JP2003216141A - Keyboard device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a keyboard device having a balance weight of a high specific gravity consisting of a material having no ill effects on the human body. <P>SOLUTION: The keyboard device is constructed to have a keyboard 1 which oscillates vertically around its intermediate portion as a rotationally moving pivot and the balance weight 5 made of the tungsten-base high-specific gravity material embedded in a front or rear position of the rotationally moving pivot of the keyboard 1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyboard device for musical instruments having a keyboard such as a piano.

[0002]

2. Description of the Related Art A keyboard device of this type is known which includes a keyboard extending in the front-rear direction, a balance rail for supporting the keyboard from below, and an action provided on the keyboard. The keyboard is vertically swingable with a balance pin portion erected on the balance rail as a center of rotation. The action is provided on the keyboard behind the center of rotation, and it is activated by rocking the front of the keyboard downward, which causes the hammer to rotate and strike a string to produce a piano sound. It is designed to let you.

The touch force of the keyboard is determined by the balance of moments around the center of rotation. Generally, since an action is provided on the rear side of the keyboard, a balance weight for reducing the touch force is embedded in front of the center of rotation. Since the balance weight has a different weight of the hammer depending on the pitch of the sound or the like, the weight is adjusted for each keyboard in order to make the touch force uniform.

Further, the balance weight has conventionally used lead formed in a cylindrical shape, and is fixed to the keyboard by inserting it into an embedding hole formed in the side surface of the keyboard and then caulking it. . Lead is suitable for use as a balance weight because it has a high specific gravity and can be easily crimped into a buried hole provided in a wooden keyboard with a press.

[0005]

However, the keyboard device has an environmental problem that it uses lead, which is harmful to the human body. Therefore, it has been desired to develop a balance weight having a high specific gravity, which is made of a material harmless to the human body, instead of the balance weight made of lead.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a keyboard device having a balance weight made of a material harmless to the human body and having a high specific gravity.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is a keyboard which swings up and down with an intermediate portion as a rotation center portion, and a rotation center portion of the keyboard. It is characterized by comprising a balance weight made of a tungsten-based high specific gravity material buried in a front or rear position.

The invention described in claim 2 is characterized in that, in the invention described in claim 1, the balance weight is fixed by press fitting into an embedded hole formed in the keyboard.

According to a third aspect of the present invention, in the invention according to the first or second aspect, the balance weight is formed in a tapered shape, and is embedded in a tapered shape formed on a side surface of the keyboard. It is characterized in that the taper is fixed to the hole by fitting them together.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the balance weight is formed of a tungsten-based sintered alloy having a specific gravity of 11.0 to 18.0. Claim 1 characterized in that
The keyboard device according to any one of 1 to 3.

According to a fifth aspect of the invention, in the invention according to the fourth aspect, the balance weight comprises Ni (nickel): 3 to 25 wt% and Cu (copper): 1 to 1 as binder phase forming components. It is characterized in that it is formed by a tungsten-based sintered alloy containing 20% by weight and the balance being tungsten as a dispersed phase forming component and unavoidable impurities.

According to a sixth aspect of the present invention, in the invention according to the fourth aspect, the balance weight comprises Ni: 3 to 25% by weight, Cu: 1 to 20% by weight and Fe ( (Iron): 1 to 20% by weight, and the balance is formed of a tungsten-based sintered alloy having a composition of tungsten as a dispersed phase forming component and unavoidable impurities.

According to a seventh aspect of the invention, in the invention according to the fourth aspect, the balance weight comprises Ni: 3 to 25% by weight, Cu: 1 to 20% by weight, Fe: as a binder phase forming component. 1 to 20% by weight and Co (cobalt):
It is characterized in that it is formed of a tungsten-based sintered alloy containing 0.5 to 10% by weight and the balance being a composition of tungsten as a dispersed phase forming component and unavoidable impurities.

The invention according to claim 8 is the invention according to claim 4, wherein the balance weight comprises Ni: 3 to 25 wt% and Fe: 1 to 2 as binder phase forming components.
It is characterized in that it is formed of a tungsten-based sintered alloy containing 0% by weight and the balance of tungsten as a dispersed phase forming component and unavoidable impurities.

According to a ninth aspect of the present invention, in the invention according to any one of the first to third aspects, the balance weight has a specific gravity including powdered tungsten and a resin as a binder of the tungsten. It is characterized by being formed of a composite material of 11 to 15. The above-mentioned resin is a concept that includes both a thermoplastic resin and a thermosetting resin.

According to a tenth aspect of the present invention, in the invention according to the ninth aspect, the balance weight contains the resin: 2 to 5% by weight, and the balance is a composite material containing the tungsten and unavoidable impurities. It is characterized by being formed by.

In the invention according to any one of claims 1 to 10 configured as described above, the tungsten-based high specific gravity material (hereinafter referred to as "W-based high specific gravity" is embedded in a position in front of or behind the center of rotation of the keyboard. A balance weight made of a material) makes it possible to adjust the balance of the moment around the center of rotation. Since the W-based high specific gravity material is a material containing tungsten (hereinafter referred to as “W”) as a main metal, the W is used as Ni, Cu, F.
A W-based sintered alloy having a binder phase forming component such as e or Co can have a high specific gravity of 11 to 18, and a W-based composite material using a resin as a binder High specific gravity of 11 to 15 can be obtained. Moreover, since metals such as W and resins are harmless to the human body, even if they are used by incorporating them into the keyboard, they will not cause environmental problems thereafter.

Since a high specific gravity equal to or higher than that of lead (specific gravity 11.34) can be obtained, the balance weight is positioned closer to the rotation center when balancing the moments around the rotation center. Can be provided. Therefore, the moment of inertia around the center of rotation can be reduced, and the touch feeling of the keyboard can be improved. Also, the number of embedded balance weights can be reduced compared to the case of lead,
It is possible to reduce the number of parts and the manufacturing cost.

According to the second aspect of the invention, the balance weight can be fixed to the keyboard by a simple operation of press-fitting it into the burial hole. Moreover, since the keyboard is usually made of wood, it can be easily pressed in with a smaller force than metal. Further, because of the wooden material, a large deformation allowance can be secured when the embedding hole is press-fitted, so that the balance weight can be reliably fixed with a large elastic deformation force.

According to the third aspect of the present invention, since the embedding hole and the balance weight are formed in a tapered shape, they can be easily fitted together, and the tapered surfaces can be securely joined together. can do.

In the invention described in claims 4 to 8, W
Since it is a sintered alloy mainly composed of
A balance weight with a high specific gravity of -18 can be obtained. Therefore, it is advantageous in reducing the moment of inertia around the center of rotation.

In the inventions of claims 9 and 10, since the balance weight is formed of a W-based composite material using a resin as a binder, for example, ordinary press molding by a cold die or hot metal is used. Injection molding method (M
IM) makes it possible to manufacture a constant weight and a constant size balance weight in large quantities and at low cost. Moreover, since it is possible to obtain a balance weight having a high specific gravity of 11 to 15 which is equal to or higher than that of lead, it is possible to reduce the moment of inertia around the center of rotation and the number of balance weights. Also, by selecting a resin having plasticity, the balance weight can be easily crimped. Therefore, the balance weight can be easily fixed to the keyboard by caulking, as in the case where the balance weight is made of lead.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) First, a first embodiment of the present invention will be described with reference to FIG.
The description will be made with reference to FIG. In FIG. 1, reference numeral 1 denotes a wooden keyboard. The keyboard 1 extends in the front-rear direction and has a shape in which a portion rearward from the substantially central portion in the longitudinal direction is bent horizontally at a predetermined angle. Has become. The keyboard 1 has a black key (not shown) on one side surface.
Is the white key that will be placed.

A front support member 2, a balance rail 3 and a pillow member 4 are provided below the front end portion, the central portion (intermediate portion) and the rear end portion of the keyboard 1. Front pins 21 are provided upright on the front support member 2 at positions corresponding to adjacent keyboards 1. The front pin 21 is fitted in a lower guide hole (not shown) formed in the keyboard 1 to guide the front end of the keyboard 1 in the vertical direction. Also, the front pin 21 has
The front punching felt 22 is fitted to the root part thereof. The front punching felt 22 serves as a stopper that restricts the front end of the keyboard 1 from moving downward.

On the balance rail 3, adjacent keyboards 1 are provided.
The balance pin 3 at the position corresponding to the center of the longitudinal direction of the
1 is erected. The balance pin 31 is fitted in a guide hole 1a that vertically penetrates the keyboard 1 to guide the keyboard 1 to swing vertically. A balance punching felt 32 is fitted to the base of the balance pin 31. The balance punching felt 32 serves as a fulcrum portion that supports the central portion of the keyboard 1 so as to be vertically swingable. That is, keyboard 1
Is swingably supported by the balance punching felt 32 with its central portion serving as the center of rotation.

The pillow member 4 is formed of a belt-shaped felt and serves as a stopper that determines the amount of upward movement of the front end of the keyboard 1.

An action (not shown) is provided on the keyboard 1 behind the center of its rotation. This action is activated when the front end of the keyboard 1 is swung downward, and a hammer (not shown) is swung to strike a string to generate a piano sound.

The touching force of the keyboard 1 is determined by the balance of the moments around the center of rotation, but since the action is provided at the rear of the keyboard 1, the touching force is forward of the center of rotation. By embedding the balance weight 5, the touch force is alleviated. In addition, the horizontal angle of the keyboard 1 varies depending on the pitch of the sound, and the weight of the hammer described above varies. Therefore, in order to make the touch force uniform, the balance weight of each keyboard 1 is different. Adjustment by 5 is required.

Further, the balance weight 5 is formed in a cylindrical shape by a cylindrical W-based sintered alloy (W-based high specific gravity material), and one end portion in the axial direction thereof has a predetermined angle. A chamfer C that is inclined is provided. And
This balance weight 5 is, as shown in FIG. 2, a keyboard 1
By being press-fitted into the buried hole 1d that vertically penetrates the left and right side surfaces 1b, 1c, the side wall 1b is fixed in the buried hole 1d. The balance weight 5 is formed so that its axial length is slightly shorter than the axial length of the embedding hole 1d, and its ends do not project outward from the side faces 1b, 1c.

Then, W forming the balance weight 5
The base sintered alloy contains Ni: 3 to 25 as a binder phase forming component.
% By weight and Cu: 1 to 20% by weight, with the balance being W as a dispersed phase forming component and unavoidable impurities.

The W-based sintered alloy contains Ni: 3 to 25% by weight, Cu: 1 to 20% by weight, and Fe: 1 to 20% by weight as a binder phase forming component, and the balance is dispersed. It may have a composition comprising W as a phase forming component and unavoidable impurities.

Further, the above W-based sintered alloy contains Ni: 3 to 25% by weight, Cu: 1 to 20% by weight, Fe: 1 to 20% by weight and Co: 0.5 to 10 as a binder phase forming component.
W as a dispersed phase forming component
It may have a composition consisting of unavoidable impurities.

Further, the above W-based sintered alloy contains Ni: 3 to 25 wt% and Fe: as binder phase forming components.
The composition may contain 1 to 20% by weight, and the balance is W as a dispersed phase forming component and unavoidable impurities.

The balance weight 5 may be formed of a resin / W composite material (W-based composite material) including powdered W and a resin as a binder of the W. . In this case, the resin / W composite material preferably has a composition containing the above resin: 2 to 5% by weight, and the balance being the above tungsten and unavoidable impurities.

In order to manufacture the balance weight 5 made of each W-based sintered alloy, for example, first, as raw material powder,
W, Ni having a predetermined average particle diameter within the range of 1 to 5 μm,
Prepare Fe, Co, Cu powders according to the above-mentioned components, mix them in a ball mill for 24 hours, and then 1-5 ton / cm ²
The green compact is molded under the pressure of 1, and then the obtained green compact is subjected to liquid phase sintering in a hydrogen atmosphere at a predetermined temperature within a range of 1200 to 1500 ° C.

In order to manufacture the balance weight 5 made of the composite material of resin and W, W having a predetermined average particle diameter within the range of 1 to 5 μm and, for example, acrylic (PBM) are used.
A) type resin, polyethylene type resin, paraffin type resin,
And a material obtained by kneading with a thermoplastic resin such as a phthalic acid solvent are molded by using an injection molding machine, or by kneading the above W with a thermosetting resin such as a phenol resin or an epoxy resin. The obtained material will be molded using a compression molding machine.

In the keyboard device constructed as described above, the balance weight 5 can be made to have a specific gravity of 11 to 18 by forming the balance weight 5 with a W-based sintered alloy. Therefore, it is possible to obtain the balance weight 5 having a high specific gravity equal to or higher than that of lead (specific gravity: 11.34). Moreover, since W and the like are harmless to the human body, even if they are used by incorporating them into the keyboard, they will not cause environmental problems thereafter.

Further, since the one having a higher specific gravity than that using lead can be obtained, the balance weight 5 can be provided at a position closer to the center of rotation when balancing the moment around the center of rotation. . Therefore, the moment of inertia around the center of rotation can be reduced, and the touch feeling of the keyboard 1 can be improved. Further, the number of embedded balance weights 5 can be reduced as compared with the case of lead, so that the number of parts and the manufacturing cost can be reduced.

Then, the balance weight 5 can be fixed to the keyboard 1 by a simple operation of press-fitting it into the embedding hole 1d. Moreover, since the keyboard 1 is made of wood, it can be easily pressed in with a small force. Further, since the keyboard 1 is made of wood, a large deformation allowance can be secured when the embedding hole 1d is press-fitted, so that the balance weight 5 can be reliably fixed to the embedding hole 1d.

Further, since the balance weight 5 has a chamfer C formed on the outer periphery of one end thereof, the positioning to the buried hole 1d is facilitated and the press-fitting resistance to the buried hole 1d is reduced. You can

On the other hand, when the balance weight 5 is made of a resin / W composite material, a large amount of the balance weight 5 having a constant weight and a constant size can be manufactured at low cost by injection molding or compression molding. be able to.
Moreover, since it is possible to obtain the balance weight 5 having a high specific gravity of about 11 to 15 which is equal to or higher than that of lead, as in the case of using the W-based sintered alloy, reduction of the moment of inertia around the center of rotation, The number of balance weights 5 can be reduced.

By selecting a resin having plasticity as the resin, the balance weight 5 can be easily crimped. Therefore, the balance weight 5 can be easily fixed to the keyboard 1 by caulking, as in the case of the balance weight 5 made of lead.

In the above embodiment, the balance weight 5 having the chamfer C at the corner on the one end side in the axial direction is shown. The balance weight 5 is shown in FIGS. 3 (a) to 3 (c). It may have a cylindrical shape as shown. That is, in the balance weight 5 shown in (a), chamfers C are formed at the corners at both ends in the axial direction, and even when the balance weight 5 is press-fitted into the embedding hole 1d from any direction in the axial direction, the position relative to the embedding hole 1d. Matching is easy.
In the balance weight 5 shown in (b), a chamfer R rounded in an arc shape is formed at a corner on one end side in the axial direction,
The chamfer R facilitates the alignment with the embedding hole 1d, and the chamfer C has an embedding hole 1d more than the case of the chamfer
It is designed to reduce the resistance to press-fitting. In the balance weight 5 shown in (c), chamfers R are formed at the corners at both ends in the axial direction, and even when the balance weight 5 is press-fitted into the embedding hole 1d from any direction in the axial direction, the alignment with respect to the embedding hole 1d is made. It is easy and the press-fitting resistance is reduced.

Further, as shown in FIG. 4, both the buried hole 1d and the balance weight 5 are formed in a tapered shape with an angle T of 1 to 5 degrees, and the tapered surfaces are fitted to each other, that is, a tapered cylinder. The balance weight 5 may be fixed to the embedding hole 1d by fitting the surfaces together. In this case, the balance weight 5 can be easily inserted into the embedding hole 1d, and only by pushing with a predetermined force,
The balance weight 5 can be easily and firmly fixed to the embedding hole 1d.

Next, a second embodiment of the present invention will be described with reference to FIG. Note that elements common to the constituent elements shown in the first embodiment are given the same reference numerals, and explanations thereof are omitted. The keyboard 1 shown in this embodiment is a white key provided at a position sandwiched between black keys. Further, the buried hole 1d and the balance weight 5 are arranged behind the center of rotation.

Further, the keyboard 1 is configured such that a pivotal joint portion 1e provided at a central portion of the keyboard 1 can freely set a horizontal angle θ of a rear portion from the central portion.

The keyboard device constructed as described above also has the same effects as the first embodiment. In addition, since the part behind the central part is bendable,
The angle θ can be easily changed according to the pitch or the like.

In the first and second embodiments described above, the example in which the embedding hole 1d and the balance weight 5 are provided in the keyboard 1 as a white key is shown, but the embedding hole in the keyboard as a black key and A balance weight may be provided. Further, the central portion in the longitudinal direction of the keyboard 1 is a rotation center portion supported by the balance punching felt 32. This rotation center portion is an intermediate portion in the longitudinal direction, that is, any direction in the longitudinal direction. It may be provided at a position deviated from.

[0049]

EXAMPLES Examples of the present invention will now be described with reference to Tables 1 and 2. Table 1 shows the measurement results of the component ratios and specific gravities of the W-based sintered alloys. Table 2 shows the measurement results of the ratio of each component and the specific gravity of the resin / W composite material.

[Table 1]

[0050]

[Table 2]

It can be seen from Table 1 above that the balance weight 5 formed of the W-based sintered alloy can have a specific gravity equivalent to that of lead and a specific gravity much higher than that of lead. Further, from Table 2, the balance weight 5 formed of the composite material of resin and W does not reach the maximum specific gravity of the W-based sintered alloy, but has a high specific gravity equal to or higher than that of the one using lead. You can see that you can get things.

[0052]

As described above, according to the invention described in claims 1 to 10, the balance weight made of the W-based high-specific-gravity material is buried in the front or rear position of the center of rotation of the keyboard. It is possible to adjust the balance of the moment around the center of rotation. Since the W-based high specific gravity material is a material containing W as a main metal,
High specific gravity of 18 or 11 to 15 can be obtained. Moreover, since W and the like are harmless to the human body, even if they are used by incorporating them into the keyboard, they will not cause environmental problems thereafter.

Further, since a high specific gravity equal to or higher than that of lead can be obtained, the balance weight can be provided at a position closer to the rotation center when balancing the moments around the rotation center. Therefore, the moment of inertia around the center of rotation can be reduced, and the touch feeling of the keyboard can be improved. Further, the number of embedded balance weights can be reduced as compared with the case of using lead, so that the number of parts and the manufacturing cost can be reduced.

According to the second aspect of the present invention, the balance weight can be fixed to the keyboard by a simple operation of press-fitting it into the buried hole. Moreover, since the keyboard is usually made of wood, it can be easily pressed in with a smaller force than metal. Further, since the keyboard is made of wood, the deformation allowance of the buried hole can be made large, so that the balance weight can be reliably fixed by a large elastic deformation force.

According to the third aspect of the invention, since the embedding hole and the balance weight are formed in a tapered shape,
These can be fitted easily, and can be surely connected by fitting the tapered surfaces.

According to the invention described in claims 4 to 8, since it is a sintered alloy containing W as a main component, 11 to 11 which is equal to or more than lead is used.
It is possible to obtain 18 high specific gravity balance weights.
Therefore, it is advantageous in reducing the moment of inertia around the center of rotation.

According to the ninth and tenth aspects of the present invention, the balance weight is formed of a W-based composite material containing a resin as a binder, and therefore, for example, by injection molding, a constant weight and a constant size are obtained. The balance weight can be mass-produced at low cost. Moreover, since it is possible to obtain a balance weight having a high specific gravity of 11 to 15 which is equal to or higher than that of lead, it is possible to reduce the moment of inertia around the center of rotation and the number of balance weights. Also, by selecting a resin having plasticity, the balance weight can be easily crimped. Therefore, the balance weight can be easily fixed to the keyboard by caulking, as in the case where the balance weight is made of lead.

[Brief description of drawings]

FIG. 1 is a perspective view of a keyboard device shown as a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a keyboard in the keyboard device.

3A and 3B are views showing another example of the balance weight in the keyboard device, wherein FIG. 3A is a front view showing a first balance weight, and FIG. 3B is a front view showing a second balance weight. (C) is a front view showing a third balance weight.

FIG. 4 is a cross-sectional view showing an example in which a balance weight and a buried hole are formed in a tapered shape in the keyboard device.

FIG. 5 is a perspective view of a keyboard device shown as a second embodiment of the present invention.

[Explanation of symbols]

1 keyboard 1d buried hole 5 Balance weight

Claims (10)

[Claims] 1. A keyboard that swings up and down with an intermediate portion as a center of rotation, and a balance weight made of a tungsten-based high specific gravity material embedded at a position in front of or behind the center of rotation of the keyboard. A keyboard device characterized by being provided. 2. The keyboard device according to claim 1, wherein the balance weight is fixed by press fitting into an embedded hole formed in the keyboard. 3. The balance weight is formed in a taper shape, and is fixed to a taper-shaped embedded hole formed on the side surface of the keyboard by fitting the tapers together. The keyboard device according to claim 1. 4. The balance weight has a specific gravity of 11.
The keyboard device according to any one of claims 1 to 3, wherein the keyboard device is formed of a tungsten-based sintered alloy of 0 to 18.0. 5. The balance weight comprises Ni: 3 to 25% by weight and Cu: 1 to 20 as a binder phase forming component.
5. The keyboard device according to claim 4, wherein the keyboard device is made of a tungsten-based sintered alloy having a composition of wt% and the balance of tungsten as a dispersed phase forming component and inevitable impurities. . 6. The balance weight contains Ni: 3 to 25% by weight, Cu: 1 to 20% by weight and Fe: 1 to 20% by weight as a binder phase forming component, and the balance is a dispersed phase forming component. The keyboard device according to claim 4, wherein the keyboard device is formed of a tungsten-based sintered alloy having a composition of tungsten and unavoidable impurities. 7. The balance weight comprises Ni: 3 to 25% by weight, Cu: 1 to 20% by weight, Fe: 1 to 20% by weight and Co: 0.5 to 10% by weight as a binder phase forming component. 5. The keyboard device according to claim 4, wherein the keyboard device is formed of a tungsten-based sintered alloy having a composition of tungsten and unavoidable impurities as a dispersed phase forming component, the balance being contained. 8. The balance weight comprises Ni: 3 to 25% by weight and Fe: 1 to 20 as binder phase forming components.
5. The keyboard device according to claim 4, wherein the keyboard device is made of a tungsten-based sintered alloy having a composition of wt% and the balance of tungsten as a dispersed phase forming component and inevitable impurities. . 9. The balance weight is formed of a composite material having a specific gravity of 11 to 15 including powdery tungsten and a resin as a binder of the tungsten. The keyboard device according to any one of 1. 10. The balance weight comprises the resin:
The keyboard device according to claim 9, wherein the keyboard device contains 2 to 5% by weight, and the balance is formed of a composite material including the tungsten and unavoidable impurities.