JPH0531530Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Purpose of the invention] (Field of industrial application) This invention relates to on-vehicle meters, and in particular, when assembling the dial, light guide plate, and internal unit, the purpose of this invention is to accurately position the three components. Concerning the structure for.

(Prior Art) As is well known, an on-vehicle meter having a transmissive illumination type display section and a self-luminous type pointer has an internal mechanism built into the case as a mechanical component, and the central axis of rotation is the internal mechanism. The pointer shaft is connected to a pointer disposed on the surface of the dial through a pointer shaft hole opened in the center of the light guide plate and the dial.

Therefore, when the inner unit, the light guide plate, and the dial are assembled, it is necessary to set the pointer shaft and the pointer shaft hole, which are the centers of the three, to coincide with each other with high precision.

In this regard, conventionally, as shown in FIGS. 4 to 6, a pair of bosses 1a for screw insertion are protruded from the periphery of the center of the light guide plate 1, and a through hole is formed in the center of the bosses 1a. Then, a screw B is screwed into this, and the screw B is screwed into a screw hole formed on the periphery of the center portion of the front surface of the inner unit 2 to fix it. Further, between the light guide plate 1 and the dial plate 3, a positioning convex portion 1 protruding from the light guide plate 1 is provided.
b and the positioning hole 3a opened in the dial plate 3, by welding the protruding end of the convex part 1b using ultrasonic waves or the like while the convex part 1b is fitted into the positioning hole 3a. Positioning both.

(Problems to be solved by the invention) However, with this positioning structure,
Since the positions of the attachment points for the three parts are different, the pointer shaft holes 1c and 3b opened at the center of the dial 3 and light guide plate 1 do not match the pointer shaft 2a of the inner unit 2 with high precision, and the pointer A state in which the boss portion 4a of the pointer 4 fitted to the shaft 2a cannot fit into the pointer hole 1c of the light guide plate 1, or a state in which the pointer shaft holes 1c and 3b are misaligned with each other is likely to occur.

In order to solve this problem, the diameter of each pointer shaft hole 1c, 3b should be made larger and the dimensional tolerance should be made larger, but in this case, the fitting part and the pointer shaft hole 1c The gap between the boss portions 4a becomes large, causing light leakage.

Since this light leakage causes halation on the dial surface, dimensional accuracy in the above-mentioned joints must be ensured, and the dimensional tolerance range must necessarily be made small.

This idea was devised in view of the above-mentioned problems, and its purpose was to provide a meter mechanism with a common mounting point for the three components to achieve highly accurate positioning and improve assembly workability. This provides a structure for positioning parts.

[Structure of the invention] (Means for solving the problem) In order to achieve the above object, this invention arranges a light guide plate on the back of the dial, and arranges an inner unit on the back of the light guide plate. A structure for positioning mechanical parts in a meter in which the three parts are fixed and integrated with a pointer shaft of an internal unit positioned in a pointer shaft hole formed in a dial and a light guide plate, wherein the pointer shaft hole of the light guide plate is At least a pair of screw rod insertion holes are formed, and a blind hole corresponding to the screw rod insertion holes is formed on the back surface of the dial plate, and the screw rod is screwed into the inner unit through the screw rod insertion holes and fixed therein. It is characterized in that the dial plate is positioned on the surface of the light guide plate by fitting the head of the screw rod protruding from the light plate into the blind hole.

(Function) In the above structure, positioning is completed by fitting the dial plate to the head of the screw rod protruding from the surface of the light guide plate after attaching the inner unit to the light guide plate. In other words, the three parts will be positioned at the same attachment point.

(Example) Hereinafter, an example of this invention will be described in detail using the drawings.

1 and 2, 10 is a case with an open front, 12 is a light guide plate arranged at the front opening of the case 10, 14 is an inner unit connected to the back of the light guide plate, and 16 is the light guide plate 12. It is a dial bonded to the surface.

These light guide plate 12, inner unit 14, and dial plate 16 are assembled together, and pointer shaft holes 12a and 16a are formed in the center of light guide plate 12 and dial plate 16, and protrude to the center of the front part of the inner unit 14. Pointer shaft 14
a is connected to the boss portion 18a of the pointer 18 protruding from the front surface of the dial 16, and the three parts are assembled into the case 10 in a state where they are integrally assembled.

Thereafter, the endpaper 20 and transparent cover 22 are attached to the front of the case 12 to complete the meter.

Both ends of the light guide plate 12 are curved toward the rear, and the curved ends are opposed to the illumination bulb 24 disposed inside the case 10 to guide light emitted from the light bulb 24 to the back side of the dial 16.

The dial plate 16 is made of a transparent or semi-transparent resin plate, and on the periphery of its surface is formed a display area such as scales and numbers made of a transparent or semi-transparent layer, and furthermore, the display area is removed to form an opaque layer. A paint layer is applied, and the light guided by the light guide plate 12 passes through the display section and illuminates the surface of the dial 16, causing the display section to transmit and emit light at night. .

In the above configuration, a pair of boss portions 26 for inserting a screw rod are protruded on the left and right sides of the center of the back surface of the light guide plate 12, and a screw rod 28 (in this embodiment, a screw 28) is inserted into the through hole 26a of the boss portion 26, and the screw rod 28 is inserted into the through hole 26a of the boss portion 26. The inner unit 14 is positioned and fixed on the back surface of the light guide plate 12 by screwing to the left and right of the center of the front part of the unit 14, thereby aligning the axis of the pointer shaft hole 12a of the light guide plate 12 and the pointer shaft 14a of the inner unit 14. matches with good accuracy.

The screw 28 has a threaded portion 28a and a
The head 28b is cylindrical and longer than a normal screw, with a cross-shaped driver groove formed on the upper portion for screwing.

Then, with the screw 28 installed, the head 2
8b protrudes from the surface of the light guide plate 12 and forms a positioning convex portion.

Opposed to this, a pair of blind holes 3 forming a positioning recess are provided on both sides of the center of the back surface of the dial.
0 is formed, and when the dial plate 16 is joined to the surface of the light guide plate 12 with the inner unit 14 assembled, the blind hole 30 is fitted into the head part 28b, so that the dial plate 16 becomes a light guide plate. 12.

In the positioning state, the centers of the pointer shaft holes 12a and 16a formed at the center of the light guide plate 12 and the dial plate coincide with each other with high precision, and the boss portion 18 of the pointer 18
a can be installed with high precision.

Note that after positioning, the dial 16 is attached to the light guide plate 1.
In order to fix it to the surface of 2, the convex portion and the hole may be fitted and welded as in the conventional method.

Next, a second embodiment of the present invention shown in FIG. 3 will be described.

In this embodiment, the screw rod 28 has a threaded portion 28a.
It consists of a bolt having a head 28b that is regular hexagonal in plan view, and a projection 28c is provided on the upper surface of the head 28b as shown.

Therefore, with the bolt 28 attached, the protrusion 28
As shown, c protrudes from the surface of the light guide plate 12 and constitutes a positioning protrusion similar to the first embodiment described above.

Note that other structures are the same as those of the first embodiment described above, so detailed explanations will be omitted here.

[Effects of the invention] As explained in detail using the embodiments above, in the structure for positioning mechanical parts in a meter according to this invention, the screw rods protruding from the surface of the light guide plate are fixed after the inner unit is attached to the light guide plate. Positioning is completed by fitting the dial to the head. In other words, the three parts will be positioned at the same attachment point.

Therefore, with this invention, positioning accuracy is improved and assembly workability is also improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the overall structure of an on-vehicle meter according to this invention, FIG. 2 is an enlarged sectional view of the main part of the first embodiment, and FIG. 3 is an enlarged sectional view of the main part of the second embodiment.
Fig. 4 is a front view showing a conventional mounting structure, Fig. 5 is a sectional view taken along the - line in Fig. 4, and Fig. 6 is a - line sectional view in Fig. 4.
FIG. 10... Case, 12... Light guide plate, 12a...
Pointer shaft hole, 14... Inner machine, 14a... Pointer shaft, 1
6... Dial plate, 18... Pointer, 18a... Boss part, 26... Boss part for screw rod insertion, 28... Screw rod (screw, bolt), 28b... Head, 30... Blind hole.

Claims (1)

[Claims for Utility Model Registration] A light guide plate is arranged on the back of the dial, an inner unit is arranged on the back of the light guide plate, and the pointer shaft of the inner unit is inserted into the pointer shaft hole formed in the dial and the light guide plate. A positioning structure for mechanical parts in a meter in which the three parts are fixed and integrated in a state where the light guide plate is positioned, and at least one pair of screw rod insertion holes for fixing the light guide plate are formed at the periphery of the pointer shaft hole of the light guide plate, and
A blind hole corresponding to the screw rod insertion hole is formed on the back surface of the dial plate, and the screw rod is screwed into the inner unit through the screw rod insertion hole and fixed, and the head of the screw rod protruding from the light guide plate is inserted into the blind hole. A structure for positioning mechanical parts in a meter, characterized in that a dial is positioned on the surface of a light guide plate by fitting into a hole.