JP5414582B2 - Tire testing equipment - Google Patents

Description

  The present invention relates to a tire testing apparatus used for testing various characteristics of a tire.

  The tire test apparatus includes a roller that is rotated by a motor, a spindle that is rotatably supported by a bearing, and a load cell that detects torque applied to the spindle, and a tire fixed to the spindle is pressed against the circumferential surface of the roller together with the roller. An apparatus for measuring the rolling resistance of a tire based on torque detected by a load cell while rotating is known (for example, Patent Document 1).

  There is also known a technique for simulating the pressure contact with the road surface of a tire in an actual vehicle by connecting a tire shaft to the hydraulic servo cylinder and applying a desired pressure to the tire shaft in the circumferential direction of the roller with the hydraulic servo cylinder. (For example, patent document 2).

JP 2004-004598 A Japanese Patent Laid-Open No. 05-5679

According to the tire test apparatus described above, it was impossible to simulate the behavior such as pitching of an automobile actually mounted with a tire.
Then, this invention makes it a subject to provide the tire testing apparatus which can simulate a real vehicle mounting state better.

  In order to achieve the above object, the present invention provides a tire testing apparatus including a roller, which is used for testing a tire and is in contact with the tire on a peripheral surface, around a predetermined swing axis with respect to the base. A swing part that supports the tire, a force applying mechanism that applies a force around the swing axis to the swing part, and the force that can be applied is variable, and the tire. And an angle formed by a line segment connecting a contact point between the roller and the roller and the swing shaft, a tangent line between the contact point and the roller, and a distance between the contact point and the swing shaft are variable. And a variable mechanism.

Here, the variable mechanism may be a mechanism that makes the position of the swing shaft variable in a biaxial direction perpendicular to the rotation axis of the tire.
Further, according to the present invention, as a tire test method for testing a tire using these tire test apparatuses, an angle formed by a line segment connecting the contact point and the swing shaft and the tangent line using the variable mechanism. Is set to coincide with the angle formed by the line segment connecting the center of gravity of the virtual vehicle, which is a virtual vehicle as the vehicle on which the tire is mounted, and the contact point between the road surface of the tire mounted on the virtual vehicle and the road surface. A setting step of setting a distance between the contact point and the swing shaft so as to coincide with a distance between the contact point and the center of gravity; and in a state where the tire is in contact with the roller, There is provided a tire test method comprising a test step of testing the tire by rotating the tire or the roller.

  Here, in the tire test method, in the setting step, a force in a direction perpendicular to a peripheral surface of the roller applied from the tire to the roller at the contact point coincides with a load applied to the tire in the virtual vehicle. As described above, the force about the swing axis applied to the swing portion by the force applying mechanism may be set.

  As described above, according to the present invention, the virtual vehicle is a vehicle in which the angle formed by the line segment connecting the contact point and the swing axis and the tangent line is virtually assumed as the vehicle on which the tire is mounted by the variable mechanism. The distance between the contact point and the rocking shaft is set so as to coincide with the angle formed by the line segment connecting the center of gravity and the ground contact point of the road surface of the tire mounted on the virtual vehicle. It is set so as to coincide with the distance between the ground contact point and the center of gravity, and the force in the direction perpendicular to the circumferential surface of the roller applied from the tire to the roller at the contact point is Since the tire test can be performed in a state where the force around the rocking shaft applied to the rocking portion by the force applying mechanism is set so as to coincide with the load applied to the tire, Suspense In an actual car, the force of the tire acting on the car and the pitching around the center of gravity of the car due to the force are simulated in a real car. A test can be performed.

  As described above, according to the present invention, it is possible to provide a tire testing apparatus that can better simulate the actual vehicle mounting state.

It is a figure showing the composition of the tire testing device concerning the embodiment of the present invention. It is a figure showing the structure of the tire testing device concerning the embodiment of the present invention. It is a figure which shows the test method using the tire test apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structural example of the control part of the tire test apparatus which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
1a to 1c show the configuration of the tire testing apparatus according to this embodiment.
Here, as shown in the figure, as defining up, down, front, back, left, and right, FIG. 1a shows the tire testing apparatus viewed from the right, FIG. 1b shows the tire testing apparatus viewed from above, and FIG. The tire test device is viewed from the left.
As shown in the figure, the tire test apparatus includes a base 1, a roller 2, a roller shaft 3 connected to the roller 2, a roller shaft bearing 4 fixed to the base 1, and a roller shaft. 3, a roller shaft torque meter 5 for detecting the torque around the axis (twist direction) applied to the roller 3, a roller tachometer 6 for detecting the rotation speed of the roller shaft 3, a roller pulley 7 fixed to the roller shaft 3, and a base 1. A roller motor pulley 9 fixed to a rotating shaft of the roller motor 8 and a roller belt 10 wound around the roller pulley 7. With this configuration, the torque generated by the roller motor 8 is transmitted to the roller 2, and the roller 2 rotates as the roller motor 8 rotates.

The tire testing apparatus also includes a moving table 101 provided on the base 1 and a stage 12.
Here, the stage 12 is provided with an arm 121 at the lower portion, and the stage 121 is swingably supported with respect to the base 1 by connecting the arm 121 to the moving base 101 so as to be swingable by the swing shaft P. Is done.
On the stage 12, a tire shaft 13 as a test object is fixed to one end of a tire shaft 13, the tire shaft 13 is rotatably supported, a tire shaft bearing 14 fixed to the stage 12, and the tire shaft 13. The tire shaft torque meter 15 detects the torque around the axis (torsion direction) applied to the tire, the tire tachometer 16 detects the rotational speed of the tire shaft 13, the tire pulley 17 fixed to the tire shaft 13, and the stage 12. A tire motor 18, a tire motor pulley 19 fixed to the rotation shaft of the tire motor 18, and a tire belt 20 wound around the tire pulley 17. With such a configuration, the torque generated by the tire motor 18 is transmitted to the tire 50, and the tire 50 rotates as the tire motor 18 rotates.

Further, as shown in FIG. 1c, the tire testing apparatus includes a load cylinder 31 that is an air cylinder.
The tip of the load cylinder 31 is pivotally supported on the lower part of the stage 12, and the main body of the load cylinder 31 is pivotally supported on the base 1.
In such a configuration, as shown in FIGS. 2 a 1 and a 2, when the pressure (output) of the load cylinder 31 is increased or decreased, it is a connection point between the arm 121 of the stage 12 and the movable table 101 with respect to the stage 12. A force around the swing axis P is applied, and this force becomes a load that presses the tire 50 against the roller 2 at the contact point of the tire 50 with the roller 2.

Further, as shown in FIGS. 2b1 and 2b, the swing axis P is provided so as to be movable in the vertical direction with respect to the moving base 101 and the arm 121 and to be fixed at an arbitrary vertical position.
Further, as shown in FIGS. 2c1 and 2c, the movable base 101 is movable in the front-rear direction with respect to the base 1, along the guide rail 102 fixed to the base 1, and fixed on the base 1 so as to be fixed at an arbitrary front-rear position. The arm 121 is connected to the lower portion of the stage 12 so as to be movable in the front-rear direction and fixed at an arbitrary front-rear direction position with respect to the stage 12. Then, by similarly moving the moving base 101 with respect to the base 1 and the arm 121 with respect to the stage 12 in the front-rear direction, the swing axis P can be moved back and forth.

Next, a tire testing method using such a tire testing apparatus will be described.
When performing a tire test, first, a virtual vehicle is modeled as shown in FIG. Here, a case where the tire 50 to be tested is mounted as a front wheel of a front wheel drive vehicle is taken as an example.
In FIG. 3a, M is the weight of the virtual vehicle, G is the center of gravity, L is the distance between the ground contact point of the front wheels and the center of gravity G, Wf is the load applied to the front wheels in a static state, and φ is the ground contact point of the front wheels. The angle between the line connecting the center of gravity G and the running surface, F is the driving force of the front wheels, and Fsf is the force acting between the front wheels and the virtual vehicle.

  Then, by adjusting the vertical position of the swing axis P with respect to the moving table 101 and the arm 121 and the position of the moving table 101 and the arm 121 in the front-rear direction, the position of the swing axis P conforms to the model of the virtual vehicle. Set to position. That is, as shown in FIG. 3b, a line segment connecting the contact point between the tire 50 and the roller 2 and the swing axis P of the stage 12 and a tangent line between the roller at the contact point between the tire 50 and the roller 2 are formed. The swing axis P is set at a position where the angle is φ and the distance between the contact point between the tire 50 and the roller 2 and the swing axis P of the stage is L.

Then, a static load W is applied by the load cylinder 31 so that Wf is applied as a force in a direction perpendicular to the peripheral surface of the roller 2 from the tire 50. The weight W can be obtained according to Wf = Wcosφ as a component force in a direction perpendicular to the peripheral surface of the roller 2 of the weight W around the swing axis P acting on the contact point between the tire 50 and the roller 2.
Then, when the position of the swing shaft P and the force W applied by the load cylinder 31 are set as described above, the tire 50 and the roller 2 are rotated by the tire motor 18 and the roller motor 8 to measure the tire characteristics. Perform the action.

The tire testing method using the tire testing apparatus has been described above.
Now, according to such a test method, the force Fsf acting between the tire 50 and the vehicle due to deformation of the tire 50 or the like in the actual vehicle is assumed as ignoring the spring constant of the suspension of the actual vehicle. The tire can be tested in a state where the pitching around the center of gravity of the vehicle by the force Fsf is simulated.
Further, since the stage 12 swings against the load from the load cylinder 31 due to the force applied from the tire 50, it is possible to simulate the fluctuation of the wheel base in an actual automobile.

  Although the case where the tire 50 is tested as a front wheel has been described above, the swing axis P is similarly set when the tire 50 is tested as a rear wheel. That is, in this case, L is replaced with the distance between the ground point of the rear wheel and the center of gravity G, Wf is replaced with a load applied to the rear wheel in a static state, and φ is the ground point and center of gravity of the rear wheel. As shown in FIG. 3 b, the position of the swing axis P and the load applied by the load cylinder 31 are set as the angle formed by the line connecting G and the traveling surface.

Next, a specific configuration example for performing the test operation performed in the tire test method described above will be described.
That is, the tire testing apparatus includes a control unit not shown in FIG. 1 in order to control the test operation.
FIG. 4 shows a configuration example of this control unit.
As shown in the figure, the control unit 200 includes a tire rotation speed conversion unit 201, a first adder 202, a tire PID control unit 203, a driving force calculation unit 204, a running resistance calculation unit 205, a roller PID control unit 206, and a measurement unit 220. And.

  In such a configuration, the measurement unit 220 includes the rotation speed of the roller 2 output from the roller tachometer 6, the rotation speed of the tire 50 output from the tire tachometer 16, and the roller shaft 3 output from the roller shaft torque meter 5. The tire loss of the tire 50 and other various characteristics are measured according to the shaft torque of the tire 50 and the shaft torque of the tire shaft 13 output from the tire shaft torque meter 15.

  On the other hand, the tire rotational speed conversion unit 201 obtains the current target vehicle speed defined by the predetermined vehicle speed schedule 250 at each time point, converts the obtained target vehicle speed into the rotational speed of the tire 50, and outputs it as the tire target rotational speed. To do. The first adder 202 obtains and outputs the difference between the tire target rotational speed and the rotational speed of the tire 50 output from the tire tachometer 16, and the tire PID control unit 203 performs the PID control so that the first adder 202 The control amount of the tire motor 18 for increasing the generated torque of the tire motor 18 as the difference to be output is calculated, and the generated torque of the tire motor 18 is controlled with the calculated control amount.

  Next, assuming that the vehicle on which the tire 50 is mounted is a virtual vehicle, the running resistance calculation unit 205 determines the peripheral speed of the roller 2 calculated from the rotation speed of the roller 2 output from the roller tachometer 6 as the virtual vehicle. As the vehicle speed, a load corresponding to the air resistance of the virtual vehicle at the vehicle speed is calculated as the running resistance.

  In the virtual vehicle model shown in FIG. 3b, where M is the weight of the virtual vehicle and F is the driving force of the front wheels of the virtual vehicle, the acceleration of the virtual vehicle is a, the running resistance (air resistance) of the virtual vehicle. Based on the motion model of F = Ma + Ra, where R is the driving force calculation unit 204, the roller 2 calculated from the angular acceleration of the roller 2 calculated from the rotational speed of the roller 2 output from the roller tachometer 6 The driving resistance calculated by the driving resistance calculation unit 205 is added to the value obtained by multiplying the acceleration of the virtual vehicle obtained by the acceleration of the peripheral speed by the weight M of the virtual vehicle to calculate the driving force of the tire of the virtual vehicle, Use target absorption.

Then, the roller PID control unit 206 controls the generated torque of the roller motor 8 so as to generate a torque corresponding to the target absorption force.
The embodiment of the present invention has been described above.
In the above embodiment, a tire testing apparatus that tests one tire at the same time has been described. However, the tire testing apparatus abuts a plurality of moving platforms 101, stages 12, and load cylinders 31 against the roller 2 by each stage. A plurality of tires can be tested at the same time by providing the tires 50 to be in contact with each other at positions where the rollers 2 are spaced apart from each other (for example, approximately facing positions).

  In the above embodiment, the case where both the roller motor 8 that rotates the roller 2 and the tire motor 18 that rotates the tire 50 are provided and the test is performed has been described. It is also possible to perform a tire test by providing only one of them. However, in this case, control by the control unit shown in FIG. 4 is not performed. Further, in this case, when the roller motor 8 is provided and the roller 2 is rotationally driven to perform the test, the tire 50 is rotatably supported by the stage 12, and the tire motor 18 is provided to rotationally drive the tire 50. When the test is performed, the roller 2 is rotatably supported by the base 1.

  DESCRIPTION OF SYMBOLS 1 ... Base, 2 ... Roller, 3 ... Roller shaft, 4 ... Roller shaft bearing, 5 ... Roller shaft torque meter, 6 ... Roller tachometer, 7 ... Roller pulley, 8 ... Roller motor, 9 ... Roller motor pulley, 10 DESCRIPTION OF SYMBOLS ... Roller belt, 12 ... Stage, 13 ... Tire shaft, 14 ... Tire shaft bearing, 15 ... Tire shaft torque meter, 16 ... Tire tachometer, 17 ... Tire pulley, 18 ... Tire motor, 19 ... Tire motor pulley, DESCRIPTION OF SYMBOLS 20 ... Tire belt, 31 ... Load cylinder, 50 ... Tire, 101 ... Moving stand, 102 ... Guide rail, 121 ... Arm, 200 ... Control part, 201 ... Tire rotational speed conversion part, 202 ... 1st adder, 203 ... Tire PID control unit 204 ... Driving force calculation unit 205 ... Running resistance calculation unit 206 ... Roller PID control unit 220 ... Measurement unit 25 ... vehicle speed schedule.

Claims (4)

A tire test apparatus including a roller used for a tire test, the roller contacting the tire on a peripheral surface,
Base and
A swinging portion for supporting the tire provided so as to be swingable around a predetermined swinging axis with respect to the base;
A force-applying mechanism that applies a force around the rocking shaft to the rocking portion, and the force to be applied is variable;
An angle formed by a line segment connecting a contact point between the tire and the roller and the swing shaft, a tangent to the roller at the contact point, and a distance between the contact point and the swing shaft. A tire testing apparatus comprising a variable mechanism that is variable.
The tire testing device according to claim 1,
The tire testing apparatus, wherein the variable mechanism is a mechanism that makes the position of the swing shaft variable in two axial directions perpendicular to the rotation axis of the tire.
A tire test method for testing a tire using the tire test apparatus according to claim 1 or 2,
Using the variable mechanism, the angle formed by the line segment connecting the contact point and the swing axis and the tangent line is set on the center of gravity of the virtual vehicle and the virtual vehicle, which is a vehicle virtualized as a vehicle on which the tire is mounted. The distance between the contact point and the swing shaft is set to be equal to an angle formed by a line segment connecting the ground point with the road surface of the tire mounted and the road surface. A setting step that is set to match the distance between and
And a test step of testing the tire by rotating the tire or the roller while the tire is in contact with the roller.
The tire test method according to claim 3,
In the setting step, the force mechanism causes the force in the direction perpendicular to the circumferential surface of the roller applied from the tire to the roller at the contact point to match the load applied to the tire in the virtual vehicle. A tire test method characterized by setting a force around the swing shaft applied to the swing portion.