JPH0621207Y2 - Chip type variable resistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement of a chip type variable resistor capable of arbitrarily adjusting a resistance value.

[Conventional technology]

Conventionally, this type of chip-type variable resistor is disclosed in, for example, Japanese Utility Model Application Laid-Open No. 58-44805, in which a metal plate is formed on the upper surface of an insulating substrate having an arc-shaped resistance film formed on the upper surface. A rotor member formed in a bowl shape and having a flange portion formed around the bowl portion is rotatably attached to a bottom plate of the bowl portion of the rotor member, and the flange portion of the rotor member has a circular shape. An arcuate cutout groove is formed over a substantially semicircle, and an outer portion of the cutout groove is formed on a sliding terminal piece that comes into contact with a resistive film on the upper surface of the substrate, while a left and right pair is formed on a flange portion of the rotor member. Is formed, and a driver tool for turning the rotor member is fitted into the pair of left and right groove holes.

[Problems to be solved by the device]

However, the rotor member in this conventional chip type variable resistor is provided with an arcuate cutout groove for forming the sliding terminal piece and a pair of left and right groove holes for the driver tool. When automatically mounting the mold variable resistor on a printed circuit board in electric equipment, when it is sucked by a vacuum suction collet, the arc-shaped cutout groove and the large opening of the bowl-shaped rotor member and the left and right Since a large amount of air is sucked from the pair of groove holes, the suction by the vacuum suction collet is uncertain and the suction error frequently occurs. In addition, the flat surface area of the upper surface of the rotor member is small, When sucked by the vacuum suction collet, the suction position of the vacuum suction collet shifts laterally or tilts, causing the chip variable resistor to A predetermined mounting position in the cement substrate, it can not be supplied properly in the correct attitude was to frequently.

Moreover, the sliding terminal piece in this conventional chip-type variable resistor has a length that only encloses a substantially half circumference of the rotor member, and the spring elasticity of the sliding terminal piece is low. When adjusting the value, when inserting the driver tool into the slot in the rotor member and turning the rotor member, the contact pressure of the sliding terminal piece against the resistance film becomes strong, and when the driver tool is removed, the sliding terminal against the resistance film As the contact pressure of the piece becomes weaker, the contact pressure of the sliding terminal piece against the resistance film greatly changes due to the pressing / releasing of the driver tool, so the resistance value adjustment is inaccurate, and the sliding Due to the low spring elasticity of the terminal piece, the sliding resistance against the resistance film was large.

An object of the present invention is to provide a chip-type variable resistor that solves these problems at once without causing an increase in size.

[Means for Solving the Problems]

In order to achieve this object, the present invention provides a rotor member in which a metal plate is formed in a substantially bowl shape on the upper surface of a substrate on which an arc-shaped resistance film is formed, and a flange portion is formed around the bowl portion. A chip type variable resistor rotatably and pivotally mounted on a bottom plate of a bowl-shaped portion of the rotor member, which is formed by bending the outer peripheral edge of a flange portion of the rotor member toward the upper surface of the rotor member in a folded shape. The surface plate is integrally connected, and on this surface plate, an engaging hole for a driver tool is formed, while a part of the outer peripheral edge of the surface plate on the side opposite to the connecting part for the rotor member,
A ring body formed by bending the rotor member in a folded shape toward the lower surface side of the flange portion is integrally connected,
The ring body is configured so that its inner diameter is larger than the outer diameter of the bowl-shaped portion of the rotor member, and the ring body is fitted into the bowl-shaped portion of the rotor member. The sliding terminal piece that comes into contact with the arcuate resistance film on the substrate is formed at a portion on the side opposite to the connection point with respect to the surface plate.

[Function and effect of device]

In this manner, the outer peripheral edge of the flange portion of the rotor member is integrally connected to the surface plate formed by folding back toward the upper surface of the rotor member, and the surface plate is engaged with the engaging hole for the driver tool. The large opening in the bowl-shaped rotor member can be covered with the surface plate, in other words, the area of the flat surface can be increased by the surface plate, and a vacuum can be applied during automatic mounting. When adsorbing with a suction type collet, it can be adsorbed on a wide flat surface, so it is possible to reliably reduce lateral displacement and tilting, and to restrict the intake of air to a small amount. By doing so, it is possible to surely reduce the occurrence of suction error.

In addition, according to the present invention, a ring body is integrally connected to the outer peripheral edge of the surface plate, and a circular arc shape of the substrate is formed on a portion of the ring body opposite to the connection part with the surface plate. By forming the sliding terminal piece that comes into contact with the resistance film, the length from the sliding terminal piece of this ring body to the connection point with the surface plate becomes longer, and the spring elasticity of the sliding terminal piece of the ring body is increased. However, since it is dramatically improved as compared with the conventional case, it is possible to reduce the fluctuation of the contact pressure of the sliding terminal piece against the resistance film due to the pressing / releasing of the driver tool to / from the rotor member, and the resistance value can be adjusted. The precision can be achieved, and the sliding resistance of the sliding terminal piece with respect to the resistance film can be significantly reduced.

Moreover, the inner diameter of the ring body with sliding terminal pieces is made larger than the outer shape of the bowl-shaped portion of the rotor member, and the ring body is covered on the lower surface side of the flange portion of the rotor member and on the bowl-shaped portion of the rotor member. Since it is configured to fit, the space between the upper surface of the substrate and the lower surface of the flange portion of the rotor member can be used for disposing the ring body with a sliding terminal piece. By providing the ring body, it is possible to avoid an increase in the height dimension from the upper surface of the substrate to the upper surface of the surface plate, and thus to prevent the chip variable resistor from becoming large.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 indicates a substrate made of an insulating material such as ceramics and having a through hole 2 substantially at the center thereof.
The resistance film 3 is formed in an arc shape with the through hole 2 as a center, and on one side surface of the substrate 1, terminal electrode films 4 and 5 for both ends of the resistance film 3 are formed.

Reference numeral 6 indicates a central terminal plate made of a metal plate disposed on the lower surface of the substrate 1, and the central terminal plate 6 is integrally formed with a hollow shaft 7 fitted in the through hole 2. .

Reference numeral 8 denotes a bowl-shaped portion made of a metal plate, and the bowl-shaped portion 8
A rotor member formed by integrally forming a flange portion 8b around a is shown, and a pair of left and right grooves 8c for inserting and engaging a driver tool (not shown) into the flange portion 8b.
Further, the rotor member 8 is fitted on the distal end of the hollow shaft 7 on the bottom plate of the bowl-shaped portion 8a of the rotor member 8 and then the distal end of the hollow shaft 7 is caulked and widened. By attaching the swaging portion (denoted by reference numeral 16), it is rotatably attached to the hollow shaft 7.

The groove 8c is formed by engraving two cutting lines in parallel and denting and deforming a portion between the cutting lines. A film 9 made of heat-resistant synthetic resin is attached to the lower surface of the center terminal plate 6 so as to close the inside of the hollow shaft 7.

A surface plate 10 is integrally connected to the outer peripheral edge of the flange portion 8b of the rotor member 8 via a connecting portion 11 having a bending line 11a.
The upper surface of the rotor member 8 is folded back along the bending line 11a at the connecting portion 11 with respect to the flange portion 8b so as to be folded back, and the surface plate 10 is provided with an engaging hole 10a for a driver tool. .

Further, a ring body 12 is integrally connected to a portion of the outer peripheral edge of the surface plate 10 opposite to the connecting portion 11 with respect to the flange portion 8b via a connecting portion 13 having a bending line 13a. The ring body 12 has an inner diameter larger than the outer diameter of the bowl-shaped portion 8a of the rotor member 8 and is provided on the lower surface side of the flange portion 8b along the bending line 13a of the connecting portion 13 to the surface plate 10. The ring body 12 faces toward the bowl-shaped portion 8 of the rotor member 8.
By bending it in a folded shape so as to fit into a, and engraving a concentric arcuate cutting line 14 on a portion of the ring body 12 opposite to the connecting portion 13 with respect to the surface plate 10, The sliding terminal piece 15 that contacts the resistance film 3 is formed.

In this way, the surface plate 10 formed by folding back the upper surface of the rotor member 8 is integrally connected to the outer peripheral edge of the flange portion 8b of the rotor member 8, and the surface plate 10 is attached to the driver tool. With the configuration in which the engagement hole 10a is formed, the large opening portion of the bowl-shaped rotor member 8 can be covered with the surface 10, so that the surface plate 10 can increase the area of the flat surface. In addition to this, the ring body 12 is integrally connected to the outer peripheral edge of the surface plate 10,
Is folded back toward the lower surface of the flange portion 8b of the rotor member 8 and the sliding terminal piece 15 is formed on the ring body 12, so that the rotor member 8 and the surface plate 10 can be formed as in the conventional case. In addition, it is possible to omit the formation of the cutout groove for forming the sliding terminal piece.

Further, by forming the sliding terminal piece 15 in contact with the resistance film 3 in a portion of the ring body 12 apart from the connecting portion 13 of the ring body 12 with respect to the surface plate 10, the sliding terminal piece 15 is formed. The length from 15 to the connecting portion 13 with respect to the surface plate 10 becomes long, and the spring elasticity of the sliding terminal piece 15 is dramatically improved.

When the ring body 12 is bent toward the lower surface of the flange portion 8b, the flange portion 8b of the rotor member 8 is sandwiched by the connecting portion 13 between the ring body 12 and the surface plate. Face plate 10
Can be firmly connected to the flange portion 8b,
By this amount, the connecting portion 11 between the surface plate 10 and the flange portion 8b
Since the width dimension (W) can be narrowed, the bending process for the flange portion 8b of the surface plate 10 can be easily performed.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a vertical sectional front view of a chip type variable resistor, FIG. 2 is a plan view, and FIG. 3 is that of FIG.
A side view seen from III-III and FIG. 4 are developed views of the rotor member. 1 ... Substrate, 2 ... Through hole, 3 ... Resistive film, 4, 5 ...
Terminal electrode film, 6 ... Central terminal plate, 7 ... Hollow shaft, 8 ...
Rotor member, 8a ... bowl-shaped part, 8b ... flange part, 1
0 ... Surface plate, 11 ... Connecting part, 12 ... Ring body, 1
3 ... connecting part, 15 ... sliding terminal piece.

Claims (1)

[Scope of utility model registration request] 1. An upper surface of a substrate on which an arc-shaped resistance film is formed,
A chip-type variable resistor in which a rotor member formed of a metal plate in a substantially bowl shape and having a flange portion formed around the bowl portion is rotatably attached to a bottom plate of the bowl portion of the rotor member. In the container, a surface plate formed by folding back the upper surface of the rotor member is integrally connected to the outer peripheral edge of the flange portion of the rotor member, and the surface plate is provided with an engaging hole for a driver tool. While setting up,
A ring body formed by bending the outer peripheral edge of the surface plate on the side opposite to the connecting portion to the rotor member in a folded shape toward the lower surface side of the flange portion of the rotor member is integrally connected, The ring body is configured such that the inner diameter thereof is larger than the outer diameter of the bowl-shaped portion of the rotor member and the ring body is fitted into the bowl-shaped portion of the rotor member, and the ring body A chip type variable resistor characterized in that a sliding terminal piece that contacts an arc-shaped resistance film on the substrate is formed at a portion opposite to a connection portion with respect to the surface plate.