DE2100363C3 - Calibration device for the position of the cutting edges of a tool of a numerically program-controlled machine tool - Google Patents

Description

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the correction of the program determines the necessary correction amount and uses this in the tax system. This process is not only time consuming, but can also lead to setting errors and scrap due to a measurement error.

There are known self-operating devices through which avoids this time consuming manuiile measuring and testing apparatus ¹ can will. With these devices, tool-dependent correction values are obtained by providing a calibration position known in the Luge within the machine coordinate system. which is approached by the tool. In DT-OS! B 52 751, a mechanical stop is provided as a calibration position against which the cutting edge of the tool can be guided. When the calibration position is reached and calibration is displayed in the eagle-eye circle. Setpoint values that correspond to the coordinates of the calibration position are given to the position control system of the numerically controlled machine.

'n the manner described are processing errors are based in the use of a machine tool, which DVV wear on the edge of the tool, poor alignment of the tool, incorrect length of the tool, etc., are automatically excluded. Less precise and therefore less expensive tools can therefore be used without introducing machining errors, and the number of different tools required for a workpiece can be reduced. The calibration process can be carried out in the course of machining the workpiece as often as it seems necessary; in the case of a simple machining process, the calibration can only be necessary once or twice during the entire machining process. This also applies to the case. that relatively large dimensional tolerances are allowed. However, if the part to be machined has complicated outlines and many cuts are required or the permitted dimensional tolerances are extremely small, the tool can be calibrated after each cut. The calibration process does not take as long as it used to be. when an operator had to measure the dimensions of the part to be machined by hand and had to set the computer so that the dimensional deviations were compensated for.

However, it is also disadvantageous that in the above-mentioned DT-OS 16 52 751 essentially mechanical measuring sensors and dial gauges can be used. This forces the operator, despite the considerably simplified handling Compared to arrangements without a calibration position, certain values can still be read off (e.g. on the dial gauge) and to be transferred to setting arrangements. It is already pointed out in DT-OS 16 52 751 that Measurement and display do not necessarily have to be mechanical, but also optically or electrically is feasible. How this is to be done is not disclosed in detail.

The object of the present invention is to also provide the necessary features for the known arrangement so that the measurement and arrangement of the movable element are carried out electrically can. It should be possible to process the measurement signal as directly as possible by the numerical machine control.

This object is achieved according to the invention in that the isolated. at least one calibration block having at least one electrically conductive side face with the input of a gate circuit of a circuit is connected. whichever circuit the tool is connected to, continues to do so in that calibration commands encoded in this way on the program carrier of the machine program as required are specified that the tool automatically after predetermined work steps by means of the operationally necessary route controls along a w μ certain path in the direction of a target position is movable behind one of the side surfaces of the calibration block and in that the tool and the I block the circuit when they touch each other close, which sends out a touch signal, which via a circuit a hamlet movement of the Tool interrupts, and the point of contact reached by the route regulations according to the position as a new reference point in the control circuit of the numerically operating modulation of the Machine tool.

This advantageously achieves that the Operation of the machine tool even more, - simplified will.without loss of accuracy.

If the calibration device is used on a machine tool, it can be used instead of a tool for For processing purposes, be equipped with a test probe for Meßzvvekke on a workpiece. The calibration facility can therefore be used in a wide variety of ways, namely both the machining of a workpiece in the machine tool as well as to check the dimensional accuracy of the workpiece before, during and after editing.

It is useful if the calibration block is automatic can be moved into a calibration position and removed from it again. As a result, it is less of a nuisance to the Movement of the workpiece and the tool.

An embodiment is particularly favorable in which the control variable occurring upon contact is used as a digital calibration value can be stored. This eliminates errors that occur in z. B. analog electrical measurement were possible. It also simplifies the connection with machine tools, most of which are also digital work.

In order to avoid other misalignment of the tool scrap when the oiler is worn, according to a Another embodiment, the machine tool is shut down by the circuit when the contact takes place between the test probe and the workpiece in a position that is not the one from the one previously saved Corresponds to the position calculated for the calibration value.

When measuring, it is advisable to display or print out the measurement results. To do this, one with the Test probe-connected display device is provided, the position of the on contact with the workpiece Indicates test probe with regard to the calibration value.

Further advantages and possible applications of the invention emerge from the following description of execution examples in connection with the drawing. It shows

F i g. 1 shows a side view and a schematic electrical illustration of part of the invention in FIG Connection with a conventional machine tool,

I ig. 2 shows a very simplified block diagram of the invention in connection with a machine tool,

! ■ "Fig. 1 is a detailed block diagram of a machine tool, to which the invention can be applied,

Fig. 4 is a partial view of a perforated tape, the supplies numerical properties for the machine tool, which in FIG. 3 can be seen

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Fig. 5 is a block diagram of a distance counting device;

6 is a logic diagram of a data transmission circuit;

Fig. 7 is a timing diagram of the signals generated by the Data transfer circuit of Fig. 6 are generated, and

F i g. 8 and 8a are logic diagrams and the electrical connections between this circuit and the circuit shown in the other figures.

The invention is used in conjunction with a numerically controlled vertical turret lathe described. However, the invention is applicable to any numerically controlled machine tool, in which a calibration setting of a movable tool or a test probe is precisely determined must be to reset this element in successive steps with extreme accuracy, the calibration setting is used as a reference.

F i g. 1 shows a vertical turret lathe on which a ring 10 for machining by a tool 12 or for assessment by a test probe 7. is upset. The tool 12 is mounted in a holder 14. The tool 12 can be moved vertically along a V-axis and horizontally along an X-axis, or a combination thereof, under numerical control.

The term "tool", used only in the following, is intended to mean both a tool, e.g. B. a cutting tool, as well as a test probe.

The dimensions of the tool 12 are predetermined by the manufacture and include the length of the Tool up to a center point 12 ;; the radius of curvature of its cutting edge 126 and the Radius of this edge. If these dimensions are accurate and the tool is properly installed. can the exact position of the tool edge can be determined. However, if the dimensions given are incorrect or the tool is improperly mounted, or if the prescribed radius changes due to tool wear has changed, the tool will be inaccurately positioned. If that Tool has been used once, is the only position that is known mathematically. the middle-point 12a of the radius of curvature of the tool edge. This has added to the time consuming measurement operations Dimensions, which were discussed above.

The invention is based on the known provision of a calibration block 18, which is a horizontal has upper surface 18a and vertical side surfaces 18b and 18c. The calibration block 18 is precisely measured, so that the position of its upper surface 18a in the V direction and the position of its side surfaces 18έ> and 18c are precisely known in the X direction. The calibration block 18 is made of an electrically conductive material is made or has a conductive coating and is separated from the rest of the machine by a Insulation material 20 isolated. The calibration block 18 is to be described with a control circuit via a Line 22 connected. The position of the calibration block 18 can either be movable or fixed. As shown is the block is mounted on a sliding device 24 to keep it out from the tool when not in use to be able to clear the way.

When using the calibration device according to the invention, the tool 12 is moved to the position shown with the channels YIb above the surface 18a and then downwards in the V-direction towards a level, as is e.g. B. is indicated at 26, which lies within the calibration block 18. When the edge 120 of the tool 12 contacts the surface 18a, an electrical signal is fed over the line 22 to the control circuit. Since the calibration block 18 is precisely measured and arranged, the exact position of the channels of the tool in the V coordinate at the point in time at which the signal is sent via the line 22 is known. The tool is then withdrawn to the home position as shown in FIG. It can then be moved downward in the V direction to the position shown in dashed lines in the figure. It is then moved to the left in the X direction until the channels Mb of the tool touches the side surface 18c of the block 18. At this point in time, another transmission signal is emitted via line 22, which serves to precisely localize the edge of the tool in the X coordinate.

After the tool is arranged in the specified manner. it is programmed to run Instructions ready. The calibration process can be repeated as often as the complexity of the Processing process required. When the part to be machined has a relatively simple outline and therefore fewer machining cuts or tests are necessary, it may be sufficient that Tool to be calibrated only before starting the machining or testing process. If that to be edited Part, on the other hand, has a relatively complicated outline, which requires many operations, it may be desirable to calibrate the tool after each cut or test. This is in the At the discretion of the programmer who carries out the calibration processes in the Machine program programmed.

Figure 2 represents a very simplified block diagram which represents the invention when applied to a conventional numerically program-controlled machine indicates. The numerical control circuit 28 of the machine, which will be described in detail later, is shown in Fig. 2 represented by a block. The control circuit 28 generates signals to the tool by a programmed number of distance increments to move from one position to another. When the tool reaches the instructed position has. a signal is sent back to the control circuit 28 to indicate the execution of the instruction. the Control circuit 28 can also generate signals for a visual output 30 which the executed Instruction or the dimensions of the tested point. These signals can also be transmitted by a Printing device such as the registration apparatus 32nd are registered.

For the numerically program-controlled machine, the machine program is in the form of a punched tape code created. If a calibration is to take place, a corresponding code is written in the program strip perforated. This signal activates a gate 34 for switching on the measuring mode. The gate 34 generates a Control signal which is fed to a gate 36 for the transmission of measured values. After the signal for the measuring operation has been transferred from the program strip to the gate 34. the tool 12 is through further instructions on the strip cause it to move in the manner described. If that Tool touches the surface of the calibration block 18, a signal via the line 22 to a gate 38 for the touch signal is sent. This causes a

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The touch signal is sent to the gate 36 together with the control signal. Coincidence of these two signals causes the gate 36 to generate a "false" transmission signal (ie, a signal generated when the tool has reached an incorrect position) for the numerical control circuit 28. The "false" transmit signal accordingly tells the control circuit 28 that the tool has carried out a given command. although no instruction has actually been executed. However, since the exact position to the tool is known in a coordinate at the timing in which the "wrong" transmission signal is generated from the gate 36 to the control circuit 28, the program can be started from this particular known position.

The block diagram of FIG. 2 also has a gate 40 for error detection. The gate 40 is used to a Signal for a shutdown circuit 42 to generate the machine under one of two abnormal conditions turn off, and to generate signals for display devices 44, the visible or audible a Display malfunction. At a pair of inputs, port 40 receives signals from ports 34 and 34 from gate 38 and generates an output signal if the Tool 12 touches the calibration block 18, although the machine is not in its measuring operating position is located. Gate 40 receives signals from control circuit 28 at another pair of inputs and from the other output of gate 34. Gate 40 becomes a shutdown signal for shutdown circuit 42 generate when a normal transmission signal from the control circuit during a measuring process 28 is generated. This case can occur if the tool 12 to be measured is too short. if the Calibration block 18 is improperly sized or if a program error exists. In each of these cases will the shutdown circuit 42 shut down the machine and actuate the display devices 44.

3 shows a simplified block diagram of a typical numerical program control, to which the invention can be applied. So much for the program control shown in FIG is well known. this will only be described insofar as it is necessary for understanding is.

The basic function of a control system as shown in FIG. 3 is shown. is for continuous To provide control of the coordinate position of two or more machine movements. For this it is necessary for each controlled movement a continuous signal for the prescribed position (position setpoint signals) and for continuous feedback (actual position value signals) of the actual machine position to care.

The position setpoint signals are in the system shown and the actual position value signals in the form of "phase-analog" voltages. One phase-analog voltage is a single-phase alternating voltage with a nominal frequency of 250 Hz. You transmits the position information by its phase relationship with respect to one provided in the system Reference voltage of 250 Hz. To indicate a change in position, the phase-analog voltage by an amount that is proportional to the change in position. out of phase.

The operation of the entire system is controlled by a square wave clock signal of 250 kHz, the from a crystal controlled clock oscillator 50 is produced. The 250 kHz square wave is fed by the clock oscillator 50 to a reference counter 52 in which it is divided down to produce a 250 Hz square wave, which is called The reference voltage for all movements in the system is used.

To generate the phase-analog voltage that provides the actual position value signal, the 250 Hz reference voltage to a SIN-COS converter 54 which converts the reference voltage to 250 Hz SIN or COS voltages, which is used as a source for Two-phase drive for an X position indicator 56 and a V position indicator 58 serve. When a position indicator is excited by a two-phase drive a single-phase sinusoidal voltage is induced in its output winding, which in Is phase shifted relative to the reference voltage depending on the axis position of the indicator. The axes of the position indicators 56 and 58 are correspondingly mechanical with the tool 12 connected whose position is scanned. This sinusoidal λ 'position isolating value signal is from the The indicator 56 is fed to a wave converter 60, which converts the sinusoidal signal into a right-angled waveform, The same phase designation for the reference voltage as for the sinusoidal wave is retained. A V-Pcsilions actual value signal is generated in a similar manner transformed by a waveform door 62 into a square wave.

The phase-analog voltage, which serves as the A ^- -PoSitions-Sollwcri signal, is generated by the 250 kHz output signal of the clock generator 50 being fed to an X-setpoint phase / counter 64. In a simplest function, the phase counter 64 divides the 250 kHz signal down to a square wave signal of 250 Hz, as is the case with the reference counter 52. A similar phase-analog voltage, which is used as the V position setpoint signal, is generated by a V target value phase counter 66 e; testifies.

The relative phases of the A 'setpoint signal from the Λ' setpoint phase counter 64 and the X setpoint signal from the wave shaper 60 are compared in an X-phase discriminator 68. The discriminator 68, together with an operational amplifier 70, generates a position error signal, the magnitude and polarity of which are a function of the relative phase shift between the two input signals of the discriminator. This X position error signal causes an A "motor controller 72 to drive an X drive motor 74 which moves the machine and position indicator 56 in one direction to reduce the position error signal and the phase shift between the two inputs to the discriminator Y position error signal generation includes a V phase discriminator 76, a ^ operational amplifier 78, a Y motor controller 80, and a Y drive motor 82. X and V controllers operate in the same manner.

The position control described so far would not be able to control the machine at a specific Hold position and bring it back to that particular positior when it has been disturbed. To a To generate controlled movement of the machine, the oscillation counting operations of the counter 6 ^ and 66 can be modified to produce a phase shift in the position setpoint signals so as to do so their rate of change of the phase shifts and the total phase shift i proportional to the desired speed

709 619/13 ¹

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Are the total displacement of the controlled movement. To accomplish this purpose, counters 64 and 66 designed so that they can receive second input signals in the form of control pulses. The effect a single control pulse, which is given to a counter, consists in the normal counting process of the counter to change momentarily in order to generate a small phase shift of its output signal. Regularly repeated feed lines of these control pulses produce repeated phase shifts of the setpoint signals in increments of approx. 0.000254 cm of machine movement with the effect of a continuous phase shift with a Speed proportional to the frequency of the applied control pulses. The source of the A dog-operated circuit for setting the feed 84 has control pulses for the counters Control for the peripheral speed 86 and a function generator 88.

The manually operated circuit for the feed 84 is controlled by a 125 kHz square wave signal which is derived from a reference point within the reference counter 52. This signal is called CL in the following. If this signal were passed directly into counters 64 and 66 as a pulse train, it would produce a maximum allowable advance rate for the system. In order to enable a lower feed rate, the signal CL is not sent directly to the counters 64 and 66, but its frequency is reduced beforehand by passing the circumferential speed control 86 and the function generator 88 through the manually operated shoe adjustment circuit 84! each of these components can reduce the frequency of its input pulse train and supply the next component of the system with a pulse train consisting of pulses approximately equally spaced with a reduced pulse repetition frequency. Due to the common activity of these three components, the counters 64 and 66 are supplied with control pulse sequences which correspond to the desired feed rate.

Input information to the system is provided by a numerical data input circuit 90. Outline instructions are sent to the controller as blocks of data, each of which is a straight line or an arc of a circle. The data is stored on a numeric data carrier such as B. a Punched tape, read in via a punched tire scanner and transferred to buffer memories within the various other components of the system are included. While the control is processing a block of data, the paper tape scanner starts usually again and fills the buffers with new information for the following block. To Completion of the processing of a given data block will receive the new instructions from the Buffer memory in the. active memory transmitted by a transmission signal and the bill with the new data block is started. Input data is obtained from the input circuit 90 of the speed controller 86, the function generator 88. the X counter 64. the K counter 66. an X distance counter 52 and a V-distance counter 94 fed.

With regard to the source for the control pulses for the counters 64 and 66, it should be noted that the basic function the manual circuit 84 is to enable the operator to manually adjust the feed rate to increase or decrease compared to the programmed speed. Dk Rate control 86 consists of a pulse rate multiplier which is the Irp.p'ilsrate; Input signal with 'Λυο a numeric decimal Instruction received from numerical input data circuit 90 multiplied.

The function generator 88 is beta-

ίο employs and dispatches gesteuei ". by data of the numerical Input circuit 90 pulses via the -Y absolute counter 92 to the A 'setpoint counter 64 and via the V distance counter 94 to the K setpoint counter 66. Function generator 88 performs two basic functions. It is designed to be at any time works in a single plane, and it emits pulse trains that control a movement longitudinally

(a) a straight line with a positive slope and a length within the capacity of the generator or

(b) an arc of any length in a quadrant of a given plane.

The output of the function generator 88 has two pulse trains DF and LJF . The pulse frequencies of these sequences control dk speeds of movement of the tool in the A 'and>''directions to produce the desired resultant speed along the contour direction. Likewise, the total number of V or V axis pulses control the length of the path .

The X-axis and V-Ächsen-Abstandszählwerkc 92 and 94 measure the displacements of the A and) -Setpoint signals by payment of Ausgangsimpuise. which they are from the function generator 88

receive. When the total number of counter pulses received by circuit 90 is a prescribed Number reached, the distance counters interrupt another transmission of the impulses to the corresponding counters 64 and 66. whereby indicated

becomes that the X and V counting is finished. Data transmission is then started by a data transmission circuit 96. The data transfer circuit 96 sends a transfer signal TF to the operations., Transfer gates of all buffers and

Counters to avoid. that a new data block is transferred from the buffer memory to the active memory. The speed controller 96 further sends a transmission reset signal TRS to the function generator 88 and to the distance counters 92 and 94 and a blocking signal TB to the function generator 88 and to the counters 92 and 94.11m to suspend the operation of these units, and a buffer reset signal BR to the function generator and the distance counters. The data transfer

Circuit 96 can also be activated by receiving a signal from port 36 for the data transmission shown in FIG Fig. 2. be operated. It is this latter signal which incorrectly indicates that the machine has reached a specified position and that to

* ° oak is used as described above.

The numerical input data validation 90 has a strip scanner and various known recognition and decoding circuits. * 5 The data input circuit 90 functions like this. that the encoded data from the punched tape, as in Figure 4 shown, reads and the decoded information about the various specified components in the

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Control directs. A typical strip of paper is approximately 1 inch (2.54 cm) wide and information is placed on the strip by punching holes in columns 1-8 and columns 0-5. ) Every column above the stripe represents a / calibration. and the number and position of the holes form a code which determines the character. In the current example, lines I through 4 indicate numbers. Line ^s > is used for a conventional type comparison check. Lines 6 and 7 are used in conjunction with lines 1 and 4 to indicate letters. Line 8 is used exclusively for a signal (HOB) which indicates the end of an information block. Perforation holes are punched between lines 3 and 4.

Column 0 contains an address letter and columns 1 through 5 contain numbers that represent tool position movement display from 0 to 9.949 inches (approximately 0-25.40092 cm) in a direction which is from the letters in column 0 are instructed. For example, columns 0 through 5 could be "Λ 3Ϊ2Ι7" which would instruct the tool to move into X-Kichuing by 3.5217ZoII (about 8.98 cm) move. This is common and well known. Columns 1 through 5 are counted down and signals become which indicate which column is decoded after column 0.

The X-Aehsenabslandszahlwerk 92 is in Γ ig. 5 shown. The V'-axis distance counter 94 is essentially identical to the A'-axis distance counter, with the exception of the axis nomenclature and the ring gear selection signals. Therefore only one of these two distance mechanisms is shown. The distance / meter is a five-digit decimal counter with connected buffers. It has a capacity of 0 to 99 999 incremental corresponding to 0-9.9999ZoII (approx. 0-25.3998 cm). In Fi g. 5, the five decades of the counter are denoted by 100.7 to 100c and the corresponding buffer memory with 102. ·; to 102c. The output spacing instruction for the axis is read into each decade of the buffer memory 102, as indicated by the signals T1 to T4 from lines 1 to 4 when the A'-axis setpoint signal is read from the punched tape. The five buffers \ 02; i to 102c respectively and successively receive signals R1 to R5 from a column counter (not shown) which is located in the numerical input data display 90. While the strip is being read in, the buffers 102; / to 102t? consecutively filled with input data. At the time when an instruction from a previous block is completed, a transmission signal TF is fed to the counter elements 100.'i to 100c, which transmits the distance instruction from the buffer memories to the corresponding counter elements. The distance counter then counts down from the previously set distance number to 0. The element 100c of the counter of the lowest digit receives clock pulses CL. The decades of the counter are thus connected to one another. that for each downward counting of ten in a decade a pulse? .u of the next larger decade of digits is passed in order to cause them to count down by one unit. Every decade 100a to 100c of the counter also receives transfer reset signals TRS and transfer blocking signals TB from the data transfer circuit 96. Each buffer memory 102a to 102c also receives a buffer reset signal BR from the data transfer circuit 96.

The distance counter also has input selection gates with two AND gates 104, 106 and one OR gate 108. The AND gate 104 receives a signal sequence UF 'from the function generator 88 and the AND gate 106 receives a signal sequence DF from the function generator 88. One or the other of the signals UF and DF is supplied depending on the direction of movement that has been instructed . A second input to each of the AND gates 104 and 106 is driven by the output of an AND gate UO. The AND gate 110 has five inputs, which are correspondingly connected to the outputs of the counter decades 100.1 to 100c. When the counter has counted down to 0, the AND gate 110 becomes controllable. This produces an output signal DXO for the data transmission sound 96. This signal also blocks the AND gates 104 and 106. Before the counter has counted down to 0, one or the other of the AND gates 104 and 106 will be controllable and an outline -increment signal PCX is passed through the OR gate 108 and fed to the V-Solw crt phase counter 64. This signal is also fed to a control input of the first decade 100c of the distance counter in order to simultaneously generate a decrease by one count in the counter and a phase shift by one increment in the command phase counter when the next following clock pulse CL is received.

Γ ig. Figure 6 provides a logic diagram of the file transmission circuit 96 which are shown in block diagram form in Fig. 3 is. Basically, it has a reset flip-flop 112 and a transfer flip-flop 114 open with different entrance and exit gates. The transfer of the data from the buffer memory to the active memory is normally started when both distance counters 92 and 94 Nu'ii have reached, which indicates it becomes that the movement has ended due to a given data block. This data transfer can, however, also be started according to this invention by a false signal from the data transmission circuit which is incorrectly the completion of a movement due to a given data block.

The transfer of the data entails four operations. These operations are in their order Occurrence:

Transmission blocking 'Tß-SignaI)
Transfer reset '77? S signal)
Transmission of the fTF signal) and
Buffer reset (BR).

These signals have a synchronous relationship with the clock signal CL. and are connected to the data storage facilities to produce coordinated parallel data transfer. The time relationship of these signals is shown in FIG. The transmission blocking signal TB suspends the operation of the function generator 88. It also switches off the counting gates of all decades, except for the "smallest decade" 102e of the distance counters 92 and 94, in order to prevent switching from one decade to the next during the transmission reset operation.

The transmission reset signal TRS resets both distance counters 92 and 94 to prepare

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for the next operation.

The transmission signal TF actuates the transmission gates in all active Pefehlsspeiehern and counters in order to match the flip-flops in both counters 92 and 94. ung with the states of the corresponding flip-flops in their buffers / u, and thus to bring about the actual transmission of the data.

The buffer reset signal BR resets the buffers in the distance counters 92 and 94. : .o that ic programmed distances are erased after they have been used once. The buffers for new distances are then zero until new values are read in.

The input to the Datenüberiragungsschaliung leads through an AND gate 116. The "AND gate 116 receives DXO and DYO signals from the distance counters 92 and 94 and a control signal from the reset flip-flop 112. The output de \ I IN D-gate 116 is connected to one input of the OR gate 118. A second input of the OR gate 118 is connected to the output of the gate 36 for the MCB value transmission, shown in Fig. 2. The output of the OR gate. Gate 118 is connected to one input of an AND gate 120 and a second input of AND gate 120 receives clock pulses CV .. An output of AND gate 120 is connected to a setting input terminal of reverse flip-flop 112. The output of OR -Tores 118 provides a setting control of the reset flip-flop 112. the flip-flop 112 is reset by an output signal from the aND gate 122. an input of the ¹ JND gate 122 receives Taktgeberimpulsc CL., and a second input of the UN D-Tores receives a control signal nal from the output of the transfer flip-flop 114.

The transfer flip-flop 114 receives a set input signal from an output of an AND gate 124. One input of AND gate 124 receives a signal from reset flip-flop 112, and a second input of this AND gate receives clock signals CL The signal from the reverse signal flip-flop 112 provides a control for setting the transmission flip-flop 114. A return entry of transfer flip-flop 114 is one output an AND gate 126 connected. One input of AND gate 126 is connected to receive clock pulses CX receives, and a second input this Tores is connected to receive an output from the transmit flip-flop 114. The signal from flip-flop 114 provides $ 0 reset control of the same flip-flop.

The output gates of the data transmission circuit have three AND gates 128, 130 and 132 or an OR gate 134, which is followed by an inverter 136. AND gate 128 is connected to receive TRG and TFC signals from reset flip-flop 112 and transmit flip-flop 114 and generates signal BR. AND gate 130 similarly receives signals from these two flip-flops, but the signals are of opposite polarity (TRG and TFG) to the signals applied to AND gate 128, and gate 30 generates signal TRS . The AND gate 132 also receives inputs from these two flip-flops, but the signals have different polarity relationships (TRG and TFG) from those signals fed to the other two AND gates, and gate Π2 produces the signal TF. The OR gate 134 receives signals (TRG) from the reset flip-flop 112 and signals from the output of the input I / ND gate j 16. 'The output of the OR gate 1J4 is only reversed by the inverter for generating the signal TB.

During the operation of the data transmission sound, the reset is! -! lip-flop 112 and transfer ilip-flop 114 both initially in reset states. When the inputs DAO and DYO for AND gate 1! 6 transition to the logical 0, indicating that the distance counters 92 and 94 have counted down to zero, causes an output signal. from the AND gate 116 the transmission blocking signal TB to the logical "1" via / usjel.en. This action also causes the reset flip-flop to be set to control.

The next input signal CV. through gate 120 sets flip-flop 120. Its output signal TRG therefore changes to a logic "1" and causes the output signal TB to be held at a logic "1" through gates 134 and 136. When the reset flip-flop 112 is set and the transmit flip-flop 114 is reset. their output signals through the AND gate 130 cause the signal TRS to transition to the logical "1". This resets all of the flip-flops in distance counters 92 and 94, causing the DAO and DYO signals to transition to a logic "1" and removing the setup control signal from the reset flip-flop 112.

The next input pulse CV. sets the transfer flip-flop 114. because the signal TRG is at the logical "0" and causes the correct control. The signal TRS then changes to the logic "0", since this signal can only be at the logic "1" while the reset flip-flop 112 is set and the transfer flip-flop 114 is reset. At the same time, the 7V ⁷ signal changes to the logical "1", since it can only be at the logical "1" if both flip-flops 112 and 1114 are set.

The next clock pulse CL resets the flip-flop 112. The flip-flop 112 was driven to reset when the flip-flop 114 was set. The output signal TF therefore changes to a logical "0" and the output signal BR to a logical "1".

The next clock pulse CL resets the transfer flip-flop 112 and thus causes a transition to the logic "0" of the signal BR. The output signals TRS. TF and TB went over to logical "0" beforehand. The flip-flops 112 and 114 are both reset and the transfer cycle is complete.

According to the invention, the same data transfer process is started by a logical "!" Signal to the OR gate 118 from the transmission measurement transfer gate 36 (Fig. 2) when the Measuring device of the invention is made operational.

The F i g. Figures 8 and 8a are logic diagrams illustrating an embodiment embodying the invention and shows its connections to the other parts of the control circuit. Those members of the F i g. 8 and 8a, the circuit already shown in FIG. I are shown in Figs. 8 and 8a with the the same reference numerals as in FIG. 2 denote !.

As in Fig. 8, the tool 12 is connected to the movable contact via the line 22; single-pole two-position switch S-ί connected. One <of the other terminals of the switch SI is marked Massi

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connected and the other is blind to one of the hanging terminals 142 of an OR gate 150 \. The OR gate 150 is connected to an input of an AND gate 152. An output of the AND gate 152 is with an adjustment input terminal of a touch guide hip hop 154 connected. E ^ i output of the flip-flop 154 is connected to a wide input of AND torc 152 to receive a setting control signal for the Generate AND gate / u.

An output of the touch sensor flip-flop 154 is connected to an input of a four-input UN D port 156. The other three inputs Hs AND gate 156 are connected in such a way that they receive clock pulses CL. an output from a sense flip-flop 158 and an output from an error detector flip-flop 160 received.

The flip-flop 158 for the measuring operation controls the point in time or the time at which or during which a calibration is carried out. The operation of the flip-flop 158 is in turn indicated by output signals controlled by the two AND gates 162 and 164. The AND gate 162 has four inputs that are so interrelated connected that the signals from the data input Schahung 90 received, and an output which is connected to a setting terminal of the flip-flop 158 is. The AND gate has four inputs in the same way, which are connected in such a way that they receive signals from the Receive data input circuit 90, and an output which has a reset input cycle of flip-flop 158 is connected. The same output terminal of the flip-flop 158th which with a Input terminal of AND gate 156 is connected is also so connected to a reset signal on a reset input cycle of the touch sensor flip-flop 154 to give.

The AND gate 156 has an output connection to an input of an inverter 166. The inverter 166 inverts the output signal from the AND gate 156 to uiic ¹ forwards it to one input of an AND gate 168. An output of the AND gate 168 leads to an adjustment input terminal of a transmission measurement flip-flop 170. An output of the transmission measurement flip-flop 170 is connected to a second input of the AND gate 168 for supplying an adjustment input control signal to the AND gate. The output of the transmission measurement transmission flip-flop 170 is also connected as an input to the OR gate 118, which is described above in connection with FIG. 6 has been described. A second input of the OR gate 118 is connected to the AND gate 116, which has been described in connection with the same figure. Therefore, the OR gate 118 provides an output to the AND gate 120 in the communications circuit in response to receipt of either a normal transmit signal from the AND gate 116 or a false transmit signal from the pass-sense transmit flip-flop 170.

The output of the OR gate 118 is also connected to an input of an AND gate 172. An output of AND gate 172 is connected to a reset input terminal of the forward sense transfer flip-flop 170. A second input of the AND gate 172 is connected in such a way that it can receive clock signals CL. The signal from the OR gate 118 to the 'IND gate 172 generates a Reset control signal for this AND gate.

The fault indicating part of the circuit comprises the fault indicating flip-flop 160 mentioned above and which receives a set input from an OR gate 174. The OR gate 174 has two inputs that receive signals from UN D ports 176 and 178.

The AND gate 176 has two inputs, one of which one is connected in such a way that it can receive a signal from the flip-flop 158 for the measuring operation and the other like that. that it can receive a signal from the AND gate 116 via an inverter 580. The UN D gate 178 also has two inputs, one of which is connected in this way. that he is a signal of that Touch sensor fiip-flop 154 can receive and the other is set to receive a signal from an OR gate 182 can receive. The OR gate 182, in turn, receives and returns a signal from one AND gate 184 around. The AND gate 184 has two inputs, one of which is connected such that he can receive a signal from the flip-flop 158 and the other is connected so that he Can receive clock signals CL.

The output signal of the error display flip-flop 160 is switched via an inverter 186 to a shutdown device 188, which is used to control the machine in response to an error signal from the display: - To stop flip-flop 160. You can also serve a or to energize several warning or signaling devices 190 of the desired type in order for an audible or a visible sign of the machine malfunction.

In normal operation, signals are passed through AND gate 116 and OR gate 118 for a Data transfer operation in the data communication framework 96 to begin. This is explained in the foregoing in connection with FIGS been. During calibration, a "wrong" signal is passed through the OR gate 118, which the Data transmission circuit operated in exactly the same way as a normal signal transmitted via the AND gate 116 is fed. A calibration process is carried out by receiving signals to initiate measurement operations from data input circuitry 90 and started by the AND gate 162. The output of flip-flop 158 causes the Flip-flops 154, if this has not already been reset.

The machine is now instructed to move in the direction of the calibration block 18. When the tool touches the block 18, this is grounded via the tool 12 and the switch S-I. Since the block 18 with a the input terminals of the OR gate 150 is connected, this input terminal is also at ground potential brought. When this input terminal is grounded, a binary "O" signal is applied to AND gate 152 forwarded.

A signal is then passed from the AND gate 152 to the touch sensor to set its flip-flop 154. This in turn generates a logic "0" signal at one input of the AND gate 156. The flip-flop 158, which has been set, also routes a logic "0" signal to another input of the AND gate 156. Provided that no Syslcmfehler is that conducts error display flip-flop 160 is also a logical "0" signal to the AND gate 156. Therefore, the next logical "O" -Taktgeberimpuls CL AND gate 156 is a logic "!" -Pass output to inverter 166. The OR gate reverses the signal and thus routes a logic "0" signal to one input of AND gate 168. When the pass-through measurement transfer flip-flop

709 619/135

21 OO

170 is in its default state. it also routes a logic "0" signal to AND gate 168. Therefore, AND gate 168 will generate a logic "1 <" signal to set the measurement transmission flip-flop 170. This causes the measurement transfer flip-s Fiop 170 to transmit a logical "!" Signal to OR gate 118. The OR gate 118 reverses this signal and redirects it to yours as a logical "0" signal AND gate 120 in the data transfer circuit.

The OR gate 118 also routes a logic "0" signal to an input of the UN D gate 172. Therefore, when the next logic "O" clock pulse is received, Cl. the AND gate 172 cause the resetting of the transmission message flip-flop 170, is

The touch sensor flip-flop 154 is reset after the calibration process either by the start of a second calibration process or by the readiness of a normal transmission signal from the AND gate 116. The first condition is shown by the connection from the flip-flop for the Melibeiricb 158 to the reset terminal of the touch sensor flip-flop 154, while connections for the latter reset operation are not shown.

The flip-flop 158 is activated upon receipt of signals on the AND gate 164 from the data input circuit 90 is reset, indicating the start of normal program operation.

The fault indicator part of the circuit causes the machine to shut down under two conditions. namely when the tool 12 contacts the calibration block 18, the measuring device not in the Calibration position is, or if during calibration a normal transmission signal is supplied.

When the first abnormality occurs, AND gate 184, inverter 182 and AND gate 178 are affected. If the circuit is not in the calibration position, e ^; n logic "0" signal passed to an input of the AND gate 184 of the flip-flop 158. Therefore, when the next logical “0” clock pulse CL arrives, a signal will be sent via the inverter 182 and appear as a logical “0” signal at an input of the AND gate 178. As a result, when the tool 12 touches the calibration block 18, a logic "0" signal will appear at the output of the touch sensor flip-flop 154. This signal is also passed to AND gate 178 so that AND gate 178 will pass a signal through OR gate 174 to set error indicator flip-flop 160. When the error indicator flip-flop 160 is set. it sends a logical "!" signal to the input of AND gate 156, so that the measuring device is inoperative. Of course, the fault indicator flip-flop 160 also passes a signal via the inverter 186 to the shutdown device 188 in order to stop the machine.

When the latter abnormality occurs, this one becomes indicated by the AND gate 176. In the setting, the flip-flop 158 sends a logic "0" signal to the Input of AND gate 176. If a normal transmission should now take place, AND gate 116 generate a logical "!" output signal. This signal is reversed and ais by the inverter 180 a logical "0" signal is sent to the second input of gate 176. This causes the feeding of a Signal from this AND gate via the OR gate 174 for setting the error display flip-flop 160 and stops the machine as described above.

Resetting the Error Indication Ilip-Flop 160 is achieved by hand control (not shown). This ensures that the machine malfunction is an operator is brought to the notice and the condition is corrected. before weuer is seeded.

After the working method for the calibration of a machine plant / euger ,. like a cutter, or a test probe has been described, the operation of the measurement will now be described below described relating to measuring the dimensions a workpiece aligns after the workpiece has been partially or fully machined.

During the measurement, the tool 12 takes on the function of a Pnifonde. The test probe can be instructed to move to various test points on the workpiece or ring 10 in order to measure the clearance of these test points. The switch S- 1 is left in the position shown in FIG. 8 is shown. and the test probe is calibrated in the same manner as described with respect to tool 12. In other words, this means that every step that is carried out to calibrate the tool 12 is carried out. is now adjusted with the Priüsontle in order to precisely calibrate the position of the probe. The calibration process is conditioned by the same factors that require calibration of the machine tool, namely poor alignment of the tool, wear on the cutting edge of the tool, and so on.

Reference is again made to FIG. 8 and 8a taken, which also have a circuit for Show how to measure a workpiece. The conductor that the flip-flop 170 with connects to the OR gate 118 is also connected to the Inputs of a pair of AND gates 200, 202 connected. The output terminals of the UN D goals 200, 202 are coupled by a pair of preset circles 204, 206 with a pair of, respectively Display devices 208, 210. Display device 208 provides an output display and is in turn connected to an A'-axis printer 211, and display device 210 provides a V-axis output display and is in turn connected with a Y-axis printer 212.

A pair of AND gates 214,216 with four inputs are connected to their input terminals with the numeric Data ingress circuit 90 and its output terminals coupled to the Adjustment terminals of a V-axis test flip-flop 218 and an A'-axis test flip-flop 220. The reset terminals of the flip-flops 218, 229 are direct connected to the output terminals of AND gate 164. Additionally, the output terminal is a Y-axis test flip-flop 218 with one of the input terminals of an AND gate 222 and one of the input terminals of a NAND gate 224. Similarly, is the output terminal of the A'-axis check flip-flop 220 with one of the input connections of an AND gate 226 and one of the fineangs connections of a NAND gate 228.

The other input connections of the AND gates 222 226 are commonly connected to the commonly connected input exclusions of AND gates 200 202, and the other F. input terminals of the NAND gates 224, 228 are commonly connected to the Conductor extending between flip-flop 158 and AND gate 176

21 OO 363 \

19 Γ 20

The output connections of the AND gates 222, 226 are, for the measurement of a / \ lmnschcn icile, the radial

accordingly with the Vhsdrucker 212 and Ahsi.ind \ erdi> ppeli can graze to an output

.Y-axis pusher 211 connected. The initial display, representative of the measurement of the diiivh-

Conclusions of the NAND Torc 224, 228 are correspondingly niessei s. / U received.

connected to the other exit connections of the ^ In der MeH. > Peraiionsw ee will be a special one

AND-'F.re 202, 200 and the function generator 88 is coded program aiii the I .och gripping. D.is l.ochs'.re-

with both the A-axis output device 208 and fen pro; ramm instructs the probe. themselves / u a l'osiiion

mild Y'-axis output request immg 210 connected. to move that would theoretically require. that the

The four hanging connections of another pair of probe mc h behind the surface of the workpiece or

of AND gates 230, 232 with four pendants are moved io of the ring K). If / wipe the probe and

Connected with the numerical data input switch- ^ "King 10 electrical conact has been manufactured

Hing 90 and its output connections are accordingly. becomes a logical,>! <· signal / u the ODl.R-1 or ISO

linked to a> -axis polarity Fhp flop. This signal causes the data to be stored in the

234 and an A-axis polarity flip-flop 23β. The counters go to a zero payment, which is

Output uncertainty of the axis polarity lipisens causes a transmission signal to be generated.

Flops 256 are with the A output device 208 which the system to / eigi. that the instructed

connected and the output terminal of the> Pokirita position has been reached. This broadcast signa!

ten-riip-Rops 2.34 are connected with the V-axis or »false signal. which he / she is born when the

dispenser 210. probe reaches a "wrong" position, causes it

When the Prüfunüvsonde. “Ie in the previous 20 tax system, move on to the next episode of the program

has been calibrated. will move the switch SI / u.

from the position as s, e in Fig. S ge / eigi./u a Die Λ -axisausgabevorriehtung 208 and the

Moved position in which the tool or the V-axis output machining 210 are in / entime-

Probe 12 with the input connection 142 of the ODFR-Tt) - tern calibrated and by the function generator.; Ior 88 for

res 150 is connected. The probe is then instructed. 2s counting of each incremental movement of the probe controlled,

in the direction of the workpiece or the ring 10 / u in order to have a continuous display of the probe

move and allow in the direction of a predetermined position. The A 'axis printer 211 and

Point on the ring at which the dimensions measured by the> -axis indenter 212 speak upon contact

should be. The command signal is similar to wiping the probe and ring 10 on. to thereby

• \ nw ary signal. which the tool during the 30 cause the display information to only be printed out

Calibration process is given. d. H. the tool will be when there is contact between the probe and the ring

instructed to move to a position under the / u consists (flour shown).

Move the test point on the ring 10 / u. This particular is advantageous in the case of the invention

Point would actually be inside the 10 ring. Device to reduce inspection time. those at one

The signals that are required by the function generator 88 35 precise processing and thus a

generate! the .Y-axis output device will reduce the amount of time required to produce a machined

umg "2Ο8 and the V-axis output device 210 th part as well as for the measurement of a machined

forwarded. The A'-axis signal is partially required by time, l'requen / doubling circuit 240 led, so daU

In addition 6 sheets of drawings

Claims (6)

21 OO claims: 1. Calibration device for the position of the cutting edge of a single or multi-edged tool of a numerically program-controlled machine tool, with a calibration block arranged on the machine tool, against which the cutting edge can be moved and with a measuring arrangement. which detects and displays this position of the cutting edge and for which a correction of the path setpoints given by the numerically operating program control is available for the individual path controls for moving the tool along different axes, characterized in that the insulated, at least one electrically conductive visual surface ( I8.i. 186.18c) having calibration block (18) is connected to the input of a gate circuit (38) of a circuit (Fig. 8, 142), with which circuit (Fig. 8, 142) the tool (12) ( connected via S 1). that on the program carrier of the machine program coded calibration commands are specified as required, that the tool (12) automatically after predetermined work steps by means of the operationally required path controls (Fig. J) along a predetermined path in the direction of a target position behind one of the side surfaces (18.7 .186,18cjdes F.ichblockcs (18) is movable, and that the tool (12) and the light block (18) when touching each other close the Sformkreis (Fig. 8, 142), which (via 36) emits a contact signal which A further movement of the tool (12; interrupts via a sound circuit (42), and (via 36) the contact point reached and registered by the position controls (Fig. 3) as a new reference point in the control circuit (28) of the numerically operating program control of the Machine tool. 2. Calibration device according to claim 1, characterized by the use in a machine tool, instead of a tool (12) for machining purposes with a test probe for measuring purposes is equipped on a workpiece. 3. Calibration device according to claim 1 or 2, characterized in that the calibration block (18) can be automatically moved into and removed from a calibration position. 4. calibration device according to one of the preceding claims, characterized in that the at The control variable occurring after the touch can be stored as a digital calibration value. 5. calibration device according to claim 2, characterized in that the circuit (42) the Machine tool switches off when the contact between test probe and workpiece (10) in a Position takes place which does not correspond to the position calculated from the previously stored calibration value. 6. calibration device according to claim 5, characterized in that one with the Prüfsonclc Display device (30, 32) is connected, which shows the position of the on contact with the workpiece (10) Indicates test probe with regard to the calibration value. The invention relates to a calibration device for the position of the cutting edge of a single or multiple cutting edge Tool of a numerically program-controlled machine tool, with one on the machine tool arranged calibration block, against which the cutting edge can be moved and with a measuring arrangement that this Position of the cutting edge detected, displays and for a Correction of the numerical working; Program control specified path setpoints for the ίο individual path controls for moving the tool provides along different axes. Such a calibration device is known from DT-C) S 16 52 751.
How numerically controlled machine tools work. which are widely used today is well known. In these machines, a tool or similar device is moved according to numerically programmed instructions. The path of movement of the tool can be straight or circular. Signals that indicate the position of the tool in relation to a given line (actual value) are compared with signals that are derived from the programmed instructions that determine the path of the tool (setpoint), and the tool moves until the two signals are the same. When the two signals are the same, it indicates that the tool is in a specified location has arrived. A transmit signal is then generated to indicate that the tool is ready. execute a new command. Usually the commands are supplied as signals, the first of which is a Show the position to which the tool is to be moved and, secondly, the size of the speed with which the tool should be moved to the new position. The programmed instructions are based on the premise that the length of the tool and the radius of the cutting edge are as great as from Manufacturer, and that the tool was precisely aligned when it was installed. this but does not necessarily apply; there may also be deviations z. B. due to tool wear result. In today's applications it is often necessary to produce a large part with extremely small dimensional tolerances to edit. In a special case it is e.g. B. no agile, the outer surface of a ring of 100 cm in diameter to be brought to various dimensions, which are accurate to ± approx. 0.002 cm have to. Such a part can be a component of a jet engine, where extreme accuracy is required Beardness is vital. So far this is one It was a time-consuming work process, since the dimensions of the workpiece after each cut through the tool had to be measured. An initial measurement was required after the first cut to avoid incorrect Dimensions of the tool, poor alignment of the tool during assembly or the like correct. A measurement was necessary after successive cuts to determine the wear and tear of the Correct tool. If any errors by manual measurement; the dimensions of the workpiece were determined, the commands or instructions for the tool were prepared by the Program modified enough to correct the errors. This is time consuming because it is a Stop the machine tools and require an operator to perform the measurement for