JP5070922B2 - Mounting structure of the drive unit in the automatic performance piano - Google Patents

Description

  The present invention relates to a drive unit mounting structure in an automatic performance piano in which a key is driven by pressing a drive force of a drive unit.

  2. Description of the Related Art Conventionally, an automatic performance piano is known in which an automatic performance is realized by driving a key by using a driving force of a drive unit made of a solenoid or the like to achieve key performance.

  For example, in Patent Document 1 described below, an acoustic performance drive unit is retrofitted to an acoustic piano, and the rear portion of the key is driven up by a plunger that projects by a solenoid of the drive unit.

An automatic performance piano is also known in which a hammer body for imparting inertia to a key is provided below the key corresponding to each key. For example, in the following Patent Document 2, the drive unit is configured to push up and drive the key rear part. Further, in Patent Document 3 below, the hammer unit is pushed up and driven by the drive unit, and the corresponding key is swung through the hammer body.
Japanese Patent Laid-Open No. 9-237082 JP 2004-29549 A JP 2005-55541 A

  However, in Patent Documents 1 and 2, the drive unit is disposed behind the key fulcrum portion that is the rocking fulcrum of the key, and particularly in Patent Document 2, the position of the drive unit is not below the key. The length of the piano in the front-rear direction (depth) is long, making it difficult to make it compact.

  On the other hand, in Patent Document 3, since the drive unit is disposed below the hammer body, it is advantageous for shortening the dimension in the front-rear direction of the piano. However, the space for arranging the drive unit itself and the movable region of the plunger are ensured. From the necessity, the dimension in the vertical direction (height) tends to be large. In the configuration in which the drive unit is disposed below the hammer body, the stroke of the plunger of the drive unit may be reduced in order to reduce the vertical dimension of the piano. For this purpose, it is convenient to dispose the drive unit at a position as close as possible to the hammer fulcrum that is the swing fulcrum of the hammer body.

  However, if the plunger stroke is small, if the drive unit is displaced in the front-rear direction even a little, the error greatly affects the rotation stroke of the hammer body and consequently the key pressing stroke. Therefore, the closer the arrangement position of the drive unit is to the hammer fulcrum, the higher the accuracy of arrangement of the drive unit is required.

  The present invention has been made in order to solve the above-described problems of the prior art, and the object thereof is to maintain high accuracy of the key pressing stroke and to suppress the dimension expansion in the front-rear direction and the vertical direction of the piano. An object is to provide a drive unit mounting structure for an automatic performance piano.

In order to achieve the above object, the drive unit mounting structure of the automatic performance piano according to claim 1 of the present invention includes a key frame (14) fixed to the instrument body and a key fulcrum ( A plurality of keys (10) swingable in the direction of pressing and releasing keys centering on PK), and arranged in parallel in the key arrangement direction in the key frame corresponding to each key, and interlocked with the corresponding keys. A plurality of hammer bodies (HM) swinging about a hammer fulcrum (PH) in a direction corresponding to the pressing / releasing key direction, fixing portions (41a, 42a) fixed to the key frame , and A drive provided with a plurality of drive parts (30) provided corresponding to each key and disposed below the corresponding hammer body and in front of the corresponding key fulcrum part and in the vicinity of the corresponding hammer fulcrum part. With unit (UNT) Each of the drive units of the drive unit is movable relative to the fixed unit and drives a corresponding hammer body to swing a corresponding key in the key pressing direction via the hammer body. 34) and positioning for determining relative positions in the vertical direction and the horizontal direction of the reference frame (41aa, 42aa), which is a fixed part of the drive unit with respect to the fixed part, and the key frame. have a means (27, 28), a substrate for said driving unit is fixed to the drive unit, in a state where the fixing portion and the substrate is fixed to the key frame is fixed to the drive unit, wherein A cover that is separate from the key frame and covers the plurality of driving units and the substrate from below is configured to be fixed to the driving unit .

  In addition, the code | symbol in the said parenthesis is an illustration.

According to the onset bright, while maintaining high accuracy of the key depression stroke, it is possible to suppress the dimensional expansion of the longitudinal direction and in the vertical direction of the piano. In addition, the keyboard, hammer body, drive unit, and drive unit board can be unitized, and product testing and operation confirmation in the manufacturing stage can be performed before they are attached to the instrument body.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view of an automatic performance piano to which a drive unit mounting structure according to a first embodiment of the present invention is applied.

  The automatic performance piano is configured to be capable of automatic performance based on automatic performance data. A leg portion (not shown) is provided below the shelf board 15 which is a part of the instrument body. This leg is not essential. Although the entire musical instrument main body of the automatic performance piano is not shown in the drawing, the shelf plate 15 and the portion above the shelf plate 15 are applicable. In the musical instrument main body, a cover (not shown) is provided above a keyboard portion including a plurality of keys 10.

  A keyboard chassis (hereinafter simply referred to as “chassis”) 14 is disposed and fixed on the shelf board 15. The chassis 14 is fixed to the shelf board 15 with a fastener (not shown), but the fixing method is not limited. Hereinafter, the player side (left side in FIG. 1) of the automatic performance piano is referred to as “front”.

  From the front part of the chassis 14 to the front part of the shelf board 15, a mouth bar part 17 is provided over the entire key width. The front portion of the chassis 14 is pressed against the shelf plate 15 by the mouth bar portion 17 via the metal fitting 18 and the elastic material 19.

  A plurality of keys 10 and hammer bodies HM corresponding to the keys 10 are individually supported on the chassis 14. The key 10 is operated to be depressed, and can be pivoted in the vertical direction (the front end swings) about the rear key pivot fulcrum PK. As the key 10, there are a plurality of white keys 10W and black keys 10B. A hammer body drive unit 11 is provided at the front lower portion of each key 10.

  Below each key 10, a hammer body HM is arranged corresponding to each key 10. The chassis 14 is provided with a hammer body rotation shaft PH corresponding to each hammer body HM, and each hammer body HM rotates in the vertical direction around the corresponding hammer body rotation shaft PH (the rear end portion swings). Movement) is free. Further, the engaging portion 21 of the hammer body HM is always in engagement with the hammer body driving portion 11 of the key 10, so that the hammer body HM rotates in conjunction with the key 10. In response to the key pressing operation by the player, the engaging portion 21 is driven by the hammer body driving portion 11 of the key 10, and the hammer body HM is counterclockwise (corresponding to the key pressing direction) about the hammer body rotation axis PH. By rotating in the direction of movement), an appropriate inertia is imparted and a good key pressing feeling is obtained. The configuration of each key 10 and the configuration of each hammer body HM are the same. In addition, in order to realize key scaling of the key press feeling, the length and weight of the hammer body HM may be made different for the white key and the black key or according to the pitch.

  In the hammer body HM, a mass member 23 is extended from the base 22 behind the hammer body rotation shaft PH. The hammer body HM is always urged clockwise by the weight of the mass member 23 (the direction corresponding to the key release direction), and the position of the hammer body HM shown in FIG. The position in the key state. In FIG. 1, the position of the hammer body HM corresponding to the key depression state is indicated by HM-e. The key 10 is shown only in the non-pressed state.

  The returning force of the key 10 from the depressed state is due to the returning force of the hammer body HM due to the weight of the mass member 23. Also at the time of return, the hammer body HM rotates in conjunction with the corresponding key 10. Note that a return spring may be provided as auxiliary means for generating a return force for returning the hammer body HM to the non-key pressing position.

  An upper stopper 12 and a lower stopper 13 such as felt are provided on the rear upper part and the rear lower part of the chassis 14, respectively. The upper stopper 12 abuts against the mass member 23 of the hammer body HM when the key is pressed, and restricts the key pressing end position of the key 10. The lower stopper 13 abuts on the mass member 23 when the key is not pressed, and restricts the return position of the key 10 to the non-key pressed state.

  Further, the automatic performance piano is provided with a two-make key switch SW on a switch board 26 disposed at the front of the chassis 14. The key switch SW is pressed by the switch pressing portion 24 of the hammer body HM, and detects a key operation including key velocity. In the case of a key pressing operation by a player, that is, a real-time performance, tone control is performed based on the detection result of the switch pressing unit 24.

  The automatic performance piano is also provided with a drive unit UNT as key drive means for automatic performance. FIG. 2 is a plan view of the drive unit UNT. The drive unit UNT includes a magnetically permeable upper yoke 35 and a lower yoke 40. The upper yoke 35 and the lower yoke 40 have a full key width. The drive unit UNT includes actuators 30 for all keys corresponding to each hammer body HM. The actuators 30 are arranged in a straight line, that is, in a staggered manner, in parallel in two rows of the front row and the rear row along the key arrangement direction. All the actuators 30 are similarly configured except for the arrangement position.

  As shown in FIG. 1, the upper yoke 35 is integrally formed in a U-shaped cross section that opens downward. The lower yoke 40 includes a U-shaped concave portion 43 that receives the upper yoke 35, a rear horizontal portion 41 that extends rearward from the concave portion 43, and a front horizontal portion 42 that extends forward from the concave portion 43. And integrally formed. The rear horizontal portion 41 is sufficiently long rearward and extends to the rear from the tip of the mass member 23. Since the lower yoke 40 has a concave 43 having a U-shaped cross section and is an inverted hat type, the rigidity of the lower yoke 40 is increased.

  The shelf plate 15 is formed with a mounting hole 15b (see FIG. 1) having a length extending at least over the entire key width. The upper yoke 35 is accommodated in the recess 43 of the lower yoke 40, whereby the actuator 30 including a portion where the upper yoke 35 and the lower yoke 40 overlap is positioned in the mounting hole 15 b. This position is close to the hammer body rotation axis PH. From the viewpoint of reducing the stroke of the plunger 33, the position of the actuator 30 is between the key rotation fulcrum PK and the hammer body rotation axis PH and as close as possible to the hammer body rotation axis PH. It is preferable to arrange.

  As shown in FIG. 1, in each actuator 30, a solenoid coil 32 is wound around the bobbin 31 inside the upper yoke 35. A plunger 33 is disposed inside the bobbin 31 so as to be able to reciprocate in the vertical direction. A drive unit 34 made of an elastic material is provided on the plunger 33. Each actuator 30 is formed by using a portion where the upper yoke 35 and the lower yoke 40 overlap as a main magnetic path.

  The upper yoke 35 and the lower yoke 40 are fixed by a plurality of screws 37 (see FIGS. 1 and 2). The fixing with the screw 37 also serves to fix the bobbin 31 and the solenoid coil 32 between the upper yoke 35 and the lower yoke 40. Since the actuators 30 are arranged in a staggered manner, the winding diameters of the solenoid coils 32 of the individual actuators 30 (the diameter of the bobbin 31) can be set large or the number of windings can be set, which is advantageous for efficient improvement of driving force. It has become.

  As shown in FIG. 2, mounting holes 41ab and 42ab for mounting to the chassis 14 are provided in the rear end portion 41a of the rear horizontal portion 41 of the lower yoke 40 and the front end portion 42a of the front horizontal portion 42, respectively. A plurality are formed. A circular first positioning hole 42aa is formed at the right end portion of the front end portion 42a of the front horizontal portion 42. A second positioning hole 41aa is formed at the left end portion of the rear end portion 41a of the rear horizontal portion 41. The second positioning hole 41aa is a long hole extending in the direction connecting the second positioning hole 41aa and the first positioning hole 42aa. The second positioning hole 41aa may be a long hole that is long in the key arrangement direction.

  When the upper yoke 35 and the lower yoke 40 are fixed to form the drive unit UNT, the plunger 33 and the drive portion 34 of each actuator 30 and the first positioning hole 42aa and the second positioning hole 41aa are horizontally arranged. Accurate positioning in the direction.

  FIG. 3A is an exploded perspective view showing a part of the drive unit UNT. FIG. 3B is a perspective view showing a part of the drive unit UNT after assembly. 3A and 3B, the plunger 33 and the drive unit 34 are not shown.

  As shown in FIG. 6A, the upper yoke 35 has a screw 37 (see FIGS. 1 and 2) for screwing and a positioning hole 35b corresponding to the upper end 31a of the bobbin 31 of each actuator 30. A hole 35a is formed. On the other hand, a screw hole 43 b for screw 37 and a positioning hole 43 a corresponding to the lower end portion 31 b of the bobbin 31 of each actuator 30 are formed in the horizontal portion of the recess 43 of the lower yoke 40.

  When the drive unit UNT is created, the lower end 31b of the bobbin 31 of each actuator 30 is fitted into the hole 43a of the lower yoke 40. Then, the upper yoke 35 is inserted into the recess 43 of the lower yoke 40 from above, and the upper end 31 a of the bobbin 31 is fitted into the hole 35 a of the upper yoke 35. As a result, the first positioning hole 42aa (FIGS. 2 and 3B) and the second positioning hole 41aa (see FIG. 2) and the bobbin 31 are positioned in the horizontal direction. 34 is also positioned in the horizontal direction. As shown in FIG. 3, the drive unit UNT is completed by screwing a plurality of screws 37 (see FIGS. 1 and 2) into the screw holes 43b through the holes 35b.

  As shown in FIG. 1, the drive unit UNT includes a plurality of screws 29 through mounting holes 41ab and 42ab (see FIG. 2) of the lower yoke 40, and a mounting portion 14 a and a front lower portion of the rear portion of the chassis 14. Are fastened and fixed to the mounting portion 14b. An escape portion 15 a for avoiding interference with the screw 29 is formed in the upper portion of the shelf board 15. Since the flange-shaped front horizontal portion 42 and rear horizontal portion 41 of the lower yoke 40 also serve as mounting brackets to the chassis 14 of the drive unit UNT, complication of the configuration is avoided.

  In addition, positioning pins 27 and 28 corresponding to the positioning holes 42aa and 41aa of the lower yoke 40 project downward from the mounting portions 14a and 14b of the chassis 14 (see also FIG. 2). When the drive unit UNT is fixed to the chassis 14, the positioning pins 27 and 28 are fitted into the positioning holes 42aa and 41aa. These define the horizontal position of the drive unit UNT with respect to the chassis 14 and the position in the horizontal direction of rotation. Further, when the drive unit UNT is fixed to the chassis 14, the lower ends of the mounting portions 14 a and 14 b of the chassis 14 are in contact with the upper surfaces of the rear end portion 41 a of the rear horizontal portion 41 and the front end portion 42 a of the front horizontal portion 42. Therefore, the vertical position of the drive unit UNT with respect to the chassis 14 is also defined.

  As shown in FIG. 1, a substrate 44 for controlling the operation of the drive unit UNT is fixed by a plurality of screws 46 immediately behind the drive unit UNT and below the shelf plate 15. Further, a unit cover 45 that covers the drive unit UNT and the substrate 44 from below is provided. The unit cover 45 is made of sheet metal, resin, or the like, and front and rear attachment portions 45 b are fixed to the lower surface of the shelf board 15 by a plurality of screws 47. An inclined portion 45a is formed in the lower part of the front half of the unit cover 45 so that it does not easily interfere with the player's feet. The shape of the inclined portion 45a may be an arc shape.

  In the non-key-pressed state, the drive unit 34 of the actuator 30 is close to the corresponding hammer body HM. In the non-key-pressed state, the drive unit 34 may abut on the hammer body HM. When the solenoid coil 32 is energized, the plunger 33 moves upward and pushes up and drives the hammer body HM through contact between the drive unit 34 and the hammer body HM. Then, in conjunction with the hammer body HM, the key 10 rotates in the key pressing direction (the direction in which the tip of the key 10 is displaced downward).

  When the energization is released, the plunger 33 is pushed by the hammer body HM along with the return of the hammer body HM and the key 10, and is returned to the original initial position (position shown in FIG. 1) by its own weight. Note that a spring or the like for forcibly returning the plunger 33 may be provided to speed up the return operation.

  The automatic performance piano is manufactured by the following procedure. First, components such as the key 10 and the hammer body HM are disposed on the chassis 14. On the other hand, the drive unit UNT in which the drive unit 34, the first positioning hole 42aa, and the second positioning hole 41aa are positioned in the horizontal direction is manufactured as described above. Then, with the positioning holes 42aa and 41aa of the drive unit UNT and the positioning pins 27 and 28 of the chassis 14 fitted and aligned in the horizontal direction, the drive unit UNT is fastened and fixed to the chassis 14 with screws 29. To do. In this state, if the board 44 is temporarily connected to the drive unit UNT, the operation of the keyboard device with the drive unit UNT can be confirmed without the chassis 14 being provided on the shelf board 15.

  Next, the chassis 14 with the drive unit UNT is fixed to the shelf board 15 with a fastener (not shown). Then, the substrate 44 and the unit cover 45 are attached to the lower part of the shelf board 15. The board 44 and the unit cover 45 may be attached to the shelf board 15 before attaching the chassis 14 with the drive unit UNT to the shelf board 15.

  According to the present embodiment, since the actuator 30 is arranged behind the key rotation fulcrum PK and below the hammer body HM, the length of the entire piano in the front-rear direction is increased by providing the actuator 30. It won't be long. Further, since the actuator 30 is disposed in the vicinity of the hammer body rotation axis PH, the stroke of the plunger 33 can be set small, and the vertical dimension expansion of the entire piano can be suppressed.

  By the way, since the actuator 30 is close to the hammer body rotation axis PH, the displacement amount of the hammer body HM with respect to the stroke of the plunger 33 becomes relatively large, and thus high positional accuracy of the plunger 33 is required. However, in the present embodiment, the position of the plunger 33 in the horizontal direction with respect to the chassis 14 is accurately defined by the fitting of the positioning holes 42aa, 41aa and the positioning pins 27, 28. In addition, the vertical position of the drive unit UNT relative to the chassis 14 is also defined by the contact between the lower ends of the mounting portions 14a and 14b of the chassis 14 and the upper surfaces of the rear horizontal portion 41 and the front horizontal portion 42 of the drive unit UNT. Thus, the arrangement error of the drive unit UNT can be minimized without increasing the number of parts. As a result, the accuracy of the rotation stroke of the hammer body HM and the key depression stroke of the key 10 can be maintained high.

  Therefore, it is possible to maintain high accuracy of the key pressing stroke and to suppress the dimension expansion in the front-rear direction and the vertical direction of the piano.

  Further, since the rear end portion 41a and the front end portion 42a, which are the fixed portions of the lower yoke 40, are fixed to the chassis 14 instead of the shelf board 15, product testing and operation confirmation of the keyboard portion and the drive unit UNT performed at the manufacturing stage. Can be performed in a state before they are attached to the instrument body.

  In the present embodiment, the function of the positioning means in the vertical and horizontal directions between the drive unit UNT and the chassis 14 is the same between the mounting portions 14a and 14b of the chassis 14 and the rear end portion 41a and the front end portion 42a of the drive unit UNT. The positioning holes 42aa, 41aa of the drive unit UNT and the positioning pins 27, 28 of the chassis 14 are combined with each other. However, the present invention is not limited to this. For example, the side where the positioning holes 42aa and 41aa and the positioning pins 27 and 28 are provided may be reversed between the drive unit UNT and the chassis 14. Further, it may be a structure that can be positioned by contact or engagement, and is not limited to the relationship between the hole and the protrusion.

  In the drive unit UNT, the upper yoke 35 and the lower yoke 40 both have the full key width, but are not limited thereto. For example, the lower yoke 40 may have a full key width and the upper yoke 35 may be divided into a plurality of predetermined octaves. The lower yoke 40 may also be divided into a plurality.

  In the present embodiment, the lower yoke 40 of the drive unit UNT is fixed to the chassis 14, but the accuracy of the key pressing stroke is kept high, and the dimensions of the piano in the front-rear direction and the vertical direction are increased. If it says only from a viewpoint of suppressing, it will not be restricted to this. For example, the rear end portion 41a, the front end portion 42a, etc., which are fixed portions in the drive unit UNT, are fixed to the chassis 14 or a portion fixed to the instrument body (for example, the shelf board 15). The configuration may be fixed directly or indirectly.

  Further, also in the drive unit UNT, the portion fixed to the chassis 14 or the instrument body is not limited to a portion having a yoke function such as the lower yoke 40, but a fixed portion in the drive unit UNT. And what is necessary is just the part by which positioning with the plunger 33 is made | formed.

  The shelf board 15 is made of wood, but may be made of resin or metal (such as sheet metal or aluminum). Further, the chassis 14 may be entirely or partially made of metal. Furthermore, all or part of the shelf board 15 and all or part of the chassis 14 may be integrally formed of resin or metal. In that case, pins corresponding to the positioning pins 27 and 28 may be provided in a portion corresponding to the shelf board 15.

(Second Embodiment)
FIG. 4 is a cross-sectional view of an automatic performance piano showing the main part of the drive unit mounting structure according to the second embodiment of the present invention. In the present embodiment, the configuration of the chassis 14, the key 10 above it, the hammer body HM, and the like, and the drive unit UNT are the same as those in the first embodiment. The second embodiment is different from the first embodiment in that a shelf board / unit cover 115 in which the shelf board 15 and the unit cover 45 in the first embodiment are integrally formed is provided.

  As shown in FIG. 4, the shelf / unit cover 115 has horizontal portions 115a and 115b and a cover concave portion 115c, and is integrally formed of resin or metal. The horizontal portions 115a and 115b serve as the shelf 15 in the first embodiment, and the cover recess 115c serves as the unit cover 45 in the first embodiment. In the present embodiment, the substrate 44 is fixed to the rear horizontal portion 41 of the lower yoke 40 of the drive unit UNT with screws 46 inside the cover recess 115c, not the shelf plate.

  According to the present embodiment, the same effects as those of the first embodiment can be obtained. In addition, since the board 44 is fixed to the drive unit UNT, the part of the keyboard device including the chassis 14, the key 10, and the hammer body HM can be unitized before being attached to the shelf / unit cover 115. it can. Thereby, the freedom degree of the time of the product test thru | or confirmation of an operation | movement confirmation of a keyboard part and the drive unit UNT in a manufacture stage can be raised further.

  In the first and second embodiments, the position of the actuator 30 in the front-rear direction is driven from the viewpoint of setting the stroke of the plunger 33 small to suppress the vertical dimension expansion of the entire piano. It is desirable to be as close as possible to the rotation fulcrum (key rotation fulcrum PK, hammer body rotation axis PH) of the member (key 10, hammer body HM), and within 1/2 of the distance from the rotation fulcrum to the free end. It is desirable to do.

  In the present embodiment, the board 44 is fixed to the drive unit UNT. However, from the viewpoint of unitizing the keyboard device portion before the shelf board / unit cover 115 is attached, the board 44 is made into the chassis 14. It may be fixed directly or indirectly.

  In the first and second embodiments, the lower yoke 40 of the upper yoke 35 and the lower yoke 40 is fixed to the chassis 14, but a modified example of the drive unit UNT is shown in FIG. In addition, the geometric relationship between the upper yoke 35 and the lower yoke 40 may be reversed.

  That is, the concave portion 43 of the lower yoke 40 is protruded upward to form a hat shape as a whole, and the upper yoke 35 having a U-shaped cross section opened upward is attached to the concave portion 43 from below. Also by this, the same effect can be produced.

  The actuator 30 may be disposed at a position below the hammer body HM and in the vicinity of the corresponding hammer body rotation axis PH in front of the corresponding key rotation fulcrum PK. The moving direction of the free end portion of the hammer body HM with respect to the key depression is not limited to that exemplified in the first and second embodiments.

  FIG. 6A is a diagram schematically showing an arrangement relationship of the key 10, the hammer body HM, and the actuator 30 in the first and second embodiments. 6B to 6D are schematic diagrams of modified examples of the arrangement relationship.

  For example, as shown in FIG. 6B, in the configuration in which the rear portion of the key 10 is engaged with the hammer body HM via the hammer body driving portion 11, and the front end portion of the hammer body HM is a free end portion. The actuator 30 may be disposed just in front of the body rotation axis PH.

  Further, as shown in FIG. 6C, the front portion of the key 10 is engaged with the hammer body HM via the hammer body driving portion 11, and the rear end which is the free end portion of the hammer body HM is accompanied by the key depression. You may employ | adopt the structure that a part moves below. In this case, the actuator 30 may be disposed immediately in front of the hammer body rotation shaft PH.

  Further, as shown in FIG. 6D, the rear portion of the key 10 is engaged with the hammer body HM via the hammer body driving portion 11, and the front end portion which is the free end portion of the hammer body HM is accompanied by the key depression. You may employ | adopt the structure which moves below. In this case, the actuator 30 may be disposed immediately behind the hammer body rotation shaft PH.

  In the example shown in FIGS. 6C and 6D, it is difficult to configure the hammer body HM to return to the non-key-pressed state by its own weight, and therefore it is desirable to provide a return spring 48. .

  In each of the above embodiments, the actuator 30 employs a system in which the plunger 33 is protruded by the solenoid coil 32, but is not limited thereto. That is, it is only necessary to have a portion fixed to the chassis 14 to the musical instrument main body and a movable portion that is movable relative to the portion and drives the hammer body HM.

It is sectional drawing of the automatic performance piano to which the attachment structure of the drive unit which concerns on the 1st Embodiment of this invention is applied. It is a top view of a drive unit. FIG. 4 is an exploded perspective view (FIG. (A)) showing a part of the drive unit, and a perspective view (FIG. (B)) showing a part of the drive unit after assembly. It is sectional drawing of the automatic performance piano which shows the principal part of the attachment structure of the drive unit which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the modification of a drive unit. The figure (figure (a)) which showed typically the arrangement | positioning relationship of the key, hammer body, and actuator in 1st, 2nd embodiment, The schematic diagram (figure (b)-(d) of this arrangement | positioning relationship )).

Explanation of symbols

  10 keys, 14 keyboard chassis (key frame), 27, 28 positioning pins (part of positioning means), 30 actuator (driving part), 33 plunger (moving part), 34 driving part (moving part), 41a rear end part (Fixed part), 42a front end part (fixed part), 41aa, 42aa positioning hole (reference part), 44 substrate, UNT drive unit, PK key rotation fulcrum (key fulcrum part), hammer body rotation shaft PH, hammer Body HM

Claims (1)

A key frame fixed to the instrument body,
A plurality of keys arranged in parallel to the key frame and swingable in the direction of pressing and releasing keys around the key fulcrum,
A plurality of keys arranged in parallel in the key arrangement direction in the key frame corresponding to each key, and swinging in a direction corresponding to the pressing / releasing key direction around a hammer fulcrum portion in conjunction with the corresponding key. Hammer body,
A fixed portion fixed to the key frame , and provided corresponding to each key, disposed below the corresponding hammer body and in the vicinity of the corresponding hammer fulcrum in front of the corresponding key fulcrum. A drive unit including a plurality of drive units,
Each drive part of the drive unit has a movable part that moves relative to the fixed part and drives the corresponding hammer body to swing the corresponding key in the key pressing direction via the hammer body. ,
Have a positioning means for determining the fixed portion of the reference portion and the key frame is a relative position in the vertical direction and the horizontal direction with respect to the stationary part of the drive unit,
A substrate for the drive unit is fixed to the drive unit;
In a state where the fixing portion is fixed to the key frame and the substrate is fixed to the driving unit, a cover that is separate from the key frame and covers the plurality of driving portions and the substrate from below is provided. A structure for mounting a drive unit in an automatic performance piano, characterized in that the structure can be fixed to the drive unit.

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