JP2014102221A - Tire evaluation method and tire evaluation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate influence of a tire on fuel economy performance of a vehicle.SOLUTION: A vehicle workload WF(kJ/L) of a vehicle with a standard tire consuming one litre of fuel and a vehicle workload WD(kJ/km) required for the vehicle to travel 1 km, in a predetermined vehicle speed schedule, are measured by a bench test of a chassis dynamometer. In a tire single body test using a tire testing apparatus, lost workloads Wt are measured for the standard tire and an evaluation object tire to travel 1 km in the predetermined vehicle speed schedule. Fuel economy (km/L) of the vehicle with the evaluation object tire is calculated by WF/[WD+ΔWt], ΔWt being calculated by multiplying a difference between the lost workloads by the number of drive wheels.

Description

  The present invention relates to a technique for evaluating the performance of a tire related to energy consumption of a vehicle such as fuel consumption and electricity consumption.

  As a technique for measuring the energy consumption of an automobile such as fuel consumption and electricity consumption, a technique for calculating the fuel consumption of the automobile by a bench test using a chassis dynamometer of the automobile is known (for example, Patent Document 1). Here, in this technology, the fuel consumption is measured while driving the vehicle at a vehicle speed according to a predetermined vehicle speed schedule in a state where a running resistance equivalent to that during actual driving is added using a chassis dynamometer. The fuel consumption of the vehicle is calculated based on the consumption amount and the travel distance.

  In addition, using a chassis dynamometer, the vehicle is driven at a vehicle speed according to a predetermined vehicle speed schedule while adding a running resistance equivalent to that during actual driving, and based on the vehicle driving force measured by the chassis dynamometer In addition, a technique for calculating the amount of work is also known (for example, Patent Document 2).

  There is also known a technique of a tire testing apparatus that can measure the loss power and loss work of a tire in a state of a single tire that is not attached to an automobile (for example, Patent Document 3).

Japanese Patent Laid-Open No. 11-14505 JP 2010-78384 A JP 2011-127953 A

  According to the technology for calculating the fuel consumption using the chassis dynamometer, when evaluating the influence of the tire on the energy consumption such as the fuel efficiency / electricity performance of the automobile, the tire is applied to the automobile for each type of tire to be evaluated. Measurements using a chassis dynamometer must be performed in the mounted state, which places a heavy burden on the measurement work.

  In addition, it is difficult to precisely match the conditions related to energy consumption other than tires (temperature of the vehicle drive system, etc.) in each measurement using a chassis dynamometer for each type of tire. It was not possible to separate and evaluate only the impact on the energy consumption of automobiles for each type of tire.

  Accordingly, an object of the present invention is to make it possible to evaluate the influence of tires on energy consumption such as fuel efficiency / electricity performance of a vehicle with less burden of measurement work.

In order to achieve the above object, the present invention provides the predetermined vehicle equipped with a predetermined type of tire as a tire evaluation method for estimating the fuel consumption of the predetermined vehicle when the evaluation target tire is mounted on the predetermined vehicle. Vehicle work WF, which is a work amount performed by a fuel of a predetermined unit capacity of the predetermined automobile equipped with the predetermined type of tire and traveling at a vehicle speed according to a predetermined vehicle speed schedule, and a predetermined unit The first step of measuring the vehicle work WD, which is the amount of work required to travel the distance, and the tire test device for performing a single unit test of the tire, at a rotational speed corresponding to the vehicle speed according to the vehicle speed schedule. Loss work WT_std when traveling the unit distance of the predetermined type of tire when rotating, and loss work WT_tgt when traveling the unit distance of the tire to be evaluated The second step of measuring each and the vehicle when the vehicle tire is changed from the predetermined type of tire to the evaluation target tire is estimated from the difference between the lost work WT_std and the lost work WT_tgt. As the change in vehicle work required to travel a unit distance is ΔWT,
A = Vehicle work WF / (Vehicle work WD + ΔWT)
To provide a third step of calculating an estimated value A of the fuel consumption of the predetermined vehicle equipped with the evaluation target tire.

In order to achieve the above object, the present invention provides a predetermined type of tire as a tire evaluation method for estimating the power consumption of a predetermined vehicle when the evaluation target tire is mounted on a predetermined vehicle that is an electric vehicle. A vehicle work WE that is a work amount performed by a predetermined unit power of the predetermined automobile, in which the predetermined automobile mounted is caused to travel at a vehicle speed according to a predetermined vehicle speed schedule and a predetermined type of tire is attached, A first step of measuring a vehicle work WD, which is a work amount required to travel a predetermined unit distance, and a tire test apparatus that performs a unit test of the tire, the vehicle speed corresponding to the vehicle speed schedule is determined. Loss work WT_std when traveling the unit distance of the predetermined type of tire when rotating at a rotational speed, and loss work when traveling the unit distance of the evaluation target tire. When the vehicle tire is changed from the predetermined type of tire to the evaluation target tire, which is estimated from the second step of measuring the amount of work WT_tgt and the difference between the work of loss WT_std and the work of loss WT_tgt. ΔWT is the change in vehicle work required for a car to travel a predetermined unit distance,
A = (Vehicle work WD + ΔWT) / Vehicle work WE
To provide a third step of calculating an estimated value of the power consumption A of the predetermined vehicle on which the evaluation target tire is mounted.

Here, in the tire evaluation method described above, the number of drive wheels of the predetermined automobile is n,
ΔWT = n × (loss work WT_tgt-loss work WT_std)
You may make it.
In the tire evaluation method described above, each measurement in the first step includes a roller on which an automobile tire is mounted, and a chassis dynamometer that measures the rotational speed of the roller and the force applied to the roller. The load corresponding to the actual driving time is applied to the predetermined vehicle via the roller in a state where the predetermined type tire of the predetermined vehicle mounted with the predetermined type tire is mounted on the roller. The tire testing apparatus may be configured to drive the tire at a vehicle speed according to the predetermined vehicle speed schedule while the tire is in contact with the tire while rotating the tire, for example. While applying a load to the tire via the tire roller, the rotational speed of the tire, the force applied to the tire, the rotational speed of the tire roller, and the It is intended to measure the force applied to the ear roller.

In order to achieve the above object, the present invention provides a tire evaluation system for estimating the fuel consumption of a predetermined vehicle when the evaluation target tire is mounted on a predetermined vehicle, while rotating the test target tire, While applying a load to the test target tire via a roller in contact with the test target tire, the rotation speed of the test target tire, the force applied to the test target tire, the rotation speed of the roller, and the roller A tire test apparatus for measuring the applied force, a rotation speed of a tire to be tested by the tire test apparatus and a load applied to the tire to be tested, a rotation speed corresponding to a vehicle speed according to a predetermined vehicle speed schedule, and the test While controlling the load corresponding to the actual driving of the predetermined vehicle equipped with the target tire, the load is applied to the test target tire measured by the tire testing apparatus. The difference between the work force of the tire determined according to the rotational force and the rotational speed of the tire to be tested, and the work amount of the roller determined according to the force applied to the roller and the rotational speed of the roller, There is provided a tire evaluation system including a lost work amount measuring means for calculating the lost work amount and an energy consumption efficiency estimating means. However, the energy consumption efficiency estimating means is configured such that when the loss work calculating means travels a predetermined distance with the predetermined type of tire obtained from the loss work calculated with the predetermined type of tire as the test target tire. The difference between the lost work amount WT_std of the vehicle and the lost work amount WT_tgt when traveling the predetermined distance with the evaluation target tire determined from the loss work amount calculated as the tire to be evaluated as the test target tire. When the tire is changed from the predetermined type of tire to the tire to be evaluated, a change in vehicle work required for the vehicle to travel a predetermined unit distance is obtained as ΔWT, and the set predetermined type of tire The amount of work performed by a predetermined unit volume of fuel when the predetermined vehicle equipped with tires travels at a vehicle speed according to the predetermined vehicle speed schedule. Vehicle work WF and the work required to travel a predetermined unit distance when traveling at a vehicle speed according to the predetermined vehicle speed schedule of the predetermined automobile equipped with the set predetermined type of tire According to the vehicle work WD which is quantity
A = Vehicle work WF / (Vehicle work WD + ΔWT)
Is used to calculate the estimated value A of the fuel consumption of the predetermined vehicle equipped with the evaluation target tire.

In order to achieve the above object, the present invention rotates a test target tire as a tire evaluation system for estimating a power consumption of a predetermined vehicle when the target vehicle is an electric vehicle. The rotational speed of the test target tire, the force applied to the test target tire and the rotational speed of the roller while driving and applying a load to the test target tire via a roller that contacts the test target tire And a tire test apparatus for measuring a force applied to the roller, and a rotation speed corresponding to a vehicle speed according to a predetermined vehicle speed schedule, the rotation speed of the tire to be tested by the tire test apparatus and the load to be applied to the tire to be tested And the test measured by the tire testing device while controlling the load corresponding to the actual driving of the predetermined vehicle equipped with the tire to be tested. The difference between the force applied to the elephant tire and the work amount of the tire determined according to the rotational speed of the test target tire, and the work amount of the roller determined according to the force applied to the roller and the rotational speed of the roller, Provided is a tire evaluation system including a lost work amount measuring means for calculating a lost work amount of a tire to be tested and an energy consumption efficiency estimating means. However, the energy consumption efficiency estimating means is configured such that the lost work amount calculating means travels a predetermined distance with the predetermined type of tire obtained from the lost work amount calculated with the predetermined type of tire as the tire to be tested. The difference between the lost work amount WT_std of the vehicle and the lost work amount WT_tgt when traveling the predetermined distance with the evaluation target tire determined from the loss work amount calculated as the tire to be evaluated as the test target tire. When the tire is changed from the predetermined type of tire to the tire to be evaluated, a change in vehicle work required for the vehicle to travel a predetermined unit distance is obtained as ΔWT, and the set predetermined type of tire A vehicle finish that is a work amount performed with a predetermined unit power when the predetermined vehicle equipped with a tire travels at a vehicle speed according to the predetermined vehicle speed schedule. The amount of work required to travel a predetermined unit distance when traveling at a vehicle speed according to the predetermined vehicle speed schedule of the predetermined vehicle equipped with the predetermined type of tire set WE According to some vehicle work WD,
A = (Vehicle work WD + ΔWT) / Vehicle work WE
Is used to calculate an estimated value A of the power consumption of the predetermined vehicle equipped with the evaluation target tire.

Here, in the above tire evaluation system, the energy consumption efficiency estimating means sets the ΔWT to n, where n is the number of driving wheels of the predetermined automobile.
ΔWT = n × (loss work WT_tgt-loss work WT_std)
You may make it calculate by.

  According to the tire evaluation method and the tire evaluation system as described above, for each of the evaluation target tires, even if the evaluation target tire is actually mounted on an automobile and measurement using a chassis dynamometer is not performed, By simply performing a unit test of each evaluation target tire, it is possible to calculate the fuel consumption and power consumption when the evaluation target tire is mounted on a predetermined vehicle, and the burden of measurement work is reduced.

  In addition, it is possible to calculate the fuel consumption and power consumption when each evaluation target tire is mounted on a car by matching the conditions related to fuel consumption and power consumption other than the tire, so the impact of each evaluation target tire on the energy consumption of the car Only the differences can be separated and evaluated.

  As described above, according to the present invention, it is possible to evaluate the influence on the energy consumption such as the fuel consumption performance / electricity performance of the automobile of the tire with less burden of measurement work.

It is a block diagram which shows the structure of the tire evaluation system which concerns on embodiment of this invention. It is a figure showing the composition of the tire testing device concerning the embodiment of the present invention. It is a figure which shows the structure of the chassis dynamometer used in embodiment of this invention. It is a figure which shows the example of the vehicle speed schedule used in embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 shows a configuration of a tire evaluation system according to this embodiment. As shown in the figure, the tire evaluation system includes a tire test apparatus 100 and a control unit 200.
First, details of the tire testing apparatus will be described.
2a1-a4 shows the configuration of the tire testing apparatus.
Here, FIG. 2a4 is a perspective view of the tire testing apparatus, and as shown in FIG. 2a4, it is assumed that the top, bottom, front, back, left, and right are defined, FIG. 2a1 shows the tire testing apparatus viewed from the right side, and FIG. FIG. 2a3 shows the tire test apparatus viewed from the left, as viewed from above.

  The tire testing device is a device for testing a tire alone. As shown in the drawing, the tire testing device is fixed to the base 1, the roller 2, the roller shaft 3 connected to the roller 2, and the roller shaft 3 rotatably supported. The roller shaft bearing 4, the roller shaft torque meter 5 for detecting the torque around the axis (twist direction) applied to the roller shaft 3, the roller tachometer 6 for detecting the rotation speed of the roller shaft 3, and the roller shaft 3 A roller pulley 7, a roller motor 8 fixed to the base 1, a roller motor pulley 9 fixed to the rotating shaft of the roller motor 8, and a roller belt 10 wound around the roller pulley 7 are provided. 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.

Further, the tire testing apparatus includes a stage 12 supported by two guide shafts 11 so as to be movable back and forth with respect to the base 1.
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. 2 b, the tire testing apparatus includes an actuator 21 inside the base 1, and the actuator 12 pushes and pulls the lower portion of the stage 12 to move the stage 12 back and forth with respect to the base 1. It is possible to move in the direction or press the peripheral surface of the tire 50 against the peripheral surface of the roller 2 with an arbitrary force.

  Here, according to such a configuration, the generated torque of the tire motor 18 and the roller motor 8 is controlled in a state where the peripheral surface of the tire 50 is pressed against the peripheral surface of the roller 2 with an arbitrary force. 50 can be rotated at a desired rotation speed while applying a desired load.

Returning to FIG. 1, details of the control unit 200 will be described next.
As illustrated, the control unit 200 includes a test execution control unit 210 and a measurement unit 220.
The test execution control unit 210 includes a rotation speed calculation unit 211, a tire torque control unit 212, a load calculation unit 213, a roller torque control unit 214, and a load control unit 215.
The measurement unit 220 includes a work calculation unit 221 and a fuel consumption / electricity cost calculation unit 222.
Here, the load control unit 215 of the test execution control unit 210 controls the actuator 21 so that the load Lm applied to the roller 2 of the tire 50 is equivalent to the weight WG of the virtual vehicle in which the tire 50 is used as a virtual vehicle. To control.
In addition, the rotational speed calculation unit 211 obtains the current target vehicle speed defined by the set vehicle speed schedule at each time point, converts the obtained target vehicle speed into the angular speed of the tire 50, and outputs it as the target angular speed. The tire torque control unit 212 performs tire control by PI control or PID control so that there is no deviation between the target angular velocity output from the rotational velocity calculation unit 211 and the current angular velocity ωtr of the tire 50 measured by the tire tachometer 16. 18 generated torque is controlled.

  The load calculation unit 213 obtains a running state of a virtual vehicle virtually assumed as a vehicle using the tire 50 based on the angular acceleration ωdy and the change in the angular velocity ωdy of the current roller 2 measured by the roller tachometer 6. A running resistance including various resistances such as air resistance and acceleration resistance, which is equivalent to the actual running of the virtual vehicle in the obtained running state, is calculated as a target load. Then, the roller torque control unit 214 eliminates the deviation between the target load calculated by the load calculation unit 213 and the load applied to the tire 50 by the current roller obtained from the torque Tdy detected by the roller shaft torque meter 5. The generated torque of the roller motor 8 is controlled by PI control or PID control.

Next, the work calculation unit 221 of the measurement unit 220 calculates the lost work amount per 1 km travel of the tire 50 as follows.
Here, the torque detected by the roller shaft torque meter 5 is Tdy, and the parasitic torque that is a potential torque loss that cannot be measured by the roller shaft torque meter 5, such as the rolling resistance of the roller bearing and the windage resistance of the roller, is Tpldy. The moment of inertia of the roller 2 is Idy, the current angular velocity of the roller 2 measured by the roller tachometer 6 is ωdy, the angular acceleration of the roller 2 obtained from the angular velocity ωdy of the roller 2 is δdy, and the radius of the roller 2 is Rdy.

  Further, Ttr represents the torque detected by the tire shaft torque meter 15, Tpltr represents a parasitic torque that is a potential torque loss that cannot be measured by the tire shaft torque meter 15, such as rolling resistance of a tire bearing and wind damage resistance of a tire. It is assumed that the moment of inertia of the tire 50 is Itr, the current angular velocity of the tire 50 measured by the tire tachometer 16 is ωtr, the angular acceleration of the tire 50 obtained from the angular velocity ωtr of the tire 50 is δtr, and the radius of the tire 50 is Rtr.

In this case, the total torque Tttldy of the roller 2 is the sum of the torque Tdy, the torque Tpldy, and the rotational inertia torque Idy × δdy of the roller 2, and the total torque Tttltr of the tire 50 is the torque Ttr, the torque Tpltr, and the tire 50. Is the sum of the rotational inertia torque Itr × δtr.
Therefore, when the torque Tttldy of the roller 2 is converted into a force Fdy acting in the tangential direction at the contact point between the roller 2 and the tire 50,
Fdy = (Tdy + Tpldy + Idy × δdy) / Rdy,
When the torque Tttltr of the tire 50 is converted into a force Ftr acting in a tangential direction at the contact point between the tire 50 and the roller 2,
Ftr = (Ttr + Tpltr + Itr × δtr) / Rtr.

Fdy is considered to be the force absorbed by the roller 2 from the tire 50, and if there is no tire loss, Fdy and Ftr will match, so the work calculation unit 221 calculates the loss resistance / rolling resistance Fr of the tire 50.
Obtained by Fr = Ftr-Fdy.

Next, the work rate Pdy of the roller 2 is obtained by the product of the torque Tttldy of the roller 2 and the angular velocity ωdy of the roller 2, and the work rate Ptr of the tire 50 is obtained by the product of the torque Tttltr of the tire 50 and the angular velocity ωtr of the tire 50. So each work rate is
Pdy = (Tdy + Tpldy + Idy × δdy) × ωdy
Ptr = (Ttr + Tpltr + Itr × δtr) × ωtr
It becomes.

The work rate Pdy of the roller 2 is the same as the work rate Fdy × Rdy × ωdy of the work by Fdy, and the work rate Ptr of the tire 50 is the same as the work rate Ftr × Rtr × ωtr of the work by Ftr.
Pdy = (Tdy + Tpldy + Idy × δdy) × ωdy
Ptr = (Ttr + Tpltr + Itr × δtr) × ωtr
Is the same formula.

If there is no tire loss, Pdy and Ptr agree with each other, so the work calculation unit 221 calculates the loss work rate Pr of the tire 50,
Obtained by Pr = Ptr-Pdy.
Next, the work amount Wdy of the roller 2 is obtained as an integral value of the work rate Pdy of the roller 2, and the work amount Wtr of the tire 50 is obtained as an integral value of the work rate Ptr of the tire 50.
Wdy = ∫Pdy
Wtr = ∫Ptr
It becomes.

Therefore, the work calculation unit 221 calculates the lost work amount Wr (kJ) of the tire 50.
Obtained by Wr = Wtr-Wdy.
Further, the tire characteristic calculation unit calculates the lost work amount Wt (kJ / km) per 1 km travel of the tire 50 by dividing the lost work amount Wr (kJ) of the tire 50 by the total travel distance ∫ωtr × Rtr. .
Therefore, according to such a control unit, it is possible to calculate the lost work amount Wt per 1 km travel of the tire 50 when the vehicle is driven at a desired vehicle speed schedule.
Hereinafter, the calculation operation of the energy consumption for each tire of the vehicle using such a tire evaluation system will be described.
First, in order to evaluate the energy saving performance of a tire, an operation in the case of calculating the fuel consumption of an automobile equipped with the tire will be described.
In this case, first, using a chassis dynamometer as shown in FIG. 3, the fuel consumption (km / L) of a car equipped with a standard tire and the vehicle work WF (kJ) performed by 1 liter of fuel of the car. / L) and the vehicle work WD (kJ / km) required to travel 1 km of the car.
Here, as shown in the figure, the chassis dynamometer is a device for performing an on-board test of an automobile, a roller 301 on which driving wheels (front tires in the figure) of the automobile are placed, and a motor 302 that rotationally drives the rollers 301. , Two arms 303 respectively connected to both sides of the frame of the motor 302, a load cell 304, a gas analyzer 305 for analyzing the exhaust gas components of the automobile, a control / measurement device 306, and a tachometer 307 for detecting the rotation speed of the roller 301; Have The chassis dynamometer shown in the figure is a chassis dynamometer for a front-wheel drive vehicle. When testing a four-wheel drive vehicle, a roller 301, a motor 302, an arm 303, and a load cell 304 for each of the front wheels and rear wheels. A tachometer 307 is provided.

The motor 302 is supported in a swingable manner, and the force acting on the arm 303 as the motor 302 swings is detected by the load cell 304, whereby the force acting between the driving wheel of the automobile and the roller 301 is detected. It can be measured.
Hereinafter, using such a chassis dynamometer, the fuel consumption F (km / L), the vehicle work WF (kJ / L) performed by 1 liter of fuel, and the vehicle work WD required to travel 1 km ( The measurement operation of kJ / km will be described.
First, in the measurement, the tester drives the vehicle at a vehicle speed according to a predetermined vehicle speed schedule.
Here, the vehicle speed schedule includes a vehicle speed schedule that simulates traveling on a congested road in Tokyo shown in FIGS. 4a to 4f, a vehicle speed schedule that simulates traveling on a general road in Tokyo, a vehicle speed schedule in 10.15 mode, a vehicle speed schedule in JC08 mode, A vehicle speed schedule that simulates traveling on local roads, a vehicle speed schedule that simulates traveling on highways, and the like are used.

  On the other hand, during a period when the automobile is driven at a vehicle speed according to such a vehicle speed schedule, the control / measurement device 306 controls the motor 302 to determine the automobile's speed based on the current angular velocity and angular acceleration of the roller 1. The running state is obtained, and a load corresponding to running resistance including various resistances such as air resistance and acceleration resistance of the automobile in the obtained running state is applied to the tire of the automobile via the roller 301.

The control / measurement device 306 calculates the driving force FV of the automobile based on the force detected by the load cell 304.
The driving force FV is a conversion value of the force detected by the load cell 304 to a force in the surface tangential direction of the roller 301, F1, and a conversion value of parasitic torque such as mechanical loss of the roller 301 to a force in the surface tangential direction of the roller 301 is F2. Assuming that the moment of inertia of the rotating system of the chassis dynamometer is IM,
FV = F1 + F2 + (IM x angular acceleration of roller / roller radius)
Ask as.

  Then, the vehicle speed obtained from the rotation speed of the roller 301 is set as V, and the sum of FV × V during the traveling period according to the vehicle speed schedule is determined as the vehicle work amount W. Then, the vehicle work W is divided by the fuel consumption during the traveling period according to the vehicle speed schedule obtained using the gas analyzer 305 to calculate the vehicle work WF (kJ / L) performed by 1 liter of fuel.

Further, the vehicle work amount W is divided by the travel distance in the travel period according to the vehicle speed schedule obtained from the rotation speed of the roller 301 and the like, and is calculated as the vehicle work WD (kJ / km) required to travel 1 km. .
Here, fuel consumption F (km / L) is
Calculated as total mileage (km) / total fuel consumption (L),
Total mileage (km) / total fuel consumption (L)
= Vehicle work WD required for driving 1 liter of fuel
Holds.

Therefore, the control / measurement device 306 obtains WF (kJ / L) / WD (kJ / km) as the fuel efficiency F (km / L) of the automobile when a standard tire is mounted.
However, such fuel consumption F (km / L), vehicle work WF (kJ / L) performed by 1 liter of fuel, and vehicle work WD (kJ / km) required to travel 1 km are the chassis. Instead of using a dynamometer, a vehicle equipped with a standard tire may be actually run on the road for measurement.
Then, the obtained WF (kJ / L) and WD (kJ / km) are set in the fuel consumption / electricity cost calculation unit 222 of the control unit 200 of the tire evaluation system.
Then, each of the standard tire used for the measurement using the above-described chassis dynamometer and the tire that evaluates the energy saving performance, which is different from the standard tire, are used in the tire testing system 100 of the tire evaluation system. The control unit 200 performs control and measurement according to the vehicle speed schedule as described above, and the work calculation unit 221 of the measurement unit 220 calculates the lost work amount Wt (kJ / km) per 1 km of tire travel. .

   Here, in the measurement of standard tires using this tire evaluation system and tires for evaluating energy saving performance, the same vehicle speed schedule as that used for the measurement using the chassis dynamometer as described above is used as the vehicle speed schedule. Is used. Further, in the load calculation unit 213, as a virtual vehicle, the vehicle used for the measurement using the chassis dynamometer as described above is virtually assumed, and the load equivalent to that added by the measurement using the chassis dynamometer as described above is used. Is added to the tire.

  Then, if the loss work Wt_std (kJ / km) for a standard tire and the loss work Wt_tgt (kJ / km) for a tire to evaluate energy saving performance are calculated, measurement The fuel consumption / electricity cost calculation unit 222 of the unit 220 calculates the fuel consumption F_tgt (km / L) when the tire for which the energy saving performance is evaluated is attached according to the following equation.

F_tgt = WF / (WD + ΔWt)
However, ΔWt = n × (Wt_tgt-Wt_std)
n is the number of driving wheels of the vehicle. Here, the vehicle work WD (kJ / km) required to travel 1 km, measured using a chassis dynamometer, is the standard tire loss work Wt_std (kJ / km) in addition to the loss work Wm (kJ / km) due to the drive system of the car,
It can be expressed as WD = (n × Wt_std) + Wm.

In addition, the vehicle work WD_tgt (kJ / km) required to travel 1km when a tire that evaluates energy-saving performance is mounted on a car, the lost work amount Wm due to the drive system of the car does not change depending on the tire.
It can be expected that WD_tgt = (n × Wt_tgt) + Wm.

And
WD + ΔWt = (n x Wt_std) + Wm + (n x ΔWt)
= (N x Wt_tgt) + Wm, so
F_tgt = WF / (WD + ΔWt)
Thus, it is possible to calculate the fuel consumption F_tgt (km / L) when the tire for evaluating the energy saving performance is mounted on the automobile.

Also, always calculate the fuel consumption F_tgt (km / L) when the tire to be evaluated is mounted on the car, with the loss work Wm (kJ / km) due to the drive system of the car, which is a condition other than the tire, being always constant. Therefore, it is possible to separate and evaluate the influence on the fuel consumption due to the tire alone.
The operation for calculating the fuel consumption of a vehicle equipped with a tire for evaluating energy saving performance has been described above.
Next, the operation for calculating the power consumption of an electric vehicle equipped with a tire for evaluating energy saving performance will be described.
Here, the electric power consumption A (Wh / km) of the electric vehicle is defined by the following equation.
A (Wh / km) = Charging energy (Wh) / 1 Charging distance LE (km)
= Vehicle work WD (kJ / km) required to travel 1km Vehicle work WE (kJ / Wh) with 1Wh of power
Therefore, in the calculation operation of power consumption, first, the WD (kJ / km) and WE (kJ / Wh) of a car equipped with standard tires are actually driven on the road using the chassis dynamometer described above, It is calculated by measuring the power consumption instead of the fuel consumption, and is set in the fuel consumption / electricity cost calculation unit 222 of the measurement unit 220. Also, WD / WE is calculated as the electricity consumption A (Wh / km) of a car equipped with standard tires.

Next, using the tire evaluation system as described above, Wt_tgt (kJ / km) and Wt_std (kJ / km) are obtained, and the electric power consumption A_tgt (Wh / km) of the vehicle when the tire for evaluating the energy saving performance is mounted The
A_tgt = (WD + ΔWt) / WE
However, ΔWt = n × (Wt_tgt-Wt_std)
Is calculated and output.

Further, the actual battery capacity WB of the vehicle is set in the fuel consumption / electricity cost calculation unit 222 of the measurement unit 220, and in the fuel consumption / electricity cost calculation unit 222, one charging travel distance LE_tgt (km) of the vehicle equipped with the tire for evaluating the energy saving performance. The
LE_tgt = WB / A_tgt
It may be calculated and output by

Now, in the case of an electric vehicle, an automobile manufacturer announced the AC power consumption rate AE (Wh / km) in JC08 mode and 1 charging mileage LE (km) with standard tires attached. Therefore, the measurement may be performed using these values.
That is, in this case, the measurement using the above chassis dynamometer is performed using the JC08 mode as the vehicle speed schedule. Also, in this measurement, the total power consumption during the running period according to the vehicle speed schedule, which is necessary for calculating WD (kJ / km) and WE (kJ / Wh), is the AC power published by the automobile manufacturer. The consumption rate AE (Wh / km) may be obtained by multiplying the travel distance.

Further, the measurement using the tire evaluation system is performed using the JC08 mode as a vehicle speed schedule, and the electric power consumption A_tgt (Wh / km) of the automobile when the tire for evaluating the energy saving performance in the JC08 mode is mounted is obtained.
In addition, the actual battery capacity WB of the car,
Calculate as WB = AE x LE.
Then, the fuel consumption / electricity cost calculation unit 222 of the measurement unit 220 further calculates the 1-charge travel distance LE_tgt (km) in the JC08 mode of the vehicle equipped with the tire for evaluating the energy saving performance,
LE_tgt = WB / A_tgt is calculated and output.
The embodiment of the present invention has been described above.

  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, 11 ... Guide shaft, 12 ... Stage, 13 ... Tire shaft, 14 ... Tire shaft bearing, 15 ... Tire shaft torque meter, 16 ... Tire tachometer, 17 ... Tire pulley, 18 ... Tire motor, 19 DESCRIPTION OF SYMBOLS ... Tire motor pulley, 20 ... Tire belt, 21 ... Actuator, 50 ... Tire, 100 ... Tire testing apparatus, 200 ... Control part, 210 ... Test execution control part, 211 ... Rotational speed calculation part, 212 ... Tire torque control part 213 ... Load calculation unit, 214 ... Roller torque control unit, 215 ... Load control unit, 220 ... Measurement unit, 221 ... Work calculation unit 222 ... fuel / electricity cost calculator, 301 ... roller, 302 ... motor, 303 ... arm, 304 ... load cell, 305 ... gas analyzer, 306 ... control / measuring device, 307 tachometer.

Claims (7)

A tire evaluation method for estimating the fuel efficiency of a predetermined vehicle when the evaluation target tire is mounted on a predetermined vehicle,
The predetermined vehicle equipped with a predetermined type of tire is driven at a vehicle speed according to a predetermined vehicle speed schedule, and a predetermined unit capacity of fuel of the predetermined vehicle mounted with the predetermined type of tire is performed. A first step of measuring a vehicle work WF that is a work amount and a vehicle work WD that is a work amount required to travel a predetermined unit distance;
Using a tire testing device that performs a unit test of a tire, when the vehicle rotates at a rotational speed corresponding to the vehicle speed according to the vehicle speed schedule, the lost work amount WT_std when traveling the unit distance of the predetermined type of tire and A second step of measuring a lost work amount WT_tgt when traveling the unit distance of the tire to be evaluated;
Vehicle required for a vehicle to travel a predetermined unit distance when the vehicle tire is changed from the predetermined type of tire to the evaluation target tire, which is estimated from the difference between the lost work amount WT_std and the lost work amount WT_tgt Let ΔWT be the change in work,
A = Vehicle work WF / (Vehicle work WD + ΔWT)
And a third step of calculating an estimated value A of the fuel consumption of the predetermined vehicle on which the evaluation target tire is mounted.
A tire evaluation method for estimating power consumption of a predetermined vehicle when the evaluation target tire is mounted on a predetermined vehicle that is an electric vehicle,
The predetermined vehicle equipped with a predetermined type of tire is driven at a vehicle speed according to a predetermined vehicle speed schedule, and the amount of work performed with the predetermined unit power of the predetermined vehicle mounted with the predetermined type of tire. A first step of measuring a vehicle work WE and a vehicle work WD that is a work amount required to travel a predetermined unit distance;
Using a tire testing device that performs a unit test of a tire, when the vehicle rotates at a rotational speed corresponding to the vehicle speed according to the vehicle speed schedule, the lost work amount WT_std when traveling the unit distance of the predetermined type of tire and A second step of measuring a lost work amount WT_tgt when traveling the unit distance of the tire to be evaluated;
Vehicle required for a vehicle to travel a predetermined unit distance when the vehicle tire is changed from the predetermined type of tire to the evaluation target tire, which is estimated from the difference between the lost work amount WT_std and the lost work amount WT_tgt Let ΔWT be the change in work,
A = (Vehicle work WD + ΔWT) / Vehicle work WE
And a third step of calculating an estimated value of the electric power consumption A of the predetermined vehicle on which the tire to be evaluated is mounted.
A tire evaluation method according to claim 1 or 2,
The number of driving wheels of the predetermined vehicle is n,
ΔWT = n × (loss work WT_tgt-loss work WT_std)
The tire evaluation method characterized by the above-mentioned.
The tire evaluation method according to claim 1, 2, or 3,
Each of the measurements in the first step includes a roller on which a tire of an automobile is placed, and uses a chassis dynamometer that measures a rotational speed of the roller and a force applied to the roller. With the predetermined type of tire of the predetermined automobile equipped with a tire mounted on the roller, the predetermined automobile is applied to the predetermined automobile while applying a load corresponding to the actual running through the roller. It is performed by running at a vehicle speed according to the predetermined vehicle speed schedule,
The tire testing apparatus that performs a unit test of the tire in the second step applies a load to the tire through a tire roller that abuts the tire while rotating the tire. A tire evaluation method characterized by measuring a rotational speed, a force applied to the tire, a rotational speed of the tire roller, and a force applied to the tire roller.
A tire evaluation system for estimating the fuel efficiency of a predetermined vehicle when the evaluation target tire is mounted on a predetermined vehicle,
The rotational speed of the test target tire and the force applied to the test target tire while applying a load to the test target tire via a roller that contacts the test target tire while rotating the test target tire And a tire testing device for measuring the rotational speed of the roller and the force applied to the roller,
The rotational speed of the tire to be tested by the tire testing apparatus and the load applied to the tire to be tested are the rotational speed corresponding to the vehicle speed according to a predetermined vehicle speed schedule, and the predetermined automobile equipped with the tire to be tested. And the load of the tire determined according to the force applied to the test object tire measured by the tire test apparatus and the rotation speed of the test object tire, while controlling the load equivalent to the actual running time of the tire, and the roller A lost work amount measuring means for calculating the difference between the force applied to the roller and the work amount of the roller determined according to the rotational speed of the roller as the lost work amount of the tire to be tested;
Energy consumption efficiency estimating means,
The energy consumption efficiency estimation means is
The lost work amount calculating means calculates the loss work amount WT_std when traveling a predetermined distance with the predetermined type of tire obtained from the lost work amount calculated with the predetermined type of tire as the test target tire, and the evaluation target From the difference between the loss work WT_tgt when traveling a predetermined distance with the tire to be evaluated obtained from the loss work calculated as the tire to be tested as the tire to be tested, the tire of the automobile is While obtaining the change in vehicle work required for the automobile to travel a predetermined unit distance when changing to the tire to be evaluated as ΔWT,
Vehicle work WF, which is the work amount of fuel of a predetermined unit capacity when traveling at a vehicle speed according to the predetermined vehicle speed schedule of the predetermined automobile equipped with the predetermined type of set tire, Vehicle work WD, which is a work amount required to travel a predetermined unit distance when traveling at a vehicle speed according to the predetermined vehicle speed schedule of the predetermined vehicle equipped with the predetermined type of set tire And according to
A = Vehicle work WF / (Vehicle work WD + ΔWT)
The tire evaluation system according to claim 1, wherein an estimated value A of the fuel consumption of the predetermined vehicle equipped with the evaluation target tire is calculated.
A tire evaluation system that estimates the power consumption of a predetermined vehicle when the evaluation target tire is mounted on a predetermined vehicle that is an electric vehicle,
The rotational speed of the test target tire and the force applied to the test target tire while applying a load to the test target tire via a roller that contacts the test target tire while rotating the test target tire And a tire testing device for measuring the rotational speed of the roller and the force applied to the roller,
The rotational speed of the tire to be tested by the tire testing apparatus and the load applied to the tire to be tested are the rotational speed corresponding to the vehicle speed according to a predetermined vehicle speed schedule, and the predetermined automobile equipped with the tire to be tested. And the load of the tire determined according to the force applied to the test object tire measured by the tire test apparatus and the rotation speed of the test object tire, while controlling the load equivalent to the actual running time of the tire, and the roller A lost work amount measuring means for calculating the difference between the force applied to the roller and the work amount of the roller determined according to the rotational speed of the roller as the lost work amount of the tire to be tested;
Energy consumption efficiency estimating means,
The energy consumption efficiency estimation means is
The lost work amount calculating means calculates the loss work amount WT_std when traveling a predetermined distance with the predetermined type of tire obtained from the lost work amount calculated with the predetermined type of tire as the test target tire, and the evaluation target From the difference between the loss work WT_tgt when traveling a predetermined distance with the tire to be evaluated obtained from the loss work calculated as the tire to be tested as the tire to be tested, the tire of the automobile is While obtaining the change in vehicle work required for the automobile to travel a predetermined unit distance when changing to the tire to be evaluated as ΔWT,
A vehicle work WE, which is a work amount performed with a predetermined unit power when traveling at a vehicle speed according to the predetermined vehicle speed schedule of the predetermined automobile equipped with the set predetermined type of tire, is set. Further, according to the vehicle work WD, which is a work amount required to travel a predetermined unit distance when traveling at a vehicle speed according to the predetermined vehicle speed schedule of the predetermined automobile equipped with the predetermined type of tire. ,
A = (Vehicle work WD + ΔWT) / Vehicle work WE
The tire evaluation system according to claim 1, wherein an estimated value A of power consumption of the predetermined vehicle equipped with the evaluation target tire is calculated.
The tire evaluation system according to claim 5 or 6,
The energy consumption efficiency estimating means sets the ΔWT to n, where n is the number of driving wheels of the predetermined vehicle.
ΔWT = n × (loss work WT_tgt-loss work WT_std)
A tire evaluation system characterized by the following calculation.