Method for controlling constant height of metering pipe

Abstract

The invention discloses a constant height control method for a metering tube, which comprises the following steps of: 1, mounting a material stirring roller adjusting bracket at a material stirring roller of a feeding machine, so that the position of the material stirring roller in the vertical direction of an elevator is adjustable; 2, a material stirring roller adjusting motor and a material stirring roller adjusting device are installed at the material stirring roller, and the distance between the material stirring roller and a lifting belt of the lifting machine is controlled; 3, the PLC obtains the operation flow of the electronic belt scale through S7 communication; 4, the actual position of the shifting roller is calculated through a constant flow control algorithm; 5, the height of the material level is detected through a metering grating; 6, the actual operation frequency of the lifting belt is finely adjusted through material level height operation. According to the invention, the stability of the instantaneous flow of the electronic belt scale in the cut-tobacco workshop can be improved, so that the problem of unstable cut-tobacco process quality caused by cut-off due to flow fluctuation of the electronic belt scale in the flow line production process of the cut-tobacco workshop is solved.

Description

Technical Field

[0001] The invention relates to the technical field of industrial automation, in particular to a method for controlling the height of materials in a metering tube in a material flow control system in the tobacco industry. Background Art

[0002] In the tobacco industry, in order to ensure the stability of the material flow entering the host equipment, a flow control system is configured in front of the host, which mainly includes three parts: electronic belt scale, metering tube, and elevator feeder. The electronic belt scale operates according to the set flow. There are three photoelectric tubes on the metering tube above the electronic belt scale, namely high material level, middle material level, and low material level photoelectric tubes. When the high material level photoelectric tube is blocked by the material, the elevator in front of the metering tube stops running; when the middle material level photoelectric tube is blocked, the elevator runs at low speed, and when it is not blocked, the elevator runs at medium speed; when the low material level is not blocked, the elevator runs at high speed; when this control method is used, the material height in the metering tube keeps changing between low material level and high material level, resulting in the compaction density of the material in the metering tube keeps changing. Therefore, the material density on the electronic belt scale keeps changing, resulting in fluctuations in the flow of the electronic belt scale. Summary of the Invention

[0003] The present invention is intended to address the deficiencies of the above-mentioned prior art and propose a control system for a constant height of a metering tube, in order to improve the stability of the instantaneous flow of the electronic belt scale in the silk-making workshop, thereby solving the problem of flow interruption caused by flow fluctuations of the electronic belt scale during the production process of the silk-making workshop assembly line, resulting in unstable silk-making process quality and other problems.

[0004] In order to achieve the above-mentioned object, the present invention adopts the following technical solutions:

[0005] The present invention provides a method for controlling the constant height of a metering tube, characterized in that it is applied to a control system consisting of an adjustment motor for a feed roller, an adjustment mechanism for the feed roller, a metering tube, an elevator, an electronic belt scale, and a PLC-based CPU controller. The feed roller is fixed to the elevator via an adjustment bracket, and the main shaft of the feed roller is fixedly connected to the bracket. The constant height control method is performed according to the following steps:

[0006] Step 1: Use the electronic belt scale to obtain the flow rate F1 of the material at the discharge port of the metering pipe on the production line and send it to the CPU controller;

[0007] Step 2: The CPU controller uses a distance measurement sensor to obtain the measured distance D between the axis center line of the feed roller and the belt of the elevator;

[0008] Step 3, the CPU controller calculates the vertical distance A=Dr between the outer surface of the feed roller and the elevator, where r is the radius of the feed roller;

[0009] Step 4: The CPU controller obtains the density ρ of the material on the elevator belt and the width e of the elevator;

[0010] Step 5: The CPU controller establishes the relationship between the current material flow F2 on the belt of the elevator: F2=e×(Dr)×V2×ρ;

[0011] Step 6: Let F1 = F2, so as to obtain the expected linear speed of the elevator V2 = F1 / [(e×(Dr)×ρ)];

[0012] Step 7: Set the operating frequency f of the lifting belt to the minimum value f min and the maximum value f max Between, and get the motor speed n of the elevator;

[0013] Step 8. Calculate the linear velocity of the hoist belt of the hoist: V1 = 2πR × n / 60i, where R is the radius of the driving wheel of the hoist and i is the speed ratio between the motor and the reducer of the hoist.

[0014] Step 9, let V1=V2, and obtain the theoretical distance between the axis centerline of the feed roller and the belt of the elevator: D'=F1×p×i / (2πR×ρ×e)+r, where p is the number of pole pairs of the elevator motor;

[0015] Step 10: The CPU controller controls the adjustment motor of the material feeding roller according to D to drive the adjustment mechanism of the material feeding roller to adjust D so that the current material flow F2 running on the lifting belt and the material flow F1 at the discharge port of the metering tube obtained by the electronic belt scale remain constant.

[0016] An electronic device of the present invention includes a memory and a processor, wherein the memory is used to store a program that supports the processor to execute the control method, and the processor is configured to execute the program stored in the memory.

[0017] The present invention provides a computer-readable storage medium, wherein a computer program is stored on the computer-readable storage medium, and the computer program executes the steps of the control method when executed by a processor.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The constant height control method for a metering tube of the present invention ensures that the material height in the metering tube is maintained within a certain range by controlling the constant flow rate of the elevator, thereby reducing fluctuations in the flow rate of the electronic belt scale caused by changes in the compaction density in the metering tube.

[0020] 2. The constant height control method of the metering tube of the present invention not only ensures the stability of the material height in the metering tube, but also reduces the number of starts and stops of the elevator, ensures the constant speed operation of the elevator, reduces elevator equipment failures, and avoids metering tube blockage caused by high-speed operation of the elevator. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a system diagram of the present invention;

[0022] Figure 2 is a control flow chart of the method of the present invention;

[0023] Numbers in the figure: 1, feeder 2, drive motor bracket 3, drive motor of feed roller 4, feed roller bracket 5, lifting belt 6, blanking photoelectric tube 7, metering tube 8, electronic belt scale 9, feed roller adjustment motor 10, feed roller adjustment mechanism 11, feed roller. DETAILED DESCRIPTION

[0024] In this embodiment, the constant height control system of the metering tube is applied to a system consisting of a feeding roller adjustment motor 9, a feeding roller adjustment mechanical device 10, a metering tube 8, a hoist and a PLC CPU controller. Figure 1 As shown, a feeding roller adjustment bracket 4 is installed at the feeding roller of the feeder 1, so that the feeding roller 11 can be adjusted in the vertical direction of the elevator. The lifting belt of the elevator is driven by an electric motor to transport the material on the bottom belt of the elevator; a feeding roller adjustment motor 9 and a feeding roller adjustment mechanical device 10 are installed at the feeding roller 11, and the feeding roller is driven by a servo motor to adjust the distance between the feeding roller and the lifting belt of the elevator, so as to control the lifting material flow to be consistent with the operating flow of the electronic belt scale 8, and keep the material level height of the metering tube 7 constant. The PLC obtains the operating flow of the electronic belt scale 8 through S7 communication, and calculates the actual position of the feeding roller 11 through the constant flow control algorithm, and then detects the material level height through the metering grating. Finally, the actual operating frequency of the lifting belt is fine-tuned through the material level calculation. Specifically, Figure 2 As shown, the method is carried out in the following steps:

[0025] Step 1: Use the electronic belt scale 8 to obtain the flow rate F1 of the material at the discharge port of the metering tube 7 on the production line and send it to the CPU controller;

[0026] Step 2: The CPU controller uses a distance measuring sensor to obtain a measured distance D between the axis center line of the feed roller 11 and the belt of the elevator;

[0027] Step 3: The CPU controller calculates the vertical distance A=Dr between the outer surface of the feeding roller 11 and the elevator, where r is the radius of the feeding roller 11;

[0028] Step 4: The CPU controller obtains the density ρ of the material on the elevator belt and the width e of the elevator;

[0029] Step 5: The CPU controller establishes the relationship between the current material flow F2 on the belt of the elevator: F2=e×(Dr)×V2×ρ;

[0030] Step 6: Let F1 = F2, so as to obtain the expected linear speed of the elevator V2 = F1 / [(e×(Dr)×ρ)];

[0031] Step 7: Set the operating frequency f of the lifting belt to the minimum value f min and the maximum value f max Between, and get the motor speed n of the elevator;

[0032] Step 8. Calculate the linear velocity of the hoist belt of the hoist: V1 = 2πR × n / 60i, where R is the radius of the driving wheel of the hoist and i is the speed ratio between the motor and the reducer of the hoist.

[0033] Step 9: Let V1 = V2, and obtain the theoretical distance D' between the axis centerline of the feed roller 11 and the belt of the elevator = F1 × p × i / (2πR × ρ × e) + r, where p is the number of pole pairs of the elevator motor;

[0034] Step 10: The CPU controller controls the adjustment motor 9 of the material dispensing roller 11 according to D' to drive the adjustment mechanism 10 of the material dispensing roller 11 to adjust D so that the current material flow F2 running on the lifting belt and the material flow F1 at the discharge port of the metering tube 7 obtained by the electronic belt scale 8 remain constant.

[0035] In this embodiment, an electronic device includes a memory and a processor, wherein the memory is used to store a program that supports the processor to execute the above method, and the processor is configured to execute the program stored in the memory.

[0036] In this embodiment, a computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are executed.

[0037] To sum up, the method of the present invention addresses the defects of the existing storage cabinet discharge control method. It adds a grating detection device at the upper end of the storage cabinet discharge port, and calculates the different bottom belt frequencies corresponding to different material levels according to the height of the material level through the Siemens PLC, thereby effectively avoiding the phenomenon of material blockage and material shortage, avoiding manual intervention, greatly reducing the fluctuation range of material flow, ensuring the normal and smooth progress of production, and has low cost investment, easy installation, simple maintenance, and strong applicability.

Claims

1. A method for controlling the constant height of a metering tube, characterized in that: The invention is applied to a control system composed of an adjustment motor for a feeding roller, an adjustment mechanism for the feeding roller, a metering tube, an elevator, an electronic belt scale, and a PLC-based CPU controller. The feeding roller is fixed on the elevator through an adjustment bracket, and the main shaft of the feeding roller is fixedly connected to the bracket. The constant height control method is performed according to the following steps: Step 1: Use the electronic belt scale to obtain the flow rate F1 of the material at the discharge port of the metering pipe on the production line and send it to the CPU controller; Step 2: The CPU controller uses a distance measurement sensor to obtain the measured distance D between the axis center line of the feed roller and the belt of the elevator; Step 3, the CPU controller calculates the vertical distance A=Dr between the outer surface of the feed roller and the elevator, where r is the radius of the feed roller; Step 4: The CPU controller obtains the density ρ of the material on the elevator belt and the width e of the elevator; Step 5: The CPU controller establishes the relationship between the current material flow F2 on the belt of the elevator: F2=e×(Dr)×V2×ρ; Step 6: Let F1 = F2, so as to obtain the expected linear speed of the elevator V2 = F1 / [(e×(Dr)×ρ)]; Step 7: Set the operating frequency f of the lifting belt to the minimum value f min and the maximum value f max Between, and get the motor speed n of the elevator; Step 8. Calculate the linear velocity of the hoist belt of the hoist: V1 = 2πR × n / 60i, where R is the radius of the driving wheel of the hoist and i is the speed ratio between the motor and the reducer of the hoist. Step 9, let V1=V2, and obtain the theoretical distance between the axis centerline of the feed roller and the belt of the elevator: D'=F1×p×i / (2πR×ρ×e)+r, where p is the number of pole pairs of the elevator motor; Step 10: The CPU controller controls the adjustment motor of the material feeding roller according to D to drive the adjustment mechanism of the material feeding roller to adjust D so that the current material flow F2 running on the lifting belt and the material flow F1 at the discharge port of the metering tube obtained by the electronic belt scale remain constant.

2. An electronic device comprising a memory and a processor, characterized in that: The memory is used to store a program that supports a processor to execute the control method according to any one of claims 1 , and the processor is configured to execute the program stored in the memory.

3. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the control method according to claim 1 are executed.

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