JP3191668B2 - Board mounting structure for electronic keyboard instruments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic keyboard instrument such as an electronic organ, an electronic piano, a portable electronic keyboard, etc., for mounting a substrate on which an elastic switch as a key switch is mounted to a resin keyboard frame. Regarding the structure.

[0002]

2. Description of the Related Art An electronic keyboard instrument has a plurality of keys rotatably supported by a keyboard frame. Above or below the keyboard frame, a key switch such as a rubber switch corresponding to each key, a diode, or the like is provided. Attach a board (printed wiring board) on which electronic components such as resistors are mounted,
A switch operating actuator that rotates in conjunction with each of the keys is provided.

When a key is pressed, an actuator interlocked with the key contacts a key switch on the substrate and presses it. Thus, the key press for each key is detected by the electronic circuit on the board, and in the case of two switches being turned on with a time difference, the key press speed can also be detected. A musical tone such as a volume corresponding to the detected key-pressing speed can be generated at a pitch according to the key-press signal for each key.

In order to reduce the cost and weight of such electronic keyboard instruments, keyboard frames made of synthetic resin (plastic) have recently been used, and chattering does not occur even as a key switch and the structure is simple. An elastic switch using a simple rubber contact has come to be used.

[0005] By the way, when the key is pressed, an actuator interlocked with the key (provided on a swinging lever or the like, which is directly or interlocked with the key) vertically contacts the elastic switch, so that the board mounting portion is required. In order for the mounting surface to be along a line passing through the center of rotation of the actuator, it is necessary to provide the mounting surface at an angle with respect to a direction perpendicular to the direction in which the keyboard frame is removed.

[0006]

In such a case, it is necessary to form a screw hole for screwing the substrate in the substrate mounting portion. A round hole for tapping perpendicular to the substrate mounting surface is required as the screw hole. It is desirable to form. However, if this is done, the direction of the center line L of the screw hole H differs from the direction A of the die removal as shown in FIG. 9A, so that the upper die U and the lower die D are combined to form the screw hole H. Also the mating surface S
Has a shape as shown in FIG. 3B, and the upper die U has a lower width w larger than its vertical upper width, so that the upper die U cannot be vertically die-cut.

Therefore, a special mold having a slide core or the like is required to form such a screw hole.
Significant cost increases. Therefore, if the screw hole is formed in the direction of the die, the screwing direction of the mounting screw will not be perpendicular to the substrate surface, and the head of the screw will hit one side of the substrate, and the fixing of the substrate will become unstable. Alternatively, a small impact or excessive screw tightening during mounting may damage the peripheral portion of the mounting hole of the substrate.

Therefore, if the round screw hole is to be formed perpendicular to the mounting surface of the board removing portion in the direction of removing the keyboard frame, the mounting surface of the board mounting portion must be oriented in a direction perpendicular to the removing direction. Cannot be disposed on a line passing through the axis of rotation of the actuator. As a result, the actuator does not come into contact with the elastic switch in a direction perpendicular to the elastic switch, causing problems such as poor switching due to torsion of the elastic member and reduced durability of members constituting the switch.

[0009] Further, since the position of the switch is largely separated from the key, the sense of directness in the input of the stitch when the key is pressed is weakened. Further, since it is necessary to form an extended portion of the actuator for each key, there arises a problem that the weight balance of the key is considerably changed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. A switch for detecting a key depression can be arranged at an ideal position, and a special metal switch can be provided. It is possible to form screw mounting holes without having to take a mold structure,
An object of the present invention is to enable a board on which an elastic switch is mounted to be securely mounted and fixed to a keyboard frame using the screw holes.

[0011]

A board mounting structure for an electronic keyboard instrument according to the present invention is provided with a plurality of keys, a plurality of keys rotatably supported and a board mounting portion, and is integrally formed of resin. A keyboard frame and an elastic switch corresponding to each key are mounted, and the board attached to the board attaching portion and the plurality of keys are rotated in conjunction with each other, and come into contact with the elastic switch to press it. In order to achieve the above object, an electronic keyboard instrument having an actuator is configured as follows.

The board mounting portion is provided to be inclined with respect to a direction perpendicular to the die-cutting direction at the time of forming the keyboard frame so that the actuator vertically contacts the elastic switch on the board. A screw hole for screwing the board is provided.
Make a circle smaller than the diameter of the screw, followed by
About a direction perpendicular to the substrate mounting surface, the interval faces along the inclined direction is formed as a through hole having a diameter smaller than two parallel faces of said tapping screw, said tapping screw through the substrate holes The board is fixed to the board mounting portion by screwing into the through hole from the opening .

[0013]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a sectional view along the longitudinal direction of a black key showing an example of a keyboard device of an electronic keyboard instrument implementing a board mounting structure according to the present invention. In FIG. 1, reference numeral 31 denotes a black key and 31 'denotes a white key. In this figure, a cross section of the black key 31 is shown.
Say 1. 32 is a keyboard frame made of resin, are respectively rotatably supported a number of keys 31 in the vicinity of the rear end portion 32a ₁ of the key supporting portion 32a.

In the lower front part of the keyboard frame 32, a slanted 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, and a swing lever for each key 31 is mounted on the shaft portion 32c. 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 a lower portion of the front end of the key 31 with an elastic member interposed therebetween. .
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 to the position shown by the solid line. When the key 31 is pressed 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 two convex portions also moves together, sequentially contacts and presses the respective contact portions of the elastic switch 33 provided on the substrate 35, and sequentially turns them on.

Thus, the key depression is detected by the electronic circuit mounted on the substrate 35, and the key depression speed is detected by the time difference between the two elastic switches being turned on. At this time, the rotation fulcrum of the actuator 39 is elastic.
Since a shaft portion 32c of the extension of the tangent of the upper surface of the switch 33, the actuator 39 impinges substantially perpendicularly against the elastic switch 33. 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 stoppers of the keyboard device are substantially the upper and lower stoppers 42 of the swing lever 36.
Only 43, which also serves as a key stopper. In addition, 4
Numerals 0 and 41 are stoppers for overpressing the black key 31 and the white key 31 '(when an infant rides on the key).

The board mounting portion 32b of the keyboard frame 32
As shown in an enlarged manner in FIG. 2, a through hole 3 having a boss portion 32 d, in which the distance between two surfaces parallel to the plane of the drawing is smaller than the diameter of the screw portion 50 a of the tapping screw 50, is rectangular.
2e is formed. In addition, an upper holding portion 32g and a lower holding portion 32h for holding the side edge 35a of the substrate 35 are provided on the upper portion of the vertical wall 32f provided with the shaft portion 32c at the upper end along the side edge 35a of the substrate 35. They are provided alternately at intervals in the direction. The distance between the upper holding portion 32g and the lower holding portion 32h in the thickness direction of the substrate 35 may be substantially equal to or slightly larger than the thickness of the substrate 35.

On the other hand, the side edge 35a of the substrate 35 is
As shown in FIG. 7, a slit-shaped notch 35b is formed 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
2g and the lower holding portion 32h, and slightly rotated in the direction of arrow B in FIG. 2, and a tapping screw 50 is inserted into the screw hole 35c of the substrate 35, and the through hole 3 of the boss portion 32d is formed.
2e in the direction indicated by the arrow Q, the screw 50
A tap is cut on two surfaces that are narrower than the diameter of a.
5 can be screwed and fixed. At this time, the portion where the upper surface of the side edge 35a of the substrate 35 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. And it is securely held without play.

In FIG. 2, the elastic switch 33 and the electronic components mounted on the substrate 35 are not shown. Reference numeral 32i denotes an opening formed in the substrate mounting portion 32b, and is provided for inserting the actuator 39 therethrough.

FIG. 4 is an explanatory view of the shape of a through hole for screw formed in the boss 32d of the board mounting portion 32b shown in FIG. The through-hole 32e in this example is inclined as shown by an arrow b with respect to the die removal direction shown by an arrow a, and the opening on the substrate mounting surface C side forms a rectangle that is long in the inclined direction. A prismatic through hole 3 of the same cross-sectional shape
2e . The distance W between the two surfaces parallel to the inclination direction is smaller than the diameter D of the screw portion 50a of the tapping screw 50.

The upper die U and the lower die D forming the through hole 32e
Has a shape as shown in the figure, and the surface U1 and the surface D1 coincide with each other at the time of molding, and are integrated. However, since the mold mating surface is also rectangular, the mold is removed in the direction of arrow a (vertical direction) when the mold is removed. There's nothing you can't get out of. When the tapping screw 50 is screwed into the through hole 32e of the boss 32d, taps are cut on two surfaces (an upper surface and a lower surface in the figure) whose interval is smaller than the diameter of the screw portion 50a. Go.

FIG. 5 shows another example of the shape of the screw through hole formed in the boss 32d. In this example, the boss 32
opening 32e ₁ of the substrate mounting surface C side of the d is a circular diameter than the small diameter of the threaded portion 50a of the tapping screws 50 shown in FIG. 6, the opening 32e ₂ of the surface opposite to the same as the diameter of the opening 32e ₁ It has two sides parallel to each other at intervals and forms an oblong shape elongated in the inclined direction, and the size of the through hole 32e in the inclined direction is gradually increased. With such a shape, the through hole 32e can be formed only by the upper mold.

Then, as shown in FIG.
When tapping screw 50 is screwed into 2e, its opening 32
Each Tafuppu the two surfaces parallel to and facing the surrounding e ₁ is gradually cut.

FIG. 7 and FIG. 8 show the upper mold U and the lower mold D for forming the through holes, with the plane of another example of the shape of the screw through holes formed in the boss portion 32d as (a). The shape of the mold matching surface is shown in FIG. In the case where the through-hole 32e is formed in the shape of a square prism shown in FIG. 7, when the tapping screw is screwed in as indicated by a virtual line, taps are cut on all four sides. Further, the through holes 32e are formed in a regular hexagonal column shape shown in FIG.
Is formed, when the tapping screw is screwed in as indicated by the imaginary line, taps are cut on all six surfaces. However, such a prismatic through-hole cannot be formed so as to be inclined too much with respect to the die-cutting direction.

As described above, the screw-through hole 32e having a prismatic shape, a long columnar shape, or a long truncated conical shape having a circular top surface is formed by using a simple mold so as to be inclined in the die removing direction. Can be.

[0027]

As described above, when the board mounting structure for an electronic keyboard instrument according to the present invention is implemented, a switch for detecting key depression can be arranged at an ideal position, and furthermore, a special switch can be provided. A screw mounting hole can be formed without the need for a mold structure, and the board on which the elastic switch is mounted can be securely mounted and fixed to the keyboard frame using the screw hole.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view taken along a longitudinal direction of a black key showing an example of a keyboard device of an electronic keyboard instrument implementing a board mounting structure according to the present invention.

FIG. 2 is an enlarged cross-sectional view of the board mounting portion.

FIG. 3 is a perspective view of a side edge of the substrate.

4 is a boss part 32d of the board mounting part 32b shown in FIG.
FIG. 3 is an explanatory view of a shape of a screwing through hole formed in the first embodiment and a molding die thereof.

FIG. 5 is a perspective view of a boss showing another example of the shape of the screw through hole.

6 is a perspective view showing a state in which a tapping screw is screwed into a through hole of the boss portion shown in FIG. 5 and then removed.

FIG. 7 is an explanatory view of another example of a screwing through hole formed in a boss portion and a mating surface thereof.

FIG. 8 is an explanatory view of still another example of a screw through hole formed in a boss portion and a mating surface thereof.

FIG. 9 is an explanatory diagram of a problem in a case where a round hole for screwing which is inclined with respect to a die-cutting direction is formed in a substrate mounting portion.

[Explanation of symbols]

31, 31 'key, 32 keyboard frame, 32b board mounting portion, 32c shaft portion, 32d boss portion, 32e through hole, 32g upper holding portion, 32h lower holding portion, 33 elastic switch, 35 ... substrate, 35a ... side edge of substrate, 35b
... Notch, 36, swing lever, 37, mass body, 38, leaf spring, 39, actuator, 50, tapping screw,
U: Upper mold, D: Lower mold, S: Mold mating surface

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G10H 1/32 G10H 1/34 B29C 45/26 H05K 7/14

Claims (1)

(57) [Claims] 1. A plurality of keys, a plurality of keys, each of which is rotatably supported, and a board mounting portion is provided. A keyboard frame integrally formed of resin and an elastic switch corresponding to each of the keys are mounted. An electronic keyboard musical instrument comprising: a board attached to the board attachment portion; and an actuator that rotates in conjunction with each of the plurality of keys, and contacts and presses the elastic switch. The board mounting portion is provided so as to be inclined with respect to a direction in which the keyboard frame is removed when the keyboard frame is formed so as to be perpendicularly applied to an elastic switch on the board, and the board mounting portion is screwed to the board mounting portion. The screw hole is an opening on the board mounting surface side.
None the less than the diameter circular about a direction perpendicular to the substrate mounting surface and subsequently, as a through hole in which the interval faces along the inclination direction has a diameter smaller than two parallel faces of the tapping screw Forming the tapping screw through the hole in the substrate and opening the
Substrate attachment structure is characterized in that so as to fix the substrate to the substrate attachment portion by screwing into et the through hole.