JP2008070417A - Keyboard device of electronic instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a keyboard device of an electronic instrument capable of controlling rolling motions of keys without disturbing rotating motions of the keys. <P>SOLUTION: A thin piece 2c is provided from the lower part to the rear of a rear end part 2b of each key. A key supporting member 3 is comprised of a supporting body part 3a, a hemi-cylindrical pressing member 3b and a hemi-cylindrical pressing member 3c. The thin piece 2c is a flat plate which is thin in a vertical direction of the key and is provided to extend in a longitudinal direction of the key and a width direction of the key, and has a function as a rotation supporting point part of the key. The pressing members 3b and 3c support the key so that a top end part 2a of the key can rotate in a touching/releasing key direction regarding a line along the width direction of the key as a rotation center line 5 by vertically pressing the thin piece 2c from the longitudinal direction of the key across the full width on the line along the width direction of the key. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a keyboard device for an electronic musical instrument, and more particularly to the structure of its pivot fulcrum.

In a conventional keyboard device for an electronic musical instrument, a key is supported by a frame via a pivot fulcrum portion behind a key body portion of each key (for example, FIG. 3, FIG. 8, FIG. 11 of Patent Document 1). FIG. 13). This rotation fulcrum is a fulcrum for the tip of the key to rotate in the direction of pressing and releasing keys.
The keyboard usually has a key position regulation structure called a key guide on the performer side of the key body, and a plurality of keys constituting the keyboard are arranged in the key rolling direction, that is, the key longitudinal direction (key depth). (Direction) as an axis, and the tip does not rotate in the key width direction (keyboard scale arrangement direction).

However, for example, when a key is formed using a mold, an error occurs or deforms with respect to the design dimension due to post-shrinkage or the like. Then, due to a slight error or key deformation, the key bends in the horizontal plane and rubs against the key guide or the adjacent key and cannot be rotated smoothly, causing problems such as generation of mechanical noise and deterioration of the key touch feeling.
Therefore, the key needs to have a degree of freedom that allows the key to rotate in the horizontal direction of the key in the horizontal plane around the pivot point.
For example, in Patent Document 1 described above, a bulging portion is provided on the right side wall surface of the projecting body provided on the base portion of the frame, a cylindrical surface is provided on the left side wall surface, and a concave curved surface is provided on the right side wall surface of the rotation fulcrum portion of the key. Provided, and the bulging portion is fitted into the concave curved surface.
On the other hand, in a keyboard in which the performer performs after-touch control by applying force in the width direction to the key during key depression, the key is positively moved in the horizontal direction around the pivot point. It needs to be able to rotate.

However, the rotation fulcrum structure described in Patent Document 1 described above requires advanced resin molding.
Further, when the key is rotated in the key release direction, the frame-side protrusion and the key rotation fulcrum slide while being in contact with each other. In addition, there is a problem that the contact portion is easily worn.

On the other hand, the piano keyboard of a natural musical instrument also includes a key fulcrum portion that is difficult to rotate in the key rolling direction and can be rotated in the left-right direction of the key. In view of this, it is conceivable to use a rotation fulcrum portion of a natural musical instrument piano for a keyboard device of an electronic musical instrument.
FIG. 14 is an explanatory diagram of a keyboard of an electronic musical instrument when a pivotal fulcrum part in a natural musical instrument piano is used.
14A is a plan view of the key, FIG. 14B is a right side view of the key, and FIG. 14C is a back portion of the key.
In the figure, 202 is a key body portion, 202a is a leading end portion (performer side), and 202b is a rear end portion thereof. The key body 202 is provided with a through hole 202c penetrating in the vertical direction.
A cylindrical protrusion (pin) 203 is erected on the frame 201. Reference numeral 203a denotes a base thereof, and the longitudinal direction of the key has a smooth inclined surface, and the lateral direction of the key is flat.

A through-hole 202c is provided in a rear region near the rear end 202b of the key body 202.
The side wall surface of the through hole 202c has a gradient that is nearly perpendicular to the longitudinal direction of the key but not perpendicular, and is perpendicular to the width direction of the key. As a result, as shown in FIG. 14A, the upper opening of the through hole 202c is an oval extending in the longitudinal direction of the key, and the lower opening is slightly larger than the outer diameter of the protrusion 203. It is almost circular. The width of the opening of the through hole 202c is slightly larger than the diameter of the protruding body 203, and there is a slight gap between the protruding body 203 and the through hole 202c.
The key body 202 is supported by the frame 201 by allowing the protruding body 203 to penetrate the through hole 202c. The key body 202 can be rotated in the direction of pressing and releasing with the upper end of the base 203a as a key rotation fulcrum, and can be rotated in the horizontal direction in the horizontal plane of the key, but does not rotate in the key rolling direction. .

As shown in FIG. 14 (c), the upper opening of the side wall surface of the through-hole 202c and the protruding body 203 are in contact with the rolling force of the key, and the lower opening and the protruding body 203 are in contact with each other. in that the contact, couple F _r acts, thereby suppressing rolling operation.
Here, since the suppressing force of this rolling operation is proportional to the distance between two points, that is, the height of the key body 202, the height of the key body 202 cannot be reduced. Therefore, it is difficult to adopt as it is as a keyboard device for an electronic musical instrument that is required to be reduced in size and weight.
In addition, since the vicinity of the key rotation fulcrum 204 is not pressed, there is a possibility that the key body 202 may come out of the protruding body 203 by a violent key pressing operation.
Therefore, in the piano keyboard, the rear portion of the key is further extended, and an action member is provided in the extended portion to prevent the piano keyboard from coming off.

Japanese Patent No. 2917859

  The present invention has been made to solve the above-described problems, and provides a keyboard apparatus for an electronic musical instrument that realizes suppression of a key rolling operation without interfering with a key rotation operation during a key pressing operation. It is for the purpose.

The present invention is the keyboard device of the electronic musical instrument according to the first aspect of the present invention, wherein the key is supported by the frame via the rotation fulcrum portion, and the key support portion is provided on the frame, and the key The moving fulcrum portion is a thin piece that is thin in the vertical direction of the key and extends in the width direction and the longitudinal direction of the key, and the key support portion includes at least two points on the width direction line of the key. When the key is pressed in the up-down direction, the key is supported so that the key can rotate in the pressing / releasing key direction with the width direction line of the key as the rotation center line.
Since the pivoting fulcrum is a thin piece, the moment that hinders the pivoting operation in the key pressing / releasing key direction is small. By pressing the thin piece from above and below at least two points on the line along the width direction of the key, the key rolling operation is suppressed. Since the key has the freedom to be positioned by moving or rotating in the horizontal direction at the key fulcrum, it prevents the key from rubbing against the key guide or adjacent key even if it is bent in the horizontal plane it can.

According to a second aspect of the present invention, in the keyboard device for an electronic musical instrument according to the first aspect, the key support portion includes an elastic member that generates an elastic repulsive force due to pressure, and the elastic repulsive force of the elastic member. Thus, the thin piece is pressed from above and below the key.
Since the elastic body absorbs shock vibration, it is possible to prevent mechanical noise from being generated at the key rotation fulcrum. The entire key support portion may be an elastic member, or may be a composite configuration in which an inelastic support body and an elastic body are combined.

According to a third aspect of the present invention, in the keyboard device for an electronic musical instrument according to the first aspect, a projecting body is erected on the frame, and the thin piece penetrates through the key in the vertical direction. Is provided, and the protruding body passes through the through hole.
Since the projecting body passes through the through hole of the thin piece, the key can move in the longitudinal direction of the key only within a slight gap between the through hole and the pin. While being determined within a predetermined range, it is possible to prevent the thin piece of the key from falling off the key support portion.

According to a fourth aspect of the present invention, in the keyboard device for an electronic musical instrument according to the third aspect, at least a part of the projecting body penetrating the through hole or one of the through holes is within a horizontal plane. It has an arcuate part centering on the center of rotation, and the other part of the through-hole or the other part of the through-hole has a contact part facing the arcuate part.
Therefore, the key can rotate in the horizontal plane while the arc-shaped portion and the contact portion face each other. As a result, even if the position is regulated by the through hole and the projecting body, it is possible to prevent the key from being bent in the horizontal plane and rubbed with the key guide or the adjacent key and cannot be smoothly rotated.
Further, since there is no need to have a gap between the arc-shaped portion and the contact portion, the rotation center line is less likely to be displaced during the rotation operation in the key pressing / releasing key direction.

According to a fifth aspect of the present invention, in the keyboard device for an electronic musical instrument according to the third aspect, at least one of the side wall surface of the portion where the protruding body passes through the through hole or the side wall surface of the through hole is provided. A non-vertical gradient is provided, and the gap between the wall surfaces on both sides is smaller in the lower opening of the through hole than in the upper opening of the through hole.
Since the gap between the side wall surface where the protrusion passes through the through hole and the side wall surface of the through hole is small in the lower opening, the key rotation center line has a gap larger than the thickness center of the thin piece. It is determined on the lower side that is getting smaller.
If the rotation center line is at the thickness center of the thin piece, a sliding motion that reciprocates in the longitudinal direction of the key occurs when the key is pressed, not only the position of the key is not fixed, but also between the thin piece and the pressing member. Due to the sliding friction, the durability of the key fulcrum is lowered.

According to a sixth aspect of the present invention, in the keyboard device of the electronic musical instrument according to the third aspect, the longitudinal edge of the key is rounded in at least one of the upper opening and the lower opening. Shape.
When the projecting body is in contact with the peripheral edge of the upper opening or the lower opening of the through-hole, it rotates while sliding, but the edge in the longitudinal direction of the key of this opening is rounded, The protrusions are less worn and the protrusions are less likely to be cut.

According to a seventh aspect of the present invention, in the keyboard device for an electronic musical instrument according to the sixth aspect, the thin piece is a sheet metal member, and a sagging surface when the through hole is punched into the sheet metal member is the through hole. It is attached to the lower surface of the key body so as to be on the side of the lower opening.
Accordingly, the through-hole can be formed by punching. In this case, the punching process naturally forms a sag surface where the periphery of the opening is rounded, so there is no need for post-processing.

According to an eighth aspect of the present invention, in the keyboard device for an electronic musical instrument according to the first aspect, the key support portion is configured such that the thin-walled piece is arranged in the vertical direction of the key in both end regions on the width direction line of the key. It is what is pressed from.
When the pressing force from the vertical direction of the key that presses the thin piece is applied at both ends of the key in the width direction of the key, the arm length of the moment that suppresses the key rolling becomes longer when applied at both ends in the width direction of the key. The effect is great.
However, the frictional resistance with respect to the rotation operation in the key pressing / releasing key direction is the total amount of the pressing force. Therefore, even if the pressing force from the up and down direction of the key that presses the thin piece is applied at the center in the width direction of the key or at both end regions in the width direction of the key, if the total amount of pressing force is the same, Since the frictional resistance with respect to the rotational movement of the key in the key pressing / releasing direction does not change, the adverse effect of the pressing force from the vertical direction of the key pressing the thin piece is the same.

  According to the present invention, the above-described configuration has an effect that the suppression of the key rolling operation can be realized by reducing the acting force that hinders the rotation operation of the key in the key pushing / releasing key direction.

FIG. 1 is an explanatory view showing a first embodiment of the present invention.
FIG. 1A is a right side view of one key and frame, and FIG. 1B is a rear view.
FIG. 2 schematically shows only a part related to the present invention, and is a key switch that is pressed by the lower part of the key main body 2 in response to a key pressing operation, a key guide described in the background art, and a key push-up / down The description of the upper and lower limit stopper pieces for regulating the position is omitted.
The keyboard device of an electronic musical instrument has a plurality of white keys and black keys. One white key will be described below.

In FIG. 1A, 1 is a frame. Reference numeral 2 denotes a key body portion of each key, the front end portion 2a of which is a free end portion, and has a thin piece 2c from the lower end of the rear end portion 2b to the rear, and this thin piece 2c is an upper portion of the rear end portion 2b. It is reinforced diagonally by a triangular rib 2d. The rib 2d is a plate having a predetermined thickness in the key width direction.
In the illustrated non-key-pressed state, the key body 2 is urged by a spring or the like (not shown) so that the front end 2a is raised above the rear end 2b.
Reference numeral 3 denotes a key support portion. In the illustrated example, an inverted L-shaped support main body portion 3a, a semi-columnar pressing member 3b fixed to the lower surface thereof, and a semi-columnar shape fixed to the upper surface of the frame 1 are shown. The support main body 3a is fixed to the rear end wall of the frame 1 by screws 4. The pressing members 3b and 3c may be filled with a content, or may be hollow or cap-shaped without a bottom surface.

The thin piece 2c is a flat plate that is thin in the vertical direction of the key and extends in the longitudinal direction of the key (the depth direction of the key) and in the width direction of the key (the scale arrangement direction of the keyboard). It has a function.
The pressing members 3b and 3c do not necessarily have a semi-cylindrical shape. The pressing members 3b and 3c may have a curved surface that comes into linear contact with the thin piece 2c. For example, the cross-section when cut in the longitudinal direction of the key is half The cross section of the ellipse when cut in the left-right direction of the key may be rectangular.

As shown in the rear view of FIG. 1 (b), the thin piece 2 c has a predetermined width in the key width direction, and is extended and extended to the left and right of the width of the key body 2.
In the illustrated example, the pressing members 3b and 3c of the key support portion 3 have substantially the same width as the thin piece 2c, and press the thin piece 2c from the vertical direction of the key over the entire width along the width direction of the key. Thus, the above-described line along the key width direction is set as the rotation center line 5 so that the tip end portion 2a of the key is supported so as to be rotatable in the pressing / releasing key direction.

The range in which the pressing members 3b and 3c of the key support portion 3 press the thin piece 2c is not a single point in the center position in the width direction of the key, but covers a predetermined range w _{1 in the} key width direction (see FIG. 1A). Therefore, the longer the w ₁ is, the more the key rolling operation is suppressed. Since the height of the key body 2 is not involved, the height of the key body 2 can be reduced.
On the other hand, even if the thin piece 2c is pressed by the pressing members 3b and 3c, the key has a degree of freedom to rotate in the horizontal direction in the horizontal plane.

FIG. 2 is a principle diagram for explaining the turning operation of the key shown in FIG.
The thin piece 2c receives the supporting force F necessary for fixing the key up / down position from the pressing member 3b at the contact point p ₁ (becomes a restraint location) with the pressing member 3b, and contacts the contact point p ₂ (restraint location) with the pressing member 3c. The force F is received from the pressing member 3c. When the key rotates in the pushing / separating direction, the rotation center line 5 is estimated to be at the midpoint of the straight line connecting the contact point p ₁ and the contact point p ₂ .
When the key body 2 is rotated (angle θ) in the pushing direction to become the key body 2 ′, the thin piece 2c is rotated into the thin piece 2c ′. What was at the contacts p ₁ and p ₂ slides and moves to the contacts p ₁ ′ and p ₂ ′. As a result, a frictional force that resists rotation is generated. When the friction coefficient is μ and the distance (thickness) between the contacts p ₁ and p ₂ is d, the moment around the key rotation center 5 is μFd and the sliding distance is dθ.
Here, since the distance d is very small because 2c is a thin-walled piece, the moment restraining the rotation can be reduced.

Therefore, it can be seen that the above-described pressing structure for suppressing the rolling operation hardly disturbs the rotating operation during the key pressing operation.
The width of the thin piece 2c pressed by the pressing members 3b and 3c should be adjusted as appropriate depending on the magnitude of the pressing force, the frictional resistance, and the like. The width may be the same as or smaller than the width of.

FIG. 3 is an explanatory view showing a modification of the embodiment shown in FIGS.
In this modified example, instead of the key support portion 3 shown in FIG. 1, a key support portion 11 having an elastic member that generates an elastic repulsive force due to pressurization is used, and a coiled spring 11d is used as the elastic member. The key support portion 3 presses the thin piece 2c from the up and down direction of the key by the elastic repulsive force of the member.
Also in the key support part 3 shown in FIG. 1, the key support part 3 or the thin piece 2c has some elasticity, but in this modification, an elastic member is positively adopted. Since the elastic member absorbs shock vibration, it is possible to prevent mechanical noise from being generated at the key rotation fulcrum.
When an elastic member such as a coiled spring 11d is used, the pressing member 11b can move in the longitudinal direction of the key. Therefore, the pressing member 11b also moves in the longitudinal direction of the key as the thin piece 2c rotates. There is a case. Therefore, the meat piece 2c does not necessarily slide with respect to the pressing member 11b.

The key support portion 11 includes an inverted L-shaped support main body portion 11a, a coiled spring 11d fixed to the lower surface thereof, a semi-columnar pressing member 11b biased by the compression spring 11d, and an upper surface of the frame 1. It consists of a fixed semi-cylindrical pressing member 11b, and the support main body 11a is fixed to the rear end wall of the frame by screws 4.
The pressing members 11b and 11c may be hard with little elastic deformation. The pressing members 11b and 11c may be hollow caps or may be filled with contents. The compression spring 11d may be provided on the pressing member 11c side. The compression spring 11d is not limited to the illustrated coil shape, and may be a leaf spring.
Instead of or in combination with the compression spring 11d, at least one of the pressing members 11b and 11c may be a different type of elastic member, for example, polyurethane foam.

In the embodiment described with reference to FIGS. 1 and 3, the rolling operation is suppressed, but the thin piece 2c moves in the horizontal plane, and the position of the rotation center line 5 of the key is the longitudinal direction of the key, the key There is a risk that the key may collide with the key guide or the adjacent key, or may be dropped from the pressing members 11b and 11c.
Therefore, a configuration is added in which the position is regulated in the width direction of the key and the longitudinal direction of the key.

FIG. 4 is a perspective view showing a structure for regulating the position in the width direction of the key and the longitudinal direction of the key in the embodiment shown in FIGS. As for the key support portion, only the pressing member is shown, and the support main body portion is not shown.
FIG. 4 (a) is provided with a key rotation shaft.
In the figure, reference numeral 21 denotes a rotation shaft portion provided on the extension of the rotation center line 5 of the thin piece 2c.
Reference numerals 22a and 22b denote rotating shaft clamping portions, which are erected on the frame 1 (not shown) and are adjacent to the right side of the end portion of the thin piece 2c in the key width direction. On the other hand, the rotating shaft clamping portions 22c and 22d are adjacent to the left side of the end portion of the thin piece 2c in the key width direction. By inserting the key rotation shaft portion 21 between them, the position of the key rotation shaft portion 21 is regulated in the key width direction and the key longitudinal direction.

FIG. 4B shows a case where a through hole and a projecting body are provided.
In the figure, 32 is a key body part, 32a is a tip part, 32b is a rear end part, 32c is a thin piece, and 32d is a rib. The thin piece 32c shown in the drawing also has a width that extends from the key body 32 to the left and right. 32e is a through-hole provided in the thin piece 32c. The arrangement is centered in the center in the width direction at the rear end portion 32 b of the key and intersects the rotation center line 35.

In principle, as in the conventional piano-type pivoting fulcrum shown in FIG. 14, a projecting body 34 is erected on a frame (not shown), and the thin-walled piece 32c has a through-hole penetrating in the vertical direction of the key. 32e is provided, and the projecting body 34 penetrates through this.
In the illustrated example, the horizontal cross section of the protrusion 34 is circular, and the through hole 32 e is a circle having a slightly larger diameter than the horizontal cross section of the protrusion 34.
When a frame (not shown) is formed by resin molding using a mold, the protruding body 34 can be molded integrally with the frame.

As described above, since the protrusion 34 is provided at the center in the width direction of the key, the pressing member of the key support portion avoids the central region in the width direction of the key. In the illustrated example, the central portions of the pressing members 3b and 3c are eliminated, and the pressing members 33a and 33b and the pressing members 33c and 33d are used. The right side region of the thin piece 32c is pressed from above and below by the pressing members 33a and 33c. The region on the left side in the width direction of the thin piece 32c is pressed from above and below by the pressing members 33b and 33d.
By inserting the protruding body 34 into the through hole 32c, the thin piece 32c (key fulcrum) can be rotated in the direction of pressing and releasing with the thickness center of the thin piece 32c (key fulcrum) as the key rotation center 35. It can rotate in the horizontal direction in the horizontal plane.

FIG. 5 is an explanatory view showing a second embodiment of the present invention.
What is applied to the second specific example shown in FIG. 4B will be described.
FIG. 5A is a perspective view showing the entire key, FIG. 5B is a right side view of the rear side of the key body, and FIG. 5C is a rear view.
In this embodiment, instead of the pressing members 33a and 33b, hemispherical pressing members 36a and 36b are used to press the upper surface of the thin piece 32c at two points in both end regions on the line along the key width direction. ing.
The half of the distance w ₃ between the two points is the arm length of the supporting force F necessary for fixing the vertical position of the key, and a rotational moment that suppresses rolling rotation.

On the other hand, as shown in FIGS. 1 to 4, when the thin pieces 2c and 32c are pressed with the indicating force evenly distributed in the width direction of the key, the support force applied to the central portion in the width direction of the key is the length of the arm. Considering this, it hardly contributes to prevention of rolling operation.
On the other hand, as shown in FIG. 2, when the key is rotated in the key pressing direction, sliding is accompanied and there is a constant frictional force of μF. Accordingly, it is most efficient to apply the pressing position intensively close to both ends in the width direction of the thin piece 32c (both end regions shown in the figure).

The hemispherical pressing members 35a and 35b may have a hollow shape or a cap shape without a bottom surface with a spherical outer shape in addition to a dense inner portion. The curved surface is not limited to a spherical surface, and may be any curved surface that comes into contact with the thin piece 32c in a point shape.
The lower pressing members 33c and 33d may be replaced with a hemispherical pressing member. If it does so, it will be two point support in the up-and-down direction.

Incidentally, as in FIG. 4, the semi-cylindrical pressing member 33a, 33b, further, the semi-cylindrical pressure member 33c, even 33d, after having reduced the width w _2, the pressing position thin piece of meat It may be added intensively close to both ends in the width direction of 32c.
In FIG. 4B, the protrusion 34 has a columnar shape, and the through hole 32e also has a circular opening, thereby enabling rotation in the key pressing direction and free rotation in a horizontal plane. However, other shapes can be employed as the protrusions and the through holes.

FIG. 6 is an explanatory diagram showing a modification of the second specific example shown in FIG.
In the figure, 42 is a key body portion, 42a is a tip portion, 42b is a rear end portion, 42c is a thin piece, and 42d is a rib. The illustrated thin-walled piece 42c also has a width that extends from the key body portion 42 to the left and right. Reference numeral 43 denotes a through hole provided in the thin piece 42c.
A protruding body 44 is erected on the frame and penetrates the through hole 43. The through holes 43 and the protrusions 44 are arranged at the center in the width direction at the rear end portion 42b of the key and intersect the rotation center line 45, and this point is set as the rotation center 46 in the horizontal plane. .
The members that press the thin piece 42c from above and below may be the linearly contacting pressing members 33a to 33d shown in FIG. 4B, as shown by the broken lines in the figure, and also shown in FIG. Alternatively, the pressing members 36a and 36b may be in point contact.

In this modification, the protruding body 44 has a prismatic shape and has side wall surfaces parallel to the longitudinal direction of the key and the width direction of the key. The horizontal cross section of the portion where the protruding body 44 passes through the through hole 43 is rectangular, but it can be rotated in the horizontal direction in the horizontal plane.
As shown in FIG. 6B, the through-hole 43 is a rectangle larger than the protruding body 44 as a whole, and has side wall surfaces parallel to the longitudinal direction of the key and the width direction of the key. A gap is formed between the two, but in the figure, the gap is represented by a dot pattern.

Contact portions 43 a to 43 d are provided on the side wall surface of the through hole 43 toward the in-horizontal rotation center 46. Only subscripts a to d are shown in the figure. The shapes of the contact portions 43a to 43d shown in the figure are protrusion shapes with rounded tips.
By providing a minute gap between each contact portion 43a to 43d and each side wall surface of the projecting body 44 opposed thereto, the thin piece 42c can be pushed and released with the rotation center line 45 as the center. Rotation in the key direction and horizontal rotation in the horizontal plane around the horizontal rotation center 46 are possible. Since the gap may be very small, the position of the key is generally restricted.

FIG. 7 is an explanatory view showing still another example of the through hole and the projecting body shown in FIG.
In Fig.7 (a), the through-hole 43 provided in the thin piece 42c is the same shape as the through-hole 43 shown in FIG. 6, and has contact parts 43a-43d. Only subscripts a to d are shown in the figure.
On the other hand, the projecting body 51 has a two-stage arc shape centering on the rotation center 46 in the horizontal plane in the cross section passing through the through-hole 43, and faces the contact portions 43a to 43d. Has a wall.
The arc-shaped side wall surfaces facing the contact portions 43a and 43c have a small diameter, and the arc-shaped portions facing the contact portions 43b and 43d have a large diameter, but are concentric arcs centered on the rotation center 46 in the horizontal plane.

With such a configuration, rotation in a horizontal plane is possible even if there is little or no gap between the contact portions 43a to 43d and the arcuate side wall surface. Therefore, rotation in the horizontal plane is restricted by another structure such as a key guide. In particular, it is suitable for a keyboard that enables a performance technique in which keys are pressed to the left and right in the horizontal direction.
Since the gap can be narrowed, the position of the rotation center line 45 in the key longitudinal direction is accurately determined.

FIG. 7B shows the reverse relationship between the shape of the through-hole 43 and the cross-sectional shape of the protruding body 51 in FIG.
The through-hole 52 has concentric arcuate side wall surfaces 52 a to 52 d centering on the rotation center 46 in the horizontal plane. Only subscripts a to d are shown in the figure. The projecting body 53 has cross-shaped contact portions 53 a to 53 d with rounded tips, with the center of rotation in the horizontal plane 46 as the center point in the cross section of the portion that penetrates the through hole 52. The contact portions 3a to 53d are opposed to the arc-shaped portions 52a to 52d, respectively.

In FIG. 7C, the through hole 54 has a fan shape, and the projecting body 55 has an isosceles triangle in the cross section of the portion passing through the through hole 54. The apex angle 55a of the isosceles triangle (only the subscript a common to the sectoral key 54a is entered) coincides with the sectoral key 54a (only the subscript a is entered), and the two outer angles 55b of the triangle , 55c (only the subscripts b and c are entered) are opposed to two points on the arc of the through hole 54. These 55a-55c become a contact part with respect to the through-hole 54. FIG.
The apex angle 55a of the isosceles triangle is set as the rotation center 46 in the horizontal plane, and the rotation center line 45 passes therethrough.

7D, the through hole 56 has a rectangular shape, and has side wall surfaces parallel to the longitudinal direction of the key and the width direction of the key. Of these, the contact portions 56a and 56b are arranged at the centers of the sides parallel to the width direction of the key. (Only subscripts a and b are entered). The contact portion 56b has a sharp knife-edge-like protrusion shape.
In the cross section of the portion passing through the through hole 56, the projecting body 57 has one side surface as an arcuate side wall surface centered on the horizontal center rotation center 46 and the opposite side surface as a sharp recess.
Opposing to the contact portion 56a is an arcuate side wall surface. A concave portion is opposed to the contact portion 56b, and this contact point is set as the horizontal rotation center 46 and the rotation center line 45 passes therethrough.

In FIG. 7 (e), arc-shaped through holes 58 and 59 having a width are provided, and two columnar projecting bodies 60 and 61 are provided and penetrated through the through holes 58 and 59. The arc itself of the projecting body 60 becomes contact portions 60a and 60b (only suffixes a and b are written), the projecting body 60 faces the through hole 58, and the arc itself of the projecting body 61 is the contact portion 61a. , 61b (only the subscripts a and b are written), and the projecting body 61 faces the through hole 59.
The arcs of the through holes 58 and 59 are centered on the rotation center 46 in the horizontal plane.

FIG. 7F shows the shape of the through holes 58 and 59 in FIG.
The rectangular through holes 62 and 63 are provided, and two arcuate protrusions 64 and 65 are provided. The through holes 62 and 63 are in contact with each other in the width direction of the key from the rotation center 46 in the horizontal plane. The parts 62a and 62b (in which only the subscripts a and b are written) protrude and face the concave parts of the projecting bodies 64 and 65. The arcs of the projecting bodies 64 and 65 are centered on the rotation center 46 in the horizontal plane.

Next, in the second specific example of the present invention described with reference to FIG. 4B, the problem of the key turning operation when the position is regulated by the through hole and the protruding body will be described. .
FIG. 8 is a vertical sectional view of the structure shown in FIG. 4B taken along the longitudinal direction of the key.
FIG. 8A is a state in which the key body is in a horizontal position, FIG. 8B is a key released state of the key body, and FIG. 8C is a cross-sectional view in a key pressed state of the key body.

There is a slight gap between the side wall surface of the through hole 32e provided in the thin piece 32c and the side wall surface of the outer periphery of the protruding body 34 erected from the frame 31. By this gap, rotation is possible in the key pressing operation.
As shown in FIG. 8B, in the key release state, the front end portion 32a (outside the range shown) of the key is raised above the rear end portion 32b of the key.
In this case, the thin meat 32c and the protruding bodies 34 abut, the longitudinal position of the key in the rear contacts p ₆ Tokyo under the opening of the front contact point p ₃ and the through hole 32e of the upper opening of the through hole 32e Is determined.
On the other hand, as shown in FIG. 8C, in the key-pressed state, the leading end portion 32a of the key is lower than the rear end portion 32b of the key.
In this case, the thin meat 32c and the protruding bodies 34 abut, the longitudinal position of the key in the lower opening of the front contact p ₅ Metropolitan on opening of the rear contact point p ₄ and the through hole 32e of the through hole 32e Is determined.

However, in the horizontal state of the key shown in FIG. 8A, since there is a gap in the longitudinal direction of the key, the position regulation by the thin piece 32c and the protruding body 34 does not work, and the longitudinal direction of the key due to external factors. The position of the direction will change. Therefore, there is a problem that the position of the rotation center line 35 is not determined.
Further, during the key pressing operation, as described with reference to FIG. 2 in the process from FIG. 8 (b) through FIG. 8 (a) to FIG. 8 (c) and vice versa, as shown in FIG. Since there is sliding between the piece 32c and the pressing members 33a to 33d, there is a problem that durability of these members is lowered.

Therefore, a specific example for reducing the gap in the longitudinal direction of the key between the thin piece 32c and the projecting body 34, the position of which is regulated, will be described below.
FIG. 9 is an explanatory view showing a specific example in which the structure of the through hole and the protruding body is improved in the second specific example shown in FIG. 8, ie, FIG. 4B.
In FIG. 9A, reference numeral 81 denotes a through-hole 81 provided in the thin-walled piece 32c, and in the longitudinal direction of the key, the side wall surface has a gradient that is nearly vertical but not vertical.
Accordingly, the cross-section in the longitudinal direction of the key of the through hole 81 is smaller in the lower opening than the upper opening, and the gap with the side wall surface of the protrusion 34 is very small in the lower opening.

9 (a), the when the key is rotated, the thin meat 32c and the protruding bodies 34, while in contact with the rear contact p ₆ in the front contacts p ₅ and the lower opening of the through-holes 81 lower opening times Move.
Therefore, the key rotation center line 82 is not the thickness center of the thin piece 32c as shown in FIG. 2, but is a point close to the contact point with the pressing members 33c and 33d closer to the lower surface. In FIG. 9A, a rotation center line 82 is shown at this contact point.

Even if the gap between the edge of the lower opening of the through-hole 81 and the side wall surface of the projecting body 34 is small, the rotation hardly affects the front contact p _{5 at} the lower opening of the through-hole 81. by the abutment of the rear contact p _6, during the key rotation operation, the longitudinal position regulation of the key, hardly move pivot axis 82.
Further, since the rotation center line 82 is close to the lower surface of the thin piece 32c, the sliding distance between the thin piece 32c and the pressing members 33c and 33d is reduced, so that the durability of these members is improved.
On the other hand, the sliding distance becomes longer between the thin piece 32c and the pressing members 33a and 33b. However, if the weight of the key is taken into account, the weight of the key is not affected between the thin piece 32c and the upper pressing members 33a and 33b, so that the influence is small.

In FIG. 9 (b), the through-hole 32c is not changed and is formed into a cylindrical vertical side wall surface, and the protruding body 83 is formed with a side wall surface at a portion passing through the through-hole 32c with respect to the longitudinal direction of the key. Inclined with a non-vertical gradient. The protrusion 83 has a truncated cone or a shape close to a truncated cone.
As a result, with respect to the longitudinal direction of the key, the gap between the side walls of the through hole 32e and the protruding body 83 is smaller at the lower opening than the upper opening of the through hole 32e, and a slight gap at the lower opening. It has become.

FIG. 9C is a combination of the configurations of FIG. 9A and FIG. 9B.
In the longitudinal direction of the key, a gradient that is not perpendicular to the side wall surface of the through hole 84 is provided. At the same time, the protruding body 85 is configured such that the side wall surface where the protruding body 85 passes through the through hole 84 is inclined with a non-perpendicular gradient in the longitudinal direction of the key.
As a result, the gap between the through hole 84 and the protruding body 85 is smaller at the lower opening than the upper opening of the through hole 84.

Therefore, in the structure shown in FIGS. 9B and 9C, when the key is rotated, the key pivot point 82 of the thin piece 32c is the same as in FIG. 9A. It is determined closer to the lower surface, and the positioning of the key in the longitudinal direction and the durability of the rotation fulcrum are improved.
In the above description, the description has been made on the assumption of the configuration shown in FIG. 4B. However, regarding the configuration of the through hole and the protrusion in the modification shown in FIGS. Can be modified in the same way.

Here, the protrusions 34 and the like abut against the edge of the lower opening of the through hole 81 and the like. This edge is sharp or right-angled and sharp. Therefore, when the thin piece 32c rotates during the key pressing operation, the thin piece 32c slides while contacting the edge. Therefore, there is a problem that the protrusions 34 and the like are scraped off.
Further, the closer the projecting body is to a cylinder like the projecting body 34 shown in FIG. 8, the more the projecting body 34 and the like are in the upper openings of the through holes shown as the contacts p ₃ and p ₄ . There is a problem that sliding occurs while abutting the edge, and the protruding body 34 is similarly scraped off.

FIG. 10 is an explanatory view showing a modified example in which the structure of the through hole is improved in the second specific example and the modified example shown in FIG. In the structure shown in FIG. 9B, the description will be made on the assumption that the gradient of the protruding body 83 is increased and the gradient is close to the vertical like the columnar protruding body 34 of FIG.
91 is a through hole provided in the thin piece 32c, and 92 is a projecting body.
The through hole 91 has a shape in which the edge in the longitudinal direction of the key is rounded at the upper opening and the lower opening. In this case, the diameter of the protrusion 92 is slightly larger than before the edge is rounded so that the side wall of the through hole 91 and the side wall of the protrusion 92 are in contact with each other.

As a result, as shown in FIG. 10 (b), when the leading end of the key is raised above the rear end 32b, the protruding body 92 has the front contact p ₃ of the upper opening of the through hole 91 and the lower opening. those wear when sliding is reduced while being in contact with the edge portion of the rear contact point p ₆ in.
On the other hand, as shown in FIG. 10 (c), the tip portion of the key when the down than the rear end portion 32b, the front contact p ₅ on the rear contacts p ₄ and the lower opening of the opening of the through-holes 91 Wear when sliding while abutting the edge is reduced.

FIG. 11 is an explanatory diagram showing an example in which the structure of the through hole is modified in the specific example shown in FIG.
FIG. 11A shows a case where the edge in the longitudinal direction of the key is rounded only for the upper opening of the through-hole 93. As a result, wear when sliding while contacting the edge of the front contact p ₃ and the rear contact p ₄ of the upper opening of the through hole 93 is reduced.
FIG. 11B shows a case where the edge in the longitudinal direction of the key is rounded only for the lower opening of the through hole 94. As a result, wear during sliding while abutting against the edges of the front contact p ₅ and the rear contact p ₆ of the lower opening of the through hole 94 is reduced. Since the weight of the key is added to the lower opening, the effect of preventing wear by rounding the edge is great.

FIG. 11C shows the thin piece 95 as a sheet metal member. When the sheet metal member is punched and the through hole 96 is provided, a sagging surface is generated on one surface. In view of this, the sagging surface has a shape in which the entire periphery of the edge of the opening is rounded. In the example shown in the figure, the opening corresponding to the sag surface is set on the lower surface side, thereby providing a structure corresponding to FIG.
The thin piece 95 is fixed to the lower surface of the key main body 97 by a fixing member such as a screw 98 in the rear end region of the key main body 94 that does not include the thin piece.

The configuration of the through hole and the protrusion in the modification shown in FIGS. 6 and 7 can also be improved in the same manner as FIGS. 10 and 11 with respect to the gap in the longitudinal direction of the key.
The second embodiment shown in FIG. 5 is provided with a through hole and a projecting body as in FIG. 4B in the first embodiment.
However, also in the second embodiment of the present invention, the rotation shaft portion shown in FIG. Moreover, the key support part may have an elastic member similarly to FIG.
Furthermore, also in the second embodiment of the present invention, the specific examples shown in FIGS. 6 to 11 in the first embodiment may be adopted as the structure of the through holes and the protrusions.

In the above description, the structure of the rotation fulcrum portion and the key support portion has been described for one white key.
However, the keyboard device can be realized only when a plurality of white keys and black keys are arranged in the scale arrangement direction. Therefore, if the same structure of the rotation fulcrum part and the key support part is adopted for any adjacent white key or black key, the width of the thin piece (2c in FIG. 1 etc.) described above is the width of the rear end part of the key. Since it cannot extend beyond the width, the width of the thin piece is made equal to the key width at the rear end of the key.
However, since the pressing position by the pressing member can suppress rolling as it moves away from the center in the width direction of the key, it is desired to expand the width of the thin piece more than the width of the rear end portion of the key.

Therefore, for example, for each adjacent key, a thin piece extending backward from the rear end of the key is extended by changing the height position of the key in the vertical direction. It suffices that the thin-walled pieces are alternately arranged in two upper and lower stages.
At this time, the arrangement of the key support portion is facilitated by shifting the position of the thin-walled piece alternately in the longitudinal direction of the key for each key.

FIG. 12 is an explanatory diagram showing an example of a keyboard structure in which a key support portion is arranged in a keyboard device in which a plurality of white keys and black keys are arranged in parallel.
FIG. 13 is a perspective view of the keyboard structure shown in FIG.
Only a plurality of keys, for example, a white key (B key) main body 102, a white key (C key) main body 103, a black key (C ^# key) main body 104, and a white key (D key) main body 105 are key frames. This is an example of being placed on (frame) 101. The subscript “a” indicates a tip portion on the key operation portion (viewing portion) side.
In FIG. 12, the white key (B key) main body 102 is indicated by an imaginary line. In this figure, illustration of the pressing member is omitted.

The illustrated key uses a long key in which the key body portion extends further rearward than the key operation portion. Thin-walled pieces 102c to 105c as key fulcrum portions are extended from rear end portions 102b to 105b at the rear of the key body portion.
The width of the thin pieces 102c to 105c is extended and extended from the key width at the rear end portions 102b to 105b.
The thin pieces 102c to 105c are provided with through holes 102d to 105d, and the protruding body 113 passes through these through the key frame 101 side.

However, the thin pieces 103c, 105c of the white key (C key) main body 103 and the white key (D key) main body 105 are directly connected to the rear ends 103b, 105b, and the white key (B key) main body 102, black The thin pieces 102c and 104c of the key (C ^# key) main body 104 are coupled to each other via connecting portions 102e and 104e extending from the rear end portions 102b and 105b in the longitudinal direction of the key.
In the illustrated example, the widths of the coupling portions 102e and 104e are equal to the key width at the rear end portion, and the thickness thereof is equal to the thickness of the thin pieces 102c and 104c. As a result, the connecting portions 102e and 104e and the thin pieces 102c and 104c in a T shape are coupled to the rear end portions 102b and 104b.

The thin pieces 103c and 105c and the thin pieces 102c and 104c described above are alternately provided in the key arrangement direction, with the former placed on the lower side and the latter placed on the upper side.
That is, the thin pieces of the C key, D key, E key, F ^# key, G ^# key, and A ^# key are on the lower side, and the C ^# key, D ^# key, F key, G key, A key, and B key The thin-walled pieces are alternately arranged on the upper side.
The latter connecting portions 102e and 104e and the like overlap the former thin pieces 103c and 105c. However, by providing the through holes 102f and 104f in the connecting portions 102e and 104e, the left and right ends of the former thin piece are exposed.
For example, from the through-hole portion 104f of the connecting portion 104e, the right end portion of the thin piece 103c of the white key (C key) main body portion 103 adjacent to the left and the thin piece of the white key (D key) main body portion 105 adjacent to the right. The left end portion of 105c is exposed.

Reference numeral 106 denotes a white key guide portion provided on the key frame 101, which is inserted between the left and right side surfaces of the white keys 102, 103, 105 to regulate the position in the width direction of the key. The through hole 107 is provided in the key frame 101, and rotates a non-drive portion of an action member (hammer mechanism) (not shown) through a drive portion provided below the white keys 102, 103, and 105.
Similarly, 108 is a black key guide portion provided on the key frame 101 and is inserted between the left and right side portions of the black key 104 to restrict the position in the width direction of the key. The through hole 109 is provided in the key frame 101, passes through the front extension 104g provided in the lower part of the black key 104 in the downward direction, and an action (not shown) by a drive unit provided at the front end of the front extension 104g. The non-driving part of the member is rotated.

Reference numeral 110 denotes a spacer provided on the key frame 101 for attaching a switch board (not shown) by screwing. Reference numeral 111 denotes a key switch through hole provided in the key frame 101, which passes through an actuator provided in the lower part of each key in the downward direction. Press.
Reference numeral 112 denotes a compression coil spring for returning the key that has been pressed to the original rotational position. Without using this compression coil spring 112, the rotational position of the key may be returned by the force in the return direction of the action mechanism.

  FIG. 13 shows pressing members 121 to 127 that press the thin pieces 102c to 105c and the like shown in FIG. Although the illustration of the structure of the key support portion other than the pressing member is omitted, for example, as shown in FIG. 3, the assembly formed by the pressing member, the spring, and the support main body portion is connected to the rear end wall 101 a of the key frame 101. Can be attached with screws.

In the figure, 121d is one of four pressing members for a white key (E key) (not shown), and 122d is one of four pressing members for a black key (D ^# key) (not shown). is there.
123a to 123c are pressing members that press the thin piece 105c from above and below, and 123d is hidden. Among these, the upper pressing member 123b enters the through-hole portion 104f provided in the connecting portion 104e and presses the thin piece 105c.
Reference numerals 124a to 124c denote pressing members that press the thin piece 104c, and 124d is hidden.

125a and 125b are pressing members that press the thin piece 103c, and 125c and 125d are hidden. Of these, the upper pressing members 125a and 125b enter the through-hole portion 104f or 102f provided in the connecting portion 104e or 102e and press the thin piece 103c.
The pressing members 125b and 127a are shown shifted upward so that the inner surface of the through hole portion 102f can be seen.
126a and 126b are pressing members that press the thin-walled piece 102c, and 126c and 126d are hidden.
127a and 127d are two of four pressing members for a black key (A ^# key) (not shown).

The upper and lower positions of the thin pieces 104c, 102c extending in the longitudinal direction of the key from the rear end portions 104b, 102b via the connecting portions 104e, 102e are thin pieces 105c, It is set higher than the vertical position of 103c.
Therefore, the lower pressing member for the upper thin piece 104c, for example, the pressing member 124c, is longer in the vertical direction than the lower pressing member 123c for the lower thin piece 105c, for example, the pressing member 123d. And mounted on the key frame 101.
Since the lower pressing members adjacent to each other, for example, the pressing members 121d and 123c are fixed to the key frame 101, they may be integrated pressing members.

It is explanatory drawing which shows the 1st Embodiment of this invention. It is a principle figure explaining the rotation operation | movement of the key shown in FIG. It is explanatory drawing which shows the modification of embodiment shown in FIG. 1, FIG. FIG. 4 is a perspective view showing a structure for regulating the position in the width direction of the key and the longitudinal direction of the key in the embodiment shown in FIGS. 1 and 3. It is explanatory drawing which shows the 2nd Embodiment of this invention. It is explanatory drawing which shows the modification of the 2nd specific example shown in FIG.4 (b). It is explanatory drawing which shows another example regarding the through-hole and protrusion which were shown in FIG. FIG. 5 is a vertical sectional view of the structure shown in FIG. 4B when cut along the longitudinal direction of the key. FIG. 8 is an explanatory diagram showing a specific example in which the structure of the through hole and the protrusion is improved in the second specific example shown in FIG. 8, that is, FIG. FIG. 5 is an explanatory view showing a modified example in which the structure of the through hole is improved in the second specific example and the modified example shown in FIG. It is explanatory drawing which shows the modification of the structure of the through-hole and protrusion which were shown in FIG. It is explanatory drawing which shows an example of the keyboard structure which has arrange | positioned the key support part in the keyboard apparatus in which the several white key and the black key were arranged in parallel. It is a perspective view of the keyboard structure shown in FIG. It is explanatory drawing of the keyboard of an electronic musical instrument at the time of using the rotation fulcrum part in the piano of a natural musical instrument.

Explanation of symbols

1,31 ... Frame,
2, 32, 42, 97 ... key body,
2c, 32c, 42c, 95 ... thin pieces,
32e, 43, 52, 54, 56, 58, 61, 62, 63, 81, 84, 91, 93, 94, 96 ... through holes,
43a-43d, 53a-53d, 55a-55c, 56a, 56b, 60a, 60b, 61a, 61b, 62a, 62b ... contact part,
3, 11 ... Key support,
3b, 3c, 11b, 11c, 33a to 33d, 36a, 36b ... pressing members,
34, 44, 51, 53, 55, 57, 60, 61, 64, 65, 83, 85, 92 ... projecting bodies,
5, 35, 45, 82 ... rotation center line,
11d ... Coiled spring (elastic member),
46 ... Rotation center in horizontal plane

  DESCRIPTION OF SYMBOLS 101 ... Key frame (frame), 102a, 103a, 105a ... The tip part of a white key main-body part, 104a ... The tip part of a black key main-body part, 102c-105c ... Thin-walled piece, 102d-105d ... Through-hole, 102e, 104e ... Connecting part, 102f, 104f ... through hole part, pressing members 121-127 ... pressing member, 113 ... projecting body

Claims (8)

A keyboard device for an electronic musical instrument in which a key is supported by a frame via a pivotal fulcrum,
A key support is provided on the frame;
The key rotation fulcrum portion is a thin piece extending thinly in the vertical direction of the key and extending in the width direction and the longitudinal direction of the key,
The key support portion presses the thin piece from the vertical direction of the key at at least two points on the key width direction line, so that the key width direction line is a rotation center line with respect to the frame. Supporting the key so that it can rotate in the direction of pressing and releasing keys;
A keyboard device for an electronic musical instrument. The key support portion has an elastic member that generates an elastic repulsion force by pressurization,
The thin piece is pressed from the vertical direction of the key by the elastic repulsive force of the elastic member.
The keyboard device for an electronic musical instrument according to claim 1. A protrusion is erected on the frame,
The thin piece is provided with a through hole penetrating in the vertical direction of the key,
The protruding body passes through the through hole,
The keyboard device for an electronic musical instrument according to claim 1. At least a part of the projecting body through which the through-hole penetrates the through-hole or at least one of the through-holes has an arcuate portion centered on the center of rotation in a horizontal plane, and the projecting body has the through-hole. The other part of the through-hole or the through-hole has a contact part facing the arc-shaped part,
The keyboard device for an electronic musical instrument according to claim 3. At least one of the side wall surface of the portion where the protruding body passes through the through hole or the side wall surface of the through hole is provided with a non-perpendicular gradient,
The gap between the side wall surfaces is smaller in the lower opening of the through hole than in the upper opening of the through hole.
The keyboard device for an electronic musical instrument according to claim 3. The through hole has a shape in which at least one of the upper opening and the lower opening has a rounded edge in the longitudinal direction of the key.
The keyboard device for an electronic musical instrument according to claim 3. The thin piece is a sheet metal member,
It is attached to the lower surface of the key main body so that the sag surface when the through hole is punched into the sheet metal member is on the lower opening side of the through hole,
The keyboard device for an electronic musical instrument according to claim 6. The key support portion presses the thin piece from above and below the key in both end regions on the width direction line of the key.
The keyboard device for an electronic musical instrument according to claim 1.

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