Key weights for keyboard instruments, keys to which the key weights are attached, and methods for attaching the key weights.

Abstract

The present invention provides a keyboard weight that can be easily manufactured using an alternative material to lead, and can also be easily attached to the keys. [Solution] The keyboard weight 1 comprises a cylindrical weight body 2 made of a material other than lead and having a predetermined diameter and length, and a hollow member 3 made of a material other than lead and having an inner diameter into which the weight body 2 can be inserted, an outer diameter into which it can be inserted into the embedded hole 11a, and a predetermined length, which is inserted into the embedded hole 11a with the weight body 2 inserted inside when attached to the key 10. The hollow member 3 is provided with a thin-walled portion 4 that extends along the entire circumference and has a predetermined width in the longitudinal direction, and is thinner than the thickness of other parts of the hollow member 3. The hollow member 3 is configured such that when the keyboard weight 1 is attached to the key 10, the hollow member 3 is pressed from both sides in the longitudinal direction, causing buckling to occur starting from the thin-walled portion 4.

Description

Technical Field

[0001] The present invention is applied to a keyboard device of a keyboard instrument such as an acoustic piano, and relates to a keyboard hammer attached to a key to obtain a desired touch weight when pressing the key, a key to which the keyboard hammer is attached, and a method for attaching the keyboard hammer.

Background Art

[0002] Conventionally, in an acoustic piano such as a grand piano, generally, a hammer is attached to a key in order to obtain a desired touch weight when pressing the key. As such a keyboard hammer (hereinafter, appropriately referred to as "keyboard hammer"), lead is used from the viewpoints of high specific gravity, low cost, and ease of processing. A buried hole penetrating in the left-right direction is provided at a predetermined position in the front portion of the key extending in the front-rear direction, and the keyboard hammer is inserted into the buried hole and caulked by pressing from the left and right using a caulking machine, whereby the keyboard hammer is attached to the key.

[0003] Since lead used as the above-described keyboard hammer is a harmful substance, it is desirable not to use it as much as possible as a keyboard hammer. The present applicant has proposed various keyboard hammers made of alternative materials to lead, and for example, those described in Patent Document 1 are known.

[0004] The keyboard hammer described in Patent Document 1 includes a columnar hammer and a cylindrical member into which the hammer can be inserted. The hammer is made of a relatively heavy material other than lead, such as iron, copper, brass, an alloy, or a composite material of a metal and a synthetic resin. On the other hand, the cylindrical member is a thin-walled cylindrical member with both ends open, and has an outer diameter slightly smaller than the diameter of the buried hole formed in the key. Further, the cylindrical member is made of a relatively easily deformable material other than lead, such as a metal such as aluminum, plastic, or an elastic material such as rubber. Furthermore, a slit extending over the entire length direction is formed in the cylindrical member.

[0005] When installing the keyboard weight configured as described above into the key's recessed hole, first, a cylindrical member is inserted into the recessed hole. Next, with the tip of the weight inserted into the cylindrical member, the weight is hammered in to press it into the cylindrical member. As a result, the cylindrical member is pushed outward radially by the pressed-in weight and pressed against the wall of the recessed hole. Consequently, the weight is securely fixed to the key via the cylindrical member. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2003-122344 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] When attaching the conventional keyboard weights described above to keys, the tip of the weight is inserted into a cylindrical member that is embedded in the key's recessed hole, and then the weight is hammered into place. This causes the entire outer surface of the cylindrical member to expand radially outward. In this case, if the weight is hammered in with a relatively large force all at once, the rapid radial expansion of the cylindrical member may cause cracks around the key's recessed hole. On the other hand, while it is possible to suppress the occurrence of such cracks by hammering in the weight little by little with a relatively small force, this takes time to attach the weight to the key, reducing the manufacturing efficiency of the keys.

[0008] The present invention was made to solve the above-mentioned problems, and aims to provide a keyboard weight that can be easily manufactured using an alternative material to lead, and that can also be easily attached to a key, a key to which the keyboard weight is attached, and a method for attaching the keyboard weight. [Means for solving the problem]

[0009] To achieve the above objective, the invention according to claim 1 is a keyboard weight that is fixedly attached in a state where it is inserted into a through-hole having a predetermined diameter formed in the key of a keyboard instrument, comprising: a weight body made of a material other than lead and formed in the shape of a cylinder having a predetermined diameter and length; and a hollow member made of a material other than lead and formed in the shape of a cylinder having an inner diameter into which the weight body can be inserted, an outer diameter into which it can be inserted into the hole, and a predetermined length longer than the weight body, and which is inserted into the hole with the weight body inserted inside when attached to the key, wherein the hollow member is provided with a thin-walled portion that extends along the entire circumferential direction and has a predetermined width in the longitudinal direction and has a predetermined thickness that is thinner than the thickness of other parts of the hollow member, and the hollow member is configured such that buckling occurs starting from the thin-walled portion when the hollow member is pressed from both sides in the longitudinal direction when the keyboard weight is attached to the key.

[0010] In this configuration, the keyboard weight, which is installed in the key's recessed hole, comprises a cylindrical weight body made of a material other than lead and a cylindrical hollow member. The hollow member also has a thin-walled section that extends along its entire circumference, has a predetermined width in the longitudinal direction, and has a predetermined thickness that is thinner than other parts. When this keyboard weight is installed in the key's recessed hole, the hollow member is pressed from both sides in the longitudinal direction, causing buckling to occur in the hollow member, starting from the thin-walled section. As a result, the surrounding portion of the hollow member, including the thin-walled section (hereinafter referred to as the "deformed portion" in this section), deforms radially inward and radially outward. Therefore, the deformed portion that deforms radially outward bites into or strongly presses against the wall surface of the key's recessed hole, while the deformed portion that deforms radially inward bites into or strongly presses against the outer surface of the weight body. As a result, the keyboard weight is securely installed in the key's recessed hole.

[0011] Since the weight body of the above-mentioned keyboard weight is formed in a cylindrical shape, the weight body can be easily obtained by, for example, cutting a long round bar having the same diameter as the weight body to the same length as the weight body. Also, since the hollow member of the above-mentioned keyboard weight is formed in a cylindrical shape, the hollow member can be easily obtained by, for example, cutting a long cylindrical tube having the same outer diameter and thickness as the hollow member to the same length as the hollow member, and providing a thin-walled section on each of them. Furthermore, as described above, when attaching the above-mentioned keyboard weight to a key, the keyboard weight inserted into the embedded hole of the key is pressed from both sides in the longitudinal direction, so the keyboard weight can be attached using a conventional crimping machine. As described above, according to the present invention, a keyboard weight can be easily manufactured using an alternative material to lead, and a keyboard weight can be easily attached to a key.

[0012] The invention according to claim 2 is characterized in that, in the keyboard weight described in claim 1, the thin-walled portion is formed by providing a groove located in the center of the length of the hollow member and opening radially outward.

[0013] With this configuration, the thin-walled portion can be easily formed on a cylindrical member that does not have the thin-walled portion described above by cutting or other means to create a groove that opens radially outward at the center of the longitudinal direction of its outer surface.

[0014] The invention according to claim 3 is a keyboard weight as described in claim 2, characterized in that both ends of the hollow member into which the weight body is inserted are provided with locking portions that are formed to protrude radially inward, for immovably locking the weight body in the longitudinal direction of the hollow member.

[0015] With this configuration, the weight body is immovably locked in the length direction of the hollow member by the locking parts provided at both ends of the hollow member into which the weight body is inserted. Therefore, when the keyboard weight is inserted into the embedded hole of the key and attached by pressing from both sides in the length direction of the hollow member, the position of the weight body does not shift in the length direction of the hollow member, and it can be attached stably.

[0016] The invention according to claim 4 comprises a key body made of wood, extending in the front-to-back direction and configured to swing freely, with a recessed hole formed at a predetermined position in the front-to-back direction that penetrates in the left-to-right direction, and a keyboard weight that is attached by being pressed from both the left and right sides of the key body while inserted into the recessed hole of the key body, wherein the keyboard weight is made of the keyboard weight described in any one of claims 1 to 3.

[0017] According to this configuration, the keyboard weight described in any of claims 1 to 3 is attached to the key by being pressed from both the left and right sides of the key body while inserted into the embedded hole in the key body, thereby obtaining a key with a keyboard weight attached that has the functions and effects of claims 1 to 3 described above.

[0018] The invention according to claim 5 is characterized by comprising: a weight component preparation step of preparing the weight body and hollow member described in claim 1; a key preparation step of preparing a key having a recessed hole as described in claim 1; a key weight manufacturing step of manufacturing a key weight by inserting the weight body into the hollow member; a key weight insertion step of inserting the manufactured key weight into the recessed hole of the key; and a key weight installation step of fixing the key weight in the recessed hole of the key by pressing the key weight from both sides in its longitudinal direction to cause buckling starting from the thin-walled portion.

[0019] According to this configuration, first, the weight body and hollow member described in claim 1, and the key with the embedded hole described in claim 1 are prepared (weight component preparation step and key preparation step). Next, the key weight is made by inserting the weight body into the hollow member (keyboard weight making step), and the made key weight is inserted into the embedded hole of the key (keyboard weight insertion step). Then, the key weight is fixed in place in the embedded hole of the key by pressing it from both sides in its longitudinal direction, thereby causing buckling starting from the thin-walled portion of the hollow member (keyboard weight installation step). As described above, by causing buckling starting from the thin-walled portion of the hollow member, the deformed portion bites into or strongly presses against the wall surface of the embedded hole of the key, as well as bites into or strongly presses against the outer surface of the weight body. As a result, the key weight is firmly attached to the embedded hole of the key. As described above, according to the present invention, a keyboard weight made of an alternative material to lead can be easily and securely attached to the embedded hole of the key.

[0020] The invention according to claim 6 is a method for attaching a keyboard weight as described in claim 5, characterized in that, in the keyboard weight manufacturing step, with the weight body inserted into the hollow member, both ends of the hollow member are pressed from both sides to deform them so as to protrude radially inward, thereby forming a locking portion for immovably locking the weight body in the longitudinal direction of the hollow member.

[0021] According to this configuration, in the process of manufacturing the keyboard weight, the locking portion is formed by pressing both ends of the hollow member from both sides while the weight body is inserted into the hollow member. This makes it possible to relatively easily form a locking portion for immovably locking the weight body inserted into the hollow member in the longitudinal direction of the hollow member. Furthermore, when attaching the keyboard weight having the above-mentioned locking portion by pressing from both sides in the longitudinal direction of the hollow member while it is inserted into the embedded hole of the key, the position of the weight body can be stably attached without shifting in the longitudinal direction of the hollow member. [Brief explanation of the drawing]

[0022] [Figure 1]FIG. 0 is a diagram for explaining the key hammer according to the first embodiment of the present invention, (a) is a perspective view showing the appearance of the key hammer, (b) is a cross-sectional view of the key hammer cut along the longitudinal direction, and (c) is a perspective view showing a state in which the hammer body and the hollow member constituting the key hammer are separated. [Figure 2] FIG. 3 is a perspective view showing the appearance of the key with the key hammer shown in FIG. 1(a) attached. [Figure 3] FIG. 6 is a diagram for explaining a method of attaching the key hammer to the key, and is an explanatory diagram of the hammer part preparation process and the key preparation process. [Figure 4] FIG. 9 is a diagram following FIG. 3 and is an explanatory diagram of the key hammer manufacturing process. [Figure 5] FIG. 12 is a diagram following FIG. 4 and is an explanatory diagram of the key hammer insertion process and the key hammer attachment process, (a) is a perspective view showing the key hammer inserted into the embedding hole and its surroundings, and (b) is a cross-sectional view of the key hammer cut along the longitudinal direction. [Figure 6] FIG. 15 is a diagram following FIG. 5 and is a diagram of a state in which the key hammer is attached to the key, (a) is a perspective view showing the key hammer and its surroundings, and (b) is a cross-sectional view of the key hammer cut along the longitudinal direction. [Figure 7] FIG. 18 is a diagram for explaining the key hammer according to the second embodiment of the present invention, (a) is a perspective view showing the appearance of the key hammer, and (b) is a cross-sectional view of the key hammer cut along the longitudinal direction. [Figure 8] FIG. 21 is an explanatory diagram for explaining a method of manufacturing the key hammer of the second embodiment shown in FIG. 7(a). [Figure 9] FIG. 24 is a diagram for explaining a method of attaching the key hammer according to the second embodiment, and is an explanatory diagram of the hammer part preparation process and the key preparation process. [Figure 10] FIG. 27 is a diagram following FIG. 9 and is an explanatory diagram of the key hammer manufacturing process, (a) is a perspective view showing a state in which the hammer body is inserted into the hollow member, and (b) is a perspective view showing a state in which a plurality of locking portions are formed at both ends of the hollow member. [Figure 11] FIG. 30 is a diagram following FIG. 10 and is an explanatory diagram of the key hammer insertion process and the key hammer attachment process. [Figure 12]This figure follows Figure 11 and shows the keyboard weights attached to the keys. [Modes for carrying out the invention]

[0023] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. Figure 1 is a diagram illustrating a keyboard weight according to a first embodiment of the present invention, where (a) is an external perspective view of the keyboard weight, (b) is a cross-sectional view of the keyboard weight, and (c) is a perspective view showing the weight body and hollow member constituting the keyboard weight separated. As shown in these figures, the keyboard weight 1 is a weight attached to the keys of a keyboard device such as a grand piano, and is made of a material other than lead with a relatively high specific gravity, such as a metal such as copper or brass.

[0024] The keyboard weight 1 consists of a weight body 2 formed in the shape of a predetermined cylinder and a hollow member 3 formed in the shape of a predetermined cylinder that can house the weight body 2 inside.

[0025] Specifically, the weight body 2 is formed in a cylindrical shape having a predetermined diameter (e.g., 12 mm) and length (e.g., 10 mm).

[0026] On the other hand, the hollow member 3 has a predetermined outer diameter (e.g., 14 mm), thickness (e.g., 0.8 mm), and length (e.g., 14 mm), and is formed in a cylindrical shape that is slightly longer than the weight body 2. Furthermore, the hollow member 3 has a thin-walled portion 4 in the center of its length direction that extends throughout its entire circumference and is thinner than other parts. Specifically, it has a predetermined thickness (e.g., 0.2 mm) and width (e.g., 0.5 to 1.0 mm). This thin-walled portion 4 is formed by cutting or other means to create a groove 5 that opens radially outward from the metal cylindrical member before the thin-walled portion 4 is added.

[0027] Figure 2 shows a key (white key) 10 to which the keyboard weight 1 described above is attached. As shown in the figure, this key 10 comprises a key body 11 extending in the front-to-back direction, a white key cover 12 attached to the front of the key body 11, and a keyboard weight 1 attached to a predetermined position on the front of the key body 11.

[0028] The key body 11 is made of a relatively lightweight, tough, and elastic wood such as spruce, has a rectangular cross-section, and extends in the front-to-back direction. The white key cover 12 is formed in an L-shape from plastic such as acrylic and is glued to the front half and front of the upper surface of the key body 11 so as to cover them. A center plate 13 is glued to the center of the upper surface of the key body 11, and a balance pin hole 14 is formed so as to penetrate them vertically. The key 10 is supported so as to be able to swing freely when this balance pin hole 14 engages with a standing balance pin (not shown).

[0029] Furthermore, a capstan screw 16 is attached to the upper surface of the key body 11 at a position behind the balance pin hole 14 via a capstan base plate 15, and an action (not shown) that transmits the operation of the key 10 to the hammer that strikes the string is mounted on this capstan screw 16.

[0030] Furthermore, a recessed hole 11a is formed at a predetermined position on the front of the key body 11, extending in the left-right direction. The key weight 1 is then attached to the key body 11 by being crimped while inserted into the recessed hole 11a.

[0031] Next, with reference to Figures 3 to 6, the method for attaching the keyboard weight 1 to the key 10 will be explained. First, as shown in Figure 3, the weight body 2 and hollow member 3 described above are prepared (weight component preparation step), and the key 10 to which the keyboard weight 1 is attached is prepared (key preparation step).

[0032] Specifically, the weight body 2 is manufactured by cutting a long copper or brass rod having the same diameter (e.g., 12 mm) into pieces of the same length as the weight body 2 (e.g., 10 mm). On the other hand, the hollow member 3 is manufactured by cutting a long copper or brass cylindrical tube having the same outer diameter (e.g., 14 mm) and thickness (e.g., 0.8 mm) into pieces of the same length as the hollow member 3 (e.g., 14 mm), and forming a groove 5 (e.g., depth 0.6 mm, width 0.5 to 1.0 mm) in each of them. Furthermore, for the key 10, a buried hole 11a (e.g., diameter 14 mm) is formed at a predetermined position in the key body 11, penetrating in the left-right direction.

[0033] Next, as shown in Figure 4, the keyboard weight 1 is manufactured by inserting the weight body 2 inside the hollow member 3 (keyboard weight manufacturing process). In this case, the weight body 2 is inserted into the hollow member 3 so that its longitudinal center coincides with that of the hollow member 3. As a result, the entire weight body 2 is housed in the hollow member 3, and both ends of the hollow member 3 protrude slightly outward from the end faces of the weight body 2.

[0034] Next, the keyboard weight 1, which was prepared as described above, is inserted into the embedded hole 11a of the key 10, as shown in Figure 5(a) (keyboard weight insertion step). In this case, the keyboard weight 1 is inserted into the embedded hole 11a such that both ends of the hollow member 3 protrude outward from the embedded hole 11a by the same length.

[0035] Then, as shown in Figure 5(b), a predetermined crimping machine 20 having two opposing press parts 21, 21 is used to press the key weight 1, which has been inserted into the embedded hole 11a of the key 10, from both left and right sides with the two press parts 21, 21 (keyboard weight installation process). Specifically, both ends of the hollow member 3 of the key weight 1 are pressed from both sides. It should be noted that a conventional crimping machine used when attaching lead to the embedded hole of the key can be used as the crimping machine 20.

[0036] Figure 6 shows the state in which the keyboard weight 1 is attached to the key 10 by the above-described pressing. In the keyboard weight 1 shown in Figure 5(b) above, when both ends of the hollow member 3 are pressed, buckling occurs in the hollow member 3, starting from the thin-walled portion 4, which is more easily deformed than other parts of the hollow member 3. As a result, in the hollow member 3, the portion surrounding the thin-walled portion 4, including the thin-walled portion 4, deforms radially inward and outward, as shown in Figure 6.

[0037] Figure 6(b) shows an example of a deformed state of the hollow member 3, including the thin-walled portion 4 and the surrounding area (hereinafter referred to as "deformed portion 6"). In this figure, the deformed portion 6 deforms relatively largely outward in the radial direction, causing it to bite into the wall surface of the embedded hole 11a of the key body 11, while deforming slightly inward in the radial direction causes it to bite slightly into the weight body 2 or strongly press against the outer surface of the weight body 2. As a result, the keyboard weight 1 is firmly attached to the embedded hole 11a of the key body 11. When the keyboard weight 1 is attached to the key 10, both end faces of the hollow member 3 are almost flush with the left and right sides of the key body 11.

[0038] As described in detail above, according to this embodiment, a keyboard weight 1 can be easily manufactured using an alternative material to lead, and can also be easily attached to the key 10. Furthermore, a key 10 with such a keyboard weight 1 securely attached can be obtained.

[0039] Next, with reference to Figure 7, a second embodiment of the keyboard weight according to the present invention will be described. In the following description, components similar to those of the keyboard weight 1 of the first embodiment described above will be denoted by the same reference numerals, and their descriptions will be omitted.

[0040] The keyboard weight 1A of this embodiment differs from the keyboard weight 1 of the first embodiment described above only in that the weight body 2 inserted inside is crimped in place by both ends of the hollow member 3. That is, as shown in Figures 7(a) and (b), the keyboard weight 1A is provided with multiple locking parts 3L and 3R at both ends of the hollow member 3 to immovably lock the weight body 2 in the longitudinal direction of the hollow member 3. Specifically, one end of the hollow member 3 of the keyboard weight 1A (the left side in Figures 7(a) and (b)) is provided with four locking parts 3L arranged at equal angles to each other along the circumferential direction of the hollow member 3. The other end of the hollow member 3 of the keyboard weight 1A (the right side in Figures 7(a) and (b)) is provided with locking parts 3R similar to the locking parts 3L described above.

[0041] Each of the locking portions 3R and 3L described above is formed as a convex shape radially inward at the end of the hollow member 3. These locking portions 3R and 3L are formed by pressing the hollow member 3 from both sides with a crimping machine 30 having a cross-shaped press portion 31, as shown in Figure 8.

[0042] Next, with reference to Figures 9 to 12, the method for attaching the keyboard weight 1A to the key 10 will be explained. First, as shown in Figure 9, the weight body 2 and the hollow member 3 are prepared (weight component preparation step), similar to the method for attaching the keyboard weight 1 described above, and the key 10 to which the keyboard weight 1A is attached is prepared (key preparation step).

[0043] Next, as shown in Figure 10(a), the weight body 2 is inserted inside the hollow member 3 to create the keyboard weight 1. Then, using the crimping machine 30 shown in Figure 8, the hollow member 3 of the keyboard weight 1 is pressed from both sides to create the keyboard weight 1A shown in Figure 10(b), that is, a keyboard weight 1A having multiple locking parts 3L and 3R at both ends of the hollow member 3 (keyboard weight manufacturing process).

[0044] Next, the key weight 1A manufactured as described above is inserted into the embedded hole 11a of the key 10, as shown in Figure 11 (key weight insertion step). Then, using the crimping machine 20 described above, the key weight 1A inserted into the embedded hole 11a is pressed from both the left and right sides of the key 10 by the two press parts 21, 21 (key weight installation step).

[0045] Figure 12 is similar to Figure 6(b) described above, and shows the state in which the keyboard weight 1A is attached to the key 10 by the pressing described above. In this method of attaching the keyboard weight 1A, the pressing described above causes buckling starting from the thin-walled portion 4, similar to when the keyboard weight 1 was attached as described above, and the portion of the hollow member 3 including the thin-walled portion 4 and its surroundings (deformed portion 6) deforms radially inward and outward.

[0046] In other words, as shown in Figure 12, the deformed portion 6 of the hollow member 3 deforms relatively large radially outward, causing it to bite into the key body 11, while deforming slightly radially inward causes it to bite slightly into the weight body 2 or strongly press against the outer surface of the weight body 2. As a result, the keyboard weight 1A is firmly attached to the embedded hole 11a of the key body 11. When the keyboard weight 1A is attached to the key 10, both end faces of the hollow member 3 are almost flush with the left and right sides of the key body 11, similar to the keyboard weight 1 of the first embodiment described above.

[0047] As described above, the keyboard weight 1A of this embodiment provides the same effects as the keyboard weight 1 of the first embodiment described above. Furthermore, in the keyboard weight 1A, the weight body 2 is fixed immovably in the longitudinal direction of the hollow member 3 by a plurality of locking parts 3L, 3R provided at both ends of the hollow member 3. Therefore, when the keyboard weight 1A is inserted into the embedded hole 11a of the key 10 and attached by pressing from both sides in the longitudinal direction of the hollow member 3, the position of the weight body 2 does not shift in the longitudinal direction of the hollow member 3, and it can be attached stably.

[0048] It should be noted that the present invention is not limited to the embodiments described above and can be implemented in various forms. For example, although copper and brass were given as examples of constituent materials for the weight body 2 and hollow member 3 of the keyboard weights 1 and 1A, the present invention is not limited thereto, and other materials other than lead, such as metals other than lead with relatively high specific gravity, synthetic resins, or composite materials of such metals and synthetic resins, can also be used. For example, a synthetic resin with a relatively low elastic modulus (e.g., polypropylene) may be used as the hollow member 3, or, if a hollow member 3 made of synthetic resin is used, locking portions 3L and 3R may be provided at both ends of the hollow member 3 by applying heat and pressing it.

[0049] Furthermore, the detailed configurations of the keyboard weights 1, 1A, weight body 2, and hollow member 3 shown in the embodiment are merely illustrative examples and can be modified as appropriate within the scope of the present invention. [Explanation of symbols]

[0050] 1. Key weights 2. Weight body 3. Hollow member 3L locking part 3R Locking part 4. Thin-walled section 5 grooves 6. Deformed parts 10 keys 11 Key body 11a Buried hole 20 Crimping machine 21 Press Department 30 crimping machine 31 Press Department

Claims

1. A keyboard weight that is fixedly attached in a state where it is inserted into a through-hole having a predetermined diameter formed in the key of a keyboard instrument, A weight body made of a material other than lead, formed in a cylindrical shape having a predetermined diameter and length, A hollow member made of a material other than lead, formed in a cylindrical shape having an inner diameter into which the weight body can be inserted, an outer diameter into which it can be inserted into the buried hole, and a predetermined length longer than the weight body, which is inserted into the buried hole with the weight body inserted inside when attached to the key, Equipped with, The hollow member is provided with a thin-walled portion that extends along the entire circumferential direction and has a predetermined width in the longitudinal direction, and has a predetermined thickness that is thinner than the thickness of other parts of the hollow member. The keyboard weight is characterized in that the hollow member is configured such that buckling occurs starting from the thin-walled portion when the hollow member is pressed from both sides in the longitudinal direction during the attachment of the keyboard weight to the key.

2. The keyboard weight according to claim 1, characterized in that the thin-walled portion is formed by providing a groove located in the center of the length direction of the hollow member and opening radially outward.

3. The keyboard weight according to claim 2, characterized in that locking portions are provided at both ends of the hollow member into which the weight body is inserted, the locking portions being formed to protrude radially inward, and for immovably locking the weight body in the longitudinal direction of the hollow member.

4. The key body is made of wood, extends in the front-to-back direction and is configured to swing freely, and has an embedded hole formed at a predetermined position in the front-to-back direction that penetrates in the left-to-right direction, A keyboard weight, which is attached by being pressed from both the left and right sides of the key body while inserted into the aforementioned embedded hole of the key body, Equipped with, A key to which a key weight is attached, characterized in that the key weight is composed of a key weight according to any one of claims 1 to 3.

5. A weight component preparation step of preparing the weight body and hollow member described in claim 1, A key preparation step of preparing a key having a buried hole formed in it as described in claim 1, A keyboard weight manufacturing process involves inserting the weight body into the hollow member to produce a keyboard weight, A key weight insertion step involves inserting the manufactured key weight into the embedded hole of the key, A keyboard weight installation step involves attaching the keyboard weight to the embedded hole of the key in a fixed state by pressing the keyboard weight from both sides in the longitudinal direction thereof, thereby causing buckling starting from the thin-walled portion; A method for attaching weights to keyboard keys, characterized by having the following features.

6. The method for attaching a keyboard weight according to claim 5, characterized in that, in the keyboard weight manufacturing step, with the weight body inserted into the hollow member, both ends of the hollow member are pressed from both sides to deform them so that they protrude radially inward, thereby forming a locking portion for immovably locking the weight body in the longitudinal direction of the hollow member.

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