阅读说明：本技术 保险杠蒙皮刚度的测量方法及基于该测量方法的测量设备 (Method for measuring rigidity of bumper skin and measuring equipment based on method ) 是由 陆嘉庆 张静 姜进京 王琼 殷雪亚 孙晓波 李伟锋 朱云峰 徐小峰 李强 潘敏 于 2020-05-18 设计创作，主要内容包括：本发明公开了一种保险杠蒙皮刚度的测量方法及基于该测量方法的测量设备,该测量方法包括以下步骤:S1、给保险杠蒙皮施加大小已知的冲击能W；S2、计算保险杠蒙皮的吸收能E,所述吸收能E是保险杠蒙皮从所述冲击能W中吸收的能量；S3、测出在所述冲击能W作用下保险杠蒙皮所受的最大冲击力N-(max)；S4、利用公式E＝0.5×N-(max)×X计算保险杠蒙皮的变形量X。该测量方法便于实施,基于该测量方法的测量设备,不需要设置百分尺系统,因此规避了百分尺系统测点与变形中心有距离、测量时需要用夹具固定以及设备分体导致的不便携等一系列问题,该测量设备具有测量结果准确、使用方便、便携等优势。(The invention discloses a method for measuring the rigidity of a bumper skin and a measuring device based on the method, wherein the method comprises the following steps of S1, applying impact energy W with known size to the bumper skin; s2, calculating the absorption energy E of the bumper skin, wherein the absorption energy E is the energy absorbed by the bumper skin from the impact energy W; s3, measuring the maximum impact force N borne by the bumper skin under the action of the impact energy W max (ii) a S4, using equation E equal to 0.5 × N max X the amount of deformation X of the bumper skin was calculated. The measuring method is convenient to implement, and measuring equipment based on the measuring method does not need to be provided with a percentile scale system, so that a series of problems that a measuring point of the percentile scale system is away from a deformation center, the measuring equipment needs to be fixed by a clamp during measurement, the equipment is split and inconvenient to carry and the like are avoided.)

1. A method for measuring the rigidity of a bumper skin is characterized by comprising the following steps:

s1, applying impact energy W with known size to the bumper skin;

s2, calculating the absorption energy E of the bumper skin, wherein the absorption energy E is the energy absorbed by the bumper skin from the impact energy W;

s3, measuring the maximum impact force N borne by the bumper skin under the action of the impact energy W_max；

S4, using equation E equal to 0.5 × N_maxX the amount of deformation X of the bumper skin was calculated.

2. The method of measurement according to claim 1, wherein the impact energy is converted from elastic potential energy or gravitational potential energy or electromagnetic energy.

3. The measurement method according to claim 1 or 2, characterized in that the absorption energy E is equal to the impact energy W; alternatively, the absorbed energy E is equal to the impact energy W minus an energy dissipation value E'.

4. The measuring method according to claim 3, wherein the energy dissipation value E' is corrected based on the comparison result by actually measuring the deformation amount X of the bumper skin and comparing the actually measured value of the deformation amount X with the calculated value of the deformation amount X obtained in S4.

5. Measuring device based on the measuring method according to any of claims 1-4, characterized in that the measuring device comprises a press head (1) for pressing against the bumper skin for measuring the maximum impact force N_maxFor applying a punch (3) of said impact energy W to a bumper skin, said dynamometer (2) being arranged between said punch (3) and said ram (1), said punch (3) directly impacting said dynamometer (2).

6. A measuring device according to claim 5, characterized in that the impact energy W is converted from the gravitational potential energy of the punch (3);

or the measuring equipment further comprises an energy storage component for storing elastic potential energy or electromagnetic energy, the energy storage component is connected with the punch (3), and the impact energy W is formed by converting the energy stored by the energy storage component.

7. A measuring device according to claim 6, characterized in that the energy accumulating member is an elastic body (4), one end of the elastic body (4) being connected to the punch (3) and the other end being connected to the load cell (2).

8. A measuring device according to claim 7, characterized in that the measuring device further comprises a scale (5), the scale (5) being adapted to indicate the distance the resilient body (4) is elongated by the punch (3) from an initial position, which initial position is the position the resilient body (4) is in when the punch (3) impacts the load cell (2).

9. A measuring device according to claim 8, characterized in that the elastomer body (4) is in tension in the initial position and exerts a pulling force on the punch (3) towards the load cell (2).

10. A measuring device according to any of claims 5-9, characterized in that the punch (3) and the ram (1) are located on the same line.

Technical Field

The invention relates to the technical field of bumper skin rigidity measurement, in particular to a method for measuring the bumper skin rigidity and a measuring device based on the method

Background

The impact of the rigidity of the bumper skin on the pedestrian safety and the perception quality of a user is large, as shown in the figure, the existing measuring equipment for the rigidity of the bumper skin comprises a pressure head 04, a dynamometer 03, a dial indicator 01 and a support 02, the dial indicator is fixedly connected with the support to form a dial indicator system, the pressure head is fixedly connected with the dynamometer to form a pressure head system, and the two systems are mutually independent.

At the start of the measurement, the dial indicator system is fixed to the bumper clip, then the dial indicator is brought into contact with the bumper skin and fixed, reading 1 from the dial indicator. Then, a worker holds the pressure head system by hand to apply specified pressure on the bumper skin according to requirements, and the position of the applied pressure needs to be as close to the contact position of the dial indicator and the bumper skin as possible. After the specified pressure is reached, reading 2 is read from the dial gauge, and the difference between reading 1 and reading 2 is used to estimate the deformation of the part.

In short, the existing method for measuring the rigidity of the bumper skin is to apply force to the bumper skin by using a pressure head system, measure the deformation of the bumper skin before and after stress by using a dial indicator system, and represent the rigidity of the bumper skin by using the deformation.

Such a measuring apparatus and measuring method have the following problems:

1. the contact position of the dial indicator and the bumper skin cannot coincide with the position of the applied pressure, so that the distance between a measuring point of the dial indicator and a deformation center is still large, and the measured deformation error is large.

2. The dial indicator system must be fixed relative to the bumper skin, usually on a bumper skin fixture, making it impossible to use this measurement method on a real vehicle or during calibration.

3. The dial indicator system and the pressure head system are independent from each other, so that the dial indicator system is inconvenient to carry.

In view of the above, the measurement apparatus and the measurement method for improving the rigidity of the bumper skin are technical problems to be solved by those skilled in the art.

Disclosure of Invention

In order to solve the technical problem, the invention provides a method for measuring the rigidity of a bumper skin, which comprises the following steps:

s1, applying impact energy W with known size to the bumper skin;

s2, calculating the absorption energy E of the bumper skin, wherein the absorption energy E is the energy absorbed by the bumper skin from the impact energy W;

s3, measuring the maximum impact force N borne by the bumper skin under the action of the impact energy W_max；

S4, using equation E equal to 0.5 × N_maxX the amount of deformation X of the bumper skin was calculated.

Optionally, the impact energy is converted from elastic potential energy or gravitational potential energy or electromagnetic energy.

Optionally, the absorption energy E is equal to the impact energy W; alternatively, the absorbed energy E is equal to the impact energy W minus an energy dissipation value E'.

Alternatively, the energy dissipation value E' may be corrected based on the comparison result by actually measuring the deformation amount X of the bumper skin and comparing the actually measured value of the deformation amount X with the calculated value of the deformation amount X obtained in S4.

According to the measuring method, the impact is applied to the bumper skin, and then the deformation is calculated through the absorbed energy and the maximum impact force according to a formula, so that measuring equipment based on the measuring method does not need to be provided with a percentile scale system, and a series of problems that a measuring point of the percentile scale system is away from a deformation center, the measuring point needs to be fixed by a clamp during measurement, the equipment is inconvenient to carry and the like due to split are solved.

The invention also provides a measuring device based on the measuring method, which comprises a pressure head for pressing the bumper skin and a measuring device for measuring the maximum impact force N_maxA punch for applying the impact energy W to a bumper skin, the dynamometer being disposed between the punch and the ram, the punch directly impacting the dynamometer.

The measuring equipment does not need to be provided with a dial indicator system, so that a series of problems that a measuring point of the dial indicator system is away from a deformation center, the dial indicator system needs to be fixed by a clamp during measurement, and the equipment is split to cause inconvenience in carrying are solved. The measuring equipment has the advantages of accurate measuring result, convenience in use, portability and the like.

Optionally, the impact energy W is converted from gravitational potential energy of the punch;

or the measuring equipment further comprises an energy storage component for storing elastic potential energy or electromagnetic energy, the energy storage component is connected with the punch, and the impact energy W is converted from the energy stored by the energy storage component.

Optionally, the energy storage component is an elastic body, one end of the elastic body is connected with the punch, and the other end of the elastic body is connected with the dynamometer.

Optionally, the measuring apparatus further comprises a scale for indicating the distance the elastomer is stretched by the punch from an initial position, the initial position being the position the elastomer is at when the punch impacts the load cell.

Optionally, the elastomer is in tension in the initial position and applies a pulling force to the punch towards the load cell.

Optionally, the punch and the ram are located on the same line.

Drawings

Fig. 1 is a schematic view of a conventional apparatus for measuring the stiffness of a bumper skin.

The reference numerals in fig. 1 are explained as follows:

01 percent meter, 02 support, 03 dynamometer, 04 pressure head and a bumper skin.

FIG. 2 is a schematic view of a bumper skin stiffness measurement device provided in accordance with the present invention with the elastomer in an initial position;

FIG. 3 is a schematic view of the elastomer of the measuring device of FIG. 2 being stretched a distance by a punch;

the reference numerals in fig. 2 to 3 are explained as follows:

1 ram, 2 dynamometer, 3 punch, 4 elastomer, 5 scale, a bumper skin.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution of the present invention is further described in detail below with reference to the accompanying drawings and the detailed description.

The invention provides a method for measuring a bumper skin, which comprises the following steps:

s1, applying impact energy W with known size to the bumper skin;

specifically, the impact energy W is converted from energy with a size that can be calculated, the energy with the size that can be calculated specifically may be elastic potential energy, and the elastic potential energy may be obtained by multiplying the elastic coefficient of the elastic body by the square of the deformation amount of the elastic body and then by 0.5. The gravitational potential energy can also be obtained by multiplying the mass of the impact member by the gravitational acceleration and then by the distance between the impact member and the impacted point. And may be electromagnetic energy, which may be obtained by multiplying the capacitance of a capacitor by the square of the voltage of the capacitor and then by 0.5.

And S2, calculating the absorption energy E of the bumper skin, wherein the absorption energy E is the energy absorbed by the bumper skin from the impact energy W.

Specifically, energy dissipation should be reduced as much as possible in the impact process, and if the energy dissipation is relatively small, the absorption energy E is substantially equal to the impact energy W, and of course, in actual implementation, the absorption energy E may also be obtained by subtracting the energy dissipation value E 'from the impact energy W, that is, the absorption energy is obtained by using a linear calculation model E ═ W-E', and of course, the calculation model may also be a non-linear calculation model.

More specifically, the energy dissipation value E' may be set empirically, and after setting, may be corrected as needed.

The correction process is to measure the deformation of the deformation center with a precise measuring device to obtain a measured value of the deformation, calculate the deformation with the subsequent step S4 to obtain a calculated value of the deformation, and compare the measured value and the calculated value of the deformation to correct the energy dissipation value E' until the measured value and the calculated value of the deformation substantially match.

S3, measuring the maximum impact force N applied to the bumper skin under the action of the impact energy W_max。

In particular, the maximum impact force can be measured with a load cell of the type commonly used in the art, and in particular the point of impact can be located on the load cell, so that the load cell can display the maximum impact force when an impact is applied.

S4, using equation E equal to 0.5 × N_maxX the amount of deformation X of the bumper skin was calculated.

Because the impact process is very short, the deformation of the bumper skin is small after each impact, the inventor finds that the performance of the bumper skin is similar to that of an elastomer when the deformation of the bumper skin is small, and the deformation rule basically conforms to the Hooke's law. Thus, E can be 0.5 × N_maxX the deformation X is calculated.

According to the measuring method, the deformation is calculated by applying impact to the bumper skin and substituting the absorbed energy and the maximum impact force into a formula, so that measuring equipment based on the measuring method does not need to be provided with a scale system for measuring the deformation, and a series of problems that the scale system is inaccurate in measurement, a clamp is required to be used for fixing during measurement, the equipment is inconvenient to carry and the like due to split are avoided.

Fig. 2 to 3 show a measuring apparatus based on the measuring method, and specifically include a ram 1, a load cell 2, a punch 3, an elastic body 4, and a scale 5. The ram 1 and the punch 3 are fixed to both ends of the dynamometer 2, respectively.

The elastic body 4 is connected to the load cell 2 at one end and to the punch 3 at the other end. In the scheme shown in the figure, two groups of elastic bodies 4 are arranged and respectively connected to two sides of the dynamometer 2, the impact points are arranged at the end part of the dynamometer 2, and the two groups of elastic bodies 4 are symmetrical about the impact points, so that the impact points can be avoided, and the punch 3 can vertically impact the impact points.

In the scheme shown in the figure, the punch 3 and the pressure head 1 are positioned on the same straight line, and when the device is used, the straight line is perpendicular to the area to be measured of the bumper skin, so that the accuracy of a measuring result can be improved.

During measurement, the pressure head 1 is in contact with an area to be measured of a bumper skin, the punch 3 directly impacts the dynamometer 2 with impact energy W with known size, the impact energy W is transmitted to the bumper skin through the dynamometer 2 and the pressure head 1, and during the period, the dynamometer 2 measures the maximum impact force N_max。

The elastic body 4 is an energy storage part and can store elastic potential energy, when the punch 3 moves towards the direction far away from the dynamometer 2, the elastic body 4 is elongated, the elastic potential energy is gradually stored in the process of elongation, and when the punch 3 is released, the elastic potential energy is converted into impact energy W of the punch 3.

The scale 5 is used to indicate the distance the elastomer 4 is elongated by the punch 3 from an initial position, which is the position the elastomer 4 is in when the punch 3 impacts the load cell 2, as shown in fig. 2.

The elastic body 4 is in a stretched state at the initial position, and applies a pulling force toward the dynamometer 2 to the punch 3. When can prevent like this that drift 3 from strikeing with dynamometer 2 mutually, drift 3 is rebounded by dynamometer 2 to can guarantee that impact in-process energy dissipation is less, and absorption energy E approximately equals impact energy W, like this, can remove the process that sets up energy dissipation value and revise energy dissipation value from, make measuring process more convenient and fast.

In practice, the energy storage member is not limited to the elastic body 4, and may be any member capable of storing energy of which the magnitude can be calculated, for example, a capacitor for storing electromagnetic energy, and the electromagnetic energy generated by discharging the capacitor is converted into the impact energy W of the punch 3. In actual practice, the impact energy W of the punch 3 may be converted by the gravitational potential energy of the punch 3 without providing an energy storage member.

The method for measuring the rigidity of the bumper skin and the measuring equipment based on the method are described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.