JPH0665824U - Instrument dial fixed structure - Google Patents

Abstract

(57) [Summary] [Purpose] An object of the present invention is to provide a dial plate fixing structure for an instrument, which does not increase the cost and allows the pointer to shine over the entire rotation range of the pointer. [Structure] The dial 10 is made of a member having a thickness t, has a central hole 12 at the center, and a piece of claw 14 is provided from the end of the hole 12 toward the center. An end portion of the dial 10 is formed so as to project, and a small hole 16 is provided at the end portion. On the other hand, a cylindrical boss portion 23 having a hole 22 at the center is formed at the center of the light guide plate 20. The dial 1 is provided on the lower portion of the outer surface of the boss portion 23.
A notch 24 is provided for inserting the claw 14 of 0. Further, the end portion of the light guide plate 20 is formed to project slightly like the dial plate 10, and a part thereof is lifted to accommodate the thickness t of the dial plate 2 in the bag-shaped portion 2.
5, 25, and a protrusion 26 that engages with the small hole 16 at the end of the dial 10 is provided on one inner surface of the bag-shaped portion 25.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dial plate fixing structure for an instrument, in which the dial plate is illuminated by the light guided by the light guide plate, and thus the dial plate is superposed and fixed on the surface of the light guide plate.

[0002]

[Prior art]

 Conventionally, in order to illuminate the dial of a measuring instrument, a method of superimposing the dial on the surface of a light guide plate made of transparent resin such as acrylic and guiding the light from the light source to the dial by the light guide plate is used. Many are used. In such an illumination method, it is necessary to closely adhere the dial plate to the surface of the light guide plate, and there are methods as shown in FIGS. 5 to 7, for example. As shown in FIG. 5, two small holes 10a, 10a are provided in the peripheral portion of the dial plate 10 where the center hole (the hole through which the pointer axis passes) 12 is provided, and two dial holes are also provided at the end portion of the dial plate 10. Small holes 10b and 10b are provided. On the other hand, the light guide plate 20 for guiding light to the dial plate 10 is also provided with projections 20a, 20b fitted to these small holes 10a, 10b at positions facing the small holes 10a, 10b of the dial plate 10. deep. Then, the dial plate 10 is superposed on the light guide plate 20, the projections 20a, 20b of the light guide plate 20 are fitted into the small holes 10a, 10b of the dial plate 10, and the portions are heat-welded.

Further, as shown in FIG. 6, the dial 10 is fixed to the light guide plate 20 by sticking the dial 10 and the light guide plate 20 with a double-sided tape 30. In addition, the one shown in FIG. 7 uses a dial pressing member 40 as shown in an enlarged view, and the leg portions 40a of the dial pressing member 40 are connected to the central hole 12 of the dial 10 and the central hole 22 of the light guide plate 20. The dial plate 10 is fixed by the disc-shaped pressing plate 40c of the dial plate pressing member 40 by penetrating through and locking the claw 40b to the back surface of the light guide plate 20.

In the first example, a dedicated jig for heat welding is required, and the number of working steps is increased, and in the second and third examples, the double-sided tape 30, the dial plate pressing member 40, etc. However, in all cases, the cost was increased.

Therefore, the applicant of the present application discloses in Japanese Patent Application No. 62-14955 a boss 2b having a retaining projection 2c at the center of the light guide plate 2, as shown in FIGS. 8 (a) to 8 (c). The dial plate 3 is integrally formed with a fitting hole for the boss 2b in the central portion thereof, and a notch 3c is formed at the edge of the fitting hole for inserting the retaining projection 2c. A dial plate fixing structure has been proposed in which the dial plate 3 is superposed on the light guide plate 2 by aligning with the retaining projections 2c, and the dial plate 3 is fixed to the light guide plate 2 by being rotated by a predetermined angle. According to this dial plate fixing structure, a dedicated jig is not required for fixing the dial plate, and other members are not required, so that the cost can be reduced.

[0006]

[Problems to be solved by the device]

 However, even with this dial fixing structure, problems may occur depending on the instrument. The light guided by the light guide plate 2 from the light source is normally reflected on the end face of the central hole 1 of the light guide plate 2 at a right angle in addition to irradiating the dial plate 3 and arranged on the surface of the dial plate 3. This is because it also guides the pointer to make the pointer shine and be visible. In this case, it is preferable that the rotation range of the pointer is as narrow as about 90 °, but if the rotation range is 250 ° as in a speedometer or tachometer, three pointers as shown in FIG. Since there are three die-cutting holes 2d for providing the retaining protrusions 2c, the light does not enter the pointer from that portion, so that the pointer does not shine at a certain position. Even if the number of the retaining projections 2c is two, there will be a position where the pointer does not shine at one location.

An object of the present invention is to provide a dial plate fixing structure for an instrument, which can cause the pointer to shine over the entire rotation range of the pointer without increasing the cost.

[0008]

[Means for Solving the Problems]

 Since the present invention illuminates the dial by the light guided by the light guide plate, in the dial plate fixing structure of the instrument in which the dial plate is superposed and fixed on the surface of the light guide plate, the central part of the dial plate is centered. A cylindrical boss that has a central hole with one claw projecting toward it, a small hole or a recess at the end of the dial, and fits in the central hole of the dial at the center of the light guide plate. Part is integrally formed, and a notch for inserting the above-mentioned claw is provided on the outer surface of the boss part, and a bag-shaped part for accommodating the end part of the dial is provided at the end part of the light guide plate. At the same time, the inner surface of the bag-shaped portion is provided with a projection that engages with a small hole or a recess at the end of the dial.

[0009]

[Action]

 Since the dial plate is structured as described above, when the dial plate is superposed and fixed on the surface of the light guide plate, first, the central hole of the dial plate is fitted into the cylindrical boss portion of the light guide plate. At this time, the claw protruding into the central hole is engaged with the notch of the boss portion. Next, when the dial is rotated and the end of the dial is stored in the bag-shaped part of the light guide plate, the small hole at the end of the dial engages the protrusion provided on the inner surface of the bag-shaped part of the light guide plate. Then, the dial is securely fixed to the light guide plate.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. The same or corresponding parts as those described in the related art will be designated by the same reference numerals.

FIG. 1A shows a plan view of an embodiment of a dial 10 used in the dial fixing structure for an instrument according to the present invention. It is made of an elastic member having a thickness t, is substantially disk-shaped, and has a central hole 12 formed in the center thereof, and a piece of a claw 14 is projected from the end of the hole 12 toward the center. In addition, the end portion of the dial 10 is slightly formed so as to project, and a small hole 16 is provided in the end portion. The two rectangular holes provided near the center are windows for displaying an integrating meter and a trip meter, and although not shown, the surface of the dial 10 has a translucent character scale or the like. Is also provided.

FIG. 1B shows a plan view of an embodiment of the light guide plate 20 used for the dial plate fixing structure of the instrument according to the present invention. The light guide plate 20 is made of a transparent resin such as acrylic and has a substantially circular plate shape in plan view like the dial plate 10. As shown in the perspective view of FIG. 2A, a cylindrical boss portion 23 having a hole 22 at the center is formed in the central portion of the light guide plate 20, and the outer surface lower part of the boss portion 23 is formed. The notch 24 is provided in the. Further, the end portion of the light guide plate 20 is formed so as to slightly project like the dial plate 10, and the partially raised bag-shaped portions 25, 25 are formed. One inner surface of the bag-shaped portion 25 is formed. Is provided with a protrusion 26 that engages with a small hole 16 at the end of the dial 10. The structure of the bag-shaped portion 25 and the structure of the boss portion 23 are shown in detail in the sectional views of FIGS. 2B to 2D, and FIG. 2B shows the boss of the light guide plate 20 shown in FIG. 2C is a cross-sectional view taken along the line C--C of the vicinity of the portion 23, and FIG. 2C is a cross-sectional view taken along the line A--A of the bag-like portion 25 having the projection 26 on its inner surface. It is the same as the length t, and is just enough to allow the dial 10 to enter. 2 (d) is a cross-sectional view of the bag-shaped portion 25 having no protrusion 26 on its inner surface, taken along line BB. Reference numeral 28 is a window such as an integrator facing the rectangular hole 18 of the dial 10.

Next, a method of fixing the dial 10 to the light guide plate 20 will be described. First, the central hole 12 of the dial plate 10 is aligned with the cylindrical boss portion 23 of the light guide plate 20, the character plate 10 is bent, and the tip of the claw 14 is cut into the notch 24 of the boss portion 23 of the light guide plate 20. According to. Next, the claw 14 is fed into the notch 24, and the boss portion 23 of the light guide plate 20 is fitted into the central hole 12 of the dial plate 10 as shown in FIG.

Next, as shown in FIG. 4, the dial 10 is rotated and the end portion of the dial 10 is housed in the bag-shaped portion 25 of the light guide plate 20. Then, the projection 26 provided on the inner surface of the bag-like portion 25 engages with the small hole 16 provided at the end of the dial plate 10, and the dial plate 10 is securely fixed to the light guide plate 20. It should be noted that instead of the small hole 16 provided at the end of the dial plate 10, a concave portion in which the projection 26 of the light guide plate 20 is engaged may be provided.

As described above, the dial plate fixing structure of the instrument according to the present embodiment does not require a dedicated jig for heat welding, which is conventionally required, or any other member such as a double-sided tape or a dial plate pressing member. Therefore, the cost can be kept low. Further, since the one notch 14 formed on the dial 10 is engaged with the notch 24 of the light guide plate 20, even if the rotation angle of the pointer is widened to about 250 °, the pointer can be changed depending on the rotation position. It is possible to eliminate the inconvenience that some parts do not shine.

[0016]

[Effect of device]

 As described above, the instrument fixing structure according to the present invention can reduce the cost and eliminate the problem that the pointer does not shine depending on the rotating position even if the pointer rotating range is wide. .

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, (a) is a plan view of a dial, and (b) is a plan view of a light guide plate.

FIG. 2 is a partial cross-sectional view of a light guide plate.

FIG. 3 is a plan view when a dial is stacked on a light guide plate.

FIG. 4 is a plan view when the dial is rotated from the state of FIG. 3 and the dial is superposed on the light guide plate.

FIG. 5 is a conventional structure for fixing a dial by heat welding.

FIG. 6 is a conventional structure in which a dial is fixed with double-sided tape.

FIG. 7 is a conventional structure for fixing a dial by using a dial pressing member.

FIG. 8 is a conventional structure for fixing a dial plate proposed by the present applicant.

[Explanation of symbols]

 10 dial 12 central hole 14 claw 16 small hole 20 light guide plate 22 hole 23 boss portion 24 notch 25 bag-like portion 26 protrusion

Claims (1)

[Scope of utility model registration request] 1. A dial fixing structure for an instrument, wherein a dial is illuminated by the light guided by the light guide plate, so that the dial is superposed and fixed on the surface of the light guide plate. Is provided with a central hole having one claw protruding toward, and a small hole or a concave portion is provided at the end of the dial, and a cylindrical shape that fits in the central hole of the dial at the central part of the light guide plate. The boss is integrally formed,
Moreover, a notch for inserting the claw is provided on the outer surface of the boss portion, and a bag-shaped portion for accommodating the end portion of the dial is further provided at the end portion of the light guide plate, and an inner surface of the bag-shaped portion is provided. A dial fixing structure for an instrument, characterized in that a projection that engages with a small hole or a recess at the end of the dial is provided.