JPH09126265A - Rotary damper and cover opening/closing device with the damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a rotary damper compact which has means for varying torque according to the direction of rotation and returning a rotor to an original position when the rotor is rotated in a casing. SOLUTION: In a rotary damper 1 for changing torque produced according to the direction of rotation by combining a projection (t) formed on a shaft 3a of a part of a rotor 3 built-in a cylindrical casing 2 receiving viscous fluid and a valve body 7 covering the projection (t), a coil spring 5 is disposed in the casing 2 to engage the casing 2 at one end and a rotor 3 at the other end. If rotary load on the rotor 3 rotating in a direction of a high torque side is removed, the rotor 3 is rotated in a direction of a low torque side to return to an original position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a rotary damper that has a damper function when opening and closing a keyboard lid of a piano, for example.

[0002]

2. Description of the Related Art Conventionally, when a heavy lid such as a piano keyboard lid is opened and closed up and down, a shock absorbing rotary damper is attached so as not to drop suddenly when the lid is lowered and closed. There is. Such a rotary damper is
Normally, when the lid is opened, it can be opened with a small rotation torque, and when the lid is closed, a large rotation torque is applied.For example, a part of the rotating member is installed in a casing filled with viscous fluid and this rotation is performed. Depending on the rotation direction of the member, high torque is generated in one rotation direction and low torque is generated in the opposite rotation direction.

As such a rotary damper, the applicant of the present invention has disclosed, for example, in Japanese Patent Application No. 7-62531, "Rotary damper and opening / closing device for lids using the damper" (2nd 1995).
(Submitted on the 7th of a month). In this technique, as shown in FIGS. 7 to 10 of the application document, a rotary damper fixed to an arbitrary position in the vicinity of a keyboard lid of a piano is provided, and the rotary damper is provided to a casing and the casing. It is composed of a rotatable rotating member. An arm with a roller at the tip is attached to the rotary member, and the roller is arranged so as to abut the inner surface of the keyboard lid. When the lid is lowered, the arm is pushed and falls down. The rotating member is rotated to generate high torque to generate a desired damper function. According to this technique, when the lid is opened, the roller at the tip of the arm is kept in contact with the inner surface of the lid. Therefore, a leaf spring or a coil spring is arranged between the arm and the support on the casing side to always open the arm. Biased in the direction.

[0004]

However, in the above technique, since the arm extends from the rotating member, the mechanism becomes large and there is room for improvement in terms of appearance. Therefore, there has been a demand for a technique in which a rotary damper having a return function is compactly configured, and even if it is attached to a keyboard lid such as a piano, it does not spoil the appearance.

[0005]

In order to solve the above-mentioned problems, according to the present invention, as described in claim 1, a rotating member is partly incorporated in a cylindrical casing containing a viscous fluid to seal the casing. In a rotary damper in which a valve mechanism is provided on the rotating member in the casing to generate a large torque when the rotating member rotates to one side and a small torque when the rotating member rotates to the opposite side, An elastic member that reversely rotates the rotated rotating member to return it to the original position is provided in the cylindrical casing. At this time, the elastic member is, for example, a coil spring or the like, and the mechanism can be downsized by providing such an elastic member in the casing.

According to a second aspect of the present invention, the valve mechanism is covered with a convex strip protruding from the outer peripheral surface of the rotary member so that the valve element has play in the rotational direction, and the convex strip covers the valve element when the rotary member rotates. The flow rate of the viscous fluid passing through the valve member is different depending on the direction of rotation. The valve mechanism according to claim 3, wherein the valve mechanism is formed by fitting a valve element protruding from an outer peripheral surface of a rotary member with no play in a rotational direction so that the valve element has a convex shape when the rotary member rotates. It is possible to slide the valve body in a predetermined direction along with, and the flow rate of the viscous fluid passing through the valve body is different depending on the rotation direction. As in claims 2 and 3, the generated torque is changed by changing the flow rate of the viscous fluid passing through the valve body depending on the rotation direction.

According to a fourth aspect of the present invention, a connecting plate is attached to a portion of the rotating member that protrudes outward from the cylindrical casing, and a load that receives a rotational load is eccentric from the axis of the rotating member in the connecting plate. The receiving roller was attached. By eccentricizing the load receiving roller from the axis center of the rotating member, the rotating member can be rotated by the load applied to the load receiving roller. Further, if the load receiving roller is directly attached to the connecting plate, it is possible to avoid the size increase of the mechanism for attaching the arm and to make it compact. In the fifth aspect, the rotary damper is applied to the lid opening / closing device, and the load receiving roller is engaged with the inner surface of the lid. The lid is required to have a cushioning function, such as a keyboard lid of a piano.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of the present invention will be described with reference to the accompanying drawings. Here, FIG. 1 is a perspective view of a first configuration example of the rotary damper according to the present invention, FIG. 2 is a vertical sectional view showing the internal structure, and FIG. 3 is an exploded perspective view of the internal structure.
FIG. 4 is a cross-sectional view taken along the line AA of FIG. 2 and is an explanatory view of a first configuration example of the valve mechanism.

As shown in FIGS. 1 to 3, a rotary damper 1 according to the present invention includes a tubular casing 2 and a rotor 3 as a rotary member, a part of which is incorporated in the tubular casing 2.
A connecting plate 4 attached to the end of the rotor 3 protruding outside the casing 2 and a load receiving roller 13 attached to the front surface of the connecting plate 4, and the inside of the tubular casing 2 has a high viscosity. A so-called torque grease or the like is filled and sealed.

A valve mechanism, which will be described later, is incorporated in the casing 2 so that high torque is generated when the rotor 3 rotates in one direction and low torque is generated when the rotor 3 rotates in the opposite direction. Inside the casing 2, a coil spring 5 is provided, one end side of which is engaged with the rotor 3 and the other end side of which is engaged with the casing 2. The coil spring 5 causes the rotor 3 rotated to the high torque side to move to the low torque side. I am trying to recover the rotation.

As shown in FIG. 3, the cylindrical casing 2 is provided with a pair of left and right overhanging portions 2a and 2a which are radially extended toward one end of the outer circumference. The overhanging portions 2a and 2a are provided with screw mounting holes a. , A, and a female screw portion 2b is formed on the inner peripheral surface of the inlet of the casing. Further, a circular recess 2c (FIG. 2) is formed in the center of the bottom surface in the casing, and a locking hole c for locking one end of the coil spring 5 is provided near the circular recess 2c. Further, a protrusion 2d (FIGS. 2 and 3) is formed on a part of the inner peripheral wall along the axial direction.

A guide shaft 6 is incorporated in the casing 2. The guide shaft 6 has a function of positioning the rotor 3 with respect to the casing 2, and a part of the rear end side thereof is a circular recess 2 on the bottom surface of the casing 2.
A flange portion 6a is provided on the outer peripheral portion of the flange portion 6a which is capable of being fitted into the fitting portion c, and a notch b for inserting one end side of the coil spring 5 in a part of the flange portion 6a. (FIG. 3) is formed. Further, a circular groove 6b is formed on the front surface of the guide shaft 6, and a circular convex portion d of the rotor 3 described later can be fitted into the circular groove 6b.

The rotor 3 has a shaft portion 3a whose one end has a small diameter.
A ridge t protruding radially in the axial direction is formed on a part of the outer circumference of the shaft portion 3a. The ridge t is combined with a valve body 7 having a substantially U-shaped cross section, which will be described later, to form a valve mechanism. Further, a large-diameter rotation support portion 3b is provided adjacent to the shaft portion 3a in the axial direction, and the rotation support portion 3b has a plurality of O-ring mounting grooves m, m along the circumferential direction (FIG. 3). Are formed. The rotor 3 is fitted to the inner surface of the casing 2 with the O-rings 8 and 8 mounted in the grooves m and m. On the side opposite to the shaft portion 3a of the rotation support portion 3b, there is provided an end portion 3c having a medium diameter, the outer end surface of which is exposed to the outside of the casing 2, and the outer end surface of the end portion 3c is provided with a screw at the center. A hole f (FIG. 3) is formed, and a pair of connecting pins 3d and 3d are provided so as to project.

Further, as shown in FIG. 2, a hollow portion h into which the guide shaft 6 can be inserted is formed in the central portion of the shaft portion 3a, and the inner diameter of the hollow portion h is the guide shaft 6. The outer diameter of the flange portion 6a is substantially the same. A circular convex portion d that can be fitted into the circular groove 6b of the guide shaft 6 is formed in the center of the bottom surface of the hollow portion h, and the other end side of the coil spring 5 is formed on the bottom surface adjacent to the outer periphery of the circular convex portion d. Is provided with a locking hole e.

As shown in FIG. 3, when the rotor 3 is assembled in the tubular casing 2, a bush 10 and a screw ring 11 are provided to prevent the rotor 3 from coming off. After being fitted to the outer periphery of the end portion 3c and pressing the step portion with the rotation support portion 3b from the outside, the screw ring 11 is screwed and fixed to the female screw portion 2b of the casing 2.

The connecting plate 4 is a disc-shaped plate having a slightly large diameter and has a hole g in the center thereof and a pair of fitting holes 4a and 4a into which the connecting pins 3d and 3d can be fitted. Further, notches k and k are provided in the peripheral portion in correspondence with the positions of the screw mounting holes a and a of the projecting portions 2a and 2a of the casing 2. Further, the load receiving roller 13 can be fixed to the periphery of the connecting plate 4 with a screw 12 so that the roller 13 can receive a rotational load.

The above rotary damper 1 comprises a cylindrical casing 2
The guide shaft 6 is inserted thereinto, one end side of the guide shaft 6 is fitted and positioned in the circular recess 2c on the bottom surface of the casing 2, the inside of the casing 2 is filled with viscous fluid, and then the rotor 3 is inserted via the coil spring 5. Can be assembled by inserting. At this time, one end of the coil spring 5 is attached to the flange portion 6 of the guide shaft 6.
It is inserted and locked in the locking hole c at the bottom of the casing through the notch b of a, and the other end is inserted and locked in the locking hole e at the bottom of the hollow portion h of the rotor 3. Further, the convex portion d on the bottom surface of the hollow portion h of the rotor 3 is fitted into the circular groove 6b at the end of the guide shaft 6, and the O-ring mounting groove m of the rotation support portion 3b of the rotor 3 is provided.
The O-rings 8 and 8 are fitted in m, and the casing 2 is hermetically sealed so that the rotor 3 can rotate relative to the casing 2 via a viscous fluid.

Thereafter, the bush 10 is fitted on the outer periphery of the end 3c of the rotor 3, and the screw ring 11 is screwed from the outer side of the bush 10 to the female screw portion 2b of the casing 2 to be assembled. Finally, after fitting the fitting holes 4a and 4a of the connecting plate 4 to the connecting pins 3d and 3d on the outer end surface of the rotor 3 to bring them into close contact with each other, the screw 14 is passed through the hole g at the center and the screw hole f of the rotor 3 is inserted. The connection plate 4 is fixed to the rotor 3 by screwing. Then, a roller 13 is attached with a screw 12 in the vicinity of the peripheral portion of the connecting plate 4 in advance or thereafter.

Next, the structure of the valve mechanism will be described. As described above, the valve mechanism is composed of the projection t of the rotor shaft portion 3a and the valve body 7 having a substantially U-shaped cross section which is covered with the projection t with play in the rotational direction, as shown in FIG. In addition, the outer peripheral portion of the valve body 7 is in close contact with the inner peripheral surface of the casing 2.
A relatively large notch p (FIG. 3), for example, is formed in one of the left and right hanging walls 7a, 7b of the valve body 7 and the other hanging wall 7b is formed. It has no notches or relatively small notches.

Further, a cutout q is formed in the middle of the ridge t.
(Fig. 3). For this reason, when the rotor 3 rotates and, for example, the ridge t presses the hanging wall 7b having no cutout portion or a small cutout area to rotate together, the flow passage of the viscous fluid U is not ensured, which is extremely difficult. A large resistance force (high torque) is exerted on the contrary, and conversely, in the direction in which the ridge t presses the drooping wall 7a having a large cutout portion p and rotates together, a small resistance force ( Low torque)
Becomes At this time, as shown in FIG. 4, the tip of the projection 2d on the inner surface of the casing 2 is in close contact with the outer peripheral surface of the rotor 3. In order to adjust the torque value during rotation, for example, as shown in FIG. 3, a groove r is formed along the circumferential direction on the outer periphery of the shaft portion 3a of the rotor 3, and the groove r is a protrusion of the casing 2. When passing the portion 2d, a fluid passage may be secured to reduce the generated torque.

The coil spring 5 constantly urges the rotor 3 to rotate with respect to the casing 2 by generating a low torque, so that the rotor 3 receives a load and generates a high torque. When rotated to the side, when the rotating load is removed, the rotor 3 is returned in the reverse direction.

By the way, in the first configuration example of the rotary damper 1 as described above, the load receiving roller 13 is mounted via the connecting plate 4 at a position eccentric from the center of the rotor 3 axis. The form that should be called the basic structure of the rotary damper 1 is a form like the second configuration example shown in FIGS. 5 and 6. That is, in the second configuration example of this rotary damper, the internal configuration incorporated in the casing 2 is the same as the first configuration described above.
Although it is almost the same as the configuration example, the shaft 3e projects from the center of the outer end surface of the rotor 3 exposed to the outside of the casing 2, and the projecting portion 3e serves as a load receiving portion or an input shaft.

Next, a second structural example of the valve mechanism will be described with reference to FIGS. 7 to 9. In this valve mechanism, a ridge t protruding radially outward from the rotor shaft portion 3a has a substantially circular cross section, and a valve element 15 as shown in FIG. 9 is fitted to the ridge t. . That is, the valve body 15 is provided with a substantially circular concave groove portion 15a having a cross-sectional shape complementary to the convex stripe t along the longitudinal direction, and the concave stripe portion 15a is fitted to the convex stripe t. In this state, the ridge t can be rotated by a predetermined angle with reference to the circular center portion thereof.

On the outer surface of the valve body 15, a notch groove 15b for allowing the viscous fluid U to flow is formed in the central portion of the portion having a small outward protrusion amount, and a portion having a large outward protrusion amount is formed. A contact surface 15c is formed on the inner peripheral surface of the casing 2 to prevent the viscous fluid U from flowing.

In such a valve mechanism, as shown in FIG. 7, when the rotor 3 rotates clockwise in the drawing, the valve body 15
Is due to the pressure of the viscous fluid U and the frictional force between the inner peripheral surface of the casing 2 and the notch groove 15b side of the valve body 15 in the casing 2
It rotates in a direction (counterclockwise direction) in contact with the inner surface of (1), and a flow path of the viscous fluid U is formed by the notch groove 15b so that resistance is low (low torque). On the contrary, as shown in FIG. 8, when the rotor 3 rotates counterclockwise in the figure, the valve body 15 rotates clockwise due to the pressure of the viscous fluid U and the frictional force between the inner peripheral surface of the casing and the contact surface 15c. Adheres to the inner peripheral surface of the casing 2 to prevent the viscous fluid U from flowing. Therefore, high torque is generated.

By the way, the rotary damper 1 of the first configuration example.
Load receiving roller 1 at a position eccentric from the center of the rotating shaft
The type provided with 3 is preferably applied to a damper for opening and closing the keyboard lid 16 of the upright piano as shown in FIG. The keyboard lid 16 of this type of piano has a horizontally long hinge 17 attached to an upper end portion of the lid 16 so as to be opened and closed vertically. Therefore, for example, as shown in the embodiment of FIG. 10, the casing 2 of the main rotary damper 1 is attached to the arm 1
8 is embedded in the inner side surface of the casing 8 and the casing 2 is passed through the screw mounting holes a, a of the overhanging portions 2a, 2a to provide screws 20, 2
The load receiving roller 13 is fixed to the arm 18 at 0, and the load receiving roller 13 is brought into contact with the guide plate 19 attached to the inner surface of the keyboard lid 16. When the valve body 7 is attached to the rotor 3 shaft portion 3a, if the valve mechanism is attached so that a high torque is generated when the keyboard lid 16 is lowered and closed, the keyboard 16 can be closed. Sometimes it is possible to suppress the problem of sudden drop, and when the keyboard cover 16 is opened, the coil spring 5 causes the rotor 3 to return to its original position while generating low torque, and the roller 13 is always brought into contact with the guide plate 19. Can be kept.

Moreover, as in the embodiment, if the rotary damper 1 is embedded in the arm 18 there is no problem that the appearance is spoiled. Of course, the lid that can give a damper action when opening and closing is not limited to the keyboard lid of the piano, and can be applied to any lid as long as it has a rotation axis.

[0028]

As described above, according to the rotary damper of the present invention, a part of the rotating member is incorporated in the cylindrical casing for containing the viscous fluid to seal the casing, and the torque generated is increased depending on the rotating direction of the rotating member. In the rotary damper that is made smaller or smaller, the elastic member that rotates the rotary member in the direction in which the rotary torque is small and returns to the original position is provided in the cylindrical casing, so that an extremely compact rotary damper is configured. Can be done.

Further, a connecting plate is attached to a portion of the rotating member protruding from the cylindrical casing to the outside, and a load receiving roller for receiving a rotating load is attached to a position of the connecting plate which is eccentric from the axial center of the rotating member. If this is the case, it is possible to avoid an increase in the size of the mechanism that attaches the arm and to make it more compact. Therefore, if this rotary damper is applied to the lid opening / closing device, it is possible to exert a sufficient damper function without impairing the appearance.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first configuration example of the present rotary damper.

FIG. 2 is a longitudinal sectional view showing the internal structure.

FIG. 3 is an exploded perspective view of the internal structure.

FIG. 4 is a transverse sectional view taken along the line AA of FIG. 2 showing a first configuration example of the valve mechanism.

FIG. 5 is a vertical sectional view similar to FIG. 2 of a second configuration example of the present rotary damper.

FIG. 6 is a front view of the second configuration example.

FIG. 7 is a cross-sectional view showing a second configuration example of the valve mechanism, and a state diagram showing rotation toward a low torque side.

FIG. 8 is a state diagram showing rotation toward the same high torque side.

FIG. 9 is a perspective view of a valve body of a second configuration example of the valve mechanism.

FIG. 10 is an explanatory diagram showing an example in which the rotary damper according to the present invention is applied to an opening / closing device for a lid of an upright piano.

[Explanation of symbols]

1 ... Rotation damper, 2 ... Cylindrical casing, 3 ... Rotor, 4
... Connection plate, 5 ... Coil spring, 7 ... Cover valve, 13
... load receiving roller, 15 ... valve member, 16 ... keyboard lid, U ... viscous fluid.

Claims (5)

[Claims] 1. When a part of a rotating member is incorporated into a cylindrical casing containing a viscous fluid to seal the casing and a valve mechanism is provided on the rotating member in the casing to rotate the rotating member in one direction. Of the elastic member that reversely rotates the rotary member that has rotated to the high torque side and returns the original position to the original position, in the rotary damper that reduces the torque that is generated when the rotary member rotates to the opposite side. A rotary damper characterized by being provided in a casing. 2. The rotary damper according to claim 1, wherein the valve mechanism covers the valve element with play in a rotational direction on a convex line protruding from an outer peripheral surface of the rotary member, and the rotary member is rotated when the rotary member rotates. A rotary damper, characterized in that it can rotate the valve body together with a ridge, and the flow rate of the viscous fluid passing through the valve body varies depending on the direction of rotation. 3. The rotary damper according to claim 1, wherein the valve mechanism is configured such that the valve element is fitted to a ridge protruding from an outer peripheral surface of the rotary member without any play in the rotational direction, It is constructed so that the valve member can be slid in a predetermined direction along the ridge shape during rotation, and the flow rate of the viscous fluid that passes through the valve body differs depending on the direction of rotation. Rotation damper characterized by. 4. The rotary damper according to claim 1, wherein a connecting plate is attached to a portion of the rotating member that is exposed to the outside from the cylindrical casing, and the connecting plate is attached to the rotating member from the axial center of the rotating member. In the eccentric position,
A rotary damper having a load receiving roller for receiving a rotary load. 5. A lid opening / closing device using the rotary damper, wherein the load receiving roller of the rotary damper according to claim 4 is engaged with an inner surface of the lid.