Tire grinding device

Abstract

To provide a tire polishing device than can measure polishing amounts of a tire accurately.SOLUTION: A tire polishing device 10 as one example of embodiments comprises a driving device 15 that rotates a tire 1, a polishing device 20 that polishes a surface of the tire 1, and a measuring device 30 that measures polishing amounts of the tire. The tire polishing device 10 is configured so that the measuring device 30 irradiates a ground contacts area 4 and a groove bottom 6 of the tire 1 respectively with laser beams to measure the polishing amounts of the tire from a difference in measurement value between the ground contact area 4 and the groove bottom 6.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a tire polishing device.

Background Art

[0002] Conventionally, a tire polishing device is known in which a polishing member such as a polishing belt is pressed against the surface of a tire while rotating the tire to polish the tire surface (see Patent Documents 1 to 4, etc.). As described in Patent Documents 1 to 3, the tire polishing device is used, for example, to polish and activate the surface of a studless tire to restore grip performance.

[0003] Patent Document 1 discloses a device in which a user can move a polishing device including a polishing belt in the tire axial direction by operating a handle mechanism. Patent Document 2 discloses a method of detecting the shape of a tire using a displacement sensor and calculating the movement locus of a polishing member from the detected shape. Further, Patent Document 3 discloses a device that polishes the surface of a tire while automatically moving a polishing member.

[0004] The device of Patent Document 4 is used to wear a tire used in a test to match the actual running state before conducting an actual running test of a vehicle. Patent Document 4 discloses that the movement of a polishing member is controlled by control means, and polishing is automatically performed while reading the shape of the tire surface using a non-contact terminal such as a laser.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, there is a demand for a tire polishing device that can accurately measure the polishing amount of a tire and can adjust the polishing amount to a target value with high precision. However, it is not easy to accurately measure the polishing amount. As a result of the study by the present inventors, it has been found that the tire expands due to the heat generated when polishing the tire, and this thermal expansion is one of the factors that hinder the accurate measurement of the polishing amount.

[0007] An object of the present invention is to provide a tire polishing device capable of accurately measuring the polishing amount of a tire.

Means for Solving the Problems

[0008] The tire polishing device according to the present invention includes a drive device for rotating the tire, a polishing device for polishing the tire surface, and a measuring device for measuring the tire polishing amount by irradiating the tire surface with laser light and detecting the reflected light from the tire surface to measure the distance. The measuring device irradiates the laser light onto the ground contact surface and the groove bottom of the tire, respectively, and is configured to measure the tire polishing amount from the difference between the measured values at the ground contact surface and the groove bottom.

Effects of the Invention

[0009] According to the tire polishing device according to the present invention, it is possible to accurately measure the polishing amount of a tire. And based on the measurement result of the accurate polishing amount, high-precision polishing can be realized.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0011] Hereinafter, with reference to the drawings, an example of an embodiment of a tire grinding device according to the present invention will be described in detail. The embodiment described below is merely an example, and the present invention is not limited to the following embodiments. Also, a form formed by selectively combining each component of the plurality of embodiments and modification examples described below is included in the present invention.

[0012] FIG. 1 is a plan view of a tire grinding device 10 which is an example of an embodiment, and FIG. 2 is a block diagram showing a schematic configuration of the tire grinding device 10. In FIG. 1, the illustration of the grinding device 20 is omitted.

[0013] As shown in FIGS. 1 and 2, the tire grinding device 10 includes a driving device 15 for rotating the tire 1 and a grinding device 20 for grinding the surface of the tire 1. The grinding device 20 is configured to be able to grind the tire surface while moving in the tire axial direction. The grinding device 20 has a grinding belt 21 (see FIG. 3 and the like described later) that contacts the tire surface as a grinding member. The tire grinding device 10 grinds the tire surface by pressing the grinding belt 21 against the tire surface while rotating the tire 1.

[0014] The tire 1 to be polished by the tire polishing device 10 is not particularly limited as long as it can be attached to the device. The tire 1 may be, for example, a summer tire, a winter tire (studless tire), or an all-season tire. Further, the tire 1 is not limited to a passenger car tire, and may be a motorcycle tire, a heavy-duty tire, or the like. The tire 1 has a tread 2 in which a plurality of blocks 3 and grooves 5 are formed. The block 3 is a portion partitioned by a plurality of grooves 5 and protruding in the tire radial direction, and is generally also called land. The ground contact surface 4 of the block 3 that contacts the road surface during use is polished by the polishing belt 21.

[0015] The tire polishing device 10 is used, for example, for performance evaluation of the tire 1. According to the tire polishing device 10, a target level of wear state can be accurately and easily achieved, so it is suitable for performance evaluation in various wear states. Further, the tire polishing device 10 may be used for activation, finishing, etc. of the tire 1.

[0016] The tire polishing device 10 includes a gantry 11 that supports a drive device 15, a polishing device 20, etc. The gantry 11 may have casters. The gantry 11 is provided with a tire support shaft 12 that rotatably supports the tire 1 and rotates by the function of the drive device 15. The tire 1 is attached to the tire support shaft 12, for example, in a state of being mounted on a wheel. That is, the wheel is attached to the tire support shaft 12. The tire support shaft 12 is installed on the gantry 11 via a bearing.

[0017] The tire polishing device 10 further includes a measuring device 30 for measuring the polishing amount of the tire 1. The measuring device 30 measures the polishing amount of the tire by irradiating the tire surface with laser light, detecting the reflected light from the tire surface, and measuring the distance. As will be described in detail later, the tire polishing device 10 is configured to measure the polishing amount of the tire 1 by irradiating the ground contact surface 4 and the groove bottom 6 of the tire 1 with laser light by the measuring device 30 and calculating the difference between the measured values at the ground contact surface 4 and the groove bottom 6. In this case, even if the tire 1 thermally expands due to polishing, it is possible to measure the accurate polishing amount.

[0018] The tire grinding device 10 includes a moving mechanism 40 for moving the grinding device 20 and a controller 50 for integrally controlling the entire device. The moving mechanism 40 has a plurality of links and a plurality of cylinders (a first cylinder 46 and a second cylinder 47). The controller 50 controls the operations of, for example, the grinding device 20 and the moving mechanism 40, and performs the grinding of the tire 1 based on a preset grinding pattern. Further, the tire grinding device 10 includes a blower 34 for blowing off the rubber dust generated by the grinding of the tire 1. The blower 34 has a blower body and an air nozzle extending from the blower body.

[0019] In the present embodiment, the tire 1 is attached to the device with its rotation axis along the horizontal direction. The moving mechanism 40 is configured to move the grinding device 20 in the XY direction along the horizontal direction. In this specification, the "X direction" means the direction along the tire axis direction, and the "Y direction" means the direction orthogonal to the X direction (tire diameter direction) and along the horizontal direction. The grinding belt 21 grinds the tire surface while moving in the tire axis direction in a state of being in contact with the tire surface by the function of the moving mechanism 40.

[0020] As shown in FIG. 2, the drive device 15, the grinding device 20, the measuring device 30, and the moving mechanism 40 are connected to the controller 50. A computer installed with software (program) for executing a series of tire grinding processes can be used as the controller 50. Further, the tire grinding device 10 includes an encoder 60. Although details will be described later, the measuring device 30 irradiates laser light to the measurement points G1, G2 of the tire grinding amount where the laser light is irradiated based on the information acquired by the encoder 60. The encoder 60 may be any device that can measure the rotation angle of the tire 1, and the detection method and the like are not particularly limited.

[0021] The drive device 15 has, for example, a motor 16 and a transmission mechanism that transmits the rotation of the motor 16 to the tire support shaft 12. Gears, chains, belts, etc. can be used for the transmission mechanism. Also, the encoder 60 may be connected to the tire support shaft 12. The tire 1 attached to the tire support shaft 12 rotates by driving the motor 16. The driving of the motor 16 is controlled by the controller 50. Note that the tire 1 is fixed to the tire support shaft 12 by a detachable structure (not shown) so that the tire 1 does not fall off the tire support shaft 12 during polishing. Details of the polishing device 20, the measuring device 30, and the moving mechanism 40 will be described later.

[0022] The controller 50 has, for example, a memory that stores various setting information including a polishing pattern, a control program, etc., and a processor that reads out the control program and executes polishing based on the polishing pattern specified by the user. The controller 50 acquires information from each device and also sends control commands to each device to execute a series of polishing processes. The controller 50 may be composed of a plurality of computers and may include a server etc. connected via a wide area communication network.

[0023] The controller 50 includes, for example, a first computer installed on the gantry 11 and a second computer connected to the first computer. The first computer may have a touch panel. The touch panel is used as an input interface operated by the user and also as a monitor on which various information is displayed. The second computer may be a dedicated device for the tire polishing device 10 or may be a device shared with other systems. The setting information of the polishing pattern is stored in the memory of the second computer and may be sent from the second computer to the first computer when executing the polishing process.

[0024] In this embodiment, an air nozzle that constitutes a blower 34 is integrated with the measuring device 30. The blower 34 blows air onto the measurement points G1 and G2. Thereby, rubber dust adhering to the measurement points G1 and G2 can be removed. For the blower 34, for example, a blower capable of supplying compressed air that can blow off rubber dust is used. Although details will be described later, the blower 34 preferably includes a first outlet for blowing air onto the tire surface and further includes a second outlet for blowing air onto the laser beam emission port in the measuring device 30.

[0025] Hereinafter, with reference to FIGS. 3 and 4 as appropriate, the configurations of the polishing device 20 and the moving mechanism 40 will be described in detail with reference to FIGS. 1 and 2. FIGS. 3 and 4 are diagrams showing the polishing device 20 and a part of the moving mechanism 40.

[0026] As shown in FIGS. 3 and 4, the polishing device 20 includes a polishing belt 21, two pulleys over which the polishing belt 21 is spanned, a motor 26 for rotating the polishing belt 21, and a support frame 27 that supports the motor 26 and the like. The polishing belt 21 is, for example, an endless belt with abrasive grains coated on the belt surface, and is spanned over a driving pulley 22 and a driven pulley 23. The driving pulley 22 is rotatably fixed to the support frame 27 and rotates by the power of the motor 26. Also, a spring 24 fixed to the support frame 27 is provided between the driving pulley 22 and the driven pulley 23. The driven pulley 23 is biased in a direction away from the driving pulley 22 by the spring 24, thereby maintaining the tension of the polishing belt 21.

[0027] As will be described in detail later, the polishing device 20 is configured to polish the tire surface while moving in the tire axial direction based on a preset polishing pattern. Further, the polishing of the tire surface is performed while rotating the tire 1. The user can set a plurality of polishing patterns according to, for example, the type of the tire 1, evaluation items, etc. Alternatively, the user can select from preset polishing patterns and input parameters necessary for polishing after selecting a pattern. Information on a plurality of polishing patterns may be stored in the memory of the controller 50. The polishing device 20 polishes the tire surface while moving from the inner side to the outer side in the tire axial direction on both sides of the tread 2 in the tire axial direction. In this case, the target polishing level can be realized with high precision, and the entire desired polishing range can be polished beautifully without polishing unevenness.

[0028] The polishing belt 21 is arranged in a state of extending in the vertical direction at a position facing the tread 2. A compression spring is used for the spring 24. The driving pulley 22 and the driven pulley 23 are arranged at intervals in the vertical direction, and the tension of the polishing belt 21 can be held by pressing the driven pulley 23 in the direction opposite to the driving pulley 22 by the reaction force of the spring 24. In the present embodiment, the reaction force of the spring 24 is configured to be applied to the bearing of the driven pulley 23. The polishing device 20 is provided with a lever 25 used when replacing the polishing belt 21. When the lever 25 is lifted, the spring 24 is compressed, the driven pulley 23 descends, and the polishing belt 21 loosens, so that the belt can be replaced.

[0029] The polishing belt 21 is pressed against the surface of the tread 2 by the function of the moving mechanism 40. In the present embodiment, the polishing pressure when polishing the tire 1 can be adjusted by changing the pressing force applied by the moving mechanism 40.

[0030] The polishing belt 21 rotates as the driving pulley 22 rotates. Since the driving pulley 22 is rotated by the motor 26, the rotation direction and rotation speed of the polishing belt 21 can be adjusted by controlling the motor 26. The polishing belt 21 preferably rotates in a direction opposite to the rotation direction of the tire 1 at the portion where it abuts on the tire surface. Also, the rotation speed of the polishing belt 21 is preferably higher than the rotation speed of the tire 1. In this case, the tire surface can be efficiently and beautifully polished. Note that the rotation direction and rotation speed of the tire 1 can also be adjusted.

[0031] The width W of the polishing belt 21 is not particularly limited, but is preferably smaller than the contact width of the tread 2 (the distance between the left and right contact ends). An example of the width W of the polishing belt 21 is 80 to 120 mm. The polishing belt 21 polishes the tire surface while moving in the tire axial direction, and preferably moves in the tire axial direction at a moving speed of a length equal to or less than 50% of the width W per rotation of the tire 1. Note that the rotation axes of the driving pulley 22 and the driven pulley 23 are parallel to each other and are in a state along the tire axial direction when the polishing belt 21 is located on the equator of the tread 2.

[0032] The polishing device 20 is attached to the base substrate 44 provided at the free end of the link of the moving mechanism 40 in a state where it can swing in a predetermined angle range. In the present embodiment, a support shaft 45 erected on the base substrate 44 is inserted into a hole provided in the support frame 27 of the polishing device 20. The support shaft 45 is a cylindrical shaft extending in the vertical direction. Since the polishing device 20 rotates in the circumferential direction of the support shaft 45, the polishing belt 21 can swing. For this reason, the polishing belt 21 abuts along the surface of the tread 2 also at both end portions in the tire axial direction of the tread 2 where the degree of curvature is large.

[0033] The pitching angle (the above-mentioned predetermined angle) of the grinding device 20 is restricted by the long hole 44a formed in the base substrate 44. The long hole 44a is a through hole formed along an arc centered on the axis of the support shaft 45. A cam follower 28 inserted into the long hole 44a is provided on the support frame 27 of the grinding device 20. The cam follower 28 is movable from one end to the other end in the length direction of the long hole 44a. Note that a pair of clamping links for moving the cam follower 28 to the center of the long hole 44a with the cam follower 28 interposed therebetween may be provided on the base substrate 44. The pair of clamping links are biased in a direction approaching each other.

[0034] As shown in FIG. 1, the moving mechanism 40 includes a first link 41 extending in the Y direction, and a second link 42 and a third link 43 pivotally supported at the free end of the first link 41. As shown in FIGS. 1, 3, and 4, a base substrate 44 for attaching the grinding device 20 is provided at the free ends of the second link 42 and the third link 43. The base end of the first link 41 is attached to the gantry 11 in a rotatable state.

[0035] The moving mechanism 40 includes a first cylinder 46 and a second cylinder 47 for moving the links. For example, the first cylinder 46 is a servo cylinder, and the second cylinder 47 is an air cylinder. The first cylinder 46 can move and stop at an arbitrary speed based on the control of the controller 50, and moves the grinding device 20 (grinding belt 21) in the X direction. The second cylinder 47 moves the grinding belt 21 in the Y direction, bringing the grinding belt 21 into contact with the tire surface or separating the grinding belt 21 from the tire surface.

[0036] In the moving mechanism 40, the rod of the first cylinder 46 is fixed to the first link 41. When the first cylinder 46 is driven, the first link 41 rotates about its base end, and the free end of the first link 41 moves in the X direction. Further, the cylinder tube of the second cylinder 47 is fixed to the first link 41, and the piston rod of the second cylinder 47 is fixed to the second link 42. By driving the second cylinder 47, the second link 42 rotates about its base end (the connection part with the first link 41), and the third link 43 moves in conjunction with the second link 42.

[0037] That is, by driving the second cylinder 47, the polishing device 20 moves in the Y direction, and the polishing belt 21 is pressed against the tire surface, or the polishing belt 21 is separated from the tire surface. Also, by driving the first cylinder 46, the polishing device 20 moves in the X direction (the tire axis direction). The motor 26 of the polishing device 20, and the first cylinder 46 and the second cylinder 47 of the moving mechanism 40 are driven under the control of the controller 50 (see FIG. 2).

[0038] Hereinafter, with reference to FIGS. 5 and 6 and FIGS. 1 and 2 as appropriate, the configuration of the measuring device 30 will be described in detail. FIG. 5 is a diagram showing measurement points of the polishing amount on the tread surface. FIG. 6 is a diagram showing a part of the measuring device 30.

[0039] As shown in FIGS. 5 and 6, the measuring device 30 for measuring the tire polishing amount irradiates laser light onto the measurement points G1 and G2 on the tire surface, detects the reflected light from the tire surface, and measures the distance, thereby obtaining information regarding the tire polishing amount. The measuring device 30 measures the distance from the device to the tire surface for the measurement points G1 and G2. When the tire polishing amount increases, the distance from the measuring device 30 to the tire surface becomes longer. Therefore, the tire polishing amount can be measured by measuring the distance using laser light.

[0040] The tire grinding device 10 is configured to measure the tire grinding amount from the difference in measurement values at each point by irradiating the measurement points G1 and G2 on the tread surface with laser light by the measuring device 30. The measuring device 30 outputs, for example, the measurement values (distances) for the measurement points G1 and G2 to the controller 50, and the controller 50 calculates the tire grinding amount from the difference in the measurement values. Alternatively, the difference in the measurement values or the tire grinding amount may be calculated in the measuring device 30. In the present embodiment, the first measurement point G1 is set on the ground contact surface 4 of the block 3, and the second measurement point G2 is set on the groove bottom 6.

[0041] The ground contact surface 4 is an area to be ground by the grinding device 20, and the groove bottom 6 is an area not to be ground. That is, the measuring device 30 irradiates laser light on the first area to be ground by the grinding device 20 and the second area not to be ground. The tire 1 expands due to the heat generated by the grinding of the tread surface, and this thermal expansion is one of the factors that prevent accurate measurement of the grinding amount. However, by obtaining the grinding amount from the difference in the measurement values between the ground contact surface 4 and the groove bottom 6, it becomes possible to measure the accurate grinding amount. Since the tire 1 expands thermally in the same manner at both the ground contact surface 4 and the groove bottom 6, the influence of thermal expansion can be effectively eliminated by using the difference in the measurement values.

[0042] In addition, when the ground contact surface 4 and the groove 5 of the tire 1 are continuous in a uniform state along the tire circumferential direction, it is possible to measure the tire grinding amount without setting the measurement points G1 and G2 at specific locations on the ground contact surface 4 and the groove bottom 6. However, when the tread pattern is complicated, such as in a studless tire, it may happen that the laser light to be irradiated on the ground contact surface 4 is irradiated on the groove 5, and the laser light to be irradiated on the groove bottom 6 is irradiated on the ground contact surface 4. In such a case, it is preferable to set the measurement points G1 and G2 at specific locations and perform the measurement using the encoder 60.

[0043] The measurement points G1 and G2 are set manually by the user, for example. The user sets a specific location on the ground plane 4 of block 3 as the measurement point G1 and a specific location on the groove bottom 6 as the measurement point G2 through the input interface of the controller 50. In this embodiment, the measurement points G1 and G2 are close to each other and arranged in the tire axial direction. The tire grinding device 10 resets the origin of the encoder 60, for example, with the measurement points G1 and G2 existing at the irradiation positions of the laser light, making it possible to detect the positional relationship between the measurement points G1 and G2 and the irradiation positions of the laser light.

[0044] Before grinding the tire 1, the tire grinding device 10 may be configured such that the measuring device 30 measures the distance from the tire surface and determines the measurement points G1 and G2. The controller 50 controls the driving device 15 to rotate the tire 1 and controls the measuring device 30 to measure the distance, for example, and automatically sets the measurement points G1 and G2. Generally, the location where the distance measured on the tread surface is the smallest is the ground plane 4, and the location where the distance is the largest is the groove bottom 6. The controller 50 may set the measurement points G1 and G2 at the ground plane 4 and the groove bottom 6 respectively based on the measurement values by the measuring device 30.

[0045] The measuring device 30 has a laser device (also called a sensor) including a laser element that emits laser light and a light receiving element that receives the laser light (reflected light) reflected from the tire surface. A conventionally known device mounted on a laser distance meter can be used for the laser device. Generally, the laser device includes a laser driver, a light receiving circuit, and a lens in addition to the laser element and the light receiving element.

[0046] The measuring device 30 includes a first laser device that irradiates the ground surface 4 with laser light and a second laser device that irradiates the groove bottom 6 with laser light. Two laser devices 31a and 31b are provided in the measuring device 30. The laser device 31a irradiates the ground surface 4 with laser light, and the laser device 31b irradiates the groove bottom 6 with laser light. Note that the laser device 31a may irradiate the groove bottom 6 with laser light, or the laser device 31b may irradiate the ground surface 4 with laser light.

[0047] In this embodiment, the tire wear amount is measured using two laser devices 31a and 31b. However, it is also possible to use one laser device, move it in the tire axial direction, irradiate the ground surface 4 and the groove bottom 6 with laser light, and measure the distance at each measurement point. Alternatively, three or more laser devices may be used. Further, measurement points may be set at two or more positions on the ground surface 4 to perform distance measurement, and the tire wear amount may be calculated from the average value, median value, or mode value of each measurement value. Similarly, for the groove bottom 6, measurement points may be set at two or more positions thereon.

[0048] The laser devices 31a and 31b have openings 32a and 32b from which laser light is emitted. The openings 32a and 32b are emission ports of the laser light and also incident ports for the reflected light. A light-transmitting cover such as a glass cover is provided on the openings 32a and 32b. Although details will be described later, since rubber dust generated when the tire 1 is polished may adhere to the covers of the openings 32a and 32b, the measuring device 30 is provided with air nozzles 36a and 36b for blowing off the rubber dust.

[0049] The measuring device 30 has frames 33a and 33b that respectively hold laser devices 31a and 31b. In the example shown in FIG. 6, the laser devices 31a and 31b are respectively fixed to the lower parts of the plate-shaped frames 33a and 33b. Further, a total of four air nozzles, two each, are provided at the upper parts of the frames 33a and 33b. In FIG. 6, only the front side portion of the measuring device 30 facing the direction of the tire 1 is illustrated, but on the rear side of the frames 33a and 33b, for example, pipes connecting the blower main body and the air nozzles, mounting brackets for the guide rails 38 described later, etc. are provided.

[0050] The measuring device 30 has moving means for moving the laser devices 31a and 31b in the XY directions. In the example shown in FIG. 1, as the moving means, two guide rails 37 and 38 are provided. The guide rail 37 extends in the Y direction, and the guide rail 38 extends in the X direction. The frames 33a and 33b are slidably attached to the guide rail 38 in the X direction, and the guide rail 38 is slidably attached to the guide rail 37 in the Y direction using a clamp or the like. For this reason, the laser devices 31a and 31b can be moved along the XY directions. Note that the laser devices 31a and 31b may be moved using a motor.

[0051] The frames 33a and 33b are not connected to each other and can move independently in the X direction. Thereby, it becomes easy to respectively arrange one of the laser devices 31a and 31b at a position facing the block 3 and the other of the laser devices 31a and 31b at a position facing the groove 5, and it becomes possible to cope with various tread patterns. Regarding the Y direction, by sliding the guide rail 38 along the guide rail 37, the distance between the laser devices 31a and 31b and the tire surface can be changed. Generally, there is an appropriate range for this distance according to the type of the laser device and the like. When setting the resolution of the tire polishing amount to 0.1 mm or less, a preferable example of the distance is 100 ± 30 mm.

[0052] The measuring device 30 is arranged on the side opposite to the polishing device 20 with the tire 1 interposed therebetween. That is, the polishing device 20 and the measuring device 30 are arranged side by side in the tire diameter direction and are located at the positions farthest from each other at the position facing the surface of the tread 2. In this case, it becomes easy to remove the rubber dust generated by the polishing device 20 from the measurement points G1 and G2 before the measurement points G1 and G2 reach the irradiation positions of the laser light. The outlets of the air nozzles 35a and 35b for blowing air onto the tire surface are arranged on the front side in the tire rotation direction with respect to the irradiation position of the laser light.

[0053] In the present embodiment, the laser device 31a and the two air nozzles 35a and 36a are fixed to the frame 33a and integrated. In this case, the setting of the device is easier compared to the case where the laser device and the air nozzles are arranged separately. Similarly, the laser device 31b and the two air nozzles 35b and 36b are fixed to the frame 33b and integrated. At the tips of the air nozzles 35a and 35b, first outlets for blowing air onto the tire surface are formed, and at the tips of the air nozzles 36a and 36b, second outlets for blowing air onto the openings 32a and 32b which are the emission ports of the laser light are formed.

[0054] The laser devices 31a and 31b of the measuring device 30 and the blower 34 operate under the control of the controller 50 (see FIG. 2). The blower 34 may be configured to blow air from the air nozzles 35a and 35b constantly or at an appropriate timing, but it is preferable to blow air onto the tire surface at a controlled specific timing. In the present embodiment, air is blown onto the measurement points G1 and G2 after the measurement points G1 and G2 pass through the polishing position by the polishing device 20 and before reaching the irradiation positions of the laser light by the measuring device 30.

[0055] The timing of injecting air from the air nozzles 35a and 35b is determined in consideration of factors such as the rotational speed of the tire 1 and the relationship between the nozzle outlet and the laser irradiation position by the measuring device 30. In the present embodiment, since the air nozzles 35a and 35b are arranged close to the laser devices 31a and 31b, for example, after the measurement points G1 and G2 pass through the polishing position, air is injected after a predetermined time has elapsed. In this case, air can be blown more efficiently onto the measurement points G1 and G2.

[0056] Specifically, when the state where the measurement points G1 and G2 are present at the laser beam irradiation position is defined as the rotation angle 0° of the tire 1, air may be injected from the air nozzles 35a and 35b when the measurement points reach the position of the rotation angle 90° in front of the irradiation position. The blower 34 causes the air nozzles 35a and 35b to inject air at least when the measurement points G1 and G2 reach the position 10° in front of the irradiation position. The blower 34 blows air onto the tire surface from the air nozzles 35a and 35b for 1 to 10 seconds at the timing when the measurement points G1 and G2 reach the positions 10° to 90° in front of the irradiation position, for example.

[0057] When blowing air onto at least the tire surface, the blower 34 injects air from the air nozzles 36a and 36b and blows air onto the openings 32a and 32b, which are the laser beam emission ports of the laser devices 31a and 31b. As described above, rubber dust generated when the tire 1 is polished may adhere to the covers provided on the openings 32a and 32b. In particular, since the rubber dust blown off from the tire surface easily adheres to the covers, it is preferable to synchronize the timing of injecting air from the air nozzles 36a and 36b with the timing of injecting air from the air nozzles 35a and 35b.

[0058] Hereinafter, with reference to FIGS. 7 to 9, the polishing pattern on the tire surface will be described in detail. FIG. 7 is a flowchart showing an example of the control procedure in the tire polishing process.

[0059] As shown in FIG. 7, when starting the tire polishing process by the tire polishing apparatus 10, an inflated tire 1 mounted on a wheel is attached to a tire support shaft 12 (step S1). The tire support shaft 12 supports the tire 1 in a rotatable state. The tire 1 rotates when the driving device 15 rotates the tire support shaft 12. The tire polishing apparatus 10 polishes, for example, a region located between the left and right grounding ends on the surface of the tread 2 while rotating the tire 1.

[0060] Next, measurement points G1 and G2 for measuring the polishing amount on the surface of the tread 2 are set, and a polishing pattern of the tread surface is set (steps S2 and S3). Note that the order of steps S2 and S3 may be reversed. The measurement points G1 and G2 may be set based on a user's operation or automatically as described above. In any case, the measurement points G1 and G2 are set on each of the grounding surface 4 and the groove bottom 6 of the block 3.

[0061] The setting information of the measurement points G1 and G2 is stored in the memory of the controller 50. At this time, the origin of the encoder 60 is reset with the measurement points G1 and G2 existing at the irradiation positions of the laser light, and the encoder 60 can detect the relative positional relationship between the irradiation position of the laser light and the measurement points G1 and G2. The information acquired by the encoder 60 may be transmitted to the controller 50, or may be transmitted to the measuring device 30 via the controller 50 or directly. The controller 50 may control the measuring device 30 based on the information of the encoder 60 and measure the tire polishing amount.

[0062] The tread surface of the tire 1 is polished by the polishing device 20. The polishing device 20 operates based on the polishing pattern set in step S3 or a pattern selected from the set polishing patterns, and polishes the tread surface (step S4). The polishing device 20 is configured to polish the tread surface while moving in the tire axis direction based on the polishing pattern preset in step S3 under the control of the controller 50.

[0063] The grinding belt 21 moves in the tire axial direction while being in contact with the tread surface of the rotating tire 1, and grinds the tread surface while rotating in the direction opposite to the rotation direction of the tire 1 at the contact portion. The rotation speed, moving speed, rotation speed, etc. of the tire 1 can be arbitrarily set, but the rotation speed of the grinding belt 21 is preferably faster than the rotation speed of the tire 1. The peripheral speed ratio of the grinding belt 21 to the tire 1 (peripheral speed of the grinding belt 21 / peripheral speed of the tire 1) is set to, for example, several times to about 150 times.

[0064] Subsequently, before the measurement points G1 and G2 reach the laser light irradiation positions by the measuring device 30 from the grinding positions by the grinding device 20, compressed air is blown onto the measurement points G1 and G2 to remove the rubber dust generated by grinding (step S5). In the present embodiment, after the measurement points G1 and G2 pass through the grinding position and before reaching the laser light irradiation position, air is ejected from the air nozzles 35a and 35b to blow air onto the measurement points G1 and G2. At the same time, air is ejected from the air nozzles 36a and 36b to blow air onto the laser light emission ports of the laser devices 31a and 31b.

[0065] Subsequently, the laser devices 31a and 31b irradiate the measurement points G1 and G2 with laser light, and measure the distances from each laser device to the measurement points G1 and G2. Then, the tire grinding amount is calculated from the difference in the measured values at the measurement points G1 and G2 (step S6). In the present embodiment, the difference in the measured values is set to 0 before starting grinding, and the change in the difference is monitored. The controller 50 may display the tire grinding amount calculated from the difference in the measured values by the measuring device 30 on a monitor such as a touch panel.

[0066] Steps S4 to S6 are repeated until the tire grinding amount reaches the target value (No in step S7). The target value is stored in the memory of the controller 50 together with, for example, the grinding pattern. When the tire grinding amount reaches the target value (Yes in step S7), the grinding of the tread surface by the grinding device 20 is stopped and the grinding process is terminated (step S8). At this time, in order to prevent the occurrence of uneven grinding, it is preferable to continue grinding until a series of grinding patterns are completed. That is, even when the tire grinding amount reaches the target value, it is preferable not to end the grinding in the middle of the grinding pattern.

[0067] Figures 8 and 9 show an example of the grinding pattern set in step S3. Z in the figure indicates the profile surface along the surface of the tread 2 (the grounding surface 4). As described above, the tire grinding device 10 performs the grinding of the tread surface while moving in the tire axial direction based on a preset grinding pattern.

[0068] The grinding pattern illustrated in Figure 8 is a pattern in which, starting from the position of X2 on the tread surface, the grinding belt 21 moves in the tire axial direction in the order of X2 → X6 → X7 → X2 → X1 while performing grinding. The grinding pattern illustrated in Figure 9 is a pattern in which X5 is inserted between X2 and X6, and the grinding belt 21 moves in the tire axial direction in the order of X2 → X5 → X6 → X7 → X2 → X1. When the grinding belt 21 moves from X7 to X2, the pressing force of the grinding belt 21 against the tread surface is reduced so that the grinding belt 21 is in contact with the tread surface. Alternatively, the grinding belt 21 may be separated from the tread surface.

[0069] Any of the polishing patterns shown in FIGS. 8 and 9 is a pattern in which the polishing belt 21 polishes the tread surface while moving from the inner side to the outer side in the tire axial direction on both sides of the tread 2 in the tire axial direction. As a result of the study by the present inventors, it has been found that when polishing is performed by moving the polishing belt 21 from the outer side to the inner side in the tire axial direction, such as X1→X2, uneven polishing is likely to occur near the grounding end. On the other hand, it has been found that if polishing is performed while moving the polishing belt 21 as in X6→X7, X2→X1, uneven polishing can be effectively reduced and the polishing state of the tread surface can be greatly improved. According to this polishing pattern, the entire desired polishing range can be polished beautifully without uneven polishing.

[0070] X1, X2, X5, X6, and X7 on the tread surface are coordinates (X coordinates) for controlling the position of the polishing belt 21 in contact with the tread surface, and can be set at arbitrary positions. The polishing belt 21 moves in the tire axial direction so that the center in the width direction of the belt is located on the designated X coordinate. The number of X coordinates defining the polishing pattern is, for example, 4 to 7. An example of X1 and X7 is a position corresponding to the left and right grounding ends of the tread 2. An example of X2 and X6 is a position where the curvature of the profile surface Z changes between the left and right grounding ends and the equator of the tread.

[0071] The polishing pattern includes, for example, in addition to the moving pattern (X coordinate, polishing order, etc.) of the polishing belt 21 in the tire axial direction, the rotation direction and rotation speed of the tire 1, the rotation direction and rotation speed of the polishing belt 21, the pressing force of the polishing belt 21 against the surface of the tread 2, the target polishing amount, and the like. In the present embodiment, each of the above parameters constituting the polishing pattern is set and stored in the memory by operating the input interface by the user. A plurality of polishing patterns may be stored in the memory. In the tire polishing apparatus 10, the target polishing pattern can be selected from a plurality of polishing patterns by operating the input interface by the user.

[0072] The pressure P2 shown in Fig. 8 is the pressing force (polishing pressure) of the polishing belt 21 against the tread surface when the polishing belt 21 moves from X2 to X6. The pressure P1 is the pressing force of the polishing belt 21 when the polishing belt 21 moves from X6 to X7 and from X2 to X1. P1 and P2 may be set to the same value or different values.

[0073] The number of polishing times N2 means the number of polishing times until the polishing belt 21 moves from position X2 to X6, that is, the number of rotations of the tire 1 during the movement. The number of polishing times N1 is the number of polishing times until the polishing belt 21 moves from X6 to X7 and from X2 to X1. N1 and N2 may be set to the same value or different values.

[0074] The polishing device 20 may polish the tread surface by repeating the movement pattern of X2 → X6 → X7 → X2 → X1, but it is more preferable to combine the second movement pattern. A suitable second movement pattern is a pattern in which the polishing belt 21 moves as X6 → X2 → X1 → X6 → X7 with the position of X6 as the starting point. Also in this case, when moving from X1 to X6, the pressing force of the polishing belt 21 is set small, and the tread surface is not substantially polished.

[0075] That is, it is more preferable that the polishing device 20 alternately repeats the first and second polishing patterns in which the moving directions at the center in the tire axis direction of the tread 2 are opposite directions to polish the tread surface. In the first polishing pattern, at the center in the tire axis direction of the tread 2, the polishing belt 21 moves from the first grounding end side to the second grounding end side (X2 → X6). In the second polishing pattern, at the center in the tire axis direction of the tread 2, the polishing belt 21 moves from the second grounding end side to the first grounding end side (X6 → X2). In this case, the effect of suppressing polishing unevenness becomes more remarkable, and the polishing accuracy can be further improved.

[0076] When switching from the first polishing pattern to the second polishing pattern, that is, when the polishing belt 21 moves from X1 to X6, the pressing force of the polishing belt 21 is set to be small so that the tread surface is not substantially polished (the same applies when switching from the second polishing pattern to the first polishing pattern). In the memory of the controller 50, for example, the first and second polishing patterns are grouped as a set and stored as one polishing pattern.

[0077] When the polishing device 20 moves to the end of the polishing range on the tire surface, it is preferable to continue polishing until the tire 1 rotates at least once. When the polishing belt 21 reaches the end of the polishing range, only a part of the tire surface in the tire circumferential direction is polished at the end. Therefore, by performing polishing for at least one rotation of the tire 1, more uniform polishing can be achieved. In the example shown in FIG. 8, when the polishing belt 21 reaches X1 or X7, polishing is performed without moving the polishing belt 21 until the tire 1 rotates at least once.

[0078] As described above, the polishing device 20 preferably performs polishing while moving in the tire axial direction at a moving speed equal to or less than the length corresponding to 50% of the width W of the polishing belt 21 per rotation of the tire 1. By controlling the moving speed of the polishing belt 21 in this way, the polishing accuracy can be further improved. In the polishing pattern shown in FIG. 8, for example, the moving speed when the polishing belt 21 moves from X2 to X6 is limited to be equal to or less than the length corresponding to 50% of the width W of the polishing belt 21 per rotation of the tire 1.

[0079] As described above, according to the tire polishing device 10 having the above configuration, it is possible to accurately measure the polishing amount of the tire 1, and high polishing accuracy can be achieved based on the accurate measurement result. The tire polishing device 10 irradiates the ground contact surface 4 and the groove bottom 6 of the tire 1 with laser light by the measuring device 30, and measures the tire polishing amount from the difference between the respective measured values. Therefore, the influence of thermal expansion due to polishing can be effectively eliminated, and an accurate polishing amount can be measured.

[0080] Further, based on the above polishing pattern, by polishing the tire surface while moving in the tire axial direction, the entire desired polishing range can be polished beautifully without polishing unevenness, and the target polishing level can be realized with high precision. Since the tire polishing apparatus 10 is configured to automatically polish the tire surface based on a preset polishing pattern, not only can high polishing accuracy be realized, but it also greatly contributes to reducing the work burden on the user.

[0081] Note that the above embodiment can be appropriately modified in design without impairing the object of the present invention. For example, the above structures of the polishing apparatus 20, the measuring apparatus 30, and the moving mechanism 40 are merely examples, and each structure is not limited to the above structure. Further, the above polishing pattern is effective in realizing the target polishing level with high precision. However, for example, within a range not impairing the object of the present invention, the tire surface may be polished while moving from the outside to the inside in the tire axial direction on both sides of the tread in the tire axial direction.

Explanation of Reference Numerals

[0082] 1 Tire, 2 Tread, 3 Block, 4 Ground Contact Surface, 5 Groove, 6 Groove Bottom, 10 Tire Polishing Apparatus, 11 Stand, 12 Tire Support Shaft, 15 Driving Device, 16, 26 Motor, 20 Polishing Apparatus, 21 Polishing Belt, 22 Driving Pulley, 23 Driven Pulley, 24 Spring, 25 Lever, 27 Support Frame, 28 Cam Follower, 30 Measuring Apparatus, 31a, 31b Laser Device, 32a, 32b Aperture, 33a, 33b Frame, 34 Blower, 35a, 35b, 36a, 36b Air Nozzle, 37, 38 Guide Rail, 40 Moving Mechanism, 41 First Link, 42 Second Link, 43 Third Link, 44 Base Substrate, 44a Long Hole, 45 Support Shaft, 46 First Cylinder, 47 Second Cylinder, 50 Controller, 60 Encoder, G1, G2 Measurement Point

Claims

1. A driving device for rotating a tire, A polishing device for polishing the ground contact surface of the tire, A measuring device for measuring the tire polishing amount by irradiating the tire surface including the ground contact surface and the groove with laser light, detecting the reflected light from the tire surface, and measuring the distance, An encoder connected to the tire support shaft for measuring the rotation angle of the tire, Comprising, The measuring device is configured to irradiate the ground contact surface and the groove bottom with the laser light respectively, and measure the tire polishing amount from the difference between the measured values at the ground contact surface and the groove bottom, The measuring device irradiates the laser light at the measurement point of the tire polishing amount where the laser light is irradiated based on the information obtained by the encoder, a tire polishing device.

2. The measuring device has a first laser device for irradiating the ground contact surface with the laser light and a second laser device for irradiating the groove bottom with the laser light, the tire polishing device according to claim 1.

3. Before polishing the tire, the measuring device is configured to measure the distance from the tire surface and determine the measurement point, the tire polishing device according to claim 1 or 2.

4. A driving device for rotating a tire, A polishing device for polishing the ground contact surface of the tire, A measuring device for measuring the tire polishing amount by irradiating the tire surface including the ground contact surface and the groove with laser light, detecting the reflected light from the tire surface, and measuring the distance, Comprising, The measuring device is configured to irradiate the ground contact surface and the groove bottom with the laser light respectively, and measure the tire polishing amount from the difference between the measured values at the ground contact surface and the groove bottom, The measuring device is arranged on the side opposite to the polishing device with the tire sandwiched therebetween, a tire polishing device.

5. A driving device for rotating a tire, A polishing device for polishing the ground contact surface of the tire, A measuring device for measuring the tire polishing amount by irradiating the tire surface including the ground contact surface and the groove with laser light, detecting the reflected light from the tire surface, and measuring the distance, A blower including a first outlet for blowing air onto the tire surface, Comprising, The measuring device is configured to irradiate the ground contact surface and the groove bottom with the laser light respectively, and measure the tire polishing amount from the difference between the measured values at the ground contact surface and the groove bottom, The blower is a tire polishing device that blows air onto the measurement point before the irradiation position of the laser light is reached after the measurement point of the tire polishing amount irradiated with the laser light passes through the polishing position by the polishing device.

6. The tire polishing device according to claim 5, wherein the blower includes a second air outlet for blowing air onto the laser light outlet in the measuring device.

7. The tire polishing device according to claim 6, wherein the blower blows air onto the laser light outlet at least when blowing air onto the tire surface.

Images