SU1521570A1 - Apparatus for program controlling of grinding machine - Google Patents

Abstract

The invention relates to a machine tool industry and can be used in the metalworking industry to control the feed of a grinding machine. The purpose of the invention is to improve the accuracy of processing by adaptive control of the size of the allowance for nursing. The goal is achieved by the fact that the value of the allowance is determined at the grinding stage; for this, the device contains a shift register, six AND elements, four controlled keys, four information storage units, eight adders, two dividers, three multipliers, three voltage adjusters, three comparison unit, displacement transducer, executive unit, spindle rotation sensor. 4 il.

Description

The invention relates to a machine tool industry and can be used in the metalworking industry to control the feed of a grinding machine.

The purpose of the invention is to improve the accuracy of processing by adaptive control of the size of the allowance for nursing.

 . 1 shows a block diagram of an apparatus for programmatically controlling a grinding machine; in fig; 2- time diagrams of voltages at the inputs and outputs of the shift register by 4ig. 3 is a schematic of the shift register} in FIG. 4 - dynamics of stock removal in time.

The device contains a shift register 1 with the first-fifth outputs A, B, C, D, E,. The first 2, second 3, third 4, seventh 5, fourth 6 fifth, sixth 8 logical elements And, the first

9, the second 10, the third 11 and the fourth 12 control keys 1, the first 13, the second 14, the third 15 and the fourth 16 blocks of information storage, the third 17, the seventh 18, the eighth 19, the fourth 20, the fifth, 21, the sixth 22 the second 23 and the first 24 adders, the first 25 and the second 26 dividers, the second 27, the third 28 and the first 29 multipliers, the logarithmic amplifier 30, the first 31., the second 32, and the third 33 reference voltage adjusters, the first 34, the second 35 and the third comparison unit 36, the interchange sensor 37, the executive unit 38, the spindle revolution sensor 39, the output of which is connected to the first inputs of the first 2, the second 3, the third 4, the seventh 5 elements And, and with the counting input of the register 1 shift. ha, the output E of which is connected to the first inputs of the fourth 6 and fifth of the 7 elements And, and the outputs A, B, C, D - to the terminal

SP

eye inputs of the first 2, second 3, third 4, and seventh 5 elements, respectively, whose outputs are connected to the control inputs of the first 9, second 10, third 11 and fourth 12 controlled keys, respectively, the first inputs of which are connected to the first inputs of the first 34 the second 35, the third 36 units of comparison and to the output of the displacement sensor 37, and the outputs to the working inputs of the first 13, second 14, third 15 and fourth 16, respectively, of the information stopping blocks, the Reset inputs of which are connected to the output of the sixth element And 8 and Input Reset Reg 1 shift, and the outputs - respectively with the positive input of the third 17, with the negative input of the third 17 and the positive input of the seventh 18, with the negative input of the seventh 18 and (the plus input of the eighth 19, minus input of the eighth 19 adders, the outputs of which are connected respectively to the first the input of the third multiplier 28 and the negative input of the fourth adder 20, to the first input of the second multiplier 27, the positive input of the fourth adder 20 and the negative input of the fifth adder 21, To the positive input of the fifth adder 21, the output of which is connected to the first The second divider 26, the conventional input of the additional adder 22, and the second input of the third multiplier 28, the output of which is connected to the negative input of the second summer 23, the positive input of which is connected to the output of the second multiplier 27, and the output of the first divider 25 whose second input is connected to the output of the first 29 multiplier, and the output to the positive input of the first adder 24, the negative input of which is connected to the output of the first reference voltage setting device 31, and the output to the second input of the first comparison unit 34, the output of which is Connected to the second input of the fourth element And 6, the output of which and the output of the fifth element And 7 are connected to the executive unit 38; The first input of the first multiplier 29 is connected to the output of the sixth adder 23, and the second - to the output of the logarithmic amplifier 30, the input of which is connected to the output of the second divider 26, the second input of which is connected to the positive input of the sixth adder 22, the second

the input of the second multiplier 27 and the output of the fourth adder 20; .the output of the second setpoint device 32 of the reference voltage is connected to the second input of the second comparison unit 35, the code of which is connected to the second input of the first element And 7, the output of the third setting reference 33 of the reference voltage is connected to the second input of the third comparison unit 36, the output of which is connected to the first the input of the sixth element And 8, the second input of which is connected to the Executive unit 38.

In the process of grinding at a constant feed rate of the skull and round circle, the removal rate of the stock is

V (t)

)

(ABOUT

where V is set at a certain time, the constant removal rate of the allowance t is the current time by notifs; T - constant system times

SIID,.

Removed during grinding at a point in time

equals

i

S (t) I) - dt I V (1-

n J

-t / r

.Vjt-TO-e-).

) -dt "(2)

Obviously, not the time t, the value of the remaining allowance is

(t) SH-S (t) SH-V t-T () J.

(3)

Taking into account (3) for four discrete points in time t, t, t, tg (. 4), following each other at regular intervals of time /} t, the following relations are valid:

S, (t2) S S «-Vy t -T (t-e).

(four)

Son (t4) Sa-S4-V ,, tt + dt-T (1

) / r

);

(five)

Son (t)., T4 + 2 L t () ir -T (1-e) J, Son (t8)., Ti + 3at- -Uj Sdtl / T-T (1-e),

Vg (t) -V ,. e

-t / r

51521570

Subtracting from (4) relation (5), from (5) relation (6), from (6), the allowance corresponding to time t is equal to -1); t (8)

wearing (7), we get:

S -Sj V -4t + Vy-T-e (e

-t, / t, .. 5

(14)

S, (t) I Vj (t). dt - Vy-T- (1-e).

S, j-S VyJt + Vj. t-

, -at / r 10

"(E -1), (9)

 -glc S3-S Vy4t + V ,,. T e

f,. (e -1).

S, (t) I Vj (t). dt - Vy-T- (1-e)

(15)

When t - the ratio (15) takes the form

S mox - V., - T (16)

The value of the allowance, which can be removed in the process of nursing, is V-- T. This value, i.e.

Subtracting from (9) the ratio (8),

and from (10) the ratio (9), we get:

(Sj-j

(St-S3) - (S,.,

Th -1); (i)

(S5-S,) - (Sj-S3) Vy-T-

Sg ais Vy-T can be determined by having information on the remaining allowance at four discrete time points 20 in the initial stage of grinding. From (8) it follows that

 f () -V., - At I

Vg (t) -V ,. e

-t / r

(14)

and allowance taken at time t is equal to t

S, (t) I Vj (t). dt - Vy-T- (1-e).

(15)

When t - the ratio (15) takes the form

S mox - V., - T (16)

i.e. value of allowance, which is

Sg ais Vy-T, can be determined by having information on the remaining allowance at four discrete points in time in the initial stage of grinding. From (8) it follows that

 f () -V., - At I

utn f -LC-G 2 e. (e -1).

(12) 25 / CVvKe -1) J.

Dividing (11) and (12) and razreshshv the resulting ratio with respect to the constant time T, we get

T 4t / b (13) (S3-S) - (Si-S3) /

Thus, having information about the remaining allowance in four discrete points in time, you can by. (13) to calculate the time constant of the sstekvl SSHSCH.

At the stage of stalking (at the end of the vshifovaki), the removal rate of the allowance is equal to

V. T - i§ I§al-iSilS2i e: ll: 5)

, IS3lStl-iSaiS3L i§irS)) SilS); (

„4ti iSirS iliSirSj) (Sa-S) - (S; L-S4

, (r. iSi-s.il- (S2-S3) 7, (SziS3l- (Si :: S7l

(S3-s; - (Si-S3) (Si-S5) - (S, -Sj) - (R3-84) - (5g-5e)

ISt-S h) D S h1§) - (S, 3 (S, 2§t) r (irCSilSill 20)

С (8г-8з) - (з, -s j- (s, -s) 4- (Si-S3) j-in {| jE |;} Ef | EifyFrom (20) it follows that if there is information about the remaining allowance in

(17)

"E

Substituting (17) into (9), we get

S2-S3 V., At + C (S, -S2) 4tJ "

lt t / r

(18)

From (18) it follows that

-lIT

„(81-5e) - (81-5g) e, .QV VN, -GTT-GGTGGU-T (“ 9)

 Zt ()

Multiplying the left and right sides of (19) by T and replacing on the right side of T with expression (13), we get:

-G, (Si-S3i- (S, j: Sa)

Q s l / s about h 7Ss-St) - () iSilSi2. e

Tey B :: 1zl1s1, :: 8.1

 (S, -S,) - (Sa-S3)

/ a t 1 -eJ

, IS3lStl-iSaiS3L i§irS)) SilS); (

iSirS iliSirSj) (Sa-S) - (S; L-S4. iSi-s.il- (S2-S3) 7, (SziS3l- (Si

4 discrete points in time, following each other through equal prog

intervals, it is possible to determine the amount of allowance Sg, which can be removed in the nursing process. To implement ratio (20), most of the blocks are entered into the device. Spindle turnout sensor 39, shift register 1, first 2, second 3, third 4 and seventh 5 elements And form pulses for short-term sequential opening at equal intervals of the first 9, second 10, third 11, fourth 12 controlled keys, providing input from the displacement sensor 37 about the remaining allowance at tj, t, t, t g (fng, 4) in the first 13, second 14, third 15, fourth 16 information storage units, at the outputs of which voltages and are formed and stored for a long time, and, Uj, UV, proportional to the remaining allowances S: ,, Sij, Sj, S, respectively, at time t2, t4, t, tg.

The difference S, -S, j, included in (20), is realized by the third adder 17, the difference 3 is the seventh adder 18, the difference Vosm lm adder 19, the difference (S5, -S,) - (S, -S, j ) - the fourth adder 20, the difference (Sj-S) - () by the fifth adder 21, the product (S iS, j) - (S c-5) - (5g-5z} by the third multiplier 28, the product (82-8z) -C (52-5z) - (8, -8) 3 - the second intellectual of 27, the difference i (Sj-S3) - (s, -S2)) - (Sa-S3) 3

the sixth adder 22, the quotient (S ,, - S3) - (S, -S) j / i: (S3-S4) - (Si-S3)} - the second divider 26, the difference t (S «- -Sj) r (S2-Sj) - (S, -Sj) Jj- (S, -S (83-84) - () 5 - BTOpbw adder 23, the natural logarithm of the quotient t (Si-S3) - (Si-S,) / C (S3-S4) - (Si-S3) j - a logarithmic amplifier 30, the product C (Si-Sj) - (Si-Si) - t S3-s,) (s, -s,) iFin {| C : .yifi: | i, the first multiplier 29.

The ratio of the numerator (20) to the denominator is ultimately realized by the first divider 25, the output of which produces a voltage proportional to the allowance, which can be removed during the nursing process, the first unit 31 of the reference voltage, the first divider 25 and the first adder 24 in the final the result

 form the magnitude of the voltage to which the allowance corresponds, from which care should begin. The first comparison unit 34, through the fourth element, And 6, forms a command for the start of nursing. The second comparison unit 35, through the fifth element, And 7, forms a command for ending the release. The third comparison unit 36, through the sixth element 8, generates a command to start the formation of voltages at the outputs A, B, C, D, E of shift register 1 (Fig. 2).

c The device works in the following way.

The operator enters the command to start grinding in the execution unit 38, which is at the input of the sixth

 element I 8 supplies the generated volt. The voltage of the third setpoint generator 33 of the reference voltage is set slightly less than the voltage corresponding to the initial allowance.

5 Therefore, in the first grinding moments, at the output of the third comparison unit 36, O takes place and, as a result, at the output of the sixth element AND 8 - O, which provides information reset in the first 13, second 14, third 15, fourth 16 information storage units and O on all the outputs of the shift register 1, despite the presence of voltage pulses arriving at its counting input from the date of the SC

5 39 spindle rotation.

At t t (j (Figs. 2 and 4), the value of the remaining allowance corresponds to the voltage set in the third after reference voltage 33 of the reference voltage.

 Therefore, at the output of the third comparison unit 36 and the sixth element 8, 1 is formed which enables the storage units and the shift register 1 to operate at outputs A, 5 B, C, D of which, due to the presence of voltage pulses from the sensor at its counting input 39 of each turn of the product spindle,, are formed through an equal number of turns of the product spindle at times t ,, tj, ty, t with a duration of different times of one turn of the product spindle, 1, which arrive at the inputs of the first 2, second 55 th 3, third 4, seventh 5 elements And, on d The other inputs are short voltage pulses from the sensor for each turn of the product spindle. As a result, the output0

dah of the named logic elements And short voltage pulses are sequentially generated, respectively, to the control inputs of the first 9, second 10, third 11, fourth 12 control keys that connect the output of the displacement sensor 37 in series at times C, t, tj, tg to first

13, to the second 14, to the third 15, to the fourth to 16 storage units of information that memorize the voltage values at the output of the displacement sensor 37, corresponding to the remaining allowance at the times t, t, t ,, tj and necessary according to the relation (20) for fop in the stress value corresponding to the maximum allowance that can be removed during the nursing process at t = 00. The formation of this stress, i.e. the implementation of the relation (20) is carried out by the third 17, the seventh 17, the eighth 19, the fourth 20, the fifth 21, the sixth 22, the second 23 adders, the second divider 26, the second 27, the third 28, the first 29 multipliers, a logarithmic amplifier 30 and the first decimal 25, from the output of which the voltage goes to the first adder 24, to the second input of which from the first setter 31 of the reference voltage the voltage set by the operator corresponding to the low voltage of the SSH1D system is supplied, guarantees the required quality of processing. At the output of the first adder 24, a voltage is formed corresponding to the allowance, at which the injection starts and which is equal to the voltage difference corresponding to the maximum allowance that can be removed in the process of landing at t (output of the first divider 25), and corresponding to the low voltage allowance of the system, which guarantees the required quality of processing.

The first comparison unit 34 at the output forms 1, if the voltage at the output of the displacement sensor 37 is equal to or less than the voltage at the output of the first adder 24, the occurrence

1 corresponds to the need to start nursing, which is realized through the fourth element And 6 and the executive unit 38. At the same time,

g

2157010

during the E register shift 1 by this time takes place 1 (Fig. 2).

The second comparison unit 35 at the output generates 1 when the voltage at the output of the displacement sensor 37 is equal to or less than the voltage at the output of the second reference voltage adjuster 32 (usually near zero); occurrence 1 corresponds to the need to complete nursing, which is realized through the fifth element AND 7 and the execution unit 38.

five

0

five

0

five

0

five

0

five

Claims (1)

Invention Formula A device for software control of a grinding machine, comprising three reference voltage adjusters, three comparison units, three controllable keys, three information storage units, an adder, a shift register, five logical gates And, an actuator, a displacement sensor, a spindle rotation sensor, an output which is connected to the first inputs of the first three logical elements And and with the counting input of the shift register, the first, second and third outputs of which are connected to the second inputs of the first, second and third elements respectively , the fourth output of the shift register is connected to the first inputs of the fourth and fifth elements And, the outputs of the first, second and third elements And are connected to the control inputs of the first, second and third controlled keys, respectively, the outputs of which are connected to the working inputs of the first, second, respectively and the third information storage unit, the output of the motion sensor is connected to the second inputs of the controlled keys and connected to the first inputs of the comparison units, the output of the first of which is connected to the second input of the fourth, and the output the second one - with the second input of the fifth elements I, whose outputs are connected to the executive body, the second inputs of the second and third comparison blocks are connected to the outputs of the second and third reference voltage adjusters, respectively, and the second input of the first one - with the output of the first adder, the negative input is connected to the output of the first reference voltage adjuster, which is due to the fact that, in order to improve processing accuracy. The sixth and seventh elements And, the fourth controlled key, the fourth information storage unit, seven adders, three multipliers, a logarithmic amplifier and two dividers, the output of the first of which is connected to the flat input of the first adder, and its first input with the output of the first multiplier, and the second input - with the output of the second adder, the positive input of which is connected to the output of the second multiplier, and the negative input - with the output of the third multiplier, the first input of which is connected to the output of the third and negative input of the fourth the second input is connected to the output of the fifth, the negative input of the sixth adder and the first input of the second divider, the second input of which is connected to the combined first input of the second multiplier, the output of the fourth adder and the positive input of the sixth adder, the output of which is connected to the first input of the first mind - but mat, the second input of which is connected to the output of a logarithmic amplifier, the input of which is connected to the output of the second divider, the second input of the second multiplier is connected to the combined positive input of the fourth, the negative input of the fifth and the output of the seventh adders, the outputs of the first, second, third and fourth information storage units are connected respectively to the positive INPUT of the third, to the minus third and plus seventh, to the minus seventh and plus eighth, to the minus eighth adders , inputs Reset information storage units connected to the input Reset shift register and the output of the sixth element And, the first input of which is connected to the output of the third unit of comparison, and the second - with An additional unit, the first input of the seventh element And is connected to the output of the spindle turnover sensor, the second input of the seventh element And is connected to the fifth output of the shift register, the output of the seventh element And is connected to the first input of the fourth control key, the second input of which is connected to the output of the displacement sensor, the output of the controlled key is connected to the first input of the fourth information storage unit, the output of the eighth adder is connected to the positive input of the fifth adder. Fig.Z F"