CN115406674A

CN115406674A - Testing machine and testing method

Info

Publication number: CN115406674A
Application number: CN202211131875.6A
Authority: CN
Inventors: 马龙
Original assignee: Xiaomi Automobile Technology Co Ltd
Current assignee: Xiaomi Automobile Technology Co Ltd
Priority date: 2022-09-16
Filing date: 2022-09-16
Publication date: 2022-11-29

Abstract

The utility model relates to a testing machine and test method for carry out cyclic impact endurance test to wheel assembly, this testing machine includes rotary drum and driven shaft, the rotary drum passes through the power device drive in order to rotate around self axis, be provided with the bellying on the periphery wall of rotary drum, the driven shaft is used for installing the wheel assembly, so that the periphery wall of wheel assembly laminate in the periphery wall of rotary drum, be provided with force transducer on the driven shaft, be used for measuring the wheel assembly with radial force when the bellying contacts. The vehicle wheel assembly impact simulation system can simulate the impact force of the whole vehicle passing through various road surface structures on an actual road so as to carry out multiple times of cyclic impact on the wheel assembly and realize the verification process of the durability under the cyclic impact.

Description

Testing machine and testing method

Technical Field

The disclosure relates to the technical field of vehicle durability tests, in particular to a testing machine and a testing method.

Background

During the whole vehicle road endurance test, the phenomena of tire cracking and wheel inner rim fracture frequently occur. Once failure occurs, a supplier needs to improve and then rearrange a road test vehicle for testing, the testing period is long, and the project development period is influenced.

In the related art, the tire and wheel of the wheel assembly are usually subjected to endurance tests by both 90 ° impact and radial impact test modes. The two impact modes are used for testing the capability of a wheel or a tire for bearing transient impact, and the actual working conditions of cycle and repeated impact in the whole road test process cannot be tested.

Disclosure of Invention

The present disclosure is directed to a testing machine and a testing method, which can perform multiple cyclic impacts on a wheel assembly to realize a verification process of durability under cyclic impacts, so as to at least partially solve the above technical problems.

In order to achieve the above object, a first aspect of the present disclosure provides a testing machine, which includes a drum and a driven shaft, wherein the drum is driven by a power device to rotate around its axis, a protrusion is disposed on an outer peripheral wall of the drum, the driven shaft is used for mounting a wheel assembly, so that the outer peripheral wall of the wheel assembly is attached to the outer peripheral wall of the drum, and a force sensor is disposed on the driven shaft and used for measuring a radial force when the wheel assembly contacts with the protrusion.

Optionally, the driven shaft has a stub shaft for passing through a central bore of the wheel assembly, the strain gauge of the force sensor being attached to the stub shaft so as to be positionable between an outer peripheral wall of the stub shaft and an inner peripheral wall of the central bore.

Optionally, the boss is removably connected to the drum for enabling replacement of bosses having different radial heights.

Optionally, a mounting groove is formed in the peripheral wall of the drum, and the protrusion is detachably mounted in the mounting groove and partially extends out of the mounting groove.

Optionally, the number of the protrusions is multiple and the protrusions are arranged at intervals along the circumferential direction of the drum, and the radial height of each protrusion protruding from the outer circumferential wall of the drum is different.

A second aspect of the present disclosure provides a test method for performing a cyclic impact endurance test on a wheel assembly through a testing machine, where the testing machine includes a drum and a driven shaft, the drum is driven by a power device to rotate around its axis, a protrusion is provided on an outer circumferential wall of the drum, and a force sensor is provided on the driven shaft, the test method includes:

mounting the wheel assembly on the driven shaft so that the peripheral wall of the wheel assembly is attached to the peripheral wall of the drum;

a debugging step, measuring the maximum value of radial force when the wheel assembly is contacted with the bulge through the force sensor, and determining the test rotating speed of the rotary drum according to the maximum value of the required radial force;

and a testing step, after the rotary drum rotates for a first preset number of revolutions at the testing rotating speed, checking whether cracks exist in the tire and/or the wheel of the wheel assembly.

Optionally, prior to the mounting step, the testing method further comprises:

the method comprises the following steps of collecting the maximum value of first impact force when a wheel assembly is in contact with a first road surface structure when a whole vehicle passes through the first road surface structure on an actual road;

in the adjusting step, the maximum value of the required radial force and the maximum value of the first impact force are within a first allowable error range.

Optionally, the first allowable error range is 0 to 5%.

Optionally, the number of the convex portions is multiple, and the convex portions are all detachably connected with the rotary drum, the radial height of each convex portion protruding from the outer circumferential wall of the rotary drum is different, the multiple convex portions include a reference convex portion and at least one additional convex portion, and the maximum value of the radial force is the maximum value of a first radial force when the wheel assembly is in contact with the reference convex portion;

the debugging step further comprises:

and measuring the maximum value of each second radial force when the wheel assembly is in contact with each additional lug boss through the force sensor, and determining the radial height of each additional lug boss protruding out of the outer peripheral wall of the rotary drum according to the maximum value of each required second radial force at the test rotating speed.

Optionally, each of the additional protrusions corresponds to an additional pavement structure, and the step of collecting further includes:

collecting the maximum value of each second impact force when the wheel assembly is in contact with each additional road surface structure when the whole vehicle passes through each additional road surface structure on an actual road;

in the debugging step, the maximum value of the required second radial force and the corresponding maximum value of the second impact force are within a second allowable error range.

Optionally, the second allowable error range is 0 to 10%.

Optionally, the radial height of the reference lobe is greater than the radial height of each of the additional lobes such that the maximum value of the first radial force is greater than the maximum value of the second radial force at the test rotational speed.

Optionally, in the adjusting step, the determining, at the test rotation speed, a radial height of each additional convex portion protruding from the outer circumferential wall of the rotary drum according to a maximum value of each required second radial force includes:

by replacing the additional projections with different radial heights, the maximum value of the second radial force is such that it meets the maximum value of the second radial force required at the test rotational speed.

Optionally, in the testing step, after checking whether the tire or the wheel has cracks after the drum rotates at the test rotation speed for a first preset number of revolutions, the method further comprises:

removing the convex part with the largest radial height from the rotary drum if the tire and the wheel have no cracks;

after the rotary drum continues to run for a second preset revolution at the test rotating speed, checking whether cracks exist in the tire and/or the wheel;

removing the one or more of the remaining lugs having the greatest radial height from the drum if neither the tire nor the wheel has cracks;

after the rotary drum continues to run for a third preset revolution at the test rotating speed, checking whether cracks exist in the tire and/or the wheel;

and repeating the steps until the tire and/or the wheel have cracks, or rotating the tire and/or the wheel again after all the convex parts are disassembled to finally preset the rotating speed, and stopping the rotating drum.

Optionally, after each lug boss is disassembled, the preset rotation number of the rotary drum is increased.

Through above-mentioned technical scheme, set up the bellying on the periphery wall of rotary drum to install the wheel assembly on the driven shaft, so that the periphery wall of wheel assembly laminates in the periphery wall of rotary drum, when power device drive rotary drum was rotatory, bellying and the periphery wall cycle collision of wheel assembly, impact, in order to realize the cycle impact to the wheel assembly, test the fatigue durability performance of wheel assembly under the cycle impact. And the radial force when the wheel assembly is contacted with the boss part is measured through the force sensor, and the change of the radial force can be realized by adjusting the rotating speed of the rotary drum so as to achieve the required radial force, so that the fatigue durability of the cyclic impact of the wheel assembly can be better verified under the cyclic impact of the required radial force. The required radial force can simulate the impact force of the whole vehicle passing through various pavement structures on an actual road, namely, the required radial force can be determined according to the impact force, and then the cyclic impact endurance test of the whole vehicle passing through various pavement structures on the actual road can be simulated, so that the road test cost can be obviously saved, and the development period can be shortened.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

FIG. 1 is a perspective view of a drum provided in an exemplary embodiment of the present disclosure in engagement with a wheel assembly;

FIG. 2 is a front view of a drum provided in an exemplary embodiment of the present disclosure in engagement with a wheel assembly;

FIG. 3 is an enlarged partial view of a drum provided in an exemplary embodiment of the present disclosure in engagement with a wheel assembly;

FIG. 4 is a partial cross-sectional view of a driven shaft provided in an exemplary embodiment of the present disclosure mated with a hub of a wheel;

FIG. 5 is a flow chart of a testing method provided in one exemplary embodiment of the present disclosure;

FIG. 6 is a flow chart of a testing method provided in exemplary embodiment two of the present disclosure;

FIG. 7 is a flow chart of a test method provided in exemplary embodiment three of the present disclosure;

FIG. 8 is a flow chart of a testing method provided in example embodiment four of the present disclosure;

fig. 9 is a flow chart of a testing method provided in example embodiment five of the present disclosure.

Description of the reference numerals

1-a wheel assembly; 110-a tire; 120-a wheel; 121-a hub; 122-a rim; 2-rotating the drum; 210-a boss; 211-a reference boss; 212-additional raised portion; 2121-first boss; 2122-a second boss; 2123-a third boss; 220-mounting grooves; 3-driven shaft; 310-a connecting disc; 320-bolt; 330-a nut; 340-a shaft head; 4-a force sensor; 410-strain gauge.

Detailed Description

The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

In this disclosure, where the context does not dictate to the contrary, use of directional words such as "inner and outer" refers to inner and outer relative to the contour of the component or structure itself. In addition, it should be noted that terms such as "first", "second", and the like are used to distinguish one element from another, and have no order or importance. In addition, in the description with reference to the drawings, the same reference numerals in different drawings denote the same elements.

In the current new energy automobile market, a plurality of automobile models are combined by large-size wheels and tires with the height-width ratio of less than or equal to 40, and the phenomena of tire cutting and wheel inner rim fracture frequently occur in the whole automobile endurance test process. Once the failure occurs, a supplier needs to improve and then rearrange a road test vehicle for testing, the testing period is long, and the project development period is influenced.

In the related art, in a 90 ° impact test, a wheel tire assembly is mounted on a testing machine. The axial position of the wheel is adjusted to ensure that the center of the section of the tire is aligned with the edge of the impact surface of the hammer. The position of the rim in the circumferential direction is adjusted to ensure that the impact part of the inner rim is positioned right below the punch hammer. And adjusting the distance from the impact surface of the impact hammer to the highest point of the tire to be equal to the falling height of the impact hammer. In the test, the ram was released and the wheel assembly was impacted.

In the radial impact test, the test apparatus and method are consistent with the 90 ° impact test, except for the radial impact of the entire rim, tire cross section.

Therefore, no matter the impact is 90 degrees or the radial impact, the capability of the wheel or the tire for bearing the transient impact is tested, and the actual working condition of bearing the cycle and multiple impacts in the whole road test process cannot be tested.

Based on this, according to a first aspect of the present disclosure, there is provided a testing machine, as shown in fig. 1 to fig. 4, the testing machine includes a drum 2 and a driven shaft 3, the drum 2 is driven by a power device to be capable of rotating around its axis, a protrusion 210 is provided on an outer peripheral wall of the drum 2, the driven shaft 3 is used for mounting a wheel assembly 1, so that the outer peripheral wall of the wheel assembly 1 is attached to the outer peripheral wall of the drum 2, and a force sensor 4 is provided on the driven shaft 3 for measuring a radial force when the wheel assembly 1 contacts with the protrusion 210.

Through the technical scheme, the boss 210 is arranged on the peripheral wall of the rotary drum 2, the wheel assembly 1 is installed on the driven shaft 3, so that the peripheral wall of the wheel assembly 1 is attached to the peripheral wall of the rotary drum 2, when the power device drives the rotary drum 2 to rotate, the boss 210 and the peripheral wall of the wheel assembly 1 are in cyclic collision and impact, cyclic impact on the wheel assembly 1 is achieved, and the endurance fatigue performance of the wheel assembly 1 under the cyclic impact is tested. And, the radial force when the wheel assembly 1 contacts the boss portion 210 is measured by the force sensor 4, and by adjusting the rotation speed of the rotary drum 2, the variation of the radial force can be realized to achieve the required radial force, so that the endurance fatigue performance of the cyclic impact of the wheel assembly 1 can be better verified under the cyclic impact of the required radial force.

The required radial force can simulate the impact force of the whole vehicle passing through various road surface structures on an actual road, namely, the required radial force can be determined according to the impact force, and then the cyclic impact endurance test of the whole vehicle passing through various road surface structures on the actual road can be simulated, so that the road test cost can be remarkably saved, and the development period can be shortened. This approach will be described in detail below.

The power means for driving the drum 2 in rotation may be configured in any suitable manner, for example, the power means may comprise a motor which may directly or indirectly drive the drum 2 in rotation, for example, the motor may be coaxially connected with the drum 2 to directly drive the drum 2 in rotation, or alternatively, the motor may indirectly drive the drum 2 in rotation through, for example, a synchronous belt transmission mechanism. The motor may be a stepping motor, a servo motor, or the like to control and feed back the rotation speed of the rotary drum 2, or the motor may be a reduction motor and is equipped with a rotation speed sensor, or the like to control and feed back the rotation speed of the rotary drum 2, and the like, which is not limited in the present disclosure. In other embodiments, the power device may also be a power device for driving the drum to rotate, such as a tire endurance testing machine, known by those skilled in the art, and the purpose of the power device is to adjust the rotation speed of the drum 2 and feed back the current rotation speed of the drum 2, which is not limited in the present disclosure.

The driven shaft 3 can be rotatably fixed on a bracket (not shown) around the axis thereof, so as to drive the wheel assembly 1 and the driven shaft 3 to rotate synchronously when the rotary drum 2 rotates.

Referring to fig. 1 to 4, the wheel assembly 1 may include a wheel 120 and a tire 110 disposed on a rim 122 of the wheel 120, and is attached to the outer circumferential wall of the drum 2 through the outer circumferential wall of the tire 110, and connected to the driven shaft 3 through a hub 121 of the wheel 120.

In some embodiments, referring to fig. 4, the driven shaft 3 may be provided with a connecting plate 310 for connecting with the hub 121 of the wheel 120, and the connecting plate 310 may be provided with a bolt 320 passing through a mounting hole on the hub 121, so as to mount the wheel 120 on the driven shaft 3 by the cooperation of the bolt 320 passing through the mounting hole on the hub 121 and a nut 330, so that the wheel assembly 1 and the driven shaft 3 may rotate synchronously.

In some embodiments, the driven shaft 3 has a stub shaft 340 for passing through the central hole of the hub 121, and the strain gauge 410 of the force sensor 4 is attached to the stub shaft 340 so as to be able to be located between the outer peripheral wall of the stub shaft 340 and the inner peripheral wall of the central hole of the hub 121. The strain gauge 410 may be, for example, a resistance strain gauge attached between the axle head 340 and the hub 121, and can detect a radial force when the wheel assembly 1 contacts the protrusion 210 according to a strain effect, that is, when a conductor or a semiconductor material is mechanically deformed under an external force, a resistance value of the conductor or the semiconductor material is correspondingly changed.

Here, the radial force between the wheel assembly 1 and the boss portion 210 refers to a force in a diameter direction between a contact position of the wheel assembly 1 and the boss portion 210 and a central axis of the wheel assembly 1, and a direction of the radial force may refer to a direction indicated by an arrow F in fig. 3.

In some embodiments, a groove is formed on the outer circumferential wall of the spindle head 340, the strain gauge 410 is installed in the groove, and a surface of a side of the strain gauge 410 facing away from the spindle head 340 is attached to the inner circumferential wall of the central hole of the hub 121, so that the mechanical deformation can be generated when the wheel assembly 1 collides and impacts with the boss 210.

In some embodiments, the protrusions 210 are removably connected to the drum 2 for enabling replacement of protrusions 210 having different radial heights. The radial height referred to in the present disclosure may be understood as a height of the boss 210 in the radial direction protruding from the outer circumferential wall of the drum 2, and may also be understood as a maximum height of the boss 210 in the radial direction protruding from the outer circumferential wall of the drum 2.

In this way, on the one hand, as described above, by adjusting the rotation speed of the rotary drum 2, the variation of the radial force between the wheel assembly 1 and the boss 210 can be achieved, so as to be able to achieve the required radial force, for example, the impact force when the vehicle passes through various road surface structures on the actual road can be simulated; on the other hand, in the case where the rotation speed of the rotary drum 2 is kept constant, the radial height of the boss portion 210 is different, and the impact force to the wheel assembly 1 is different, that is, different from the radial force between the wheel assemblies 1, and therefore, the boss portion having a different radial height may also be replaced so that the radial force between the wheel assembly 1 and the boss portion 210 reaches the required radial force. Thereby, when adjusting the radial force between the wheel assembly 1 and the boss 210, two adjustable variables are provided, namely, the rotation speed of the rotary drum 2 and the radial height of the boss 210 can be adjusted. In a specific operation, the rotating speed of the rotary drum 2 and the radial height of the boss 210 can be adjusted comprehensively, so that the rotating speed of the rotary drum 2 is not too fast or too slow under the condition of meeting the required radial force, or the radial height of the boss 210 is not too large or too small, so that the cyclic impact endurance test of the wheel assembly 1 better conforms to the working condition of the whole vehicle on an actual road, and the test result has a reference value.

In some embodiments, referring to fig. 1, the outer circumferential wall of the drum 2 is provided with a mounting groove 220, and the protrusion 210 is detachably mounted in the mounting groove 220 and partially extends out of the mounting groove 220. The boss 210 can be more stably assembled by providing the mounting groove 220, and the connection of the boss 210 to the drum 2 can be more stable when the boss 210 impacts the wheel assembly 1.

In addition, the protruding portion 210 may be connected to the rotary drum 2 in any suitable manner, for example, a through hole is provided on the protruding portion, a threaded hole is provided on the bottom surface of the mounting groove 220, and a threaded fastener such as a bolt may be inserted through the through hole and then screwed into the threaded hole to connect the protruding portion 210 to the rotary drum 2.

In some embodiments, the number of the protrusions 210 is multiple and the protrusions are arranged at intervals along the circumferential direction of the drum 2, and the radial height of each protrusion 210 protruding from the outer circumferential wall of the drum 2 is different.

In this way, in the cyclic impact test of the wheel assembly 1, the wheel assembly 1 is subjected to the cyclic impact test with the protrusions 210 having different radial heights or different impact forces (radial forces) to verify the fatigue durability of the wheel assembly 1 under the action of the different impact forces (radial forces).

In addition, the radial force between each protrusion 210 and the wheel assembly 1 can simulate the impact force when the whole vehicle is in contact with different road surface structures during running on the actual road, so as to simulate the cyclic impact of various road surface structures on the wheel assembly 1, so that the test result is more in line with the road condition when the whole vehicle runs on the actual road, and the test result has more reference value. This approach will be described in detail below.

Referring to fig. 1 to 9, according to a second aspect of the present disclosure, there is provided a test method for performing a cyclic durability test on a wheel assembly 1 by a testing machine, the testing machine includes a drum 2 and a driven shaft 3, the drum 2 is driven by a power device to be capable of rotating around its axis, a boss 210 is provided on an outer peripheral wall of the drum 2, and a force sensor is provided on the driven shaft 3. The testing machine provided by the first aspect of the present disclosure may be used as the testing machine, and/or the testing machine provided by the first aspect of the present disclosure may also perform a cyclic endurance test on the wheel assembly 1 by using the testing method.

In the first embodiment, as shown with reference to fig. 5, the test method can be implemented by the following steps.

An installation step S110 of installing the wheel assembly 1 on the driven shaft 3 such that the outer peripheral wall of the wheel assembly 1 is attached to the outer peripheral wall of the drum 2;

a debugging step S120, measuring the maximum value of radial force when the wheel assembly 1 is contacted with the boss 210 through the force sensor 4, and determining the test rotating speed of the rotary drum 2 according to the required maximum value of the radial force;

in the test step S130, the drum 2 is rotated at the test rotation speed for a first predetermined number of revolutions, and then the tire 110 and/or the wheel 120 of the wheel assembly 1 is checked for cracks.

Through the technical scheme, the boss 210 is arranged on the peripheral wall of the rotary drum 2, the wheel assembly 1 is installed on the driven shaft 3, so that the peripheral wall of the wheel assembly 1 is attached to the peripheral wall of the rotary drum 2, when the power device drives the rotary drum 2 to rotate, the boss 210 and the peripheral wall of the wheel assembly 1 are in cyclic collision and impact, cyclic impact on the wheel assembly 1 is achieved, and fatigue durability of the wheel assembly 1 under the cyclic impact is tested. And, the radial force when the wheel assembly 1 contacts the boss portion 210 is measured by the force sensor 4, and by adjusting the rotation speed of the rotary drum 2, the variation of the radial force can be realized to achieve the required radial force, so that the fatigue durability of the cyclic impact of the wheel assembly 1 can be better verified under the cyclic impact of the required radial force.

The mounting step S110 may be implemented in the following manner.

The wheel 120 may be sleeved on the stub shaft 340 and connected to the connecting disc 310 through the hub 121 such that the strain gauge 410 of the force sensor 4 is located between the outer circumferential wall of the stub shaft 340 and the inner circumferential wall of the central hole of the hub 121 for detecting the radial force when the wheel assembly 1 is in contact with the boss 210.

The debugging step S120 can be realized in the following manner.

The rotary drum 2 is driven by the power device to rotate in an accelerated mode gradually, the maximum value of the radial force when the wheel assembly 1 is in contact with the boss portion 210 is measured through the force sensor 4, the maximum value of the radial force is gradually increased along with continuous acceleration of the rotary drum 2, when the required maximum value of the radial force is reached, the current rotating speed of the rotary drum is kept, and the current rotating speed is the test rotating speed. Here, the maximum value of the radial force is understood to mean that, during the contact process between the wheel assembly 1 and the boss portion 210, the value of the radial force changes with the change of the contact position, and during this period, the maximum value of the radial force is taken as a reference value, that is, when the maximum value of the radial force detected by the force sensor 4 is the maximum value of the required radial force, the current rotation speed of the rotary drum 2 is kept unchanged to serve as a subsequent test rotation speed.

In the test step S130, after the drum 2 rotates at the test rotation speed at the first preset rotation speed, the tire 110 and/or the wheel 120 of the wheel assembly 1 are/is inspected for the presence of cracks, if cracks exist, the fatigue durability of the wheel assembly 1 under the cyclic impact is judged to be unsatisfactory, and if cracks do not exist, the fatigue durability of the wheel assembly 1 under the cyclic impact is judged to be satisfactory.

Referring to fig. 6, in the second embodiment, the test method can also be realized by the following steps.

A collecting step S210, wherein the maximum value of a first impact force when the wheel assembly 1 is contacted with a first road surface structure when the whole vehicle passes through the first road surface structure on an actual road is collected;

an installation step S220 of installing the wheel assembly 1 on the driven shaft 3 such that the outer peripheral wall of the wheel assembly 1 is fitted to the outer peripheral wall of the drum 2;

a debugging step S230 of measuring the maximum value of the radial force when the wheel assembly 1 contacts the boss 210 by the force sensor 4, and determining the test rotation speed of the drum 2 according to the maximum value of the required radial force, where the maximum value of the required radial force and the maximum value of the first impact force are within a first allowable error range;

in the test step S240, the drum 2 is rotated at the test rotation speed for a first predetermined number of revolutions, and then the tire 110 and/or the wheel 120 of the wheel assembly 1 is checked for cracks.

Through this technical scheme, in the testing process for the maximum value of the radial force that wheel assembly 1 received and the maximum value of the first impact force that whole car received when passing through first road surface structure can simulate the atress of whole car when passing through first road surface structure in first allowed error range, and then can simulate the atress condition of whole car when going on actual road through first road surface structure, and then make the actual conditions that the test result more laminated, more accurate. Compared with the prior art, the durability test is carried out on the actual road through the whole vehicle, the road test cost can be obviously saved, and the development period is shortened.

In some embodiments, the first allowable error range may be 0 to 5%. The first allowable error range may be understood as an absolute value of a difference between the maximum value of the radial force and the maximum value of the first impact force, which is within 5% of the maximum value of the radial force or the maximum value of the first impact force, so as to better conform to the stress of the entire vehicle wheel assembly on the actual road.

In the collecting step S100, the maximum value of the first impact force when the entire vehicle passes through the first Road surface structure on an actual Road is collected, and the maximum value of the first impact force when the wheel assembly 1 contacts with the first Road surface structure can be collected through Road spectrum collection, where the Road spectrum collection is a common mode of collecting working condition information in the automobile industry, in the automobile field, the Road spectrum generally refers to a Road load spectrum (Road load data) when the vehicle runs on the Road surface, and refers to a time history of an external load applied to the structure during the running process of the vehicle, so as to cause a response of the structure, and the response signal generally includes stress, strain, acceleration, force (moment), and the like. In the present disclosure, the force applied to the wheel assembly by the road surface structure may be collected, for example, the force may be measured by installing various sensors such as a wheel six-component sensor and a strain gauge on the wheel, and the installation and measurement methods thereof are known to those skilled in the art and will not be described herein again. The forces of the wheel assembly 1 in the X direction (corresponding to the length direction of the vehicle) and the Z direction (corresponding to the height direction of the vehicle) obtained in the road spectrum collecting process may be used in the present disclosure, and the impact force received by the wheel assembly 1 may be obtained through the forces in the X direction and the forces in the Z direction, for example, the impact force may be a force in a diameter direction between a contact position of the wheel assembly 1 and the road surface structure and a central axis of the wheel 120, and the impact force may be expressed as a resultant force of the forces in the X direction and the forces in the Z direction in the diameter direction. In addition, the value of the impact force of the wheel may vary when the wheel passes through the road surface structure, and the maximum value of the impact force may be used as a reference value to determine the range of the maximum value of the required radial force according to the maximum value of the impact force in the adjusting step S300.

In addition, the present disclosure illustratively shows various road surface structures that affect the behavior of the wheel assembly, which are common in the entire vehicle road endurance test, as shown in table 1 below.

TABLE 1 road surface structure information Table influencing the wheel behavior

Referring to table 1, the pavement structure includes, but is not limited to, splash roads, trench roads, 26-inch potholes, square pits, vibration roads, concrete patches, manhole covers, bumpy roads, twisted roads, and the like, which are typical pavement structures in the durability test of the entire vehicle pavement, and the structure of the pavement structure is not described in detail in the present disclosure. The first pavement structure can adopt any one pavement structure in the table 1 according to test requirements so as to simulate the endurance fatigue test of the wheel assembly under the pavement structure.

Wherein the height or depth (mm) represents a height protruding from the ground or a depth recessed from the ground corresponding to the road surface structure.

When the vehicle speed (kph) is collected by a road spectrum, the vehicle speed of the whole vehicle, taking the road surface structure as a square pit as an example, the depth of the square pit is 114mm, and when the whole vehicle passes through the square pit to collect the impact force applied to the wheel assembly 1, the vehicle speed can be kept at 40kph.

In a third embodiment, referring to fig. 1 to 3, the number of the protrusions 210 may be multiple and each of the protrusions may be detachably connected to the drum 2, the radial height of each protrusion 210 protruding from the outer circumferential wall of the drum 2 is different, the multiple protrusions 210 include a reference protrusion 211 and at least one additional protrusion 212, and the maximum value of the radial force when the wheel assembly 1 contacts the protrusions 210 is the maximum value of the first radial force when the wheel assembly 1 contacts the reference protrusion 211;

in this third embodiment, the test method can be realized by the following steps.

An acquisition step S310, which is to acquire the maximum value of a first impact force when the wheel assembly 1 is in contact with a first road surface structure when the whole vehicle passes through the first road surface structure on an actual road;

an installation step S320 of installing the wheel assembly 1 on the driven shaft 3 such that the outer peripheral wall of the wheel assembly 1 is attached to the outer peripheral wall of the drum 2;

a debugging step S330, measuring the maximum value of the first radial force when the wheel assembly 1 contacts the reference boss part 211 through the force sensor 4, determining the test rotating speed of the rotary drum 2 according to the required maximum value of the first radial force, wherein the required maximum value of the first radial force and the required maximum value of the first impact force are in a first allowable error range;

measuring the maximum value of each second radial force when the wheel assembly 1 is in contact with each additional lug boss 212 through the force sensor 4, and determining the radial height of each additional lug boss 212 protruding out of the outer peripheral wall of the rotary drum 2 according to the maximum value of each required second radial force at the test rotating speed;

in the test step S340, after the drum 2 rotates at the test rotation speed for the first preset number of revolutions, the tire 110 and/or the wheel 120 of the wheel assembly 1 are checked for cracks.

With this configuration, after the test rotation speed of the rotary drum 2 is determined based on the maximum value of the first radial force required when the wheel assembly 1 is in contact with the reference boss 211, the radial height of each additional boss 212 protruding from the outer peripheral wall of the rotary drum 2 is determined based on the maximum value of each second radial force required at the test rotation speed. In this way, the wheel assembly 1 can be subjected to the cyclic impact test with the convex portions 210 having different radial directions or different impact forces (radial forces) in the cyclic impact test of the wheel assembly 1 to verify the fatigue durability of the wheel assembly 1 under the influence of the different impact forces (radial forces).

Herein, the radial height of the present disclosure refers to the radial height of the corresponding protrusion 210 protruding from the outer circumferential wall of the drum 2.

In the fourth embodiment, each of the additional protrusions 212 may correspond to one additional road surface structure, that is, each of the additional protrusions 212 may correspond to one of the road surface structures as listed in table 1, and the test method may be further implemented by the following steps.

An acquisition step S410, which is to acquire the maximum value of a first impact force when the wheel assembly 1 contacts with a first road surface structure when the whole vehicle passes through the first road surface structure on an actual road;

collecting the maximum value of each second impact force when the whole vehicle passes through each additional road surface structure on an actual road and the wheel assembly 1 is in contact with each additional road surface structure;

an installation step S420 of installing the wheel assembly 1 on the driven shaft 3 such that the outer circumferential wall of the wheel assembly 1 is fitted to the outer circumferential wall of the drum 2;

a debugging step S430, measuring the maximum value of the first radial force when the wheel assembly 1 contacts the reference boss part 211 through the force sensor 4, determining the test rotating speed of the rotary drum 2 according to the required maximum value of the first radial force, wherein the required maximum value of the first radial force and the required maximum value of the first impact force are in a first allowable error range;

measuring the maximum value of each second radial force when the wheel assembly 1 contacts each additional lug boss 212 through the force sensor 4, and determining the radial height of each additional lug boss 212 protruding out of the outer peripheral wall of the rotary drum 2 according to the maximum value of each required second radial force at the test rotating speed, wherein the maximum value of the required second radial force and the maximum value of the second impact force are within a second allowable error range;

in the test step S440, the drum 2 rotates at the test rotation speed for a first predetermined number of revolutions, and then checks whether cracks exist in the tire 110 and/or the wheel 120 of the wheel assembly 1.

Through the technical scheme, the maximum value of the second radial force between the wheel assembly 1 and each additional lug boss 212 can simulate the maximum value of the second impact force between the wheel assembly 1 and each additional road surface structure when the whole vehicle is on an actual road, so that the impact force applied to the wheel assembly 1 on the actual road when the wheel assembly 1 passes through different road surface structures can be simulated through the collision impact of the wheel assembly 1, the reference lug boss 211 and the additional lug boss 212 in the test process.

Wherein the second allowable error range may be 0 to 10%. The second allowable error range may be understood as an absolute value of a difference between the maximum value of the second radial force and the corresponding maximum value of the second impact force, which is within 10% of the maximum value of the second radial force or the maximum value of the second impact force, so as to better conform to the actual road load of the whole vehicle wheel assembly.

In some embodiments, the radial height of the reference lobe 211 is greater than the radial height of each additional lobe 212 such that the maximum value of the first radial force is greater than the maximum value of the second radial force at the test rotational speed.

In this way, since the radial height of the reference protruding portion 211 is defined to be greater than the radial height of each additional protruding portion 212, under the condition that the rotation speed of the rotary drum 2 is constant, the maximum value of the first radial force between the wheel assembly 1 and the reference protruding portion 211 is greater than the maximum value of the second radial force between the wheel assembly 1 and each additional protruding portion 212, and since the reference protruding portion 211 and each additional protruding portion 212 respectively correspond to one road surface structure, the impact force of the first road surface structure corresponding to the reference protruding portion 211 on the wheel assembly 1 can be obtained to be greater than the impact force of each additional road surface structure on the wheel assembly 1, so that in the test process, the impact force of each additional road surface structure on the wheel assembly 1 can be simulated by taking the maximum value of the first radial force between the reference protruding portion 211 and the wheel assembly 1 as a reference, so that the test process includes more road conditions.

For example, referring to table 1, when the road spectrum is collected, the depth of the square pit is deepest, the vehicle speed is fastest when the road spectrum passes through the square pit, and the impact force of the square pit on the wheel assembly is largest. The first road surface structure may be made to correspond to a square pit, that is, the maximum value of the first radial force when the reference projecting portion 211 is in contact with the wheel assembly 1 simulates the maximum value of the first impact force between the square pit and the wheel assembly. Thus, second radial forces between the additional lugs 212 and the wheel assembly 1 may simulate second impact forces between the remaining road surface structure and the wheel assembly 1.

In some specific embodiments, referring to fig. 1 and 2, additional lobe 212 may include a first lobe 2121, a second lobe 2122, and a third lobe 2123, wherein a maximum value of radial force between first lobe 2121 and wheel assembly 1 may simulate a maximum value of impact force between wheel assembly 1 and any one of a splash path, a trench, and a 26-inch hollow, such as shown in table 1. The maximum value of the radial force between the second boss portion 2122 and the wheel assembly 1 may simulate the maximum value of the impact force between a bumpy road or a twisted road and the wheel assembly 1 shown in table 1, for example. The maximum value of the radial force between the third boss portion 2123 and the wheel assembly 1 may simulate, for example, the maximum value of the impact force between any one of the vibration path, the concrete patch, and the manhole cover shown in table 1 and the wheel assembly 1.

In some embodiments, in the commissioning step S300, the radial height of each additional protrusion 212 protruding from the outer circumferential wall of the rotary drum 2 is determined according to the maximum value of each required second radial force at the test rotation speed, which may be achieved in the following manner.

For example, by replacing the additional projection 212 with a different radial height, the maximum value of the second radial force is such that it meets the maximum value of the second radial force required at the test rotational speed. In the case where the rotational speed of the rotary drum 2 is constant, the greater the radial height of the additional boss 212, the greater the impact on the wheel assembly 1, and therefore, the additional boss 212 having a different radial height may be replaced so that the maximum value of the second radial force satisfies the maximum value of the second radial force required at the test rotational speed, that is, the maximum value of the required second radial force and the maximum value of the second impact force are within the second allowable error range.

In some specific embodiments, referring to fig. 1 and 2, a mounting groove 220 is formed on the outer circumferential wall of the drum 2, and the protrusion 210 is detachably mounted in the mounting groove 220 and partially extends out of the mounting groove 220. The boss 210 can be more stably fitted by providing the mounting groove 220, and the connection of the boss 210 to the drum 2 can be made more stable when the boss 210 impacts the wheel assembly 1.

In the fourth embodiment, the test method can be implemented by the following steps.

An acquisition step S510, which is to acquire the maximum value of a first impact force when the wheel assembly 1 contacts with a first road surface structure when the whole vehicle passes through the first road surface structure on an actual road;

an installation step S520 of installing the wheel assembly 1 on the driven shaft 3 such that the outer circumferential wall of the wheel assembly 1 is fitted to the outer circumferential wall of the drum 2;

a debugging step S530, measuring the maximum value of the first radial force when the wheel assembly 1 contacts the reference boss part 211 through the force sensor 4, determining the test rotating speed of the rotary drum 2 according to the required maximum value of the first radial force, wherein the required maximum value of the first radial force and the required maximum value of the first impact force are in a first allowable error range;

a test step S540, after the drum 2 rotates for a first preset number of revolutions at the test revolution speed, checking whether there is a crack in the tire 110 and/or the wheel 120 of the wheel assembly 1;

removing the convex portion 210 having the largest radial height among the plurality of convex portions 210 from the drum 2 if neither the tire 110 nor the wheel 120 has cracks;

after the drum 2 continues to run for a second preset number of revolutions at the test speed, checking whether cracks exist in the tire 110 and/or the wheel 120;

if neither the tire 110 nor the wheel 120 has cracks, detaching the largest projection 210 in the remaining one or more projections 210 from the rotating drum 2;

after the drum 2 continues to run at the test rotation speed for a third preset number of revolutions, checking whether the tire 110 and/or the wheel 120 have cracks;

and so on, until there is a crack in the tire 110 and/or the wheel 120, or after all the protrusions 210 are removed and then rotated again to the final preset rotation speed, the drum 2 stops running.

Through the technical scheme, in the actual running of the vehicle, the frequency of the vehicle in the case of meeting the road condition with larger impact is lower, so that the cycle test of the wheel assembly 1 under the larger impact force can be adaptively reduced, and the test result is more consistent with the actual situation. Therefore, the plurality of bosses 210 are sequentially detached in the order of the radial heights from large to small, so that the number of times of cyclic impact of the boss 210 with the large radial height on the wheel assembly 1 is small, and the number of times of cyclic impact of the boss 210 with the small radial height on the wheel assembly 1 is large, so that the test result is more accurate.

In some embodiments, the predetermined number of revolutions that the drum 2 operates may be increased after each removal of one of the protrusions 210. Since the maximum impact force to the wheel assembly 1 is gradually reduced as the bosses 210 having a greater radial height are sequentially removed, the preset number of revolutions in which the drum 2 is operated can be increased to obtain a more reliable verification result.

Taking as an example that the additional lobe 212 includes a first lobe 2121, a second lobe 2122 and a third lobe 2123, and the radial heights of the third lobe 2123, the first lobe 2121 and the second lobe 2122 decrease in sequence, test step S540 is exemplarily described, where the radial height of the reference lobe 211 is 127mm, the radial height of the third lobe 2123 is 101.6mm, the radial height of the first lobe 2121 is 76.2mm, the radial height of the second lobe 2122 is 50.8mm, the test rotation speed is 40km/h, the maximum value of the radial force between the wheel assembly 1 and the reference lobe 211 is 38KN, the maximum value of the radial force between the wheel assembly 1 and the third lobe 2123 is 21KN, the maximum value of the radial force between the wheel assembly 1 and the first lobe 2121 is 12KN, and the maximum value of the radial force between the wheel assembly 1 and the second lobe 2122 is 7.5KN.

On this basis, after the drum 2 has been operated at a test speed at a first preset speed, which may be, for example, 1000 revolutions, the tyre 110 or the wheel 120 is checked for the presence of cracks;

if neither the tire 110 nor the wheel 120 has cracks, the reference boss 211 is removed from the drum 2;

after the drum 2 continues to operate at the test rotation speed at a second preset rotation speed, which may be 2000 revolutions for example, the tire 110 or the wheel 120 is checked for cracks;

if neither the tire 110 nor the wheel 120 has cracks, the third boss 2123 is removed from the drum 2;

after the drum 2 continues to operate at the test rotation speed at a third preset rotation speed, which may be, for example, 4000 revolutions, the tire 110 and the wheel 120 are inspected for the presence of cracks;

if neither the tire 110 nor the wheel 120 has cracks, the first boss 2121 is removed from the rotating drum 2;

after the drum 2 continues to run at the test rotation speed at a fourth preset rotation speed, which may be 10000 revolutions for example, and then checks whether the tire 110 and the wheel 120 have cracks;

if neither the tire 110 nor the wheel 120 has cracks, the second boss 2122 is removed from the rotating drum 2;

after the drum 2 continues to operate at the test rotational speed for a final preset rotational speed, which may be, for example, 500000 revolutions, the tire 110 and the wheel 120 are inspected for cracks.

The purpose of continuing to operate the rotary drum 2 at the final preset rotation speed after removing all the bosses 210 is to continue to test the durability of the wheel assembly 1, i.e., to simulate the durability in the case of a flat road or an expressway.

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should be noted that the various features described in the foregoing embodiments may be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, various possible combinations will not be separately described in this disclosure.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. The utility model provides a testing machine, its characterized in that includes rotary drum and driven shaft, the rotary drum passes through the power device drive in order to rotate around self axis, be provided with the bellying on the periphery wall of rotary drum, the driven shaft is used for installing the wheel assembly, so that the periphery wall laminating of wheel assembly in the periphery wall of rotary drum, be provided with force sensor on the driven shaft, be used for measuring the wheel assembly with radial force when the bellying contacts.

2. The testing machine of claim 1, wherein the driven shaft has a stub shaft for passing through a central bore of the wheel assembly, the strain gauge of the force sensor being attached to the stub shaft so as to be positionable between an outer peripheral wall of the stub shaft and an inner peripheral wall of the central bore.

3. The testing machine according to claim 1 or 2, characterized in that the projections are removably connected with the drum for enabling the replacement of projections having different radial heights.

4. The testing machine of claim 3, wherein a mounting groove is provided on the peripheral wall of the drum, and the projection is detachably mounted in the mounting groove and partially extends out of the mounting groove.

5. The testing machine of claim 3, wherein the number of the protrusions is multiple and the protrusions are arranged at intervals along the circumferential direction of the rotary drum, and the radial height of each protrusion protruding from the outer circumferential wall of the rotary drum is different.

6. A test method is characterized by being used for carrying out cyclic impact endurance test on a wheel assembly through a testing machine, wherein the testing machine comprises a rotary drum and a driven shaft, the rotary drum is driven by a power device to rotate around the axis of the rotary drum, a boss is arranged on the peripheral wall of the rotary drum, a force sensor is arranged on the driven shaft, and the test method comprises the following steps:

mounting the wheel assembly on the driven shaft so that the outer peripheral wall of the wheel assembly is attached to the outer peripheral wall of the rotary drum;

a debugging step, measuring the maximum value of radial force when the wheel assembly is contacted with the bulge part through the force sensor, and determining the test rotating speed of the rotary drum according to the maximum value of the required radial force;

7. The testing method of claim 6, wherein prior to the installing step, the testing method further comprises:

the method comprises the steps of collecting the maximum value of first impact force when a wheel assembly is in contact with a first road surface structure when a whole vehicle passes through the first road surface structure on an actual road;

8. The test method according to claim 7, wherein the first allowable error range is 0 to 5%.

9. The test method according to claim 7, wherein the plurality of projections are provided in plurality and are each detachably connected to the drum, and each of the plurality of projections has a different radial height from the outer circumferential wall of the drum, and includes a reference projection and at least one additional projection, and the maximum value of the radial force is a maximum value of a first radial force when the wheel assembly is in contact with the reference projection;

the debugging step further comprises:

10. The test method of claim 9, wherein each of the additional raised portions corresponds to an additional pavement structure, the step of collecting further comprising:

11. The test method according to claim 10, wherein the second allowable error range is 0 to 10%.

12. The testing method of claim 10, wherein a radial height of the reference lobe is greater than a radial height of each of the additional lobes such that a maximum value of the first radial force is greater than a maximum value of the second radial force at the test rotational speed.

13. The testing method of claim 9, wherein in the commissioning step, determining a radial height of each of the additional lugs projecting from the peripheral wall of the drum based on a maximum value of each required second radial force at the testing rotational speed comprises:

by replacing the additional protrusions with different radial heights, the maximum value of the second radial force is made to satisfy the maximum value of the second radial force required at the test rotational speed.

14. The test method according to claim 9, wherein a mounting groove is provided on the outer peripheral wall of the drum, and the projection is detachably mounted in the mounting groove and partially extends out of the mounting groove.

15. The test method as claimed in claim 9, wherein in the testing step, after checking whether the tire or the wheel has a crack after the drum is rotated at the test rotation speed for a first preset number of revolutions, further comprising:

and repeating the steps until the tire and/or the wheel have cracks, or rotating again after all the convex parts are disassembled and finally rotating at the preset rotating speed, and stopping the rotating drum.

16. The test method of claim 15, wherein the predetermined number of revolutions the drum is operated at increases after each removal of one of the bosses.