Patent Application
20200320967
The present invention relates to a rotating mechanism. In addition, the present invention relates to a keyboard apparatus provided with a rotating mechanism.
Existing acoustic pianos such as grand pianos and upright pianos are composed of a large number of component parts. In addition, assemblage of these component parts is extremely complicated, so that the time required for an assembling operation would be long. Particularly, an action mechanism provided correspondingly to each key requires a large number of component parts, and an assembling operation thereof is also extremely complicated.
The action mechanism has a hammer provided with a weight on the lower side of the key, for giving a feeling (hereinafter, referred to a touch feeling) to a player's finger through the key. The hammer is rotated such as to lift up the weight provided for the hammer, according to a key depressing operation on the key. For instance, a hammer depicted in PTL 1 is mounted to a frame by fitting a bearing section, which is opened in a circular shape, to a shaft section. In PTL 1, the bearing section is mounted to the shaft section by a so-called snap-fit wherein the width between opening ends of the bearing section is narrow as compared to the diameter of the shaft section.
JP 2002-207484A
In the structure of the general snap-fit depicted in PTL 1, an opening provided in the bearing section holds the shaft section. The opening is flexible in a normal direction at a point of contact between the bearing section and the shaft section in the vicinity of the opening end. Owing to the flexibility of the opening ends, the attachment and detachment of the shaft section and the bearing section to and from each other are performed. However, with the bearing section provided with the opening, the rigidity of the bearing section in the vicinity of the opening is lowered. In addition, when the rigidity of the bearing section is lowered, the bearing section may be deformed in such a manner as to increase the opening diameter of the opening. When the opening of the bearing section is deformed, a rotating operation of the bearing section relative to the shaft section would be chattered, leading to the problem of an instable rotating operation.
One of objects of the present invention is to realize a rotating mechanism by which a bearing section is stably rotated relative to a shaft section.
A rotating mechanism according to one embodiment of the present invention includes a shaft section, and a bearing section that has an inner peripheral surface making contact with an outer peripheral surface of the shaft section and that is rotated around a rotational axis relative to the shaft section. The inner peripheral surface of the bearing section is formed with an extension portion extending from the inner peripheral surface toward the rotational axis, and the outer peripheral surface of the shaft section is formed with a groove in an inside of which the extension portion in an inserted state can be moved when the bearing section is rotated relative to the shaft section.
In addition, the extension portion may shield a region containing the rotational axis.
Besides, the extension portion may have a projecting portion projecting from the extension portion toward the inside of the groove.
In addition, the shaft section may have a projecting portion projecting from an inner surface of the groove toward the extension portion, inside the groove.
Besides, the projecting portion may be provided in a region containing the rotational axis.
In addition, the extension portion may be provided with a through-hole penetrating the extension portion in a plate thickness direction.
Besides, the extension portion may be disposed at an end portion of the bearing section, in a first direction parallel to the rotational axis.
In addition, the extension portion may be disposed between both ends of the bearing section, in the first direction.
Besides, the bearing section may have a rib at an end portion on a side opposite to an end portion where the extension portion is provided, in the first direction, at an outer peripheral surface of the bearing section.
In addition, the shaft section may be provided with a plurality of grooves arranged in the first direction.
A keyboard apparatus according to one embodiment of the present invention includes a key, a hammer assembly rotated around the rotating mechanism in response to depression of the key, a sensor that is disposed under the key and detects an operation on the key, and a sound source section that generates a sound waveform signal according to an output signal from the sensor.
According to the present invention, it is possible to realize a rotating mechanism by which a bearing section is stably rotated relative to a shaft section.
A keyboard apparatus in one embodiment of the present invention will be described in detail below, referring to the drawings. The following embodiments are examples of the embodiments of the present invention, and the invention is not to be limited to these embodiments. Note that in the drawings referred to in the present embodiments, the same parts or the parts having similar functions are denoted by the same or similar reference symbols (reference symbols composed simply of numerals followed by A, B or the like), and repeated descriptions of them may be omitted. In addition, dimensional ratios (ratios between components, ratios between dimensions in a longitudinal direction and dimensions in a transverse direction, etc.) in the drawings may be different from the actual ratios for convenience of description, and some of the components may be omitted from the drawings. Besides, in the following description, “rotating” means a relative motion. For example, “a member A is rotated relative to a member B” may mean that the member B is moved relative to the member A which is fixed, or may mean that, in contrast, the member A is rotated relative to the member B which is fixed, or may mean that both of the members are rotated.
The keyboard apparatus 1 includes a keyboard assembly 10. The keyboard assembly 10 includes white keys 100w and black keys 100b. Pluralities of the white keys 100w and black keys 100b are arranged in an aligned pattern. The number of keys 100 is N, which is 88, in this example. The direction in which the keys 100 are arranged is referred to as a scale direction. In the case where the white keys 100w and the black keys 100b can be described without any special discrimination therebetween, they may be referred to as the keys 100. In the case where a reference symbol is accompanied by “w” at the last of the symbol, it means a component corresponding to the white key. In addition, in the case where a reference symbol is accompanied by “b” at the last of the symbol, it means a component corresponding to the black key.
Part of the keyboard assembly 10 is present inside a housing 90. As the keyboard apparatus 1 is viewed from above, that part of the keyboard assembly 10 which is covered by the housing 90 is referred to as a non-visible part (non-external-appearance part) NV, whereas that part of the keyboard assembly 10 which is exposed from the housing 90 and is visible from the user is referred to as a visible part (external appearance part) PV. That is, the visible part PV is the part of the keys 100, and depicts a region where a user's playing operation can be performed. In the following, that part of the key 100 which is exposed as the visible part PV may be referred to as a key main body part.
A sound source device 70 and a speaker 80 are disposed inside the housing 90. The sound source device 70 generates a sound waveform signal attendant on depression of a key 100. The speaker 80 outputs the sound waveform signal generated in the sound source device 70 to the external space. Note that the keyboard apparatus 1 may include a slider for controlling sound volume, a switch for changing over tone color, a display for displaying various kinds of information, or the like.
Note that in the description herein, the directions or sides such as the upper side, the lower side, the left side, the right side, this side, and the depth side indicate the directions or side as the keyboard apparatus 1 is viewed from the player at the time of playing. Therefore, for example, it can be expressed that the non-visible part NV is located on the depth side as compared to the visible part PV. In addition, the directions or sides may be indicated with the keys 100 as a reference, such as the key front end side (key front side) and the key rear end side (key rear side). In this case, the key front end side indicates the front side (player's side) as viewed from the player with reference to the key 100, and the key rear side indicates the depth side as viewed from the player with reference to the key 100. According to this definition, it can be expressed that the part of the black key 100b which ranges from the front end to the rear end of the key main body part of the black key 100b is a part projecting upward as compared to the white key 100w.
The signal conversion section 710 acquires output signals from the sensors 300 (sensors 300-1, 300-2, . . . , 300-88 corresponding to the 88 keys 100), and generates and outputs operation signals according to the operation state of each of the keys 100. In this example, the operation signal is a signal in MIDI format. Therefore, according to a key depressing operation, the signal conversion section 710 outputs a note-on signal. In this instance, a key number indicating which one of the 88 keys 100 is operated and a velocity signal corresponding to the key depression velocity are also output in correspondence with the note-on signal. On the other hand, according to a key parting operation, the signal conversion section 710 outputs a key number and a note-off signal in correspondence with each other. Signals according to other operations such as an operation of a pedal may be input to the signal conversion section 710, and they may be reflected on the operation signals.
The sound source section 730 generates sound waveform signals, based on the operation signals output from the signal conversion section 710. The output section 750 outputs the sound waveform signals generated by the sound source section 730. The sound waveform signals are output, for example, to the speaker 80, a sound waveform signal output terminal or the like.
The configuration of the keyboard assembly 10 will be described using
The key 100 includes a front end key guide 151 and side key guides 153. The front end key guide 151 is in slidable contact with a front end frame guide 511 of the frame 500 in the state of covering the front frame guide 511. The front end key guide 151 is in contact with the front end frame guide 511 on both sides in regard of the scale direction of an upper portion and a lower portion thereof. The side key guides 153 are in slidable contact with a side frame guide 513 on both sides in regard of the scale direction. In this example, the side key guides 153 are disposed in those regions at side surfaces of the key 100 which correspond to the non-visible part NV, and is present on the key front end side as compared to the connection section 180 (the plate-shaped flexible member 181), but may be disposed in regions corresponding to the visible part PV.
The hammer assembly 200 is rotatably mounted to the frame 500. In this instance, the hammer assembly 200 has a shaft section 520 of the frame 500 supported by a bearing section 220 and a support section 240, and the shaft section 520 makes sliding contact with the bearing section 220 and the support section 240 at least three points. A front end portion 210 of the hammer assembly 200 makes contact with a hammer support section 120 of the key 100 slidably in substantially the front-rear direction in an internal space of the hammer support section 120. The sliding part, or the part where the front end portion 210 and the hammer support section 120 make contact with each other, is located on the lower side of the key 100 in the visible part PV (the front side as compared to the rear end of the key main body part). Note that the configuration of a connection part between the shaft section 520 and the bearing section 220 (rotating mechanism) will be described in detail later.
The hammer assembly 200 has a metallic weight part 230 disposed on the depth side as compared to the rotational axis. At normal time (when a key is not depressed), the weight part 230 is in the state of being placed on a lower stopper 410, and the front end portion 210 of the hammer assembly 200 is pushing back the key 100. When the key is depressed, the weight part 230 is moved upward, to collide on an upper stopper 430. The hammer assembly 200 applies a load to key depression by the weight part 230. The lower stopper 410 and the upper stopper 430 are formed from a buffer material (nonwoven fabric, elastic material or the like).
Under the hammer support section 120 and the front end portion 210, the sensor 300 is attached to the frame 500. When the sensor 300 is crushed on the lower surface side of the front end portion 210 due to key depression, the sensor 300 outputs a detection signal. The sensor 300 is provided correspondingly to each key 100, as aforementioned.
The bearing section 220 is rotated around a rotational axis (a rotational axis 620 in
The rib 270 is provided at a position on the opposite side of the bearing section 220 from the position where the opening 630 is formed. The rib 270 has a shape of projecting to the outside from an outer peripheral surface 228 of the bearing section 220 on the side opposite to the opening 630, and extends in a circumferential direction of a circle on a plane orthogonal to the rotational axis of the bearing section 220, with one point on the rotational axis on the outside of the bearing section 220 as a center. In the D1 direction, the rib 270 is provided on the outer peripheral surface 228 on the opposite side of the bearing section 220 from the inner peripheral surface 226 on the side where the shielding plate 650 is provided. In addition, in the present embodiment, in the D1 direction, the rib 270 is provided at an end portion of the bearing section 220 on the side opposite to an end portion of the bearing section 220 where the shielding plate 650 is provided. The bearing section 220 and the rib 270 are formed integrally.
With the shielding plate 650 provided, mechanical strength of the bearing section 220 provided with the opening 630 is enhanced. With the rib 270 provided, the mechanical strength of the bearing section 220 is further enhanced. Thus, the bearing section 220 is enhanced in mechanical strength on the inner circumference side and the outer circumference side thereof, as compared to a bearing section not provided with the shielding plate 650 or the rib 270. Besides, with the rib 270 provided on the opposite side of the bearing section 220 from the shielding plate 650 in the D1 direction, mechanical strength at both end portions of the bearing section 220 is enhanced. While the rib 270 may be provided over the whole range in the above-mentioned circumferential direction on the outside of the bearing section 220, the rib 270 need only be provided at least partly in the circumferential direction. The rib 270 may be formed separately from the bearing section 220 and may be joined to the bearing section 220.
The width between opening ends 602 and 612 of the opening 630 is not smaller than a maximum diameter of the shaft section 520. In other words, the rotating mechanism 900 has a structure in which the shaft section 520 is not locked by the bearing section 220. It is to be noted, however, that a structure in which the width between the opening ends 602 and 612 is smaller than the maximum diameter of the shaft section 520, or so-called snap-fit structure, may be adopted. In the case where the rotating mechanism 900 is of the snap-fit structure, the support section 240 may be disposed at such a position that the tip of the support section 240 does not contact the shaft section 520, and the support section 240 may be omitted.
The inner peripheral surface 226 of the opening 630 is further provided with a groove 222 extending in the D1 direction. The groove 222 can be utilized as a grease sump. Furthermore, with the groove 222 provided, the area of contact between the shaft section 520 and the bearing section 220 can be reduced, and a frictional force in a rotating operation of the shaft section 520 and the bearing section 220 can be reduced.
The support section 240 is fixed to the bearing section 220 through the connection section 250 and the body section 260. The connection section 250 is provided on the opposite side of the body section 260 from the bearing section 220. The connection section 250 extends from the body section 260 toward the lower side of the body section 260. The support section 240 is connected to a lower end of the connection section 250, and extends from the connection section 250 toward the bearing section 220. The shaft section 520 is supported by a tip (an end portion on the bearing section 220 side) of the support section 240.
The support section 240 is flexible, and can be flexed at least in the direction of approaching the body section 260. In the present embodiment, the support section 240 can be flexed in the direction of approaching the body section 260 and in the direction of coming away from the body section 260. With the support section 240 flexed in the direction of approaching the body section 260, attachment and detachment of the bearing section 220 to and from the shaft section 520 are performed. Here, the support section 240 is of a structure wherein flexure thereof in such a direction that the bearing section 220 is detached from the shaft section 520 (namely, the direction from the shaft section 520 toward the support section 240) is restrained.
The configuration wherein the projecting portion 660 is provided in the region containing the rotational axis 620 reduces the region in which the projecting portion 660 slides on the inner surface 542 of the groove 540 when the bearing section 220 is rotated. Therefore, the rotating operation of the bearing section 220 can be smoothened, and friction between the projecting portion 660 and the inner surface 542 can be restrained. With the shielding plate 650 provided with the through-hole 670, the through-hole 670 can be utilized as a grease sump.
In the case where the bearing sections 220 and the shielding plates 650 as well as the grooves 540 of the shaft section 520 are produced by resin molding, it is difficult to accurately form relative positions of the shielding plates 650 and the grooves 540, from the viewpoint of characteristics of the mold used for the resin molding. However, with the shielding plate 650 provided at an end portion of the bearing section 220 in regard of the D1 direction, the shape of the shielding plate 650 can be formed only by the mold of either a cavity or a core. Therefore, the positions of the shielding plates 650 relative to the bearing sections 220 and the shapes of the shielding plates 650 themselves can be formed accurately.
Note that a configuration wherein the projecting portion 660 is provided on the shielding plate 650 is depicted as an example in
As has been described above, according to the rotating mechanism 900 according to the first embodiment, the shielding plate 650 is provided on one side surface side of the opening 630 provided in the bearing section 220 in regard of the D1 direction, whereby mechanical strength of the bearing section 220 is enhanced. Therefore, deformation of the bearing section 220 is restrained, and, accordingly, a rotating mechanism 900 enabling stable rotation of the bearing section 220 relative to the shaft section 520 can be realized.
On the other hand, when the finger is detached from the key, the weight part 230 is moved downward, the hammer assembly 200 is rotated, and the key 100 is rotated upward. With the weight part 230 coming into contact with the lower stopper 410, rotation of the hammer assembly 200 is stopped, and the key 100 is returned into the rest position. In the keyboard apparatus 1 in the first embodiment, the key 100 is rotated by depression of the key and detachment of the finger from the key, at the connection section 180, as aforementioned.
In a second embodiment, a rotating mechanism 900A having a configuration different from that of the rotating mechanism 900 in the first embodiment will be described.
The shielding plate 650A of the rotating mechanism 900A is provided between both ends of the bearing section 220A in regard of the D1 direction. In
As has been described above, according to the rotating mechanism 900A according to the second embodiment, the same or similar effect to that of the rotating mechanism 900 in the first embodiment can be obtained.
In the aforementioned embodiments, an electronic piano has been depicted as an example of the keyboard apparatus to which a hammer assembly is applied. On the other hand, the hammer assembly in the above embodiments can also be applied to a rotating mechanism of an acoustic piano (for example, a grand piano or an upright piano). For instance, in an upright piano, the opening mechanism in the above embodiments can be applied to a rotating mechanism which has a rotating component part and a support section rotatably supporting the rotating component part. In this case, a sound generating mechanism corresponds to hammers and strings. The rotating mechanism in the above embodiments can also be applied to rotating component parts of other things than the piano.
Note that the present invention is not limited to the above embodiments, and modifications can be appropriately made within the scope of the gist of the invention.
1: Keyboard apparatus, 10: Keyboard assembly, 70: Sound source device, 80: Speaker, 90: Housing, 100: Key, 100b: Black key, 100w: White key, 120: Hammer support section, 151: Front end key guide, 153: Side key guide, 180: Connection section, 181: Plate-shaped flexible member, 183: Key side support section, 185: Rod-shaped flexible member, 200: Hammer assembly, 210: Front end portion, 220: Bearing section, 222: Groove, 230: Weight part, 240: Support section, 250: Connection section, 260: Body section, 270: Rib, 300: Sensor, 410: Lower stopper, 430: Upper stopper, 500: Frame, 511: Front end frame guide, 513: Side frame guide, 520: Shaft section, 540: Groove, 542: Inner surface, 585: Frame side support section, 602, 612: Opening end, 620: Rotational axis, 630: Opening, 650: Shielding plate, 660: Projecting portion, 670: Through-hole, 710: Signal conversion section, 730: Sound source section, 750: Output section, 900: Rotating mechanism
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-061696 | Mar 2016 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2017/006253 | 2/21/2017 | WO | 00 |
