JPH0547837B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a keyboard musical instrument, and more particularly to a keyboard musical instrument with increased flexibility in its design.

(Prior Art) As a conventional keyboard lid opening/closing device, for example, one disclosed in Japanese Utility Model Application Publication No. 54-50527 is known. This opening/closing device has a cushioning member, such as an air cushion or a spring, disposed on the keyboard lid or a clapboard to soften the impact caused by the closing operation of a rotatably provided keyboard lid.

In this device, the shock caused by the closing operation of the keyboard lid is softened by the cushioning member such as the air cushion.

However, in such a conventional opening/closing device, the resistance force against the closing operation of the keyboard lid is always constant during the closing operation of the keyboard lid. As a result, even if the initial resistance can be satisfied,
It was not possible to satisfy the terminal resistance.
In other words, it was not possible to sufficiently absorb the impact force upon closing.

Therefore, in order to solve this drawback, the applicant filed a patent application on August 8, 1985 (hereinafter referred to as the "prior application"). The keyboard lid opening/closing device according to this prior application has a rotary damper interposed between the keyboard lid and a arm supporting the keyboard lid. This rotary damper consists of a case attached to the keyboard lid, a damper shaft that is rotatably supported by the case and whose rotation is regulated on the arm arm, and a spring that generates a resistance force by tightening the damper shaft. It was composed of. Therefore, when the keyboard lid rotates around the damper shaft in the direction of closing by a predetermined angle, the spring tightens the damper shaft and generates a resistance force against the rotation, thereby softening the impact upon closing.

(Problems to be Solved by the Invention) However, in general, the inner surface of the keyboard lid must be formed flat because the keyboard lid must not interfere with performance operations when it is open.
Furthermore, in the closed state, the outer surface of the instrument needs to be formed integrally with the main body of the instrument, such as the arm. Furthermore, in the case of a grand piano, the keyboard lid is removed to insert and remove the action mechanism, so the keyboard lid must have a shape that corresponds to the opening necessary for insertion and removal, and the base end of the keyboard lid must be shaped to accommodate the opening required for insertion and removal. The wall thickness at the tip must be considerably thinner than the thickness.

In this case, in the case of the keyboard lid opening/closing device related to the earlier application, the rotary damper was constructed by wrapping a spring around the outer surface of the damper shaft, which is the central axis of rotation, and further storing these in a case. , the rotary damper itself had a predetermined size and volume.

When the rotary damper is to be mounted on the keyboard lid, the mounting positions are limited because the keyboard lid has certain restrictions due to its structure as described above. Therefore, the keyboard lid opening/closing device according to the prior application had a problem in that a part of the damper 51 or the damper mounting member 52 protruded from the inner surface of the keyboard lid 53, as shown in FIG.

(Means for Solving the Problems) Therefore, the keyboard instrument according to the present invention is a keyboard instrument having a keyboard lid opening/closing device, and this keyboard lid opening/closing device has a rotary damper 3, a rotation center shaft 14, The rotary damper 3 is attached to the side surface of the keyboard lid 2 and generates a resistance force against the rotation of the keyboard lid 2 in the closing direction, and a gear 11 is fixed to the damper shaft 6. The rotation center axis 1
4 is attached to the musical instrument body 1 and acts as a center of rotation for the keyboard lid 2, and has a gear 12 fixed thereto, and the gear 1 of the rotary damper 3 is connected to the gear 12
1 are provided so that they mesh with each other, and the damper shaft 6 is
It is eccentric with respect to the rotation center axis 14 of the keyboard lid 2.

(Operations and Effects) In the keyboard instrument according to the present invention, the resistance force against the rotation of the keyboard lid 2 in the opening direction is small, unlike the resistance force against the rotation in the closing direction. Therefore, the opening operation can be performed smoothly. Further, in the closing operation, the spring 7 tightens the damper shaft 6. As a result, a resistance force against the closing operation is generated. Therefore, as the opening angle of the keyboard lid 2 becomes smaller, the resistance force against its rotation becomes larger. As a result, the initial resistance during the closing operation can be set small and the final resistance can be set large, and the closing operation of the keyboard lid 2 can be made smooth as a whole. That is, when closing the keyboard lid 2, the rotary damper 3
generates a predetermined resistance force against the rotational force of the keyboard lid 2 in the closing direction. As a result, even a heavy keyboard lid for a grand piano, for example, can be closed gently at the final stage of closing, thereby preventing the occurrence of impact.

Further, in this keyboard instrument, the rotary damper 3 is attached to the keyboard lid 2, but the damper shaft 6 of the rotary damper 3 is provided eccentrically with respect to the rotation center axis 14 of the keyboard lid 2. Therefore, the degree of freedom in attaching the rotary damper 3 to the keyboard lid 2 is greatly increased. As a result, a part of the rotary damper 3 or its damper mounting member will not protrude from the inner surface of the keyboard lid 2, and will not interfere with playing or cause any problems in appearance.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

1 to 4 show an embodiment in which the present invention is applied to a keyboard lid of a grand piano. first,
Let's start with the configuration.

In FIG. 1, 1 is a piano arm (the main body of the musical instrument). Further, 2 indicates a keyboard lid rotatably supported by this arm 1. Further, numeral 3 designates a rotary damper embedded and fixed in the thick part of the keyboard lid 2, that is, in the side surface of the base end of its rotation.

As shown in FIG. 6, the rotary damper 3 includes a cylindrical case 5, a damper shaft 6 rotatably supported and housed within the case 5, and a damper shaft 6 wrapped around the outer peripheral surface of the damper shaft 6 inside the case 5. Spring 7
and a closing plate 8 that closes the opening of the case 5 and pivotally supports the damper shaft 6.

An arcuate groove 9 is formed in the inner peripheral surface of the opening end of the case 5 at a predetermined angle in the circumferential direction, and one end of the spring 7 is provided on the wall surface of the arcuate groove 9 so as to be able to come into contact with it. (The other end is considered unconstrained.) That is, this rotary damper 3
When the case 5 rotates relative to the damper shaft 6, one end of the spring 7 is locked to the case 5, and as a result, the spring 7 tightens the damper shaft 6, causing the keyboard lid 2 to rotate in the closing direction. It generates a predetermined resistance force against motion.

Further, a gear 11 is fixed to one end of the damper shaft 6 protruding from the closing plate 8.

On the other hand, a gear 12 that meshes with the gear 11 of the damper shaft 6 is fixed to one end at a predetermined position on the side surface of the arm 1 facing the side surface of the keyboard lid 2 (the optimal position as the center of rotation of the keyboard lid 2). A rotary shaft 14 is attached thereto. That is, the other end 14A of the rotating shaft 14 has a so-called barrel-shaped cross-sectional shape, and is non-rotatably inserted and locked into the groove 15A of the metal fitting 15 fixed to the side surface of the arm 1 (see Fig. 1). reference).

FIG. 2 shows a meshing part (gear mechanism) between these gears 11 and 12, and this meshing part is housed in a holder case (gear shaft positioning fitting) 16. For example, this holder case 16
An arcuate groove is formed at a predetermined angle around the rotating shaft 14, and the damper shaft 6 is guided and moved within this groove.

Therefore, the keyboard lid 2 rotates around this rotating shaft 14 to be opened and closed. That is, the rotation axis 14 represents the rotation center axis of the keyboard lid 2, while the damper shaft 6 represents the rotation center axis of the rotary damper 3, and these rotation center axes 14 and 6 are provided eccentrically from each other. It is being done.

Next, the operation of the present invention will be explained with reference to FIGS. 3, 4, and 5.

FIG. 3 shows the relative positional relationship between the rotation center shafts 6 and 14 when the keyboard lid 2 is open, and FIG. 4 shows their positional relationship when the keyboard lid 2 is approximately half closed.
FIG. 5 shows their relationship when the keyboard lid 2 is closed.

When opening the keyboard lid 2, the rotary damper 3 does not generate any resistance force against the rotation of the keyboard lid 2.
The keyboard lid 2 can be lifted smoothly. This is because in the case of this opening, in the rotary damper 3, a force acts on the spring 7 in a direction opposite to the direction in which the damper shaft 6 is tightened, so that no resistance force is generated against the opening operation. Therefore, the only resistance force when opening is due to the weight of the keyboard lid 2 itself.

On the other hand, when the keyboard lid 2 is closed from the open state shown in FIG. 3, the procedure is as follows.

In the state shown in the figure, the damper shaft 6 is located at a predetermined angular position with respect to the rotating shaft 14. When the keyboard lid 2 is approximately half closed to the state shown in FIG. 4, the rotary damper 3 generates a predetermined resistance force against rotation in the closing direction. In other words, almost no resistance is generated from the beginning of closing the keyboard lid 2 until halfway through, but when the keyboard lid 2 is closed to approximately 45 degrees (Fig. 4), one end of the spring 7 is pressed against the wall surface of the arcuate groove 9 of the case 5. The spring 7 tightens the damper shaft 6. As a result, a predetermined resistance force is generated by the rotary damper 3 against the rotation of the keyboard lid 2 in the closing direction, and the keyboard lid 2 is closed slowly. FIG. 5 shows the state in which the keyboard lid 2 is closed as a result. Further, in this case, the shaft torque of the rotary damper 3 is transmitted to the rotating shaft 14 via the gears 11, 12, etc.

In the series of operations of the keyboard lid 2, the damper shaft 6 rotates around the rotating shaft 14 through the gears 12 and 11 within an angular range of approximately 90 degrees.

In this case, by appropriately changing the gear ratio of these gears 11, 12, etc., the opening/closing angle of the keyboard lid 2 can be arbitrarily set. For example, if the gear ratio is 1:1, the damper shaft 6 rotates approximately 90 degrees with respect to the rotating shaft 14, as described above. Furthermore, even if the rotary damper 3 with a constant torque is used, the torque transmitted to the rotating shaft 14 can be adjusted by changing the gear ratio. In addition, in this embodiment, the gear 11,
By changing the diameter of the damper shaft 12, the eccentric distance of the damper shaft 6 with respect to the rotating shaft 14 can also be appropriately set. That is, the rotation center axis 14 of the keyboard lid 2
The position of the damper shaft 6 of the rotary damper 3 with respect to,
Therefore, the mounting position of the rotary damper 3 can be freely selected and arranged on the side surface of the keyboard lid 2. As a result, the degree of freedom in designing the switching device as a whole can be significantly increased compared to the device of the prior application. By incorporating a one-way clutch or the like into these gears, the device can be operated only when the keyboard lid is closed.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of essential parts showing an embodiment of the keyboard lid opening/closing device for a keyboard instrument according to the present invention, Fig. 2 is a side view showing a gear mechanism in the embodiment, Figs. Figure 5 is a schematic side view showing the positional relationship between the central axis of rotation of the keyboard lid and the central axis of rotation of the rotary damper during the opening/closing operation of the keyboard lid in the embodiment, and Figure 6 is the same as the embodiment. FIG. 7 is a sectional view showing the rotary damper in FIG. 7, and FIG. 7 is a schematic side view showing the attachment portion of the rotary damper to the keyboard lid of the keyboard lid opening/closing device according to the prior application. 1...Archive (musical instrument body), 2...Keyboard lid, 3...
...Rotary damper, 6... Damper shaft (rotation center axis), 14... Rotation shaft (rotation center axis of keyboard lid).

Claims (1)

[Claims] 1. A keyboard instrument having a keyboard lid opening/closing device, which includes a rotary damper 3,
The rotary damper 3 is attached to the side surface of the keyboard lid 2 and generates a resistance force against the rotation of the keyboard lid 2 in the closing direction. A gear 11 is fixedly attached to the rotation center shaft 14, which is attached to the instrument body 1 and acts as a rotation center for the keyboard lid 2, and has a gear 12 fixedly attached to it. A keyboard instrument in which the gears 11 of the rotary damper 3 are provided so as to mesh with each other, and the damper shaft 6 is eccentric with respect to the central rotation axis 14 of the keyboard lid 2.