JPS6231373B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a device for detecting a position specified by a magnetic generator for position specification, and in particular, a device for detecting a position specified by a magnetic generator for position specification, and in particular a device for detecting a position specified by a magnetic generator for position specification, using magnetostrictive vibration waves propagating through a magnetostrictive transmission medium having a magnetostrictive effect. The present invention relates to a position detection device that detects a position specified by a magnetic generator.

Conventional technology and problems Conventional devices of this type include, for example, the Japanese Patent Publication No. 56-32668
As seen in the publication, from the time when an instantaneous magnetic field fluctuation is generated by a magnetic generator for position specification, a magnetostrictive vibration wave generated in a magnetostrictive transmission medium due to this instantaneous magnetic field fluctuation propagates through the magnetostrictive transmission medium. Generally, a processing device calculates the time required for detection by a detection coil provided at the end of the magnetostrictive transmission medium, and a position specified by a magnetic generator for specifying the position is detected from this calculated value. . However, in such a configuration,
Because it is necessary to notify the processing device of the timing at which the instantaneous magnetic field fluctuation is generated by the position specification magnetic generator, it is necessary to connect the position specification magnetic generator to the processing device by a signal line. The disadvantage is that the movement range and handling of the magnetism generator are severely restricted, and the scope of its application is also narrow. especially,
When the position detection surface is planar, the movable range of the position specifying magnetic generator becomes wider, requiring a long signal line, which has the disadvantage of deteriorating operability.

OBJECTS OF THE INVENTION The present invention has been made to overcome these conventional drawbacks, and an object of the present invention is to provide a position detecting device with a wide range of applications in which the magnetic generator for specifying a position is not connected anywhere.

Principle of the Invention When a magnetostrictive vibration wave propagates in a magnetostrictive transmission medium, a part of the mechanical vibration energy is converted into magnetic energy in a region where the magnetostriction vibration wave exists, and a magnetic field fluctuation occurs in a polar region. The magnitude of this magnetic field fluctuation increases as the coefficient (hereinafter referred to as electromechanical coupling coefficient) indicating the conversion efficiency from mechanical energy to electrical energy (or from electrical energy to mechanical energy) increases, and The coupling coefficient becomes maximum near a certain bias magnetic field. Therefore, if magnetism is applied from a position specifying magnetic generator to a certain portion of a magnetostrictive transmission medium in which a coil is wound over almost the entire length, the magnetism will propagate through the magnetostrictive transmission medium. When the magnetostrictive vibration waves reach that position, a large magnetic field fluctuation occurs, and at that time, a large induced electromotive force (induced voltage due to the magnetostriction vibration waves) is generated in the coil.
occurs. Therefore, by detecting the timing of generation of this large induced electromotive force, it is possible to know the time required for the magnetostrictive vibration wave to reach the specified position by the position specifying magnetic generator, and from this time it is possible to determine the specified position. This makes it possible to detect the position of the user. or,
The magnitude of the magnetostrictive vibration waves generated by applying an instantaneous varying magnetic field to the magnetostrictive transmission medium also increases as the electromechanical coupling coefficient increases. Therefore, if a magnetostrictive transmission medium in which a coil is wound over almost its entire length is subjected to a magnetism strong enough to increase the electromechanical coupling coefficient from a position specifying magnetic generator, it is possible to apply a pulse voltage to that coil. When applied, large magnetostrictive oscillation waves are generated only in designated areas. Therefore, if the magnetostrictive vibration waves are detected with another coil installed at the end of the magnetostrictive transmission medium, when a large magnetostrictive vibration wave reaches that coil, the induced electromotive force (induced voltage due to the magnetostrictive vibration waves) will increase, and this By detecting the timing, it becomes possible to detect the designated position as before.

The present invention detects a position specified by a position specifying magnetic generator based on the above principle, and embodiments will be described below with reference to the drawings.

Embodiment of the Invention FIG. 1 is an explanatory diagram of the configuration of an embodiment of the present invention. In the figure, 1a to 1d are magnetostrictive transmission media made of a material having a magnetostrictive effect, and are arranged substantially parallel to each other. Magnetostrictive transmission media 1a to 1d
Although any ferromagnetic material can be used, a material with a large magnetostrictive effect, such as an amorphous alloy containing a large amount of iron, is particularly desirable in order to generate strong magnetostrictive vibration waves. Further, it is preferable to use a material with a small coercive force that is difficult to magnetize even when a magnet is brought close to the material.
Examples of amorphous amorphous alloys include
Fe ₆₇ Co ₁₈ B ₁₄ Si ₁ (atomic%), Fe ₈₁ B _13.5 Si _13.5 C ₂
(atomic %) etc. can be used. Magnetostrictive transmission medium 1a~
1d has an elongated shape, and its cross section is preferably a rectangular thin strip or a circular linear shape, and in the case of a thin strip, the width is about several mm and the thickness is about several μm to several tens of μm, which is easy to manufacture and has characteristics. is also good. Amorphous alloys can be manufactured into thin pieces with a thickness of 20 to 50 μm, so they can be cut into thin plates or lines. In this example, a magnetostrictive transmission medium made of Fe ₈₁ B _13.5 Si _13.5 C ₂ (atomic %) and having a width of 2 mm and a thickness of 0.02 mm is used.

Reference numeral 2 denotes a first coil wound around one end of the magnetostrictive transmission media 1a to 1d, and the number of turns is two in the illustrated example, but it may be wound once or more than three times. This first coil 2 is used to generate instantaneous magnetic field fluctuations perpendicular to the coil surface to generate magnetostrictive vibration waves at the wound portions of each of the magnetostrictive transmission media 1a to 1d, and one end 2a of the coil 2 is , is connected to the + terminal of a pulse current generator 3 that generates a pulse current sufficient to generate magnetostrictive vibration waves, and the other end 2b is connected to its - terminal.
Connected to the terminal.

Numerals 4a to 4d are biasing magnetic bodies that apply a bias magnetic field parallel to the longitudinal direction of the magnetostrictive transmission media 1a to 1d to the wound portions of the first coils 2 of the magnetostrictive transmission media 1a to 1d. The reason why a bias magnetic field is applied in this way is to enable generation of large magnetostrictive vibration waves with a small amount of current. That is,
Since the electromechanical coupling coefficients of the magnetostrictive transmission media 1a to 1d are maximum at a certain bias magnetic field as shown in FIG.
By applying it to the wound portion of the coil 2, magnetostrictive vibration waves can be efficiently generated. From this point of view, in cases where some loss in power consumption can be ignored, the bias magnetic body 4 may be omitted. In addition, the bias magnetic material 4
The polarities of the bias magnetic bodies 4b and 4d are opposite to those of the bias magnetic bodies 4b and 4d. The reason for this will be explained later.

Further, in FIG. 1, second coils 5a to 5b wound around the magnetostrictive transmission media 1a to 1d are for detecting induced voltages due to magnetostrictive vibration waves propagating through the magnetostrictive transmission media 1a to 1d. The magnetostrictive transmission medium is wound over a wide range, and the wound area becomes a position detection area. The winding pitch is preferably large in order to increase the induced electromotive force, and is set to 7 turns/cm in this embodiment, for example.

The winding directions of each coil 5a to 5d are all the same (left-handed winding), between the end of winding of coils 5a and 5b, between the beginning of winding of coils 5b and 5c, and between coils 5c and 5d.
are connected to each other between the winding ends of the coils 5a, 5.
The beginnings of winding d are connected to the input terminals of the processor 6, respectively. That is, in this embodiment, the coils 5a to 5
d are connected in series, and the polarity of the connection is reversed between adjacent ones. Note that the second coil 5 is configured by the coils 5a to 5d. Reference numeral 7 denotes a bar magnet constituting the position specifying magnetic generator, and in this embodiment, a bar magnet with a diameter of 3 mm and a length of 50 mm is used. In this embodiment, the position designated by this bar magnet 7 is to be detected.

Now, in FIG. 1, the position designating bar magnet 7 is
It is located above the magnetostrictive transmission medium 1a at a distance l from the center of the coil surface of the first coil 2 with the pole facing down, and applies magnetism to a part of the magnetostrictive transmission medium 1a directly below to the extent that the electromechanical coupling coefficient becomes large. shall be.

In such a state, the pulse current generator 3
When a pulsed current is applied to the first coil 2, an instantaneous magnetic field fluctuation occurs in the first coil 2,
This causes magnetostrictive vibration waves to occur in the wound portions of the first coils 2 of the magnetostrictive transmission media 1a to 1d. This magnetostrictive vibration wave is transmitted to the magnetostrictive transmission media 1a to 1d at a propagation velocity (approximately 5000 m/sec) specific to the magnetostrictive transmission media 1a to 1d.
propagates along the longitudinal direction. During this propagation, mechanical energy is converted into magnetic energy at a portion of the magnetostrictive transmission medium 1a to 1d where the magnetostrictive vibration wave exists, depending on the magnitude of the electromechanical coupling coefficient at that portion. Therefore, an induced electromotive force is generated in the second coil 5.

FIG. 3 shows an example of a temporal change in the induced electromotive force generated in the second coil 5, with the time when the pulse current is applied to the first coil 2 being t=0. As shown in the figure, the amplitude of the induced electromotive force becomes large immediately after time t=0 and around _t1 to _t2 seconds after time _t0 , and becomes small at other times. The reason why the amplitude of the induced electromotive force becomes large immediately after time t=0 is due to the electromagnetic induction effect between the first coil 2 and the second coil _{5, and the amplitude of the induced electromotive force becomes large immediately after time t=0 .} The amplitude of the induced electromotive force (induced voltage due to magnetostrictive oscillating waves) increases because the magnetostrictive oscillating waves generated in the winding portion of the first coil 2 propagate through the magnetostrictive transmission medium 1a and cause the position specifying bar magnet 7 to increase in amplitude. This is because the electromechanical coupling coefficient becomes large at that point as it reaches the vicinity directly below. When the position specifying bar magnet 7 is moved along the longitudinal direction of the magnetostrictive transmission medium, the voltage induced by the magnetostrictive vibration waves also moves on the time axis accordingly. Therefore, by measuring the time from time t ₀ to t ₁ to _{t 2} , it is possible to calculate the position designated by the position designating bar magnet 7, that is, the distance. As the propagation time for calculating the position, for example, as shown in Fig. 3, the time _t3 is when the amplitude of the induced voltage due to magnetostrictive vibration becomes smaller than the threshold value _-E1 , and the time _t4 is when it becomes larger than the threshold value _E1 . Alternatively, the zero cross point _t5 may be used. However, since the amplitude of the induced voltage due to magnetostrictive vibration tends to be larger in the first half cycle, it is desirable to use time t ₃ or t ₅ .

In addition, in FIG. 1, the position designating bar magnet 7 is moved in parallel in a direction perpendicular to the longitudinal direction of the magnetostrictive transmission media 1a to 1d, so that the N pole of the position designation bar magnet 7 is above the magnetostrictive transmission media 1b to 1d. 3, an induced voltage similar to that shown in FIG. 3 can be obtained. This is because the connection polarities of the coils 5a, 5c and the coils 5b, 5d are opposite, but the polarities of the biasing magnetic bodies 4a to 4d are opposite. Therefore, it is possible to always extract the induced voltage due to the magnetostrictive vibration of the same polarity, and it is possible to improve the detection accuracy. Also,
Since the connection polarities of the coils 5a, 5c and the coils 5b, 5d are reversed, the induced voltages directly induced from the first coil 2 to the second coil 5 immediately after t0 in FIG. ₃ cancel each other out. It becomes smaller. Therefore, the distance between the first coil 2 and the second coil 5 can be narrowed, and the position detection area can be expanded accordingly. Generally, this effect can be obtained by reversing the connection polarity of the second coil portion, which is wound around approximately half of the magnetostrictive transmission medium.

In addition, in the configuration shown in FIG. 1, when the position specifying bar magnet 7 is placed on the magnetostrictive transmission medium 1a, when the polarity of the position specifying bar magnet 7 or the polarity of the bias bar magnet 4a is reversed from that shown in the figure. , when the winding direction of the first coil 2 or the second coil 5a is reversed, and when the connection of the first coil 2 or the second coil 5a is reversed, magnetostrictive vibration waves are generated. It has been confirmed through experiments that the polarity of the induced voltage is reversed.

Therefore, if the winding methods of 5b and 5d are reversed in FIG. 1, the bias magnetic bodies 4b and 4
By reversing the polarity of d, it is possible to always extract the induced voltage due to magnetostrictive vibration of the same polarity. however,
In this case, there is a drawback that the induced voltage is directly induced from the first coil 2 to the coil 5, and the induced voltage becomes large. Furthermore, although the induced electromotive force becomes smaller, the coils 5a to 5d
It is also possible to have a configuration in which these are connected in parallel. In addition, the third
When detecting zero cross point _t5 in the figure, the polarity of the induced voltage due to magnetostrictive vibration is
Even if it is inverted every time, there is little effect on accuracy.

FIG. 4 is a partially cutaway plan view showing an embodiment of the detection section of the position detection device, and FIG. 5 is a sectional view along the longitudinal direction thereof. As shown in the figure, magnetostrictive transmission medium 1
The second coils 5a to 5d containing coils a to 1d are inserted into recesses provided on the internal bottom surface of the housing 30, and fixed with adhesive or the like as necessary. At this time, since the present invention utilizes the transmission of magnetostrictive vibration waves by the longitudinal vibration mode of the magnetostrictive transmission medium 1, it is desirable not to limit the degree of freedom of the magnetostrictive transmission media 1a to 1d in the vertical direction. The second coil 5 and the first coil 2 are taken out from the side of the housing 30 and connected to the pulse current generator 3 and processor 6 shown in FIG. 1. The bias magnetic bodies 4a to 4d are mounted in the housing 3 so as to face the ends of the magnetostrictive transmission media 1a to 1d.
As shown in FIG. 1, magnetostrictive transmission media 1a to 1
They may be arranged in parallel above, below, or to the sides of d. The housing 30 is covered with a lid 31, and the position specifying bar magnet 7 is moved on the lid 31.

FIG. 6 is an electrical circuit diagram showing an embodiment of the pulse current generator 3, in which a capacitor 50 is connected to resistors 51 and 5.
By turning on the thyristor 54 connected in parallel to the series circuit of the capacitor 50 and the resistor 52, the electric charge charged by the DC power supply 53 via the capacitor 50 and the resistor 52 is discharged through the thyristor 54 and the resistor 52, and the electric charge is discharged from the terminal of the resistor 52. The configuration is such that a voltage is applied to the first coil 2. In addition, thyristor 5
4 is turned on by inputting a trigger pulse from the processor 6 of FIG. 1 to the gate.

FIG. 7 is a main part block diagram showing an embodiment of the processor 6. As shown in FIG. In the figure, a resistor 60 and a capacitor 61 are connected in series between the power supply Vc and ground, and a switch 63 is connected in parallel to the capacitor 61.
constitutes a manual pulse generator 64, and the pulse output is taken out from the terminal of the capacitor 61 and input to the changeover switch 65. The measurement command pulse is sent to the manual pulse generator 6 via this changeover switch 65.
4. Applied to the one-shot multivibrator 68 from a pulse generator 66 or computer 67 that generates one pulse at a predetermined period. This one-shot multivibrator 68 operates at the rising edge of the measurement command pulse, outputs a pulse with a pulse width of about 15 μsec, clears the 16-bit counter 69, and resets the RS flip-flop 70 and latch circuit 71. RS flip flop 70
Since the output of is inputted to the AND circuit 72 as a gate signal, when the RS flip-flop 70 is reset, the 16-bit counter 69 starts counting the output pulses (pulse repetition frequency is 100 MHz, for example) of the reference clock pulse generator 73. . Also, one-shot multivibrator 68
The output of is also input to a differentiation circuit 74 which outputs only the + polarity of the differential waveform.
A trigger pulse to the pulse current generator 3 is generated at 4, and a pulse current is applied to the first coil 2.

The induced electromotive force generated in the second coil 5 is amplified by the signal amplifier 75 and input to the + input terminal of the comparator 76 and the - input terminal of the comparator 77. For example, the - input terminal of the comparator 76 has the threshold value _E1 shown in FIG.
A voltage Er corresponding to is applied, and comparator 7
6, while the output of the signal amplifier 75 is higher than the voltage Er, that is, when the positive polarity portion of the voltage induced by the magnetostrictive oscillation wave is detected, the output is set to a high level.
For example, a voltage -Er corresponding to the threshold value _-E1 in FIG. When the negative polarity portion of the induced voltage is detected, the output is set to high level. The information as to whether the polarity of the comparators 76 and 77 exceeds the positive or negative polarity threshold, or the operation order of the comparators 76 and 77 is transmitted to the magnetostrictive transmission medium 1 of the position specifying bar magnet 7. This information indicates whether the opposing pole is N or S, and the information is latched by the latch circuit 71 and output from the output terminals 83 and 84 as the polarity output of the detected magnetic substance. Note that when polarity detection is not performed, the latch circuit 71 can be omitted, and either one of the comparators 76 and 77 can be omitted.

Now, the outputs of the comparators 76 and 77 are output from the OR circuit 78.
Since the RS flip-flop 70 is set via the output, the AND circuit 72 is closed and the 16-bit counter 69 stops counting. In this way, when an induced voltage appears in the second coil 5 due to magnetostrictive vibration waves, the 16-bit counter 69 stops counting, so the elapsed time since the first measurement command is issued can be known as the digital value of the counter. I can do it. Further, this value corresponds to the distance from the first coil 2 to the position specifying magnetic body 7 because the magnetostrictive vibration waves travel at a speed of about 5000 m/s. The position data thus obtained as a digital value is input to the AD converter 80 via the buffer circuit 79.
It is taken out from the output terminal 81 as an analog value,
Alternatively, it may be taken out as a digital value from the output terminal 82 or input to the computer 67 and processed.

FIG. 8 is an external perspective view showing another embodiment of a magnetic generator for position designation, in which a cylindrical magnetic body 90 with a circular cross section is fixed to the tip of an elongated pen-shaped container 91. As the cylindrical magnetic body 90, a short one or a long one can be used.
FIG. 9a shows the magnetic field line distribution of a short cylindrical magnetic body, and FIG. 9b shows the magnetic field line distribution of a long cylindrical magnetic body. As shown in FIG. 10a, when the cylindrical magnetic body 90 is arranged perpendicularly to the magnetostrictive transmission medium 1, the magnetostrictive vibration waves are directed in parallel to the magnetostrictive transmission medium 1 when approaching and away from the cylindrical magnetic body 90. Since the direction of the magnetic field is reversed, the polarity of the induced voltage due to the magnetostrictive vibration induced in the second coil 5 is reversed centering right below the cylindrical magnetic body 90, as shown in FIG. 9b.

FIG. 11 is an external perspective view showing still another embodiment of the magnetic generator for position designation, in which the ring-shaped magnetic body 1
00 is inserted horizontally into a through hole 102 provided in the head of a cursor body 101 with a flat bottom and fixed therein. The magnetic field line distribution of the ring-shaped magnetic body 100 has almost the same effect as that of placing one cylindrical magnetic body on its center line, so it can be used as a magnetic generator for position specification. Note that the magnetization direction can be either vertical or horizontal, and a ring-shaped magnetic body magnetized horizontally is suitable for use close to the magnetostrictive transmission medium 1; The magnetized ring-shaped magnetic body is suitable for use at a distance.

FIG. 12 is a configuration explanatory diagram of another embodiment of the present invention. In this embodiment, two parallel magnetostrictive transmission media 1a' to 1d' are arranged in the coils 5a to 5d, respectively.
1a'' to 1d'', and the other configuration is almost the same as that in FIG. In addition, one coil 5
At least one or more magnetostrictive transmission media accommodated in a to 5d will be referred to as a magnetostrictive line flux in this specification.

In the above embodiment, the second
The coil 5 was used for detecting magnetostrictive vibration waves. Therefore, the electromotive force induced by the magnetostrictive vibration waves becomes extremely large, and the voltage value of the pulse voltage applied to the first coil 2 can be reduced accordingly, making it possible to simplify the circuit and save energy. be. However, as described in the section on the principle of the invention, the second coil 5 is connected to the pulse current generator 3 for generating magnetostrictive vibration waves, and the first coil 2 is connected to the processor 6 for detecting magnetostrictive vibration waves. It is also possible to configure

As is clear from the above description, the position detection device of the present invention can be used as a device for inputting graphic data etc. into a computer etc., and can also be used to detect the movement of a moving object by attaching a magnetic body for specifying the position of the moving object. By placing a magnetostrictive transmission medium along the path, it can also be used as a device that automatically detects the position of a moving object.

Effects of the Invention As described above, according to the present invention, a first coil and a second coil are wound around a plurality of magnetostrictive wire bundles arranged substantially parallel to each other and each made of at least one magnetostrictive transmission medium. The configuration is such that signals are sent and received between these two coils, and the position designating magnetic generator for specifying the position is not connected to any part of the device, so it is within the movement range of the position designating magnetic generator. This has the effect of eliminating restrictions and making handling much easier. Therefore, it becomes possible to apply the present invention to a wide range of applications, such as a device that automatically detects the position of a moving object by attaching a position specifying magnetic generator to the moving object. Further, in the present invention, since a plurality of magnetostrictive wire bundles are arranged substantially in parallel, there is an advantage that the position detection surface can be widened. Furthermore, the conventional magnetostrictive coordinate position detection device required the troublesome operation of occasionally rubbing a magnet bar to magnetize the magnetostrictive transmission medium, but the present invention can adjust the electromechanical coupling coefficient only in certain areas. Since the position is specified by changing the position, such operations are completely unnecessary. In addition, since the electromechanical coupling coefficient of the magnetostrictive transmission medium reaches its maximum at an amount of several Oe, the magnetic generator for position specification does not necessarily need to be placed close to the detection surface, and even if it is separated by several centimeters or more, the coefficient of electromechanical coupling is extremely high. It becomes possible to easily manufacture a device that can detect a position with high resolution. Further, a second coil is wound in series with the plurality of magnetostrictive wire fluxes in the same winding direction, and a plurality of biasing magnetic bodies are provided to apply a bias magnetic field to the winding portion of the first coil of the magnetostrictive wire flux. , the connection polarity of a second coil portion around which approximately half of the plurality of magnetostrictive wire fluxes is wound is reversed to the connection polarity of a second coil portion around which the remaining magnetostrictive wire fluxes are wound; Reversing the polarity of the bias magnetic body that applies a bias magnetic field to the first coil winding portion of the magnetostrictive wire flux and the polarity of the bias magnetic body that applies a bias magnetic field to the first coil winding portion of the remaining magnetostrictive wire flux. By doing so, the induced voltage value generated by the electromagnetic induction action between the first coil and the second coil can be reduced. Therefore, the distance between the first coil and the second coil can be narrowed, and the position detection area can be expanded accordingly.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of one embodiment of the present invention, and FIG.
The figure shows the characteristics of magnetic bias versus electromechanical coupling coefficient.
FIG. 3 is a diagram showing an example of a temporal change in the induced electromotive force generated in the second coil 5, FIG. 4 is a partially cutaway plan view showing an example of the detection section of the position detection device, and FIG. 6 is a sectional view along the longitudinal direction, FIG. 6 is an electric circuit diagram of an embodiment of the pulse current generator 3, FIG. 7 is a main part block diagram showing an embodiment of the processor 6, and FIGS. 8 and 11. 9 is an external perspective view showing different embodiments of the position specifying magnetic generator, FIG. 9 is a magnetic field line distribution diagram of the cylindrical magnetic body 90, and FIG. 10 is a diagram showing the relationship between magnetostrictive vibration waves and the position specifying magnetic generator. FIG. 12, which is a diagram for explaining the relationship, is a configuration explanatory diagram of another embodiment of the present invention. 1a to 1d... Magnetostrictive transmission medium, 2... First coil, 3... Pulse current generator, 4a, 4b... Magnetic body for bias, 5... Second coil, 6... Processor, 7
...A bar magnet that constitutes a magnetic generator for position specification.

Claims (1)

[Scope of Claims] 1. A plurality of magnetostrictive wire bundles arranged substantially parallel to each other and each consisting of at least one magnetostrictive transmission medium, and a first coil commonly wound around one end of the plurality of magnetostriction wire bundles. and a second coil wound in series or in parallel over a wide range of the plurality of magnetostrictive wire fluxes, and applying a pulse current to either the second coil or the first coil to A pulse current generator that simultaneously generates magnetostrictive vibration waves in a magnetostrictive transmission medium, and a time period from when the magnetostrictive vibration waves are generated until an induced voltage due to the magnetostrictive vibration waves appears in the other of the first coil or the second coil. A position detection device characterized by comprising a processor for detecting. 2 arranged substantially parallel to each other and each having at least one
A plurality of magnetostrictive wire fluxes made of a magnetostrictive transmission medium,
a first coil commonly wound around one end of the plurality of magnetostrictive wire bundles; a second coil wound in series in the same winding direction over a wide range of the plurality of magnetostrictive wire bundles; a pulse current generator that applies a pulse current to one of the second coil or the first coil to simultaneously generate magnetostrictive vibration waves in each of the magnetostrictive transmission media; a processor that detects the time until an induced voltage by the magnetostrictive vibration wave appears in the other of the first coil or the second coil; and a plurality of biases that apply a bias magnetic field to the winding portion of the first coil of the magnetostrictive wire flux. a magnetic material for use, and a connection polarity of a second coil portion around which approximately half of the magnetostrictive wire flux of the plurality of magnetostrictive wire fluxes is wound, and a connection polarity of a second coil portion around which the remaining magnetostrictive wire flux is wound; are opposite, and the polarity of the biasing magnetic body that applies a bias magnetic field to the winding portion of the first coil containing approximately half of the magnetostrictive wire flux and the polarity of the biasing magnetic body that applies a bias magnetic field to the winding portion of the first coil that has the remaining magnetostrictive wire flux. A position detection device characterized in that the polarity of the biasing magnetic body that applies a magnetic field is reversed.