Conveyor belt

Abstract

To provide a conveyor belt that can suppress meandering and stably transport materials. [Solution] The conveyor belt 10 comprises a resin layer 11 having a roller contact surface 11b that the rollers contact, and a knitted fabric 12 having a conveying surface 12a with a lower coefficient of dynamic friction than the resin layer 11, on which the conveyed object is placed. Preferably, the resin layer 11 has a coefficient of dynamic friction of 0.5 or more on the roller contact surface 11b. As a result, when the conveyor belt 10 rotates, the roller contact surface 11b is less likely to slip on the multiple rollers, which suppresses meandering on the rollers and allows for more stable conveyance of the conveyed object.

Description

Technical Field

[0001] The present invention relates to a conveyor belt.

Background Art

[0002] In recent years, due to the diversification of the shapes of conveyed objects, a conveyor belt is stretched over an existing roller conveyor that conveys the conveyed object with a plurality of rollers, and the conveyor belt is rotated by the rollers to convey the conveyed object placed on the conveyor belt. A belt conveyor is known (for example, see Patent Document 1). In a belt conveyor, since a roller conveyor that does not assume the use of a conveyor belt is used, the roller conveyor does not have a belt adjustment mechanism, and an endless belt called an elastic belt having stretchability and elasticity is used for the conveyor belt.

[0003] In addition to the roller conveyor that horizontally conveys the conveyed object, various roller conveyors such as a roller conveyor that goes up and down an incline and a roller conveyor that moves the conveyed object to the end are considered for the existing roller conveyor, and it is necessary to use an optimal conveyor belt according to the form of the roller conveyor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] For example, when moving transported items, such as those packaged in cardboard boxes or plastic containers, to the edge of the transport surface, or when sliding transported items on the transport surface, it is preferable to use a transport belt with a low coefficient of dynamic friction and excellent sliding properties. However, on the other hand, because the transport belt becomes more prone to slipping on multiple rollers, the transport belt may meander, and it may not be possible to transport the transported items stably when moving them on the transport surface.

[0006] This invention has been made in view of the above problems, and aims to provide a conveying belt that can suppress meandering and stably convey materials. [Means for solving the problem]

[0007] The conveying belt of the present invention is a conveying belt stretched over a plurality of rotatable rollers, comprising: a resin layer having a roller contact surface in contact with the rollers; and a woven fabric having a conveying surface with a lower coefficient of dynamic friction than the resin layer, on which the conveyed object is placed, wherein the resin layer has a coefficient of dynamic friction of 0.5 or more on the roller contact surface. [Effects of the Invention]

[0008] According to the present invention, meandering can be suppressed and conveyed materials can be transported stably. [Brief explanation of the drawing]

[0009] [Figure 1] This is a top view showing the configuration of a belt conveyor using a conveying belt according to the present invention. [Figure 2] This is a cross-sectional view showing the cross-sectional configuration of the conveying belt according to the first embodiment. [Figure 3] This is a top view showing the configuration of a conventional belt conveyor that does not use roller conveyors. [Figure 4] This is a cross-sectional view showing the cross-sectional configuration of the conveying belt according to the third embodiment. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described in detail below with reference to the drawings. The same reference numerals are used for identical components, and redundant descriptions are omitted.

[0011] (1) First Embodiment <Conveyor Belt Configuration> Figure 1 is a top view showing the configuration of a belt conveyor 1 equipped with a conveying belt 10 according to this embodiment. The belt conveyor 1 has a plurality of parallel rollers 2 arranged at predetermined intervals between parallel frames 3. Each roller 2 is made of a metal material such as stainless steel (SUS) and is rotatably mounted relative to the frame 3. An endless conveying belt 10 is stretched over the plurality of rollers 2. The conveying belt 10 is wrapped around one roller 2 located furthest downstream in the conveying direction of the conveyed object (for example, the left end in Figure 1) and the other roller 2 located furthest upstream (in this case, the right end in Figure 1), and is stretched over the plurality of rollers 2 from one roller 2 to the other. Note that the rollers 2 may be configured with annular sleeves made of an elastic material.

[0012] In the belt conveyor 1, for example, a predetermined roller 2 among a plurality of rollers 2 is rotated by a power source such as a drive motor (not shown), and the conveying belt 10 rotates as the rollers 2 rotate. In the belt conveyor 1, the surface of the conveying belt 10 becomes a conveying surface 12a on which conveyed objects (not shown) are placed, and the conveying belt 10 rotates in one direction, causing the conveyed objects on the conveying surface 12a to move in one direction. At this time, the conveyed objects are pushed by an arm (not shown), etc., and move (slid) along the width direction of the conveying belt 10 on the rotating conveying surface 12a, and are brought to a predetermined position such as one end of the conveying surface 12a in the belt width direction.

[0013] Examples of belt conveyors that slide conveyed objects on the conveying surface 12a include belt conveyors with a dispensing mechanism, belt conveyors with a width adjustment mechanism such as a skew conveyor, belt conveyors that slide heavy objects in the belt width direction, and belt conveyors with a stopper mechanism. The conveying belt 10 according to this embodiment is particularly preferably used in a belt conveyor that slides conveyed objects on the conveying surface 12a in this manner.

[0014] <Structure of the conveyor belt> Next, the conveyor belt 10 according to the first embodiment will be described. As shown in Figure 2, the conveyor belt 10 consists of a resin layer 11 and a knitted fabric 12, with the knitted fabric 12 laminated on the resin layer 11. In this case, the back surface 12b of the knitted fabric 12 is fixed to the surface 11a of the resin layer 11, and the resin layer 11 and the knitted fabric 12 are integrated. The exposed flat surface of the knitted fabric 12 of the conveyor belt 10 becomes the conveying surface 12a on which the conveyed object is placed. The exposed back surface of the resin layer 11 of the conveyor belt 10 becomes the back surface of the conveyor belt 10 and becomes the roller contact surface 11b that contacts the outer circumferential surface of each roller 2. The conveyor belt 10 according to this embodiment has optimal elasticity and flexibility so that it can be used as an elastic belt that can be stretched over the rollers 2 of an existing roller conveyor.

[0015] The thickness (total thickness) of the conveyor belt 10 is preferably 0.4 mm or more and 3.0 mm or less, and more preferably 0.6 mm or more and 2.0 mm or less. In the following description, the left-right direction in Figure 2 is defined as the conveying direction of the conveyor belt 10, and the depth direction of the paper in Figure 2 is defined as the width direction of the conveyor belt 10 perpendicular to the conveying direction. The same applies to the descriptions of other embodiments described later.

[0016] <Resin layer> The resin layer 11 has a structure in which the roller contact surface 11b, which is exposed to the outside and in contact with the roller 2, is formed smoothly. The resin layer 11 is made of a flexible resin such as an ether-based thermoplastic polyurethane resin, an ester-based polyurethane resin, or a polycarbonate-based urethane resin. Furthermore, it is preferable that the resin layer 11 has a durometer hardness of A85 or less even at 23°C, which is equivalent to room temperature. This durometer hardness A is an index that indicates the hardness of rubber, thermoplastic elastomers, etc., and in JIS K7311, it is measured using a durometer type A. By making the resin layer 11 have a durometer hardness of A85 or less at 23°C, flexibility can be imparted to the resin layer 11 itself. Because the resin layer 11 that contacts the roller 2 of the conveyor belt 10 has flexibility, the adhesion between the roller contact surface 11b of the resin layer 11 and the outer surface of the roller 2 can be improved, and meandering can be further suppressed.

[0017] Furthermore, the thermoplastic resin constituting the resin layer 11 may be, for example, a thermoplastic resin having a glass transition temperature of -30°C or lower. In addition, the thermoplastic resin constituting the resin layer 11 may be a thermoplastic resin with a durometer hardness of A85 or lower as specified in JIS K7311 at -30°C. The resin layer 11 can be formed from a resin that has sufficient flexibility even in low-temperature environments where resins are generally considered to harden easily, thereby maintaining sufficient flexibility even at room temperature.

[0018] In this case, for example, the conveying belt 10 according to this embodiment can be used in a belt conveyor used in a low-temperature environment. If the resin layer 11 has a durometer hardness of A85 or less at -30°C, the conveying belt 10 will not harden even in a low-temperature environment of -30°C, and furthermore, it can convey objects while suppressing meandering. In addition, since the conveying belt 10 does not harden even in a low-temperature environment of -30°C, even if it is stretched on the roller 2 in a low-temperature environment, the load on the drive motor of the belt conveyor 1 and the roller 2 can be reduced, damage to the drive motor etc. can be prevented, and objects can be conveyed stably even in a low-temperature environment.

[0019] The resin layer 11 preferably has a kinetic friction coefficient of 0.5 or more on the roller contact surface 11b, and more preferably 0.6 or more. By setting the kinetic friction coefficient of the roller contact surface 11b of the conveyor belt 10 to 0.5 or more, it becomes difficult to slip on the outer peripheral surface of the roller 2, and meandering during running can be suppressed. Further, by setting the kinetic friction coefficient of the roller contact surface 11b of the conveyor belt 10 to 0.5 or more, for example, even if an external force is generated on the belt surface side as the conveyed object on the conveyance surface 12a is pushed by an arm or the like and the conveyed object slides and moves on the conveyance surface 12a, meandering on the roller 2 can be suppressed. Furthermore, by setting the kinetic friction coefficient of the roller contact surface 11b of the conveyor belt 10 to 0.6 or more, meandering can be suppressed even when various conveyed objects are slid and moved on the conveyance surface 12a. Although the roller contact surface 11b of the resin layer 11 is formed smoothly, due to the characteristics of the material, the kinetic friction coefficient is 0.5 or more even if the roller contact surface 11b is formed smoothly. Since the roller contact surface 11b of the resin layer 11 is formed smoothly, the adhesion with the outer peripheral surface of the roller 2 can be improved, and meandering during running can also be suppressed thereby.

[0020] The kinetic friction coefficient is preferably measured by the following method. The kinetic friction coefficient is preferably measured using a friction coefficient measuring machine (HEIDON-14D manufactured by Shin-Toh Kagaku Co., Ltd.). Here, a conveyor belt 10 having a length of 60 [mm] and a width of 60 [mm] is prepared as a test piece. A plate made of SUS303 is provided on the support base (test bench) of the friction coefficient measuring machine in an environment of a temperature of 23 [°C] and a humidity of 50 [%]. The test piece is installed on the indenter of the friction coefficient measuring machine such that the roller contact surface 11b is on the lower surface, and a load of 500 [gf] (8.2 [kPa]) is applied to the test piece via the indenter. In this state, the support base provided with the plate is moved at a speed of 5 [mm / sec] in the surface direction of the roller contact surface 11b (the longitudinal direction of the test piece) so that the roller contact surface 11b slides on the plate, and the kinetic friction coefficient at that time is measured.

[0021] Measure the coefficient of kinetic friction for the roller contact surface 11b of the resin layer 11 provided on such a conveyor belt 10 a plurality of times (for example, 5 times), and obtain the average value of the measurement results of the plurality of obtained coefficients of kinetic friction. Here, the coefficient of kinetic friction obtained in this way is used as the coefficient of kinetic friction of the roller contact surface 11b.

[0022] Examples of the resin layer 11 that satisfies such performance include, for example, Pandex T-8375 (registered trademark: manufactured by DIC Covestro Polymer Co., Ltd.), which is an ether-based thermoplastic polyurethane resin. Pandex T-8375 has a durometer hardness A of 77 at 23 [°C]. Pandex T-8375 has a durometer hardness A of 85 or less at -30 [°C]. The color of the resin constituting the resin layer 11 is not particularly limited, and it may be transparent or colored and opaque. In addition, in order to ensure the strength at the joint portion of the belt end when connecting the belt ends to form an endless conveyor belt 10, the thickness dimension of the resin layer 11 is preferably 0.3 [mm] or more.

[0023] <Woven fabric> The woven fabric 12 imparts slipperiness and cut resistance to the conveying surface 12a of the conveyor belt 10. The woven fabric 12 is not particularly limited as long as it is obtained by weaving fibers. The woven fabric generally used for an elastic belt can be used as the woven fabric 12 of the conveyor belt 10 according to this embodiment. The weaving method of the woven fabric 12 may be either warp knitting or weft knitting. The fibers forming the woven fabric 12 can be selected from, for example, polyester fibers, nylon fibers, aramid fibers, glass fibers, and cotton yarns. The fibers used for the woven fabric 12 may be single or two or more different types.

[0024] The knitted fabric 12 may be impregnated with resin in the gaps between the stitches. By impregnating the knitted fabric 12 with a thermoplastic urethane resin commonly used for adhesive treatment, the adhesion to the resin layer 11 can be improved. Preferred thermoplastic urethane resins for impregnation include ether-based polyurethane resins, ester-based polyurethane resins, and polycarbonate-based urethane resins. The knitted fabric 12 can be formed by dipping or coating and impregnating it with a thermoplastic urethane resin.

[0025] The knitted fabric 12 preferably has a dynamic friction coefficient of less than 0.3 on its conveying surface 12a, and more preferably has a dynamic friction coefficient of 0.1 or more and 0.2 or less. By making the dynamic friction coefficient of the conveying surface 12a of the conveying belt 10 less than 0.3, the conveyed object placed on the conveying surface 12a becomes more likely to slide on the conveying surface 12a due to external forces, and the conveyed object can be moved to a predetermined position such as one end of the conveying surface 12a.

[0026] The coefficient of dynamic friction is preferably measured in the same manner as described above for the resin layer 11. That is, the coefficient of dynamic friction of the knitted fabric 12 is also measured using a friction coefficient measuring machine (HEIDON-14D, manufactured by Shinto Kagaku Co., Ltd.), with a plate made of SUS303 placed on the support stand (test stand) of the friction coefficient measuring machine. The test piece is placed on the indenter of the friction coefficient measuring machine with the transport surface 12a facing downwards, and a load of 500 [gf] (8.2 [kPa]) is applied to the test piece via the indenter. In this state, the support stand with the plate is moved at a speed of 5 [mm / sec] in the direction of the surface of the test piece (the longitudinal direction of the test piece), causing the transport surface 12a to slide against the plate (slid while in contact with the test piece), and the coefficient of dynamic friction at that time is measured.

[0027] The coefficient of dynamic friction of the conveying surface 12a of the knitted fabric 12 provided on the conveying belt 10 is measured multiple times (for example, 5 times), and the average value of the multiple measurement results of the coefficient of dynamic friction is calculated. Here, the coefficient of dynamic friction obtained in this way is referred to as the coefficient of dynamic friction of the conveying surface 12a.

[0028] <Method for manufacturing a conveyor belt> The conveyor belt 10 can be manufactured by any method that ensures the sheet-shaped resin layer 11 and the knitted fabric 12 are fixed together and do not peel off. For example, a thermoplastic sheet to form the resin layer 11 is produced using a predetermined thermoplastic polyurethane resin with a calender or extruder. The size of the sheet is adjusted to match the size of the knitted fabric 12. The sheet can then be fixed to the knitted fabric 12 using thermoplastic resin.

[0029] The knitted fabric 12 is pre-impregnated with a thermoplastic resin. The thermoplastic resin can be impregnated into the knitted fabric 12 using an application method such as a coater or brush. Alternatively, the knitted fabric 12 may be immersed in the thermoplastic resin to impregnate it. The knitted fabric 12 impregnated with thermoplastic resin is placed on the resin layer 11 and the two are fixed together under heat and pressure conditions. By performing heat and pressure bonding, the resin layer 11 and the knitted fabric 12 are fixed together, and a conveyor belt 10 can be manufactured in which the knitted fabric 12 is laminated on the resin layer 11. The conveyor belt 10 thus obtained can be processed into an endless shape by joining both ends with finger joints or the like, and used as an elastic belt in roller conveyors and the like.

[0030] <Mechanism and Effects> With the above configuration, the conveying belt 10 is stretched over a plurality of rotatable rollers 2 of a roller conveyor. The conveying belt 10 comprises a resin layer 11 having a roller contact surface 11b that the rollers 2 come into contact with, and a woven fabric 12 having a conveying surface 12a with a lower coefficient of dynamic friction than the resin layer 11, on which the conveyed object is placed. Preferably, the resin layer 11 has a coefficient of dynamic friction of 0.5 or more at the roller contact surface 11b. As a result, when the conveying belt 10 rotates, the roller contact surface 11b is less likely to slip on the plurality of rollers 2, which suppresses meandering on the rollers 2 and allows for more stable conveying of the conveyed object.

[0031] Furthermore, by setting the dynamic friction coefficient of the conveying surface 12a of the conveying belt 10 to less than 0.3, the conveyed object placed on the conveying surface 12a can be easily slid and moved to a predetermined position on the conveying surface 12a by pushing it with an arm or the like as needed. In this case, since the conveying belt 10 uses a resin layer 11 on the back surface of the belt with a high dynamic friction coefficient of the roller contact surface 11b, even if an external force is generated on the belt surface side as the conveyed object moves on the conveying surface 12a, meandering on the roller 2 can be suppressed.

[0032] Here, Figure 3 is a top view showing the configuration of a conventional belt conveyor 100 that does not use roller conveyors. In a conventional belt conveyor 100 that uses a conveying belt 110, a roller 2a provided on one side in the conveying direction and a roller 2b provided on the other side are rotatably mounted on a frame 3. In a typical belt conveyor 100, a plate-shaped support plate 101 is provided to support the conveying belt 110 between the pair of rollers 2a and 2b that are arranged in parallel, in order to prevent the conveying belt 110 from sagging.

[0033] In this case, the conveyor belt 110 is stretched over rollers 2a, 2b and a support plate 101, and rotates in conjunction with the rotation of the rollers 2a, 2b. At this time, the conveyor belt 110 rotates as the roller contact surface, which is the back surface of the conveyor belt 110, slides against the flat surface of the support plate 101. As a result, a large sliding resistance is generated between the roller contact surface of the conveyor belt 110 and the support plate 101. When heavy objects are placed on the conveyor surface as conveyed objects, the weight of the conveyed objects causes the roller contact surface to come into even closer contact with the support plate 101, resulting in an even greater sliding resistance. Since the conveyor belt 110 used in conventional belt conveyors 100 runs under these conditions, it is preferable that the coefficient of dynamic friction of the roller contact surface that slides against the support plate 101 be low, and it is preferable that the coefficient of dynamic friction of the roller contact surface be less than 0.5.

[0034] When an object placed on the conveying surface 110a of the conveying belt 110 is pushed by an arm or the like to slide the object on the conveying surface 110a and move it in the width direction of the conveying belt 110, the low coefficient of dynamic friction of the roller contact surface may cause the object to meander on the rollers 2a, 2b and support plate 101 due to the external force generated as the object moves on the conveying surface 110a. For this reason, the conveying belt 110 used in conventional belt conveyors 100 requires measures such as providing lagging on the drive rollers or pulleys that supply rotational power to the conveying belt 110 in order to suppress meandering.

[0035] In contrast, the conveying belt 10 according to this embodiment is designed to be used only by being stretched over a plurality of rollers 2 that are rotatably mounted on the frame 3, so there is no need to consider sliding with the support plate. For this reason, the conveying belt 10 can have a large dynamic friction coefficient of 0.5 or more on the roller contact surface 11b. Furthermore, by making the dynamic friction coefficient of the roller contact surface 11b of the conveying belt 10 0.5 or more, when an object placed on the conveying surface 12a is pushed by an arm or the like to slide and move the object on the conveying surface 12a, even if an external force is generated as the object moves on the conveying surface 12a, meandering on the rollers 2 can be suppressed. In summary, the conveying belt 10 can achieve a high meandering suppression function while maintaining the slipperiness of the conveying surface 12a and ensuring smooth movement of the conveyed object in the width direction.

[0036] (2) Second Embodiment In the first embodiment described above, a non-conductive conveying belt 10 was described, but the present invention is not limited thereto. Conveying belts according to other embodiments may be made conductive and have an antistatic effect. Methods for making the belt conductive include, for example, including a conductive filler in at least one of the resin layer 11 or the knitted fabric 12, or weaving conductive threads or metal wires into the threads that make up the knitted fabric 12.

[0037] The conductive filler that provides the antistatic effect is not particularly limited as long as it can be made conductive when blended into the resin constituting the resin layer 11 or the resin impregnated into the knitted fabric 12. For example, carbon-based materials such as carbon black, carbon nanotubes, carbon fibers, and graphite, or oxides such as iron and copper can be used. Carbon-based conductive fillers are particularly preferred because they have high conductivity. In addition, as conductive yarn that provides the antistatic effect, metallic yarns such as iron and copper, or carbon fibers can be used.

[0038] With the above configuration, the conveying belt 10 according to the second embodiment can also achieve the same effects as the first embodiment by having the resin layer 11 and the braided fabric 12, and furthermore, it can achieve an antistatic effect by being conductive.

[0039] (3) Third Embodiment In the first embodiment, a conveyor belt 10 consisting of a resin layer 11 and a braided fabric 12 was described, but the present invention is not limited to this, and a conveyor belt may also have other intermediate layers between the resin layer 11 and the braided fabric 12. For example, as shown in Figure 4, a conveyor belt 20 may have a conductive layer 21 as an intermediate layer between the resin layer 11 and the braided fabric 12. In this case, the conveyor belt 20 according to the third embodiment has a structure in which the resin layer 11, the conductive layer 21 and the braided fabric 12 are laminated in order from bottom to top, with the back surface 21b of the conductive layer 21 fixed to the surface 11a of the resin layer 11, and the back surface 12b of the braided fabric 12 fixed to the surface 21a of the conductive layer 21.

[0040] As the conductive layer 21, a conductive resin layer can be applied, in which conductivity is added by containing a conductive filler in the resin. In this case, the conductive layer 21 can be, for example, Pandex T-8375 (registered trademark: manufactured by DIC Covestro Polymer Co., Ltd.), which is the ether-based thermoplastic polyurethane resin mentioned above, and the conductive filler described in the second embodiment may be contained in the ether-based thermoplastic polyurethane resin.

[0041] With the above configuration, the conveyor belt 20, having the resin layer 11 and the braided fabric 12, can achieve the same effects as in the first embodiment, and the conductive layer 21 can provide an antistatic effect to the conveyor belt 20. [Explanation of symbols]

[0042] 10, 20 Conveyor belts 11 Resin layer 11b Roller contact surface 12 Knitted fabric 12a Conveying surface

Claims

1. A conveying belt stretched over multiple rotatable rollers, A resin layer having a roller contact surface that the roller contacts, A knitted cloth having a conveying surface with a coefficient of dynamic friction smaller than that of the resin layer, on which the conveyed object is placed, Equipped with, The resin layer has a coefficient of dynamic friction of 0.5 or more on the roller contact surface. A conveyor belt.

2. The coefficient of dynamic friction of the conveying surface is less than 0.

3. The conveying belt according to claim 1.

3. The aforementioned resin layer has a durometer hardness of A85 or less as defined in JIS K7311 at 23 [°C], and is flexible. The conveying belt according to claim 1.

4. Having conductivity or nonconductivity The conveying belt according to claim 1.

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