JPH0744094B2 - Semi-fixed variable resistor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a semi-fixed variable resistor that is used by being assembled and fixed to a circuit board of an electronic device or the like.

(Prior Art) When adjusting a current or a voltage in an electronic device or the like, a semi-fixed variable resistor is generally used in a portion that does not require frequent adjustment.

FIG. 3 shows a resistor part of one component of such a semi-fixed variable resistor, and FIGS. 3 (a) and 3 (b) respectively show a resistor part T and a molded resistor formed by resin-molding it. It is a perspective view of the part M.

In FIG. 1 (a), reference numeral 1 is a horseshoe-shaped resistor having an opening 2 formed therein and electrodes 3a and 3b provided at both ends thereof, to which external terminals 4a and 4b are fixed and connected by eyelets e or the like. . As shown in FIG. 2B, the resistor portion T has a central opening 5, end face engaging portions 6a, 6b, a resistor surface 7 for ensuring a certain rotation angle, and the outer terminals 4a, 4b. Resin molding is performed as described above, and the mold resistor portion M
Is formed.

FIG. 4 shows a slider portion which is assembled so as to face the mold resistor portion M, and FIGS. 4 (a), (b) and (c) show
The slider C, the center terminal N, and the assembly CN are shown, respectively. First, the slider C in FIG. 1A is formed of a metallic material having elasticity, and has a non-round circular central opening 8 for stopping rotation with respect to the rotating shaft 9 described in detail in FIG. , The side edge portion is elastic and has the mold resistor portion M.
A protrusion 10 that contacts the resistor surface 7 and a protrusion 11 that protrudes in the opposite direction are formed.

Further, in the middle terminal N of FIG. 7B, reference numerals 12a and 12b are projections for sandwiching and engaging the end surface engaging portions 6a and 6b formed in the mold resistor portion M, and are formed on the side edges at right angles to the projecting direction. The cut-and-raised portion 13 is formed by reversing the projecting direction, and the take-out terminal portion 14 is formed on the opposite side edge as the middle terminal N projecting in the opposite direction. In addition, 15 is a central opening. The slider C and the center terminal N are overlapped as shown in FIG. 7C, and resin outsert molding is performed on the central openings 8 and 15 and rotated by the resin bodies 9a and 9b protruding on the upper and lower surfaces respectively. The shaft 9 is formed to form the assembly CN. The resin bodies 9a and 9b are formed in the same body, and are formed so as to be rotatable integrally with the slider C with respect to the middle terminal N.
Has a cylindrical body 9'a and an adjustment groove 16a at the tip thereof, and the other resin body 9b has a cross-shaped adjustment groove 16b, and a rotation stopper 17 that abuts against the cut-and-raised portion 13 of the middle terminal N. (See FIG. 5) are formed.

As described above, the slider C and the middle terminal N are outserted by the resin in a state of being pressed against each other to form the rotating shaft 9, and at that time, one protrusion 11 of the slider C is connected to the middle terminal N. It is elastic and in contact.

The assembly CN including the slider C and the middle terminal N configured as described above is combined with the molded resistor portion M to form a semi-fixed variable resistor.

FIG. 5 is an exploded perspective view before the combination, in which an assembly CN including a slider C and a middle terminal N rotatably attached thereto by a rotating shaft 9 has a resin body 9a fitted in a central opening 5. Meanwhile, the projecting portions 12a, 12b are fitted to the end surface engaging portions 6a, 6b provided on the side surfaces of the molded resistor portion M, and they are integrally formed by caulking or the like.

FIG. 6 is a sectional view of the semi-fixed variable resistor assembled as described above, FIG. 6 (a) is an overall sectional view, and FIG.

As described above, the conventional semi-fixed variable resistor is assembled, and at that time, the one protrusion 10 of the slider C elastically contacts the resistor surface 7 of the resistor 1 and, as a result, the electrical resistance is increased. The output is taken out to the outside by the outer terminals 4a and 4b which are arranged in a triangular shape and protrude, and the lead-out terminal portion 14 of the middle terminal N. To change the resistance value, the adjustment groove 16a at the tip of the rotary shaft 9 or 1
6b is rotated by an adjusting tool, eg a screwdriver.

The rotation of the rotary shaft 9 in the conventional semi-fixed variable resistor having such a configuration is performed by rotating the rotary shaft 9 outserted to the middle terminal N.
And the middle terminal N, and the slider C that is in close contact with the middle terminal N
It is regulated by the frictional force with.

(Problems to be Solved by the Invention) However, in the conventional semi-fixed variable resistor as described above, the frictional force is extremely lost due to the reduction of resin after molding, etc., and the rotation of the rotary shaft 9 is very light. In some cases,
As a result, there is a problem that vibration resistance and impact resistance such as displacement of the rotary shaft 9 are deteriorated, resulting in poor contact as a resistor.

The present invention is intended to solve the above conventional problems.

(Means for Solving Problems) The present invention has the above-mentioned object to form a protrusion on the surface of the rotating shaft which is in contact with the center terminal by resin-molding the middle terminal N having the recess and allowing the resin to flow into the recess. This is achieved by increasing the contact frictional force between the protrusion and the middle terminal.

(Operation) In addition to the frictional force generated by the conventional structure, the force that prevents the rotation of the rotary shaft is generated by the above means, and the resin portion of the protrusion formed on the rotary shaft by flowing into the concave portion of the middle terminal N and the middle terminal N The frictional force with the flat surface is added, and the rotation can be significantly restricted. .

(Embodiment) FIG. 1 shows an essential part of a semi-fixed variable resistor according to an embodiment of the present invention. FIG. 1 (a) is a side sectional view of a rotary shaft portion,
FIG. 7B is a top perspective view of the same.

In both of these figures, the reference numerals used in FIGS. 3 to 6 are applied correspondingly, where N is a middle terminal, C is a slider, and 9 is a rotary shaft formed by resin outsert molding. After forming the recess P in the center terminal N, the rotary shaft 9 is molded, and the resin is caused to flow into the recess P to rotate the rotary shaft 9
A protrusion Q is formed on the surface in contact with the middle terminal N.

FIG. 2 shows the rotary shaft 9 formed by the projection Q provided as described above.
FIG. 6 is a diagram for explaining the generation of the rotation restricting force related to the above, and when the protrusion Q is not formed, the rotation of the rotating shaft 9 is the same as that of the rotating shaft 9 outserted to the middle terminal N as described in FIG. It is restricted only by the friction between the middle terminal N and the slider C that is in close contact with the middle terminal N, but in the case of the semi-fixed variable resistor of the present invention, as shown in the cross section in FIG. In addition to the frictional force in the conventional semi-fixed variable resistor, the contact frictional force between the protrusion Q formed on the rotary shaft 9 and the middle terminal N is applied. That is, the rotation of the rotary shaft 9 of the semi-fixed variable resistor according to the present invention is reliably regulated as compared with the conventional example.

(Effects of the Invention) As is apparent from the above description, according to the present invention, the protrusion Q formed by outsert molding slides in contact with the center terminal N when the rotary shaft rotates, so that the rotation shaft is largely rotated. Since the regulation force is generated, the deterioration of seismic resistance and shock resistance due to the time-reduced phenomenon of resin as in the conventional example is improved. Therefore, the structure of the semi-fixed variable resistor as an electronic component that is recently miniaturized It will contribute to the improvement of reliability.

[Brief description of drawings]

FIG. 1 is a sectional view showing an essential part of an embodiment of the present invention, FIG. 2 is a sectional view for explaining the operation of the present invention, and FIGS. 3 to 6 are conventional semi-fixed variable resistors. FIG. 3 is a perspective view of the resistor part, FIG. 4 is a view showing the assembly of the slider and the middle terminal, and FIG. 5 is a main part shown in FIG. 3 and FIG. FIG. 6 is an exploded perspective view of the semi-fixed variable resistor to be assembled, and FIG. 6 is a sectional view of a main part of a conventional semi-fixed variable resistor. 1 ... Resistor, 2 ... Aperture, 3a, 3b ... Electrode, 4a, 4b ...
Outer terminals, 5 ... central opening, 6a, 6b ... end face engaging part, 7
...... Resistor surface, 8 ...... Central opening, 9 ...... Rotation axis, 9
a, 9b …… Resin body, 9′a …… Cylinder body, 10,11 …… Projection part, 12a, 12b …… Projection part, 13 …… Cut and up, 14 …… Extraction terminal part, 15 …… Center Openings, 16a, 16b …… Adjustment groove, 17
...... Rotation stop, T ...... resistor part, C ...... slider, N ......
Middle terminal, M: Molded resistor part, CN: Assembly.

Claims (1)

[Claims] 1. A mold resistor part, which is resin-molded with an outer terminal, and a slider, which is elastic and has protrusions formed on both sides thereof, and which is made of a metal material, are made of a metal material. The plate-shaped middle terminal is rotatably assembled by a rotatable shaft formed outsert using a resin body, and the protrusion formed on one surface of the slider is brought into contact with the middle terminal. The other protrusion is brought into contact with the resistor of the mold resistor to slide, and the protrusion formed on the side surface of the mold resistor and the protrusion provided on the middle terminal are fitted to each other so as to be integrally separated by caulking or the like. A semi-fixed variable resistor characterized in that a projection is provided at a portion formed and slidingly contacting with a center terminal of a rotating shaft.