CH642761A5 - CONTROL DEVICE FOR CHECKING A DETERMINED POSITION OF A PART. - Google Patents

Description

The invention relates to a control device for checking a miss signal when actuated by the pushbutton element

3rd

642 761

generated so that the time period specified by the delay element does not have to be fully waited for if an error message is present.

In a preferred embodiment of the invention, it is provided that the switch essentially short-circuits the DC motor, that the control comprises means for determining the resistance between the connection terminals of the motor and that a circuit is provided for comparing the resistance between the motor connection terminals and a fixed value if the resistance is above the fixed value, a signal corresponding to the open state of the switch is generated, if the resistance is below the fixed value, a signal corresponding to the closed state of the switch is generated. This configuration makes it possible to check the closed state of the switch without the need for separate control lines for the switch. In this way, the closed state can be checked via the connection cables of the DC motor itself.

The period after which the delay element actuates the control is preferably adjustable. The control device can thus be adjusted to different swivel ranges of the probe element.

In a preferred embodiment, it is provided that a stop member is connected in a rotationally fixed manner to the shaft of the direct current motor, which stops when a stop element is pivoted beyond the required position, and that the stop and stop member are designed to be electrically conductive and are each electrically connected to a connecting terminal of the direct current motor are connected. A particularly simple structural design of the switch is thus obtained, which is itself formed by the stops which are necessary anyway.

It is particularly expedient if the stop member is electrically conductively connected to the motor shaft, which is in conductive connection with a connecting terminal of the motor, and if the stop is kept electrically insulated on the housing of the motor.

Furthermore, a second stop can be provided to limit the rotation of the motor in the opposite direction.

According to a further advantageous embodiment, it is provided that the switch, which essentially short-circuits the motor connection terminals, is preceded by a resistor which is small in relation to the internal motor resistance. This makes it possible, after closing the switch and short-circuiting the motor and reversing the voltage applied to the motor connection terminals, to allow the DC motor to run back despite the switch being closed, since a small current flows through the motor due to the switch series resistor, which is sufficient to compensate for the Turn the engine back a little and open the switch again.

The following description of preferred embodiments of the invention serves in conjunction with the drawing for a more detailed explanation. Show it:

1 shows a side view of a control device according to the invention;

FIG. 2 shows a side view of a DC motor for actuating the pushbutton element in the control device of FIG. 1;

Fig. 3 is a sectional view taken along line 3-3 in Fig. 2 and

Fig. 4 is a simplified circuit diagram of a preferred embodiment of a control of a control device according to the invention.

In Fig. 1 the probe for the control device according to the invention is shown in a side view. It comprises a cylindrical housing 1 with an external thread, onto which two nuts 2, 3 are screwed, which are used to fasten the housing in a bore in a machine frame or a holder. Inside the housing 1 there is a DC motor 4, which is shown in FIGS. 2 and 3 without the housing 1 surrounding it. This cylindrical motor 4 has two connecting terminals 5, 6, which are connected s to the wires 7, 8 of a supply cable 9. One of the connection terminals is also connected to the motor housing 11 via a connection wire 10, so that this, like the motor shaft 12, is in electrically conductive connection with the one connection terminal.

On the front side opposite the supply cable 9, the motor housing 11 carries two axially directed stop pins 13 and 14, which are kept insulated at a radial distance from the motor shaft 12 with respect to the motor housing 11. For this purpose, for example, a retaining ring 15 made of an insulating plastic material can be applied to the motor housing 11. One of the two stop pins (13) is electrically conductively connected to the other connection terminal 6 via a connecting wire 16 (FIG. 2).

On the motor shaft 12, a 20 sleeve 19 is held in a rotationally fixed manner by means of a screw 20, which carries a cover disk 18 on its side facing away from the motor and a radially outwardly projecting pin 17 on its side facing the motor, which pin is so long that its Stop on the stop pins 13 and 14, the rotational movement of the Mo-25 gate shaft is limited.

The radial pin 17 and the stop pin 13 connected to the connecting wire 16 are made of electrically conductive material, so that when the pin 17 is placed on the stop pin 13 an electrical connection 5 and 6 short-circuiting 30 is produced. A series resistor, which is small in comparison to the internal motor resistance, is switched into this short-circuit connection in a manner that is not apparent from the drawing.

The structural unit shown in FIGS. 2 and 3 is inserted into the housing 1 of FIG. 1 in such a way that only the motor shaft 12 protrudes from the housing; at its free end it carries a radially projecting probe element 21 which is connected to it in a rotationally fixed manner and which has the shape of a pointer and preferably consists of a thin spring wire. A control circuit is also assigned to the scanning head of the control device according to the invention shown in FIGS. 1 to 3, the preferred configuration of which is explained in more detail below with reference to the circuit diagram of FIG. 4 reduced to the essential components. 45 In this circuit, a bridge circuit is provided for the DC motor, which has the reference number 4 in accordance with the above description, which comprises four transistors 22, 23, 24 and 25. Transistors 22 and 24 are PNP transistors, transistors 23 and 25 are 50 NPN transistors. One motor connection 26 is connected to the collectors 27 and 28 of the transistors 22 and 23, the second motor connection 29 is connected to the collector 30 and 31 of the transistors 24 and 25. The emitters 32 and 33 of the transistors 22 and 24 are direct, the base connections 34 55 and 35 of the transistors 22 and 24 are connected via base voltage divider resistors 36 and 37 to a point M, which is connected to the output of a device known per se and in the drawing therefore only schematically illustrated stabilized DC voltage source with current limiter 38 is connected.

The emitters 39 and 40 of the transistors 23 and 25 are grounded, the base connection 41 of the transistor 23 is connected via a base resistor 42 and an inverter 43, the base connection 44 of the transistor 25 only via a base resistor 45 with a control line 46 in connection. Finally, in this bridge circuit, the collectors 27 and 30 of the transistors 22 and 24 are also connected via a base resistor.

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47 and 48 were connected to the base connection 3 5 and 34 of the respective AND gate 68. The differentiator is connected to other transistors 24 and 22, respectively. the one on the one hand grounded protective diode 88 and a

In parallel with the two motor connections 26 and 29, a resistor 89 to interference suppression capacitor 80, which is connected in parallel with this protective diode, is provided, and one connects in an orderly manner.

Short-circuit line 82, the motor connections 26 and 29, into which a further input of the AND gate 87 is connected to an operating voltage source, a switch 83 and a resistor connected upstream thereof, the other two inputs 84 being switched on. The resistor 84 has in comparison gears with the Q outputs of the flip-flops 67 or the internal resistance of the DC motor 4 a low 73 in connection.

value. The output of the AND gate 87 leads to the clock input

The DC motor 4 and the short-circuit line 82 io gang of a further flip-flop 90, whose D input is also with the switch 83 and the resistor 84, as are the D input of the flip-flop 69 with an operating voltage — the preferred exemplary embodiment in Readhead itself, voltage source is connected. The Q output of the flip-flop 90, the remaining parts are located in a distance from the scanning head and leads to the set input S of the flip-flop 73, the reset-in control circuit, which is only connected to the second input R of the flip-flop 90 Reset input R of the lead 9 is connected to the scanning head. 15 flip-flops 73 connected.

This is shown in FIG. 4 by the dashed frame of the delay element 91 known per se.

Readhead arranged elements shown. hen whose Q output is connected to the control line 46

The point M is connected to the first manure via a line 47a. The time constant of this delay element 91, input 48a of a first comparator 49 in connection, can be set differently by different resistors 92, 93, 94, 95 or 96 in the same way via line 50 with the first input 20.

51 of a second comparator 52. For smoothing the time delay in triggering element 91

output voltages is a smoothing capacitor 53 with which it is connected to the output of an inverter 99, the measuring point M is connected, furthermore 47a and 50 filter elements 54 and 55 are located in the lines of the collector line of an NPN transistor 100, each of which a wid. The collector of the transistor 100 is connected to an operating voltage source via a resistor 56 or 57 and a capacitor 101 connected to ground, which comprises sensors 58 and 59, respectively. The second input 60 of the emitter is grounded. The base line is connected via a first comparator 49, a fixed voltage is connected, the resistor 102 and a test switch 103 are connected to a voltage drive voltage source comprising two resistors 61 and 62; a resistor 104 voltage divider circuit is generated. Likewise, a fixed line 30 is connected to the second input 63 of the second comparator 52 and a capacitor 105 connected in parallel therewith, the base line to ground.

Voltage is applied which is generated by resistors 64 and 65. In operation, a voltage divider circuit that is too extensive is generated at the start of a test process. The fixed next the test switch 103 closed. In the case of the first comparator 49, this can be done, for example, at the input that is rotating by a clock signal of a machine tool, in the case of the second comparator a test rator 52 in the non-inverting one before the next processing step. 35 Process starts. By closing the test switch 103

The output 66 of the first comparator 49 is connected to the transistor 100, so that a flip-flop 67 is connected to the output of the in-clock input, the data converter 99 of which produces a positive signal (“high”). In the following, such signals as 1, zero Si are connected to the preparation for preparation for the association (D input) with the control line 46 times. On the one hand, its Q output leads to signals (“low”) designated as 0.

gang of an AND gate 68, the output of which the clock input 40 This 1 at the output of the inverter means that the gang of another flip-flop 69 is fed. The Q-out delay element 91 is triggered and at its Q output of this further flip-flop 69, the output line is a 1 appears. This 1 generates via the differential 70 for a GUT signal. This output line 70 is connected to a capacitor 77, a reset pulse to the reset with an input of an OR gate 71, set inputs R of the flip-flops 69, 73 and 90. In addition, its output to the reset input R of the flip-flop 67 45 is 1 at the D input of the flip-flop 67 and at one leads. Input of the AND gate 74 on.

The output 72 of the second comparator 52 leads to the by 1 at the Q output of the delay element 91

Clock input of a further flip-flop 73, whose D input is also connected to the bridge gear assigned to the electric motor 4 with the output of an AND gate 74 in connection with the circuit such that the transistor 25 is conductive. Its input is connected to the control line 46, while the transistor 23 is blocked. By tied, the other with the Q output of the flip-flop 69. Line of the transistor 25 is connected via the resistor 48 to the Q output of the flip-flop 73, the output line forms the base 34 of the transistor 22 at a low potential -tung 75 for a FAULT signal. This is connected to the other, so that this transistor is also switched through, the input of the OR gate 71 is connected, and to the reverse transistor 24 is connected via the resistance of an input of an OR gate 76, the output of which to the 55 47 the blocking of the transistor 23 also leads to the reset input R of the flip-flop 69. becomes. In this state, the engine 4 is opened

The control line 46 is flowed through by the current via a differentiating capacitor switch 83 in such a way that the pushbutton 77 rotates in connection with the reset input R of the flip-flop 73 in the direction of the part to be monitored, one being used to prevent peak voltages . With this free rotation, the motor has a relatively protective diode 78 connecting to ground. Parallel 60 high internal resistance, so that the flowing through the motor to the protection diode 78, a resistor 79 is provided. Of the transmit current is below the maximum value, which is determined by the connecting line between this differentiator and current limiter 38. As a result, the reset input R of the flip-flop 73 results in a rise in the voltage at the measuring point M which is fed to the connecting line to the other input of the OR gate 76 aisle 48a of the first comparator 49. This off. 65 Voltage is above if the motor can rotate freely

The control line 46 is via an inverter 85 and one of the fixed voltage at the other input 60 of the comparator differentiating capacitor 86 with an input of an AND-49. As a result, a gate 87 with four inputs and the other input of FIG. 1 appears at the output of the comparator 49 Clock input of the flip-flop 67 is supplied.

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This produces a 1 at its Q output, which is now to be noted that the FAULT signal is present at an input of the AND gate 68. occurs as soon as the switch 83 is closed, that is, before the switch 83 remains open, is the time period at the inverting end of the input 51 of the second flip-flop 52 determined by the delay element 91.

The amount of voltage is greater than that at the first input 63 s. A GOOD signal, on the other hand, cannot be generated because the fixed voltage is present, so that the flip-flop 67 is reset by the FAULT signal at the output of the second

Comparator 52 a 0 appears, which is the clock input of the and since the voltage at the measuring point M in terms of amount

Flip-flops 73 is supplied. At its D input there is a voltage below the fixed voltage at the inverting input 60 of the

1, since the one input of the AND gate 74 drops the 1 of the Qth comparator 49, so that at the clock input of the

Output of the timing element 91 is supplied, the other one 10 flip-flops 67 is 0.

gang of the AND gate 74 of the Q output of the flip-flop 69, after the preselected period of time has elapsed, this has been reset by the triggering of the timing element 91 and a 0 appears at the Q output of the delay element. 91 only to reverse the direction of rotation of the motor 4. Da

As soon as the delay set on the delay element 91 due to the series resistor 84 has a lower current or proper time elapsed, appears at the Q output 15 through which the motor flows, this slowly moves back in the delay element 91 again to a 0, the over the inverter downward and thereby opens the switch 83, see above

85 and the differentiating capacitor 86 a 1 to the other that the motor turn back to the starting position

Input of the AND gate 68 sets. This can be generated at the output.

this AND gate 68 is a 1, which corresponds to the clock input of the motor when the test switch is actuated

Flip-Flops 69 is supplied so that at its Q output 20 does not rotate for any reason, then there is no rise, a signal appears which the output line 70 as the internal resistance, so that the voltage at the input 48a

GOOD signal is supplied. This signal leads to one of the first comparators 49 in terms of amount below the fixed chip

Reset flip-flop 67. voltage at inverting input 60 of this comparator

So you can see that after the delay the delay remains. Then there is a 0 at the clock input of flip-flop 67

approximately a predetermined time a GUT signal is generated, 2s, so that the one input of the AND gate 87 via the when the switch 83 remains open, ie when the stylus Q output of the flip-flop 67 is supplied with a 1.

due to the part to be monitored at its further point. 1 cannot be on the clock input of the flip-flop 73

Pivot and prevented from actuating the switch 83, so that its Q output is the same. AND gate 87 feeds a 1.

After the time has expired at the Q output of the delay 30, a 1 appears at the fourth input of the AND gate 87,

The pending 91 also switches the direction of rotation when the time of the delay element 91 and the DC motor has elapsed, since a 0 occurs on the control line at its Q output due to the 0. As a result, the device 46 is switched through the transistor 23 and the transistor clock input of the flip-flop 90 is supplied with a 1, which for

25 be blocked. As a result, the transi setting of the flip-flop 73 is carried out at the same time and thus

stor 24 turned on and the transistor 22 blocked. The 35th FAULT signal on output line 75.

The motor now runs back to the starting position and remains in this starting position until the test process by closing the switch 103, which is switched off in the meantime. This gives a check as to whether the motor

has been opened, starts again. Has started properly in this starting position at the beginning of the test period.

A further rotation of the direct current motor is made possible by the control device according to the invention, so that the stop member 17 lies against the stop pin 14, thus initially preventing a check of whether the scanning element (FIG. 2). is pivoted properly. In addition, if the probe element receives a GOOD signal after this time has elapsed after the expiry of the direction from the delay element 91 towards the part to be checked, if the switch 83 is not prevented from pivoting, it does not close 45 , that is, when the pushbutton element is closed by the switch 83 so that the motor 4, which is to be monitored essentially briefly, is pivoted further. The drop in resistance between those being changed. However, if the part is not in the required terminals 26 and 29 of the motor, causing the clamping position, the probe element can pivot further and drop at the measuring point M, to a value that the switch 83 closes that a Fault signal is generated immediately after closing below the fixed voltage value at the input 63 of the second switch 83, comparator 52. As a result, a 1 is generated at the output 72 of the second comparator 52, which is fed to the clock integration of the switch 83 by the control circuit by measuring the flip-flop 73, at whose D- Input solution of the resistance between the motor terminals is fixed in the manner described above. This leads to poses. Of course, with another configuration of a DISTURB signal on the output line 55, it would also be possible to close the switch 83 directly to the line 75. In addition, this signal also monitors the flip, but then there are additional control lines for flops 67 and 69 reset. the switch 83 necessary.

C.

2 sheets of drawings

Claims (8)

642 761 2 PATENT CLAIMS of a specific position of a part or for review 1. Control device for checking a certain position, the presence of a part by means of a pivotable ge-tion of a part or for checking the presence of a stored probe element, which can be pivoted against and against the part by means of a direct current motor part by means of a pivotably mounted probe element this strikes, which uses a DC motor against the part 5 when the part assumes the required position, but which is pivotable and strikes against it when the part extends beyond the required position, if the part assumes the non-required position, but which over the dipped into the path of movement of the probe element. position expires when the part is not in the position. immersed path of the probe element, characterized by avoidance 30 13 054 have been proposed. In the case of this older one, a switch (83), which was activated by the pushbutton element (21) or a patent application, the element which is rotatably connected to it when the pushbutton element is struck, if the increase in the in- If a part is missing, the feeler element (21) is used beyond the required position resistance of this part to make a statement about tion, and by a delay element (91) which detects the presence of the part in the required position or ches to make a period of time from the beginning of the movement of the key - its absence. elements (21) in the direction of the required position 15 Furthermore, from DE-OS 30 03 431 a control device and after the expiry of the period, which is larger than that of the known, in which a probe element by means of a constant movement of the probe element (21) until the current motor is pivoted against the part to be monitored, the switch (83) is normally required if the part is missing. The presence of the part in the required posi period is a control operated, which, when not operated, generates a GOOD signal in this previously known device, for example switch (83). 20 indicated by the current increase of the DC motor, 2. Control device according to claim 1, characterized in that when the pushbutton element is stopped on the net to be monitored, that the control is designed such that the part occurs when actuated. In this previously known device supply of the switch (83) by the pushbutton element (21) or the moreover relatively complicated devices are necessary in order to generate a FAULT signal associated with the element connected to it immediately in the absence of the part to be monitored. Get 25 signal. In the known device 3. Control device according to claim 1 or 2, thereby provided for this purpose angle measuring devices, which indicates that the switch (83) is connected in a complicated monitoring circuit, the respective winch connection to the DC motor (4) is switched in that Show the kelposition of the probe element, so that means for determining the resistance between the comparison of the angular position and the current consumption of the terminals (5,6) of the motor (4) and 30 of the DC motor signal from a control means that a circuit for comparing the Resistance can be drawn between whether the part is in the required motor connection terminals (5,6) and a fixed value in the forward position or not. This angle measurement is provided and is designed in such a way that it is structurally complex in the case of over directions, has a large resistance lying at the fixed value and the opening space requirement and is only by means of additional control lines of the switch (83) and one below the fixed value. 35 to operate, the resistance from a control to the control device tes the closed state of the switching operation. ters (83) corresponding signal generated. The invention has for its object a control 4. Control device according to claim 1, 2 or 3, to improve device of this type in such a way that the presence indicates that the period of time after which the delay of a part in the required position with the simpler locking element (91) Control operated, is adjustable. 40 structural means can be determined, especially without the emergency 5. Control device according to one of claims 3 or 4, maneuverability, except for the supply lines of the DC characterized by the fact that additional control lines to the current motor control unit (4) are connected to the shaft (12) of the DC motor in a rotationally fixed manner to have to provide. This is achieved according to the invention by a required position at a stop (13) when the push-button element (21) is pivoted. The trolling device of the type described at the outset, which moves and that stop (13) and stop member ( 17) is electrically characterized by a switch which is formed by the key element and which can be electrically conductively connected to a connecting terminal (5 element or a rotatably connected element or 6) of the direct current motor (4), if the probe element is missing the part. required position, and by a delay 6. Control device according to claim 5, characterized in that a time period from the start of the movement of the net that the stop member (17) is connected in an electrically conductive manner to the Mo pushbutton element in the direction of the required position, defining the gate shaft (12), which is in conductive connection with a connecting terminal and after the period of time which is greater than that of the start (6) of the motor (4), and that the movement of the pushbutton element begins until the stop (13) on the housing (11 ) of the motor (4) electrically iso switch is kept in the time normally required in the absence of a part. 55 space is actuated, a control that when not operated 7. Control device according to claim 5 or 6, thereby GE switch generates a GOOD signal. indicates that a second stop (14) for limitation. With this embodiment according to the invention, when the motor (4) is rotating in the opposite direction, the control device can be provided on a complicated angle measuring device. be waived, since the 8. Control device according to one of claims 3 to 7, since it has been determined at the beginning of the elapsed time whether the fixge is characterized by the fact that the period connected to the motor terminals is actuated by the switch or (5,6) essentially short-circuiting switch ( 83) one im not. If the switch is not actuated, this is preceded by a relationship to the internal motor resistance with a small resistance, a statement about the correct positioning of the part (84). scored in the required position, but takes place within If a switch is operated during this period, this is considered a mistake avoidance. It is particularly advantageous if the switch