A belt tensioning system based on compound variable control

Abstract

The utility model belongs to the technical field of belt tensioning equipment, concretely is a kind of belt tensioning system based on composite variable control. Including tensioning trolley, the driven roller of belt conveyor is installed on the tensioning trolley, tensioning oil cylinder, the tensioning oil cylinder output end connection tensioning trolley, and tensioning oil cylinder is fixed on cement platform;Analog output type pressure sensor, the pressure of tensioning oil cylinder is detected by analog output type pressure sensor;Belt scale, the belt scale is arranged on the belt on belt conveyor, for time detection belt machine load change condition;Rotational speed detection switch element, rotational speed detection switch element is arranged in the driven roller of belt conveyor, for detecting the rotational speed of driven roller;Hydraulic system, the hydraulic system controls tensioning oil cylinder;Control system, the information of analog output type pressure sensor, belt scale and rotational speed detection switch element is collected by control system, and the instruction information of hydraulic system output is controlled.

Description

Technical Field

[0001] This utility model belongs to the technical field of belt tensioning equipment, specifically a belt tensioning system based on composite variable control. Background Technology

[0002] The automatic hydraulic belt tensioning device mainly consists of a tensioning trolley, a tensioning cylinder, a hydraulic system, a pressure detection device, hydraulic valves, and an electrical control system. The tensioning cylinder is connected to the tensioning trolley, allowing for arbitrary adjustment of the tensioning pressure. To address the different tensioning requirements during belt startup and normal operation, the starting tension and normal operation tension can be adjusted arbitrarily according to the belt conveyor's tension needs, ensuring that the starting pressure is 1.3-1.5 times the normal operation pressure.

[0003] When the conveyor belt starts, it is in an oscillating state under the action of stress waves. The rapid contraction of the tensioning cylinder ensures that the belt tension is constant and compensates for the elastic oscillation of the belt in time, so that the start-up is smooth and reliable, reducing the impact dynamic load during start-up, avoiding "belt buckling" and over-tightening, and also reducing the occurrence of "belt drifting" and belt breakage accidents.

[0004] When a belt conveyor is in operation, the tensioning device must reach the pre-tension pressure, and the conveyor belt must be in a normal tensioned state before the main motor of the belt conveyor can be started. The belt hydraulic automatic tensioning device adopts a typical pressure-maintaining circuit, which is composed of a hydraulic system and a PLC automatic control system. The system pressure is monitored at any time through pressure detection elements.

[0005] Because the tensioning system adopts a constant pressure control mode, the conveyor belt is in a state of tension throughout the entire working process. When the conveyor belt is subjected to sudden load, it cannot respond quickly or compensate for changes in the length of the conveyor belt. The belt is prone to fatigue, which accelerates the aging of the belt and, in severe cases, can lead to belt breakage. Summary of the Invention

[0006] To address the problem that the constant pressure control mode of the tensioning system cannot quickly respond to and compensate for changes in the conveyor belt length, leading to belt fatigue and accelerated aging, this invention provides a belt tensioning system based on composite variable control.

[0007] This utility model adopts the following technical solution: a belt tensioning system based on composite variable control, comprising:

[0008] A tensioning trolley, on which driven rollers of a belt conveyor are mounted.

[0009] A tensioning cylinder, the output end of which is connected to a tensioning trolley, is fixed to a cement platform;

[0010] An analog output pressure sensor is used to detect the pressure of the tensioning cylinder.

[0011] A belt scale is installed on the belt of a conveyor belt and is used to detect changes in the load of the conveyor belt in real time.

[0012] A speed detection switch element is installed on the driven roller of the belt conveyor to detect the speed of the driven roller;

[0013] A hydraulic system that controls the tensioning cylinder;

[0014] The control system acquires information from analog output pressure sensors, belt scales, and speed detection switches, and outputs command information to the hydraulic system.

[0015] In some embodiments, the hydraulic system includes:

[0016] The hydraulic pump is driven by an electric motor, and its inlet is connected to an oil tank via a filter.

[0017] A proportional control valve, wherein the inlet of the proportional control valve is connected to the outlet of the hydraulic pump;

[0018] A manual directional valve is provided, wherein the P port of the manual directional valve is connected to the oil outlet of the proportional regulating valve, and the A and B ports of the manual directional valve are respectively connected to the inlet and outlet ports of the tensioning cylinder. An analog output type pressure sensor is installed at the A port of the manual directional valve.

[0019] In some embodiments, a check valve and a relief valve I are provided between the outlet of the hydraulic pump and the inlet of the proportional control valve.

[0020] In some embodiments, a pressure gauge I is installed between the oil outlet of the proportional control valve and the P port of the manual directional valve.

[0021] In some embodiments, port A of the manual directional valve is connected to relief valve II, pressure gauge II, accumulator and shut-off valve respectively, and the shut-off valve is connected to the oil tank.

[0022] In some embodiments, the control system outputs signals to the proportional control valve and the motor.

[0023] In some embodiments, the control system includes a PLC and a text display. The PLC is signal-connected to an analog output pressure sensor, a belt scale, a speed detection switch element, a proportional control valve, and a motor. The text display is signal-connected to the PLC.

[0024] In some embodiments, a hydraulic check valve is also provided between the A and B ports of the manual directional valve and the inlet and outlet ports of the tensioning cylinder.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention inputs the real-time setpoints and feedback values ​​of variables such as pressure, belt volume, and belt speed during the operation of the conveyor belt machine into the corresponding loop, forming a composite setpoint, which is then input into the system control loop. The control loop uses conventional PID control algorithms, feedforward control algorithms, and dedicated coupling algorithms to form a control mathematical model of the controlled variable. Finally, the control loop controls the opening of the proportional regulating valve to achieve a fast, smooth, and stable control effect. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the hydraulic system of the present invention;

[0029] Figure 3 This is a schematic diagram of the control system principle;

[0030] Figure 4 This is a schematic diagram illustrating the control principle of a composite variable proportional control valve for a conveyor belt machine.

[0031] Figure 5 This is a schematic diagram of the tension force in the starting state of the conveyor belt machine;

[0032] Figure 6 This is a schematic diagram showing the tension force during the operation of a conveyor belt machine.

[0033] Figure 7 A schematic diagram showing the tension force in a slipping conveyor belt machine.

[0034] In the diagram, 1-filter, 2-hydraulic pump, 3-motor, 4-check valve, 5-relief valve I, 6-manual directional valve, 7-pressure gauge I, 8-hydraulic check valve, 9-relief valve II, 10-analog output pressure sensor, 11-proportional regulating valve, 12-pressure gauge II, 13-accumulator, 14-stop valve, 15-tensioning cylinder, 16-belt, 17-tensioning trolley, 18-hydraulic system, 19-speed detection switch element, 20-belt scale, 21-driven roller. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0036] like Figure 1 As shown, a belt tensioning system based on composite variable control includes:

[0037] A tensioning trolley 17 is equipped with driven rollers 21 of a belt conveyor.

[0038] A tensioning cylinder 15 is provided, the output end of which is connected to a tensioning trolley 17. The tensioning cylinder 15 is fixed on a cement platform.

[0039] Analog output pressure sensor 10, the analog output pressure sensor 10 detects the pressure of tension cylinder 15;

[0040] A belt scale 20 is installed on the belt 16 of the conveyor belt and is used to detect changes in the load of the conveyor belt in real time.

[0041] A speed detection switch element 19 is disposed on the driven roller 21 of the belt conveyor and is used to detect the speed of the driven roller.

[0042] Hydraulic system 18, which controls tension cylinder 15;

[0043] The control system acquires information from the analog output pressure sensor 10, the belt scale 20, and the speed detection switch element 19, and outputs command information to the hydraulic system 18.

[0044] like Figure 2 As shown, the hydraulic system includes:

[0045] Hydraulic pump 2, which is driven by motor 3, has its inlet connected to oil tank via filter 1;

[0046] A proportional regulating valve 11, the oil inlet of which is connected to the outlet of the hydraulic pump 2;

[0047] The manual directional valve 6 has its P port connected to the oil outlet of the proportional regulating valve 11, and its A and B ports connected to the inlet and outlet ports of the tensioning cylinder, respectively. An analog output pressure sensor is installed at the A port of the manual directional valve 6.

[0048] Specifically, an analog output pressure sensor monitors the pressure of the tensioning cylinder 15 in real time; the belt scale of the conveyor belt monitors the load changes of the conveyor belt in real time, and a speed detection switch element is added at the driven roller of the conveyor belt. When the conveyor belt slips, the control system automatically increases the tension of the cylinder; when the conveyor belt breaks, an alarm is triggered and the machine is interlocked to stop. The tension of the conveyor belt is automatically adjusted through an electro-hydraulic proportional regulating valve with adjustment function.

[0049] The control system has two control modes: multivariable coupled output and single-variable output. When using multivariable coupled output, the control system inputs the setpoints and feedback values ​​of variables such as real-time pressure, belt volume, and belt speed during the operation of the conveyor belt into the corresponding loop, forming a composite setpoint, which is then input into the system control loop. The control loop uses conventional PID control algorithms, feedforward control algorithms, and dedicated coupling algorithms to form a control mathematical model of the controlled variable. Finally, the control loop controls the opening of the proportional regulating valve to achieve a fast, smooth, and stable control effect.

[0050] By employing a multivariable dedicated control algorithm, the pre-tensioning pressure required by the tensioning device during belt conveyor startup is met, ensuring the conveyor belt is in a normally tensioned state. The tension gradually increases with startup time, smoothly rising until it reaches the preset value before the main motor of the belt conveyor is allowed to start. During operation, the tension is automatically adjusted according to the belt load measured by the belt scale, ensuring appropriate tension and preventing over-tensioning, thus increasing the belt conveyor's service life. If belt slippage occurs, the tension increases rapidly to prevent material accumulation. The following diagram illustrates the actual tension effect of the belt conveyor under various operating conditions.

[0051] A check valve 4 and a relief valve I5 are installed between the outlet of the hydraulic pump 2 and the inlet of the proportional regulating valve 11.

[0052] A pressure gauge I7 is installed between the oil outlet of the proportional regulating valve 11 and the P port of the manual directional valve 6.

[0053] Port A of the manual directional valve 6 is connected to relief valve II9, pressure gauge II12, accumulator 13 and shut-off valve 14 respectively, and shut-off valve 14 is connected to the oil tank.

[0054] The control system outputs signals to the proportional control valve 11 and the motor 3.

[0055] The control system includes a PLC and a text display. The PLC signal is connected to the analog output pressure sensor 10, belt scale 20, speed detection switch element 19, proportional control valve 11 and motor 3. The text display signal is connected to the PLC.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A belt tensioning system based on composite variable control, characterized in that, include: A tensioning trolley, on which driven rollers of a belt conveyor are mounted. A tensioning cylinder, the output end of which is connected to a tensioning trolley, is fixed to a cement platform; An analog output pressure sensor is used to detect the pressure of the tensioning cylinder. A belt scale is installed on the belt of a conveyor belt and is used to detect changes in the load of the conveyor belt in real time. A speed detection switch element is provided, which is installed on the driven roller of the belt conveyor and is used to detect the speed of the driven roller; A hydraulic system that controls the tensioning cylinder; The control system acquires information from the analog output pressure sensor, belt scale, and speed detection switch, and outputs command information to the hydraulic system. The hydraulic system includes: The hydraulic pump is driven by an electric motor, and its inlet is connected to an oil tank via a filter. A proportional control valve, wherein the inlet of the proportional control valve is connected to the outlet of the hydraulic pump; A manual directional valve, wherein the P port of the manual directional valve is connected to the oil outlet of the proportional regulating valve, and the A port and B port of the manual directional valve are respectively connected to the inlet and outlet ports of the tensioning cylinder, and an analog output type pressure sensor is installed at the A port of the manual directional valve. A check valve and a relief valve I are provided between the outlet of the hydraulic pump and the inlet of the proportional regulating valve. The A port of the manual reversing valve is connected to the relief valve II, pressure gauge II, accumulator and shut-off valve respectively, and the shut-off valve is connected to the oil tank. The control system outputs signals to the proportional control valve and the motor.

2. The belt tensioning system based on composite variable control according to claim 1, characterized in that, A pressure gauge I is installed between the oil outlet of the proportional regulating valve and the P port of the manual directional valve.

3. The belt tensioning system based on composite variable control according to claim 1, characterized in that, The control system includes a PLC and a text display. The PLC signal is connected to an analog output pressure sensor, a belt scale, a speed detection switch, a proportional control valve, and a motor. The text display signal is connected to the PLC.

4. The belt tensioning system based on composite variable control according to claim 1, characterized in that, A hydraulic check valve is also provided between the A and B ports of the manual reversing valve and the inlet and outlet ports of the tensioning cylinder.

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