JPS63118190A - Assembling of upright piano - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention provides a reference protrusion on the frame and uses this as a reference surface during assembly to minimize assembly errors and improve quality. This article concerns how to assemble a vertical piano.

[Conventional technology]

Normally, when assembling vertical pianos such as upright pianos and electric pianos, the soundboard is attached to the support body.

A frame, pin plates, etc. are assembled to form a bag, and this bag is vertically fixed to the upper surface of the bottom plate, and both sides of the bag are fixed to the inner surfaces of a pair of left and right parent plates, respectively. in this case,
Attaching the back to the main plate is done by fitting dowels protruding from each side of the support body into dowel holes formed on the inner side of the main plate. Also, the dowel holes are provided based on the top and side surfaces of the parent plate. After such a bag is assembled between the main boards, it is attached between all the armrests of the shelf board, and then a key and an action mechanism are installed on the shelf board. At this time, if the dimensional accuracy of the horizontal distance from the nine-mouth stick located on the upper surface of the front end of the shelf board to the string striking point is poor, the touch feel of the keys will be poor, and at the same time, the action a barrel will not operate smoothly. Therefore, precision is required in assembling the key and the action mechanism.

[Problem that the invention seeks to solve]

However, in conventional vertical pianos, manufacturing and processing errors tend to accumulate structurally, making it difficult to assemble with high precision. In other words, when drilling the dowel mounting holes on the side of the strut body, an error inevitably occurs, and if this is added to the dimensional error from the back of the girder to the string rest, the dimensional error from the string rest to the dowel will increase. If the string is large, or if the back is warped or curved, this will result in an error, and in the end, these errors will accumulate and greatly disturb the dimension between the zero rod and the string-striking point.

Hereinafter, this invention will be explained in detail based on the 5A embodiment shown in the second drawing.

Therefore, it is an object of the present invention to solve the above-mentioned conventional problems and provide a method for assembling a vertical piano in which the frame and the support main body can be assembled to the main plate with high precision using a simple method. This is the purpose.

[Means for solving problems]

In order to achieve the above object, the present invention provides a pair of left and right first reference projections on both sides of the surface of the frame.

Second reference protrusions are integrally provided on the lower end of the surface, and the first reference protrusions are provided between the reference gap for determining the string striking point and the fixing member provided on the side surface of the support body and coupled to the parent plate. a reference surface for determining the mounting position; the second reference protrusion has a reference surface for determining the front-rear direction of the frame; and after strings are stretched on the frame, the mounting position of the first reference protrusion is determined. The fixing member is positioned and fixed to the side surface of the column main body based on a reference plane, and the column main body is positioned and fixed to the parent plate via the fixing member.

[Effect]

Based on #c1 and the second reference protrusion provided on the frame, the mounting point of the 2nd string string and the vertical mounting position of the frame can be determined.

〔Example〕

Hereinafter, a method for assembling a vertical piano according to the present invention will be explained in detail based on the drawings.

FIG. 1 is a sectional view showing an embodiment of an upright piano employing the assembly method according to the present invention, FIG. 2 is an enlarged front view of the back, and FIG. 3 is a side sectional view of the back. In these figures, the exterior main body 2 of the upright piano 1 includes a pair of left and right parent plates 3A, 3B, a roof plate 4. Bottom plate 5. Upper front plate 6.
It is formed into a substantially box shape by the lower front plate 7 and the like, and the rear opening 1 of the exterior main body 2 is located inside the box! 1, a bag 8 is disposed in front of the bag 8, and an action mechanism 9, which will be described later, is housed in front of the bag 8.

The bag 8 is erected substantially vertically on the bottom plate 5,
A frame 11 and a soundboard 12 are fixed to the inner surfaces of the main plates 3A and 3B, and are made up of 10 tons of strings with a valley pitch.
It is composed of a support main body 13 and the like. The support main body 13 has an upper girder 149, a rear girder 1S, a middle girder 16. Large base 17.
A vertical frame is formed by a pair of left and right columns 18A, t8B, etc., and functions as a support member for the frame 11 and soundboard 12, and at the same time as a strength member for the exterior main body 2, and its upper end portion The upper end of the frame 11 is firmly fixed to the front surface via a bin plate 19. A pair of upper and lower dowels (fixing members) 20 are provided on the outer surfaces of the pair of pillars 18A and 18B, respectively.
m, 20b, 21m, 21b are provided protrudingly,
Correspondingly, there are pairs of dowel holes 22a, 22b, 23m+ on the inner surfaces of the parent plates 3A and 3B, respectively.
23b is formed. Therefore, each dowel 2Gm
, 20b.

Dowel holes 22a and 22 corresponding to 21a and 2jb
b, 23a.

23b, the back 8 is restricted from moving in the front-rear, left-right, and up-down directions, and the pair of main plates 3A.

It is positioned and fixed between 3B.

The frame 11 is integrally formed of a casting such as cast iron, and has a plurality of openings 24. Reinforcing rib 25.
A tuning pin installation portion 27 into which a plurality of tuning pins 26 are driven. Similarly, multiple frame bins 28
Frame bin installation part 299 String receiving part 30.
31 etc., the lower end of which is fixed to the lower end surface of the sound board 12. Further, a pair of left and right reference protrusions 33A having the same shape are provided near the top of both ends of the surface of the frame 11.
, 33B are integrally provided. These reference protrusions 33A and 33B project from the lower surface of the frame 11 at approximately the same height position, and their upper surface a is parallel to the horizontal plane.
The front faces each form a vertical surface.

The front surfaces of each of the reference protrusions 33A and 33B form the same plane, and the dowels 2 described above are made with this front surface as the reference surface.
The mounting positions of 0a, 20b, 21m, and 21b are determined. On the other hand, each reference protrusion 33A, 33B
The upper surface a forms a reference surface for determining the string-striking point of each string 10, that is, the point at which the string is struck by a hammer, which will be described later.

It is set to coincide with a virtual line 40 (see FIG. 2) connecting the upper surface a of 33B. In this case, the imaginary line 4° can be easily obtained by fixing a thread to the upper surface a of each reference projection 33B and tightening it. Furthermore, the frame 11
A second reference protrusion 41 is integrally provided on the lower end surface of the holder.

The peripheral edge of the soundboard 12 is fixed to the front surface of the support main body 13 via a ram 43, and extends from the bass to the treble part on the front side, and extends from the bass to the treble part on the front side.

A long bridge 44 that supports the middle part of the treble part 10 and a bass part 10
Short pieces 45 supporting the are fixed with adhesive. The strings 10 of each pitch are connected to the tuning bin 26 and the seven-frame bin 28 at both ends, and the long bridge 44 or the short bridge 45 and the string receiving 30.3 at the middle.
1, the pitch is tuned to a predetermined pitch by adjusting the support pitch and the rotation of the tuning bin 26.

The action mechanism 9 is disposed corresponding to each string 10 of each pitch, and is operated in conjunction with a key press operation, which will be described later, to strike the corresponding string 10t, as shown in FIG. As shown, wippens 49 are rotatably disposed on the center rail 48. Bat 50. Wipen 4
a jack 51 disposed at 9 and pushing up the bat 50;
．． It is composed of a hammer 52 and the like on which a bat 50 is disposed. The center rail 48 extends commonly to all the action machines lff9, and both ends and a middle portion thereof are fixed to a plurality of brackets 53. These brackets 53 are erected in a height-adjustable manner on a shelf board 56 constituting a keyboard section 55, which will be described later, and are connected to the frame 11 at the upper end via an action pole 57t. Therefore, when mounting the bracket 53, by changing the height and moving the center rail 48 up and down, each hammer 52 can be set at a height position corresponding to the striking point of the string 10.

The n-board portion 55 is disposed on the front surface of the exterior main body 2 and approximately at the center in the height direction, and extends over almost the entire length of the main body 2 in the width direction. The shelf board 56 is formed by arranging a large number of corresponding keys 60 in parallel in the left-right direction. A pair of left and right arms 6 that support both ends of the shelf board 56
1A, 61B (61B is not shown), keyboard lid 622
It is composed of a rod 63 and the like, and protrudes to the front of the exterior main body 2.

The rear end portions of the pair of arms 61A and 61B are firmly fixed to the inner surfaces of the parent plates 3A and 3B by means of set screws, adhesive, or a combination thereof.

When assembling an upright piano with such a configuration, first the frame 11. #Plate 12゜Strut body 13
etc. are integrally connected to assemble the back 8t and string 10.
is stretched on the frame 11 with a predetermined tension. Then, the outer periphery of the bag is shaved to a predetermined size, and the pillars 18A, 18
Dowel 20a on the inside surface of B.

Holes for 20b, 21a, 2Ib (not shown) t
- Distance L from the front surface of the first reference projections 33A and 33B
(See Figure 3). This distance can be set arbitrarily, but since it is determined after the strings 10 are stretched on the frame 11, it can be formed with high precision regardless of any warping or tearing of the back 8 due to stringing. Keep errors to a minimum. Moreover, the dowel holes 22a, 22b, 23a, and 23b of the main plates 3A and 3B are drilled with the front surface of the main plate as a reference. After drilling, dowel holes 22a, 22b, 23a,
Dowels 20a, 20b, 21a, 2 on 23b
1b T-fitting, the bag 8 is positioned in the vertical, horizontal, and front-back directions, and is therefore incorporated into the exterior main body 2 with high precision.

In this case, the machining error of the holes for the dowels drilled in the struts 18A and 18B is concentrated at the dimension L+ (see Figure 3), but the machining error is smaller than the conventional positioning using the string receiving, back of the girder, and dowel holes. This error is small, and this error is action machine 99. This value is within the allowable range when assembling Ken 6G, etc., and if the width of the main plates 3A and 3B is designed large in advance,
Errors can be sufficiently absorbed by letting them escape to the rear, and the support main body 13 can be prevented from protruding to the rear of the exterior main body 2.

The keyboard section 55 is attached to the exterior main body 2 using the front surfaces of the first reference protrusions 33A and 33B as reference surfaces.

Therefore, the horizontal distance from the zero rod 63 to the string-striking point of the string 10 is also set with high precision. In addition, the key 60 is the 0 bar 63
Since it is arranged on the shelf board 56 with the inner surface of the board as a reference, it can be assembled with high precision.

That is, 33 first reference protrusions provided on the frame 11,
33B as a reference, calculate the dimensions of the back of the string receiving shell 1, and drill a dowel hole from the back of the 1st string. This will prevent the addition of recoil and twist due to stringing after that, so the key 609 rod 63.
Drilling holes in the action mechanism 9, etc., does not introduce errors due to machining, which makes it possible to assemble them with high precision.

Therefore, there is little variation in assembly accuracy and uniform quality can be obtained, and AGO and action machine gI9
The operation is also smooth. In addition, the first reference protrusion 33A,
Since the upper surface a of 33B allows the striking points of the strings 10 to be aligned, the height of the action mechanism 9 can be easily adjusted.

Although the above embodiment has been described with reference to the case where it is applied to an upright piano, the present invention is of course not limited to this and can be applied to a vertical electric piano as well.

Furthermore, although the above embodiment uses dowels and dowel holes as fixing members for the main plates 3A and 3B of the bag 8, bolts or the like may also be used.

〔Effect of the invention〕

As described above, the method for assembling the vertical piano according to the present invention includes integrally providing the first and second reference protrusions on the front side of the frame, and using these as references for the assembly jig (not shown), the back is Since the strings are assembled into the exterior body after being stretched on the frame, the bag can be positioned and fixed in the vertical, horizontal, and front-back directions while minimizing the accumulation of manufacturing and processing errors. Since the reference protrusion 8 is used to determine the string striking point and the installation position of the 0 bar, the relative positions of the string, key string 2, axicon mechanism, etc. can be set with high precision, and the performance is good. In addition, reliable key pressing and string striking operations can be obtained, improving the accuracy of piano assembly.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention applied to an upright piano, FIG. 2 is an enlarged front view of the back, and FIG. 3 is a side sectional view of the back. 2... Exterior main body, 3A, 3B... Main board, 5...-
φ・Bottom plate, 8-Fist/Fist hack, 10...-String, 11・
ψΦ・Frame, 12・φ・・Soundboard, 13・・・・Strut body, 20g, 20b, 21a, 21b・
... Dowel (fixing member), 22m, 22b, 2
3-a. 23b ---@7 hole, 33A, 33B ""
”-first reference protrusion, 41...-second reference protrusion, *,
b, e...Φ・Reference surface.

Claims (1)

[Claims] A strut body is fixed to the inner side of a pair of left and right parent plates, a frame is placed on the front of this strut body and has multiple strings stretched thereon, and a frame is integrally provided on both sides of the surface of this frame. The pair of left and right first reference protrusions includes a pair of left and right reference protrusions and a second reference protrusion that is integrally provided at the lower end of the surface of the frame, and the left and right pair of first reference protrusions are for determining the string-striking point. and a reference surface for determining the attachment position of a fixing member provided on the side surface of the support main body and coupled to the parent plate, and the second reference protrusion is a reference surface for determining the front-rear direction of the frame. After the string is stretched on the frame, the fixing member is positioned based on the reference plane of the first reference protrusion and fixed to the side surface of the support main body, and the support member is attached to the support via the fixing member. A method for assembling a vertical piano, characterized in that the main body is positioned and fixed to the main plate.