changing means for keeping the distance between the second imaging means and the road surface constant;
A tire shape measuring device comprising:

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