JP2019056874A - Bearing structure, electronic keyboard instrument and device - Google Patents

Abstract

To provide a bearing structure capable of preventing rattling of a bearing with respect to a shaft, and an electronic keyboard instrument and a device including the same.SOLUTION: The bearing structure comprises: a bearing portion 28 which is provided with a hammer support shaft 8a and an insertion hole 33, and is elastically deformed by inserting the hammer support shaft 8a from the insertion hole 33; and projections 34 which are provided on an inner peripheral surface of the bearing portion 28 and slidably contact along the rotation direction of the hammer support shaft 8a with an outer peripheral surface of the hammer support shaft 8a inserted into the bearing portion 28. Therefore, since the plurality of projections 34 provided on the inner peripheral surface of the bearing portion 28 elastically deformable in the radial direction of the hammer support shaft 8a can be elastically pressed against the outer peripheral surface of the hammer support shaft 8a, the plurality of projections 34 can be resiliently slid along the outer peripheral surface of the hammer support shaft 8a. By this, it is possible to prevent the rattling of the bearing portion 28 with respect to the hammer support shaft 8a and to rotate the bearing portion 28 smoothly.SELECTED DRAWING: Figure 3

Description

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

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

Japanese Patent Laying-Open No. 2015-87592

  In this type of keyboard device, a plurality of hammer members are attached to the keyboard chassis so as to be rotatable in the vertical direction in a state corresponding to each of the plurality of keys. Therefore, a bearing portion of the hammer member is attached to a shaft portion provided in the keyboard chassis. It has a structure. In this case, the bearing portion includes a fitting hole in which the shaft portion is rotatably fitted 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 whole is substantially C-shaped. Is formed.

  In such a keyboard device, when the shaft portion of the keyboard chassis and the bearing portion of the hammer member are molded, if the dimensions of the shaft portion and the bearing portion vary, the fitting hole between the outer peripheral surface of the shaft portion and the bearing portion is formed. Since a gap is generated between the inner peripheral surface and the gap, 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 the key pressing operation, the bearing portion of the hammer member rattles with respect to the shaft portion of the keyboard chassis due to the decrease or deterioration of the lubricant, resulting in abnormal noise. The problem that occurs occurs.

  The problem to be solved by the present invention is to provide a bearing structure capable of preventing the backlash of the bearing portion with respect to the shaft, and an electronic keyboard instrument and apparatus including the same.

  The present invention includes a shaft, an insertion hole, a bearing portion that is elastically deformed when the shaft is inserted through the insertion hole, and one of an outer peripheral surface of the shaft and an inner peripheral surface of the bearing portion. A protrusion that is slidably in contact with the other of the outer peripheral surface of the shaft and the inner peripheral surface of the bearing portion along the rotational direction of the shaft inserted into the bearing portion; It is the bearing structure characterized by having.

  According to this invention, rattling of the bearing portion with respect to the shaft can be prevented.

It is sectional drawing which showed one Embodiment which applied this invention to the keyboard apparatus of the electronic keyboard musical instrument. FIG. 2 is an enlarged side view showing a hammer member of the keyboard device shown in FIG. 1. It is an enlarged view of the principal part which showed the bearing part of the hammer member shown by FIG. In the keyboard apparatus shown in FIG. 1, it is the expansion perspective view of the principal part which looked at the hammer support part of the keyboard chassis which rotatably supports a hammer member from the back surface side.

Hereinafter, an embodiment in which the present invention is applied to a keyboard apparatus for an electronic keyboard instrument will be described with reference to FIGS.
As shown in FIG. 1, the keyboard device includes a keyboard chassis 1 made of a synthetic resin such as ABS resin, and a plurality of keys 2 arranged on the keyboard chassis 1 and attached to be rotatable in the vertical direction. A plurality of hammer members 3 that apply an action load to each of the keys 2 in accordance with a key pressing operation of the plurality of keys 2, and a switch unit 4 that is turned on in response to a 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 protrude upward from the bottom portion. On the upper part of the front leg portion 5, key guide portions 6 for preventing the lateral movement of the key 2 are provided corresponding to the respective keys 2.

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

  Further, as shown in FIG. 1, the board mounting portion 10 is one step lower in the middle of the keyboard chassis 1 in the front-rear direction (left-right direction in FIG. 1), that is, at the upper rear of the hammer key mounting portion 7. It is provided. Above the substrate platform 10, the switch unit 4 is attached in a state straddling both the hammer platform 7 and the substrate support unit 11. In this case, the substrate support unit 11 is provided upright on the upper surface of the rear side (left side in FIG. 1) of the substrate platform 10.

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

  Further, as shown in FIG. 1, a rear leg portion 14 for supporting the rear end portion of the keyboard chassis 1 is directed from the top of the keyboard chassis 1 to the bottom, as shown in FIG. Is drooping. A lower limit stopper portion 15 such as a felt for restricting the lower limit position of the hammer member 3 is provided at the lower end portion of the rear leg portion 14.

  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) vertically moved by a key support shaft 13 a of a key support portion 13 provided on the key placement 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 a substantially middle portion of the key 2 in the front-rear direction (left-right direction in FIG. 1). Protrusively provided.

  In this case, as shown in FIG. 1, the switch unit 4 includes a dome-shaped bulging portion 18 bulging a rubber sheet disposed on the switch substrate 17. 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 switch substrate 17 in the switch unit 4 has a front end portion (right end portion in FIG. 1) disposed on the hammer placement portion 7 and the other end portion (left end portion in FIG. 1) provided on the substrate placement portion 10. It is arranged on the substrate support part 11 thus mounted, and is attached in such a state that it floats above the substrate platform 10.

  Further, as shown in FIG. 1, when the bulging portion 18 of the rubber sheet is pressed by the switch pressing portion 16, the switch portion 4 elastically deforms the bulging portion 18 so that the movable contact inside the bulging portion 18 An ON signal is output by contacting the fixed contact of the switch board 17. In this case, on the switch board 17, tone information is generated based on the ON signal from the switch unit 4, and a tone generator 17 a for emitting a tone from a speaker (not shown) based on the generated tone information. Is provided.

  Further, as shown in FIG. 1, a hammer pressing portion 20 is provided projecting toward the lower side of the key 2 at the location of the key 2 located on the front side (right side in FIG. 1) of the switch pressing portion 16 of the key 2. It has been. A hammer holding portion 21 that slidably holds a later-described key abutting sliding portion 26 of the hammer member 3 is provided below the hammer pressing portion 20.

  As shown in FIGS. 1 and 2, the hammer member 3 includes a hammer body 23, a weight portion 24 provided on the rear portion (left side portion in FIG. 2) of the hammer body 23, and the front side of the hammer body 23 ( 2 is provided on the right side), and a rotation attachment portion 25 serving as the rotation center of the hammer body 23 and a key abutting slide provided on a front end portion (right end portion in FIG. 2) located on the front side of the hammer body 23. Moving part 26.

  As shown in FIGS. 1 and 2, the hammer member 3 has a key abutting sliding portion 26 of the hammer body 23 in an opening 9 a provided in the front descending 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 mounted on 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 rotates in the vertical direction about the shaft 8a.

  As shown in FIGS. 1 and 2, the hammer member 3 is configured such that when the rotation mounting portion 25 of the hammer body 23 is rotatably mounted on the hammer support shaft 8 a of the hammer support portion 8, A key abutting sliding portion 26 provided at a front end portion (right end portion in FIG. 1) located on the front side is slidably inserted into a hammer holding portion 21 provided in a hammer pressing portion 20 of the key 2. It has become so.

  Thereby, as shown in FIGS. 1 and 2, the hammer member 3 rotates counterclockwise around the hammer support shaft 8a of the hammer support portion 8 by the weight of the weight portion 24 in the normal state. The rear end portion (left end portion in FIG. 1) of the hammer main body 23 abuts against the lower limit stopper portion 15, and the position of the hammer main body 23 is restricted. The hammer 2 is pushed up to restrict the position of the key 2 to the upper limit position.

  In addition, as shown in FIGS. 1 and 2, when the key 2 is depressed from above, the hammer member 3 causes the key abutting sliding portion 26 of the hammer body 23 to be hammered by the hammer pressing portion 20 of the key 2. The hammer body 23 is pushed down against the weight of the weight portion 24 of the main body 23, and the hammer body 23 rotates clockwise around the hammer support shaft 8 a of the hammer support portion 8. The rear end portion comes into contact with an upper limit stopper 12a such as a felt provided on the lower surface of the key placing portion 12 of the keyboard chassis 1, and the rotation of the hammer body 23 is stopped.

  By the way, as shown in FIG. 2 and FIG. 3, the rotation attachment portion 25 of the hammer member 3 is provided on the bearing attachment portion 27 attached to the notch portion 30 of the hammer body 23 and attached thereto, and the bearing attachment portion 27. And 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 obliquely upward from the notch lower side portion 23 a located at the lower portion of the notch portion 30 and the front end portion of the notch lower side portion 23 a. A notch inclined portion 23b, a notch front portion 23c extending vertically from the upper front side of the notch inclined portion 23b, and an upper side of the notch located above the notch portion 30 from the upper end portion of the notch front side portion 23c. Part 23d.

  As a result, the bearing mounting portion 27 includes, as shown in FIGS. 2 and 3, a lower mounting portion 27a attached to the notched lower side portion 23a of the hammer body 23 and an inner peripheral portion of the notched inclined portion 23b of the hammer body 23. An inclined attachment portion 27b attached to the front end portion 27c attached to the inner peripheral portion of the notch front portion 23c of the hammer body 23, and an upper attachment portion 27d attached to the notch upper side portion 23d of the hammer body 23; It has.

  As shown in FIGS. 2 and 3, the bearing mounting portion 27 includes a lower mounting portion 27a, an inclined mounting portion 27b, a front mounting portion 27c, and an upper mounting portion 27d that are integrally provided. It is mounted around the part 30 and attached.

  As shown in FIGS. 2 and 3, the bearing portion 28 is provided integrally with the inner peripheral portion of the bearing mounting portion 27 and is disposed in the notch portion 30 of the hammer 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 FIG. 2 and FIG. 3, the bearing portion 28 includes a bearing main body 31 and a hammer support shaft provided in the hammer support portion 8 of the keyboard chassis 1 provided at a substantially central portion of the bearing main body 31. A fitting hole 32 into which 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 are provided.

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

  As a result, the bearing body 31 is formed 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, as shown in FIGS. A clearance is provided, and 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.

  As shown in FIGS. 2 and 3, the bearing body 31 has a plurality of openings 31 b formed by a plurality of ribs 31 c at the lower portion corresponding to the lower mounting portion 27 a of the bearing mounting portion 27. In this case, the plurality of ribs 31c are provided so as to be elastically bendable. For this reason, this bearing body 31 has a plurality of ribs 31c flexibly bent and a plurality of openings 31b deformed, so that the lower side of the bearing body 31 corresponding to the lower mounting portion 27a of the bearing mounting portion 27 has a diameter. It is elastically displaced in the direction.

  2 to 4, the fitting hole 32 of the bearing portion 28 is provided in a substantially circular shape at the center portion of the bearing main body 31, and is half on the inner peripheral surface located on the side opposite to the insertion hole 33. An arcuate recess 32a is provided. Thus, the fitting hole 32 is configured such that a hammer support shaft 8a provided in the hammer support portion 8 of the keyboard chassis 1 is rotatably fitted therein. In this case, the hammer support shaft 8a of the hammer support portion 8 is formed in a round bar shape with 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 (the left side in FIG. 3) 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 8 a of the hammer support portion 8. Further, the insertion hole 33 is formed such that the groove width at the position located in the fitting hole 32 is slightly narrower than the outer diameter of the hammer support shaft 8a.

  Thereby, as shown in FIG. 2 and FIG. 3, the insertion hole 33 is used when guiding the hammer support shaft 8 a from the outer peripheral portion located on the rear side (the left side in FIG. 3) 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 increases. The hammer support shaft 8 a 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 in contact with the outer peripheral surface of the hammer support shaft 8 a so as to be slidable in the rotational direction of the bearing portion 28. A protrusion 34 is provided. The 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 projecting portions 34 are provided at two positions located at the upper and lower portions of the insertion hole 33 at the boundary between the fitting hole 32 and the insertion hole 33.

  In this case, as shown in FIG. 2 and FIG. 3, each of the plurality of protrusions 34 may be formed in a first mountain shape in which the top is in point contact, and the second mountain shape in which the top is in line contact. It may be formed. 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 the second mountain shape, the frictional resistance is reduced by sliding in a line contact with the outer peripheral surface of the hammer support shaft 8a.

  In this case, as shown in FIG. 3, when the hammer support shaft 8 a is fitted, the fitting holes 32 come into contact with the outer peripheral surface of the hammer support shaft 8 a, and the plurality of projections 34. The outer peripheral surface of the hammer support shaft 8a is in contact with each edge of the recess 32a located on the opposite side. Thus, the fitting hole 32 is configured such that the outer peripheral surface of the hammer support shaft 8a contacts the inner peripheral surface at four points.

  Further, as shown in FIG. 3, lubrication reservoir portions 35 that accumulate lubricant (not shown) such as grease are provided on the inner peripheral surface of the fitting hole 32 of the bearing portion 28, as shown in FIG. 3. ing. That is, the outer peripheral surface of the hammer support shaft 8 a is in contact with the inner peripheral surface of the fitting hole 32 at four points by the plurality of protrusions 34. For this reason, the plurality of lubricating reservoirs 35 are provided between the upper projection 34 and the upper edge of the recess 32a, and between the lower projection 34 and the lower edge of the recess 32a, respectively. It has been.

  In this case, the hammer support shaft 8a of the hammer support portion 8 is provided between a pair of support pieces 8b provided on the lower surface of the hammer placement portion 7 of the keyboard chassis 1, as shown in FIG. Further, the bearing portion 28 of the hammer member 3 has an axial length (thickness) of the central axis thereof that is the same as the length (width) between the pair of support pieces 8b, that is, the axial length of the hammer support shaft 8a. Is formed. For this reason, as for the bearing part 28 of the hammer member 3, the both side surfaces of the axial direction of the central axis contact each opposing surface of a pair of support piece 8b.

  Accordingly, as shown in FIGS. 3 and 4, the plurality of lubrication reservoirs 35 are configured so that the axially opposite side surfaces of the bearing portion 28 come into contact with the opposing surfaces of the pair of support pieces 8 b. Both side portions of the lubricating reservoir 35 positioned in the axial direction are closed by the opposing surfaces of the pair of support pieces 8b. For this reason, the plurality of lubrication reservoirs 35 are filled 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, when the key 2 is in an initial state where the key is not depressed, the hammer member 3 rotates counterclockwise around the hammer support shaft 8a of the hammer support portion 8 by the weight of the weight portion 24 as shown in FIG. The rear end portion of the hammer member 3 on the side of the weight portion 24 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 abutting sliding portion 26 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 provided on the key placement portion 12 of the keyboard chassis 1 and is restricted to the upper limit position. In this state, the switch pressing portion 16 of the key 2 is located above the switch portion 4 and separated.

  In this state, when the key 2 is pressed, the key 2 rotates clockwise around the key support shaft 13a of the key support portion 13 in FIG. 1, and the hammer holding portion 21 of the hammer pressing portion 20 becomes the hammer member. 3 key abutting sliding part 26 is pushed down. Thereby, the hammer member 3 rotates clockwise in FIG. 1 against the weight of the weight portion 24. At this time, since the action load is applied to the key 2 by the rotation of the hammer body 23 of the hammer member 3, the key load becomes heavy.

  As the key 2 is pressed, the hammer member 3 further rotates clockwise, 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 placement portion 12 of the keyboard chassis 1. The upper limit stopper 12a such as felt is approached from below. At this time, the switch portion 4 is pressed by the switch pressing portion 16 of the key 2 and the bulging portion 18 of the rubber sheet is elastically deformed, so that the switch portion 4 outputs a switch signal.

  As a result, the sound generation unit 17a generates musical sound information based on the ON signal from the switch unit 4, and the musical sound is emitted from a speaker (not shown) based on the generated musical sound information. Thereafter, 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 placement portion 12 of the keyboard chassis 1 from below, and the hammer body 23 is The rotation of the hammer member 3 is stopped by the upper limit position.

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

  Thus, 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.

  Thereby, as shown in FIG. 1, the key 2 is pushed up by the key abutting 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 positioned above the switch portion 4 and is separated.

  Thus, when the rotation 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 main body 31 of the bearing portion 28 moves in the radial direction of the hammer support shaft 8a. The plurality of projections 34 provided on the inner peripheral surface of the fitting hole 32 in the bearing portion 28 are elastically point-contacted or line-contacted with the outer peripheral surface of the hammer support shaft 8a. In this state, the bearing portion 28 rotates around 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 periphery of the hammer support shaft 8a is provided at each edge of the recess 32a located on the opposite side of the plurality of protrusions 34. The surfaces touch. Thereby, 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. For this reason, there is little frictional resistance of the bearing part 28 with respect to the hammer support shaft 8a, the bearing part 28 does not rattle with respect to the hammer support shaft 8a, and rotates smoothly.

  Further, at this time, since the lubricating reservoir 35 for storing a lubricant (not shown) such as grease is provided on the inner peripheral surface of the fitting hole 32 of the bearing 28 by the plurality of protrusions 34, the hammer support is provided. When the bearing portion 28 rotates with respect to the shaft 8a, a lubricant such as grease stored in the plurality of lubricating reservoir portions 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 respectively provided between the upper projection 34 and the upper edge of the recess 32a, and between the lower projection 34 and the lower edge of the recess 32a. Therefore, even if the bearing portion 28 rotates repeatedly with respect to the hammer support shaft 8a, the lubricant such as grease stored in the plurality of lubricant reservoir portions 35 is smoothly and satisfactorily applied to the outer peripheral surface of the hammer support shaft 8a. Can be applied.

  In this case, the plurality of lubrication reservoirs 35 are such that the bearing portions 28 rotate with respect to the hammer support shaft 8a in a state where both axial side surfaces of the bearing portions 28 are in contact with the opposing surfaces of the pair of support pieces 8b. Thus, both sides in the axial direction of the plurality of lubricant reservoirs 35 can be closed with the opposing surfaces of the pair of support pieces 8b. For this reason, 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 unit 28 rotates repeatedly with respect to the hammer support shaft 8a. , Can prevent the reduction of lubricant.

  Thus, according to the keyboard device of this electronic keyboard instrument, the hammer support shaft 8 a and the insertion hole 33 are provided, and the bearing portion 28 that is elastically deformed by inserting the hammer support shaft 8 a 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 play of the bearing part 28 with respect to the hammer support shaft 8a can be prevented.

  That is, in this keyboard device, a plurality of protrusions 34 provided on the inner peripheral surface of the bearing portion 28 that is 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. For this reason, the play of the bearing part 28 with respect to the hammer support shaft 8a can be prevented and the bearing part 28 can be smoothly rotated.

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

  In addition, the bearing portion 28 is provided with a plurality of openings 31b in the bearing body 31 by a plurality of elastically bendable ribs 31c, whereby the plurality of ribs 31c are elastically bent and a plurality of openings are formed. Since the part 31b can be deformed, the bearing body 31 can be elastically displaced in the radial direction also by this.

  Further, in this keyboard device, the bearing portion 28 includes a bearing body 31, a fitting hole 32 into which the hammer support shaft 8 a is fitted, and an insertion hole for guiding the hammer support shaft 8 a from the outer periphery of the bearing body 31 to the fitting hole 32. 33, when attaching the bearing portion 28 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 inserted into the fitting hole 32 through the insertion hole 33. Can lead to sure.

  In this case, in the insertion hole 33, the groove width on the outer peripheral side of the bearing body 31 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 on the hammer support shaft 8a. Since the diameter 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 so that the hammer support shaft 8a is fitted into the fitting hole. 32 can be securely and satisfactorily fitted, and when the hammer support shaft 8a is fitted into the fitting hole 32, the hammer support shaft 8a is prevented from inadvertently coming out of the insertion hole 33. it can.

  In this keyboard device, the plurality of protrusions 34 are provided at the boundary between the insertion hole 33 and the fitting hole 32, so that the hammer support shaft 8 a is fitted into the fitting hole 32 from the insertion hole 33. At this time, the plurality of protrusions 34 can reliably prevent the hammer support shaft 8a from being accidentally pulled out of the insertion hole 33. That is, since the plurality of protrusions 34 are provided at two positions located at the upper and lower portions of the insertion hole 33 at the boundary between the fitting hole 32 and the insertion hole 33, the hammer support shaft 8 a is inserted into the insertion hole 33. So that you do n’t get out of it.

  In this case, the protrusion 34 is brought into contact with either the point contact or the line contact with the outer peripheral surface of the hammer support shaft 8a, thereby reducing the contact area of the protrusion 34 with respect to the outer peripheral surface of the hammer support shaft 8a. Accordingly, the frictional resistance when the bearing portion 28 rotates with respect to the hammer support shaft 8a can be greatly reduced.

  That is, when the plurality of protrusions 34 are formed in a mountain shape having one apex, they can be slid by point contact with the outer peripheral surface of the hammer support shaft 8a, thereby greatly reducing the frictional resistance. be able to. In addition, since the plurality of protrusions 34 can be slid in line contact with the outer peripheral surface of the hammer support shaft 8a when the apex is formed in a mountain shape continuous in the axial direction of the hammer support shaft 8a, This also reduces the frictional resistance.

  In this case, when the hammer support shaft 8a is fitted, the fitting hole 32 brings the plurality of protrusions 34 into contact with the outer peripheral surface of the hammer support shaft 8a and 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 32.

  For this reason, the fitting hole 32 can contact the outer peripheral surface of the hammer support shaft 8a at four points with the inner peripheral surface thereof. The contact area of the peripheral surface can be reduced. For this reason, 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 is rotated with respect to the hammer support shaft 8a by providing the lubrication reservoir portion 35 in which a lubricant such as grease is accumulated by the projection 34 on the inner peripheral surface of the bearing portion 28. In doing so, a lubricant such as grease can be reliably and satisfactorily applied to the outer peripheral surface of the hammer support shaft 8a, and thereby the bearing portion 28 can be smoothly and satisfactorily rotated with respect to the hammer support shaft 8a. Can do.

  That is, the lubrication reservoir 35 has an upper surface of the upper protrusion 34 and the recess 32a because the outer peripheral surface of the hammer support shaft 8a contacts the inner peripheral surface of the fitting hole 32 at four points by the plurality of protrusions 34. Are provided between the lower edge of the protrusion 34 and the lower edge of the recess 32a, so that when the bearing portion 28 rotates relative to the hammer support shaft 8a, the hammer is supported. A lubricant 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 between the pair of support pieces 8 b provided on the lower surface of the hammer mounting portion 7 of the keyboard chassis 1 with the hammer support shaft 8 a of the hammer support portion 8. The both side surfaces in the axial direction of the central axis of the bearing portion 28 can be brought into contact with the opposing surfaces of the pair of support pieces 8b.

  For this reason, in the bearing portion 28 of the hammer member 3, both side portions in the axial direction of the plurality of lubrication reservoir portions 35 can be closed by the opposing surfaces of the pair of support pieces 8 b, so that the inside of the plurality of lubrication reservoir portions 35 It is possible to enclose a lubricant such as grease filled in the shaft 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 projecting portions 34 are provided on the inner peripheral surface of the fitting hole 32 of the bearing portion 28 has been described. However, the present invention is not limited thereto, and for example, the plurality of projecting portions 34. May be provided on the outer peripheral surface of the hammer support shaft 8a.

  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 lubricant 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 oozes when the bearing portion 28 rotates with respect to the hammer support shaft 8a. .

  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. For example, a bearing portion 28 may be provided at the rear end portion of the key 2, and the bearing portion 28 of the key 2 may be rotatably attached to the key support shaft 13 a of the keyboard chassis 1.

  Furthermore, in the above-described embodiment, the case where the present invention is applied to a keyboard device for an electronic keyboard instrument has been described. However, the present invention is not limited to this, and a bearing structure that includes a shaft and a bearing portion and relatively rotates them. It can also be applied to equipment equipped.

As mentioned above, although one Embodiment of this invention was described, this invention is not restricted to this, The invention described in the claim and its equal range are included.
The invention described in the claims of the present application will be appended below.

(Appendix)
The invention according to claim 1 is provided with a shaft, an insertion hole, a bearing portion that is elastically deformed by being inserted from the insertion hole, an outer peripheral surface of the shaft, and an inner periphery of the bearing portion. Provided on any one of the surfaces, and slidably contacts with the other of the outer peripheral surface of the shaft and the inner peripheral surface of the bearing portion along the rotational direction of the shaft inserted into the bearing portion. And a protrusion.

  The invention according to claim 2 is the bearing structure according to claim 1, wherein the bearing portion includes 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. .

  According to a fourth aspect of the present invention, in the bearing structure according to any one of the first to third aspects, the protrusion is one of a point contact and a line contact with respect to the outer peripheral surface of the shaft. It is a bearing structure characterized by contacting.

  According to a fifth aspect of the present invention, in the bearing structure according to any one of the first to fourth aspects, a lubricating reservoir for collecting a lubricant by the protrusion is provided on the inner peripheral surface of the fitting hole. It is the bearing structure characterized by being characterized.

  A sixth aspect of the present invention includes a keyboard device including the bearing structure according to any one of the first to fifth aspects, and a sound generation unit that generates a musical sound in response to an operation of the keyboard device. It is an electronic keyboard instrument characterized by

  According to a seventh aspect of the present invention, in the electronic keyboard instrument according to the sixth aspect, 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 electronic keyboard instrument characterized in that each rotating portion of a plurality of hammer members for applying 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.

DESCRIPTION OF SYMBOLS 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 Sound generation part 23 Hammer main body 24 Weight part 25 Rotation attachment part 26 Key contact sliding part 27 Bearing attachment Part 28 Bearing part 30 Notch part 31 Bearing body 31a Elastic support part 31b Opening part 31c Rib 32 Fitting hole 32a Recess 33 Insertion hole 34 Projection part 35 Lubrication reservoir part

Claims (8)

The axis,
A bearing portion provided with an insertion hole and elastically deformed by insertion of the shaft from the insertion hole;
The shaft that is provided on either the outer peripheral surface of the shaft or the inner peripheral surface of the bearing portion, and is inserted into the bearing portion on either the outer peripheral surface of the shaft or the inner peripheral surface of the bearing portion. A protrusion that slidably contacts along the rotational direction of
A bearing structure characterized by comprising:   The bearing structure according to claim 1, wherein the bearing portion includes a fitting hole into which the shaft is fitted.   The bearing structure according to claim 2, wherein the protrusion is provided at a boundary between the fitting hole and the insertion hole.   4. The bearing structure according to claim 1, wherein the protrusion is in contact with the outer peripheral surface of the shaft in one of point contact and line contact. 5. .   5. The bearing structure according to claim 1, wherein a lubrication reservoir for collecting a lubricant by the protrusion is provided on an inner peripheral surface of the fitting hole. 6. Construction. A keyboard device comprising the bearing structure according to any one of claims 1 to 5;
A sound generator that generates a musical sound in response to an operation of the keyboard device;
An electronic keyboard instrument characterized by comprising:   The electronic keyboard instrument according to claim 6, wherein the keyboard device rotates according to a key pressing operation of each of a plurality of keys rotatably provided on the keyboard chassis, and applies an action load to each of the plurality of keys. An electronic keyboard instrument, wherein each of the rotating parts of the plurality of hammer members has the bearing structure. An apparatus comprising the bearing structure according to any one of claims 1 to 5.

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