Keyboard device and keyboard instrument

A keyboard device is provided whose entire device body can be compactified even if a hammer member length in its front and rear direction is increased and a keyboard instrument including the keyboard device. The keyboard device includes a plurality of keys, a transmission member which is rotated in response to a key depression operation performed on a key among the plurality of keys, and a hammer member which is rotated in response to rotation of the transmission member and applies an action load to the key, in which the hammer member includes a hammer arm and a hammer head provided on a front side of the hammer arm, and the hammer arm is rotated around a hammer rotation center located on a rear side of the hammer arm in response to the key depression operation performed on the key.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2017-052433, filed Mar. 17, 2017, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a keyboard device for use in a keyboard instrument such as a piano, and a keyboard instrument including the keyboard device.

2. Description of the Related Art

For example, a keyboard device such as a piano is known which includes keys that are supported on a base plat in a manner to be rotatable in a vertical direction by balance pins serving as key support shafts, wippens that are rotated by key depression operations performed on the keys, jacks that are driven in response to the rotating motions of the wippens, and hammer members that are driven by the jacks and strike strings, and has a structure where the wippens, the jacks, and the hammer members are provided corresponding to the plurality of keys, as described in Japanese Patent Application Laid-Open (Kokai) Publication No. 2002-258835.

This type of keyboard device is structured such that each hammer member, which is rotated by a jack driven in response to the rotating motion of a wippen by a key depression operation on a key, includes a hammer arm and a hammer head, its hammer rotation center at one end of the hammer arm is arranged closer to a rear portion of the key than an area above a balance pin which supports the key, and the hammer head at the other end of the hammer arm is arranged above a substantially rear end of the key.

In this keyboard device, if the length of the hammer member in the front and rear direction is formed large without the position of the hammer rotation center on the hammer arm being changed, the hammer head projects backward from the rear end of the key, and the length of the entire keyboard device in the front and rear direction of the key becomes large. However, there is a need to compactify the entire keyboard device.

An object of the present invention is to provide a keyboard device whose entire size is compact even when the lengths of its hammer members in a front and rear direction are formed larger, and a keyboard instrument including this keyboard device.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, there is provided a keyboard device comprising: a plurality of keys; a transmission member which is rotated in response to a key depression operation performed on a key among the plurality of keys; and a hammer member which is rotated in response to rotation of the transmission member and applies an action load to the key, wherein the hammer member includes a hammer arm and a hammer head provided on a front side of the hammer arm, and wherein the hammer arm is rotated around a hammer rotation center located on a rear side of the hammer arm in response to the key depression operation performed on the key.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment in which the present invention has been applied in an electronic keyboard instrument will hereinafter be described with reference toFIG. 1toFIG. 7.

This electronic keyboard instrument includes a keyboard device1, as shown inFIG. 1toFIG. 3. This keyboard device1, which is incorporated into an instrument case (not shown), includes a plurality of keys2arranged in parallel and action mechanisms3each of which applies an action load to the corresponding one of the plurality of keys2in response to a key depression operation on the corresponding key2.

The plurality of keys2includes white keys2aand black keys2b, as shown inFIG. 1toFIG. 3. The total number of white keys2aand black keys2barranged in parallel is 88, for example. By a balance pin4aor4bserving as a key support shaft, a substantially intermediate portion of each key2in a front and rear direction (a lateral direction inFIG. 2) is supported such that it is rotatable in a vertical direction. In this state, the keys2are arranged in parallel on a base plate5.

That is, the white keys2aand the black keys2bhave different lengths in the front and rear direction, and the lengths of the white keys2aare larger than the lengths of the black keys2b, as shown inFIG. 1toFIG. 3. In this embodiment, the white keys2aand the black keys2bare arranged such that their rear ends (left ends inFIG. 2) are aligned with each other. Also, the white keys2aare supported on the base plate5by the balance pins4aserving as key support shafts, and the black keys2bare supported on the base plate5by the balance pins4bserving as key support shafts.

Accordingly, on the base plate5, cushion members6afor the white keys2aand cushion members6bfor the black keys2bwith which the under surfaces of front end portions (right end portions inFIG. 2) of the plurality of keys2separably come in contact are provided along the array direction of the keys2, as shown inFIG. 2andFIG. 3. Also, on the base plate5, cushion members7with which the under surfaces of rear end portions (left end portions inFIG. 2) of the plurality of keys2separably come in contact are provided along the array direction of the keys2.

As a result, for each of the plurality of keys2, a key stroke is set by a cushion member6aor6bon the front side thereof and a cushion member7on the rear side thereof, as shown inFIG. 2andFIG. 3. Further, on the base plate5, guide pins8afor the white keys2aand guide pins8bfor the black keys2bfor preventing the plurality of keys2from rolling in the array direction of the keys2are provided upright.

The action mechanisms3include a plurality of transmission members10each of which is rotated in the vertical direction in response to a key depression operation on the corresponding one of the plurality of keys2, and a plurality of hammer members11each of which is rotated in the vertical direction in response to the rotating motion of the corresponding one of the plurality of transmission members10and applies an action load to the corresponding one of the plurality of keys2, as shown inFIG. 2toFIG. 3. In this embodiment each key2is rotated in the counterclockwise direction around a balance pin4aor4bby the weight of the corresponding one of the plurality of transmission members10, so that an initial load is applied to each key2by it being pressed up to its initial position.

Also, the action mechanisms3include a plurality of transmission holding members12each of which rotatably holds the corresponding one of the plurality of transmission members10and a plurality of hammer holding members13each of which rotatably holds the corresponding one of the plurality of hammer members11, as shown inFIG. 2andFIG. 3. The plurality of transmission holding members12are mounted on a transmission support rail14arranged along the array direction of the keys2. Also, the plurality of hammer holding members13are mounted on a hammer support rail15arranged along the array direction of the keys2.

The transmission support rail14and the hammer support rail15are supported by the plurality of rail support members16and arranged above the plurality of keys2, as shown inFIG. 2andFIG. 3. The plurality of rail support members16are mounted upright on the base plate5such that they are positioned in a plurality of predetermined areas located over the entire length of the base plate5in the array direction of the keys2, as shown inFIG. 1.

In this embodiment, the plurality of keys2includes a total of 38 keys2, as shown inFIG. 1. Accordingly, the plurality of rail support members16are respectively arranged in a plurality of areas including both end areas in the array direction of the plurality of keys2and three areas located, for example, every twenty keys2and positioned between keys2. That is in the present embodiment the rail support members16are arranged in the five areas over the entire length of the keys2in the array direction.

Each of the plurality of rail support members16is constituted by hard synthetic resin such as ABS (Acrylonitrile Butadiene Styrene) resin, and has a mounting section16amounted on the base plate5and a bridge section16bintegrally formed on the mounting section16a, as shown inFIG. 2andFIG. 3. As a result, the rail support members16are arranged in areas corresponding to rear portions of the plurality of keys2with the bridge sections16bprojecting above the keys2by the mounting sections16abeing mounted on the base plate5.

In this embodiment, on lower front portions of the bridge sections16b, that is, on upper front portions (upper right portions inFIG. 2) of the mounting sections16a, transmission rail support sections16care provided which support the transmission support rail14above an area behind the balance pins4aand4bserving as key support shafts, as shown inFIG. 2andFIG. 3. Also, on upper rear portions (upper left portions inFIG. 2) of the bridge sections16b, hammer rail support sections16dare provided which support the hammer support rail15above the rear ends of the keys2.

Moreover, stopper rail support sections16e, which hold an upper-limit stopper rail34described later, are provided on upper front portions (upper right portions inFIG. 2) of the bridge sections16b, as shown inFIG. 2andFIG. 3. Furthermore, substrate rail support sections16f, which hold a substrate support rail37described later, are provided on upper end portions of the bridge sections16b.

The transmission support rail14is formed by both side portions of a band plate being folded downward along its longitudinal direction, and is provided over the entire length of the plurality of keys in the array direction2, as shown inFIG. 2andFIG. 3. Plural portions (five areas) of this transmission support rail14in the array direction of the keys2are mounted on the transmission rail support sections16cof the plurality of rail support members16.

As a result, the transmission support rail14is arranged above the area behind the balance pins4aand4bwhich support the keys2as shown inFIG. 2andFIG. 3, and the bottom of the front end (the bottom on the right side inFIG. 2) of the transmission support rail14is arranged and supported on upper end portions of the balance pins4bfor the black keys2bin this state.

On this transmission support rail14, the plurality of transmission holding members12and a plurality of stopper support sections17are mounted along the array direction of the keys2, as shown inFIG. 2andFIG. 3. In this case, the plurality of stopper support sections17are each constituted by a metal plate, and are mounted in predetermined areas (five areas) on the transmission support rail14corresponding to the plurality of rail support members16with them projecting above the plurality of transmission holding members12.

Each transmission holding member12is constituted by hard synthetic resin such as ABS resin, and includes a body plate12aand a plurality of shaft support sections18, as shown inFIG. 4AandFIG. 48. On the body plate12a, the plurality of shaft support sections18are integrally provided along the array direction of the keys2with them respectively corresponding to, for example, ten keys2. Each of the shaft support sections18prevents the rolling of the corresponding transmission member10by the transmission member10being rotatably mounted thereon.

That is, each shaft support section18has a pair of guide walls18aand a transmission holding shaft18bprovided between the pair of guide walls18a, as shown inFIG. 4AandFIG. 4B. These guide walls18aare provided corresponding to the plurality of transmission members10, on a front end portion (a right end portion inFIG. 4A) of the body plate12aof the corresponding transmission holding member12.

The pair of guide walls18aserves as a guide section which rotatably guides a transmission fitting section21of the corresponding transmission member10with the transmission fitting section21of the transmission member10being slidably interposed therebetween, as shown inFIG. 4A. The transmission holding shaft18bhas a substantially round-bar shape and has a non-circular shape in cross section because both sides of its outer peripheral surface are cut out, as shown inFIG. 4B. The transmission holding shaft18bis arranged above the area behind the balance pins4aand4bwhich support the keys2, as shown inFIG. 2andFIG. 3.

Also, each transmission holding member12includes a regulating section19which regulates the rolling of the corresponding transmission member10when the keyboard device1is packaged and transported, as shown inFIG. 4AandFIG. 4B. The regulating section19is a pair of regulating walls provided on a rear portion (a left side portion inFIG. 4A) of the body plate12aof the transmission holding member12in a manner to correspond to the transmission member10. The regulating section19regulates the rolling of the transmission member10when the keyboard device1is packaged and transported, in addition to rotatably guiding the transmission member10with a lower front portion of the transmission member10being interposed therebetween.

Each transmission member10is constituted by hard synthetic resin such as ABS resin, and includes the transmission body section20which is rotated in the vertical direction in response to a key depression operation on the corresponding key2so as to rotate the corresponding hammer member11in the vertical direction, and the transmission fitting section21serving as a rotation holding section provided integrally with the transmission body section20and rotatably mounted on the transmission holding shaft18bof the corresponding transmission holding member12, as shown inFIG. 2toFIG. 5.

The transmission body section20is formed in a substantially waffle shape, as shown inFIG. 5AandFIG. 5B. That is, the transmission body section20has a thin vertical plate section20aand a plurality of rib sections20bprovided in a substantially lattice shape on an outer peripheral portion and both side surfaces of the vertical plate section20a, which form a waffle shape. In this case, the transmission body section20is structured such that the weight of the transmission member10is adjusted by the shape and thickness of the vertical plate section20aand the formation density of the plurality of rib sections20b.

Also, each transmission member10is structured such that its rigidity is ensured by the plurality of rib sections20beven though the vertical plate section20aof the transmission body section20is thin, and that the occurrence of a shrink in the vertical plate section20awhen it is formed of synthetic resin is prevented by the plurality of rib sections20b, as shown inFIG. 5AandFIG. 5B.

The transmission fitting section21is formed in a C shape as a whole, and is provided projecting forward on a front end portion (a right end portion inFIG. 5A) of the transmission body section20, as shown inFIG. 2,FIG. 3, andFIG. 5. That is the transmission fitting section21is provided such that its thickness in the array direction of the keys2is substantially equal to a length between the pair of guide walls18aof the corresponding shaft support section18, and is slidably inserted between the pair of guide walls18a, as shown inFIG. 5A.

Also, this transmission fitting section21has a fitting hole21awhich is provided in its center and into which the transmission holding shaft18bof the transmission holding member12is to be fitted, as shown inFIG. 5A. This fitting hole21ais a transmission rotation center of the transmission member10. In addition, the transmission fitting section21has an insertion port21bwhich is provided in its portion around the fitting hole21a, i.e., its front portion around the fitting hole21aand into which the transmission holding shaft18bis removably inserted.

As a result, the transmission fitting section21is rotatably mounted on the transmission holding shaft18bwhen the transmission holding shaft18bis inserted into the fitting hole21avia the insertion port21b, as shown inFIG. 2andFIG. 3. In this case, the transmission fitting section21is arranged above the area behind the balance pins4aand4bwhich support the keys2.

Also, a lower portion of the transmission body section20of the transmission member10projects toward the upper surface of the key2, as shown inFIG. 2,FIG. 3, andFIG. 5. In a lower end portion of the transmission body section20, a transmission felt22is provided. This transmission felt22comes in contact with a capstan23provided on an upper rear portion of the key2from above.

As a result, when the key2is depressed, the transmission member10is rotated around the transmission holding shaft18bin the clockwise direction by the transmission felt22being pressed upward by the capstan23on the key2, as shown inFIG. 2andFIG. 3. Also, the transmission body section20of the transmission member10is provided such that its upper rear end is higher than its upper front end, and therefore its upper side portion is inclined downward and frontward (rightwardFIG. 2).

On the upper rear end of the transmission body section20, a support section20cis provided projecting upward, as shown inFIG. 2,FIG. 3, andFIG. 5A. That is, the support section20cis moved in the vertical direction along a side surface of the hammer member11without coming in contact with the hammer member11. Also, on a side surface of the support section20c, an interlock projecting section24aof an interlock control section24described below is provided.

On the other hand, as with the transmission support rail14, the hammer support rail15has a shape formed by both side portions of a band plate being folded downward along its longitudinal direction, and is provided over the entire length of the plurality of keys2in the array direction, as shown inFIG. 1toFIG. 3. Plural (five) portions of this hammer support rail15located in the array direction of the keys21are mounted on the hammer rail support sections16dof the plurality of rail support members16. In this embodiment, the hammer support rail15is arranged with its rear end portion (its left end portion inFIG. 2) positioned above the rear ends of the keys2.

On this hammer support rail15, the plurality of hammer holding members13are mounted along the array direction of the keys2, as shown inFIG. 2andFIG. 3. The hammer holding members13are constituted by hard synthetic resin such as ABS resin, and includes a rail-shaped body plate13awhose top is open and shaft support sections25, as shown inFIG. 6AandFIG. 6B. The shaft support sections25are integrally provided for each group of about ten keys2along the array direction of the keys2, on the front end of the rail-shaped body plate13a.

Each of the shaft support sections25prevents the rolling of the corresponding hammer member11by the hammer member11being rotatably mounted thereon, as shown inFIG. 6AandFIG. 6B. That is, each shaft support section25has a pair of guide walls25aand a hammer holding shaft25bprovided between the pair of guide walls25a.

These guide wall25aare provided corresponding to the plurality of hammer members11, on rear end portions (right end portions inFIG. 6B) of the body plate13a, as shown inFIG. 6AandFIG. 6B. The pair of guide walls25aserves as a guide section which rotatably guides a hammer fitting section28of the corresponding hammer member11with the hammer fitting section28of the hammer member11being slidably interposed therebetween.

As with each transmission holding shaft18b, each hammer holding shaft25bhas a substantially round-bar shape, and has a non-circular shape in cross section because both sides of its outer peripheral surface are cut out, as shown inFIG. 63. In this embodiment, the hammer holding shaft25bis arranged on the hammer support rail15with it corresponding to an area above a rear end portion of the transmission body section20, i.e., between the capstan23on the key2and the rear end of the key2in the front and rear direction of the key2, as shown inFIG. 2andFIG. 3.

Each hammer member11is constituted by hard synthetic resin such as ABS resin, and includes a hammer head26and a hammer arm27which are integrally formed, as shown inFIG. 7AandFIG. 7B. The hammer head26has a scoop-shaped vertical plate section26aand a plurality of rib sections26b. The plurality of rib sections26bare provided on an outer peripheral portion and both side surfaces of the vertical plate section26a. The hammer head26is structured such that the weight of the hammer member11is adjusted by the shape of the scoop-shaped vertical plate section26aand the formation density of the plurality of rib sections26b. These hammer heads26are arranged in a middle area in the direction perpendicular to the array direction of the keys2and located above the key support shafts4aand4bwhich support the keys2.

The hammer arm27has a lateral plate section27awhose length in the front and rear direction is larger than the length of the transmission member10in the front and rear direction and rib sections27bprovided on an outer peripheral portion and both side surfaces of the lateral plate section27a, as shown inFIG. 2,FIG. 3, andFIG. 7. On a rear end portion (a left end portion inFIG. 7A) of the hammer arm27, the hammer fitting section28serving as a hammer rotation center of the hammer member11, which is rotatably mounted on the hammer holding member13, is provided.

This hammer fitting section28is formed in an inverted C shape as a whole, and projects backward on the rear end portion of the hammer arm27, as shown inFIG. 7AandFIG. 7B. That is, the hammer fitting section23is provided such that its thickness in the array direction of the keys2is substantially equal to a length between the pair of guide walls25a, and is slidably inserted between the pair of guide walls20, as shown inFIG. 6A.

Also, the hammer fitting section28has a fitting hole28awhich is provided in its center and into which the hammer holding shaft25bof the hammer holding member13is fitted as shown inFIG. 7AandFIG. 78, and an insertion port28bwhich is provided in its portion around the fitting hole28a, i.e., its rear portion around the fitting hole28aand into which the hammer holding shaft25bis removably inserted.

This hammer fitting section28is rotatably mounted on the hammer holding shaft25bby the hammer holding shaft25bbeing inserted into the fitting hole28avia the insertion port28b, as shown inFIG. 7AandFIG. 78. Also, this hammer fitting section28is arranged above the rear end of the transmission body section20, i.e., above the area between the capstan23on the key2and the rear end of the key2in the front and rear direction of the key2, as shown inFIG. 2andFIG. 3.

Also, on the lower rear end of the hammer arm27, a mounting section27cis provided projecting downward, as shown inFIG. 7AandFIG. 7B. More specifically, the mounting section27cis opposed to a side surface of the support section20con the transmission member10and moved in the vertical direction along the side surface of the support section20c. Also, the mounting section27cis provided with an interlock hole24binto which the interlock projecting section24aof an interlock section24described below is inserted.

Also, the hammer arm27is regulated at a lower-limit position serving as its initial position by its lower front end (lower right end inFIG. 2) coming in contact with a lower-limit stopper30from above, as shown inFIG. 2andFIG. 3. More specifically, the lower-limit stopper30is formed of a cushion material such as felt.

This lower-limit stopper30is mounted on a lower-limit stopper rail31supported by the plurality of stopper support sections17provided on the transmission support rail14, as shown inFIG. 2andFIG. 3. As a result, by the lower front end of the hammer arm27coming in contact with the lower-limit stopper30from above, the hammer member11is positionally regulated at the initial position with it being inclined at its front end.

Also, an upper-limit position of the hammer arm27is regulated by a stopper contact section32on the upper front end of the hammer arm27coming in contact with an upper-limit stopper33from below when the key2is depressed, as shown inFIG. 2,FIG. 3, andFIG. 7. The upper-limit stopper33is formed of a cushion material such as felt, and is mounted on the under surface of the upper-limit stopper rail34mounted on each of the stopper rail support sections16eof the plurality of rail support members16, as with the lower-limit stopper30.

In this embodiment, the upper-limit stopper rail34is formed by a metal band plate being folded in a substantially Z shape in cross section, and is arranged over the entire length of the plurality of keys2in the array direction, as shown inFIG. 2,FIG. 3, andFIG. 7. As a result, the upper-limit position of the hammer member11is regulated by the stopper contact section32on the upper front end of the hammer arm27coming in contact with the upper-limit stopper33from below when the hammer arm27is rotated around the hammer holding shaft25bin the hammer holding member13in the counterclockwise direction.

On the other hand, on the upper rear end of the hammer arm27, a switch pressing section35is provided, as shown inFIG. 7AandFIG. 7B. On the pair of substrate support rails37positioned above the switch pressing section35on the hammer arm27, a switch substrate36is arranged, as shown in FIG.2andFIG. 3. These substrate support rails37are long plates each formed in an L shape in cross section, and are arranged over the entire length of the keys2in the array direction.

That is, the pair of substrate support rails37is mounted with their respective horizontal portions being away from each other by a predetermined distance on the substrate support section16fof each of the plurality of support members16, as shown inFIG. 1toFIG. 3. The switch substrate36includes a plurality of switch substrates36, as shown inFIG. 1. That is in the present embodiment, the switch substrate36is divided into four switch substrates36each having a length corresponding to about twenty keys2, and mounted on the pair of substrate support rails37.

On the under surface of each switch substrate36, rubber switches38are provided, as shown inFIG. 2andFIG. 3. Each rubber switch38has an inverted-dome-shaped bulging section33aprovided on a rubber sheet elongated in the array direction of the keys2in a manner to correspond to each of the plurality of hammer arms27. In the bulging section38a, a plurality of movable contacts (not shown) which separably come in contact with a plurality of fixed contacts (not shown) provided on the under surface of the switch substrate36are provided along the front and rear direction of the hammer arms27.

As a result of this structure, each rubber switch38outputs, when the corresponding hammer member11is rotated around the hammer holding shaft25bof the hammer holding member13in the counterclockwise direction and the rubber switch38is pressed from below by the switch pressing section35of the hammer arm27, a switch signal corresponding to the strength of the key depression on the key2by the corresponding inverted-dome-shaped bulging section38abeing elastically deformed and the plurality of movable contacts therein sequentially coming in contact with the corresponding fixed contacts at time intervals, as shown inFIG. 2andFIG. 3. This switch signal is supplied to a sound source section36a, and a musical sound corresponding to the strength of the key depression on the key2is generated.

The interlock section24has the interlock projecting section24awhich is provided on the support section20con the transmission member10and the interlock hole24bwhich is provided in the mounting section27cof the hammer member11and into which the interlock projecting section24ais inserted, as shown inFIG. 2,FIG. 3,FIG. 5, andFIG. 7. The transmission member10and the hammer member11are connected to each other by the interlock projecting section24aand the interlock hole24b.

As a result of this structure, by the interlock projecting section24aand the interlock hole24b, the interlock section24transmits the rotating motion of the transmission member10corresponding to the depressed key2to the hammer member11, and rotates the hammer member11in conjunction with the key depression operation of the key2, as shown inFIG. 2,FIG. 3,FIG. 5, andFIG. 7.

Next, the operation of the above-described keyboard device1in the electronic keyboard instrument is described.

When the keyboard device1enters an initial state where no key depression operation is performed on the keys2, each transmission member10rotates by its self weight around the transmission holding shaft18bof the transmission holding section12in the counterclockwise direction inFIG. 2, and the transmission felt22provided on the under surface of the transmission body section20comes in contact with the capstan23on the corresponding key2from above.

Here, the weight of the transmission member10, that is, the weight set by the shape and thickness of the vertical plate section20aof the transmission body section20and the formation density of the plurality of rib sections20bis applied to the capstan23on the key2from above. As a result, the key2is depressed by the transmission member10to rotate around the balance pins4aand4bin the counterclockwise direction inFIG. 2, and the rear end portion of the key2comes in contact with the cushion member7to regulate the key2at its initial position while regulating the transmission member10at its initial position.

Also, here, each hammer member11rotates by its self weight around the hammer holding shaft25bof the hammer holding member13in the clockwise direction inFIG. 2, and the hammer arm27is regulated at its lower-limit position by coming in contact with the lower-limit stopper36from above. In this state, the switch pressing section35on the hammer member11is arranged at a position below and away from the rubber switch38on the switch substrate36. As a result the rubber switch38enters a free state where the bulging section38ahas bulged, and enters an OFF state by the plurality of movable contacts being away from the fixed contacts (both not shown).

Next, a case where a key2is depressed in the above-described state so as to perform a musical performance is described.

In this case, when a key2is depressed, this key2is rotated around the balance pins4aand4bin the clockwise direction inFIG. 3, and the capstan23on the key2presses the transmission member10upward. Here, the weight of the transmission member10set by the shape and the thickness of the vertical plate section20aof the transmission body section20and the formation density of the plurality of rib sections20bis applied to the key2as an initial load.

As a result, the transmission member10is rotated against its self weight around the transmission holding shaft18bof the transmission holding member12in the clockwise direction inFIG. 2. Then, the rotating motion of the transmission member10is transmitted to the hammer member11by the interlock section24, and the hammer member11is pressed upward against its self weight. That is, when the transmission member10is rotated in the clockwise direction inFIG. 2, the interlock projecting section24aof the interlock section24presses the interlock hole24bupward along with the rotation of the transmission member10, as shown inFIG. 3.

As a result, the hammer member11is rotated around the hammer holding shaft25bof the hammer holding member13in the counterclockwise direction inFIG. 3, and applies an action load to the key2. That is, when the hammer member11is rotated around the hammer holding shaft25bin the counterclockwise direction inFIG. 2, an action load is applied to the key2by the moment of inertia of the hammer member11. In this embodiment, the hammer arm27has been formed such that its length in the front and rear direction of the key2is larger than the length of the transmission member10in the front and rear direction, and the hammer head26has been provided on the front end of the hammer arm27, as shown inFIG. 2.

The hammer fitting section28on the hammer arm27has been rotatably mounted on the hammer holding shaft25bin this state. Accordingly, when the hammer member11is rotated around the hammer holding shaft25bin the counterclockwise direction inFIG. 2, a moment of inertia occurs in the hammer member11. A load caused by this moment of inertia is applied as an action load to the key2via the interlock section24and the transmission member10. As a result, a key-touch feel close to that of an acoustic piano can be acquired.

When the hammer member11is rotated as described above around the hammer holding shaft25bin the counterclockwise direction, the switch pressing section35on the hammer arm27presses the inverted-dome-shaped bulging section38aof the rubber switch3provided on the switch substrate36from below, as shown inFIG. 3. As a result, the inverted-dome-shaped bulging section35ais elastically deformed, and the plurality of movable contacts in the bulging section38asequentially comes in contact with the plurality of fixed contacts at time intervals.

Here, a switch signal corresponding to the depressed key2is supplied to the sound source section36a, and musical sound data is generated in the sound source section36a. Then, based on the generated musical sound data, a musical sound is emitted from a loudspeaker (not shown) serving as a sound emitting section. When the hammer member11is further rotated around the hammer holding shaft25bin the counterclockwise direction, the stopper contact section32on the hammer arm27comes in contact with the upper-limit stopper33from below to regulate and stop the rotation of the hammer member11in the counterclockwise direction, as shown inFIG. 3.

Then, a key release motion (returning motion) for returning the key2to its initial position is started. Here, the hammer member11is rotated by its self weight in the clockwise direction to return to its initial position and the transmission member10is rotated by its self weight and the weight of the hammer member11in the counterclockwise direction to return to its initial position, with the interlock section24connecting the hammer member11and the transmission member10by the interlock projecting section24abeing inserted into the interlock hole24b. As a result, the transmission member10presses the capstan23on the key2downward and the key2returns to the initial position, as shown inFIG. 2.

As described above, the keyboard device1in this electronic keyboard instrument includes the transmission members10each of which is rotated in the vertical direction in response to a key depression operation performed on a key2, and the hammer members11each of which is rotated in response to the rotation of a transmission member10so as to apply an action load to a key2, in which each hammer member11includes the hammer arm27and the hammer head26, and the hammer fitting section28serving as a hammer rotation center provided on the rear end of the hammer arm27is arranged behind the hammer head26. As a result of this structure, compactification of the entire keyboard device1can be achieved even though the lengths of the hammer members11in the front and rear direction of the keys2are long.

That is, in this keyboard device1, by the hammer fitting section28that is a hammer rotation center provided on the rear end of the hammer arm27being arranged above the rear portion of the key2, the hammer head26on the front end of the hammer arm27can be arranged toward the front of the key2even though the length of the hammer arm27in the front and rear direction is long. Accordingly, the hammer member11can be favorably arranged above the key2without projecting toward the rear portion of the key2. As a result of this structure, compactification of the entire keyboard device1can be achieved even though the length of the hammer member11in the front and rear direction is long.

Also, in this keyboard device1, each transmission member10includes the transmission body section20and the transmission fitting section21serving as a rotation holding section, and the transmission fitting section21serving as a transmission rotation center on the front end of the transmission body section20is arranged on the front side of the transmission body section20, whereby the transmission member10can be compactly arranged below the hammer member11.

In this embodiment, the hammer fitting section28of the hammer arm27serving as a hammer rotation center is arranged above the rear portion of the key2. As a result, the hammer head26can be arranged toward the front of the key2and the hammer filling section28serving as a hammer rotation center does not project backward as compared to the rear end of the key2. Therefore, the hammer member11can be reliably and favorably arranged above the key2even though the length of the hammer member11in the front and rear direction is long.

Also, the transmission fitting section21of the transmission member10serving as the transmission rotation center of the rotation holding section is arranged substantially above the balance pin4aor4bserving as a key support shaft that rotatably supports the key2, and a rear portion of the transmission body section20is arranged close to the hammer fitting section28on the hammer arm27. As a result, the transmission member10can be efficiently and compactly arranged in an area corresponding to an area between the balance pin4aor4bsupporting the key2and the rear end of the key2.

Also, the hammer support rail15which holds the hammer members11is arranged such that its rear end is positioned above the rear ends of the keys2, so that the hammer support rail15can be favorably arranged not to project backward as compared to the rear ends of the keys2. As a result, the hammer members11, which are held by the hammer support rail15, can be arranged such that their rear ends do not project backward as compared to the rear ends of the keys2.

That is, the hammer support rail15is arranged behind and above the transmission members10, the hammer holding members13are arranged on the top of the hammer support rail15, and each hammer fitting section28serving as the rotation holding section of a hammer member11is rotatably mounted on the corresponding hammer holding member13. As a result, upper rear portions of the transmission members10can be provided corresponding to bottom rear portions of the hammer arms27positioned ahead of the hammer fitting sections28.

Accordingly, in this keyboard device1, when the transmission members10are rotated in response to key depression operations on the keys2, the hammer members11are rotated by upper rear portions of the transmission members10pressing up the rear sides of the hammer arms27positioned ahead of the hammer fitting sections28, whereby the moment of inertia of each hammer member11can be increased. As a result, an action load can be favorably applied to each key2.

In this embodiment, a length of the hammer arm27of each hammer member11from the hammer fitting section28serving as the hammer rotation center of the hammer member11to the hammer head26is larger than the length of the transmission body section20of each transmission member10in the front and rear direction. Thus, the length of the hammer arm27can be made sufficiently larger from an area corresponding to the rear end of the key2toward the front side of the key2. In addition, even if the length of the hammer arm27in the front and rear direction is increased, the entire keyboard device1does not become large, and the compactification of the entire keyboard device1can be achieved.

Also, the hammer fitting section28serving as the hammer rotation center of the hammer member11is arranged closer to the rear portion of the key2than the capstan23serving as a contact section that comes in contact with the key2, and the interlock section24which causes the transmission member10and the hammer member11to be interlocked with each other is arranged between the hammer fitting section28of the hammer member11and the capstan23on the key2in the front and rear direction of the key2. As a result, the hammer member11can be favorably rotated by the rotating motion of the transmission member10.

That is, in this keyboard device1, when the transmission member10is rotated in response to a key depression operation, the interlock section24presses up the vicinity of the hammer fitting section28serving as the hammer rotation center of the hammer arm27. Accordingly, the moment of inertia of the hammer member11can be increased. As a result, an action load can be favorably applied to the key2. Thus, a key-touch feel close to that of an acoustic piano can be acquired.

Furthermore, in this keyboard device1, the transmission support rail14, which holds the transmission members10, is supported on the balance pins4bserving as key support shafts that support keys2on the base plate5. Accordingly, the transmission support rail14can be reliably and firmly supported above the keys2. As a result, the transmission support rail14can be prevented from bending and vibrating when the transmission members10are rotated in response to key depression operations so as to rotate the hammer members11, whereby the transmission members10and the hammer members11can be stably rotated.