JPH03179395A - Pedal driving device for automatic keyboard musical instrument - Google Patents

Abstract

PURPOSE:To reduce mechanical noise in the operation of a pedal driving system by providing a fixed yoke which is fixed to a coil and a movable yoke which is associated with the pedal driving system, and corresponding saw-tooth shaped parts on the opposite surfaces of the fixed yoke and movable yoke. CONSTITUTION:The above device is equipped with the fixed yoke 2 which is fixed to the coil 1 fitted on the reverse surface of a shelf plate 58 while projecting down and the movable yoke 3 which is arranged below the fixed yoke 2 opposite it, and the corresponding saw-tooth shaped parts 2d and 3d are formed on the opposite surfaces of the fixed yoke 2 and movable yoke 3. Then when a driving current flows from a controller to the coil 1, an attractive force is generated between the fixed yoke 2 and movable yoke 3 to lift the movable yoke 3, and the thrust rod 51 of the pedal driving system P moves up through a suspension wire 6. The angle theta of slanting surfaces alpha of the saw- tooth shaped parts 2d and 3d, the number of the slanting surfaces alpha, etc., are set properly to set attraction characteristics optionally. Thus, the attractive force in a noncontact state is used, so the noise in the operation of the pedal driving system P is reducible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pedal drive device for an automatic keyboard instrument, and more particularly to a pedal drive device that can reduce noise during operation of a pedal drive system and is easy to implement. It is something.

"Prior Art" Automatic keyboard instruments (for example, automatic pianos, etc.) are equipped with a pedal drive device for automatic performance based on performance information recorded in advance or performance information supplied from the outside.

FIG. 7 and FIG. 8 show an example. In the figure, reference numeral 50 is a pedal balance that is swingably disposed at the bottom of the automatic keyboard instrument, and one end of this balance 50 (right end in Figure 7).
A damper pedal (not shown), a tenuto pedal (not shown), and other pedals are attached to the lever 5.
A push-up rod 51 is connected to the other end (left end in the figure) of 0 (
(See FIG. 8), the upper end of the push-up rod 51 is mechanically connected to mechanisms such as a damper mechanism, a damper mechanism, and a tenuto mechanism (not shown).

A pedal drive system P is constituted by the above-mentioned balance 50, damper pedal, etc., push-up rod 51, damper mechanism, etc.

In addition, a pedal hanging metal fitting 52 is attached to a part of the balance 50 that is slightly shifted toward the center from the point where the push-up rod 51 is connected. connected via. A solenoid 56 electrically connected to a controller 57 is incorporated in the pedal drive unit 54 .

In the pedal drive device described above, when the solenoid 56 is activated based on a signal issued from the controller 57, one end of the balance 50 is pulled up via the wire 55 and the hanging fitting 52, and the push-up rod 51 is raised accordingly. The damper mechanism, sostenuto mechanism, etc. connected to the upper end of the push-up rod 51 are operated. In this way, the pedal drive system P can be automatically operated.

"Problems to be Solved by the Invention" By the way, the above-described conventional pedal drive device for an automatic keyboard instrument has the following drawbacks.

- When the solenoid 56 operates, a sliding sound is generated from the plunger 56a incorporated inside, and an air leakage sound is generated from the solenoid case, causing musical problems during automatic performance.

■ The driving force is obtained based on the sliding of the plunger 56a, and during repeated use, the plunger 56a
Reliability and durability are reduced due to abrasion and damage to a and its supporting parts.

■ Since a relatively large solenoid 56 is used, mounting efficiency is poor.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a pedal drive device for an automatic keyboard instrument that has low mechanical noise during operation of the pedal drive system, has excellent reliability, and is easy to mount. do.

``σ Means to Solve Problems'' To achieve the relevant purpose, this book! I! The configuration according to claim 1 includes a coil built into the automatic keyboard instrument, a fixed yoke fixed to the coil, and a coil arranged to face the fixed yoke and interlocked with a pedal drive system of the automatic keyboard instrument. The movable yoke is characterized in that the fixed yoke and the movable yoke have corresponding sawtooth-shaped portions formed on mutually opposing surfaces of the fixed yoke and the movable yoke.

The configuration according to claim 2 of the present application is characterized by comprising a plurality of sets of the coil, the fixed yoke, and the movable yoke, and a differential mechanism for transmitting the resultant force of the forces acting on each movable yoke to the pedal drive system. do.

"Operation" In the configuration described in claim 1, when the coil is energized,
A magnetic field is generated through the fixed yoke, creating an attractive force between the fixed and movable yokes. Here, sawtooth-shaped sections corresponding to each other are formed on the facing surfaces of the fixed yoke and the movable yoke, and by setting the angle and interval of each inclined surface of the sawtooth-shaped sections, the suction characteristics between the two can be adjusted. Can be set arbitrarily.

Therefore, for example, it is possible to set the thrust force characteristics relative to the travel distance (ζ stroke) of the pedal push-up rod to a flat characteristic that is easy to control, and also by adjusting the amount of current supplied to the coil. The thrust can be controlled.

Further, in the configuration according to claim 2 of the present application, a plurality of sets of coils, fixed yokes, and movable yokes are provided, and the pedal drive system is actuated by differential control of their mutual attraction forces, so that fine control is possible. It is also possible to control the rising speed of the pedal push-up rod and control to quickly remove the thrust force on the pedal push-up rod.

“Example J Hereinafter, each embodiment of the invention will be described with reference to the drawings.

First Embodiment FIGS. 1A and 1B show a first embodiment of the present invention. In these figures, the same reference numerals are given to the respective components corresponding to those in FIGS. 7 and 8, and the explanation thereof will be omitted.

As shown in FIG. 1(a), the pedal drive device of this embodiment includes a coil 1 attached to the lower surface of a shelf board 58, and a fixed yoke 2 fixed to the coil 1 so as to protrude downward.
and a movable yoke 3 disposed below the fixed yoke 2 so as to face it.

The coil 1 is electrically connected to the controller 57, and an electrical signal of an appropriate value is sent thereto.

The fixed yoke 2 is formed into a U-shaped cross section by bending a plate made of a high magnetic permeability material, and includes a flat plate part 2a that is inserted into the central hole of the coil l, and an upright side part 2b that rises from the flat plate part 2a. and has.

The movable yoke 3 is made of a material with high magnetic permeability, and has an arm portion 3a integrally formed on the side. It is supported so that it can swing freely. Furthermore, the movable yoke 3 is connected to the fixed yoke 2.
Similarly, the entire section is formed into a U-shape by the flat plate portion 3b and the upright side portions 3c.

On the opposing surfaces of the fixed yoke 2 and the movable yoke 3, that is, on the end surfaces of the upright side portions 2b and 3C of both,
Corresponding sawtooth shaped portions 2d and 3d are formed, respectively. The sawtooth-shaped portions 2d and 3d are configured such that a plurality (preferably an even number) of inclined surfaces σ are arranged in an M-shaped pattern in opposing directions.

The upper end of the lifting wire 6 is connected to a part of the movable yoke 3 that is slightly shifted toward the swing fulcrum (pin 5) than the part facing the fixed yoke 2, and the lower end of the lifting wire 6 is connected to the connecting member 7. It is directly connected to the push-up rod 51 via the push-up rod 51. As shown in FIG. 8(a), the push-up rod 51 has a small diameter portion 51a at the lower end.
is inserted into a small hole in the balance 5o from above, and can be moved upward by the push-up rod 51 alone. Further, 8 is a sensor provided near the swinging fulcrum (pin 5) of the movable yoke 3, and detects the movement of the movable yoke 3. Note that the pedal drive system P is provided with a stopper (not shown), so that the movement of the movable yoke and the push-up rod 51 is regulated before the movable yoke 3 contacts the fixed yoke 2.

Next, the operation of the pedal drive device configured as described above will be explained.

When the drive current flows from the controller 57 to the coil l,
A magnetic field is generated around the fill 1 according to the direction of the current, and a magnetic loop is formed between the fill 1 and the movable yoke 3 through the fixed yoke 2. Then, fixed yoke 2 and movable yoke 3
A suction force is generated between the two, and the movable yoke 3 is pulled upward by this suction force. Along with this, the lifting wire 6
The push-up rod 51 rises through the.

Here, the lifting of the push-up rod 51 described above is ultimately caused by the suction force generated between the fixed yoke 2 and the movable yoke 3, and the suction force changes somewhat depending on the vertical position of the movable yoke 3. This change is mainly determined by the angle θ of the inclined surface σ of the sawtooth-shaped portions 2d and 3d, the number of inclined surfaces α, etc., assuming that the current applied to the coil 1 is kept constant.

Therefore, by appropriately setting the angle and number of the inclined surfaces α, it is possible to adjust the characteristics of the thrust force with respect to the vertical position of the push-up rod 51. In addition, it can also be adjusted by controlling the current supplied to the coil l.

Further, the coil 1 is attached to the shelf board 84, and compared to the case where the coil 1 is provided on the movable yoke 3, which is the movable side, the wiring for energization is easier and it is superior in terms of mounting.

In addition, in this embodiment, the swinging tip of the movable yoke 3 faces the fixed yoke 2, and the lifting wire 6 is connected to the fulcrum side of the part facing the fixed yoke 2, thereby achieving the so-called lever principle. This has the advantage that the push-up rod 51 can be raised with a small amount of suction force.

Note that the sawtooth shaped portions 2d of the fixed yoke 2 and the movable yoke 3,
Since the number of inclined surfaces α constituting 3d is set to an even number, the vertical component of the magnetic force generated between the two effectively acts as thrust, while the horizontal component cancels each other out. will no longer affect the pedal driving force.

Second Embodiment FIG. 2 shows a second embodiment of the present invention. In addition, Fig. 1, No. 7 [! 1. Components that are the same as those shown in FIG. 8 are designated by the same reference numerals and their explanations will be omitted. A feature of this embodiment is that the lower end of the lifting wire 6 connected to the movable yoke 3 is directly connected to a balance 50 via a hanging fitting 52. Even with this configuration, the same effects as in the first embodiment can be obtained.

Third Embodiment FIG. 3 shows a third embodiment of the present invention. In this example,
a fixed yoke 2 fixed to the coil 11 and the coil l;
A pedal drive unit U, which also includes a movable yoke 3 corresponding to the fixed yoke 2, is installed horizontally on the lower surface of the shelf board 58, and a lifting wire 6 extending from the pedal drive unit U is suspended via a pulley 9, as shown in FIG. Similarly, it is connected to a balance 50 via a lifting fitting. As described above, the pedal drive device according to the present invention can be set not only in the vertical state but also in the horizontal state, which is advantageous in that the degree of freedom in design increases.

Fourth Embodiment FIG. 4 shows a fourth embodiment of the present invention. In this example, a plurality of pedal drive units U consisting of the coil 11 fixed yoke 2 and movable yoke 3 are provided, and the lifting rod 51 is raised by differential control of these units U. Note that the same components as in the above embodiment are given the same reference numerals, and their explanations will be omitted.

That is, the pedal drive unit U is mounted on both left and right sides of the bracket 4 for supporting the movable yoke.
are placed respectively. The movable yokes 3, which are the output parts of both pedal drive units U, are both integrally formed, and a bridge part 1 provided at the center thereof.
0 is swingably supported by the bracket 4. Also,
A lifting wire 6 connected to a balance 50 is connected to the lower part of the movable yoke 3 on the left side in the figure. That is, in this embodiment, the left and right movable yokes 3.3, the bridge portion 10, and the bracket 4, which are integrally formed, constitute a differential mechanism S that transmits the resultant force of both the pedal drive units U to the pedal drive system P. are doing.

Note that the above-mentioned lifting wire 6 may be replaced with a rod member as necessary.

In this embodiment, the pedal drive system P is actuated by differential control by the left and right pedal drive units U. Specifically, the pedal drive system P is operated by changing the voltage supplied to the pedal drive units U. Both return and return operations can be performed. Therefore, control accuracy is improved, and it becomes possible to faithfully reproduce various pedal techniques such as half-pedaling, quick pedal changes, and stepping up (slow return).

Fifth Embodiment FIG. 5 shows a fifth embodiment of the present invention. This embodiment is similar to the fourth embodiment in that pedal drive units U are arranged on the left and right sides of the bracket 4, and the lifting wire 6 is lifted and operated by differential control between them. is connected to the balance 50 via a hanging fitting 52, so that the push-up rod 51 can be indirectly raised. Even in this case, the same effect as above can be obtained.

Sixth Embodiment FIG. 6 shows a sixth embodiment of the present invention. In this example, a pedal drive unit U consisting of the coil 11 fixed yoke 2 and movable yoke 3 is provided in series on one side of a bracket 4 that supports the movable yoke 3, and the pedal drive unit U consisting of the coil 11 fixed yoke 2 and movable yoke 3 is installed in series on one side of the bracket 4 that supports the movable yoke 3. A lifting wire 6 is connected to the lower side. The other configurations are the same as those of the fourth embodiment, and their explanation will be omitted here.

In the case of this embodiment, the force for lifting the lifting wire 6 connected to the lifting rod 51 can be increased, and the pedal drive units U on both sides can be individually controlled, so that there is an advantage that finer lifting control can be performed.

"Effects of the Invention" 8. The configuration described in claim 1 of the present application provides the following effects.

■ Almost no noise is generated because it is a non-contact drive method rather than a contact drive method using a plunger or the like.

■ Also, since there are no mechanical contact parts, reliability and durability are improved.

■ The combination of a fixed yoke fixed to the coil and a movable yoke is thinner than a solenoid, and can be installed horizontally or vertically, making it easy to mount.

■ Simple structure reduces manufacturing costs.

■ The thrust characteristics relative to the travel distance (stroke) can be changed arbitrarily by simply changing the shape of the sawtooth-shaped part.

B9 According to the configuration described in claim 2 of the present application, fine control is possible by differential control of the unit consisting of the coil, fixed yoke, and movable yoke, and therefore control accuracy is improved, and the It becomes possible to faithfully reproduce and perform various pedal techniques such as stepping on the pedal, pressing the pedal up (slowly returning the pedal), etc.

[Brief explanation of drawings]

Fig. 1 shows a first embodiment of the present invention, Fig. 1 (a) is a side view of the main part of the pedal drive device, and Fig. 1 (b) is a sectional view taken along line A-A in Fig. 1 (a). , FIG. 2 is a side view of a main part showing a second embodiment of the invention, FIG. 3 is a side view of a third embodiment of the invention, and FIG. 4 is a main part showing a fourth embodiment of the invention. Side view,
FIG. 5 is a side view of main parts showing a fifth embodiment of the present invention, and FIG. 6 is a side view of main parts showing a sixth embodiment of the invention. Figure 7 is a rear view showing the pedal drive mechanism of a conventional automatic keyboard instrument; Figure 8 (a) is the same (partially enlarged view of the conventional pedal drive mechanism; figure (b) is B of figure (a)). It is an arrow view. l... Coil 2... Fixed yoke 3... Movable yoke 2d, 3d... Serrated section P... Pedal drive system S.・・・・・・Differential mechanism

Claims (1)

[Claims] 1) A coil built into an automatic keyboard instrument, a fixed yoke fixed to the coil, and arranged to face the fixed yoke and interlocked with a pedal drive system of the automatic keyboard instrument. 1. A pedal drive device for an automatic keyboard instrument, comprising a movable yoke, the fixed yoke and the movable yoke having corresponding sawtooth shaped portions formed on mutually opposing surfaces thereof. 2) The automatic keyboard according to claim 1, further comprising a plurality of sets of the coil, fixed yoke, and movable yoke, and a differential mechanism for transmitting the resultant force of the forces acting on each movable yoke to the pedal drive system. Pedal drive device for musical instruments.