Tread rubber rolling resistance testing device and testing method

Abstract

The invention discloses a tread rubber rolling resistance testing device and a tread rubber rolling resistance testing method, and relates to the field of tread rubber rolling resistance testing. The test trolley comprises a trolley body and wheels located at the lower end of the trolley body, and the wheels are sleeved with tread rubber to be tested; the test track comprises an arc-shaped track and a horizontal track which are connected in sequence, the head end of the arc-shaped track is higher than the horizontal plane, the tail end of the arc-shaped track is connected into the horizontal track, and an experimental material is laid on the horizontal track to simulate an experimental road surface. According to the invention, the rolling resistance of the coupled tread rubber can be effectively measured, the measurement is convenient, the measurement cost is low, and the development period of coupled tread rubber products is effectively shortened.

Description

Technical Field

[0001] The invention relates to the field of tread rubber rolling resistance testing, and in particular to a tread rubber rolling resistance testing device and a testing method. Background Art

[0002] Tire rolling resistance is one of the important indicators of tire performance. There are two methods for testing the rolling resistance of automobile tread rubber in the prior art: direct and indirect measurement. Direct measurement includes force measurement, torque measurement, power measurement, deceleration measurement, etc., and the measurement cost of these methods is relatively high. Rolling resistance is caused by the deformation caused by the hysteresis loss of the material, and tanδ is one of the important parameters used to characterize the energy loss of the tire, which is proportional to the rolling resistance. Therefore, the indirect measurement method is to indirectly measure the rolling resistance by measuring the loss factor tanδ of the material. However, the bionic coupled tread rubber is composed of at least 2 or more tread rubbers, and the indirect measurement (loss factor tanδ) cannot be used to simply measure and take the average value. Summary of the invention

[0003] In view of the above-mentioned defects of the prior art, the present invention provides a tread rubber rolling resistance coefficient testing device, comprising:

[0004] A test trolley, the test trolley comprising a body and wheels located at the lower end of the body, the wheels being provided with a tread rubber to be tested;

[0005] The test track comprises an arc track and a horizontal track connected in sequence, the head end of the arc track is higher than the horizontal plane, the tail end of the arc track is connected to the horizontal track, and the horizontal track is paved with experimental materials to simulate the experimental road surface.

[0006] Furthermore, a buckle is provided at the head end of the arc track, and the buckle is connected to the test trolley.

[0007] Furthermore, the buckle is connected to the head end of the arc track through a return spring.

[0008] Furthermore, the testing device includes a fixed platform, the head end of the arc track is fixed to the top of the fixed platform, and the reset spring is installed on the fixed platform.

[0009] Furthermore, both sides of the arc track and the horizontal track are provided with side walls protruding upwards.

[0010] Furthermore, asphalt or gravel is laid on the horizontal track to simulate an asphalt road surface and a gravel road surface.

[0011] A second aspect of the present invention provides a tread rubber rolling resistance testing method, which is implemented based on the tread rubber rolling resistance testing device and comprises the following steps:

[0012] Lay experimental materials on the horizontal track to build an experimental road surface. After releasing the test car from the head end of the arc track, the test car enters the experimental road surface along the arc track, and record the forward distance L of the test car on the experimental road surface;

[0013] When L≥L1, the rolling resistance coefficient f of the to-be-tested tread rubber is:

[0014] When (L1 + L2) / 2≤L<L1, the rolling resistance coefficient f of the to-be-tested tread rubber is:

[0015] When L2≤L<(L1 + L2) / 2, the rolling resistance coefficient f of the to-be-tested tread rubber is:

[0016] When (L2 + L3) / 2≤L<L2, the rolling resistance coefficient f of the to-be-tested tread rubber is:

[0017] When L3<L<(L2 + L3) / 2, the rolling resistance coefficient f of the to-be-tested tread rubber is:

[0018] When L≤L3, the rolling resistance coefficient f of the to-be-tested tread rubber is:

[0019] Wherein, L1, L2, and L3 are the standard rubber distances respectively, L1>L2>L3, and f1, f2, and f3 are the standard rubber coefficients corresponding to the standard rubber distances respectively.

[0020] Compared with the prior art, the present invention has the following technical effects:

[0021] The present invention designs a rolling resistance coefficient testing device, which simulates different road surfaces through a horizontal track, and tests the corresponding rolling resistance coefficient according to the distance of the car on different road surfaces. The structure of the testing device is simple and the cost is low; the value of the rolling resistance coefficient is estimated according to the moving distance of the test car on the horizontal track, and the measurement of the rolling resistance coefficient of the coupled tread rubber composed of a variety of different tread rubbers is realized.

[0022] The following will further illustrate the concept, specific structure and technical effects generated by the present invention with reference to the accompanying drawings, so as to fully understand the purpose, features and effects of the present invention. Brief Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the overall structure of the measuring device in a specific embodiment of the present invention;

[0024] Figure 2It is a schematic structural diagram of the connection between the buckle and the test trolley in a specific embodiment of the present invention;

[0025] Figure 3 It is a schematic structural diagram of the buckle in a specific embodiment of the present invention. Specific embodiments

[0026] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0027] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0028] For the purpose of illustration, some exemplary embodiments of the present invention are described. It should be understood that the present invention can be implemented in other ways not specifically shown in the drawings.

[0029] As Figure 1 shown, in a specific embodiment, a tread rubber rolling resistance coefficient test device is provided, including a test trolley and a test track.

[0030] The test trolley includes a vehicle body 1. The vehicle body 1 is a vehicle body 1 structure with a certain weight. Two rotating shafts 3 are installed below the vehicle body 1. Two wheels 2 are respectively installed at both ends of the two rotating shafts 3. A to-be-tested tread rubber is sleeved on each wheel 2.

[0031] The test track includes an arc track 4 and a horizontal track 5 connected in sequence. The head end of the arc track 4 is higher than the horizontal plane, and the tail end of the arc track 4 is connected to the horizontal track 5. Different experimental materials are laid on the horizontal track 5 to simulate different experimental road surfaces, so as to obtain the rolling resistance coefficients of the coupled tread rubber under different road surfaces. In a specific embodiment, the experimental materials can be asphalt, concrete, or gravel, etc., to simulate asphalt roads, concrete roads, or gravel roads.

[0032] In a specific embodiment, taking a car with a tire model of 225 / 45R18 and a weight of 1.2 tons as an example, the width is 225 millimeters, the rim diameter is 18 inches (457.2 millimeters), and the car weight is 1.2 tons (1,200,000 grams); according to the sample parameters of the Akron abrasion machine (National Standard "GB / T 1689-2014"), the tire size of the car is reduced, with a width of 12.7 millimeters and a diameter of 68 millimeters, based on the unchanged contact area pressure between the car tire and the ground;

[0033] Assume: The contact area pressure (pressure) between the tire and the ground remains unchanged.

[0034] Original contact area (simplified calculation as a rectangle):

[0035] Original contact area = 225mm × 457.2mm ≈ 102,870mm 2 ;

[0036] Original pressure:

[0037] Original pressure = 102,870mm21.2 tons × 1,000,000 grams / ton ≈ 11.67 grams per square millimeter;

[0038] Contact area after scaling (simplified calculation as a rectangle):

[0039] Contact area after scaling = 12.7mm × 68mm ≈ 863.6mm 2 ;

[0040] Car weight after scaling:

[0041] Weight after scaling = 11.67 grams per square millimeter × 863.6mm2 ≈ 10,100 grams ≈ 10kg.

[0042] In this embodiment, the arc track is made of aluminum alloy, with a Vickers hardness ≥ 8 degrees and a surface roughness Ra < 0.5um; the head end of the arc track 4 is fixed at the top of the fixed platform 6, and there is a height difference between the fixed platform 6 and the horizontal track 5, and there is also a height difference between the head end of the arc track 4 and the horizontal track 5. When performing the rolling resistance coefficient test, the test trolley slides down from the top of the arc track 4 into the horizontal track 5 under the action of gravity, and the horizontal track 5 simulates different test roads, and the test trolley will slide different distances on different simulated roads.

[0043] In a specific embodiment, in order to prevent a slight force from being exerted on the test trolley when manually lowering it, which may give the test trolley a certain initial velocity and affect the final test results, a buckle 7 is provided at the head end of the arc-shaped track 4. The buckle 7 is connected to the test trolley. During measurement, after the buckle 7 is opened, the test trolley is subjected to the minimum human force and slides downward only under the action of gravity and friction.

[0044] To improve the simplicity of the operation of the buckle 7, in this embodiment, the buckle 7 is connected to the head end position of the arc-shaped track 4 through a return spring 9. As Figure 2 shown, the buckle 7 is located at the top of the fixed platform 6. One end of the buckle 7 is provided with a hook 8, and the hook 8 extends into the arc-shaped track 4. One end of the test trolley is hung on the hook 8 to fix the test trolley. The return spring 9 is located at the lower end of the buckle 7. When the buckle 7 is pressed downward, the buckle 7 compresses the return spring 9, and at the same time, the hook 8 disengages from the test trolley, and the test trolley slides downward along the arc-shaped track 4. When the pressing of the buckle 7 stops, the return spring 9 makes the buckle 7 return to its original position under the action of the elastic force.

[0045] In this embodiment, the buckle 7 and the return spring 9 are located inside the fixed platform 6. The upper end of the buckle 7 protrudes upward to form a button 10. The hook 8 extends out of the fixed platform 6 and is connected to the test trolley. During the test, the buckle 7 is pressed by pressing the button 10. The fixed platform 6 makes the return spring 9 drive the buckle 7 to move within a fixed range, improving the simplicity of the operation and the operation safety at the same time.

[0046] Since the test trolley itself has a certain weight, during the test, the sliding speed of the test trolley may be relatively large due to accidental factors, and it may deviate from the track during the movement, causing potential safety hazards and damage to the test trolley. Therefore, in this embodiment, both sides of the arc-shaped track 4 and the horizontal track 5 are provided with upwardly protruding side walls, which play a good protective role.

[0047] Based on the tread rubber rolling resistance coefficient test device described in the above embodiment, in a specific embodiment, a method for testing the tread rubber rolling resistance coefficient is provided.

[0048] The rolling resistance coefficient f is the ratio of the thrust required for the wheel to roll under certain conditions to the wheel load, and its calculation formula is as follows:

[0049] f = Fp1 / W;

[0050] where Fp1 is the rolling resistance and W is the gravity of the vehicle, that is, the thrust required per unit vehicle gravity.

[0051] The rolling resistance test method includes the following steps:

[0052] The weight of the test trolley is 10 KG. The diameter of the inner groove of the wheel 2 is 56 mm, the width is 12 mm, and the thickness is 2 - 3 mm. This enables the test trolley to directly install the sample after the Akron abrasion test onto this device for the rolling resistance coefficient test, or it can first conduct the rolling resistance coefficient test and then the Akron abrasion test.

[0053] When testing asphalt or concrete pavements, the experimental material laid on the horizontal track 5 is asphalt. After setting up the experimental asphalt pavement, when the test trolley is released from the head end of the arc track 4, the test trolley enters the said experimental pavement along the arc track 4, and the advancing distance L of the test trolley on the experimental pavement is recorded.

[0054] When L≥L1, the rolling resistance coefficient f of the to - be - tested tread rubber is:

[0055] When (L1 + L2) / 2≤L<L1, the rolling resistance coefficient f of the to - be - tested tread rubber is:

[0056] When L2≤L<(L1 + L2) / 2, the rolling resistance coefficient f of the to - be - tested tread rubber is:

[0057] When (L2 + L3) / 2≤L<L2, the rolling resistance coefficient f of the to - be - tested tread rubber is:

[0058] When L3<L<(L2 + L3) / 2, the rolling resistance coefficient f of the to - be - tested tread rubber is:

[0059] When L≤L3, the rolling resistance coefficient f of the to - be - tested tread rubber is:

[0060] Among them, L1, L2, and L3 are the standard rubber distances respectively, L1>L2>L3, and f1, f2, and f3 are the standard rubber coefficients corresponding to the standard rubber distances.

[0061] According to GB / T 29040 - 2012 Test Method for Rolling Resistance of Automotive Tires, the test standard rubbers on the asphalt pavement are obtained respectively, and the coefficients are: f1 = 0.010, f2 = 0.015, f3 = 0.020; through experiments, the measured rolling distances of the standard rubbers are respectively: L1 = 245 mm, L2 = 220 mm, L3 = 198 mm; the rolling conditions are: the angle is 10 degrees, and the height is 70 mm.

[0062] When the test road surface is a gravel road surface, the test process is the same as that of the above embodiment. The test standard rubber coefficients of the gravel road surface are: f1 = 0.020, f2 = 0.023, f3 = 0.025; the standard rubber rolling distances are respectively: L1 = 198 cm, L2 = 182 cm, L3 = 155 cm.

[0064] The test device and test method of the present invention can effectively measure the rolling resistance of the coupled tread rubber, with convenient measurement and low cost, and effectively shorten the development cycle of the coupled tread rubber product.

[0065] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A tread compound rolling resistance testing device, characterized in that Comprising: A test trolley, the test trolley comprising a vehicle body and wheels located at the lower end of the vehicle body, and a to-be-tested tread rubber sleeved on the wheels; A test track, the test track comprising an arc track and a horizontal track connected in sequence, the head end of the arc track being higher than the horizontal plane, the tail end of the arc track being connected to the horizontal track, and experimental materials being laid on the horizontal track to simulate an experimental road surface.

2. The tread compound rolling resistance testing device according to claim 1, wherein A buckle is provided at the head end of the arc track, and the buckle is connected to the test trolley.

3. The testing device for rolling resistance of tread rubber according to claim 2, characterized in that, The buckle is connected to the head end position of the arc track through a return spring.

4. The tread compound rolling resistance testing device according to claim 3, characterized in that The test device comprises a fixed platform, the head end of the arc track being fixed to the top of the fixed platform, and the return spring being installed on the fixed platform.

5. The tread compound rolling resistance testing device according to claim 1, wherein Side walls protruding upwards are provided on both sides of the arc track and the horizontal track.

6. The tread compound rolling resistance testing device according to claim 1, characterized in that, Asphalt or gravel is laid on the horizontal track to simulate an asphalt road surface and a gravel road surface.

7. A method for testing the rolling resistance of tread rubber, characterized in that, Implemented based on the tread rubber rolling resistance test device according to any one of claims 1-6, comprising the following steps: Laying experimental materials on the horizontal track to build an experimental road surface, releasing the test trolley from the head end of the arc track, and the test trolley entering the experimental road surface along the arc track, and recording the forward distance L of the test trolley on the experimental road surface; When L ≥ L1, the rolling resistance coefficient f of the tread compound to be measured is: When (L1 + L2) / 2 ≤ L < L1, the rolling resistance coefficient f of the tread compound to be measured is: When L2 ≤ L < (L1 + L2) / 2, the rolling resistance coefficient f of the tread compound to be measured is as follows: When (L2 + L3) / 2 ≤ L < L2, the rolling resistance coefficient f of the tread compound to be measured is: When L3 < L < (L2 + L3) / 2, the rolling resistance coefficient f of the tread compound to be measured is: When L ≤ L3, the rolling resistance coefficient f of the tread compound to be measured is: Wherein, L1, L2, and L3 are the distances of standard rubber respectively, L1>L2>L3, and f1, f2, and f3 are the standard rubber coefficients corresponding to the distances of standard rubber respectively.

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