JP2587775B2 - Variable speed device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable speed device for varying the return speed of a member that rotates or slides by utilizing the shear resistance of viscous grease.

[0002]

2. Description of the Related Art In gate closers, door closers, tape cassette lids, foot brake devices for automobiles, etc., the speed of movable bodies such as gate doors, cassette lids, brake arms, etc. is set to a low speed, and damage to members and operational safety. In order to improve the speed, a variable speed mechanism is mounted. In a conventional variable speed mechanism, viscous grease is interposed between a fixed body and a movable body that rotates or slides with respect to the fixed body, and the movable body is moved by a return device such as a return spring that returns the movable body. Has been energized. Then, the urging force of the return device is weakened by the shear resistance of the viscous grease to operate the movable body at a slow speed.

[0003]

However, in the conventional variable speed mechanism, since the relative position between the fixed body and the movable body is fixed, the shear resistance of the viscous grease has a constant value. Therefore, since the variable speed range is also constant, it is not possible to adjust the return device according to the urging force, and the above adjustment is performed by individually selecting a variable speed mechanism that matches the urging force. I have. For this reason, when the urging force of the return device is large, not only does the speed variable mechanism become large, but also there is a problem that if the urging force of the return device decreases over time, automatic return cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned circumstances, and provides a speed variable device capable of continuously varying a shearing force and continuously varying a speed of a movable body in an operating state. It is intended to be.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a function of changing an effective wrap portion between a movable body and a fixed body. In a device for alleviating the speed of a movable body by shear resistance of viscous grease interposed therebetween, the fixed body and the movable body include a male screw and a female screw that are screwed together, and an effective wrap portion between the fixed body and the movable body is provided. The feature is that the area is variable.

In the present invention, the effective area means an area where a shear resistance obtained from a viscous grease acts as an effective resistance force between a fixed body and a movable body. In general, the shear resistance of viscous grease increases when the effective area of the viscous grease contacting the fixed body and the movable body is large, and decreases when the effective area is small. According to the present invention, the amount of viscous grease that comes into contact with the fixed body and the movable body is indirectly adjusted by making the effective area of the wrap portion variable.

[0007]

The fixed body and the movable body are composed of a male screw and a female screw that are screwed together. If the effective area of the wrap portion between the fixed body and the movable body is made variable, the shear resistance of the viscous grease interposed between them is changed. Is changed, the shearing force can be continuously varied in the operating state, and the speed of the movable body can be continuously changed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an embodiment according to the present invention, and FIG.
Is a plan view of the same. In FIG. 1 and FIG.
Is a fixed frame that serves as a fixed body, and 14 is a shaft body. A female screw 13 is engraved on the fixed frame 12, and a male screw 15 screwed to the female screw 13 is formed on the shaft 14.
The male screw 15 is formed to be slightly smaller than the female screw 13 so that viscous grease is filled between them.

The upper part of the shaft 14 is, as shown in FIG.
It is formed in a flat D-shape, and an output plate 16 serving as a movable body is fitted on this upper part. The output plate 16 is rotatably attached to the upper end of the fixed frame 12.
The shaft 14 is integrally rotated by the rotation of the output plate 16 because the shaft 6 and the shaft 14 are fitted in a D-shape and the relative rotation is regulated. Move straight up and down. Therefore, the male screw 1 of the shaft 14
The length (effective area as a whole) at which the screw 5 is screwed into the female screw 13 of the fixing frame 12 changes, and the amount of viscous grease interposed between them and effectively acting changes. Be variable.

In this adjustment, the effective area increases or decreases in proportion to the screwing length of the male screw 15 and the female screw 13, so that the required torque can be varied according to the screwing amount and the rotation of the output plate 16 As a result, the shaft 14 moves linearly, resulting in an increase or decrease in the effective area, thereby making the rotation speed variable. Therefore, when the present embodiment is applied to a door closer or the like, when the effective area at the time of closing the door is set to be small at first and large at the end,
The closing operation is gradually gradual to improve safety, and finally the effective area becomes extremely large, so that the door can be closed quietly.

[0011]

As mentioned above, according to the present invention, the fixed body and the movable body are screwed into a male screw and a female screw, and the effective area of the lap portion between the fixed body and the movable body is made variable so that the shear resistance of the viscous grease is reduced. Is changed, the shearing force can be continuously varied in the operating state, and the speed of the movable body can be continuously varied.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment according to the present invention.

FIG. 2 is a plan view of the same.

[Explanation of symbols]

 12 Fixed frame (fixed body) 13 Female screw 14 Shaft body 15 Male screw 16 Output plate (movable body)

Claims (1)

(57) [Claims] 1. An apparatus for alleviating the speed of a movable body by shearing resistance of viscous grease interposed between the fixed body and the movable body, wherein the fixed body and the movable body comprise a male screw and a female screw which are screwed together, A variable speed device, wherein an effective area of a wrap portion between the fixed body and the movable body is variable.