Belt conveyor with snake correction function

Abstract

To provide a belt conveyor with a function for automatically correcting the meandering of the belt at low cost.SOLUTION: A belt conveyor of the invention includes: a frame 2; an endless belt 1 that circulates within the frame 2 and is capable of conveying an object; idler rollers 3 that support the belt 1 at key points by protruding shaft ends on both sides in the axial direction; and at least a pair of brackets 4 which are attached to the frame 2 and have elongated holes in the gravitational direction over which the ends of the shaft are respectively hung, wherein each of the pair of brackets 4 is provided with a fixing member 5 fixed to the frame 2, and a follower member 6 attached to the fixed member 5 so as to be rotatable about an axis parallel to the shaft and on which the end of the shaft of the idler roller 3 is hung.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a belt conveyor with a meandering correction function.

Background Art

[0002] A belt conveyor generally includes a frame assembled to surround a space, pulleys respectively fixed to the front end and the rear end of the frame so that the rotation axes are horizontal, and an endless belt spanned between both pulleys and circulating within the frame to convey an object. The object is placed on the upper surface of the belt on the carrier side and conveyed.

[0003] The belt conveyor is further provided with idler rollers for supporting the belt at key points so that the belt does not sag and contact other objects during conveyance, and the idler rollers are rotatably provided on the frame around the belt. The idler rollers are fixed to the frame by hanging both ends of the shaft on a pair of brackets attached to both sides of the frame in the running direction of the belt (Patent Document 1). Since the idler rollers are suspended from the frame via the brackets, the brackets are also called hangers.

[0004] During operation, the belt may meander. If left uncorrected, the edge of the belt may contact the bracket, causing damage to the belt and the bracket or resulting in energy loss. Therefore, various measures have been taken to correct the meandering. The simplest one is to attach the bracket to the frame with bolts and nuts, make the mounting holes long in the running direction of the belt, and loosen the nuts and shift the bracket slightly forward or backward each time the belt meanders. Also, a more elaborate method is to hold the idler roller not with the bracket but with a movable frame having a rotation axis in the direction of gravity, and automatically correct it with the component force generated during the turning of the movable frame (Patent Document 2).

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Utility Model Publication No. 63-110414 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-60038 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] However, every time the belt meanders, loosening the nut and shifting the bracket as described above is time-consuming. On the other hand, a correction device having a movable frame is expensive because it has a large number of parts and straddles the width of the belt. Therefore, an object of the present invention is to provide an inexpensive belt conveyor with a function of automatically correcting the meandering of the belt. [Means for Solving the Problems]

[0007] In order to solve the problem, the belt conveyor of the present invention includes a frame, an endless belt that circulates within the frame and can convey an object, an idler roller having shaft ends protruding from both axial sides to support the belt at key points, and at least a pair of brackets attached to the frame and having elongated holes that are long in the direction of gravity and in which the shaft ends are respectively hung. And each of the at least a pair of brackets includes a fixing member fixed to the frame, a member rotatably attached to the fixing member about an axis parallel to the shaft and having the shaft end of the idler roller hung thereon Driven and is characterized by comprising.

[0008] The idler roller has the ends of its shaft protruding on both axial sides, and usually has bearings built in between the shaft and the idler roller body. The ends of the shaft are each placed in the long holes of the bracket, whereby the idler roller is fixed to the frame via the bracket. The idler roller rotates along with the running speed of the belt. The shafts of the idler rollers may be separated on one side and the other side with the central part of the idler roller body in between as long as they are on the same axis line.

[0009] When the belt on the idler roller snakes, the belt approaches one of the brackets on the left or right and moves away from the other bracket. In this invention, since the bracket is divided into the fixing member and the Driven member as described above, the idler roller is carried by the belt and slightly moves in the traveling direction, and accordingly, the Driven member swings passively. Then, a difference occurs in the amount of swing of the left and right Driven members due to the deviation of the belt. For this reason, the idler roller forms an angle in the direction of correcting the deviation of the belt with respect to the traveling direction in plan view. At the same time, a height difference occurs at both axial ends of the idler roller, and the idler roller tilts at an angle for correcting the deviation of the belt even in front view. Thus, the belt returns to the center, and accordingly, the amount of swing of both Driven members becomes the same, and the idler roller becomes perpendicular and horizontal with respect to the traveling direction.

[0010] The fixing member usually has a bush penetrating in the axial direction, the Driven member has a pivot that can be fitted into the bush, and the Driven member is rotatable with respect to the fixing member with the bush and the pivot as a pair.

[0011] The DrivenThe member preferably includes a shield that is integrated with the pivot and has the elongated hole, and a stopper that is detachably attached to the shield and prevents the end of the shaft placed in the elongated hole from lifting. Thereby, it is possible to prevent the end of the shaft from lifting, and it is also possible to remove the idler roller by removing the stopper. The stopper may be, for example, in a form that closes the upper part of the elongated hole after placing the end of the shaft in the elongated hole.

[0012] The shield preferably includes a guard portion formed perpendicular to the pivot, relief portions extending from both sides of the guard portion at an angle in a direction away from the belt, and a tongue portion extending at an angle from the lower end of the guard portion in a direction approaching the belt and then hanging downward. Although the form including the guard portion and the tongue portion is similar to an existing bracket, since the shield has the relief portions, even if the belt meanders and contacts the shield, the frictional resistance is smaller than that of the existing bracket, and damage to the belt is reduced.

[0013] The shaft of the idler roller is planed in the axial direction in the vicinity of the end. The elongated hole is formed to straddle from the guard portion to the tongue portion, and is widened to be able to receive the end of the shaft in the range of the guard portion and the tongue portion extending in the direction approaching the belt, and is narrowed in the range of the tongue portion hanging downward so that the planed portion of the shaft is loosely fitted.

[0014] Therefore, the idler roller is mounted without axial detachment by passing the end of the shaft through the widened portion of the elongated hole and dropping the planed portion of the shaft into the narrowed portion of the elongated hole. In this regard, it is the same as the relationship between the existing idler roller and the bracket. Therefore, in this case, by simply replacing the bracket from the existing one with the one of the present invention, the configuration of the belt conveyor of the present invention can be achieved. Also, since the planed portion of the shaft is loosely fitted, it is easy to cause a difference in the amount of vibration of the members on the left and right, and it is easy to exert the above-mentioned corrective action. Driven The amount of vibration of the members on the left and right is likely to be different, and it is easy to exert the above-mentioned corrective action.

[0015] The long hole may have an axially-viewed drum shape in which the inner surfaces on both sides of the narrow-width portion thereof restrain the shaft so as to be swingable about the center line of the shaft. Thereby, the amount of runout of the left and right members is more likely to differ than in the case where they are merely loosely fitted as described above, and it becomes easier to exhibit the above-described corrective action. Usually, a plurality of idler rollers are installed in the traveling direction of the belt. In this case, a plurality of pairs of brackets corresponding to the number of idler rollers are required. The paired brackets are symmetric with each other, but the front and rear brackets do not have to have the same shape. For example, brackets having a narrow-width portion of the long hole that allows the loose fit and brackets having the drum shape may be alternately arranged, or those having the drum shape may be intermittently arranged in the traveling direction. Driven This makes it easier to cause a difference in the amount of runout between the left and right members and easier to exhibit the corrective action. Usually, a plurality of idler rollers are installed in the traveling direction of the belt. In this case, a plurality of pairs of brackets corresponding to the number of idler rollers are required. The paired brackets are symmetric with each other, but the front and rear brackets do not have to have the same shape. For example, brackets having a narrow-width portion of the long hole that allows the loose fit and brackets having the drum shape may be alternately arranged, or those having the drum shape may be intermittently arranged in the traveling direction.

Advantages of the Invention

[0016] As described above, since the belt conveyor of this invention has a function of automatically correcting the meandering of the belt, the burden on the operator is significantly reduced. Moreover, depending on the shape of the idler roller, it is sufficient to replace only the bracket, so that a belt conveyor with the above-described correction function can be provided at low cost.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiment for Carrying Out the Invention

[0018] - Embodiment 1 - As shown in FIG. 1, the belt conveyor of the first embodiment includes an endless belt 1, frames 2 installed on both the left and right sides of the belt 1, which are installed on both sides of the belt 1 and are long in the running direction of the belt 1, idler rollers 3 that support the belt 1 at key points, brackets 4 for fixing the idler rollers 3 to the frames 2, and at least two pulleys (not shown).

[0019] To avoid the complexity of the illustration, except for the bracket 4, the others may be conventional products, so they are drawn with phantom lines. The bracket 4 consists of a fixing member 5 and Driven member 6. The end portions of the shaft protrude from both end faces of the idler roller 3. Hereinafter, when referring to the axial direction, it refers to the direction of the shaft of the idler roller 3, and when referring to the running direction, it refers to the running direction of the belt 1.

[0020] One of the at least two pulleys is rotatably fixed to the frame 2 at the front end position in the running direction, and the other one is also rotatably fixed to the frame 2 at the rear end position. The belt 1 is wound around these pulleys, so that it can be circulated inside the frame 2. FIG. 1 shows the configuration of the return side of the belt 1 in the belt conveyor of this embodiment, and above it, each component on the carrier side exists with a similar configuration. A plurality of idler rollers 3 are installed in the running direction on both the carrier side and the return side, and brackets 4 are attached to each of them correspondingly. The shaft of the idler roller 3 is cylindrical, but it is machined to form two planes parallel to the axial direction near its end portion.

[0021] The following will mainly elaborate on the bracket 4. As shown in FIGS. 2 and 3, the fixing member 5 has an inverted isosceles trapezoid shape when viewed axially, and has a bush 51 that protrudes axially on one side near the center of the inverted isosceles trapezoid and penetrates axially, and an attachment surface 52 that extends axially on the other side from the upper side of the inverted isosceles trapezoid integrally. Two long holes are formed in the attachment surface 52. By aligning these long holes with the bolt holes of the frame 2 and tightening with bolts through nuts, the fixing member 5 is fixed to the frame 2.

[0022] Driven As shown in FIG. 2, the member 6 consists of a shield 7 and a stopper 8. As shown in FIGS. 2 and 4, the shield 7 has a guard portion 71 that is substantially square when viewed axially and has a pivot 72 welded to protrude axially at its center, escape portions 73, 73 that are continuous on both sides of the guard portion 71 and extend in a direction bent 30 degrees toward the pivot 72 side with respect to the guard portion 71, and a tongue portion 74 that extends at an angle axially in the direction opposite to the pivot 72 from the lower end of the guard portion 71 and then hangs downward.

[0023] A long hole 75 is formed in the shield 7 from near the lower end of the guard portion 71 to the tongue portion 74. The long hole 75 is formed wide in the axial portions of the guard portion 71 and the tongue portion 74, and is formed narrow in the hanging portion of the tongue portion 74. The idler roller 3 is mounted on the bracket 4 by passing the end of its shaft through the wide portion of the long hole 75 once and dropping the flattened portion into the narrow portion of the long hole 75. A clearance is provided between the narrow portion of the long hole 75 and the flattened portion.

[0024] As shown in FIGS. 2 and 5, the stopper 8 has a portion 81 having a main surface along the gravitational direction and a portion 82 having a main surface along the horizontal direction, which are continuous, and forms an L-shape when viewed from the side, that is, from the traveling direction of the belt 1. The horizontal portion 82 has a width and length complementary to the axial portion in the long hole 75, and the gravitational direction portion 81 has a width larger than that and slightly smaller than the width of the guard portion 71. By inserting the horizontal portion 82 into the axial portion in the long hole 75 and pressing the gravitational direction portion 81 against the guard portion 71 and fixing it with bolts and nuts, the wide portion of the long hole 75 is blocked with the axis of the idler roller 3 spanned as shown in FIG. 6. For this reason, the end of the axis of the idler roller 3 does not float up.

[0025] The shield 7 fits the pivot 72 into the bush 51 and inserts a radial retaining pin 76 (FIG. 1) into the portion of the pivot 72 protruding from the bush 51, thereby fixing the bush 51 and the pivot 72 as a pair and rotatably fixing them to the fixing member 5.

[0026] When the belt 1 on the idler roller 3 meanders, the belt 1 approaches one of the brackets 4 on the left or right and moves away from the other bracket 4. The bracket 4 is divided into a fixing member 5 and Driven a member 6, Driven and since the member 6 is rotatable with respect to the fixing member 5, the idler roller 3 is carried by the belt 1 and slightly moves in the traveling direction, and accordingly, as shown by the phantom line in FIG. 2(b), Driven the member 6 swings passively.

[0027] Then, a difference occurs in the amount of swing of the left and right Driven members 6, 6 due to the deviation of the belt 1. The play between the narrow portion of the long hole 75 and the planar portion of the axis of the idler roller 3 facilitates this differential movement. For this reason, the idler roller 3 forms an angle in the direction of correcting the deviation of the belt 1 with respect to the traveling direction in plan view. At the same time, a height difference occurs at both axial ends of the idler roller 3, and the idler roller 3 inclines at an angle for correcting the deviation of the belt 1 even in a front view. In this way, the belt 1 returns to the center, and accordingly, both DrivenThe deflection amount of the member 6 becomes the same, and the idler roller 3 is perpendicular and horizontal to the traveling direction.

[0028] The shield 7 has relief portions 73, 73 on both sides of the guard portion 71 as described above. Since each relief portion 73 forms an angle with respect to the guard portion 71, that is, an angle in a direction away from the belt 1 as it moves away from the guard portion 71, even if the belt 1 meanders and contacts the shield 7, the frictional resistance is smaller than that of the existing bracket, and damage to the belt 1 is reduced.

[0029] In this embodiment, if the distance between the two long holes provided on the mounting surface 52 of the fixing member 5, the size of each, the shape and size of the long hole 75 of the shield 7, and the positional relationship of the long hole 75 with respect to the long hole on the mounting surface 52 are the same as those of the existing bracket, it is sufficient to replace only the existing bracket with the bracket 4. Therefore, a belt conveyor can be provided with a meandering correction function at extremely low cost.

[0030] -Embodiment 2- In Embodiment 1, the inner surfaces on both sides of the narrow portion of the width of the long hole 75 were planes facing the plane portion where the axis of the idler roller 3 is taken. However, in this embodiment, as shown in FIG. 7, it has a drum shape in the axial direction view that restrains the axis to be swingable about the center line of the axis. As a result, as shown in the figure, a larger difference in the deflection amount between the left and right Driven members 6, 6 is allowed. In the present invention, the brackets of Embodiment 1 and the brackets of Embodiment 2 may be alternately arranged in the traveling direction, or either one may be arranged in a larger number and the other in a smaller number.

Explanation of Reference Numerals

[0031] 1 Belt 2 Frame 3 Idler Roller 4 Bracket 5 Fixing Member 6 Driven Member 7 Shield 8 Fastener

Claims

1. A belt conveyor comprising a frame, an endless belt that circulates within the frame and is capable of conveying an object, an idler roller having shaft ends protruding on both axial sides to support the belt at key points, and at least a pair of brackets attached to the frame and having elongated holes extending in the direction of gravity over which the shaft ends are respectively placed. Each of the at least a pair of brackets comprises a fixing member fixed to the frame, a driven member rotatably attached to the fixing member about an axis parallel to the shaft and over which the shaft end of the idler roller is placed. The belt conveyor is characterized in that.

2. The belt conveyor according to claim 1, wherein the fixing member has a bush penetrating in the axial direction, the driven member has a pivot that can be fitted into the bush, and the driven member is rotatable with respect to the fixing member with the bush and the pivot as a pair.

3. The driven member comprises a shield integrated with the pivot and having the elongated hole, and a stopper that is detachably attached to the shield and prevents the shaft end placed in the elongated hole from lifting. The belt conveyor according to claim 2.

4. The shield comprises a guard portion formed perpendicular to the pivot, a relief portion extending from both sides of the guard portion at an angle in a direction away from the belt, and a tongue portion extending at an angle in a direction approaching the belt from the lower end of the guard portion and then hanging downward. The shaft of the idler roller is flattened axially parallel in the vicinity of the end. The elongated hole is formed to straddle from the guard portion to the tongue portion, and is widened to be able to receive the shaft end in the range where the guard portion and the tongue portion extend in the direction approaching the belt, and is narrowed in the range where the tongue portion hangs downward so that the flattened portion of the shaft is loosely fitted. The belt conveyor according to claim 3.

5. The belt conveyor according to claim 4, wherein the inner surfaces on both sides of the narrow portion of the elongated hole form a drum shape in the axial view that restrains the shaft to swing about the center line of the shaft.

6. The belt conveyor according to any one of claims 1 to 5, wherein the idler roller is a return idler roller.

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