JP2005265748A - Treading part measuring method of tire tread - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely and efficiently measure a skid and force on a tire surface. <P>SOLUTION: At first, a test tire is attached to a tire travel device to contact with a transparent measuring instrument built-in road face, a treading portion is photographed by a coordinate measuring camera, and a photographed image is imaged on a TV monitor. An operator assigns a plurality of measuring positions (points) desired to be measured, using a mouse or the like while watching the image. Position coordinates of the measuring points are computed to be stored correlated with the displayed image. Then, the points are rearranged by traveling under a condition joined with an SF, an SA, a CA, a brake, a drive and the like to be compared (pattern-matched) with the image acquired at first. A start position of the test tire and an arrangement position of a three-component force sensor are computed to conform the measuring position with a contact part of the three-component force sensor, at least one of the start position of the test tire and the position of a three-component force sensor is automatically regulated, and the test tire is rotated thereafter on the road surface to detect a level of force acting on the measuring position and a skid quantity. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tire tread contact portion measuring apparatus and a tire tread contact portion measuring method, and more particularly to a ground contact portion measuring apparatus capable of measuring a slip amount on a road surface of a tire tread during rolling of the tire, and a tire. The present invention relates to a method for measuring a ground contact portion of a tread.

Conventionally, when measuring relative displacement and movement with the tire tread road surface, measurement points are drawn at measurement points in the tread, the tire is run with measurement conditions applied, and the arrangement of the points in that state is computerized. The rolling start position of the tire is adjusted so that the point and the force sensor are in good contact with each other (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2002-116119

  However, in this method, it is necessary to make a measurement point by paint or the like before the test. If the hit point is peeled off or becomes thin, it cannot be recognized, and automatic operation may not be continued.

  The method to coordinate the hit measurement points is to recognize the white of the hit points and the black of the tire surface, so that the recognition lines drawn in various colors on the tread of the new tire are removed. Preparations that make the surface paint difficult to peel off, preparation of a template for accurately writing points, etc. were necessary and were not efficient.

  In addition, when the measurement point is hit, the portion slightly swells, which may affect the contact pressure, shearing force, and slip of the portion.

  In consideration of the above-described facts, the present invention has an object to provide a method for measuring a contact portion of a tire tread that can efficiently and efficiently measure slip and force on a tire surface.

  According to the first aspect of the present invention, when the test tire rolls on the road surface and the measurement point in the tire tread contacts the road surface, the magnitude of the force in the direction along at least the road surface acts on the measurement point. Is a tire contact point measurement method for detecting a slip amount of the measurement point with respect to the road surface using a reading sensor, wherein the test tire is placed on a test road surface at least partially transparent. The step of photographing and photographing the ground contact portion of the test tire through the transparent portion from the side opposite to the test tire side of the test road surface, and the photographed ground contact portion is displayed on the image display means and displayed on the image display means. Instructing a measurement point in correspondence with an image, calculating a position coordinate of the measurement point, storing the measurement point in correspondence with the displayed image, and the force sensor disposed on the test road surface After automatically adjusting at least one of the start position of the test tire and the position of the force sensor so as to come into contact with each other, the magnitude of the force acting on the measurement point by rolling the test tire on the road surface And a step of detecting the slip amount.

  Next, a method for measuring the contact portion of the tire tread according to claim 1 will be described.

  First, in the first step, the test tire is run on the test road surface, and the grounded portion of the test tire is photographed with a video camera or the like through the transparent portion.

  Next, the photographed grounding portion is displayed on an image display means such as a television monitor, the measurement point is indicated in correspondence with the displayed image, the position coordinates of the measurement point are calculated, and the corresponding image is displayed. Remember.

  In the next step, at least one of the start position of the test tire and the position of the force sensor is automatically adjusted by the control means so that the measurement point contacts the force sensor arranged on the test road surface, and the test tire rolls on the road surface. Thus, the magnitude of the force acting on the measurement point and the amount of slippage are detected.

  The tire tread surface contact portion measuring apparatus according to claim 2 rolls the test tire on the road surface, and the measurement point in the tire tread surface is along at least the road surface surface acting on the measurement point when it contacts the road surface. A method for measuring a ground contact portion of a tire that detects a magnitude of a directional force using a force sensor and detects a slip amount of the measurement point with respect to the road surface using a reading sensor, wherein at least a part is transparent A test tire is run on the road surface, and a step of photographing the ground contact portion of the test tire through a transparent portion from the opposite side of the test tire surface of the test road surface, and the photographed ground contact portion is displayed on an image display means and the image is displayed. A measuring point indicating step for indicating a measuring point corresponding to the image displayed on the display means, a test condition is given to the test tire, the test tire is run on the test road surface, and the test road surface is tested. Pattern matching between the step of photographing the ground contact portion of the test tire through the transparent portion from the opposite side of the ear side, the image photographed with the test conditions and the image instructing the measurement point in the measurement point instruction step Performing the steps of rearranging the measurement points on the image photographed with the test conditions and calculating and storing the position coordinates of the measurement points, and the force that the measurement points are arranged on the test road surface The force acting on the measurement point by rolling the test tire on the road surface after automatically adjusting at least one of the start position of the test tire and the position of the force sensor so as to come into contact with the sensor. And a step of detecting the slip amount.

  Next, a method for measuring the contact portion of the tire tread according to claim 2 will be described.

  First, in the first step, the test tire is run on the test road surface, and the grounded portion of the test tire is photographed with a video camera or the like through the transparent portion.

  Next, the photographed grounding portion is displayed on an image display means such as a television monitor, and a measurement point is instructed corresponding to the displayed image (measurement point instruction step).

  Next, test conditions (slip angle, camber angle, load, braking / driving force, etc.) are applied to the test tire and run on the test road surface, and the grounded portion of the test tire is photographed with a video camera or the like through the transparent portion. .

  In the next step, pattern matching is performed between the image captured with the test conditions and the image instructing the measurement points, and the measurement points are rearranged with respect to the images captured with the test conditions. The position coordinates of the measured points are calculated and stored.

  In the next step, at least one of the start position of the test tire and the position of the force sensor is automatically adjusted by the control means so that the measurement point contacts the force sensor arranged on the test road surface, and the test tire rolls on the road surface. The magnitude of the force acting on the measurement point and the amount of slippage are detected.

  In the conventional ground contact portion measuring apparatus, the tire surface treatment and the hitting work are required. However, according to the tire tread ground contact portion measuring apparatus according to claim 1, these troublesome operations are not required and the image is displayed on the image. Since the measurement points are specified, working hours can be reduced.

  According to the tire tread surface contact portion measuring apparatus according to claim 2, since the measurement points are rearranged even when the pattern deviates from the initial position, automatic measurement over a plurality of conditions is possible.

  An embodiment of a tire tread contact portion measuring apparatus according to the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the grounding part measuring apparatus 10 includes a long base frame 12.

  As shown in FIGS. 1 to 3, slide rails extending along the longitudinal direction (arrow L direction and arrow R direction) of the base frame 12 on both sides in the width direction (arrow F direction and arrow B direction) of the base frame 12. 14 is attached, and a road surface 16 extending in the longitudinal direction is provided at a substantially intermediate portion in the width direction.

  A tire traveling device 20 is slidably mounted on the slide rail 14 via a linear motion guide 18.

A ball screw 24 rotated by a servo motor 22 is supported by a bearing 26 on the side surface of the base frame 12.
A nut 30 into which the ball screw 24 is screwed is fixed to the frame-shaped frame 28 of the tire traveling device 20, and the tire traveling device 20 can be moved along the slide rail 14 by rotating the ball screw 24.

  The frame-like frame 28 is provided with an encoder 21 (see FIG. 6) that detects the position of the tire traveling device 20. As shown in FIG. 6, the servo motor 22 and the encoder 21 are connected to a control device 23 including a computer.

  A slide rail 32 extending along a direction orthogonal to the longitudinal direction of the base frame 12 is attached to the upper portion of the frame-shaped frame 28, and a moving base 36 is attached to the slide rail 32 via a linear motion guide 34. Is slidably mounted.

  A ball screw 40 rotated by a servo motor 38 is supported by a bearing 42 on the upper portion of the frame-shaped frame 28.

  A nut (not shown) to which the ball screw 40 is screwed is fixed to the moving base 36, and the moving base 36 can be moved along the slide rail 32 by rotating the ball screw 40.

  The frame-shaped frame 28 is provided with an encoder 43 (see FIG. 6) for detecting the position of the moving base 36, and the servo motor 38 and the encoder 43 are connected to the control device 23.

  A frame-like frame 46 is rotatably provided at the center upper portion of the moving base 36 via a thrust bearing 44.

  A bearing 48 is attached to the center of the frame 46.

  A shaft 50 is supported by the bearing 48 so as to be slidable in the vertical direction.

  A screw jack 51 for changing a slip angle using a servo motor 49 as a power is attached to the upper part of the moving base 36, and a pin 56 provided on a bearing 54 at the tip of the screw 52 of the screw jack 51 is attached to the bearing 42. It is inserted into a hole (not shown) at the tip of the lever 58 protruding outward.

  Therefore, by moving the screw 52 in the axial direction, the shaft 50 supported by the bearing 42 can rotate within a certain range with respect to the moving base 36.

  A load jack screw jack 64 powered by a servo motor 62 is attached to the upper portion of the frame 46, and a screw 66 of the screw jack 64 is connected to the shaft 50.

  Therefore, the shaft 50 supported by the bearing 42 moves up and down by moving the screw 66 in the axial direction.

  The moving base 36 is provided with a rotary encoder 61 (see FIG. 6) for detecting the angle (slip angle) of the bearing 42 (shaft 50), and an encoder 63 for detecting the vertical position of the shaft 50. The rotary encoder 61, the servo motor 62 and the encoder 63 are connected to the control device 23.

  A T-shaped horizontal rotating frame 68 is attached to the lower end of the shaft 50 so as to be suspended.

  The horizontal rotating frame 68 includes a horizontal portion 68A extending in the horizontal direction and a vertical portion 68B extending downward from the center of the horizontal portion 68A, and the shaft 50 is fixed to one end of the horizontal portion 68A.

  A shaft 70 is horizontally attached to the lower end of the vertical portion 68 </ b> B of the horizontal rotating frame 68.

  A tire support frame 72 is swingably supported on the shaft 70.

  A cam jack angle changing screw jack 74 powered by a servo motor 73 is attached to the horizontal portion 68A of the horizontal rotating frame 68, and a pin 80 provided on a bearing 78 at the tip of the screw 76 of the screw jack 74 is provided. It is inserted into a hole (not shown) of the tire support frame 72.

  Therefore, the tire support frame 72 swings around the shaft 70 by moving the screw 76 in the axial direction.

  The horizontal rotary frame 68 is provided with a rotary encoder 81 (see FIG. 6) that detects the angle (camber angle) of the tire support frame 72. The servo motor 73 and the rotary encoder 81 are connected to the control device 23.

  The tire support frame 72 is provided with a hub shaft 84 on which the test tire 82 is mounted, a braking / driving servomotor 86 that rotates the hub shaft 84, and a rotary encoder 87 that detects the rotational position of the hub shaft 84.

  Further, the hub axle 84 is provided with a load cell 89 (see FIG. 6) for detecting a force (load load or the like) acting on the test tire 82.

  The braking / driving servo motor 86, the rotary encoder 87, and the load cell 89 are connected to the control device 23.

  A part of the road surface 16 is provided with a recess 88 that is lowered by one step. A slide rail 90 extending along a direction orthogonal to the longitudinal direction of the road surface 16 is attached to the bottom surface of the recess 88. A road surface 92 with a built-in measuring instrument is attached to the slide rail 90 via a linear motion guide 91. It is mounted slidably.

  A ball screw 97 rotated by a servo motor 95 is supported by a bearing 99 on the bottom surface of the recess 88.

  A nut (not shown) to which the ball screw 97 is screwed is fixed to the road surface 92 with a built-in measuring instrument. By rotating the ball screw 97, the road surface 92 with a measuring instrument is set in a direction orthogonal to the longitudinal direction of the road surface 16. Can be moved.

  The road surface 16 is provided with an encoder 93 (see FIG. 6) that detects the position of the road surface 92 with a built-in measuring instrument. The encoder 93 is connected to the control device 23.

  On the road surface 92 with a built-in measuring instrument, a slip measuring unit 94 and a coordinate measuring unit 96 are provided.

  The slip measuring unit 94 includes a transparent road plate 98 made of a transparent synthetic resin (acrylic or the like).

  The measuring instrument built-in road surface 92 includes a recess 100 below the transparent road surface plate 98.

  The transparent road surface 98 is provided with a three-component force sensor 102 capable of measuring the magnitude of each of the three directions received from the tread surface of the test tire 82 (the longitudinal direction of the road surface 16, the width direction of the road surface 16, and the vertical direction of the road surface 16). Is attached, and the contact portion (upper end) 102 </ b> A of the three-component force sensor 102 projects from the hole 104 of the transparent road surface plate 98. The contact portion 102A has a circular shape.

  In the recess 100, a slip measurement camera (CCD camera) 108 and a light source 110 for photographing are provided upward.

  On the other hand, the coordinate measuring unit 96 includes a transparent road plate 112 made of a transparent synthetic resin (acrylic or the like).

  A coordinate measuring camera (CCD camera) 116 and a light source 118 are arranged upward in a recess 114 provided below the transparent road surface plate 112.

  The three component force sensor 102, the slip measurement camera 108, and the coordinate measurement camera 116 are connected to the control device 23.

The control device 23 is connected to a television monitor 120, a keyboard 122 for performing various settings, a storage device 124, and the like.
(Function)
Next, operation | movement of the grounding part measuring apparatus 10 of this embodiment is demonstrated based on the flowchart of FIG.

  First, the test tire 82 is attached to the hub axle 84, and the tire traveling device 20 is disposed on the coordinate measuring camera 116 (the shaft 50 is in the raised position).

  In step 100, test conditions are set. As test conditions, there are a slip angle (SA), a camber angle (CA), a load, a braking force, a driving force, and the like, which can be set respectively. These values can be input from the keyboard 122. A braking / driving force can be applied to the test tire 82 traveling on the road surface 16 by adjusting the moving speed of the tire traveling device 20 and the rotational speed of the braking / driving servomotor 86.

  In the next step 102, the coordinate measuring camera 116 is placed under the traveling locus of the test tire 82, and the test tire 82 is lowered and brought into contact with the road surface 92 with a built-in measuring instrument. The image of the grounding portion is displayed on the TV monitor 120, and the operator designates one or more measurement points P to be measured in the image using the mouse 106 (see FIG. 6) while viewing the screen (FIG. 8A). reference.).

  By designating the measurement point P on the image (measurement point instruction step), the coordinates of the measurement point P are calculated and stored corresponding to the image.

  In the next step 104, the tire traveling device 20 is moved in the arrow L direction while the test tire 82 is grounded, the test conditions set in step 100 are applied, and the tire traveling device 20 is moved in the arrow R direction. Then, the ground contact portion of the rolling test tire 82 is photographed by the coordinate measuring camera 116 and the image is stored.

  Since the test conditions (slip angle, etc.) are given to the test tire 82 after photographing the contact portion in step 102, the image photographed in step 104 (FIG. 8B) is the image photographed in step 102. Deviation occurs with respect to (FIG. 8A).

  For this reason, in step 104, pattern matching is performed between the image taken in step 102 before the test condition is given and the image taken after the test condition is given (based on the contour of the block, groove, tread texture, etc.) The amount of deviation (X, Y direction) is calculated, and as shown in FIG. 8B, the measurement points P are rearranged with respect to the image after the test conditions are applied (photographed at step 104).

  Note that the coordinates of the new rearranged measurement point P are calculated and stored in correspondence with the image.

  In the example of FIG. 8, the displacement and the rotation angle after pattern matching are expressed by dX, dY, dθ (see FIG. 8B).

  Using this value, the rearrangement of the point position data after inputting the measurement conditions can be performed from the initially designated measurement position coordinates by using the following equation.

X ₂ = X ₁ cos θ−Y ₁ sin θ + dX
Y ₂ = X ₁ sin θ−Y ₁ cos θ + dY
By using the same procedure, various deformations such as a rhombus (shear direction) deformation and a fan shape (bending direction) deformation can be parameterized by pattern matching, so that it is possible to cope with any grounding surface distortion or misalignment. .

  In the next step 106, a start position for measuring the three component force is determined. Specifically, based on the diameter of the test tire 82 inputted in advance, the coordinates of the measurement point P, and the rotation position of the test tire 82, the first measurement point P to be measured first is the contact portion of the three-component force sensor 102. The start position (rotation position) of the test tire 82 and the arrangement position of the three-component force sensor 102 (and / or the arrangement position of the moving base 36) are calculated so as to coincide with 102A.

  In the next step 108, the tire traveling device 20 is moved in the reverse direction (arrow L direction) to stop the tire traveling device 20 at the start position, and the arrangement position obtained by moving the measuring instrument built-in road surface 92 and calculating it. The three-component force sensor 102 is positioned (and / or the moving base 36 is positioned). Thereafter, the tire traveling device 20 is moved in the arrow R direction, and the test tire 82 is rolled on the road surface 92 with a built-in measuring instrument.

  When the test tire 82 passes the measuring instrument built-in road surface 92, the slip measurement camera 108 takes images of the tire tread at least before and after the tire tread comes into contact with the three-component force sensor 102 and is separated, The image is stored, and the three-component force sensor 102 measures the magnitude of the force in the three directions acting on the measurement point P.

  The control device 23 rearranges the measurement points P for the images until the tire tread comes into contact with the three-component force sensor 102 and moves away by pattern matching, and measures the contact portion 102A of the three-component force sensor 102. The coordinate shift (that is, slip) of the point P is calculated and stored.

  In the next step 100, the control device 23 calculates and stores the wear energy at the measurement point P based on the three component force and the slip amount of the measurement point P.

  In step 112, it is determined whether the calculation and storage of the wear energy has been completed for all measurement points P. Here, when it is determined that the calculation and storage of the wear energy has not been completed for all the measurement points P, the process returns to step 106 and the same processing is performed for the next measurement point. On the other hand, if it is determined that the calculation and storage of wear energy has been completed for all measurement points, the routine proceeds to step 114.

  In step 114, it is determined whether measurement has been completed under all measurement conditions. If it is determined that the measurement has not been completed under all measurement conditions, the process returns to step 104 to change to the next measurement condition and proceed with the process. On the other hand, if it is determined that measurement has been completed under all measurement conditions, the process ends.

  As described above, in the present embodiment, the three component forces and the slip of the test tire 82 are measured under various test conditions in which the slip angle (SA), the camber angle (CA), the load, the braking / driving force, and the like are changed. Measurement and wear energy calculation can be performed fully automatically.

  Further, in the conventional ground contact portion measuring device, the tire surface treatment and the spotting work are necessary, but in the ground contact portion measuring device 10 of the present embodiment, these complicated operations are not necessary, and the operator is displayed. It is only necessary to determine the measurement point P on the image, and the working time can be reduced.

  In addition, since the shape of the tire surface does not change due to paint or the like, the contact pressure, shearing force, slip, etc. of the measurement site can be accurately measured.

  Further, in the present embodiment, the location to be measured can be arbitrarily specified later on the screen.

1 is a plan view of a tire tread contact portion measuring apparatus according to an embodiment of the present invention. It is a front view of the grounding part measuring apparatus shown in FIG. It is a right view of the grounding part measuring apparatus shown in FIG. It is a top view of a road surface with a built-in measuring instrument. It is explanatory drawing for demonstrating a start position. It is a block diagram which shows the structure of a control system. It is a flowchart of control. It is a footprint of a test tire.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Grounding part measuring apparatus 16 Road surface 21 Encoder (control means)
22 Servo motor (control means)
23 Control device (control means)
38 Servo motor (control means)
43 Encoder (control means)
49 Servo motor (control means)
61 Rotary encoder (control means)
63 Encoder (control means)
72 Servo motor (control means)
81 Rotary encoder (control means)
82 Test tire 86 Braking drive servo motor (control means)
87 Rotary encoder (control means)
89 Load cell (control means)
92 Road surface with built-in measuring instrument 94 Servo motor (control means)
93 Encoder (control means)
102 3 component force sensor (force sensor)
108 Slip measurement camera 116 Coordinate measurement camera P Measurement point

Claims (2)

The test tire is rolled on the road surface, and the magnitude of the force in at least the direction along the road surface acting on the measurement point when the measurement point in the tire tread contacts the road surface is detected using a force sensor. A method for measuring a contact portion of a tire that detects a slip amount of the measurement point with respect to the road surface using a reading sensor,
Running a test tire on a test road surface that is at least partially transparent, and photographing a ground contact portion of the test tire through a transparent portion from a side opposite to the test tire side of the test road surface;
The photographed grounding portion is displayed on the image display means, the measurement point is indicated in correspondence with the image displayed on the image display means, the position coordinate of the measurement point is calculated, and the image is displayed in correspondence with the displayed image. Memorizing process;
After automatically adjusting at least one of the start position of the test tire and the position of the force sensor by the control means so that the measurement point contacts the force sensor arranged on the test road surface, the test tire is placed on the road surface. Detecting the magnitude of the force acting on the measurement point and the amount of slip;
A method for measuring a ground contact portion of a tire tread characterized by comprising: The test tire is rolled on the road surface, and the magnitude of the force in at least the direction along the road surface acting on the measurement point when the measurement point in the tire tread contacts the road surface is detected using a force sensor. A method for measuring a contact portion of a tire that detects a slip amount of the measurement point with respect to the road surface using a reading sensor,
Running a test tire on a test road surface that is at least partially transparent, and photographing a ground contact portion of the test tire through a transparent portion from a side opposite to the test tire side of the test road surface;
A measurement point indicating step of displaying a photographed grounding portion on an image display means and indicating a measurement point corresponding to the image displayed on the image display means;
Giving test conditions to the test tire and running the test tire on the test road surface, photographing a grounded portion of the test tire through a transparent portion from a side opposite to the test tire side of the test road surface;
Pattern matching is performed between the image photographed with the test condition and the image instructed the measurement point in the measurement point instruction process, and the measurement point is rearranged with respect to the image photographed with the test condition. Calculating and storing the position coordinates of the measurement points;
After automatically adjusting at least one of the start position of the test tire and the position of the force sensor by the control means so that the measurement point contacts the force sensor arranged on the test road surface, the test tire is placed on the road surface. Detecting the magnitude of the force acting on the measurement point and the amount of slip;
A method for measuring a ground contact portion of a tire tread characterized by comprising:

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