JP3477776B2 - Electronic musical instrument keyboard device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyboard device for an electronic musical instrument having a keyboard such as an electronic organ and an electronic piano. 2. Description of the Related Art There are various types of keyboard devices for electronic musical instruments such as electronic organs.
The structure shown in Japanese Patent Publication No. 56 is widely used. This will be briefly described with reference to FIG. 9. An engagement hole 1 formed at the rear end of a keyboard frame 12 serving as a key support member is described.
An engagement portion 11a formed by projecting downward from the rear end of the key 11 is engaged with the key 2a, and the key 11 is pushed and released from the keyboard frame 12 about the engagement point P (directions indicated by arrows A and B). ) To be rotatable. A key return leaf spring 13 is mounted on both ends of a spring locking portion 11b provided on the key 11 and a spring locking portion 12b provided on the keyboard frame 12 so that the key 11 is always returned in the returning direction. (In the direction of arrow B), and at an angle with respect to the pushing / separating direction so that both fulcrum portions (engagement points P) of the key 11 and the keyboard frame 12 are pressed against each other. The spring locking portion 12 on the keyboard frame 12 side
“b” forms a hook portion with respect to the end portion of the leaf spring 13 by using a drop of an iron plate such as press working. Alternatively, instead of this, a plastic part called a spring seat is provided on a keyboard frame. [0005] As such a keyboard apparatus, as shown in FIG.
And the key-side locking portion C locks the leaf spring 13 at three points (or three points), or locks the leaf spring 13 at points X and C passing through points A and B. Due to the nature of the leaf spring, the spring load and the amount of deflection are determined by the constraint of two points. Therefore, due to variations in the dimensions of the leaf springs 13 at the points A and B and variations in the dimensions of the points A and B on the frame side in the X-Y direction, the loads are not actually evenly applied at the points A and B. Therefore, one of the points A and B floats in a severe case. In this case, when the leaf spring contact angle at the time of key depression changes, mechanical noise is likely to be generated at the point where the leaf spring is approaching. Further, since an unbalanced load is generated in the leaf spring 13, the point C is to be swung right and left (X direction).
As a result, a lateral load is applied to the key, and the upper surface of the key is inclined, a gap between adjacent keys is varied, and a variation in touch feeling due to frictional resistance is likely to occur. The present invention has been made in view of such a problem, and in the above-described keyboard device for an electronic musical instrument, a key return leaf spring and a keyboard frame or the like for locking both ends thereof when a key is pressed. The object is to prevent mechanical noise from occurring between the key support member and the key spring locking portion, the inclination of the upper surface of the key, the variation in the gap between the keys, and the variation in touch feeling. . According to the present invention, there is provided a key support member, a key rotatably supported by the key support member in a pushing and releasing direction, and a spring member having one end provided on the key. Locked to the stop,
The other end is engaged with the spring engaging portion provided in the key support member, thereby urging constantly returning direction keys, arranged both fulcrum of the key and the key support member so as to pressure-contact with each other In order to achieve the above-mentioned object, a keyboard device for an electronic musical instrument provided with a key-returning leaf spring is configured as follows. The locked portions are formed at both ends in the longitudinal direction of the leaf spring on concave or convex curved surfaces in the longitudinal direction of the leaf spring, respectively, and the keys for locking the locked portions are formed. And each spring locking portion of the key support member is formed with a curvature different from the curved surface of the locked portion on a curved surface or a flat surface which is convex or concave in the locking direction of the leaf spring. The locked portions and the respective spring locking portions of the key and the key support member are brought into point contact with each other . In the keyboard device for an electronic musical instrument according to the present invention, a leaf spring for giving the key a return behavior is basically associated with two points, one each for the key and a key support member such as a keyboard frame. Supported together. Even when other parts come into contact with each other, they come in contact with each other on a line parallel to the rotation axis of the leaf spring, passing through the above-described engagement points,
No frictional resistance or mechanical noise due to sliding. In addition, since the displacement of the leaf spring in the width direction is regulated on the above-mentioned line, and the spring engaging portion of the key and the key support member and the engaged portion of the leaf spring have curved surfaces with different curvatures, There is a centering function and an automatic spring falling adjustment function, and the leaf spring is always maintained in an appropriate position and state. Therefore, the upper surface of the key does not tilt, the gap between adjacent keys does not vary, and the touch feeling does not vary due to frictional resistance. Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 2 is a cross-sectional view of a keyboard device according to an embodiment of the present invention, taken along a key longitudinal direction. The key 1 is integrally formed of resin in a U-shaped cross section with an open lower surface, and has an opening 1e vertically penetrating at a rear portion thereof and a projection 1a projecting downward at a rear end portion and a rear portion. A protruding boss 1b is formed, and an L-shaped stopper piece 1c hanging down integrally from both side walls is vertically provided at a front portion. The front edge of the projection 1a is substantially perpendicular to the longitudinal direction of the key 1. The illustrated key 1 is a white key,
The black key is different from the white key only in the shape of the first half, and the shape of the second half is the same as the white key. On the other hand, a long fulcrum member 20 common to each key is fixed to a rear end bent portion 2a of a keyboard frame (hereinafter, simply referred to as a "frame") 2 serving as a key support member. In addition, holes 20a are formed in rows corresponding to the keys, and serve as key fulcrum portions having a substantially V-shaped vertical cross section. The boss 1b at the rear end of each key 1 is swingably supported in the hole 20a, and the key return leaf spring 3 engaged with the frame 2 moves the boss 1b around the key fulcrum in the pushing and releasing direction. The key 1 that is rotatable by a predetermined stroke is urged in the return direction (clockwise in FIG. 1), and the boss 1b is pressed against the key fulcrum member 20 from the front to form a key rotation fulcrum. The key return leaf spring 3 is locked at both ends by a spring locking portion 1f formed on the upper inside inside the rear end of the key 1 and a spring locking portion 2f formed on the frame 2. It is mounted so as to be convexly curved toward the key side with respect to an action axis Lf (indicated by a dashed line) connecting the contact points with the locking portions 1f and 2f. At the rear of the horizontal surface 2b of the frame 2, below the opening 1e of the key 1 supported by the frame 2,
A slit 2d that allows the key 1 to move in the longitudinal direction is formed so that the projection 1a of the key 1 can be inserted from above and the boss 1b can be engaged with and disengaged from the hole 20a of the fulcrum member 20. On the lower surface of the frame 2, for example, a retaining member 4 made of a molded product of an elastic metal plate formed in a comb tooth shape of a stainless steel plate is attached by a plurality of set screws 5. This retaining member 4 is common to a plurality of keys. The front portion of the horizontal portion 2b of the frame 2 is bent downward and forms a horizontal surface 2c again, and the front end portion is bent upward again. The lower horizontal surface 2c is formed of felt or rubber or the like. A lower limit stopper 6 made of an elastic material is stuck, and a key guide 7 integrally formed by outsert with a sound absorbing material such as a soft elastomer or a foam is attached to an outer peripheral portion in front of the upper horizontal surface 2b. The key 7 is inserted between the pair of stopper pieces 1c, 1c to prevent the key 1 from swaying. Reference numeral 8 denotes an upper limit stopper, which is integrally formed of the same material as the key guide 7. A substrate 9 is fixed on the rear surface of the upper horizontal surface 2b of the frame 2, and a flexible contact rubber member 10 having a bowl-shaped bulge disposed on the substrate 9 corresponding to each key. When the contact rubber member 10 is pressed by the actuator 1d of the key 1, the key switch 10a is turned on to generate a musical sound. FIG. 1 shows an example of the shape of a key-returning leaf spring (hereinafter simply referred to as “leaf spring”) 3 in this keyboard device, and a spring locking portion 1 f and a frame 2 formed inside the rear end of the key 1.
FIG. 6 is an exploded perspective view showing a shape example of a spring locking portion 2f formed in FIG. The leaf spring 3 is formed in a band shape having a substantially constant width, and the locked portions 3a and 3b are formed on both ends thereof in a concave curved surface (3a) and a convex curved surface (3b) in the longitudinal direction of the leaf spring 3, respectively. . Each of the spring locking portions 1f of the key 1 for locking one locked portion 3a of the leaf spring 3 has a locked portion 3a.
Of forming a vertical locking portion 1f ₁ and the upper engaging portion 1f ₂ which is large curvature (small radius of curvature) formed in Totsukyokumen than the concave curved surface together. On both sides of the locked portion 3a of the leaf spring 3, a pair of upwardly bent shift regulating claws 3c, 3c are provided.
c is formed integrally, and both sides of the spring engaging portion 1f of the key 1 are also spaced apart from each other at a required interval to form the two roof-shaped auxiliary supporting portions 1 respectively.
h, a pair of triangular prism-shaped displacement control portions 1g, 1g
Is formed. The locking portion 2f of the frame 2 for locking the other locked portion 3 of the leaf spring 3 is formed by a punched hole 2g together with the displacement restricting portions 2h, 2h on both sides thereof. Is formed in a concave shape or a flat shape having a smaller curvature (having a larger radius of curvature) than the convex curved surface of the locked portion 3b in the width direction, and forms a downwardly inclined slope in the longitudinal direction, and in the middle of the slope. The engaged portion 3a of the leaf spring 3 is engaged with the spring. On both sides of the locked portion 3b of the leaf spring 3, substantially arc-shaped deviation preventing claws 3d, 3d whose outer edges bulge symmetrically in the spring width direction are integrally formed. ing. The punched hole 2g of the frame 2 is formed in a size that allows the slip preventing claws 3d, 3d of the leaf spring 3 to be inserted exactly between the spring locking portion 2f and the shift regulating portions 2h, 2h on both sides thereof. I have. The plate spring 3 thus formed is connected to the locked portions 3a and 3b by the spring locking portion 1f of the key 1 and the frame 2
Each key 1 is urged upward by engaging with each key and the frame 2 by engaging the respective spring engaging portions 2f. At this time, the leaf spring 3 engages with the key 1 and the frame 2 such that the axes aa and bb shown in FIG. 1 overlap with each other. In this state, points where substantial loads are applied are two points of engagement points c and d on the center line Lc of the width of the leaf spring 3, and a straight line Lf passing through these two points is a line of action of the spring load. The vertical sides e, which are the ridges of the triangular prism-shaped shift restricting portions 1g, 1g on both sides of the spring locking portion 1f of the key 1, serve as a guide when the leaf spring 3 is inserted. After mounting, it does not basically contact the leaf spring 3. Even if there is any contact, the point p is located on the axis aa, so that sliding friction and mechanical noise due to rotation do not occur. Further, even if the base lower surface of the displacement regulating claw portions 3c, 3c of the leaf spring 3 is in contact with the roof-shaped auxiliary support portion 1h, it is the portion of the top side g where sliding friction is least. When the leaf spring 3 is displaced in the width direction, the position regulating pawls 3c, 3c are displaced by the displacement regulating portions 1g, 1g of the key 1.
1g at point p to regulate the displacement of the leaf spring 3 in the direction of the axis aa of rotation of the leaf spring 3 accompanying the rotation of the key 1. On the other hand, at the engaging portion between the locked portion 3b of the leaf spring 3 and the spring locking portion 2f of the frame 2, the two make point contact at the point d and lightly at the ridge h on the axis bb. Touch Further, when the leaf spring 3 is displaced in the width direction, the position thereof is regulated by contacting the displacement restricting portions 2h, 2h on both sides, and the contact point f is also the axis of rotation of the leaf spring 3 accompanying the rotation of the key 1. bb
Since it is above, no sliding friction or mechanical noise due to rotation is generated. FIG. 3 is a top view of the vicinity of the engagement point c between the key 1 and the leaf spring 3.
since two curved surfaces contacts with different curvatures between the vertical locking part 1f ₁ of c and the key 1, and is maintained so as to be self-aligning, always engages vertex on the center line Lc of the spring load . FIG. 4 shows an engagement point c between the key 1 and the leaf spring 3.
It is the figure which looked at the neighborhood from the side. Leaf spring 13 is key 1 at worst
Is inserted so as to come into contact with the top side g of the auxiliary support portion 1h,
Thereafter, when the key is repeatedly pressed, the action line Lf of the spring load is applied.
Since There oblique upward, upper engaging portion 1f ₂ of contact surface S locked portion 3c leaf spring 3 until it hits the motion displacement upwards, automatically engaging point c on the axis a-a shown in FIG. 1 Reach to. Actually, since the distance between the engagement point c and the top side g is determined by the mold, the distance between the engagement point c and the top side g is considerably reduced . When the key is pressed , the state before the stroke shown in FIG. State. FIG. 6 is a sectional view in the key width direction near the engagement point c between the key 1 and the leaf spring 13 before the stroke. When the key is pressed for the first time, the leaf spring 3 is pushed up by the top side g of the auxiliary support portion 1h of the key, and is locked at a position as close as possible to the point c. Since the leaf spring 3 is substantially held only at the two engagement points c and d shown in FIG.
Rotation around an axis passing through points c and d (direction indicated by R in FIG. 1)
There is no restriction on the spring width, but the fall before the stroke is only the gap between the engagement point c and the top g and the leaf spring 3 with respect to the spring width. By the above-described operation, when the key is repeatedly pressed, the spring falling automatic adjustment function operates. FIG. 7 shows an engagement point d between the frame 1 and the leaf spring 3.
It is a side view of the vicinity. In this engaging portion, the angle θ between the contact line between the line of action Lf of the spring load and the locked portion 3b of the leaf spring 3 of the spring locking portion 2f on the frame 1 side is such that the leaf spring 3 is convex. The oblique angle is always set on the curved side so that the leaf spring 3 does not come off or the contact point moves. Further, the pawl portions 3d, 3 for preventing the leaf spring 3 from shifting.
Since d outer edge of is formed in an arc shape around the point of engagement d, even if the plate spring 3, as shown in FIG. 8 Toritsui inclined laterally with respect to the frame 2, the edge line h, the contact f , And the engagement point d are on the axis bb, so that they rotate without friction. When the key is repeatedly pressed in the same manner as in the engagement portion with the key 1, the automatic spring fall function and the automatic centering function are activated, and a proper mounting state is maintained. The shape of the locked portion of the leaf spring and the shape of the key and the spring of the frame may be exchanged between the key side and the frame side in the above-described embodiment, or the leaf spring side and the key and the frame side. May be reversed. Further, the material of the leaf spring and the frame is not limited to the iron plate, but may be another metal or plastic, and the spring locking portion on the frame side may be formed as a dedicated spring seat. As described above, according to the present invention, the key and the key support member (keyboard frame) are provided with two leaf springs for giving the key a return behavior. Basically, it is engaged and supported, and even when other parts come into contact, it passes through the above points and comes into contact on a line parallel to the axis of rotation of the leaf spring accompanying the rotation of the key, so that sliding No frictional resistance or mechanical noise is generated. In addition, the displacement of the leaf spring in the width direction is restricted on the line, and the locking portion of the key and the key support member and the locked portion of the leaf spring form curved surfaces having different curvatures. There is a centering function and an automatic spring falling adjustment function, and the leaf spring is always maintained in an appropriate position and state. For this reason, the top of the key may tilt, the gap between adjacent keys may vary,
There is no variation in touch feeling due to frictional resistance.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a shape example of a key return leaf spring 3 and a shape example in the vicinity of a key side spring locking portion 1f and a frame side spring locking portion 2f in the keyboard device of FIG. It is a principal part exploded perspective view. FIG. 2 is a cross-sectional view of a keyboard device according to an embodiment of the present invention, taken along a key longitudinal direction. FIG. 3 is a top view of the vicinity of an engagement point between the key 1 and the leaf spring 3 shown in FIG. 1; FIG. 4 is a side view of the vicinity of the point of engagement between the key 1 and the leaf spring 3; FIG. 5 is a diagram for explaining the operation when the key is pressed. FIG. 6 is a sectional view in the key width direction near the engagement point between the key 1 and the leaf spring 13 before the stroke. FIG. 7 is a side view near an engagement point d between the frame 1 and the leaf spring 13 shown in FIG. FIG. 8 is a view for explaining the same operation. FIG. 9 is a sectional view similar to FIG. 2, showing an example of a conventional keyboard device. FIG. 10 is an explanatory view of the locked state of the key return leaf spring. [Description of Signs] 1 ... key, 1f ... key side spring locking portion, 1g ... shift restriction portion,
1h: Auxiliary support portion, 2: Keyboard frame, 2f: Spring locking portion on the keyboard frame side, 2g: Punched hole, 2h: Displacement restricting portion, 3: Key leaf spring, 3a, 3b: Locked portion, 3
c, 3d: claw for controlling displacement, c, d: engagement point

Claims (1)

(1) A key support member, a key rotatably supported by the key support member in a pushing and releasing direction, and a spring locking portion provided at one end with the key. And the other end is locked by a spring locking portion provided on the key support member, and constantly urges the key in the return direction, and both fulcrum portions of the key and the key support member are A key device for an electronic musical instrument, comprising: a key return leaf spring disposed so as to be pressed against each other. Each of the locked portions is provided at both ends in the longitudinal direction of the leaf spring, The key and the key locking member are each formed with a curved surface that is concave or convex in the longitudinal direction, and each of the locking portions of the key and the key support member has a different curvature from the curved surface of the locked portion. A convex or concave curved surface or a flat surface in the locking direction of the leaf spring, and each locked portion of the leaf spring and the key and the key support member. Of each spring locking portion for contacting respective points
Electronic musical instrument keyboard apparatus according to claim that it has to.