JP4456126B2 - Tire uniformity testing equipment - Google Patents

Description

  The present invention relates to a tire uniformity testing apparatus.

  Conventionally, a uniformity test for measuring a variation in force generated by a rotating tire is known. The uniformity test is configured to measure load fluctuations in the radial direction and the thrust direction of the tire by rotating the tire with a rotating drum pressed against the outer peripheral surface of the tire.

As a test apparatus for performing the uniformity test and the dynamic balance test, for example, there is a tire uniformity and dynamic balance combined test apparatus described in Patent Document 1. In the test apparatus described in the above publication, a tire is attached to a spindle that is rotatably supported in a spindle housing via a ball bearing, and is rotated at a predetermined rotational speed.
JP-A-11-183298

  Here, the tire is attached to the spindle by sandwiching the tire between the upper rim and the lower rim, which are disk-shaped members, in the tire rotation axis direction.

  During the uniformity test, the tire is rotated with the spindle while the rotating drum is pressed against the outer peripheral surface of the tire with a force of several hundred kgf or more, and the fluctuation of the load at that time is measured by a load cell installed in the rotating drum. ing.

  The uniformity test is usually performed based on the automobile standard “JASO (Japan Automobile Standards Conference) C607”. In the standard “JASO C607”, the rotation speed of the tire is set to 60 rpm.

  However, since the tire rotation speed of 60 rpm is approximately 7 km / hour when converted to the speed of an automobile, the uniformity test according to the above standards does not necessarily reflect the behavior of the tire during driving. Therefore, what is called a high-speed uniformity test is desired in which the tire is rotated at a faster rotational speed and the above-described load fluctuation is measured.

  In particular, when the tire rotates at high speed, the tire tends to suffer from a variation in force in the circumferential direction of the tire, that is, a traction force variation (TFV), which is difficult to detect in the uniformity test according to the above standard. Therefore, it is desired that TFV can be accurately measured in the high-speed uniformity test.

  In order to simplify the tire testing process, it is desirable that the uniformity testing apparatus be capable of performing both the uniformity testing and the dynamic balance test for measuring the eccentric state of the tire.

  However, since the test apparatus described in the above publication measures load fluctuations with a strain gauge attached to the rotating drum side, the rotation speed is particularly large during high-speed uniformity tests where the fluctuation range of TFV load tends to be large. Since the error due to the distortion of the drum itself increases to a level that cannot be ignored, the high-speed uniformity cannot be accurately measured by the test apparatus described in the above publication.

  In addition, when trying to perform a high-speed uniformity test using the test apparatus described in the above publication, there is a problem that a measurement error occurs in the TFV due to the weight imbalance of the upper rim and the lower rim that sandwich and fix the tire during the uniformity test. It was.

  Further, since the test apparatus described in the above publication uses different load sensors for the uniformity test and the dynamic balance test, the apparatus configuration is large and complicated.

  In view of the circumstances described above, an object of the present invention is to provide a uniformity testing apparatus capable of accurately measuring the uniformity of a tire rotating at a high speed.

  In order to solve the above problems, the apparatus of the present invention is a spindle housing that supports the spindle in a freely rotatable manner and is rigidly supported, and is installed in contact with the surface of the spindle housing and acts in an arbitrary direction. A three-component piezoelectric element capable of measuring a force as an orthogonal three-component force, and a piezoelectric element fixing member sandwiching the three-component piezoelectric element between a spindle housing and a rigid support, and a three-component piezoelectric element Computation means for computing tire uniformity from the measured load variation of the tire, and a double row cylindrical roller radial bearing provided between the spindle housing and the spindle, through which the spindle is A spindle housing that is rotatably supported in the spindle housing.

  Preferably, the outer periphery of the portion of the spindle that engages with the double row cylindrical roller radial bearing is tapered, and the inner periphery of the double row cylindrical roller radial bearing has the same gradient as the outer periphery of the tapered spindle. The double-row cylindrical roller radial bearing is a double-row cylindrical roller radial bearing by being pushed in the thrust direction from the small diameter side toward the large diameter side of the outer periphery of the tapered spindle. The double-row cylindrical roller radial bearing is inserted into the spindle so that the inner ring of the inner ring and the outer periphery of the spindle formed in a tapered shape are in close contact with each other.

  The piezoelectric element fixing member is fastened to the spindle housing via the piezoelectric element, and a three-component piezoelectric element is provided close to a screw for fastening the piezoelectric element fixing member to the spindle housing. The screw for fastening the member to the spindle housing may be arranged at the same height as the double row cylindrical roller radial bearing.

  Preferably, the three-component piezoelectric element is formed in a cylindrical shape, and a screw for fastening the piezoelectric element fixing member to the spindle housing is inserted into the cylinder of the three-component piezoelectric element.

  Further, the double-row cylindrical roller radial bearing may be provided in each of an upper stage and a lower stage of a space between the spindle housing and the spindle.

  Preferably, the three-component piezoelectric element is disposed at each vertex of a rectangle having four sides extending in an axial direction of the spindle and a direction perpendicular to the axial direction.

  With the tire uniformity testing apparatus of the present invention having the above-described configuration, it is possible to accurately measure the uniformity of a tire rotating at a high speed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing a basic configuration of a uniformity and dynamic balance combined testing apparatus 1 (hereinafter referred to as combined testing apparatus 1) according to an embodiment of the present invention. In the following description, “upper” and “lower” are defined as shown in FIG. 1. However, the configuration of the composite test apparatus 1 may be upside down or horizontally.

  The apparatus frame of the composite test apparatus 1 includes a base 50, a column 52 extending vertically upward from the base 50, and a top plate 54 supported by the column 52. A spindle 120 that holds and rotates the tire T is attached to the base 50.

  The composite test apparatus 1 is configured to sandwich and hold the tire T between the lower rim 10 and the upper rim 20 in the vertical direction. First, a configuration for supporting the tire T will be described.

  FIG. 2 is a side sectional view showing the spindle 120. The spindle 120 includes a hollow portion 120a and a bracket portion 120b. Further, the upper end of the hollow portion 120a of the spindle 120 protrudes in the horizontal direction to form a flange portion 120e. The spindle 120 is rotatably supported by the spindle housing 110 (via the double row cylindrical roller bearings 112a and 112b and the combined angular ball bearing 113). Here, the double-row cylindrical roller bearings 112a and 112b support the spindle shaft from the radial direction, and the combined angular ball bearing 113 supports the spindle shaft from both the radial and thrust directions.

  A hollow shaft 170 is fixed to the flange portion 120e of the spindle 120 coaxially (so that the central axes are aligned). Further, the upper end portion of the hollow shaft 170 is fitted into the lower rim 10. The lock shaft 300 with the upper rim 20 fixed to the upper end portion is inserted into the bracket portion 120b through the hollow shaft 170, and the tire T is sandwiched and held between the lower rim 10 and the upper rim 20. Can do.

  Here, the middle of the hollow portion into which the lock shaft 300 of the bracket portion 120b is inserted is constricted. When the lock shaft 300 is inserted into the bracket portion 120b, the fitting portion, which is a constricted portion, comes into close contact with the side surface of the lock shaft 300. That is, during the uniformity test, the fitting portion of the bracket portion 120 b supports the bending load applied to the lock shaft 300 from the rotating drum together with the hollow shaft 170.

  In addition, since this fitting portion is formed between the double row cylindrical roller bearing 112a and the combination angular contact ball bearing 113, the radial load applied from the lock shaft 300 to the fitting portion of the bracket portion 120b is double. It is firmly supported by both the row cylindrical roller bearing 112a and the combined angular ball bearing 113.

  Lock grooves 302 are formed in a multistage shape on the outer periphery of the middle portion of the lock shaft 300. Further, a through hole is formed in the side surface of the hollow shaft 170. A lock member 160 is inserted in the through hole, and the lock member 160 is driven by the lock cylinder 165 in the direction of approaching / separating from the outer peripheral surface of the lock shaft 300 through the through hole.

  Note that the vertical length of the hollow shaft 170 is suppressed to be slightly larger than the vertical width of the through hole drilled in the side surface of the hollow shaft 170. Therefore, since the bending moment at the position of the fitting portion of the bracket portion 120b is minimized, deformation of the lock shaft 300 and the hollow shaft 170 in the radial direction is suppressed, and more accurate uniformity can be measured.

  FIG. 3 shows an enlarged cross-sectional view of the spindle 120 and the lock shaft 300 around the lock member 160. Four sets of the lock member 160 and the lock cylinder 165 are provided radially every 90 ° with respect to the central axis of the lock shaft 300 (only two sets are shown in FIG. 3). A lock claw 162 is formed at the tip of the lock member 160 facing the outer peripheral surface of the lock shaft 300. The lock claws 162 are vertically arranged in six stages, and the lock claws 162 engage with the lock grooves 302 of the lock shaft 300.

  The lock member 160 is attached to the distal end portion of the plunger 166 of the lock cylinder 165. By supplying air to the lock cylinder 165, the plunger 166 and the lock claw 162 are pressed toward the lock shaft 300. The supply of air to the lock cylinder 165 will be described later. The plunger 166 is biased in a direction away from the lock shaft 300 by a spring 168 provided in the main body of the lock cylinder 165. That is, the lock member 160 is biased in a direction away from the lock shaft 300. Thus, when the lock cylinder 165 is on (air is supplied to the lock cylinder 165), the lock member 160 is engaged with the lock shaft 300, and the lock cylinder 165 is off (air is supplied to the lock cylinder 165). When not being performed), the lock member 160 releases the lock shaft 300.

  Since the lock shaft 300 is inserted into the bracket portion 120b of the spindle 120 and the lock cylinder 165 is turned on, the tire T is securely sandwiched between the lower rim 10 and the upper rim 20 because of the above configuration. Can be held in. Further, the tire T can be removed from between the lower rim 10 and the upper rim 20 by turning off the lock cylinder 165 to release the lock and pulling out the lock shaft 300 from the spindle 120. A configuration for driving the lock shaft 300 will be described later.

  A proximity sensor (not shown) is provided at a position close to each of the locking cylinders 165. This proximity sensor is fixed on the spindle housing 110, and can detect whether the distance between the locking cylinder 165 and the proximity sensor is within 1 mm. When the lock cylinder 165 is off, the distance between the lock cylinder 165 and the proximity sensor is within 1 mm. Otherwise, the proximity sensor is positioned so that the distance between the lock cylinder 165 and the proximity sensor exceeds 1 mm. is set up. Therefore, by monitoring the proximity sensor, it is possible to confirm whether the lock member 160 is in a position where the lock member 160 is engaged with the lock shaft 300 (lock position) or in a position away from the lock shaft 300 (lock release position). .

  A method of fitting the double row cylindrical roller bearing 112a into the spindle 120 will be described with reference to FIG. A collar 121 a having a square cross section is fitted into the bracket portion 120 b of the spindle 120. Here, the upper surface of the collar 121a abuts on the lower surface of the flange portion formed at the upper end of the bracket portion 120b.

  Here, the outer periphery of the portion of the bracket portion 120b that engages with the double-row cylindrical roller bearing 112a forms a tapered surface 120d that becomes thicker upward. Further, the inner circumference of the double row cylindrical roller bearing 112a is formed in a tapered shape having the same gradient as the tapered surface 120d and becoming thicker upward. The diameter of the upper end portion of the tapered surface 120d is slightly larger than the diameter of the inner periphery of the double row cylindrical roller bearing 112a.

  Further, a collar 121b having a square cross section is inserted between the double row cylindrical roller bearing 112a and the combination angular ball bearing 113. Here, the upper surface of the collar 121b contacts the lower end of the double row cylindrical roller bearing 112a. Similarly, the lower surface of the collar 121b abuts on the upper end of the combined angular ball bearing 113. Furthermore, a collar 121c having a square cross section is fitted into the bracket portion 120b. Here, the upper surface of the collar 121 c comes into contact with the lower end of the combination angular contact ball bearing 113.

  Furthermore, the external thread part 120c is screwed by the bracket part 120b. The male screw portion 120c is screwed downwardly from the lower surface of the collar 121c when the collar 121a, the double row cylindrical roller bearing 112a, the collar 121b, the combination angular ball bearing 113, and the collar 121c are fitted into the bracket portion 120b.

  Here, the collar 121a, the double row cylindrical roller bearing 112a, the collar 121b, the combination angular ball bearing 113, and the collar 121c are sequentially fitted into the bracket portion 120b. At this time, the double-row cylindrical roller bearing 112a is fitted into the bracket portion 120b.

  Next, the double-row cylindrical roller bearing 112a is formed by screwing a biasing nut 114a having a female thread portion that can be screwed to the male thread portion 120c on the inner periphery thereof, and further tightening with a predetermined torque. Pushed upwards. Next, in order to prevent the biasing nut 114a from loosening, the locking nut 114b is screwed onto the male screw portion 120c, and the upper surface of the locking nut 114b is biased against the lower surface of the biasing nut 114a.

  As described above, the diameter of the upper end portion of the tapered surface 120d is slightly larger than the inner diameter of the double row cylindrical roller bearing 112a. As a result, the tapered surface 120d and the inner circumference of the double row cylindrical roller bearing 112a are in close contact with each other. . Therefore, since the inner ring of the spindle 120 and the double row cylindrical roller bearing 112a is completely integrated, rattling between the spindle 120 and the double row cylindrical roller bearing 112a is prevented. Further, since the clearance between the inner ring and the steel ball of the combined angular ball bearing 113 and the clearance between the steel ball and the outer ring is minimized, the rattling between the inner ring and the steel ball of the combined angular ball bearing 113 and between the steel ball and the outer ring is minimized. Is prevented.

  The method of fitting the double row cylindrical roller bearing 112b into the spindle 120 is the same as the method of fitting the double row cylindrical roller bearing 112a into the spindle 120. Here, since the radial load applied to the double row cylindrical roller bearing 112b is smaller than the radial load applied to the double row cylindrical roller bearing 112a, the biasing nut directly biases the double row cylindrical roller bearing 112b. Do not use a locking nut. That is, after the double row cylindrical roller bearing 112b is fitted into the hollow portion 120a of the spindle 120, the urging nut 114c is screwed onto the male screw portion screwed to the outer periphery of the hollow portion 120a.

  The spindle housing 110 is a prismatic member, and a through-hole into which the double-row cylindrical roller bearings 112a and 112b and the combined angular ball bearing 113 can be mounted is drilled in the central thrust direction. The spindle housing 110 is rigidly supported on the base 50 by a support shaft (not shown) extending from the apparatus frame of the composite test apparatus 1.

  In the uniformity test, the rotating drum 300 provided on the side of the spindle 120 is used. The rotary drum 30 is mounted on a movable housing 32 slidable on a rail 31 extending in a direction approaching / separating from the tire T, and a rack and pinion mechanism 35 (pinion 36 / rack 38) driven by a motor (not shown). To move in the approach / separation direction with respect to the tire T. The rotating drum 30 can be rotated at an arbitrary number of rotations by a motor (not shown).

  When the uniformity test is performed, the rotating drum 30 is brought into contact with the tire T by the rack and pinion mechanism 35, and the rotating drum 30 is further pressed against the tire T with a force of several hundred kgf or more. Next, the rotating drum 30 is rotated in this state (therefore, the tire T in contact with the rotating drum 30 also rotates with the rotating drum 30), and the force generated by the rotating tire from the fluctuation of the load at that time It is a test to measure the variation of.

  On the other hand, the dynamic balance test is a test in which the tire T is rotated together with the spindle 120 in a state where the rotary drum 30 is separated from the tire T, and the eccentric state of the tire is measured from the excitation force generated from the unbalance of the tire T at that time. It is.

  In the embodiment of the present invention, the load fluctuation in the uniformity test and the excitation force in the dynamic balance test are measured by the three-axis piezoelectric elements 185 installed at four locations on one side of the spindle housing 110. .

  The piezoelectric element 185 is a cylindrical sensor such as a quartz piezoelectric force sensor 9067 manufactured by KISTLER, for example, and detects a load applied in an arbitrary direction as an orthogonal three-component force and converts it into an electrical signal. The measurement range of the piezoelectric element 185 is approximately 0 to 20000 kgf for the component in the cylindrical axis direction (that is, the direction in which the rotating drum presses the tire during the uniformity test), and approximately −2000 to 2000 kgf for the other two components. Further, the piezoelectric element 185 is integrated with the spindle housing 110 in order to accurately measure the load received by the spindle 120.

  In other words, in order to integrate the piezoelectric element 185 with the spindle housing 110, the piezoelectric element 185 is sandwiched between the piezoelectric element fixing plate 102 and one side surface of the spindle housing 110. A through-hole 102 a having substantially the same diameter as the hole of the piezoelectric element 185 is drilled in the thickness direction of the piezoelectric element fixing plate 102 at a location where the piezoelectric element 185 of the piezoelectric element fixing plate 102 abuts. Similarly, at a portion where the piezoelectric element 185 of the spindle housing 110 is in contact, a through hole 110a having substantially the same diameter as the hole of the piezoelectric element 185 in the plate thickness direction on one side surface of the spindle housing 110 to which the piezoelectric element 185 is attached. Is perforated. A female screw is threaded on the inner periphery of the through hole 110 a of the spindle housing 110.

  A cylindrical bar 186 in which a male screw that can be screwed with a female screw of the through hole 110a of the spindle housing 110 is threaded on all sides is provided in the through hole 102a and the piezoelectric element 185 of the piezoelectric element fixing plate 102. It is inserted. Further, the bar 186 is screwed into the through hole 110 a of the spindle housing 110. The tip of the bar 186 is in contact with the double row cylindrical roller bearing 112a or 112b.

  Here, a nut 187 is screwed to a portion of the bar 186 protruding from the piezoelectric element fixing plate 102 (left side in FIG. 2). The nut 187 is tightened with a predetermined torque. As a result, the nut 187 presses the piezoelectric element fixing plate 102 with an axial force of about 5000 kgf. Accordingly, the piezoelectric element 185 is sandwiched between the piezoelectric element fixing plate 102 and one side surface of the spindle housing 110 with a force of about 5000 kgf, and is integrated with the piezoelectric element fixing plate 102 and the spindle housing 110.

  A pulley 140 for rotating the spindle 120 during a dynamic balance test is attached to the lower end of the spindle 120. The base 50 is provided with a spindle drive motor 130 that can be moved back and forth horizontally toward the spindle by a rack and pinion mechanism (not shown). A drive pulley 144 is attached to the rotation shaft of the spindle drive motor 130 at the same height as the pulley 140 of the spindle 120. A pair of driven pulleys 144 are rotatably installed on the same plane as the driving pulley 144 and the pulley 140 of the spindle 120. The driven pulley 144 moves forward and backward with the spindle drive motor 130 by the rack and pinion mechanism (not shown). Here, the endless belt 142 is stretched around the drive pulley 144 and the driven pulley 143, and the endless belt 142 can be advanced at a predetermined speed by the spindle drive motor 130.

  A method of rotationally driving the pulley 140 of the spindle 120 (via the endless belt 142) by the spindle drive motor 130 is shown in FIG. The drive pulley 144 of the spindle drive motor 130 rotates at a predetermined rotational speed in a predetermined direction (counterclockwise in FIG. 6).

  When the pulley 140 of the spindle 120 is not rotationally driven by the spindle drive motor 130, the spindle drive motor 130, the drive pulley 144, the driven pulley 143, and the endless belt 142 prevent the endless belt 142 from coming into contact with the pulley 140 of the spindle 120. Retracted (broken line portion in FIG. 6). From this state, the spindle drive motor 130, the drive pulley 144, the driven pulley 143, and the endless belt 142 are moved toward the spindle 120 by the rack and pinion mechanism (not shown) so that the endless belt 142 biases the pulley 140 of the spindle 120. To. Since the endless belt 142 advances in a predetermined direction (arrow direction in the figure) by the spindle drive motor 130, the drive pulley 144, and the driven pulley 143, the pulley 140 of the spindle 120 that contacts the endless belt 142 is rotated in the rotational direction of the drive pulley 144. And in the opposite direction (clockwise in FIG. 6). Therefore, the spindle 120 rotates while holding the tire T between the lower rim 10 and the upper rim 20.

  The spindle 120 is configured to send air into the tire T from a rotary joint 145 provided at the lower end of the hollow portion 120a. Therefore, an air pipe 115 is provided in the hollow portion 120a of the spindle 120 so as to penetrate the hollow portion 120a up and down. An upper end portion of the air pipe 115 is fixed to the air pipe 115 by a flange 116, and a lower end portion is connected to the rotary joint 145.

  An air hose 132 for sending air into the air pipe 115 is connected to the rotary joint 145. The air sent from the air hose 132 via the rotary joint 145 passes through the air pipe 115 upward, further passes through the air passage 138 formed in the bracket portion 120b, and reaches the switching valve 131. The switching valve 131 switches whether the air that has passed through the air passage 138 is sent to the bracket portion 120b or the air passage 135 toward the air passage 172 of the hollow shaft 170. When testing the tire T with no wheel mounted, the air that has escaped into the air passage 138 is set to go to the air passage 135. Therefore, the air sent from the air hose 132 via the rotary joint 145 is sent into the tire T through the air passage 172 of the hollow shaft 170.

  Thus, the portion from the rotary joint 145 to the air passage 172 constitutes an air supply system for inflating the air into the tire T. An air passage 136 for supplying air to the aforementioned locking cylinder 165 branches off from the air passage 135. An on-off valve 133 is installed in the middle of the air passage 136. That is, when the lock cylinder 165 is turned on, the on-off valve 133 is opened and air is supplied to the lock cylinder 165.

  An engagement flange portion 320 that is engaged with a chuck claw 210 (described later) from the outside is provided at the tip of the attachment member 310 for attaching the upper rim 20 to the lock shaft 300.

  The inserter unit 200 that drives the lock shaft 300 up and down and inserts (or pulls out) it into the spindle 120 is attached to an elevating housing 60 disposed further above the top plate 54 shown in FIG. The elevating housing 60 is supported by four sets of linear guides 61 extending in the vertical direction so as to be movable up and down. The elevating housing 60 is driven up and down by a ball screw 65 driven by a servo motor 66 and an arm portion 67 having a screw hole that is screwed into the ball screw 65 provided on the outer surface of the elevating housing 60.

  FIG. 5 is a side view showing the structure of the inserter unit 200. The inserter unit 200 has a unit body 240 having a substantially cylindrical shape. The unit main body 240 is attached to the elevating housing 60 so that the substantially cylindrical unit main body 240 and the spindle 120 are coaxial (the central axes are aligned in a straight line).

  Three chuck claws 210 (only two are shown in FIG. 5) that are engaged with the engagement flange portion 320 of the lock shaft 300 from the outside are provided at the lower portion of the unit main body 240. The chuck claw 210 is urged toward the outside in the radial direction of the unit main body 240 by a spring member (not shown).

  The chuck claws 210 are driven in the radial direction of the unit main body 240 by air pressure. That is, when air is supplied to an air supply port (not shown) provided in the unit main body 240, the air urges the chuck claws 210 toward the inside of the unit main body 240 in the radial direction. Accordingly, by supplying air to the unit main body 240, the chuck claw 210 moves radially inward of the unit main body 240 and chucks the engagement flange portion 320 of the lock shaft 300. On the other hand, when air is extracted from the unit main body 240 from this state, the chuck claws 210 are moved radially outward of the unit main body 240 by the biasing force of the spring member, and the chuck is released.

  The holding of the tire T by the combined test apparatus 1 configured as described above is performed as follows. First, air is supplied to the unit main body 240 of the inserter unit 200, the lock shaft 300 is chucked by the chuck claws 210, the ball screw 65 is driven to raise the elevating housing 60, and the lock shaft 300 is pulled out from the spindle 120. Next, after setting the tire T on the lower rim 10, the ball screw 65 is driven again to lower the elevating housing 60 to an appropriate position according to the rim width of the tire T. Next, the lock cylinder 165 is turned on, and the lock member 160 is engaged with the lock shaft 300. Further, the air is removed from the unit main body 240 of the inserter unit 200 to release the chuck by the chuck claw 210 so that the upper rim can rotate with the spindle 120.

  The distance between the upper rim 10 and the lower rim 20 is adjusted according to the tire width depending on which stage of the multistage lock groove 302 of the lock shaft 300 is engaged with the lock claw 162 (of the lock member 160). Can do. Description of this adjustment is omitted.

  Next, a uniformity test and a dynamic balance test using the composite test apparatus 1 will be described. In the embodiment of the present invention, a uniform test, a high-speed uniformity test, and a dynamic balance test according to the JASO C607 standard are continuously performed on one tire.

  First, the tire T is held between the lower rim 10 and the upper rim 20 using the inserter unit 200, and then air is inflated into the tire T. At this time, the spindle drive motor 130, the drive pulley 144, the driven pulley 143, and the endless belt 142 are on the spindle 120 side, and the endless belt 142 biases the pulley 140 of the spindle 120. Since the spindle drive motor 130 is stopped, the spindle is prevented from rotating by the frictional force between the endless belt 142 and the pulley 140 of the spindle 120.

  Next, a uniformity test according to the JASO C607 standard is performed. Here, prior to the implementation of the uniformity test, the spindle drive motor 130, the drive pulley 144, the driven pulley 143, and the endless belt 142 are retracted so that the endless belt 142 does not contact the pulley 140 of the spindle 120. Next, the control unit (not shown) of the composite test apparatus 1 presses the rotating drum 30 against the tire T with a predetermined load by the rack and pinion mechanism 35. Note that the load with which the rotating drum 30 presses the tire T varies depending on the type of tire, and is about 1 ton for a tire for a passenger car, for example.

  Next, the rotary drum 30 is driven to rotate, and the tire T is rotated at 60 rpm. Then, the load variation that the tire T receives is detected by the piezoelectric element 185. Since the method for calculating the uniformity based on the detected load fluctuation is known, the description thereof is omitted.

  Next, the rotational speed of the rotary drum 30 is increased and a high-speed uniformity test is performed. The rotational speed of the tire T during the high-speed uniformity test differs depending on the outer diameter of the tire. 30 causes the tire T to be driven to rotate at 1238.5 rpm. Then, the load variation that the tire T receives is detected by the piezoelectric element 185. Since the method for calculating the uniformity based on the detected load fluctuation is known, the description thereof is omitted. At this time, the spindle drive motor 130 drives the drive pulley 144 so that the traveling speed of the endless belt 142 is the same as the peripheral speed of the pulley 140 rotating with the spindle 120.

  Subsequently, a dynamic balance test is performed. That is, the spindle drive motor 130, the drive pulley 144, the driven pulley 143, and the endless belt 142 are moved toward the spindle 120 by the rack and pinion mechanism, and the rotating drum 30 is separated from the tire T by the rack and pinion mechanism 35. Since the spindle drive motor 130, the drive pulley 144, the driven pulley 143, and the endless belt 142 are moved and the rotary drum 30 is separated in a very short time, the driving source of the tire T (the tire T is decelerated). (Without switching) to the spindle drive motor 130 smoothly.

  Next, a change in load applied to the piezoelectric element 185 during the rotation of the spindle 120 is detected. Since a method for calculating the dynamic balance based on the detected load fluctuation is known, the description thereof is omitted. Further, the unbalance of the upper rim and the lower rim is calculated from the load fluctuation detected at this time, and the uniformity TFV is calibrated from the unbalance.

  The composite test apparatus 1 calculates which part of the tire T is to be cut based on the uniformity calculation result and the high-speed uniformity calculation result according to the JASO C607 standard, and the tire T is cut by a cutting apparatus (not shown). . Similarly, the composite test apparatus 1 calculates which part of the tire T should be loaded with the balance weight based on the calculation result of the dynamic balance, and marks the corresponding part with a marking apparatus (not shown).

  In the embodiment of the present invention, the tire T is rotated at a rotational speed equivalent to a circumferential speed of 140 km / h during the high-speed uniformity test. However, the tire T may be rotated at a higher rotational speed. . For example, the tire T may be rotated at a rotational speed of about 3000 rpm so that the tire T having an outer diameter of 600 mm is rotated at a peripheral speed equivalent to a peripheral speed of 340 km / h, and the high-speed uniformity test may be performed.

  Moreover, the composite measuring apparatus 1 of this embodiment can measure both uniformity and dynamic balance not only for the tire before the wheel mounting as described above but also for the tire after the wheel mounting. When a test is performed on a tire after the wheel is mounted, a top adapter that presses the wheel from above is used instead of the lock shaft 300 to which the upper rim 20 is fixed, and a hollow shaft 170 to which the lower rim 10 is fixed. In addition, a pull-in unit that supports the tire wheel from below and pulls the top adapter downward is used. In other words, a wheeled tire has its wheel part sandwiched between the top adapter and the pull-in unit.

It is a side view which shows the basic composition of the uniformity and dynamic balance combined testing apparatus of embodiment of this invention. It is a sectional side view which shows the spindle of embodiment of this invention. It is an expanded sectional view of a lock member periphery of a spindle and a lock shaft of an embodiment of the invention. FIG. 3 is a partially cut perspective view of the spindle and the lock shaft according to the embodiment of the present invention in the vicinity of the lock member. It is a side view which shows the internal structure of the inserter unit of embodiment of this invention. In the embodiment of the present invention, a method for rotationally driving a spindle by a spindle drive motor is schematically shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Composite test apparatus 10 Lower rim 20 Upper rim 30 Rotating drum 50 Base 60 Elevating housing 65 Ball screw 66 Servo motor 67 Arm part 102 Piezoelectric element fixed plate 110 Spindle housing 112a Double row cylindrical roller bearing 112b Double row cylindrical roller bearing 113 Combination angular Ball bearing 114 Collar 120 Spindle 120b Bracket part 120c Male thread part 120d Tapered surface 130 Spindle drive motor 140 Pulley 142 Endless belt 143 Driven pulley 144 Drive pulley 160 Lock member 162 Lock claw 185 Piezoelectric element 187 Nut 200 Inserter unit 240 Unit body 210 Chuck Claw 300 Lock shaft 302 Lock groove 320 Engagement flange

Claims (9)

A tire uniformity test apparatus configured to perform a tire uniformity test on a tire mounted on a rotatable spindle, comprising:
A spindle housing that rotatably supports the spindle and is supported by a rigid body;
A three-component piezoelectric element installed in contact with the surface of the spindle housing and capable of measuring a force acting in an arbitrary direction as an orthogonal three-component force;
A piezoelectric element fixing member that sandwiches the three-component piezoelectric element with the spindle housing and is rigidly supported;
A calculation means for calculating the uniformity of the tire from the load fluctuation received by the tire measured by the three-component piezoelectric element;
A double row cylindrical roller radial bearing provided between the spindle housing and the spindle, wherein the spindle is rotatably supported in the spindle housing via the double row cylindrical roller radial bearing. And what
Have
The three-component piezoelectric element is formed in a cylindrical shape;
The piezoelectric element fixing member is fastened to a spindle housing via the three-component piezoelectric element,
A screw for fastening the piezoelectric element fixing member to the spindle housing is inserted into the cylinder of the three-component piezoelectric element,
A screw for fastening the piezoelectric element fixing member to the spindle housing is disposed at the same height as the double row cylindrical roller radial bearing and is in contact with the double row cylindrical roller bearing. Mitty test equipment. An outer periphery of a portion of the spindle that engages with the double row cylindrical roller radial bearing is formed in a tapered shape,
The inner periphery of the double row cylindrical roller radial bearing is formed in a tapered shape having the same gradient as the outer periphery of the spindle formed in the tapered shape,
The double-row cylindrical roller radial bearing is pushed in the thrust direction from the small diameter side to the large diameter side of the outer peripheral portion of the spindle formed in the taper shape, so that the inner ring of the double-row cylindrical roller radial bearing and The double-row cylindrical roller radial bearing is inserted into the spindle so that the outer periphery of the spindle formed in a tapered shape is in close contact with the spindle.
The tire uniformity testing apparatus according to claim 1.   3. The tire uniform according to claim 1, wherein each of the double row cylindrical roller radial bearings is provided in each of an upper stage and a lower stage of a space between the spindle housing and the spindle. Mitty test equipment. At least a part of the side surface of the spindle housing is formed with a plane portion substantially parallel to the rotation axis of the spindle,
The piezoelectric element fixing member is formed in a flat plate shape,
The three-component piezoelectric element is provided on the planar portion;
The piezoelectric element fixing member and the plane portion are parallel.
The tire uniformity testing apparatus according to any one of claims 1 to 3. The spindle housing is formed in a polygonal column shape in which a hole portion through which the spindle is inserted and supported is formed in the thrust direction,
The planar portion is one side of the polygonal columnar spindle housing.
The tire uniformity testing apparatus according to claim 4, wherein   6. The three-component piezoelectric element is arranged at each vertex of a rectangle having four sides extending in an axial direction of the spindle and a direction perpendicular to the axial direction. Uniformity test equipment for tires as described in 1.   The three-component piezoelectric element receives a compressive load from the spindle housing and the piezoelectric element fixing member, and the direction of the compressive load is the same direction as one of the three orthogonal components measured by the three-component piezoelectric element. The tire uniformity testing apparatus according to any one of claims 1 to 6, wherein the tire uniformity testing apparatus is characterized in that:   8. The tire uniformity test according to claim 1, wherein the tire is rotated by rotationally driving a rotating drum of the tire uniformity testing apparatus to perform a uniformity test. 9. apparatus. The uniformity testing device is:
A rotating drum that presses the tire during the uniformity test;
Rotating drum driving means for rotating the rotating drum;
Spindle driving means for rotationally driving the spindle;
The rotating drum driving means is controlled so that the rotating drum is rotationally driven during a uniformity test, and the spindle driving means is controlled so that the spindle is rotationally driven, so that a tire dynamic balance test can be performed. Drive control means for
The tire uniformity testing apparatus according to any one of claims 1 to 8, further comprising:

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