JP2023148694A - Key of keyboard device - Google Patents

Abstract

To provide a key of a keyboard device, which can rigidly hold a weight part stored inside a key body, and can suppress manufacture cost by simplifying a mold for molding.SOLUTION: A key of a keyboard device includes: a resin key body 51 which has at least an upper face part and a pair of side face parts, is formed in a hollow shape in which a lower part is opened, and extends in a cross direction by a prescribed length; and a weight part 54 which is formed of an elastically deformable material and is stored in a prescribed position inside the hollow shape of the key body 51. The key body 51 includes one or a plurality of groove parts 53 extending along the cross direction on each inner face of a pair of side face parts. The weight part 54 includes one or a plurality of engaged protrusions 55 which are formed in positions facing the one or the plurality of groove parts 53 in the prescribed positions, and hold the weight part 54 inside the key body 51 by engaging with the one or the plurality of groove parts 53.SELECTED DRAWING: Figure 11

Description

The present invention relates to a key for a keyboard device applied to a keyboard instrument such as an electronic piano, and particularly to a key for a keyboard device in which a weight component is attached inside the key.

Conventionally, keys for keyboard devices are known in which a weight is attached to a hollow interior of the key in order to adjust the touch feeling of the key. For example, in Patent Document 1, the key body has a hole that opens downward, and inside this hole, a protruding fall-off prevention part and a slippage prevention part are provided, and an elastically deformable weight part is provided therein. A key for a keyboard instrument is disclosed that prevents the weight from falling off and prevents vertical wobbling by pushing the key.

Japanese Patent Application Publication No. 2017-44989

In the key of the keyboard instrument of Patent Document 1, a plurality of protruding drop-off prevention parts and slippage prevention parts are provided in order to hold the weight inside the hole of the key body. Therefore, there is a problem that the structure of the mold used for molding becomes complicated and the cost increases.

Furthermore, keys for keyboard devices have been known in which a wooden material is attached to the side surface of a key body made of resin in order to impart a wooden texture to the key at low cost. Normally, such keys have a structure in which the top surface of the key body protrudes laterally beyond the side surfaces so as to cover the top surface of the wooden board so that the top surface of the wood material is not exposed to the outside. When the key body is shaped like this, there is a problem that the cooling rate of the upper surface part becomes uneven during molding, resulting in uneven shrinkage of the resin material, which tends to cause molding defects called so-called sink marks on the upper surface part. There is.

The present invention has been made in order to solve the above-mentioned problems, and is capable of firmly holding the weight part housed inside the key body, and simplifying the mold for molding. The purpose is to provide a key for a keyboard device that can reduce manufacturing costs. Another object of the present invention is to provide a key for a keyboard device that can prevent sink marks from occurring on the top surface during molding of the key body.

To achieve the above object, the key of the keyboard device according to claim 1 has at least an upper surface portion and a pair of side surface portions, is formed in a hollow shape with an open bottom, and extends a predetermined length in the front-rear direction. The key body includes a key body made of resin, and a weight part formed of an elastically deformable material and housed in a predetermined position inside a hollow part of the key body, and the key body has an inner surface of each of a pair of side parts. has one or more grooves extending along the front-rear direction, and the weight is formed at a position facing the one or more grooves at a predetermined position, and the weight can be adjusted by engaging with the one or more grooves. The key body is characterized by having one or more engaging protrusions that hold the key body inside the key body.

According to this configuration, one or more grooves extending in the front-rear direction are formed on the inner surface of the side surface of the hollow key body whose bottom is open, and the weight part is formed on the inner surface of the side surface of the hollow key body. Since it has one or more engaging protrusions formed at a position facing one or more grooves at a predetermined position inside the key body, when the weight part is housed in a predetermined position inside the key body, the engaging protrusions do not fit into the groove. By engaging with the key body, the weight portion can be firmly held inside the key body.

In addition, since the key body can hold the weight part only by one or more grooves provided on the inner surface of the side part, there is no need to provide multiple protruding drop-off prevention parts, etc., and it is easy to mold. The mold can be simplified and manufacturing costs can be reduced.

The invention according to claim 2 is the key for the keyboard device according to claim 1, in which the one or more grooves are formed at the top of the pair of side parts, and the thickness of the top part of the pair of side parts of the key body is The key body is characterized in that the thickness is smaller than the thickness of the upper surface of the key body.

According to this configuration, one or more grooves are formed at the top of the inner surface of the pair of side surfaces of the key body, and the thickness of the side surface at the top where the grooves are formed is the same as that of the key body. It is formed to be thinner than the thickness of the upper surface portion. As a result, even if, for example, a wooden board is attached to the side surface of the key body and the left and right ends of the top surface protrude laterally to cover the top end surface of the wooden board, the top surface The difference in wall thickness between the connecting part of the side surface and the other part of the top surface becomes very small, making it difficult for a difference in cooling rate to occur during molding, thus preventing the occurrence of sink marks on the top surface. can do.

In the invention according to claim 3, in the key for the keyboard device according to claim 1 or 2, the vertical length dimension of the engagement convex part of the weight part is the vertical length dimension of the one or more groove parts. It is characterized by being formed to be smaller than.

According to this configuration, the length in the vertical direction of the groove provided on the inner surface of the side surface of the key body is larger than the length in the vertical direction of the engagement protrusion provided in the weight. When the weight part is glued to the inside of the key body using the adhesive, the adhesive accumulates in the gap created in the groove where the engagement convex part engages, making it possible to more firmly adhere the weight part to the inside of the key body. . The gap also functions as a space for excess adhesive to escape.

1 is a perspective view showing a part (for one octave) of a keyboard device of an electronic piano to which the present invention is applied, in which (a) shows the external appearance of the keyboard device, and (b) shows keys other than the leftmost white keys and black keys. Indicates the state where is omitted. FIG. 2 is a perspective view showing the keyboard device shown in FIG. 1(b) in which the white keys and black keys are removed from the keyboard chassis together with their respective key support mechanisms. 1(a) is a plan view of the keyboard device shown in FIG. 1(b), and FIG. 1(b) is a sectional view taken along line AA. FIG. 3 is a perspective view showing a white key and a key support mechanism, in which (a) shows a state in which the white key and the key support mechanism are connected, and (b) shows a state in which the white key and the key support mechanism are disassembled. FIG. 3 is a perspective view showing a black key and a key support mechanism, in which (a) shows a state in which the black key and the key support mechanism are connected, and (b) shows a state in which the black key and the key support mechanism are disassembled. FIG. 4 is a diagram for explaining the operation of a white key in a keyboard device, in which (a) shows a key-released state and (b) shows a key-pressed state. FIG. 3 is a diagram for explaining the operation of a black key in a keyboard device, in which (a) shows a key-released state, and (b) shows a key-pressed state. (a) is a side view showing the key body of a white key, and (b) is a bottom view showing the key body. 8(a) is a sectional view taken along line BB in FIG. 8(a), and FIG. 8(b) is a sectional view showing a white key according to a modified example. (a) is a perspective view showing a weight part, and (b) is a perspective view showing a weight part according to a modification. (a) is a cross-sectional view showing the key body in a state in which a weight part is accommodated, and (b) is a perspective view showing the key body in a state in which a weight part according to a modification is accommodated.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1A shows only one octave of a keyboard device 1 for an electronic piano to which the present invention is applied. In the following description, the basic configuration and operation of the keyboard device 1 will be explained first, and then the main parts of the present invention will be explained.

FIG. 1(b) shows a state in which keys 2 other than the white key 2a and black key 2b at the left end are omitted in the keyboard device 1 of FIG. 1(a), and FIG. 2 shows the white key 2a and the black key. 2b is shown removed from the keyboard chassis 4 together with the key support mechanism 6.

This keyboard device 1 consists of a keyboard chassis 4, white keys 2a and black keys 2b, a plurality of keys 2 arranged in a row in the left and right direction, and each key 2 is rotatably attached to the keyboard chassis 4. It includes a key support mechanism 6 that supports the corresponding key 2 from below, a key switch 3 for detecting key press information of each key 2, and the like.

The keyboard chassis 4 includes a chassis body 4a made of a resin molded product having a predetermined shape by injection molding a predetermined resin material (for example, ABS resin). As shown in FIG. 3, in this chassis body 4a, a front portion 11, an intermediate portion 12, and a rear portion 13 are all formed to extend in the left-right direction (left-right direction in FIG. 3(a)). It is integrally formed with a plurality of ribs 14 spaced apart from each other in the left-right direction and each extending in the front-back direction. In the following description, in the keyboard chassis 4, the front part 11, middle part 12, and rear part 13 of the chassis body 4a are referred to as "chassis front part 11," "chassis middle part 12," and "chassis rear part 13," respectively. shall be.

The chassis front part 11 is mainly used to guide the white key 2a when the key is pressed, and to regulate the upper and lower limit positions of the front end thereof. In this chassis front part 11, a plurality of white key guides 11a are inserted from below for each white key 2a to prevent the white keys 2a from wobbling laterally, and are arranged vertically in the left-right direction. Further, in the chassis front part 11, engagement holes 11b, 11b are provided on both left and right sides of each white key guide 11a, and the engagement holes 11b, 11b penetrate in the vertical direction. The two left and right upper limit position regulating portions 21, 21 are engaged with each other in a penetrating state. Further, the chassis front portion 11 is provided with a stopper mounting portion 11c at its front end that projects forward and extends in the left-right direction over the entire chassis body 4a, and a white key is provided on the lower and upper surfaces of the stopper mounting portion 11c, respectively. A key upper limit stopper 16a and a key lower limit stopper 16b are attached to extend in the left-right direction. In addition, the chassis front part 11 is provided with a black key stopper attachment part 11d extending in the left-right direction over the entire chassis body 4a at a predetermined position behind the white key guide 11a. A key upper limit stopper 17 for the key is attached so as to extend in the left-right direction.

The chassis intermediate portion 12 mainly guides the black key 2b when the key is pressed, and also allows the first arm 31 and the second arm 32, which will be described later, to swing freely. I support it. The chassis intermediate portion 12 includes a flat plate-like portion 12a extending in the left-right direction, and a plurality of black key guides 12b erected on the flat portion 12a and arranged at appropriate intervals in the left-right direction. are doing. Each black key guide 12b is inserted from below for each black key 2b to prevent the black key 2b from swinging laterally. Furthermore, a first arm support portion 18 that supports the first arm 31 of the key support mechanism 6 is provided at the front portion of the chassis intermediate portion 12 . This first arm support part 18 has a plurality of first support shafts 18a provided so as to extend in the left-right direction between adjacent ribs 14, 14, and these first support shafts 18a, A first arm 31 is swingably supported. Furthermore, a second arm support section 19 that supports the second arm 32 of the key support mechanism 6 is provided at the rear of the chassis intermediate section 12 . The second arm support portion 19 has a plurality of second support shafts 19a provided between adjacent ribs 14, 14 so as to extend in the left-right direction. The plurality of second support shafts 19a are arranged on the same axis extending in the left-right direction at a higher position rearward than the first support shaft 18a, and a second arm 32 is attached to these second support shafts 19a. is swingably supported. Note that a first arm lower limit stopper 10b extending in the left-right direction over the entire chassis body 4a is provided at a predetermined position on a middle rail 8, which will be described below, provided on the lower side of the chassis intermediate portion 12.

Further, the key switch 3 is attached to the lower part of the keyboard chassis 4 between the chassis front section 11 and the chassis middle section 12. The key switch 3 includes a horizontally long printed circuit board 3a extending in the left-right direction, and a plurality of switch bodies 3b each consisting of a rubber switch attached to each key 2 on the printed circuit board 3a and pressed by a first arm 31 when the key is pressed. It is made up of.

The rear chassis 13 is mainly used to guide the key 2 in the vertical direction at its rear end while preventing it from swinging laterally, and to regulate the upper limit position of the rear end of the first arm 31 . As shown in FIGS. 2 and 3(a), the rear chassis 13 has a plurality of partition walls 13a spaced from each other at a predetermined interval in the left-right direction so as to partition the adjacent keys 2, 2 from each other. Further, as shown in FIG. 3(b), a first arm upper limit stopper 10a is provided at a predetermined position on the upper part of the chassis rear part 13, and extends in the left-right direction over the entire chassis body 4a. This first arm upper limit stopper 10a and the first arm lower limit stopper 10b provided in the chassis intermediate portion 12 are respectively connected to the first arm 31 which has a function as a hammer for applying touch weight to the key 2. , is for regulating the upper limit position when the first arm 31 rotates upward and the lower limit position when the first arm 31 rotates downward. Furthermore, a metal cover plate 15 is attached to the upper part of the chassis rear part 13 and extends in the left-right direction over the entire chassis body 4a and is arranged to cover the rear end of the key 2.

As shown in FIGS. 2 and 3(a), the chassis main body 4a of the keyboard chassis 4 configured as described above has a plurality of first openings 5a that open upwardly and forwardly, and a plurality of first openings 5a that open upwardly. A second opening 5b is provided. The first arm 31 of the key support mechanism 6 is engaged with the first support shaft 18a from the outside through each of the first openings 5a, and the first arm 31 of the key support mechanism 6 is engaged with the first support shaft 18a from the outside through each of the second openings 5b. The second arm 32 is engaged with the second support shaft 19a from the outside.

Further, in the above keyboard chassis 4, the plurality of chassis bodies 4a are connected to each other in a state in which they are lined up in the left-right direction. It is mounted on the front rail 7, middle rail 8, and rear rail 9 and is secured with screws. The keyboard chassis 4 is fixed onto a shelf (not shown) of the electronic piano via the front rail 7 and rear rail 9 described above.

Next, the key 2 and the key support mechanism 6 will be explained. FIG. 4(a) shows an enlarged view of the white key 2a and its key support mechanism 6a, and FIG. 4(b) shows them in an exploded view. As shown in the figure, the white key 2a is formed by injection molding of a predetermined resin material (for example, AS resin) into a hollow shape that extends a predetermined length in the front-rear direction and opens downward. A pair of left and right upper limit position regulating portions 21, 21 are provided at the front end of the white key 2a, extending downward from the left and right side walls and having lower end portions bent forward. As described above, these upper limit position regulating parts 21, 21 penetrate and engage with the left and right engagement holes 11b, 11b of the chassis front part 11, respectively.

Furthermore, a key front side connecting portion 22 connected to the first arm 31 of the key support mechanism 6a is provided at a predetermined position behind the upper limit position regulating portion 21 on the front portion of the white key 2a. This key front side connecting portion 22 has a connecting recess 22a formed in a U-shape that has a long hole-like side surface and opens forward. Further, this connecting recess 22a is provided so as to cover the entire inner circumferential surface of the connecting recess 22a, in order to suppress the generation of noise when a connecting shaft 35b (described later) of the first arm 31 slides within the connecting recess 22a. A key-side noise suppression member 20 is attached.

Further, at the rear of the white key 2a, a key rear connecting portion 23 is provided which is connected to the second arm 32 of the key support mechanism 6a. This key rear side connecting part 23 hangs downward from the center part in the left-right direction of the white key 2a, and has a plate-shaped connecting body part 23a having a predetermined thickness in the left-right direction, and a left and right side of this connecting body part 23a. It has a pair of left and right engagement protrusions 23b, 23b coaxially protruding from the side surfaces, respectively. Further, the rear part of the white key 2a is penetrated in the vertical direction, and a predetermined tool is provided when releasing the connection between the white key 2a and the second arm 32 of the key support mechanism 6a during maintenance of the keyboard device 1, etc. A tool insertion hole 24 is formed for inserting the tool from above.

On the other hand, the key support mechanism 6a includes a first arm 31 and a second arm 32 that engage with each other and are respectively connected to the key front side connecting part 22 and the key rear side connecting part 23 of the white key 2a.

As shown in FIG. 4(b), the first arm 31 includes an arm body 33 and two weights 34, 34 attached to the arm body 33. The arm body 33 is made of a resin molded product having a predetermined shape by injection molding a predetermined resin material (for example, polyacetal). This arm body 33 extends for a predetermined length in the front-rear direction, and is provided with a first arm front connecting portion 35 connected to the key front connecting portion 22 of the white key 2a at its front end. The first arm front connecting portion 35 extends in the left-right direction, connecting a box portion 35a formed in a box shape that opens upward and forward, and the front upper ends of the left and right side walls of the box portion 35a. It has a connecting shaft 35b provided as shown in FIG. The connecting shaft 35b is rotatably connected to the connecting recess 22a of the front-key connecting portion 22 of the white key 2a and slidably in the front-rear direction.

Further, the arm body 33 has a U-shaped bearing portion 36 with a downwardly opening side surface at a predetermined position immediately behind the first arm front connecting portion 35, and this bearing portion 36 is connected to the keyboard. It is rotatably engaged with the first support shaft 18a in the chassis 4. Further, the arm main body 33 is provided with a first arm rear connecting portion 37 that connects with the second arm 32 at a predetermined position behind the bearing portion 36 . Specifically, the first arm rear connecting portion 37 has a connecting shaft 37a that extends in the left-right direction and has both ends protruding outward from the left and right side surfaces of the arm body 33, respectively. Then, both ends of this connecting shaft 37a engage with connecting recesses 45b, 45b of a second arm front side connecting portion 45 of the second arm 32, which will be described later.

Two elongated plate-shaped weights 34, 34 are attached to the weight attachment part 38, which is the rear part of the arm body 33, with the weight attachment part 38 sandwiched from both sides. Each weight 34 is made of a material (for example, metal such as iron) that has a higher specific gravity than the arm body 33, and is formed into a predetermined shape by pressing a metal plate.

The second arm 32 is made of a resin molded product having a predetermined shape by injection molding the same resin material as the arm body 33 of the first arm 31 . This second arm 32 is shorter than the first arm 31 and extends a predetermined length in the front-rear direction. Further, the second arm 32 has a C-shaped bearing portion 41 with a side surface that opens forward near the center in the length direction, and this bearing portion 41 is connected to the second support shaft of the keyboard chassis 4. 19a in a rotatable manner.

Furthermore, a second arm rear connecting portion 42 is provided at the rear of the second arm 32, which is connected to the key rear connecting portion 23 of the white key 2a. The second arm rear side connecting portion 42 is formed in a bifurcated shape and has two left and right connecting arm portions 43, 43 that extend a predetermined length in parallel with each other along the length direction of the second arm 32. There is. A connecting hole 43a penetrating in the left-right direction is formed at the rear end of each connecting arm portion 43. The connecting arms 43, 43 sandwich the connecting body 23a of the key rear connecting part 23 of the white key 2a from both left and right sides between their rear ends, and each connecting hole 43a is connected to the rear side of the key. It is rotatably fitted into the corresponding engagement convex portion 23b of the connecting portion 23.

Furthermore, a second arm front connecting portion 45 that is connected to the first arm rear connecting portion 37 of the first arm 31 is provided at the front portion of the second arm 32 . The second arm front connecting portion 45 has a pair of left and right connecting pieces 45a, 45a spaced apart from each other by a predetermined distance in the left-right direction. An open U-shaped connecting recess 45b is formed. The left and right connecting pieces 45a, 45a of the second arm front side connecting part 45 are rotatably and slidably attached to both ends of the connecting shaft 37a of the first arm 31 via their connecting recesses 45b, 45b, respectively. Engage freely.

FIG. 5(a) shows an enlarged view of the black key 2b and its key support mechanism 6b, and FIG. 5(b) shows them in an exploded view. The black key 2b is formed by injection molding of the same resin material as the white key 2a, so that it is shorter than the white key 2a, extends a predetermined length in the front-rear direction, and is hollow and opens downward. At the front lower end of the black key 2b, a key front connecting portion 26 is provided which is formed in substantially the same manner as the key front connecting portion 22 of the white key 2a. This key front side connecting portion 26 has a connecting recess 26a that has a long hole-like side surface and a U-shape that opens forward. Further, the key front side connecting portion 26 has an extending portion 26b extending a predetermined length forward of the front surface of the main body of the black key 2b at the lower front end portion of the connecting recess 26a. It functions as an upper limit position regulating section for the black key 2b. In the following explanation, the same components as the white key 2a and the key support mechanism 6a mentioned above will be given the same reference numerals regarding the black key 2b and the key support mechanism 6b, and detailed explanation will be omitted. .

The key support mechanism 6b that supports the black key 2b is configured almost the same as the key support mechanism 6a for the white key described above. Specifically, the arm body 33 of the first arm 31 and the second arm 32 of the key support mechanism 6b are different in shape and size from the arm body 33 and the second arm 32 of the key support mechanism 6a for white keys. are configured exactly the same. Note that the two right and left weights 34, 34 of the key support mechanism 6b for black keys have different rear shapes from the weight 34 of the key support mechanism 6a for white keys.

Next, the operations of the key 2 and the key support mechanism 6 in the keyboard device 1 configured as described above will be explained. FIG. 6 shows the operation of the white key 2a and its key support mechanism 6a, and FIG. 7 shows the operation of the black key 2b and its key support mechanism 6b.

In the key-released state shown in FIG. 6(a), when the front end of the white key 2a is pressed down by the player's finger, the key front connecting portion 22 of the white key 2a moves downward, thereby causing the first arm 31 to move downward. rotates counterclockwise around the first support shaft 18a. Further, as the first arm 31 rotates, the second arm front connecting portion 45 that engages with the connecting shaft 37a of the first arm 31 via the connecting recess 45b moves upward. Thereby, the second arm 32 rotates clockwise about the second support shaft 19a. As the second arm 32 rotates, the key rear connecting part 23 connected via the second arm rear connecting part 42 at its rear end is pulled down, and the rear end of the white key 2a is moved downward. Move to.

In addition, when the first arm 31 rotates as described above, as the box portion 35a of the first arm front side connecting portion 35 moves downward, the pressed key 2 is moved by the bottom wall of the box portion 35a. Press the switch body 3b of the key switch 3 corresponding to the key switch 3 from above. As a result, in the electronic piano, key press information of the pressed key 2 is detected, and sound is generated from a speaker (not shown) based on the detected key press information.

As described above, when the white key 2a is pressed down, as the first arm 31 rotates counterclockwise, the weight 34 of the first arm 31 tilts backward upward, as shown in FIG. 6(b). The rear end portion contacts the first arm upper limit stopper 10a from below. This prevents further rotation of the first arm 31. When the front end of the white key 2a is pushed down to the lowest position, the front end of the white key 2a abuts the key lower limit stopper 16b, and further depression of the white key 2a is prevented.

The white key 2a pressed in the manner described above rotates around the virtual fulcrum P located behind its rear end. The position of this virtual fulcrum P is set, for example, so that the distance from the front end of the white key 2a is approximately twice the length of the white key 2a itself. As a result, when the front end of the white key 2a is pushed down to the lowest position, the front end of the white key 2a is pushed down to the predetermined key stroke ( For example, the rear end portion is located downward by a distance of approximately 1/2 of the key stroke (for example, 5 mm).

On the other hand, when you release your finger from the pressed down white key 2a, the first arm 31 of the key support mechanism 6a rotates in the opposite direction to the above due to the weight of the weight 34, and accordingly, the second arm 32 also rotates in the opposite direction. rotate in the direction. Accordingly, the white key 2a rotates upward about the virtual fulcrum P. Then, a predetermined portion of the first arm 31 behind the first support shaft 18a contacts the first arm lower limit stopper 10b from above, and both upper limit position regulating portions 21, 21 of the white key 2a contact the key upper limit stopper 16a from below. Then, the white key 2a comes into contact with the key 2a, preventing further rotation of the white key 2a, and returns to the original key-released state.

Further, the operation when the black key 2b is pressed is performed in the same manner as the white key 2a and the key support mechanism 6a described above. That is, when the front end of the black key 2b is pressed down in the key-release state shown in FIG. The black key 2b rotates clockwise about the support shaft 19a, thereby causing the black key 2b to rotate about the virtual support Q at the rear. Note that the position of this virtual fulcrum Q is set so that, for example, the distance from the front end of the black key 2b is approximately twice the length of the black key 2 itself, similar to the virtual fulcrum P of the white key 2a described above. There is. Therefore, when the front end of the black key 2b is pushed down to the lowest position, compared to the released state shown in FIG. The rear end portion is located downward by a distance of approximately 1/2 of the key stroke.

On the other hand, when you release your finger from the depressed black key 2b, the first arm 31 and second arm 32 of the key support mechanism 6b rotate in the opposite direction to the above, and accordingly, the black key 2b moves around the virtual fulcrum Q. Rotate upwards around the center. Then, the extending portion 26b of the key front connecting portion 26 of the black key 2b contacts the key upper limit stopper 17 from below, preventing further rotation of the black key 2b, and returning to the original key-released state.

Next, the main parts of the present invention will be explained with reference to FIGS. 8 to 11. The main part of the present invention is the mounting structure of the weight inside the key body. In this embodiment, an example will be described in which the weight part attachment structure is applied to a white key, but a similar attachment structure may be applied to a black key.

FIG. 8(a) is a view of the key body of a white key viewed from one side, and FIG. 8(b) is a view of the same key body viewed from below. As described above, the key body 51 of the white key 2a is formed by injection molding a predetermined resin material (for example, AS resin). The white key 2a in this embodiment is, for example, the A key (a key for the A note), and the key body 51 of the white key 2a has a wide part 51a adjacent to another white key 2a and a wide part 51a adjacent to the black key 2b. and a narrow portion 51b. Wooden boards 52 are attached to the left and right side surfaces of the wide portion 51a and the narrow portion 51b to give the key a woody texture. As the wood board 52, in addition to wood, wood materials such as a wood-grain decorative board, plywood, and medium density fiberboard (MDF) may be used. In this embodiment, the wooden board 52 is made of soft wood with a specific gravity of 0.5 or less. Examples of such woods include spruce and certain South Sea woods.

As shown in FIG. 8(b), the key body 51 is formed in a hollow shape with an open bottom, and a wide part 51a has a space for accommodating weight parts 54, 54a, and 54b, which will be described later. An internal space S is provided.

FIG. 9(a) shows a cross section taken along line BB in FIG. 8(a). As shown in the figure, grooves 53 are provided on the inner surfaces of the pair of left and right side surfaces of the key body 51. The groove portion 53 is formed at the top of the inner side surface of the side surface portions of the wide portion 51a and the narrow portion 51b of the key body 51 so as to extend long along the front-rear direction. Further, the upper surface portions of the wide portion 51a and the narrow portion 51b of the key body 51 have left and right ends protruding laterally than the pair of side portions, and cover the upper end surfaces of the wooden boards 52 attached to the side portions. This makes the key look similar to a wooden key when viewed from the side.

FIG. 10(a) shows the weight portion 54 of this embodiment. The weight portion 54 is housed inside the key body 51 of each key in the keyboard device to adjust the weight balance of each key, thereby adjusting the touch feeling of the key. The weight portion 54 of this embodiment is made of an elastically deformable material and is formed into a substantially rectangular parallelepiped shape. The weight portion 54 can be made of an elastic material such as synthetic rubber or a thermoplastic elastomer, and in this embodiment, the weight portion 54 is made of, for example, chloroprene rubber. The upper end portions of each of the pair of opposing side surfaces of the weight portion 54 engage with the groove portion 53 when the weight portion 54 is accommodated in the internal space S of the key body 51, thereby moving the weight portion 54 into the internal space S. An engaging convex portion 55 is formed to be held inside.

The length dimension between the above-mentioned pair of side surfaces of the weight portion 54 is configured to be approximately the same as the length dimension between the respective inner surfaces of the pair of side surfaces of the key body 51. Further, the length between the respective engaging convex portions 55 formed on the pair of side surfaces of the weight portion 54 is larger than the length between the inner surfaces of the pair of side portions of the key body 51, and the groove portion 53 is formed. The length dimension between the inner surfaces is approximately the same as the length dimension between the inner surfaces at the position where the

FIG. 11A shows the key body 51 with the weight portion 54 housed in a predetermined position within the internal space S. FIG. The weight portion 54 is attached to a predetermined position inside the key body 51, for example, by pushing the weight portion 54 toward the internal space S from the open bottom of the key body 51. When pushing the weight portion 54 from below the key body 51, the engagement protrusion 55 first hits the pair of side surfaces of the key body 51, but the weight portion 54 is elastically deformed and the engagement protrusion 55 pushes the weight portion 54. By bending in the opposite direction, the weight portion 54 is fitted into the internal space S.

Thereafter, the weight part 54 is further pushed upward, and when the weight part 54 reaches a predetermined position in the internal space S, the engaging convex part 55 that has been elastically deformed returns to its original shape within the groove part 53. , the engagement protrusion 55 fits into the groove 53 and engages with it. When the weight portion 54 is accommodated in the predetermined position within the internal space S in this manner, the weight portion 54 can be firmly held inside the key body 51 by the engagement between the engagement convex portion 55 and the groove portion 53.

Note that the weight portion 54 may be more firmly adhered to the inside of the key body 51 by, for example, applying an adhesive to the upper surface of the weight portion 54 or pasting double-sided tape.

As described above, in the key body 51 of this embodiment, the weight portion 54 can be firmly held only by the groove portion 53 provided on the inner surface of the side portion. There is no need to form a protruding portion. This makes it possible to simplify the mold for molding the key body 51, thereby reducing manufacturing costs.

Note that in the key body 51, which is a molded product made of a resin material, care must be taken to prevent sink marks from occurring in portions that are thicker than others, such as the connection portion between the top surface and the side surface. In particular, since the upper surface of the key body 51 serves as the keying surface during performance, it is important to effectively suppress the occurrence of sink marks on the upper surface in order to prevent deterioration of the aesthetic appearance and the touch feeling during performance. In the key body 51 of this embodiment, the groove portion 53 is formed at the top of the inner surface of the pair of side portions, so that the thickness L1 at the top of the side portion is greater than the thickness L2 at the top portion. is also smaller. That is, in the key body 51 of the present embodiment, the groove portion 53 formed at the top of the side surface portion reduces the difference in wall thickness between the connection portion between the top surface portion and the side surface portion and the other portion of the top surface portion. It has the effect of stealing meat. As a result, during molding, a difference in cooling rate is less likely to occur between the connecting portion of the top surface and side surfaces and other parts of the top surface, and it is possible to effectively suppress the occurrence of sink marks on the top surface. .

FIG. 10(b) shows a weight portion 54a according to a modified example. The difference between the weight portion 54 described above and the weight portion 54a according to the modified example is that in the weight portion 54, the engagement convex portion 55 extends along the entire upper end portion of each of the pair of opposing side surfaces of the weight portion 54. In contrast, in the weight portion 54a, a plurality of engaging convex portions 55a are formed at the upper end portions of each of the pair of opposing side surfaces of the weight portion 54a. In this way, the weight part 54a has a plurality of engagement protrusions 55a formed shorter than the engagement protrusion 55, so that when pushing the weight part 54a into the internal space S of the key body 51, a smaller It becomes possible to deform the engaging convex portion 55a by force, and the weight portion 54a can be easily attached. Further, when the engagement protrusion 55a engages with the groove 53, a space is created in the groove 53 facing the discontinuous portion of the engagement protrusion 55a. In this case, the adhesive accumulates in this space, so that the weight portion 54a can be more firmly bonded to the key body 51. The space also functions as a space for excess adhesive to escape.

Moreover, FIG. 11(b) shows a state in which a weight portion 54b according to another modification is accommodated at a predetermined position within the internal space S of the key body 51. The weight portion 54b is characterized in that the engaging convex portion 55b is formed to be smaller than the groove portion 53. For example, the length dimension of the engaging convex portion 55b in the vertical direction is smaller than that in the vertical direction of the groove portion 53. It is configured to be smaller than the length dimension of. Thereby, when the engagement protrusion 55b engages with the groove 53, a gap G is created between the engagement protrusion 55b and the groove 53. As a result, when adhesive is applied to the upper surface of the weight portion 54b, for example, the adhesive accumulates in the gap G, thereby making it possible to more firmly adhere the weight portion 54b to the key body 51. This gap G also functions as a space for excess adhesive to escape.

As described above, according to the present embodiment, when the weight part 54 is housed in a predetermined position in the internal space S of the key body 51, the weight part By fitting and engaging the engagement convex portions 55 of 54, the weight portion 54 can be firmly held inside the key body 51. Furthermore, since there is no need to separately provide a protruding portion on the key body 51 to prevent the weight from falling off, the mold for molding the key body 51 can be simplified, and manufacturing costs can be reduced. can.

Furthermore, by forming the groove 53 at the top of the side surface of the key body 51, the thickness L1 at the top of the side surface becomes smaller than the thickness L2 at the top. As a result, when molding the key body 51, a difference in cooling rate is less likely to occur between the connection part between the top surface part and the side surface part and other parts of the top surface part, and the occurrence of sink marks on the top surface part is effectively suppressed. can do.

Note that the present invention is not limited to the above-described embodiments, and can be implemented in various forms. For example, in the embodiment, a description has been given of the key body 51 with the wooden plate 52 attached to the side surface, but as shown in FIG. It is also possible to adopt a weight attachment structure. In the case of the key body 51a shown in the same figure, the left and right ends of the top surface part do not have a structure that protrudes laterally beyond the side surface parts, so when molding, the connection part between the top surface part and the side surface part, and the top view The difference in cooling rate between the upper surface and other parts is small, and the possibility of sink marks occurring on the upper surface is extremely small. In this case, the position where the groove 53a is formed is not limited to the top of the inner surface of the side surface of the key body 51a, and the groove 53a can be formed at any position on the side surface. Furthermore, since it is not necessary to extend the groove 53a long along the front-rear direction of the inner surface of the side surface of the key body 51a to prevent sink marks, the groove 53a is limited to the position necessary for attaching the weight 54. For example, the groove portion 53a may be formed only within the range of the internal space S. In addition, it is possible to change the detailed structure as appropriate within the scope of the spirit of the present invention.

1 Keyboard device 2 Key 2a White key 2b Black key 51 Key body 51a Wide portion 51b Narrow portion 52 Wooden board 53 Groove portion 54 Weight portion 54a Weight portion modification 54b Weight portion modification 55 Engagement protrusion 55a Engagement protrusion Modification example 55b of the engagement protrusion S Inner space of the key body G Gap between the groove and the engagement protrusion

Claims (3)

A key body made of resin, which has at least an upper surface portion and a pair of side portions, is formed in a hollow shape with an open bottom, and extends a predetermined length in the front-rear direction;
a weight part made of an elastically deformable material and housed in a predetermined position inside the hollow part of the key body;
The key body has one or more grooves extending along the front-rear direction on the inner surface of each of the pair of side surfaces,
The weight portion is formed at a position facing the one or more groove portions at the predetermined position and retains the weight portion inside the key body by engaging with the one or more groove portions. A key for a keyboard device, characterized by having an engaging protrusion. The one or more grooves are formed at the top of the pair of side surfaces,
2. The key body according to claim 1, wherein a thickness of the top of the pair of side surfaces of the key body is smaller than a thickness of the top surface of the key body. The key to the keyboard device described. Claim 1, wherein the vertical length of the engaging convex portion of the weight portion is smaller than the vertical length of the one or more groove portions. or the key of the keyboard device according to 2.

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