JP6652820B2 - Controller for contact type displacement sensor and displacement gauge using the same - Google Patents

Description

  The present invention relates to a control unit (controller) used for a contact-type displacement sensor using a transformer type detector that outputs an analog signal and a scale type detector that outputs a digital signal, and a displacement gauge using the same. In particular, the present invention is suitable for a displacement gauge for measuring a large work diameter for which a reference position is confirmed by a scale type detector and a minute displacement is obtained by a differential transformer type.

2. Description of the Related Art As a contact-type electric measurement, a contact-type displacement sensor for measuring a mechanical contact (contact) in contact with a measurement unit is known. The contact is a movable part provided in the detector (length measuring device or sensor head), and the mechanical displacement amount is converted into an electric signal, and finally converted into digital, calculated and calculated as required measurement value. It is processed. As a contact displacement sensor, a transformer method using a coil and a scale method including a scale and a detector for acquiring position information from a scale are widely used.
The transformer method is suitable for measuring a minute displacement with low measuring force and high resolution with high accuracy, and the scale method is suitable for accurately measuring a wide measurement range.

  The transformer method includes a detector and a main body (amplifying instruction unit), and the detector captures a mechanical displacement amount of an object to be measured as a movement of a contact. Then, it is converted to an electric signal by the built-in differential transformer and sent to the main unit which is the control unit, the main unit amplifies the electric signal sent from the detector, and displays the displacement amount in analog or digital, etc. For example, it is described in Patent Document 1.

  The scale method uses a glass scale as a reference for the length, detects a change in the amount of light using a light emitting element and a light receiving device from the grid scale, and obtains a two-phase AB sinusoidal signal from the light receiving device. Then, the obtained AB-phase sine wave is electrically divided by an interpolation circuit of a control unit, and a square wave (pulse) is counted.

JP-A-8-210804 JP-A-1-210823

  In the above prior art, the transformer system is an analog signal as an input to a control unit, and the control unit requires an oscillator and a detection circuit. On the other hand, in the scale method, an A-phase voltage and a B-phase voltage having a phase difference of 90 °, which are digital signals, are input to the control unit. Therefore, when a transformer-type length measuring device and a scale-type length measuring device using a linear encoder coexist, it is necessary to prepare a plurality of separate control units, which not only increases costs but also improves convenience. Remarkably low.

  In the case where only two types of control units are provided, a switch, a jumper wire, a relay, and the like are required for switching the input, which increases the circuit scale and the number of terminals.

  In addition, for displacement gauges that measure the diameter of large workpieces, it is desirable to check the reference position using a scale method with a wide measurement range, and to obtain minute deviations using a highly sensitive differential transformer method, but with a simpler circuit configuration Switching or simultaneous detection is required.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a transformer type detector (also referred to as a differential transformer detector in the present invention) and a scale type detector (also referred to as a linear encoder detector in the present invention). ), There is no need to prepare multiple control units (controllers), a single control unit can be used for both detectors, and the contact type displacement sensor has a simpler circuit configuration. An object of the present invention is to obtain a controller for use and a displacement gauge using the same, and to further enhance convenience and reliability.

In order to achieve the above object, the present invention provides a transformer type detector using a coil and a scale type detector using a scale which can be connected to the transformer type detector and the scale type detector. In a controller for a contact type displacement sensor that processes a signal as a digitally converted measurement value, a difference between a DC power supply for supplying power to the scale type detector and an excitation signal source for supplying an AC signal to the transformer type detector is provided. A balanced connection transceiver that receives an output of the scale system detector by a dynamic input line, a counter IC that counts pulses based on an output signal received by the balanced connection transceiver, and an output of the transformer system detector, A differential transformer detection circuit that outputs an analog signal according to the amount of change in displacement; An AD converter for digital conversion, the excitation signal source and the coupling capacitor connected to both of the differential input line, is connected to the differential input line, wherein the coupling capacitor is connected, to the transformer type detector A terminal to which the transformer type detector can be connected so as to supply the AC signal.

  Further, in the controller for a contact type displacement sensor described above, a scale type detector that outputs a two-phase signal can be connected, and the transceiver has a transceiver connected by two sets of differential input lines. And two coupling capacitors connected to one of the two sets of differential input lines.

  Furthermore, it is preferable that the controller for a contact type displacement sensor described above includes a counter IC that counts a pulse multiplied based on a phase difference of an output signal received by the balanced connection transceiver.

  Further, in the contact-type displacement sensor controller described above, the first terminal to which the DC power supply is connected, the second and third terminals to which the excitation signal source and the differential input line are connected, Fourth and fifth terminals to which the dynamic input line and the input of the differential transformer detection circuit are connected, and a sixth terminal to which ground lines of the scale type detector and the transformer type detector are connected. Is desirable.

  Furthermore, in the controller for a contact type displacement sensor described above, there is provided a differential transformer disconnection detection circuit that is connected to the input side of the balanced connection transceiver and the differential transformer detection circuit and detects disconnection of the transformer type detector. Is desirable.

  Furthermore, in the contact-type displacement sensor controller described above, it is desirable to determine which of the scale type detector and the transformer type detector is connected.

  Furthermore, in the contact-type displacement sensor controller described above, it is desirable that the output of the excitation signal source be stopped according to the output of the differential transformer disconnection detection circuit.

Further, according to the present invention, a transformer type detector using a coil and a scale type detector using a scale can be connected, and the signals detected by the transformer type detector and the scale type detector are converted into digital signals. A displacement gauge using a contact-type displacement sensor controller for processing as a measured value, the transformer-type detector and the scale-type detector connected to the contact-type displacement sensor controller, and a power supply to the scale-type detector. DC power supply, an excitation signal source for supplying an AC signal to the transformer type detector, a balanced connection transceiver for receiving the output of the scale type detector by a differential input line, and a signal received by the balanced connection transceiver. A counter IC for counting pulses based on the output signal; A differential transformer detection circuit that receives a force and outputs an analog signal according to the amount of change in displacement, an AD converter that converts the analog signal into a digital signal, and connects the excitation signal source to both the differential input line. A coupling capacitor; and the transformer-type detector connected to the differential input line to which the coupling capacitor is connected and to which the AC signal is supplied.

  Further, in the displacement gauge described above, a scale type detector that outputs a two-phase signal is connectable, and the balanced connection transceiver having a transceiver connected by two sets of differential input lines; And four coupling capacitors connected to each of the set of differential input lines.

  Further, in the displacement gauge described above, a first terminal to which the DC power supply is connected, a second terminal to which a ground wire of the scale type detector is connected, the excitation signal source, and the differential input line It is desirable to have third to sixth terminals connected, and seventh and eighth terminals connected to the input of the differential transformer detection circuit.

  According to the present invention, a coupling capacitor is connected to both of the differential input lines of the balanced connection transceiver that receives the output of the scale type detector, and an excitation signal source is supplied to the transformer type detector via the differential input line. Therefore, it is possible to prevent the excitation signal source from affecting the balanced connection transceiver. This allows the controller to share the connection between the scale detector and the transformer detector. Therefore, even when a length measuring device using a transformer type detector and a scale type detector are mixed, it is not necessary to prepare a plurality of control units, and the circuit configuration can be further simplified.

Schematic diagram according to one embodiment of the present invention Block diagram of a controller in one embodiment FIG. 2 is a block diagram when a scale type detector according to an embodiment is connected to a controller. FIG. 2 is a block diagram when a transformer type detector according to an embodiment is connected to a controller. FIG. 6 is a block diagram showing a displacement gauge according to another embodiment of the present invention. Block diagram when scale type detector according to another embodiment is used alone FIG. 4 is a block diagram when an HBT detector according to another embodiment is used alone. FIG. 4 is a block diagram when the LVDT type detector according to another embodiment is used alone.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The transformer method using a coil as a contact displacement sensor converts the movement of the coil in a magnetic field generated by passing a current through the coil into a detectable electric signal, and is called an LVDT (Linear Voltage Differential Transformer). The method and the HBT (half bridge transducer) method are widely used.

  In the LVDT method, a mutual inductance change is output as a voltage as a magnetic core provided on a contact moves in a primary side coil and a secondary side coil. The magnetic core has a structure in which it moves inside the cavity of a cylindrical coil, and utilizes that a primary coil is connected to an AC power source, a voltage is generated in a secondary coil, and a voltage difference occurs depending on the position of the magnetic core.

  Normally, the secondary coils A and B are located on opposite sides of the primary coil, the voltage VA of the secondary coil A and the voltage VB of the secondary coil B are in opposite phases, and the output of the detector is VA. -VB. When the magnetic core is located at the center, the voltages of the two secondary coils are equal but opposite in phase, so that the output voltage is zero. When the magnetic core moves in either direction, the output voltage of the secondary coil on the side to which the magnetic core moves increases, and the output voltage of the secondary coil on the opposite side decreases by the same amount. That is, the substantial output voltage is an analog signal and is proportional to the amount of change in displacement.

  In the HBT method, two coils A and B are provided, and the magnetic core detects the imbalance of the inductance of the two coils by a Wheatstone bridge circuit according to the position inside the coil cavity. The two coils form one side of a Wheatstone bridge circuit, the other of which is integrated into the amplifier. When the magnetic core is in the center of the coil, both electrical signals of voltage VA of coil A and voltage VB of coil B become equal, and as the magnetic core moves, the voltage detected by the Wheatstone bridge circuit changes.

  As a scale method using a scale as a contact type displacement sensor, a transmission type photoelectric scale and a reflection type photoelectric scale are used. In each case, a linear encoder is constructed that detects a change in the amount of light using a light-emitting element and a light-receiving device from a grid scale using a glass scale as a reference for length, and digitally outputs a displacement amount. A method of converting a change in the amount of transmitted light of a glass scale into an electric signal is called a transmission photoelectric scale, and a method of using reflected light is called a reflection photoelectric scale. In each case, a two-phase sine wave signal of AB is obtained from the light receiving device, and a square wave (pulse) is counted by the control unit.

  Since the signal of the linear encoder has a periodic property, even a very small scale displacement during a certain period can be reliably measured. Further, since the reference point can be recorded, the displacement position does not become ambiguous even after the system power is turned off.

  FIG. 1 is a schematic diagram showing a configuration of a contact displacement sensor and a controller thereof according to an embodiment of the present invention. Reference numeral 1 denotes a scale type scale detector (also referred to as a linear encoder detector in the present invention), and reference numeral 2 denotes a transformer type transformer type detector (also referred to as a differential transformer detector in the present invention). , One is connected to the controller 3.

  When the linear encoder detector 1 is connected, the controller 3 receives the AB two-phase sine wave signal or the shaped square wave by the balanced connection transceiver 4, and shapes it as a square wave whose phase is shifted by ４ period from each other. The counter IC5 counts pulses obtained by multiplying and dividing the shaped AB2 phase based on the phase difference.

  That is, the pulses obtained by differentiating the rising and falling waveforms of each of the A phase and the B phase are counted, and an output with a resolution of 4 times is obtained. In the case of an incremental type linear encoder, the count value is added or subtracted according to the advance or delay of the phase of the phase B with respect to the phase A. In the incremental type, the count value of the counter is reset at a reference position and the number of pulses from that position is cumulatively added, so that the reference position can be arbitrarily selected. Further, as shown in FIG. 1, the signal output from the balanced connection transceiver 4 is a two-phase digital signal.

  On the other hand, when the differential transformer detector 2 based on the LVDT method is connected, the controller 3 automatically determines that the differential transformer detector 2 is connected. The voltage VA of the secondary coil A and the voltage VB of the secondary coil B are input to the differential transformer detection circuit 6, and the output is an analog signal proportional to the amount of change in displacement, which is the difference therebetween. Therefore, the output of the differential transformer detection circuit 6 is digitally converted by the AD converter 7.

  Regardless of which of the linear encoder detector 1 and the differential transformer detector 2 is connected, the controller 3 transmits the digitally converted measured value via a interface to a CPU or a network that performs the following processing as a measured value. Then, it is calculated and processed as a required measurement value. If necessary, the signal is used as a statistical signal or a correction signal to a processing machine.

  Further, since the controller 3 handles both the linear encoder detector 1 and the differential transformer detector 2, the linear encoder detector 1 and the differential transformer detector 2 share a connection terminal with the controller 3. Further, switching is performed automatically without using switches, jumpers, relays, and the like.

  FIG. 2 is a block diagram showing a detailed configuration of the controller 3. Reference numeral 8 denotes a DC power supply, which supplies power to the two-phase output linear encoder detector 1 via a terminal 12-1. Reference numeral 9 denotes an excitation signal source which excites the primary coil of the differential transformer detector 2 at a constant frequency (8 kHz) to generate an induced voltage in the secondary coil. Reference numeral 10 denotes two coupling capacitors which supply an excitation signal source 9 which is an AC signal to a primary coil of the differential transformer detector 2 via a terminal 12-2. Reference numeral 11 denotes a differential transformer disconnection detection circuit, which is connected to the secondary coil of the differential transformer detector 2 via terminals 12-4 and 12-5, and detects disconnection of the secondary coil.

  Reference numeral 4 denotes a balanced connection transceiver, which is a communication interface with a differential input line that receives a digital signal by voltage difference between the two lines, and performs two-phase AB communication so that two sets of differential input lines and It has a transceiver. Two coupling capacitors 10 are connected to one of the two sets of differential input lines. Further, since the balanced connection communication is used, noise removal can be performed on the AB two-phase sine wave signal of the linear encoder detector 1.

  Reference numeral 6 denotes a differential transformer detection circuit, which detects the voltage VA of the secondary coil A and the voltage VB of the secondary coil B of the differential transformer detector 2 via terminals 12-4 and 12-5, and detects a transformer-type detector. And outputs an analog signal proportional to the amount of change in displacement. Reference numeral 5 denotes a counter IC, which counts pulses multiplied based on the phase difference between the two-phase signals received by the balanced connection transceiver 4.

  FIG. 3 is a block diagram when the linear encoder detector 1 is connected to the controller 3. In the linear encoder detector 1, a DC power supply 8 is connected to a transmission unit 13 and an encoder 14 via a terminal 12-1. The terminal 12-6 serves as a GND that serves as a ground line for the encoder 14 and the transmission unit 13.

  The encoder 14 outputs a change in the amount of light due to a grid scale using a light emitting element and a light receiving device as a two-phase AB sinusoidal signal. The transmission unit 13 sends the output of the encoder 14 on one line for each of the AB phases, the original signal, and the other line, the signal with the inverted phase (opposite phase), that is, the differential signal. The two signal lines are connected by a balanced circuit that is neither grounded, and the sine wave signal is shaped into a digital signal. As a result, a ground loop is not formed and noise is reduced, so that the distance between the linear encoder detector 1 and the controller 3 can be increased to about 10 m. The transmitting unit 13 connects the A phase of the encoder 14 to the terminals 12-2 and 12-3, and connects the B phase to the terminals 12-4 and 12-5. In addition, since the transmitting unit 13 transmits a differential signal, it has a high output impedance, and since the current is small, it is not detected by the differential transformer detection circuit 6 having a low input impedance.

  An excitation signal source 9 for exciting the primary coil of the differential transformer detector 2 is connected to the A-phase terminals 12-2 and 12-3, and a differential signal is generated at terminals 12-2 and 12-3. Therefore, the influence of the excitation signal source 9 on the balanced connection transceiver 4 can be canceled. Thus, the terminals 12-2 and 12-3 can be shared between the case where the linear encoder detector 1 is connected and the case where the differential transformer detector 2 is connected. Accordingly, it is not necessary to newly provide input terminals for the voltage VA of the secondary coil A and the voltage VB of the secondary coil B of the differential transformer detector 2 to the controller 3. The excitation signal source 9 is not necessary for the linear encoder detector 1, but does not need to be stopped.

  The signal received by the balanced connection transceiver 4 is output to the counter IC 5 as an AB two-phase digital signal whose phase is shifted by ４ period from each other. The counter IC5 counts pulses obtained by multiplying and dividing the AB2 phase based on the phase difference. The counted measurement value is transmitted as an output of the controller 3 to the CPU or a network that performs the next process via an interface.

  As described above, the controller 3 includes the first terminal 12-1 to which the DC power supply 8 is connected, the second terminal 12-2 and the third terminal 12 to which the excitation signal source 9 and the differential input line of the balanced connection transceiver 4 are connected. -3, the fourth terminal 12-4 and the fifth terminal 12-5 to which the differential input line and the input of the differential transformer detection circuit 6 are connected, and the grounding of the linear encoder detector 1 and the differential transformer detector 2. Only the sixth terminal 12-6 to which the line GND is connected is required.

  FIG. 4 is a block diagram when the differential transformer detector 2 is connected to the controller 3. The excitation signal source 9 cuts off the DC component to the primary coil 15 of the differential transformer detector 2 via the coupling capacitor 10 and the terminal 12-2, and supplies only the AC component to the primary coil 15. The terminal 12-6 serves as a ground line GND for the primary coil 15 and the secondary coils 16, 17.

  The excitation signal source 9 is also connected to the terminal 12-3 via the coupling capacitor 10, that is, connected to both the A-phase differential inputs of the balanced connection transceiver 4, and is in phase. Not output by transceiver 4.

  The magnetic core provided in the contact moves through the primary coil 15 and the secondary coils 16 and 17 to induce a voltage in the secondary coils 16 and 17 and a voltage difference occurs depending on the position of the magnetic core. The voltage VA of the secondary coil 16 and the voltage VB of the secondary coil 17 have opposite phases.

  The output of the secondary coil 16 is connected to a terminal 12-4, and the output of the secondary coil 17 is connected to a terminal 12-5. The output is connected to the balanced connection transceiver 4 and the differential transformer detection circuit 6. However, since the DC resistances and impedances of the secondary coils 16 and 17 are small and the input impedance of the balanced connection transceiver 4 is sufficiently high, the current induced in the secondary coils 16 and 17 uses the differential transformer detection circuit 6 having a small input impedance. Flows to

  The differential transformer detection circuit 6 outputs the difference between the voltage VA of the secondary coil 16 and the voltage VB of the secondary coil 17, or VA-VB, to the AD converter 7 as an analog signal proportional to the amount of change in displacement. The analog signal is converted into a digital signal by the AD converter 7 and transmitted as a measurement value to the CPU or a network as an output of the controller 3 via an interface.

  At the same time, the outputs of the secondary coils 16 and 17 are input to the differential transformer disconnection detection circuit 11, that is, the input side of the differential transformer disconnection detection circuit 11 is the same as the balanced connection transceiver 4 and the differential transformer detection circuit 6. Are connected to terminals 12-4 and 12-5, respectively. That is, the input side of the differential transformer disconnection detection circuit 11 is connected to the input side of the balanced connection transceiver 4 and the input side of the differential transformer detection circuit 6. If any one of the secondary coils 16 and 17 has a disconnection, an abnormal output, for example, if there is no disconnection, 1 is output, and if there is a disconnection, 0 is output to determine that a disconnection has occurred. it can.

  Furthermore, when the linear encoder detector 1 is connected, no current flows to the differential transformer disconnection detection circuit 11, so that it can be determined that the differential transformer detector 2 is not connected to the controller 3. By utilizing this fact, the output of the excitation signal source 9 may be stopped when the linear encoder detector 1 is not connected to the controller 3. Further, it is possible to determine which of the scale type detector (linear encoder detector) 1 and the transformer type detector (differential transformer detector) 2 is connected, and display the fact.

  FIG. 5 is a block diagram showing another embodiment and showing an example of a displacement gauge for measuring the diameter of a large-diameter work. In a displacement gauge for measuring the diameter of a large workpiece, two contacts 24 and 25 are used. First, the contacts 24 and 25 are moved from the center position of the diameter to the outer diameter direction. Calculate a small deviation using a sensitive method.

  The measurement is performed by a scale method having a wide measurement range from a substantially center position to a reference position having a substantially outer diameter. In FIG. 5, the contact 25 is fixed, and the contact 24 moves in the outer diameter direction. Then, the moving distance from the fixed fulcrum 22 to the size changing fulcrum 23 is measured by the scale 21 and the encoder 14 having the light emitting element and the light receiving device, and the encoder 14 outputs a signal of two phases AB and two phases out of phase. I do. The contacts 24 and 25 are lever-type, and the right side contacts the outer diameter of the workpiece, and rotates around the size change fulcrum 23 and the fixed fulcrum 22, respectively.

  Coils 20-1 and 20-2 are provided on the opposite side of the size changing fulcrum 23 from the work side of the contact 24, and the magnetic core fixed to the contact 24 moves inside the cavity. Similarly, coils 19-1 and 19-2 are provided on the opposite side of the fixed fulcrum 22 in the contact 25, and the magnetic core fixed to the contact 25 moves inside the cavity. That is, it constitutes an HBT type detector.

  The imbalance of the inductances of the two coils 20-1 and 20-2 is detected by a Wheatstone bridge circuit based on the position of the magnetic core in the two coils 20-1 and 20-2. The two coils 20-1, 20-2 form one side of a Wheatstone bridge circuit, the other of which is incorporated in the differential transformer detection circuit 6. When the magnetic core is at the center of the coils 20-1 and 20-2, both electric signals of the voltage VA of the coil 20-1 and the voltage VB of the coil 20-2 become equal. The voltage detected by the circuit changes. The same applies to the two coils 19-1 and 19-2.

  The controller 3 has a DC power supply 8 and supplies the DC power to the light emitting element and the light receiving device of the transmitter 13 and the encoder 14 via the terminal 30-1. The terminal 30-2 serves as a ground line GND for the encoder 14 and the transmission unit 13.

  The encoder 14 outputs a change in light amount by the scale 21 using a light emitting element and a light receiving device as a two-phase AB sinusoidal signal. The transmission unit 13 transmits the output of the encoder 14 to the balanced connection transceiver 4 of the controller 3 by transmitting the original signal to one line and the differential signal of the opposite phase to the other line for each AB phase. The two signal lines are connected by a balanced circuit that is neither grounded, and the sine wave signal is shaped into a digital signal.

  The signal received by the balanced connection transceiver 4 is output to the counter IC 5 as an AB two-phase digital signal whose phase is shifted by １ ／ period from each other. The counter IC5 counts pulses obtained by multiplying and dividing the AB2 phase based on the phase difference. The counted measurement value is transmitted as an output of the controller 3 to the CPU or a network that performs the next process via an interface.

  Reference numeral 9 denotes an excitation signal source, which is an AC excitation signal source of a constant frequency (8 kHz) for two coils constituting an HBT type detector. An excitation signal is supplied to both the contact 24 and the contact 25. Then, power is supplied to the coil 20-1 via the terminal 30-6, and the coil 20-1 returns from the coil 20-2 via the terminal 30-4. At the same time, the coil 19-1 is energized via the terminal 30-5, and returns from the coil 19-2 via the terminal 30-3.

  The midpoint between the coils 20-1 and 20-2 is input to the differential transformer detection circuit 6 via the terminal 30-7. Similarly, the midpoint between the coils 19-1 and 19-2 is input to the differential transformer detection circuit 6 via the terminal 30-8. Therefore, the differential transformer detection circuit 6 has two amplifiers corresponding to two inputs.

  The excitation signal source 9 is connected to a communication line between the balanced connection transceiver 4 and the transmission unit 13 via a coupling capacitor 10, and is supplied to each coil of the detector via a detection side coupling capacitor 18. The balanced connection transceiver 4 has a transceiver connected by two sets of differential input lines, and four coupling capacitors 10 are connected to each of the two sets of differential input lines. Since the input impedance of the balanced connection transceiver 4 and the output impedance of the transmission unit 13 are high, the excitation signal does not flow to the balanced connection transceiver 4 and the transmission unit 13 side.

  With the above configuration, the controller 3 receives and outputs the output from the encoder 14 from the time when the two contacts 24 and 25 are moved from the center position of the diameter to the outer diameter direction to the time when the contact moves to the vicinity of the maximum diameter. A detection value corresponding to the amount of movement of the contacts 24, 25, that is, the rotation angle can be obtained. Therefore, the controller 3 does not need any special operation to switch between the input from the encoder 14 and the input from the two coils constituting the HBT-type detector, and does not need any switches, jumper wires, relays and the like. Also, since the communication line between the balanced connection transceiver 4 and the transmission unit 13 and the supply of the excitation signal to the two coils constituting the HBT detector are shared, the number of terminals is simply a combination of the two functions. It can be reduced compared to.

  Further, the controller 3 according to the embodiment of FIG. 5 enables simultaneous use of the encoder 14 and the HBT type detector, but can also cope with the single use and the single use of the LVDT type detector, respectively.

  Further, in the displacement gauge, the connection between the controller 3, the encoder 14, and the HBT detector is performed by connecting the first terminal 30-1 to which the DC power supply 8 is connected and the second terminal for connecting the ground wire of the scale detector to GND. A third terminal 30-3, a fourth terminal 30-4, a fifth terminal 30-5, and a sixth terminal 30-2 to which two sets of differential input lines of the excitation signal source 9 and the balanced connection transceiver 4 are connected to the terminal 30-2. A terminal 30-6 and a seventh terminal 30-7 and an eighth terminal 30-8 to which the input of the differential transformer detection circuit 6 is connected are required.

  FIG. 6 shows a block diagram when the encoder 14 is used alone, and shows that the scale type linear encoder detector 1 can be used alone. In the case of FIG. 6, the excitation signal source 9 is not required. However, the balanced connection transceiver 4 is a communication interface in which each of the two phases receives a digital signal by a voltage difference between two lines, and the excitation signal from the excitation signal source 9 is in phase in each phase. , Has no effect. Further, since there is no input to the differential transformer detection circuit 6, it may be determined that the excitation signal source 9 is stopped.

  The encoder 14 outputs a light amount change by the scale 21 using the light emitting element and the light receiving device as an AB two-phase sine wave signal, and the transmission unit 13 outputs the output of the encoder 14 to one and the other input lines as a differential signal having opposite phases. The signal is transmitted to the balanced connection transceiver 4 of the controller 3.

  The signal received by the balanced connection transceiver 4 is output to the counter IC 5 as an AB two-phase digital signal whose phase is shifted by 周期 cycle from each other, and the counter IC 5 counts the pulses obtained by multiplying and dividing the AB two phase. The counted measurement value is transmitted as an output of the controller 3 to the CPU or a network that performs the next process via an interface.

  FIG. 7 shows a block diagram when the HBT type detector is used alone. The excitation signal source 9 is connected to a communication line between the balanced connection transceiver 4 and the transmission unit 13 via the coupling capacitor 10, and is supplied to the coils 20-1 and 20-2 of the detector.

  The balanced connection transceiver 4 is a communication interface in which each of the two phases receives a digital signal by a voltage difference between two lines, and has a high input impedance and an excitation signal from the excitation signal source 9 in each phase. Since they are in phase, the excitation signal is canceled and the balanced connection transceiver 4 does not output anything.

  The excitation signal source 9 energizes the coil 20-1 constituting the HBT type detector via the terminal 30-6, and returns from the coil 20-2 via the terminal 30-4. The midpoint between the coils 20-1 and 20-2 is input to the differential transformer detection circuit 6 via the terminal 30-7. The differential transformer detection circuit 6 detects the imbalance of the inductance of the two coils based on the position of the magnetic core in the two coils 20-1 and 20-2. As the magnetic core moves, the detected voltage changes.

  FIG. 8 shows a block diagram when the LVDT type detector is used alone. The excitation signal source 9 is connected to the communication line between the balanced connection transceiver 4 and the transmission unit 13 via the coupling capacitor 10, is supplied to the primary coil 15 via the terminal 30-6, and is supplied via the terminal 30-4. Return. The middle point of the secondary coils 16 and 17 returns to GND via the terminal 30-2, and the magnetic core provided on the contactor moves through the primary coil 15 and the secondary coils 16 and 17 so that A voltage is induced in the next coils 16 and 17, and a voltage difference occurs depending on the position of the magnetic core.

  The voltage VA of the secondary coil 16 and the voltage VB of the secondary coil 17 have opposite phases. The output of the secondary coil 16 is connected to a terminal 30-7, and the output of the secondary coil 17 is connected to a terminal 30-8, respectively. Connected to transformer detection circuit 6. The differential transformer detection circuit 6 outputs the difference between the voltage VA of the secondary coil 16 and the voltage VB of the secondary coil 17, VA-VB, and becomes an analog signal proportional to the amount of change in displacement. The analog signal is converted into a digital signal in the same manner as that shown in FIG. 4 and transmitted as a measurement value to the CPU or a network via an interface as an output of the controller 3.

  As described above, if the controller 3 of the present embodiment is used, simultaneous use of the encoder 14 which is the scale type detector and the detector of the HBT type, single use of the encoder 14, single use of the HBT type detector, detection of the LVDT type It can be used independently without switching with switches, jumpers, relays, etc.

1 linear encoder detector (scale type detector)
2 Differential transformer detector (Transformer detector)
3 Controller 4 Balanced connection transceiver 5 Counter IC
Reference Signs List 6 Differential transformer detection circuit 7 AD converter 8 DC power supply 9 Excitation signal source 10 Coupling capacitor 11 Differential transformer disconnection detection circuit 12-1, 12-2, 12-3, 12-4, 12-5, 12-6 Terminal 13 Transmitter 14 Encoder 15 Primary coil 16, 17 Secondary coil 18 Detection side coupling capacitor 19-1, 19-2, 20-1, 20-2 Coil 21 Scale 22 Fixed fulcrum 23 Size change fulcrum 24, 25 Contact Child 30-1, 30-2, 30-3, 30-4, 30-5, 30-6, 30-7, 30-8 Terminal

Claims (10)

A transformer-type detector using a coil and a scale-type detector using a scale can be connected, and the signals detected by the transformer-type detector and the scale-type detector are processed as digitally converted measurement values. In the controller for contact type displacement sensor,
A DC power supply for supplying power to the scale type detector,
An excitation signal source for supplying an AC signal to the transformer type detector,
A balanced connection transceiver for receiving the output of the scaled detector via a differential input line;
A counter IC for counting pulses based on the output signal received by the balanced connection transceiver;
An output of the transformer type detector is input, and a differential transformer detection circuit that outputs an analog signal according to the amount of change in displacement,
An AD converter that converts the analog signal into a digital signal;
A coupling capacitor for connecting the excitation signal source to both of the differential input lines,
A terminal connected to the differential input line to which the coupling capacitor is connected, and to which the transformer-type detector can be connected so as to supply the AC signal to the transformer-type detector;
A controller for a contact-type displacement sensor, comprising: The controller for a contact displacement sensor according to claim 1,
A balanced connection transceiver to which a scale type detector for outputting a two-phase signal is connectable, the transceiver having a transceiver connected by two sets of differential input lines;
Two coupling capacitors connected to one of the two sets of differential input lines;
A controller for a contact-type displacement sensor, comprising:   3. The contact type displacement sensor controller according to claim 2, further comprising a counter IC for counting a pulse multiplied based on a phase difference of an output signal received by the balanced connection transceiver. controller. The controller for a contact displacement sensor according to any one of claims 1 to 3,
A first terminal to which the DC power supply is connected;
Second and third terminals to which the excitation signal source and the differential input line are connected;
Fourth and fifth terminals to which the differential input line and the input of the differential transformer detection circuit are connected;
A sixth terminal to which a ground wire of the scale type detector and the transformer type detector is connected;
A controller for a contact-type displacement sensor, comprising:   5. The contact type displacement sensor controller according to claim 1, wherein the differential type is connected to an input side of the balanced connection transceiver and the differential transformer detection circuit, and detects a disconnection of the transformer type detector. 6. A controller for a contact-type displacement sensor, comprising a transformer disconnection detection circuit.   6. The controller for a contact displacement sensor according to claim 5, wherein the controller determines which of the scale type detector and the transformer type detector is connected.   6. The controller for a contact displacement sensor according to claim 5, wherein the output of the excitation signal source is stopped according to the output of the differential transformer disconnection detection circuit. A transformer-type detector using a coil and a scale-type detector using a scale can be connected, and the signals detected by the transformer-type detector and the scale-type detector are processed as digitally converted measurement values. In a displacement gauge using a contact type displacement sensor controller,
The transformer type detector and the scale type detector connected to the contact type displacement sensor controller,
A DC power supply for supplying power to the scale type detector,
An excitation signal source for supplying an AC signal to the transformer type detector,
A balanced connection transceiver that receives the scaled detector output via a differential input line;
A counter IC for counting pulses based on the output signal received by the balanced connection transceiver;
An output of the transformer type detector is input, and a differential transformer detection circuit that outputs an analog signal according to the amount of change in displacement,
An AD converter that converts the analog signal into a digital signal;
A coupling capacitor for connecting the excitation signal source to both of the differential input lines,
The transformer-type detector connected to the differential input line to which the coupling capacitor is connected and supplied with the AC signal,
A displacement gauge comprising: The displacement gauge according to claim 8,
A balanced connection transceiver to which a scale type detector for outputting a two-phase signal is connectable, the transceiver having a transceiver connected by two sets of differential input lines;
Four coupling capacitors connected to each of the two sets of differential input lines;
A displacement gauge comprising: The displacement gauge according to claim 8 or 9,
A first terminal to which the DC power supply is connected;
A second terminal to which a ground wire of the scale type detector is connected;
Third to sixth terminals to which the excitation signal source and the differential input line are connected;
Seventh and eighth terminals to which inputs of the differential transformer detection circuit are connected;
A displacement gauge comprising: