JP2018155990A - Hammer device for electronic keyboard musical instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hammer device for electronic keyboard musical instrument capable of eliminating mounting and adjustment work of a conventional capstan screw by omitting it, and capable of achieving reduction in manufacturing cost of electronic keyboard musical instrument.SOLUTION: In an electronic keyboard musical instrument including a key 2 extending in the front-to-back direction and freely swingable around central vicinity, a hammer device for electronic keyboard musical instrument includes a hammer 5 which is placed at a rear end part of the key 2, and which rotates by being pushed up by the depressed key 2. The hammer device includes: a hammer body 51 made of synthetic resin which extends in the front-to-back direction and which is supported in a vertically rotatable manner around a fulcrum of the rear end part; and a contact protrusion part 57 which is molded integrally with the hammer body 51 in a state of protruding downward at a position further frontward than the fulcrum of the hammer body 51, and which comes into contact with the rear end part of the key 2 from above in a key release state.SELECTED DRAWING: Figure 2

Description

  The present invention is applied to an electronic keyboard instrument such as an electronic piano, and relates to a hammer device for an electronic keyboard instrument provided with a hammer that is rotated by being pushed up by a pressed key.

  Conventionally, as this type of hammer device, for example, the one disclosed in Patent Document 1 already filed by the present applicant is known. This hammer device extends in the front-rear direction and has a hammer support arranged behind each of a plurality of keys that can swing around the center in the length direction, and is provided for each key, and can rotate freely on the hammer support. And a plurality of hammers supported by the motor. Each hammer is formed in an arm shape extending in the front-rear direction, and includes a hammer body made of a synthetic resin molded product and a metal weight plate attached to the front end portions of the left and right side surfaces. An arc-shaped shaft hole is formed in the rear end portion of the hammer body, and this shaft hole is rotatably engaged with a hammer fulcrum shaft extending in the left-right direction of the hammer support. In addition, a capstan screw is screwed into the lower surface of the hammer body in front of the shaft hole so as to be able to advance and retract. Each hammer is placed on the key with the head at the lower end of the capstan screw in contact with the rear end of the corresponding key from above.

  In the hammer device configured as described above, when the key is depressed, when the front end of the key is lowered and the rear end is swung up, the hammer corresponding to the key is interposed via the capstan screw. It is pushed up and pivots upward about the hammer fulcrum shaft. When the key is pushed all the way, the hammer comes into contact with the upper hammer stopper, and the upward rotation of the hammer is completed. Thereafter, when the key is released, the key swings in the opposite direction to that when the key is pressed, and accordingly, the hammer also rotates downward to return to the original key released state.

  Since the key of the above keyboard device is made of wood, the thickness in the vertical direction is likely to vary due to manufacturing errors and expansion / contraction due to dry / wet conditions in the usage environment. Further, in the keyboard device as described above, in order to make the rotation angle of the hammer during key pressing uniform and to keep the key pressing stroke that is the key pressing amount constant, from the side in the key release state. It is required that the hammer position (posture) is the same when viewed. Therefore, as described above, when the thickness of the keys varies, especially when the upper surface height of the rear end of the key varies, the positions of the hammers are the same for all hammers in the key release state. The capstan screw is turned to adjust the amount of protrusion from the hammer body.

JP 2013-125236 A

  As described above, in the conventional keyboard device, it is necessary to attach the capstan screw so as to be screwed into the hammer body at the time of manufacture, and the attaching operation is complicated. In addition, it is necessary to adjust the capstan screw in accordance with the height of the upper surface of the rear end of the key, and the adjustment work is complicated.

  The present invention has been made to solve the above-described problems, and the conventional capstan screw can be omitted, so that the installation and adjustment work can be made unnecessary. It is an object of the present invention to provide a hammer device for an electronic keyboard instrument that can reduce the manufacturing cost.

  In order to achieve the above object, an invention according to claim 1 is placed at the rear end of a key in an electronic keyboard instrument that includes a key that extends in the front-rear direction and that can swing around the center. In addition, a hammer device for an electronic keyboard instrument having a hammer that rotates by being pushed up by a pressed key, extends in the front-rear direction and is supported so as to be rotatable in the vertical direction around a fulcrum at the rear end. The molded synthetic resin hammer body, and is molded integrally with the hammer body in a state of protruding downward at a predetermined position in front of the fulcrum of the hammer body, and in the key release state, it is located above the rear end of the key. And an abutment convex part that abuts from above.

  According to this configuration, the hammer main body is made of synthetic resin, and the contact convex portion that protrudes downward to a predetermined position ahead of the fulcrum of the rear end portion of the hammer main body is formed integrally with the hammer main body. Yes. Further, in the key release state, the contact convex portion of the hammer body contacts the rear end portion of the key from above. In this state, when the key is pressed so that the front end of the key is lowered and the rear end is swung so that the rear end is raised, the hammer corresponding to the key is pushed up through the abutting convex portion, and the rear It pivots upward about the fulcrum of the end.

  In this case, in the key release state, the upper surface of the rear end portion of the key with which the abutting convex portion of the hammer abuts is held at a constant height, so that the abutting convex portion can be replaced with the conventional capstan screw Instead, it can be used to push up a hammer with a key. Therefore, according to the present invention, since the conventional capstan screw can be omitted, the installation and adjustment work can be eliminated, and the manufacturing cost of the electronic keyboard instrument can be reduced accordingly.

  The invention according to claim 2 is the hammer device of the electronic keyboard instrument according to claim 1, wherein the convex cover attached to the hammer body is made of a predetermined elastic material and covers the contact convex part. It is further provided with the feature.

  According to this configuration, since the convex cover made of an elastic material is attached to the hammer body so as to cover the abutting convex portion, for example, the abutting convex portion is made of a hard synthetic resin. In this case, when the key is depressed, the abutment convex part directly contacts the key again after being once separated from the key or slides relative to the key. It can be greatly reduced.

  According to a third aspect of the present invention, in the hammer device for an electronic keyboard instrument according to the second aspect, the convex cover is opened upward, and a cover main body that accommodates the abutting convex portion, and projects upward from the cover main body. The hammer body is formed in a concave shape that opens downward, and the hook has a hook receiving portion that engages in a retaining state.

  According to this configuration, the convex cover has the cover main body and the hook, and when attached to the abutting convex portion of the hammer, the cover main body accommodates the abutting convex portion and has a concave shape that opens downward. The hook engages with the hook receiving portion in a state of being prevented from coming off. Thereby, since the convex cover is firmly attached to the hammer body, even if the hammer is repeatedly pushed up as the key is pressed, the convex cover does not fall off from the contact convex part of the hammer. In addition, by releasing the engagement of the hook of the convex cover with the hook receiving portion, the convex cover can be easily removed from the hammer body, and the convex cover can be easily replaced if necessary. it can.

  According to a fourth aspect of the present invention, in the hammer device for an electronic keyboard musical instrument according to the third aspect, the hook receiving portion is provided at a predetermined position in front of the contact convex portion of the hammer body.

  According to this configuration, the concave hook receiving portion that opens downward is provided at a predetermined position in front of the contact protrusion of the hammer body, that is, at a position away from the fulcrum of the rear end portion. As a result, for example, the hook receiving portion is in contact with the hammer body when the key is pressed, as compared with the case where the hook receiving portion is provided behind the contact protrusion of the hammer body, that is, at a position closer to the fulcrum of the rear end portion of the hammer body. The stress acting near the base of the convex portion can be reduced. As a result, the hammer (hammer body) can be prevented from being damaged even when the hammer is repeatedly pushed up through the abutting convex portion with the key depression.

It is a perspective view which shows a part (1 octave part) of the keyboard apparatus of the electronic piano to which the hammer apparatus by one Embodiment of this invention is applied. It is a side view which shows the keyboard apparatus of FIG. It is a perspective view which shows a part before a front pin and a collar. It is a perspective view which shows the state when a part of front side is seen from the bottom face side, (a) is the state which connected two front moldings, (b) is before connecting two front moldings Shows the state. FIG. 5 is a schematic diagram for explaining displacement between pin holes due to shrinkage due to drying and drying in a state where two molded products before heel are connected, and (a) to (c) are molded products before heel used in the present embodiment. (D)-(f) has shown the pre-molded article of a comparative example. It is a perspective view which shows an example of a white key and a black key. It is a perspective view which shows the hammer contact height prescription | regulation part attached to the rear-end part of a key. It is a figure which shows the hammer contact height prescription | regulation part of FIG. 7, (a) is a right view, (b) is a left view. It is a perspective view which shows a hammer support, (a) shows the whole hammer support for 1 octave, (b) shows the state which notched the part, and expands and shows the cross section of a hammer fulcrum shaft . It is a figure which shows a hammer support, (a) is a top view, (b) is a front view. It is a perspective view which shows the hammer for white keys, and the hammer for black keys. It is a figure for demonstrating the convex part cover attached to a hammer and its contact convex part, (a) is a side view of a hammer, (b) is one of the hammers centering on a contact convex part and a convex part cover. It is sectional drawing which cut | disconnected the part vertically, (c) is a perspective view which shows a convex part cover. It is a figure for demonstrating the attitude | position of the hammer in a key release state, (a) shows the hammer for black keys, (b) shows the hammer for white keys, (c) is after the hammers for black keys and white keys The engagement part of an edge part is expanded and shown. It is a figure for demonstrating the removal of the hammer from a hammer support, (a) has shown the hammer for black keys, (b) has shown the hammer for white keys.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. 1 and 2 show a part of a keyboard device of an electronic piano to which a hammer device according to an embodiment of the present invention is applied in a key release state. As shown in both figures, the keyboard device 1 includes a large number of keys 2 (eight white keys 2a and five black keys 2b shown in FIG. 1) arranged in the left-right direction of the electronic piano, and these keys 2. A keyboard chassis 3 to be supported, a hammer support 4 connected to the rear end of the keyboard chassis 3, and a number of hammers 5 provided for each key 2 and rotating in conjunction with the depressed key 2 (see FIG. In FIG. 1, eight white key hammers 5a and five black key hammers 5b are shown, and a number of let-off components 6 provided for each hammer 5 to give a let-off feeling when the key 2 is depressed (see FIG. 2, only one is shown), and a key switch 7 for detecting key press information of the key 2.

  The keyboard chassis 3 is an assembly of three support rails 9 including a front rail 9a, a middle rail 9b, and a rear rail 9c extending in the left-right direction, and a plurality of reinforcing ribs 10 extending in the front-rear direction. It is fixed on a shelf board (not shown). Each of these support rails 9 and ribs 10 is made of a metal plate formed into a predetermined shape by stamping and bending with a press.

  A saddle front 11 and a saddle center 12 are fixed to the lower surface of the front rail 9a and the upper surface of the middle rail 9b, respectively. The saddle front 11 and the saddle center 12 are thick plate-like materials made of synthetic resin (for example, ABS resin), and extend in the left-right direction over the entire front rail 9a and middle rail 9b. In the saddle 12, a large number of balance pins 13 (eight white key balance pins 13a and five black key balance pins 13b are shown in FIG. 1) at the front and rear positions corresponding to the white key 2a and the black key 2b. Are erected in a state of being lined up in the left-right direction. In addition, a large number of front pins 14 are erected on the front 11 in a state of being arranged in the left-right direction.

  FIG. 3 shows a part of the front 11 where the front pin 14 is erected. As shown in the figure, the front 11 is configured by connecting a plurality of (for example, 2 to 5) molded products 15 (hereinafter referred to as “front moldings”) 15 extending in the left-right direction to each other in the left-right direction. ing. Each pre-molded product 15 is formed with a large number of pin holes 15a into which the lower end portion of the front pin 14 is inserted along the length direction, and the pre-molded product 15 itself is screwed to the front rail 9a. A plurality of mounting holes 15b for stopping are formed. Each of these attachment holes 15b is formed in a long hole shape extending in the length direction (left-right direction) of the pre-molded product 15. Moreover, the pre-molded articles 15 and 15 adjacent to each other are connected as follows.

  FIG. 4 shows a state when the connecting parts of the two pre-molded articles 15 and 15 are viewed from the bottom surface side, (a) shows a connected state, and (b) shows a state before connecting. . As shown in both figures, on the bottom surface of each pre-molded product 15, there are a large number of convex shapes projecting downward (upward in FIG. 4) and having a predetermined diameter corresponding to the numerous pin holes 15 a, respectively. A boss 16 is formed. Further, one end (the left end portion of FIG. 4 (b)) has an end portion (left end portion) of the pre-molded product 15 on the other side (the left end portion of FIG. 4 (b)). ) Of the boss 16 is formed.

  As described above, in the front 11 constructed by connecting a plurality of front moldings 15 made of synthetic resin to each other, the front 11 is moved in the length direction (due to a temperature change in the usage environment of the electronic piano). It may expand and contract in the horizontal direction). In this case, the front 11 made of synthetic resin has a larger amount of change than the front rail 9a made of metal, and due to the connecting structure of the pre-molded product 15 described above, the moldings adjacent to each other as described below. The change in the distance between the pin holes 15a and 15a of the products 15 and 15 can be suppressed.

  FIGS. 5A to 5C schematically show a state in which the pre-molded articles 15A and 15B in the present embodiment are contracted in a state where they are connected to each other and screwed to the front rail 9a. . As shown in FIG. 2A, the two front moldings 15A and 15B shown in FIG. 2A are provided with the right end boss 16 of the left front molding 15A in the fitting hole 17 of the right front molding 15B. They are connected in a fitted state ((b) in the figure). In this state, when the pre-molded products 15A and 15B are contracted, the distance α between the pin holes 15a and 15a is slightly reduced, but is substantially the same distance β ((c) in the figure).

  On the other hand, FIGS. 5 (d) to (f) schematically show the state when the pre-molded articles 15C and 15D in the comparative example contract with each other in a state where they are in contact with each other and screwed to the front rail 9a. Yes. The two front moldings 15C and 15D shown in FIG. 4D are in contact with each other on the surfaces facing each other (FIG. 4E). In this case, the distance between the pin holes 15a and 15a that are closest to each other in the two-sided pre-formed products 15C and 15D is set to the distance α, as is the distance between the other pin holes 15. In this state, when the heel moldings 15C and 15D contract, the distance between the pin holes 15 in the respective heel moldings 15C and 15D is the same as that of the heel moldings 15A and 15B of the present embodiment described above. β. However, a distance γ (> α, β) larger than the distances α, β between the pin holes 15a, 15a closest to each other in the pre-molded products 15C, 15D. In this case, a gap larger than the other keys 2 is generated between the two adjacent keys 2 and 2 which are respectively engaged with the front pins 14 at the ends of the pre-molded products 15C and 15D. End up.

  As described above, in the connection structure of the pre-molded products 15A and 15B in the present embodiment, unlike the pre-molded products 15C and 15D in the comparative example, even when the front 11 is contracted, the pin holes 15a and 15a are connected to each other. The distance β can be maintained at a distance α that is substantially the same as that before the contraction. Thereby, the malfunction mentioned above at the time of using the pre-molded articles 15C and 15D of a comparative example, ie, the malfunction that a big clearance gap arises between the two keys 2 and 2 adjacent to each other, can be prevented.

  FIG. 6 shows the white key 2a and the black key 2b. As shown in the figure, the key 2 includes a wooden key body 21 that extends in the front-rear direction and has a rectangular cross section, and a key cover 22 made of synthetic resin that is bonded to the upper surface and the front surface of the front half thereof. Have. Near the center of the key body 21 in the length direction, a balance pin hole 23 is formed, and the key 2 swings on the balance pin 13 erected in the cage 12 through the balance pin hole 23. It is supported freely.

  Each balance pin hole 23 is formed with a substantially circular hole near the lower surface of the key body 21, and the entire upper part connected to the hole is formed in a long hole shape extending in the length direction of the key body 21. Yes. Further, felts 23 a are provided on the left and right inner surfaces of the balance pin hole 23 in order to smoothly slide the key 2 relative to the balance pin 13 when the key 2 swings. A cushion 20 is adhered to the upper surface of the key body 21 on the back side of the balance pin hole 23. With this cushion 20, the front end of the hammer 5 directly contacts the key 2 during performance or maintenance. It is prevented.

  Further, a front pin hole 24 (see FIG. 2) that opens downward is formed at a predetermined position on the front portion of the key body 21, and the front pin hole 24 is a front pin that is erected on the front side 11. By engaging 14, the shaking in the left-right direction when the key 2 swings is prevented.

  Further, as shown in FIG. 6, at the rear ends of the white key 2a and the black key 2b, a height at which a lower end of a key contact portion 56 (to be described later) of the hammer 5 in the key release state contacts the key 2 is set to a predetermined height. A hammer contact height defining portion 25 for defining the thickness is attached. The hammer contact height defining portion 25 is formed of a molded product having a predetermined shape made of hard synthetic resin (for example, ABS resin).

  Specifically, as shown in FIGS. 7 and 8, the hammer contact height defining portion 25 is connected to the upper piece 31 extending a predetermined length in the front-rear direction and the rear end portion of the upper piece 31 and extends downward. The side piece is formed in a U-shape by the rear piece 32 and the lower piece 33 that continues to the lower end of the rear piece 32 and extends forward by a predetermined length. Further, a side wall 34 connected to the upper piece 31 and the rear piece 32 is provided on the left side surface of the hammer contact height defining portion 25.

  The upper piece 31 constitutes the front half of the upper piece 31 and constitutes the upper piece fixing portion 31a for fixing the upper piece 31 itself to the rear upper end portion of the key 2 and the latter half of the upper piece 31, and the upper face is It has a hammer receiving portion 31b that is formed flat and receives the key abutting portion 56 of the hammer 5 from below. Most of the upper piece fixing portion 31a is formed thinner than the hammer receiving portion 31b, and the U-shaped fixing bracket 35 is driven into the upper piece fixing portion 31a from the outside, so that the upper piece 31 is The key 2 is fixed to the rear end portion of the upper surface.

  After the rear piece 32 is connected to the hammer receiving portion 31b of the upper piece 31, and is formed in a rearward convex upper part 32a, and the rear piece upper part 32a extends downward and is formed to be thin. It has the piece fixing | fixed part 32b and the back piece lower part 32c which continued to the lower end part of this rear piece fixing | fixed part 32b, and was formed in convex shape back. The rear piece 32 configured in this manner is fixed to the rear end surface of the key 2 by driving a U-shaped fixing bracket 36 into the rear piece fixing portion 32b from the outside.

  The lower piece 33 extends obliquely upward from the lower end portion of the rear piece 32, and a lower piece convex portion 33 a that comes into contact with the lower surface rear end portion of the key 2 is provided at the upper surface front end portion. Further, the lower piece 33 has a spring property that can be bent in the vertical direction with a connection portion with the rear piece 32 as a fulcrum.

  As shown in FIG. 8A, the side wall 34 is connected to the lower left end portion of the upper piece 31 and the front left end portion of the rear piece 32 and protrudes inward, and the side surface shape is formed in an L shape. The hammer contact height defining portion 25 reduces the amount of resin at the time of molding and reduces the weight of the molded product, and also prevents hammer sinks 31b of the upper piece 31 in order to prevent sink marks and deformation at the time of molding. In addition, a cavity open to the right is appropriately formed in the rear piece upper part 32a and the rear piece lower part 32c of the rear piece 32.

  In the hammer contact height defining portion 25 configured as described above, the lower surface of the upper piece 31, the front surface of the rear piece 32, and the three surfaces of the side wall 34 are the upper surface, rear end surface, and left side surface of the rear end portion of the key 2, respectively. The lower piece convex portion 33a of the lower piece 33 is attached to the rear end portion of the key 2 in a state where the lower piece convex portion 33a is in contact with the lower end of the lower surface of the key 2. When the hammer contact height defining portion 25 is attached to each key 2, an adhesive is applied to the three surfaces of the hammer contact height defining portion 25, and the hammer contact height defining portion 25 is locked to the key. The hammer contact height defining portion 25 is firmly fixed to the key 2 by driving the two fixing brackets 35 and 36 from above and behind the key 2 while temporarily fixed to the rear end portion of the key 2. .

  As shown in FIG. 2, the key 2 to which the hammer contact height defining portion 25 is attached is fixed to the rear rail 9c with the rear piece lower portion 32c of the hammer contact height defining portion 25 in the key release state. Is placed on the cushion 38. Thereby, in all the keys 2 in the key release state, the heights of the hammer receiving portions 31b of the hammer contact height defining portion 25 are the same height.

  9 and 10 show the hammer support 4. As shown in the figure, the hammer support 4 is made of a synthetic resin, and is formed by, for example, connecting a plurality of molded products for one octave to each other in the left-right direction. These are screwed to the rear rail 9c of the keyboard chassis 3. The hammer support 4 includes a hammer support portion 41 standing upright from the vicinity of the rear rail 9c, a switch mounting portion 42 extending obliquely upward from the upper end portion thereof, and the like. A hammer fulcrum shaft 43 for rotatably supporting each hammer 5 is provided at the upper end portion of the hammer support portion 41.

  The hammer support 4 has a plurality of partition walls 44 that partition adjacent hammers 5 with a predetermined interval in the left-right direction, and the hammer fulcrum is located between the adjacent partition walls 44, 44. The shaft 43 extends in the left-right direction. As shown in FIG. 9B, the hammer fulcrum shaft 43 has a so-called oval cross-sectional shape in which two places around the circle centered on the axis of the hammer fulcrum shaft 43 are cut out.

  Specifically, the outer peripheral surface of the hammer fulcrum shaft 43 includes a pair of upper and lower curved surface portions 43a and 43a and a pair of front and rear flat surface portions 43b and 43b extending between the curved surface portions 43a and 43a. . In the hammer fulcrum shaft 43 configured in this way, the upper and lower curved surface portions 43a and 43a are set to an arc having a diameter of the length L1, while the length L1 is between the front and rear plane portions 43b and 43b. Is set to a shorter length L2.

  FIG. 11 shows the white key and black key hammers 5 (5a and 5b). As shown in the figure, the white key hammer 5a and the black key hammer 5b are configured in substantially the same manner as a whole. In the following description, the white key hammer 5 (5a) will be representatively described. Shall.

  As shown in FIGS. 11 and 12 (a), the hammer 5 includes an arm-shaped hammer body 51 extending in the front-rear direction and two weight plates 52 attached to the front end portions of the left and right side surfaces via rivets 50. , 52. The hammer body 51 is made of a hard synthetic resin, and the weight plate 52 is made of a metal material such as iron having a relatively large specific gravity. The side surfaces of the white and black key hammer bodies 51 are marked with “W” and “B”, respectively.

  An engagement portion 53 that engages with the hammer fulcrum shaft 43 of the hammer support 4 is provided at the rear end portion of the hammer body 51. The engaging portion 53 is formed with an arc-shaped shaft hole 54 whose side surface is formed in a C-shape, and front and rear guide surfaces formed so as to spread outward in the opening. 55 and 55 are provided. The shaft hole 54 has a slightly larger diameter than the diameter (length L1) of the upper and lower curved surface portions 43a and 43a of the hammer fulcrum shaft 43, and the opening width L3 is a flat portion 43b before and after the hammer fulcrum shaft 43. , 43b is slightly larger than the length L2 and smaller than the length L1. The hammer 5 can be attached to and detached from the hammer fulcrum shaft 43 of the hammer support 4 through the opening of the shaft hole 54, and when the shaft hole 54 is fitted to the hammer fulcrum shaft 43, the hammer 5 The support 4 is rotatably supported.

  Further, as shown in FIG. 12A, a key abutting portion 56 that protrudes downward at a predetermined position on the bottom rear portion of the hammer 5 and abuts against the above-described hammer abutting height defining portion 25 of the key 2 from above. Is provided. The key abutting portion 56 includes an abutting convex portion 57 formed integrally with the hammer main body 51 of the hammer 5 and a convex portion cover 58 attached to the hammer main body 51 so as to cover the abutting convex portion 57. It consists of and.

  As shown in FIG. 12B, the contact convex portion 57 of the key contact portion 56 protrudes downward, and the lower surface is formed in an arc shape. Further, the hammer body 51 is formed with a hook receiving portion 59 that engages a hook 62 described later of the convex cover 58 on the upper front side of the contact convex portion 57. The hook receiving portion 59 is formed in a concave shape that opens downward, and has a locking recess 59a at its upper end.

  On the other hand, the convex cover 58 is made of a predetermined elastic material (for example, an elastomer) and is formed of a molded product having a predetermined shape. Specifically, as shown in FIGS. 12B and 12C, the convex portion cover 58 is opened upward and accommodated in a state of covering the abutting convex portion 57, and the cover. A hook 62 extends upward from a front end portion of the main body 61 and engages with a hook receiving portion 59 of the hammer main body 51. The cover main body 61 has a bottom surface formed in an arc shape like the contact convex portion 57 of the hammer main body 51. A hook 62a is provided at the upper end of the hook 62. The hook 62 is locked to the locking recess 59a of the hook receiving portion 59, so that the convex cover 58 is in contact with the convex. In the state of being attached to the portion 57, it is securely attached to the hammer body 51.

  The bottom surface of the convex cover 58 is formed with two grooves 61a and 61a that extend parallel to each other and open downward (see FIG. 12C). These grooves 61a are for retaining the low-viscosity lubricating oil applied to the bottom surface of the convex cover 58 for a long period of time. With this lubricating oil, the key contact portion 56 and the hammer contact height are increased. The friction between the defining portion 25 and the hammer receiving portion 31b is greatly reduced, and the smoothness between both the portions 56 and 31b is enhanced.

  The hammer 5 is coated with a lubricant having a relatively high viscosity, such as grease, between the shaft hole 54 and the hammer fulcrum shaft 43 of the hammer support 4. Thereby, smooth rotation of the hammer 5 is ensured while preventing the occurrence of rattling and noise when the hammer 5 rotates.

  However, the lubricant may flow out from between the shaft hole 54 of the hammer 5 and the hammer fulcrum shaft 43 depending on the usage environment of the electronic piano. When the lubricant that has flowed out travels along the side surface of the hammer 5 and adheres to the key abutting portion 56 in front of the shaft hole 54, that is, the above-described outflow flows into the key abutting portion 56 to which lubricating oil has been applied in advance. When the applied lubricant adheres, due to the change in characteristics of the lubricant and lubricant, the key contact portion 56 on the hammer 5 side and the hammer contact height defining portion 25 (hammer receiving portion 31b) on the key 2 side The friction between them changes, and as a result, the rotation characteristics of the hammer 5 during key depression change. In order to avoid such a problem, two symmetrical lubricants are provided on the left and right side surfaces of the hammer main body 51 on the front side of the engagement portion 53 at the rear end portion and on the rear side of the key contact portion 56. A blocking portion 65 (only the right side is shown in FIGS. 11 and 12 (a)) is provided. Each lubricant blocking portion 65 is formed in an arc shape surrounding the engaging portion 53 and in a concave shape opened to the side of the hammer body 51.

  Thus, even if the lubricant from the engaging portion 53 side flows along the side surface of the hammer body 51 by forming the lubricant blocking portion 65 on the left and right side surfaces of the hammer body 51, The lubricant can be effectively prevented from exceeding the concave lubricant blocking portion 65.

  Further, as shown in FIGS. 11 and 12 (a), the hammer main body 51 includes an actuator for actuating the hammer switch 51 by pressing the key switch 7 on the front upper portion of the engagement portion 53 at the rear end. A portion 66 is provided. Further, the hammer body 51 is provided with a plate-like engagement protrusion 67 that engages with the let-off component 6 when the key is depressed, in the vicinity of the center of the upper surface in the front-rear direction.

  As shown in FIG. 2, the letoff component 6 is formed of a molded product of a predetermined elastic material, and is attached to the switch attachment portion 42 of the hammer support 4. The let-off component 6 extends obliquely rearward and downward from the switch mounting portion 42, and a head portion 6a is formed at a tip portion thereof via a constricted portion. The head 6a faces the engagement protrusion 67 of the hammer 5 in the key release state.

  As shown in FIGS. 1 and 2, the key switch 7 includes a switch board 7a made of a printed circuit board and a switch body 7b made of a rubber switch provided for each key 2 on the lower surface of the switch board 7a. Has been. The switch board 7 a has a rear end portion inserted into the switch mounting portion 42 of the hammer support 4 and a central portion screwed to the switch mounting portion 42. Further, the switch body 7b faces the actuator portion 66 of the hammer 5 with a gap in the key release state.

  Further, as shown in FIGS. 1 and 2, the switch mounting portion 42 of the hammer support 4 is provided with a hammer stopper 68 for restricting the upward rotation of the hammer 5 on the bottom surface of the front end portion. The hammer stopper 68 is made of urethane foam or the like, and is attached to the switch attachment portion 42 so as to extend in the left-right direction.

  Here, the difference between the white key hammer 5a and the black key hammer 5b in the keyboard device 1 described above will be described with reference to FIGS. FIGS. 13A and 13B respectively show the black key hammer 5b and the white key hammer 5a in the key release state. As shown in both figures, in the key release state, the height H1 of the black key hammer 5b is between the lower end of the key contact portion 56 of the hammer 5 and the upper end of the weight plate 52 at the front end portion of the hammer 5. The white key hammer 5a is higher than the height H2 by a predetermined height. As a result, the rotation angle of the black key hammer 5b is smaller than that of the white key hammer 5a in the hammer 5 that rotates as the key 2 is pressed and contacts the hammer stopper 68. As a result, as shown in FIG. The key pressing stroke (for example, 9 mm) of the black key 2b is shorter than the key pressing stroke (for example, 10 mm) of the white key 2a.

  FIG. 13C shows the hammer fulcrum shaft 43 of the hammer support 4 and the black key hammer 5b (solid line) and the white key hammer 5a (two-dot chain line) engaged with the hammer fulcrum shaft 43 in the key released state. ) Is an enlarged view of the engaging portion 53 at the rear end portion. As shown in the figure, the front and rear guide surfaces 55a and 55a formed so as to spread outward from each other at the opening of the shaft hole 54 of the white key hammer 5a are the guide surfaces of the black key hammer 5b. With respect to 55b and 55b, it is formed in a state slightly inclined in the clockwise direction in FIG. Due to the difference in the guide surface 55, the removal angle of the hammer 5 from the hammer support 4 during maintenance or the like differs between the black key hammer 5b and the white key hammer 5a as follows. When the hammer 5 is removed, the corresponding key 2 is removed from the keyboard chassis 3.

  FIGS. 14A and 14B show a state where the black key hammer 5b and the white key hammer 5a are removed from the hammer fulcrum shaft 43 of the hammer support 4, respectively. Note that a black key hammer 5b and a white key hammer 5a indicated by a two-dot chain line in FIG. As shown in FIG. 14 (a), when the black key hammer 5b is rotated from the key-released position so that the front end reaches the vicinity of the upper end of the black key balance pin 13b, The front guide surface 55b of the engaging portion 53 is in a state (vertical) parallel to the front flat portion 43b of the hammer fulcrum shaft 43, and the shaft hole 54 of the black key hammer 5b and the hammer fulcrum shaft 43 of the hammer support 4 are provided. The contact with the upper curved surface portion 43a is released. As a result, the black key hammer 5 b can be detached from the hammer fulcrum shaft 43.

  On the other hand, as shown in FIG. 14B, the white key balance pin 13a that supports the white key 2a corresponding to the white key hammer 5a is positioned in front of the black key balance pin 13b. Therefore, the white key hammer 5a does not interfere with the white key balance pin 13a even if it is pivoted downward from the upper end of the black key balance pin 13b. Further, as described above, the white key hammer 5a is more than the black key hammer 5b due to the difference between the guide surface 55a at the rear end of the white key hammer 5a and the guide surface 55b of the black key hammer 5b. When pivoting downward greatly, the front guide surface 55a of the rear end portion is in a state (vertical) parallel to the front plane portion 43b of the hammer fulcrum shaft 43, and like the black key hammer 5b described above, The white key hammer 5 a can be detached from the hammer fulcrum shaft 43.

  As described above, the white key hammer 5a can be detached from the hammer fulcrum shaft 43 in a state of being largely rotated downward as compared with the black key hammer 5b. In other words, the white key hammer 5a is engaged with the hammer fulcrum shaft 43 in a non-removable state within a large angle range with respect to the hammer fulcrum shaft 43 as compared with the black key hammer 5b. . For this reason, in the key release state, the white key hammer 5a is firmly attached to the hammer fulcrum shaft 43, like the black key hammer 5b, although the height of its front end is lower than that of the black key hammer 5b. Since they are engaged, it is possible to effectively prevent rattling and noise when rotating. In addition, the degree of freedom in designing the white key hammer 5a can be increased.

  Next, the operation of the keyboard apparatus 1 configured as described above will be described. When the key 2 is pressed from the key release state shown in FIGS. 1 and 2, the key 2 rotates about the balance pin 13 in the counterclockwise direction of FIG. It is pushed up via the contact portion 56 and rotates upward (clockwise in FIG. 2) about the hammer fulcrum shaft 43.

  During the rotation of the hammer 5, the engaging projection 67 engages with the head 6a of the let-off component 6 and presses the let-off component 6 while compressing the let-off component 6 through the head 6a. The reaction force acting on the hammer 5 increases. When the rotation of the hammer 5 proceeds, the reaction force from the let-off component 6 disappears abruptly because the engagement protrusion 67 is detached from the head 6a. Due to the increase and disappearance of the reaction force of the let-off component 6, a let-off feeling similar to that of an acoustic piano can be obtained.

  Thereafter, when the front end portion of the hammer 5 abuts on the upper hammer stopper 68, the upward rotation of the hammer 5 is completed. During the upward rotation of the hammer 5, the actuator 66 presses the switch body 7 b of the key switch 7 and turns on the key switch 7, thereby pressing the key 2 according to the rotation amount of the hammer 5. Key information is detected and output to a sound generation control device (not shown). The sound generation control device controls the sound generation of the electronic piano based on the detected key press information.

  After that, when the key 2 is released, the key 2 is rotated in the opposite direction to that when the key is pressed, and returns to the key released state shown in FIGS. 1 and 2, and the hammer 5 is also rotated downward. To return to the key release state.

  As described in detail above, according to the present embodiment, the hammer contact height defining portion 25 made of synthetic resin is provided at the rear end portion of the key 2, and the hammer 5 protrudes downward in the key release state. It is placed in a state of being in contact with the hammer receiving portion 31b of the hammer contact height defining portion 25 from above via the key contact portion 56 that performs the above operation. In this case, since the height of the hammer receiving portion 31b is always the same by the above-described hammer contact height defining portion 25, a capstan screw is not required for the hammer 5, unlike the conventional case. Therefore, in this embodiment, since the conventional capstan screw can be omitted, the attachment and adjustment work can be eliminated, and the manufacturing cost of the electronic piano can be reduced accordingly.

  Further, in the key released state, the hammer contact height defining portions 25 of all the keys 2 have the rear piece lower portions 32c placed on the cushions 38 on the rear rail 9c. In this case, even when the vertical thickness of the rear end portion of the key 2 varies, the height of the hammer receiving portion 31b of the hammer contact height defining portion 25 in the key release state is the hammer contact height. This is determined by the state when the defining portion 25 is placed on the cushion 38. Accordingly, by providing the hammer contact height defining portion 25 at the rear end portion of all the keys 2, all the hammer contact height defining portions are absorbed while absorbing variations in the thickness of the rear end portion of the key 2. The height of the 25 hammer receiving portions 31b can be set to a certain predetermined height.

  Further, in the hammer 5, the key contact portion 56 is configured by attaching the convex cover 58 made of an elastic material to the contact convex portion 57 of the hammer body 51. Even if the key abutting portion 56 is once separated from the hammer receiving portion 31b of the hammer abutting height defining portion 25 and then comes into contact again or slides against the hammer receiving portion 31b, the noise at that time Can be sufficiently suppressed. Further, since the convex cover 58 is firmly attached to the hammer main body 51 via the hook 62, the convex cover 58 is removed from the contact convex portion 57 even if the hammer 5 is repeatedly pushed up with the key depression. Never do. Further, the convex cover 58 can be easily removed from the hammer body 51, and the convex cover 58 can be easily replaced as necessary.

  Further, a hook receiving portion 59 that opens to the lower side of the hammer body 51 is provided on the upper front side of the contact protrusion 57 of the hammer body 51. Thereby, for example, compared to the case where the hook receiving portion 59 is provided on the rear upper side of the contact convex portion 57 of the hammer body 51, that is, at a position closer to the rotation fulcrum of the hammer 5, when the key is pressed. The stress acting on the vicinity of the base portion of the contact convex portion 57 of the hammer body 51 can be reduced. As a result, even if the hammer 5 is repeatedly pushed up through the key abutting portion 56 as the key is pressed, damage to the hammer 5 (hammer body 51) can be prevented.

  Further, since the hammer 5 is formed with concave lubricant blocking portions 65 that are opened laterally on the left and right side surfaces of the hammer body 51, the shaft hole 54 of the hammer 5 and the hammer fulcrum shaft 43 of the hammer support 4. Can be prevented from flowing out to the front key abutting portion 56. Thereby, it is possible to prevent the friction between the key abutting portion 56 of the hammer 5 and the hammer receiving portion 31b of the hammer abutting height defining portion 25 with which the hammer 5 abuts from being changed. Good rotation characteristics of the hammer 5 can be maintained.

  In addition, this invention can be implemented in various aspects, without being limited to the said embodiment described. For example, in the embodiment, the convex cover 58 made of an elastic material is attached to the abutting convex portion 57 of the hammer main body 51. However, when the key is depressed, the abutting convex portion 57 and the hammer abutting height defining portion 25 If noise can be prevented from occurring between the hammer receiving portion 31b and sufficient slipperiness can be secured, the convex portion cover 58 may be omitted, and the hammer of the hammer contact height defining portion 25 may be omitted. A member made of an elastic material may be disposed in the receiving portion 31b.

  The detailed configurations of the keyboard device 1, the key 2, and the hammer 5 shown in the embodiment are merely examples, and can be appropriately changed within the scope of the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Keyboard apparatus 2 Key 4 Hammer support 5 Hammer 5a White key hammer 5b Black key hammer 25 Hammer contact height regulation part 31b Hammer receiving part 43 Hammer support shaft 51 Hammer main body 53 Engagement part 54 Shaft hole 56 Key contact Part 57 abutting convex part 58 convex part cover 59 hook receiving part 61 cover main body 62 hook 62a claw part

Claims (4)

In an electronic keyboard instrument that extends in the front-rear direction and has a key that is swingable around the center, a hammer that is placed on the rear end of the key and rotated by being pushed up by the pressed key. A hammer device for an electronic keyboard instrument comprising:
A synthetic resin hammer body that extends in the front-rear direction and is supported so as to be pivotable in the vertical direction around the fulcrum of the rear end;
An abutment projection that is molded integrally with the hammer body in a state of projecting downward at a predetermined position ahead of the fulcrum of the hammer body, and abuts against the rear end of the key from above in the key-released state. When,
A hammer device for an electronic keyboard instrument, comprising:   2. The hammer of an electronic keyboard instrument according to claim 1, further comprising a convex cover made of a predetermined elastic material and attached to the hammer body in a state of covering the contact convex part. apparatus. The convex cover has a cover body that opens upward and accommodates the contact convex part, and a hook that is provided so as to protrude upward from the cover main body.
3. The hammer device for an electronic keyboard instrument according to claim 2, wherein the hammer main body is formed in a concave shape that opens downward, and has a hook receiving portion that engages the hook in a retaining state.   The hammer device for an electronic keyboard instrument according to claim 3, wherein the hook receiving portion is provided at a predetermined position in front of the abutting convex portion of the hammer body.

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