JPH0115133Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention relates to a small semi-fixed variable resistor.

(Prior Art) Recently, as the automatic mounting and automatic adjustment of circuit components of electronic devices has progressed, the required resistance value of semi-fixed variable resistors has also come to be automatically set. For this reason, the slider, which can be rotated on the resistance coating to adjust the resistance value, is protected from damage by external forces, and has a large operation part that is easy to adjust.
There is a need for a semi-fixed variable resistor in which the operating portion can engage and interlock with the slider. In this semi-fixed variable resistor, a slider is rotatably attached to an insulating substrate having a resistance coating, and the resistance value is adjusted by rotating and sliding the contacts of the slider in contact with the resistance coating. It has a structure that allows for adjustments. However, a drive hole is formed in the slider as an operation part for rotating it, and the driver is inserted into the drive hole of the slider, which is a live part and the main part that changes the resistance value, to operate it. Damage to the drive hole was the cause of the accident. Moreover, in response to the miniaturization of electronic devices, variable resistors have also become smaller, and the diameter of their sliders has become approximately several millimeters.As a result, the drive hole has become even smaller, making it even more difficult to change the resistance value. There was a problem in that the symbols such as resistance values and model names displayed on the sliders were also small, making it difficult to distinguish between them. As described in Japanese Utility Model Application Publication No. 57-161207, a variable resistor that solves these problems has an operating section molded from synthetic resin on top of the conventional slider as described above. A rotating body is provided,
When molding this rotating body, a part of the resin is projected downward from the through hole of the slider to engage the rotating body and the slider, and this protrusion is used to insulate between the resistance coating on the insulating substrate and the slider. A variable resistor is known in which a spacer is used, a rotating body is rotatably mounted on an insulating substrate, and a cross groove is formed on the rotating body.

In this variable resistor, the slider is slid by engaging a Phillips screwdriver in the cross groove of the rotating body and rotating the rotating body, so the screwdriver does not come into direct contact with the slider, and the cross groove is rotated. There is an advantage that the groove is also of sufficient size to facilitate operation.

(Problem to be solved by the invention) However, in the structure of the above-mentioned Japanese Utility Model Application Publication No. 57-161207, the insulating spacer protruding from the through hole of the slider comes into contact with the resistive coating formed on the insulating substrate. , when this insulating spacer rotates the rotating body,
Since it rotates together with the rotating body and frictionally slides on the resistance coating, there is a risk that the resistance coating may peel off and change the resistance value.

In addition, when a force is applied to the slider to prevent it from rotating beyond the effective rotation angle of the rotating body, the slider made of a thin metal plate becomes a blade at the through-hole position and cuts the insulating spacer protruding from the rotating body. There is also a possibility.

Furthermore, resin leaked from the through holes of the slider during molding of the rotating body adheres to the connecting portion of the rotating shaft that forms the current-carrying circuit at the base of the slider, causing poor contact. In addition, when molding the rotating body, a slider is inserted and molded, but the insulating spacer protrudes from the through hole of the slider, which complicates the structure of the mold and makes the molding operation complicated. There is.

In view of the above-mentioned problems, the purpose of the present invention is to prevent the resistance coating from peeling off due to the insulating spacer when the rotating body rotates, to ensure that the rotating body is connected to the slider, and to prevent sliding. To provide a variable resistor in which a rotary body having a child inserted therein can be easily molded.

[Structure of the idea]

(Means for Solving the Problems) The variable resistor of the present invention includes an insulating substrate, an intermediate terminal plate disposed on the lower surface of the insulating substrate, and an insulating spacer disposed on the upper surface of the insulating substrate. , a slider rotatably disposed on the upper surface of the insulating spacer, a rotary body to which the slider is coupled to the lower surface, and a conductive support shaft, the insulating substrate having an arcuate shape on the upper surface. A resistive coating is formed on the slider, and the slider is formed into a substantially disk shape, and a pair of cut and raised pieces are formed at the substantially center portion with heads wider than the base portions facing each other. A substantially rectangular punched hole is formed by the raised piece, and an arcuate elastic piece is formed by punching at the outer peripheral position of one of the cut and raised pieces, and the central part of this arcuate elastic piece is bent downward to form the above-mentioned A contact point that slides in contact with the resistance coating is formed, and the rotating body is molded from synthetic resin and passes through a rectangular first rotating groove in the center at the same position as the punched hole of the slider. At the same time, a second rotation groove is formed which intersects with the first rotation groove in a cross shape and has a depth from the upper surface to the middle of the thickness, and the sliding groove that comes into contact with the lower surface of the rotating body is formed. A pair of cut-and-raised pieces of the child are embedded and connected from the lower surface of the rotating body, and the support shaft has a flange portion formed at the lower end and an engagement piece cut and raised on the upper end surface, and the support shaft is The flange portion of this support shaft is slidably and rotatably engaged with the lower surface of the intermediate terminal board by loosely fitting the intermediate terminal board, the insulating substrate, and the insulating spacer from below into the substantially center portions of the support shaft. The engaging piece is inscribed in the upper surface of the insulating spacer so as to be electrically connected to the punched hole of the slider which is rotatably disposed, and is engaged with the upper surface of the slider. A contact point formed on the mover is brought into slidable contact with the resistance coating of the insulating substrate.

(Function) The variable resistor of the present invention is coupled to the rotating body by a pair of cutting pieces by engaging a Phillips screwdriver in the first and second rotation grooves of the rotating body and rotating the variable resistor. The slider rotates, and the contacts of the slider slide on the resistive coating, changing the resistance value. In addition, the head of the pair of cut-and-raised pieces that fix the slider to the rotating body is wider than the base, and because they are integrally insert-molded when the rotating body is molded, the connection is reliable and the slider slides easily. The torsional strength of the slider against dynamic operations is improved.

(Example) An example of the present invention will be described with reference to the accompanying drawings.

Reference numeral 1 denotes an insulating substrate having a substantially horseshoe shape in plan view, and a resistive film 2 made of a carbon film is formed on the upper surface thereof.

The resistive coating 2 has a substantially arcuate plane, and electrode coatings 3, 3 are connected to both ends to form a substantially horseshoe shape as a whole, and terminals 4, 4 are connected to the electrode coatings 3, 3. These terminals 4 are connected to the insulating substrate 1, respectively.
The head is placed on the lower surface of both ends and bent downward,
The tips of the tongues 5 on both sides of the head are crimped to the electrode film 3 so as to embrace the ends of the insulating substrate 1.

Further, a substantially disk-shaped slider 7 is arranged on the resistive film 2 with an insulating spacer 6 interposed therebetween. This slider 7 has a pair of cut and raised pieces 10, 10 cut and raised in a T-shape with the heads 9 facing each other so that a rectangular punched hole 8 is formed in the center. Double substantially semicircular arc-shaped punched holes 11 and 12 are formed concentrically at the outer circumferential position of the cut and raised piece 10, and the outer circumferential edge of the slider 7 formed by the punched holes 11 and 12 and A pair of arcuate elastic pieces 13 are located slightly inwardly,
14 is formed, and further this arcuate elastic piece 13,1
Contact points 15 and 16 are formed by bending the center portions of the resistive film 4 downward, respectively, and protruding the center portions by bending the center portions downward to contact the resistive coating 2 .

17 is a rotating body made of synthetic resin, and a rectangular rotation groove 18a is formed in the center at the same position as the punched hole 8 of the slider 7, and a groove 18a is formed halfway from the top surface so as to intersect with the groove 18a in a cross shape. A rotation groove 18b with a depth of are combined into one.

Reference numeral 19 denotes an intermediate terminal plate which is attached to the back surface of the insulating substrate 1 apart from the terminals 4, 4.
An intermediate terminal piece 20 is bent and protruded downward from a position opposite to 4.

Reference numeral 21 denotes a hollow cylindrical rotary support shaft made of metal with a closed upper surface and having conductivity.The lower end flange portion 22 is connected to the intermediate terminal plate 19.
9. Cut and raised engagement pieces 24, 24 that rotatably penetrate the insulating substrate 1 and the insulating spacer 6 and are cut and raised forward and backward from the center of the upper end surface 23 are inscribed in the punched holes 8 of the slider 7. The protruding and raised engagement pieces 24, 2
4 is bent outward to engage with the upper surface of the slider 7, and the support shaft 21 is coupled to the slider 7. The intermediate terminal piece 20, intermediate terminal plate 19, support shaft 21, and slider 7 are integrally connected to the electric droplet.

Next, the operation of the above embodiment will be explained.

When a Phillips head screwdriver is inserted into the rotation grooves 18a and 18b of the rotation body 17 and rotated, the slider 7 integrally connected to the rotation groove 18a and 18b by the cut-and-raised piece 10 rotates, and a pair of arc-shaped sliders 7 are rotated. Contact point 1 of elastic pieces 13 and 14
5 and 16 slide on the resistive coating 2, and this contact 1
5 and 16 slide on the resistive coating 2, and this contact 1
5 and 16, the intermediate terminal piece 20 connected via the support shaft 21, and the terminal 4 connected to the resistive coating 2, the resistance value is adjusted to a desired value.

Since the slider 7 is a small metal plate with a diameter of about several mm, a large number of sliders 7 are punched out in series in the longitudinal direction of the band-shaped metal plate 25, as shown in FIG. At the same time, a cut and raised piece 10, an arcuate elastic piece 13,
14, contacts 15 and 16 are also formed.

Next, the cut and raised pieces 10 are each inserted into a mold for molding the rotary body 17 with the plurality of sliders 7 arranged in series, and insert molding is performed. After molding, the slider 7 is cut at the boundary between the chain line and the solid line in FIG. 6 and separated into individual pieces.

[Effect of idea]

According to the present invention, the slider is engaged with the rotating body by the cut and raised piece embedded in the rotating body so as not to escape, and the slider is slid by the head wider than the base of the cut and raised piece. The slider does not move in the engaging portion even when the slider is slid. Further, the head portion, which is wider than the base portion of the cut and raised piece, can be formed by directly utilizing the punched holes in the slider. In addition, during manufacturing, when molding the synthetic resin rotating body, the cut and raised pieces of the slider can be easily embedded into the rotating body by insert molding, which allows the slider to be easily embedded in the rotating body. Compared to molding an insulating spacer by protruding resin from the through hole of the slider inserted during molding, there are no problems such as poor contact of the slider due to resin leakage, and the structure of the mold for molding is simpler. can do. In addition, since the insulating spacer is a separate member from the rotating body and is not engaged with the support shaft, it does not rotate as the rotating body rotates, so there is no chance of it rubbing against the resistance coating and damaging it. .

[Brief explanation of the drawing]

Fig. 1 is a plan view of a variable resistor showing an embodiment of the present invention, Fig. 2 is a longitudinal sectional side view of the same, Fig. 3 is a bottom view of the same, and Fig. 4 is a bottom view of a rotating body with a slider attached. 5 is an exploded longitudinal sectional view of the slider and rotating body, FIG. 6 is a plan view of the slider, and FIG. 7 is a front view of the same. DESCRIPTION OF SYMBOLS 1...Insulating substrate, 2...Resistive coating, 6...Insulating spacer, 7...Slider, 8...Punching hole, 9...
Head, 10... cut and raised piece, 13, 14... arcuate elastic piece, 15, 16... contact, 17... rotating body, 18
a, 18b... Rotation groove, 19... Intermediate terminal plate, 21... Support shaft, 24... Cut and raised engagement piece.

Claims (1)

[Scope of Claim for Utility Model Registration] An insulating substrate, an intermediate terminal plate disposed on the lower surface of the insulating substrate, an insulating spacer disposed on the upper surface of the insulating substrate, and a rotatable spacer disposed on the upper surface of the insulating spacer. The slider includes a slider disposed, a rotating body with the slider coupled to the lower surface, and a conductive support shaft, the insulating substrate has a resistive coating formed in an arc shape on the upper surface, and the sliding The child is formed approximately in the shape of a disk, and has a pair of cut and raised pieces with a head wider than the base facing each other in the center, and a roughly rectangular shaped piece is formed by the cut and raised pieces. A contact having a punching hole and forming an arcuate elastic piece by punching on the outer periphery of one of the cut and raised pieces, the central part of the arcuate elastic piece being bent downward and sliding in contact with the resistance coating. The rotating body is molded from synthetic resin, and has a rectangular first rotation groove formed through the center at the same position as the punched hole of the slider, and the first rotation groove a second rotation groove having a depth from the top surface to the middle of the thickness is formed by intersecting the two grooves in a cross shape; The support shaft is embedded and connected from the lower surface of the body, and the support shaft has a flange portion formed at the lower end and an engaging piece cut and raised on the upper end surface. The flange portion of this support shaft is loosely fitted from below approximately at the center and is slidably and rotatably engaged with the lower surface of the intermediate terminal plate, and the engaging piece of this support shaft is cut and raised to the upper surface of this insulating spacer. The slider is rotatably disposed in a punched hole in the slider so as to be electrically connected to the upper surface of the slider, and the contacts formed on the slider are connected to the insulating substrate. A variable resistor characterized in that it is in slidable contact with a resistive coating.