JP2012047251A - Device for damping external force - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for damping external force that is made compact in size by integrating a variable mass element, a spring element and a damper element.SOLUTION: The device is constituted of a cylinder 1 filled with an operation fluid 3, a rotating blade 4 which rotates by receiving a flow of the operation fluid 3, and a flywheel 5 which is rotationally driven by the rotating blade 4, and the operation fluid 3 moves in the cylinder 1 and forms a flow when applied with an external force. The flow of the operation fluid 3 rotates the rotating blade 4 of a rotation movement converter 40 arranged in the cylinder 1, the flywheel 5 is rotationally driven by the rotating blade 4, and the rotational drive acts on the movement of the operation fluid 3 by an inertia force of the flywheel 5.

Description

  The present invention relates to a control device for external force such as vibration, and to a device for buffering the influence of external force.

  When considering the operation of a general mechanical system, its components can be considered to be decomposed into a spring element, a damper element, and a mass element, respectively, but when applied to an automobile suspension mechanism, For example, an oil cylinder using oil and an orifice is used as a spring and a damper element as a spring element, but no special device has been made with respect to the mass element, and it is arranged under the spring. Generally, the weight itself is handled as a mass element.

However, the mass element is not necessarily set to an optimal value for the vehicle. This optimization of the mass element can be realized by making the mass element variable. Specifically, the vibration of a mechanical system called a mass damper is converted into kinetic energy using the mass of the mass damper itself to obtain a damping effect, or the apparent mass effect using the inertial mass of the rotating body. There is a method for obtaining (inertial mass effect). (Patent Document 1)
By introducing a variable mass element, there is an effect of further stabilizing the vehicle posture at the time of overcoming a vehicle step, sudden acceleration / deceleration, sudden turning, and the like.

  As shown in FIG. 10, in a conventional method of obtaining a mass effect using the inertial mass of a rotating body (hereinafter referred to as a conventional mechanism), a rack is formed on the plunger, and the plunger moves linearly. Then, the pinion engaged with the rack is rotated, and further, the rotational force of the pinion absorbs the external force applied to the plunger by rotating the gear wheel of the mass body via a gear or the like.

  As shown in FIG. 11, a system using a working fluid and a gear pump has been proposed instead of the rack and pinion system. In this system, a cylinder and a double-acting piston are formed, and the working fluid is filled in the cylinder. Both ends of the cylinder are connected to a pipe, and the pipe is connected to a gear pump.When the piston moves in the cylinder by an external force, the working fluid is guided to the pipe and drives the gear pump to which the flywheel is connected. It absorbs.

Special Publication No. 2004-537209

The conventional mechanism uses a rack and pinion to transmit the relative motion of the mounting terminals of the device, and it has been difficult to reduce the weight and size. In addition, in the case of using a fluid cylinder, the gear pump is driven by the fluid in the cylinder, and the rotational movement of the gear pump is transmitted to the flywheel, the gear pump is provided separately from the cylinder. It is difficult to reduce the size and weight, and it is difficult to install it in automobiles and motorcycles where it is difficult to newly install a mounting space. .
Further, when the conventional mechanism is connected to the suspension system, the suspension system connected to the conventional mechanism is fixed when a force greater than a set value is applied to the conventional mechanism. Therefore, there is a problem that unexpected external force is applied to the suspension system, resulting in damage.

As described above, when a conventional mechanism is used, a new mounting space is required, and when the size of the system is limited because the spring element and the damper element are not integrated, freedom of design is achieved. Since the degree is reduced, the conventional mechanism is only used for stabilizing the vehicle posture of a racing vehicle such as an F1 machine.
In order to improve the degree of freedom in mechanical system design using variable mass elements, it is necessary to integrate existing mechanical elements such as springs and damper devices with mass elements, and to have a structure that does not require a new mounting space. is necessary.
The present invention reduces the weight of a component that functions as a variable mass element, makes it possible to connect this component in parallel with an existing spring element, etc., and enables integration with the spring element and the damper element. It is an object of the present invention to eliminate the necessity of newly providing a device mounting space.

  An external force buffering device for buffering the influence of an external force, the cylinder, a working fluid filled in the cylinder, and a rotational motion for converting the movement of the working fluid in the cylinder caused by the external force into a rotational motion An external force buffering device characterized in that the rotational motion converting device generates a reaction force in a direction opposite to the moving direction of the working fluid by an inertial force corresponding to a mass of the rotational motion converting device. The external force acting on the external force buffering device is absorbed by the rotation of the rotary motion conversion means.

Since it is composed of a rotary motion conversion means that rotates by the flow of the cylinder, piston, and working fluid and a variable mass element that functions by incorporating a flywheel, compactness is achieved, and a new mounting space is not required, Further, parallelization of the spring element and the damper element can be solved simultaneously.
Since the rotary motion conversion means provided in the cylinder is a rotary blade, the rotary blade that rotates by the flow of the working fluid slips against the working fluid that moves at a high speed by receiving a force exceeding the set value. The wheel rarely rotates. Since the system can be prevented from being fixed, damage to the apparatus can be prevented.

The conceptual diagram of 1st Embodiment which concerns on this invention. Sectional drawing of the external force buffer device for an experiment which confirms the effect of the external force buffer device of this invention. The graph of the experimental result by the external force buffer device for experiment. The conceptual diagram of the modification of 1st Embodiment. Sectional drawing which shows 2nd Embodiment of the external force buffering device which concerns on this invention. Schematic at the time of mounting 2nd Embodiment in a motor vehicle. Schematic at the time of mounting 2nd Embodiment in a two-wheeled vehicle. The mechanical model figure of 2nd Embodiment. The graph of the vibration characteristic of 2nd Embodiment. The conceptual diagram of the external force buffering device using the conventional rack and pinion. The conceptual diagram of the external force buffering device using the conventional gear pump.

  Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments.

FIG. 1 shows a first embodiment of the external force shock absorber according to the present invention.
The external force shock absorber according to the present invention includes a cylinder 1 filled with a working fluid 3, a piston 2 that reciprocates inside the cylinder 1, and a rotary motion converting means 40 that rotates in response to the flow of the working fluid 3. 4 and a flywheel 5 that is rotationally driven by the rotary blades 4, and is provided with a throttle 7 that restricts the flow of the working fluid 3 as necessary. The piston 20 also has a function for sealing the working fluid 3.

When an external force acts on the piston 2 and slides and moves in the cylinder 1, the working fluid 3 is pushed by the piston 2 and moves in the cylinder 1 to generate a flow. The flow of the working fluid 3 rotates the rotary blade 4 of the rotary motion converting means 40 provided in the cylinder 1 and rotates the flywheel 5 that is integrated with the rotary blade 4 or connected by an appropriate means.
At this time, the inertial force of the flywheel 5 acts as an inertial resistance against the movement of the piston 2 when rotating, and a reaction force is generated in the piston 2 to suppress the movement of the piston 2. It functions as a variable mass element corresponding to the magnitude of the moment of inertia.

It was confirmed by the following experiment that the flywheel 5 in the present invention functions as a variable mass element and that the reaction force of the variable mass element increases as the inertia moment of the flywheel increases.
Water as the working fluid 3 was filled in the cylinder 1 of the experimental external force buffer shown in the sectional view of FIG. In this external force shock absorber, flywheels (A, B, C) having the same shape and different moments of inertia shown in Table 1 are mounted on the rotating blades 4, the cylinder 1 is fixed vertically downward, and the piston 2 and the working fluid 3 are connected to each other. The inside of the cylinder 1 was lowered by gravity.
FIG. 3 shows a graph for each flywheel (A, B, C, D) by observing the position (x) of the piston 2 descending due to gravity at regular time intervals from the start of descending. In the graph of FIG. 3, the flywheel D was fixed so that the flywheel A was not rotated.
However, the moment values of A and B are normalized based on the moment of inertia of the flywheel C. Further, the horizontal axis of the graph of FIG. 3 is a time axis, but the predetermined elapsed time is divided into five equal parts for easy understanding of the effect.

  As can be seen from the graph of FIG. 3, as the inertia moment of the flywheel 5 increases, the gradient of the lowering of the piston 2 in the vicinity of the movement of the piston 2 decreases, and the piston is obtained by changing the inertia moment of the flywheel 5. It was confirmed that the resistance force acting on 2 changed, and the external force shock absorber of the present invention functions as a variable mass element.

4 (1) to 4 (4) are modifications of the first embodiment of the external force buffer device of the present invention.
In FIG. 4 (1), the rotational motion conversion means 40 is comprised by the rotary blade 4 and the flywheels 5 and 51, and in FIG.4 (2), (3), (4), the rotary blade 4 and the flywheel 5 are included. Consists of.
In FIG. 4 (1), flywheels 5 and 51 are arranged on the outside and inside of the cylinder 1, respectively, and the repulsion and attractive force of the magnets (S pole and N pole) provided on the flywheels 5 and 51. Is used to transmit the rotation of the inner flywheel 51 to the outer flywheel 5. As an example, the arrangement of the magnets may be arranged as shown in (b) along the rotation direction. Although not shown in the drawing, the outer flywheel 5 is rotatably fixed to the cylinder 1 by a fixing tool for fixing the position.
The spring 9 functions to return the piston 20 that has received an external force and moved in the direction of the arrow in the direction opposite to the direction of the arrow, and may be attached as necessary.

  4 (2) is effective when a highly viscous working fluid is used. Specifically, a gear 41 is interposed between the rotary blade 4 and the flywheel 5. As the viscosity of the working fluid increases, the viscous frictional force of the fluid increases, so that the moving speed of the rod 8 when receiving an external force decreases. Since the rotational speed of the rotary blade 4 decreases due to the decrease in the moving speed, the inertial resistance value also decreases accordingly. Therefore, the rotational speed of the flywheel 5 is increased by interposing the gear 41 between the rotary blade 4 and the flywheel 5. By doing so, the inertia resistance value at the time of using a high-viscosity working fluid can be raised.

  In FIG. 4 (3), two pistons 2 and 20 are connected by a rod 21, and a rotary blade 4 and a flywheel 5 are coaxially supported on the rod 21 so as to be rotatable. Since the principle of generating inertial resistance is the same as that of the first embodiment, description thereof is omitted.

  4 (4) has a structure in which the piston 2 is omitted and the rotary blade 4 and the flywheel 5 are fixed to the rod 8. FIG. When an external force acts on the rod 8, the rotary blade 4 and the flywheel 5 connected to the rod 8 slide in the cylinder 1 and the rotary blade 4 and the flywheel 5 rotate. Although the inertial resistance is generated by this movement, the principle of generation of the inertial resistance is the same as that in the first embodiment, and the description thereof is omitted.

5 shows a combination of a spring element and a damper element to a variable mass element composed of a rotary blade 4 and a flywheel 5 using the fluid of the present invention. 6 is arranged, and the throttle part 7 which restricts the flow of the working fluid 3 is provided inside the cylinder 1.
When the working fluid passes through the restricting portion 7, a viscous frictional force corresponding to the speed of the piston 2 is generated, so that it functions as a damper element, and a reaction force is generated by the coil spring 6 depending on the position of the piston 2, and as a spring element Function.
As described above, the external force buffering device 10 of this embodiment is an integrated combination of a spring and a damper with a variable mass mechanism using a fluid, and a mass element can be installed in a mounting space without requiring a new mounting space. It can be installed in cars and motorcycles that have little room.

FIG. 6 shows an example in which the external force shock absorber 10 of this embodiment is mounted on a suspension system of an automobile, and FIG. 7 shows an example in which it is mounted on a motorcycle. As described above, since the spring element, the damper element, and the variable mass element can be integrally mounted, a great effect can be exhibited when the mounting space is limited.
In addition to the variable mass element, it is not always necessary to mount the spring element and the damper element at the same time, and if necessary, a combination of one of the two elements and the variable mass element, or a variable mass element. It is also possible to constitute an external force shock absorber only by using the above.

In this embodiment, a damper element, a spring element, and a mass element are integrated in parallel, and a dynamic model of this integrated apparatus is as shown in FIG. The equation of motion (1) is solved when an external force of forced vibration of frequency ω is applied to a system in which the mass point M is connected in series to this dynamic model, and the dimensionless amplitude is divided by the excitation force and static displacement F / k. If An is calculated | required, Formula (2) will be obtained.
It is assumed that the mass point displacement is x, the spring constant is k, the damping constant is c, and the mass element generates an inertial force b times the acceleration.

Here, Table 2 shows the states when (A) damper element and mass element are not used, (B) only damper element is used, and (C) damper element and mass element are used. When the parameters are employed, a graph of the amplitude with respect to the frequency in FIG. 9 is obtained from Equation (2). The graph of FIG. 9 shows that the amplitude decreases in the high frequency region as compared with the case where only the damper element is used as the reaction force of the mass element increases.

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Piston 3 Working fluid 4 Rotary blade 40 Rotary motion conversion means 5, 51 Flywheel 6 Spring 7 Constriction part 8 Rod 41 Gear

Claims (5)

An external force shock absorber for buffering the influence of external force,
A cylinder, a working fluid filled in the cylinder, and a rotational motion converting means for converting the movement of the working fluid in the cylinder caused by an external force into a rotational motion,
The external force buffering device, wherein the rotational motion converting means generates a reaction force in a direction opposite to a moving direction of the working fluid by an inertial force corresponding to a mass of the rotational motion converting means. 2. The external force shock absorber according to claim 1, wherein the rotational motion converting means is constituted by a rotary blade and a flywheel. The rotational motion converting means, a spring element, and a damper element,
The spring element is disposed coaxially with a cylinder constituting the external force buffer device,
3. The external force shock absorber according to claim 1, wherein the damper element is disposed in the cylinder. 4. The external force shock absorber according to claim 3, wherein the damper element is provided in a cylinder and is a restricting portion for restricting movement of the working fluid in the cylinder. 5. The rotation ratio between the rotary blade and the flywheel is converted by interposing a gear between the rotary blade and the flywheel constituting the rotary motion converting means. The external force shock absorber described.