JP3109432B2 - Electronic musical instrument board holding structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a board holding structure for holding a board on which a key switch, electronic components and the like are mounted in a predetermined position in an electronic musical instrument such as an electronic organ and an electronic piano.

[0002]

2. Description of the Related Art For example, in an electronic keyboard instrument, a key switch operated by an actuator of each key and an on / off switch thereof are provided at predetermined positions above or below a keyboard frame.
Electronic components, such as a diode and a resistor, for detecting an OFF state and performing output processing are mounted, and a substrate (printed wiring substrate) on which the wiring pattern is formed is fixed and held.

In order to fix such a substrate to a supporting member such as a keyboard frame, the following substrate holding structure has conventionally been adopted. 11 and 12 show the substrate 1
Are fixed to a large number of bosses 2 a formed on the support member 2 with screws 3.

In FIGS. 13 and 14, the substrate 1 is fixed to a supporting member 2 at a portion close to one side edge 1a to a boss portion arranged in the supporting member 2 with a screw 3, and the other side. Are arranged side by side on the support member 2 and engaged with the hooks 4 (FIG. 14 (a)) or the snap pins 5 (FIG. 14 (b)) to be fixed. In some cases, both sides 1a and 1b of the substrate 1 are engaged with the hooks 4 or the snap pins 5 and fixed without using any screws.

[0005]

However, fixing the entire board 1 with the screws 3 as in the former case not only increases the number of screws to be used but also increases the cost, but also increases the man-hour for the screw tightening. And the workability is poor. When using the latter hook 4, FIG.
As shown in FIG. 4A, unless the dimension t of the hook 4 sandwiching the substrate 1 is larger than the thickness tk of the substrate 1, the substrate 1 cannot be fitted. Therefore, there is a problem that a slight gap is generated between the substrate 1 and the hook 4, and the substrate 4 dances and mechanical noise is generated due to vibration at the time of key depression or acoustic vibration due to generation of musical sound.

Further, when the snap pin 5 shown in FIG. 14B is used, the substrate 1
Can be held without any gap between the engaging surface and the engaging surface. However, due to the limitation of the mold, the place where the snap pin is provided is limited, and the substrate 1 is deformed in one direction. Distortion occurs in the substrate, and this distortion lowers the response accuracy of a touch response switch or the like of the contact time difference detection method, or changes the touch sensitivity due to plastic deformation due to aging.

SUMMARY OF THE INVENTION The present invention relates to the problems of cost and mounting workability in the above-described conventional board holding structure of an electronic musical instrument.
To solve the problem of mechanical noise caused by board dance, the problem of touch accuracy, etc., to be inexpensive, to have good mounting workability, to be able to fix and hold the board without mechanical noise, and with little influence of aging. With the goal.

[0008]

In order to achieve the above object, a substrate holding structure for an electronic musical instrument according to the present invention, in an electronic musical instrument, includes a substrate on which a key switch, an electronic component, and the like are mounted, which is provided on one side edge of the substrate. The upper holding portion that abuts and holds the surface of the substrate and the lower holding portion that abuts and holds the other surface are alternately displaced in the direction along the side edge of the substrate, and in the thickness direction of the substrate. It is arranged with a space smaller than the thickness.

On the other hand, a slit-shaped notch is provided at a side edge of the substrate at a position corresponding to a gap or an overlap between the upper holding portion and the lower holding portion in a direction along the side edge of the substrate. The substrate is alternately bent slightly in a direction opposite to the thickness direction in a portion between the notches of the side edge portions, and is held between the upper holding portion and the lower holding portion. .

[0010]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line CC. FIG. 3 to FIG. 5 are partially enlarged views for explanation. Reference numeral 10 denotes a board (printed wiring board) provided on a keyboard device or the like of an electronic musical instrument, similar to the above-described board 1, on which key switches, electronic components, and the like are mounted, but these are not shown.

Reference numeral 20 denotes a substrate holding member, as shown in FIG. 2, for example, a resin supporting member 2 serving as a keyboard frame.
Are formed integrally with the boss 2a.
The substrate 10 is attached to the side edge portion 10 of the substrate holding member 20.
3A, an upper holding portion 21 that abuts and holds one surface (upper surface) 11 as shown in an enlarged view in FIG. 3, and an abutment with the other surface (also lower surface) 12 as shown in an enlarged view in FIG. The lower holding portions 22 are provided alternately at different positions in the direction along the side edge of the substrate 10 (the left-right direction in FIG. 1).

The upper holding portion 21 and the lower holding portion 22 are spaced from each other in the thickness direction of the substrate 10 by a dimension t smaller than the thickness tk, as shown in FIG.
A gap S is formed below the upper holding portion 21 of the substrate holding member 20 in a direction along the side edge of the substrate 10 and wider than the width of the upper holding portion 21. A relief portion 23 (FIG. 2) for enabling the mold to be removed during molding.
Is provided.

On the other hand, a slit-shaped notch 13 is provided at a side edge 10a of the substrate 10 at a position corresponding to the gap S between the upper holding portion 21 and the lower holding portion 22 of the substrate holding member 20. Further, a screw hole 14 (FIG. 2) corresponding to the boss 2a is provided near the other side edge 10b.

Then, the substrate 10 is connected to its side edge 10.
a between the notches 13 and 13 (the side edge 10 shown in FIG. 6).
a ₁ and 10a ₂ ) are pushed into the upper holding portion 21 and the lower holding portion 22 of the substrate holding member 20 while the upper surface 11 and the lower surface 12 thereof are alternately brought into contact with each other, whereby the side edge portion 10a ₁ shown in FIG. bending downwards upper surface by the upper holding part 3 is pushed downward, the side edge portion 10a ₂ deflects upward the lower surface by the lower holding portion 22 is pushed upward as shown in FIG.

Therefore, one side edge 10a of the substrate 10
Are held by the substrate holding member 20 without play due to the elasticity of the substrate 10 itself. After that, the screw 3 is inserted into the screw hole 14 of the substrate 10 and screwed into the boss 2a of the support member 2,
The substrate 10 is securely attached and fixed to the support member 2 without falling out of the substrate holding member 20. Since the slits 13 are formed in the substrate 10, the distortions of the substrates that are applied in opposite directions in this mounting state are appropriately dispersed, and the substrate 10 has no room for dance.

According to this embodiment, since the number of screws used can be reduced, the cost can be reduced, the mounting workability can be improved, and there is no backlash, so that there is no danger of mechanical noise due to board dancing and the influence of aging. Not so easy. When a tape or the like is attached to the upper surface, the lower surface, or both surfaces of the side edge portion 10a of the substrate 10, the thickness tk of the substrate includes the thickness of the tape or the like. The upper holding unit 21 and the lower holding unit 22 correspond to FIG.
May be larger or the same size as seen in the plan view of FIG.

Although an example has been described in which the upper holding portion 21 and the lower holding portion 22 are provided integrally with the support member 2 as the substrate holding member 20, the substrate holding member 20 is formed as a separate member from the support member 2 and attached. Alternatively, the upper holding portion 21 and the lower holding portion 22 may be separately attached to the support member. However, if they are integrally formed together with the boss portion 2a, the number of parts is reduced, and the number of assembling steps is greatly increased. There is an advantage that can be reduced.

As shown in FIG. 7, even when the upper holding portion 21 and the lower holding portion 22 partially overlap, the notch 13 is formed at a position corresponding to the overlapping portion of the side edge 10a of the substrate 10. If so, the side edge 10a of the substrate 10 can be pushed in and held. Both side edges of the substrate 10 may be held by the upper holding portion 21 and the lower holding portion 22, so that the use of screws can be eliminated.

Further, by extending the present invention, the distance between the upper holding portion and the lower holding portion in the direction along the side edge of the substrate can be increased or the substrate can be made relatively flexible without providing a notch in the substrate. When there is a property, the side edge of the substrate can be pushed and held between the upper holding part and the lower holding part. In addition, the present invention can be applied to holding a plate-shaped member other than a substrate, and can be used, for example, for holding a cover of an electronic component.

Next, an example of a keyboard device of an electronic musical instrument using the board holding structure according to the present invention will be described with reference to FIGS. In FIG. 8, 31 is a black key and 31 'is a white key. In this figure, the cross section of the black key 31 is shown. Hereinafter, both keys are collectively referred to as a key 31. Reference numeral 32 denotes a resin-made keyboard frame which rotatably supports a large number of keys near a rear end 32a.

At the front lower portion of the keyboard frame 32, an inclined board mounting portion 32b and a shaft portion 32c are integrally formed at the rear end thereof. An elastic switch 33 (glass type 2 make switch) as a key switch and a substrate 35 on which electronic components (not shown) are mounted are mounted and supported on the substrate mounting portion 32b. 36 is pivotably mounted on the base.

The swing lever has a bifurcated engagement portion 36a at the front end thereof, and engages an engagement piece 31a provided at the lower part of the front end of the key 31 via an elastic member. .
In the rear, a rod-shaped mass body 3 whose rear end is folded back.
7 is extended. Then, a leaf spring 38 is engaged between the shaft support portion of each swing lever 36 and the rear end of the corresponding key 31 to urge the key 31 and the swing lever 36 so as not to come off. ing.

The swing lever 36 is normally in a right-turn position as shown by the solid line due to its own weight, and pushes the key 31 up to the position shown by the solid line. When the key 31 is depressed in the direction indicated by the arrow P, the key 31 rotates to the position indicated by the imaginary line, and causes the swing lever 36 to turn left around the shaft portion 32c to the position indicated by the imaginary line. At this time, the 2 fixed to the swing lever 36
The actuator 39 having the two convex portions also moves, and sequentially presses each contact portion of the elastic switch 33 provided on the substrate 35 to turn it on.

Thus, the key depression is detected, and the time difference between when the two elastic switches are turned on is determined by
A key pressing speed is detected. At this time, the actuator 39
The rotation fulcrum is the shaft portion 32c close to the extension of the substrate 35, so that the actuator 39 is connected to the elastic switches 33, 3
It is almost perpendicular to 4. The swing lever 36 having the mass body 37 as one body gives the same key-pressing touch as a piano hammer due to its inertial force. The upper and lower limit stoppers of the keyboard device are substantially the upper and lower limit stoppers 4 of the swing lever 36.
Only 2 and 43 serve as a key stopper. Reference numerals 40 and 41 denote stoppers when the black key 31 and the white key 31 'are overpressed (when an infant rides).

The board mounting portion 32b of the keyboard frame 32
A through hole 32e having a boss portion 32d and having a rectangular cross section, in which the distance between two surfaces parallel to the paper of the drawing is smaller than the diameter of the screw portion 50a of the tapping screw 50, is formed therein. In addition, above the vertical wall 32f provided with the shaft portion 32c at the upper end,
As shown in FIG. 9, which is a perspective view in which FIG. 8 is turned upside down, an upper holding portion 32g for holding the side edge portion 35a of the substrate 35
The lower holding portions 32h are alternately provided at intervals in a direction along the side edge 35a of the substrate 35. Holding part 3
The distance t between 2 g and the lower holding portion 32h in the thickness direction of the substrate 35 may be smaller than the thickness tk of the substrate 35, or may be slightly larger.

On the other hand, a slit 35b is formed in the side edge 35a of the substrate 35 at a position between the upper holding portion 32g and the lower holding portion 32h. Therefore, the side edge 35a of the substrate 35 is connected to the upper holding portion 32g and the lower holding portion 32.
When pressed in between, the portion where the upper surface contacts the upper holding portion 32g is bent downward, and the portion where the lower surface contacts the lower holding portion 32h is bent upward as shown in FIG. Is held. Then, the tapping screw 50 is inserted into the screw hole of the substrate 35, and the through hole 3 of the boss 32d is inserted.
As you crowded screwed to 2e, spacing than the diameter of the screw portion 50a is cut tap narrow two sides, the substrate 35 can be screwed.

In FIG. 9, illustration of the elastic switch 33 and the screw 50 mounted on the substrate 35 is omitted.
You. Further, W is a rib wall for reinforcement provided every few keys.

In FIG. 9, it is assumed that the distance t in the thickness direction C of the substrate between the upper holding portion 32g and the lower holding portion 32h is set to t ≧ tk with respect to the thickness tk of the substrate 35. When inserted in the direction A from the position indicated by the line, the end surface of the side edge of the substrate 35 abuts on the surface of the vertical wall 32f without being pushed. At this time, the substrate contact surfaces of the upper holding portion 32g and the lower holding portion 32h are provided so that the substrate surface with respect to the surface of the substrate mounting portion 32b is not completely parallel and is inclined by about 2 to 20 degrees.

From this state, the keyboard 35 is screwed by the screw 50 while pressing the substrate 35 against the surface of the substrate mounting portion 32b in the direction of arrow B. By doing so, the end surface of the substrate 35 can be brought into contact with the vertical wall 32f without a pushing force, and can be screwed in that state, so that the substrate mounting operation becomes extremely easy. Furthermore, even if the number of screw portions provided in the key arrangement direction is reduced to less than half of the conventional number by the above-mentioned substrate sandwiching method, the substrate can be mounted without rattling or mechanical noise. The substrate mounting operation is simplified.

Further, as shown in FIG.
g, 32h and the substrate 35 may be provided. In this embodiment, the width of each of the holding portions 32g and 32h is small. As a result, the “bend” in the key arrangement direction x between the notches 35b is also reduced.
Since they can cooperate with each other, the length of the slit of the notch 35b can be shortened, so that the substrate can be less cracked.

[0031]

As described above, the board holding structure for an electronic musical instrument according to the present invention is inexpensive, has good mounting workability, and does not generate mechanical noise. And there exists an effect which is hard to produce a secular change and a plastic deformation inside a board | substrate.

[Brief description of the drawings]

FIG. 1 is a plan view showing one embodiment of a substrate holding structure according to the present invention.

FIG. 2 is a sectional view taken along line CC of FIG.

FIG. 3 is an enlarged cross-sectional view of a contact portion between the upper holding portion and the substrate.

FIG. 4 is an enlarged sectional view of a contact portion between the lower holding portion and the substrate.

FIG. 5 is an enlarged cross-sectional view showing the relationship between the distance between the upper holding portion and the lower holding portion of the substrate in the plate thickness direction and the plate thickness.

FIG. 6 is a partially enlarged plan view for explaining notches and bending directions of side edges of the substrate.

FIG. 7 is a plan view illustrating a positional relationship between an overlapping portion and a notch of a substrate when an upper holding portion and a lower holding portion partially overlap each other.

FIG. 8 is a cross-sectional view along the key length direction showing an example of a keyboard device of an electronic musical instrument in which the board holding structure according to the present invention is implemented.

FIG. 9 is a perspective view showing the vicinity of the substrate mounting portion of FIG.

FIG. 10 is a perspective view showing another embodiment of the upper holding unit, the lower holding unit, and the substrate in the substrate mounting structure according to the present invention.

FIG. 11 is a plan view showing an example of a substrate holding structure of a conventional electronic musical instrument.

FIG. 12 is a sectional view taken along the line AA in FIG. 11;

FIG. 13 is a plan view showing another example of a substrate holding structure of a conventional electronic musical instrument.

FIG. 14 is a cross-sectional view taken along line BB of FIG. 13 and a similar cross-sectional view showing still another example.

[Explanation of symbols]

2 ... support member, 2a ... boss part, 3 ... screw, 10 ... board,
10a: side edge of substrate; 11: one surface (upper surface) of substrate; 12: other surface (lower surface) of substrate; 13: notch;
20: board holding member, 21: upper holding portion, 22: lower holding portion, 23: escape portion, 31: key, 32: keyboard frame, 3
2b: board mounting portion, 32c: shaft portion, 32d: boss portion, 3
2e: through hole, 32g: upper holding part, 32h: lower holding part,
33 elastic switch, 35 board, 35a side edge of board, 35b notch, 36 swing lever, 37 mass body, 38 leaf spring, 39 actuator, 50 tapping screw

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G10H 1/32 G10H 1/34 H05K 7/14

Claims (1)

(57) [Claims] In an electronic musical instrument, an upper holding portion for holding a board on which a key switch, an electronic component and the like are mounted in contact with one surface of a side edge portion thereof, and a lower holding portion for holding in contact with the other surface thereof. Are alternately arranged with their positions shifted in a direction along the side edge of the substrate, and a gap in the direction along the side edge between the upper holding portion and the lower holding portion at the side edge portion of the substrate. Alternatively, a slit-shaped notch is provided at a position corresponding to the overlapping portion, and the upper holding portion is formed by alternately bending the portion of the substrate between the notches on the side edges thereof in the direction opposite to the thickness direction. A substrate holding structure for an electronic musical instrument, wherein the substrate holding structure is sandwiched between and held by a lower holding portion.