Method and device for measuring the circumferential length of a conveyor belt

Abstract

To provide a method and device for accurately and rapidly measuring a length in a belt circumferential direction at bot ends in a width direction of a conveyance belt having a predetermined width.SOLUTION: A method for measuring a length in a belt circumferential direction of a conveyance belt 4 comprises: winding only an end part 41 on one side in a width direction of a conveyance belt 4 between a first pulley 2 and a second pulley 3, and measuring a length in a belt circumferential direction of the end part 41 with a predetermined tension applied; and winding only an end part 42 on the other side in a width direction of the conveyance belt 4 between the first pulley 2 and the second pulley 3, and measuring a length in a belt circumferential direction of the end part 42 with a predetermined tension applied, where when the difference between the length in the belt circumferential direction of the end part 41 of the conveyance belt 4 and the length in the belt circumferential direction of the end part 42 of the conveyance belt 4 is less than or equal to a predetermined threshold value, it is determined to pass, and when it exceeds the predetermined threshold value, it is determined to be failed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for measuring the circumferential length of a conveyor belt wound between pulleys, and an apparatus for measuring the same. [Background technology]

[0002] Generally, an example of a device for measuring belt length (measurement device) is the device disclosed in Patent Document 1. The device disclosed in Patent Document 1 measures the length of a transmission belt by placing the belt around a pair of measuring pulleys and measuring the distance between the axes of the pulleys while applying a predetermined force in a direction that pulls the pulleys apart. This type of device measures one belt length for one belt. In other words, it is not possible to measure the difference in length between both ends of the belt in the width direction (the difference in length between the left and right sides of the belt).

[0003] Among the "belts" that are also called power transmission belts are conveyor belts used in belt conveyors. In these belt conveyor systems, an endless (circular) conveyor belt is attached to multiple pulleys, including a drive pulley. The conveyor belt is constructed by laminating a resin (or elastomer) such as polyvinyl chloride or polyurethane onto a base fabric (core canvas) made of synthetic fibers such as polyester. The base fabric, which bears the tension, is usually attached to the belt conveyor system so that it faces the side that contacts the pulley, and the resin layer on the back side of the base fabric forms the conveying surface. The conveyor belt rotates under the driving force of the drive pulley, allowing it to transport objects placed on it. Conveyor belt widths vary depending on the size of the objects being transported, but some products are as wide as 2000 mm. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Jippan Hei 3-70303 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0005] In a wide conveyor belt as described above, the difference in length between both ends of the belt in the width direction can become a problem, even though it is not so much of a problem in the case of a power transmission belt. Specifically, if the difference in length between both ends of the conveyor belt in the width direction is large, the conveyor belt is likely to run while leaning to one side in the width direction, a phenomenon known as "off-axis running." When this "off-axis running" occurs, the conveyor belt is likely to deviate from the pulley and come off. Therefore, there is a demand for a small difference in length between both ends of the belt in the width direction, and it is necessary to measure the length of the belt at both ends in the width direction individually.

[0006] Another problem when measuring belt length is that the belt may not be aligned sufficiently around the length-measuring pulley, resulting in lifting. This problem becomes more pronounced when the belt has high bending rigidity or when it is not possible to apply a large force in the direction of separating the pulleys to prevent the belt from stretching or being damaged. If the belt is not aligned sufficiently around the measuring pulley, the calculated belt length will be shorter than the actual belt length, making it impossible to measure the belt length accurately.

[0007] As such, measuring the length of a conveyor belt has traditionally been done manually using a ruler or other measuring device, since it is difficult to say that length measuring devices for power transmission belts are sufficiently functional. Specifically, as shown in Figure 8, the conveyor belt is placed on a flat surface such as a desk, and the length of the flat portion is repeatedly measured using a steel tape measure or metal ruler. The sum of these measurements is used to determine the belt length. In the example shown in Figure 8, the length between the flat portions AB is first measured, then the conveyor belt is rotated so that the portion BC is the flat portion, and the length between the flat portions BC is measured. The conveyor belt is then rotated and measured repeatedly in the same manner, measuring the lengths between CD and DA. The measured lengths of the flat portions are then summed to calculate the overall length of the conveyor belt. The belt length calculated using this method is the length connecting the center points of the conveyor belt in the thickness direction (the center length). Based on the relationship between this center length and the conveyor belt's position in the thickness direction, the inner circumference of the conveyor belt and the length corresponding to the portion bearing tension (the pitch length) can also be calculated.

[0008] However, although it is possible to determine the left and right lengths of the conveyor belt by performing such measurements at both ends of the width of the conveyor belt (left and right ends), this requires a lot of labor and is prone to errors depending on the person making the measurement.

[0009] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method and a measuring device for accurately and quickly measuring the length in the belt circumferential direction of both ends in the width direction of a conveyor belt having a predetermined width. [Means for solving the problem]

[0010] The present invention includes a step of hooking one end of a width direction of a conveyor belt between pulleys and measuring the length of the one end in the belt circumferential direction; a step of hooking the other end of the conveyor belt in the width direction between pulleys and measuring the length of the other end in the belt circumferential direction; The method for measuring the length of a conveyor belt in the circumferential direction of the belt includes:

[0011] According to the above method, by separately measuring the circumferential length of the belt at both ends in the width direction of a conveying belt having a predetermined width, it is possible to detect the difference in the circumferential length of the belt at both ends in the width direction of the conveying belt, which causes lopsided running.

[0012] Further, the present invention provides the method for measuring the circumferential length of a belt, calculating a difference between the measured length of one end of the conveyor belt in the circumferential direction of the belt in the width direction and the measured length of the other end of the conveyor belt in the circumferential direction of the belt in the width direction; determining that the test piece is acceptable when the calculated difference is equal to or smaller than a predetermined threshold value, and determining that the test piece is unacceptable when the calculated difference is greater than the predetermined threshold value; may also include:

[0013] According to the above method, the difference in the circumferential length of the conveyor belt between both ends in the width direction can be calculated, and based on this difference, the appropriateness of the circumferential length required for the conveyor belt at both ends in the width direction can be automatically determined, thereby improving convenience for the person making the measurement.

[0014] Further, the present invention provides the method for measuring the circumferential length of a belt, The length of the outer periphery of the pulley in the width direction may be 5 mm or more and half or less of the total width of the conveyor belt.

[0015] According to the above method, only the ends of the conveyor belt are placed between the pulleys, and the circumferential lengths of both ends of the conveyor belt in the width direction can be measured. If the width direction length of the outer periphery of the pulley (length in the axial direction of the pulley) is too long, adjustment is required when placing only the ends of the conveyor belt on the pulley, which increases the amount of work required. On the other hand, if the width direction length of the outer periphery of the pulley is too short, the conveyor belt is likely to come off the pulley, making measurement difficult.

[0016] Further, the present invention provides the method for measuring the circumferential length of a belt, The length of the belt circumferential direction at both ends of the width direction of the conveying belt at the pitch height position may be measured, taking into account the pitch height, which is the position of the conveying belt that corresponds to the tension-bearing portion in the belt thickness direction, stored in a memory device.

[0017] According to the above method, it is possible to measure the length (pitch circumference) of the belt circumferential direction connecting the pitch height (for example, the center position of the core canvas layer), which is the position corresponding to the tension bearing portion in the belt thickness direction, in the conveying belt. It is also possible to measure the pitch circumference length used in practice, further improving convenience.

[0018] Further, the present invention provides the method for measuring the circumferential length of a belt, The outer periphery of the conveyor belt wound between the pulleys may be pressed in contact with the conveyor belt in the width direction.

[0019] According to the above method, since the pulleys only contact the ends of the conveyor belt, the conveyor belt may bulge outward in the areas where it is not in contact with the pulleys, which may reduce measurement accuracy. Therefore, measurement accuracy can be improved by measuring the circumferential length of both ends of the conveyor belt while the outer periphery of the conveyor belt wound between the pulleys is in contact with and pressed in the width direction.

[0020] Further, the present invention provides the method for measuring the circumferential length of a belt, The position at which the outer periphery of the conveying belt wound between the pulleys is contacted and pressed in the width direction may be at a distance within a range of "thickness of the conveying belt - 0.5 mm" or more and "thickness of the conveying belt + 1.0 mm" or less from a straight line connecting the contact points of the common tangents of the two pulleys on which the conveying belt is wound, toward the outer periphery of the conveying belt.

[0021] If the position where the outer periphery of the conveyor belt is pressed is too far from the line connecting the tangent points of the common tangent lines of the two pulleys (exceeding "conveyor belt thickness + 1.0 mm"), the conveyor belt may not be pressed, or the pressing force may be too weak, and the conveyor belt may not be able to sufficiently prevent bulging toward the outer periphery. On the other hand, if the position where the outer periphery of the conveyor belt is pressed is too close to the line connecting the tangent points of the common tangent lines of the two pulleys (less than "conveyor belt thickness - 0.5 mm"), the angle at which the conveyor belt wraps around the pulleys becomes too large, reducing measurement accuracy. Therefore, the above problem was solved by setting the position where the outer periphery of the conveyor belt comes into contact and presses in the width direction within the above range.

[0022] The present invention also provides a measuring device that measures the length of one end of a width direction of a conveyor belt in a belt circumferential direction while the end is hung between pulleys and a predetermined tension is applied to the one end, the measuring device comprising: The length of the outer periphery of the pulley in the width direction is 5 mm or more and is equal to or less than half the total width of the conveyor belt.

[0023] According to the above configuration, by separately measuring the circumferential length of the belt at both ends in the width direction of a conveying belt having a predetermined width, it is possible to detect the difference in the circumferential length of the belt at both ends in the width direction of the conveying belt, which causes lopsided running.

[0024] Further, the present invention provides a measuring device for measuring the length of a belt in a circumferential direction, comprising: The conveyor belt may further include at least one pressing member that contacts and presses the outer periphery of the conveyor belt wound between the pulleys in the width direction.

[0025] According to the above configuration, since the pulleys only contact the ends of the conveyor belt, the conveyor belt may bulge outward in the areas where it is not in contact with the pulleys, which may reduce measurement accuracy. Therefore, by measuring the length of the conveyor belt in the circumferential direction at both ends of the conveyor belt while the outer periphery of the conveyor belt wound between the pulleys is in contact with and pressed in the width direction, measurement accuracy can be improved.

[0026] Further, the present invention provides a measuring device for measuring the length of a belt in a circumferential direction, comprising: The pressing member may be positioned at a distance within a range of "thickness of the conveying belt - 0.5 mm" or more and "thickness of the conveying belt + 1.0 mm" or less from a straight line connecting the contact points of the common tangents of the two pulleys on which the conveying belt is hung, on the outer peripheral side of the conveying belt.

[0027] If the position where the outer periphery of the conveyor belt is pressed is too far from the line connecting the tangent points of the common tangent lines of the two pulleys (exceeding "conveyor belt thickness + 1.0 mm"), the conveyor belt may not be pressed, or the pressing force may be too weak, and the conveyor belt may not be able to sufficiently prevent bulging toward the outer periphery. On the other hand, if the position where the outer periphery of the conveyor belt is pressed is too close to the line connecting the tangent points of the common tangent lines of the two pulleys (less than "conveyor belt thickness - 0.5 mm"), the angle at which the conveyor belt wraps around the pulleys becomes too large, reducing measurement accuracy. Therefore, the above problem was solved by setting the position where the outer periphery of the conveyor belt comes into contact and presses in the width direction within the above range. [Effects of the Invention]

[0028] It is possible to provide a method and a measuring device for accurately and quickly measuring the length in the belt circumferential direction of both ends in the width direction of a conveyor belt having a predetermined width. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a perspective view of a measuring device and a top view of the measuring device; [Figure 2] 1 is a perspective view of a measuring device with a conveyor belt set therein, and a top view of the measuring device; [Figure 3] A side view of the measuring device with the conveyor belt of Figure 2 set [Figure 4] Illustrative diagram of the position of the holding member [Figure 5] Descriptive diagram of the holding member [Figure 6] Illustrative diagram of conveyor belt pitch length [Figure 7] (A) Bar graph showing the difference between the "length measured by the measuring device" and the "length measured manually" in Example 1. (B) Bar graph showing the difference between the "length measured by the measuring device" and the "length measured manually" in Example 2. [Figure 8] Explanatory diagram of conventional belt circumference measurement method (side view of belt) [Figure 9] FIG. 10 is an explanatory diagram of a measuring device equipped with a load-applying mechanism according to another embodiment 2. [Figure 10] 10 is an explanatory diagram of a procedure for applying tension to a conveyor belt according to another embodiment 2. [Figure 11] 10 is an explanatory diagram of a procedure for applying tension to a conveyor belt according to another embodiment 2. [Figure 12] 10 is an explanatory diagram of a fixed support plate and a movable support plate according to another embodiment 3. [Figure 13] 10 is an explanatory diagram of a first pulley and a second pulley according to another embodiment 4. BEST MODE FOR CARRYING OUT THE INVENTION

[0030] (Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a measuring device 1 is described as an example, which measures the circumferential length of the end 41 (or the end 42) on one side of the belt width direction of the conveyor belt 4 by wrapping only the end 41 (or the end 42) on the other side of the belt width direction of the conveyor belt 4 between the first pulley 2 and the second pulley 3 shown in Figure 1.

[0031] (Measuring device 1) As shown in Figure 1, the measuring device 1 includes a linear guide rail 11, a fixed support plate 12 fixed to one end of the guide rail 11, a movable support plate 13 that is movable on the guide rail 11, a load-applying mechanism 14 that pulls the movable support plate 13 toward the other end of the guide rail 11, a computing device 15, and a display unit 16 connected to the computing device 15.

[0032] (Guide rail 11) The guide rail 11 is a linear rail, and has a fixed support plate 12 fixed to one end and a load applying mechanism 14 attached to the other end. A movable support plate 13 (a carriage (not shown) attached to the underside of the movable support plate 13 moves on the guide rail 11) that is movable on the guide rail 11 is placed on the guide rail 11 between the fixed support plate 12 and the load applying mechanism 14, which will be described later.

[0033] (Fixed support plate 12 and movable support plate 13) The fixed support plate 12 is a plate-shaped base on which the first pulley 2, two pressing members 61 and 62, and the laser transmitting / receiving unit 51 of the laser length measuring device 5 are installed. The movable support plate 13 is a plate-shaped movable base on which the second pulley 3, two pressing members 63 and 64, and the reflecting part 52 of the laser length measuring device 5 are installed. The movable support plate 13 is also provided with a stopper (not shown) that fixes it at any position on the guide rail 11.

[0034] (First pulley 2 and second pulley 3) As shown in Figures 1 and 3, the first pulley 2 and the second pulley 3 are the same type of pulleys, and are fixed to a fixed support plate 12 and a movable support plate 13, respectively, so that the line connecting the central axis of the first pulley 2 and the central axis of the second pulley 3 is parallel to the guide rail 11. The first pulley 2 and the second pulley 3 preferably have a large pulley diameter so that the conveyor belt 4 can easily fit around the first pulley 2 and the second pulley 3 and improve measurement accuracy. On the other hand, the pulley diameter is preferably small so that the conveyor belt 4, which has a short length in the belt circumferential direction, can be measured. Therefore, the outer diameters of the first pulley 2 and the second pulley 3 are preferably in the range of about 20 mm to 100 mm. The shapes of the first pulley 2 and the second pulley 3 do not necessarily have to be circular, but may be semicircular or a partially cut-out circular shape (see Alternative Embodiment 4 described later).

[0035] Furthermore, from the viewpoint of separately measuring the circumferential lengths of both ends (ends 41, 42) of the conveyor belt 4 in the width direction by winding only one end 41 or only the other end 42 between the first pulley 2 and the second pulley 3, it is preferable that the outer periphery width length PH (axial length) of each of the first pulley 2 and the second pulley 3 be short. On the other hand, if the outer periphery width PH is too short, the conveyor belt 4 is likely to come off the first pulley 2 and the second pulley 3, making measurement difficult. Therefore, it is preferable that the outer periphery width length PH (axial length) of each of the first pulley 2 and the second pulley 3 be 5 mm or more and half or less of the total width (belt width) of the conveyor belt 4 (see FIG. 3). For example, if the conveyor belt 4 has a belt width of 20 to 350 mm, the outer periphery width length PH of each of the first pulley 2 and the second pulley 3 is preferably in the range of 5 to 50 mm, particularly 10 to 20 mm.

[0036] Even if the widthwise length PH of each of the outer peripheries of the first pulley 2 and the second pulley 3 is long, the purpose of separately measuring the circumferential lengths of both ends (ends 41, 42) of the conveyor belt 4 in the widthwise direction can be achieved by winding the end 41 (or end 42) of the conveyor belt 4 only around the tip portions of the first pulley 2 and the second pulley 3. However, since it is necessary to adjust the extent of the belt width to be wound around the first pulley 2 and the second pulley 3, it is preferable that the widthwise length PH of each of the outer peripheries of the first pulley 2 and the second pulley 3 is sufficiently short compared to the belt width of the conveyor belt 4. If the widthwise length PH of each of the outer peripheries of the first pulley 2 and the second pulley 3 is sufficiently short, even if the conveyor belt 4 is wound around the first pulley 2 and the second pulley 3, only the end 41 (or end 42) of the conveyor belt 4 is wound around the first pulley 2 and the second pulley 3, improving workability.

[0037] (Pressing members 61 to 64) The pressing members 61 to 64 are cylindrical and have a height greater than the belt width of the conveyor belt 4. In this embodiment, the pressing members 61 to 64 (four members) have the same specifications (diameter 10 mm, height 100 to 500 mm). The pressing members 61 to 64 are fixed to the fixed support plate 12 and the movable support plate 13, respectively, at positions where they contact and press the outer periphery of the conveyor belt 4 wound between the first pulley 2 and the second pulley 3 in the belt width direction from end 41 to end 42.

[0038] Specifically, as shown in FIG. 4, the pressure members 61 to 64 are arranged at a distance on the outer circumferential side of the conveyor belt 4 within a range of "thickness of conveyor belt 4 -0.5 mm" or more and "thickness of conveyor belt 4 +1.0 mm" or less (a range of 1.5 mm in the Y direction shown in FIG. 4) from the straight line CL1 or straight line CL2 (the straight line CL1 connecting the tangent points A1 and A4, and the straight line CL2 connecting the tangent points A2 and A3) connecting the tangent points of the common tangent lines of the outer periphery of the first pulley 2 and the outer periphery of the second pulley 3 around which the conveyor belt 4 is wound, and at a distance within a range of 15 mm or more and 35 mm or less from one tangent point (for example, tangent point A3) to the other tangent point (for example, tangent point A2) of the common tangent lines of the outer periphery of the first pulley 2 and the outer periphery of the second pulley 3 (a range of 15 to 35 mm in the X direction shown in FIG. 4).

[0039] According to the measuring device 1 of this embodiment, without the pressing members 61 to 64, only the end 41 (or end 42) of the conveyor belt 4 would come into contact with the first pulley 2 and the second pulley 3. This would cause the conveyor belt 4 to bulge outward at the portions where it is not in contact with the first pulley 2 and the second pulley 3, possibly resulting in a decrease in measurement accuracy (see FIG. 5). In particular, if the conveyor belt 4 has high rigidity or cannot bear a large load, the conveyor belt 4 may not be able to move sufficiently along the first pulley 2 and the second pulley 3. In such cases, the center distance C between the central axis of the first pulley 2 and the central axis of the second pulley 3 would be shortened, causing the calculated length of the conveyor belt 4 to be shorter than it actually is. Therefore, by measuring the length of the end 41 (or end 42) of the conveyor belt 4 in the belt circumferential direction while the outer periphery of the conveyor belt 4 wound between the first pulley 2 and the second pulley 3 is contacted and pressed in the belt width direction by the pressing members 61 to 64, the conveyor belt 4 can be easily aligned with the first pulley 2 and the second pulley 3 even with a small load, thereby improving measurement accuracy (see Figure 5).

[0040] Furthermore, if the position where the outer periphery of the conveyor belt 4 is pressed is too far from the line CL1 or the line CL2 (exceeding "thickness of the conveyor belt 4 + 1.0 mm"), the conveyor belt 4 may not be pressed, or the pressing force may be weak, and the bulge of the conveyor belt 4 toward the outer periphery may not be sufficiently suppressed. On the other hand, if the position where the outer periphery of the conveyor belt 4 is pressed is too close to the line CL1 or the line CL2 (less than "thickness of the conveyor belt 4 - 0.5 mm"), the angle at which the conveyor belt 4 wraps around the first pulley 2 or the second pulley 3 may become too large, which may result in a decrease in measurement accuracy. Therefore, the above problem was solved by setting the position where the outer periphery of the conveyor belt 4 is pressed in contact with the belt width direction within the above range.

[0041] (Laser length measuring device 5) The laser length measuring device 5 is made up of a laser transmitting / receiving unit 51 and a reflecting unit 52, and is capable of measuring the center distance C between the center axis of the first pulley 2 and the center axis of the second pulley 3 and transmitting the measured value to the computing device 15. Note that the laser length measuring device 5 may be a displacement sensor, a distance sensor, a time-of-flight system, or the like, or an encoder (rotary type, magnetic type) may be used to measure the center distance C.

[0042] (Load applying mechanism 14) 1, the load-applying mechanism 14 is composed of a wire 141, three pulleys 142, and a weight 143. The movable support plate 13 is attached to one end of the wire 141, and the weight 143 can be attached to the other end of the wire 141 via the three pulleys 142. By changing the weight of this weight, a predetermined tension can be applied to the conveyor belt 4 wound between the first pulley 2 and the second pulley 3. Note that the load-applying mechanism 14 may be a mechanism that combines air or hydraulic pressure with a load cell.

[0043] (Arithmetic unit 15) In this embodiment, the arithmetic device 15 is a personal computer, and when operated by a user, it can receive data from the laser length measuring device 5, input various data and requests, store and save data, and perform calculations. The arithmetic device 15 may be used by connecting (combining) other measuring devices such as a positioning counter to a personal computer or the like. The arithmetic device 15 has a control unit 151, a memory unit 152 (storage device), an input unit 153, and a display unit 16 for external output.

[0044] The control unit 151 controls the computer in the arithmetic unit 15 (CPU, etc.). The storage unit 152 is composed of a ROM (Read Only Memory) in which a system program is stored, a RAM (Random Access Memory) which is a rewritable storage area, a flash memory, etc. In this embodiment, the storage unit 152 is capable of storing information such as the center distance C measured by the laser length measuring device 5, the outer diameter D of the pulleys, and the pitch height a of the conveyor belt 4, and also stores a program (described later) for calculating the length of the conveyor belt 4 in the belt circumferential direction. The input unit 153 is an operating device for a user to input various types of data, requests, and commands, and may be, for example, a touch panel. The display unit 16 displays information based on commands from the control unit 151 .

[0045] (Conveyor belt 4) In this embodiment, the conveyor belt 4, whose circumferential length is to be measured, has a structure in which a resin layer 4A is laminated on the outer periphery and a core canvas layer 4B is laminated on the inner periphery, as shown in FIG. 6. The length connecting the pitch height a (for example, the center position of the core canvas layer 4B), which corresponds to the tension-bearing portion of the conveyor belt 4 in the belt thickness direction, is defined as the pitch circumference Lp. The conveyor belt 4 is not limited to a two-layer structure as in this embodiment, but may also have a three-layer or higher structure in which resin layers and core canvas layers are alternately laminated, and the structure is not particularly limited. The pitch height a, which determines the pitch circumference Lp, is determined accordingly, since the position of the tension-bearing portion varies depending on the structure and specifications of the conveyor belt 4.

[0046] (Measurement processing (method)) Next, a measurement process (method) for measuring the length in the belt circumferential direction of one end 41 (or the other end 42) in the belt width direction of the conveyor belt 4 using the measuring device 1 will be described.

[0047] The conveyor belt 4 used had a belt width of 100 mm, a belt thickness of 1.14 mm, and a pitch height a of 0.29 mm. The presser members 61 to 64 had a diameter of 15 mm and a height of 250 mm, and were positioned 1.5 mm toward the outer periphery of the conveyor belt 4 from CL1 (or CL2), and 15 mm from one tangent point A3 (or tangent point A4) of the common tangent between the outer periphery of the first pulley 2 and the outer periphery of the second pulley 3 to the other tangent point A2 (or tangent point A1). The outer diameter D of the first pulley 2 and the second pulley 3 was 40 mm, and the length PH of the outer periphery in the width direction was 10 mm.

[0048] (Enter the required information) First, the user uses the input unit 153 of the calculation device 15 of the measuring device 1 to store information such as the outer diameter D (e.g., 40 mm) of the first pulley 2 (second pulley 3 having the same specifications as the first pulley 2) and the pitch height a (0.29 mm) of the conveying belt 4 in the memory unit 152.

[0049] (Wrapping of end 41 of conveyor belt 4) Next, only one end 41 of the conveyor belt 4 to be measured in the belt width direction is wound between the first pulley 2 and the second pulley 3. At this time, the conveyor belt 4 is wound so that the outer periphery thereof comes into contact with the pressing members 61 to 64 (see FIGS. 2 and 3). As a result, the widthwise length PH (10 mm) of each outer periphery of the first pulley 2 and the second pulley 3 is 5 mm or more and half the belt width (50 mm) or less of the conveying belt 4, so the conveying belt 4 is less likely to come off the first pulley 2 and the second pulley 3, and the circumferential length of only the end 41 of the conveying belt 4 can be measured. Furthermore, the outer periphery of the conveyor belt 4 wound between the first pulley 2 and the second pulley 3 can be brought into contact with and pressed in the width direction by the pressing members 61 to 64, so that the length of the end 41 of the conveyor belt 4 in the belt circumferential direction can be measured with high accuracy.

[0050] (Applying tension to conveyor belt 4) Next, in the load-applying mechanism 14, a weight 143 of a predetermined weight is attached to the wire 141, and the movable support plate 13 is pulled, thereby applying a predetermined tension to the conveyor belt 4 wound between the first pulley 2 and the second pulley 3 (see Figures 2 and 3).

[0051] (Calculation of the length of the end 41 of the conveyor belt 4 in the belt circumferential direction) Next, with a predetermined tension applied to the conveyor belt 4, the laser length measuring device 5 measures the center distance C between the central axis of the first pulley 2 and the central axis of the second pulley 3 in response to a command from the computing device 15 by the user. The measured center distance C is then transmitted to the computing device 15 and stored in the memory unit 152.

[0052] Next, the calculation device 15 calculates the length Li of the end 41 of the conveyor belt 4 in the belt circumferential direction by program processing based on the value of the center distance C, the value of the outer diameter D of the first pulley 2 and the second pulley 3 stored in the memory unit 152, and the following (Equation 1). Li = 2C + πD (Eq. 1) For example, if C=369.2 mm and D=40 mm, the length Li of the end 41 of the conveyor belt 4 in the belt circumferential direction is calculated as Li=864 mm. The length connecting the outer peripheries of the first pulley 2 and the second pulley 3 (the inner periphery length of the conveyor belt 4) can be calculated using the above (Equation 1).

[0053] In addition, as a more practical length of the conveying belt 4, the pitch circumference length Lp can also be calculated, which is the length connecting the pitch height a (in this embodiment, for example, the center position of the core canvas layer 4B), which is the position corresponding to the tension-bearing portion of the conveying belt 4 in the belt thickness direction. Specifically, the calculation device 15 calculates the pitch circumference Lp of the end 41 of the conveyor belt 4 by program processing based on the value of the center distance C, the value of the outer diameter D of the first pulley 2 and the second pulley 3, the value of the pitch height a, and the following (Equation 2), all of which are stored in the memory unit 152. Lp=2C+π(D+2a)=Li+2aπ...(Formula 2) For example, if C=369.2 mm, D=40 mm, and a=0.29 mm, the pitch circumference length Lp of the end 41 of the conveyor belt 4 is calculated as Lp=865.9 mm.

[0054] In addition, when determining the outer circumferential length of the conveyor belt 4, the value of the thickness of the conveyor belt 4 is substituted for the value of the pitch height a, and the calculation can be performed based on (Equation 2).

[0055] The calculated length Li of the end 41 of the conveyor belt 4 in the belt circumferential direction and the calculated pitch circumference Lp of the end 41 of the conveyor belt 4 are stored in the memory unit 152 and displayed on the display unit 16 (see Figure 2).

[0056] (Calculation of the length of the end 42 of the conveyor belt 4 in the belt circumferential direction) Next, using a procedure similar to the method for measuring the circumferential length Li of the end 41 of the conveyor belt 4, etc., the circumferential length Li of the end 42 of the conveyor belt 4 and the pitch circumferential length Lp of the end 42 of the conveyor belt 4 are calculated, stored in the memory unit 152, and displayed on the display unit 16.

[0057] (Conveyor belt 4 pass / fail judgment) Next, the calculation device 15 calculates the difference between the length Li of the end 41 of the conveyor belt 4 in the belt circumferential direction and the length Li of the end 42 of the conveyor belt 4 in the belt circumferential direction. Then, if the calculated difference is equal to or less than a predetermined threshold value that has been set in advance, the arithmetic unit 15 determines that the test is pass, and displays a message to that effect on the display unit 16. On the other hand, if the calculated difference exceeds a predetermined threshold, the arithmetic unit 15 determines that the test is unacceptable and displays a message to that effect on the display unit 16. This allows the difference in the length in the belt circumferential direction between both ends 41, 42 in the belt width direction of the conveyor belt 4 to be calculated, and based on this difference, it is possible to automatically determine whether the length in the belt circumferential direction at both ends 41, 42 in the belt width direction required for the conveyor belt 4 is appropriate. This improves convenience for the person making the measurement.

[0058] In determining whether the conveyor belt 4 passes or fails, if the calculated difference is less than a predetermined threshold set in advance, the conveyor belt 4 may be determined to pass, and a message indicating this may be displayed on the display unit 16. In addition, if the calculated difference is equal to or greater than a predetermined threshold, the conveyor belt 4 may be determined to fail, and a message indicating this may be displayed on the display unit 16. The handling of the threshold value for determining whether the conveyor belt 4 passes or fails (selection of less than the threshold, less than the threshold, greater than the threshold, or more than the threshold) can be set as desired, and is a change within the scope of the same configuration of the present invention.

[0059] According to the above-mentioned measuring device 1 and measuring method, by separately measuring the circumferential length of both ends 41, 42 of the width direction of the conveyor belt 4 having a predetermined width, it is possible to detect the difference in the circumferential length of the conveyor belt 4 at both ends 41, 42 of the width direction of the conveyor belt 4, which causes the conveyor belt 4 to run unevenly.

[0060] (Other embodiment 1) In the above embodiment, the lengths in the belt circumferential direction of both ends 41, 42 in the width direction of the conveyor belt 4 having a predetermined width are measured separately, but only the center distance C between the central axis of the first pulley 2 and the central axis of the second pulley 3 at both ends 41, 42 in the width direction of the conveyor belt 4 may be measured separately. In other words, the belt circumferential length is a concept that includes not only the length of one revolution of the conveyor belt 4 in the belt circumferential direction, but also the length of only the center distance. In this case, the difference between the center distance C of the end 41 of the conveyor belt 4 and the center distance C of the end 42 of the conveyor belt 4 is calculated, and if the calculated difference is equal to or less than a predetermined threshold value for the center distance set in advance (or less than the predetermined threshold value), it is determined to be pass, and a message to that effect is displayed on the display unit 16. On the other hand, if the calculated difference exceeds a predetermined threshold value for the center distance set in advance (or is equal to or greater than the predetermined threshold value), it is determined to be fail, and a message to that effect is displayed on the display unit 16. This allows the pass / fail judgment of the conveyor belt 4 to be performed simply without going through the calculations related to (Equation 1) and (Equation 2) above.

[0061] (Other embodiment 2) The load applying mechanism 14 of the measuring device 1 of the above embodiment has a simple configuration in which the movable support plate 13 is attached to one end of the wire 141 and a weight 143 can be attached to the other end of the wire 141. In this case, if it is desired to be able to measure conveyor belts 4 from short to long, the vertical movement distance of weight 143 must also be increased, which may limit the installation location of measuring device 1. Therefore, the load applying mechanism 114 of the measuring device 1 may be configured to be able to switch between connecting and disconnecting the weight 143 and the movable support plate 13.

[0062] Specifically, as shown in FIG. 9, the load-applying mechanism 114 mainly comprises a wire 141, three pulleys 142, a weight 143, an air cylinder 144, a shaft 145, a connecting member 146, a carriage 147, and a set collar 148 with a clamp lever attached to the underside of the movable support plate 13 (parts other than the lever are not shown).

[0063] A carriage 147 that is movable on the guide rail 11 is attached to the underside of the connecting member 146, and one end of the wire 141 and one end of the shaft 145 are further connected to the connecting member 146. This allows the shaft 145, connecting member 146, carriage 147, wire 141, and weight 143 attached to the other end of the wire 141 to move integrally (load applying portion).

[0064] Furthermore, a set collar 148 with a clamp lever is attached to the underside of the movable support plate 13, and the shaft 145 passes through the set collar. This set collar 148 with a clamp lever can connect and fix the shaft 145 and the movable support plate 13 by tightening the clamp lever to the shaft 145. This allows the load-applying parts such as the weight 143 and the movable support plate 13 to move integrally on the guide rail 11. Note that when the clamp lever is loosened, the movable support plate 13 is detached from the shaft 145, and the movable support plate 13 can move on the guide rail 11 independently of the load-applying parts such as the weight 143.

[0065] When air is applied to the air cylinder 144, the cylinder is extended to press the connecting member 146, and the connecting member 146 can be moved toward the fixed support plate 12. When air is released from the air cylinder 144, the cylinder is contracted to release the pressure on the connecting member 146.

[0066] Next, a method for applying tension to the conveyor belt 4 by the load applying mechanism 114 will be described. (1) By applying air to the air cylinder 144, the cylinder is extended and presses the connecting member 146, thereby lifting up the weight 143 (see FIG. 10). (2) Loosen the clamp lever of the clamp lever-equipped set collar 148 and move the movable support plate 13 to a position slightly shorter than the axial distance between the first pulley 2 and the second pulley 3 when measuring the circumferential length of the end 41 of the conveying belt 4 (when a predetermined tension is applied) (see Figure 10). (3) The clamp lever of the set collar 148 with clamp lever is tightened to connect and fix the shaft 145 and the movable support plate 13 (see FIG. 10). (4) After wrapping one end 41 of the conveyor belt 4 in the belt width direction between the first pulley 2 and the second pulley 3, the air is released from the air cylinder 144 to contract the cylinder and release the pressure of the connecting member 146, and the load of the weight 143 is applied to the conveyor belt 4 via the shaft 145 (see Figure 11).

[0067] With a measuring device equipped with the load-applying mechanism 114, the movement distance of the weight 143 only needs to be the extension / contraction distance of the air cylinder 144, regardless of the length of the conveyor belt 4. This makes it possible to measure the length of the conveyor belt 4 by placing the measuring device on a table, thereby increasing the flexibility of the installation location.

[0068] Regarding steps (2) and (4) above, when roughly adjusting the center distance between the first pulley 2 and the second pulley 3, if the approximate length of the conveyor belt 4 is known, the above steps will be followed. However, if the approximate length of the conveyor belt 4 is not known, in step (2), the end 41 of the conveyor belt 4 is wound between the first pulley 2 and the second pulley 3 while the movable support plate 13 is moved to an appropriate position, and in step (4), only the operation of retracting the air cylinder 144 by releasing the air is performed.

[0069] (Other embodiment 3) Some conveyor belts have anti-snaking bars on the inner circumferential surface of the conveyor belt along the belt circumferential direction, such as at the center of the belt width along the belt circumferential direction, or at both ends of the belt width along the belt circumferential direction. Therefore, when measuring the circumferential length of the end of a conveying belt having anti-snake bars provided at both ends along the circumferential direction of the belt, in order to prevent interference between the anti-snake bars and the first and second pulleys, instead of fixing the first pulley 2 and the second pulley 3 to the fixed support plate 12 and the movable support plate 13, respectively, a structure may be used in which the first pulley 2 and the second pulley 3 are inserted and removed from shafts 71 and 81 provided on the fixed support plate 12 and the movable support plate 13, respectively, as shown in Figure 12 (a mechanism that allows the axial positions of the first pulley 2 and the second pulley 3 to be adjusted).

[0070] Specifically, as shown in Figure 12, a stopper 72 (stopper 82) of an appropriate size corresponding to the height of the anti-snake bar is placed under the first pulley 2 (second pulley 3) that is inserted into the shaft 71 (shaft 81) of the fixed support plate 12 (movable support plate 13), and fixed with a key 73 (key 83), thereby preventing interference between the anti-snake bar and the first pulley 2 (second pulley 3) and making it possible to measure the circumferential length of the end of the conveying belt. Simply increasing the position at which the first pulley 2 (second pulley 3) is fixed makes it difficult to measure the circumferential length of the end of a narrow conveying belt. However, by adjusting the axial position of the first pulley 2 (second pulley 3) by the presence, size, and number of the cam 72 (cam 82), it becomes possible to freely measure the circumferential length of the end of any conveying belt.

[0071] (Other embodiment 4) In the above embodiment, the measuring device 1 using the circular first pulley 2 and second pulley 3 has been described (see FIG. 2). However, the shapes of the first pulley 2 and the second pulley 3 may be such that the first pulley 2 has a cutout portion 21 and the second pulley 3 has a cutout portion 31, as shown in Figure 13, in which part of a circle is cut out in an arch shape. According to this, when the cutout portion 21 of the first pulley 2 and the cutout portion 31 of the second pulley 3 are opposed to each other, the axial distance between the first pulley 2 and the second pulley 3 can be made shorter than in the case of a circular first pulley 2 and second pulley 3, and therefore even a short conveying belt 4 can be measured.

[0072] In addition, in the case of the structure described in Other embodiment 3 above, in which the first pulley 2 and the second pulley 3 are inserted and removed from the shaft 71 and the shaft 81 provided on the fixed support plate 12 and the movable support plate 13, respectively, as shown in Figure 13, it is preferable that the hole in the first pulley 2 (second pulley 3) through which the shaft 71 (shaft 81) passes is provided at a position opposite the cutout portion 21 (cutout portion 31), and the first pulley 2 (second pulley 3) covers the entire outer circumference of the shaft 71 (shaft 81). [Example]

[0073] Example 1 To evaluate the measurement accuracy of the above-mentioned measuring device, the circumferential lengths of 217 conveyor belts, each with a width of 20 to 350 mm, a circumferential length of 360 to 2070 mm, and a thickness of 0.8 to 2.6 mm, were measured using the measuring device and compared with the circumferential lengths measured by the manual method described in the prior art (a method in which the length of the flat portion is continuously measured using a metal ruler). The measuring device was configured as follows: First and second pulleys: outer diameter D 40 mm, outer width PH 10 mm Presser foot: diameter 15mm x height 250mm Position of the pressing member: 1.5 mm from CL1 (or CL2) to the outer periphery of the conveyor belt, and 15 mm from one contact point A3 (or contact point A4) of the common tangent line between the outer periphery of the first pulley and the outer periphery of the second pulley to the other contact point A2 (or contact point A1). Weight: 1.0kgf Length measuring device: rotary encoder (Mutoh Industries Ltd.) Calculation device: Positioning counter Figure 7(A) shows the difference between the "length measured by the measuring device" and the "length measured manually" in a bar graph. According to this, there was no significant difference between the "length measured by the measuring device" and the "length measured manually."

[0074] Example 2 A laser-type length measuring device (manufactured by Keyence Corporation) was used as the length measuring device, and a comparison similar to that in Example 1 was carried out. 84 conveyor belts were used, each having a belt width of 20 to 250 mm, a circumferential length of 320 to 2000 mm, and a belt thickness of 1.1 to 2.6 mm. The configuration of the measuring device was the same as in Example 1, except for the length measuring device. Figure 7(B) shows the difference between the "length measured by the measuring device" and the "length measured manually" in a bar graph. According to this, there was no significant difference between the "length measured by the measuring device" and the "length measured manually."

[0075] (Comparison of measurement times) It took 21 seconds to manually measure and record the length of a conveyor belt with a circumferential length of 1,200 mm, but using the measuring device it only took 9 seconds, demonstrating that a significant time reduction is possible. [Explanation of symbols]

[0076] 1. Measuring equipment 2 No. 1 pulley 3 No. 2 pulley 4 conveyor belt 5 Laser length measuring device 11 Guide rail 12 Fixed support plate 13 Movable support plate 14 Load application mechanism 15 Arithmetic unit 16 Display section 61~64 Retaining member

Claims

1. a step of hooking one end of the conveyor belt in the width direction between pulleys, and measuring the length of the one end in the belt circumferential direction while contacting and pressing the outer periphery of the conveyor belt wound between the pulleys in the width direction with a linear pressing member; a step of hooking the other end of the conveyor belt in the width direction between the pulleys, and measuring the length of the other end in the belt circumferential direction while contacting and pressing the outer periphery of the conveyor belt wound between the pulleys in the width direction of the conveyor belt with the pressing member; Including, A method for measuring the circumferential length of a conveyor belt, wherein the position at which the pressing member contacts and presses the outer periphery of the conveyor belt wound between the pulleys in the width direction of the conveyor belt is at a distance within a range of "thickness of the conveyor belt - 0.5 mm" or more and "thickness of the conveyor belt + 1.0 mm" or less from a straight line connecting the contact points of the common tangents of the two pulleys around which the conveyor belt is wound, on the outer periphery side of the conveyor belt.

2. calculating a difference between the measured length of one end of the conveyor belt in the circumferential direction of the belt in the width direction and the measured length of the other end of the conveyor belt in the circumferential direction of the belt in the width direction; determining that the test piece is acceptable when the calculated difference is equal to or smaller than a predetermined threshold value, and determining that the test piece is unacceptable when the calculated difference is greater than the predetermined threshold value; The method for measuring the length of a conveyor belt in a circumferential direction of the belt according to claim 1, comprising:

3. 2. The method for measuring the circumferential length of a conveyor belt according to claim 1, wherein the length of the outer periphery of the pulley in the width direction is 5 mm or more and is half or less of the overall width of the conveyor belt.

4. 2. A method for measuring the circumferential length of a conveyor belt according to claim 1, wherein the circumferential lengths of both ends of the conveyor belt in the width direction at the pitch height positions are measured, taking into account the pitch heights, which are positions corresponding to the tension-bearing portions of the conveyor belt in the belt thickness direction, as stored in a storage device.

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