Graduation design of mine hoist

1. PLC control system of mine hoist (1) current situation of domestic hoist (1) AC drive mode adopts series resistance speed regulation AC drive mode, including single rope and multi rope series. Most of them adopt the speed regulation method of changing slip ratio s, which proces a lot of slip power in speed regulation and consumes a lot of electric energy on the additional resistance of rotor, The result is that the economy of speed regulation becomes worse. Few hoists adopt cascade speed regulation method, which has narrow speed regulation range and large investment 2 DC drive mode is widely used in coal mines in China, but most of them are SCR-D electric control system of mine hoist introced in 1980s and made in China before mid-1990s. The regulation, control and protection circuits of these electronic control systems are basically analog. This system has some defects e to the limitation of component design and manufacturing level 3 Research and development 1. Domestic large DC hoist and electric control system has been graally improved and promoted. 2. The efficiency of high-power variable-frequency speed control electric hoist can reach 98%. Domestic organizations have studied this system and applied it to actual proction. 2、 PLC hardware composition and principle PLC is mainly composed of power supply, CPU, communication unit, high count unit, analog I / O unit, digital I / O unit and other hardware 1 The main control PLC system consists of power supply, CPU, communication unit, high count unit, analog I / O unit, digital I / O unit and other hardware. Installed in the main control cabinet. The auxiliary control PLC system consists of power supply, CPU, communication unit, high count unit, analog I / O unit, digital I / O unit and other hardware 2 Basic characteristics of each unit: 1. Power supply unit: the input voltage of power supply is 100-240V AC, which provides bus power and basic power for PLC; 2. CPU unit: CPU unit is the core of PLC, including memory interface and programming interface, which is the carrier of program execution. A memory mole inserted on the memory mole uses a lithium battery to keep the contents of ram; PLC can be set to "stop" or "run" mode for program execution. 3、 Control principle (1) stator control loop when the wellhead or bottom of the well sends a start-up signal to the machine room, if the main power supply and control power supply are connected at this time; The oil pump motor has been running; Oil temperature and oil pressure are normal; The brake handle and control handle are in the zero position, the overwinding reset, brake adjustment change-over switch, maintenance phase change-over switch and maintenance shift change-over switch are in the normal position, the brake change-over switch is in the pedal position, and it is ready to start the hoist (winch). Under normal conditions, if the brake handle is pushed forward slowly to release the brake, when the oil pressure reaches the opening voltage, the control handle is pushed forward or backward at the same time, the main contactor is closed immediately, and the main motor stator is connected with power, then the hoist (winch) starts to rotate forward or backward, so as to lift or lower the load 2 After the stator circuit of the rotor control circuit is powered on, the control handle is still in the power supply state, the additional resistance of the rotor circuit of the main motor is added, and the output torque of the motor shaft is only 30-40% of the rated torque. This torque can eliminate the gear clearance of the transmission system and smoothly tighten the steel rope to rece the impact. It can also start the hoist (winch) with light load. At this time, the hoist (winch) runs stably on the preparatory stage. At this time, the hoist (winch) will proce a crawling speed of 0.3-0.5 M / s when it is under light load, so as to check the shaft and wire rope, and meet the requirements of the tramcar crawling on the throwing Lane in the inclined shaft lifting. Push the control handle forward or backward gear by gear, PLC will close 1jc-5jc (or 8jc) respectively according to the starting current and gear delay, and cut off the rotor resistance of the motor in sections, so as to realize the transformation from the preparatory stage to the acceleration stage, and the motor will accelerate graally. When the handle is pushed to the front end or the last end, the constant speed contactor (the last acceleration contactor) acts, all the additional resistance is cut off, and the hoist (winch) accelerates and enters the constant speed stage. The cutting off of motor rotor is based on the principle of current function and time function. The series of external resistance of motor is determined by motor power and rotor parameters. Generally, grade 5 or grade 8 starting resistance is adopted. The hoist (winch) can be adjusted from low speed to high speed or from high speed to low speed. At this time, as long as the control handle is pushed out or pulled back to any gear position, the hoist (winch) can stably operate at the corresponding speed of the position 3 When the deceleration control hoist (winch) runs to the deceleration point (which can be set by PLC), PLC will give the deceleration signal, JSJ will act, the deceleration bell will ring and the deceleration indicator light will be on, causing the winch driver's attention. At the same time, the winch will automatically decelerate to the last two or three gears; After receiving the deceleration signal, the winch driver shall, according to the operation experience, retract the operating handle gear by gear to graally decelerate the hoist (winch) and make the motor decelerate to the crawling speed. When the hoist (winch) runs to the terminal position, the brake handle and operating handle shall be quickly pulled back to the zero position. When the hoist (winch) is running fast to the end point, the adjustable mechanical brake can be used to rece the speed until it runs to the end point 4 Speed limit protection circuit when the hoist (winch) enters the deceleration stage, on the one hand, PLC will automatically rece the gear, on the other hand, it will speed limit according to the speed given curve. In the deceleration stage, more than 10% PLC will brake safely 5 When the hoist (winch) enters the stage of constant speed operation, the voltage signal detected by the tachometer generator, on the one hand, is sent to the PLC through the transmitter for processing, and 15% of the rated speed PLC is used for safety braking; On the other hand, the over speed protection signal is given by setting the over speed relay GSJ. One signal of GSJ enters the hardware safety circuit for safety braking, and the other signal enters the PLC for software safety circuit for safety braking. 2. When the hoist (winch) enters the stage of constant speed operation, a rotary encoder is installed beside the recer or low-speed shaft to detect the rope speed, which is processed by PLC, and 15% of the rated speed is used for safe braking. Free paper website: http://www.xoock.com

2. I have a mine hoist design

3. The design of double hinged scissor hydraulic lifting table

has this

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4. To draw an assembly drawing of No.0 drawing, No.1 part drawing of drum, No.2 drawing of main shaft, No.2 drawing of crown wheel, No.3 drawing of crown wheel shaft, No.2 drawing of brake. I think so, make a reference, ha ha.

5. Abstract

this paper will introce the design of frequency conversion speed regulation system of mine hoist based on single chip microcomputer control, through the single chip microcomputer control frequency converter, the frequency converter to control the rotation of the motor, realize the positive and negative speed control of mine hoist, and real-time display the speed and position of the lifting object
with the development of variable frequency speed regulation technology, variable frequency speed regulation has become the mainstream of AC speed regulation, and has been widely used in chemical fiber, textile, iron and steel, machinery, paper and other instries. The control panel of frequency converter is equipped with keyboard and LCD display window, but it can only realize manual operation. In order to carry out automatic control, MCU technology is introced to realize data communication between MCU and frequency converter, so as to improve the control ability and control range of frequency converter
the variable frequency speed controller composed of single-chip microcomputer can realize starting from low frequency (1-2HZ) to 50 Hz, eliminate the impact of direct starting at 50 Hz in the past, and extend the service life of the motor. At the same time, the output voltage of the inverter can be adjusted adaptively, so that the load motor can work below the rated voltage, It can not only save energy but also prolong the service life of the motor< Key words: mine hoist; 8051 single chip microcomputer; Frequency converter; Asynchronous motor

contents
1Introction .... 2
1.3 work I have done..... 2
2 related basic theory..... 3
2.1 hoist..... 3
2.1 hoist overview 3
2.1.2 speed diagram of hoist 6
3 hardware design 9
3.1 single chip microcomputer control system 9
3.1 single chip microcomputer control system block diagram 9
3.1.1 single chip microcomputer control system 9
3.1.2 clock circuit 10
3.1.3 reset circuit 10
3.1.4 keyboard circuit 10
3.1.5 display circuit 10
3.1.6 connection of proximity switch 11
3.2 inverter circuit 11
3.2.1 inverter main circuit connection 12
3.2.2 connection of external control terminal of frequency converter 12
3.3 setting of function parameters of frequency converter 14
3.4 power supply circuit 14
3.5 selection of components and calculation of relevant parameters Speed chart calculation 15
4 software design 17
4.1 main program flow chart 17
4.2 keyboard design flow chart and subroutine 18
4.3 display design flow chart and subroutine Flow chart and subroutine of position calculation 21
5 system operation 24
5.1 description of working process 24
5.2 system protection 25
references 27
conclusion 28
thanks ... 29
appendix

6. Graation thesis, which refers to college thesis, undergraate thesis (Bachelor's degree thesis), master's thesis (Master's degree thesis), doctoral thesis (doctor's degree thesis), is one of the important parts of teaching or scientific research activities. Its main purpose is to cultivate students' ability to comprehensively use the knowledge and skills they have learned, integrate theory with practice, independently analyze and solve practical problems, so as to enable students to engage in their own professional work and carry out relevant basic training
its main purpose is to cultivate students' ability to comprehensively use the knowledge and skills they have learned, integrate theory with practice, independently analyze and solve practical problems, so as to enable students to engage in their own professional work and carry out relevant basic training. Graation thesis should reflect that the author can accurately grasp the basic professional knowledge, basically learn to comprehensively use the knowledge to carry out scientific research methods, and have certain experience on the research topic. The scope of thesis topic should not be too wide, and generally choose one side of an important problem in the discipline.

7. When you see my news, I hope you don't get angry. I don't have a paper. If no one answers, please accept me

8. I can't tell you that

9. Do you have a picture? If so, can you give me a ? Thank you

10. Give me an email. I've sent it to you