JP6997944B2 - Bearing structure, electronic keyboard instruments and equipment - Google Patents

Description

The present invention relates to a bearing structure used for an electronic keyboard instrument such as an electronic piano and a device having a rotation mechanism, and an electronic keyboard instrument and device provided with the bearing structure.

For example, in a keyboard device, as described in Patent Document 1, when a plurality of keys provided on a keyboard chassis are pressed, the hammer member is rotated by the key pressed. As a result, a structure is known in which an action load is applied to a key that has been pressed.

JP-A-2015-87592

In this type of keyboard device, in order to mount a plurality of hammer members on the keyboard chassis so as to be rotatable in the vertical direction in a state corresponding to each of the plurality of keys, a bearing portion of the hammer member is attached to a shaft portion provided on the keyboard chassis. It has a structure. In this case, the bearing portion includes a fitting hole in which the shaft portion rotatably fits in the center portion and a shaft insertion portion that guides the shaft portion from the outer periphery of the bearing portion to the fitting hole, and the entire bearing portion has a substantially C shape. Is formed in.

In such a keyboard device, if the dimensions of the shaft portion and the bearing portion vary during molding of the shaft portion of the keyboard chassis and the bearing portion of the hammer member, the outer peripheral surface of the shaft portion and the fitting hole of the bearing portion may be formed. Since a gap is generated between the inner peripheral surface and the inner peripheral surface, it is necessary to fill the gap with a lubricant such as grease.

However, in such a keyboard device, when the hammer member is repeatedly rotated by pressing a key, the bearing portion of the hammer member rattles with respect to the shaft portion of the keyboard chassis due to a decrease or deterioration of the lubricant, resulting in abnormal noise. The problem arises.

An object to be solved by the present invention is to provide a bearing structure capable of preventing rattling of a bearing portion with respect to a shaft, and an electronic keyboard instrument and an apparatus provided with the bearing structure.

In the present invention, a bearing portion provided with a shaft, an insertion hole and a fitting hole , elastically deformed when the shaft is inserted from the insertion hole, and the shaft fits into the fitting hole, and the bearing. It is provided at the boundary between the fitting hole and the insertion hole on the inner peripheral surface of the portion , and is slidably contacted with the outer peripheral surface of the shaft along the rotational direction of the shaft inserted into the bearing portion. It is a bearing structure characterized by having a protrusion.

According to the present invention, it is possible to prevent the bearing portion from rattling with respect to the shaft.

It is sectional drawing which showed one Embodiment which applied this invention to the keyboard apparatus of an electronic keyboard instrument. It is an enlarged side view which showed the hammer member of the keyboard apparatus shown in FIG. It is an enlarged view of the main part which showed the bearing part of the hammer member shown in FIG. In the keyboard device shown in FIG. 1, it is an enlarged perspective view of a main part of the hammer support portion of the keyboard chassis that rotatably supports the hammer member as viewed from the back surface side.

Hereinafter, an embodiment in which the present invention is applied to a keyboard device of an electronic keyboard instrument will be described with reference to FIGS. 1 to 4.
As shown in FIG. 1, this key device includes a key chassis 1 made of synthetic resin such as ABS resin, and a plurality of keys 2 arranged on the key chassis 1 and rotatably mounted in the vertical direction. A plurality of hammer members 3 that apply an action load to each of the keys 2 in response to the key pressing operation of the plurality of keys 2, and a switch unit 4 that is turned on in response to the key pressing operation of the plurality of keys 2. I have.

The keyboard chassis 1 is arranged in a musical instrument case (not shown). As shown in FIG. 1, a front leg portion 5 is provided at the front end portion (right end portion in FIG. 1) of the keyboard chassis 1 so as to project upward from the bottom portion. A key guide portion 6 for preventing lateral vibration of the key 2 is provided on the upper portion of the front leg portion 5 corresponding to each key 2.

Further, as shown in FIG. 1, a hammer mounting portion 7 is provided on the rear side (left side portion in FIG. 1) of the front leg portion 5 in the keyboard chassis 1 at a height slightly higher than that of the front leg portion 5. .. A hammer support portion 8 for supporting the hammer member 3 is provided on the lower surface of the hammer mounting portion 7 so as to project downward. The hammer support portion 8 is provided with a hammer support shaft 8a that rotatably supports the hammer member 3 in the vertical direction.

Further, as shown in FIG. 1, the board mounting portion 10 is one step lower in height at the substantially middle portion of the keyboard chassis 1 in the front-rear direction (horizontal direction in FIG. 1), that is, behind the upper part of the hammer key mounting portion 7. It is provided by the chassis. Above the board mounting portion 10, the switch portion 4 is mounted so as to straddle both the hammer mounting portion 7 and the board supporting portion 11. In this case, the substrate support portion 11 is provided upright on the upper surface on the rear side (left side in FIG. 1) of the substrate mounting portion 10.

Further, as shown in FIG. 1, a key mounting portion 12 is provided at the rear portion of the keyboard chassis 1, that is, on the rear side of the board mounting portion 10, at a height slightly lower than the upper portion of the key guide portion 6. There is. A key support portion 13 is provided on the upper surface of the key mounting portion 12 so as to project upward. The key support portion 13 is provided with a key support shaft 13a that rotatably supports the rear end portion of the key 2 in the vertical direction.

Further, at the rear end portion of the key mounting portion 12 in the keyboard chassis 1, as shown in FIG. 1, a rear leg portion 14 supporting the rear end portion of the keyboard chassis 1 is directed from the upper portion to the bottom portion of the keyboard chassis 1. It is hanging down. At the lower end of the rear leg portion 14, a lower limit stopper portion 15 such as felt for regulating the lower limit position of the hammer member 3 is provided.

On the other hand, the key 2 has a white key and a black key. However, in this embodiment, one white key will be described. As shown in FIG. 1, the key 2 has a rear end portion (left end portion in FIG. 1) in the vertical direction by a key support shaft 13a of a key support portion 13 provided on a key mounting portion 12 of the keyboard chassis 1. It is rotatably supported. A switch pressing portion 16 for pressing the switch portion 4 mounted on the board mounting portion 10 of the keyboard chassis 1 is located on the lower side in the substantially middle portion of the key 2 in the front-rear direction (horizontal direction in FIG. 1). It is provided so as to protrude.

In this case, as shown in FIG. 1, the switch portion 4 includes a dome-shaped bulging portion 18 in which a rubber sheet arranged on the switch substrate 17 is bulged. The dome-shaped bulging portion 18 is provided on the switch substrate 17 corresponding to the switch pressing portion 16 of the key 2. The front end (right end in FIG. 1) of the switch board 17 in the switch portion 4 is arranged on the hammer mounting portion 7, and the other end (left end in FIG. 1) is provided on the substrate mounting portion 10. It is arranged on the board support portion 11 and is mounted in a state of floating above the board mounting portion 10 in this state.

Further, as shown in FIG. 1, in this switch portion 4, when the bulging portion 18 of the rubber sheet is pressed by the switch pressing portion 16, the bulging portion 18 is elastically deformed and the movable contact inside thereof is formed. The ON signal is output by contacting the fixed contact of the switch board 17. In this case, the switch board 17 generates musical sound information based on the on signal from the switch unit 4, and the sounding unit 17a for emitting the musical sound from the speaker (not shown) based on the generated musical sound information. Is provided.

Further, as shown in FIG. 1, a hammer pressing portion 20 is provided at a position of the key 2 located on the front side (right side in FIG. 1) of the switch pressing portion 16 of the key 2 so as to project toward the lower side of the key 2. Has been done. At the lower part of the hammer pressing portion 20, a hammer holding portion 21 for slidably holding the key contact sliding portion 26 described later of the hammer member 3 is provided.

As shown in FIGS. 1 and 2, the hammer member 3 includes a hammer main body 23, a weight portion 24 provided at the rear portion (left side portion in FIG. 2) of the hammer main body 23, and a front side (front side) of the hammer main body 23. The key contact slide provided on the right end portion in FIG. 2) and the rotation mounting portion 25 which is the center of rotation of the hammer body 23 and the tip portion (right end portion in FIG. 2) located on the front side of the hammer body 23. It has a moving part 26 and.

As shown in FIGS. 1 and 2, the hammer member 3 has a key contact sliding portion 26 of the hammer body 23 in an opening 9a provided in the front descent portion 9 of the hammer mounting portion 7 of the keyboard chassis 1. In the inserted state, the rotary mounting portion 25 of the hammer body 23 is rotatably attached to the hammer support shaft 8a of the hammer support portion 8 provided on the lower surface of the hammer mounting portion 7, so that the hammer body 23 supports the hammer. It is designed to rotate in the vertical direction around the shaft 8a.

Further, as shown in FIGS. 1 and 2, the hammer member 3 is attached to the hammer body 23 when the rotary mounting portion 25 of the hammer body 23 is rotatably attached to the hammer support shaft 8a of the hammer support portion 8. The key contact sliding portion 26 provided at the tip portion (right end portion in FIG. 1) located on the front side is slidably inserted into the hammer holding portion 21 provided at the hammer pressing portion 20 of the key 2. It has become so.

As a result, as shown in FIGS. 1 and 2, the hammer body 23 rotates counterclockwise around the hammer support shaft 8a of the hammer support portion 8 due to the weight of the weight portion 24 under normal conditions. Then, the rear end portion (left end portion in FIG. 1) of the hammer body 23 on the weight portion 24 side abuts on the lower limit stopper portion 15 to regulate the position, and the key contact sliding portion 26 of the hammer body 23 is the key 2. The hammer pressing portion 20 of the above is pushed up to restrict the position of the key 2 to the upper limit position.

Further, as shown in FIGS. 1 and 2, when the key 2 is pressed from above, the hammer pressing portion 20 of the key 2 causes the key contact sliding portion 26 of the hammer body 23 to be hammered. It is pushed down against the weight of the weight portion 24 of the main body 23, and accordingly, the hammer main body 23 rotates clockwise around the hammer support shaft 8a of the hammer support portion 8 and is on the weight portion 24 side of the hammer main body 23. The rear end portion abuts on the upper limit stopper 12a such as felt provided on the lower surface of the key mounting portion 12 of the keyboard chassis 1, and the rotation of the hammer body 23 is stopped.

By the way, as shown in FIGS. 2 and 3, the rotary mounting portion 25 of the hammer member 3 is provided in the bearing mounting portion 27 mounted and mounted on the notch 30 of the hammer main body 23 and the bearing mounting portion 27. The bearing portion 28 is provided, and these are integrally formed of a highly rigid synthetic resin such as polyacetal (POM). In this case, the notch 30 of the hammer body 23 is provided on the front side (right side in FIG. 2) of the hammer body 23 and is opened toward the rear side (left side in FIG. 2) of the hammer body 23.

That is, as shown in FIGS. 2 and 3, the hammer main body 23 is inclined diagonally upward from the notch lower side portion 23a located at the lower part of the notch portion 30 and the front end portion of the notch lower side portion 23a. The notch inclined portion 23b, the notch front portion 23c extending vertically from the front upper portion of the notch inclined portion 23b, and the notch upper side located above the notch portion 30 from the upper end portion of the notch front side portion 23c. A section 23d and a section 23d are provided.

As a result, as shown in FIGS. 2 and 3, the bearing mounting portion 27 has a lower mounting portion 27a attached to the notch lower side portion 23a of the hammer main body 23 and an inner peripheral portion of the notch inclined portion 23b of the hammer main body 23. The inclined mounting portion 27b to be attached to the hammer body 23, the front mounting portion 27c to be attached to the inner peripheral portion of the notch front portion 23c of the hammer main body 23, and the upper mounting portion 27d to be attached to the notch upper side portion 23d of the hammer main body 23. Is equipped with.

As shown in FIGS. 2 and 3, the bearing mounting portion 27 is integrally provided with a lower mounting portion 27a, an inclined mounting portion 27b, a front mounting portion 27c, and an upper mounting portion 27d, and is notched in the hammer body 23. It is attached around the portion 30 so that it can be attached.

As shown in FIGS. 2 and 3, the bearing portion 28 is integrally provided on the inner peripheral portion of the bearing mounting portion 27, and is arranged in the notch portion 30 of the hammer main body 23. The bearing portion 28 has a substantially circular outer shape and is provided on the inner peripheral portion of the bearing mounting portion 27 in a state where it can be elastically deformed in the radial direction.

That is, as shown in FIGS. 2 and 3, the bearing portion 28 is provided in the bearing main body 31 and a hammer support shaft provided in the hammer support portion 8 of the keyboard chassis 1 provided at substantially the center of the bearing main body 31. It is provided with a fitting hole 32 into which the 8a is rotatably fitted, and an insertion hole 33 for guiding the hammer support shaft 8a from the outer peripheral side of the bearing portion 28 to the fitting hole 32.

As shown in FIGS. 2 and 3, the bearing main body 31 is integrally provided with the upper mounting portion 27d of the bearing mounting portion 27, and the outer peripheral portion other than the upper portion is inclined by the elastic support portion 31a. It is supported by the inner peripheral portion of the mounting portion 27b. That is, the elastic support portion 31a is provided between the inner peripheral portion of the inclined mounting portion 27b of the bearing mounting portion 27 and the outer peripheral portion of the bearing body 31 facing the inner peripheral portion.

As a result, as shown in FIGS. 2 and 3, the bearing body 31 is located between the outer peripheral surface of the bearing body 31 and the inner peripheral surface of the bearing mounting portion 27, except for the upper mounting portion 27d of the bearing mounting portion 27. A gap is provided so that the outer peripheral portion on the lower side of the bearing body 31 corresponding to the lower mounting portion 27a of the bearing mounting portion 27 is elastically displaced in the radial direction with the elastic support portion 31a as a fulcrum.

Further, as shown in FIGS. 2 and 3, the bearing body 31 is provided with a plurality of openings 31b at the lower portion corresponding to the lower mounting portion 27a of the bearing mounting portion 27 by a plurality of ribs 31c. In this case, the plurality of ribs 31c are provided so as to be elastically bendable. Therefore, in the bearing body 31, the diameter of the lower portion of the bearing body 31 corresponding to the lower mounting portion 27a of the bearing mounting portion 27 is large due to the elastic bending of the plurality of ribs 31c and the deformation of the plurality of openings 31b. It is designed to be elastically displaced in the direction.

Further, as shown in FIGS. 2 to 4, the fitting hole 32 of the bearing portion 28 is provided in a substantially circular shape in the central portion of the bearing main body 31, and is half on the inner peripheral surface located on the opposite side to the insertion hole 33. An arc-shaped recess 32a is provided. As a result, the fitting hole 32 is rotatably fitted with the hammer support shaft 8a provided in the hammer support portion 8 of the keyboard chassis 1 inside the fitting hole 32. In this case, the hammer support shaft 8a of the hammer support portion 8 is formed in the shape of a round bar having a circular cross section.

Further, as shown in FIGS. 2 and 3, the insertion hole 33 of the bearing portion 28 is provided from the outer peripheral portion located on the rear side (left side in FIG. 3) of the bearing main body 31 to the fitting hole 32. .. In this case, the insertion hole 33 is formed so that the groove width on the outer peripheral side of the bearing body 31 is the same as or slightly wider than the outer diameter of the hammer support shaft 8a of the hammer support portion 8. Further, the insertion hole 33 is formed so that the groove width at the portion located in the fitting hole 32 is slightly narrower than the outer diameter of the hammer support shaft 8a.

As a result, as shown in FIGS. 2 and 3, the insertion hole 33 guides the hammer support shaft 8a from the outer peripheral portion located on the rear side (left side in FIG. 3) of the bearing body 31 to the fitting hole 32. The insertion pressure inserted by the hammer support shaft 8a gradually increases. Therefore, the insertion hole 33 is elastically deformed so that the bearing body 31 gradually expands in the radial direction as the hammer support shaft 8a approaches the fitting hole 32, so that the groove width of the insertion hole 33 gradually expands. The hammer support shaft 8a is fitted into the fitting hole 32.

By the way, as shown in FIGS. 2 and 3, the inner peripheral surface of the fitting hole 32 of the bearing portion 28 is slidably contacted with the outer peripheral surface of the hammer support shaft 8a in the rotational direction of the bearing portion 28. A protrusion 34 is provided. These plurality of protrusions 34 are provided at the boundary between the fitting hole 32 and the insertion hole 33 of the bearing portion 28. That is, the plurality of protrusions 34 are provided at two locations located at the upper part and the lower part of the insertion hole 33 at the boundary between the fitting hole 32 and the insertion hole 33.

In this case, as shown in FIGS. 2 and 3, each of the plurality of protrusions 34 may be formed in a first mountain shape in which the tops are in point contact, and a second mountain shape in which the tops are in line contact. It may be formed in. That is, when the protrusion 34 has the first mountain shape, the frictional resistance is reduced by sliding on the outer peripheral surface of the hammer support shaft 8a by point contact. Further, when the protrusion 34 has a second mountain shape, the frictional resistance is reduced by sliding on the outer peripheral surface of the hammer support shaft 8a by line contact.

In this case, as shown in FIG. 3, in the fitting hole 32, when the hammer support shaft 8a is fitted, the plurality of protrusions 34 come into contact with the outer peripheral surface of the hammer support shaft 8a, and these plurality of protrusions 34 The outer peripheral surface of the hammer support shaft 8a comes into contact with each edge of the recess 32a located on the opposite side of the hammer support shaft 8a. As a result, the outer peripheral surface of the hammer support shaft 8a comes into contact with the inner peripheral surface of the fitting hole 32 at four points.

Further, as shown in FIG. 3, a lubrication reservoir 35 for accumulating a lubricant (not shown) such as grease is provided on the inner peripheral surface of the fitting hole 32 of the bearing portion 28 by a plurality of protrusions 34. ing. That is, in the fitting hole 32, the outer peripheral surface of the hammer support shaft 8a comes into contact with the inner peripheral surface thereof at four points by the plurality of protrusions 34. Therefore, the plurality of lubrication reservoirs 35 are provided between the protrusion 34 on the upper side and the upper edge of the recess 32a, and between the protrusion 34 on the lower side and the lower edge of the recess 32a, respectively. Has been done.

In this case, as shown in FIG. 4, the hammer support shaft 8a of the hammer support portion 8 is provided between the pair of support pieces 8b provided on the lower surface of the hammer mounting portion 7 of the keyboard chassis 1. Further, the bearing portion 28 of the hammer member 3 has a length (thickness) of its central axis in the axial direction equal to the length (width) between the pair of support pieces 8b, that is, the length in the axial direction of the hammer support shaft 8a. It is formed in the ken. Therefore, in the bearing portion 28 of the hammer member 3, both side surfaces in the axial direction of the central axis thereof come into contact with each facing surface of the pair of support pieces 8b.

As a result, as shown in FIGS. 3 and 4, the plurality of lubrication reservoirs 35 have the bearing portions 28 so that both side surfaces of the bearing portion 28 in the axial direction come into contact with each facing surface of the pair of support pieces 8b. Both sides of the lubrication reservoir 35 located in the axial direction are closed by the facing surfaces of the pair of support pieces 8b. For this reason, the plurality of lubrication reservoirs 35 are encapsulated with a lubricant such as grease without leaking from the axial direction of the bearing portion 28.

Next, the operation of such a keyboard device will be described.
First, in the initial state in which the key 2 is not pressed, the hammer member 3 rotates counterclockwise around the hammer support shaft 8a of the hammer support portion 8 due to the weight of the weight portion 24, as shown in FIG. However, the rear end portion of the hammer member 3 on the weight portion 24 side is in contact with the lower limit stopper 15 provided at the lower end portion of the rear leg portion 14 of the keyboard chassis 1 from above.

At this time, as shown in FIG. 1, the hammer holding portion 21 of the hammer pressing portion 20 of the key 2 is pushed up by the key contact sliding portion 26 located at the tip end portion (right end portion in FIG. 1) of the hammer body 23. Therefore, the key 2 is restricted to the upper limit position by rotating counterclockwise around the key support shaft 13a of the key support portion 13 provided on the key mounting portion 12 of the key chassis 1. In this state, the switch pressing portion 16 of the key 2 is located above and separated from the switch portion 4.

When the key 2 is pressed in this state, in FIG. 1, the key 2 rotates clockwise around the key support shaft 13a of the key support portion 13, and the hammer holding portion 21 of the hammer pressing portion 20 is a hammer member. Push down the key contact sliding portion 26 of 3. As a result, the hammer member 3 rotates clockwise in FIG. 1 against the weight of the weight portion 24. At this time, the action load is applied to the key 2 by the rotation of the hammer body 23 of the hammer member 3, so that the key load becomes heavy.

Then, the hammer member 3 further rotates clockwise as the key 2 is pressed, and the rear end portion (left end portion in FIG. 1) of the hammer body 23 is placed on the lower surface of the key mounting portion 12 of the keyboard chassis 1. It approaches the upper limit stopper 12a such as the provided felt from below. At this time, the switch unit 4 is pressed by the switch pressing unit 16 of the key 2, and the bulging portion 18 of the rubber sheet is elastically deformed, so that the switch unit 4 outputs a switch signal.

As a result, the sounding unit 17a generates musical sound information based on the on signal from the switch unit 4, and emits musical sound from the speaker (not shown) based on the generated musical sound information. After that, the rear end portion (left end portion in FIG. 1) of the hammer body 23 comes into contact with the upper limit stopper 12a such as felt provided on the lower surface of the key mounting portion 12 of the keyboard chassis 1 from below, and the hammer body 23 comes into contact with the hammer body 23. Restricted by the upper limit position, the rotation of the hammer member 3 is stopped.

Then, when the finger is separated from the key 2 and the key 2 starts the key release operation, the hammer body 23 of the hammer member 3 rotates counterclockwise around the hammer support shaft 8a of the hammer support portion 8 due to the weight of the weight portion 24. Then, the key 2 starts rotating counterclockwise around the key support shaft 13a of the key support portion 13 due to the elastic return force of the bulging portion 18 of the switch portion 4.

In this way, the hammer body 23 further rotates counterclockwise around the hammer support shaft 8a of the hammer support portion 8, and the key 2 further rotates counterclockwise around the key support shaft 13a of the key support portion 13. .. Then, the rear end portion of the hammer body 23 on the weight portion 24 side comes into contact with the lower limit stopper 15 provided at the lower end portion of the rear leg portion 14 of the keyboard chassis 1 from above.

As a result, as shown in FIG. 1, the key 2 is pushed up by the key contact sliding portion 26 in which the hammer holding portion 21 of the hammer pressing portion 20 is located at the tip end portion (right end portion in FIG. 1) of the hammer body 23. Therefore, the key 2 rotates counterclockwise around the key support shaft 13a of the key support portion 13 and is restricted to the upper limit position. In this state, the key 2 returns to the initial position, and the switch pressing portion 16 of the key 2 is located above the switch portion 4 and separates.

In this way, when the rotary mounting portion 25 of the hammer member 3 rotates about the hammer support shaft 8a of the hammer support portion 8 of the keyboard chassis 1, the bearing body 31 of the bearing portion 28 is radially in the hammer support shaft 8a. Since the bearing portion 28 is provided so as to be elastically deformable, a plurality of protrusions 34 provided on the inner peripheral surface of the fitting hole 32 in the bearing portion 28 elastically make point contact or line contact with the outer peripheral surface of the hammer support shaft 8a. In this state, the bearing portion 28 rotates about the hammer support shaft 8a.

That is, when the plurality of protrusions 34 elastically contact the outer peripheral surface of the hammer support shaft 8a, the outer circumference of the hammer support shaft 8a is attached to each edge of the recess 32a located on the opposite side of the plurality of protrusions 34. The faces come into contact. As a result, the inner peripheral surface of the fitting hole 32 of the bearing portion 28 elastically contacts the outer peripheral surface of the hammer support shaft 8a at four points. Therefore, the frictional resistance of the bearing portion 28 with respect to the hammer support shaft 8a is small, and the bearing portion 28 does not rattle with respect to the hammer support shaft 8a and rotates smoothly.

Further, at this time, since the lubrication reservoir 35 for accumulating the lubricating material (not shown) such as grease is provided on the inner peripheral surface of the fitting hole 32 of the bearing portion 28 by the plurality of protrusions 34, the hammer is supported. When the bearing portion 28 rotates with respect to the shaft 8a, a lubricating material such as grease stored in the plurality of lubricating reservoirs 35 can be reliably and satisfactorily applied to the outer peripheral surface of the hammer support shaft 8a.

That is, the plurality of lubrication reservoirs 35 are provided between the protrusion 34 on the upper side and the upper edge of the recess 32a, and between the protrusion 34 on the lower side and the lower edge of the recess 32a, respectively. Therefore, even if the bearing portion 28 repeatedly rotates with respect to the hammer support shaft 8a, the lubricating material such as grease stored in the plurality of lubrication reservoirs 35 can be smoothly and satisfactorily applied to the outer peripheral surface of the hammer support shaft 8a. Can be applied.

In this case, in the plurality of lubrication reservoirs 35, the bearing portion 28 rotates with respect to the hammer support shaft 8a in a state where both side surfaces of the bearing portion 28 in the axial direction are in contact with each facing surface of the pair of support pieces 8b. As a result, both sides of the plurality of lubrication reservoirs 35 in the axial direction can be closed by the facing surfaces of the pair of support pieces 8b. Therefore, since the lubricant such as grease stored in the plurality of lubrication reservoirs 35 does not leak from both sides of the plurality of lubrication reservoirs 35, even if the bearing portion 28 repeatedly rotates with respect to the hammer support shaft 8a. , It is possible to prevent the decrease of the lubricant.

As described above, according to the keyboard device of this electronic keyboard instrument, the hammer support shaft 8a and the bearing portion 28 provided with the insertion hole 33 and elastically deformed by the hammer support shaft 8a being inserted from the insertion hole 33. A protrusion 34 provided on the inner peripheral surface of the bearing portion 28 and slidably contacting the outer peripheral surface of the hammer support shaft 8a inserted into the bearing portion 28 along the rotation direction of the hammer support shaft 8a. By providing the bearing portion 28, it is possible to prevent the bearing portion 28 from rattling with respect to the hammer support shaft 8a.

That is, in this keyboard device, a plurality of protrusions 34 provided on the inner peripheral surface of the bearing portion 28 elastically deformable in the radial direction of the hammer support shaft 8a are elastically pressed against the outer peripheral surface of the hammer support shaft 8a. Therefore, when the bearing portion 28 rotates with respect to the hammer support shaft 8a, the plurality of protrusions 34 can be elastically slid along the outer peripheral surface of the hammer support shaft 8a. Therefore, the bearing portion 28 can be smoothly rotated by preventing the bearing portion 28 from rattling with respect to the hammer support shaft 8a.

In this case, the bearing portion 28 includes a bearing main body 31, and the outer peripheral portion of the bearing main body 31 is supported by the elastic support portion 31a on the inner peripheral portion of the bearing mounting portion 27 attached to the notch portion 30 of the hammer member 3. As a result, a gap can be provided between the outer peripheral surface of the bearing body 31 and the inner peripheral surface of the bearing mounting portion 27, so that the bearing body 31 is elastically displaced in the radial direction with the elastic support portion 31a as a fulcrum. Can be made to.

Further, in the bearing portion 28, since the plurality of openings 31b are provided in the bearing body 31 by a plurality of ribs 31c that can be elastically bent, the plurality of ribs 31c are elastically bent to a plurality of openings. Since the portion 31b can be deformed, the bearing body 31 can also be elastically displaced in the radial direction.

Further, in this keyboard device, the bearing portion 28 has a fitting hole 32 in which the bearing body 31 and the hammer support shaft 8a are fitted, and an insertion hole for guiding the hammer support shaft 8a from the outer periphery of the bearing body 31 to the fitting hole 32. When the bearing portion 28 is attached to the hammer support shaft 8a, the hammer support shaft 8a is inserted into the insertion hole 33, and the hammer support shaft 8a is fitted into the fitting hole 32 in the insertion hole 33. Can be surely guided to.

In this case, the groove width on the outer peripheral side of the bearing body 31 of the insertion hole 33 is the same as or slightly wider than the diameter of the hammer support shaft 8a, and the inner peripheral side of the fitting hole 32 is the hammer support shaft 8a. Since it is slightly narrower than the diameter, when the hammer support shaft 8a is inserted into the insertion hole 33 and guided to the fitting hole 32, the insertion hole 33 is elastically expanded and the hammer support shaft 8a is inserted into the fitting hole. It can be securely and satisfactorily fitted to 32, and when the hammer support shaft 8a is fitted into the fitting hole 32, the hammer support shaft 8a can be prevented from inadvertently coming out of the insertion hole 33. can.

Further, in this keyboard device, since a plurality of protrusions 34 are provided at the boundary between the insertion hole 33 and the fitting hole 32, the hammer support shaft 8a is fitted from the insertion hole 33 to the fitting hole 32. At that time, the plurality of protrusions 34 can reliably prevent the hammer support shaft 8a from inadvertently coming out of the insertion hole 33. That is, since the plurality of protrusions 34 are provided at two locations located at the upper part and the lower part of the insertion hole 33 at the boundary between the fitting hole 32 and the insertion hole 33, the hammer support shaft 8a is provided in the insertion hole 33. You can keep it from getting out of.

In this case, the protrusion 34 makes contact with the outer peripheral surface of the hammer support shaft 8a in either point contact or line contact, thereby reducing the contact area of the protrusion 34 with respect to the outer peripheral surface of the hammer support shaft 8a. This makes it possible to significantly reduce the frictional resistance when the bearing portion 28 rotates with respect to the hammer support shaft 8a.

That is, when the plurality of protrusions 34 are formed in a mountain shape having one apex, they can be slid on the outer peripheral surface of the hammer support shaft 8a by point contact, so that the frictional resistance is significantly reduced. be able to. Further, when the apex of the plurality of protrusions 34 is formed in a mountain shape continuous in the axial direction of the hammer support shaft 8a, the plurality of protrusions 34 can be slid on the outer peripheral surface of the hammer support shaft 8a by line contact. This can also reduce the frictional resistance.

In this case, the fitting hole 32 brings a plurality of protrusions 34 into contact with the outer peripheral surface of the hammer support shaft 8a when the hammer support shaft 8a is fitted, and the fitting hole 32 is located on the opposite side of the insertion hole 33. The outer peripheral surface of the hammer support shaft 8a can be brought into contact with each edge of the recess 32a provided on the inner peripheral surface of the 32.

Therefore, since the outer peripheral surface of the hammer support shaft 8a can be brought into contact with the inner peripheral surface of the fitting hole 32 at four points, the inner surface of the fitting hole 32 with respect to the outer peripheral surface of the hammer support shaft 8a can also be brought into contact with the fitting hole 32. The contact area of the peripheral surface can be reduced. Therefore, the frictional resistance when the bearing portion 28 rotates with respect to the hammer support shaft 8a can be further reduced.

Further, in this keyboard device, the bearing portion 28 rotates with respect to the hammer support shaft 8a because the lubrication reservoir 35 for storing the lubricating material such as grease is provided on the inner peripheral surface of the bearing portion 28 by the protrusion 34. When this is done, a lubricant such as grease can be reliably and satisfactorily applied to the outer peripheral surface of the hammer support shaft 8a, whereby the bearing portion 28 can be smoothly and satisfactorily rotated with respect to the hammer support shaft 8a. Can be done.

That is, in the lubrication reservoir 35, the outer peripheral surface of the hammer support shaft 8a comes into contact with the inner peripheral surface of the fitting hole 32 at four points by the plurality of protrusions 34, so that the protrusion 34 on the upper side and the upper side of the recess 32a Since it is provided between the edge of the bearing portion and between the protrusion 34 on the lower side and the lower edge of the recess 32a, the hammer supports the bearing portion 28 when the bearing portion 28 rotates with respect to the hammer support shaft 8a. A lubricating material such as grease can be reliably and satisfactorily applied to the outer peripheral surface of the shaft 8a.

In this case, the bearing portion 28 of the hammer member 3 is provided so that the hammer support shaft 8a of the hammer support portion 8 is provided between the pair of support pieces 8b provided on the lower surface of the hammer mounting portion 7 of the keyboard chassis 1. , Both side surfaces of the central axis of the bearing portion 28 in the axial direction can be brought into contact with each facing surface of the pair of support pieces 8b.

Therefore, in the bearing portion 28 of the hammer member 3, both sides of the plurality of lubrication reservoirs 35 in the axial direction can be closed by the facing surfaces of the pair of support pieces 8b, so that the inside of the plurality of lubrication reservoirs 35 can be closed. Lubricating material such as grease filled in the bearing portion 28 can be sealed so as not to leak from the axial direction of the bearing portion 28.

In the above-described embodiment, the case where the plurality of protrusions 34 are provided on the inner peripheral surface of the fitting hole 32 of the bearing portion 28 is described, but the present invention is not limited to this, and for example, the plurality of protrusions 34 are provided. May be provided on the outer peripheral surface of the hammer support shaft 8a.

Further, in the above-described embodiment, the case where the lubricating reservoir 35 provided on the inner peripheral surface of the fitting hole 32 of the bearing portion 28 is filled with a lubricating material such as grease has been described. Not limited to this, the bearing portion 28 of the hammer member 3 may be formed of a synthetic resin impregnated with silicone oil so that the silicone oil seeps out when the bearing portion 28 rotates with respect to the hammer support shaft 8a. ..

Further, in the above-described embodiment, the case where the bearing portion 28 of the hammer member 3 is rotatably attached to the hammer support shaft 8a of the keyboard chassis 1 in the keyboard device of the electronic keyboard instrument has been described. Not limited to this, for example, a bearing portion 28 may be provided at the rear end portion of the key 2 so that the bearing portion 28 of the key 2 can be rotatably attached to the key support shaft 13a of the keyboard chassis 1.

Further, in the above-described embodiment, the case where it is applied to the keyboard device of an electronic keyboard instrument has been described, but the present invention is not limited to this, and the present invention includes a shaft and a bearing portion, and a bearing structure in which these are relatively rotated. It can also be applied to equipped equipment.

Although one embodiment of the present invention has been described above, the present invention is not limited to this, and includes the invention described in the claims and the equivalent range thereof.
Hereinafter, the inventions described in the claims of the present application will be added.

(Additional note)
The invention according to claim 1 has a shaft, a bearing portion provided with an insertion hole and elastically deformed when the shaft is inserted through the insertion hole, an outer peripheral surface of the shaft, and an inner circumference of the bearing portion. It is provided on one of the surfaces and slidably contacts the outer peripheral surface of the shaft and the inner peripheral surface of the bearing portion along the rotational direction of the shaft inserted in the bearing portion. It is a bearing structure characterized by having a protrusion.

The invention according to claim 2 is the bearing structure according to claim 1, wherein the bearing portion is provided with a fitting hole into which the shaft is fitted.

The invention according to claim 3 is the bearing structure according to claim 2, wherein the protrusion is provided at a boundary portion between the fitting hole and the insertion hole. ..

The invention according to claim 4 is the bearing structure according to any one of claims 1 to 3, wherein the protrusion has either point contact or line contact with the outer peripheral surface of the shaft. It is a bearing structure characterized by contact.

According to a fifth aspect of the present invention, in the bearing structure according to any one of claims 1 to 4, a lubrication reservoir for accumulating a lubricant by the protrusion is provided on the inner peripheral surface of the fitting hole. It is a bearing structure characterized by being lubricated.

The invention according to claim 6 includes a keyboard device having the bearing structure according to any one of claims 1 to 5, and a sounding unit that generates a musical sound in response to the operation of the keyboard device. It is an electronic keyboard instrument characterized by being present.

The invention according to claim 7 is the electronic keyboard instrument according to claim 6, wherein the keyboard device is rotated according to a key pressing operation of each of a plurality of keys rotatably provided on the keyboard chassis. It is an electronic keyboard instrument characterized in that each rotating portion of a plurality of hammer members that apply an action load to each of the plurality of keys has the bearing structure.

The invention according to claim 8 is an apparatus comprising the bearing structure according to any one of claims 1 to 5.

1 Keyboard chassis 2 Key 3 Hammer member 4 Switch part 8 Hammer support part 8a Hammer support shaft 13 Key support part 13a Key support shaft 17a Sounding part 23 Hammer body 24 Weight part 25 Rotation mounting part 26 Key contact sliding part 27 Bearing mounting Part 28 Bearing part 30 Notch 31 Bearing body 31a Elastic support 31b Opening 31c Rib 32 Fitting hole 32a Recess 33 Insertion hole 34 Protrusion 35 Lubrication reservoir

Claims (6)

Axis and
A bearing portion provided with an insertion hole and a fitting hole , elastically deformed when the shaft is inserted from the insertion hole, and the shaft fits into the fitting hole .
It is provided at the boundary between the fitting hole and the insertion hole on the inner peripheral surface of the bearing portion, and can slide on the outer peripheral surface of the shaft along the rotation direction of the shaft inserted in the bearing portion. With the protrusions that come into contact,
Bearing structure characterized by being equipped with. The bearing structure according to claim 1 , wherein the protrusion is in contact with the outer peripheral surface of the shaft in either point contact or line contact. The bearing structure according to claim 1 or 2 , wherein a lubrication reservoir for accumulating a lubricating material is provided on the inner peripheral surface of the fitting hole by the protrusion. A keyboard device having the bearing structure according to any one of claims 1 to 3 .
A sounding unit that generates musical tones in response to the operation of the keyboard device,
An electronic keyboard instrument characterized by being equipped with. In the electronic keyboard instrument according to claim 4 , the keyboard device rotates in response to a key pressing operation of each of a plurality of keys rotatably provided on the keyboard chassis, and an action load is applied to each of the plurality of keys. An electronic keyboard instrument characterized in that each rotating portion of a plurality of hammer members has the bearing structure. An apparatus comprising the bearing structure according to any one of claims 1 to 3 .

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