JP4017213B2 - Anti-vibration mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of abnormal sound caused by stick slipping without increasing spring stiffness in the rod axial direction. SOLUTION: Out of the inner walls of the center holes for vibration-proofing rubbers 22 and 23, swelled parts 32 and 33 provided to a hole center are formed at positions corresponding to portions coming in contact with the side walls 12a and 13a of receiving parts 12 and 13, let contact pressure against the side walls of the receiving parts in the direction perpendicular to the axial direction, be increased at the time of assembly with a rod 4 by deforming and retreating the swelled parts in the direction perpendicular to the axial direction by means of the rod 4 and the like without increasing spring stiffness in the rod axial direction, the occurrence of abnormal sound caused by stick slipping is thereby prevented, and concurrently, control stability is also enhanced.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vibration isolating mechanism such as a vehicle, and particularly relates to an effective anti-vibration mechanisms Using the upper support of the suspension.
[0002]
[Prior art]
In general, the suspension includes a suspension arm that suspends a wheel from a vehicle body, a spring that alleviates vehicle vibration, and a shock absorber that attenuates the free vibration of the spring.
[0003]
FIG. 1 is a cross-sectional view showing an example of an assembled state of the shock absorber. As shown, the shock absorber 1 is generally composed of a cylinder type oil damper interposed between the vehicle body 2 and a suspension arm or wheel axle (both not shown). Connected to the housing, the upper end of the piston rod 4 is supported on the vehicle body 2 side via a support mechanism such as an upper support 5.
[0004]
The support mechanism such as the upper support 5 is provided with an anti-vibration mechanism 6 in order to mitigate transmission of vibrations to the vehicle body side as the vehicle travels. The vibration isolating mechanism 6 is provided on a pair of upper and lower cushion retainers 7 and 8 attached to the piston rod 4 of the shock absorber 1 and a vehicle body side mounting plate 9, and penetrates the rod 4 in the center of the bottom portion to displace the displacement. A pair of upper and lower cup-shaped receiving portions 12 and 13 in which permissible holes 10 and 11 are formed, and interposed between the receiving portions 12 and 13 and the cushion retainers 7 and 8, absorb the displacement of the piston rod 4. A pair of upper and lower donut-shaped anti-vibration rubbers 15 and 16 are provided.
[0005]
The pair of upper and lower anti-vibration rubbers 15 and 16 absorbs the stress when the wheel bounces and rebands. Further, by forming the receiving portions 12 and 13 of the anti-vibration rubbers 15 and 16 in a cup shape, they are interposed between the side walls 12a and 13a (see FIG. 2) and the sleeve 17 fitted on the piston rod 4. Further, the anti-vibration rubber portion absorbs the displacement of the rod 4 in the direction perpendicular to the axis, thereby improving the steering stability.
[0006]
However, due to the receiving portions 12 and 13 of the anti-vibration rubbers 15 and 16 being cup-shaped, the side walls 12a and 13a of the receiving portions 12 and 13 and the outer peripheral contact portions 15a of the anti-vibration rubbers 15 and 16 are provided. , 16a (see FIG. 4), there is a possibility that noise due to stick-slip may occur due to relative displacement between the two when the wheel bounces and rebounds.
[0007]
As shown in FIG. 4, the conventional anti-vibration rubbers 15 and 16 have rod holes 18 and 19 having the same diameter through the rod 4 and the sleeve 17 on the outer periphery thereof, and the upper and lower sides of the cushion retainers 7 and 8. Increasing the amount of pinching prevented the generation of abnormal noise due to stick-slip. That is, by increasing the compression rate of the vibration isolating rubbers 15 and 16 in the rod axis direction and expanding the vibration isolating rubbers 15 and 16 in the direction perpendicular to the rod axis, the side walls 12a and 13a of the receiving portions 12 and 13 are The contact pressure was increased to prevent the generation of noise due to stick-slip.
[0008]
[Problems to be solved by the invention]
However, in the conventional measures for preventing abnormal noise due to stick-slip, the compression rate in the rod axis direction of the vibration isolating rubbers 15 and 16 is increased, and the spring characteristics in the rod axis direction of the absorber cushion are increased, so that the riding comfort is deteriorated. There were difficulties. Further, since the tightening force in the rod axis direction is high, there is a problem in that the vibration-proof rubbers 15 and 16 have locally high strain portions and durability is lowered.
[0009]
The present invention, without increasing the spring stiffness of the rod axis direction, and aims to provide a vibration isolating mechanism to prevent stick-slip that obtained by preventing the generation of abnormal noise.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, as a result of earnest research, the present inventor increased the rubber volume of the inner wall of the vibration-proof rubber, and increased the tightening allowance in the radial direction (the direction perpendicular to the rod axis) in the assembled state. Stick slip was prevented while keeping the amount of pinching (compression rate in the axial direction) between the cushion retainer and the receiving portion in a normal state.
[0011]
That is, the present invention is interposed between a cushion retainer attached to the rod and a cup-shaped receiving part having a hole through which the rod can be penetrated at the bottom in order to absorb the displacement and vibration of the rod. The anti-vibration rubber has a rod hole that can penetrate the rod, and the outer periphery of the rod is compressed in the axial direction of the rod so that it can come into contact with the side wall of the receiving portion. In order to prevent stick-slip that occurs between the outer periphery of the anti-vibration rubber and the anti-vibration rubber, the center of the hole is located at the axial position corresponding to the portion of the inner wall of the central rod hole of the anti-vibration rubber that contacts the side wall of the receiving part An anti-vibration rubber characterized by forming a bulging portion that protrudes in a direction and deforms and retreats in a direction perpendicular to the axis by a rod or a sleeve fitted on the rod when assembled to the rod.
[0012]
By adopting such a configuration, since the amount of pinching in the rod axis direction remains normal, the contact pressure with the receiving side wall in the direction perpendicular to the axis can be increased without increasing the spring rigidity in the rod axis direction, and the stick There is an advantage that abnormal noise due to slip can be prevented. In this case, since the spring characteristic in the direction perpendicular to the axis is also improved compared to the conventional case, when it is desired to increase the spring rigidity in the direction perpendicular to the axis without increasing such characteristics, that is, in the axial direction. It is particularly effective. Furthermore, this stick-slip prevention measure does not increase the tightening force in the rod axis direction, so it can also prevent local distortion and greatly improve durability compared to conventional stick-slip prevention measures. It will be.
[0013]
Therefore, the present invention can be applied to any portion where the rod is displaced and vibrated not only in the axial direction but also in the direction perpendicular to the axis. In other words, the present invention can be applied to any anti-vibration mechanism for preventing vibration from the vibrating body to the object. For example, the present invention can be applied not only to an anti-vibration mechanism for automobiles but also to a mechanism for preventing vibration from a vibrating body such as a motor or a pump to a support floor. In addition, the present invention can be applied not only to a suspension mechanism but also to a steering mechanism and other automobile parts in an anti-vibration mechanism of an automobile.
[0014]
In particular, the vibration-proof rubber according to the present invention is preferably used as a component of the vibration-proof mechanism of the upper support of the suspension mechanism. That is, the present invention is provided in the cushion retainer attached to the piston rod and the vehicle body side mounting plate in the vibration isolating mechanism used for the suspension upper support that supports the upper part of the piston rod of the shock absorber on the vehicle body side. A cup-shaped receiving part having a hole through which the piston rod can be penetrated at the bottom, and a rod hole which is interposed between the receiving part and the cushion retainer and can penetrate the piston rod at the center. In order to prevent stick slip that occurs between the receiving part and the outer peripheral part due to the axial displacement of the rod, including an anti-vibration rubber formed on the outer diameter so that the outer peripheral part can come into contact with the side wall of the receiving part in the compressed state In addition, the piston protrudes toward the center of the hole at the axial position corresponding to the portion of the inner wall of the central rod hole of the anti-vibration rubber that contacts the side wall of the receiving portion. During assembly of the head, it is possible to provide a vibration damping mechanism to form a bulging portion that deforms backward in the axis-perpendicular direction by the piston rod or sleeve which is fitted on.
[0015]
By adopting such a configuration, not only can abnormal noise due to stick-slip be prevented, but the amount of pinching in the rod axis direction remains normal, so the spring stiffness in the vertical direction is not increased and the ride comfort is improved. No adverse effect. In addition, since the spring characteristics in the direction perpendicular to the axis of the anti-vibration rubber are improved as compared with the conventional one, the steering stability can be improved.
[0016]
Here, the anti-vibration rubber used as the anti-vibration mechanism for the upper support may be applied only to the anti-vibration rubber on either the bounce side or the rebound side. Is possible.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS. 1 is a cross-sectional view showing an example of an assembled state of a shock absorber, FIG. 2 is an enlarged cross-sectional view of an upper support, and FIG. 3 is a cross-sectional view of a vibration-proof rubber according to the present invention. In addition, since each component demonstrated about FIG. 1 by the term of a prior art is the same components except the vibration isolator which concerns on this invention, while using the same code | symbol, it demonstrates about the function and effect | action of each component. Since it was explained in the section of the prior art, a duplicate explanation is omitted.
[0018]
As shown in the figure, a vibration isolating mechanism 21 according to the present invention is provided on a pair of upper and lower cushion retainers 7 and 8 attached to a piston rod 4 of a shock absorber 1 of a suspension mechanism, and a vehicle body side mounting plate 9 at the center of the bottom. A pair of upper and lower cup-shaped receiving portions 12 and 13 having holes 10 and 11 penetrating the rod 4 and permitting displacement thereof, and interposed between the receiving portions 12 and 13 and the cushion retainers 7 and 8. In addition, a pair of upper and lower donut-shaped anti-vibration rubbers 22 and 23 (bound and rebound-side anti-vibration rubbers) that absorb the displacement of the piston rod 4 are provided.
[0019]
The upper and lower cushion retainers 7 and 8 are attached to the small diameter portion at the tip of the piston rod 4 of the shock absorber 1 by nuts 24 and 25 so as not to come out. The upper cushion retainer 7 is formed in a disk shape having a central hole that can penetrate the tip small diameter portion of the piston rod 4 at the center. The lower retainer 8 is formed in a cup shape so as to fit the lower portion of the lower vibration isolating rubber 23, and has a central hole that can penetrate the small diameter portion of the piston rod 4 at the center of the bottom. An outer flange 26 protruding outward is formed at the upper end. The distance between the retainers 7 and 8 is determined by the length of the inner sleeve 17 having an outer diameter larger than that of the central hole.
[0020]
Further, a bound stopper 27 is attached to the lower surface of the lower retainer 8 so as to reach the lower surface of the flange 26. The bounce stopper 27 can be attached to the lower retainer 8 by either vulcanizing and bonding the bounce stopper to the lower retainer or by pressing the bounce stopper 27 into the lower retainer and attaching it to the lower retainer. May be. Although not shown, reinforcing ribs are formed on the surfaces of the retainers 7 and 8 that face the antivibration rubbers 22 and 23.
[0021]
The receiving portions 12 and 13 are formed on the vehicle body side mounting plate 9, and holes 10 and 11 that can penetrate the small diameter portion of the piston rod 4 and the inner sleeve 17 are formed at the center of the bottom portion. The mounting plate 9 and the lower receiving portion 13 are integrally formed, and the mounting plate 9 is fixedly mounted on the vehicle body side by bolts 28. The upper receiving portion 12 is fixed to the upper surface of the lower receiving portion 13 by welding.
[0022]
These receiving portions 12 and 13 are formed in a cup shape in order to absorb the displacement of the rod 4 in the direction perpendicular to the axis and improve the steering stability. That is, the receiving portions 12 and 13 have a structure capable of absorbing the vertical displacement by interposing the anti-vibration rubbers 22 and 23 between the bottom portions 12b and 13b and the upper and lower retainers 7 and 8, and the side wall 12a. , 13a is employed to increase the spring constant of the anti-vibration rubbers 22 and 23 in the direction perpendicular to the axis and to ensure steering stability. Further, the holes 10 and 11 formed in the center of the bottom of the receiving portions 12 and 13 are formed to be considerably larger than the outer diameter of the sleeve 17 so as to be able to cope with the displacement of the rod 4 in the direction perpendicular to the axis.
[0023]
As shown in FIG. 3, the anti-vibration rubbers 22 and 23 are formed in a donut shape having holes 30 and 31 that can penetrate the rod 4 and the sleeve 17 at the center thereof, and the retainers 7 and 8 and the receiving portions 12 and 13 are formed. Intervened in a non-adhered state. In the center holes 30 and 31 of the anti-vibration rubbers 22 and 23, as the shape before the sleeve 17 is attached, bulged portions 32 and 33 having a semicircular cross section are formed on the inner wall.
[0024]
The bulging portions 32 and 33 are projected in the hole center direction over the entire circumference of the axial position corresponding to the portions of the inner walls of the holes 30 and 31 that contact the side walls 12a and 13a of the receiving portions 12 and 13. Therefore, when assembled to the rod 4, the sleeve 17 is fitted into the rod 4 so as to be deformed and retracted in the direction perpendicular to the axis. The amount of protrusion of the bulging portions 32 and 33 is determined by the set contact pressure with the side walls 12a and 13a of the receiving portions 12 and 13. For example, the anti-vibration rubber 12 on the upper side (rebound side) protrudes locally at the axial position of the hole 30 and the anti-vibration rubber 13 on the lower side protrudes long in the axial direction. Further, the bulging portions 32 and 33 are not only formed at the side wall corresponding positions, but also at other portions, for example, the lower (bound side) vibration isolating rubber 23, the side wall corresponding portions of the cup-shaped retainer 8. You may make it project.
[0025]
Also, large-diameter hollow recesses 34 and 35 are formed on the opposed surfaces of the receiving portions 12 and 13 on the bottom side of the bulging portions 32 and 33. On the other hand, grooves 36 and 37 capable of engaging with the ribs of the retainers 7 and 8 are formed on the opposing surfaces of the anti-vibration rubbers 22 and 23 on the retainers 7 and 8 side, respectively. Further, the lower vibration isolating rubber 13 is formed with a bound portion 38 for absorbing a collision between the lower retainer 8 and the receiving portion 13.
[0026]
As shown in FIG. 1, a dust cover 39 surrounding the lower vibration isolating rubber 23 and the bound stopper 27 is fitted on the outer periphery of the piston rod 4.
[0027]
The anti-vibration mechanism including the anti-vibration rubbers 22 and 23 is assembled when the tip of the piston rod 4 is attached to the vehicle body side. The assembly process will be briefly described. As shown in FIG. 2, the lower cushion retainer 8 is fitted and mounted on the stepped portion caused by the difference in diameter between the small diameter portion of the piston rod 4 and the large diameter portion on the base side. Then, the lower vibration isolating rubber 23, the receiving parts 12 and 13, and the upper vibration isolating rubber 22 are sequentially fitted on the upper side, and the sleeve 17 is fitted in the center holes 30 and 31 of the anti vibration isolating rubbers 22 and 23, and thereafter Then, the upper retainer 7 is fitted and the nut is tightened to complete the incorporation of the vibration isolation mechanism. Thereafter, the vibration isolation mechanism is assembled to the vehicle body with a bolt to complete the assembling work.
[0028]
When the sleeve 17 is assembled, the bulging portions 32 and 33 of the holes 30 and 31 of the anti-vibration rubbers 22 and 23 are pushed by the sleeve 17 and retreat in the direction perpendicular to the axis. The contact pressure with the receiving portion side walls 12a and 13a at the outer peripheral portions of the vibration isolating rubbers 22 and 23 increases as the rubber of the bulging portions 32 and 33 recedes.
[0029]
Accordingly, compressive stress acts on the vibration isolating rubbers 22 and 23 as the piston rod 4 is displaced in the axial direction, and noise is generated due to stick slip between the receiving portion side walls 12a and 13a and the vibration isolating rubbers 22 and 23. Will be prevented.
[0030]
In the above embodiment, the bulging portions 32 and 33 are retracted in the direction perpendicular to the axis by pushing the sleeve 17, but there is no sleeve, that is, without using the sleeve, the piston rod 4 directly. The present invention can also be applied to a vibration isolating mechanism having a structure in which the bulging portions 32 and 33 are moved backward by the above.
[0031]
【The invention's effect】
As is apparent from the above description, according to the present invention, the bulge protruding in the hole center direction at the axial position corresponding to the portion of the inner wall of the central rod hole of the anti-vibration rubber that contacts the side wall of the receiving portion. By forming the portion, the contact pressure between the side wall of the mounting plate and the outer peripheral portion of the anti-vibration rubber in contact with the mounting plate is increased, so that the generation of noise due to stick-slip between the two can be prevented. Further, when this is used for a vibration isolation mechanism of the suspension upper support, there is an effect that the driving stability can be improved without affecting the riding comfort performance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a suspension mechanism of the present invention. FIG. 2 is a cross-sectional view of the upper support. FIG. 3 is a cross-sectional view of the vibration-proof rubber of the present invention. Sectional view of [Figure]
1 Shock absorber 4 Piston rod 7, 8 Retainer 10, 11 Hole 12, 13 Receiving part 12a, 13a Side wall 21 Anti-vibration mechanism 22, 23 Anti-vibration rubber 30, 31 Hole 32, 33 Swelling part

Claims (1)

In the vibration isolation mechanism used for the upper support for suspension that supports the upper part of the piston rod of the shock absorber on the vehicle body side,
A pair of upper and lower cushion retainers attached to the rod, an upper open cup-shaped receiving portion provided on the vehicle body side mounting plate facing the cushion retainer and having a hole through which the rod can be penetrated at the bottom , and a lower Side-opening cup-shaped receiving part, rebound-side vibration isolating rubber sandwiched between the upper retainer and the upper-opening receiving part, and bounce sandwiched between the lower retainer and the lower-opening receiving part Including side anti-vibration rubber,
The rebound side anti-vibration rubber and the bounce side anti-vibration rubber have a rod hole that can penetrate the rod in the center, and the outer peripheral part has an outer diameter that can contact the side wall of the receiving part in a compressed state in the rod axis direction. Formed ,
In order to prevent stick slip that occurs between the receiving portion and the outer peripheral portion due to the axial displacement of the rod without increasing the tightening force in the rod axial direction, the center rod hole of the anti-vibration rubber A bulging portion that protrudes toward the center of the hole is formed at an axial position corresponding to a portion of the inner wall that contacts the side wall of the receiving portion, and the bulging portion is formed when the vibration isolating rubber is assembled to the rod. by fitted into the sleeve to the central rod bore after fitted in the receiving portion of anti-vibration rubber, antivibration mechanism, wherein the benzalkonium be deformed retracted in the axis-perpendicular direction.

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