JPH03155362A - Moving coil type linear motor - Google Patents

Abstract

PURPOSE:To prevent overrun positively by arranging permanent magnets having high magnetic flux density at the opposite ends of a stator, arranged alternately with N and S poles of permanent magnets in the longitudinal direction, and then detecting fluctuation of magnetic field through a field converting element carried by a mover and holding the detected value. CONSTITUTION:Permanent magnets 12a having high flux density are disposed at the opposite ends of a stator 18, arranged alternately with N and S poles of permanent magnets in the longitudinal direction, so that a field conversion element or a Hall element 16 corresponds when a mover 15 arrives the end of the stator. A sensor probe 17 is disposed in the center on the side face of the mover 15 and a position detecting sensor 19 is disposed on one side of the stator 18. A CPU 20 connected with the position detecting sensor 19 is connected with a drive IC 22, which is connected through a drive circuit 21 with the coils 7a-7c in the mover 15, thus forming a drive circuit 23. Output from a comparator 25, connected with the Hall element 16 and a reference voltage 24, is held in an FF 26 and forms an AND gate 26 together with an output from the CPU 20. By such arrangement, a positive overrun preventing circuit 28 can be formed.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a moving coil type linear motor.

BACKGROUND OF THE INVENTION Currently, there are various types of moving coil type linear motors. Therefore, the device disclosed in Japanese Unexamined Patent Publication No. 59-70178 will be described as a conventional example of a moving coil type linear motor with reference to FIGS. 6 to 8. This moving coil type linear DC motor consists of a mover 1 and a stator 2. First, the movable element 1 includes a yoke 3, a coil board 4 attached to the bottom surface of the yoke 3, and a coil board 4 attached to the bottom surface of the yoke 3.
a shaft 5 fixed to the four corners of the shaft 5, a wheel 6 rotatably attached to each shaft 5, and a wheel 6 fixed to the lower surface of the coil substrate 4 and arranged continuously in the moving direction of the movable element 1. It consists of an armature coil section 7 made up of three coil conductors 78 to 7C. These coil conductors 7a to 7C are connected to printed wiring 8 of a predetermined pattern formed on the coil board 4.
and is drawn out to a terminal (not shown) in the connector 9.

Note that this connector 9 is connected to the CPU (Central P
processing unit) control circuit (not shown).

On the other hand, the stator 2 includes a long base plate lO having a groove or step-shaped guide portion 10a for guiding the transfer of the wheel 6, and a stator yoke fixed on the center line on the base plate lO. 11, and a large number of magnets 12 provided on this stator yoke II. Each magnet 1
Reference numeral 2 is a strip-shaped strip whose longitudinal direction is the width direction of the base plate 10, and N poles and S poles are alternately magnetized and arranged in the longitudinal direction of the base plate 10. The armature coil portion 7 always faces the magnet 12 with a constant gap therebetween.

Further, in this moving coil type linear motor, Hall elements 13ax13c, which are magnetic field conversion elements, are attached to the lower surface of the coil board 4 for each of the coil conductors 78 to 7C, and are connected to the control circuit of the CPU via the terminals of the connector 9. has been done.

In such a configuration, a drive current is applied from an external drive control circuit to the coil conducting wires 78 to 7c via the connector 9, and the movable element 1 linearly moves on the stator 2 due to the magnetic action with the magnet 12.

In addition, in the above-mentioned moving coil type linear DC motor, in order to control the excitation switching timing, the magnetic field generated by the magnets 12 facing each other is detected by the Hall elements 13a to 13c connected to the control circuit of the CPU, and the brush The position of the movable element 1 can be detected without using.

Problems to be Solved by the Invention In the above-mentioned moving coil type linear motor, the movable element 1 is freely linearly moved by program control of energization to each of the coil conductors 78 to 7C by a control circuit of the CPU. However, the CPU of the above-mentioned device may run out of control due to external noise or the like, and in this case, a malfunction will occur in the program-controlled energization of each coil conducting wire 78 to 7c. Then, mover 1 becomes uncontrollable.

For example, the device may be damaged by overrunning the stator 2 and coming off the base plate IO.

Means for Solving the Problems The invention according to claim 1 provides a stator in which N-pole and S-pole magnets are arranged alternately in the longitudinal direction, and a movable member movably disposed on the stator. In a moving coil type linear motor, a coil facing the magnet is attached to the coil, a drive circuit is provided to input a drive current to the coil of this mover, and a control circuit is provided to control the output of this drive circuit. Terminal indicating magnets with high density are provided near both ends of the stator, and a magnetic field conversion element facing the stator magnet is attached to the mover, and the output of the drive circuit connected in parallel with the control circuit is connected to the magnetic field conversion element. It is equipped with an overrun prevention circuit that regulates in response to the detection of the end indicator magnet, and features a holding circuit that holds the detection signal of the magnetic field conversion element that detects the end indicator magnet during the wiring from the magnetic field conversion element to the overrun prevention circuit. The invention according to claim 2 provides a stator in which N-pole and S-pole magnets are arranged alternately in the longitudinal direction, and a movable element movably disposed on the stator has a position on the stator. A magnetic field conversion element that outputs a detected value corresponding to the magnetic field conversion element and a coil facing the magnet are installed, a drive circuit is provided that inputs a drive current to the coil of this mover, and the output of this drive circuit is converted into the detected value of the magnetic field conversion element. In a moving coil type linear motor equipped with a control circuit that controls based on An overrun prevention circuit is provided that regulates in response to the detection of the end indicating magnet of the magnetic field conversion element, and retains the detection signal of the magnetic field conversion element that detects the end indicating magnet during the wiring from the magnetic field conversion element to the overrun prevention circuit. Connect the holding circuit.

The invention described in the functional and resultant term 1 is provided with a stator in which N-pole and S-pole magnets are arranged alternately in the longitudinal direction, and a movable element movably disposed on the stator faces the magnets. In a moving coil type linear motor, in which a coil is attached, a drive circuit is provided to input drive current to the coil of the mover, and a control circuit is provided to control the output of this drive circuit. A magnetic field conversion element facing the magnet of the stator is attached to the movable element, and the output of the drive circuit connected in parallel with the control circuit is connected to the end indicating magnet of the magnetic field conversion element. By providing an overrun prevention circuit that regulates in response to detection, even if the control circuit goes out of control and the movable element becomes uncontrollable, the magnetic field conversion element will still be activated when the movable element moves close to the end of the stator. The overrun prevention circuit is activated by detecting the terminal indicating magnet, and the output of the drive circuit is regulated to stop the movement of the movable element, which prevents the movable element from overrunning and damaging the device. By connecting a holding circuit that holds the detection signal of the magnetic field converting element that detects the end indicating magnet in the wiring from the magnetic field converting element to the overrun prevention circuit, the stop position of the movable element that stops when the overrun prevention circuit is activated can be changed. Since the overrun prevention circuit continues to operate even if the magnetic field converting element is displaced from the top of the end indicating magnet, the movable element is reliably stopped regardless of the stop position.

The invention according to claim 2 provides a stator in which N-pole and S-pole magnets are arranged alternately in the longitudinal direction, and a movable element movably disposed on the stator is arranged at a position on the stator. A magnetic field conversion element that outputs a corresponding detected value and a coil facing the magnet are installed, a drive circuit is provided that inputs a drive current to the coil of this mover, and the output of this drive circuit is based on the detected value of the magnetic field conversion element. In a moving coil type linear motor equipped with a control circuit that controls the control circuit, terminal indicating magnets with higher magnetic flux density than other magnets are installed near both ends of the stator, and the output of the drive circuit connected in parallel with the control circuit is controlled by the magnetic field. By providing an overrun prevention circuit that regulates in response to the detection of the end indicating magnet of the conversion element, overrun of the mover can be prevented by simply providing an overrun prevention circuit and an end indicating magnet to an existing moving coil type linear motor. It is possible to obtain a moving coil type linear motor that is prevented from overrun, and in addition, a holding circuit is connected in the wiring from the magnetic field converting element to the overrun prevention circuit to hold the detection signal of the magnetic field converting element that detects the terminal indicating magnet. Therefore, the movable element that is stopped due to the operation of the overrun prevention circuit is reliably stopped regardless of the stop position.

Embodiment An embodiment of the invention set forth in claim 1 will be described based on FIGS. 1 to 4. Incidentally, the same parts as those of the moving coil type linear motor illustrated in FIGS. 6 to 8 are given the same names and numerals, and explanations thereof will be omitted. First, in the moving coil type linear motor 14 of this embodiment, a Hall element 16, which is a magnetic field conversion element, is attached to the bottom of the movable element 15, and a sensor probe 17 is attached to the side.

In addition, near both ends of the stator 18, there are end pointing magnets 12 of the same polarity that have a higher magnetic flux density than the other magnets 12.
a are provided, and these terminal indicating magnets 1
2a faces the Hall element 16 when the movable element 15 is located at the end of the moving region. Furthermore, a rail-shaped position detection sensor 19 is provided on the side of the stator 18 at a position facing the sensor probe 17 of the movable element 15 .

Next, the circuit structure of this moving coil type linear motor 14 will be explained based on FIG. 3. First, the CPU 20, which is a control circuit to which the position detection sensor 19 is connected, controls each coil conductor 7aX? of the movable element 15. It is connected to a drive IC 22 connected to C via a drive circuit 21, and a drive circuit 23 is formed by these circuit components 21 and 22.

On the other hand, a comparator 25 to which the Hall element 16 and the reference voltage @@24 are connected is connected to an AND gate 27 in parallel with the CPU 20 via an FF (flip-flop) circuit 26 which is a holding circuit. 27
is connected to the drive IC 22, so that the circuit component 2
4 to 27 form an overrun prevention circuit 28.

In this configuration, in this moving coil type linear motor 14, a position detection signal is output from the position detection sensor 19 corresponding to the position of the sensor probe 17 attached to the movable element 15, and the position detection signal is output based on this position detection signal. CPU2
0 program controls the drive IC 22. Then, the drive IC 22 controls the power supplied from the drive circuit 21 to each of the coil conductors 7a to 7c, and the movable element 15 performs operations such as moving in a predetermined direction and stopping.

Note that the program control of the drive IC 22 by the CPU 20 is performed using, for example, a Start/Stop signal and a CW/
CCW signal (C1ock Wise/Counter
This is executed by outputting C1ockWise) as Hi/Low signals, respectively.

Here, in this moving coil type linear motor 14, when the movable element 15, which has become uncontrollable due to, for example, the CPU 20 going out of control, moves to the vicinity of the end of the stator 18, the end pointing magnet 12a is moved by the Hall element 16. Detected. That is, as illustrated in FIG.
6 indicates each magnet 1 that faces each other according to the movement of the movable element 15.
The magnetic flux density of 2 is constantly detected, and the difference between this detection signal and the reference voltage of the reference voltage power supply 24 is calculated by the comparator 25. Therefore, this calculated value becomes a Hi times signal and a Low signal for the normal magnet 12 and the end pointing magnet 12a having a large magnetic flux density. here,
As mentioned above, the CPU 20 executes Start/St.
Since the OP signal is also output as a Hi/Low signal, this signal and the output signal of the comparator 25 which has passed through the FF circuit 26 are combined by the 7nd gate 27 and sent to the drive IC 2'.
2 is input.

Therefore, the drive I controlled by the output of the comparator 25 of the moving coil type linear motor 14 and the CPU 20
The output state of C22 is illustrated in the table below.

In other words, in this moving coil type linear motor 14, since the output signal of the comparator 25 is always in the 1i state, the driving of the movable element 15 is controlled by the CPU 20, and when the movable element 15 moves to the end of the moving area, , the output signal of the comparator 25 inevitably becomes a Low state, and the CPU
The movable element 15 will stop regardless of the output signal of the movable element 20.

As mentioned above, this moving coil type linear motor 14 is
The Hall element 16 on the bottom surface of the movable element 15 detects the end pointing magnet 12a to prevent the movable element 15 from overrunning.
If the stop position of the mover 15 shifts, the Hall element 16 comes off from above the end indicating magnet 12a and detects the magnet 12 or the outside where the magnetic flux density is small, and the output signal of the comparator 25 becomes Hi state again, causing the movable element 15 to move. There are concerns that the rampage will resume. However, this moving coil type linear motor 1
In No. 4, the output signal of the comparator 25 which is in the low state is held by the FF circuit 26 connected in the wiring from the comparator 25 to the AND gate 27, and continues to be output to the AND gate 27. It will stop reliably regardless of the stop position.

Next, an embodiment of the invention according to claim 2 will be described based on FIG. This moving coil type linear motor 29 has a mechanical structure similar to the moving coil type linear motor illustrated in FIGS. 6 to 8, and one of the Hall elements 13a to 13c for detecting excitation switching timing is It is connected to the comparator 25 of the overrun prevention circuit 28.

In such a configuration, the moving coil linear motor 29 functions in the same manner as the moving coil linear motor 14 described above.

Here, the moving coil type linear motor 29 prevents the movable element 15 from overrunning by using the detection value of the Hall element 13a used to detect the timing of excitation switching. In other words, the moving coil type linear motor 29 of this embodiment can be used, for example, by adding a comparator 2 to an existing moving coil type linear motor.
Overrun prevention circuit 2 consisting of 5, AND gate 27, etc.
To manufacture a moving coil type linear motor 29 which can be implemented by providing an end pointing magnet 12a having a large magnetic flux density on the stator 2, and which has an extremely simple structure and prevents overrun of the mover 15. Can be done.

Note that this moving coil type linear motor 29 also operates on the movable element 1 by means of an FF circuit 26 provided in the overrun prevention circuit 28.
5 is designed to stop reliably regardless of the stop position.

Further, the method of providing the end pointing magnet 12a with a large magnetic flux density on the stator 2 can be easily realized by transplanting a magnet with a large magnetic force or increasing the thickness of the magnet by a predetermined value.

Effects of the Invention The invention described in claim 1 is provided with a stator in which N-pole and S-pole magnets are arranged alternately in the longitudinal direction, and a movable element movably disposed on the fixed axis facing the magnet. In a moving coil type linear motor, a moving coil type linear motor is equipped with a coil that inputs a drive current to the coil of the mover, and a control circuit that controls the output of this drive circuit. Indicating magnets are provided near both ends of the stator, and magnetic field conversion elements facing the stator magnets are attached to the mover, and the output of the drive circuit connected in parallel with the control circuit is divided by the terminal indication of the magnetic field conversion By installing an overrun prevention circuit that regulates the detection of magnets, even if the control circuit goes out of control and the mover becomes uncontrollable, the magnetic field will be converted when the mover moves close to the end of the stator. When the element detects the terminal indicating magnet, the overrun prevention circuit is activated, and the output of the drive circuit is regulated and the movement of the movable element is stopped, thereby preventing the movable element from overrunning and damaging the device. Moreover, since the overrun prevention circuit and the control circuit are connected to the drive circuit in parallel, the drive of the movable element is controlled by the control circuit under normal conditions, and only when the equipment is abnormal, the movable element is activated regardless of the output of the control circuit. This will improve the reliability of the device without interfering with normal performance.Furthermore, the magnetic field conversion that detects the terminal indicating magnet during the wiring from the magnetic field conversion element to the overrun prevention circuit. By connecting a holding circuit that holds the detection signal of the element, the overrun prevention circuit will be activated even if the stop position of the movable element shifts and the magnetic field conversion element comes off from the top of the end indicating magnet. Since this continues, the movable element will surely stop regardless of the stop position, and an extremely reliable device can be obtained. A stator in which magnets are arranged alternately is provided, and a magnetic field conversion element that outputs a detected value corresponding to the position on the stator to a mover movably arranged on the stator, and a coil facing the magnet. A moving coil type linear motor is equipped with a drive circuit that inputs a drive current to the coil of this mover, and a control circuit that controls the output of this drive circuit based on the detected value of the magnetic field conversion element. End indicator magnets, which have a higher magnetic flux density than the magnets, are installed near both ends of the stator to prevent overruns by regulating the output of the drive circuit connected in parallel with the control circuit in response to the detection of the end indicator magnet of the magnetic field conversion element. By providing the circuit, it is possible to obtain a moving coil linear motor in which overrun of the mover is prevented by simply providing an overrun prevention circuit and an end indicating magnet to an existing moving coil linear motor. In addition, by connecting a holding circuit that holds the detection signal of the magnetic field converting element that detects the end indicating magnet in the wiring from the magnetic field converting element to the overrun prevention circuit, the movable element that would otherwise stop due to activation of the overrun prevention circuit will stop. It will stop reliably regardless of its position, so
This has the advantage that an extremely reliable moving coil linear motor can be manufactured with a simple structure.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the invention as claimed in claim 1, FIG. 2 is a front view, FIG. 3 is a block diagram, FIG. 4 is a characteristic diagram showing detected values of magnetic flux density, and FIG. A block diagram showing an embodiment of the invention as claimed in claim 2, FIG. ff16 is a plan view showing a conventional example, FIG. 7 is a side view, and FIG. 1.15...Mover, 2,18...Stator, 7...
- Coil, 12... Magnet, 12a... Terminal indicator magnet, 13.16... Magnetic field conversion element, 14
, 29... Moving coil type linear motor, 20... Control circuit, 23... Drive circuit, 26... Holding circuit, 2
8...Overrun prevention circuit

Claims (1)

[Claims] 1. A stator in which N-pole and S-pole magnets are arranged alternately in the longitudinal direction is provided, and a movable member movably disposed on the stator has a coil facing the magnets. In a moving coil type linear motor, which is equipped with a drive circuit that inputs a drive current to the coil of this mover, and a control circuit that controls the output of this drive circuit, it is used for terminal indication with a higher magnetic flux density than other magnets. A magnet is provided near both ends of the stator, a magnetic field conversion element facing the magnet of the stator is attached to the movable element, and the output of the drive circuit connected in parallel with the control circuit is used to indicate the end of the magnetic field conversion element. An overrun prevention circuit that regulates in response to magnet detection is provided, and a holding circuit that holds a detection signal of the magnetic field conversion element that has detected the end indicating magnet in the wiring from the magnetic field conversion element to the overrun prevention circuit. A moving coil type linear motor characterized by being connected. 2. A stator is provided in which N-pole and S-pole magnets are arranged alternately in the longitudinal direction, and a movable element movably arranged on the stator is provided with a detected value corresponding to the position on the stator. A magnetic field conversion element for output and a coil facing the magnet are attached, a drive circuit is provided for inputting a drive current to the coil of the movable element, and the output of this drive circuit is controlled based on the detected value of the magnetic field conversion element. In a moving coil type linear motor provided with a control circuit, end indicating magnets having a higher magnetic flux density than other magnets are provided near both ends of the stator, and the output of the drive circuit connected in parallel with the control circuit is connected to the magnetic field. An overrun prevention circuit is provided that regulates in response to the detection of the end indicating magnet of the conversion element, and a detection signal of the magnetic field conversion element that detects the end instruction magnet during wiring from the magnetic field conversion element to the overrun prevention circuit. A moving coil type linear motor characterized by being connected to a holding circuit that holds.