Conveyor belt

Abstract

To provide a conveyor belt capable of having through holes prevented from deforming more than before.SOLUTION: A conveyor belt 14 comprises an elastic layer 25 formed of woven fabric and first thermoplastic material provided on a top surface of the woven fabric, and a surface resin layer 22 provided on a top surface of the elastic layer 25 and formed of second thermoplastic material having less hardness than the first thermoplastic material, and a plurality of through holes 20 which penetrate the woven fabric, elastic layer 25 and surface resin layer 22 along the thickness and suck and hold a workpiece 11 mounted on the surface resin layer 22 by sucking air are formed in the woven fabric, elastic layer 25 and surface resin layer 22. The thickness of the surface resin layer 22 and distances between outer edges of adjacent through holes 20 are so selected that the conveyor belt 14 has the through holes 20 prevented from expanding in surface directions by the elastic layer 25 when expanding in surface directions of the surface resin layer 22 as the surface resin ayer 22 wears away more with a brush.SELECTED DRAWING: Figure 5

Description

[Technical field]

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

[0002] As an example of a polishing device, a deburring device that removes burrs from a workpiece is known (see, for example, Patent Document 1). In the deburring device, a workpiece having burrs formed on its upper surface is transported by a conveyor belt, and a rotating roll-shaped brush comes into contact with the workpiece from above. This removes the burrs from the workpiece. The conveyor belt used in the deburring device (hereinafter also referred to as the conveyor belt for the deburring device or simply the conveyor belt) is an endless belt with both ends joined. A plurality of brushes are provided at positions that equally divide the rotation plane centered on an axis perpendicular to the conveying surface of the conveyor belt. Each of the plurality of brushes rotates around a horizontal axis, and the plurality of brushes also rotate around the perpendicular axis, so that the plurality of brushes are pressed against the surface of the workpiece from various directions.

[0003] The conveyor belt has a plurality of through holes (penetrating holes). The through holes penetrate the thickness of the conveyor belt from the conveying surface to the back surface, and a suction device sucks air from the back surface of the conveyor belt through the plurality of through holes to generate negative pressure. The workpiece is conveyed while being adsorbed to the conveying surface.

[0004] A known conveyor belt is one that is made up of at least two layers: a core layer made of woven fabric and a surface resin layer having elasticity (see, for example, Patent Document 2). The core layer is harder than the surface resin layer. For the surface resin layer, for example, polyurethane (PU) or polyvinyl chloride (PVC) softened by adding a plasticizer is used to increase adhesion and ensure high friction on the conveying surface.

[0005] In the case where the surface resin layer is made of soft polyurethane (PU) softened by adding a plasticizer, the adhesiveness becomes strong. When forming through holes in a conveyor belt having a surface resin layer of soft PU, the thickness of the surface resin layer is required to be sufficient to tolerate wear caused by a brush. Here, 1001 in FIG. 8 shows a cross section of the conveyor belt 100 in an initial state, for example. As shown in 1001 in FIG. 8, the conveyor belt 100 includes a surface resin layer 102 having a thickness T1 (for example, 5 mm) and a resin layer 101 having a thickness T2 (for example, 2.5 mm) below the surface resin layer 102. The conveyor belt 100 is provided with a plurality of through holes 103 having a diameter φA penetrating the thickness. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2013-107139 A [Patent Document 2] Patent No. 7228953 Summary of the Invention [Problem to be solved by the invention]

[0007] However, as shown in 1002 of FIG. 8, when the workpiece 104 placed on the surface resin layer 102 is polished by a brush of a deburring device (not shown), the conveying surface 102a of the surface resin layer 102 is also polished by the brush and worn away. When the surface resin layer 102 is worn away, the through-hole 103 may widen in the thickness direction of the surface resin layer 102 or in the surface direction of the conveying surface 102a. In this case, for example, the through-hole 103 may have an inverted truncated cone-shaped funnel opening 105 formed at the opening on the conveying surface 102a side by polishing with the brush. For example, the funnel opening 105 is worn away into a large-diameter circle on the conveying surface 102a side, and the diameter gradually decreases from the large-diameter circle in the thickness direction, forming an inverted truncated cone shape that connects to the through-hole 103 of the original diameter.

[0008] In the conveyor belt 100, the funnel openings 105 on the conveying surface 102a side of the through holes 103 are worn in the thickness direction and widen in the surface direction as well, as a result of long-term use. As a result, there is a risk that adjacent funnel openings 105 may be connected to each other on the conveying surface 102a. If adjacent through holes 103 are connected to each other on the conveying surface 102a in this way, there is a risk that negative pressure will leak and the suction of the workpiece 104 will be weakened, and the holding force of the workpiece 104 required for deburring by the brush may decrease. Therefore, it is desirable that the conveyor belt used in the deburring device has a configuration that can suppress the deformation of the through holes 103. Also, in a polishing device that polishes the surface of the workpiece 104 with a brush for purposes other than deburring, such as simple polishing, the conveyor surface of the conveyor belt on which the workpiece 104 is placed is also polished with the brush in the same manner as above. Therefore, it is desirable that the conveyor belt used in various other polishing devices has a configuration that can suppress the deformation of the through holes in the same manner as above.

[0009] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a conveyor belt capable of suppressing deformation of the through holes more than ever before. [Means for solving the problem]

[0010] The conveying belt according to the present invention is a conveying belt that is installed in a polishing device that polishes the surface of a workpiece with a brush, and that suction-holds the workpiece and transports it to the brush, and comprises a woven fabric, an elastic layer made of a first thermoplastic material provided on the upper surface of the woven fabric, and a surface resin layer made of a second thermoplastic material having a hardness lower than that of the first thermoplastic material, and the woven fabric, elastic layer, and surface resin layer are formed with a plurality of through holes that penetrate through the thicknesses of the woven fabric, elastic layer, and surface resin layer and suck in air to suction-hold the workpiece placed on the surface resin layer, and by selecting the thickness of the surface resin layer and the distance between the outer edges of adjacent through holes, when the surface resin layer is worn away by the brush and the through holes expand in the surface direction of the surface resin layer, the elastic layer suppresses the expansion of the through holes in the surface direction. Effect of the Invention

[0011] According to the conveying belt of the present invention, even if the surface resin layer is worn away by the brush and the through holes become wider, the elastic layer can suppress the widening of the through holes, and accordingly, deformation of the through holes can be suppressed more than in the conventional case. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a side view showing the configuration of the deburring device. [Diagram 2] 4 is a plan view showing a configuration of a plurality of through holes formed in a conveyor belt. FIG. [Diagram 3] FIG. 2 is a cross-sectional view showing a cross-sectional configuration of a conveyor belt. [Figure 4] 10 is a plan view showing the configuration of the through holes in an initial state when viewed from above the conveying surface. FIG. [Diagram 5] These are cross-sectional views showing the deformation of the through hole of the conveyor belt of this embodiment in a chronological order, where 1011 is a cross-sectional view showing the initial state of the through hole, 1012 is a cross-sectional view showing the state of the through hole when the conveyor belt is polished by a brush, and 1013 is a cross-sectional view showing the state of the through hole when the conveyor belt is polished by a brush over a long period of time. [Figure 6] FIG. 4 is a cross-sectional view showing a cross-sectional configuration (1) of a conveyor belt according to another embodiment. [Figure 7] FIG. 11 is a cross-sectional view showing a cross-sectional configuration (2) of a conveyor belt according to another embodiment. [Figure 8] These are cross-sectional views showing deformation of a through hole that occurs in a conventional conveying belt, where 1001 is a cross-sectional view showing the initial state of the through hole, and 1002 is a cross-sectional view showing the state of the through hole when the conveying belt has been polished by a brush over a long period of time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In this specification and the drawings, substantially the same components are designated by the same reference numerals, and duplicated description will be omitted.

[0014] 1. Overview of the deburring device 1, the deburring device 10 includes a belt conveyor 12 that conveys a workpiece 11 in a conveying direction, and a brush mechanism 13 that polishes the surface of the workpiece 11. The brush mechanism 13 is disposed above the belt conveyor 12. The brush mechanism 13 includes a plurality of brushes 131 and a support shaft 132 on which each brush 131 is rotatably mounted. The brush mechanism 13 according to this embodiment has a configuration in which, for example, four brushes 131 are arranged to extend radially (in a cross shape) around the support shaft 132 in a top view of a conveying surface 14a of a conveying belt (a conveying belt for the deburring device, and simply referred to as a conveying belt) 14 described later.

[0015] The support shaft 132 is disposed with its axial direction aligned along a surface normal to the conveying surface 14a of the conveyor belt 14. The brushes 131 are rotatably provided on the peripheral surface of the tip end of the support shaft 132. The support shaft 132 is provided so as to be rotatable in the circumferential direction about the axial direction. Thus, the support shaft 132 rotates in the circumferential direction to revolve the brushes 131 extending radially from the peripheral surface.

[0016] Since each brush 131 has the same configuration, the following description focuses on one brush 131. The brush 131 is in a roll shape and rotates around an axis (core member) 13a as a rotation axis. The brush 131 has a configuration in which countless brush bristles are planted in a roll shape around the core member 13a, for example. While rotating, the brush 131 comes into contact from above with the workpiece 11 placed on the conveyor belt 14 of the belt conveyor 12. In this way, the brush 131 polishes the upper surface of the workpiece 11 and removes burrs on the upper surface.

[0017] In this manner, in the deburring device 10, the multiple brushes 131 revolve around the support shaft 132, and each brush 131 rotates individually. This allows the deburring device 10 to polish the surface of the workpiece 11 placed on the conveyor belt 14 with the brushes 131 from various directions, and to scrape off burrs on the surface of the workpiece 11.

[0018] The workpiece 11 may be, for example, a metal plate that has been subjected to hole punching. The workpiece 11 may also be a substantially plate-like member that has been punched into a desired shape by blanking (outline punching / punching), and a member made of paper, resin, metal, or non-ferrous metal having a predetermined rigidity may be applied. Burrs are protrusions or thorns (burrs or burrs) that occur when materials such as metal, non-ferrous metal, resin, wood, and paper are processed. The workpiece 11 has such burrs, for example, on the surface such as the top surface or side surface, in holes formed in the surface, on the edges of the surface, etc.

[0019] The belt conveyor 12 is composed of a conveyor belt 14, a driving roller 15, a driven roller 16, and a suction device 18. The endless conveyor belt 14 is wound around the driving roller 15 and the driven roller 16. The driving roller 15 is driven to rotate, and rotates the conveyor belt 14 between the driving roller 15 and the driven roller 16, thereby conveying the workpiece 11 placed on the conveying surface 14a of the conveyor belt 14 in the conveying direction.

[0020] The suction device 18 is disposed so as to face the brush 131 with the conveyor belt 14 interposed therebetween. More specifically, the suction device 18 is disposed on the belt back surface 14b of the conveyor belt 14 passing through the outward side (conveying side) which is the side that comes into contact with the brush 131. The suction device 18 generates negative pressure by sucking air on the conveying surface 14a side to the belt back surface 14b side through a plurality of through holes (described later) formed in the conveyor belt 14. As a result, the workpiece 11 is adsorbed to the conveying surface 14a of the conveyor belt 14. The workpiece 11 is conveyed while being adsorbed and held by the conveyor belt 14, and passes under the rotating brush 131. The surface of the workpiece 11 is polished by the rotating brush 131 as it passes through the rotating brush 131.

[0021] 2. Structure of the conveyor belt for deburring equipment <Overall structure of conveyor belt for deburring device> Next, the overall configuration of the conveyor belt 14 will be described. As shown in Fig. 3, the conveyor belt 14 includes a core layer 23 which is a lower layer, and a surface resin layer 22 provided as a cover layer (upper layer) of the core layer 23. The core layer 23 has a configuration in which a first elastic layer 25, a first woven fabric 24, a second elastic layer 26 which is an additional elastic layer, a second woven fabric 27 which is an additional woven fabric, a third elastic layer 28 which is an additional elastic layer, and a third woven fabric 29 which is an additional woven fabric are laminated in this order from the lower surface of the surface resin layer 22.

[0022] In this example, the core layer 23 is configured by laminating three layers, each of which is an elastic layer and a woven fabric provided on the lower surface thereof. The first woven fabric 24, the second woven fabric 27, and the third woven fabric 29 have a different weaving method of warp and weft threads from that of knitted fabrics, and do not have the same elasticity as the knitted fabrics. In this example, the first woven fabric 24, the second woven fabric 27, and the third woven fabric 29 are described as using woven fabrics of the same configuration, but the present invention is not limited to this. For example, different types of woven fabrics may be applied, such as by changing the materials of the warp and weft threads in the first woven fabric 24, the second woven fabric 27, and the third woven fabric 29, or by changing the thicknesses of the first woven fabric 24, the second woven fabric 27, and the third woven fabric 29.

[0023] The first elastic layer 25 is provided on the first woven fabric 24, the second elastic layer 26 is provided on the lower surface of the first woven fabric 24, the second woven fabric 27 is provided on the lower surface of the second elastic layer 26, the third elastic layer 28 is provided on the lower surface of the second woven fabric 27, and the third woven fabric 29 is provided on the lower surface of the third elastic layer 28. The first elastic layer 25, the second elastic layer 26, and the third elastic layer 28 are made of a first thermoplastic material. Note that, although a case where the first elastic layer 25, the second elastic layer 26, and the third elastic layer 28 are elastic layers of the same configuration will be described, the present invention is not limited thereto, and the first elastic layer 25, the second elastic layer 26, and the third elastic layer 28 may be made of different thermoplastic materials, or the thicknesses of the first elastic layer 25, the second elastic layer 26, and the third elastic layer 28 may be different. The surface resin layer 22 is made of a second thermoplastic material having a lower hardness (JIS-A) than the first thermoplastic material, and the surface on which the workpiece 11 is placed serves as a smooth transfer surface 14a.

[0024] The conveyor belt 14 has a plurality of through holes 20 formed at a predetermined interval so as to penetrate the thickness from the conveyor surface 14a to the belt back surface 14b. The through holes 20 penetrating the thickness between the surface resin layer 22 and the core layer 23 have an opening of a substantially circular shape when viewed from above the conveyor surface 14a, as shown in FIG. 2. The shape of the through holes 20 viewed from above the conveyor surface 14a may be an ellipse, a triangle, a rectangle, or the like, instead of a circle. In this embodiment, for example, the plurality of through holes 20 are arranged in a staggered arrangement. The staggered arrangement here refers to a configuration in which, for example, in a row of a plurality of through holes 20 arranged in a row in the width direction, the positions of the through holes 20 in the conveyor direction are shifted from each other between adjacent rows of a plurality of through holes 20, and the through holes 20 are arranged alternately in the conveyor direction. The arrangement of the through holes 20 may be an arrangement in which the through holes 20 are arranged in a matrix at a predetermined interval, or various other arrangements. In this embodiment, a case where a plurality of through holes 20 having the same configuration is provided will be described, but the present invention is not limited to this, and a plurality of through holes 20 having different opening shapes such as a circle, an ellipse, a triangle, a rectangle, etc. Details of the through holes 20 will be described later.

[0025] <Woven fabric> In this embodiment, the first woven fabric 24, the second woven fabric 27, and the third woven fabric 29 are woven fabrics of the same configuration, so in order to avoid duplication of explanation, the following description will mainly focus on the first woven fabric 24. In addition, when the first woven fabric 24, the second woven fabric 27, and the third woven fabric 29 are not particularly distinguished from each other, they are also referred to individually or collectively as simply woven fabrics. The first woven fabric 24 is not particularly limited as long as it is obtained by weaving fibers. The weaving method of the first woven fabric 24 may be any weaving method such as plain weave or twill weave. The fibers forming the first woven fabric 24 can be selected from, for example, polyester fibers, nylon fibers, aramid fibers, glass fibers, cotton threads, and the like. The fibers used for the first woven fabric 24 may be one type or two or more different types.

[0026] Since the conveyor belt 14 uses a woven fabric, unlike a knitted fabric, it does not have substantial stretchability in the conveying direction, and has a different structure from an elastic belt that has stretchability and elasticity. The thickness of the fibers forming the first woven fabric 24 is not particularly limited, and is, for example, about 20 to 280T (decitex). The thickness of the first woven fabric 24 is preferably about 0.3 to 0.8 mm, and more preferably about 0.4 to 0.6 mm. The second woven fabric 27 and the third woven fabric 29 may have the same structure as the first woven fabric 24, or may have a different structure.

[0027] <Elastic layer> In this embodiment, the first elastic layer 25, the second elastic layer 26, and the third elastic layer 28 have the same configuration, so in order to avoid duplication of description, the following description will mainly focus on the first elastic layer 25. When the first elastic layer 25, the second elastic layer 26, and the third elastic layer 28 are not particularly distinguished from each other, they are also referred to individually or collectively as simply elastic layers. The first elastic layer 25 is formed from a first thermoplastic material and provides flexibility and strength to the conveyor belt 14. Examples of the first thermoplastic material include thermoplastic elastomers made of polyurethane, polyolefins such as polyethylene and polypropylene, and polyesters. Polyurethane elastomers are particularly preferred because of their excellent processability and high strength. The thickness of the first elastic layer 25 is preferably about 0.2 to 1.5 mm, and more preferably about 0.3 to 0.8 mm. The second elastic layer 26 and the third elastic layer 28 may have the same configuration as the first elastic layer 25, or may have different configurations.

[0028] <Surface resin layer> The surface resin layer 22 is made of a second thermoplastic material having a lower hardness (JIS-A) than the first thermoplastic material. The surface of the surface resin layer 22 opposite to the first elastic layer 25 is the conveying surface 14a, and this conveying surface 14a is flat. Since the conveying surface 14a of the surface resin layer 22 is flat, a gap is unlikely to be formed between the workpiece 11 and the through hole 20, and therefore, a suction force from the through hole 20 can be applied to the workpiece 11, and the workpiece 11 can be reliably sucked and held against the conveying surface 14a. Since the surface resin layer 22 is made of a thermoplastic material, it has excellent abrasion resistance. The second thermoplastic material may be, for example, a mixture of the first thermoplastic material and an additive described later. As the second thermoplastic material, for example, a resin such as low-hardness polyurethane having a hardness (JIS-A) of 70 or less is desirable.

[0029] The thickness T1 of the surface resin layer 22 is preferably about 0.2 to 2.5 mm, and more preferably about 0.3 to 0.8 mm. The thickness T1 of the surface resin layer 22 is preferably selected in consideration of the distance between the outer edges of the adjacent through holes 20 formed in the conveyor belt 14 and the wear deformation of the through holes 20 caused by the brush 131. Specifically, it is preferable that the thickness T1 of the surface resin layer 22 and the distance between the outer edges of the adjacent through holes 20 are selected so that when the surface resin layer 22 is worn by the brush 131 due to long-term use of the conveyor belt 14, the wear of the through holes 20 in the thickness direction is suppressed by the first elastic layer 25 having a high hardness immediately below the surface resin layer 22, thereby preventing the worn through holes 20 from connecting with each other on the conveyor surface 14a. Details will be described later.

[0030] <Through hole configuration> The through holes 20 in the initial state before the conveyor belt 14 is polished by the brush 131 have a configuration in which they penetrate through the thicknesses of the surface resin layer 22, the first elastic layer 25, the first woven fabric 24, the second elastic layer 26, the second woven fabric 27, the third elastic layer 28, and the third woven fabric 29 with approximately the same opening area. The through holes 20 allow the suction device 18 to suck air from the belt back surface 14b side to the conveyor surface 14a side, and the workpiece 11 placed on the surface resin layer 22 is sucked and held by the suction of air by the suction device 18. For example, the ratio of the through holes 20 to the total area of ​​the conveyor surface 14a (opening ratio) is 1 to 50%, preferably 1 to 20%.

[0031] Fig. 4 is a plan view showing the configuration of the through holes 20 in an initial state when the conveying surface 14a is viewed from above. In Fig. 4, the diameter of the through holes 20 is φA, and the center-to-center distance (conveying direction distance) between adjacent through holes 20 in the conveying direction including different rows is shown as P1. Also, in Fig. 4, the center-to-center distance (width direction distance) between adjacent through holes 20 in the same row in the width direction is shown as P2. Furthermore, in Fig. 4, the minimum center-to-center distance between the closest through holes 20 is shown as R, and the distance (minimum distance) between the outer edges of the closest through holes 20 is shown as L.

[0032] Here, in the conveyor belt 14 in which the distance L between the outer edges of adjacent through holes 20 is shortened, the number of places for adsorbing the workpieces 11 increases, and the suction holding force of the workpieces increases. However, this causes an issue that the adjacent through holes 20 are easily connected to each other due to wear of the through holes 20 by the brushes 131, shortening the lifespan due to wear.

[0033] On the other hand, in the conveyor belt 14 in which the distance L between the outer edges of adjacent through holes 20 is increased, the adjacent through holes 20 are less likely to be connected to each other due to wear of the through holes 20 caused by the brushes 131, and therefore the lifespan due to wear is longer. However, there is an issue that the suction holding force of the workpiece 11 is reduced because the number of points for adsorbing the workpiece 11 is reduced.

[0034] In this embodiment, it is desirable to select the distance L between the outer edges of adjacent through-holes 20 so as to increase the suction holding force of the workpiece by increasing the number of locations where the workpiece 11 is adsorbed, and to select the thickness T1 of the surface resin layer 22 so as to prevent the expansion of the through-hole 20 in the thickness direction and the plane direction by the first elastic layer 25.

[0035] The thickness T1 of the surface resin layer 22 is preferably less than the distance L between adjacent through-holes 20 (that is, T1 < L). For example, when the thickness T1 of the surface resin layer 22 is 2.5 mm or less, the diameter φA of the through-hole 20 is preferably 2 to 8 mm, more preferably 2 to 5 mm, the minimum distance R between the centers of the closest adjacent through-holes 20 is preferably 15 to 40 mm, more preferably 20 to 30 mm, and the minimum distance L between the outer edges of the closest adjacent through-holes 20 is preferably 10 to 30 mm, more preferably 20 to 30 mm.

[0036] Also, for example, when the thickness T1 of the surface resin layer 22 is 2.5 mm or less, the distance P1 between the centers of adjacent through-holes 20 (transport direction distance) including different rows in the transport direction is preferably 10 to 30 mm, more preferably 20 to 30 mm, and the distance P2 between the centers of adjacent through-holes 20 (width direction distance) in the same column in the width direction is preferably 15 to 40 mm, more preferably 20 to 30 mm.

[0037] <Coefficient of static friction> The conveyor belt 14 preferably has a coefficient of static friction of 0.5 to 1.0 on the conveying surface 14a of the surface resin layer 22. By configuring the surface resin layer 22 from the second thermoplastic material, a coefficient of static friction within a predetermined range can be ensured. If the coefficient of static friction of the conveying surface 14a is 0.5 or more, even when the conveyor belt 14 is installed inclined, the workpiece 11 can be reliably conveyed without suction holding through the through-hole 20 by the suction machine 18. Considering the characteristic of a high coefficient of friction for object conveyance, the upper limit of the coefficient of static friction is preferably defined as 1.0. The coefficient of static friction is preferably 0.6 or more, more preferably 0.7 or more.

[0038] The static friction coefficient is measured using a surface property measuring device (manufactured by Shinto Scientific Co., Ltd.). The conveyor belt 14 is a test piece of 20 mm x 30 mm, and cardboard is used as the object. The test piece is placed on the cardboard, and while applying a load of 0.8 kPa, the test piece is moved at a speed of 5 mm / min to determine the static friction coefficient.

[0039] 3. Degree of deformation of through holes due to long-term use Next, the use state of the conveyor belt 14 according to the present embodiment will be described with reference to Fig. 5. Of the surface resin layer 22 and the core layer 23 of the conveyor belt 14, the following description focuses on the surface resin layer 22 and the first elastic layer 25 located directly under the surface resin layer 22. In Fig. 4, the first woven fabric 24, the second elastic layer 26, the second woven fabric 27, the third elastic layer 28, and the third woven fabric 29 in the core layer 23 are omitted from illustration. In the initial state, as shown by 1011 in Fig. 5, the through-hole 20 has a diameter that penetrates the thickness of the surface resin layer 22 and the first elastic layer 25 with approximately the same diameter.

[0040] In the example shown in FIG. 5, the thickness of the surface resin layer 22 is represented as T1, the thickness of the first elastic layer 25 as T2, the diameter of the through hole 20 as φA, the distance between the outer edges of adjacent through holes 20 as L, and the center-to-center distance of adjacent through holes 20 as R. For example, the thickness T1 of the surface resin layer 22 is selected to be less than the distance L between the outer edges of adjacent through holes 20 (T1 <L)。

[0041] As the conveyor belt 14 is used in the deburring device 10, the outer periphery of the through hole 20 exposed to the conveyor surface 14a is worn away by polishing with the brush 131. As a result, as shown in 1012 of FIG. 5, the surface opening 34a of the through hole 20 on the conveyor surface 14a side widens in the planar direction, and the surface opening 34a is also worn away in the thickness direction. By polishing the through hole 20 with the brush 131, the surface opening 34a becomes larger in diameter than the initial opening diameter. As a result, for example, a funnel opening 34 having an inverted truncated cone shape may be formed at the surface opening 34a of the through hole 20 in the surface resin layer 22. The diameter of the surface opening 34a of the funnel opening 34 gradually decreases as it approaches the first elastic layer 25 from the conveyor surface 14a. The funnel opening 34 has an inverted truncated cone shape that connects a surface opening 34a and a small-diameter opening 34b, which has a smaller diameter than the surface opening 34a and is on the first elastic layer 25 side, by an inclined surface.

[0042] When the conveyor belt 14 is further used in the deburring device 10, the surface opening 34a on the conveying surface 14a side is polished by the brush 131, so that the wear of the funnel opening 34 of the through hole 20 progresses further, and the diameter of the funnel opening 34 becomes larger as shown by 1013 in FIG. 5. Here, the first elastic layer 25 provided as a lower layer of the surface resin layer 22 is formed of a first thermoplastic material having a harder hardness (JIS-A) than the surface resin layer 22. Therefore, the wear of the through hole 20 progresses in the surface resin layer 22, and when the small diameter opening 34b of the funnel opening 34 reaches the first elastic layer 25, the wear of the small diameter opening 34b is suppressed by the first elastic layer 25. In the surface resin layer 22, the wear of the funnel opening 34 in the thickness direction is suppressed by the first elastic layer 25, so that the wear in the surface direction (toward the conveying surface 14a) accompanying the wear in the thickness direction is also suppressed accordingly.

[0043] Therefore, even if the conveyor belt 14 is used for a long period of time in the deburring device 10, the first elastic layer 25 directly under the surface resin layer 22 can suppress the expansion of the through holes 20 in the planar direction, and accordingly, deformation of the through holes 20 that would cause adjacent through holes 20 to communicate with each other can be suppressed. In this way, by selecting the thickness T1 of the surface resin layer 22 and the distance L between the outer edges of adjacent through holes 20, the conveyor belt 14 is less deformed than the through holes 103 of the conventional conveyor belt 100 described in FIG. 8.

[0044] 4. Manufacturing method of conveyor belt for deburring device The following describes a method for manufacturing the conveyor belt 14. The conveyor belt 14 can be manufactured by any method as long as the first elastic layer 25, the first woven fabric 24, the second elastic layer 26, the second woven fabric 27, the third elastic layer 28, and the third woven fabric 29 are fixed to each other and the first elastic layer 25 and the surface resin layer 22 are fixed to each other so as not to be peeled off.

[0045] First, a thermoplastic sheet that will become the first elastic layer 25, the second elastic layer 26, and the third elastic layer 28 is produced using a predetermined thermoplastic elastomer by a calendar device or an extrusion device. The size of the sheet is adjusted to the size of the woven fabrics (first woven fabric 24, second woven fabric 27, and third woven fabric 29). The sheet can be fixed to the first woven fabric 24, the second woven fabric 27, and the third woven fabric 29 by using rubber cement.

[0046] The woven fabrics (here, the first woven fabric 24, the second woven fabric 27, and the third woven fabric 29) are impregnated with rubber cement in advance. The rubber cement can be impregnated into the woven fabrics using a coating means such as a coater or a brush. Alternatively, the woven fabrics may be immersed in the rubber cement to impregnate the woven fabrics with the rubber cement.

[0047] The third elastic layer 28, the second woven fabric 27 impregnated with rubber cement, the second elastic layer 26, the first woven fabric 24 impregnated with rubber cement, and the first elastic layer 25 are placed in this order on the third woven fabric 29 impregnated with rubber cement, and are fixed under heat and pressure conditions. In this manner, the core layer 23 is obtained in which the woven fabrics (the first woven fabric 24, the second woven fabric 27, and the third woven fabric 29) and the elastic layers (the first elastic layer 25, the second elastic layer 26, and the third elastic layer 28) made of the first thermoplastic material are alternately laminated.

[0048] On the other hand, a surface resin layer 22 made of a second thermoplastic material is prepared using a predetermined raw material composition. The raw material composition can be prepared, for example, by mixing an ether-based thermoplastic polyurethane elastomer (hereinafter referred to as ether-based TPU) as the first thermoplastic material, a hydrogenated styrene-based thermoplastic elastomer (hereinafter referred to as styrene-based TPE) as an additive, a compatibilizer, and a wax. By using such a raw material composition, a second thermoplastic material having a lower hardness (JIS-A) than the first thermoplastic material can be obtained.

[0049] The ratio of each component in the raw material composition can be, for example, as follows. Ether-based TPU: 50-65% by mass Styrene-based TPE: 10 to 30% by mass Compatibilizer: 0 to 10% by mass Wax: 5 to 15% by weight Calcium carbonate: 0 to 25% by mass If necessary, optional components may be further added to prepare the raw material composition.

[0050] As the ether-based TPU, for example, an ether-based thermoplastic urethane resin having a hardness equivalent to 80 as measured by a type A durometer according to the Japanese Industrial Standard JISK6253 can be used. As the compatibilizer, a mixture of a hydrogenated styrene-based elastomer and a thermoplastic urethane resin can be used. As the wax, commercially available solid paraffin oil can be used.

[0051] A raw material composition prepared by blending each component in a specified ratio is used to produce a resin sheet that will become the surface resin layer 22 using a calendar device. That is, the raw material composition in a molten state is continuously poured between two rolls arranged at a specified distance, while the two rolls are rotated in the same direction to obtain a strip-shaped resin sheet. The size of the resin sheet is adjusted to the size of the woven fabrics (first woven fabric 24, second woven fabric 27, and third woven fabric 29).

[0052] The obtained resin sheet is placed on the first elastic layer 25 of the core layer 23 prepared in advance to obtain a laminate. This laminate is laminated during extrusion, or is processed to a predetermined thickness by heat-pressing after sheet molding. By performing heat-pressing, the first elastic layer 25 and the surface resin layer 22 of the core layer 23 are fixed to each other.

[0053] In this way, a conveyor belt is obtained in which the surface resin layer 22 is laminated on the core layer 23 having three layers of woven fabric and elastic layers. Then, a plurality of through holes 20 are formed in the obtained conveyor belt by hole processing, thereby obtaining a conveyor belt 14 to be used in the deburring device 10. The conveyor belt 14 can be applied to a belt conveyor or the like by processing the conveyor belt 14 into an endless shape by joining both ends with finger joints. In addition, as a manufacturing method of the conveyor belt 14, the conveyor belt 14 may be previously made to have a twice the length in the width direction, and after hole processing to open a plurality of through holes 20 in the conveyor belt 14 of this size, the width direction length may be cut in half to process it into a specified width size.

[0054] The static friction coefficient of the transport surface 14a of the surface resin layer 22 depends on the hardness (JIS-A) of the second thermoplastic material constituting the surface resin layer 22. The static friction coefficient of the transport surface 14a can be changed between 0.5 and 1.0 by adjusting the blending ratio of each component in the raw material composition. For example, the higher the ratio of styrene-based TPE to ether-based TPU in the raw material composition, the higher the static friction coefficient.

[0055] 5. Action and Effects The conveyor belt 14 according to this embodiment is formed with a plurality of through holes 20 that penetrate the thickness of the woven fabric, the elastic layer, and the surface resin layer 22 and suck in air to hold the workpiece 11 placed on the surface resin layer 22. In addition, the conveyor belt 14 is configured such that, by selecting the thickness T1 of the surface resin layer 22 and the distance L between the outer edges of adjacent through holes 20, when the surface resin layer 22 is worn down by the brush 131 and the through holes 20 are expanded in the surface direction of the surface resin layer 22, the first elastic layer 25 suppresses the expansion of the through holes 20 in the surface direction.

[0056] As a result, even if the surface resin layer 22 of the conveying belt 14 is worn away by the brush 131 and the through holes 20 become wider, the first elastic layer 25 can stop the through holes 20 from widening, and accordingly deformation of the through holes 20 can be suppressed more than before.

[0057] The conveyor belt 14 according to the present embodiment includes a woven fabric and an elastic layer made of a thermoplastic material provided on the woven fabric. The conveyor belt 14 has sufficient strength by including at least the woven fabric and the elastic layer.

[0058] The surface resin layer 22 provided on the first elastic layer 25 is made of a thermoplastic material having a lower hardness (JIS-A) than the first elastic layer 25, and has a smooth conveying surface 14a. As is generally known, the lower the hardness (JIS-A) of a thermoplastic material, the higher the friction coefficient, so the conveying surface 14a of the surface resin layer 22 has a larger static friction coefficient than the conveying surface (surface) of the first elastic layer 25. The static friction coefficient of the conveying surface 14a is in the range of 0.5 to 1.0. The conveying belt 14 according to this embodiment can reliably convey the workpiece 11 even during inclined conveying, even without suction by the suction device 18, and also has sufficient wear resistance.

[0059] In addition, the conveyor belt 14 has a surface resin layer 22 formed of low-hardness polyurethane, which is the same polyurethane-based material as the first elastic layer 25, and this increases the adhesive strength between the surface resin layer 22 and the first elastic layer 25, thereby preventing peeling during use. In addition, in the conveyor belt 14, no plasticizer is added to the low-hardness polyurethane forming the surface resin layer 22, thereby preventing a decrease in abrasion resistance and preventing adhesion inhibition due to bleeding of the plasticizer. Furthermore, in the conveyor belt 14, the surface resin layer 22 is formed of a second thermoplastic material obtained by mixing a styrene-based TPE as an additive into the first thermoplastic material, so that the surface resin layer 22 can achieve abrasion resistance, low hardness, and a high friction coefficient.

[0060] In addition, in the conveyor belt 14, the thickness T1 of the surface resin layer 22 is set to 2.5 mm or less, and the thickness T1 of the surface resin layer 102 is reduced, thereby making it possible to reduce the weight of the entire conveyor belt 14. In addition, in the conveyor belt 14, elastic layers (the first elastic layer 25, the second elastic layer 26, and the third elastic layer 28) having a higher hardness (JIS-A) than that of the surface resin layer 22 and a hardness of more than 70 are provided in the core layer 23. This allows the conveyor belt 14 to maintain its overall strength, and also maintains the strength of the joints when both ends are joined to form an endless shape.

[0061] 6. Other embodiments The present invention is not limited to the embodiments described herein, and can be modified as appropriate within the scope of the present invention.

[0062] In the above-described embodiment, the core layer 23 having a three-layer structure of a woven fabric and an elastic layer, in which the first elastic layer 25, the first woven fabric 24, the second elastic layer 26, the second woven fabric 27, the third elastic layer 28, and the third woven fabric 29 are laminated, is used as the core layer having an elastic layer on the upper surface of the woven fabric. However, the present invention is not limited to this. As another conveyor belt, for example, as shown in Fig. 6, a conveyor belt 14A including a core layer 23A in which the first woven fabric 24 and the first elastic layer 25 are laminated and fixed in order on the second elastic layer 26 may be used.

[0063] In this case, the core layer 23A is provided with a first elastic layer 25 and a second elastic layer 26, which are elastic layers, on both the front and back sides of the first woven fabric 24, which is a woven fabric, and a surface resin layer 22 is provided on one of the first elastic layers 25. The conveyor belt 14A also has a plurality of through holes 20 formed therethrough so as to penetrate the thickness, as in the above-described embodiment. The second thermoplastic material used for the second elastic layer 26 may be the same as or different from the first thermoplastic material used for the first elastic layer 25. The second thermoplastic material is not limited to being a mixture of the first thermoplastic material and an additive, and may be a mixture of a thermoplastic material different from the first thermoplastic material and an additive.

[0064] As another conveyor belt, as shown in Fig. 7, a conveyor belt 14B may be used, which includes a core layer 23B having a single-layer structure of a woven fabric and an elastic layer, in which a first elastic layer 25 and a first woven fabric 24 are laminated. In the core layer 23B, a surface resin layer 22 is provided on the first elastic layer 25. In the conveyor belt 14B, a plurality of through holes 20 are formed so as to penetrate the thickness, as in the above-mentioned embodiment. Even with such a configuration, the same effect as that of the conveyor belt 14 of the above-mentioned embodiment can be achieved.

[0065] In the above-described embodiment, the conveyor belts 14, 14A, and 14B used in the deburring device 10 that removes burrs from the workpiece 11 by polishing the surface of the workpiece 11 with the brush 131 have been described as conveyor belts used in the polishing device that polishes the surface of the workpiece with a brush, but the present invention is not limited thereto. For example, the conveyor belt may be used in various polishing devices that perform other surface processing such as polishing the surface of the workpiece with a brush and polishing the surface, without the purpose of deburring. Note that, like the above-described conveyor belts 14, 14A, and 14B, the conveyor belt for such a polishing device also sucks and holds the workpiece on the conveying surface by sucking air from the through holes, and conveys the workpiece to the brush of the polishing device. The conveyor belt for the polishing device can also be configured to suppress the spread of the through holes in the surface direction by the elastic layer when the wear of the surface resin layer progresses due to the brush and the through holes spread in the surface direction of the surface resin layer by selecting the thickness T1 of the surface resin layer and the distance L between the outer edges of adjacent through holes in the same manner as in the above-described embodiment. [Explanation of symbols]

[0066] 10 Deburring device (polishing device) 11, 104 Work 14, 14A, 14B, 100 Conveyor belt (conveyor belt for deburring device, conveyor belt for polishing device) 14a, 102a Conveying surface 18 Suction machine 20, 103 Through hole 22, 102 Surface resin layer 24 First Weaving Fabric (Woven Fabric) 25 First elastic layer (elastic layer) 26 Second elastic layer (additional elastic layer) 27 Second weaving (additional weaving) 28 Third elastic layer (additional elastic layer) 29 Third Fabric (Additional Fabric) 34, 105 funnel opening 131 Brush

Claims

1. A conveyor belt that is provided in a polishing device that polishes a surface of a workpiece with a brush, and that suction-holds the workpiece and conveys it to the brush, Woven fabric and an elastic layer made of a first thermoplastic material provided on an upper surface of the woven fabric; a surface resin layer provided on an upper surface of the elastic layer and made of a second thermoplastic material having a hardness lower than that of the first thermoplastic material; Equipped with The woven fabric, the elastic layer, and the surface resin layer are a plurality of through holes are formed through the thicknesses of the woven fabric, the elastic layer, and the surface resin layer, and the through holes suck air to hold the workpiece placed on the surface resin layer by suction; By selecting a thickness of the surface resin layer and a distance between outer edges of adjacent through holes, when the wear of the surface resin layer progresses due to the brush and the through holes widen in the surface direction of the surface resin layer, the elastic layer suppresses the widening of the through holes in the surface direction. Conveyor belt.

2. The elastic layer is The conveyor belt according to claim 1, wherein when the through holes of the surface resin layer are worn in the thickness direction by the brush, the elastic layer suppresses the wear of the through holes in the thickness direction, thereby suppressing the expansion of the through holes in the surface resin layer in the planar direction.

3. 2. The conveyor belt according to claim 1, which is an endless belt having both ends joined together, and the through holes are formed at predetermined intervals.

4. 2. The transport belt of claim 1, further comprising an additional elastic layer of thermoplastic material on the lower surface of the woven fabric.

5. The conveyor belt according to claim 4 , further comprising an additional woven fabric provided in contact with the lower surface of the additional elastic layer.

6. The conveyor belt according to any one of claims 1 to 5, wherein the polishing device is a deburring device that polishes the surface of the workpiece with the brush to remove burrs from the surface.

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