JP2023050756A - Keyboard device for keyboard musical instrument - Google Patents

Abstract

To provide a keyboard device for a keyboard musical instrument capable of effectively suppressing detachment of a hammer from a support shaft when the impact is applied and easily removing the hammer.SOLUTION: A keyboard device 1 of the present invention includes: a keyboard chassis 4 (chassis); rotatable keys 2; and first arms 31 (hammers) rotatably supported on first spindles 18a (support shafts) of the keyboard chassis 4 and rotating in conjunction with the depressed keys 2. The first arm 31 includes: a shaft hole 36a which can be fitted to the first spindle 18a; and a guide groove 36b which extends obliquely upward from the lower surface of the first arm 31 so as to continue to the shaft hole 36a, has a groove width W smaller than the diameter D of the first spindle 18a and guides the shaft hole 36a to the first spindle 18a when the first arm 31 is mounted.SELECTED DRAWING: Figure 8

Description

The present invention is applied to a keyboard instrument such as an electronic piano, and relates to a keyboard device for a keyboard instrument having a hammer that rotates in conjunction with a depressed key.

2. Description of the Related Art As a conventional keyboard device of this type, for example, the one disclosed in Patent Document 1 is known. This keyboard device has a chassis made of synthetic resin, and a hammer is rotatably supported on a hammer support shaft (hereinafter simply referred to as "support shaft") of the chassis. The support shaft is integral with the chassis, projects laterally, and has a circular cross section. On the other hand, the hammer is made of synthetic resin and integrally has a hammer body extending in the front-rear direction and a bearing portion provided in the middle thereof and supported by a support shaft. The bearing portion is formed in a C shape that opens rearward, and has a central circular holding hole and a guide groove that continues to the holding hole and opens rearward. The guide groove extends substantially horizontally in the key-released state, tapers toward the holding hole, and has a minimum width smaller than the diameter of the support shaft.

In the above configuration, when the hammer is attached to the support shaft, the bearing portion of the hammer is positioned on the front side of the support shaft, the guide groove is engaged with the support shaft, and then the hammer is pushed rearward. As a result, the hammer moves backward while being guided by the guide groove while the guide groove is expanded by the support shaft. Then, the guide groove crosses over the support shaft and the holding hole is fitted to the support shaft, so that the hammer is rotatably supported by the support shaft via the bearing portion.

Further, in the keyboard device disclosed in Patent Document 2, the hammer has a shaft hole fitted to the support shaft of the chassis, and a guide groove connected to the shaft hole and opened downward. It is fitted onto the support shaft from above.

JP 2016-191832 A JP 2015-87591 A

A keyboard device is often subjected to impact mainly in the front-rear direction and the vertical direction when it is transported as a product. On the other hand, in the above-described keyboard device of Patent Document 1, the hammer is fitted to the support shaft from the front through a substantially horizontal guide groove. Therefore, if an impact is applied in the front-to-rear direction during transportation, etc., the direction of the inertial force due to the impact and the insertion direction of the hammer are almost the same. may detach from the support shaft. Similarly, in the keyboard device of Patent Document 2, since the hammers are fitted onto the support shaft from above, there is a risk that the hammers will detach from the support shaft when a vertical impact is applied.

In addition, in the keyboard device of Patent Document 1, when removing the hammers for repair or maintenance, the hammers must be moved forward relatively far along the guide grooves, making it difficult to remove them easily.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and is capable of effectively suppressing separation of the hammer from the support shaft when an impact is applied, and of facilitating the removal of the hammer. To provide a keyboard device for a keyboard instrument capable of

In order to achieve this object, the invention according to claim 1 comprises a chassis, a rotatable key, and a rotatable key which is rotatably supported by a support shaft of the chassis and which rotates in conjunction with a depressed key. a hammer, the hammer having a shaft hole that can be fitted to the support shaft; and a guide groove for guiding the shaft hole to the support shaft during mounting.

According to this configuration, when the hammer is attached to the support shaft, the shaft hole and the guide groove of the hammer are positioned obliquely above the support shaft, and after the guide groove is engaged with the support shaft, the hammer is inserted into the guide groove. Press obliquely downward along the As a result, the guide groove having a narrow groove width is elastically expanded by the support shaft, and the hammer moves obliquely downward while being guided by the guide groove. Then, when the guide groove overcomes the support shaft, the guide groove is elastically restored and at the same time, the shaft hole is fitted (snap-fitted) to the support shaft. Thereby, the hammer is attached to the support shaft through the shaft hole and is rotatably supported.

As described above, the hammer is snap-fitted to the support shaft through the shaft hole. A guide groove extends obliquely from the lower surface of the hammer to between the shaft holes. Therefore, when the keyboard device is subjected to impact in the front-rear direction or the vertical direction during transportation of the product, the direction of the force of inertia due to the impact is greatly different from the direction of the guide grooves, and the force of inertia is dispersed. As a result, separation of the hammer from the support shaft when impact is applied can be effectively suppressed.

The invention according to claim 2 is the keyboard device for a keyboard instrument according to claim 1, wherein the guide groove extends obliquely at an angle of 45±15 degrees with respect to the horizontal when the key is released. Characterized by

If the angle of inclination of the guide groove with respect to the horizontal is greater than 60 degrees, the guide groove becomes nearly vertical, resulting in insufficient dispersion of inertial force when a vertical impact is applied. On the other hand, if the inclination angle of the guide grooves is less than 30 degrees, the guide grooves become nearly horizontal, resulting in insufficient dispersion of the inertial force when a front-rear impact is applied. According to this configuration, since the inclination angle of the guide groove with respect to the horizontal is 45±15 degrees, the detachment of the hammer can be effectively suppressed by sufficiently dispersing the inertial force due to the impact.

The invention according to claim 3 is the keyboard device for a keyboard instrument according to claim 1 or 2, wherein the hammer is formed with an uneven portion for engaging a tool for moving the hammer obliquely upward from the support shaft and removing the hammer. It is characterized by

In the keyboard device of claim 1 or 2, since the hammers are snap-fitted to the support shafts, it is difficult to remove the hammers for repair or the like. According to this configuration, the hammer is formed with the uneven portion, and the tool engaged with the uneven portion is operated to move the hammer obliquely upward in the direction in which the guide groove extends, thereby moving the hammer toward the support shaft. can be easily removed from the

1 is a perspective view showing a part (for one octave) of a keyboard device of an electronic piano to which the present invention is applied, (a) showing the appearance of the keyboard device, and (b) showing keys other than the leftmost white key and black key. is omitted. 1B is a perspective view showing a state in which the white keys and the black keys are removed from the keyboard chassis together with the respective key support mechanisms in the keyboard device shown in FIG. 1B; FIG. 1(a) is a plan view of the keyboard device shown in FIG. 1(b), and FIG. 1(b) is a sectional view taken along line AA. FIG. 3 is a perspective view showing a white key and a key support mechanism, where (a) shows a state in which the white key and the key support mechanism are connected, and (b) shows a state in which the white key and the key support mechanism are disassembled. FIG. 3 is a perspective view showing a black key and a key support mechanism, where (a) shows a state in which the black key and the key support mechanism are connected, and (b) shows a state in which the black key and the key support mechanism are disassembled. 2A and 2B are diagrams for explaining the operation of a white key in a keyboard device, where (a) shows a key release state and (b) shows a key depression state; 2A and 2B are diagrams for explaining the operation of a black key in a keyboard device, where (a) shows a key-released state and (b) shows a key-pressed state; It is a figure which expands and shows typically the bearing part of a 1st arm, and the state (a) before attachment of the 1st support shaft which supports this, and (b) after attachment. FIG. 10 is a diagram for explaining how the keyboard device is packaged and how impact is applied during transportation; (a) is a perspective view of a first arm in which uneven portions for removal are formed, and (b) to (d) are partial enlarged views showing different examples of uneven portions in part B of (a). . 11A and 11B are diagrams showing a state after (a) removal of the first arm from the first support shaft using the concave/convex portion of FIG. 10 and (b) after removal;

Preferred embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1(a) shows only one octave of an electronic piano keyboard device 1 to which the present invention is applied. In the following description, first, the basic configuration and operation of the keyboard device 1 will be described, and then the main part of the present invention will be described.

FIG. 1(b) shows a state in which the keys 2 other than the white key 2a and the black key 2b at the left end are omitted from the keyboard device 1 shown in FIG. 1(a). 2b is removed from the keyboard chassis 4 together with the key support mechanism 6. FIG.

This keyboard device 1 comprises a keyboard chassis 4, white keys 2a and black keys 2b. It includes a key support mechanism 6 for supporting the corresponding key 2 from below, a key switch 3 for detecting key depression information of each key 2, and the like.

The keyboard chassis 4 includes a chassis body 4a made of a resin molded product having a predetermined shape by injection molding a predetermined resin material (such as ABS resin). As shown in FIG. 3, the chassis body 4a has a front portion 11, an intermediate portion 12 and a rear portion 13 which extend in the horizontal direction (the horizontal direction in FIG. 3(a)) as a whole. It is formed integrally with a plurality of ribs 14 spaced apart in the left-right direction and each extending in the front-rear direction. In the following description, in the keyboard chassis 4, the front portion 11, intermediate portion 12 and rear portion 13 of the chassis body 4a are referred to as "chassis front portion 11", "chassis intermediate portion 12" and "chassis rear portion 13" respectively. and

The chassis front portion 11 mainly serves to guide the white key 2a when the key is pressed and to regulate the upper and lower limit positions of the front end portion. A plurality of white key guides 11a, which are inserted into each white key 2a from below and prevent lateral vibration of the white key 2a, stand in a row in the left-right direction in the front portion 11 of the chassis. Engagement holes 11b, 11b penetrating in the vertical direction are provided on the left and right sides of each white key guide 11a in the chassis front part 11. The left and right two upper limit position restricting portions 21, 21 engage with each other in a state of being penetrated. Further, the front end of the chassis front portion 11 is provided with a stopper attachment portion 11c which protrudes forward and extends in the left-right direction over the entire chassis body 4a. A key upper limit stopper 16a and a key lower limit stopper 16b are attached so as to extend in the left-right direction. A black key stopper attachment portion 11d extending in the left-right direction over the entire chassis body 4a is provided on the chassis front portion 11 at a predetermined position behind the white key guide 11a. A key upper limit stopper 17 for a key is attached so as to extend in the left-right direction.

The chassis intermediate portion 12 mainly guides the black key 2b when the key is pressed, and also swings a first arm 31 and a second arm 32, which will be described later, of the key support mechanisms 6a and 6b for the white and black keys. It supports. The chassis intermediate portion 12 has a flat plate-like portion 12a extending in the left-right direction, and a plurality of black key guides 12b standing on the flat portion 12a and arranged at appropriate intervals in the left-right direction. are doing. Each black key guide 12b is inserted into each black key 2b from below to prevent lateral vibration of the black key 2b. A first arm support portion 18 that supports the first arm 31 of the key support mechanism 6 is provided at the front portion of the chassis intermediate portion 12 . The first arm support portion 18 has a plurality of first support shafts 18a extending in the left-right direction between adjacent ribs 14, 14. These first support shafts 18a are provided with: A first arm 31 is swingably supported. Further, a second arm support portion 19 that supports the second arm 32 of the key support mechanism 6 is provided at the rear portion of the chassis intermediate portion 12 . The second arm support portion 19 has a plurality of second support shafts 19a provided between adjacent ribs 14, 14 so as to extend in the left-right direction. A plurality of second support shafts 19a are arranged on the same axis extending in the left-right direction at positions rearward and higher than the first support shafts 18a. is swingably supported. A first arm lower limit stopper 10b extending in the left-right direction over the entire chassis body 4a is provided at a predetermined position of a middle rail 8, which will be described later, provided on the lower side of the chassis middle portion 12. As shown in FIG.

The key switch 3 is attached to the lower portion of the keyboard chassis 4 between the chassis front portion 11 and the chassis intermediate portion 12 . The key switch 3 includes a horizontally long printed circuit board 3a extending in the left-right direction, and a plurality of switch bodies 3b each composed of a rubber switch mounted on the printed circuit board 3a for each key 2 and pressed by a first arm 31 when the key is depressed. It consists of

The rear portion of the chassis 13 mainly serves to guide the key 2 in the vertical direction at its rear end portion while preventing lateral vibration, and to regulate the upper limit position of the rear end portion of the first arm 31 . As shown in FIGS. 2 and 3(a), the chassis rear portion 13 has a plurality of partition walls 13a spaced apart from each other by a predetermined interval in the left-right direction so as to separate the adjacent keys 2, 2 from each other. Further, as shown in FIG. 3B, a first arm upper limit stopper 10a extending in the left-right direction over the entire chassis body 4a is provided at a predetermined position on the upper portion of the chassis rear portion 13. As shown in FIG. The first arm upper limit stopper 10a and the first arm lower limit stopper 10b provided on the chassis intermediate portion 12 are respectively attached to the first arm 31 having a function as a hammer for imparting touch weight to the key 2. , the upper limit position when the first arm 31 is rotated upward, and the lower limit position when the first arm 31 is rotated downward. Further, a metal cover plate 15 is attached to the upper portion of the chassis rear portion 13 so as to extend in the left-right direction over the entire chassis body 4 a and cover the rear end portion of the key 2 .

As shown in FIGS. 2 and 3A, the chassis body 4a of the keyboard chassis 4 configured as described above has a plurality of first openings 5a opening upward and forward and a plurality of openings opening upward. A second opening 5b is provided. The first arm 31 of the key support mechanism 6 is engaged with the first support shaft 18a from the outside through the first openings 5a. The second arm 32 is engaged with the second support shaft 19a from the outside.

In the keyboard chassis 4 described above, a plurality of chassis bodies 4a are connected to each other in a laterally aligned state, and all extend in the lateral direction. are mounted on a front rail 7, a middle rail 8 and a rear rail 9 and screwed. The keyboard chassis 4 is fixed on a shelf (not shown) of the electronic piano via the front rail 7 and the rear rail 9 .

Next, the key 2 and the key support mechanism 6 will be explained. FIG. 4(a) shows an enlarged view of the white key 2a and its key support mechanism 6a, and FIG. 4(b) shows them disassembled. As shown in the figure, the white key 2a is formed by injection molding a predetermined resin material (for example, AS resin) so as to extend a predetermined length in the front-rear direction and to have a hollow shape opening downward. At the front end of the white key 2a, a pair of left and right upper limit position regulating portions 21, 21 are formed so as to extend downward from the left and right side walls and bend forward at the lower ends thereof. These upper limit position regulating portions 21, 21 engage with the right and left engagement holes 11b, 11b of the chassis front portion 11 in a state of being penetrated, respectively, as described above.

A key front side connecting portion 22 connected to the first arm 31 of the key support mechanism 6a is provided at a predetermined position behind the upper limit position regulating portion 21 on the front portion of the white key 2a. The key front connecting portion 22 has a U-shaped connecting concave portion 22a whose side surface is elongated and which opens forward. Further, the coupling recess 22a is provided so as to cover the entire inner peripheral surface thereof, and is used to suppress the generation of noise when the later-described coupling shaft 35b of the first arm 31 slides within the coupling recess 22a. key-side noise suppressing member 20 is attached.

Further, a key rear side connecting portion 23 connected to the second arm 32 of the key support mechanism 6a is provided at the rear portion of the white key 2a. The key rear side connecting portion 23 hangs down from the center portion of the white key 2a in the left-right direction, and includes a plate-like connecting body portion 23a having a predetermined thickness in the left-right direction, and left and right sides of the connecting body portion 23a. It has a pair of right and left engaging protrusions 23b, 23b coaxially protruding from the side surfaces thereof. In addition, the rear part of the white key 2a is penetrated in the vertical direction so that a predetermined tool can be used to disconnect the white key 2a from the second arm 32 of the key support mechanism 6a during maintenance of the keyboard device 1 or the like. A tool insertion hole 24 for inserting from above is formed.

On the other hand, the key support mechanism 6a includes a first arm 31 and a second arm 32 that engage with each other and are connected to the key front side connecting portion 22 and the key rear side connecting portion 23 of the white key 2a, respectively.

As shown in FIG. 4B, the first arm 31 is composed of an arm body 33 and two weights 34, 34 attached to the arm body 33. As shown in FIG. The arm body 33 is formed of a resin molded product having a predetermined shape by injection molding a predetermined resin material (for example, polyacetal). The arm main body 33 extends for a predetermined length in the front-rear direction, and is provided with a first arm front-side connecting portion 35 at the front end thereof to be connected to the key front-side connecting portion 22 of the white key 2a. The first arm front connecting portion 35 extends in the left-right direction in a state in which a box portion 35a formed in a box shape that opens upward and forward and front upper ends of left and right side walls of the box portion 35a are connected to each other. It has a connecting shaft 35b provided as follows. The connecting shaft 35b is connected to the connecting concave portion 22a of the key front side connecting portion 22 of the white key 2a so as to be rotatable and slidable in the front-rear direction.

Further, the arm body 33 has a U-shaped bearing portion 36 whose side surface opens downward at a predetermined position immediately behind the front connecting portion 35 of the first arm. It is rotatably engaged with the first support shaft 18a of the chassis 4. As shown in FIG. Further, the arm body 33 is provided with a first arm rear side connecting portion 37 that connects with the second arm 32 at a predetermined position behind the bearing portion 36 . Specifically, the first arm rear side connecting portion 37 has a connecting shaft 37 a that extends in the left-right direction and has both ends that protrude outward from the left and right side surfaces of the arm body 33 . Both ends of the connecting shaft 37a are engaged with connecting concave portions 45b, 45b of a second arm front side connecting portion 45 of the second arm 32, which will be described later.

Two elongated plate-like weights 34, 34 are attached to a weight attachment portion 38 at the rear portion of the arm body 33, with the weight attachment portion 38 sandwiched from both sides. Each weight 34 is made of a material (for example, a metal such as iron) having a higher specific gravity than that of the arm body 33, and is formed into a predetermined shape by pressing a metal plate.

The second arm 32 is formed of a resin molded product having a predetermined shape by injection molding the same resin material as the arm body 33 of the first arm 31 . The second arm 32 is shorter than the first arm 31 and extends for a predetermined length in the front-rear direction. Further, the second arm 32 has a C-shaped bearing portion 41 whose side surface opens forward near the center in the length direction. 19a to be rotatably engaged.

Further, at the rear portion of the second arm 32, a second arm rear side connecting portion 42 that is connected to the key rear side connecting portion 23 of the white key 2a is provided. The second arm rear side connecting portion 42 is formed in a bifurcated shape, and has two left and right connecting arm portions 43, 43 extending a predetermined length parallel to each other along the longitudinal direction of the second arm 32. there is A connecting hole 43a is formed in the rear end portion of each connecting arm portion 43 so as to penetrate therethrough in the left-right direction. Between the rear end portions of the connecting arm portions 43, 43, the connecting main body portion 23a of the key rear side connecting portion 23 of the white key 2a is sandwiched from both left and right sides, and each connecting hole 43a is located on the key rear side. The corresponding engaging projections 23b of the connecting portion 23 are rotatably fitted.

Further, a front portion of the second arm 32 is provided with a front second arm connecting portion 45 that is connected to the rear first arm connecting portion 37 of the first arm 31 . The second arm front side connecting portion 45 has a pair of left and right connecting pieces 45a, 45a which are spaced apart from each other by a predetermined distance in the left-right direction. An open U-shaped connecting recess 45b is formed. The left and right connecting pieces 45a, 45a of the second arm front connecting portion 45 are rotatably and slidably attached to both ends of the connecting shaft 37a of the first arm 31 via the connecting concave portions 45b, 45b. Engage freely.

FIG. 5(a) shows an enlarged view of the black key 2b and its key support mechanism 6b, and FIG. 5(b) shows them disassembled. The black keys 2b are formed by injection molding the same resin material as the white keys 2a, so that they are shorter than the white keys 2a, extend in the front-rear direction by a predetermined length, and have a hollow shape that opens downward. At the lower front end of the black key 2b, there is provided a key front connecting portion 26 which is formed in substantially the same manner as the key front connecting portion 22 of the white key 2a. The key front side connecting portion 26 has a connecting concave portion 26a formed in a U shape whose side surface shape is elongated and which opens forward. Further, the key front side connecting portion 26 has an extending portion 26b extending a predetermined length forward from the front surface of the main body of the black key 2b at the lower front end portion of the connecting concave portion 26a. It functions as an upper limit position regulating portion for the black key 2b. In the following description, regarding the black key 2b and the key support mechanism 6b, the same components as those of the white key 2a and the key support mechanism 6a described above are denoted by the same reference numerals, and detailed description thereof will be omitted. .

The key support mechanism 6b for supporting the black keys 2b is constructed substantially in the same manner as the key support mechanism 6a for the white keys described above. Specifically, the arm body 33 and the second arm 32 of the first arm 31 of the key support mechanism 6b are different in shape and size from the arm body 33 and the second arm 32 of the key support mechanism 6a for white keys. configured exactly the same. The two left and right weights 34, 34 of the key support mechanism 6b for black keys are different in rear shape from the weight 34 of the key support mechanism 6a for white keys.

Next, operations of the keys 2 and the key support mechanism 6 in the keyboard device 1 configured as described above will be described. 6 shows the operation of the white key 2a and its key support mechanism 6a, and FIG. 7 shows the operation of the black key 2b and its key support mechanism 6b.

In the key-released state shown in FIG. 6(a), when the front end of the white key 2a is pushed down by the player's finger, the key front side connecting portion 22 of the white key 2a moves downward, thereby causing the first arm 31 to move downward. rotates counterclockwise about the first support shaft 18a. Further, as the first arm 31 rotates, the second arm front connecting portion 45 that engages with the connecting shaft 37a of the first arm 31 via the connecting concave portion 45b moves upward. As a result, the second arm 32 rotates clockwise about the second support shaft 19a. As the second arm 32 rotates, the key rear side connecting portion 23 connected via the second arm rear side connecting portion 42 at the rear end portion is pulled down, and the rear end portion of the white key 2a is lowered. move to

When the first arm 31 rotates as described above, the bottom wall of the box portion 35a of the first arm front-side connecting portion 35 moves downward, and the depressed key 2 is pushed by the bottom wall of the box portion 35a. The switch body 3b of the key switch 3 corresponding to is pressed from above. As a result, in the electronic piano, the key depression information of the depressed key 2 is detected, and a sound is generated from a speaker (not shown) based on the detected key depression information.

As described above, when the white key 2a is pushed down, as the first arm 31 rotates counterclockwise, the weight 34 of the first arm 31 tilts rearward and upward as shown in FIG. 6(b). Then, the rear end contacts the first arm upper limit stopper 10a from below. This prevents further rotation of the first arm 31 . When the front end portion of the white key 2a is pushed down to the lowest position, the front end portion of the white key 2a abuts against the key lower limit stopper 16b, preventing further depression of the white key 2a.

The white key 2a pressed as described above rotates around the virtual fulcrum P located behind the rear end thereof. The position of this virtual fulcrum P is set, for example, so that the distance from the front end of the white key 2a is about twice the length of the white key 2a itself. As a result, when the front end of the white key 2a is pushed down to the lowest position, the front end of the white key 2a has a predetermined key stroke ( for example 10 mm), and the rear end is positioned below a distance of about 1/2 of the key stroke (for example 5 mm).

On the other hand, when the finger is released from the depressed white key 2a, the weight of the weight 34 causes the first arm 31 of the key support mechanism 6a to rotate in the direction opposite to the above, and accordingly the second arm 32 also rotates in the opposite direction to the above. direction. Accordingly, the white key 2a rotates upward about the virtual fulcrum P. As shown in FIG. A predetermined portion of the first arm 31 behind the first support shaft 18a abuts the first arm lower limit stopper 10b from above, and both upper limit position regulating portions 21, 21 of the white key 2a contact the key upper limit stopper 16a downward. Further rotation of the white key 2a is prevented, and the original key release state is restored.

Also, the operation of pressing the black key 2b is performed in the same manner as the white key 2a and the key support mechanism 6a described above. 7(a), when the front end of the black key 2b is pushed down, the first arm 31 moves counterclockwise about the first support shaft 18a, and the second arm 32 moves to the second position. The black key 2b rotates clockwise about the support shaft 19a, thereby rotating the black key 2b about the virtual fulcrum Q on the rear side. The position of this virtual fulcrum Q is set, for example, so that the distance from the front end of the black key 2b is approximately twice the length of the black key 2 itself, similar to the virtual fulcrum P of the white key 2a. there is Therefore, when the front end portion of the black key 2b is pushed down to the lowest position, the front end portion of the black key 2b is pushed down by a predetermined key stroke, compared to the key release state shown in FIG. 7(a). It is positioned downward, with the trailing end positioned downward at a distance of about 1/2 of the keystroke.

On the other hand, when the finger is released from the depressed black key 2b, the first arm 31 and the second arm 32 of the key support mechanism 6b rotate in the direction opposite to the above. Rotate upward about the center. Then, the extended portion 26b of the key front connecting portion 26 of the black key 2b abuts against the key upper limit stopper 17 from below, preventing further rotation of the black key 2b and returning to the original key released state.

Next, the main part of the present invention will be described with reference to FIGS. 8 to 11. FIG. FIG. 8 shows an enlarged view of the bearing portion 36 of the arm body 33 of the first arm 31 and the first support shaft 18a that supports it. It should be noted that FIG. 8 is schematically shown such that the guide groove 36b is drawn slightly longer than it actually is, for easy understanding of the configuration.

As described above, the first support shaft 18a is provided integrally with the chassis intermediate portion 12 (not shown in FIG. 8) of the keyboard chassis 4, extends horizontally, and has a circular cross section and a predetermined diameter (diameter ) D. The bearing portion 36 has a circular shaft hole 36a formed near the lower surface of the arm body 33, and a guide groove 36b that opens in the lower surface of the arm body 33, extends obliquely upward from there, and continues to the shaft hole 36a.

The groove width W of the guide groove 36b is slightly smaller than the diameter D of the first support shaft 18a, and the diameter of the shaft hole 36a is adjusted to fit the first support shaft 18a so as to be rotatable. It is set substantially the same as the diameter D. Further, the inclination angle A of the guide groove 36b with respect to the horizontal in the key released state is preferably in the range of 45±15 degrees for the reasons described later, and is set to about 45 degrees in the example of FIG.

Based on the above configuration, the first arm 31 is attached to the first support shaft 18a in the following manner. First, after the first arm 31 is positioned as shown in FIG. 8A, it is moved obliquely downward (in the direction of the arrow X) toward the first support shaft 18a so that the tip of the guide groove 36b moves toward the first support. It is pressed against the shaft 18a to engage it. After that, when the first arm 31 is further pressed in the same direction, the first arm 31 is guided by the guide groove 36b in a state where the narrow guide groove 36b is elastically expanded by the first support shaft 18a. , move diagonally downward. Then, when the guide groove 36b gets over the first support shaft 18a, the guide groove 36b is elastically restored, and at the same time, the shaft hole 36a is fitted (snap-fitted) to the first support shaft 18a. As a result, as shown in FIG. 4B, the first arm 31 is attached to the first support shaft 18a via the shaft hole 36a and is rotatably supported.

As described above, the first arm 31 is snap-fitted to the first support shaft 18a via the bearing portion 36. As shown in FIG. A guide groove 36b obliquely extends from the lower surface of the first arm 31 to between the shaft holes 36a. Therefore, when the keyboard device 1 is subjected to impacts in the front-rear direction or the vertical direction during transportation of the product, the direction of the inertia force due to the impact is greatly different from the direction of the guide grooves 36b, and the inertia force is dispersed. do. As a result, separation of the first arm 31 from the first support shaft 18a when an impact acts can be effectively suppressed.

For example, when an electronic piano including the keyboard device 1 of the embodiment is transported as a product, the four corners of the electronic piano are usually covered with cushioning materials C such as polystyrene foam, as shown in FIG. , and stored in a packing box P made of cardboard or the like. Therefore, in many cases, the impact on the keyboard device 1 during transportation acts in the front-rear direction (H) or in the vertical direction (V).

When the impact to the keyboard device is in the front-rear direction, in the keyboard device of Patent Document 1 mentioned above, the hammer is fitted into the support shaft from the front, and the direction of the inertial force due to the impact and the fitting direction of the hammer are almost the same. , the hammer may detach from the support shaft. Further, when the impact to the keyboard device is in the vertical direction, in the keyboard device of Patent Document 2, the hammer is fitted into the support shaft from above, and the direction of the inertial force due to the impact and the fitting direction of the hammer are almost the same. , there is also a risk that the hammer will detach from the support shaft.

On the other hand, in the keyboard device 1 of the present embodiment, as described above, when an impact is applied in the front-rear direction or the vertical direction, the direction of the inertial force due to the impact is greatly different from the direction of the guide groove 36b. As a result of the inertial force dispersing, it is possible to effectively suppress separation of the first arm 31 from the first support shaft 18a.

As shown in FIG. 9, when the impact to the keyboard device 1 acts in an oblique direction (I), the direction of the inertial force due to the impact may coincide with the direction of the guide groove 36b. However, in this case, the crushing of the packaging box P absorbs part of the impact, and the first arm upper limit stopper 10a against which the rotated first arm 31 abuts supports part of the impact. The arm 31 never leaves.

Next, the concave and convex portion for removing the first arm 31 will be described with reference to FIGS. 10 and 11. FIG. As shown in FIG. 10( a ), the uneven portion 51 is formed on the arm body 33 (weight mounting portion 38 ) of the first arm 31 . More specifically, as shown in FIG. 4(b), the concave-convex portion 51 is formed integrally with the rear end portion of the upper surface of the arm body 33, and is constituted by a projection 51a protruding upward over the entire width thereof. .

According to this configuration, the projection 51a is used to remove the first arm 31 from the first support shaft 18a in the following manner. First, as shown in FIG. 11(a), after removing the key 2 from the assembled keyboard device 1, a rod-shaped tool R such as a screwdriver is inserted from above, and the tip of the tool R is thrust into the front surface of the projection 51a. Apply (engage). Then, the intermediate portion of the tool R is pressed against a suitable portion S of the keyboard chassis 4 (chassis rear portion 13) existing in the front side of the vicinity thereof, and the tool R is moved with this portion S as a fulcrum, and the arrow Y in FIG. direction. As a result, the first arm 31 is driven obliquely upward and rearward along the guide groove 36b as indicated by the arrow Z, and is removed from the first support shaft 18a.

As described above, the first arm 31 is removed by turning the rod-shaped tool R against the projection 51a formed on the upper surface of the first arm 31 with the portion S of the keyboard chassis 4 as a fulcrum. be As a result, the snap-fitted first arm 31, which is difficult to remove, can be easily removed from the first support shaft 18a without using a special tool.

It should be noted that the present invention is not limited to the above described embodiments and can be implemented in various ways. For example, in the embodiment, the inclination angle A of the guide groove 36b of the first arm 31 with respect to the horizontal in the key released state is set to about 45 degrees, but it may be in the range of 45±15 degrees. This is because if the inclination angle A is greater than 60 degrees, the guide groove 36b becomes nearly vertical, and the dispersion of the inertial force becomes insufficient when a vertical impact is applied. This is because if the angle is smaller than 30 degrees, the guide groove 36b becomes nearly horizontal, resulting in insufficient dispersion of the inertial force when a front-rear impact is applied. Therefore, if the inclination angle A is in the range of 45±15 degrees, the separation of the first arm 31 can be effectively suppressed by sufficiently dispersing the inertial force due to the impact, and the same effect can be obtained.

Further, in the embodiment, the projection 51a shown in FIG. Any configuration can be employed as long as it is possible. FIGS. 11C and 11D show other examples of such uneven portions 51, respectively. In the example of (c), the concave-convex portion 51 is composed of concave portions 51b formed over the entire width of the upper surface of the arm body 33, and in the example of (d), the concave and convex portions 51b are formed to be spaced apart in the width direction of the upper surface of the arm body 33. It is composed of a pair of cutouts 51c. In these configurations, as in the case of the projection 51a described above, the first arm 31 can be easily removed from the first support shaft 18a by engaging a suitable tool R with the recess 51b or the notch 51c and turning it. .

Furthermore, the detailed configuration shown in the embodiment, for example, the configuration and dimensional relationship of the bearing portion 36 of the first arm 31 shown in FIG. Is possible.

1 keyboard device 2 keys 2a white keys 2b black keys 4 keyboard chassis (chassis)
31 1st arm (hammer)
33 Arm body (hammer) of the first arm
36 Bearing portion 36a Shaft hole (shaft hole) of the bearing portion
36b Guide groove of bearing (guide groove)
51 Concavo-convex portion 51a Projection 51b Concave portion 51c Notch D Diameter of first support shaft (diameter of support shaft)
W: Width of guide groove A: Angle of inclination of guide groove

Claims (3)

a chassis;
a rotatable key;
a hammer that is rotatably supported by the support shaft of the chassis and that rotates in conjunction with the depressed key;
The hammer has a shaft hole that can be fitted to the support shaft, a groove that extends obliquely upward so as to connect to the shaft hole from the lower surface of the hammer, and a groove width that is smaller than the diameter of the support shaft. and a guide groove for guiding the shaft hole to the support shaft when attaching the keyboard device of a keyboard instrument. 2. A keyboard device for a keyboard instrument according to claim 1, wherein said guide groove extends obliquely at an angle of 45±15 degrees with respect to the horizontal when said key is released. 3. The keyboard of a keyboard instrument according to claim 1, wherein the hammer is formed with an uneven portion for engaging a tool for moving the hammer obliquely upward from the support shaft and removing the hammer. Device.

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