JPH0632641Y2 - Positioning structure of potentiometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a structure for positioning and fixing a potentiometer in an instrument such as a tachograph, and is intended to make the instrument compact.

[Conventional technology]

A tachograph can be given as an example of the instrument using the potentiometer. FIG. 5 (a) is a front view showing a tachograph, and FIG. 5 (b) is a vertical sectional view.

That is, the collar portion (protruding portion) 13 of the case 12 of the potentiometer A ₁ is positioned and fixed to the mounting plate 11 in the tachograph B. The potentiometer A
₁ is driven by a motor 14 via an operational amplifier (not shown), and an output unit (pinion) 15 drives a pen 16 to record the vehicle speed on a chart paper 17 and a pointer 18
Is followed by displaying the speed on the meter 19.

FIG. 3 shows a conventional potentiometer positioning structure.

That is, the positioning is necessary for defining the sliding contact range between the annular resistance circuit 21 of the substrate 20 fixed in the case 12 and the contact 23 of the rotating body 22 axially attached to the case 12, To this end, perforations 2 are provided on both sides of the case 12.
A collar portion (projection portion) 25 having 4 is integrally formed, and a positioning pin 26 for the perforation 24 is projectingly provided on the mounting plate 11. The positioning pin 26 is provided with a female screw hole 27, and the hole 2 of the collar portion 25 of the potentiometer A ₁ is formed.
4 is fitted to the positioning pin 26, and is fastened with a screw 29 via a flat washer 28 to fasten the collar portion 25 to the mounting plate surface 11.

FIG. 3 shows another positioning structure for the potentiometer A ₂ , in which a positioning pin 32 is projected from the flange 31 of the case 30, and the positioning pin 3 is attached to the mounting plate 33.
The fitting hole 34 for 2 is penetrated. The positioning pin 32 is provided with a female screw hole 35. The positioning pin 32 is fitted into the fitting hole 34 and is fastened with a screw 37 via a flat washer 36, and the flange 31 is attached to the mounting plate surface 33. Fasten to.

However, in the above conventional example, the cases 12, 3
Since the collar portions 25, 31 of 0 project with respect to the mounting plates 11, 33, the collar portions 25, 31 are an obstacle, and at the same time, the collar portions 25, 31 are fastened to the mounting plate surfaces 11, 33. As it is worn, the potentiometers A ₁ and A ₂ are attached to the mounting plates 11 and 33.
The thickness was increased by the amount corresponding to the above, which was _one of the causes of enlargement of the measuring instruments (potentiometers A ₁ and A ₂ ).

[Problems to be solved by the device]

The present invention has been made in view of the above points, and an object of the present invention is to provide a potentiometer positioning structure that eliminates the protrusion of the flange (protrusion) associated with the positioning of the potentiometer and enables the instrument to be made compact.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention provides a substrate having an annular resistance circuit in a case, and rotatably supports a rotating body having a contactor for the resistance circuit on the case by an output shaft. , Positioning and fixing the potentiometer, which is formed by projecting a pair of flanges having projecting screw holes for screwing with respect to the mounting plate in the instrument at the end edge in the output shaft direction of the case, to the mounting plate. In the structure, the mounting plate is provided with an insertion hole for an end edge portion in the output shaft direction of the case, and a pair of fitting grooves for the pair of flanges are provided so as to communicate with the insertion hole. The sum of the head height of the fixing screw inserted into the screw hole with the portion embedded in the fitting groove and the height of the collar portion is the same or smaller than the depth of the fitting groove. It is characterized by

[Action]

If a flange portion is formed on the case of the potentiometer and the flange portion is fitted into the fitting groove of the mounting plate, the flange portion is positioned, and the flange portion does not project on the mounting plate and does not interfere.

Further, by forming a collar portion on the edge of the case and inserting the collar portion into the fitting groove while inserting the case into the hole of the mounting plate, the potentiometer is accommodated in the mounting plate by the fitting dimension, and It becomes possible to make it compact.

〔Example〕

FIG. 1 shows a potentiometer positioning structure according to the present invention.

That is, in the positioning structure, a pair of flange portions (protruding portions) 3 and 3 are integrally formed on the end edge portion 2 of the potentiometer A case 1 in the direction of the output shaft 38, and screw holes ( (Punching) 4 and 4 are provided, and the end portion 2 of the case 1 is attached to the mounting plate 5 (see 11 in FIG. 5) in the instrument (tachograph).
And the fitting grooves 7 and 7 for the flanges 3 and 3, and the bottom walls 8 and 8 of the fitting grooves 7 and 7,
The female screw holes 9 and 9 are formed.

Then, the flange portion 3 is fitted into the fitting groove 8 while inserting the end portion 2 of the case 1 into the insertion hole 6 of the mounting plate 5, and the screw 10 is inserted into the screw hole 4 of the flange portion 3 to attach the mounting plate. When the potentiometer A is screwed into the female screw hole 9 of 5, the potentiometer A is positioned by the flange portion 3, and the flange portion 3 is fastened to the bottom wall 8 of the fitting groove 7 so that the potentiometer A is firmly attached to the mounting plate 5. Fixed.

FIG. 2 is a longitudinal cross-sectional view of a main part showing a state in which the potentiometer A is positioned and fixed to the mounting plate 5.

Here, the head portion 10a of the screw 10 is located in the fitting groove 7 and does not project onto the mounting plate 5, so that a component (not shown) is mounted on the mounting plate 5 close to the case 1 of the potentiometer A. You can Further, the potentiometer A penetrates into the mounting plate 5 by the depth L of the fitting groove 7, and the instrument (tachograph) can be made compact by the dimension L. Further, since the screw hole 4 of the collar portion 3 needs to be formed to have a small diameter so as to fit the screw 10, the conventional flat washer is not necessary, and naturally the positioning pin is also unnecessary.

[Effect of device]

As described above, according to the present invention, positioning is performed by the flange portion of the potentiometer and the fitting groove of the mounting plate, and the collar portion does not need to be projected on the mounting plate. And other parts can be assembled on the mounting plate. Furthermore, since the potentiometer enters the mounting plate by the amount that the flange is fitted in the fitting groove,
Therefore, the instrument can be made compact.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of a main portion showing a positioning and fixing state thereof, FIG. 3 is a partially cutaway exploded perspective view showing a conventional example, and FIG. Is an exploded perspective view showing another conventional example, FIG. 5 is a tachograph, (a) is a front view, and (b) is a longitudinal sectional view. A ... Potentiometer, 1 ... Case, 2 ... Edge, 3 ... Collar (projection), 5 ... Mounting plate, 6 ... Insertion hole, 7 ... Fitting groove.

Claims (1)

[Scope of utility model registration request] 1. A substrate having an annular resistance circuit is provided in a case, and a rotating body having contacts for the resistance circuit is rotatably supported on the case by an output shaft, and an output shaft direction of the case is provided. In the positioning structure of the potentiometer in which a pair of flange portions having screw holes for screwing to the mounting plate inside the instrument are formed to project at the end edge of the An insertion hole is provided for an end edge portion of the case in the output shaft direction, and a pair of fitting grooves for the pair of flange portions are provided so as to communicate with the insertion hole, and the pair of flange portions are provided for the fitting groove. The potentiometer is characterized in that the sum of the head height of the fixing screw inserted into the screw hole in the embedded state and the height of the collar portion is the same or smaller than the depth of the fitting groove. Positioning structure.