JPH0451442Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Field of industrial use) The present invention relates to a multi-rotation type variable resistor.

(Prior Art) A conventional multi-rotation variable resistor will be described with reference to FIGS. 4 to 7 of the accompanying drawings. A worm gear 10 is formed on the rotatable shaft 8. The rotor 4 includes an arcuate portion 7 without teeth and an arcuate portion with a gear 6 forming a rotor gear, and a wiper 14 pressed by a pad 15 is housed in a groove 13 on the bottom of the rotor. Further, an arcuate resistor 16 is provided on the upper surface of a substrate 18 provided below the rotor 4, with which the wiper 14 can come into sliding contact. A slit groove 22 is formed in the main body of the rotor 4 so as to curve in the radial direction from the toothless portion 7 of the rotor toward the portion where the rotor gear 6 is provided. (Towards Figure 4)
A finger-like elastic member 24 is formed which is eccentrically curved, and the root portion of this finger-like elastic member 24 is formed integrally with the rotor 4 body.

A protrusion 26 is provided on the upper end surface of the finger-like elastic member 24. When a screwdriver or the like is applied to the upper end slit 12 of the shaft 8 and rotated in a predetermined direction, the worm gear 10 and the rotor gear 6 formed as a part of the rotor 4 are engaged with each other, and the rotor 4 is moved into the worm gear 10.
The rotor gear 6 rotates to the end of the meshing state with the rotor gear 6. In response to this rotation, one of the outer surfaces 26a and 26b of the protrusion 26 of the finger-like elastic member 24 opens into an arcuate groove 28 (see FIG. 5) on the inner surface of the housing 2 in the direction of the rotor 4. ), the finger-like elastic member 24 is deformed, and its repulsive force attempts to return the rotor gear 6 to its original state.
At the final end of engagement between the rotor gear 6 and the rotor gear 6, the rotor gear 6 is allowed to idle, thereby stopping the rotation of the rotor 4.

Due to the operation of the rotor 4 as described above, the wiper 14, which is assembled together with the pad 15 in the recess 13 of the rotor 4, is connected to the arc-shaped resistor 16 provided on the upper surface of the substrate 18.
Slide on the top surface. The contact resistance value change due to this sliding is taken out to the outside through a pin terminal 20 connected to the resistor 16 and electrode 17 provided on the substrate 18.

In the above configuration, the housing 2, the rotor 4
The shaft 8, the worm gear 10, etc. are preferably made of metal.

(Problems to be Solved by the Invention) In the conventional example, when the rotor 4 is housed in the housing 2, there is no possibility of smooth rotation of the rotor 4 between the housing 2 and the substrate 18 on which the resistor 16 is provided. In order to achieve this, a small gap is created. The above-mentioned gap is necessary for smooth rotation of the rotor 4. It goes without saying that a clearance is required between the rotor gear 6 formed in an arc shape on a part of the rotor 4 and the worm gear 10 of the shaft 8 so that the gears 6 and 10 can mesh with each other and the rotor 4 can rotate. When operating the shaft 8 and rotating the rotor 4 by meshing the worm gear 10 with the rotor gear 6 of the rotor 4,
Due to the gap existing between the housing 2 and the substrate 18, when the rotor 4 rotates in the radial direction, it moves in the direction of arrow C, and the gap between the worm gear 10 of the shaft 8 and the rotor gear 6 of the rotor 4 A slight gap D is generated between the two (Fig. 6). As a result, the worm gear 10 of the shaft and the rotor gear 6 are not completely engaged, resulting in a so-called backlash. , since the rotor 4 does not rotate in the correct meshing state, the wiper 14 of the rotor 4 cannot make the desired smooth sliding contact with the resistor 16 on the substrate 18.
A so-called hysteresis phenomenon was observed, and there were problems such as not being able to obtain a desired variable resistance change value.

(Means and operations for solving the problem) In view of the above problems, the present invention includes a worm gear 10 formed on a rotatable shaft 8, and a portion 7 having no teeth on a part of its outer periphery. and a rotor 4 formed with a rotor gear 6 having teeth that mesh with the worm gear 10, and a wiper 1 housed in the bottom of the rotor 4 and sliding on a resistor 16.
4, a slit groove 22 is formed in the rotor 4 in the radial direction from the toothless portion 7, and a finger-shaped elastic member is provided within the slit groove 22 so as to extend in the direction of the rotor gear 6. A protrusion 26 is formed on the upper surface of the member 24, and an arcuate groove 28 is formed on the inner surface of the housing 2, opening in the rotor 4 direction and allowing the protrusion 26 to move. According to rotation, rotor gear 6
When the rotor 4 rotates with the finger-like elastic member 24
One side 26a, 26b of the protrusion 26
comes into contact with one of the inner walls of the arcuate grooves 28 and deforms the finger-like elastic members 24, thereby creating a repulsive force that attempts to return the rotor gear 6 to its original state, causing the worm gear 10 and the rotor gear 6 to In a multi-rotation type variable resistor in which the rotor gear 6 idles to stop the rotation of the rotor 4 at the final end of meshing, the lower tooth base 5 of the rotor gear 6 formed on a part of the outer circumference of the rotor 4 has a protruding shape. A multi-rotation type variable resistor characterized in that a guide portion B is formed is disclosed.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings. Note that this embodiment employs the multi-rotation type variable resistor described in the conventional example, so the same reference numerals as in the attached drawings of the conventional example indicate the same members, and detailed explanations thereof will be omitted. Omitted.

FIG. 2 shows a protruding guide portion B (hereinafter simply FIG. 4 is a side view of a rotor 4 provided with a guide section. FIG. 3 is an enlarged perspective view of FIG. 2. As shown in FIG. 3, this guide portion B is optimally formed so that the center part of the rotor gear group arranged in an arc shape is thick and the thickness becomes thinner toward the outside from the center. This guide portion is provided to prevent problems in meshing, which are the problems of the conventional example described above. In Figures 1 and 4, shaft 8
When a screwdriver or the like is applied to the groove 12 and rotated in a predetermined direction, the rotor 4 which is interlocked with the shaft 8 via the worm gear 10 and the rotor gear 6
is prevented from moving in the direction of the arrow by the protruding guide portion B provided on the outer periphery of the root portion 5 of the rotor gear 6, and there is no problem in the meshing state between the worm gear 10 of the shaft 8 and the rotor gear 6. ,
The occurrence of so-called backlash is prevented. Therefore, the rotor 4 smoothly rotates via the worm gear 10 and the rotor gear 6 in response to the rotation of the shaft 8, and at the same time the wiper 14 housed within the rotor 4 rotates smoothly.
slides smoothly on the resistor 16 to obtain a desired variable resistance value.

Incidentally, since the clearance required for smooth rotation of the rotor 4 housed in the housing 2, that is, the clearance between the housing 2 and the resistor board 18, is maintained sufficiently, the space above the resistor 16 of the wiper 14 of the rotor 4 is maintained sufficiently. It does not have any adverse effect on the sliding action.

(Effects) In the present invention, by providing a protruding guide portion on the outer periphery of the tooth base of the rotor gear formed in an arc shape in a part of the rotor, the rotor gear of the rotor rotates in response to the rotation of the worm gear of the shaft. This has the effect of preventing incomplete meshing between the rotor gear and the worm gear, preventing the occurrence of so-called backlash, eliminating problems in meshing between the rotor gear and the worm gear, and helping to improve the performance of the multi-rotation type variable resistor.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a part of a multi-rotation type variable resistor according to the present invention. FIG. 2 is a side view of the rotor of the multi-rotation type variable resistor according to the present invention, in which a protruding guide portion is provided at the tooth base. FIG. 3 is a perspective view of FIG. 2. FIG. 4 is a plan view of a multi-rotation type variable resistor without a protruding guide provided at the tooth base. FIG. 5 is a central cross-sectional view of the variable resistor. FIG. 6 is a sectional view taken along line A-A in FIG. 4. 7th
The figure is a side view of the rotor shown in FIG. 4. B is a protruding guide portion, 2 is a housing, 4 is a rotor, 5 is a root portion, 6 is a rotor gear, 7 is a portion without teeth, 8 is a shaft, 10 is a worm gear, 14 is a wiper, and 16 is a resistor. , 18 is a substrate,
22 is a curved slit groove, 24 is a finger-like elastic member,
26 is a protrusion of the finger-like elastic member, 26a and 26b are side surfaces of the protrusion, and 28 is an arcuate groove of the housing.

Claims (1)

[Scope of utility model registration request] A worm gear formed on a rotatable shaft, a rotor formed with a rotor gear having a portion without teeth on a part of its outer periphery and a tooth portion that meshes with the worm gear, and a rotor housed in the bottom of the rotor and arranged on a resistor. A sliding wiper is provided, the rotor has a slit groove formed in the radial direction from a portion having no teeth, and a finger-like elastic member is provided in the slit groove so as to extend in the direction of the rotor gear. A protrusion is formed on the upper surface, and an arcuate groove is formed on the inner surface of the housing that opens toward the rotor and allows the protrusion to move. When the finger-like elastic member rotates, one side of any one of the protrusions of the finger-like elastic member comes into contact with one of the inner walls of the arcuate groove, deforming the finger-like elastic member, thereby causing the rotor gear to rotate. In multi-rotation type variable resistors, in which a repulsive force acts to restore the original state, and at the end of the engagement between the worm gear and the rotor gear, the rotor gear idles and stops the rotation of the rotor. A multi-rotation type variable resistor characterized in that a protruding guide portion is formed at the root of a lower end of a rotor gear.