JPH034044A - Rotary damper - Google Patents

Abstract

PURPOSE:To linearly change generated braking force by forming two fluid chambers, divided by a movable member, to communicate with a groove further the groove, having a sectional area different in accordance a position, in internal wall surfaces of a casing or a closing member. CONSTITUTION:Turning force of a turning unit, not shown, is transmitted to a movable member 5, when a blade 5a is turned in the direction of an arrow head (a), by this turning, operating fluid in a fluid chamber 3a receives compression force to flow in a fluid chamber 3b through a groove 4, and by resistance generated at this time, braking force is generated to act on the turning unit through the member 5. Since a sectional area of the groove 4 is decreased following the turning in the direction of the arrow head (a) of the blade 5a, the braking force is increased by reducing a flow amount of the operating fluid. Accordingly, in the case of forming the groove 4 with its sectional area in a fixed reduction rate, the torque characteristic of the generated braking force almost linearly rises. While in the case of turning the member 5 in the direction of an arrow head (b), compression force acts on the operating fluid in the fluid chamber 3b, thus a check valve 8 is opened.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a rotary damper that can apply a braking force corresponding to the rotation angle to a rotating body that reciprocates within a certain angle range.

<Prior Art> Conventionally, examples of devices that perform a desired function by reciprocating a rotating body within a certain angle range include the opening/closing lid of a mechanical device or a door.

Among the above-mentioned opening/closing lids, especially when closing the vertical opening/closing lid that rotates in the vertical direction by free fall, the distance from the axis of rotation of the lid to the center of gravity increases from the time of opening to the time of closing. As a result, the rotational torque of the lid increases, and a large impact occurs when the lid is closed.

The present applicant has developed a rotary damper that can apply a braking force in accordance with the fluctuation of torque to a rotating body, such as the opening/closing lid, which reciprocates within a certain angle range and whose torque varies according to the rotation angle. has been developed and has already applied for a patent (patent application filed in 1982).
-252587).

The rotary damper forms two fluid chambers inside the case by housing a fixed vane and a rotating vane inside the main case, and also forms two fluid chambers inside the main case by fitting an outer cylinder into the outside of the main case. A conduction chamber is formed between the main body case and the outer cylinder, and a plurality of orifices communicating with the conduction chamber are formed in the circumferential direction of the main body case, and the fluid chamber and the conduction chamber are filled with working fluid. There is.

In the above configuration, when the rotational force of the rotating body is transmitted to the rotating body, the rotating fan rotates in a predetermined direction, expelling the working fluid from the fluid chamber to the conduction chamber through the orifice, and At this time, the resistance acting on the working fluid becomes a braking force on the rotating body. Further, as the orifice is sequentially closed as the rotary vane rotates, the flow path area of the working fluid decreases sequentially, and the braking force generated accordingly increases.

<Problems to be Solved by the Invention> 1- In the conventional rotary damper, the working fluid is discharged from the fluid chamber to the conduction chamber via an orifice, so the damping characteristics of the rotary damper are It has a tendency to change in stages at the orifice. Therefore, when the rotary damper is attached to a light-weight opening/closing lid,
The closing operation of the opening/closing lid may occur in stages.

Furthermore, the conventional rotary damper described above requires components for forming the conduction chamber, which may increase manufacturing costs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary damper that can linearly change the generated braking force and reduce costs.

<Means for Solving the Problems> To solve the above problems, the rotary damper of the present invention includes gauging that forms a void inside, and a closing member that closes the void to form a fluid chamber. In the rotary damper, the rotary damper includes a movable member that is housed in the fluid chamber and divides the fluid chamber into two fluid chambers and that rotates reciprocally by the rotational force of a rotating body. It is constructed by forming a groove that communicates two fluid chambers divided by a movable member and has a different cross-sectional area depending on the position.

<Operation> According to the above means, a groove is formed on the inner wall surface of the casing or the closing member constituting the rotary damper, communicating the two fluid chambers divided by the movable member, and having a different cross-sectional area depending on the position. Therefore, the upper groove can have the function of the conduction chamber in the prior art. Further, the change in the cross-sectional area of the upper groove can be made to have the same effect as the change in the flow path area of the working fluid, that is, the closing of the orifice in the prior art.

That is, when the rotational force of the rotating body is transmitted to the movable member and the movable member rotates in one direction, the rotational force of the rotating body is transmitted through the movable member to the working fluid in the fluid chamber in the rotational direction of the movable member. The working fluid flows into the other fluid chamber through the groove formed in the inner wall surface of the casing. At this time, since the cross-sectional area of the groove differs depending on the position, the flow path area of the working fluid changes sequentially in accordance with the rotation of the movable member.

Therefore, if the cross-sectional area of the groove is formed to monotonically decrease or monotonically increase, linear braking characteristics can be obtained in accordance with the rotation of the movable member.

<Example> An example of a rotary damper to which the above means is applied will be described below with reference to the drawings.

Figure 1 is a cross-sectional explanatory diagram of the rotary damper, and Figure 2 is the same as in Figure 1.
3 (A) and (B) are explanatory diagrams of the shape of the groove.

In the figure, a fluid chamber 3 having a fan-shaped cross section is formed inside a casing 1 by a partition member 2 . Further, a groove 4 covering substantially the entire area of the fluid chamber 3 is formed in the bottom surface 1a of the casing 1. That is, the a4 is formed over substantially the entire circumference of the fan-shaped fluid chamber 3.

The groove 4 is formed at a position corresponding to a blade 5a protruding from a movable member 5, which will be described later. The open portion of the groove 4 is closed by the blade 5a, so that a rectangular cross section can be formed.

The groove 4 is formed to have a different cross-sectional area depending on its position, and as shown in FIG. 3(A), it opens at a constant angle from left to right and has a constant depth. ing. Therefore, when the blade 5a rotates with the open portion of the groove 4 closed, the cross-sectional area of the groove 4 is defined by the width dimension at a position corresponding to the rotational position of the blade 5a. That is, when the blade 5a rotates, the cross-sectional area of the groove 4 changes depending on the rotational position of the blade 5a.

As shown in FIG. 4B, the 'dII4 can be formed so that the entire length of the line groove 4 has the same width and has different depths depending on the position.

A movable member 5 having a protruding blade 5a is rotatably housed in the fluid chamber 3, and the fluid chamber 3 is further divided into two fluid chambers 3a and 3bζ by the partition 115a.

Further, the fluid chambers 3a and 3b are configured to communicate with each other through a groove 4 formed in the casing l.

As shown in the figure, the movable member 5 is constructed by integrally forming a wing msa and a shaft 5b. Since the movable member 5 reciprocates within the fluid chamber 3, there are approximately A gap of 0.02fi is formed.

Further, a two-sided middle part 5c is formed at the end of the shaft 5b to which a transmission means such as a pulley or a gear is fixed. Rotational force is transmitted.

The fluid chamber 3 housing the movable member 5 is filled with an incompressible working fluid, such as silicone oil, and then closed by a closing member 6.

The closing member 6 is formed to have an outer diameter approximately equal to the diameter of the open end of the casing 1, and has a hole 6a formed in the center thereof into which the shaft 5b of the movable member 5 is fitted. Also, the predetermined value of hole 6a! An O-ring 7 is fitted into the fluid chamber 3 to prevent leakage of the working fluid filled in the fluid chamber 3.

Said casing 1. Movable member 5. The closing member 6 can be formed by selecting a material such as plastic or metal according to a preset braking torque of the rotary damper.

In this embodiment, the casing 1. Movable member 5. Closing member 6
are each formed by plastic molding. Therefore, the casing l and the partition member 2 can be integrally molded, and the groove 4 can also be molded simultaneously when the casing 1 is molded.

Further, when each member is formed by plastic molding as in this embodiment, it is possible to seal the fluid chamber 3 by thermally welding the fitting surfaces of the casing 1 and the closing member 6.

If the preset braking torque of the rotary damper is large,
Alternatively, in the case where braking torque is generated only when the rotating body rotates in a specific direction, it is preferable to provide a check valve 8 at a predetermined position of the wing 15a of the movable member 5.

The check valve 8 has a hole 8a formed in the blade 5a and a cough hole 8a.
The valve stem 8b is fitted into the valve rod 8b so as to be movable in the axial direction. The valve body 8 formed at the end of the valve stem 8b
By arranging c on the fluid chamber 3a side, the movable member 5
When rotated in the direction of arrow a, the check valve 8 is closed, and when rotated in the direction of arrow a, the check valve 8 is opened.

In the rotary damper configured as described above, the rotational force of the rotating body (not shown) is transmitted to the movable member 5, thereby causing the blade l
When '15a rotates in the direction of arrow a, the working fluid in the fluid chamber 3a receives a compressive force due to this rotation. Therefore, the working fluid flows into the fluid chamber 3b through the groove 4, and the resistance generated at this time generates a braking force, which acts on the rotating body via the movable member 5.

As the blade 5a rotates in the direction of arrow a, the cross-sectional area of the groove 4 decreases, so the flow rate of the working fluid decreases and the braking force increases. Therefore, when the groove 4 is formed with a constant reduction rate of il in the cross-sectional area, the generated braking torque characteristic increases approximately linearly.

Further, when the movable member 5 is rotated in the direction indicated by the arrow, a compressive force acts on the working fluid in the fluid chamber 3b, and the check valve 8 is opened by this compressive force. Therefore, the working fluid in the fluid chamber 3b flows into the fluid chamber 3a through the check valve 8.

At this time, almost no braking force is generated.

In the above embodiment, a rotary damper was described which generates a braking force when the movable member 5 rotates in the direction of the arrow a, but does not generate a braking force when the movable member 5 rotates in the direction indicated by the arrow. By forming the rotary damper in the opposite direction to that shown in FIG. 2, a braking force is generated when the rotary damper, that is, the movable member 5 rotates in the direction of the arrow a, and a braking force is generated when the movable member 5 rotates in the direction of the arrow a. It is possible to construct a rotary damper that does not generate any braking force.

Further, in the above-mentioned embodiment, the line groove 4 was formed on the bottom surface 1a of the casing l, but the line groove 4 may be formed on the inner circumferential surface of the casing wedge, or the groove 4 may be formed on the inner surface of the closing member 6. In other words, it can be formed on any surface of the circumferential surface for forming the fluid chamber 3.

Further, in the above embodiment, the groove 4 is formed in a rectangular shape, but the groove is not limited to this shape, and a curved groove may be formed. In this case, it becomes possible to improve the mold releasability during molding.

<Effects of the Invention> As explained in detail above, the rotary damper of the present invention communicates two fluid chambers divided by a movable member on the inner wall surface of a casing or a closing member, and:! 11 Accordingly, since grooves having different cross-sectional areas are formed, the cross-sectional area of the grooves is changed according to the rotation of the movable member, and the working fluid in one fluid chamber is transferred to the other fluid through the linear groove. It can be distributed throughout the room. That is, the groove can function as the conduction chamber and orifice in the prior art. Therefore, there is no need to specially form a conduction chamber, and therefore,
Costs can be reduced by eliminating the need for the part I for forming the conduction chamber.

Furthermore, if the cross-sectional area of the groove is monotonically decreased or monotonically increased, it is possible to obtain linear braking characteristics in accordance with the rotation of the movable member.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view of the rotary damper, FIG. 2 is a view in the direction of the low arrow in FIG. 1, and FIGS. 3(A) and 3(B) are explanatory views of the shape of the groove. 1 is a casing, 2 is a partition member, 3.3a, 3b are fluid chambers, 4 is a groove, 5 is a movable member, 5a is a blade, 5b is a shaft, 6
8 is a closing member, and 8 is a check valve.

Claims (1)

[Claims] a casing having a vacant chamber formed therein; a closing member for closing the vacant chamber to form a fluid chamber; In a rotary damper having a movable member that reciprocates by power, two fluid chambers divided by the movable member are communicated with the inner wall surface of the casing or the closing member, and the damper has a cross-sectional area that differs depending on the position. A rotary damper characterized by the formation of grooves.