JP2022092302A - Four-node rotation mechanism - Google Patents

Abstract

To provide a four-node rotation mechanism that can obtain a deceleration effect both when opening and closing a lid without imposing restrictions on design of the lid.SOLUTION: A four-node rotation mechanism used to open and close a lid, includes: a link, one end of which is connected to a rotary shaft A of the lid; a link b one end of which is connected to a rotary shaft B of the other end of the link a; a link c one end of which is connected to a rotary shaft C of the other end of the link b and provided with a gear at its other end; and a link d one end of which is connected to a rotary shaft D of the gear and the other end of which is a fixed link connected to the rotary shaft A of the lid; and a unidirectional rotary damper which engages with the gear and has viscous resistance to rotation in one direction. And a position of dead center as of when the link c is a prime mover node, is included within a movable range of the lid.SELECTED DRAWING: Figure 3

Description

The present invention relates to a four-node rotation mechanism used for opening and closing a lid.

Patent Document 1 is, for example, a conventional example of a lid opening / closing device used for opening / closing a lid of a keyboard instrument. The lid opening / closing device of Patent Document 1 has a simple structure and aims to realize smooth and safe opening / closing. Equipped with a rotary damper. The first lid gear and the second lid gear have the lid rotation axis as the axis of rotation, and are arranged at different positions in the axial direction of the lid rotation axis. The first braking gear has the first axis of rotation as the axis of rotation. The second braking gear has a second axis of rotation as the axis of rotation. The unidirectional rotary damper is arranged on the first rotation axis or the second rotation axis. The first braking gear and the second braking gear are in a state of being meshed with each other so as to rotate in opposite directions. The first lid gear meshes with the first braking gear between the first state and the closed state. The second lid gear meshes with the second braking gear between the second state and the open state. The unidirectional rotary damper brakes the rotational operation when the first lid gear and the first braking gear are engaged with each other and the lid is moving in the closing direction.

Japanese Unexamined Patent Publication No. 2015-212996

According to the lid opening / closing device of Patent Document 1, it is necessary to provide two gears (first lid gear and second lid gear) on the rotation shaft of the lid. It was necessary to enlarge these two gears in order to obtain a sufficient deceleration effect, which restricted the design of the lid.

Therefore, it is an object of the present invention to provide a four-node rotation mechanism capable of obtaining a deceleration effect both when the lid is opened and when the lid is closed, without causing restrictions on the design of the lid.

The four-node rotation mechanism of the present invention is a four-node rotation mechanism used for opening and closing the lid, and one end of the link a is connected to the rotation axis A of the lid and one end thereof is the rotation shaft of the other end of the link a. The link b connected to B, one end thereof is connected to the rotating shaft C at the other end of the link b, the link c provided with a gear at the other end, and one end thereof is connected to the rotating shaft D of the gear, and the other end. Includes a link d, which is a fixed link connected to the rotation axis A of the lid, and a unidirectional rotary damper that meshes with gears and has viscous resistance to one-way rotation, and links c within the movable range of the lid. The position of the dead point in the case of the driving node is included.

According to the four-node rotation mechanism of the present invention, the deceleration effect can be obtained both when the lid is opened and when the lid is closed, without restricting the design of the lid.

The cross-sectional view which shows the state S1, S2, S3 of the four-section rotation mechanism of Example 1. FIG. The cross-sectional view which shows the state S4, S5, S6 of the four-section rotation mechanism of Example 1. FIG. The figure explaining the rotation direction of the link c accompanying the rotation operation of the link a which is a driving node. The figure which shows the size and transition of | IC | / | IB | in the states S1 to S3.

Hereinafter, embodiments of the present invention will be described in detail. The components having the same function are given the same number, and duplicate explanations are omitted.

Hereinafter, the structure of the musical instrument incorporating the four-node rotation mechanism of the first embodiment will be described with reference to FIGS. 1 and 2. As shown in the state S1, the musical instrument 1 includes a lid 10, a rotation axis A, a first arm 11, a rotation axis B, a second arm 12, a rotation axis C, and a third arm 13. , Includes a gear 21, a rotary shaft D, a unidirectional rotary damper 22, and a lower case 14.

<Cover 10>
The lid 10 is rotatably connected to the rotation shaft A. By contacting with the lower case 14 in the state S1, the rotation of the lid 10 in the closing direction is locked. In the state S6, the upper end of the second arm 12 comes into contact with the lock plate 14a provided on the lower case 14, so that the rotation of the lid 10 in the opening direction is locked.

<First arm 11>
The first arm 11 includes a leg portion 11a connected to the back surface of the lid 10 and an arm portion 11b having one end connected to the leg portion 11a and extended in a direction different from the extension direction of the leg portion 11a (state S3). (See), the other end of the arm portion 11b is rotatably connected to the rotation shaft B.

<Second arm 12>
One end of the second arm 12 is rotatably connected to the rotation shaft B, and the other end is rotatably connected to the rotation shaft C.

<Third arm 13>
One end of the third arm 13 is rotatably connected to the rotation shaft C, and a gear 21 is provided at the other end. The other end of the third arm 13 and the gear 21 are rotatably connected to the rotation shaft D.

<Gear 21>
The gear 21 is provided at the other end of the third arm 13 and meshes with the unidirectional rotary damper 22.

<One-way rotary damper 22>
The unidirectional rotary damper 22 meshes with the gear 21 and has viscous resistance to rotation in one direction (counterclockwise rotation in the figure).

<Link a>
The mechanism composed of the above parts group is a four-node rotation mechanism, which is a kind of lever crank mechanism. As shown in FIG. 3, the intersection with the plane orthogonal to the rotation axes A, B, C, and D is referred to as a point A, B, C, and D, and the line segment AB connecting the points A and B is referred to as a link a. Then, the link a corresponds to the driving node in the four-node rotation mechanism. One end of the link a is rotatably connected to a rotating shaft A which is a kinematic pair. The other end of the link a is rotatably connected to the link b described later on the rotation axis B corresponding to the kinematic pair. The link a is actually composed of a part of the lid 10, a leg portion 11a connected to the lid portion 10, and a rigid body including an arm portion 11b extended from the leg portion 11a.

<Link b>
Assuming that the line segment BC connecting the points B and C is called a link b, one end of the link b is rotatably connected to the link a on the rotation axis B which is a kinematic pair. The other end of the link b is rotatably connected to the link c described later on the rotation axis C corresponding to the kinematic pair. The link b corresponds to an intermediate node in the four-node rotation mechanism.

<Link c>
Assuming that the line segment CD connecting the points C and D is called a link c, one end of the link c is rotatably connected to the link b on the rotation axis C which is a kinematic pair. A gear 21 is provided at the other end of the link c, and is rotatably connected to the link d described later on the rotation shaft D corresponding to the kinematic pair. The gear 21 rotates in conjunction with the link c with the point D as the center of rotation. The link c corresponds to a driven node in the four-node rotation mechanism.

<Link d>
Assuming that the line segment DA connecting the points D and A is called the link d, one end of the link d is connected to the link c on the rotation axis D which is a kinematic pair. The other end of the link d is connected to the link a on the rotation axis A. The link d corresponds to a stationary node (fixed link) in the four-node rotation mechanism.

<Dead center (thinking point)>
As shown in FIG. 3, in the four-node rotation mechanism of this embodiment, the link c is used as the driving node within the movable range of the lid (the state where the lid is completely closed S1 to the state where the lid is completely opened S6). The position of the dead center in the case (state S4: a state in which points A, B, and C are aligned on a straight line, and it is not determined whether point B rotates to the left or right when the link c is rotated or swung) is included. It is characterized by that.

By including the position of the dead center (S4) when the link c is the driving node in the movable range (S1 to S6) of the lid, the position of the above dead center when the rotation direction of the link a is constant. The rotation direction of the link c changes with (S4) as a boundary. For example, when the rotation direction of the link a is clockwise (S1 → S6), the rotation direction of the link c is counterclockwise in S1 to S3, stationary in S4, and then clockwise in S5 to S6.

Therefore, when the link a is rotated counterclockwise (rotated in the direction of closing the lid) starting from the state S4, the link c rotates clockwise. On the other hand, even when the link a is rotated clockwise (rotated in the direction of opening the lid) starting from the state S4, the link c also rotates clockwise.

Therefore, regardless of which direction the link a is rotated starting from the state S4, the gear 21 rotates clockwise, and the unidirectional rotary damper 22 that meshes with the gear 21 rotates counterclockwise. Become. Since the unidirectional rotary damper 22 has viscous resistance to counterclockwise rotation, a deceleration effect is produced in any of the above cases. Therefore, the deceleration effect in the direction of closing the lid prevents adverse effects such as pinching fingers, and the deceleration effect in the direction of opening the lid prevents the musical instrument from tipping over or being damaged, and gives a luxurious feel to the product.

Here, as shown in FIG. 2, the first range of motion θ ₁ , which is the range of motion in the direction of closing the lid, opens the lid with reference to the position of the dead center (S4) when the link c is the driving node. If the design is made so as to be larger than the second range of motion θ ₂ , which is the range of motion in the direction (θ ₁ > θ ₂ ), the design can be made with more emphasis on the deceleration effect in the direction of closing the lid, which is preferable. ..

Further, as shown in FIG. 4, the intersection of the straight line AB and the straight line CD is set as the point I, and the more the lid 10 is inclined in the direction of closing the lid 10, the longer the length of the line segment IC is set to the length of the line segment IB. It is more preferable to design so that the divided value becomes large. When the speed of closing the lid is V _B and the rotation speed of the link _c is _VC , the relationship of VC = (| IC | / | IB |) · V _B holds (three-center theorem, reference non-patent document). 1) Therefore, when V _B is constant, the more the lid 10 is tilted in the direction of closing the lid 10, the larger the _VC becomes, and the unidirectional rotary damper 22 obtains a large deceleration effect proportional to the _VC . It will be.

(Reference Non-Patent Document 1: Hirofumi Miura, "Mechanical Dynamics", 1st Edition, Morikita Publishing Co., Ltd., December 1995, p.92-93)
When considering a general piano, it is unlikely that the speed V _B will be kept constant from the beginning to the end of closing the lid, and there is a possibility that the user has released his hand from the lid around the state S2. high. Therefore, in S2 → S1, it is considered that V _B is determined exclusively by the weight of the lid itself, and it is considered that the speed is already considerably decelerated as compared with V _B and the like in the state S3. Therefore, since the _VC is determined by multiplying the decelerating V _B by an increasing coefficient, a reliable and non-excessive deceleration effect can be obtained even at the end of closing the lid. As a result, the user does not feel excessive resistance when closing the lid, while a reliable and non-excessive deceleration effect can be obtained even after the user releases the hand, and harmful effects such as pinching a finger can be prevented. And can give a sense of quality to the feel of the product.

<Another expression example>
Another expression example of the four-node rotation mechanism of this embodiment is as follows. The four-node rotation mechanism of this embodiment is connected to a driving node (link a) connected to the lid 10, an intermediate node (link b) connected to the driving node (link a), and an intermediate node (link b). A driven clause (link c), a stationary clause (link d) connected to the driven clause (link c) and the prime mover clause (link a), a gear 21 that rotates with the driven clause (link c), and a gear 21. The position of the dead point when the driven node (link c) in the movable range of the lid 10 is used as the driving node, including the unidirectional rotary damper 22 that meshes with the gear 21 and has viscous resistance to one-way rotation. included. It is more preferable if the first range of motion, which is the range of motion in the direction of closing the lid 10, is larger than the second range of motion, which is the range of motion in the direction of opening the lid 10, with respect to the position of the dead center.

Claims (5)

It is a four-node rotation mechanism used to open and close the lid.
A link a whose end is connected to the rotation axis A of the lid,
A link b whose end is connected to the rotation shaft B at the other end of the link a,
A link c having one end connected to the rotating shaft C at the other end of the link b and having a gear at the other end.
A link d, which is a fixed link whose one end is connected to the rotation shaft D of the gear and whose other end is connected to the rotation shaft A of the lid.
Includes a unidirectional rotary damper that meshes with the gear and has viscous resistance to one-way rotation.
A four-node rotation mechanism that includes the position of the dead center when the link c is used as the driving node within the movable range of the lid. The four-section rotation mechanism according to claim 1.
The first range of motion θ ₁ , which is the range of motion in the direction of closing the lid, is the second range of motion, which is the range of motion in the direction of opening the lid, with reference to the position of the dead center when the link c is used as the driving node. Four-node rotation mechanism larger than θ ₂ . The four-section rotation mechanism according to claim 1 or 2.
The intersection with the plane orthogonal to the rotation axes A, B, C, and D is defined as points A, B, C, and D, the intersection of the straight line AB and the straight line CD is defined as point I, and the lid is inclined in the direction of closing the lid. The more the line segment IC is divided by the length of the line segment IB, the larger the value is. It is a four-node rotation mechanism used to open and close the lid.
The driving node connected to the lid and
An intermediate clause connected to the driving clause and
The driven clause connected to the middle clause and
The driven clause, the stationary clause connected to the driving clause, and
A gear that rotates with the driven node,
Includes a unidirectional rotary damper that meshes with the gear and has viscous resistance to one-way rotation.
A four-node rotation mechanism that includes the position of the dead center when the driven node is the driving node within the movable range of the lid. The four-node rotation mechanism according to claim 4.
The first range of motion, which is the range of motion in the direction of closing the lid, is larger than the second range of motion, which is the range of motion in the direction of opening the lid, based on the position of the dead center when the driven node is used as the driving node. Large four-section rotation mechanism.

Images