JPH09269772A - Automatic player of keyboard musical instrument and assemblying method of electromagnetic actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the assembling easiness and to reduce the weight of an electromagnetic actuator for automatic playing of a keyboard musical instrument such as a piano. SOLUTION: While incorporating a solenoid 110 into a yoke 100 which is made of the combination of first and second yokes 101 and 102, first and second holding plate sections 105 and 106 of the yokes 101 and 102 are beforehand bent slightly to the direction in which the sections 105 and 106 are made closer to each other. Then, the solenoid 110 are held between the sections 105 and 106 and the sections 105 and 106 are strongly pushed to the solenoid 110 side and deformed. Thus, the solenoid 110 is simply assembled without using screws.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic playing device which is attached to a keyboard musical instrument such as a piano for automatically playing and an assembling method of an electromagnetic actuator used for the automatic playing device.

[0002]

2. Description of the Related Art Generally, an automatic musical instrument of a keyboard instrument is constructed so that a plunger of an electromagnetic actuator arranged to face a key is projected to a pivoting end of the key to perform a key depression operation. FIG. 7 shows a Japanese Patent Application No. 7-343687 filed by the applicant.
The electromagnetic actuator presented in No. The electromagnetic actuator includes a yoke 200 made of a magnetic material and forming a magnetic path, a cylindrical solenoid 210 supported by the yoke 200, and a plunger 220 fitted in the solenoid 210.

The yoke 200 has a first crank-shaped cross section.
The yoke 201 and the second yoke 202 having a U-shaped cross section are coupled to each other by screws 230, and have a cross-sectional shape in which the flanges 203 are formed at both ends of the U-shape as a whole. The first and second yokes 201 and 202 are
It has sandwiching plate portions 205 and 206 which are parallel to each other and sandwich the solenoid 210 therebetween. Solenoid 21
0 is the yoke 200 that is between the sandwiching plate portions 205 and 206.
Of the holding plate portions 205, 2 having upper and lower end surfaces in the concave portion on the open side of
It is installed so as to abut against 06. Solenoid 2
10 is sandwiched between the sandwiching plate portions 205 and 206, and the screw 230 is mounted over the sandwiching plate portions 205 and 206.
It is fixed to the yoke 200 so as not to fall off. The plunger 220 is made of a magnetic material, and the upper and lower ends are
The upper and lower holding plate portions 205 and 206 respectively project vertically.

A large number of the electromagnetic actuators are attached to a keyboard instrument such as a piano, for example, in a frame provided below a pivoting end portion of the keyboard on the rear end side of the key, corresponding to the key. The frame is a plate-like member that extends substantially along the key arrangement direction, and the upper and lower flanges 203 are fixed to the frame by fixing means such as screws. Then, in order to assemble the electromagnetic actuator, the solenoid 210 is sandwiched between the upper and lower plate portions 205 and 206 of the yoke 200, and then the screw 230 is tightened, and then the first and second yokes 201 and 202 are fixed by the screw 240. After coupling, the plunger 220 is then inserted into the solenoid 210.

[0005]

However, in the above electromagnetic actuator, the through hole for inserting the screw 230 for fixing the solenoid 210 to the yoke 200 and the screw hole for screwing are separated, that is, the upper and lower clamping plate portions 205, 206 are separated. However, since the screw 230 inevitably becomes long, there is a dissatisfaction in assembling that it takes time to tighten the screw 230. In addition, the first and second yokes 205 and 206 are usually formed by forming through holes and screw holes and then bending them. In that case, there is a risk that the through holes and screw holes may be distorted. Further, since the screw 230 is long, the weight is increased by mounting a large number of electromagnetic actuators, and accordingly, the weight of the frame is increased in order to improve the strength of the frame, and the cost is also increased. There was also a face.

The present invention has been made in view of the above circumstances, and provides an automatic playing device for a keyboard instrument and a method for assembling an electromagnetic actuator used therefor, in which the assemblability is improved, the weight is reduced, and the cost is reduced accordingly. Is intended.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and the automatic musical instrument of a keyboard instrument according to claim 1 faces a plurality of keys in the arrangement direction of these keys. In an automatic performance device for a keyboard instrument, in which an extending frame is provided, and an electromagnetic actuator that gives a key pressing operation to the key is mounted on the frame for each key, the electromagnetic actuator includes a cylindrical solenoid and an internal solenoid. A plunger inserted into the solenoid and a yoke that supports the solenoid and forms a magnetic path of the solenoid, and is configured to actuate the plunger by supplying a drive current to the solenoid to give a key pressing operation to the key. The yoke has a main plate portion having both ends, and a pair of sandwiching plate portions extending in the same direction from both ends of the main plate portion substantially orthogonal to the main plate portion and facing each other. Solenoid in its axial end surfaces, by contact in a state where the holding plate sections of the yoke is energized, sandwiched between the holding plate portion is characterized in that it is supported on the yoke.

According to a second aspect of the present invention, in assembling the electromagnetic actuator according to the first aspect, at least one of the pair of holding plate portions of the yoke has a bent portion that is substantially orthogonal to the main plate portion. It is characterized in that it is made to approach the other side in advance by making an acute angle or an obtuse angle, then the solenoid is sandwiched between the sandwiching plate portions, and each sandwiching plate portion is pressed toward the solenoid as necessary. .

According to the automatic performance device for a keyboard instrument of claim 1 of the present invention, the electromagnetic actuator of the automatic performance device for giving a key pressing action is sandwiched between a pair of sandwiching plate portions each having a solenoid as a yoke. However, since the holding plate portions are in contact with both end surfaces of the solenoid in a biased state, the movement of the solenoid is restricted and a stable support state is obtained. Fastening parts such as screws for sandwiching and fixing the solenoid are not required, and therefore, assemblability is improved and cost reduction is achieved along with weight reduction.

According to the electromagnetic actuator assembling method of the second aspect of the present invention, it is possible to easily realize a state in which each holding plate portion of the yoke is urged to both end surfaces of the solenoid.
It is very suitable as a method for assembling the electromagnetic actuator described in (1).

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. A. Configuration of one embodiment A-1. Configuration of Main Part FIG. 1 shows a main part of a grand piano in which the automatic performance device of the present embodiment is incorporated. In the figure, reference numeral 1 is a key constituting a keyboard, and 2 is a shelf board. A large number of keys 1 are arranged in the front-back direction of the drawing, and each key 1 is supported by a key bed 3 fixed on a shelf board 2 so as to be vertically rotatable about a rotation fulcrum. . The performer plays by depressing the front end portion of the key 1 on the left side in FIG. The rotation fulcrum is on the front end side of the key 1 in FIG. 1 and is not shown. Above the pivoting end on the rear end side of the key 1, the front-back direction (left-right direction in the drawing)
A string (not shown) extending horizontally to the key 1 is stretched corresponding to the key 1. An action 20 for striking the string by the action of the key 1 is provided between the string and the key 1. Next, the action 20 will be described.

A-2. Configuration of Action Reference numerals 21 and 22 in FIG. 1 denote a support rail and a shank rail which are horizontally fixed fixing members extending in the left-right direction of the piano. At the rear end of the support rail 21, the rear end of the whip pen 23 arranged along the key 1 is
It is rotatably connected by a pin 24. Whip pen 2
A substantially L-shaped (inverted L-shaped in FIG. 1) jack 25 including a large jack 25a and a small jack 25b is rotatably provided at a front end of the free end 3 of the jack 3 near its bent portion. Pin-coupled. The wippen 23 is supported by the key 1 via a capstan 26 at a portion slightly forward from the center in the longitudinal direction, and is pushed upward when the key 1 is pressed.

A column 27 extending upward is fixed to the central portion of the whip pen 23, and an upper end of the column 27 has an upper end.
An intermediate portion of the repetition lever 28 is rotatably pin-connected. A long hole 28a penetrating in the vertical direction is formed at the front end of the repetition lever 28 along the longitudinal direction of the repetition lever 28, and the upper end of the large jack 25a is inserted into the long hole 28a. .

A shank flange 30 is fixed to the upper surface of the shank rail 22, and a hammer 31 is rotatably pin-connected to the shank flange 30. The hammer 31 has a hammer head 33 fixed to the tip of a hammer shank 32.
2 has a base end rotatably pin-connected to the shank flange 30. On the lower surface of the hammer shank 32, which is slightly behind the pin connecting portion to the shank flange 30, a roller 34 having a horizontal axis as its axis is mounted.
The lower surface of the roller 34 is in contact with the upper surface of the repetition lever 28 with a slight gap between the lower surface of the roller 34 and the upper end surface of the large jack 25a. Also, shank rail 2
A regulating rail 35 is fixed to 2 along the longitudinal direction of itself. This regulating rail 35 is provided with a regulating button 36 whose position can be adjusted vertically. On the lower end surface of the regulating button 36, a small jack 25
A cushion 36a, such as a cloth, is attached to which the tip portion of b contacts. A back check 37 extending toward the hammer head 33 is attached to the rearmost end of the key 1.

The above is the action 20, and a damper mechanism 40 for pressing the strings is provided on the back side of the action 20. Reference numeral 41 denotes a damper rail provided over the entire length of the keyboard. One end of a damper lever 43 extending in the front-rear direction is rotatably pin-connected to the damper rail 41 via a damper lever flange 42. The damper lever 43 is provided for each key 1. A damper block 44 is rotatably attached to a front end, which is a free end of the damper lever 43, and a damper wire 45 extending upward is attached to the damper block 44. A damper (not shown) for pressing the strings from above is attached to the upper end of the damper wire 45. According to this damper mechanism 40, the damper lever 43 is pushed up by the rear end portion of the depressed key 1, and the damper is separated upward from the string just before the hammer 33 hits the string. By such an operation, resonance of the string corresponding to the unpressed key 1 is prevented.

The action of the action 20 is as follows. When the key 1 is pressed (pressed), the wippen 2
3 is pushed up by the capstan 26 and rotates clockwise about the pin 24 in FIG. Then, the jack large 25a pushes up the roller 34 to rotate the hammer shank 32 counterclockwise, and the hammer head 33 strikes the string corresponding to the depressed key 1.
As a result, a musical sound corresponding to the key 1 is emitted. At the time of this string striking operation, the small jack 25b rotates counterclockwise before the hammer head 33 hits the string,
The upper end of the large jack 25a moves forward and the roller 34
The tip of the small jack 25b comes into contact with the cushion 36a of the regulating button 36. After hitting the string, the hammer head 33 rotates downward due to the repulsive force of the string and its own weight, and is received by the back check 37 and stands still. Next, when the key 1 is released, the whip pen 23 rotates counterclockwise and the hammer shank 32 rotates clockwise. Along with this, the small jack 25b gradually separates from the regulating button 36, and the large jack 25a
Rotates clockwise and moves right below the roller 34 to come into contact again, and returns to the initial state before key depression.

A-3. Hammer Sensor Now, this piano is equipped with a hammer sensor that detects a key-pressing operation, that is, a string-striking timing and a string-striking speed, based on the operation of the hammer shank 32. This hammer sensor employs, for example, an optical sensor as a detection element, and the roller 3 in the hammer shank 32 is used.
A signal is output based on the amount of light that is changed by the shutter 52 that is mounted on the slightly rear side of 4. Then, the signal is recorded in a recording means such as a floppy disk as performance data for driving the key 1 during reproduction performance. This recording means is designed to be inserted into and removed from a reading device (not shown) provided on the front surface of the shelf board 2, for example, so that performance data read by this reading device is inputted to a controller described later. It has become.

Note that a key sensor for directly detecting a key operation may be additionally provided in order to detect a key pressing operation. This key sensor employs a configuration in which a shutter attached to the pivotal end of the key detects a key pressing operation using an optical sensor or the like.

B. Configuration of Automatic Performance Device Next, the automatic performance device of this embodiment will be described.
As shown in FIGS. 1 and 2, the key 1 on the shelf 2 is
A storage hole 60 is formed in a portion facing the rear end portion. The storage hole 60 has a long rectangular shape extending over the entire length of the keyboard, and the automatic performance device 61 of the present embodiment is incorporated in the storage hole 60. The automatic playing device 61 gives a key-pressing operation to the key 1 by pushing up the rear end portion of the key 1, and as shown in FIG. 2, a frame 62 detachably attached to the shelf board 2 and a frame 62. It is composed of an electromagnetic actuator 63 attached to the frame 62 corresponding to the key 1.

B-1. The frame 62 has a length corresponding to the storage hole 60, and is configured by a combination of a base plate 70 and a central plate 80 attached to the base plate 70. Of these plates 70, 80, at least the center plate 80 is made of a magnetic material such as soft iron. The base plate 70 has a U-shaped cross section as shown in FIG.
Collars 71 are formed at both ends in the width direction. The base plate 70 is arranged with the open concave side facing downward, and the horizontal plate portion 73, which is the upper portion, has a mounting hole 74 at the center in the width direction.
And an appropriate number of wire passage holes 75 at both ends are formed. The mounting holes 74 and the wire passage holes 75 are formed at equal pitches in the longitudinal direction of the base plate 70.

The central plate 80, as shown in FIG.
A plurality of mounting pieces 82 are formed by bending from one end of the plate body 81 in the width direction. The attachment piece 82 is a rectangle having a width that can be fitted into the attachment hole 74 of the base plate 70, and is formed at the same pitch as the attachment hole 74 along the longitudinal direction of the plate body 81. A plurality of through holes 84 are formed in two rows above and below the plate body 81.
These through holes 84 are long holes extending in the longitudinal direction of the plate main body 81, and the upper row and the lower row are formed in a zigzag shape, and the outer through holes 84 and the inner through holes 84 are aligned in the width direction. It is in a state of The pitch of the through holes 84 vertically adjacent to each other along the longitudinal direction of the plate body 81 is set to be substantially equal to the pitch of the key 1. Each mounting piece 82
Are inserted into the respective mounting holes 74 from above the base plate 70 to be aligned with the inner surface of the lateral plate portion 73, and this overlapping portion is fixed with a screw 89. The horizontal plate portion 73 of the base plate 70 and the attachment piece 82 of the central plate 80 are formed with a through hole 76 and a screw hole 83 through which the screw 89 is inserted. As a result, the central plate 80 is attached to the base plate 70 to form the frame 62.

As shown in FIG. 2, the frame 62 is
It is attached to the shelf board 2 via brackets 90 screwed to the front and rear edges of the storage hole 60 on the lower surface of the shelf board 2. That is, the frame 62 includes the base plate 7
With the horizontal plate portion 73 of 0 and the central plate 80 standing upright, the screw 92 that has passed through the through hole 72 that is a long hole formed in the collar 71 is screwed into the screw hole 91 of the bracket 90. , Is attached to the bracket 90.
The frame 62 can be adjusted in position in the longitudinal direction by the through hole 72 and can be adjusted in position in the vertical direction by the amount of screwing the screw 92 into the bracket 90.

When the frame 62 is attached to the shelf board 2 as described above, the base plate 70 is arranged below the storage hole 60, and the upper end portion thereof can be fitted into the storage hole 60. Further, the plate body 81 of the central plate 80 stands substantially vertically along the longitudinal direction of the storage hole 60 and is arranged substantially at the center of the storage hole 60 in the width direction.

As shown in FIG. 2, below the frame 62, there is a block strip 93 which prevents the frame 62, that is, the automatic musical instrument 61 from dropping to the floor even if the screw 92 comes off. It is fixed at 2. The block band 93 has a U-shaped cross section, and both ends thereof are screwed to the lower surface of the shelf board 2. For example, two to three block bands 93 are appropriately provided in the longitudinal direction of the frame 62.

The plate body 81 of the central plate 80
Both sides, that is, the front and back surfaces of the electromagnetic actuator 6
3, and the electromagnetic actuator 63 will be described below.

B-2. Electromagnetic actuator B-2-1. Configuration of Electromagnetic Actuator As shown in FIGS. 2 and 5, the electromagnetic actuator 63 includes a yoke 100 made of a magnetic material and forming a magnetic path,
A solenoid 110 built into this yoke 100,
A plunger 120 made of a magnetic material is inserted into the solenoid 110.

The yoke 100 has a first crank-shaped cross section.
The yoke 101 and the second yoke 102 having a U-shaped cross section are coupled to each other with screws, and have a cross-sectional shape in which the flanges 103 are formed at both ends of the U-shape as a whole. The first yoke 101 has a main plate portion 104, and the first and second yokes 101, 102 have sandwiching plate portions 105, 106 for sandwiching the solenoid 110 between them, which face each other in parallel. Have 1st, 2nd
1 consisting of a combination of the yokes 101 and 102
00 as a whole, the main plate portion 104 of the first yoke 101 and the main plate portion 1 from the upper and lower end portions of the main plate portion 104.
Both yokes 1 extending in the same direction orthogonal to 04 and facing each other
The holding plate parts 105 and 106 of 01 and 102, and the holding plate parts 105 and 106 from the ends of the holding plate parts 105 and 106.
Each of the collars 103 extends orthogonally to. In addition, the collar 10 of the holding plate portions 105 and 106 of the second yoke 102
A coupling piece 107, which serves as a coupling portion with the first yoke 101, is provided at the end portion on the side opposite to the portion 3. This connecting piece 107
Are orthogonal to the sandwiching plate portion 106.

Each of the collars 103 of the first and second yokes is formed in a trapezoidal shape and has a pair of upper and lower screw holes 103a. Further, the end portion of the main plate portion 104 of the first yoke 101 on the side opposite to the flange 103 and the connecting piece 107 of the second yoke 102 that is joined to this end portion are also trapezoidal. Has been done. The holding plate portion 105 of the first yoke 101 has a rectangular shape, but both sides on the flange 103 side are cut to form a cutout 105a. On the other hand, the sandwiching plate portion 106 of the second yoke 102 is also rectangular, but notches 106a and 106b are formed by cutting both sides of the flange 103 side and the coupling piece 107 side.
The holding plate portion 105 of the first and second yokes 101 and 102,
Fitting holes 108 into which both ends of the solenoid 110 are fitted are formed in 106.

In the yoke 100, the connecting piece 107 of the second yoke 102 is aligned with the trapezoidal end portion 104a of the main plate portion 104 of the first yoke 101, and the sandwiching plate portions 105, 1 of both sides are formed.
The trapezoidal ends 104a and the connecting pieces 107 are connected by screws 109 in a state in which 06 are opposed to each other and the collars 103 extend in mutually opposite directions.

The solenoid 110 is brought into contact with both end surfaces in the axial direction of the solenoid 110 by abutting the sandwiching plate portions 105 and 106 of the yoke 100 in a biased state, thereby sandwiching the sandwiching plate portion 10 from each other.
It is sandwiched between 5, 106 and supported by the yoke 100. In the solenoid 110, flanges 113 are formed at both ends of a cylindrical bobbin 112 having a through hole 111, and a coil 114 is wound around the outer circumference of the bobbin 112, which is between the upper and lower holding plate portions 105 and 106. York 1
No. 00 has an open side concave portion, and both end surfaces have these holding plate portions 10
It is installed in a state of abutting on 5, 106. An annular ridge 1 along the through hole 111 is formed on the inner edge of the flange 113.
15 are formed, and these ridges 115 form the yoke 1
Fitting holes 10 formed in the sandwiching plate portions 105 and 106 of No. 00.
8 is fitted to the yoke 100, so that the yoke 100 is positioned in the horizontal direction.

An annular stopper 121 is formed at one end of the plunger 120, and the plunger 120 is slidably inserted into the through hole 111 of the bobbin 112 of the solenoid 110 from the other end. In this fitted state, the upper and lower ends of the plunger 120 project vertically from the sandwiching plate portions 105 and 106, respectively. This plunger 120 has a stopper 121.
By hitting the upper holding plate portion 105, further downward movement is restricted.

B-2-2. How to assemble an electromagnetic actuator
The above is the configuration of the electromagnetic actuator 63. Next, a method of assembling the electromagnetic actuator 63 will be described. FIG. 6 shows a state in which the first and second yokes 101 and 102 are combined. In the first yoke 101, the internal angle α formed by the main plate portion 104 and the sandwiching plate portion 105 is
The angle is slightly smaller than the right angle (90 °) which is the set angle after assembly, and is set to about 90 °-(1 to 3 °), for example. That is, the holding plate portion 105 of the first yoke 101 approaches the holding plate portion 106 side of the second yoke 102 by bending the bent portion from the main plate portion 104 further than the set angle of 90 °. are doing.

On the other hand, in the second yoke 102, the internal angle β formed by the coupling piece 107 and the sandwiching plate portion 106 is an obtuse angle slightly larger than the right angle which is the set angle after assembly, for example, 90 ° + (1 to It is set to about 3 °). That is, the bent portion of the sandwiching plate portion 106 from the coupling piece 107 is bent at an acute angle to the sandwiching plate portion 106 side of the first yoke 101 with respect to the set angle of 90 °, and the sandwiching plate portion 106 is at the first angle.
Of the yoke 101 is closer to the holding plate portion 105 side.

As a procedure for assembling the electromagnetic actuator 63, first, the solenoid 110 is sandwiched between the sandwiching plate portions 105 and 106 of the first and second yokes 101 and 102, and the ridges 115 on both end faces are formed. Holding plate portions 105, 10
6 is fitted into each fitting hole 108 to be in a temporary assembled state. In this temporarily assembled state, a part of the holding plate portions 105 and 106 of the first and second yokes 101 and 102 on the flange 103 side contacts the flange 113 of the bobbin 112, and the main plate portion 104 side bends as described above. Flange 11 according to the angle (1-3 °)
3 away. Next, the holding plate portions 105 and 106 are connected to the solenoid 11 with an appropriate jig (such as a vise).
The solenoid 110 is sandwiched by pressing it to the 0 side to apply pressure. Then, as shown in FIG. 5B, the main plate portion 104 is bent outward in a concave state, and the flange 11 of the bobbin 112 is bent.
It is pressed against both end faces of 3 without a gap. By bending the main plate part 104, the second part connected by the screw 109
The connecting piece 107 of the yoke 102 of FIG. As a result, the entire surface of the coupling piece 107 contacts the trapezoidal end 104a of the main plate portion 104. Next, the trapezoidal end portion 104a and the coupling piece 107 are coupled with the screw 109 to assemble the first and second yokes to each other. After that, the jig is removed to obtain the electromagnetic actuator 63.

The obtained electromagnetic actuator 63 has the holding plate portions 105 of the first and second yokes 101 and 102 on both flanges 113 of the bobbin 112 of the solenoid 110.
When 106 abuts tightly without a gap, the solenoid 110 is sandwiched between these sandwiching plate portions 105 and 106.
Are supported by the yoke 100. Also,
When pressure is applied in the temporarily assembled state as described above, the angles α and β of the bent portions widen and approach 90 °, and the main plate portion 1
04 bends. Due to the bending of the main plate portion 104 and the expansion of the angles α and β of the bent portions, the solenoid 110 receives the biasing force of the first and second holding plate portions 105 and 106.
Therefore, the solenoid 110 includes the holding plate portions 105,
The solenoid 110 is sandwiched by receiving a certain amount of urging force, so that the solenoid 110 is restrained from moving in the axial direction and fixed to the yoke 100.

B-2-3. Mounting of Electromagnetic Actuators The electromagnetic actuators 63 are arranged on the front and rear mounting surfaces 81a and 81b of the central plate 80 in a staggered manner along the longitudinal direction of the central plate 80 while alternately changing the front and rear arrangements. As shown in, the upper and lower flanges 103 of the yoke 100 are attached to the central plate 80 by screws 141. That is, the pitches of the rows of the front electromagnetic actuators 63 mounted on the mounting surface 81a and the rows of the rear electromagnetic actuators 63 mounted on the mounting surface 81b are arranged in correspondence with two pitches of the key 1. . The electromagnetic actuator 63 is attached to the central plate 80 by screwing the screw 141 through the through hole 84 of the central plate 80 into the collar 10.
It is performed by screwing it into the screw hole 103a of No. 3. In this mounted state, the plunger 120 of each electromagnetic actuator 63 is arranged immediately below the rear end of the key 1. As described above, the central plate 80 supports the electromagnetic actuators 63 and is made of a magnetic material as described above.
The magnetic path forming portion forms one magnetic path.

As shown in FIG. 2, a substrate 151 provided with a drive circuit for driving the electromagnetic actuator 63 is fixed to the lower surface of the base plate 70 of the frame 62, and the drive current from this drive circuit is applied to the solenoid 110. Is supplied to the coil 114, and the electromagnetic actuator 63 is operated. The coil 114 and the drive circuit are connected by an electric wire 152 that is passed through the electric wire insertion hole 75 of the base plate 70. A control current is supplied to the drive circuit of the substrate 151 from a control circuit provided on another substrate (not shown). The board incorporates the above-mentioned controller that outputs a control current to the drive circuit based on the performance data. The control circuit and the controller may be collectively provided on the substrate 151.

C. The operation of the automatic performance device and the
Effect Next, the operation of the automatic performance device 61 of this embodiment in which the electromagnetic actuator 63 corresponding to the key 1 is attached to the frame 62 will be described. The performance data recorded in the recording means is sequentially read out as time passes. When a drive current is supplied from the drive circuit of the substrate 151 to the coil 114 of the solenoid 110 based on this performance data, a magnetic field that circulates in the cross section of the solenoid 110 is generated. At that time, the yoke 100 and the central plate 80 are
It functions as a magnetic path. Due to the generated magnetic field, an upward force acts on the electromagnetic plunger 120, and the plunger 12
0 moves up and pushes up the rear end of key 1. It should be noted that by adjusting the height of the base plate 70 so that the key pressing operation is accurately performed, the upper end of the plunger 120 and the key 1 are adjusted.
Is set to an appropriate interval (for example, about 0.5 to 1 mm). As a result, the action 20 is actuated in the same manner as when the key is pressed, and a musical sound is played. When this key pressing operation is completed, the supply of the drive current to the solenoid 110 is stopped, and the plunger 120 moves downward and returns to its original position. By such movement of the plunger 120 of the electromagnetic actuator 63, a key depression operation is performed based on the performance data, and an automatic performance is performed.

In the electromagnetic actuator 63, the solenoid 110 includes the first and second yokes 10
It is fixed to the yoke 100 by receiving the urging force of each of the sandwiching plate portions 105 and 106 of Nos. 1 and 102, and unlike the prior art, when assembling the solenoid to the yoke, it is not tightened with a relatively long screw across each sandwiching plate portion. . Therefore,
The work of tightening such screws is omitted. As described above, the electromagnetic actuator 63 of this embodiment uses the jig to fix the solenoid 110 to the yoke 100.
The sandwiching plates 105 and 106 are pressed against the bobbin 112 side of the solenoid 110 to sandwich the solenoid 110,
Then, it is assembled by mounting the screw 109. Therefore, it takes less time and effort to assemble the electromagnetic actuator 63 than before, and the assembling property can be improved. Further, since the screw is not provided, the weight is lighter than the conventional one, and accordingly, the strength of the frame 62 on which a large number of electromagnetic actuators 63 are mounted can be suppressed,
Therefore, the frame 62 can also be reduced in weight. Therefore, the cost of materials and manufacturing can be reduced.

When the electromagnetic actuator 63 is attached to the front and rear attachment surfaces 81a and 81b of the central plate 80 with the screws 141, the attachment surfaces 81a and 81b of the holding plate portions 105 and 106 of the first and second yokes 101 and 102 are attached. Notches 105a and 106a are formed on the front side of the first yoke 101, and further on the inner side of the holding plate portion of the second yoke 102 (the coupling piece 1).
Since the notch 106b is also formed on the 07 side), a tightening tool such as a driver can be easily inserted without the adjacent electromagnetic actuator 63 interfering. Therefore, the work of attaching / detaching the electromagnetic actuator 63 to / from the central plate 80 can be easily performed.

Further, in the automatic musical instrument 61, the electromagnetic actuators 63 are alternately mounted on the front and rear mounting surfaces 81a and 81b of the central plate 80 of the frame 62 along the longitudinal direction thereof. A sufficient distance can be secured between the electromagnetic actuators 63 adjacent to each other on the left and right. Therefore, the electromagnetic actuator 63 is
It can be of a size having sufficient thrust to give a key depression action, and can be sufficiently installed on a piano of a type in which the pitch of the keys 1 is relatively small.
In addition, the zigzag arrangement in the front and rear rows allows the plunger 12
The value of 0 may be the minimum necessary length at which problems such as vibration and bending are unlikely to occur. For these reasons, the key pressing operation is stabilized.

Further, most of them are accommodated in the storage holes 60 formed in the shelf board 2 and the projecting length of the shelf board 2 to the lower side is suppressed, so that parts arranged below the shelf board 2 (for example, There is almost no possibility of interfering with pedals such as loud pedals). In addition to this, each electromagnetic actuator 63 can be individually moved in the left-right direction to facilitate position adjustment or pitch adjustment, as well as height adjustment of the automatic performance device 63 itself. Therefore, it is easy to install and is very suitable as a retrofit type to a ready-made piano. Further, since the central plate 80 forms a part of the magnetic path of the electromagnetic actuator 63 together with the yoke 100, the number of parts forming the electromagnetic actuator 63 can be reduced, and the assembling can be facilitated and the cost can be reduced.

D. Modifications The present invention is not limited to the above embodiment, and the following modifications are possible, for example. Although both the sandwiching plate portions 105 and 106 are bent at an acute angle or an obtuse angle, at least one of them may be bent at an acute angle or an obtuse angle. The yoke 100 includes the first and second yokes 101 and 102.
However, when the length of the bobbin 112 of the solenoid 110 is constant or known,
The first and second yokes 101 and 102 may be integrated. Alternatively, the second yoke 102 may be coupled to the upper and lower sides of the main plate portion 104. In this case, the upper and lower sandwiching plate portions can be used in common and the cost can be reduced. Although the automatic performance device 61 is incorporated in the piano body, it can be applied to a so-called bolsessor type arranged on the key 1. Further, although the piano is applied to a grand piano, the present invention is not limited to this embodiment, and can be applied to any keyboard musical instrument such as a harpsichord, a celesta, and an organ.

[0044]

According to the automatic musical instrument playing device of the keyboard instrument of the first aspect of the present invention, the sandwiching plate portion constituting the yoke is in contact with both end faces of the solenoid in a biased state. A stable supporting state can be obtained, and a fastening component such as a screw for sandwiching and fixing the solenoid is not required. Therefore, the assemblability is improved and the cost is reduced due to the weight reduction. Further, according to the electromagnetic actuator assembling method of the second aspect of the present invention, it is possible to easily realize the state in which the sandwiching plate portion of the yoke is urged to both end surfaces of the solenoid, and the electromagnetic actuator according to the first aspect is assembled. It is extremely suitable as a method.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a main part and an action of a grand piano in which an automatic performance device according to an embodiment of the present invention is incorporated.

FIG. 2 is a side view showing details of the automatic musical instrument.

FIG. 3 is a top view of a base plate forming a frame.

FIG. 4 (a) of a central plate constituting a frame
It is a front view and a (b) top view.

FIG. 5A is a top view, FIG. 5B is a side view, and FIG. 5C is a front view of an electromagnetic actuator according to an embodiment of the present invention.
(D) It is a bottom view.

FIG. 6 is a side view showing a state in which first and second yokes are combined.

7A is a top view showing an example of a conventional electromagnetic actuator, FIG. 7B is a side view, FIG. 7C is a front view, and FIG. 7D is a bottom view.

[Explanation of symbols]

1 ... Key, 61 ... Automatic performance device, 62 ... Frame, 63 ...
Electromagnetic actuator, 100 ... Yoke, 104 ... Main plate part, 105 ... First holding plate part, 106 ... Second holding plate part, 110 ... Solenoid, 120 ... Plunger.

Claims (2)

[Claims] 1. A keyboard instrument in which a frame is provided which faces a plurality of keys and extends in the arrangement direction of the keys, and an electromagnetic actuator for giving a key-pressing operation to the keys is mounted on the frame for each key. In the automatic musical instrument, the electromagnetic actuator includes a cylindrical solenoid, a plunger inserted in the solenoid, and a yoke that supports the solenoid and forms a magnetic path of the solenoid, and supplies a drive current to the solenoid. The plunger is actuated to give a key pushing action to the key, and the yoke extends in the same direction from the both ends of the main plate portion substantially orthogonal to the main plate portion and faces each other. The solenoid has a pair of holding plate portions that contact each other in a state where the holding plate portions of the yoke are urged to contact both end surfaces of the solenoid in the axial direction. Automatic musical instrument keyboard instrument, characterized in that interposed between the plate portion is supported by the yoke. 2. When assembling the electromagnetic actuator, at least one of the pair of sandwiching plate portions of the yoke is made to approach the other side by making a bent portion substantially orthogonal to the main plate portion an acute angle or an obtuse angle in advance. Next, sandwich the solenoid between the sandwiching plate portions,
A method for assembling an electromagnetic actuator, comprising pressing each holding plate portion toward a solenoid as needed.