JPH0748155B2 - Hammer device for keyboard instruments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention effectively absorbs the kinetic energy of a hammer that returns after turning a sounding body by striking it, and prevents its rebound and noise. The present invention relates to a hammer device for a keyboard instrument.

[Conventional technology]

A keyboard instrument such as a piano is one in which an hammer is rotated by an action mechanism that operates in synchronization with the operation of pressing a key, and a sounding body (for example, a string) is struck with this hammer to produce a sound. Then, the hammer which is returned to the rotation is temporarily stopped by the back check so as to be decelerated and then returned to the initial position. In the case of the upright piano, the hammer that returns to the turning position after striking the string is received by the hammer rail cloth fixed to the hammer rail, and is stopped at the initial position. Also, in the case of a grand piano, there is no hammer rail cross, and the hammer strike contacts the hammer shock stop felt, or the hammer roller attached to the hammer shock strikes the repetition lever to strike the strings. The hammer that returns after turning is made to stand still at the initial position.

[Problems to be Solved by the Invention]

By the way, in normal key-pressing operation, the key is pressed down sufficiently at a moderate speed, so the hammer can be slowed down by the back-tick, but a shallow and fast key-pressing operation like a trill or a slow key-pressing operation can be performed. When the key is operated, the hammer cannot be decelerated by the back check, and the return speed when the hammer is rotated back to the initial position may be considerably high. Therefore, if the backlash does not work, the hammer hits the strings and then returns by turning due to the repulsive force of the strings.The faster the return speed, the more the hammer rail cloth hits the bouncing back and the initial position. There was an inconvenience that the return to was delayed. In particular, if the return to the initial position is delayed, the key movement is not accurately transmitted to the hammer and a normal string striking operation is hindered in the case of performing a rapid continuous hitting performance with the same key. The delay in the return to the initial position is particularly remarkable if the backcheck does not work, but even if the backcheck works, the complete deceleration effect cannot be obtained. Further, as for the upright piano, the hammer not only hits the hammer rail cross but also hits the tip of the jack, so that the impact force from the jack is transmitted to the keyboard via the wippen, capstan, and the like. Moreover, while the hammer is rotating, the keyboard is free from the action, and when the hammer returns, it rebounds and causes unnecessary vibration. Also, when the hammer rebounds, it takes time for the hammer itself to sway, and for the action mechanism to fully return, this adversely affects the key touch feeling, and the damper mechanism linked to the action mechanism also has a delay in returning. , Causing a noise stop
It adversely affects the stats playing method. Therefore, it is extremely important for performance improvement to return the initial position to the initial position as quickly as possible each time the hammer hits the string, and the kinetic energy of the hammer is particularly large, and it is easy to induce unnecessary vibration of each part. It is also important in terms of preventing unnecessary vibration.

Therefore, conventionally, in order to prevent the rebound of the hammer, a control means for absorbing kinetic energy when the hammer is returned is provided at the rear of the hammer (eg, JP-A-52-96).
No. 522 and JP-A No. 58-186797) have been proposed.
However, since all of them use springs, it is impossible to completely prevent the hammer from rebounding, which causes a problem. That is, when the hammer hits the control means,
Even if the shock is absorbed by the elastic deformation of the spring, the absorption is temporary, and the spring at the next moment tries to elastically return by releasing the stored elastic strain energy, so the restoring force (elastic force) ) Acts so as to push the hammer back, and this return force increases in proportion to the impact, which delays the return of the hammer during a hard hit performance.

[Means for Solving the Problems]

The hammer device for a keyboard instrument according to the present invention has been made in view of the above-mentioned points, and a hammer (1) that operates in conjunction with a key to strike a sounding body when a key is pressed, and the hammer (1). And an air damper (7) for receiving the hammer (1) which is arranged at the rear of the sleeve (1) and which returns to rotate. The air damper (7) has a sleeve (9,51) having an air hole (14) for communicating the inside and the outside. , 60) and this sleeve (9,51,6)
(0, 50A, 60A) and the plunger (10, 50A, 60A) disposed in the sleeve (9, 51, 60).
And a spring (11) for urging A) to abut the rear end surface of the hammer (1).

[Work]

In the present invention, when the player presses a key, the hammer flies and hits the strings to return to a rotation. At the final stage of the return from the rotation, the hammer abuts the air damper to apply the braking force to the air damper. While receiving a return motion from the damper, it is locked in the initial position by a locking means such as a hammer rail cloth. At this time, the air in the air damper is replenished from the outside during the flight of the hammer arm, is compressed when the hammer arm comes into contact with the air, passes through the narrowed flow path, and flows out to the outside. Then, the air damper transmits the force resulting from the pressure increase to the hammer as a main reaction force to brake the hammer. Further, a considerable amount of the kinetic energy of the hammer is discarded along with the outflow air to the outside of the atmosphere (other than the hammer and the air damper) as kinetic energy of the fluid flowing out of the damper and heat energy caused by friction and viscosity of the fluid. Therefore, the kinetic energy of the hammer is effectively absorbed by the air damper and discarded to the outside.
The amount of energy absorbed by the air damper returning to the hammer is small. The check valve facilitates the return of the plunger by opening the air hole when the plunger returns.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a side sectional view showing an embodiment in which the present invention is applied to a hammer device for an upright piano. In the figure, reference numeral 1 is a hammer, and this hammer 1 has a hammer shank 2 whose lower end is connected and fixed to a butt (not shown).
And a hammer felt 3 mounted on the upper end of the hammer shank 2 so as to be orthogonal to the longitudinal direction of the shank 2, and a hammer felt 4 mounted on the tip of the hammer wood 3 for striking a string (not shown). When the shank 2 comes into contact with the hammer rail cross 6 attached to the rear surface of the hammer rail 5, the shank 2 is inclined at a predetermined angle to the player side (right side) and locked at the initial position. An air damper 7 corresponding to the hammer wood 3, which is the subject matter of the present invention, is arranged on the hammer rail 5 via a bracket 8.

The air damper 7 absorbs the kinetic energy of the hammer 1 which is returned by turning after the string striking operation and absorbs the kinetic energy of the hammer 1 to remarkably reduce the impact when the hammer shank 2 comes into contact with the hammer rail cross 6 and rebound of the hammer 1. And a bottomed cylindrical sleeve 9 having an open end on the side of the hammer wood 3 and a flange 9a integrally formed at the open end, and a plunger 10 slidably inserted into the sleeve 9. Similarly, a spring 11 having a relatively weak spring force, which is also disposed in the sleeve 9 and urges the plunger 10 in a projecting direction, covers the opening end of the sleeve 9 to prevent the plunger 10 from coming off, and to the bracket 8. It is composed of a stopper plate 12 for fixing the sleeve 9 and the like. The sleeve 9 is fitted in a sleeve mounting hole 13 provided in the tip portion 8a of the bracket 8, and the brim 9a is fixed to the tip portion 8a by a stopper plate 12. Further, a minute air hole 14 having a hole diameter of about 0.5 mm to 0.6 mm is formed at the center of the bottom surface of the sleeve 9.

The plunger 10 includes a large-diameter portion 10A and a small-diameter portion 10B which is integrally provided in the center of the rear end surface of the large-diameter portion 10A so as to project to the outside from the plunger insertion hole 15 of the stopper plate 12, and the large-diameter portion 10A. 0.03m between the outer peripheral surface of the sleeve and the inner peripheral surface of the sleeve 9.
A small gap of about m to 0.05 mm is provided to prevent the air in the sleeve 9 from entering and exiting from other than the air holes 14. On the other hand, cushion members 16 and 17 such as felt are adhered to the base portion and the tip surface of the small-diameter portion 10B, and the cushion member 17 on the tip surface side is the hammer 1
In the stationary state, the hammer wood 3 is in contact with the front end surface of the hammer wood 3.

18 is a cushion member adhered to the inner bottom surface of the sleeve 9,
19 is a set screw for fixing the stopper plate 12 to the bracket 8, and 20 is a set screw for fixing the bracket 8 to the hammer rail 5. The air damper 7
In order to reduce the noise caused by, the lubricating portion of the plunger 10 may be coated with a lubricating oil, or Teflon (trademark) or the like may be coated as a lubricant.

Next, the operation of the air damper 7 in the hammer device having the above structure will be described.

In the initial position of the hammer 1, the hammer shank 2 is in contact with the hammer rail cloth 6, and the hammer wood 3 is in contact with the cushion member 17 provided on the tip surface of the small diameter portion 10B of the plunger 10 as shown in the figure. In this state, since the hammer wood 3 presses the cushion member 17 against the spring 11, the plunger 10 is moved to the right, that is, the player side, and the cushion member 16 provided at the base of the small diameter portion 10B is moved. Separated from the stopper plate 12.

When the hammer 1 flies in the counterclockwise direction in the drawing in conjunction with the action mechanism, the plunger 10 is released from the hammer wood 3, so that the spring 11 moves back to the stopper plate 12 side to restore the cushion member. 16 is pressed against the plate 12. Then, the hammer 1 is rotated and returned by the repulsive force of the string after the hammer felt 4 hits the string, and the hammer wood 3 first collides with the cushion member 17 to push the plunger 10 back against the spring 11. Therefore, some of the air in the sleeve 9 is
With the movement of 10, the air is discharged to the outside from the air hole 14, but this air hole 14 is sufficiently small, and therefore the flow velocity of the discharged air is high, and the kinetic energy of the hammer is considerably absorbed as the kinetic energy of the outflow fluid. It In addition to this, the hammer 1 is caused by viscous resistance of fluid as air passes through the hole 14.
The kinetic energy of is absorbed in proportion to its speed, and the impact when the hammer shank 2 collides with the hammer rail cross 6 is made extremely small. The energy absorbed by the air damper 7 is discarded to the outside such as the atmosphere, and the amount of absorbed energy returning to the hammer 1 is small. Therefore, the hammer 1 gently abuts the hammer rail cross 6, so that the hammer 1 does not rebound and quickly returns to the initial position and stands still to enable the next string striking operation.

Here, due to the collision of the hammer wood 3, the plunger 10
Moves to the right and compresses the spring 11, the reaction force due to this compression acts on the plunger 10 and tries to push the plunger 10 back and forth, but in that case, the air hole 14 is small and the inside of the sleeve 9 The pressure becomes negative and brakes the plunger 10. Therefore, the plunger 10 does not push the hammer 1 back by the reaction force of the spring 11.

In addition, a proper air damping effect can be obtained by appropriately selecting the air holes 14.

2 (a), (b), and (c) are sectional views showing other embodiments of the air damper, and FIG. 2 (a) is a sleeve 9
(B) in the figure, one end is open to the inner end surface of the large diameter portion 10A of the plunger 10 and the other end is the small diameter portion 1A.
The air hole 14 that opens on the peripheral surface of 0B is provided, and FIG. 7C shows 0.1 mm that allows air to flow in and out between the peripheral surface of the large diameter portion 10A of the plunger 10 and the inner peripheral surface of the sleeve 9. A gap A of about 0.2 mm is provided to form an air hole, and the kinetic energy of the air passing through this air hole and the kinetic energy of the hammer that returns due to the fluid viscosity resistance are absorbed to soften the impact on the hammer rail cloth. It was done. In the structure shown in FIG. 2B, it is needless to say that the openings at both ends of the air hole 14 may be opened at both ends of the large diameter portion of the plunger.

FIG. 3 is a sectional view showing another embodiment of the air damper.
4 (a) and 4 (b) are a plan view and a sectional view of the check valve. In this embodiment, air holes 14 are formed on the peripheral surface of the sleeve 9 and a hole diameter (1-2 m) which is sufficiently larger than the air holes 14 is formed on the bottom surface.
A hole 25 of about m) is formed, and a check valve 26 is arranged on the inner bottom surface of the sleeve 9 corresponding to the hole 25. The check valve 26 is formed of a rubber sheet or the like, and has a substantially C-shaped groove 27 formed in the center thereof to have an elastically deformable tongue piece 28. The hole 25 is closed, and when the plunger 10 is released from the hammer and moved upward in FIG. 3 by the force of the spring 11 in response to the string striking operation, the tongue 28 is elastically deformed upward and the hole 25 is moved. It is designed to facilitate the return of the plungeer 10 by opening it.

That is, when the plunger 10 starts to rise due to the force of the spring 11, the pressure inside the flexible sleeve 9 having a small air hole 14 momentarily becomes negative pressure and brakes the plunger 10, but the negative pressure at this time causes the tongue piece In FIG. 4 (b), 28 elastically deforms upward to open the hole 25 and return the pressure in the sleeve 9 to the atmospheric pressure, so that the plunger 10 is quickly raised and returned by the force of the spring 11.

In this case, in this embodiment, the air holes 14 exhibiting the air damping effect are formed on the peripheral surface of the sleeve 9, but the air holes shown in FIGS. 2B and 2C may be adopted. As shown in FIG. 5, the air hole 14 is formed in the center of the tongue piece 28 of the check valve 26.
Of course, it may be provided.

FIG. 6 is a side sectional view showing another embodiment of the hammer device according to the present invention. In this embodiment, a hammer rail 5 is formed into a substantially ∠ shape by extrusion molding of aluminum or the like, and an air damper 7 is directly attached to a vertical portion 5a of the hammer rail 5 facing the hammer shank 2, and only the air damper 7 is formed. The hammer 1 is configured to be locked in the initial position. Since the air damper 7 itself is substantially the same as that of the embodiment shown in FIG. 1, its explanation is omitted.

In such a structure, since the initial position of the hammer 1 is determined by the cushion member 17 provided on the projecting end surface of the plunger 10, the spring force of the spring 11 needs to be slightly stronger than that of the embodiment shown in FIG. Further, since the spring force of the spring 11 is strong, the air damping effect of the air holes 14 can be obtained in both directions of reciprocation of the plunger 10.

Also in this embodiment, the hammer rail cloth 6 can be arranged on the hammer rail 5 as shown by the chain line, and in this case, the hammer rail cloth 6 determines the initial position of the hammer 1. As in the embodiment shown in FIG. 1, it is necessary to weaken the spring force of the spring 11.

FIG. 7 is a cross-sectional view of an air damper showing another embodiment of the present invention, in which the sleeve 9 is inserted into the opening 40 provided in the hammer rail 5 and the collar 41 provided on the outer peripheral surface of the opening is used for the opening. A lid 42 removably engaged with and fixed to the portion 40 is pressed and fixed to the peripheral portion of the surface of the opening 40 through a spacer 43. Incidentally, 44 is a cushion flange made of rubber or the like, and 45 is a cap fitted to the tip of the plunger 10. The cushion member 46 attached to the front end surfaces of the spacer 43 and the cap 45 is made of exene (a kind of synthetic leather and of suede tone). The lid 42 is made of synthetic resin and integrally has elastically deformable engaging legs 47 that engage with the opening 40.

FIG. 8 is a sectional view showing another embodiment of the air damper. The first case 50 made of rubber is fitted in the opening of the hammer rail 5, and the opening of the first case 50 is made of synthetic resin. The second case 51 is provided as a sleeve that is fitted so as to close the case, and the spring 11 is housed and arranged in both cases 50 and 51 to reduce the number of parts. In this case, the dome portion 50A of the first case 50 is elastically deformable and has a function as a plunger.

Similarly, the air damper shown in FIG. 9 also has a rubber case in which a sleeve is formed on the hammer rail 5 in order to reduce the number of parts.
A case in which 60 is arranged and the spring 11 is housed and arranged therein, the cylindrical portion 60A of the case 60 is elastically deformable, and has a function as a plunger. In addition, 62 is a clamp plate and 63 is a set screw.

Also, in the embodiment of FIGS. 8 and 9, the first case
When the dome portion 50A of 50 and the cylindrical portion 60A of the rubber case 60 have sufficient elasticity, the spring 11 can be omitted.

The present invention is not limited to the embodiment described above, and various variations are possible. For example, in the embodiment shown in FIG. 6, the check valve 26 shown in FIG. Plunger 10 with valve 26 shown in FIG. 2 (b)
It is also possible to arrange it on the lower surface of.

Further, in the embodiment shown in FIG. 1, the air damper 7 is arranged above the hammer rail 5 to receive the hammer wood 3, but it may be arranged below the hammer rail 5 to receive the hammer shank 2. .

〔The invention's effect〕

As described above, the hammer device for a keyboard instrument according to the present invention is provided with the air damper that locks the hammer in the initial position, receives the hammer that is pivotally returned by the air damper, and absorbs the kinetic energy of the hammer. Since it is configured to be dumped to the outside, unlike the spring and the air spring, the absorbed energy rarely returns to the hammer, and the hammer rebound and impact noise can be effectively prevented. Therefore, it takes a short time to return the hammer to the initial position and stop it, and it is possible to prevent unnecessary vibration of the hammer and other movable parts of the keyboard and various parts of the damper mechanism. This enables a quick and accurate repeated hitting performance with the same key, and the quicker the hammer returns, the faster the return of the action mechanism, keyboard and damper mechanism, resulting in a good key touch feeling and sound-stopping effect. , Further improve the performance of the musical instrument itself.

Also, the air damper has a simple structure and can be manufactured at low cost.
Moreover, since air is used as the damping material, it is easy to maintain and exhibits stable performance against temperature changes.

Further, when the air damper is provided with a check valve, the plunger can be restored more smoothly, and the movement can be made smoother.

Further, although the upright piano has been described in the present embodiment, it goes without saying that it can be applied to a grand piano.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment when the hammer device according to the invention is applied to an upright piano, and FIGS. 2 (a), (b) and (c) are other embodiments of an air damper, respectively. FIG. 3 is a cross-sectional view showing still another embodiment of the air damper, FIGS. 4 (a) and 4 (b) are plan views and cross-sectional views showing the check valve taken out, and FIG. FIG. 6 is a plan view showing another embodiment of the check valve, FIG. 6 is a side sectional view showing another embodiment of the hammer device according to the present invention, and FIG. 7 is a sectional view showing another embodiment of the air damper, FIG. 8 is a sectional view showing another embodiment of the air damper, and FIG. 9 is a sectional view showing another embodiment of the air damper. 1 ... Hammer, 2 ... Hammer shank, 3 ... Hammerwood, 4 ... Hammer felt, 5 ... Hammer rail, 7 ... Air damper, 9 ... Sleeve, 10 ...
Plunger, 11 …… Spring, 14 …… Air hole, 26 ……
Check valve.

Claims (2)

[Claims] 1. A hammer (1) which operates in synchronism with a key to strike a sounding body when a key is pressed, and air which is arranged behind the hammer (1) and receives the hammer (1) which returns to rotate. The air damper (7) is provided with a damper (7), and the air damper (7) is arranged in the sleeve (9,51,60) having an air hole (14) communicating between the inside and the outside and the sleeve (9,51,60). Plunger (10,50A, 60A) and sleeve (9,51,60)
A hammer for a keyboard instrument, characterized in that the hammer (1) is arranged inside the spring (11) to urge the plunger (10, 50A, 60A) to abut against the rear end surface of the hammer (1). apparatus. 2. The air damper (7) is usually a sleeve (9,
51, 60) air holes (14) are closed and the plunger (1
The hammer device for a keyboard instrument according to claim 1, further comprising a check valve (26) that opens the air hole (14) when the air pressure (0, 50A, 60A) is restored.