JPH06207635A - Variable hydrauric damper - Google Patents

Abstract

PURPOSE:To provide a variable hydraulic damper capable of being extremely simply constructed and smoothly controlled at a predetermined position to a predetermined damper effect. CONSTITUTION:A variable hydraulic damper consists of a body 3 having the left side 9 closed, the central part having a large opening sectional area and the inner wall having the opening sectional area narrowed toward both left and right ends 17, 37 in the truncated form, a shaft 7 inserted into the body 3 movably and right, a cap 5 for tightly shutting the right side 11 of the body 3 while the shaft 7 is slidable and viscous fluid 13 filled in the body 3. While resistance is increased in a position having narrow gap between the shaft 7 and the inner wall of the body 3 (the opening sectional area is small), i.e., in both left and right ends 17, 37, and the resistance is reduced in a position having wide gap between the shaft 7 and the inner wall of the body 3 (the opening sectional area is large), i.e., in the central part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic damper having a variable braking force, which can be used for various applications requiring positioning accuracy for precision machining robot joints, OA equipment, electric appliances and the like.

[0002]

2. Description of the Related Art Conventionally, various hydraulic dampers have been studied in which the strength of movement resistance of a shaft that moves in a longitudinal direction in a main body is variable at a predetermined position. For example, in Japanese Utility Model Laid-Open Publication No. 3-41238, a variable orifice, a shutter, or a bar with a taper is electrically or mechanically moved with respect to a fixed orifice to continuously change the effective orifice area, thereby continuously changing the effective orifice area. Disclosed is a variable damper capable of obtaining a constant and gradually increasing damping force.

Further, in Japanese Utility Model Laid-Open No. 28338/1993, a liquid chamber in a cylinder is divided into two chambers, and a second opening is formed in the partition cylinder in relation to a first opening. There is disclosed a variable damping damper capable of obtaining a damper effect by rotating the cylindrical rotor and changing the diaphragm amount by the relative change in the circumferential direction at both openings.

However, the dampers disclosed in Japanese Utility Model Laid-Open No. 3-41238 and Japanese Utility Model Laid-Open No. 3-28338 move the variable orifice, the shutter, the tapered rod, or the cylindrical rotor. It was expensive because it required a motor, etc.

In this regard, in JP-A-64-58827, a grease spill hole of a piston moving in the grease is closed by a partition plate having a projection which is in sliding contact with a spiral groove engraved in the main body. Disclosed is a damper device that changes the damper force by changing the area of a piston that comes into contact with grease at a predetermined position. According to this damper device, it is possible to obtain a predetermined damper effect at a predetermined position of the piston without using a motor or the like.

[0006]

However, in any of the above dampers, a special member is required to change the resistance, and the relative position of the two members is changed to change the area through which the fluid passes. Therefore, the structure was complicated. Therefore, it is difficult to design so that the damper effect can be varied at a predetermined position.
Further, it was difficult to reduce the size. In a damper that performs a simple repetitive operation, it is desired that the structure be extremely simple and that a predetermined damper effect be smoothly controlled at a predetermined position.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to solve the above problems and to provide a variable hydraulic damper having an extremely simple structure and capable of smoothly controlling a predetermined damper effect at a predetermined position. And

[0008]

A variable hydraulic damper according to the present invention has a liquid-tight body having an inner wall whose inner diameter changes at a predetermined position in the lengthwise direction, and one end of the body penetrates in a tightly contacted state. And the viscous fluid filled in the body is provided to increase the strength of movement resistance of the shaft with respect to the body in the length direction. The feature is that it can be increased or decreased depending on the position in the depth direction.

[0009]

According to the variable hydraulic damper of the present invention, the inner wall of the main body has an inner diameter changed at a predetermined position in the length direction. As a result, the opening cross-sectional area in the main body changes, and the distance between the shaft moving in the main body and the inner wall changes depending on the position in the longitudinal direction. That is, there are positions where these intervals are narrow and positions where they are wide. At positions where these intervals are small, the viscous fluid increases the movement resistance of the shaft. On the contrary, at a position where these distances are wide, the movement resistance is reduced. Therefore, this interval is narrow at the position where the resistance needs to be increased (the stop or start position of the operation, or the position where the speed is decelerated), and the position where the resistance needs to be lowered (the position to operate at high speed or to accelerate). In the position), by designing this interval to be wide, it is possible to increase or decrease the desired movement resistance at a predetermined position. Furthermore, if the distance between the shaft and the inner wall is changed in a curved shape without steps, it is possible to smoothly adjust the change in the movement resistance.

In addition, according to the variable hydraulic damper of the present invention, only the inner wall of the main body is changed, and it is possible to configure the extremely small number of parts without requiring special parts. That is, the structure is extremely simple, and it becomes easy to design so as to obtain a highly accurate damper effect at a predetermined position. In addition, the size can be reduced and the cost can be reduced.

[0011]

Preferred embodiments of the present invention will be described below in order to further clarify the constitution and operation of the present invention described above. [Embodiment 1] FIGS. 1, 2, 3 and 4 show a variable hydraulic damper 1 of this embodiment. 1 is its front view, FIG. 2 is its right side view, FIG. 3 is its A-A sectional view, and FIG. 4 is its BB end view.

Variable hydraulic damper 1 of this embodiment
Consists of a body 3, a cap 5 and a shaft 7. The structure is such that the shaft 7 is inserted from the right side surface 11 into the cylindrical main body 3 with the left side surface 9 sealed, and the shaft 7 is slidable.
The right side surface 11 is liquid-tightly sealed by the cap 5. The viscous fluid 13 is injected into the main body 3.

In FIGS. 5, 6 and 7, the main body 3 (ring 31
Is removed). 5 is its front view, FIG. 6 is its right side view, and FIG. 7 is its CC sectional view. The main body 3 has a cylindrical shape with a closed left side surface 9 and a hollow interior. The inner wall 15 has a frustum shape in which the opening cross-sectional area is gradually narrowed from the right side surface 11 side toward the left side surface 9, and the left end portion 17 is provided at a left front end portion 19 of the shaft 7 described later. It has substantially the same shape as the blade 21. In addition, the grooves 22 along the blades 21 of the shaft 7 are arranged so that the shaft 7 can move in the left-right direction.
Is provided from the central portion 23 to the left end portion 17. The blade 21 and the groove 22 and the groove 39 of the ring 31 described later are slidably fitted to each other to prevent the shaft 7 from rotating. On the right side surface 11, a circular O-ring groove 27 is provided from the outermost periphery 25 to a little center, and the O-ring a is filled during assembly to seal the gap between the cap 5 and the main body 3 in a liquid-tight manner. Stop. A screw thread 29 is formed on the right side surface 11 side of the inner wall 15 so that the cap 5 described later can be screwed. Furthermore, a protrusion 32 that fits in the recess 38 of the ring 31 and that faces inward is fitted from the right side from the central portion 23 of the inner wall 15 so as to fit the ring 31 described below and prevent the ring 31 from rotating in the circumferential direction. Two are provided.

A ring 31 is attached to the inner wall 15a on the right side of the central portion 23 of the main body 3. The ring 31 is shown in FIGS. 8, 9, 10 and 11. 8 is its front view, FIG. 9 is its right side view, FIG. 10 is its left side view,
And FIG. 11 is the DD sectional view. Ring 31
Is a tubular body fitted to the inner wall 15 a on the right side of the main body 3. The outer peripheral surface 33 on the right side is reduced in diameter so as to fit with the cap 5 described later. The opening cross-sectional area of the inner wall 35 of the left end portion 34 has the same size as the opening cross-sectional area of the inner wall 15 of the central portion 23 of the main body 3, and the left end portion 34 to the right end portion 37.
It becomes narrow like a frustum toward. Also, the right end 3
A part of the blade 21 of the shaft 7 described later has substantially the same shape as the blade 21 of the shaft 7 from the center. Further, a groove 39 extending along the blade 21 of the shaft 7 is provided from the left end portion 34 to the right end portion 37 to a little center so that the shaft 7 can move in the left-right direction. Therefore, when the inner wall 15 is arranged in the main body 3, the inner wall 15 has a symmetrical shape from the central portion 23, the opening cross-sectional area of the central portion 23 is large, and the inner wall 15 is narrowed toward the left and right end portions 17 and 37. A recess 38 that fits into the protrusion 32 of the main body 3 is formed in the left end portion 34, and prevents rotation in the circumferential direction with respect to the main body 3. A shaft hole 44 into which the shaft 7 can be inserted is formed in the right end portion 37. Further, the right side surface 41
Circular O-ring groove 4 from the outermost periphery 43 to slightly center
5 is provided, and the O-ring b is fitted at the time of assembly to liquid-tightly seal the gap between the cap 5, the main body 3 and the shaft 7.

Next, the cap 5 will be described. Figure 1
2, FIG. 13, FIG. 14 and FIG. 15 show the cap 5. 12 is its front view, FIG. 13 is its right side view, FIG. 14 is its left side view, and FIG. 15 is its EE sectional view.
The cap 5 is a convex hexagonal screw protruding leftward, and has a shaft hole 51 penetrating left and right formed in the center. A thread 55 to be screwed into the main body 3 is formed on the outer peripheral surface 53 protruding on the left side. Further, the inside 57 is formed so as to be fitted to the outer peripheral surface 33 on the right side of the ring 31.

Next, the shaft 7 will be described. The shaft 7 is shown in FIGS. 16, 17, 18, and 19. 16 is its front view, FIG. 17 is its plan view, FIG. 18 is its right side view, and FIG. 19 is its left side view. The shaft 7 is a cylindrical rod body, and a blade 21 protruding forward and backward is provided on the left tip portion 19. The right end portion 57 is formed in a substantially rectangular shape for attaching the shaft 7 to a device or the like.

Variable hydraulic damper 1 of this embodiment
Is assembled as follows. Axis 7 on the ring 31
After being injected with a predetermined fixed amount of viscous fluid 13 into the main body 3, the blade 2 is integrated.
1 is engaged with the grooves 22 and 39 and fitted, and the O-ring a,
By arranging b and sealing the inside of the main body 3 with the cap 5, it is configured as shown in FIG. Although the gap between the ring 31, the cap 5 and the shaft 7 is closed by the O-ring b so that the viscous fluid 13 does not leak,
Gas can freely flow in and out of the gap, and absorbs a change in internal volume due to the movement of the shaft 7.

Next, the operation of the variable hydraulic damper 1 of this embodiment will be described. When the shaft 7 is moved left and right with respect to the main body 3, the viscous fluid 13 filled inside the main body 3
The shaft 7 receives resistance due to, but the resistance varies depending on the position because the opening cross-sectional area of the main body 3 differs depending on the position. In other words, the distance at which the viscous fluid 13 passes between the shaft 7 and the inner wall 15 during movement changes, so the resistance changes. At a portion where the distance between the shaft 7 and the inner wall 15 of the main body 3 is narrow (small opening cross-sectional area), that is, at the left and right end portions 17, 37, the resistance becomes large, while the distance between the shaft 7 and the inner wall 15 of the main body 3 becomes large. The resistance is small in a wide portion (large opening cross-sectional area), that is, in the central portion 23. For this reason, the positions where the operation is stopped and started (the left and right ends 17, 37) are made narrower to increase the resistance, while the parts which are operated at high speed (the central part 2).
In 3), the distance between them can be widened to lower the resistance. Moreover, during that time, the resistance changes smoothly and there is no impact, so it is possible to control to a predetermined movement resistance at a fixed position, and stop quickly and accurately at the position where it should be stopped, and after that stop the position accurately. Can be held at.

Since the strength of resistance is determined by the interval, it is possible to change the resistance change pattern and size by changing the shape of the inner wall 15 of the main body 3. For example, it is possible to have a structure in which the resistance is sharply increased immediately before the position to be stopped and there is almost no resistance at other positions. Further, by providing a plurality of portions having the maximum interval and the minimum interval, it is possible to cope with the motion of a motion such as a pause.
Therefore, it is possible to reliably control the speed by using a simple repetitive motion in the mechanism.

Moreover, according to the variable hydraulic damper 1 of this embodiment, a remarkably excellent effect can be obtained with an extremely simple structure in which only the shape of the inner wall 15 of the main body 3 is changed. That is, the damper effect can be controlled by the change rate of the distance between the shaft 7 and the inner wall 15 of the main body 3. Therefore, the design is easy and the size can be reduced. Moreover, the cost is low because a driving device such as a motor is not required to change the resistance.

Further, since only the ring 31 is a separate component and the shape of the inner wall 15 of the main body 3 is variable by the ring 31, it can be easily diverted to another structure.
In this embodiment, the damper effect is exerted at the beginning and the end of the stroke (the left and right ends 17, 37), but the present invention is not limited to this, and various shapes can be used depending on the application. Of course, it can be designed freely.

Further, the shaft 7 can be designed so as to penetrate from the left end portion 9 of the main body 3 to be applied to various uses. In this case, since there is no change in the internal volume due to the movement of the shaft 7 as described above, a completely sealed state can be achieved. In addition, the cross-sectional shapes of the main body 3 and the shaft 7 are not limited to the circular shape shown in FIG. For example, if the shaft 7 has a quadrangular cross section, the shaft 7 is prevented from rotating. In this way, it is possible to take various shapes. [Application Example 1] Various application examples using the variable hydraulic damper as described above will be shown.

In this application example 1, a case where the variable hydraulic damper as described above is attached to a shutter or a gate will be described. FIG. 20 shows a schematic diagram when applied to the shutter 100. Two variable hydraulic dampers 104 are attached to the bottom end portion 102 of the shutter 100. Here, the main body 106 is fixed to the bottom end portion 102 of the shutter 100, and the shaft 108 projects downward therefrom. The inner wall of the main body 106 has a truncated cone shape that narrows upward, and the more the shaft 108 enters the main body 106, the greater the damper effect and the stronger the resistance.

Further, FIG. 21 shows a case where it is applied to the gate 110. Similar to the above, the left and right ends 112 of the gate 110
One variable hydraulic damper 114 is attached to each. Here, the main body 116 is fixed to the left and right ends 112 of the gate 110, and the shafts 118 respectively project from the left and right directions in the left and right directions. The inner wall of the main body 114 has a truncated cone shape that narrows toward the center of the gate 110, and the shaft 118 is
The more it goes into 4, the greater the damper effect and the stronger the resistance. Incidentally, after the shaft 118 has entered the main body 114, in order to project the shaft 118 from the main body 114 as before, it is sufficient to provide a biasing means such as a spring in the main body 114.

The shutter 100 and the gate 1 of this application example 1
10, the variable hydraulic dampers 104, 1 in which the shapes of the inner walls of the main bodies 106, 116 are appropriately formed.
The provision of 14 enables the following control. That is, hitherto, a shutter and a gate that are opened and closed electrically are subject to a large impact when they are fully opened or closed even if they are opened and closed at a very low speed due to weight and the like. In addition, even with a manual shutter or gate, a large impact was generated unless the force was adjusted when opening and closing. However,
By applying the variable hydraulic dampers 104 and 114 having the inner wall of an appropriate shape, the resistance can be gradually strengthened when stopped, so that
And it became possible to stop it smoothly. Therefore, the impact at the time of full opening and full closing can be minimized. Therefore, failure can be prevented and maintenance can be minimized. Also, noise due to impact is prevented. Further, when the conventional mechanical friction brake is used, maintenance is required after long-term use due to the friction of the brake, but according to the variable hydraulic damper of the application example 1, the mechanical friction is used. There is no need for maintenance. [Application Example 2] In Application Example 2, a case will be described in which the variable hydraulic damper as in Example 1 is attached to an opening / closing mechanism such as a trunk, a hood, and a door of an automobile.

FIG. 22 shows a schematic diagram when applied to the hood 120 of an automobile. Variable hydraulic damper 1 at the connection between the bonnet 120 and the car body 122
24 is attached. Here, the main body 126 is fixed to the automobile main body 122, and the shaft 128 is fixed to the bonnet 120. Also, the inner wall of the main body 126 is
As in the variable hydraulic damper of the first embodiment, the central portion is wide and narrowed toward the left and right end portions, and the resistance is strong toward both end portions where the shaft 128 enters and leaves the main body 126. Has become.

In the bonnet 120 of this application example 2, the following control is possible by providing the variable hydraulic damper 124 in which the shape of the inner wall of the main body 126 is appropriately formed. That is, since the damper effect is maximum at the beginning of opening the bonnet 120, the resistance is high and the bonnet 120 can be opened slowly. As a result, when the bonnet 120 is opened, it is prevented that the bonnet 120 is opened suddenly and hits a person or an object in the vicinity. In the middle part, the damper effect is minimal, so the resistance is low and the opening speed is fast. The damper effect is maximized again immediately before fully opening, so that the bonnet 120 and the vehicle body 122 can be stopped without impact. Also, even when closing, since the damper effect is maximized immediately before it is completely closed, it does not suddenly close when it is closed with force, and it does not pinch hands or objects, and it does not impact the bonnet 120 or the vehicle body 122. Can be closed without giving. Further, since the variable hydraulic damper 124 has an extremely simple structure, it is extremely inexpensive and can be miniaturized, and even if it is installed in a small space in the bonnet 120, it does not interfere.

The variable hydraulic damper 124 of the second application example can be equally applied to the trunk and doors of automobiles as described above. Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it is needless to say that the present invention can be implemented in various modes without departing from the scope of the present invention.

[0029]

As described above, according to the variable hydraulic damper of the present invention, the structure is extremely simple, and it is possible to smoothly control a predetermined damper effect at a predetermined position. Produce the effect.

[Brief description of drawings]

FIG. 1 is a front view of a variable hydraulic damper of the above embodiment.

FIG. 2 is a right side view thereof.

FIG. 3 is a sectional view taken along the line AA.

FIG. 4 is a sectional view taken along the line BB.

FIG. 5 is a front view of the main body of the above embodiment.

FIG. 6 is a right side view thereof.

FIG. 7 is a sectional view taken along the line CC.

FIG. 8 is a front view of the ring of the above embodiment.

FIG. 9 is a right side view thereof.

FIG. 10 is a left side view thereof.

FIG. 11 is a DD cross-sectional view thereof.

FIG. 12 is a front view of the cap of the above embodiment.

FIG. 13 is a right side view thereof.

FIG. 14 is a left side view thereof.

FIG. 15 is a cross-sectional view taken along the line EE.

FIG. 16 is a front view of the shaft of the above embodiment.

FIG. 17 is a plan view thereof.

FIG. 18 is a right side view thereof.

FIG. 19 is a left side view thereof.

FIG. 20 is a schematic diagram showing a shutter of the first application example.

21 is a schematic diagram showing a gate of the application example 1. FIG.

FIG. 22 is a schematic view showing a hood of an automobile of the application example 2 described above.

[Explanation of symbols]

1, 104, 114, 124 ... Variable hydraulic damper, 3 ... Main body, 5 ... Cap, 7 ...
Shaft, 13 ... Viscous fluid, 15 ... Inner wall of main body, 21
... wings, 31 ... rings.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidekazu Yasui 2-24-15 Chiyoda, Naka-ku, Nagoya-shi, Aichi Kitagawa Industry Co., Ltd. (72) Inventor Asaharu Nakagawa, Aichi-ken 2-chome, Chiyoda 24 No. 15 Kitagawa Industry Co., Ltd.

Claims (1)

[Claims] 1. A liquid-tight body having an inner wall whose inner diameter changes at a predetermined position in a lengthwise direction, and one end of the body is pierced in a close contact state so as to be movable in the lengthwise direction in the body. Since the shaft and the viscous fluid filled in the main body are provided, the strength of movement resistance in the length direction of the shaft with respect to the main body can be increased or decreased depending on the position in the length direction. Adjustable hydraulic damper.