JPS63240085A - Magnetic potentiometer - Google Patents

Abstract

PURPOSE:To improve the performance of a potentiometer detecting the angle of rotation by disposing a magnetic transmitting slit for a magnetic shield plate between the opposed surfaces of a magnetic detecting element and a permanent magnet and moving the magnetic shield plate or the magnetic detecting element and the permanent magnet in the longitudinal direction of the magnetic transmitting slit. CONSTITUTION:A magnetic shield plate 13 or a permanent magnet 12 and a magnetic detecting element 15 are constituted so as to be able to be moved in the longitudinal direction of slits 16, 17. That is, the permanent magnet 12 and the magnetic detecting element 15 are fixed, the magnetic shield plate 13 in which a pair of the arcuate slits 16, 17 are shaped symmetrically is fastened to a shaft 14, a pair of the slits 16, 17 are formed to an arcuate shape that they are formed to semicircles having different radii in predetermined width in a concentric manner with the center of rotation of the magnetic shield plate 13, and magnetic detecting patterns 19, 20 are formed to a circular shape concentric with each of the slits 16, 17. Accordingly, one revolution is regarded as a cycle when the magnetic shield plate 31 or the permanent magnet 12 and the magnetic detecting element 15 are turned and shifted, and output characteristics uniformly increasing or decreasing in the cycle are acquired.

Description

[Detailed Description of the Invention] [Summary] In a non-contact type magnetic potentiometer equipped with a magnetic detection element and a permanent magnet, a magnetically transparent slit of a magnetic shielding plate is arranged between the magnetic detection element and the permanent magnet, A high-performance magnetic potentiometer is realized by configuring the magnetic shielding plate or the magnetic detection element and the permanent magnet to move in the length direction of the magnetically transparent slit.

[Industrial application field]

The present invention relates to a magnetic potentiometer equipped with a magnetic detection element and a permanent magnet, particularly to a potentiometer that detects a rotation angle.

[Conventional technology]

In conventional magnetic potentiometers for detecting rotational angles that utilize a magnetic detection element, a semicircular permanent magnet faces the magnetic detection element, and one of the magnetic detection element and the permanent magnet (generally a permanent magnet) is fixed to a rotating shaft, and the rotation angle is The configuration was such that the rotation angle of the ' axis was detected from the output voltage of the magnetic detection element.

Figure 3 shows a side view (A) showing the main components of the conventional magnetic potentiometer, a plan view (0) of its permanent magnet, a plan view (C) of the magnetic detection pattern formed on its magnetic detection element, and the output. This is a characteristic diagram (d).

In Fig. 3 (a), potentiometer 1 is half open.

Permanent magnet 2 formed into a circular plate shape and having polarity in the thickness direction
, a rotary shaft 3 to which a permanent magnet 2 is fixed and rotatable, and a magnetic detection element 4 fixed to face the permanent magnet 2.

In FIG. 3 (II), the permanent magnet 2 has a semicircular shape in which the center of the straight end face 9 coincides with the center of the rotating shaft 3.
As shown in c), the magnetic detection pattern 5 formed on the non-magnetic insulating plate is formed in a sawtooth or comb-like shape and has an almost circular shape as a whole, with one end and the other end at the 0 degree angle of the magnetic detection element 4. It is connected to terminals 6 and 7 sandwiching the positions thereof, and the center in the length direction is connected to a terminal 8 provided at a position of 180 degrees of the magnetic detection element 4.

In such a potentiometer 1, when a predetermined current is passed through a bridge configured by combining a magnetic detection pattern 5 and a pair of resistance elements, the rotation angle of the rotating shaft 3 can be determined from the output voltage of the bridge.

In FIG. 3 (=), the vertical axis is the output voltage of the potentiometer 1, and the horizontal axis is the rotation angle of the permanent magnet 2 (rotating shaft 3). When it coincides with the 180 degree position, it becomes a chevron with maximum output. However, since the magnetic detection pattern 5 is discontinuous at the ends connected to the terminals 6 and 7, the rotation angle of the permanent magnet 2 is 0.
Invariant area (invariant angle) of output voltage near degree (360 degrees)
Can be done.

[Problem to be Solved by the Invention 3] As explained above, in the conventional potentiometer 1, the output characteristic A is a chevron shape, and the output range with linearity and good detection accuracy is, for example, 40 to 140 degrees and 220 to 3 degrees.
Limited to 20 degrees.

Therefore, there is a problem that the range in which the rotation angle of the rotating shaft 3 can be accurately detected is narrow, and in order to distinguish between 90 degrees and 270 degrees from the output characteristic A, it is necessary to compare the values before and after them. There was a problem.

[Means for solving problems]

The magnetic potentiometer of the present invention eliminates the above-mentioned problems, and includes a magnetic shielding plate in which a pair of magnetically permeable slits are formed symmetrically, and opposing faces in the thickness direction of the magnetic shielding plate so as to sandwich at least a part of the slits. a permanent magnet and a magnetic detection element, the magnetic detection element facing the slit and comprising a magnetic detection pattern formed with an appropriate width and length, and the magnetic shielding plate or the permanent magnet and the magnetic detection element According to the embodiment shown in FIG. 1, the permanent magnet 12 and the magnetic detection element 15 are fixed, and a pair of arc-shaped slits 16, 17
A magnetic shielding plate 13 having a symmetrical shape is fixed to a rotating shaft 14, and a pair of sulins (16, 17) are circular arcs formed in semicircles with predetermined widths and different radii concentrically with the rotation center of the magnetic shielding plate 13. , magnetic detection pattern 19.20 has slit 6,
It is characterized by being formed into a circular shape concentric with each of the 17.

[Effect]

According to the above means, when the magnetic shielding plate or the permanent magnet and the magnetic sensing element move, the magnetically permeable slit changes the length or width of the magnetic flux entering the magnetic sensing element from the permanent magnet depending on the amount of movement. For example, when the movement is rotation, one rotation is defined as a cycle, and an output characteristic that uniformly increases or decreases within the cycle can be obtained.

〔Example〕

EMBODIMENT OF THE INVENTION Below, the magnetic potentiometer by the Example of this invention is demonstrated using drawing.

FIG. 1 is a side view (A) showing the main structure of a magnetic potentiometer according to an embodiment of the present invention, a plan view (0) of its magnetic shielding plate, and a plan view of a magnetic detection pattern formed on its magnetic detection element. (c) and an output characteristic diagram (d).

In FIG. 1(a), the potentiometer 1) is made of a permanent magnet 12 formed in a disc shape and provided with polarity in the thickness direction, and a pair of magnetically permeable magnets (16.17) made of a magnetic shielding material such as permalloy. A magnetic shielding disk 13 provided, a rotating shaft 14 to which the magnetic shielding disk 13 is fixed and rotatable, and a magnetic detection element 15 having a magnetic detection pattern formed on a non-magnetic insulating plate.
The permanent magnet 12 and the magnetic detection element 15 are fixed to, for example, a housing (not shown) with the magnetic shielding disk 13 sandwiched therebetween in the thickness direction thereof without contacting each other.

In FIG. 1C4>, (0), the magnetic shielding disk 13
16 and 17 are formed symmetrically around the center of rotation of the rotating shaft 14 and having a pair of arc-shaped magnetically permeable rings (16, 17) with different radii.

In FIGS. 1() and (c), the magnetic detection element 15 has a sawtooth circular magnetic detection pattern 19 on an insulating disk 18 with the same radius as the slit 16, and a sawtooth circular magnetic detection pattern with the same radius as the slit 17. A pattern 20 is formed.

The magnetic detection patterns 19 and 20 are formed, for example, from a thin film of indium antimony by photoetching, and the center part of the magnetic detection pattern 19 is connected to a terminal (through hole) 21, and the left end of the magnetic detection pattern 19 and the left end of the magnetic detection pattern 20 are connected to a terminal (through hole) 21. is connected to terminal (through hole) 22,
The right end of the magnetic detection pattern 19 and the right end of the magnetic detection pattern 20 are connected to a terminal (through hole) 23, and the center portion of the magnetic detection pattern 20 is connected to a terminal (through hole) 24.

In the magnetic potentiometer 1) configured in this way, the magnetic detection patterns 19 and 2 connected to the terminals 21 to 24 are
0 is full bridge configuration, slit 16 or 17
The resistance value changes depending on the magnetic flux of the permanent magnet 12 that passes through.

Therefore, terminals 21 and 24 are output terminals, 22 is a ground terminal, and 23 is a voltage application terminal. When the axes LIs passing through the center of pattern 19 and 20 and dividing it into left and right overlap, the rotation axis 14
Assuming that the origin (0 point) of the rotational coordinate is the magnetic detection element 15
The output characteristics B and B2 of the terminal 21 are shown in Fig. 1 (d).
As shown by the solid line for characteristic B1 and the dotted line for characteristic B2, the curves become almost linear. However, near 0 degrees where magnetic detection patterns 19 and 20 are interrupted, the output characteristic BI+B! creates an immutable region.

FIG. 2 is a side view (A) showing the main structure of a magnetic potentiometer according to another embodiment of the present invention, a plan view (0) of its magnetic shielding plate, and a plan view of a magnetic detection pattern formed on its magnetic detection element. (C) and an output characteristic diagram (D).

In FIG. 2, in which the same reference numerals are used for parts common to those in FIG. A rotary shaft 14 that can rotate freely, and a magnetic detection element 4 that has a magnetic detection pattern formed on a non-magnetic insulating plate.
3, the permanent magnet 12 and the magnetic detection element 43 are fixed to, for example, a housing (not shown) without sandwiching the magnetic shielding disk 42 in its thickness direction and contacting it.

Fig. 2<4''), (0), magnetic shielding disk 4
2 is formed symmetrically with a pair of arcuate rings 44 and 45 having different radii and close to a circular shape, with the center of rotation of the rotating shaft 14 as the center. However, while the slit 44 has a width that continuously decreases in the direction of rotation of the clock hands, the slit 45 has a shape that continuously decreases in width in the counter-rotation direction of the clock hands.

In FIG. 2 ((), (c), the magnetic detection element 43
A comb-shaped magnetic detection pattern 47 facing a part of the slit 44 and a comb-shaped magnetic detection pattern 4B facing a part of the slit 45 are formed on an insulating disk 46.

One end of the magnetic detection pattern 47 formed in a substantially square area with one side wider than the maximum width of the slit 44 is connected to a terminal (through hole) 49, and the other end of the magnetic detection pattern 47 and one end of the magnetic detection pattern 48 are connected to the terminal. (through hole)
50, and the other end of the magnetic detection pattern 48, which is formed to have a width wider than the maximum width of the slit 45, is connected to a terminal (through hole) 51.

In the magnetic potentiometer 41 configured in this way, the magnetic detection patterns 47 and 48 are connected to a pair of resistors (not shown) via the terminals 49 to 51 to form a magnetic detection bridge circuit, which is shown by solid lines in FIG. 2(d). As shown, an output characteristic C similar to the output characteristic B is obtained.

Since the width dimension of the slits 44 and 45 changes in the direction of rotation of the rotating shaft 14, the characteristic C obtained by controlling the magnetic flux passing through the magnetic shielding disk 42 is 44.
By changing the width dimension change conditions of 45, for example, the second
Output characteristics as shown by the dotted line in Figure (d) are obtained.

In addition, in the above embodiment, the magnetic potentiometer is
The magnetic shield plate rotates. However, the present invention is not limited to such embodiments. For example, the magnetic shielding plate is fixed and the permanent magnet and the magnetic detection element rotate, or the permanent magnet, the magnetic shielding plate,
It should be noted that a linear potentiometer can be realized by using a configuration in which the magnetic detection element is rectangular and its magnetic shielding plate moves in a straight line.

〔Effect of the invention〕

As explained above, according to the present invention, when the magnetic shielding plate or the permanent magnet and the magnetic sensing element move, the magnetically permeable slit changes the amount of magnetic flux entering the magnetic sensing element from the permanent magnet depending on the amount of movement. Control is performed within a cycle, for example, when the movement is rotation, control is performed within a cycle of one rotation, so that an output characteristic that uniformly increases or decreases can be obtained.

Therefore, when the present invention is applied to a magnetic potentiometer for detecting rotational angles, linearity is ensured and the range of highly accurate measurement is expanded, and the phase differs by 180 degrees.14Measures conventionally required for determining rotational angles This has the effect of making it unnecessary.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the main structure and output characteristics of a magnetic potentiometer according to an embodiment of the present invention, FIG. 2 is a diagram showing the main structure and output characteristics of a magnetic potentiometer according to another embodiment of the invention, Figure 3 is a diagram showing the main configuration and output characteristics of a conventional magnetic potentiometer. In the figure: 1). 41 is a magnetic potentiometer, 12 is a permanent magnet, 13.42 is a magnetic shielding plate, 14 is a rotating shaft, 15.43 is a magnetic detection element, 16.17.44.45 is a magnetic transmission slit, 19.2
0.47.48 indicates a magnetic detection pattern. Rotating corner platform (d) According to the single stirrup row of the present invention. Tsuchisara Fukarasu 28° and ± Ka9 now 4th grade of magnetic waste tensicomerg Ho τ solid 1-machizu [? ] (B) (Nori rotation lit skin (D)

Claims (4)

[Claims] (1) A pair of magnetically permeable slits (16, 17, 44, 4
5) are formed symmetrically with magnetic shielding plates (13, 42) facing in the thickness direction of the magnetic shielding plates (13, 42) so as to sandwich at least a part of the slits (16, 17, 44, 45). a permanent magnet (12) and a magnetic detection element (15,
43), and the magnetic detection element (15, 43) is connected to the slit (16, 1
The magnetic shielding plate (13, 42) or the permanent magnet (12) is provided with a magnetic detection pattern (19, 20, 47, 48) formed with an appropriate width and length to face the magnetic shielding plate (13, 42) or the permanent magnet (12).
and the magnetic detection element (15, 43) are connected to the slit (16).
, 17, 44, 45) is configured to be movable in the length direction. (2) The permanent magnet (12) and the magnetic detection element (15)
, 43) are fixed, and the arc-shaped slits (16, 43) are fixed.
the magnetic shielding plate (13, 17, 44, 45) formed thereon;
42) The magnetic potentiometer according to claim 1, wherein the magnetic potentiometer is configured to be rotatable. (3) The pair of slits (16, 17) are semicircular arcs of predetermined width and different radii concentrically with the rotation center of the magnetic shielding plate (13), and the magnetic detection patterns (19, 20) 3. The magnetic potentiometer according to claim 2, wherein the slits (16, 17) are formed in a circular shape concentric with each of the slits (16, 17). (4) The pair of slits (44, 45) have a substantially circular shape that continuously decreases in width in opposite directions concentrically with the rotation center of the magnetic shielding plate (42), and the magnetic detection pattern (
3. The magnetic potentiometer according to claim 2, wherein the slits (47, 48) are formed to be wider than the maximum width of the slits (44, 45) and have an appropriate length.