Device and method for automatically and stably adjusting tightness of conveying belt

Abstract

The invention belongs to the technical field of belt conveying, and particularly relates to a device and method for automatically and stably adjusting the tightness of a conveying belt, and the device comprises a frame-shaped guide rail, a sliding block, a shaft, a belt wheel, a screw rod, a linear stepping motor, a pressure sensor and a controller; the sliding block is provided with a threaded hole penetrating front and back, the threaded rod is in threaded fit with the threaded hole of the sliding block, the sliding block is arranged in the frame-shaped guide rail, one end of the threaded rod is rotationally connected with the side wall of the frame-shaped guide rail, and the other end of the threaded rod penetrates through the side wall of the frame-shaped guide rail and then is connected with the linear stepping motor. The lower end of the shaft is fixedly connected to the upper surface of the sliding block, the upper end of the shaft is connected with the belt wheel through a bearing, a circle of groove is formed in the side surface of the belt wheel, and the pressure sensor is arranged in the groove. According to the technical scheme, by designing data of the ratio of the maximum outer diameter of the screw to the outer diameter of the belt wheel and the ratio of the screw pitch of the screw to the maximum outer diameter of the screw, the influence on the conveying belt due to the fact that the sliding block slides too fast in the frame type guide rail is controlled.

Description

Technical Field

[0001] The invention belongs to the technical field of belt conveyors, and in particular relates to a device and an adjustment method for automatically and stably adjusting the tightness of a conveyor belt. Background Art

[0002] The circular conveyor belt of the cigarette packaging equipment is used to transport small boxes of cigarette packs to the next process. As the conveyor belt loses its elasticity after being used for a long time, the conveyor belt will be stretched, which makes it very easy to fall off the track during the process of transporting cigarette packs. In order to ensure the stability of the tension of the conveyor belt, there are many tensioning devices for the conveyor belt in the prior art, including manual adjustment devices or automatic adjustment devices. For example, CN118830655A discloses an automatic control method and system for the tension of the suction belt. The tension sensor detects whether the tension of the suction belt is stable, and then the linear stepper motor drives the tension wheel assembly to adjust the tension. The principles of other tensioning devices are basically the same.

[0003] However, even if it is an automatic tensioning device for conveyor belt tension, in other fields, such as conveyor belts used in mines, the adjustment process of its tension force has little effect on the entire production system. Therefore, there are no excessive requirements for the tensioning device of the conveyor belt, and all devices that can achieve conveyor belt tensioning can be used. However, for cigarette packaging production lines, especially small-box cigarette packaging production lines, the production speed is fast and the interval between two adjacent small-box cigarettes is small. In this case, small changes in the conveyor belt will affect the balanced production of the entire production line. On the one hand, when the tension of the conveyor belt becomes smaller, the follow-up speed of the conveyor belt decreases. The magnitude of these decreases is not large, but it still affects the spacing between two adjacent small packages, which affects the control of the subsequent sequence, and then affects the quality stability of the small-box cigarette packaging, and increases the scrap rate; on the other hand, when adjusting through the tensioning device, the existing devices all increase the tension of the conveyor belt to the set range in a relatively short time, which in turn causes the speed of the conveyor belt to change too quickly, which will increase the distance between two adjacent small-box cigarette packages, and also cause problems. However, the prior art does not realize the problem caused by the adjustment speed of the tensioning belt. Summary of the invention

[0004] The object of the present invention is to provide a device and method for automatically and smoothly adjusting the tightness of a conveyor belt, so as to solve the problems existing in the above-mentioned background technology.

[0005] A device for automatically and stably adjusting the tightness of a conveyor belt comprises a frame-type guide rail, a slider, a shaft, a pulley, a screw, a linear stepping motor, a pressure sensor and a controller;

[0006] The slider is provided with a threaded hole that passes through the front and back, the screw rod is threadedly matched with the threaded hole of the slider, and the slider is arranged in the frame-shaped guide rail, one end of the screw rod is rotatably connected to the side wall of the frame-shaped guide rail, and the other end passes through the side wall of the frame-shaped guide rail and is connected to the linear stepping motor;

[0007] The lower end of the shaft is fixedly connected to the upper surface of the slider, and the upper end of the shaft is connected to the pulley through a bearing.

[0008] The side surface of the pulley is provided with a circle of grooves, the pressure sensor is arranged in the groove, and the pressure sensor and the linear stepping motor are both connected to the controller by electrical signals;

[0009] The ratio of the maximum outer diameter of the screw to the outer diameter of the pulley is 1:10-1:30.

[0010] Furthermore, a baffle is provided on the outer wall of the frame-type guide rail on the side where the screw rod extends out, and three through holes are provided on the baffle, wherein the middle through hole is used for passing the screw rod, and the through holes on both sides are used for fixed connection with the frame-type guide rail.

[0011] Furthermore, the slider is a rectangular parallelepiped structure, and the cooperation between the slider and the frame-type guide rail is a tightly connected sliding cooperation.

[0012] Furthermore, a threaded hole is arranged at the center point of the upper surface of the slider, and an external thread is arranged at the lower end of the shaft, and the external thread of the shaft is threadably matched with the threaded hole on the upper surface of the slider.

[0013] Furthermore, the ratio of the screw pitch to the maximum outer diameter of the screw is 1:15-30.

[0014] Furthermore, the linear stepper motor is a low-speed linear stepper motor, and the rotation speed does not exceed 20 revolutions per minute.

[0015] A control method for the device for automatically and smoothly adjusting the tension of a conveyor belt according to any one of the above items comprises the following steps:

[0016] S1. Determine the pressure range PL-PH of the conveyor belt on the pulley during normal operation;

[0017] S2, a pressure sensor on the pulley rotating with the conveyor belt detects the instantaneous pressure Pt of the conveyor belt on the pulley and transmits it to the controller;

[0018] S3. The controller makes a judgment. If Pt is within the PL-PH range, no adjustment signal is sent. If Pt is not within the PL-PH range, an adjustment signal is sent to the linear stepper motor. The linear stepper motor starts, driving the screw to rotate, thereby driving the slide to move in the frame guide rail to adjust the conveyor belt.

[0019] Further, in step S3, the linear stepper motor is started to drive the screw to rotate, thereby driving the slider to move in the frame guide rail, so as to adjust the conveyor belt in the following steps:

[0020] S31, determining the absolute difference Δ between PL-Pt or Pt-PH;

[0021] S32, the linear stepper motor drives the slider and the pulley to move at a normal speed R, and the pressure sensor synchronously detects the pressure Pt1 during the movement of the pulley and sends it to the controller;

[0022] S33, when the controller calculates that the absolute difference Δ1 of PL-Pt1 or Pt1-PH is 0.5Δ, the controller sends a control signal to the linear stepping motor, and the linear stepping motor reduces the rotation speed to 0.5R;

[0023] S34, the pressure sensor synchronously detects the pressure Ptx during the movement of the pulley and sends it to the controller, and when the absolute difference Δx of PL-Ptx or Ptx-PH decreases by 0.1Δ, the linear stepper motor reduces the speed by 0.1R until the instantaneous pressure Pt enters the PL-PH range and the linear stepper motor stops.

[0024] The beneficial effects of the present invention are:

[0025] This technical solution controls the impact of the slider sliding too fast in the frame guide rail on the conveyor belt by designing the ratio of the maximum outer diameter of the screw to the outer diameter of the pulley and the ratio of the screw pitch to the maximum outer diameter of the screw. At the same time, by controlling the speed of the linear stepper motor to gradually decrease, the tension on the conveyor belt is slowly increased, further avoiding the tension of the conveyor belt from increasing or decreasing too quickly, which would affect the conveying interval of the conveyor belt for small boxes of cigarettes. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a schematic diagram of the structure of a device for automatically and smoothly adjusting the tightness of a conveyor belt.

[0027] Description of reference numerals:

[0028] 1. Frame guide rail; 2. Baffle; 3. Screw; 4. Slider; 5. Shaft; 6. Pulley; 7. Groove. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, but cannot be construed as limiting the technical solution of the present invention.

[0030] like Figure 1As shown, the present application provides a device for automatically and smoothly adjusting the tightness of a conveyor belt, including a frame guide rail 1, a slider 4, a shaft 5, a pulley 6, a screw 3, a linear stepper motor, a pressure sensor and a controller.

[0031] The outer contour of the frame-type guide rail of the present application is a rectangular structure, a rectangular guide rail hole is arranged in the middle position of the rectangular structure, an opening is arranged on a wide side of the frame-type guide rail, the opening is blocked by a baffle 2, three through holes are arranged on the baffle, the middle through hole is used to pass the screw, and the through holes on both sides are used for fixed connection with the frame-type guide rail.

[0032] The slider is a rectangular parallelepiped structure, and the slider and the frame-type guide rail are tightly connected and slide together, thereby preventing the slider from shaking left and right relative to the frame-type guide rail, thereby affecting the adjustment accuracy.

[0033] The slider is provided with a threaded hole that penetrates front and back. The front and back penetration here refers to the front and back penetration along the long side. The screw is threadedly matched with the threaded hole of the slider, and the slider is set in the frame-type guide rail. One end of the screw is rotatably connected to the side wall of the frame-type guide rail, and the other end passes through the side wall of the frame-type guide rail and is connected to the linear stepper motor.

[0034] The lower end of the shaft is fixedly connected to the upper surface of the slider, and the upper end of the shaft is connected to the pulley through a bearing. A threaded hole is provided at the center point of the upper surface of the slider, and an external thread is provided at the lower end of the shaft. The external thread of the shaft is threadedly matched with the threaded hole on the upper surface of the slider.

[0035] A circle of grooves 7 is provided on the side surface of the pulley, a pressure sensor (not shown in the figure) is arranged in the groove, and the pressure sensor and the linear stepper motor are both connected to the controller electrical signal. In this application, the controller is an existing conventional product, and technicians in this field can obtain the required model through commercial channels.

[0036] In the present application, the ratio of the maximum outer diameter of the screw to the outer diameter of the pulley is 1:10-1:30. This outer diameter ratio can minimize the effect of excessive adjustment of the tension of the pulley caused by the rotation of the screw, which affects the spacing of the small boxes of cigarettes transported on the conveyor belt.

[0037] In the present application, the ratio of the screw pitch to the maximum outer diameter of the screw is 1:15-30. The improvement here is to reduce the moving speed of the slider by reducing the pitch, thereby further ensuring the adjustment accuracy and stability of the conveyor belt tension.

[0038] In the present application, the linear stepper motor (not shown in the figure) is a low-speed linear stepper motor with a rotation speed not exceeding 20 rpm. It can be obtained through commercial channels or the rotation speed can be adjusted by a reducer. The specific situation is selected according to the actual situation.

[0039] The present application also provides a control method for the device for automatically and smoothly adjusting the tightness of a conveyor belt according to any one of the above items, comprising the following steps:

[0040] S1. Determine the pressure range PL-PH of the conveyor belt on the pulley during normal operation; the low pressure is PL and the high pressure is PH. The specific relative data is obtained through multiple tests on the production line.

[0041] S2. The pressure sensor on the pulley rotating with the conveyor belt detects the instantaneous pressure Pt of the conveyor belt on the pulley and transmits it to the controller. By arranging the pressure sensor on the pulley, the technical solution can detect the instantaneous pressure data of the conveyor belt and transmit the detected instantaneous pressure data to the controller.

[0042] S3. The controller makes a judgment. If Pt is within the PL-PH range, no adjustment signal is sent. If Pt is not within the PL-PH range, an adjustment signal is sent to the linear stepper motor. The linear stepper motor starts, driving the screw to rotate, thereby driving the slide to move in the frame guide rail to adjust the conveyor belt.

[0043] Specifically, the linear stepper motor is started to drive the screw to rotate, thereby driving the slider to move in the frame guide rail to adjust the conveyor belt in the following steps:

[0044] S31, determine the absolute difference Δ between PL and Pt. This step is when the instantaneous pressure Pt is less than the minimum pressure PL, indicating that the conveyor belt is stretched, and the device moves to tighten the conveyor belt. The absolute difference Δ between Pt and PH indicates that the instantaneous pressure Pt is greater than the maximum pressure PH, indicating that the conveyor belt is over-tensioned at this time, and the conveyor belt needs to be reduced by moving the device. In this embodiment, the absolute difference Δ between PL and Pt, that is, the conveyor belt needs to be tightened, is used as an example for explanation.

[0045] S32. The linear stepper motor drives the slider and the pulley to move at a normal speed R, and the pressure sensor synchronously detects the pressure Pt1 during the movement of the pulley and sends it to the controller; in this technology, the normal speed R is the speed of the aforementioned linear stepper motor not exceeding 20r / min, and the speed of 20r / min is used for explanation here.

[0046] S33, when the controller calculates that the absolute difference Δ1 of PL-Pt1 or Pt1-PH is 0.5Δ, the controller sends a control signal to the linear stepping motor, and the linear stepping motor reduces the rotation speed to 0.5R;

[0047] S34, the pressure sensor synchronously detects the pressure Ptx during the movement of the pulley and sends it to the controller, and the linear stepper motor reduces the speed by 0.1R every time the absolute difference Δx of PL-Ptx or Ptx-PH decreases by 0.1Δ, until the instantaneous pressure Pt enters the PL-PH range, and the linear stepper motor stops. This step gradually reduces the speed of the linear stepper motor, so that the device and the slider move at a lower speed, gradually move to the final position, and realize the smooth and slow tensioning of the conveyor belt.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for automatically and stably adjusting the tension of a conveyor belt, characterized in that: Including frame guide rails, sliders, shafts, pulleys, screws, linear stepper motors, pressure sensors and controllers; The slider is provided with a threaded hole that passes through the front and back, the screw rod is threadedly matched with the threaded hole of the slider, and the slider is arranged in the frame-shaped guide rail, one end of the screw rod is rotatably connected to the side wall of the frame-shaped guide rail, and the other end passes through the side wall of the frame-shaped guide rail and is connected to the linear stepping motor; The lower end of the shaft is fixedly connected to the upper surface of the slider, and the upper end of the shaft is connected to the pulley through a bearing. The side surface of the pulley is provided with a circle of grooves, the pressure sensor is arranged in the groove, and the pressure sensor and the linear stepping motor are both connected to the controller by electrical signals; The ratio of the maximum outer diameter of the screw to the outer diameter of the pulley is 1:10-1:

30.

2. The device for automatically and stably adjusting the tension of a conveyor belt according to claim 1, characterized in that: A baffle is arranged on the outer side wall of the frame-type guide rail where the screw rod extends out. The baffle is provided with three through holes, wherein the middle through hole is used for passing the screw rod, and the through holes on both sides are used for fixed connection with the frame-type guide rail.

3. The device for automatically and stably adjusting the tension of a conveyor belt according to claim 1, characterized in that: The slider is a rectangular parallelepiped structure, and the cooperation between the slider and the frame-type guide rail is a tightly connected sliding cooperation.

4. The device for automatically and stably adjusting the tension of a conveyor belt according to claim 3 is characterized in that: A threaded hole is arranged at the center point of the upper surface of the slider, and an external thread is arranged at the lower end of the shaft. The external thread of the shaft is threadably matched with the threaded hole on the upper surface of the slider.

5. The device for automatically and stably adjusting the tension of a conveyor belt according to claim 1, characterized in that: The ratio of the pitch of the screw to the maximum outer diameter of the screw is 1:15-30.

6. The device for automatically and stably adjusting the tension of a conveyor belt according to claim 1, characterized in that: The linear stepper motor is a low-speed linear stepper motor, and the rotation speed does not exceed 20 revolutions per minute.

7. A control method for the device for automatically and smoothly adjusting the tension of a conveyor belt according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Determine the pressure range PL-PH of the conveyor belt on the pulley during normal operation; S2, a pressure sensor on the pulley rotating with the conveyor belt detects the instantaneous pressure Pt of the conveyor belt on the pulley and transmits it to the controller; S3. The controller makes a judgment. If Pt is within the PL-PH range, no adjustment signal is sent. If Pt is not within the PL-PH range, an adjustment signal is sent to the linear stepper motor. The linear stepper motor starts, driving the screw to rotate, thereby driving the slide to move in the frame guide rail to adjust the conveyor belt.

8. The control method of the device for automatically and smoothly adjusting the tension of a conveyor belt according to claim 7, characterized in that: In step S3, the linear stepper motor is started to drive the screw to rotate, thereby driving the slider to move in the frame guide rail, so as to adjust the conveyor belt in the following steps: S31, determining the absolute difference Δ between PL-Pt or Pt-PH; S32, the linear stepper motor drives the slider and the pulley to move at a normal speed R, and the pressure sensor synchronously detects the pressure Pt1 during the movement of the pulley and sends it to the controller; S33, when the controller calculates that the absolute difference Δ1 of PL-Pt1 or Pt1-PH is 0.5Δ, the controller sends a control signal to the linear stepping motor, and the linear stepping motor reduces the rotation speed to 0.5R; S34, the pressure sensor synchronously detects the pressure Ptx during the movement of the pulley and sends it to the controller, and when the absolute difference Δx of PL-Ptx or Ptx-PH decreases by 0.1Δ, the linear stepper motor reduces the speed by 0.1R until the instantaneous pressure Pt enters the PL-PH range and the linear stepper motor stops.

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