keyboard instruments

Abstract

The present invention provides a keyboard musical instrument, which includes a hammer unit and a keyboard base, the hammer unit having: a plurality of hammer components, each of which has a force point portion provided on one end side, a load point portion provided on the other end side, and a fulcrum portion provided between the force point portion and the load point portion; and a hammer holder that rotatably holds the plurality of hammer components, the keyboard base having a restriction component that restricts the rotation of the plurality of hammer components corresponding to key operation within a restriction range, and the hammer unit is installed therein, the hammer holder having a plurality of force point portion side contacts that contact the force point portion side of each of the plurality of hammer components when the hammer unit is in a state in which the hammer unit is reversed upside down.

Description

[0001] This invention patent application is a divisional application of the invention patent application with application date of August 2, 2019, application number 201910712314.7, and invention name “Keyboard Musical Instrument”. Technical Field

[0002] The present invention relates to a keyboard musical instrument such as an electronic piano. Background Art

[0003] For example, in keyboard instruments, the following structure is known: as described in Japanese Utility Model Application Laid-Open No. 7-34480, a plurality of keys are mounted on a keyboard base so as to be rotatable in the vertical direction, and a plurality of hammer members for applying action loads to each of the plurality of keys are mounted on the lower surface of the keyboard base by hammer holders. Summary of the Invention

[0004] Problems to be solved by the invention

[0005] When assembling a keyboard instrument having a structure in which multiple hammer members are mounted on the lower surface of a keyboard base via a hammer holder, the multiple hammer members are rotatably mounted to the hammer holder via their respective shafts to assemble a hammer unit, which is then mounted on the keyboard base. However, in this process, the multiple hammer members rotate independently about their respective shafts, causing the hammers of the hammer members to sag significantly, resulting in poor assembly workability.

[0006] An object of the present invention is to provide a keyboard musical instrument capable of improving assembly workability.

[0007] Solutions to Problems

[0008] A keyboard musical instrument according to an embodiment of the present invention comprises a hammer unit and a keyboard base.

[0009] The hammer unit includes: a plurality of hammer members each including a force point portion provided at one end, a load point portion provided at the other end, and a fulcrum portion provided between the force point portion and the load point portion; and

[0010] a hammer holder that rotatably holds the plurality of hammer components;

[0011] The keyboard base has a limiting member for limiting the rotation of the plurality of hammer members corresponding to key operations within a limiting range, and is equipped with the hammer unit.

[0012] The hammer retainer has a plurality of force point side contacts that contact the force point side of each of the plurality of hammer components when the hammer unit is inverted upside down, in order to form a structure in which the first length is longer than the second length. The first length is the length in the front-to-back direction of the key between the fulcrum portion of each of the plurality of hammer components and the other end of each hammer component when the hammer unit is inverted upside down so as to be installed in the keyboard base in the upside-down state. The second length is the length in the front-to-back direction of the key between the fulcrum portion and one end of the limiting component on the fulcrum side.

[0013] Effects of the Invention

[0014] According to the present invention, assembly workability can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a cross-sectional view showing an embodiment of a keyboard musical instrument to which the present invention is applied.

[0016] Figure 2 Yes Figure 1 A cross-sectional view of a keyboard instrument showing a state where white keys are depressed is shown.

[0017] Figure 3 Yes Figure 1 An enlarged perspective view of a main portion of a hammer unit of a keyboard musical instrument is shown.

[0018] Figures 4A to 4C express Figure 3 The hammer part of the white key of the hammer unit shown, Figure 4A 1 is a perspective view showing a hammer component. Figure 4B This is a three-dimensional diagram showing the hammer body. Figure 4C It is a perspective view showing the shaft portion.

[0019] Figures 5A to 5C express Figure 3 The hammer component of the black key of the hammer unit shown, Figure 5A 1 is a perspective view showing a hammer component. Figure 5B This is a three-dimensional diagram showing the hammer body. Figure 5C It is a perspective view showing the shaft portion.

[0020] Figure 6 Yes Figure 3 A perspective view of the hammer holder of the hammer unit is shown.

[0021] Figure 7A and Figure 7B express Figure 6 The cross section of the hammer holder is shown, Figure 7A yes Figure 6 An enlarged sectional view of the main part of the hammer holder as viewed in the direction of AA, Figure 7B yes Figure 6 An enlarged sectional view of a main portion of the hammer holder as viewed along the BB line.

[0022] Figure 8 It is a partial cross-sectional view showing a state where the hammer member is mounted on the hammer holder.

[0023] Figure 9 It is a diagram showing the rotation range of the hammer member relative to the hammer holder.

[0024] Figure 10 It means to make Figure 9 The hammer holder and hammer member shown are in a state where they are turned upside down and arranged on a placement surface such as a workbench.

[0025] Figure 11 It means Figure 10 The diagram shows a state where the hammer holder and the hammer member are being assembled from above onto the keyboard base that has been turned upside down.

[0026] Figure 12 Yes Figure 10 The diagram shows a state in which the hammer holder and the hammer member are assembled to the keyboard base which has been turned upside down.

[0027] Figure 13A and Figure 13B express Figure 12 The positioning structure of the hammer holder relative to the keyboard base is shown. Figure 13A This is a back view showing the main parts of the keyboard base. Figure 13B This is a rear view of the hammer holder. DETAILED DESCRIPTION

[0028] Below, refer to Figures 1 to 13B , an embodiment of a keyboard instrument to which the present invention is applied is described.

[0029] like Figure 1 and Figure 2 As shown, the keyboard instrument comprises: a keyboard base 1 made of a synthetic resin such as ABS resin; a plurality of keys 2 arranged on the keyboard base 1 and mounted rotatably in the up and down directions; a plurality of hammer units 3 for applying action loads to each key 2 as the keys 2 are pressed; and a plurality of switch portions 4 for performing a connection action according to the key pressing actions of the keys 2.

[0030] The keyboard base 1 is a component disposed in the instrument housing (not shown). Figure 1 and Figure 2 As shown, at the front end of the keyboard base 1 ( Figure 1A front leg portion 5 is provided in a state of protruding upward from the bottom of the keyboard base 1 (right end). A plurality of key guides 6 are provided on the upper portion of the front leg portion 5 corresponding to each key 2 for preventing lateral vibration of each key 2. In addition, on the rear side ( Figure 1 A unit placement portion 7 is provided in the middle (left side) in a state where the unit placement portion 7 protrudes at approximately the same height as the front leg portion 5.

[0031] like Figure 1 and Figure 2 As shown, in the front and rear directions of the keyboard base 1 ( Figure 1 A substrate mounting portion 8 is provided approximately in the middle (in the left-right direction), that is, at the upper rear portion of the unit mounting portion 7, projecting to a position one level higher than the unit mounting portion 7. Above the substrate mounting portion 8, the switch unit 4 is supported by a plurality of substrate support portions 9. The plurality of substrate support portions 9 are provided in an upright position at the front and rear portions of the upper surface of the substrate mounting portion 8.

[0032] Moreover, if Figure 1 and Figure 2 As shown, a key receiving portion 10 is provided at the rear of the keyboard base 1, that is, at the rear side of the base receiving portion 8, projecting to a position slightly lower than the upper portion of the key guide portion 6. A plurality of key support portions 11 are provided on the upper surface of the key receiving portion 10, projecting upward and spaced evenly along the arrangement direction of the keys 2. Each of the plurality of key support portions 11 is provided with a key support shaft 11a that vertically rotatably supports the rear end of the key 2.

[0033] In addition, if Figure 1 and Figure 2 As shown, a rear leg portion 12 is provided at the rear end of the keyboard base 1 in a state of hanging down from the upper portion to the bottom of the keyboard base 1 to support the rear end of the keyboard base 1. A lower limit stopper 13 such as felt is provided near the lower end of the rear leg portion 12 for limiting the lower limit position of a hammer member 20 of the hammer unit 3, which will be described later.

[0034] On the other hand, Figure 1 and Figure 2 As shown in FIG. 1 , the plurality of keys 2 are composed of white keys and black keys. However, here, a white key is used as an example for explanation. The rear end portion of the key 2 ( Figure 1 The left end portion of the key 2 is supported by the key support shaft 11a of the key support portion 11 provided on the key placement portion 10 of the keyboard base 1 so as to be rotatable in the vertical direction. Figure 1 A switch pressing portion 14 for pressing the switch portion 4 mounted on the substrate mounting portion 8 of the keyboard base 1 is provided in a substantially middle portion (in the left-right direction) in a state of protruding downward.

[0035] In addition, if Figure 1 and Figure 2As shown, the switch portion 4 includes a dome-shaped protrusion 16 that partially protrudes from a rubber plate disposed on the switch substrate 15. A plurality of these dome-shaped protrusions 16 are provided above the switch substrate 15, corresponding to the switch pressing portions 14 of the keys 2. The switch substrate 15 is mounted on the keyboard base 1 in a state of floating above the substrate mounting portion 8. Figure 1 middle, right end) and the other end ( Figure 1 The left end portion) is arranged on a substrate supporting portion 9 provided on a substrate placing portion 8.

[0036] In addition, if Figure 1 and Figure 2 As shown, the switch unit 4 is configured such that when pressed by the switch pressing portion 14, the bulged portion 16 of the rubber plate elastically deforms, causing the movable contact inside to contact the fixed contact of the switch substrate 15, thereby outputting an ON signal. Furthermore, the switch substrate 15 is provided with a sound generating portion 15a for generating music information based on the ON signal output from the switch unit 4 and playing music based on the generated music information from a speaker (not shown).

[0037] Moreover, if Figure 1 and Figure 2 As shown, in the key 2, the switch pressing portion 14 is located on the front side ( Figure 1 A hammer pressing portion 17 is provided at a position (in the middle, right side) so as to protrude downward from the key 2. A hammer coupling portion 18 is provided below the hammer pressing portion 17 to which a key coupling portion 25 serving as a power point of a hammer member 20, described later, constituting the hammer unit 3, is disposed.

[0038] like Figures 1 to 3 As shown, each hammer unit 3 includes: a plurality of hammer components 20 that rotate in response to key operations of the plurality of keys 2 and independently apply an action load to each key 2; and a hammer holder 21 that is mounted on the lower surface of the unit mounting portion 7 of the keyboard base 1 where the keys 2 are arranged, and that rotatably holds the plurality of hammer components 20.

[0039] like Figures 4A to 4C As shown, the hammer member 20 for the white key comprises: a hammer body 22; a rear portion ( Figure 4A The hammer portion 23 as the load point portion is provided on the front side of the hammer body 22 ( Figure 4A The hammer body 22 is provided with a rotating shaft portion 24 as a fulcrum portion of the center of rotation of the hammer body 22; and a front end portion of the hammer body 22 ( Figure 4A The key connection portion 25 (in the middle, right end) serves as a force point.

[0040] Likewise, if Figures 5A to 5C As shown, the black key hammer member 20 comprises: a hammer body 22; a rear portion ( Figure 5A The hammer portion 23 as the load point is provided on the front side of the hammer body 22 ( Figure 5A The hammer body 22 is provided with a rotating shaft portion 24 as a fulcrum portion of the center of rotation of the hammer body 22; and a front end portion of the hammer body 22 ( Figure 5A The key connecting portion 25 serving as the power point portion (in the middle, right end portion) is slightly different in shape from the hammer member 20 used for the white key.

[0041] like Figures 3 to 6 As shown, the hammer holder 21 includes a pedestal-shaped base portion 26 disposed below the unit mounting portion 7 of the keyboard chassis 1 along the arrangement direction of the keys 2; and a plurality of hammer holders 27 provided on the upper surface of the base portion 26 and independently and rotatably holding the plurality of hammer members 20. Each of the plurality of hammer holders 27 includes a pair of retaining pieces 27a for retaining the rotating shaft portion 24 of the hammer body 22 of the hammer member 20. Bearing holes 27b are provided on both sides of the pair of retaining pieces 27a, the centers of which are coaxial.

[0042] In addition, if Figures 4A to 4C as well as Figures 5A to 5C As shown, the hammer body 22 of the hammer member 20 is formed by stamping and punching a metal plate. Furthermore, the rotating shaft portion 24 of the hammer member 20 is formed of a highly rigid synthetic resin such as polyacetal (POM), and includes a shaft body 24a that fits into a mounting hole 22a formed by punching in the hammer body 22, and a flange-shaped flange portion 24b provided on the shaft body 24a.

[0043] Here, if Figures 4A to 8 As shown, the axial length of the shaft body 24a is slightly longer than the length between the pair of retaining pieces 27a of the hammer retaining portion 27 of the hammer retainer 21. The ends of the shaft body 24a are rotatably inserted into the bearing holes 27b of the respective retaining pieces 27a. The flange portion 24b is positioned on one side of the surface of the hammer body 22 where burrs are generated at the edge of the mounting hole 22a during the punching process, thereby preventing the burrs on this surface from coming into contact with the pair of retaining pieces 27a.

[0044] In addition, if Figures 1 to 5C As shown, the key-connecting portion 25 of the hammer member 20, which serves as a power point, includes a contact body portion 25a that is embedded in the hammer-connecting portion 18 of the hammer pressing portion 17 of the key 2, and a contact sliding portion 25b that is provided in an arc shape on the upper surface of the contact body portion 25a and is capable of sliding while contacting the hammer-connecting portion 18 of the key 2. The key-connecting portion 25 is formed of a highly rigid synthetic resin such as polyacetal (POM), similar to the rotating shaft portion 24.

[0045] Therefore, if Figure 1 and Figure 2As shown, in a state in which the hammer member 20 rotatably holds the shaft body 24a of the rotating shaft portion 24 on a pair of holding pieces 27a of the hammer holding portion 27 of the hammer holder 21 and the abutting body portion 25a of the key connecting portion 25 serving as a power point portion is embedded in the hammer connecting portion 18 of the hammer pressing portion 17 of the key 2, when the key connecting portion 25 is pressed by the hammer pressing portion 17 of the key 2 as the key 2 is pressed, the front and rear portions of the hammer body 22 rotate in the vertical direction around the shaft body 24a of the rotating shaft portion 24, thereby applying an action load to the pressed key 2.

[0046] That is, Figure 1 and Figure 2 As shown, the hammer member 20 has a key coupling portion 25 side that protrudes from the hammer holder 21 toward the front side of the key 2, and a hammer portion 23 side that protrudes from the hammer holder 21 toward the rear side of the key 2. Furthermore, in order to impart an operating load to the key 2 due to the moment of inertia when the hammer member 20 rotates in response to a key operation, the length of the hammer portion 23 side that protrudes from the hammer holder 21 is set to be sufficiently longer than the length of the key coupling portion 25 side that protrudes from the hammer holder 21.

[0047] Therefore, if Figure 1 As shown, the hammer member 20 is configured such that, in a normal state, the weight of the hammer 23 as a load point portion rotates counterclockwise around the shaft body 24a of the rotating shaft portion 24 as a fulcrum portion held by the hammer holding portion 27 of the hammer holder 21, and the rear end portion ( Figure 1 In the middle, the left end portion) abuts against the lower limit stopper 13, thereby limiting the rotation position, whereby the key connecting portion 25 pushes the hammer pressing portion 17 of the key 2, so that the front end portion of the key 2 is configured in the initial position as the upper limit position.

[0048] In addition, if Figure 2 As shown, the hammer component 20 is constructed so that when the key 2 is pressed from above, the key connecting portion 25, which serves as a force point, is pressed down by the hammer pressing portion 17 of the key 2 against the weight of the hammer portion 23, which serves as a load point, and then rotates clockwise around the rotation axis 24 of the hammer holding portion 27 held by the hammer holding member 21, thereby applying an operating load to the key 2.

[0049] At this time, if Figure 2 As shown, the hammer body 22 of the hammer member 20 rotates clockwise about the shaft body 24a of the rotating shaft portion 24, which is inserted into the bearing holes 27b of the pair of retaining pieces 27a of the hammer retaining portion 27 of the hammer retaining member 21. The hammer portion 23 at the rear end of the hammer body 22 abuts against an upper limit stopper 28, such as a felt stopper, provided on the rear lower surface of the base plate mounting portion 8 of the keyboard base 1, thereby stopping the rotation. In other words, the rear end of the hammer member 20 rotates between the lower limit stopper 13 and the upper limit stopper 28.

[0050] However, the details of the pair of holding pieces 27a of the hammer holding portion 27 of the hammer holding member 21 are as follows. Figure 8 As shown, the lower sides of the mutually opposing surfaces of the pair of retaining pieces 27a are parallel to each other, and the upper sides of the mutually opposing surfaces are inclined so that the width increases as they go upward. In other words, the hammer retaining portion 27 of the hammer retainer 21 has a structure that facilitates the insertion of the rotating shaft portion 24 of the hammer member 20 between the pair of retaining pieces 27a from above.

[0051] In addition, as shown in Figure 7 and Figure 8 As shown, a plurality of contact ribs 30 extending in the vertical direction are provided on each opposing surface of the pair of retaining pieces 27a. Specifically, these contact ribs 30 are located on the front and rear sides of the bearing hole 27b and extend from the bottom to the top of the pair of retaining pieces 27a. Furthermore, except for the inclined upper sides of the pair of retaining pieces 27a, the contact ribs 30 are perpendicular to the upper surface, which serves as the horizontal surface of the base portion 26 of the hammer holder 21, and these portions do not have a draft angle.

[0052] Further, if the plurality of contact ribs 30 are described, it is as follows. Figure 8 As shown, the length of a contact rib 30 in the front-to-back direction ( Figure 7B The lateral width (in the figure) is the minimum length sufficiently shorter than the inner diameter of the bearing hole 27b. Specifically, the multiple contact ribs 30 are formed to minimize the contact area of ​​the hammer member 20 with the pair of retaining tabs 27a of the hammer retaining portion 27. Furthermore, annular chamfers (not shown) are provided at the front-to-back corners of these multiple contact ribs 30. Therefore, even without a draft angle, the multiple contact ribs 30 can be easily released from the molding die.

[0053] Moreover, if Figure 8 As shown, the hammer holding portion 27 of the hammer holding tool 21 is configured such that, with both ends of the shaft body 24a of the rotating shaft portion 24 of the hammer member 20 inserted into the bearing holes 27b of the pair of holding pieces 27a, the flange portion 24b disposed on the burr-side surface of the hammer body 22 is received between a plurality of contact ribs 30 of one holding piece 27a. Furthermore, the hammer holding portion 27 is configured such that, when the hammer member 20 rotates in response to a key press, the movement of the hammer member 20 in the left-right direction (the direction in which the keys 2 are arranged) is restricted by the contact ribs 30 of the pair of holding pieces 27a that sandwich the hammer member 20.

[0054] Therefore, if Figure 8As shown, due to the presence of the contact ribs 30, the contact area of ​​the hammer member 20 with respect to the pair of retaining pieces 27a of the hammer retaining portion 27 is reduced. The hammer retaining portion 27 is configured to prevent lateral vibration of the hammer member 20 and to well retain the hammer member 20 while reducing the frictional resistance between the pair of retaining pieces 27a and the hammer member 20.

[0055] In addition, if Figure 7B As shown, on one of the opposing surfaces of the pair of retaining pieces 27a (strictly speaking, the one of the opposing surfaces that does not contact the flange portion 24b), a stepped recess 31 is provided between contact ribs 30 on the periphery of the bearing hole 27b. This stepped recess 31 serves as an oil reservoir for storing lubricant such as grease. Both sides of the stepped recess 31 in the front-to-back direction are surrounded by contact ribs 30, thereby preventing the lubricant from leaking out and ensuring lubrication performance provided by the lubricant for a long period of time.

[0056] Further, if Figure 6 、 Figure 7A as well as Figure 7B As shown in FIG. 1 , support protrusions 27c serving as identifiers are selectively provided at the upper ends of the front and rear portions of the pair of retaining pieces 27a. Each support protrusion 27c is provided at the upper ends of the pair of retaining pieces 27a that retain the hammer members 20 for the white keys, and is higher than the upper ends of the pair of retaining pieces 27a that retain the hammer members 20 for the black keys.

[0057] Thus, each supporting protrusion 27c serves as a mark for distinguishing whether the white-key hammer member 20 or the black-key hammer member 20 can be mounted on each pair of holding pieces 27a when the white-key hammer member 20 and the black-key hammer member 20 are mounted on the hammer holder 21.

[0058] Here, if Figure 3 As shown, the hammer holder 21 holds, for example, five hammer members 20 for black keys and seven hammer members 20 for white keys. Therefore, the support protrusions 27c can be provided on the holding pieces 27a of the hammer holder 21 for black keys. However, it is more preferable to provide the support protrusions 27c on the holding pieces 27a of the hammer holder 21 for white keys. This is because, as Figure 10 As shown, when the hammer unit 3 is placed on the mounting surface T after being inverted upside down, the hammer unit 3 has more contact points with the mounting surface T, and the inverted hammer unit 3 is more stable on the mounting surface T.

[0059] In addition, if Figure 9As shown, when the hammer holder 21 holding the hammer member 20 is in a state before being attached to the keyboard base 1, the hammer member 20 is freely rotatable within a range of M0 to M3. This range of M0 to M3 is referred to as a free rotation range F. The hammer holder 27 includes a first hammer restricting portion 32a, which serves as a restricting member for restricting movement of the hammer member 20 upward from the position M0, and a second hammer restricting portion 32b, which serves as a restricting member for restricting movement of the hammer member 20 downward from the position M3.

[0060] In addition, when the hammer holder 21 is assembled to the keyboard base 1, the rotation range of the hammer member 20 is limited by the lower limit stopper 13 and the upper limit stopper 28. Figure 9 As shown, the hammer member 20 rotates only within the range of M1 to M2. This range of M1 to M2 is referred to as a restriction range E serving as a rotation restriction range.

[0061] That is, the upper limit M0 of the free rotation range F within which the hammer member 20 can freely rotate is outside the restriction range E. Therefore, the first hammer restriction portion 32a does not affect the swinging of the hammer member 20 in response to the player's key press. In addition, the lower limit M3 of the free swinging range F within which the hammer member 20 can freely swing is outside the restriction range E. Therefore, the second hammer restriction portion 32b does not affect the swinging of the hammer member 20 in response to the player's key press.

[0062] like Figure 11 As shown, of the first and second hammer restraints 32a and 32b, the first hammer restraint 32a serves as a contact point on the force-point side, specifically, the key-connecting portion 25 side. Furthermore, when the hammer holder 21 is reversed and lifted while the hammer assembly 20 is rotatably mounted, the portion of the hammer body 22 located between the rotational shaft 24, serving as the fulcrum, and the key-connecting portion 25, serving as the force-point, abuts against the first hammer restraint 32a. This restrains the rotation of the hammer assembly 20, and reduces drooping of the hammer 23 compared to a case in which the first hammer restraint 32a is not provided.

[0063] That is, Figure 11 As shown, the first hammer restricting portion 32a restricts the rotation of the hammer member 20 so that the downward movement of the hammer portion 23 of the hammer member 20 is limited compared to a case where the first hammer restricting portion 32a is not provided, thereby holding the hammer member 20 in a nearly horizontal position relative to the hammer holder 21. In other words, the first hammer restricting portion 32a, which serves as a contact point on the power point side, facilitates assembly of the hammer holder 21 to which the hammer member 20 is mounted on the keyboard base 1.

[0064] In addition, if Figure 10As shown, when the hammer holder 21 is inverted upside down and arranged on a loading surface T such as an assembly workbench in a state where the hammer component 20 is rotatably mounted thereon, the lower surface of the hammer portion 23 side of the hammer component 20 and the supporting protrusions 27c of each retaining piece 27a abut against the loading surface T, thereby being arranged on the loading surface T in a stable state.

[0065] In addition, if Figure 10 As shown, the hammer member 20, with the shaft body 24a of the rotating shaft portion 24 supported by the bearing holes 27b of the pair of retaining pieces 27a of the hammer holder 27, rotates about the shaft body 24a. When the lower surface of the hammer member 20 on the hammer portion 23 side abuts the mounting surface T, the hammer member 20 is in a state where the hammer body 22 and the first and second hammer restricting portions 32a and 32b are not in contact. As a result, the hammer holder 21 can also be placed on the mounting surface T in a stable state.

[0066] In particular, in the case of this embodiment, Figure 10 As shown, when the hammer holder 21 to which the hammer member 20 is rotatably mounted is turned upside down and arranged on the mounting surface T, the support protrusions 27c of the pair of holding pieces 27a of the hammer member 20 for holding the white keys, among the plurality of support protrusions 27c provided on the pair of holding pieces 27a, abut against the mounting surface T, and the lower surface of the hammer member 20 on the hammer portion 23 side is arranged on the mounting surface T.

[0067] In addition, if Figure 10 As shown, the hammer portion 23 has a substantially triangular shape, and one side of the upper side of the hammer portion 23 ( Figure 10 A portion P (a lower side) has a straight, unbent shape so as to stably abut against the mounting surface T when the hammer unit 3 is turned upside down and arranged on the mounting surface T.

[0068] On the other hand, Figure 9 As shown, the second hammer limiter 32b is a contact point on the load point side, that is, a contact point on the hammer 23 side. When the hammer member 20 freely rotates within the free rotation range F of M0 to M3, it limits the rotation limit of the hammer member 20 in one direction to the position M3. Specifically, when the hammer unit 3 is not installed in the keyboard base 1, the hammer member 20 rotates within the free rotation range F from the position of the second hammer limiter 32b, which serves as the load point contact point, to the position of the first hammer limiter 32a, which serves as the force point contact point. Furthermore, when the hammer unit 3 is installed in the keyboard base 1, the hammer member 20 rotates within the limit range E in response to key operation, so that the hammer body 22 does not contact the first and second hammer limiters 32a and 32b.

[0069] In addition, if Figure 13A and Figure 13BAs shown, the hammer holder 21 is mounted to the lower surface of the unit mounting portion 7 of the keyboard base 1 by screws (not shown) while rotatably holding the plurality of hammer members 20. Specifically, screws are inserted into screw insertion holes 26a provided in the base portion 26 corresponding to substantially cylindrical mounting bosses 33 provided on the lower surface of the unit mounting portion 7, and the inserted screws are threadedly fastened to the mounting bosses 33, thereby mounting the hammer holder 21 to the lower surface of the unit mounting portion 7 of the keyboard base 1.

[0070] In addition, if Figure 13A and Figure 13B As shown, the hammer holder 21 includes a first positioning portion 34 positioned by a mounting protrusion 33 provided on the lower surface of the unit mounting portion 7 of the keyboard base 1 and a second positioning portion 36 positioned by a reinforcing rib 35 provided across the substrate mounting portion 8 from the unit mounting portion 7 of the keyboard base 1.

[0071] The keyboard base 1 has a plurality of mounting protrusions 33 provided on the lower surface of the unit mounting portion 7 of the keyboard base 1 at predetermined intervals along the arrangement direction of the keys 2. The keyboard base 1 also has a plurality of reinforcing ribs 35 provided at predetermined intervals along the arrangement direction of the keys 2 between the unit mounting portion 7 and the substrate mounting portion 8.

[0072] The first positioning portion 34 is a gap into which one of the mounting protrusions 33 of the keyboard base 1 is inserted. By inserting one of the mounting protrusions 33 of the keyboard base 1 into this gap, the position of the hammer holder 21 in the arrangement direction of the keys 2 is correctly controlled. The second positioning portion 36 is an engaging protrusion that engages with a cutout 35a of a predetermined reinforcement rib 35 provided on the keyboard base 1. By engaging this engaging protrusion with the cutout 35a of the reinforcement rib 35, the position of the hammer holder 21 in the front-rear direction of the keys 2 is correctly controlled.

[0073] Next, the function of such a keyboard instrument will be described.

[0074] When assembling this keyboard instrument, first, the hammer assembly 20 is manufactured and attached to the hammer holder 21, thereby assembling each hammer unit 3. When manufacturing the hammer assembly 20, a metal plate is subjected to press working and punching to form the hammer body 22, the hammer portion 23, and the mounting hole 22a of the hammer body 22. Then, the rotating shaft portion 24 is attached to the mounting hole 22a of the hammer body 22, and the key connection portion 25 is attached to the front end of the hammer body 22.

[0075] When the rotating shaft portion 24 is mounted in the mounting hole 22a of the hammer body 22, the shaft body 24a of the rotating shaft portion 24 is inserted into the mounting hole 22a from the side of the hammer body 22 on the burr side where burrs are generated on the outer peripheral edge and the edge of the mounting hole 22a due to the punching process, and the flange portion 24b of the rotating shaft portion 24 is pressed against the surface of the hammer body 22 on the burr side.

[0076] Therefore, even if burrs are generated on the edge of the mounting hole 22a of the hammer body 22, the shaft body 24a of the rotating shaft portion 24 can be mounted to the mounting hole 22a of the hammer body 22 with the burrs covered by the flange portion 24b of the rotating shaft portion 24.

[0077] When attaching the key coupling portion 25 to the front end of the hammer body 22, the abutment body 25a of the key coupling portion 25 is fitted into the front end of the hammer body 22, with the arcuate abutment sliding portion 25b provided on the upper surface of the abutment body 25a of the key coupling portion 25 facing upward. Thus, the key coupling portion 25 is attached to the front end of the hammer body 22. By performing the above-described operation on each hammer component 20, each hammer component 20 is assembled.

[0078] When attaching the hammer member 20 to the hammer holder 21, a lubricant such as grease is previously filled into one of the stepped recesses 31 on the opposing surfaces of the pair of retaining pieces 27a provided on the hammer holder 27. In this state, when attaching the hammer member 20 to the hammer holder 21, the hammer members 20 for white keys and the hammer members 20 for black keys are separately attached to the hammer holder 21 for each pair of retaining pieces 27a, using the support protrusions 27c serving as identifiers provided on the predetermined pair of retaining pieces 27a of the hammer holder 27 as markers.

[0079] Specifically, the hammer members 20 for the white keys are mounted on the pair of higher retaining pieces 27a having the support protrusions 27c, while the hammer members 20 for the black keys are mounted on the pair of lower retaining pieces 27a having no support protrusions 27c. Thus, when the hammer members 20 are mounted on the hammer holder 21, the rotating shaft portion 24 of the hammer main body 22 is inserted from above between the pair of retaining pieces 27a of the hammer holder 27, and the two ends of the shaft main body 24a of the rotating shaft portion 24 are then inserted into the bearing holes 27b of the pair of retaining pieces 27a.

[0080] At this time, the upper sides of the opposing surfaces of the pair of retaining pieces 27a are inclined so that their widths expand upward. Therefore, the shaft body 24a of the rotating shaft portion 24 expands the pair of retaining pieces 27a, making it easier to insert the shaft body 24a of the rotating shaft portion 24 between the pair of retaining pieces 27a. When the rotating shaft portion 24 is inserted between the pair of retaining pieces 27a, the flange portion 24b of the rotating shaft portion 24, which is located on the burr-side surface of the hammer body 22, is positioned between the burr-side surface of the hammer body 22 and the opposing surface of one of the retaining pieces 27a. This prevents contact between the burr-side surface of the hammer body 22 and the opposing surface of one of the pair of retaining pieces 27a.

[0081] Furthermore, contact ribs 30 are provided extending in the vertical direction on the opposing surfaces of the pair of retaining pieces 27a. Thus, the flange portion 24b, which is disposed on the burr-side surface of the hammer body 22, is disposed in contact with the contact rib 30 of one retaining piece 27a. Furthermore, the surface of the hammer body 22, which is opposite the burr side, is disposed in contact with the contact rib 30 of the other retaining piece 27a.

[0082] Furthermore, the contact ribs 30 have no draft angle except for the upper portion, which is perpendicular to the horizontal upper surface of the base portion 26 of the hammer holder 21. Consequently, the flange portion 24b located on the burr-side surface of the hammer body 22 is evenly pressed by the contact ribs 30 of one retaining piece 27a, while the surface of the hammer body 22 opposite the burr side is evenly pressed by the contact ribs 30 of the other retaining piece 27a.

[0083] Specifically, the flange portion 24b of the rotating shaft portion 24 and the surface of the hammer body 22 opposite the burr side contact the contact ribs 30 of the pair of retaining pieces 27a. This reduces the contact area between the hammer member 20 and the pair of retaining pieces 27a of the hammer retaining portion 27. Consequently, the frictional resistance between the pair of retaining pieces 27a and the hammer member 20 is reduced, preventing lateral vibration of the hammer member 20. Consequently, the hammer member 20 is securely and effectively retained in the hammer retaining member 21 in a rotatable state. By performing the above steps for each hammer member 20, a single hammer unit 3 is assembled.

[0084] When the hammer unit 3 assembled in this way is mounted on the keyboard base 1, first, the hammer unit 3 and the keyboard base 1 are turned upside down. Figure 10 As shown, the hammer holder 21 is turned upside down together with the plurality of hammer components 20 and arranged on a mounting surface T such as an assembly workbench, and as shown in FIG. Figure 11 As shown, the keyboard base 1 is turned upside down and placed on a placement surface T such as an assembly workbench.

[0085] At this time, the support protrusions 27c provided on the upper end portions of the pair of holding pieces 27a of the hammer member 20 for holding the white keys are arranged on the mounting surface T. In this state, the hammer member 20 rotates around the shaft body 24a of the rotating shaft portion 24 due to the weight of the hammer portion 23, and the lower surface of the hammer member 20 on the hammer portion 23 side contacts the mounting surface T.

[0086] In addition, at this time, if Figure 10 As shown, the hammer member 20 is held by the hammer holder 21 in a state where the shaft body 24a of the rotating shaft portion 24 is supported by the bearing holes 27b of the pair of holding pieces 27a of the hammer holder 27, and the key connection portion 25 side of the hammer body 22 does not contact the first and second hammer restriction portions 32a and 32b. Therefore, the hammer member 20 and the hammer holder 21 are arranged on the mounting surface T in a stable state.

[0087] In this state, when the hammer holder 21 is lifted from the mounting surface T by an automatic assembly machine (not shown), Figure 11 As shown, due to the weight of the hammer portion 23, the hammer member 20 rotates around the shaft body 24a of the rotating shaft portion 24. However, the hammer body 22 abuts against the first hammer restriction portion 32a, a contact point on the power point side of the hammer holder 21, thereby restricting the rotation of the hammer member 20.

[0088] That is, the first hammer restricting portion 32a, which is the contact point on the force point side of the restricting member, minimizes the downward movement of the hammer portion 23 of the hammer member 20, thereby maintaining the hammer member 20 in a nearly horizontal position relative to the hammer holder 21. This facilitates assembly of the hammer holder 21, to which the hammer member 20 is attached, onto the keyboard base 1 using an automatic assembly machine.

[0089] Then, the hammer holder 21 to which the plurality of hammer members 20 are attached is mounted on the upper surface ( ) of the unit mounting portion 7 of the keyboard base 1 which has been turned upside down. Figure 1 At this time, the plurality of hammer members 20 are held in a nearly horizontal position on the hammer holder 21 by the first hammer restraining portions 32a, and the individual hammer members 20 do not droop significantly. Therefore, the hammer holder 21 can be properly mounted on the upper surface of the unit mounting portion 7 of the keyboard base 1 without being hindered by the plurality of hammer members 20 drooping significantly.

[0090] At this time, the hammer holder 21 is positioned relative to the keyboard base 1 using the first and second positioning portions 34 and 36. Specifically, the first positioning portion 34 is inserted into one of the mounting protrusions 33 of the keyboard base 1 to thereby regulate the position of the hammer holder 21 in the direction in which the keys 2 are arranged. The second positioning portion 36 is engaged with a cutout 35a of a predetermined reinforcement rib 35 provided on the keyboard base 1 to thereby regulate the position of the hammer holder 21 in the front-rear direction of the keys 2.

[0091] As a result, the screw insertion hole 26a provided in the base portion 26 of the hammer holder 21 is guided to a position corresponding to the substantially cylindrical mounting protrusion 33 provided on the lower surface of the unit mounting portion 7. In this state, a screw (not shown) is inserted into the screw insertion hole 26a of the base portion 26 of the hammer holder 21, and the inserted screw is screwed and fastened to the mounting protrusion 33. Figure 12 As shown, the hammer holders 21 are mounted on the unit mounting portion 7 of the keyboard base 1. By performing the above steps on each hammer holder 21, all the hammer holders 21 are mounted on the unit mounting portion 7.

[0092] Afterwards, the keyboard base 1 and hammer unit 3 are turned upside down to return to the normal position. In this position, the switch unit 4 is mounted on the base mounting portion 8 of the keyboard base 1. At this time, a rubber sheet having a dome-shaped protrusion 16 is pre-attached to the switch base 15. The front end and the other end of the switch base 15 are then placed on the base support portion 9 provided on the base mounting portion 8.

[0093] Next, the plurality of keys 2 are mounted on the keyboard base 1. First, the key guide 6 of the keyboard base 1 is inserted into the front end of each key 2, and the contact sliding portion 25b of the key coupling portion 25 of the hammer member 20 is inserted into the hammer coupling portion 18 provided below the hammer pressing portion 17 of each key 2. In this state, the rear end of each key 2 is mounted to the key support portion 11 of the keyboard base 1 via the key support shaft 11a so as to be rotatable in the vertical direction.

[0094] In this manner, when the key guide 6 is inserted into the front portion of the key 2 and the contact sliding portion 25b of the key connecting portion 25 of the hammer member 20 is inserted into the hammer connecting portion 18 provided below the hammer pressing portion 17 of the key 2, the switch pressing portion 14 of the key 2 is arranged at a position corresponding to the bulged portion 16 of the switch portion 4 of the keyboard base 1. Thus, the keyboard musical instrument is assembled.

[0095] Next, the case of using the keyboard instrument assembled in this manner will be described.

[0096] First, in the initial state where key 2 is not pressed, as shown in FIG. Figure 1 As shown, the hammer member 20 rotates counterclockwise around the shaft body 24a of the rotating shaft portion 24 of the hammer body 22 by the weight of the hammer portion 23. The rear end portion of the hammer member 20 on the hammer portion 23 side abuts from above against the lower limit stopper 13 provided near the lower end portion of the rear leg portion 12 of the keyboard base 1. As a result, the rotational position of the hammer member 20 is restricted to the position M2.

[0097] At this time, if Figure 1 As shown, the hammer body 22 is not in contact with the second hammer limiting portion 32b of the hammer holder 21, but is separated from it. In addition, the hammer connecting portion 18 of the hammer pressing portion 17 of the key 2 is located at the tip end portion ( Figure 1 The key 2 is rotated counterclockwise about the key support shaft 11a of the key support portion 11 provided on the key receiving portion 10 of the keyboard base 1, and the tip of the key 2 is positioned at the upper limit. In this state, the switch pressing portion 14 of the key 2 is separated from the switch portion 4 and is located above it.

[0098] In this state, if the key 2 is pressed, Figure 2As shown, the key 2 rotates clockwise about the key support shaft 11a of the key support portion 11, and the hammer coupling portion 18 of the hammer pressing portion 17 depresses the key coupling portion 25 of the hammer member 20. As a result, the hammer member 20 rotates clockwise against the weight of the hammer portion 23. At this time, the rotation of the hammer member 20 applies an operating load to the key 2, increasing the key pressing load.

[0099] Then, as the key 2 is pressed, the hammer member 20 further rotates clockwise, and the rear end portion ( Figure 2 The left end of the key 2 (in the middle) approaches the upper limit stopper 28, such as a felt, provided on the lower surface of the key placement portion 10 of the keyboard base 1 from below. At this time, the switch portion 4 is pressed by the switch pressing portion 14 of the key 2, and the bulged portion 16 of the rubber plate elastically deforms, thereby outputting an on signal from the switch portion 4.

[0100] Thus, the sound generating unit 15a generates music information based on the ON signal from the switch unit 4, and plays music from the speaker (not shown) based on the generated music information. Figure 2 The left end portion (in the middle) contacts the upper limit stopper 28, such as a felt or the like, provided on the lower surface of the key placement portion 10 of the keyboard base 1 from below, thereby limiting the rotational position of the hammer member 20 to the upper limit position M1, and the hammer member 20 stops rotating. At this time, the hammer member 20 is no longer in contact with the first hammer limiter 32a of the hammer holder 21, but is separated therefrom.

[0101] Then, if the finger leaves the key 2 and starts the key-off action, the hammer component 20 rotates counterclockwise around the shaft body 24a of the rotating shaft portion 24 due to the weight of the hammer portion 23, and the key 2 uses the elastic restoring force of the bulge portion 16 of the switch portion 4 to start rotating counterclockwise around the key support shaft 11a of the key support portion 11.

[0102] Thereafter, if the hammer member 20 further rotates counterclockwise around the shaft body 24a of the rotating shaft portion 24, and the key 2 further rotates counterclockwise around the key support shaft 11a of the key support portion 11, the rear end portion of the hammer body 22 on the hammer portion 23 side abuts against the lower limit stopper 13 provided at the lower end portion of the rear leg portion 12 of the keyboard base 1 from above.

[0103] like Figure 1 As shown, the hammer connecting portion 18 of the hammer pressing portion 17 is located at the front end portion ( Figure 1 The key connecting portion 25 (at the right end) is pushed upward, causing the key 2 to rotate counterclockwise about the key support shaft 11a of the key support portion 11, with its front end positioned at the upper limit. In this state, the key 2 returns to its initial position, the hammer body 22 is no longer in contact with the second hammer limiter 32b, and the switch pressing portion 14 of the key 2 is separated from the switch portion 4 and positioned above it.

[0104] Thus, when the rotating shaft portion 24 of the hammer member 20 rotates about the bearing holes 27b of the pair of retaining pieces 27a of the hammer retaining portion 27 of the hammer retainer 21, the flange portion 24b of the rotating shaft portion 24 presses against the burr-side surface of the hammer body 22. Therefore, even if there is a burr on the edge of the mounting hole 22a of the hammer body 22, the burr is covered by the flange portion 24b, thereby preventing the influence of the burr.

[0105] Furthermore, with both ends of the shaft body 24a of the rotating shaft portion 24 inserted into the bearing holes 27b of the pair of retaining pieces 27a of the hammer retaining portion 27, the rotating shaft portion 24 is sandwiched between the pair of retaining pieces 27a, thereby retaining the hammer assembly 20 on the hammer retaining portion 27. Specifically, the flange portion 24b is positioned between the burr-facing surface of the hammer body 22 and the opposing surface of the retaining piece 27a. Consequently, the burr-facing surface of the hammer body 22 and the opposing surface of the retaining piece 27a do not contact each other. Therefore, when the hammer assembly 20 rotates, the retaining piece 27a is prevented from being ground by the burr on the hammer body 22.

[0106] Furthermore, the contact ribs 30 provided on the opposing surfaces of the pair of retaining pieces 27a are perpendicular to the horizontal upper surface of the base portion 26 of the hammer holder 21, except for the inclined upper portions, and are not provided with a draft angle. Consequently, when the rotating shaft portion 24 of the hammer member 20 is held between the pair of retaining pieces 27a, the flange portion 24b of the hammer body 22 facing the burr is evenly pressed by the contact ribs 30 of one retaining piece 27a, while the surface of the hammer body 22 opposite the burr is evenly pressed by the contact ribs 30 of the other retaining piece 27a.

[0107] As a result, when the hammer member 20 rotates while being held by the hammer holder 27, the contact area between the hammer member 20 and the pair of holding pieces 27a of the hammer holder 27 is reduced. Consequently, the frictional resistance between the pair of holding pieces 27a and the hammer member 20 is reduced, and lateral vibration of the hammer member 20 is prevented. As a result, the hammer member 20 rotates smoothly while being well held by the hammer holder 21.

[0108] At this time, a lubricant such as grease is filled into the stepped recess 31 provided between the contact ribs 30 and around the bearing hole 27b of one of the opposing surfaces of the pair of retaining pieces 27a. This ensures smooth and efficient rotation of the hammer member 20 when held by the hammer retaining portion 27. Furthermore, the contact ribs 30 surround both sides of the stepped recess 31 in the front-to-back direction, preventing the lubricant from leaking out and ensuring the lubricating performance of the lubricant over a long period of time.

[0109] As described above, this keyboard musical instrument includes a hammer unit 3 and a keyboard base 1. The hammer unit 3 includes a plurality of hammer members 20 each including a key-connecting portion 25 as a power point portion at one end side, a hammer 23 as a load point portion at the other end side, and a rotation shaft portion 24 as a fulcrum portion between the key-connecting portion 25 and the hammer 23; and a hammer holder 21 for rotatably holding the plurality of hammer members 20. The keyboard base 1 includes a lower limit stopper 13 and an upper limit stopper 28 as limiting members for limiting the rotation of the plurality of hammer members 20 within a limited range, and is provided with the hammer unit 3 mounted thereon.

[0110] Furthermore, in this keyboard instrument, when the hammer unit 3 is inverted vertically for installation in the keyboard base 1, the length in the front-to-back direction of the key 2 between the rotational shaft portion 24, serving as the fulcrum portion, of each of the plurality of hammer members 20 and the front end portion of the hammer member 20 on the hammer portion 23 side is longer than the length in the front-to-back direction of the key 2 between the rotational shaft portion 24 and one end of the upper limit stopper 28 on the rotational shaft portion 24 side. Consequently, the hammer holder 21 includes a plurality of first hammer restricting portions 32a, which serve as contact points on the key connection portion 25 side, serving as the respective force points, of the plurality of hammer members 20 when the hammer unit 30 is inverted vertically. This restricts the rotation of the plurality of hammer members 20 to a specific range, namely, the free rotation range F.

[0111] Specifically, in this keyboard instrument, when the rotational position of the hammer member 20 exceeds the limit range E, which is the rotational range within which the hammer member 20 rotates when a key 2 is pressed, that is, exceeds the rotational range within which the hammer member 20 rotates between the lower limit stopper 13 and the upper limit stopper 28, the rotation of the hammer member 20 can be restricted by the first hammer restricting portion 32a, which serves as a contact point on the power point side. Therefore, when the hammer holder 21, which rotatably retains the hammer member 20, is assembled to the keyboard base 1, the first hammer restricting portion 32a can prevent the hammer member 20 from significantly drooping, thereby improving assembly workability.

[0112] Furthermore, in this keyboard instrument, as described above, when the rotational position of the hammer member 20 exceeds the limit range E, which is the rotational range of the hammer member 20 when the key 2 is pressed, that is, exceeds the range within which the hammer member 20 rotates between the lower limit stopper 13 and the upper limit stopper 28, the first hammer limiter 32a, which serves as a contact point on the power point side, limits the rotation of the hammer member 20. Specifically, when the hammer member 20, while mounted on the keyboard base 1 by the hammer holder 21, rotates in response to a key press of the key 2 to apply an operating load to the key 2, the rotational movement of the hammer member 20 is not hindered by the first hammer limiter 32a.

[0113] Furthermore, in this keyboard instrument, the first hammer restricting portion 32a, serving as a contact point on the power point side, restricts the rotation of the hammer member 20, thereby minimizing drooping of the hammer 23 side of the hammer member 20. Therefore, when the hammer member 20 is rotatably held by the hammer holder 21 and the hammer holder 21 is turned upside down and assembled to the keyboard base 1, the hammer member 20 can be prevented from significantly drooping. This improves assembly workability.

[0114] Furthermore, in this keyboard musical instrument, when the hammer unit 3 is turned upside down and placed on the placement surface T for installation in the keyboard base 1, the hammer holder 21 holds the plurality of hammer members 20 in such a manner that the support protrusion 27c serving as the upper end thereof and the hammer portions 23 serving as the load points of the plurality of hammer members 20 contact the placement surface T. This allows the hammer holder 21 to be placed on the placement surface T in a stable state, thereby improving assembly workability.

[0115] That is, when the hammer portion 23 of the hammer member 20 and the hammer holder 21 are in contact with the placement surface T, the hammer member 20 does not contact the first and second hammer restricting portions 32a and 32b, which serve as restricting members of the hammer holder 21. Therefore, when the hammer holder 21 is turned upside down and assembled to the keyboard base 1 while the hammer member 20 is rotatably held, the hammer holder 21 can be well held and lifted by an automatic assembly machine, thereby improving assembly workability.

[0116] In this keyboard instrument, the plurality of hammer members 20 do not come into contact with the first hammer restricting portion 32 a, which serves as a contact point on the power point side, but rotate within the restriction range E in response to key operation. That is, when the hammer members 20 rotate within the restriction range E in response to key operation of the key 2, thereby applying an operating load to the key 2, the rotational movement of the hammer members 20 is not hindered by the first hammer restricting portion 32 a, so that the key 2 can be smoothly pressed.

[0117] Furthermore, the hammer holder 21 of this keyboard instrument includes a second hammer stopper 32b, which serves as a load-point contact point with which the hammers 23 of the plurality of hammer members 20, serving as load-point contacts, contact before the hammer unit 3 is installed in the keyboard base 1. Before the hammer unit 3 is installed in the keyboard base 1, the plurality of hammer members 20 are freely rotatable within a free rotation range F, from a position where they contact the second hammer stopper 32b, serving as a load-point contact point, to a position where they contact the first hammer stopper 32a, serving as a force-point contact point. When the hammer unit 3 is installed in the keyboard base, the hammer members 20 do not contact the second hammer stopper 32b, serving as a load-point contact point, but rotate within a restricted range E in response to key operation. Therefore, when the hammer members 20 rotate in response to a key operation of a key 2, applying an operating load to the key 2, the rotational movement of the hammer members 20 is not hindered by the second hammer stopper 32b, allowing for smooth key operation of the key 2.

[0118] In addition, in this keyboard instrument, since the hammer holder 21 can hold a plurality of hammer members 20, the plurality of hammer members 20 can be assembled to the keyboard base 1 at once using the hammer holder 21. This also improves assembly workability.

[0119] Furthermore, in this keyboard instrument, the hammer holder 21 can rotatably hold the hammer member 20 by the hammer holding portion 27 , and can reliably and satisfactorily hold the hammer member 20 .

[0120] Specifically, the hammer holding portion 27 is configured such that the bearing holes 27b are provided on both sides of the pair of holding pieces 27a so that the centers of the bearing holes 27b are coaxial. Therefore, when the rotating shaft portion 24 of the hammer member 20 is inserted into the bearing holes 27b, the rotating shaft portion 24 can be well clamped by the pair of holding pieces 27a. Thus, the hammer holding portion 27 can reliably and well hold the hammer member 20 in a rotatable state.

[0121] In this keyboard instrument, a given holding portion 27 includes a support protrusion 27c. This support protrusion 27c serves as an identifier for identifying whether the holding portion 27 is to hold the hammer assemblies 20 for the white keys or the hammer assemblies 20 for the black keys, before the holding portion 27 holds the plurality of hammer assemblies 20. Thus, the hammer assemblies 20 for the white keys and the hammer assemblies 20 for the black keys can be mounted separately on each of the plurality of holding portions 27 using the support protrusion 27c as a marker.

[0122] That is, the identifier of this keyboard instrument is a plurality of support protrusions 27c provided on the upper end of the holding portion 27 that holds the hammer members 20 for the white keys, and the height of the support protrusions 27c is higher than the upper end portion of the hammer holding portion 27 to which the hammer members 20 for the black keys are mounted. Thus, when the hammer members 20 for the white keys and the hammer members 20 for the black keys are mounted, the support protrusions 27c of the hammer holding portion 27 serve as markers to distinguish the hammer members 20 for the white keys from the hammer members 20 for the black keys.

[0123] Furthermore, the hammer holder 21 holds the plurality of hammer members 20 in such a manner that, when the hammer unit 3 is turned upside down and placed on the placement surface T for installation in the keyboard base 1, the plurality of support protrusions 27c and the hammer portions 23 of the plurality of hammer members 20, which serve as load points, contact the placement surface T. This prevents the hammer members 20 from contacting the first and second hammer restriction portions 32a and 32b, which serve as restriction members, of the hammer holder 21, allowing the hammer holder 21 to be stably positioned on the placement surface T. This also improves assembly workability.

[0124] Furthermore, in this keyboard instrument, the rotating shaft portion 24 of the hammer member 20 includes a shaft body 24a that is inserted into the bearing holes 27b of the pair of retaining pieces 27a, and a flange-shaped flange portion 24b provided on the shaft body 24a. Therefore, by pressing the flange portion 24b against the burr-facing surface of the hammer body 22, the burr can be covered with the flange portion 24b. Therefore, even if there is a burr on the edge of the mounting hole 22a of the hammer body 22, the burr can be covered to prevent its influence.

[0125] Furthermore, the hammer assembly 20 is held by sandwiching the rotating shaft 24 between the pair of retaining tabs 27a, with both ends of the shaft body 24a of the rotating shaft 24 inserted into the bearing holes 27b of the pair of retaining tabs 27a of the hammer retaining portion 27. This allows the flange 24b to be positioned between the burr-facing surface of the hammer body 22 of the hammer assembly 20 and the opposing surface of one retaining tab 27a, preventing contact between the burr-facing surface of the hammer body 22 and the opposing surface of one retaining tab 27a. This prevents the retaining tab 27a from being ground by the burrs of the hammer body 22 during rotation of the hammer assembly 20.

[0126] Furthermore, the upper sides of the opposing surfaces of the pair of retaining pieces 27a are inclined so as to expand upward. Thus, when the rotating shaft portion 24 of the hammer body 22 is inserted between the pair of retaining pieces 27a, the shaft body 24a of the rotating shaft portion 24 can be easily inserted between the pair of retaining pieces 27a while the rotating shaft portion 24 expands the pair of retaining pieces 27a.

[0127] Furthermore, the multiple contact ribs 30 on each opposing surface of the pair of retaining pieces 27a are perpendicular to the horizontal upper surface of the base portion 26 of the hammer retainer 21, except for the inclined upper portions, and have no draft angle in these portions. This allows the flange portion 24b, located on the burr-side surface of the hammer body 22, to be uniformly pressed against the contact ribs 30 of one retaining piece 27a, while also allowing the surface of the hammer body 22, opposite the burr side, to be uniformly pressed against the contact ribs 30 of the other retaining piece 27a.

[0128] Therefore, the contact ribs 30 can reduce the contact area between the hammer member 20 and the pair of retaining pieces 27a of the hammer retaining portion 27 during the rotation of the hammer member 20. This reduces the frictional resistance between the pair of retaining pieces 27a and the hammer member 20, and prevents lateral vibration of the hammer member 20. Therefore, the hammer member 20 can be smoothly rotated while being well retained.

[0129] Furthermore, on one of the opposing surfaces of the pair of retaining pieces 27a, a stepped recess 31 is surrounded by contact ribs 30 located on both sides of the retaining piece 27a in the front-to-back direction. This allows the stepped recess 31 to be filled with a lubricant such as grease, and by preventing the filled lubricant from flowing out, the lubricating performance of the lubricant can be maintained for a long period of time.

[0130] Furthermore, this keyboard instrument includes first and second positioning portions 34 and 36 for positioning the hammer holder 21 relative to the keyboard base 1. Thus, the first and second positioning portions 34 and 36 accurately regulate the position of the hammer holder 21 in the arrangement direction of the keys 2 and in the front-to-back direction of the keys 2, allowing the hammer holder 21 to be attached to the keyboard base 1 with high positioning accuracy.

[0131] Specifically, the first positioning portion 34 is a gap into which one of the mounting bosses 33 of the keyboard base 1 is inserted. By inserting one of the mounting bosses 33 of the keyboard base 1 into this gap, the position of the hammer holder 21 in the arrangement direction of the keys 2 can be accurately controlled. The second positioning portion 36 is an engaging protrusion that engages with a cutout 35a of a predetermined reinforcement rib 35 provided on the keyboard base 1. By engaging this engaging protrusion with the cutout 35a of the reinforcement rib 35, the position of the hammer holder 21 in the front-back direction of the keys 2 can be accurately controlled.

[0132] Furthermore, in the above-described embodiment, the hammer member 20 is provided with the rotating shaft portion 24, and the bearing holes 27b are provided on both the pair of retaining pieces 27a of the hammer retaining portion 27 of the hammer holder 21 so that their centers are coaxial. However, the present invention is not limited to this. For example, a configuration may be employed in which the bearing hole 27b is provided on the hammer member 20, and the rotating shaft portion 24 is provided on the opposing surfaces of the pair of retaining pieces 27a of the hammer retaining portion 27 of the hammer holder 21 so that their centers are coaxial.

[0133] As mentioned above, although several embodiments of the present invention have been described, the present invention is not limited thereto but includes the invention described in the claims and their equivalents.

Claims

1. A method for manufacturing a keyboard musical instrument, characterized in that: The keyboard instrument comprises a hammer unit and a keyboard base. The hammer unit has: a plurality of hammer members each having a force point portion provided at one end side, a load point portion provided at the other end side, and a fulcrum portion provided between the force point portion and the load point portion; and a hammer holder that holds the plurality of hammer members in a swingable manner; The aforementioned keyboard dock features: a unit mounting portion for mounting the hammer holder; and an upper limit limiting member that, when the load point portion of the hammer member moves upward in response to a key operation with the hammer holder attached to the lower surface of the unit mounting portion, abuts against the load point portion to limit the upper limit of the swing range of the plurality of hammer members; When assembling the above-mentioned keyboard instrument, Turn the keyboard base upside down. With the plurality of hammer members mounted on the hammer holder, the hammer unit is turned upside down and lifted. By bringing the power point side of each of the plurality of hammer members into contact with a contact point on the power point side of the hammer holder, the plurality of hammer members are held on the hammer holder in a predetermined holding state in which the plurality of hammer members do not droop to a predetermined angle or more. While maintaining the above-mentioned predetermined holding state, after the above-mentioned load point parts of the above-mentioned multiple hammer components are brought into contact with the above-mentioned upper limit limiting part of the above-mentioned keyboard base which is turned upside down, the above-mentioned hammer holder which is turned upside down is placed on the unit placing part of the above-mentioned keyboard base which is turned upside down.

2. The method for manufacturing a keyboard musical instrument according to claim 1, wherein: The predetermined holding state is a state in which a length of the key in the front-to-rear direction between the fulcrum portion and the other end of the load point portion of each of the plurality of hammer members is longer than a length of the key in the front-to-rear direction between the fulcrum portion and one end of the upper limit limiting member on the fulcrum portion side.

3. The method for manufacturing a keyboard musical instrument according to claim 1, wherein: Turn the keyboard base upside down and place it on the mounting surface of the assembly workbench. With the hammer unit in which the plurality of hammer members are mounted on the hammer holder in an upside-down state, the end portion of the hammer holder is brought into contact with the load point portions of the respective plurality of hammer members on the placement surface, thereby placing the hammer holder on the placement surface in a stable state. Thereafter, the hammer unit is lifted while being kept in an upside-down state and placed on the unit placement portion of the upside-down keyboard base.

4. The method for manufacturing a keyboard musical instrument according to claim 3, wherein: The hammer holder includes a plurality of holding pieces for respectively holding the plurality of hammer components. A plurality of protrusions are provided on the upper end of the retaining piece. When the hammer unit is inverted vertically, the plurality of projections and the load point portions of the plurality of hammer members abut against the placement surface, whereby the hammer holder is placed on the placement surface in a stable state.

5. The method for manufacturing a keyboard musical instrument according to claim 4, wherein: The plurality of hammer members include at least one hammer member for a white key and at least one hammer member for a black key having a shape different from that of the at least one hammer member for a white key. The plurality of holding pieces have identifiers, and when the plurality of holding pieces do not hold the plurality of hammer members, the identifiers are used to identify which of the hammer members, the at least one white key hammer member or the at least one black key hammer member, is held by the plurality of holding pieces. The identifiers are the plurality of protrusions provided on upper ends of a pair of holding pieces holding the at least one hammer member for the white key among the plurality of holding pieces.

6. The method for manufacturing a keyboard musical instrument according to any one of claims 1 to 5, wherein: The hammer holder has a plurality of load-point-side contacts that contact the load-point side of each of the plurality of hammer members when the hammer unit is not mounted on the keyboard base. This allows the plurality of hammer members to swing within a free swing range from the position of the load-point-side contacts to the position of the force-point-side contacts when the hammer unit is not mounted on the keyboard base. In response to the key operation in a state in which the hammer unit is mounted on the keyboard base, when the plurality of hammer members swing within the swing range, the plurality of hammer members do not come into contact with the load point side contacts.

7. A keyboard musical instrument, characterized in that: Equipped with hammer unit and keyboard base, The hammer unit has: a plurality of hammer members each having a force point portion provided at one end side, a load point portion provided at the other end side, and a fulcrum portion provided between the force point portion and the load point portion; and a hammer holder that holds the plurality of hammer members in a swingable manner; The aforementioned keyboard dock features: a unit mounting portion for mounting the hammer holder; and an upper limit limiting member that, when the load point portion of the hammer member moves upward in response to a key operation with the hammer holder attached to the lower surface of the unit mounting portion, abuts against the load point portion to limit the upper limit of the swing range of the plurality of hammer members; The hammer holder has a plurality of contact points on the force point side that come into contact with the force point side of each of the plurality of hammer members when the hammer unit that has been inverted vertically is installed in the keyboard base that has been inverted vertically. The plurality of hammer members are held by the hammer holder in a predetermined holding state in which the plurality of hammer members do not droop to a predetermined angle or more by the force point side of each of the plurality of hammer members contacting the force point side contact point of the hammer holder. While maintaining the above-mentioned predetermined holding state, after the above-mentioned load point parts of the above-mentioned multiple hammer components are brought into contact with the above-mentioned upper limit limiting part of the above-mentioned keyboard base which has been inverted vertically, the above-mentioned hammer holder which has been inverted vertically is placed on the unit placing part of the above-mentioned keyboard base which has been inverted vertically.

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