JPH0429632A - Rotary damper - Google Patents

Abstract

PURPOSE:To prevent the sticking of a cover member to a casing in such a condition that a viscous liquid has been intruded into the space between the contact surfaces of both by forming an escape groove for the viscous liquid in the fitly fixing part of the cover member and the casing. CONSTITUTION:In the peripheral part of the opening 2c of a casing 2, a stepped part 2e for fitly fixing a cover member 5 is formed, and also an escape groove 3 is provided to the bottom of the stepped part 2e, so that a surplus viscous liquid 6 overflowed from an inner chamber 2a can be reserved. Thus, the intrusion of the viscous liquid 6 into the space between the contact surfaces of the cover member 5 and the stepped part 2e, and resultant weakening in adhesive strength between both can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to the soft landing of the head of a floppy disk drive, the soft eject mechanism of the cover member of a cassette tape recorder, a video table recorder, etc., and other rotation mechanisms. Regarding rotary dampers.

[Prior Art] In general, this type of opening/closing lid has one end base supported by a rotating shaft, and the other end is a free end so as to be rotatable vertically or horizontally.

When opening and closing the lid mechanism of such a rotating object, such as the above-mentioned cassette tape recorder, in order to slow down the opening/closing operation and operate it softly, conventional methods that utilize the viscous resistance of liquid, friction Various types of rotary dampers, such as those using resistance, have been installed.

[Problems to be Solved by the Invention] Among these, in a rotary damper that uses a viscous liquid, an operating shaft that partially protrudes outward and is connected to the rotating shaft of the rotating object is located inside the casing. The casing is disposed in contact with the viscous liquid, and has a structure in which a lid member is fitted and fixed to the opening of the casing in order to keep the viscous liquid in the casing in a liquid-tight manner.

Therefore, when the inner chamber of the casing is filled with a viscous liquid and the operating shaft is inserted through the inner chamber, the viscous liquid is exposed to the parts other than the sliding part between the inner circumferential surface of the casing and the outer circumferential surface of the operating shaft. may accumulate between the joint surfaces with the lid member. Therefore, even if the lid member is fitted to the casing and bonded, etc., the adhesion between the two components will be impaired by the viscous liquid, and the lid member may be removed and the viscous liquid leaks, or even the operating shaft may be removed. There were problems such as

The present invention has been made to solve the above problems, and provides a rotary damper with a novel structure in which the lid member does not come off and is firmly fitted and fixed to the opening of the casing. The purpose is to

[Means for Solving the Problems] In order to achieve the above object, the rotary damper of the present invention includes a bottomed cylindrical casing, and an actuator disposed in contact with a viscous liquid filled in the inner chamber of the casing. and a lid member having a shaft insertion hole, at least one end of the actuating shaft protruding outward from the shaft insertion hole, and fluid-tightly fitted and fixed to the opening of the casing. In the rotary damper, near the fitting part of the casing with the lid member,
A feature is that by arranging the operating shaft in the inner chamber, an escape groove is provided to retain excess viscous liquid that overflows, thereby preventing the viscous liquid from entering between the contact surface between the casing and the lid member. shall be.

[Function 1] In this configuration, when the operating shaft is inserted into the casing and excess viscous liquid overflows, the viscous liquid flows into the escape groove provided in the casing and is retained.

Therefore, when the lid member is attached, viscous liquid does not enter between the contact surfaces of the lid member and the casing, and the two are firmly fixed.

[Example] Hereinafter, the present invention will be described in further detail based on an example shown in the drawings.

In the figure, 1 indicates a rotary damper according to the present embodiment, and the rotary damper 1 includes a casing 2, an operating shaft 4, a lid member 5, a viscous liquid 6, and the like.

The casing 2 is formed into a bottomed cylindrical shape having a bottom wall portion 2b that closes one end, and has an opening portion 2c at the other end.
The inner space portion is configured as an inner room 2a. Bottom wall part 2
In order to rotatably support an operating shaft 4, which will be described later, b has a convex portion 2d protruding toward the inner chamber 2a at approximately the center thereof.

Further, the peripheral edge of the opening 2C of the casing 2 is formed with a stepped portion 2e for fitting and fixing a lid member 5, which will be described later, and the bottom of the stepped portion 2e has a substantially triangular cross section, for example. A relief groove 3 is provided. As shown in FIG. 2, this relief groove 3 retains the excess viscous liquid 6 overflowing from the inner chamber 2a, and prevents the viscous liquid 6 from entering between the contact surface between the lid member 5 and the stepped portion 2e. This prevents the adhesive strength between the two from weakening.

The actuation shaft 4 has a large diameter portion 4a housed in the inner chamber 2a of the casing, and at least one end protrudes to the outside through a lid member 5, which will be described later, and serves as a rotation axis of an object to be rotated (not shown). It is composed of a small-diameter operating portion 4b that is connected. In this embodiment, both are integrally molded, but it goes without saying that they may be constructed as separate members. Further, the large diameter portion 4a is formed with a recess 4C that engages with a protrusion 2d protruding from the bottom wall 2b of the casing 2, thereby supporting the operating shaft 4 in a freely rotatable manner.

The lid member 5 is formed into a substantially circular shape in plan to liquid-tightly close the opening 2C of the casing 2, and is fitted and fixed to a stepped portion 2e formed at the peripheral edge of the opening 2C of the casing 2. . Any fixing method may be used as long as the two are firmly fixed to each other, but for example, as shown in FIG. The parts can be welded using an ultrasonic welding machine and fixed as shown in FIG. 2 with a force of <=. Alternatively, it is also possible to create a structure in which the f-difference part 2e is not provided with a tapered part, but is processed into the shape shown in Fig. 2, and the two are bonded together using arbitrary bonding or IJ. 〇Also, a shaft insertion hole 5 for inserting the upper two operating shafts 4 is provided approximately at the center of the lid member 5.
a#' is bored, and at least one end of the actuating portion 4b protrudes outward from the casing to support it. In addition, 7(
This is a seal for sealing the gap between the operating shaft 4 and the lid member 5.

The viscous liquid 6 is made of silicone oil or the like, and is filled into the inner chamber 2a of the casing 2. Therefore, due to the arrangement of the operating shaft 4, the gap between the circumferential surface of the inner chamber 2a and the back surface of the lid member 5, and the circumferential surface of the large diameter portion 4a of the operating shaft 4 is filled, and due to the viscous resistance. , functions to slow down the rotation of the operating shaft 4.

According to the rotary damper 1 of this embodiment, the excess viscous liquid 6 that overflows when the operating shaft 4 is disposed in the inner chamber 2a is
It flows into the escape groove 3 provided in the stepped portion 2e of the casing 2 and is held therein. Therefore, the viscous liquid 6 does not enter between the contact surfaces between the lid member 5 and the stepped portion 2e, and the lid member 5 is firmly fixed.

Note that the rotary damper 1 of the present invention is not limited to the above-described embodiments. For example, in the above-mentioned embodiment, the operating shaft 4 is composed of the large-diameter portion 4a that contacts the viscous liquid 6 filled in the inner chamber 2a and the operating portion 4b, but both are constructed from separate members. At the same time, the large diameter part is formed into a hollow body, and the actuating part is inserted into the hollow part, and a one-way clutch is disposed between the two, so that, for example, when the rotating object rotates in the closing direction, It is also possible to adopt a configuration in which viscous resistance acts only on the

Further, in the above-described embodiment, the relief groove 3 has a substantially triangular cross-sectional shape, but is not limited to this, and may have a substantially semicircular shape or the like.

Effects of the Invention 1 According to the rotary damper of the present invention, the viscous liquid escape groove is formed in the fitting and fixed portion of the lid member and the casing, so that the viscous liquid does not enter between the joint surfaces of the two. It won't be stuck. Therefore, the lid member does not come off easily and can be used for a long period of time.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing one embodiment of the rotary damper according to the present invention, FIG. 1 shows the state before the lid member is attached, and FIG. 2 shows the state with the lid member attached, respectively. show. 1... Rotary 2... Casing 3... Relief 4... Operating shaft 5... Lid member 6... Viscous liquid damper patent applicant: Fuji Seiki Co., Ltd. IT Agent/Patent Attorney 2,000 1) Minoru τ Nima Diagram

Claims (1)

[Claims] It has a cylindrical casing with a bottom, an operating shaft disposed in contact with the viscous liquid filled in the inner chamber of the casing, and a shaft insertion hole, through which the shaft is inserted. A rotary damper having at least one end of an actuating shaft protruding outward and a lid member that is fluid-tightly fitted and fixed to an opening of the casing, the rotary damper having at least one end portion of the casing protruding outward, and a lid member that is fluid-tightly fitted and fixed to an opening of the casing. , by arranging the operating shaft in its inner chamber, an escape groove is provided to retain excess viscous liquid that overflows, and the viscous liquid is prevented from entering between the contact surface between the casing and the lid member. Features a rotary damper.