JPH06129464A - Sliding bush - Google Patents

Abstract

PURPOSE:To make riding quality and control stability either satisfiable as well as to form it into being less in the number of part items. CONSTITUTION:A large diametral part 21 is installed in the central part of an inner cylinder 2. A fiber layer 4 being good in slidability is installed there so as to make it slidingly contact with the whole surface of a circumference of the inner cylinder 2. In addition, a plastic insert 1 is installed in an outer side of this fiber layer 4 so as to go along the large diametral part 21, making it join this fiber layer 4. In succession, vibrationproof rubber 5 is installed there so as to cover the plastic insert 1 and the fiber layer 4 as well as join these elements. Then, an outer cylinder 3 is installed there so as to join an outer circumferential surface of this vibrationproof rubber 5. Therefore, owing to work of the plastic insert 1 installed so as to go along the large diametral part 21, riding quality and control stability either are thus ensured. In consequence, the number of part items becomes lessened, leading to a reduction in cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding bush used for a rotation support portion of a swing arm or the like of a vehicle suspension device, and particularly to improve both riding comfort and steering stability. That is the purpose.

[0002]

2. Description of the Related Art In order to improve the ride comfort of an occupant in a vehicle, the mounting portion (rotary support portion) of the suspension arm is elastically supported and the suspension is used when the vehicle gets over a road surface protrusion or the like. In order to allow the arm to smoothly rotate, it is necessary that the above-mentioned rotation support part is supported by rotation in a state of low frictional resistance. Further, from the viewpoint of steering stability of the vehicle, the attachment portion of the suspension arm needs to be attached with high rigidity in the front-rear direction of the vehicle. Considering these things,
The conventional suspension arm mounting portion (rotary support portion) is provided with a sliding bush as shown in FIG.

However, this one has an inner cylinder 20 and an outer cylinder 30 made of metal, a vibration-proof rubber 50 between them, and a relative sliding motion (rotational motion) with the inner cylinder 20. In addition to having a plastic insert 40 that does the above, a backup sleeve 80 that reinforces the insert 40 is provided. And
Further, a minute play (G) is provided between the inner cylinder 20 and the insert 40 in order to smooth the sliding movement, and the minute play (G) is filled with grease or the like as lubricating oil. It is composed of In order to prevent the leakage of the lubricating oil, a seal member including an oil seal 70 and a seal ring 60 is provided at both ends of the inner cylinder 20. Therefore, this one not only increases the number of components,
The structure is complicated, and there are problems in productivity and durability.

[0004]

In order to solve these problems, a dry type without using a lubricating oil as shown in FIG. 3 is considered. This is a large diameter part 2 having a larger outer diameter than both ends of the inner cylinder 20 at the center.
10 is provided, on the other hand, the vibration-proof rubber 50 joined to the outer cylinder 30.
The fiber layer 40 having a low friction coefficient is provided in a portion that makes sliding contact with the inner cylinder 20.
Therefore, in this structure, the relative rotational movement between the inner cylinder 20 and the outer cylinder 30 is obtained by the sliding movement between the outer peripheral surface of the inner cylinder 20 and the fiber layer 40. On the other hand, the thrust force generated between the inner cylinder 20 and the outer cylinder 30 is provided integrally with the bulging portion formed by the large diameter portion 210 and along the bulging portion. It is carried between the above-mentioned fiber layer 40 and the vibration-proof rubber 50. However, in this case, when the thrust force becomes a large value, the large diameter portion 210 and the vibration-proof rubber 50 are
It may not be possible to carry it alone. As a result, there is a problem that the inner cylinder 20 comes out of the sliding bush under a high thrust force. Furthermore, there is a problem in that the sliding portion such as the fiber layer 40 is worn due to repeated operation (rotational sliding) under a high load, causing play in the radial direction. It is an object (problem) of the present invention to provide a sliding bush for a suspension arm, which is excellent in both riding comfort and steering stability and has a small number of parts, which solves these problems. is there.

[0005]

In order to solve the above-mentioned problems, the following measures are taken in the present invention. That is, it has an outer cylinder and an inner cylinder that are capable of relative rotational movement, and is integrally joined to the outer cylinder between the outer cylinder and the inner cylinder and is capable of sliding motion with the inner cylinder. In the sliding bush having the vibration isolating rubber provided in the above, a large diameter portion or a bulging portion having an outer diameter larger than the end portion is provided in the central portion of the inner cylinder, while the inner circumference of the antivibration rubber is provided. On the surface side, a fiber layer having a small sliding friction coefficient is provided integrally with the anti-vibration rubber, and on the outside of the fiber layer along the large diameter portion or the bulge portion of the inner cylinder, and A plastic insert is provided so as to be bonded to the vibrating rubber and the fiber layer, and further, a part of the vibration isolating rubber is extended so as to cover the small diameter portion formed near both ends of the inner cylinder to form a seal rubber. It was decided to adopt a configuration in which parts are provided.

[0006]

By adopting the above-mentioned structure, in the present invention, both performances of riding comfort and steering stability are satisfied. That is, in FIG. 1, the force (vibration) in the P direction is absorbed and attenuated by the anti-vibration rubber 5 provided between the outer cylinder 3 and the inner cylinder 2, so that the internal force from the outer cylinder 3 side is reduced. It is not transmitted to the cylinder 2 side. Therefore, the vibration and the like are not transmitted to the vehicle body side. On the other hand, when the wheel gets over a large bump or the like, a rotational movement (swing) with a large displacement angle of the suspension arm is generated based on the vertical movement of the wheel. It is processed by the smooth sliding motion between the cylinder 2 and the fiber layer 4 provided on the inner peripheral surface of the vibration isolating rubber 5. Therefore, no force (vibration) is transmitted from the outer cylinder 3 side where the suspension arm is mounted to the inner cylinder 2 side where the suspension arm is mounted, and pitching or bouncing of the vehicle body is not caused. For these reasons, good riding comfort can be obtained in a vehicle that employs the sliding bush.

Next, with respect to the load (T) in the thrust direction of the sliding bush, the plastic insert 1 provided along the large diameter portion 21 of the inner cylinder 2 is basically the thrust load (T). T) will be received. That is, while the load (T) in the thrust direction has a small value, force and vibration are caused by shear deformation of the vibration isolating rubber 5 provided between the outer cylinder 3 and the plastic insert 1. Is absorbed. On the other hand, when the thrust load (T) has a large value, the plastic insert 1 formed along the large diameter portion 21 of the inner cylinder 2 receives the thrust load (T). By holding, the relative displacement between the outer cylinder 3 and the inner cylinder 2 is suppressed. This prevents the inner cylinder 2 from slipping out of the sliding bush. As a result, the mounting rigidity in the thrust direction is increased and the steering stability is also improved.

Further, even when the inner cylinder 2 is twisted, the fiber layer 4 having good slipperiness is provided so as to wrap the large-diameter portion 21, so that the vibration-proof rubber 5 is simply deformed. It is different from the one to deal with and will exhibit better followability. As a result, the followability of the suspension arm is improved, and riding comfort is improved. Regarding this point, in the case where the bulging portion 21 'provided in the central portion of the inner cylinder 2 as shown in FIG. 2 has a spherical shape, a function similar to a so-called ball joint is exhibited. Therefore, better riding comfort and steering stability can be obtained.

Further, in this sliding bush, a part of the vibration-proof rubber 5 is extended to form a seal rubber portion 51, and the small diameter portions 22 formed at both ends of the inner cylinder 2 are formed by the seal rubber portion 51. Since it covers the fiber layer 4 that is in sliding contact with the outer peripheral surface of the inner cylinder 2, a seal between the fiber layer 4 and the outer peripheral surface of the inner cylinder 2 is provided. It will be surely done. As a result, it is not necessary to separately provide a seal member as in the conventional one, and due to the tension of the seal rubber portion 51,
Since the outer peripheral surface of the inner cylinder 2 is reliably sealed, invasion of earth and sand and rainwater can be prevented, and abrasion of the sliding surface and the like can be prevented.

[0010]

EXAMPLE A first example of the present invention will be described with reference to FIG. The configuration of the present embodiment has an inner cylinder 2 having a large-diameter portion 21 having a larger outer diameter than both ends of the inner cylinder 2, and an outer cylinder 3 provided so as to be capable of relative rotational movement with the inner cylinder 2. When,
Between the inner cylinder 2 and the outer cylinder 3, the outer cylinder 3 side is integrally joined, and the inner cylinder 2 side is a sliding bush made of a vibration-proof rubber 5 or the like provided so as to allow sliding movement. Is basically formed.

In such a basic structure, a fiber layer 4 is integrally provided with the vibration isolating rubber 5 on the inner peripheral surface side of the vibration isolating rubber 5 so as to extend along the outer peripheral surface of the inner cylinder 2. There is.
The fiber layer 4 has, for example, a double woven structure of Teflon fiber and polyester fiber, and the Teflon fiber appears on one side and the polyester fiber appears on the other side. It is woven. Such a fiber layer 4 is installed so that Teflon fibers having good slipperiness come on the side of the inner cylinder 2 and polyester fibers having good bondability with rubber come on the side of the vibration-proof rubber 5. It Further, on the outer side of the fiber layer 4, the inner cylinder 2
The plastic insert 1 is provided so as to be along the large-diameter portion 21 and to be bonded to both the vibration isolating rubber 5 and the fiber layer 4. here,
The plastic insert 1 is made of ultra-high molecular weight polyethylene, polyamide resin (nylon), or the like. Further, in the case of the ultra high molecular weight polyethylene, the joining with the vibration isolating rubber 5 is performed by fusing at the same time as molding due to heat, pressure, etc. at the time of molding the vibration isolating rubber 5. In the case of etc., it is performed by separately bonding with an adhesive.

Further, the plastic insert 1
In the state of the material, as shown in the two-dot chain line in FIG. 1, it is made of a straight pipe shape, and when it is attached to the outside of the fiber layer 4 provided on the outside of the inner cylinder 2, The vibration damping rubber 5 is integrally formed when it is placed in a mold and then the vibration damping rubber 5 is injection molded. That is,
Since the plastic insert 1 is made of a material having a low melting point and low fluidity, it is deformed by heat and pressure during rubber molding, and at that time, the large diameter portion 21 provided in the inner cylinder 2 is used. Along the large diameter portion 21
It will be automatically molded into a shape that wraps around.

Further, a construction is adopted in which a part of the anti-vibration rubber 5 is extended and seal rubber parts 51 are provided so as to cover the small diameter parts 22 provided near both ends of the inner cylinder 2. I have decided. The seal rubber portion 51 is made of the same rubber material as the small diameter portion 22 when the vibration damping rubber 5 is molded.
And, it is integrally molded so as to wrap the fiber layer 4 provided on the outer side of the inner cylinder 2. Therefore, when the sliding bush itself is cooled after the above-mentioned molding, the vibration-proof rubber 5 is
Also, a portion made of a rubber material such as the seal rubber portion 51 contracts due to cooling. Along with this contraction, the part of the seal rubber part 51 also contracts, so that the tension force is held between the seal rubber part 51 and the small diameter part 22 of the inner cylinder 2. As a result, the sealing performance is improved.

Next, the operation of this embodiment having these configurations will be described. When vibration (shock) due to a small bump on a wheel is transmitted to the suspension arm to which the sliding bush is attached, the force (vibration) is the load (vibration) in the P direction in FIG. Is transmitted as. However, this force (vibration) in the P direction is absorbed and attenuated by the anti-vibration rubber 5 provided between the outer cylinder 3 and the inner cylinder 2, and the outer cylinder 3 side to the inner cylinder 2 side is absorbed. Is not transmitted to. Therefore, the vibration and the like are not transmitted to the vehicle body side. Further, when the wheel gets over a large bump or the like, a rotational movement (swing) of the suspension arm occurs due to the vertical movement of the wheel,
This swing motion is processed by the smooth sliding motion between the inner cylinder 2 and the fiber layer 4 provided on the inner peripheral surface of the vibration isolating rubber 5. Therefore, no force (vibration) is transmitted from the outer cylinder 3 side to which the suspension arm is attached to the inner cylinder 2 side to be attached to the vehicle body side, and pitching or bouncing of the vehicle body is not caused. As a result, due to the action of the sliding bush, good riding comfort can be obtained in a vehicle that employs the sliding bush.

Next, with respect to the load (T) in the thrust direction of the sliding bush, which affects the steering stability, the plastic insert 1 provided along the large diameter portion 21 of the inner cylinder 2 is Basically, the thrust load (T) is received. That is, while the load (T) in the thrust direction has a small value, force and vibration are generated due to shear deformation of the vibration isolating rubber 5 provided between the outer cylinder 3 and the plastic insert 1. Etc. are absorbed. On the other hand, the thrust load (T)
Is large, the large diameter portion 21 of the inner cylinder 2 is
Since the plastic insert 1 molded along the line bears the thrust load (T), the relative displacement between the outer cylinder 3 and the inner cylinder 2 is suppressed. This prevents the inner cylinder 2 from slipping out of the sliding bush. Than these things,
The mounting rigidity in the thrust direction will be increased,
The steering stability will also be improved.

Further, even when the inner cylinder 2 is twisted, the fiber layer 4 having a good slidability so as to wrap the large diameter portion 21.
With the provision of the above, unlike the case where only the deformation of the anti-vibration rubber 5 is dealt with, better followability is exhibited. As a result, the followability of the suspension arm is improved, hysteresis and the like are reduced, and riding comfort is improved.

Further, in this embodiment, a part of the vibration-proof rubber 5 is extended to form a seal rubber portion 51, and the seal rubber portion 51 covers the small-diameter portions 22 provided at both ends of the inner cylinder 2. And the fiber layer 4 that is in sliding contact with the outer peripheral surface of the inner diameter 2 is covered. Therefore, the sealing between the fiber layer 4 and the outer peripheral surface of the inner cylinder 2 is surely performed. As a result, it is not necessary to separately provide a seal member as in the conventional one, and the sealing force of the seal rubber portion 51 reliably seals the outer peripheral surface of the inner cylinder 2, so that the intrusion of earth and sand and rainwater is prevented. Is prevented and wear of the sliding surface can be prevented.

Next, a second embodiment of the present invention will be described with reference to FIG.
It will be explained based on. This embodiment is also basically the same as the previous first embodiment. The difference is in the portion of the bulging portion 21 ′ provided in the central portion of the inner cylinder 2. That is, in the present embodiment, as shown in FIG.
The inner cylinder 2 is provided with a spherical bulging portion 21 ′ at the center thereof, and the fiber layer 4 and the plastic insert 1 are provided along the bulging portion 21 ′. By adopting such a configuration, as compared with that of the first embodiment described above, with respect to the prying movement of the inner cylinder 2,
It operates in a state of low resistance, and the better followability of the suspension arm is exhibited. That is, the present embodiment exhibits a function close to that of a ball joint, and when used in a link mechanism of a rear suspension, for example, the rear suspension geometry is set to the understeer side or the toe-in side during braking. It will be possible to use it for the structure that wants to be actively changed. Except for the function for the prying movement, the one in the first embodiment,
All have the same function.

[0019]

According to the present invention, there are an outer cylinder and an inner cylinder capable of relative rotational movement, and the outer cylinder and the inner cylinder are integrally joined to each other between the outer cylinder and the inner cylinder. A sliding bush having a vibration-proof rubber provided so as to be slidable with respect to the inner cylinder side, wherein a large diameter portion or a bulging portion having an outer diameter larger than an end portion of the inner cylinder is provided in a central portion of the inner bush. On the other hand, on the inner peripheral surface side of the vibration isolating rubber, a fiber layer having a small sliding friction coefficient is integrally provided with the vibration isolating rubber, and on the outer side of the fiber layer, a large diameter portion of the inner cylinder is provided. Alternatively, a plastic insert is provided so as to be joined to the anti-vibration rubber and the fiber layer along the bulge portion, and further, to cover the small diameter portion formed near both ends of the inner cylinder. A structure in which a part of the rubber vibration isolator is extended to provide a seal rubber portion, As a result, the anti-vibration rubber absorbs vibrations against small vibrations in the direction perpendicular to the axis, and the sliding motion of the fiber layer, which excels in sliding performance against vibrations with large displacements, allows the suspension arm to follow By reducing the amount of hysteresis, the ride comfort for riding over a small bump can be improved, as well as the ride comfort for pitching and bouncing of the vehicle. At the same time, the adoption of plastic inserts has increased the rigidity in the direction perpendicular to the axis and the rigidity in the axial direction (thrust direction), and has made it possible to obtain steering stability. Also, by providing a large diameter part or a bulged part in the center of the inner cylinder, the followability to the twisting motion between the inner cylinder and the outer cylinder is improved, which improves ride comfort and stabilizes straight running during braking. It has become possible to improve the sex. Further, by adopting the plastic insert, even if the fiber layer is worn, the plastic insert can bear the load, so that there is no rattling with the outer peripheral surface of the inner cylinder, and steering stability is secured. It has become possible. Furthermore, it becomes possible to configure the sliding bush that exhibits these various functions with a small number of parts, and it is possible to reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a half cross-sectional view showing the overall structure of a sliding bush according to a first embodiment of the present invention.

FIG. 2 is a half cross-sectional view showing the overall structure of a sliding bush according to a second embodiment of the present invention.

FIG. 3 is a half sectional view showing the overall structure of a dry type sliding bush related to the present invention.

FIG. 4 is a half sectional view showing an overall configuration of a conventional example.

[Explanation of symbols]

 1 Plastic Insert 2 Inner Cylinder 21 Large Diameter Part 21 'Swelling Part 22 Small Diameter Part 3 Outer Cylinder 4 Fiber Layer 5 Anti-Vibration Rubber 51 Seal Rubber Part

Claims (1)

[Claims] 1. An outer cylinder and an inner cylinder which are capable of relative rotational movement, and are integrally joined to the outer cylinder side between the outer cylinder and the inner cylinder and slide with the inner cylinder side. In a sliding bush having anti-vibration rubber provided so as to be movable, a large diameter portion or a bulging portion having an outer diameter larger than the end portion is provided in the central portion of the inner cylinder, while On the inner peripheral surface side of the vibrating rubber, a fiber layer having a small sliding friction coefficient is integrally provided with the vibration isolating rubber, and on the outer side of the fiber layer, along the large diameter portion or the bulging portion of the inner cylinder, Further, a plastic insert is provided so as to be bonded to the vibration isolating rubber and the fiber layer, and further, a part of the vibration isolating rubber is covered so as to cover the small diameter portion formed near both ends of the inner cylinder. A sliding bush characterized by having a structure in which a seal rubber portion is provided by being extended. U.