JPH09244655A - Substrate holding structure of electronic musical instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix and hold the substrate of the electronic musical instrument at low cost with good fitting operability and small influence of a secular change without generating any mechanical noise. SOLUTION: An upper holding part 21 which holds the substrate 10 where key switches, electronic components, etc., are mounted by abutting against one surface of its side edge part and a lower holding part 22 which holds it by abutting against the other surface are arranged alternately at an internal close to the thickness of the substrate 10 along the plate thickness while shifted alternately along the side edge of the substrate 10. Then slit cuts 13 are formed in the side edge part 10a of the substrate 10 at positions corresponding to the gap part S between the upper holding part 21 and lower holding part 22, and the substrate 10 is held by curving the parts between the cuts 13 slightly and alternately in the opposite direction from the plate thickness direction and clamping them between the upper holding part 21 and lower holding part 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate holding structure for holding a substrate on which key switches, electronic components, etc. 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 is provided at a predetermined position on the upper side or the lower side of a keyboard frame and its on / off switch.
An electronic component such as a diode and a resistor for detecting an off state and performing output processing is mounted, and a board (printed wiring board) 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 been conventionally used. What is shown in FIGS. 11 and 12 is the substrate 1
Are fixed to a large number of boss portions 2a formed on the support member 2 with screws 3.

In the structure shown in FIGS. 13 and 14, the substrate 1 is fixed to the support member 2 at a portion near one side edge portion 1a to a boss portion arranged in line on the support member 2 with a screw 3, and the other end is fixed. The side edge portions 1b of the above are arranged in a row on the support member 2 so as to be engaged with and fixed to the hooks 4 (FIG. 14A) or the snap pins 5 (FIG. 14B). Further, there is also one in which both side edge portions 1a and 1b of the substrate 1 are engaged with the hook 4 or the snap pin 5 and fixed without using any screws.

[0005]

However, if the board 1 is entirely fixed with the screws 3 as in the former case, the number of screws to be used increases, which not only increases the cost, but also increases the number of steps for tightening the screws. However, there is a problem in that workability is poor. If the latter hook 4 is used, it is shown in FIG.
As shown in (a) of FIG. 4, the board 1 is not fitted unless the dimension t of the hook 4 for sandwiching the board 1 is larger than the plate thickness tk of the board 1. Therefore, there is a problem that a slight gap is generated between the board 1 and the hook 4, and the board 4 dances to generate mechanical noise due to vibrations at the time of key depression and acoustic vibration due to the generation of musical sound.

Further, when the snap pin 5 shown in FIG. 14 (b) is used, the elastic force of the snap pin 5 causes the substrate 1 to move.
Can be held without forming a gap between the engaging surface and the engaging surface, but due to the restriction of the mold, the place where the snap pin can be provided is limited, and the substrate 1 is deformed in one direction. There is a problem in that the substrate is distorted, and this distortion lowers the response accuracy of a touch response switch of the contact time difference detection method or the like, or the touch sensitivity changes due to plastic deformation due to aging.

The present invention has the problems of cost and mounting workability in the conventional substrate holding structure for an electronic musical instrument as described above.
To solve the problem of mechanical noise due to board dance, touch accuracy problem, etc. so that the board can be fixed and held at a low cost, with good workability for installation, without mechanical noise, and less affected by aging. With the goal.

[0008]

In order to achieve the above-mentioned object, the substrate holding structure for an electronic musical instrument according to the present invention has a substrate on which a key switch, an electronic component, etc. are mounted, in one side edge portion of the electronic musical instrument. Of the upper holding portion that abuts and holds the surface of the lower holding portion that abuts and holds the other surface of the lower holding portion that alternates in the direction along the side edge of the substrate, and in the plate thickness direction of the substrate. Spaced by a dimension smaller than the thickness.

On the other hand, a slit-like notch is provided at a side edge portion of the substrate at a position corresponding to a gap or an overlapping portion between the upper holding portion and the lower holding portion along the side edge of the substrate. The board is held by sandwiching it between the upper holding portion and the lower holding portion by slightly bending the board in the opposite direction of the plate thickness alternately at the portions between the notches on the side edges. .

[0010]

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

Reference numeral 20 denotes a substrate holding member, and as shown in FIG. 2, for example, a resin supporting member 2 which becomes a keyboard frame.
Is integrally formed with the boss portion 2a.
The substrate holding member 20 includes the substrate 10 on the side edge portion 10 thereof.
a of the upper holding portion 21 that abuts and holds one surface (upper surface) 11 as shown in FIG. 3 enlarged, and abutting the other surface (also lower surface) 12 as shown in an enlarged view of FIG. The lower holding portions 22 that are held by being alternately provided while being displaced in the direction along the side edge of the substrate 10 (the left-right direction in FIG. 1).

As shown in an enlarged view in FIG. 5, 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.
In addition, below the upper holding portion 21 of the substrate holding member 20, a gap S is formed between the lower holding portion 22 and wider than the width of the upper holding portion 21 in the direction along the side edge of the substrate 10. Together with the relief part 23 (FIG. 2) to enable die cutting at the time of molding
Is provided.

On the other hand, the side edge portion 10a of the substrate 10 is provided with a slit-shaped notch 13 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 portion 2a is provided near the other side edge 10b.

Then, the substrate 10 is attached to the side edge portion 10 thereof.
The portion between the notches 13 and 13 of the a (side edge portion 10 shown in FIG. 6).
to a _1, 10a ₂₎ of the upper holding portion 21 and the lower holding portion 22 of the substrate holding member 20, is pushed while abutting the upper surface 11 and lower surface 12 are alternately side edges 10a ₁ shown in FIG. 6, As shown in FIG. 3, the upper holding portion pushes the upper surface downward and bends downward. As shown in FIG. 4, the lower holding portion 22 pushes the lower surface upward and bends the side edge portion 10a ₂ upward.

Therefore, one side edge portion 10a of the substrate 10
However, due to the elasticity of the substrate 10 itself, it is held by the substrate holding member 20 without play. After that, by inserting the screw 3 into the screw hole 14 of the substrate 10 and screwing in the boss portion 2a of the support member 2,
The substrate 10 is securely attached and fixed to the support member 2 without coming off from the substrate holding member 20. Since the substrate 10 has the slit-shaped notches 13, the strains of the substrate, which are pressed in opposite directions in this mounting state, are appropriately dispersed, and the substrate 10 has no room for dancing.

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 mechanical noise due to the board dance is not generated and the influence of secular change. It's not too bad. 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 portion 21 and the lower holding portion 22 are shown in FIG.
Whichever size is larger in plan view, or the same size, may be the same, and if the arrangement order is alternating, either one may be first.

An example in which the upper holding portion 21 and the lower holding portion 22 are provided integrally with the supporting member 2 as the substrate holding member 20 has been described, but the substrate holding member 20 is formed as a member different from the supporting member 2 and attached. Alternatively, the upper holding portion 21 and the lower holding portion 22 may be separately attached to the support member, but if these are all integrally formed with the boss portion 2a, the number of parts is reduced and the number of assembling steps is also significantly increased. There is a merit that can be reduced.

Further, as shown in FIG. 7, even if the upper holding portion 21 and the lower holding portion 22 partially overlap each other, the notch 13 is formed at a position corresponding to the overlapping portion of the side edge portion 10a of the substrate 10. If so, the side edge portion 10a of the substrate 10 can be pushed and held. It is also possible to eliminate the use of screws by holding both side edge portions of the substrate 10 by the upper holding portion 21 and the lower holding portion 22.

Further, the present invention is expanded to increase the distance between the upper holding portion and the lower holding portion in the direction along the side edge of the substrate without providing a notch in the substrate, or to make the substrate relatively flexible. If there is a property, the side edge portion of the substrate can be pushed and held between the upper holding portion and the lower holding portion. Further, the present invention can be diverted to hold a plate-shaped member other than the substrate, and can be used for holding a cover of an electronic component, for example.

Next, an example of a keyboard device for an electronic musical instrument which has the substrate 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, a cross section of the black key 31 is shown, but hereinafter both keys are generically referred to as a key 31. Reference numeral 32 denotes a resin keyboard frame, which rotatably supports a large number of keys near the rear end portion 32a.

On the lower front portion of the keyboard frame 32, an inclined board mounting portion 32b and a shaft portion 32c at the rear end are integrally formed. An elastic switch 33 (eyeglass 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, and a swing lever for each key 31 is mounted on the shaft portion 32c. 36 is pivotally attached.

A front end portion of the swing lever has a bifurcated engagement portion 36a, and an engagement piece 31a provided at a lower portion of the front end of the key 31 is engaged so as to be sandwiched by an elastic member. .
In the rear, a rod-shaped mass body 3 with its rear end folded back.
7 are extended. Then, a leaf spring 38 is engaged between the pivotally supporting portion of each rocking lever 36 and the corresponding rear end portion of the key 31 to urge the key 31 and the rocking lever 36 so as not to come off. ing.

The rocking lever 36 is normally in the right-handed position by its own weight as shown by the solid line, and pushes up the key 31 to the position shown by the solid line. When the key 31 is pressed in the direction of arrow P, the key 31 rotates to the position indicated by the imaginary line, and the swing lever 36 rotates left about the shaft portion 32c to the position indicated by the phantom line. At that time, the 2 fixed to the swing lever 36
The actuator 39 having two convex portions is also driven to sequentially press each contact portion of the elastic switch 33 provided on the substrate 35 to turn it on.

As a result, when the key depression is detected, the time difference between the two elastic switches being turned on causes
The key pressing speed is detected. At this time, the actuator 39
Since the rotation fulcrum of is the shaft portion 32c close to the extension line of the substrate 35, the actuator 39 moves the elastic switches 33, 3
Hits 4 almost vertically. The swing lever 36 having the mass body 37 integrally provides a touch feeling similar to a hammer of a piano due to its inertial force. The upper and lower limit stoppers of this keyboard device are substantially the upper and lower limit stoppers 4 of the swing lever 36.
Only 2 and 43 also serve as a key stopper. Reference numerals 40 and 41 denote stoppers when the black key 31 and the white key 31 'are over-depressed (when an infant rides on the key).

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

On the other hand, the side edge portion 35a of the substrate 35 is provided with slit-shaped notches 35b corresponding to the positions between the upper holding portion 32g and the lower holding portion 32h. Therefore, the side edge portion 35a of the substrate 35 is connected to the upper holding portion 32g and the lower holding portion 32.
When pushed between h, the part where the upper surface is in contact with the upper holding portion 32g is bent downward, and the part where the lower surface is in contact with the lower holding portion 32h is bent upward as shown in FIG. Held in. Then, the screw hole 35 of the substrate 35
When the tapping screw 50 is inserted into c and is screwed into the through hole 32e of the boss portion 32d in the direction of the arrow Q, taps are cut on two surfaces having a smaller interval than the diameter of the screw portion 50a,
The substrate 35 can be fixed with screws.

In FIG. 9, the elastic switch 33, the screw 50, etc. mounted on the substrate 35 are not shown. Reference numeral 32i denotes an opening formed in the board mounting portion 32b, which is provided for inserting the actuator 39.
W is a reinforcing rib wall provided for every several keys.

In FIG. 9, assuming that the distance t between the upper holding portion 32g and the lower holding portion 32h in the board thickness direction C is set to t ≧ tk with respect to the board thickness tk of the board 35, the board 35 is hypothesized. When it is inserted in the direction A from the position shown by the line, the end face of the side edge of the substrate 35 comes into contact with 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 such that the substrate surface is not perfectly parallel to the surface of the substrate mounting portion 32b and is inclined by 2 to 20 degrees.

From this state, the board 35 is pressed against the surface of the board mounting portion 32b in the direction of arrow B, and the keyboard frame 32 is screwed by the screw 50. By doing so, the end face of the substrate 35 can be brought into contact with the vertical wall 32f without pushing force, and the vertical wall 32f can be screwed in that state, so that the substrate mounting operation becomes extremely easy. Furthermore, by the board sandwiching method, even if the number of screw parts provided in the key arrangement direction is less than half of the conventional number, board mounting can be performed without rattling or mechanical noise. Board mounting work is simplified.

Further, as shown in FIG.
You may arrange g, 32h and the board | substrate 35. In this embodiment, the width of each holding portion 32g, 32h is small. As a result, the notches 35b can cooperate with each other with "bending" in the key arrangement direction x, so that the slit length of the notches 35b can be shortened, whereby cracks in the substrate can be prevented. You can make a few things.

[0031]

As described above, the substrate holding structure for an electronic musical instrument according to the present invention is inexpensive, has a good mounting workability, and does not generate mechanical noise. The inside of the substrate has an effect of hardly causing secular change and plastic deformation.

[Brief description of drawings]

FIG. 1 is a plan view showing an 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 also an enlarged cross-sectional view of a contact portion between the upper holding portion and the substrate.

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

FIG. 5 is an enlarged cross-sectional view showing the relationship between the board thickness and the distance between the upper holding section and the lower holding section in the board thickness direction.

FIG. 6 is a partial enlarged plan view for explaining the notch of the substrate and the bending direction of the side edge portion.

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

FIG. 8 is a sectional view taken along the longitudinal direction of the key, showing an example of a keyboard device for an electronic musical instrument in which the substrate holding structure according to the present invention is implemented.

9 is a perspective view showing an enlarged view of the vicinity of a board mounting portion of FIG. 8 by turning it upside down.

FIG. 10 is a perspective view showing another embodiment of the upper holding part, the lower holding part and the board in the board 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 conventional substrate holding structure for an electronic musical instrument.

FIG. 14 is a cross-sectional view taken along the 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 ... Substrate,
10a ... Side edge of substrate, 11 ... One surface (upper surface) of substrate, 12 ... Other surface (lower surface) of substrate, 13 ... Notch,
20 ... Substrate holding member, 21 ... Upper holding part, 22 ... Lower holding part, 23 ... Escape part, 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

Claims (1)

[Claims] 1. In an electronic musical instrument, an upper holding portion that holds a board on which a key switch, an electronic component, etc. are mounted by contacting one surface of a side edge portion thereof, and a lower holding portion that holds the substrate by contacting the other surface thereof. And are arranged alternately by shifting the position in the direction along the side edge of the substrate, and at the side edge portion of the substrate, a gap portion in the direction along the side edge between the upper holding portion and the lower holding portion. Alternatively, a slit-like notch is provided at a position corresponding to the overlapping portion, and the substrate is slightly bent in the opposite direction of the plate thickness alternately at the portions between the notches at the side edge portions thereof to form the upper holding portion. A substrate holding structure for an electronic musical instrument, characterized in that it is sandwiched between a lower holding portion and a lower holding portion and held.