JPH0735653A - Apparatus for testing running performance of tire - Google Patents

Abstract

PURPOSE:To provide an apparatus which can measure the performance of a tire correctly and easily. CONSTITUTION:A tractor 10 and a load are coupled each other by a wire rope 14 with a load cell 16. A torque detecting part is set to each wheel thereby to detect a torque added to each tire. A detecting part 33 for detecting the rotating frequency of the tire is set to each wheel to correctly detect the rotation. Moreover, a running distance sensor 58 is provided in the vehicle to measure the length of a drawn thread 60 to detect the correct running distance. Since not only the data of the net tracking force is obtained by the load cell 16, but the torque of each tire can be measured, the performance of each tire set in the actual vehicle can be correctly and easily detected. Moreover, since the rotating frequency of the tire and the running distance of the vehicle can be measured correctly, the correct slipping rate can be detected for each tire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire running performance testing apparatus suitable for measuring various characteristics of a tire mounted on a vehicle, and particularly for measuring driving / braking performance of the tire.

[0002]

2. Description of the Related Art Conventionally, in order to measure a running performance of a tire, for example, a traction performance, a so-called load cell is set between a vehicle to be measured and a towed vehicle or a load serving as a load, and tire data is measured from the load cell. I was measuring traction.

To measure the slip ratio of a tire, a mark is attached to a predetermined position on the side of the tire, a vehicle to be measured is run, and, for example, a mark is made on the ground every time the mark is located directly below the rotation axis. Then, the distance between the markings was measured, and the slip ratio was calculated by comparing with the previously measured reference tire rolling distance.

[0004]

However, when the above method is applied to, for example, an agricultural tractor, the following problems (1) to (3) occur.

(1) Variation in soil hardness is larger than the original difference in tire performance, making accurate measurement difficult.

(2) From the traction data of the entire vehicle,
There is no way but to predict the performance of each tire, front and rear wheels,
Alternatively, the performance of each tire such as the left and right wheels cannot be measured. For example, the effect of weight distribution when mounted on an actual vehicle is unknown.

(3) In order to carry out marking for measuring the slip ratio, a marking worker is required. In addition, it is difficult to perform accurate marking for each rotation of the tire, and it is impossible to manually handle when the vehicle speed is high.

In consideration of the above facts, an object of the present invention is to provide a tire running performance testing device capable of accurately and easily measuring the running performance inherent in a tire.

[0009]

According to a first aspect of the present invention, there is provided a tire running performance test apparatus for detecting a torque acting on a tire of a vehicle during traveling and a traction force of the vehicle during towing. And a traction force detection unit for detecting the traction force.

A tire running performance testing apparatus according to a second aspect of the present invention comprises a running distance detecting unit for detecting a running distance of a vehicle during running, and a tire rotation speed detecting unit for detecting a rotation speed of a tire. It is characterized by that.

A tire running performance testing apparatus according to a third aspect of the present invention is the tire running performance testing apparatus according to the first aspect of the present invention, wherein the torque detection unit is integrally provided between an axle and a wheel of the vehicle. It is characterized by being inserted.

According to a fourth aspect of the present invention, there is provided the tire running performance testing device according to the second aspect of the invention, wherein the running distance detecting section pulls out the yarn while applying a tensile force. -Features a reel for rewinding.

According to a fifth aspect of the present invention, there is provided the tire running performance testing device according to the second aspect of the invention, wherein the tire running performance detecting device has a slit for rotating in synchronization with the tire. It is characterized in that it is provided with a disk and a sensor section for detecting a slit passing through a predetermined position during rotation of the disk with slits.

Further, the tire running performance testing device of the invention described in claim 6 is the tire running performance testing device according to claim 1 or 2, wherein the torque detecting portion and the tractive force detecting portion, or the running condition. It is characterized by comprising a data accumulating section for accumulating data output from the distance detecting section and the tire rotation speed detecting section.

[0015]

In the tire running performance testing apparatus according to the first aspect of the present invention, the traction force measuring unit detects the traction force of the vehicle during towing, and the torque detecting unit detects the torque acting on the tire of the vehicle during towing. To do. The tangential force acting on each tire can be calculated from the torque acting on each tire of the vehicle. Also, the sum of tangential forces = vehicle traction force + running resistance (for example,
The running resistance can be calculated from the soil loss, etc.). By calculating the running resistance that could not be calculated conventionally, it is possible to study a tire that reduces the running resistance as much as possible and increases the traction force.

According to another aspect of the tire running performance testing apparatus of the present invention, the slip of the tire is determined by the running distance of the vehicle detected by the running distance detecting section and the tire rotation speed detected by the tire rotation speed detecting section. The rate can be calculated accurately. As a result, the tire slip ratio can be calculated accurately as compared to the conventional case, without requiring manual labor for measurement work, and regardless of the traveling speed of the vehicle, and further, regardless of the weather or the road surface condition.

In the tire running performance test apparatus according to the third aspect of the present invention, since the torque detecting portion is integrally provided between the axle and the wheel, the torque detecting portion is twisted integrally with the axle, so that The rotating torque acting on the tire can be directly and accurately measured.

According to another aspect of the tire running performance testing apparatus of the present invention, the odometer is fixed to the vehicle and the tip of the yarn drawn from the reel of the odometer is set at a predetermined position (reference) on the road surface. By fixing, the actual distance traveled by the vehicle can be known by measuring the length of the yarn drawn from the reel. Further, since a predetermined tensile force is applied to the yarn and the yarn is pulled out from the reel, the yarn is not loosened during towing or braking, and the traveling distance of the vehicle can be accurately detected. The reel may be fixed at a predetermined position (reference) on the road surface, and the tip of the yarn drawn out from the reel may be fixed to the vehicle. This also makes it possible to know the actual traveling distance of the vehicle.

In the tire running performance testing device of the fifth aspect of the present invention, the number of times the slit of the disk with slits that rotates in synchronization with the tire passes through a predetermined position is counted by the sensor unit. It can be calculated accurately.

In the tire running performance testing apparatus according to the sixth aspect of the present invention, data output from the torque detecting section and the traction force measuring section, or the running distance detecting section and the tire rotational speed detecting section during the towing run is accumulated. The parts are processed together at the same time. Therefore, the running performance of the tire can be calculated by statistically processing these accumulated data.

[0021]

EXAMPLE An example in which the tire running performance testing apparatus of the present invention is applied to a tire for an agricultural tractor will be described with reference to FIGS. 1 to 5.

As shown in FIGS. 1 and 2, the tractor 1
A load tractor 12 is connected to the rear of 0 with a wire rope 14, for example.

At the intermediate portion of the wire rope 14, the load cell 1 as a traction force detecting portion for measuring the tensile force applied to the wire rope 14 (that is, the traction force of the tractor 10).
6 is attached. The load cell 16 is connected to a data collecting device 18 as a data collecting unit via an electric wire (not shown). The data collection device 18
As the above, a data logger, a data recorder, or the like can be used.

As shown in FIG. 3, one end of a cylindrical torque detecting portion 24 is fixed to a hub 22 at the tip of the axle 20 of the tractor 10 with a bolt 26.

The other end of the torque detector 24 is the wheel 2
It is fixed to 8 with bolts 32.

At the wheel-side center of the torque detecting unit 24, a disc 34 with a slit constituting a tire rotation speed detecting unit 33 is coaxially fixed.
In the center of the vehicle outer side surface (the surface on the arrow A direction side) of No. 4, the axle 2 with respect to a photo sensor 56 as a sensor unit described later
One end of a rotary connector 36 that blocks the rotational force from 0 is fixed coaxially. Disk with slit 3
4, a plurality of slits 37 are formed at a predetermined pitch along the circumferential direction. In this embodiment, the number of slits in the slitted disk 34 is 100.

A disc-shaped fixed plate 38 is fixed to the other end of the rotary connector 36, and the cylindrical portion 4 of the cup-shaped cover 40 is provided on the outer peripheral surface of the fixed plate 38.
The side of OA is screwed. The edge portion of the cover 40 is inserted into an annular groove 42 provided on the vehicle outer side surface of the slitted disk 34 with a predetermined gap.

The fixing plate 38 is fixed to the vehicle body of the tractor 10 via a fixing member (not shown).

A strain gauge (strain gauge) 44 is attached to the outer peripheral surface of the torque detecting portion 24 for measuring the strain generated on the outer peripheral surface of the cylindrical portion. It should be noted that the strain gauge 44 is the data mounted on the tractor 10 as shown in FIG. 1 via the electric wire 46, the rotary connector 36, the electric wire 48, the connector 50 attached to the cover 40, the electric wire 52 and an amplifier (not shown). It is connected to the stacking device 18.

Here, by measuring the strain (torsional strain) generated in the torque detecting section 24 with the strain gauge 44, the torque acting on the torque detecting section 24, that is, the torque acting on the tire 54 is measured. be able to.

Near the outer periphery of the fixed plate 38, a reflection type photo sensor 56 which constitutes another part of the tire rotation speed detecting section 33 is attached.
6 emits light to the slit side of the disk 34 with slits, and the slit 37 can be detected by the presence or absence of reflected light. The photo sensor 56 is connected to the data integration device 18 via an amplifier (not shown).

As shown in FIGS. 1 and 2, the tractor 1
0 is equipped with a odometer 58 as a mileage detector.

As shown in FIG. 4, this odometer 58
2 is provided with a reel 62 around which a thread 60 is wound, and as shown in FIG. 2, the tip of the thread 60 is fixed to a support column 66 that stands on the ground and serves as a distance measurement reference.

An intermediate portion of the yarn 60 is wound around a pulley 70 connected to a rotary shaft 68A of a rotary encoder 68 provided in the vicinity of the reel 62, and the pulley 70 extends the length of the yarn 60 drawn from the reel 62. It is designed to rotate according to the size.

Further, on the reel 62, the pulled-out yarn 6
A motor 74 for rewinding 0 is attached,
Further, the reel 62 has a built-in gear mechanism that applies a predetermined tension to the drawn yarn. The rotary encoder 68 is connected to the data accumulation device 18 via a D / A converter (not shown).

Further, on both sides of the pulley 70, the thread 60
In order to prevent the looseness of the yarn 60, a holding roller 72 that holds the yarn 60 with a predetermined force is provided.

On the other hand, a printer (not shown) is connected to the data accumulator 18, and the tensile force measured by the load cell 16 (the traction force of the tractor 10) and the rotation of the wheel 28 (tire) measured by the photo sensor 56. number,
The strain amount of the torque detector 24 (driving force of the tire) measured by the strain gauge 44 and the traveling distance of the tractor 10 measured by the odometer 58 can be printed out on recording paper.

The traction force detecting unit, the torque detecting unit, the mileage detecting unit, and the tire rotation speed detecting unit described above constitute a tire running performance testing device.

Next, the measuring method of an example of various characteristics of the tire and the operation of this embodiment will be described. As shown in FIGS. 1 and 2, the tractor 10 pulls the load tractor 12 for a predetermined distance in a predetermined field 64.

Each data is recorded during towing. Next, load running is performed with a load higher than the initial load, each data is recorded, the load is gradually increased, and the measurement is repeated.

The measured data is summarized and a graph is drawn with the traction force on the vertical axis and the slip ratio on the horizontal axis (see FIG. 5).

The slip ratio referred to here is the following equation (1).
Is a value calculated by. L ₀ : A reference rolling distance per one rotation of the tire. L: Rolling distance per one rotation of the tire when loaded in the field.

Here, the rolling distances L ₀ and L per one rotation of the tire can be obtained by accumulating in the data accumulating device 18 and arithmetic processing by the data arithmetic unit. The slip ratio is calculated from the traveling distance and the tire rotation speed.

The above-mentioned test is carried out on, for example, two types of tires A and B, and it is possible to compare the performances of the A tire and the B tire from the difference in the data curves.

In this embodiment, the torque of each tire can be measured in addition to the data of the net traction force by the load cell 16 as in the conventional case, so that the performance of each tire mounted on the actual vehicle can be accurately measured. , And can be easily grasped.

Further, the traveling distance, the tire rotation speed, the torque,
By simultaneously measuring the traction and arranging the data for each time, it is possible to find the original running performance of the tire in consideration of changes in the road surface and field due to variations in soil hardness, water content, and the like.

In this embodiment, the strain gauge 44 is used to measure the torque, but the means for measuring the torque is not limited to this, and torque measuring means having other structures such as a magnetic flux type torque sensor is used. May be used.

Further, in the present embodiment, the odometer 58 is designed to measure the amount of yarn 60 sent out, but the odometer 58 can measure the distance from the reference point of the field, for example, laser measurement. A range finder or the like may be used.

Further, for the resistance measurement during braking, the braking performance of the tire can be measured, for example, by measuring a vehicle equipped with the measuring device of the present invention as a towed vehicle.
Further, it is possible to calculate the tire tangential force during self-propelling, which can be easily applied to passenger cars, trucks and the like.

[0050]

As described above, in the tire traveling performance test apparatus according to the first aspect of the invention, the traction force measuring unit detects the traction force of the vehicle during traction traveling, and the torque detection unit traction traveling is performed as described above. Since the torque acting on the tire of the vehicle at the time is detected, the traction force, the tangential force acting on the tire, and the running resistance, which are the evaluation criteria of the running performance of the tire, can be accurately calculated, so the original running performance of the tire It has an excellent effect that it can be evaluated accurately. As a result, it is possible to design a tire with a low running resistance and a high traction force.

According to the tire running performance testing apparatus of the second aspect of the present invention, the running distance detecting unit detects the running distance of the vehicle and the tire rotating speed detecting unit detects the tire rotating speed. Therefore, the work for the measurement is easy, and the tire slip ratio can be accurately calculated regardless of the traveling speed of the vehicle and further regardless of the weather or the road surface condition.

Since the tire running performance test apparatus according to the third aspect of the present invention is configured as described above, the torque acting on the tire is accurately measured as the driving performance or braking performance of the tire during driving or braking of the vehicle. It has an excellent effect that the tangential force of the tire can be calculated.

Since the tire running performance testing device of the invention described in claim 4 has the above-mentioned configuration, it has an excellent effect that the actual running distance of the vehicle can be accurately measured.

Since the tire running performance testing device of the fifth aspect of the present invention is configured as described above, it has an excellent effect that the number of rotations of the tire can be accurately measured.

Further, since the tire running performance testing device of the invention according to claim 6 has the above-mentioned constitution, during the towing traveling, from the torque detecting portion and the traction force measuring portion, or the traveling distance detecting portion and the tire rotational speed detecting portion. Since the data output from the devices can be integrated at the same time, there is an excellent effect that the work of collecting the data is easy. Furthermore, the running performance of the tire can be calculated by performing statistical processing or the like based on these accumulated data.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a tire traveling performance testing device of the present invention.

FIG. 2 is a side view of the tire running performance testing device shown in FIG.

FIG. 3 is a cross-sectional view around a wheel on which a tire is mounted.

FIG. 4 is a perspective view of an odometer.

FIG. 5 is an example of a characteristic diagram of a tire obtained by the tire running performance testing device of the present embodiment.

[Explanation of symbols]

 10 tractor (vehicle) 16 load cell (traction force detection unit) 18 data accumulation device (data accumulation unit) 24 torque detection unit 28 wheel 33 tire rotation speed detection unit 34 disk with slit 44 strain gauge (strain gauge) 54 tire 56 photo sensor 58 Odometer (distance detector) 62 reels

Claims (6)

[Claims] 1. A tire running performance test, comprising: a torque detecting section for detecting a torque acting on a tire of a vehicle during traveling, and a traction force detecting section for detecting a traction force of the vehicle during towing traveling. apparatus. 2. A tire running performance test apparatus comprising: a running distance detecting unit that detects a running distance of a vehicle during running; and a tire rotation speed detecting unit that detects a rotation speed of a tire. 3. The tire running performance testing device according to claim 1, wherein the torque detection unit is integrally provided between an axle and a wheel of the vehicle. 4. The tire running performance testing device according to claim 2, wherein the running distance detecting section includes a reel that pulls out and rewinds the yarn in a state where a tensile force is applied. 5. The tire rotation speed detection unit includes a disk with a slit that rotates in synchronization with the tire, and a sensor unit that detects a slit that passes a predetermined position while the disk with the slit rotates. The tire running performance test device according to claim 2, wherein 6. A data accumulating unit for accumulating data output from the torque detecting unit and the tractive force detecting unit, or the traveling distance detecting unit and the tire rotation speed detecting unit. The tire running performance test device according to claim 1 or claim 2.