JPH02150718A - Moving quantity detector - Google Patents

Abstract

PURPOSE:To cause the title device to favorably act against a disturbance with a simple constitution by providing a signal detector incorporating plural detection coils and forming a signal indicating the relative moving quantity between a detecting signal generating member and the detector. CONSTITUTION:A detecting signal corresponding to the movement of a moving body is sent from a detecting section 10 as the moving body moves and the moving quantity and moving speed of the moving body are calculated at a signal processing system 15. The detecting section 10 is provided with a detecting signal generating member 24 and signal detector 29 and the detector 29 is formed by inserting the member 24 through a box body 28. When a high-frequency signal S1 is inputted, the member 24 is inserted into a primary coil 30 and detection coils 32 and 34. In the course of the relative movement, an envelope signal section having a phase difference of 90 deg. is formed of the coils 32 and 34. Then the same detecting signal as the signal S1 is led out and sine-wave and cosine-wave signals are extracted from led-out two-wave modulated signals. A moving quantity detecting signal S10 indicating the relative moving quantity between the member 24 and detector 10 is outputted from the sine- and cosine-wave signals. Therefore, this detecting device can favorably act against a disturbance with such simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a movement amount detection device. Respective signals derived from the two sets of detection coils under the cooperation of a signal detector consisting of a pair of detection coils and a detection signal generation member disposed within the primary coil and the detection coil. Based on the above, the present invention relates to a movement amount detection device capable of detecting the relative movement amount, relative speed, etc. between the detection signal generating member and the signal detector with a relatively simple configuration.

[Background of the invention] Recently, the length and speed of a moving body or the rotational speed of a rotating body,
When measuring a so-called relative movement amount such as a rotation angle, a movement amount detection device employing various displacement sensors is often used. The displacement sensor includes a detection signal generation member in which detection signal generation functional units having different functions are arranged alternately so as to change the magnetic flux density or light intensity as the displacement sensor moves, and a detection signal generation member that detects the amount of the change. It includes a sensing element etc. that derives a signal.

In this movement amount detection device, a linear displacement sensor is used to measure the length or speed of a moving body, and a Rochley displacement sensor is used to measure the rotational speed or rotation angle of a rotating body. For example, in a linear type detection means that employs a magnetic displacement sensor as the detection signal generation function section, the detection signal is generated by alternately arranging S-polarity and N-polarity magnets or magnetized portions of the same width. A magnetic scale as a generating member is fixed to the moving body. A signal corresponding to the movement of the magnetic scale is derived from the magnetic sensing element, and the velocity of the moving object and the like are calculated from the derived signal.

In a movement amount detection device that employs this type of displacement sensor, for example, in a displacement sensor that uses a light receiving and emitting element, strong light from the outside may have an adverse effect, and the receiving and emitting element may be covered with dust, etc. This is accompanied by a decline in detection ability over time. Furthermore, displacement sensors that utilize magnets and magnetic sensing elements have their own disadvantages, such as a decrease in magnetic force over time.

[Object of the Invention] The present invention has been made to overcome the above-mentioned disadvantages, and includes a detection signal generating member in which magnetic and non-magnetic annular bodies of the same width are alternately arranged, and a high-frequency signal input. The signal detector includes a primary coil for excitation, and two sets of detection coils sandwiching the primary coil and for deriving signals that take an electromagnetic induction state, and the detection signal generation member is the primary coil. and the same frequency as the high frequency signal (hereinafter referred to as the two-wave modulation signal) which is passed through two sets of detection coils, and a 90" phase difference envelope line signal section is formed from the two sets of detection coils during their relative movement. derive a detection signal, extract a sine wave and a cosine wave signal from the derived two-wave modulation signal, and calculate the relative movement amount between the detection signal generating member and the detector from the sine wave and cosine wave signals. The structure is configured to form a movement amount detection signal that indicates the amount of movement, and thereby, based on a relatively simple structure, there is no need for a contact member in detecting relative movement, and it is relatively advantageous for disturbances such as light, magnetic fields, vibrations, etc. An object of the present invention is to provide a movement amount detection device that acts on the following.

[Means for Achieving the Object] In order to achieve the above object, the present invention provides a signal detector including a detection signal generating member, a primary coil and a plurality of detection coils, and a signal detector that sends a high frequency signal to the signal detector. A movement amount detection device comprising a signal processing system that detects the relative movement amount between the detection signal generation member and the signal detector from signals derived together, the movement amount detection device comprising magnetic and non-magnetic annular members having the same width. A detection signal generation member whose bodies are arranged alternately on the outer peripheral surface, at least one primary coil for excitation that is inserted through the detection signal generation member and to which a high frequency signal is supplied, and the primary coil. and is in an electromagnetic induction state and is inserted into the detection signal generation member and transmits a first signal in which an envelope signal portion of a sine wave is generated upon relative movement with the detection signal generation member. at least one first detection coil disposed near one surface of the primary coil, which is in an electromagnetic induction state with the primary coil and inserted into the detection signal generating member; Said 1 so as to send out a second signal in which a cosine wave envelope signal portion is generated upon relative movement with the signal generating member.
at least one second detection coil disposed near the other surface of the primary coil; high-frequency signal generating means for supplying a carrier wave signal to the excitation primary coil; movement amount detection signal generation means for deriving a detection signal indicating the relative movement amount between the detection signal generation member and the signal detector using the sine wave signal and cosine wave signal extracted from the signal of step 2. It is characterized by

[Embodiment] Next, a preferred embodiment of the movement amount detection device according to the present invention will be described in detail below with reference to the accompanying drawings. In order to avoid clutter in the text, the same components are given the same reference numerals, and duplicate explanations will be omitted.

The movement 1 detection device shown in FIG. 1 detects the movement amount of the moving body or It is roughly configured with a signal processing system 15 that calculates the moving speed.

The detection unit IO includes a detection signal generation member 24 attached to a moving body 22 and a metal frame 28 attached to a fixed device 26 that also serves as a shield, with the detection signal generation member 24 inserted through it. It has a signal detector 29. As can be understood from the figure, the signal detector 29 includes a primary coil 30 for excitation to which a high frequency signal S is input, and a primary coil 30 for excitation.
It includes a first sensing coil 32 and a second sensing coil 34 that are placed on both sides of 0 and have the same center line. In this case, the primary coil 30, the first sensing coil 32, and the second sensing coil 34 are connected to the bobbin members 30a, 32a, and 34, respectively.
The ring wires are formed in a uniform winding direction, for example, right-handed, and are installed in the frame body 28 through an attachment member (not shown). Then, the first detection coil 32 and the second detection coil 34 send out detection signals S2 and S generated when the detection signal generation member 24 moves in the direction Vl or V. , are input to the signal processing system 15.

The signal processing system 15 will now be explained. FIG. 2 shows the configuration of main blocks of the signal processing system 15.

The signal processing system 15 includes an oscillation means 38 that oscillates a high frequency signal S1 of a carrier wave of 100 KHz and applies it to the primary coil 30, for example. Furthermore, the first detection coil 32
A rectifier circuit 42 to which the detection signal S2 derived from the
A DC amplifier 44 is provided to which a rectified signal S4 half-wave rectified by the rectifier circuit 42 is supplied, and which sends out an amplified signal S6 amplified to a predetermined value. Further, a rectifier circuit 46 to which the detection signal S derived from the second detection coil 34 is input, and a rectification signal S half-wave rectified by the rectifier circuit 46 are supplied and amplified to a predetermined value. Amplified signal S
, and a DC amplifier 48 that sends out. and,
A phase dividing circuit 50 is provided to which the amplified signals S6 and S are respectively supplied.

Here, the detection signal generating member 24 will be explained.

FIG. 3 shows a partial cross section of the detection signal generating member 24. As shown in FIG. This detection signal generating member 24 is made of 545C (carbon wA) as an example, as can be understood from FIG.
n) and the non-magnetic part (P,, P2, Ps...P,,)
are arranged alternately with the same width l. The magnetic part is made of 345C material, and the non-magnetic part is formed by the following method. First, grooves are formed alternately by removing a portion of the surface layer of the material that will become the non-magnetic material portion to a predetermined depth. Next, non-magnetic chrome plating is applied to fill the grooves and polish the surface. In this way, a detection signal generating member 24 is created in which magnetic parts (N+, N2, N, . . . N, ) and non-magnetic parts (Pt SF3, P3...P,) are alternately formed. . As a next example, in the example shown in FIG. 3B, first, the surface of a member such as a 345C round bar is subjected to a coating process,
Furthermore, a layering process of magnetic material plating, for example, chrome plating is performed. Further, the plating layer is removed by performing an etching process alternately with a width β.

Furthermore, non-magnetic chrome plating or the like is performed to fill in the grooves removed by the etching, and finally the surface is polished. In this way, the magnetic part (N, , N2, Nl-N
) and the non-magnetic part (P,,P2,P,...P,,
) is formed alternately on the detection signal generating member 24.

Next, referring to FIG. 4, the primary coil 30 and the first
The detection coil 32, the second detection coil 34 and the magnetic body part (Nl
-N2, Ns...N,) and non-magnetic parts (P+, P
2, P3...P,) will be explained.

Primary coil 30 and first detection coil 32 in frame 2B
The width d (thickness) of the second sensing coil 34 is formed between the width l of the magnetic material portion and the non-magnetic material portion. The first sensing coil 32 is arranged such that the center line a when the thickness is divided is the same as the center line a when the width l of the magnetic body portion P2 is divided. Further, the second sensing coil 32 is arranged so that its center line in its thickness is as close as possible to the junction line between the non-magnetic portion P and the magnetic portion N. The first detection coil 3
The primary coil 30 is attached between the primary coil 2 and the second sensing coil 340. With this arrangement, the first sensing coil 32 and the second sensing coil 34 have magnetic parts (
The maximum value of the signal is obtained when the signals are opposed to each other (Nl, N2, N, . . . Nh). Also, non-magnetic parts (P+, P'2
, P3...P,), a signal with the minimum value is derived, and a corresponding signal is derived at a position straddling between them. Further, the signals derived from the first right and second detection coils 32 and 34 include a 90° phase difference signal and are sent out.

The movement amount detection device according to the present invention is basically configured as described above, and the operation and effects of this embodiment will be explained next.

When a high frequency signal Sl for excitation of, for example, induced voltage (hereinafter referred to as
(called induced voltage). The induced voltages are derived as detection signals S2 and S, respectively.

In this state where induced voltage is generated in the first and second sensing coils 32 and 34, the direction v1 of the moving body 22 is
or movement to vm, that is, detection signal generation member 2
4 is moved in the direction V+ or V, the magnetic material portions (N3, N
2, N,...N,) and non-magnetic material a (p, , P2
, ps ・P,), and as shown in the fifth prisoner, for the carrier wave of the high frequency signal S1,
Detection signals S2 and S are modulated as they move.
, is derived. The distance between the sine wave envelope part S□ and the cosine wave envelope part Ss, l of the detection signals S2 and Ss is 90
A phase difference of ° is formed.

Next, the detection signal S is rectified by the rectifier circuit 42,
As shown in FIG. 5B, a sine wave envelope portion S2° is extracted from the modulated detection signal S as a rectified signal S. The rectified signal S4 is amplified to a predetermined value by the DC amplifier 44, and a sinusoidal amplified signal S6 is derived as shown in FIG. 5C.

On the other hand, the detection signal Ss is similarly rectified by the rectifier circuit 46, and from the modulated detection signal S, as shown in FIG.
The rectified signal S extracted as
8, amplification is performed to a predetermined value, and a cosine wave amplified signal S is derived as shown in FIG. 5C.

The sine wave and cosine wave amplified signals S and S derived in this way are supplied to the phase division circuit 50, respectively. Here, sine wave and cosine wave amplified signals S6 and S
, and generates an output signal S1° formed into a pulse signal corresponding to the period, and outputs it to the output terminal 54.

The output signal S,. For example, in a counter, the number of pulses is counted on the time curve axis, and the relative movement of the detection signal generation member 24 and the detection unit 10, that is, the moving body 2
The amount of movement in the direction v1 or vl of the second direction is calculated.

Next, modified examples of the signal detection section will be explained using FIGS. 6 to 8.

In both of these modified examples, two sets of detection units corresponding to the detection unit 10 are used. The aim is to increase the output level of the sensing signals S2 and S.

In FIG. 6, the primary coil 8 is composed of a first detection section 70 and a second detection section 75, and is housed in a frame 78 that also serves as a shield.
0, and first and second sensing coils 82 and 84 having the same circular center line with the primary coil 80 in between. On the other hand, the second detection unit 75 also uses the primary coil 90 in the same manner.
, first and second sensing coils 92 and 94.

Here, the magnetic material portion (
Nl, N2, N5-N, ) and the non-magnetic part (P,,
P2, P, .

In this case, each of the coils is formed with the same width d, and the magnetic body portions (N, , N
2, N3...N,) and the non-magnetic part (P+, P2,
P3...P,,) are arranged.

The first sensing coil 82 is arranged so that the center line C of the non-magnetic part P2 is the same, and the second sensing coil 84 is arranged so that the center line e of the non-magnetic part P2 is the same as that of the magnetic part N1. moreover,
The center line f of the first sensing coil 92 is arranged on the same line as the joining line between the non-magnetic part P and the magnetic part N6. The center line g of the second sensing coil 94 is a magnetic part N, a non-magnetic part P,
It is located on the same line as the joining line. By being arranged in this way, first, the high frequency signal S1 is transmitted from the transmitting means 38.
is supplied to the primary coils 80 and 90, and the detection signal generating member 24 is moved to VI or v. As a result, the first and second detection coils 92 and 94 derive detection signals in which the carrier wave of the high-frequency signal S1 is modulated. The detection signal includes substantially sine wave and cosine wave signals having a phase difference of 90° between the formed envelope portions. However, the detection signals of the first detection coil 82 and the second detection coil 84 have opposite phases. Therefore, as shown in the figure, the connection wires of the second sensing coil 84 are connected in reverse in advance. Note that the first detection coil 9
The same applies to the second detection coil 2 and the second detection coil 94.

Therefore, the obtained detection signal S2b is
and the detection signal of the second detection coil 84, that is, the value of the signal obtained by superimposing and adding the induced voltages with the same phase. Similarly, the detection signal Sob has a value obtained by superimposing and adding the induced voltages of the first detection coil 92 and the second detection coil 94 with the same phase.

This configuration is advantageous, for example, when remote control is employed and the detection signals S2b and SSb are sent to a relatively remote location, that is, when transmission loss is relatively large.

Further, in FIG. 7, the first detection coil 82 and the second detection coil 84 are in the same phase, and the first detection coil 9
2 and the second detection coil 94 are also in the same phase.

Further, in the example of FIG. 8, the width β of the primary coils 80a, 90a and the first sensing coils 80a, 90a and the second sensing coils 84a, 94a is the same as that of FIGS. 4, 6 and 7. It is formed larger than in the figure, and is an example of a configuration in which the output voltage is increased and derived, for example. The functions and the like in FIGS. 7 and 8 are basically the same as those in the example shown in FIG. 6, and a redundant explanation thereof will be omitted.

[Effects of the Invention] As described above, according to the present invention, there is provided a detection signal generating member in which magnetic and non-magnetic annular bodies of the same width are alternately arranged on the outer peripheral surface, and an excitation member in which a high frequency signal is manually applied. A signal detector including a primary coil and two sets of detection coils sandwiching the primary coil and for deriving signals that take an electromagnetic induction state,
The detection signal generating member is inserted through the primary coil and the two sets of detection coils, and during its relative movement, the high frequency signal is generated from the two sets of detection coils, in which an envelope signal portion with a phase difference of 90° is formed. A detection signal of the same frequency is derived, a sine wave and a cosine wave signal are extracted from the derived two-wave modulation signal, and a relative relationship between the detection signal generating member and the detector is extracted from the sine wave and cosine wave signals. The structure is configured to generate a movement amount detection signal indicating the amount of movement, which results in a relatively simple structure, and since detection of movement does not require a contact member, wear of the member does not occur.
It also has a relatively advantageous effect on disturbances such as light, magnetic fields, and vibrations, and has the effect of effectively preventing deterioration in detection ability over time.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments.
It goes without saying that various improvements and changes in design are possible without departing from the spirit of the invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an embodiment of the movement amount detection device according to the present invention, FIG. 2 is a circuit block diagram showing the main part of the signal processing system of the movement amount detection device shown in FIG. 3 is a partial sectional view showing the configuration of a detection signal generating member in an embodiment of the movement amount detection device shown in FIG. 1, and FIG. 4 is an embodiment of the movement amount detection device shown in FIG. 1. 5 is a processing waveform diagram in a signal processing system of an embodiment of the movement amount detection device shown in FIG. 1, and FIG. FIG. 7 is a cross-sectional view showing the configuration of another modification of the sensing portion shown in FIG. 1; FIG. 8 is a further modification of the sensing portion shown in FIG. 1; It is a sectional view showing the composition of the modification. 10... Detection unit 15... Signal processing system 22... Moving body 24... Detection signal generation member 26... Fixing device 2
9... Signal detector 30... Primary coil 32... First detection coil 34... Second detection coil S1...
- High frequency signal for excitation S2...Detection signal S5 from the first detection coil...Detection signal 31G from the second detection coil...Output signal FIG, 5

Claims (1)

[Claims] (1) A signal detector including a detection signal generation member, a primary coil, and a plurality of detection coils, which transmits a high frequency signal to the signal detector and connects the detection signal generation member and the signal detector from the derived signal. A movement amount detection device consisting of a signal processing system that detects the relative movement amount between at least one primary coil for excitation that is inserted through the detection signal generation member and supplied with a high frequency signal; and at least one primary coil for excitation that is in an electromagnetic induction state with the primary coil and inserted through the detection signal generation member. At least one coil disposed near one surface of the primary coil so as to transmit a first signal in which a sinusoidal envelope signal portion is generated upon relative movement with the detection signal generating member. A cosine envelope signal portion is generated when the first sensing coil is in an electromagnetic induction state with the primary coil, is inserted into the sensing signal generating member, and is moved relative to the sensing signal generating member. at least one or more second detection coils disposed near the other surface of the primary coil so as to send out a second signal, and a high frequency wave that supplies a carrier wave signal to the excitation primary coil. Deriving a detection signal indicating a relative movement amount between the detection signal generation member and the signal detector using a signal generation means and a sine wave signal and a cosine wave signal extracted from the first signal and the second signal. A movement amount detection device comprising a movement amount detection signal generating means.