JP2005099610A - Hammer unit of piano - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hammer unit of a piano that has superior shape retainability and size stability and is lightweight and high in rigidity so as to secure stable operation and rich sound volume of a hammer. <P>SOLUTION: The hammer unit 1 of the piano including a hammer 2 which turns as a key 11 is pressed, is equipped with a shank flange 5 which is made of a molding of synthetic resin and has a couple of two-pronged arm parts 5b and 5b extending in parallel to each other, wherein the hammer 2 has a hammer shank 3 which is formed of a molding of synthetic resin and formed in a rod shape whose section is constant and containing length-directionally continuous carbon fiber as a reinforcing material, has one end part supported rotatably between the couple of arm parts 5b and 5b of the shank flange 5 and rotates as the key 11 is pressed, and a hammer head 4 which is provided at the other end of the hammer shank 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hammer device for a piano including a hammer that rotates when a key is pressed in an acoustic piano or the like.

  FIG. 4 shows a hammer device 51 of a grand piano, which is provided for each key 11 (see FIG. 5). The hammer device 51 includes a hammer 52 having a hammer shank 53 and a hammer head 54, a shank flange 55, and the like. The hammer shank 53 is generally made of wood. This is because wood has the advantages that it is easy to obtain, has good workability, is lightweight, and has high rigidity. The hammer shank 53 is formed in an elongated rod shape, and a hammer head 54 is provided at the rear end thereof. In addition, two arm portions 53a and 53a branched in a bifurcated shape are formed at the front end portion of the hammer shank 53, and these arm portions 53a and 53a extend forward in parallel with each other.

  For the same reason as the hammer shank 53, the shank flange 55 is generally made of wood. The shank flange 55 has a rectangular cross section, and is fixed to the hammer shank rail 13 via the flange screw 8 (see FIG. 5). At the rear end of the shank flange 55, an engagement portion 55a having a predetermined width is formed so as to protrude rearward. This engagement portion 55a is engaged between the arm portions 53a and 53a of the hammer shank 53. Match. Further, a pin 56 is passed through the arm portions 53a, 53a and the engaging portion 55a, and the hammer shank 53 is supported by the shank flange 55 via the pin 56 so as to be rotatable around the horizontal axis. Yes.

  Further, both side surfaces of the engaging portion 55a of the shank flange 55 are formed in parallel with each other and face the inner side surfaces of the arm portions 53a and 53a of the hammer shank 53 with a slight clearance. Further, a cylindrical shank roller 7 is attached to the front end portion of the lower surface of the hammer shank 53, and the hammer shank 53 is attached to the repetition lever 10 (see FIG. 5) of the action 9 via the shank roller 7. It is placed.

  With the above configuration, when the key 11 is pressed, the hammer shank 53 is pushed up by the jack 12 of the action 9 via the shank roller 7, so that the hammer shank 53 and the hammer head 54 are integrally rotated upward. When the hammer head 54 strikes the string S, the piano is pronounced (see FIG. 5). Further, at the time of these rotations, the hammer shank 53 is guided by the arm portions 53a, 53a and the engaging portion 55a, so that the hammer shank 53 is rotated without shaking left and right.

  Moreover, what was disclosed by patent document 1 is known as a conventional hammer apparatus. This hammer device includes a shank frenzy, a shank holder, a hammer shank, and the like. The shank flange is made of a synthetic resin such as ABS resin and has the same shape as the shank flange 55 described above. The shank holder is made of a synthetic resin having the same quality as the shank flange, and is formed in an elongated rectangular parallelepiped shape with a rectangular cross section. At the front end of the shank holder, two arms that are bifurcated are formed, and these arms extend forward in parallel with each other. Moreover, between these arm parts engages with the engaging part of the shank flange, the shank holder is rotatably supported by the shank flange. The hammer shank is made of wood and is formed in an elongated bar shape, and its front end is fixed to the rear end of the shank holder. Thereby, the hammer shank is rotatably supported by the shank flange via the shank holder. In addition, by configuring the shank holder with arms with a synthetic resin molded product, the wooden hammer shank can be made into a simple shape that is easy to process like a round bar. By improving the manufacturing cost, the manufacturing cost is reduced.

  As described above, as a material for the hammer shank 53 and the shank flange 55, conventionally, wood having both light weight and high rigidity has been used. In particular, in the case of the hammer shank 53, the hammer head 54 attached to the hammer shank 53 functions as a string striking member of the string S. Therefore, even when the key 11 is struck, the key pressing energy is sufficiently transmitted to the string S. Therefore, high rigidity is required so that a rich sound volume can be obtained. Further, in order to ensure the sound volume, it is preferable to increase the rotation speed of the hammer, and thus lightness is required.

  However, on the other hand, wood, which is a natural material, has the disadvantages that it has poor homogeneity, and therefore its rigidity and weight vary and deformation such as warping and twisting is likely to occur due to residual stress. Further, since the dimensional change due to dry and wet is large, wood is used between the engaging portion 55a of the shank flange 55 and the arm portions 53a and 53a of the hammer shank 53 when used in the hammer device 51 shown in FIG. The clearance varies relatively greatly depending on the moisture. In particular, in this hammer device 51, the clearance between the two is originally set narrow for the reasons described above. Therefore, if the amount of change is large, the hammer shank 53 becomes looser or tighter than the shank flange 55. As a result, the rotation speed of the hammer 52 corresponding to the key pressing strength of the key 11 may not be stably obtained.

  On the other hand, as disclosed in Patent Document 1, when the shank flange and the shank holder are made of a synthetic resin such as ABS resin, the above-described problems in the case of wood are eliminated. However, the hammer of Patent Document 1 has a relationship in which a part of a conventional wooden hammer shank is replaced with a synthetic resin shank holder. Since it is made of synthetic resin, its rigidity is small and it tends to be insufficient. As a result, the key pressing energy when the key 11 is pressed is not sufficiently transmitted to the string S, and problems such as insufficient volume occur. Also, since synthetic resin such as ABS resin has a higher specific gravity than wood, the weight of the hammer increases as the shank holder is made of synthetic resin, and the rotation speed of the hammer cannot be obtained sufficiently. It leads to shortage.

  Further, in addition to the shank flange and the hammer shank, a shank holder is separately required, and accordingly, the number of parts and the number of assembling steps are increased, thereby increasing the manufacturing cost. In addition, because ABS resin has high electrical insulation, static electricity generated by rubbing the shank holder against the shank flange cannot be escaped due to the operation of the hammer, etc., and it is easy to be charged. There are also drawbacks such as causing defects and deteriorating the appearance.

  The present invention has been made in order to solve such problems, and is excellent in shape retention and dimensional stability, and is lightweight and has high rigidity, so that the stable operation and richness of the hammer can be achieved. An object of the present invention is to provide a piano hammer device capable of ensuring sound volume.

JP 2001-543971 A

  In order to achieve this object, the invention according to claim 1 is a piano hammer device including a hammer that rotates when a key is depressed, and is composed of a synthetic resin molded product, and extends parallel to each other. With a shank frenzy having a pair of bifurcated arms, the hammer is formed of a synthetic resin molded product containing a carbon fiber that is formed in a rod shape with a constant cross section and continuous in the length direction as a reinforcing material, One end portion is rotatably supported between a pair of arm portions of the shank flange, and has a hammer shank that rotates when the key is depressed, and a hammer head provided at the other end portion of the hammer shank. It is characterized by.

  According to this configuration, when the key is pressed, the hammer shank rotates while being guided by the pair of arm portions of the shank flange. In the case of an acoustic piano, the hammer head integrated with the hammer shank has a string. Pronunciation is performed by striking the string. In addition, since hammer shanks and shank frenzy are made of synthetic resin molded products, they are superior in shape retention and dimensional stability compared to wood, and they have deformation and distortion such as their own warpage and twist. Expansion and contraction due to moisture can be suppressed to a very small level. As a result, the clearance between the hammer shank and the pair of arm portions hardly changes, so that stable operation of the hammer can be ensured. In addition, since the hammer shank is made of a synthetic resin containing carbon fibers that are continuous in the length direction as a reinforcing material, a very high rigidity can be obtained compared to a case where it is made of only a synthetic resin such as ABS resin. And can obtain rigidity equal to or higher than that of wood. As a result, the deflection of the hammer shank when the key is struck can be suppressed, and the key pressing energy is efficiently transmitted from the hammer to the string, so that a rich volume can be obtained.

  Also, if a pair of arms are provided on the hammer shank side as in the conventional case, the hammer shank contains carbon fibers that are continuous in the length direction as a reinforcing material, and therefore, molding by injection molding is difficult. is there. On the other hand, according to the present invention, by providing a pair of arms on the shank flange side, the hammer shank has a rod-like shape with a constant cross section, so that it can be formed by extrusion molding and is continuous in the length direction. It is possible to easily and accurately form a hammer shank containing carbon fiber to be used as a reinforcing material.

  Carbon fiber has higher conductivity than other reinforcing materials such as glass fiber. Therefore, as described above, by using the carbon fiber as a reinforcing material, the electrical conductivity of the hammer shank can be increased, thereby preventing the charging. Thereby, adhesion of dust and the like to the hammer shank and its periphery can be suppressed, and therefore the operation and appearance of the hammer can be maintained well.

  The invention according to claim 2 is the piano hammer device according to claim 1, wherein the hammer shank is formed in a hollow shape.

  According to this configuration, since the hammer shank is formed in a hollow shape, the hammer can be reduced in weight by that amount, and thereby the rotation speed of the hammer can be increased, thereby obtaining a richer sound volume. it can. Further, as described above, in the present invention, since the rigidity is increased by the carbon fiber, it is possible to ensure the required rigidity even if the hammer shank is formed in a hollow shape. In this way, the weight can be maximized while ensuring the required rigidity.

1 is a perspective view of a hammer device for a grand piano according to an embodiment of the present invention. FIG. 2 is a perspective view of the hammer shank and shank flange of FIG. 1. It is a side view of the keyboard apparatus of a grand piano including the hammer device of FIG. It is a perspective view of the conventional hammer apparatus. It is a side view of the keyboard apparatus of the grand piano containing the hammer apparatus of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, when the grand piano is viewed from the performer, the front side (right side in FIG. 3) is “front”, the back side (left side in FIG. 3) is “rear”, and the arrangement direction of the keys 11 The description will be made with the “left-right direction” as “”. First, the hammer device 1 will be described with reference to FIG. As shown in the figure, the hammer device 1 includes a hammer 2 having a hammer shank 3 and a hammer head 4, a shank flange 5, and the like.

  The shank Frenzy 5 is composed of a synthetic resin injection molded product having excellent impact resistance such as ABS resin. As shown in FIG. 1, the shank flange 5 extends in the front-rear direction and has an elongated main body portion 5 a having a rectangular cross section, and a pair of bifurcated arm portions 5 b extending rearward in parallel from the rear end portion of the main body portion 5 a. , 5b are integrally provided. A pair of arms 5b, 5b are formed with holes (cable only one) 5c, 5c penetrating sideways in a straight line, and a bushing cloth (not shown) is formed in these holes 5c, 5c. The pin 6 is attached via

  An attachment hole 5d for attaching the shank flange 5 to a hammer shank rail 13 to be described later is formed at the center of the main body 5a so as to penetrate in the vertical direction. Further, a screw hole 5e penetrating in the vertical direction is formed at the rear of the main body 5a, and a drop screw 14 for restricting upward rotation of the repetition lever 10 to be described later is formed in the screw hole 5e. It is screwed in so that it can move forward and backward from below.

  The hammer shank 3 is made of an extruded product of synthetic resin such as ABS resin. This synthetic resin contains carbon fiber as a reinforcing material. This carbon fiber is formed in a woven shape with a relatively large length, and is contained in the synthetic resin so as to be continuous in the length direction. As shown in FIG. 2, the hammer shank 3 is formed in an elongated cylindrical shape extending in the front-rear direction and having a constant cross section.

  The front end portion of the hammer shank 3 is engaged between the pair of arm portions 5b, 5b of the shank flange 5 with a slight clearance. A hole (not shown) is formed at a predetermined position at the front end of the hammer shank 3 so as to penetrate sideways. Then, by passing the above-described pin 6 through this hole, the hammer shank 3 can be rotated around the horizontal axis between the pair of arm portions 5b, 5b of the shank flange 5 via the pin 6. It is supported.

  Further, a groove 3a is cut in the front end portion of the lower surface of the hammer shank 3 in the direction (left-right direction) perpendicular to the length direction of the hammer shank 3 behind the hole, and the shank roller core is formed in the groove 3a. 15 is attached so as to protrude downward. A cylindrical shank roller 7 is attached so as to cover the protruding portion of the shank roller core 15 from the front and the back.

  A hammer head 4 is provided at the rear end of the hammer shank 3 so as to be orthogonal thereto. The hammer head 4 is composed of a hammer wood 4a made of wood or the like, and an under felt 4b and a top felt 4c that are wound in order so as to wrap the tip.

  Next, the configuration of the action 9 for rotating the hammer 2 as the key 11 is pressed will be described with reference to FIG. The action 9 is provided for each of a large number of keys 11 (only one is shown). As shown in the figure, the action 9 includes a pivotable whippen 16 extending in the front-rear direction, a repetition lever 10 and a jack 12 pivotably attached to the whippen 16, and left and right brackets 17, 17. (Only one is shown). The left and right brackets 17 and 17 are respectively fixed to left and right ends of a cage (not shown) on which the key 11 is placed, and a Wippen rail 18 is passed between them. A rear end portion of the wippen 16 is rotatably attached to each stopped wippen frenzy 19. Each whippen 16 is placed on a capstan button 20 provided at the rear of the upper surface of the corresponding key 11 via a whippen heel 21.

  A hammer shank rail 13 is passed between the left and right brackets 17 and 17. The hammer shank rail 13 is formed with a large number of screw holes (not shown) arranged in the left-right direction. The shank flange 5 is connected to the hammer shank rail 13 with the frenzy screw 8 passed through the mounting hole 5d. It is fixed to the hammer shank rail 13 by being screwed into and tightened.

  The repetition lever 10 has a rectangular cross section, extends obliquely forward and backward in the front-rear direction, and is rotatably attached to the wippen 16 at the center. A lever screw 22 is threadably engaged with the rear end portion of the repetition lever 10 in a vertically penetrating manner, and a lever button 23 is integrally provided at the lower end portion thereof. The repetition lever 10 is biased in the return direction (counterclockwise in FIG. 3) by a repetition spring 24 attached to the wippen 16. With the above configuration, when the key 11 is released, the repetition lever 10 is rotated to the return side by the spring force of the repetition spring 24, the lever button 23 is in contact with the upper surface of the wippen 16, and the lever By turning the screw 22, the angle of the repetition lever 10 in the key release state can be adjusted.

  A jack guide hole 10 a penetrating in the vertical direction is formed at a predetermined position in the front portion of the repetition lever 10. A hammer 2 is placed via a shank roller 7 near the jack guide hole 10 a on the upper surface of the repetition lever 10. A lever skin 25 is attached to the front end portion of the upper surface of the repetition lever 10 and faces the drop screw 14. With this configuration, the let-off position where the repetition lever 10 abuts can be adjusted by turning the drop screw 14 and adjusting the downward protrusion amount.

  The jack 12 is formed in an L shape from a hammer push-up portion 12a having a rectangular cross section extending in the vertical direction and a regulating button abutting portion 12b extending substantially perpendicularly rearward from the lower end portion thereof. In FIG. 1, the front end of the whippen 16 is rotatably attached. The upper end portion of the hammer push-up portion 12a engages with the jack guide hole 10a of the repetition lever 10 so as to be movable in the front-rear direction, and faces the shank roller 7 with a small gap in the key release state. Yes. Further, the jack 12 is biased in the return direction (counterclockwise in FIG. 3) by a repetition spring 24 that biases the repetition lever 10.

  Further, a jack button screw 26 for adjusting the angular position of the jack 12 is screwed into an intermediate portion of the hammer push-up portion 12a of the jack 12 so as to freely advance and retreat in a state of penetrating in the front-rear direction. A jack button 27 is integrally provided at the tip of the jack button screw 26, and the jack button 27 is in contact with a spoon 28 standing on the wippen 16 in a key-released state. Therefore, the angular position of the jack 12 in the key release state can be adjusted by turning the jack button screw 26.

  On the other hand, a regulating rail 29 is screwed to the lower surface of the hammer shank rail 13, and a regulating button 30 for restricting the upward rotation of the jack 12 is freely movable on the lower surface of the regulating rail 29. It is screwed and faces the front end portion of the regulating button contact portion 12b of the jack 12 with a predetermined interval.

  According to the action 9 having the above-described configuration, when the key 11 is pressed from the key release state shown in FIG. 3, the whippen 16 is pushed up through the capstan button 20 to rotate upward, The repetition lever 10 and the jack 12 attached to the whippen 16 also rotate upward. Accordingly, first, the repetition lever 10 swings the shank roller 7 and pushes up the hammer shank 3 of the hammer 2 through the swing lever 7, whereby the hammer shank 3 is guided to the pair of arms 5 b and 5 b of the shank flange 5. It is rotated upward while being. Next, when the repetition lever 10 is engaged with the drop screw 14, the rotation is prevented, so that the jack 12 pushes up the hammer shank 3 through the shank roller 7. Thereafter, when the hammer shank 3 and the hammer head 4 integrated therewith rotate until just before the string S stretched upward is hit, the jack 12 engages with the regulating button 30 and rotates. As a result, the shank roller 7 comes off. As a result, the hammer shank 3 and the hammer head 4 are disconnected from the action 9 and the key 11 to be freely rotated, and the hammer head 4 strikes the string S to produce sound.

  As described above, according to the present embodiment, the hammer shank 3 and the shank flange 5 are formed of ABS resin molded products, so that they are excellent in shape retention and dimensional stability as compared with the case of wood. Therefore, deformation such as their own warpage and twisting and expansion and contraction due to wet and dry can be suppressed to a very small level. As a result, the clearance between the hammer shank 3 and the pair of arm portions 5b, 5b hardly changes, so that stable operation of the hammer 2 can be ensured. In addition, since the hammer shank 3 contains carbon fibers that are continuous in the length direction as a reinforcing material, the hammer shank 3 has extremely high rigidity as compared with the case where it is composed only of synthetic resin such as ABS resin, and is equivalent to wood. Or more rigidity can be obtained. As a result, the deflection of the hammer shank 3 when the key 11 is struck can be suppressed, and the key pressing energy is efficiently transmitted from the hammer 2 to the string S, whereby a rich volume can be obtained.

  In the present embodiment, by providing the pair of arms 5b, 5b on the shank flange 5 side, the hammer shank 3 has a rod-like shape with a constant cross section. The hammer shank 3 containing continuous carbon fibers as a reinforcing material can be easily and accurately formed.

  Furthermore, in this embodiment, since the carbon fiber is used as the reinforcing material contained in the hammer shank 3, the electrical conductivity of the hammer shank 3 can be increased, thereby preventing the charging. Thereby, adhesion of dust or the like to the hammer shank 3 and its periphery can be suppressed, and therefore the operation and appearance of the hammer 2 can be maintained well.

  Furthermore, in this embodiment, since the hammer shank 3 is formed in a hollow shape, the hammer 2 can be reduced in weight by that amount, and thereby the rotation speed of the hammer 2 can be increased, thereby further enriching the hammer 2. Volume can be obtained. In addition, as described above, the hammer shank 3 of the present embodiment is enhanced in rigidity by the carbon fibers continuous in the length direction, so that the required rigidity can be ensured even if the hammer shank 3 is formed in a hollow shape. Is possible. In this way, the weight can be maximized while ensuring the required rigidity.

  In addition, this invention can be implemented in various aspects, without being limited to the described embodiment. For example, in the present embodiment, the hammer shank 3 is formed in a cylindrical shape, but instead, a hollow shape whose cross section is formed in a polygonal shape such as a rectangle may be adopted. In the present embodiment, the hammer shank 3 is formed in a hollow shape in order to reduce the weight of the hammer 2. However, when priority is given to rigidity, the hammer shank 3 may be solid, for example, a cross section. However, H-shaped or I-shaped may be adopted. Furthermore, although the embodiment is an example in which the present invention is applied to an action of a grand piano, the present invention can be applied to other types of pianos, for example, a grand electronic piano having a hammer, an automatic performance piano, and an upright piano. Of course, it may be applied to. In addition, it is possible to appropriately change details within the scope of the present invention.

Explanation of symbols

1 Hammer Device 2 Hammer 3 Hammer Shank 4 Hammer Head 5 Shank Frenzy 5b Arm 11 Key

Claims (2)

A hammer device for a piano including a hammer that rotates as the key is depressed,
It is composed of a synthetic resin molded product, and includes a shank flange having a pair of bifurcated arms extending in parallel with each other,
The hammer is
It is formed of a synthetic resin molded article containing carbon fibers that are formed in a rod shape with a constant cross section and continuous in the length direction as a reinforcing material, and one end is freely rotatable between the pair of arms of the shank flange A hammer shank that is supported by the key and rotates when the key is depressed,
A hammer head provided at the other end of the hammer shank;
A hammer device for a piano, characterized by comprising:   The piano hammer device according to claim 1, wherein the hammer shank is formed in a hollow shape.

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