JPH11273506A - Rotary switch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen the number of components and to lower costs, in the rotary switch device where plural rotary knobs are arranged in parallel. SOLUTION: The number of components is lessened by forming plural printed resistors 25, 26, 27 on a common circuit board 15. The plural printed resistors 25, 26, 27 are made of a same material, and printing widths of them are varied according to resistive characteristics, thereby the resistors 25, 26, 27 having different resistive characteristics are formed on the common circuit board 15 in one printing process, thus the printing costs are lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rotary switch device having a plurality of rotary knobs arranged in parallel.

[0002]

2. Description of the Related Art Generally, a rotary switch device of this type is provided with a shaft b of a rotary knob a as shown in FIG.
Circuit board e on which a movable contact d and a printed resistor that makes sliding contact with the movable contact d are formed on a switch case c rotatably mounted on the switch case c.
And a rotary unit a of each of the plurality of switch units is mounted in a knob mounting hole f formed in parallel with the switch body e, and a connection terminal g protruding from each switch case c is connected to the switch body e. The switch unit is fixed by soldering to a circuit board h also serving as a back cover of the switch unit.

[0003]

In the conventional rotary switch device, since a switch unit is formed by attaching a printed resistor having a required resistance characteristic to each of the plurality of rotary knobs a, the number of parts is reduced. More and more expensive. Further, since the resistors are printed on separate circuit boards using materials having different specific resistance values for each type of rotary knob, the printing cost increases. In view of the above, an object of the present invention is to provide a rotary switch device having a small number of parts and a low cost.

[0004]

According to a first aspect of the present invention, there is provided a rotary switch in which a rotary knob is rotatably mounted in a plurality of knob mounting holes formed in parallel with a switch body. Each of the printing resistors to which the movable contact that rotates in conjunction with the sliding contact is made of the same material, and is printed on a common circuit board with a printing width according to a required resistance characteristic.

[0005]

According to the first aspect of the present invention,
Since a plurality of printed resistors are formed on a common circuit board, the number of components is reduced and the cost can be reduced. Also,
Since the same material is used and the printing width is changed according to the resistance characteristics, resistors having different resistance characteristics can be formed on a common circuit board by one printing, and the printing cost can be reduced.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a rotary switch device 10 for a car air conditioner according to an embodiment of the present invention. The rotary switch device 10 includes a switch body 11, a rotary knob 12 for setting a mode of a car air conditioner, a rotary knob 13 for temperature adjustment, and a rotary knob 1 for air volume adjustment.
4 and a circuit board 15 also serving as a back cover. Knob mounting holes 16 are formed in parallel at three places on the upper surface of the switch body 11. A fitting ridge 17 protruding inside the switch body 11 is formed in a ring shape at the inner peripheral end of each knob mounting hole 16. Each rotary knob 12, 13, 1
A fitting groove 18 is formed in a ring shape at the lower end of the groove 4, and a concave portion 19 is formed in a ring shape on the lower surface of the fitting groove 18. A contact holder 20 is integrally suspended from a part of the lower surface of the fitting groove 18, and the movable contact 21 is held by the holder 20. A tubular body 22 is provided upright on the circuit board 15. A rib 23 is formed in a ring shape on the outer peripheral portion of the cylindrical body 22. Each rotary knob 12, 1
3 and 14 are fitted rotatably in the knob mounting hole 16 of the switch body 11 by fitting the fitting ridge 17 into the fitting groove 18 and supporting the recess 23 by the rib 23 of the cylindrical body 22. I have.

As shown in FIG. 2, carbon printed resistors 25, 26, 27 to which the movable contacts 21 of the rotary knobs 12, 13, 14 are in sliding contact with the circuit board 15, and a fixed pair formed with each carbon printed resistor. The contacts 28, 29, 30 are fixed. Each of the carbon print resistors 25, 26, 27 is formed in an arch shape by one printing using the same material. Then, in order to obtain resistance characteristics according to the types of the rotary knobs 12, 13, and 14, printing is performed while changing the printing width. The carbon printing resistor 25 with which the movable contact 21 of the mode setting rotary knob 12 slides contacts the starting point.
The area of 5 degrees is 2.06 mm in width, the area of 45 to 90 degrees is 2.33 mm in width, and the area of 90 to 135 degrees is 3.1 in width.
An area from 8 mm, 135 degrees to 180 degrees at the end point is printed with a width of 2.00 mm, and the terminal 31 is fixed to the boundary of each area. By changing the printing width in this way, a resistance characteristic as shown in FIG. 3 is obtained. The carbon print resistor 26 of the rotary knob 13 for temperature adjustment is 30
The area of degree is 2.00 mm in width, the area of 30 to 180 degrees is 2.9 mm in width, the area of 210 degrees from 180 to end is 2.00 mm in width, and the terminal 31 is fixed to the start point and end point. I have. Thus, the resistance characteristics shown in FIG. 4 are obtained. The carbon print resistor 27 of the air volume adjustment rotary knob 14 has a width of 2.00 mm and a width of 36 mm from the starting point.
The area from 72 degrees to 72 degrees and the area from 72 degrees to 108 degrees are printed with a width of 5.27 mm, the area from 108 degrees to 144 degrees and the area from 144 degrees to the end point of 180 degrees are printed with a width of 4.46 mm. The terminal 31 is fixed to the boundary. Thereby, the resistance characteristics shown in FIG. 5 are obtained.

The structure of the rotary switch device 10 according to the present embodiment is as described above, and the three printed resistors 2
Since 5, 26 and 27 are formed on the common circuit board 15,
The number of parts is reduced and the cost can be reduced. Also, since the rotary knobs 12, 13, and 14 are rotatably fitted to the knob mounting holes 16 by providing the fitting ridges 17 and the fitting grooves 18, the rotary knobs 12, 13, and 14 are fitted into the knob mounting holes 16. Eccentric mounting can be prevented. Also, by using the same material for the three printed resistors 25, 26, and 27 and changing the printing width according to the resistance characteristics, the resistors 25, 26, and 27 having different resistance characteristics in one printing process.
Since 27 is formed on the common circuit board 15, printing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a rotary switch device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a circuit board in the rotary switch device.

FIG. 3 is a graph showing resistance characteristics of a printed resistor of the rotary switch device.

FIG. 4 is a graph showing resistance characteristics of another printed resistor in the rotary switch device.

FIG. 5 is a graph showing resistance characteristics of still another printed resistor of the rotary switch device.

FIG. 6 is a sectional view showing a conventional rotary switch device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Rotary switch device, 11 ... Switch body, 12, 13, 14 ... Rotary knob, 15 ... Circuit board, 16 ... Knob mounting hole, 17 ... Fitting ridge, 18 ... Fitting groove, 21 ... Movable contact, 25 , 26, 27 ... Printed resistor.

Claims (1)

[Claims] 1. A rotary switch in which a rotary knob is rotatably mounted in a plurality of knob mounting holes formed in parallel with a switch body, wherein a movable contact that rotates in conjunction with each rotary knob slides. A rotary switch device wherein each of the bodies is formed by printing on a common circuit board using the same material and with a printing width according to required resistance characteristics.