JPH0893846A - Vibration control device - Google Patents

Abstract

PURPOSE: To exhibit a damping effect through utilization of viscous resistance of a viscoelastic ring without impairing a spring characteristic of a compression coil spring by arranging the viscoelastic ring between an upper cap and a lower housing case to attain a moving characteristic of the upper cap identically and smoothly. CONSTITUTION: This vibration control device is constituted of a compression coil spring 1 for supporting a load; a lower housing case 9 with an opened upper face for housing the compression coil spring 1; an upper cap 3 larger than an outer diameter of the lower housing case 9 and fitted thereto from the above with a clearance K between it and the case 9; and a viscoelastic ring 24 arranged in the clearance K so as to roll in accordance with relative movement between the upper cap 3 and the lower housing case 9 in the insertion direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention utilizes a viscoelastic resistance of a viscoelastic ring without impairing the spring characteristics of a compression coil spring by disposing a viscoelastic ring between an upper cap and a lower storage case. The present invention relates to a new anti-vibration device capable of exerting a damper effect.

[0002]

2. Description of the Related Art An anti-vibration device is provided between a lower mount and an upper mount to support the load of a mechanical device on the upper mount and absorb vibrations and shocks generated by the mechanical device. However, in the case of using only the compression coil spring, there is a problem of resonance, and effective vibration isolation over a wide area is insufficient.

Therefore, as shown in FIG. 6, the lower mount (2
1 ') Insert the compression coil spring (1') that carries the load into the lower storage case (9 ') with the upper opening installed, and then fit the upper cap (3') of the lower opening from the top. , Attach the elastic body (26 ') to the opening edge of this lower storage case (9'), and
From the outer periphery of the upper cap (3 ') to the lower surface opening edge direction, an elastic brim (26a') is projected over the entire circumference, and an elastic brim (26a ') is provided on the inner circumference of the upper cap (3'). Was hitting.

As a result, the elastic brim (5b ') is attached to the upper cap.
Anti-vibration device (B ') for elastic contact over the entire inner circumference of (3')
When the inside of the anti-vibration device (B ') is shock-loaded to some extent, the inside of the anti-vibration device (B') instantly becomes a high pressure and withstands this impact, and the spring body (4 ') It was designed to prevent large bending and increase in amplitude. The small through hole (9a ') formed in the lower storage case (9') serves as an orifice and serves to adjust the dashpot effect. Also, depending on how the load is applied, the upper cap
Lower storage case (3 ') tilts or shifts to one side
The upper cap (3 ') comes into contact with (9') and may hinder the spring characteristics of the compression coil spring (1 '), but the elastic flange (26a') is
It also has the effect of preventing this.

Although the elastic brim (26a ') has the dashpot effect and the contact prevention effect, it has the following drawbacks. That is, when the upper cap (3 ') moves in the direction of sinking downward against the elastic force of the compression coil spring (1'), the moving direction is the forward direction of the elastic brim (26a ') (elastic brim).
The force generated because (26a ') is in the direction of stretching') is the elastic collar.
(26a ') and the upper cap (3') is only the contact resistance, and as the upper cap (3 ') descends, the internal volume decreases and the internal pressure rises. Air comes out to reduce the contact pressure with the upper cap (3 ') of the elastic brim (26a'), and as a result, the upper cap (3 ') has the dashpot effect described above and is relatively smooth. On the contrary, when the upper cap (3 ') tries to move upward due to the elastic force of the compression coil spring (1'), the elastic brim (26
It moves in the opposite direction to [a ') [the direction that compresses the elastic brim (26a')], and the contact resistance increases, and at the same time the internal volume increases, so the inside becomes decompressed and the outside air Atmospheric pressure is generated between them, and the pressure difference causes the elastic brim (26a ') to cap.
The upper cap (3 ') moves upward more slowly than when it descends because it works in a direction of strongly pressing the inner peripheral surface of (3').

In other words, since there is a difference in the vertical movement of the upper cap (3 '), a dashpot effect is produced, but quick response is difficult, and the frictional resistance is large, so that the compression coil spring (1') The spring characteristics were also impaired, and it was not possible to obtain the anti-vibration effect as designed. This point will be further detailed in comparison with the present invention according to FIGS.

[0007]

An object of the present invention is to arrange a viscoelastic ring between the upper cap and the lower storage case so that the vertical movement characteristics of the upper cap can be made uniform and smooth. By virtue of this, the internal damping due to the viscous resistance of the viscoelastic ring is utilized without impairing the spring characteristics of the compression coil spring, and the viscoelastic ring is used to provide the airtightness of the space composed of the upper cap and the lower storage case. Thus, the air damper effect is exerted when the upper cap is moved up and down, and the amplification of the amplitude at the resonance point of the compression coil spring can be suppressed.

[0008]

A vibration-damping device (A) according to claim 1 comprises: a compression coil spring (1) for carrying a load, and a lower contraction case having an upper opening for accommodating the compression coil spring (1). 9)
And an upper cap (3) which is larger than the outer diameter of the lower contraction case (9) and is fitted from above with a gap (K) between the side surface of the lower contraction case (9) and the upper cap (3). It is placed in the gap (K) so that it makes contact with the entire side surface of the lower contraction case (9) and rolls in accordance with the relative movement of the upper cap (3) and the lower contraction case (9) in the insertion direction. It is composed of a viscoelastic ring (24).

As a result, frictional resistance unlike the conventional case does not occur in accordance with the relative movement of the upper cap (3) in the insertion direction with respect to the lower contraction case (9) (in this embodiment, the lifting and lowering of the upper cap (3)). Since the viscoelastic ring (24) rolls with good responsiveness, the upper cap (3) does not generate a large resistance force.
Moves smoothly in the vertical direction and there is no difference in the vertical movement, and the internal damping due to the viscous resistance of the viscoelastic ring (24) can be effectively used without substantially impairing the spring characteristics of the compression coil spring (1). The lower contraction case (9) and the upper cap (3) are formed by disposing the viscoelastic ring (24) between the lower contraction case (9) and the upper cap (3). By utilizing the airtightness of the space, the air damper effect can be exerted, and the amplification of the amplitude at the resonance point can be suppressed.

A second aspect of the present invention is "a compression coil spring for carrying a load.
(1), between the lower contraction case (9) of the upper surface opening for accommodating the compression coil spring (1) and the outer diameter of the lower contraction case (9), and between the side surface of the lower contraction case (9). An upper cap (3) that is fitted from above with a gap (K), and an upper cap
(3) and the lower contraction case (9) are in contact with the entire circumference of the side surface, and the gap (K) is formed so that the upper cap (3) and the lower contraction case (9) roll in accordance with the relative movement in the insertion direction. And a orifice (25) provided in at least one of the upper cap (3) and the lower contraction case (9) ”.

In this case, in addition to the above-mentioned action, the air damper function utilizing the closed space constituted by the lower contraction case (9) and the upper cap (3) can be adjusted by the orifice, and the wider vibration isolation function can be achieved. It becomes possible to control. The orifice may be variable by using a throttle valve, and by adjusting the throttle valve, the air damper effect can be set to the optimum condition to reduce the amplitude at the resonance point with almost no loss of the spring characteristics of the compression coil spring (1). Can be achieved.

[0012]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a cross-sectional view of an embodiment of a vibration isolator (A) according to the present invention, in which a lower storage case (9) having an upper opening is covered with an upper cap (3) having a lower opening, and a compression coil spring ( 1) is stored. An inner cylinder supporting cylinder part (10) is provided so as to project from the center of the lower storage case (9), and an engaging inner collar part (11) is formed on the inner periphery of the upper part of the inner cylinder supporting cylinder part (10). ing. On the inner circumference of the outer cup part (12) of the lower storage case (9), lower positioning projections (9a) are vertically projected at regular intervals, and the lower outer circumference of the compression coil spring (1) is positioned almost at the lower position. It is designed to fit in the ridge (9a).

The surging prevention member (2) is not always necessary in the present invention, but may be installed as shown by a virtual line. Briefly explaining the surging prevention member (2), the cylindrical tubular portion (2a), the engaging flange portion (2b) and the tubular portion (2b) protruding in the outer peripheral direction at the lower end of the tubular portion (2a) ( 2a) is composed of a plurality of viscoelastic pieces (2c) vertically protruding from the outer peripheral surface. The number of protruding viscoelastic pieces (2c) in the embodiment of FIG.
Although four sheets are provided at 90 ° intervals, the number of sheets is not limited to this and may be three sheets or four sheets or more.

The surging prevention member (2) is a viscoelastic member (a highly damped vibration damping rubber excellent in shock vibration absorption and internal damping) as a whole and has a property of absorbing little energy even if external force is applied. It is made of a special rubber.), But only the tubular part (2a) of the surging member (2) or the tubular part (2a) and the engaging flange part (2b) are made of a metal member such as iron or brass. Department (2
A viscoelastic piece (2c) having a small spring constant may be integrally projected from a). If the engaging collar portion (2b) is composed of a viscoelastic member,
It is more preferable because the lower storage case (9) and the compression coil spring (1) can be insulated. Note that the viscoelastic member is not limited to the above-mentioned member, but is one such as low repulsion rubber (a material that has a small elasticity, but has a restoring force that returns to its original shape even when deformed). But needless to say.

The height of the surging prevention member (2) is formed smaller than the minimum size when the compression coil spring (1) is compressed, and the inner cylinder support cylinder part (10) is inserted into the cylinder part (2a). Has been done. The engaging collar (2b) of the surging prevention member (2) is
The compression coil spring (1) is projected from the outer periphery of the lower end of (a).
Is engaged with the lower end of.

The upper cap (3) is fitted over the lower storage case (9), and the compression coil spring (1) is elastically contacted with the ceiling surface of the upper cap (3). A plurality of elastic hook arms (4) are provided so as to protrude downward at the center of the upper cap (3), and an engaging hook portion (5) is provided at the lower end on the inner peripheral side thereof.

The fall prevention member (16) is composed of a columnar part (19), a conical head (17) and a lower end engaging flange (18), and a conical shape is formed at the upper end of the columnar part (19). A head portion (17) is formed, and a lower end engaging collar portion (18) is formed at the lower end. Conical head (1
7) is an upper cap (3) composed of elastic hook arms (4)
Inserted in the recess (3a) located in the center of the conical head (17)
Engages with the engaging hook portion (5) and is suspended by the elastic hook arm (4). Conical head (17)
Is loaded via the upper cap (3), and when the compression coil spring (1) is bent, the lower end engaging flange (18) is located below the engaging inner flange (11). .

The upper pad (6) is disposed on the upper surface of the upper cap (3), and the upper insertion convex portion is projected from the lower end of the upper pad (6).
(7) said recess formed by elastic hook arms (4)
It is designed to fit into (3a). Top Insert Convex (7)
The tip of the head is not in contact with the edge of the conical head (17), and the conical head (17) can be freely swung with the engaging hook (5) engaged. There is. Further, the upper pad (6) has an uneven surface (8) formed on its upper surface (contact surface with the upper pedestal (20)).

The lower pad (13) is disposed below the lower storage case (9) and is used. The lower pad (13) is placed in the inner cylinder supporting cylinder portion (10) of the lower storage case (9). The lower insertion convex portion (15) protruding from the central portion of () is fitted.
Further, hanging pieces (14) are hung from both sides of the lower pad (13) so as to sandwich the lower mount (21) from both sides as shown in FIG.

The viscoelastic ring (24) is made of, for example, a very soft high-viscosity material (= high-viscosity silicone resin, soft rubber, low-repulsion rubber), and the upper cap.
Inserted between (3) and lower storage case (9), upper cap
The inner peripheral surface of (3) and the outer peripheral surface of the lower storage case (9) are used in contact with each other. The viscoelastic ring (24) is a solid body in FIG. 1, but is not limited to this and may be a hollow body. Further, the surface of the viscoelastic ring (24) has a very high coefficient of friction and rolls around the central axis.

An orifice (25) is connected to the upper cap (3), and the aperture ratio can be varied by a throttle valve in this embodiment. Of course, the aperture ratio may be fixed without providing the throttle valve. The installation location of the orifice (25) is not limited to the upper cap (3) but may be provided in the lower storage case (9).

At the lower end opening of the upper cap (3), a fall prevention collar (26) is installed to prevent the viscoelastic ring (24) from coming off.

Next, a method of assembling this embodiment will be described. If necessary, first insert the tubular portion (2a) of the surging prevention member (2) into the inner tubular support tubular portion (10) of the lower storage case (9), and then insert the compression coil spring (1) into the lower storage case (10). 9), and position the compression coil spring (1) with the lower positioning ridge (9a). As a result, the outer circumference of the compression coil spring (1) approaches the lower positioning protrusion (9a), so that the (non-contact) compression coil spring (1) is erected accurately at the center of the lower storage case (9). . At this time, if the surging prevention member (2) is installed, the viscoelastic piece (2c)
It will contact the inner circumference of (1) and be bent. The lower end of the stored compression coil spring (1) presses the engaging flange (2b) against the bottom surface of the lower storage case (9), and the engaging flange (2b) is pressed by the lower end of the compression coil spring (1). It will be engaged and fixed.

Then, the fall prevention member (16) is inserted into the inner cylinder support cylinder portion (10), and the conical head portion (17) of the fall prevention member (16) is disengaged from the engaging inner flange portion (11). After that, place the lower pad (13) on the lower surface of the lower storage case (9) and insert the lower insertion convex part (15) into the inner cylinder support cylindrical part (10) to lower it. Secure the lower pad (13) to the bottom of the storage case (9).

Next, a viscoelastic ring (24) is fitted around the lower storage case (9), an upper cap (3) is fitted over the lower storage case (9), and the compression coil spring (1) is compressed. As shown in FIG. 4, the conical head (17) of the captive prevention member (16) is pushed into the recess (3a) of the center of the elastic hook arm (4) while flexing. ) Is inserted while flexing outward, and the conical head (17) is engaged. Since the elastic hook arm (4) has elasticity, when the conical head (17) passes through the engaging hook part (5), the elastic hook arm (4) naturally returns to its original position, and as shown by the phantom line in FIG. The part (17) and the engaging hook part (5) are engaged with each other. When the hand is released in this state, the compression coil spring (1) extends, the lower end engaging flange (18) is engaged with the engaging inner flange (11), and the side surface and the lower portion of the upper cap (3). The viscoelastic ring (24) enters between the side surface of the storage case (9) and closes the gap (K) between them.

During the above assembly, the viscoelastic ring (24)
Rolls with the movement of the upper cap (3), but the movement amount is half that of the upper cap (3). Also viscoelastic ring
The coefficient of friction of the surface of (24) is very high, so the upper cap
There is no slip when moving (3), and it will roll along the side of the upper cap (3) and the lower storage case (9) exactly in accordance with the movement of the upper cap (3). .

Next, the upper pad (6) is placed on the upper surface of the upper cap (3), and the upper insertion convex portion (7) is inserted into the recess (3a) formed by the elastic hook arm (4). Cap the upper pad (6)
(3) Fix on the upper surface. In this way, the vibration damping device (A) according to the present invention is assembled.

Next, the operation of this embodiment will be described. The anti-vibration device (A) according to the present invention is used by being disposed between the upper mount (20) and the lower mount (21) as shown in FIGS. The lower pad (13) is placed on the lower part, and the hanging pieces (14) sandwich the lower mount (21) from both sides. The upper pad (6) comes into contact with the lower surface of the upper mount (20) and carries the load applied to the upper mount (20).

When a load is applied, the compression coil spring (1) bends by a predetermined dimension, and the lower end engaging flange (18) of the drop-out preventing member (16) is below the engaging inner flange (11) as shown in FIG. It will be in the state of being separated. When a mechanical device on the upper pedestal (20) operates to transmit vibrations or disturbance vibrations from the floor are transmitted through the lower pedestal (21), the compression coil spring (1) expands and contracts in accordance with this vibration, It will absorb vibration.

Next, the present invention and the conventional example will be described with reference to the graphs shown in FIGS. In this case, neither surging prevention member (2) is attached. FIG. 7 shows the first embodiment of the vibration isolator (A) of the present invention without orifice control [= (a)]. ] And the vibration isolation characteristic curve when using only the compression coil spring (1) described for comparison [= (d)
Indicate. ], And FIG. 8 shows the second embodiment of the vibration isolator (A) of the present invention.
When the orifice control according to the embodiment is performed [indicated by (B)]. ] And the compression coil spring described for comparison (1)
When only is used, it is indicated by [= (d). 9] FIG. 9 is a vibration-damping characteristic curve of the conventional vibration-damping device (B ′) shown in FIG.
It shows with (C). ] And the vibration-damping characteristic curve [= (d) when only the compression coil spring (1) described for comparison is used. ]. 7 to 9, the horizontal axis represents frequency (H
z), and the vertical axis is the transfer function (dB).

According to FIG. 7, when there is no orifice control [in other words, the upper cap (3) and the lower storage case (9),
When the closed space composed of the viscoelastic ring (24) mounted in the gap (K) is sealed, in this case, at the resonance frequency of the compression coil spring (1) (at about 5 Hz). Although the transfer function (dB) is slightly lowered and the damping effect of the viscoelastic ring (24) is seen, the air pressure in the closed space is increased and the air spring constant is increased, which is the compression coil spring (1).
The characteristic curve is added to the spring constant of
Compared to the case of using only the compression coil spring (1), the valley is shallower, and the improvement of the vibration isolation characteristics in the frequency region above the resonance frequency is slightly impaired. Of course, it is remarkably improved as compared with the conventional example described later.

FIG. 8 shows the case where the orifice control is performed against this, and the effect of improving the resonance frequency is remarkable by adjusting the diameter of the orifice (25), and the entire vibration-damping characteristic curve is compressed coil spring (1). It is quite close to the above case, and it can be seen that the air damper effect and the internal damping effect by the viscoelastic ring (24) are significantly working. In other words, the resonance phenomenon is suppressed with almost no loss of spring characteristics.

FIG. 9 shows the case of the conventional example of FIG. 6, in which the resonance frequency moves to the high frequency side of 22 Hz and the valley on the high frequency side above the resonance frequency is also very shallow, and the spring characteristic is only the compression coil spring (1). It is significantly deteriorated compared to the case of. From the above, it can be seen that the effect of the viscoelastic ring (24) is more remarkable than that of the conventional example, and in addition to this, further improvement is achieved by performing orifice control. By using the surging prevention member (2), surging appearing in a high frequency region can be reduced.

FIG. 10 is a graph showing the amplitude convergence state of the compression coil spring (1) of the vibration isolator (A) of the present invention equipped with the viscoelastic ring (24), and FIG. 11 is the compression coil spring.
It is a graph which shows the convergence state of the amplitude when only (1) is used. The horizontal axis is time and the vertical axis is the amplitude of the compression coil spring (1). According to this, it can be seen that the internal damping effect and the air damper effect of the viscoelastic ring (24) are exerted and the amplitude thereof is rapidly converged.

[0035]

According to the present invention, viscoelasticity is provided between the upper cap and the lower shrinkable case, contacting the entire circumferences of both sides, and rolling in accordance with the relative movement of the upper cap and the lower shrinkable case in the insertion direction. Since the ring is arranged, the internal damping due to the viscous resistance of the viscoelastic ring can be effectively used without significantly impairing the spring characteristics of the compression coil spring, and the amplitude of the compression coil spring at the resonance point can be suppressed. As a result, the damper function can be effectively exerted, and further, even at the resonance frequency or higher, the spring characteristics are not significantly deteriorated and the excellent vibration damping characteristics are exhibited. Further, since the orifice is provided in at least one of the upper cap and the lower contraction case, the damper effect can be adjusted, whereby the resonance suppression and the spring characteristic deterioration prevention can be more effectively performed.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of one embodiment of a vibration isolation device according to the present invention.

FIG. 2 is a front view of a vibration damping device according to the present invention.

FIG. 3 is a plan sectional view of FIG.

FIG. 4 is a cross-sectional view for explaining a state in the case where the fall prevention member according to the present invention is elastically engaged with the elastic hook arm.

FIG. 5 is a perspective view of a surging prevention member used in the present invention.

FIG. 6 is a vertical sectional view of a conventional example.

FIG. 7 is a vibration-damping characteristic curve of the first embodiment of the vibration-damping device according to the present invention, in which the orifice control is not performed and when only the compression coil spring described for comparison is used.

FIG. 8 is a vibration isolation characteristic curve when an orifice control is performed which is a second embodiment of the vibration isolation device of the present invention and when only the compression coil spring described for comparison is used.

9 is a vibration-damping characteristic curve when the conventional vibration-damping device shown in FIG. 6 is used and when only the compression coil spring described for comparison is used.

FIG. 10 is a graph showing a state in which the amplitude of the compression coil spring of the vibration isolator according to the present invention equipped with a viscoelastic ring is converged.

FIG. 11 is a graph showing a state of amplitude convergence when only a compression coil spring is used.

[Explanation of symbols]

 (1)… Compression coil spring (2)… Surging prevention member (2a)… Cylinder part (2b)… Engagement collar part (2c)… Viscoelastic piece (3)… Upper cap (3a)… Lower positioning ridge (4) )… Elastic hook arm (5)… Engagement hook part (6)… Upper pad (6a)… Upper spring fitting part (7)… Upper insertion convex part (8)… Uneven part (9)… Lower storage case

Claims (2)

[Claims] 1. A compression coil spring for carrying a load,
A lower contraction case having an upper opening for accommodating the compression coil spring, and an upper cap that is larger than the outer diameter of the lower contraction case and is fitted from above with a gap between the side surface of the lower contraction case and the upper cap and the lower contraction. A viscoelastic ring arranged in the gap so as to come into contact with the entire circumference of the side surface of the case and roll in accordance with relative movement of the upper cap and the lower shrinkable case in the insertion direction. Anti-vibration device. 2. A compression coil spring for carrying a load,
A lower contraction case having an upper opening for accommodating the compression coil spring, and an upper cap that is larger than the outer diameter of the lower contraction case and is fitted from above with a gap between the side surface of the lower contraction case and the upper cap and the lower contraction. At least the viscoelastic ring disposed in the gap so as to come into contact with the entire circumference of the side surface of the case and roll in accordance with the relative movement of the upper cap and the lower shrinkable case in the insertion direction, and at least the upper cap or the lower shrinkable case. An anti-vibration device comprising an orifice provided on either side.