JP2018031689A - Grounding force measuring method of tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grounding force measuring device and method of a tire that can confirm a grounding force measurement position of the tire.SOLUTION: When grounding force of a tire (12) is measured, a tire load barycenter (G) is calculated by measuring a load on the tire (12) at three places, to learn a lateral position of the tire (12) the grounding force of which is measured by using the tire load barycenter (G) as a marker. In addition, positions of the tire load barycenter (G) are calculated in time series, and connected, thereby finding a trajectory (GT) of the tire load barycenter, and conducting a test while confirming behavior of the tire.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for measuring a contact force that a tire receives from a road surface.

  In recent years, attempts have been made to accurately grasp the load (contact force) applied to the tire rolling on the road surface. For example, in Patent Document 1, a tire contact force measuring device combining a plate, a load sensor, and a contact force sensor is embedded in the road surface, and the contact force when the tire passes is divided into three component forces (vertical force, longitudinal force, lateral force). Force) can be measured. A plurality of contact force sensors are arranged in a line in a direction perpendicular to the rolling direction of the tire, and the contact force of the tire can be measured at multiple locations in the tire width direction. The force distribution can be measured. These contact force sensors are arranged in a plurality of rows depending on the situation, and the distribution and fluctuation of the contact force can be measured even in the rolling direction of the tire.

Japanese Patent Application No. 2015-19596 Japanese Patent No. 4367613

  The tread pattern of the tire affects the contact force, and measurements are taken at multiple locations to confirm the effect. For this reason, it is desired to perform a tire contact force measurement test in which the tire contact force measurement position can be confirmed and compared.

  On the other hand, for example, in Document 2, a marker device that attaches paint to the tire is installed near the sensor that measures the contact force, and the measurement position is confirmed by marking the tire that has traveled on the sensor. ing. However, this makes it impossible to confirm the contact force measurement position in the width direction of the tire and causes unevenness in the shape of the applied paint, which may cause the value to vary depending on the person to be measured. Furthermore, it is necessary to erase the paint every time a test is performed.

  In view of such circumstances, an object of the present invention is to provide a tire contact force measuring method that can accurately and easily confirm a tire contact force measurement position.

  In order to solve the above problems, as claimed in claim 1, a contact force measuring step for measuring the contact force of a tire, and a load measuring step for measuring the load of the tire at at least three locations, simultaneously with the contact force measuring step. And an analysis step for calculating a load center of gravity of the tire.

  Since the tire contact force is measured and the tire load is measured at three or more locations, the load center of gravity of the tire when the contact force is measured can be calculated. The tire's load center of gravity is always the same location in the width direction even if the tire rolls if the same tire, wheel, load, etc. are the same. Can be used as

  Further, as claimed in claim 2, the load measuring step is performed before and after the grounding force measurement step in addition to being performed simultaneously with the grounding force measurement step. .

  The trajectory of the tire load center of gravity can be obtained by measuring the tire load before, after, or before and after the contact force measurement, and calculating and tying the tire load center of gravity in addition to the measurement of the contact force.

  Furthermore, as claimed in claim 3, a plate embedded in a road surface on which the tire contacts the ground, a grounding force sensor fixed in an embedded state on the plate and measuring a grounding force when the tire contacts, and a load applied to the plate The contact force measuring method according to claim 1 or 2, wherein a contact force and a tire load center of gravity are obtained using a tire contact force measuring device including at least three load sensors that measure the load.

  A grounding force sensor is embedded and fixed to the plate, and at the same time as measuring the grounding force with the grounding force sensor, the load of the tire can be measured with the load sensor. Since the load is measured at three or more locations, the center of gravity of the tire load can be obtained. Therefore, it is possible to know the center of gravity of the tire load when measuring the contact force as well as the contact force. In addition, the locus of the center of gravity of the tire load on the plate can be obtained.

  According to the present invention, it is possible to grasp the relative position in the width direction when measuring the ground contact force using the tire load center of gravity as a mark. As the mark is the center of gravity of the tire load, there is no need to apply paint or erase paint compared to when paint is used as a mark, and the position where the contact force is measured is easy. And it can be confirmed accurately.

  Furthermore, it is possible to determine whether or not it is the same position in the width direction as the previous time during the retest. When the contact force is measured at a plurality of locations on the tire, the contact force can be compared with the tire load center of gravity as a reference.

The perspective view which shows schematic structure of the tire ground-contact force measuring apparatus which concerns on embodiment of this invention. Longitudinal sectional view showing the tire contact force measuring device embedded in the road surface A perspective view showing a grounding force sensor Block diagram schematically showing the configuration of the tire contact force measuring device Flowchart of tire contact force measurement method according to an embodiment of the present invention Tire contact force measuring device plan view showing the trajectory of the tire load center of gravity Tire contact force measuring device plan view showing tire load center of gravity

  Hereinafter, a preferred embodiment of a grounding force measurement method according to the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a tire contact force measuring apparatus according to an embodiment of the present invention.

  The tire contact force measuring device 10 is a device for measuring contact force and load. The tire contact force measuring device 10 mainly includes a plate 14, a load sensor 16, a contact force sensor 18, and a base 20. The plate 14 and the base 20 are formed in a rectangular shape having substantially the same size. The plate 14 and the base 20 are spaced apart from each other in the vertical direction, and load sensors 16 are disposed at the four corner positions therebetween. The load sensor 16 is a sensor that measures the load on the plate 14 and its configuration is not particularly limited. For example, a load cell is used. In the case of the load cell, the fixed portion of the strain generating body is fixed to the base 20, the movable portion of the strain generating body is fixed to the plate 14, and the load acting on the plate 14 by a gauge attached to the deformation portion of the strain generating body. Is detected. Each load sensor 16 is connected to a control device 24 described later.

  In this embodiment, four load sensors 16 are provided. However, the present invention is not limited to this, and at least three load sensors 16 are required, and five or more may be used. Since the load acting on the plate 14 is measured at at least three locations, the position of the center of gravity of the tire load applied to the plate 14 when the tire 12 rolls on the plate 14, that is, the tire load center of gravity G can be obtained. .

  FIG. 2 is a longitudinal sectional view of the tire contact force measuring device 10. A state where the tire 12 is rolling on the tire contact force measuring device 10 is shown. A concave portion 14A is formed in the center position of the plate 14 in the width direction of the tire 12, and a plurality of ground force sensors 18 are arranged in a row in the concave portion 14A.

  FIG. 3 shows the ground force sensor 18. As shown in FIG. 3, a strain-generating body 18A formed in a columnar shape and a strain gauge 18B attached to the side surface thereof are provided. The lower portion of the strain generating body 18A is fixed to the concave portion 14A of the plate 14, and the grounding force sensor 18 and the plate 14 are integrated. The upper portion of the strain body 18A is formed so as to slightly protrude in the rolling direction (front-rear direction) of the tire 12, and the top surface of the strain body 18 is formed to be flush with the top surface of the plate 14. The Further, the strain body 18A is arranged with a slight gap with respect to the plate 14 except for the lower portion thereof, so that the strain body 18A can be delicately deformed. On the other hand, the gauge 18B is connected to a control device 24, which will be described later, so that the control device 24 can calculate three component forces (vertical force, longitudinal force, lateral force). Note that the configuration of the grounding force sensor 18, particularly the shape of the strain generating body 18 </ b> A, is not limited to the above-described example, and may be anything that can measure the force received from the tire 12. FIG. 1 shows an example in which ten ground force sensors 18 are arranged in a line, but the number and arrangement of the ground force sensors 18 are not limited to this. For example, a larger number (for example, about 60) of the ground force sensors 18 may be arranged in a line, or may be arranged in a plurality of lines in the rolling direction of the tire 12.

  The tire contact force measuring device 10 configured as described above is disposed in the concave portion 22A of the road surface 22 as shown in FIG. The recess 22A of the road surface 22 is formed slightly larger than the plate 14 so that the plate 14 does not contact the recess 22A. Further, the depth of the recess 22 </ b> A matches the height of the tire contact force measuring device 10, and the upper surface of the plate 14 and the road surface 22 are flush with each other.

  FIG. 4 is a block diagram schematically showing the configuration of the tire contact force measuring apparatus 10. Each load sensor 16 and each ground force sensor 18 are connected to the control device 24. The control device 24 includes an amplifier, an AD converter, an arithmetic circuit, a memory, etc., and amplifies the signal of the load sensor 16 and the signal of the grounding force sensor 18 to perform AD conversion, and performs various arithmetic processes. These data can be recorded. As the arithmetic processing, for example, the tire load gravity center G is calculated based on the signal of the load sensor 16, or the three component force applied to each contact force sensor 18 is calculated based on the signal of the contact force sensor 18. It has become.

  The control device 24 is connected to the display unit 26 and various information is displayed on the display unit 26. For example, the horizontal axis indicates the position coordinate of the grounding force sensor 18 and the vertical axis indicates the load in the vertical direction when the time (or the position coordinate converted in the front-rear direction) is set, or the vector in the front-rear direction and the horizontal direction is vectorized. The figure displayed with can be displayed. The tire load gravity center G can be displayed together with these displays. In addition, the stored past test results can be recalled and displayed simultaneously with the new test results.

  Next, a preferred embodiment of a tire contact force measuring method using the tire contact force measuring apparatus 10 configured as described above will be described.

  FIG. 5 is a flowchart of a contact force measurement test using the contact force measurement method according to the embodiment of the present invention.

  First, in step 1, the start position is adjusted. As will be described later, the first test may be at an arbitrary position, but the second and subsequent tests are adjusted based on the first test result.

  Next, in step 2, the tire 12 is rolled on the road surface 22, and various data at the time of rolling are acquired. When the tire 12 comes into contact with the plate 14, the load sensor 16 measures the load on the tire 12. When rolling on the plate 14, the load is continuously measured. Further, the grounding force sensor 18 measures the grounding force of the tire 12. Since the contact force sensor 18 is embedded in the plate 14, the load sensor 16 can measure the tire load even when the contact force sensor 18 measures the tire contact force. All these measurement data are sent to the control device 24 and stored.

  In step 3, the contact force is calculated. Based on the stored measurement data, the controller 24 calculates. The three component forces may be displayed on the display unit 26.

  In step 4, the tire load center of gravity G is calculated. Since the tire load is measured by three or more load sensors 16, the tire load gravity center G can be calculated. The tire load center of gravity GS when the contact force is measured and the locus GT of the tire load center of gravity on the plate 14 are calculated.

  If the tire load center of gravity G is the same tire, wheel, load, etc., the tire load center of gravity when the contact force is measured is always the same in the width direction even if the tire rolls. Using the GS as a mark, the tire position in the width direction where the contact force is measured can be confirmed. That is, it is possible to relatively grasp the contact force measurement position in the tire width direction.

  FIG. 7 is a plan view of the tire contact force measuring device showing the tire load gravity center GS at the time of contact force measurement. Reference sign D is the distance between the tire load center of gravity GS1 when the contact force is measured in the first test and the tire load center of gravity GS2 when the contact force is measured in the second test.

  For example, when the tire contact force is measured again under the same conditions, the tire contact force is measured in the left-right direction (width direction) more than the previous test. It can be confirmed how much it has shifted to the left or right rather than the test.

  Next, in step 5, the test is performed again using the above result. For example, the start position is adjusted by correcting the width direction using the distance D (step 1), the tire is rolled in the same procedure, data is collected and calculated (step 2 to step 4). Thus, the measurement is repeated while confirming the contact force measurement position in the width direction and the locus GT of the tire load center of gravity.

  Finally, as step 6, all the data are totaled and the test is terminated.

  The effect when measured by the tire contact force measurement method of the above embodiment will be described.

  By the above method, it is possible to know the tire load center of gravity GS at the time of the contact force measurement as well as the contact force, and this can be used as a mark or a reference at the time of the contact force measurement.

  For example, when the contact force is measured at a plurality of locations on the tire, the contact force can be compared with the tire load center of gravity as a reference. Using the tire load center of gravity GS when the contact force is measured as a landmark, when the contact force is measured again, it is possible to grasp how much the displacement occurs in the width direction.

  In this embodiment, the locus GT of the center of gravity of the tire load on the plate is calculated. FIG. 6 is a plan view of a tire contact force measuring apparatus showing an example of a tire load center of gravity locus. The position of the contact force measurement can be grasped while checking the locus of the tire load center of gravity. The ground contact force can be measured while checking the behavior of the tire, such as lateral slip and slip. Further, when the test is performed again under the same conditions, it can be confirmed whether the trajectory is the same, and even if the contact force measurement position is displaced in the width direction, the deviation can be corrected.

  When performing the test multiple times, the tire load center of gravity G is used as a mark, so there is no need to apply paint, etc., and it is only necessary to roll the tire on the plate, so there is no need to mark or erase the mark. The test results can be easily compared.

  Although not particularly shown in the above-described embodiment, when the contact force is displayed on the display unit 26, the tire load gravity center GS may be displayed together with the contact force. In addition, when past measurement results are stored in the control device 24 and repeated tests are performed, if a deviation occurs in the position of the center of gravity of the tire when the tire contact force is measured, a display or The value may be corrected. In addition, it is possible to perform pass / fail judgment as to whether measurement is performed at the tire contact force measurement position in the same width direction, averaging of the results, or the like.

  When performing repeated tests under the same conditions, if the measurement positions in the circumferential direction are aligned, the accuracy of the contact force can be substantially improved by overlaying the test results multiple times with the tire load center of gravity as a mark. it can. At that time, when adjusting the start position, the distance D can be used to correct the deviation.

  The resolution in the width direction of the contact force measurement is the distance M between the contact force sensors. While checking the distance D, the start position is adjusted by gradually shifting in the width direction (step 1), and the test is performed. Thus, the resolution of the contact force distribution in the width direction when measuring the contact force can be substantially increased. Thereby, the influence of a tread pattern, especially a longitudinal groove can be confirmed.

DESCRIPTION OF SYMBOLS 10 Tire contact force measuring apparatus 14 Plate 14A Plate recessed part 16 Load sensor 18 Ground force sensor 18A Straining body 18B Strain gauge 20 Base 22 Road surface 24 Control apparatus 26 Display apparatus D Distance G Tire load gravity center GS (at the time of contact force measurement) Tire Load Center of Gravity GT Tire Load Center of Gravity M Distance between Ground Force Sensors

Claims (3)

A contact force measurement step for measuring the contact force of the tire;
A load measuring step for measuring the load of the tire at least at three or more locations simultaneously with the contact force measuring step;
An analysis step of calculating a load center of gravity of the tire;
A tire contact force measurement method comprising: In addition to being performed simultaneously with the contact force measurement step, the load measurement step is also performed before and after the contact force measurement step.
The grounding force measuring method according to claim 1, wherein: A plate embedded in the road surface on which the tire contacts,
A grounding force sensor that is fixed in an embedded state on the plate and measures the grounding force when the tire is in contact with the plate;
At least three load sensors for measuring a load applied to the plate;
Using the tire contact force measuring device equipped with, determine the contact force and the load center of gravity of the tire,
The grounding force measuring method according to claim 1 or 2.