JP6536296B2 - Impact resistance evaluation method for conveyor belts - Google Patents

Description

  The present invention relates to a method of evaluating the impact resistance of a conveyor belt, and more particularly, to a method of evaluating the impact resistance of a conveyor belt capable of efficiently grasping the impact resistance of the conveyor belt meeting the use conditions with high accuracy. .

  Various things including mineral resources such as iron ore and limestone are transported by a conveyor belt. When an object is conveyed by the conveyor belt, the conveyed object is thrown into the upper cover rubber of the conveyor belt from a hopper or another conveyor belt. The input conveyed article is loaded on the upper cover rubber and conveyed in the traveling direction of the conveyor belt. When a conveyed product is introduced into the upper cover rubber of the conveyor belt, the upper cover rubber is subjected to an impact, and if the surface of the conveyed product is sharp, cut damage may occur. The size and damage mode of the cut flaws generated on the upper cover rubber due to the input conveyance change greatly depending on the use conditions of the conveyor belt.

  Conventionally, various methods for evaluating the impact resistance of a conveyor belt have been proposed (see, for example, Patent Documents 1 to 3). Generally, in order to evaluate the impact resistance of rubber, an impactor is impacted against a test sample. By this, the damage state of the test sample is grasped and the impact resistance is evaluated. However, the settable ranges of the impact velocity, impact load and contact area of the impacting body with respect to the test sample may differ depending on each test method. Further, even within the settable ranges of these conditions, there is a range in which the impact resistance of the actual conveyor belt can be accurately reproduced and a range in which the reproducibility is reduced. Therefore, in order to accurately evaluate the impact resistance of an actual conveyor belt, it is necessary to select a test method that is compatible with the use conditions of the conveyor belt.

Unexamined-Japanese-Patent No. 2010-216852 JP, 2011-257187, A JP 2012-189533 A

  An object of the present invention is to provide a conveyor belt impact resistance evaluation method capable of efficiently grasping the impact resistance of the conveyor belt meeting the use conditions with high accuracy.

  In order to achieve the above object, the method for evaluating the impact resistance of a conveyor belt according to the present invention relates to a method for testing the impact resistance of a conveyor belt in which an impactor collides with a test sample of the conveyor belt. A database in which application ranges of impact velocity, impact load, and contact area are set is prepared beforehand, and the actual impact velocity, impact load, and contact area of an article fed to the conveyor belt on an actual conveyor line with respect to the conveyor belt Based on the acquired results and the database, the test method having the acquired collision velocity, collision load and contact area within the applicable range is selected from the plurality of test methods, and the selected test method is selected. Assume that the impact velocity, the impact load and the contact area are the same as the obtained result Set in a range, and evaluating the impact resistance of the conveyor belt of the actual conveyor line performing the selected test methods.

  According to the present invention, a method of testing the impact resistance of a conveyor belt matching the actual use conditions from the database created in advance and the impact velocity, impact load and contact area of the impacting body against the conveyor belt in the actual conveyor line It can be selected efficiently. Then, in the selected test method, the collision velocity, the collision load and the contact area of the impacting body with respect to the test sample are set in a range that can be regarded as identical to the obtained result, and the test is performed by approximating to actual use conditions. . Therefore, it is possible to grasp with high accuracy the impact resistance of the conveyor belt that matches the actual use conditions.

  Here, the application range of the external environment temperature of each of the test methods is also set to create the database in advance, the external environment temperature in the actual conveyor line is also acquired, and the acquired result is the application of the external environment temperature It is also possible to select a test method in the range from the plurality of types of test methods, set the external environment temperature in the selected test method to a range that can be considered identical to the obtained result, and perform the selected test method. it can. Since the external environmental temperature at the time of using the conveyor belt has a relatively large influence on the impact resistance of the conveyor belt, it is possible to grasp the impact resistance more accurately by considering the external environmental temperature.

  As the actual contact area, for example, the contact area of the conveyed product of the median particle size of the particle size distribution of the conveyed product with the conveyor belt is adopted. Thereby, the actual contact area can be easily approximated.

  The database can also be created for each type of the conveyed product. Since the type of the conveyed product also has a relatively large effect on the impact resistance of the conveyor belt, it is possible to grasp the impact resistance with higher accuracy by creating and using a database for each type of the conveyed product.

It is explanatory drawing which simplifies and illustrates a conveyor belt line. It is AA sectional drawing of FIG. It is explanatory drawing which shows the speed of a conveyed product at the time of colliding with a conveyor belt. It is explanatory drawing which illustrates the basic structure of an impact test apparatus. It is explanatory drawing which illustrates the structure of a database. It is a graph which illustrates the particle size distribution of a conveyed product.

  Hereinafter, the impact resistance evaluation method of the conveyor belt of this invention is demonstrated based on embodiment shown to the figure.

  In the conveyor belt line illustrated in FIG. 1, the conveyed object C conveyed by another conveyor belt 7 is introduced into the conveyor belt 1 and conveyed by the conveyor belt 1 to the conveyance destination. The conveyed product C may be input to the conveyor belt 1 through a hopper or the like. The conveyor belt 1 is stretched between the pulleys 5a and 5b and stretched with a predetermined tension.

  As illustrated in FIG. 2, the conveyor belt 1 is composed of a core layer 2 composed of a core such as canvas or steel cord, an upper cover rubber 3 and a lower cover rubber 4 sandwiching the core layer 2. There is. The core layer 2 is a member that bears a tension for stretching the conveyor belt 1. The lower cover rubber 4 is supported by the support roller 6 on the carrier side of the conveyor belt 1, and the upper cover rubber 3 is supported by the support roller 6 on the return side. On the carrier side of the conveyor belt 1, three support rollers 6 are arranged in the belt width direction, and the conveyor belt 1 is concavely supported at a predetermined trough angle a by these support rollers 6. By driving the pulley 5a on the drive side to rotate, the conveyor belt 1 operates in one direction at a predetermined traveling speed V1. The conveyed product S is put on the upper cover rubber 3, stacked on the upper cover rubber 3 and conveyed.

In this conveyor belt line, as illustrated in FIG. 3, the conveyor belt 1 and another conveyor belt 7 are arranged at a vertical difference h (a difference h in the height position of the respective conveying surfaces). On the other conveyor belt 7, the conveyed object C is conveyed at the horizontal velocity V0 (V0 <V1). At the moment when the input conveyed material C collides with the conveyor belt 1 from another conveyor belt 7, the conveyed material C has a horizontal velocity V0. On the other hand, the vertical velocity of the conveyed object C is accelerated from zero to V2. The vertical velocity V2 is (2 gH) ^1/2 . Therefore, the actual collision velocity Vr when the conveyed product C collides with the upper cover rubber 3 of the conveyor belt 1 is (V0 ² + V2 ² ) ^1/2 = (V0 ² +2 gH) ^1/2 . g is gravity acceleration.

  Then, from the actual contact area Ar and the collision load Fr when the input conveyed article C collides with the upper cover rubber 3, the actual surface pressure Pr of the conveyed article C against the upper cover rubber 3 is Pr = It becomes Fr / Ar. The collision load Fr can be regarded as the weight W of the conveyed object C. The degree of damage to the upper cover rubber 3 due to the collision of the conveyed product C is largely affected by the magnitude of the surface pressure Pr. Besides, the actual collision velocity Vr, the external environmental temperature Tr, etc. also affect the degree of damage to the upper cover rubber 3.

  The impact test device 8 for rubber is generally illustrated in FIG. 4 as an impact applying body 9, a holding mechanism 10 for detachably holding the impact applying body 9, and a support base for supporting the test sample S of the conveyor belt. 11 and a tensioner 12 for applying tension to the test sample S. In a test method using this impact test device 8, a test sample S in a predetermined tensioned state is supported by a support base 11 spaced apart. Then, the impact applying body 9 is dropped to the position between the support 11 and the support 11 with respect to the test sample S so as to collide with the test sample S.

  By this test, the flaw depth and the flaw mode of the test sample S in which the impact applying body 9 collides is grasped. In the conventional impact resistance tests, the specifications of the impact applying body 9 and the support base 11, the drop height of the impact applying body 9, and the like are different.

Therefore, in the present invention, as illustrated in FIG. 5 with regard to a plurality of impact test methods, the impact velocity V, the collision load F and the contact area A of the impact imparting body 9 of each of the test methods E1 to E5 with respect to the test sample S each coverage _{(Z V1, Z V2, Z} V3, Z V4, Z V5), (Z F1, Z F2, Z F3, Z F4, Z F5) and _{(Z A1, Z A2, Z} A3, Z A4 , Z _A5 ) are created in advance. In this embodiment, the application range (Z _T1 , Z _T2 , Z _T3 , Z _T4 , Z _T5 ) of the external environment temperature T of each test method is also set to create the database DB. In each test method, the surface pressure P of the impact applying body 9 with respect to the test sample S is F / A.

Here, the application range (Z _V1 ,..., Z _V5 ) of the collision velocity V in each of the test methods is the range of the collision velocity V at which stable results with less variation can be obtained in the test method. For example, the application range Z _V1 is crash velocity V is set to 0.1m / s~1m / s, the other respective coverage Z _V2, · ·, set concrete numerical range in Z _V5 There is.

The application range (Z _F1 ,..., Z _F5 ) of the collision load F in each test method is the range of the collision load F at which stable results with less variation are obtained in the test method. A specific numerical range is set in the application range of each collision load F. The collision load F can be regarded as the weight of the impact applying body 9.

The applicable range (Z _A1 ,..., Z _A5 ) of the contact area A of each test method is the range of the contact area A at which stable results with less variation are obtained in the test method. A specific numerical range is set in the application range of each contact area A.

The application range (Z _T1 ,..., Z _T5 ) of the external environment temperature T of each test method is a range of the external environment temperature T at which stable results with less variation are obtained in the test method. Specific numerical ranges are set in the application range of each external environment temperature T.

  When evaluating the impact resistance of the conveyor belt 1 installed on an actual conveyor line, the actual collision velocity Vr, collision load Fr, contact area of the conveyed object C fed to the conveyor belt 1 with respect to the conveyor belt 1 Get Ar and external environmental temperature Tr. Then, based on the acquired actual collision velocity Vr, collision load Fr, contact area Ar and external environment temperature Tr, and the database DB created in advance, it is suitable for evaluating the impact resistance of the conveyor belt 1 Select the test method.

  Specifically, a test method in which all the acquired actual collision velocity Vr, collision load Fr, contact area Ar and external environment temperature Tr are within the applicable range is selected from a plurality of test methods recorded in the database DB Do. Then, in the selected test method, the collision velocity V, collision load F, contact area A and external environment temperature T can be regarded as identical to the acquired actual collision velocity Vr, collision load Fr, contact area Ar and external environment temperature Tr, respectively. Conduct a shock test with the selected test method set in the range.

  As a test sample S used in the selected test method, a cut sample of the conveyor belt 1 to be evaluated, a sample manufactured to a specification equivalent to the conveyor belt 1 or the like is used. The test sample S is preferably one in which the core layer 2, the upper cover rubber 3 and the lower cover rubber 4 are integrated, but may be only the upper cover rubber 3.

  The actual collision velocity Vr, the collision load Fr, the contact area Ar, and the range that can be considered identical to the external environment temperature Tr are, for example, the actual collision velocity Vr, the collision load Fr, the contact area Ar, and the external environment temperature Tr, respectively. In the range of ± 5%, more preferably in the range of ± 2%. Then, the scratch depth and scratch mode of the test sample S according to the test method are grasped to evaluate the impact resistance of the conveyor belt 1 of the actual conveyor line. The mode of scratching is a form of scratching, such as a simple holed or sculpted in an unusual shape.

  As described above, according to the present invention, the conveyor DB is created from the database DB created in advance and the collision velocity Vr of the load C against the conveyor belt 1 in the actual conveyor line, the collision load Fr, the contact area Ar and the external environment temperature Tr. The impact test method of the conveyor belt 1 (upper cover rubber 3) can be efficiently selected in accordance with the actual use conditions of the belt 1. That is, the time and effort required to select an appropriate impact test can be reduced.

  Further, in the selected appropriate test method, all of the impact velocity V, impact load F, contact area A and external environment temperature T of the impact applying body 9 with respect to the test sample S are actual impact velocity Vr, impact load Fr, Since the contact area Ar and the external environment temperature Tr are set in the same range, the test can be performed by approximating the actual use conditions. As a result, it is possible to grasp with high accuracy the impact resistance of the conveyor belt 1 that matches the actual use conditions.

  The external environmental temperature Tr of the conveyor belt 1 at the use site has a relatively large influence on the impact resistance of the conveyor belt 1. Therefore, in this embodiment, the application range of the external environment temperature T of each test method is also set, the database DB is created in advance, the actual external environment temperature Tr is also acquired, and the test method is selected. As a result, it is possible to grasp the impact resistance of the conveyor belt 1 more accurately.

  The actual contact area Ar required to calculate the actual surface pressure Pr is difficult to grasp exactly because the size, shape, and the like of the conveyed objects C are different. Therefore, for example, the particle diameter of the median value CL of the particle size distribution of the conveyed product C illustrated in FIG. And it is good to use the contact area with the conveyor belt 1 (upper cover rubber 3) of the conveyed product C of this particle size as actual contact area Ar. Specifically, for example, the planar projected area of the conveyed object C having the particle diameter of the median value CL is set as the actual contact area Ar. Alternatively, when the conveyed product C is entirely sharp, for example, about 30% (20% to 50%) of the planar projected area of the conveyed product C having the particle diameter of the median value CL is set as the actual contact area Ar. An appropriate numerical value is set within the range of this percentage according to the sharpness of the conveyed item C. By setting the contact area Ar in this manner, it becomes easy to calculate an approximate value of the actual surface pressure Pr.

  The database DB can also be created for each type of the transported item C. When the type of the conveyed product C is different, the specific gravity of the conveyed product C, the surface roughness, the hardness, and the like are also different, and therefore the impact resistance of the conveyor belt 1 may be affected relatively greatly. Therefore, by creating and using the database DB for each type of the conveyed product C, it is possible to grasp the impact resistance of the conveyor belt 1 more accurately.

  When selecting from a plurality of types of test methods recorded in the database DB, if there are a plurality of test methods that meet the conditions, the plurality of types of test methods may be implemented. And if the results obtained by each test method are compared with each other and there is no big difference in each other's result, it can be judged that each is an appropriate test result.

  On the other hand, when there is a large difference between the test results of each other, it is presumed that either or each is an inappropriate test result. In this case, the impact resistance of the actual conveyor belt 1 is grasped to some extent, and then an appropriate test method and an inappropriate test method are determined. And about the test method judged to be unsuitable, database DS can be improved by reviewing the application range etc.

DESCRIPTION OF SYMBOLS 1 conveyor belt 2 core layer 3 upper cover rubber 4 lower cover rubber 5a, 5b pulley 6 support roller 7 another conveyor belt 8 impact test device 9 impact applying body 10 holding mechanism 11 support base 12 tensioner S test sample C transported material

Claims (4)

  About the impact resistance test method of the conveyor belt which makes a shock sample collide with the test sample of a conveyor belt, the database which set the application range of the collision speed, the collision load and the contact area to the test sample of the shock body beforehand is created In the actual conveyor line, the actual collision velocity, collision load and contact area of the conveyed articles fed to the conveyor belt with the conveyor belt are acquired, and the acquired is based on the acquired result and the database. A test method having an impact velocity, impact load and contact area within the applicable range is selected from the plurality of test methods, and in the selected test method, the impact velocity, impact load and contact area can be regarded as identical to the obtained result. Set to the range and carry out the selected test method Impact resistance evaluation method of the conveyor belt and evaluating the impact resistance of the conveyor belt down.   The application range of the external environment temperature of each of the test methods is also set, the database is prepared in advance, the external environment temperature in the actual conveyor line is also acquired, and the acquired external environment temperature is in the application range. The conveyor belt according to claim 1, wherein the external environment temperature selected from the plurality of types of test methods is set to a range that can be considered identical to the obtained result in the selected test method, and the selected test method is performed. Impact resistance evaluation method.   The impact resistance evaluation method of a conveyor belt according to claim 1 or 2, wherein a contact area of a conveyed product having a median particle diameter of the particle size distribution of the conveyed product with the conveyor belt is adopted as the actual contact area.   The impact resistance evaluation method of a conveyor belt according to any one of claims 1 to 3, wherein the database is created for each type of the conveyed product.

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