JP2005009996A - Magnetic potentiometer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a mounting structure capable of simultaneously positioning and fixing a magnet 5 to a shaft 1 of a magnetic potentiometer and improve assembling work efficiency. <P>SOLUTION: The magnetic potentiometer comprises holders 30 and 40 coupled and fixed to a shaft 1 and is constituted so as to grasp the magnet 5 at the mounting position of the shaft 1 with the holders 30 and 40. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic potentiometer, and more particularly to a structure for attaching a magnet to a shaft.
[0002]
[Prior art]
First, the structure of the magnetic potentiometer will be described with reference to FIG.
In this potentiometer, when the shaft 1 is rotated, an electrical output corresponding to the shaft 1 is obtained. The shaft 1 is rotatably supported inside the case 2 via bearings 3 and 4, and one end portion thereof protrudes from the case to serve as an operation portion 1a.
[0003]
A magnet 5 is attached to the shaft 1 inside the case 2, and a magnetic detection element 6 such as a magnetoresistive element or a Hall element is fixed to the side portion of the case 2 correspondingly. Further, an electric circuit board 7 is incorporated in the case 2, and the magnetic detection element 6 is electrically connected to the electric circuit board 7 via a flexible wiring board 8, and output from the electric circuit board 7. The code 9 is derived. Reference numeral 10 denotes a cap that covers the case 2 in a state where the above-described components are incorporated.
[0004]
And the potentiometer comprised in this way rotates the operation part 1a of the shaft 1, the magnet 5 rotates integrally with the shaft 1, the rotation of this magnet 5 is detected by the magnetic detection element 6, and the shaft An output signal corresponding to the rotation of 1 is output from the cord 9.
[0005]
[Problems to be solved by the invention]
In such a magnetic potentiometer, in order to obtain a highly accurate output, it is necessary to accurately position the magnet 5 and attach it to the shaft 1. Here, in the above example, the magnet 5 is fitted and bonded to the notch-shaped recess 11 provided in the shaft 1, but in this case, is the magnet positioned visually and fixed in the center? Alternatively, it was fixed using a special jig.
[0006]
FIG. 2 shows an example in which a guide holder 20 is used as means for easily positioning the magnet. In other words, the guide holder 20 is a cylindrical member having an opening 21 on the peripheral surface. The guide holder 20 is attached to the recess 1b from the axial direction of the shaft 1, and the magnet 5 is inserted from the opening 21 in this state. And it fits in the recessed part 1b of the shaft 1, and adhere | attaches with an adhesive agent.
[0007]
However, even when this guide holder is used, it is necessary to fix the magnets by some method until the magnets do not move completely when bonding the magnets.
The present invention has been made in view of such problems, and an object of the present invention is to realize a mounting structure capable of simultaneously positioning and fixing a magnet in a magnetic potentiometer.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a shaft that is rotatably supported on a case so as to be rotatable or movable, a magnet attached to the shaft, and a magnetic detection element fixed to the case corresponding to the magnet, In this magnetic potentiometer, a holder fitted and fixed to the shaft is provided, and a magnet is held by the holder at a predetermined mounting position.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 3A shows a first embodiment of the present invention, and FIG. 3B shows a second embodiment. Each of these embodiments shows the structure of the attachment portion of the magnet 5 in the magnetic potentiometer of FIG. 1, and here, plastic holders 30 and 40 fitted and fixed to the shaft 1 are provided. The magnet 5 is held by 40 and is positioned and fixed to the shaft 1.
[0010]
Each of the holders 30 and 40 is formed in a deformed cylindrical shape in which a part of its peripheral surface is cut out, and is fitted to the shaft 1 from the lateral direction (direction perpendicular to the axial direction of the shaft 1). To fix.
[0011]
In the first embodiment shown in FIG. 3A, first, the magnet 5 is fitted into the recess 11 of the shaft 1, and in this state, the holder 30 is fitted to the shaft 1 from the opposite side of the magnet 5 and assembled. In this case, the holder 30 is provided with a pair of holding arms 31, 32 having engaging claws 31 a, 32 a on the inner side of the tip, and when the holder 30 is fitted to the shaft 1, the holding arms 31, 32 are provided. When the engaging claws 31 a and 32 a are engaged with the magnet 5, the magnet 5 is fixedly held in the recess 11.
[0012]
3B, the magnet 5 is fitted into the concave portion 11 of the shaft 1, and the holder 40 is fitted to the shaft 1 so as to cover the magnet 5. As shown in FIG. In this case, the holder 40 is provided with a pair of holding arms 41 and 42. When the holder 40 is fitted to the shaft 1, the holding arms 41 and 42 come into contact with both sides of the magnet 5. The magnet 5 is fixed and held in the recess 11.
[0013]
As described above, in the above embodiment, the magnet 5 is held by the holders 30 and 40 fitted and fixed to the shaft 1, so that the magnet 5 can be positioned and fixed simultaneously. Therefore, it is possible to easily fix the magnet at an accurate position without requiring labor for mounting the magnet in the assembly process of the potentiometer.
[0014]
In the above embodiment, the case where the present invention is applied to the rotary operation type magnetic potentiometer as shown in FIG. 1 is shown. However, the present invention is not limited to this, and the linear movement operation type magnetic potentiometer is also used. Applicable.
[0015]
【The invention's effect】
As described above, the present invention includes a shaft that is pivotally supported by the case so as to be rotatable or movable, a magnet attached to the shaft, and a magnetic detection element fixed to the case corresponding to the magnet. In this magnetic potentiometer, a holder that is fitted and fixed to the shaft is provided, and the magnet is held by the holder at a predetermined mounting position, so that the magnet can be positioned and fixed simultaneously. In this assembly process, there is no need to install a magnet, and as a result, there is an effect that a potentiometer with good assembly workability can be realized.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a magnetic potentiometer to which the present invention is applied.
FIG. 2 is an explanatory diagram of a conventional example in which a guide holder is used for magnet positioning in a magnet mounting portion.
FIGS. 3A and 3B are exploded perspective views of a magnet mounting portion showing an embodiment of the present invention, in which FIG. 3A is a first embodiment and FIG. 3B is a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Shaft, 2 ... Case, 5 ... Magnet, 6 ... Magnetic detection element, 30, 40 ... Holder

Claims (1)

In a magnetic potentiometer comprising a shaft that is pivotally or movably supported by a case, a magnet attached to the shaft, and a magnetic detection element fixed to the case corresponding to the magnet,
A magnetic potentiometer characterized in that a holder fitted and fixed to the shaft is provided, and the magnet is held by the holder at a predetermined mounting position.

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