JPH066483Y2 - Potentiometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a potentiometer, and more particularly to a potentiometer capable of changing a resistance value in a non-contact state and having excellent durability.

[Conventional technology and its problems]

As shown in FIG. 9, a conventional general potentiometer is a resistor 1 which is a conductor made by winding a metal resistance wire or the like.
2 and a slider 13 that slides while being in contact with the resistor 12.
And a lead a and a lead c on the resistor 12.
, And the lead b is connected to the slider 13.

Then, in order to change the resistance value between the lead a and the lead b, the slider 13 is slid while being in contact with the resistor 12, so that the position of the slider 13 on the resistor 12 is changed. Thus, the resistance value between the lead a and the lead b is changed.

However, in the conventional potentiometer configured as described above, since the slider 13 slides while being in contact with the resistor 12, the slider 13 and the resistor 12 do not contact each other.
Friction occurs between the slider 13 and the resistor 12
However, there is a problem in that the contact voltage may be worn out to cause contact failure, and when incorporated into an electric circuit or the like, this contact failure causes instability of the output voltage.

The present invention solves the problems of the conventional ones described above, and provides a potentiometer capable of improving durability by enabling the resistance value of a resistor to be changed in a non-contact manner. It is intended to be provided.

[Means for Solving the Problems]

In order to solve the above problems, the present invention provides a movable shaft inside a cylindrical case so as to be movable in the axial direction thereof, and an inner surface of the case from one end to the other end in the axial direction, A plurality of strip-shaped magnetoresistive element pieces having different lengths are provided at predetermined intervals in the order of length, and each is orthogonal to the axial direction, and further, one end or the other end of adjacent magnetoresistive element pieces is When it is made conductive to form one magnetoresistive element as a whole, a disk-shaped magnet is integrally provided on the movable shaft so that magnetic lines of force are formed in the axial direction, and when the magnet moves integrally with the movable shaft. , A means configured to change the resistance value of the magnetoresistive element according to the length of the magnetoresistive element piece surrounding the magnet at the moving position.

[Action]

According to the present invention, by adopting the above-mentioned means, a plurality of strip-shaped magnetoresistive element pieces having different lengths are provided on the inner surface of the cylindrical case at predetermined intervals in the order of length, and each of them has an axis line. One magnetoresistive element composed of a plurality of magnetoresistive element pieces is formed by connecting one end or the other end of adjacent magnetoresistive element pieces to each other while being provided orthogonal to the direction. Become. And
When a given displacement is applied to the movable shaft that is movable inside the case in the axial direction, the disk-shaped magnet is displaced integrally with the movable shaft, and the resistance of the magnetoresistive element changes according to the position of the magnet at that time. The value will change. That is, since the amount of the magnetoresistive element piece of the magnetoresistive element surrounding the magnet differs depending on the position of the magnet, a resistance value corresponding to the amount can be obtained.

〔Example〕

 Embodiments of the present invention shown in the drawings will be described below.

FIG. 1 shows a longitudinal sectional view of an embodiment of a potentiometer according to the present invention. The potentiometer has a cylindrical case 1 having open ends, and a case 1 having a cylindrical shape.
Of the lids 2 and 3 arranged at both ends of the lid 2 and closing the lids, bearings 4 and 5 arranged at the central portions of the lids 2 and 3, and moving in the axial direction through the bearings 4 and 5. A movable shaft 6 that is movably disposed, and a disk-shaped member that is fitted to the movable shaft 6 and that is movable in the axial direction integrally with the movable shaft 6 within a range of contacting the inner surfaces of the lids 2 and 3. It comprises a magnet 9 and a magnetoresistive element 8 arranged on the inner surface of the case 1.

The magnetoresistive element 8, as shown in a developed view in FIG.
On the inner surface 7 of the case, from one end to the other end in the axial direction, magnetoresistive element pieces 8a made of a material such as a plurality of strip-shaped ferromagnetic bodies having different lengths are arranged in the order of length (longer from one end to the other end. At a predetermined interval, and so as to be orthogonal to the axial direction,
One end or the other end of the adjacent magnetoresistive element pieces 8a, 8a are electrically connected to each other in the axial direction to form one magnetoresistive element 8 having a zigzag shape as a whole.

Magnetic lines of force are formed in the magnet 9 in the axial direction of the movable shaft 6 over the entire circumference thereof, and a magnetic field H is formed in a direction orthogonal to the current i flowing in each magnetoresistive element piece 8a. (See FIGS. 3 and 4).

That is, in general, a magnetoresistive element made of a ferromagnetic material is
When magnetized in a direction orthogonal to the current flowing therethrough, the resistance is reduced, so that the magnetoresistive element 8 is formed in a zigzag shape and the disk-shaped magnet 9 is formed as described above.
By using, it is possible to increase or decrease the magnetization area of the magnetoresistive element 8 according to the moving position of the magnet 9,
The change in the magnetized area can reduce or increase the resistance value of the magnetoresistive element 8, and the change in the resistance value can change the output voltage.

Next, the operation of the above will be described.

FIG. 5 shows an example of a connection diagram of the potentiometer according to this embodiment. A bias resistor 10 is attached to the potentiometer, and a current is supplied from the power supply 11 to the magnetoresistive element 8 in the case 1 to output voltage. V ₀ is output.

Then, in order to measure the output voltage V ₀ of the potentiometer according to this embodiment connected as described above, first, the movable shaft 6 is moved so that the magnet 9 contacts the inner surface of the one lid 2. Here, when the moving distance of the movable shaft 6 in the axial direction (the right direction in the drawing) is X and a current is supplied to the connection circuit, in the state where the movable shaft 6 does not move in the axial direction, the case inner surface 7 is There are few magnetic resistance element pieces 8a surrounding the magnet 9 arranged on the movable shaft 6 (there are few magnetic resistance element pieces 8a orthogonal to the magnetic field of the magnet 9), and the resistance value of the entire magnetic resistance element 8 changes. However, as shown in FIG. 6, the output voltage V ₀ is the output voltage V _{0 due} to the bias resistor 10.
Only ₁ .

Next, when the movable shaft 6 is displaced in the axial direction and the magnet 9 is moved integrally with the movable shaft 6, many magnetoresistive element pieces 8a surrounding the magnet 9 (magnetic resistance orthogonal to the magnetic field of the magnet 9 are generated). The number of element pieces 8a is increased), the resistance value of the magnetoresistive element 8 as a whole decreases, and the output voltage V ₀ increases.

Therefore, according to the moving position of the magnet 9, the magnetoresistive element 8
It is possible to change the resistance value of and to obtain the output voltage V ₀ according to the moving position of the magnet 9, and in this case,
Since the magnet 9 is in a non-contact state with the magnetic resistance element 8, there is no possibility that the magnet 9 or the magnetic resistance element 8 will be worn, and durability will be improved.

The change in the resistance value of the magnetoresistive element 8 can be made desired by setting the rate of increase of the length of the magnetoresistive element piece 8a with respect to the total length of the magnetoresistive element 8 to an appropriate value. It is one. That is, as shown in FIG. 7, if the increase rate is small, the change in resistance value with respect to the moving distance X is small, and as shown in FIG. 8, if the increase rate is large, the change in resistance value with respect to the moving distance X is large. Become.

Further, in this embodiment, the magnetoresistive element piece 8a constituting the magnetoresistive element 8 is made of a ferromagnetic material, but the invention is not limited to this, and a semiconductor may be used as a material. In this case, the resistance value of the magnetoresistive element 8 made of a semiconductor increases with the displacement of the magnet 9 to the right in the figure.

Further, in the above description, one magnetoresistive element 8 is configured by connecting a plurality of magnetoresistive element pieces 8a, but one magnetoresistive element piece 8a may be bent in a zigzag shape to form the magnetoresistive element 8. It is good that the magnetoresistive element 8 may be formed by punching in a zigzag shape from a flat plate, and the magnetoresistive element 8 having a width of 10 μm is formed on the inner surface 7 of the case. A minute movement distance X can be detected by combining a minute magnet 9 on the inner surface of which a ferromagnetic material is vapor-deposited using a mask pattern, or on the inner surface of a case which is laser-formed to form a pattern.

[Effect of device]

With this configuration, the present invention is configured as described above, so that the amount of the magnetoresistive element pieces of the magnetoresistive element that surrounds the circumference of the magnet depending on the moving position of the disk-shaped magnet ( Amount) can be changed. Therefore, it is possible to change the resistance value of the magnetoresistive element in a non-contact state according to the moving position of the magnet, thereby preventing abrasion of the magnet and each magnetoresistive element piece of the magnetoresistive element. Therefore, the durability can be remarkably improved. Further, since the magnet is moved in a non-contact state, the action force required when moving the magnet can be small, and the energy consumption can be greatly reduced. Further, a plurality of magnetoresistive element pieces having different lengths are arranged in the order of length and orthogonal to the axial direction, and one end or the other end of the adjoining magnetoresistive element pieces is electrically connected in the axial direction, and Since it is an integral magnetoresistive element, the rate of change of the resistance value of the magnetoresistive element is made desired by setting the rate of increase of the length of the magnetoresistive element piece with respect to the total length of the magnetoresistive element to an appropriate value. Therefore, it has an excellent effect such that versatility can be improved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the potentiometer according to the present invention, FIG. 2 is an explanatory view of the one shown in FIG. 1 developed so that the magnetoresistive element is not cut, and FIG. 3 is shown in FIG. Explanatory diagram showing the relationship between the magnetoresistive element piece and the magnetic field,
FIG. 4 is an explanatory view showing the direction of magnetic force lines of the magnet shown in FIG. 1, FIG. 5 is an explanatory view showing an example of connection of the magnet shown in FIG. 1, and FIG. 6 is a diagram showing the magnet of the magnet shown in FIG. Explanatory diagram showing the relationship between the movement amount and the output voltage, FIGS. 7 and 8 are explanatory diagrams showing the relationship between the total length of the magnetoresistive element and the increase rate of the length of the magnetoresistive element piece, and FIG. It is a circuit diagram of a potentiometer of. 1 ... Case 2, 3 ... Lid 4, 5 ... Bearing 6 ... Movable shaft 7 ... Case inner surface 8 ... Magnetoresistive element 8a ... Magnetoresistive element piece 9 ... Magnet 10 ... Bias resistor 11 ... … Power supply 12 …… Resistor 13 …… Slider a, b, c …… Lead V0, V1 …… Output voltage H …… Magnetic field i …… Current

Claims (1)

[Scope of utility model registration request] 1. A cylindrical case is provided with a movable shaft movably in the axial direction thereof, and a plurality of strips having different lengths are provided on an inner surface of the case from one end to the other end in the axial direction. The magnetoresistive element pieces are provided at predetermined intervals in the order of length and so as to be orthogonal to the axial direction, and one end or the other end of the adjoining magnetoresistive element pieces are electrically connected to each other. In addition to the magnetic resistance element, a disk-shaped magnet is integrally provided on the movable shaft so that magnetic lines of force are formed in the axial direction, and when the magnet moves integrally with the movable shaft, the magnet at the moving position A potentiometer characterized in that the resistance value of the magnetoresistive element is changed in accordance with the surrounding magnetoresistive element piece.