Patent Publication Number: US-10783461-B2

Title: Conveyor belt management system

Description:
TECHNICAL FIELD 
     The present invention relates to a conveyor belt management system and particularly relates to a conveyor belt management system capable of determining a suitable replacement period of the conveyor belt as early as possible and lowering the running costs of the conveyor belt. 
     BACKGROUND ART 
     Various conveyed objects, including mineral resources such as iron ore and limestone, are conveyed by a conveyor belt. An upper cover rubber of a conveyor belt is worn over time by conveyed objects being fed onto the upper cover rubber. When the amount of wear of the upper cover rubber becomes great, the conveyor belt becomes unusable. 
     If a conveyor belt becomes unusable, the belt line is stopped, and the conveying of the conveyed objects is significantly affected. Also, if the replacement period of a conveyor belt is unknown, then more replacement conveyor belts than necessary must be kept in inventory and inventory management becomes necessary. As a result, running costs are greatly increased. Furthermore, if the type of conveyed objects conveyed by the conveyor belt changes, the replacement conveyor belts in inventory may not be used. If the time at which the conveyor belt becomes unusable (replacement period) is known in advance, the stoppage period of the belt line can be kept to a minimum, and there is no need to have excessive conveyor belts in the inventory. 
     In the related art, various management systems for determining the replacement period of a conveyor belt are proposed (for example, see Patent Document 1). In this management system, the amount of wear of the conveyor belt is determined and a remaining service life is calculated. Thus, the management system is not capable of determining the remaining service life unless the conveyor belt has been used and the rubber worn a certain amount. Additionally, when the amount of wear of the rubber is low, the prediction accuracy of the remaining service life is low. 
     If a more suitable replacement period of the conveyor belt can be determined as quickly as possible, it is not necessary to have excessive replacement conveyor belts in the inventory, or it is possible to shorten the period of time the replacement conveyor belt spends in the inventory. Thus, there is room for improvement to lower the running costs of the conveyor belt by determining a more suitable replacement period for the conveyor belt as early as possible. 
     CITATION LIST 
     Patent Literature 
     Patent Document 1: WO 2013/179903 A 
     SUMMARY OF INVENTION 
     Technical Problem 
     An object of the present invention is to provide a conveyor belt management system capable of determining a suitable replacement period of the conveyor belt as early as possible and lowering the running costs of the conveyor belt. 
     Solution to Problem 
     To achieve the object described above, a conveyor belt management system according to an embodiment of the present invention comprises: 
     an input unit with an amount of wear of at least an upper cover rubber of a conveyor belt installed at a use site as an input item; and 
     a server into which data of the input item is input; 
     the server comprising a calculation unit and a storage unit, 
     the storage unit being configured to store a belt specification database in which specifications of the conveyor belt are input in advance and a tolerance range database in which a tolerance range for the input item input into the server per each of the specifications of the conveyor belt is input in advance, and 
     the calculation unit being configured to calculate a remaining service life of the conveyor belt based on the data of the input item input into the server, the specifications of the conveyor belt input into the belt specification database, and the tolerance range input into the tolerance range database; and 
     the calculation unit is configured to calculate before the conveyor belt is installed on the belt conveyor device an expected service life of the conveyor belt based on a use condition of the belt conveyor device at the use site, specifications of the conveyor belt input into the belt specification database, and a correlation determined in advance between the use condition and the specifications of the conveyor belt and an actual service life of the conveyor belt. 
     Advantageous Effects of Invention 
     According to an embodiment of the present invention, the remaining service life of the conveyor belt is calculated using at least the amount of wear of the upper cover rubber of the conveyor belt in use. Furthermore, the expected service life of the conveyor belt is calculated beforehand based on the correlation between the use condition and belt specifications of the conveyor belt used up until present and the actual service life, the use condition of the conveyor belt, and the belt specifications. When the two service lives, the expected service life and the remaining service life, are known, it is easy to determine a more suitable replacement period for the conveyor belt without relying on only one service life. Also, because the expected service life can be determined before using the conveyor belt, the time and funds needed for preparing the replacement conveyor belt can be easily secured. This is advantageous in that excess inventory of the conveyor belt can be reduced, the time in inventory can be easily shortened, and the running costs of the conveyor belt can be lowered. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an explanatory diagram illustrating an overview of a conveyor belt management system according to an embodiment of the present invention. 
         FIG. 2  is an explanatory diagram illustrating a belt specification database. 
         FIG. 3  is an explanatory diagram illustrating a tolerance range database. 
         FIG. 4  is an explanatory diagram illustrating a use condition database. 
         FIG. 5  is an explanatory diagram illustrating an inventory database. 
         FIG. 6  is an explanatory diagram simply illustrating a belt conveyor device mounted with a conveyor belt in a side view. 
         FIG. 7  is a cross-sectional view taken along A-A of  FIG. 6 . 
         FIG. 8  is an explanatory diagram illustrating the structure of an endless portion of the conveyor belt of  FIG. 6  in a plan view. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A conveyor belt management system according to embodiments of the present invention will be described below with reference to the drawings. 
     A conveyor belt management system  1  (hereinafter referred to as management system  1 ) according to an embodiment of the present invention illustrated in  FIG. 1  calculates during use period a remaining service life Ja of a conveyor belt  12  installed on a belt conveyor device  9  at a use site illustrated in  FIGS. 6 and 7 . The management system  1  calculates an expected service life Jf before the conveyor belt  12  is used. 
     In the belt conveyor device  9 , the conveyor belt  12  is mounted around a drive pulley  10   a  and a driven pulley  10   b  at a predetermined tension. Between the drive pulley  10   a  and the driven pulley  10   b , the conveyor belt  12  is supported by support rollers  10   c  disposed at appropriate intervals in the belt longitudinal direction. 
     The conveyor belt  12  is constituted by a core layer  14  including a core  15  made of a steel cord or canvas, and an upper cover rubber  13   a  and a lower cover rubber  13   b  that sandwich the core layer  14  therebetween. The core layer  14  is a member bearing the tension caused when the conveyor belt  12  is mounted at tension. The conveyor belt  12  may include additional necessary members, such as a width direction end portion rubber  13   c  or a reinforcing layer, as appropriate. 
     The lower cover rubber  13   b  is supported by the support rollers  10   c  on a carrying side of the conveyor belt  12 , and the upper cover rubber  13   a  is supported by the support rollers  10   c  on a return side of the conveyor belt  12 . Three of the support rollers  10   c  are arranged on the carrying side of the conveyor belt  12  side by side in the belt width direction. The conveyor belt  12  is supported by these support rollers  10   c  in a recessed shape having a prescribed trough angle. 
     The drive pulley  10   a  is rotationally driven by a drive motor. A take-up mechanism  11  moves the driven pulley  10   b  to apply a desired tension to the conveyor belt  12  (core layer  14 ) by changing the interval between the drive pulley  10   a  and the driven pulley  10   b.    
     The conveyor belt  12  may be formed from a plurality of conveyor belts of any length by splicing together the longitudinal end portions of the core layers  14  of the conveyor belts to form an annular shape. In a case of the conveyor belt  12  having a short circumferential length, the longitudinal end portions of the core layer  14  of one conveyor belt  12  may be spliced together to form an annular shape. Thus, as illustrated in  FIG. 8 , the conveyor belt  12  includes a portion where the core layer  14  is spliced together in the longitudinal direction (an endless portion  16 B) and a non-endless portion  16 A disposed adjacent to one another in the longitudinal direction. In the conveyor belt  12 , the core layer  14  is formed from a plurality of steel cords  15  arranged side by side in the belt width direction. In the endless portion  16 B, every second steel cord  15  extending from each of the non-endless portions  16 A on opposite sides in the belt longitudinal direction is inserted between the steel cords  15  on the other side in the belt width direction. 
     In a case in which the core layer  14  is made of canvas, in the endless portion  16 B, the canvas extending from each of the non-endless portions  16 A on opposite sides in the belt longitudinal direction may have a known structure such as being joined in a step shape. In the non-endless portion  16 A, the core layer  14  is continuous without a joint, but in the endless portion  16 B, the core layer  14  has such a joint. Thus, the endless portion  16 B and the non-endless portion  16 A show differences in elongation, tensile strength, and flexibility (bending rigidity). 
     Conveyed objects C conveyed by another conveyor belt are fed onto the upper cover rubber  13   a  of the conveyor belt  12  and conveyed to a conveying destination by the conveyor belt  12 . The conveyed objects C may be fed onto the conveyor belt  12  via a hopper or the like. 
     The upper cover rubber  13   a  is subjected to impact from the fed conveyed objects C. Additionally, on the upper cover rubber  13   a , the conveyed objects C immediately after being fed and placed press against the upper cover rubber  13   a  with a predetermined surface pressure and move in a direction opposite to the running direction of the conveyor belt  12 . At this time, friction force acts on the upper cover rubber  13   a . The upper cover rubber  13   a  is worn primarily by this behavior of the conveyed objects C. The width direction end portion rubber  13   c  may slide and wear against a guide or the like of the belt conveyor device  9 . The lower cover rubber  13   b  may slide and wear against the support rollers  10   c  that cannot rotate or not rotate smoothly. The lower cover rubber  13   b  may wear due to slippage between the lower cover rubber  13   b  and the pulleys  10   a ,  10   b  due to insufficient tension acting on the conveyor belt  12  or the like. The lower cover rubber  13   b  may slide and wear against a scraper provided to remove the conveyed objects C that have dropped onto the lower cover rubber  13   b.    
     The management system  1  includes an input unit  5  ( 5   a  to  5   g ) and a server  2  into which data is input by the input unit  5 . The server  2  includes a calculation unit  3  (microprocessor) and a storage unit  4  (memory). 
     The input unit  5  and the server  2  are communicably connected. In this embodiment, the management system  1  includes seven types of input units  5   a  to  5   g , and the input units  5  are connected to a transmission unit  6 . The data input by the input unit  5  is transmitted from the transmission unit  6  to the server  2 . In addition, the server  2  is communicably connected to a customer terminal device  7  and a manufacturer terminal device  8 . For example, a personal computer or the like is used for the customer terminal device  7  and the manufacturer terminal device  8 . The server  2 , the input unit  5 , the customer terminal device  7 , and the manufacturer terminal device  8  can each be connected through, for example, an Internet network. 
     The server  2  is installed, for example, in the company of the distributor that distributes the conveyor belt  12 . The input unit  5  is disposed, for example, at the use site of the conveyor belt  12 . The customer terminal device  7  is installed, for example, in the company of the user of the conveyor belt  12 . The manufacturer terminal device  8  is installed, for example, in the company (factory) of the manufacturer of the conveyor belt  12 . When the distributor and the manufacturer of the conveyor belt  12  are the same (manufacturer/distributor of the conveyor belt  12 ), for example, the server  2  and the manufacturer terminal device  8  are disposed in the company of the manufacturer/distributor. 
     The frequency at which data is input to the server  2  by the input units  5  may be irregular, with an appropriate number of times during one week or one month, but the frequency is preferably regular with a certain time period. The frequency of input may be, for example, once per day, once per week, once per month, or the like. 
     The wear amount input unit  5   a  has as an input item an amount of wear P 1  of the rubber including at least the upper cover rubber  13   a  of the conveyor belt  12 . The input item of the wear amount input unit  5   a  may only include the amount of wear of the upper cover rubber  13   a . However, for example, the amount of wear of the lower cover rubber  13   b  and/or the width direction end portion rubber  13   c  may also be included as an input item. For the wear amount input unit  5   a , various types of wear amount sensors can be employed for detecting the amount of wear of the upper cover rubber  13   a . Alternatively, an input terminal device (such as a personal computer) into which a worker inputs the amount of wear P 1  data into the server  2  can be used as the wear amount input unit  5   a.    
     The input item of the impact force input unit Sb is an impact force P 2  that acts on the conveyor belt  12 , the input item of the tensile force input unit  5   c  is a tensile force P 3  that acts on the conveyor belt  12 , the input item of the core state input unit  5   d  is an indicator P 4  indicating the state of the core  15 , the input item of the endless portion state input unit Se is an indicator P 5  indicating the state of the endless portion  16 B, the input item of the device state input unit  5   f  is an indicator P 6  indicating the state of the belt conveyor device  9 , and the input item of the use environment input unit  5   g  is an indicator P 7  indicating the use environment of the conveyor belt  12 . 
     In general, because the amount of wear P 1  of the upper cover rubber  13   a  is most affected by the remaining service life Ja of the conveyor belt  12 , in an embodiment of the present invention, the input unit  5  is required to have at least this amount of wear P 1  as an input item. In other words, inputting the six input items (P 2  to P 7 ) described above to the server  2  during the use period of the conveyor belt  12  is a discretionary matter. Thus, a configuration may be employed in which, in addition to the amount of wear P 1 , one, two, three, four, five, or six input items selected from the six input items (P 2  to P 7 ) are input by the input unit  5 . 
     For the impact force input unit  5   b , various types of impact force sensors can be employed for detecting the impact force P 2  acting on the conveyor belt  12  (upper cover rubber  13   a ). Alternatively, an input terminal device (such as a personal computer) into which a worker inputs the impact force P 2  data into the server  2  can be used as the impact force input unit  5   b.    
     For the tensile force input unit  5   c , various types of tensile force sensors can be employed for detecting the tensile force P 3  acting on the conveyor belt  12  (core layer  14 ). Alternatively, an input terminal device (such as a personal computer) into which a worker inputs the tensile force P 3  data into the server  2  can be used as the tensile force input unit Sc. 
     An example of the indicator P 4  indicating the state of the core  15  includes the gap between the cores  15  arranged side by side in the belt width direction. For example, an X-ray device that detects the gap in the width direction by X-ray radiation may be used for the core state input unit  5   d . Alternatively, an input terminal device (such as a personal computer) into which a worker inputs the indicator P 4  data into the server  2  can be used as the core state input unit  5   d.    
     An example of the indicator P 5  indicating the state of the endless portion  16 B includes a bonding length of the endless portion  16 B. For the endless portion state input unit  5   e , for example, a length sensor that detects the interval between marks (colored rubber, engravings, or the like) embedded at both positions at the longitudinal ends of the endless portion  16 B, and the like may be employed. Alternatively, an input terminal device (such as a personal computer) into which a worker inputs the indicator P 5  data into the server  2  can be used as the endless portion state input unit  5   e.    
     Examples of the indicator P 6  indicating the state of the belt conveyor device  9  include the conveyance speed of the conveyed objects C, the conveyance weight per unit time, the outer diameter of the pulleys  10   a ,  10   b  and the support rollers  10   c , and the like. For the device state input unit  5   f , for example, a speed sensor for detecting the conveyance speed of the conveyed objects C, a weight sensor for detecting the conveyance weight per unit time, and the like may be employed. Alternatively, an input terminal device (such as a personal computer) into which a worker inputs the indicator P 6  data into the server  2  can be used as the device state input unit  5   f.    
     Examples of the indicator P 7  indicating the use environment of the conveyor belt  12  include the use environment temperature and humidity, values identifying specifications of the conveyed objects C (material (hardness, oil content), shape, temperature, and the like), and the like. For the use environment input unit  5   g , for example, a temperature sensor, a humidity sensor, a hardness sensor, a digital camera that recognizes the shape of the conveyed objects C, and the like can be employed. Alternatively, an input terminal device (such as a personal computer) into which a worker inputs the indicator P 7  data into the server  2  can be used as the use environment input unit  5   g.    
     The storage unit  4  stores a belt specification database  4   a  in which the specifications of the conveyor belt  12  are input in advance, an tolerance range database  4   b  in which the tolerance ranges for each of the input items (P 1  to P 7 ) are input in advance per specification of the conveyor belt  12 , a use condition database  4   c , and a correlation database  4   d.    
     In this embodiment, an inventory database  4   e  is stored in the storage unit  4 . An inventory amount (inventory length) of replacement conveyor belts  12   a  for the conveyor belt  12  at the use site of the conveyor belt  12  or at a stockyard near the use site of the conveyor belt is input into the inventory database  4   e . Note that the currently used conveyor belt  12  and the replacement conveyor belt  12   a  may have the same specifications but may also have different specifications. For example, the currently used conveyor belt  12  and the replacement conveyor belt  12   a  may differ in the material of the upper cover rubber  13   a.    
     As illustrated in  FIG. 2 , the material, size, and the like of the constituent members per conveyor belt specification (specification A, B, C, . . . ) are input into the belt specification database  4   a . For example, rubber types (rubber physical properties) and layer thicknesses of the upper cover rubber  13   a  and the lower cover rubber  13   b , the material (physical properties) and the outer diameter of the core  15 , the number of cores  15  constituting the core layer  14 , the gap in the width direction between the cores  15  arranged side by side, the bonding length of the endless portion  16 B, and the like are input. 
     As illustrated in  FIG. 3 , the tolerance range for each input item (P 1  to P 7 ) per specification (specification A, B, C, . . . ) of the conveyor belt  12  are input into the tolerance range database  4   b . In this embodiment, seven input items (P 1  to P 7 ) are input into the server  2 , with the tolerance ranges of the seven input items. However, in an embodiment in which only the amount of wear P 1  of the upper cover rubber  13   a  is input into the server  2  as an input item, then only the tolerance range of the amount of wear P 1  is required to be input into the tolerance range database  4   b . Also, in an embodiment in which three input items are input into the server  2 , it is only required that the tolerance ranges of these three input items are input into the tolerance range database  4   b.    
     Over time, excessively high levels of the amount of wear P 1  of the upper cover rubber  13   a  may cause failure. Thus, for example, a tolerance range with a predetermined upper limit is set for the amount of wear P 1 . 
     Excessively high levels of the impact force P 2  may cause failure. Thus, for example, a tolerance range with a predetermined upper limit is set for the impact force P 2 . 
     Excessively high levels of the tensile force P 3  may cause failure. Excessively low levels may cause failure due to wandering. Thus, for example, a tolerance range with a predetermined upper limit and lower limit is set for the tensile force P 3 . 
     Over time, excessively high levels and low levels of the gap in the width direction between the cores  15 , which is an example of the indicator P 4 , may cause failure. Thus, for example, a tolerance range with a predetermined upper limit and lower limit is set for the gap in the width direction P 4 . 
     Over time, excessively high levels of the bonding length of the endless portion  16 B, which is an example of the indicator P 5 , may cause peeling at the bond. Thus, for example, a tolerance range with a predetermined upper limit is set for the bonding length P 5 . 
     Excessively high levels of the conveyance speed P 6   1 , which is an example of the indicator P 6 , may cause the amount of wear P 1  of the upper cover rubber  13   a  to increase. Excessively low levels may cause the load weight of the conveyed objects C per unit area to increase, increasing the load on the conveyor belt  12 . Thus, for example, a tolerance range with a predetermined upper limit and lower limit is set for the conveyance speed P 6   1 . Excessively high levels of the conveyance weight P 6   2  per unit time, which is an example of the indicator P 6 , may cause the load on the conveyor belt  12  to increase. Thus, for example, a tolerance range with a predetermined upper limit is set for the conveyance weight P 6   2  per unit time. 
     Excessively high levels and low levels of the typical use environment temperature P 7   1  and humidity P 7   2 , which are examples of the indicators P 7   1  may cause failure of the conveyor belt  12 . Thus, for example, a tolerance range with a predetermined upper limit and lower limit is set for the temperature P 7   1  and the humidity P 7   2 . Excessively high levels of the hardness P 7   3  of the conveyed objects C, which is another example of the indicator P 7 , may cause damage to the upper cover rubber  13   a . Thus, for example, a tolerance range with a predetermined upper limit is set for the hardness P 7   3 . When the shape P 7   4  of the conveyed objects C, which is another example of the indicator P 7 , includes a portion with an acute angle on the outer surface, the upper cover rubber  13   a  may be damaged. Thus, for example, a tolerance range with a predetermined upper limit for the proportion of fed conveyed objects C including a portion with an acute angle on the surface of the conveyed objects C is set for the shape P 7   4  of the conveyed objects C. 
     As illustrated in  FIG. 4 , the use condition for the belt conveyor device  9  at the use site has been input into the use condition database  4   c . Examples of the use condition include the conveyance speed of the conveyed objects C, the conveyance weight per unit time, the outer diameter of the pulleys  10   a ,  10   b  and the support rollers  10   c , and the like. Other examples of the use condition include the use environment temperature and humidity of the conveyor belt  12 , specifications of the conveyed objects C (material (hardness, oil content), shape, temperature, and the like), and the like. 
     In other words, the use condition overlaps with the input items P 6 , P 7  described above. Thus, the device state input unit  5   f  and the use environment input unit  5   g  can be used to input the use condition data into the server  2 . The use condition is newly updated each time the use condition change, such as when the type of the conveyed objects C changes. 
     Data indicating the correlation between the use condition and conveyor belt specifications of the multiple conveyor belts used up until the present and an actual service life Jr of the conveyor belt is input into the correlation database  4   d . In other words, by analyzing the data of the use condition (input items P 6 , P 7  described above), the belt specifications, and the actual service life Jr of the conveyor belt  12  collected up until the present, the correlation between the use condition, the belt specifications, and the actual service life Jr is determined in advance. 
     For example, quantitative correlations including: as the conveyance speed P 6   1  becomes faster, the actual service life Jr decreases and as the conveyance weight P 6   2  per unit time increases, the actual service life Jr decreases; are input into the correlation database  4   d . Also, quantitative correlations including: as the use environmental temperature P 7   1  and humidity P 7   2  increase, the actual service life Jr decreases and as the hardness P 7   3  of the conveyed objects C increases, the actual service life Jr decreases; and as shape P 7   4  of the conveyed objects C corresponding to the proportion of conveyed objects C including a portion with an acute angle on the outer surface increases, the actual service life Jr decreases; are input into the correlation database  4   d.    
     As illustrated in  FIG. 5 , the inventory amount (inventory length) per conveyor belt specification (specification A, B, C, . . . ) is input into the inventory database  4   e . The inventory database  4   e  is updated when a replacement conveyor belt  12   a  comes in or goes out. Thus, it corresponds to the state of the most current input of the inventory amount. 
     The calculation unit  3  is configured to calculate the remaining service life Ja of the conveyor belt  12  on the basis of the input item (P 1  to P 7 ) data input by the input unit  5 , the specifications of the conveyor belt  12  input into the belt specification database  4   a , and the tolerance ranges of the input items (P 1  to P 7 ) input into the tolerance range database  4   b.    
     Specifically, the data of each input item input into the server  2  and the corresponding tolerance range are compared over time. Here, the change in the amount of wear P 1  has the greatest impact on the remaining service life Ja compared to other input items. Thus, for example, the variation (rate of variation) of the wear amount P 1  data relative to the tolerance range is calculated. Based on the calculated variation, the time required for the data of the input amount of wear P 1  to be outside of the tolerance range is calculated, and the calculated time is taken as the remaining service life Ja. 
     Because the change in the bonding length P 5  of the endless portion  16 B has a relatively great impact on the remaining service life Ja as compared to other input items, the time required for the input bonding length P 5  to be outside of the tolerance range is calculated based on the variation (variation rate) of the bonding length P 5  data relative to the tolerance range, and the calculated time is taken as a temporary remaining service life Jb 2 . Then, the time required for the amount of wear P 1  data described above to be outside of the tolerance range is taken as a temporary remaining service life Jb 1 , and the shortest one of the temporary remaining service lives Jb 1 , Jb 2  can be taken as the remaining service life Ja. 
     For other input items (P 2  to P 4 , P 6 , P 7 ), for example, if the data input into server  2  is within the tolerance range, the remaining service life Ja is calculated without taking these data into account. However, if these data are outside of the tolerance range, the remaining service life Ja is calculated using these data as described below. 
     In the case of these input item (P 2  to P 4 , P 6 , P 7 ) data being outside of the tolerance range, the load on the conveyor belt  12  may be considered greater than in the case of the data being within the tolerance range. Thus, for each of these input items, a coefficient K (0&lt;K&lt;1) is set that causes the remaining service life Ja to be calculated short. The magnitude of the coefficient K is not uniform, and may be varied depending on the input item by weighting the importance of each input item based on the previously accumulated performance data. 
     First, the temporary remaining service life Jb is calculated as described above without using the input item (P 2  to P 4 , P 6 , P 7 ) data. Next, in a case in which these data are outside of the tolerance range, the coefficients K (K 1 , K 2 , K 3 , . . . ) set for each input item and the calculated temporary remaining service life Jb are multiplied together to calculate the remaining service life Ja (Ja=Jb×K 1 ×K 2  . . . ). 
     In an embodiment of the present invention, the actual service life Jr of the conveyor belt  12  is identified based on the calculated remaining service life Ja. In other words, the conveyor belt  12  use start time point and the time point when the remaining service life Ja of the conveyor belt  12  was calculated are known. Thus, the time period from the use start time point to the time point when the remaining service life Ja was calculated is found. The calculated remaining service life Ja is added to this found time period to identify the actual service life Jr. The actual service life Jr in an embodiment of the present invention in principle means a service life identified in this way based on the calculated remaining service life Ja. 
     The calculation unit  3  calculates the remaining service life Ja at a predetermined period (e.g., two weeks or one month). In this embodiment, an email notifying of the calculated remaining service life Ja is sent from the server  2  to the customer terminal device  7 . 
     In the management system  1 , expected service life Jf of the conveyor belt  12  is calculated by the calculation unit  3  before the conveyor belt  12  is attached to the belt conveyor device  9 . As described above, because the correlation database  4   d  is input into the storage unit  4 , the data of the use condition (input items P 6 , P 7  described above) of the conveyor belt  12 , the data of the specifications of the conveyor belt, and the correlation database  4   d  are used to calculate the expected service life Jf. The calculated expected service life Jf is transmitted from the server  2  to the customer terminal device  7 . 
     The calculated expected service life Jf has a slight error margin. Thus, the remaining service life Ja is calculated as described above, making it easier to determine a more suitable replacement period for the conveyor belt  12 . 
     In other words, in an embodiment of the present invention, in addition to the remaining service life Ja described above, the expected service life Jf is calculated before use of the conveyor belt  12 . When the two service lives, the expected service life Jf and the remaining service life Ja, are known, it is easy to determine a more suitable replacement period for the conveyor belt  12  without relying on only one service life. Also, because the expected service life Jf can be determined before using the conveyor belt  12 , the time and funds needed for preparing the replacement conveyor belt  12   a  can be easily secured. This is advantageous in that excess inventory of the conveyor belt  12  ( 12   a ) can be reduced, the time in inventory can be easily shortened, and the running costs of the conveyor belt  12  can be lowered. 
     In this embodiment, at least one input item of the other input items P 2  to P 7  is used in addition to the amount of wear P 1  of the upper cover rubber  13   a  as a basis for calculating the remaining service life Ja. This is advantageous in calculating the remaining service life Ja that is more in conformance with the actual status of the use site of the conveyor belt  12 . 
     In this embodiment, a communication is transmitted from the server  2  to the customer terminal device  7  notifying of an order period for the replacement conveyor belt  12   a  or a prompt to order the replacement conveyor belt  12   a  based on the amount of the conveyor belt  12  in inventory input into the inventory database  4   e  and the calculated remaining service life Ja of the conveyor belt  12 . 
     Specifically, each time the calculation unit  3  calculates the remaining service life Ja, the amount of the conveyor belt  12  in inventory input into the inventory database  4   e  at the current time point is confirmed. If the required length of the replacement conveyor belt  12   a  is longer than the confirmed amount in inventory, the amount in inventory is insufficient. In this case, an email notifying of an order period of the replacement conveyor belt  12   a  identified by referencing the calculated remaining service life Ja and a predetermined period of time needed for delivery is sent from the server  2  to the customer terminal device  7 . When the order period approaches, an email prompting the order of the replacement conveyor belt  12   a  is sent from the server  2  to the customer terminal device  7 . As a result, sufficient preparation can be done for the replacing the conveyor belt  12 . 
     When there is communication of an order for the replacement conveyor belt  12   a  from the customer terminal device  7 , the communication is transmitted to the manufacturer terminal device  8  via the server  2  or directly to the manufacturer terminal device  8 . Based on this order, the manufacturer delivers the conveyor belt  12   a  of the ordered specifications and length to the stockyard of the customer. 
     Note that for conveyor belts  12  with a short circumferential length, all (the entire circumferential length) of the conveyor belt  12  can be replaced, and for conveyor belts  12  with a long circumferential length, only the necessary portions (required length) can be replaced. Thus, for example, for input items (P 1 , P 4 , and P 5 ), input data and data for identifying the position on the conveyor belt  12  in the circumferential direction corresponding to this data are both input into the server  2 . In this way, the position and length of the conveyor belt  12  in need of replacement can be determined. 
     A database in which the cost required to replace the conveyor belt  12  is input, a database in which the time required for replacement is input, and the like can be stored in the storage unit  4  of the server  2 . In such a configuration, the cost information required to replace the conveyor belt  12  can be transmitted from the server  2  to the customer terminal device  7 . In addition, schedule management required for replacement of the conveyor belt  12  can be performed in a centralized manner using the server  2 . 
     In a case in which the amount of wear P 1  of the lower cover rubber  13   b  is added as an input item, the tolerance range (upper limit value) for the amount of wear P 1  is input in advance into the tolerance range database  4   b . Furthermore, in a case in which the amount of wear P 1  of the lower cover rubber  13   b  input into the server  2  is outside of the tolerance range, an email may be sent to the customer terminal device  7  and/or the manufacturer terminal device  8  notifying that the amount of wear P 1  is outside of the tolerance range. The customer or manufacturer that receives this email performs an inspection such as checking the rotation state of the support rollers  10   c  of the belt conveyor device  9 , checking whether slippage is occurring between the conveyor belt  12  and the pulleys  10   a ,  10   b , and checking whether the scraper is coming into contact with the lower cover rubber  13   b . As a result, defects in the belt conveyor device  9  can be eliminated in the early stages. 
     REFERENCE SIGNS LIST 
     
         
           1  Management system 
           2  Server 
           3  Calculation unit 
           4  Storage unit 
           4   a  Belt specification database 
           4   b  Tolerance range database 
           4   c  Use condition database 
           4   d  Correlation database 
           4   e  Inventory database 
           5  Input unit 
           5   a  Wear amount input unit 
           5   b  Impact force input unit 
           5   c  Tensile force input unit 
           5   d  Core state input unit 
           5   e  Endless portion state input unit 
           5   f  Device state input unit 
           5   g  Use environment input unit 
           6  Transmission unit 
           7  Customer terminal device 
           8  Manufacturer terminal device 
           9  Belt conveyor device 
           10   a  Drive pulley 
           10   b  Driven pulley 
           10   c  Support roller 
           11  Take-up mechanism 
           12  Conveyor belt 
           13   a  Upper cover rubber 
           13   b  Lower cover rubber 
           13   c  Width direction end portion rubber 
           14  Core layer 
           15  Core (steel cord) 
           16 A Non-endless portion 
           16 B Endless portion 
         C Conveyed object