Research of common lathe numerical control and transform a design

Adaptability is strong, suit to machine sheet or the intricate work of small lot; When the change on numerical control machine tool processes work, want the machine program of new work of new authorized strength only, can realize new work treatment. 2.

Treatment precision is tall; 3.

Manufacturing efficiency is tall; 4.

Reduce labor intensity, improve labor condition; 5.

Good economic benefits; 6.

Be helpful for the modernization of manufacturing management. Numerical control machine tool already made the mainstream product of demand of our country market, increase sharply of demand year after year. Machine tool of machine of our country numerical control is developed in industrialization and product in last few years obtained apparent progress, change in the high speed of the machine tool especially, much axis is changed, compound change, nicety changes an aspect progress is very great. But, the congener product photograph of machine tool of homebred numerical control and advanced country is compared, return existence difference, return the need that cannot satisfy a country to build. Our country is big country of a machine tool, have three general accuracy machine tool. But the quality of the machine tool is poor, performance is laggard, the average production value of only station machine tool has the 1/10 of advanced industry country to control only, difference is too big, wait for urgently transform. The numerical control of old machine tool is changed transform, just as its name implies adds personal computer control equipment on general accuracy machine tool namely, make its have certain automation capacity, with achieving booked treatment craft goal. Charge a machine tool as number more and more gaining ground application, the technical economic benefits of numerical control machine tool is understood for everybody. In the technical reformation of domestic factory, the personal computer numerical control of the machine tool is changed transform already became important facet. A lot of factory one side purchase one side of numerical control machine tool to use numerical control, number to show, PC technical reformation general accuracy machine tool, obtained good economic benefits. Natural resources of our country economy is limited, the country is big, amount of machine tool need is large, because this takes out quite big fund impossibly to buy new-style numerical control machine tool, and the old machine tool of our country is very much, transform general accuracy machine tool with system of economy numerical control, in investment little state of affairs falls, make its can satisfy the need of treatment already, can raise the automation rate of the machine tool again, accord with the national condition of our country quite. 1984, our country begins to produce system of economy numerical control, use at transforming old machine tool. So far, already a lot of manufacturer produce system of economy numerical control. Can expect, henceforth, the economy of the machine tool numerical control is changed transform will develop quickly and gain ground. Say so, this graduation design example has a typical case gender and practical. 2, the design of overall program 2.

1 design task designs the job originally is common to CA6140 lathe undertake numerical control is transformed. Use personal computer to undertake to system of vertical, transverse feed open loop is controlled, fore-and-aft (Z to) pulse equivalent is 0.

01mm/ pulse, transverse (X to) pulse equivalent is 0.

005mm/ pulse, drive component uses a pace to enter electric machinery, transmission system uses ball guide screw deputy, tool carrier uses automatic dislocation tool carrier. 2.

The argumentation of 2 overall program is transformed to the economy of general accuracy machine tool numerical control, when defining overall design program, below the premise that Lv of take an examination asks in contented design, to the machine tool alter should as far as possible little, in order to reduce cost. The system of affirmatory numerical control of way of movement of system of 1) numerical control can separate system of the position control that it is a dot, aspect by athletic way linear control system, successive control system. Because ask CA6140 lathe machines complex outline spare parts, so system of this personal computer numerical control uses two axes linkage to control a system continuously. The transforms machine tool of design numerical control servo feed system of system of 2) servo feed has the branch of open loop, half closed circuit and closed circuit. Because open loop control has a structure,simple, design makes precision of easy, control be debugged weller, easily, low-cost, use maintenance is convenient wait for an advantage. So, this design decides to use open loop to control a system. The system of numerical control of any of hardware circuit design of system of 3) numerical control is mixed by hardware two parts comprise software. Hardware is the foundation of numerical control system, the stand or fall of function affects the character of service of system of integral numerical control directly. Had hardware, software ability moves effectively. In the numerical control device of the design, the choice of CPU is crucial, choice CPU should consider the following essential factor: (1) clock frequency and word grow the athletic speed with object be accusinged and precision closely related; (2) can expand of the capacity of memory and numerical control function lose by force relevant; (3) the ability with I/O patulous mouth and establish pilot ability external relevant. Besides, still answer to wait according to object of the applied circumstance of numerical control system, control and requirement of all sorts of function, parameter, rise integratedly consideration in order to decide CPU. Be in our country, numerical control of general accuracy machine tool transforms respect application more general is Z80CPU and MCS-51 series sheet piece machine, because chip of their form a complete set is cheap,basically be, popularize gender, versatility strong, make and maintenance is convenient, of machine tool of complete can contented economy numerical control transform need. It is in this design with MCS-51 series sheet piece machine, 51 series dictate relative to 48 series richer, relative to 96 series price cheaper, in 51 series, be 8051 what do not have ROM, 8751 be 8051 what replace ROM with EPROM. Current, labour accuses the application in machine most is 8031 sheet piece machine. This design is core with 8031 chip, the control system that adds memory to expand circuit, interface and switch of face plate operation are comprised. 2.

After 3 overall program decide the argumentation via overall design program really, firm CA6140 lathe economy numerical control transforms sketch map. The part of main shaft rotate speed of CA6140 lathe retains the function of primary machine tool, namely the hand uses speed change. Of lathe fore-and-aft (Z axis) and transverse (X axis) feed motion uses a pace to take electric machinery drive. By 8031 sheet piece the core that aircrew regards numerical control as device into personal computer, control a pace to turn into electric machinery together by I/O interface, annular alloter and power amplifier, via roll of ball guide screw is being driven after gear decelerate, the fore-and-aft, transverse feed that realizes lathe thereby moves. Tool carrier changes by personal computer pilot the automatic dislocation tool carrier of the automata of drive of classics electric machinery. To maintain the function of cutting whorl, must install generator of main shaft pulse, use main shaft to rely on belt of synchronous tooth form to make pulse generator synchronism rotates for this, issue two signal: The pulse that every transmit gives number and a synchronous signal, give personal computer via keeping apart circuit and I/O interface. 3, circuit of hardware of system of personal computer numerical control is designed 3.

Overall program designs circuit of hardware of system of numerical control of 1 personal computer the central processing unit that this system chooses 8031CPU to regard numerical control as the system. A 2764EPROM is received outside, regard the program of monitoring program as memory and the machine program that deposit commonly used spare parts. Reelection is used at depositing parameter of the part program that need modifies randomly, job with a 6264RAM. Use coding law to undertake finding site to patulous chip, use 74LS138 encoder to fulfil this function. The 8279 inputs that serve as a system output a mouth to expand, the input that receives clavier respectively, output shows, the 8255 annular alloter that receive a pace to enter electric machinery, run paralell respectively the stage that commands X axis and Z axis enters electric machinery. Additional, consider machine tool and sheet even piece the photoelectricity segregation between machine, power enlarge circuit. Each bring crural function brief introduction is as follows: 1) source brings crural VSS: Power source ground connection is carried. VCC: ＋ 5V power source is carried. 2) is inputted / output (I/O) buccal line 8031 sheet piece machine have P0, P1, P2, P3 4 port, every port 8 I/O line. Expand when the system when exterior memory, p0 mouth uses output low 8 collateral data, p2 mouth uses output 8 tall address, p3 mouth except outside can serving as to follow two-way and collateral opening 8 times, still have the 2nd function, each cite a base the 2nd function defines as follows: P3.

0RXD: Serial data inputs end. P3.

1TXD: Serial number carries P3 according to output.

2INT0: Exterior interrupt 0 requests signal to input end. P3.

3INT1: Exterior interrupt 1 request signal to input end. P3.

4T0: Timer / 0 exterior inputs carry tally P3.

5T1: Timer / 1 exterior input carries tally P3.

6WR: Outside data memory is written anthology. P3.

7RD: Outside data memory is read anthology. Before undertaking the 2nd function is operated, the output Suo Cunqi to the 2nd function must by program put 1. RST/VPD of 3) signal control line: RST cites a base for restoration line input, after working in clock circuit, should bring the tall n that above of two machines cycle appears on the foot, complete restoration operation. 8031 sheet piece machine use means of two kinds of restoration: One kind is to append report automatic restoration, another kind is switch restoration. ALE/PROG: ALE is address lock puts enabling signal. Its action is a CPU from missive of P0 mouth time-sharing low 8 addresses lock up existence in an adscititious Suo Cunqi. Exterior program memory is read pick communication name. Have when its are low n effect. VPP: It is tall n when EA and the program in memory of program of executive interior of the CPU when PC value is less than 0FFFH. When EA is low n, CPU executes the order in exterior program memory only. XTAL1: Concussion implement turn over photograph amplifier input, use external shock implement when must ground connection; XTAL2: Concussion implement oppose photograph amplifier output, use external shock implement when, receive periphery concussion signal; 3.

2 outside structure of 3 bus line is simple a machine in applying actually, often want mouth of patulous and exterior memory, I/O to wait. Odd of a machine cite a base, besides input of power source, restoration, clock and user I/O mouth, of the others citing a base is to come true to the system expands and be installed, these brought a foot to make form of 3 bus line: Width of bus line of address of AB of 1) address bus line is 16. Accordingly, exterior memory searchs location limits to be 64KB directly. What by address of P0 mouth classics Suo Cunqi provides 16 addresses bus line is low 8 addresses (A7 ～ A0) , p2 mouth is offerred directly 8 tall address (A15 ～ A8) . Width of bus line of data of DB of 2) data bus line is 8, offer by P0 mouth. The control line RST of the P3 opening that bus line of control of CB of 3) control bus line leaves by condition of the 2nd function and 4 independence, EA, ALE and PSEN are comprised. 8255A but process designing is collateral I/O mouth is patulous chip 8255A but process designing is collateral I/O mouth is patulous chip is OK and direct as odd as MCS series a join of engine system bus line, it has 3 8 collateral I/O mouth, have kind of 3 kinds of jobs, can use conveniently through process designing termless deferent, inquiry conveys or interrupt deferent means to complete the information trade between CPU and peripheral equipment. The structure of 8255A reachs the function that cite a base: The internal composition of the structural 8255A of 8255A includes port of I/O of 3 8 collateral data, 2 works way dominates circuit, one is read / write control logic circuit and bumper of a 8 data bus line. Each part function introduces as follows: (1) mouth of A of port of 3 8 collateral I/O, B, CA: Have a 8 digit to be put according to outputting a lock / bumper and Suo Cunqi of a 8 data input. But process designing is inputted for 8, or 8 output, or 8 two-way register. B mouth: Have a 8 digit to be put according to outputting a lock / bumper and a register of 8 inputs or output, but cannot two-way input / output. C mouth: Have a 8 digit to be put according to outputting a lock / bumper and bumper of a 8 data input, c mouth can divide two 4 mouth, use at input or output, also can choose the condition when connecting means to work to control signal as A mouth and B mouth. (2) A of circuit of working way control, B controls circuit two groups to divide 3 port into A, B two groups, everybody of mouth of A of A group control and C mouth are 4 tall, everybody of mouth of B of B group control and C mouth are low 4. Circuit of two groups of control has a control to command register each, with will receive the control word that writes by CPU, in order to decide the working way of two groups of port. Also can be opposite according to controlling the demand of the word C mouth is positional clear " 0 " or buy " 1 " . (3) read / write control logic circuit it receives the address signal that comes from CPU and signal of a few control, control the working state of each mouths. (4) bumper of data bus line it is a 3 condition two-way bumper, use at be linked together directly with data bus line of the system, in order to realize CPU and 8255A between of information deferent. CNC Milling