JP2014210663A - Slip detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slip detector which has a simple structure and thereby unfailingly detects slip between a belt and a pulley.SOLUTION: A slip detector of the invention includes: a rotary member 11 which rotates with a return roller 2; and a proximity sensor 12 which detects rotations of the rotary member 11. The rotary member 11 comprises: an arc shaped detection part 11a which is detected by the proximity sensor 12; and a non-detection part 11b which is not detected by the proximity sensor 12. The proximity sensor 12 includes measurement means which measures the number of detection of the detection part 11a. The slip detector accurately detects the occurence of slip from rotations of the return roller 2.

Description

  The present invention relates to a slip detection device that detects a slip between a belt and a pulley of a belt conveyor. Specifically, the present invention relates to a device that detects slip by detecting rotation of a return roller, not a drive pulley or a driven pulley.

  When using a belt conveyor, the belt and the pulley for driving the belt may slip. This slip occurs, for example, when an object to be conveyed is caught between the belt and the pulley due to overload on the belt conveyor or elongation of the belt. When such a slip occurs, the conveyance amount per unit time of the belt conveyor decreases, which may adversely affect the subsequent process. In addition, when a certain amount of the object to be conveyed is always supplied to the belt conveyor, there is also a problem that the object to be conveyed gradually accumulates on the conveyor.

  Therefore, when a slip occurs, it is necessary to detect it quickly and take a countermeasure. In order to detect slip, a method of detecting rotation of a driven pulley or drum by a proximity sensor or the like is generally known as disclosed in, for example, Patent Documents 1-3. Or the method of detecting rotation of the tension roller (return roller) provided in the lower side of the belt conveyor like patent document 4 is also known.

  However, the method for detecting the rotation of the driven pulley (drum) has the following problems. That is, the driven pulley needs to have a structure that can move in a direction orthogonal to the axial direction of the rotating shaft. This is because when the slip occurs, the driven pulley is moved away from the drive pulley, so to speak, the belt is pulled to correct the slip. If a device for detecting rotation is further attached to the driven pulley having such a movable structure, the structure becomes extremely complicated. This is because it is necessary to cause the detection device to follow the moving driven pulley, and also to follow the wiring to the detection device.

  In addition, since the wiring to the detection device cannot be a robust fixed wiring, there is a problem that, for example, an operator may be caught by the wiring and disconnected during work such as belt tension.

  On the other hand, if it is the method of detecting rotation of a tension roller (return roller) like patent document 4, although the above problems can be avoided, there existed the following problems. That is, since the return roller is generally much smaller in diameter than the driven pulley and has a short time per rotation, it is difficult to accurately detect the rotation with the proximity sensor. For this reason, it is not easy to increase the accuracy of slip detection.

JP-A-8-217222 JP-A-9-301520 JP 2012-71925 A JP 2001-72226 A

  In view of the above problems, an object of the present invention is to provide a slip detection device that can detect a slip between a belt and a pulley with a simple structure.

  The present invention made to solve the above problems is a slip detection device for detecting a slip of a belt conveyor having a return roller, the rotating member rotating together with the return roller, and detecting the rotation of the rotating member. A proximity sensor, and the rotating member includes an arc-shaped detection unit that is detected by the proximity sensor and a non-detection unit that is not detected by the proximity sensor. It is characterized by comprising a measuring means for measuring.

  In addition, as in claim 2, the rotating member is composed of two arc-shaped detection units and a linear non-detection unit that connects the respective ends of the two detection units. And the two non-detecting parts are arranged to face each other, and the arc-shaped detecting part forms a part of the circumference of a virtual circle centered on the rotation center of the rotating member, and The center angle of the non-detection part in the virtual circle may be two or more times the center angle of the detection part.

  According to a third aspect of the present invention, the rotating member includes a detection part obtained by cutting a part of one cylinder and a non-detection part obtained by cutting a part of one disc. Both of which form a circumference of a virtual circle centered on the rotation center of the rotating member, and in the virtual circle, the central angle of the arc forming the detection portion is 120 ° to 180 ° can do.

  Since the slip detection device of the present invention is attached to the return roller, the structure can be made simple. Further, unlike the conventional method of detecting the rotation of the driven pulley (drum), the wiring to the detection device can be a fixed wiring, so that the reliability of the wiring is improved. Furthermore, by making the detection part of the rotating member arc, even if the return roller has a small diameter, the rotation can be accurately detected. As described above, according to the present invention, it is possible to accurately detect the occurrence of slip by reliably detecting the actual moving speed of the belt from the rotation of the return roller and calculating the difference from the circumferential speed of the pulley. It becomes possible.

  According to the invention of claim 2, since the range of the non-detection part is set to be twice or more that of the detection part, the rotation can be reliably detected even when the rotation speed of the return roller is fast and the detection time is short.

  According to a third aspect of the present invention, the rotating member is composed of a detection part obtained by cutting a part of one cylinder and a non-detection part obtained by cutting a part of one disc, and the detection / non-detection range is maximized. Since the shape can be secured as much as possible, rotation can be detected more reliably even when the detection time is short.

It is a front view of the belt conveyor in which the slip detection apparatus of this invention is used. It is side surface sectional drawing (A) of a belt conveyor, and the front view (B) of the slip detection apparatus of the 1st Embodiment of this invention. It is the top view (A) and front view (B) of the slip detection apparatus of 1st Embodiment. (The safety cover is not shown) It is an enlarged view of the rotation member of the slip detection apparatus of 1st Embodiment. It is side surface sectional drawing (A) of the belt conveyor in the 2nd Embodiment of this invention, and the front view (B) of the slip detection apparatus of 2nd Embodiment. It is the top view (A) and front view (B) of the slip detection apparatus of 2nd Embodiment. (The safety cover is not shown) It is an enlarged view of the rotation member of the slip detection apparatus of 2nd Embodiment.

  Hereinafter, embodiments of a slip detection device of the present invention will be described in detail with reference to the drawings.

(First embodiment)
The slip detection device of the present invention is used in a belt conveyor 1 with a return roller 2 as shown in FIG. The belt conveyor 1 includes a return roller 2, a drive pulley 3, a driven pulley 4, a take-up unit 5, and an endless belt 6. The return roller 2 is disposed on the non-conveying side (the lower side of the belt conveyor 1) of the endless belt 6, and is alternately disposed on the upper side and the lower side of the endless belt 6 so as to apply tension to the endless belt 6.

  The endless belt 6 is wound around the driving pulley 3 and the driven pulley 4, and the driving pulley 3 is rotated by driving a reduction motor (not shown) to convey the object to be conveyed. In the present embodiment, the transport direction is from left to right in FIG.

  The driven pulley 4 can be moved in the lateral direction (left-right direction in FIG. 1) by the take-up unit 5. When slip occurs, the endless belt 6 can be pulled by moving the driven pulley 4 in the left direction to eliminate the slip.

  An object to be conveyed such as foundry sand is supplied onto the endless belt 6 via the hopper 7 and conveyed. As shown in FIG. 2, a carrier roller 8 is provided on the transport side of the endless belt 6 (upper side of the belt conveyor 1) to receive the load of the transported object.

  The slip detection device 10 of the present invention is attached to one of the return rollers 2. As shown in FIG. 2, the slip detection device 10 includes a rotating member 11 attached to the return roller 2, a proximity sensor 12 attached in the vicinity of the return roller 2, and a measurement unit (not shown) connected to the proximity sensor 12. Consists of. A safety cover 13 is attached so as to surround the rotating member 11.

  As shown in FIG. 4, the rotating member 11 includes two arc-shaped detection units 11 a and 11 a detected by the proximity sensor 12 and two linear non-detection units 11 b and 11 b that are not detected by the proximity sensor 12. . The detection units 11a and 11a and the non-detection units 11b and 11b face each other, and the non-detection units 11b and 11b connect the ends of the detection units 11a and 11a, respectively.

  As the rotating member 11 rotates, the detection units 11a and 11a and the non-detection units 11b and 11b pass through the front of the proximity sensor 12, and the proximity sensor 12 detects the passage of the detection units 11a and 11a. Then, the number of passages of the detection units 11a and 11a per unit time is measured by a measuring unit (not shown), and thereby the number of rotations of the rotating member 11, that is, the number of rotations of the return roller 2 is measured. If the measured rotational speed is less than the predetermined rotational speed, it is determined that a slip has occurred, and adjustment is performed by the take-up unit 5.

  In the present embodiment, as shown in FIG. 4, when the rotation center of the rotating member 11 is O and a virtual circle C (dotted line) centered on O is drawn, the detection units 11 a and 11 a Matches part of the circumference. At this time, the non-detecting portions 11b and 11b are strings of the virtual circle C.

  And the central angle (alpha) of the circular arc which forms the detection part 11a is 60 degrees. The central angle β of the string forming the non-detecting part 11b is 120 °. Thus, by setting the central angle β to be twice or more of the central angle α, the non-detection range of the rotating member 11 can be set to be twice or more the detection range. Thereby, even when the return roller 2 with a small diameter rotates at a high speed and the detection time of the proximity sensor 12 is short, the rotation of the rotating member 11 can be reliably detected, and the number of rotations can be reliably detected by the measuring means. Can be entered.

(Second Embodiment)
Next, based on FIGS. 5-7, the 2nd Embodiment of this invention is described. Only parts different from the first embodiment will be described, and description of similar parts will be omitted.

  In the second embodiment, a rotating member 20 having the shape shown in FIG. 7 is used. As shown in FIG. 7, the rotating member 20 includes a detection unit 20a obtained by cutting a part of one cylinder and a non-detection unit 20b obtained by cutting a part of one disk. Specifically, the detection unit 20a has a semi-cylindrical shape, and the non-detection unit 20b has a substantially semicircular shape with a flat plate. The rotating member 20 is formed by attaching both ends of the detection unit 20a to the non-detection unit 20b. The reason why the non-detecting portion 20b is made substantially semicircular instead of circular is to balance the weight of the rotating member 20.

  Similar to the first embodiment, when a virtual circle centered on the rotation center of the rotating member 20 is drawn, the detection unit 20a and the non-detection unit 20b form the circumference of the virtual circle. And it is preferable that the center angle of the detection part 20a in the virtual circle is 120 to 180 degrees.

  As described above, in the second embodiment, by ensuring the maximum detection range and non-detection range of the rotating member 20, the rotation of the rotating member 20 is reliably detected by the proximity sensor 12, and the number of rotations is measured. It is possible to measure with certainty. If a high-speed counter is used in combination, it can cope with further high-speed rotation.

  As described above, the slip detection device of the present invention can reliably detect the slip between the belt and the pulley with a simple structure. For this reason, the slip can be suppressed by adjusting the take-up unit 5.

DESCRIPTION OF SYMBOLS 1 Belt conveyor 2 Return roller 3 Drive pulley 4 Driven pulley 5 Take-up unit 6 Endless belt 7 Hopper 8 Carrier roller 10 Slip detection apparatus 11 Rotating member 11a Detection part 11b Non-detection part 12 Proximity sensor 13 Safety cover 20 Rotation member 20a Detection part 20b Non-detection part

Claims (3)

  A slip detection device for detecting a slip of a belt conveyor having a return roller, comprising: a rotating member that rotates together with the return roller; and a proximity sensor that detects the rotation of the rotating member, wherein the rotating member is the proximity sensor Slip detection, characterized in that it comprises an arc-shaped detection unit that is detected by a non-detection unit that is not detected by the proximity sensor, and the proximity sensor includes a measuring unit that measures the number of detections of the detection unit. apparatus.   The rotating member is composed of two arc-shaped detection units and linear non-detection units that connect the respective ends of the two detection units, and these two detection units and two non-detection units are: The arc-shaped detectors are arranged to face each other, and the arc-shaped detectors form a part of the circumference of a virtual circle centered on the rotation center of the rotating member, and are non-detectors in the virtual circle The slip detection device according to claim 1, wherein the center angle of the detector is at least twice the center angle of the detector.   The rotating member includes a detection unit obtained by cutting a part of one cylinder and a non-detection unit obtained by cutting a part of one disk, and both the detection unit and the non-detection unit are rotated by the rotation member. 2. The center angle of a circular arc that forms a circumference of a virtual circle centered at the center and that forms a detection portion in the virtual circle is 120 ° to 180 °. Slip detection device.

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