JP4803020B2 - Evaluation method for chipping resistance of automotive paint outer panels - Google Patents

Description

  The present invention relates to a method for evaluating chipping resistance of automobile paint outer plates.

As a method for evaluating the chipping resistance of an automobile paint outer plate, as shown in Patent Document 1, a method has been proposed in which crushed stone is jetted upward by air to form a crushed stone curtain in front of a traveling vehicle. According to this configuration, it is possible to perform accurate simulation that approximates chipping that actually occurs.
Japanese Patent Laid-Open No. 10-054780

  However, in the above-described chipping resistance evaluation method, not only an actual vehicle is used, but also the apparatus for performing the chipping resistance evaluation method has to be large.

  The present invention has been made in view of the above circumstances, and its technical problem is to provide a chipping resistance evaluation method for an automobile coating outer plate that can perform chipping resistance evaluation as easily as possible while ensuring accuracy. There is to do.

In order to achieve the technical problem, in the present invention (the invention according to claim 1),
The rate of occurrence of coating film peeling caused by each coating film breaking energy by performing a test to apply various different coating film breaking energy to the test plate of the same specification as the target outer plate with each stepping stone multiple times for each coating film breaking energy. Is a characteristic equation obtained by examining each of the above, and preparing a relationship between the coating film breaking energy and the coating film peeling rate,
Next, the condition of the stepping stone to fly to the target outer plate is obtained, and the estimated coating film breaking energy is calculated for each part in the height direction of the target outer plate, and each of the assumed coating film breaking energy and the Based on the characteristic formula, the respective expected coating film peeling occurrence rate corresponding to each assumed coating film breaking energy is obtained,
Next, the coating film for each part in the height direction of the target outer plate according to the stepping stone presence distribution for each part in the height direction of the target outer plate and the respective assumed coating film peeling occurrence rate obtained in advance. Find the number of peels,
Next, while calculating the total number of the coating film peeling number, calculating the coating film peeling occurrence rate of the entire target outer plate from the total, and comparing the coating film peeling occurrence rate and the evaluation criteria,
It is set as the structure used as the chipping-proof evaluation method of the automotive painting outer plate | board characterized by this.

  With the above-mentioned configuration, a simple test is performed on a test plate with the same specifications as the target outer plate (the number of stepping stones can be reduced, etc.), and a characteristic equation indicating the relationship between the coating film breaking energy and the coating film peeling occurrence rate is obtained. If it is prepared, it can be processed later by calculation, and it is not necessary to use an actual vehicle or a large-scale device every time the coating film peeling occurrence rate of the entire outer plate is obtained. On the other hand, basic data is obtained by performing tests on test plates with the same specifications as the target outer plate, and the rate of occurrence of coating film peeling on the entire target outer plate is obtained using this data. Is not low.

  As a preferred aspect of claim 1, it is possible to adopt a configuration in which each of the various different coating film breaking energies is obtained by changing at least one of the weight, speed, and approach angle of the stepping stone with respect to the test plate. 2 correspondence). Based on the fact that the vertical component of the energy given to the coating film by the stepping stone can be regarded as the coating film breaking energy, the coating material is changed by changing at least one of the weight, speed, and approach angle of the stepping stone with respect to the test plate. The film breaking energy can be varied. For this reason, by differentiating the coating film breaking energy, the coating film peeling occurrence rate caused by each coating film breaking energy was investigated, and the test plate showing the relationship between the coating film breaking energy and the coating film peeling occurrence rate. The characteristic formula can be obtained accurately.

  As a preferred aspect of claim 1, as a stepping stone to fly to the target outer plate, it is possible to adopt a configuration in which the weight of the stepping stone, the speed, and the approach angle of the stepping stone with respect to each part of the target outer plate are obtained. 3 correspondence). With this configuration, it is possible to accurately calculate the assumed coating film breaking energy for each part in the height direction of the target outer plate.

  As a preferred aspect of claim 1, when determining the stepping stone approach angle with respect to each part of the target outer plate, the relationship between the stepping stone approach angle with respect to each part of the target outer plate and the height position of each part is used. The structure which carries out can be taken (corresponding to claim 4). With this configuration, a stepping stone for each part of the target outer plate is used by preparing in advance the relationship between the approach angle of the stepping stone with respect to each part of the target outer plate and the height position of each part. Can be quickly and easily obtained.

  As a preferred aspect of claim 1, when determining the speed of the stepping stone, it is possible to adopt a configuration utilizing the relationship between the weight of the stepping stone and the speed of the stepping stone (corresponding to claim 5). With this configuration, the speed of the stepping stone can be simplified and handled based on the knowledge found by the present inventor, and the assumed coating film breaking energy can be easily calculated.

  As a preferable aspect of claim 1, when calculating the assumed coating film breaking energy, it is performed for each stone weight of the stepping stone for each part in the height direction of the target outer plate, and in the height direction of the target outer plate. When determining the number of coating film peeling for each part, a configuration using the stone weight distribution of the stepping stones for each part in the height direction of the target outer plate and the respective assumed coating film peeling occurrence rate obtained in advance. It can be taken (corresponding to claim 6). With this configuration, the weight of each stepping stone will increase the accuracy of the assumed coating film peeling occurrence rate, and accordingly, the accuracy of the number of coating film peeling for each part in the height direction of the target outer plate can be increased. it can.

  As a preferable aspect of claim 1, a configuration in which the target outer plate is a bonnet can be taken (corresponding to claim 7). With this configuration, even when the target outer plate is a bonnet, the chipping resistance evaluation can be performed as easily as possible while ensuring accuracy.

  According to the present invention (the invention according to claim 1), it is possible to perform the chipping resistance evaluation as easily as possible while ensuring accuracy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
This case evaluation method is performed according to the order shown in FIG.
(1) First, a test plate is prepared.
The test plate is the same as the bonnet as the outer plate to be evaluated, and a coating film similar to the bonnet is formed on the test plate.

(2) Next, with respect to the test plate, a characteristic equation indicating the relationship between the coating film breaking energy and the coating film peeling occurrence rate is obtained. This is because an assumed coating film peeling occurrence rate can be obtained in a later process.
1) In order to obtain the above characteristic equation, specifically, a test for applying various different coating film breaking energies to the test plate with stepping stones is performed a plurality of times for each coating film breaking energy. The rate of occurrence of film peeling caused by energy is examined.
1-1) For applying the coating film breaking energy to the test plate, a flying stone testing machine (gravelo testing machine, diamond shot testing machine, etc.) that blows stones is used. ) To the test plate.
1-2) The coating film breaking energy Ec is defined by the formula (1). This is because, as shown in FIG. 2, the vertical component of the energy given by the stepping stone 1 to the coating film of the test plate 2 is considered to be the coating film breaking energy Ec. For this reason, the coating film breaking energy Ec has, as shown in (Equation 1), the stone weight m, the stone velocity v, and the approach angle θ with respect to the test plate 2 as constituent factors.

Ec = 1/2 · (mv ² ) · sinθ (Expression 1)

1-3) Various different coating film breaking energies are imparted to the test plate because there is a correlation between the coating film breaking energy and the rate of occurrence of coating film peeling, and the coating plate breaking energy is imparted to the test plate. This is because it is considered that a coating film peeling occurrence rate corresponding to that can be obtained. As shown in FIG. 3, there is a correlation between the coating film peeling occurrence rate and the stone weight m, and there is a correlation between the coating film peeling occurrence rate and the stepping angle θ of the stepping stone. This is based on the fact that there is also a correlation between the coating film breaking energy and the coating film peeling occurrence rate with the stone weight m and the stepping stone approach angle θ as constituent factors. For this reason, based on the fact that the coating film breaking energy Ec has the stone weight m, the stone velocity v, and the stone entry angle θ with respect to the test plate as constituent factors, It is assumed that at least one of the weight m, the stone velocity v, and the approach angle θ of the stone (stepping stone) with respect to the test plate is changed.
1-4) The test for imparting various different coating film breaking energy is performed a plurality of times for each coating film breaking energy by counting the number of coating film peelings for each coating film breaking energy and peeling the coating film on the test plate. This is to guide the incidence. In this case, a plurality of stones are used for each coating film breaking energy. At this time, the stones may collide with the test plate one by one under the same coating film breaking energy. A plurality of stones may collide with the test plate at once.

1-5) Application of various different coating film breaking energies to the test plate, for example, as shown in FIG. 4, while making the stone weight m and the stone velocity v constant, only the stone entrance angle θ with respect to the test plate Is performed under different conditions.
1-6) Regarding the coating film peeling occurrence rate of the test plate, in this embodiment, the sum of numbers such as “peeling” and “scraping” generated as scratches on the test plate is defined as the sum, and “peeling” of the sum is calculated. The ratio of the number is defined as the rate of occurrence of film peeling on the test plate. This is based on the fact that it is not easy to count intact ones of the stepping stones that hit the bonnet when measuring the weight distribution of stepping stones that will be used in the subsequent steps.

2) The above characteristic equation is expressed by the following (Equation 2) from the correlation between the coating film breaking energy and the coating film peeling occurrence rate, and the characteristic equation is a linear equation as shown in FIG. As shown. Here, PR is the coating film peeling occurrence rate, Ec is the coating film breaking energy, a is a proportionality constant, and b is an intercept. Of course, this characteristic equation can be obtained in advance by performing the above-described contents.

PR = aEc + b (2)

(3) Next, the condition of the stepping stone to fly to the bonnet to be evaluated is obtained, and the assumed coating film breaking energy is calculated for each part in the height direction (projection height direction (vertical direction)) of the bonnet. In addition, an assumed coating film peeling occurrence rate corresponding to each assumed coating film breaking energy is obtained based on each assumed coating film breaking energy and the characteristic formula (see Equation 1).
1) The assumed coating film breaking energy is calculated for each part in the height direction of the bonnet based on the characteristic equation (see Equation 1), and the assumed coating film peeling occurrence rate corresponding to each assumed coating film breaking energy. This is because each can be calculated.

2) Each assumed coating film breaking energy is calculated based on the stepping stone condition to fly to the bonnet to be evaluated. As the stepping stone condition, the weight of the stepping stone, the speed, and the stepping stone approach angle with respect to each part of the bonnet are obtained. This is because the assumed coating film breaking energy also has them as constituent factors as the coating film breaking energy Ec, and these factors are reflected in the assumed coating film peeling occurrence rate. Each assumed coating film breaking energy may be calculated in advance.
2-1) About the weight of each stone as the stepping stone condition for calculating the assumed coating film breaking energy, the weight of No. 6 crushed stone (5 to 13 mm size) is used so as to assume a stone that is a practical problem. For this reason, in the range of the weight of No. 6 crushed stone, for example, 0.15,0.25,0.35,0.45,0.55,0.65g is used as each stone weight (refer FIG. 9 etc.). . In the present embodiment, from the viewpoint of improving accuracy, the assumed coating film breaking energy is calculated by dividing the stone weight into a plurality of pieces, but of course, for simplification, the average value of these stone weights is one. Can also be used.

2-2) The knowledge obtained by the present inventor is used for the speed (stepping stone condition) of the stone for calculating the assumed coating film breaking energy. As shown in FIG. 6, the present inventor divides No. 6 crushed stone (stone) by weight, and by rotating the tire 3 (corresponding to 150 km / h), the stone 1 of each weight is skipped, and the stone of each weight 1 was shot with a high-speed VTR 4 and the speed of the stone 1 for each weight was measured from image analysis. As shown in FIG. 7, the speed of the stone was 80 km / h to 120 km / h. I found it. Therefore, when calculating the assumed coating film breaking energy, an intermediate value of 100 km / h between 80 km / h and 120 km / h is used as the speed of the stone (see FIG. 9).
2-3) As the stepping stone approach angle θ (stepping stone condition) for calculating the assumed coating film breaking energy, those reflecting the position of each part in the height direction of the bonnet to be evaluated are used. As shown in FIG. 8, the angle (for example, θs1 to θs3) formed by the imaginary line 6 and the bonnet 5 extending in the horizontal direction from each portion (Hs1 to Hs3) in the projection height direction (height direction) of the bonnet 5 is It can be seen that the stepping stone enters the bonnet 5, and each part in the projected height direction of the bonnet 5 is related to the stepping stone entering angle with respect to the bonnet 5. For this reason, here, the approach angles θs1 to θs3 of the stepping stones corresponding to the respective parts in the projection height direction of the bonnet are obtained from the data (coordinate points and other various information) of the bonnet 5 to be evaluated prepared in advance. In order to calculate the assumed coating film breaking energy, the approach angle of each stepping stone indicates each part in the projected height direction of the bonnet 5 and reflects each part in the projected height direction of the bonnet 5. Used.
2-4) In this embodiment, it is considered that the upper surface of the bonnet 5 can be conceptually shown with a plurality of inclination angles (for example, θ0 to θ3) as shown in FIG. That is, as shown in FIG. 14, when the bonnet 5 is shown with a plurality of inclination angles θ0 to θ3, each part in the projection height direction of the bonnet 5 is based on a predetermined range in the vertical direction. The angle between the virtual line 6 extending in the horizontal direction and the bonnet 5 indicates substantially the same state (isotopic angle), and the angle is equal to the inclination angle of the bonnet 5 to which the virtual line 6 reaches at that time ( Reverse angle). For this reason, from the bonnet data to be evaluated prepared in advance, the inclination angles θ0 to θ3 of the bonnet 5 and the height positions H0 to H3 of the respective inclination angle change points are extracted, and by using them, Up to a portion H0 to H1 (first angle change point height) in the projection height direction of the bonnet 5 is an approach angle θ0 (for example, θ0 = 30 °) and a portion H1 to H2 (second angle change point height). Is the approach angle θ1 (for example, θ1 = 20 °), the part H2 to H3 (the third angle change point height) is the approach angle θ2 (for example, θ2 = 15 °), and the part exceeding the part H3 is the approach angle θ3 ( For example, it corresponds to correspond to θ3 = 10 °).
2-5) Of course, in this case, as shown in FIG. 15, even when the shape of the bonnet is different from that of the bonnet 5 (for example, in the case where the inclination angle of the upper surface of the bonnet is large), it should be evaluated in advance. Based on the data of the hood 5 ′, the same processing as described above is performed. That is, the inclination angle θ0 ′ to θ3 ′ of the bonnet 5 ′ and the height positions H0 ′ to H3 ′ of the inclination angle change points are extracted from the data of the bonnet 5 ′ to be evaluated prepared in advance. , The entry angle θ0 ′ and the portions H1 ′ to H2 ′ (second angle change point heights) up to the portions H0 to H1 ′ (first angle change point heights) in the projection height direction of the bonnet 5 are used. ) Up to the approach angle θ1 ′, the parts H2 ′ to H3 ′ (the third angle change point height) up to the approach angle θ2 ′, and the parts H3 ′ and above correspond to the approach angle θ3 ′.
2-6) Each assumed coating film breaking energy is calculated as shown in FIG. 9 using each of the above factors and the equation (1). In FIG. 9, instead of the part in the projected height direction of the bonnet, the entry angles θ0 = 30 °, θ1 = 20 °, θ2 = 15 °, θ3 = 10 ° reflecting each of the flying stones (FIG. 14). Is shown).

3) Based on each assumed coating film breaking energy and the above-mentioned characteristic formula (see Equation 1), the estimated coating film peeling occurrence rate corresponding to each assumed coating film breaking energy is determined on the bonnet in a later step. This is because it is possible to calculate the number of coating film peeling for each part (for each stepping angle θ of the stepping stone with respect to the bonnet) in the projected height direction of the bonnet 5 in relation to the stepping stone distribution (see FIG. 12 described later).
3-1) Specifically, the assumed coating film peeling occurrence rate is obtained from each assumed coating film breaking energy shown in FIG. 9 and the characteristic formula shown in FIG. It is done. In FIG. 10, m1, m2, m3,... Are assumed coating film peeling occurrence rates (numerical values) for each stone weight at each site in the bonnet projection height direction (stepping angle θ of the stepping stone with respect to the bonnet). ).

(4) Next, for each part in the projected height direction of the bonnet, the distribution of the weight (number of scratches) of the stepping stones in the projected height direction of the bonnet and the estimated coating film peeling occurrence rate obtained in advance. The number of coating films peeled for each stone weight is determined.
1) The distribution of the weight of each stone in the projected height direction of the bonnet is obtained in advance by a chipping survey on an actual vehicle. As shown in FIG. 11, the chipping survey for the actual vehicle was conducted by dividing No. 6 crushed stones by weight, laying stones 1 of each weight under the rear wheel 8 of the front wheel 7, and fixing the front wheel to the rear wheel 8. Is idled and the stone 1 is blown toward the rear car 9. Then, the distribution of scratches (peeling, scraping, etc.) on the hood of the rear wheel 9 is obtained as a projected image from the front by the stepping stones 1 of the respective weights, and the distribution of the weight of each stepping stone in the height direction of the bonnet is obtained. And In this case, it is considered that the lateral distribution of the bonnet is uniformly distributed.

    The distribution of the weight of each stone in the projected height direction of the bonnet is determined for each site in the projected height direction of the bonnet associated with the stepping stone approach angle obtained for the above-described calculation of the assumed coating film breaking energy. Rearranged. If the bonnet 5 shown in FIG. 14 is described as a bonnet to be evaluated, first, the position H1 (the first position) that is the upper limit height when the stepping stone approach angle is θ0 (= 30 °) with respect to the bonnet 5. The angle change point height) is extracted from the data for calculating the assumed coating film breaking energy described above, and based on that, the data from the stone weight distribution data in the projected height direction to the portion position H1 (data) (Number of scratches)), and the weight of each stone from the collected data (0.15, 0.25, 0.35, ... g, corresponding to the stone weight of each assumed coating breaking energy) Each piece of data is selected, and the data (number of flaws) for each stone weight is used as data in the range of the parts H0 to H1 corresponding to the stepping stone approach angle θ0. That is, in the distribution data, data included up to the site position H1 in the projection height direction is set as data corresponding to the stepping stone approach angle θ0 with respect to the bonnet 5. Similarly, from the distribution data, data from the position H1 where the stepping stone approach angle is θ1 (= 20 °) to the upper limit position H2 is collected, and data for each stone weight is collected from the collected data. And the data for each stone weight is set as data in the range of the portions H1 to H2 corresponding to the approach angle θ1. Next, from the distribution data, data is collected from the part position H2 where the stepping stone approach angle is θ2 (= 15 °) to the upper limit part position H3, and data for each stone weight is obtained from the collected data. The data for each stone weight is selected and used as data in the range of the parts H2 to H3 corresponding to the approach angle θ2. Next, from the distribution data, the data of the height exceeding the part position H3 where the stepping stone approach angle forms θ3 (= 10 °) is collected, and the data for each stone weight is selected from the collected data. The data for each stone weight is data in a range exceeding the position H3 position corresponding to the approach angle θ3. FIG. 12 shows the stepping stone distribution (the number of scratches based on the stones of each weight) for the bonnet determined as described above, and FIG. 12 shows the above-mentioned respective assumed coating film peeling occurrence rates. Corresponding to FIG. 10, each stone weight for each part in the projected height direction of the bonnet (exceeding H0 to H1, H1 to H2, H2 to H3, and H3 corresponding to each approach angle in FIG. 10) Will be shown. In FIG. 12, n1, n2, n3,... Are scratches (peeling) for each stone weight at each site in the bonnet projection height direction (corresponding to each approach angle in FIGS. 9 and 10). , Scraping, etc.), and Tn represents the total number of scratches.

    2) The number of coating films peeled off for each stone weight at each part in the projected height direction of the bonnet is the distribution of the stone weights n1, n2 for each part (corresponding to each approach angle in FIGS. 9 and 10). ,... (FIG. 12) is obtained by multiplying the corresponding assumed coating film peeling occurrence rates m1, m2,... (FIG. 10). FIG. 13 shows the number of coating film peeling m1, n1, m2, n2,... For each stone weight in each part in the projection height direction of the bonnet (corresponding to each approach angle in FIGS. 9 and 10). Is shown.

(5) Next, the total sum of the numbers of peeled coating films is obtained, and the coating film peeling occurrence rate of the entire bonnet is calculated from the sum, and the coating film peeling occurrence rate is compared with the evaluation criteria.
1) The total number of peeled films is obtained by adding the number of peeled films m1, n1, m2, n2,... Shown in FIG. This is shown as the total number Tmn of coating film peeling.
2) The occurrence rate of coating film peeling of the entire bonnet is Tmn / Tn obtained by dividing the total number Tmn of coating film peeling shown in FIG. 13 by Tn shown in FIG.
3) The comparison between the film peeling rate Tmn / Tn of the entire bonnet and the evaluation standard is performed in order to determine the degree of coating of the bonnet. The peeling occurrence rate Tmn / Tn is appropriately used.

  In order to confirm the accuracy of the method, a test on the bonnet itself (tertiary test site) and the method performed on the test plate of the bonnet were carried out. In this method, the total number of scratches Tn (total number of scratches Tn counted in FIG. 12) is less than 249. Thus, the total number of coating film peeling Tmn was 115, and the coating film peeling occurrence rate Tmn / Tn was 46%. Thus, both showed the value close | similar to each other, and the validity of the evaluation method which concerns on this method was confirmed.

Process drawing which shows the order of the method of embodiment. Explanatory drawing which shows coating-film destruction energy. Explanatory drawing explaining the relationship between coating-film peeling incidence and coating-film destruction energy (stone weight, stone approach angle). Explanatory drawing explaining the specific example of various different coating-film destruction energy provision. The figure showing the characteristic formula which shows the relationship between coating-film peeling incidence and coating-film destruction energy. Explanatory drawing explaining the experimental method which investigates the relationship between each stone weight of stepping stone, and stepping stone speed. Explanatory drawing explaining the relationship between each stone weight of stepping stone and stepping stone speed. Explanatory drawing explaining the relationship between the site | part in the projection height direction of a bonnet, and the angle which the imaginary line extended in the horizontal direction from each site | part and a bonnet makes. Explanatory drawing explaining the assumed coating-film destruction energy which should be calculated. Explanatory drawing explaining the assumption coating-film peeling incidence which should be calculated. Explanatory drawing explaining the experimental method which investigates each weight distribution of the stepping stone with respect to a bonnet. Explanatory drawing explaining the distribution about each weight of stepping stones for each part in the height direction of the bonnet. Explanatory drawing explaining that the coating film peeling number about each stone weight for every site | part in the projection height direction of a bonnet is obtained based on the content of FIG. 10, and the content of FIG. Explanatory drawing explaining obtaining required information (the approach angle with respect to a bonnet, the maximum height position in the projection height direction of a bonnet corresponding to the approach angle, etc.) based on the data of the bonnet to be evaluated. Explanatory drawing explaining calculating | requiring required information based on the data of another bonnet which should be evaluated.

Explanation of symbols

1 Stepping stone 2 Test plate 5 Bonnet (outside plate)
Tn Total number of scratches Tmn Total number of film peeling Tmn / Tn Total film peeling rate

Claims (7)

The rate of occurrence of coating film peeling caused by each coating film breaking energy by performing a test to apply various different coating film breaking energy to the test plate of the same specification as the target outer plate with each stepping stone multiple times for each coating film breaking energy. Is a characteristic equation obtained by examining each of the above, and preparing a relationship between the coating film breaking energy and the coating film peeling rate,
Next, the condition of the stepping stone to fly to the target outer plate is obtained, and the estimated coating film breaking energy is calculated for each part in the height direction of the target outer plate, and each of the assumed coating film breaking energy and the Based on the characteristic formula, the respective expected coating film peeling occurrence rate corresponding to each assumed coating film breaking energy is obtained,
Next, the coating film for each part in the height direction of the target outer plate according to the stepping stone presence distribution for each part in the height direction of the target outer plate and the respective assumed coating film peeling occurrence rate obtained in advance. Find the number of peels,
Next, while calculating the total number of the coating film peeling number, calculating the coating film peeling occurrence rate of the entire target outer plate from the total, and comparing the coating film peeling occurrence rate and the evaluation criteria,
A method for evaluating chipping resistance of an automobile paint outer plate characterized by the above. In claim 1,
Each of the various different coating film breaking energies is a change in at least one of the weight, speed, and entry angle of the stepping stone with respect to the test plate.
A method for evaluating chipping resistance of an automobile paint outer plate characterized by the above. In claim 1 or 2,
As a stepping stone to fly to the target outer plate, the weight of the stepping stone, the speed, and the approach angle of the stepping stone with respect to each part of the target outer plate,
A method for evaluating chipping resistance of an automobile paint outer plate characterized by the above. In claim 3,
When determining the approach angle of the stepping stone for each part of the target outer plate, utilizing the relationship between the stepping stone approach angle for each part of the target outer plate and the height position of each part,
A method for evaluating chipping resistance of an automobile paint outer plate characterized by the above. In claim 3,
When determining the speed of the stepping stone, use the relationship between the weight of the stepping stone and the speed of the stepping stone.
A method for evaluating chipping resistance of an automobile paint outer plate characterized by the above. In claim 1,
When calculating each of the assumed coating film breaking energy, for each stone weight of stepping stone for each part in the height direction of the target outer plate,
When obtaining the number of coating film peelings for each part in the height direction of the target outer plate, the stone weight distribution of the stepping stones for each part in the height direction of the target outer plate and the respective assumed coatings obtained in advance. Using the film peeling occurrence rate,
A method for evaluating chipping resistance of an automobile paint outer plate characterized by the above. In any one of Claims 1-6,
The target outer plate is a bonnet;
A method for evaluating chipping resistance of an automobile paint outer plate characterized by the above.

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