JP5072762B2 - Stabilizer bush - Google Patents

Description

  The present invention relates to a stabilizer bush that is fixed to a vehicle body by a bracket in a state in which the stabilizer bar is inserted through an insertion hole that penetrates in the axial direction and elastically supports the stabilizer bar on the vehicle body.

The stabilizer bar is a torsional rigid spring (torsion bar) that is attached to reduce the tilt of the vehicle body, and both ends thereof are attached to the left and right suspensions, and acts to suppress this when the left and right wheels move differently up and down.
For example, when turning a corner, the suspension tends to contract on the outer ring side due to centrifugal force and to extend on the inner ring side. As a result, the vehicle body tends to tilt outward due to centrifugal force.
In this way, the stabilizer bar generates torsion when the left and right wheels move in the opposite phase (when rolling), and suppresses the movement of the left and right wheels in the opposite phase by resistance due to the torsional rigidity, and accumulates by twisting. The left and right wheels, which have moved in the opposite phase with the elastic restoring force, work to quickly return them to their original positions.

As described above, the stabilizer bar has a function of suppressing the roll angle, thereby improving the steering stability (running stability) of the vehicle.
When the stabilizer bar is attached to the vehicle body, a stabilizer bush as a vibration insulating member is interposed between the vehicle body and the stabilizer bar so that the stabilizer bar is elastically supported by the vehicle body.

The stabilizer bar has a generally U-shaped planar shape as a whole, and a central portion extending substantially linearly in the vehicle width direction (the left-right direction of the vehicle) is fixed to the vehicle body via a pair of stabilizer bushes. Each end of the arm is fixed to a suspension that supports the wheel.
The stabilizer bush is composed of a rubber elastic body having an insertion hole that penetrates in the axial direction at the center in the radial direction, and is fixed to the vehicle body by a rigid bracket in a state in which the stabilizer bar is inserted through the insertion hole. .

FIG. 8 shows an example of a conventionally used stabilizer bush. In the figure, 200 denotes a stabilizer bush, and 202 denotes an insertion hole penetrating in the axial direction through which the stabilizer bar is inserted.
As shown in FIG. 8, the stabilizer bush 200 is formed with rubber flange portions 204 projecting radially outward at both ends in the axial direction along the circumferential direction.

The stabilizer bush 200 has a slit 206 in the axial direction. The stabilizer bush 200 is fitted to the stabilizer bar through the slit 206 in the direction perpendicular to the axis, and is fixed to the vehicle body by the bracket 208 in this state.
The bracket 208 includes an outer fitting portion 210 that is fitted on the stabilizer bush 200 and a fixing portion 212 that protrudes horizontally from both ends in the circumferential direction. The outer fitting portion 210 is fitted on the stabilizer bush 200. In this state, the fixing portion 212 is fixed to the vehicle body, and the stabilizer bush 200 is attached to the vehicle body.

By the way, as shown in FIG. 9, when the wheel moves in the upside down phase, a force in a twisting direction indicated by P in the figure acts from the stabilizer bar 214.
At this time, a so-called mouth opening phenomenon occurs in which the insertion hole 202 is opened, and a gap S is generated there as shown in the partially enlarged view of FIG. 9, and the inside of the stabilizer bush 200 through the gap S, more specifically, the insertion hole. When muddy water or pebbles (for example, about several millimeters in size) enter inside 202 and the stabilizer bar 214 and the stabilizer bush 200 move relative to each other in this state, the stabilizer bush 200 is rubbed and damaged by pebbles or the like that have entered. There was a problem that could occur.

Therefore, the present applicant has proposed a stabilizer bush aimed at solving this problem in a previous patent application (Patent Document 1 below).
The one disclosed in Patent Document 1 has a stabilizer bush protruding outward in the axial direction from the bush main body configured of a cylindrical rubber elastic body, the axial end surface of the bush main body and the periphery of the insertion hole, A seal lip that elastically fits to the outer peripheral surface of the stabilizer bar and performs a sealing action, and the seal lip has a small diameter radially inward toward the distal end in the axial direction before the stabilizer bar is inserted. It is formed in the tapering shape which turns into.

  Although the provision of the seal lip in the stabilizer bush in this way has improved the problems caused by the intrusion of muddy water, sand, etc. into the stabilizer bush due to the formation of the gap S, it is still not always necessary to solve the problem. It was not enough and further improvement was required.

Incidentally, there is a technique disclosed in the following Patent Document 2 as a technique seemingly similar to the present invention.
This is intended to increase the left and right spring rigidity of the vehicle of the stabilizer bush, and is different from the present invention. For this reason, the one disclosed in Patent Document 2 Unlike the stabilizer bush, the seal lip is not provided, and the embedding position of the reinforcing member is an intermediate position or an outer position in the radial direction of the bush body, which is different from the present invention.

JP 2007-203756 A JP-A-11-82625

  The present invention is based on the above circumstances, and even when a twisting force is input to the stabilizer bar, the axial end portion of the insertion hole in the stabilizer bar does not cause a so-called opening phenomenon, and is inserted through the gap. The purpose of the present invention is to provide a stabilizer bushing that can better prevent the problem of muddy water, sand and the like invading into the hole than before.

  Thus, according to the first aspect of the present invention, (a) a cylindrical rubber elastic body has an axially penetrating insertion hole through which a stabilizer bar is inserted in the central portion in the radial direction, and both axial ends. A bushing body having a rubber flange part at the part; (b) projecting outward in the axial direction from the axial end surface of the bushing body and the periphery of the insertion hole, and elastically fitting to the outer peripheral surface of the stabilizer bar A seal lip made of a rubber elastic body having a tapered shape that decreases in diameter radially inward toward the distal end in the axial direction before the stabilizer bar is inserted. In a stabilizer bush fixed to a vehicle body by a bracket in a state of being inserted into the insertion hole and elastically supporting the stabilizer bar to the vehicle body, a flange portion protruding radially outward at both axial end portions An intermediate plate having a cylindrical shape and a rigidity higher than that of the rubber elastic body is embedded in the bush body, and the intermediate plate is a radial inner wall of a rubber inner layer located on the inner peripheral side of the intermediate plate of the bush body. The thickness is thinner than the thickness of the outer rubber layer located on the outer peripheral side of the intermediate plate, and the inner peripheral position of the intermediate plate is radially inward from the outer peripheral position of the root on the bush body side of the seal lip. It is embedded in the bush body in a state of being located in the position.

  According to a second aspect of the present invention, in the first aspect of the present invention, the cylindrical intermediate plate is provided with a notch at a predetermined portion in the circumferential direction over the entire length in the axial direction and perpendicular to the notch. The portion facing in the direction is a flexible portion having an opening-shaped window portion formed between both ends in the axial direction, and the portion between the flexible portion and the notch portion of the intermediate plate is the first portion. The rubber elastic body has a self-lubricating property containing a lubricant therein, and the intermediate plate is not bonded to the rubber elastic body. And a plurality of through-holes for connecting the outer rubber layer and the inner rubber layer are provided in each cylindrical wall portion of the first semi-cylindrical portion and the second semi-cylindrical portion of the intermediate plate. The through hole is filled with the rubber elastic body.

  According to a third aspect of the present invention, in the second aspect of the present invention, the flange portion of the intermediate plate is provided with a plurality of through holes that connect the rubber flange portion to the inside and outside in the axial direction. It is filled with an elastic body.

Effects and effects of the invention

  As described above, the present invention embeds an intermediate plate having a flange portion projecting radially outward at both axial end portions and having a rigidity higher than that of the rubber elastic body in the bush body, and the intermediate plate is The thickness of the inner rubber layer positioned on the inner peripheral side of the intermediate plate of the bush body is thinner than the thickness of the outer rubber layer positioned on the outer peripheral side, and the inner peripheral position of the intermediate plate is on the bush main body side of the seal lip. It is embedded in the bushing body in a state of being located radially inward from the outer peripheral side position of the root.

  In the stabilizer bush of the present invention, the rubber inner layer located inside the intermediate plate, that is, the rubber inner layer inside the intermediate plate that is in direct contact with the stabilizer bar is thin and the spring is hard. When a force in the twisting direction is input to the stabilizer bar, the stabilizer bush is moved together with the seal lip along with the stabilizer bar due to the hard spring characteristics of the rubber inner layer, that is, due to the restraining action by the intermediate plate, and integrally displaced in the twisting direction. Can be made.

  As a result, when the stabilizer bar is displaced relative to the stabilizer bush in the twisting direction, the phenomenon of opening at the axial end of the insertion hole, that is, the phenomenon of generating the gap S can be effectively prevented. In addition, it is possible to effectively prevent muddy water, sand, etc. from entering the stabilizer bush through the clearance, specifically the insertion hole, and to prevent the stabilizer bush from being worn or worn by the intruded sand, etc. be able to.

  In the present invention, flange portions are provided at both axial ends of the intermediate plate, which can increase the rigidity of the intermediate plate in the twisting direction and also increase the restraining force in the twisting direction on the bushing body and the seal lip. As a result, the stabilizer bush can be made to follow the displacement in the twisting direction of the stabilizer bar more favorably, and the phenomenon of the mouth opening can be further effectively prevented.

  In addition, since the inner peripheral position of the intermediate plate is located radially inward from the outer peripheral position of the base of the seal lip on the bushing body side, the phenomenon of the opening of the seal lip itself is more effective than before. Can be prevented.

  In the present invention, the intermediate plate embedded in the bush main body also has a function of stiffening the spring characteristics in the direction perpendicular to the axis, thereby improving the steering stability.

  By the way, the stabilizer bush is required to improve the steering stability (running stability) of the vehicle by increasing the deformation resistance in the twisting direction and the direction perpendicular to the axis when the vehicle turns around the corner. It is required to smoothly rotate the stabilizer bar with respect to the stabilizer bush when overcoming the road level difference, thereby suppressing the transmission of the impact when the wheel gets over the level difference to the vehicle body.

In order to realize this, a self-lubricating rubber having a self-lubricating property containing a lubricant is used as a rubber elastic body of the stabilizer bush.
This rubber elastic body having self-lubricating properties (self-lubricating rubber) is formed by allowing a lubricant such as silicon oil contained therein to exude to the surface including the inner peripheral surface of the insertion hole contacting the outer peripheral surface of the stabilizer bar. A lubricant is interposed between the bar and the rubber elastic body, thereby lowering the sliding resistance between the stabilizer bar and the rubber elastic body, thereby facilitating the rotational movement of the stabilizer bar.

However, this lubricant also oozes out to the surface of the intermediate plate embedded in the rubber elastic body, that is, the surface of the rubber elastic body in contact with the intermediate plate, where the intermediate plate slides against the rubber elastic body. It will make it easier.
Further, the lubricant which oozes out on the surface of the intermediate plate and is interposed between the intermediate plate and the rubber elastic body causes a problem of hindering the adhesion between the intermediate plate and the rubber elastic body.

  When embedding the intermediate plate in the rubber elastic body, usually, an adhesive is applied to the surface of the intermediate plate in contact with the rubber elastic body in advance, and the rubber elastic body and the intermediate plate are simultaneously applied during the vulcanization molding of the rubber elastic body. However, in the case of self-lubricating rubber, especially when the rubber elastic body contains a large amount of lubricant, a large amount of lubricant oozes out on the surface of the intermediate plate to form a lubricant film there. The film inhibits the adhesion reaction between the adhesive applied to the intermediate plate and the rubber elastic body, making it difficult to bond the intermediate plate to the rubber elastic body by vulcanization. .

  Thus, if the intermediate plate is not firmly bonded and fixed to the rubber elastic body, slippage occurs between the intermediate plate and the rubber elastic body, the above-mentioned restraining function by the intermediate plate is lowered, and the rubber elastic body The stiffness of the spring in the above-described twisting direction and the direction perpendicular to the axis is lowered.

  In this case, the rubber elastic body having self-lubricating property and the intermediate plate are made non-bonded, and the notch portion in the intermediate plate and the portion opposed to the axis perpendicular to the notch are allowed. A plurality of through-holes for connecting the outer rubber layer and the inner rubber layer are provided in each cylindrical wall portion between the first semi-cylindrical portion and the second semi-cylindrical portion between the flexible portions.

  Here, the notch provided in the intermediate plate is provided to allow the stabilizer bar to pass in the direction perpendicular to the axis when the stabilizer bush is fitted in the direction perpendicular to the axis with respect to the stabilizer bar. When the stabilizer bush is opened and deformed in the circumferential direction at the cut portion, the intermediate portion embedded in the intermediate plate can be easily flexibly deformed integrally with the intermediate portion. Is.

According to the second aspect, the outer rubber layer and the inner rubber layer are connected to each other through the plurality of through holes provided in the cylindrical wall portions of the first semi-cylindrical portion and the second semi-cylindrical portion of the intermediate plate. Therefore, despite the fact that the intermediate plate is not bonded to the rubber elastic body, it is good that the intermediate plate slides against the rubber elastic body due to the anchor effect of the rubber embedded in the through hole. Can be prevented.
As a result, the restraining action by the intermediate plate and the effect of increasing the stiffness of the elastic elastic body by the intermediate plate in the twisting direction and the direction perpendicular to the axis can be exhibited well.

The plurality of through holes provided in the intermediate plate also have the following function.
That is, the lubricant that has oozed out to the inner peripheral surface of the insertion hole of the rubber inner layer that is in contact with the outer peripheral surface of the stabilizer bar is gradually lost due to rubbing by the stabilizer bar.

  When the lubricant is lost at the portion in contact with the surface of the stabilizer bar in this way, the stabilizer bar cannot be smoothly rotated with respect to the inner peripheral surface of the insertion hole, and abnormal noise is generated due to an increase in frictional resistance generated there. To be generated.

The lubricant contained in the rubber inner layer is gradually supplied to the inner peripheral surface of the insertion hole. In the present invention, the thickness of the rubber inner layer in the direction perpendicular to the axis is thin, and the lubricant contained in the rubber inner layer. The amount of is not much.
However, in this second aspect, since the intermediate plate is provided with a plurality of through holes, the lubricant contained in the outer rubber layer is also inserted into the inner rubber layer through the through holes and further into the outer peripheral surface of the stabilizer bar. It is continuously supplied to the inner peripheral surface.
As a result, a lubricant film can be always formed and held between the outer peripheral surface of the stabilizer bar and the inner peripheral surface of the rubber inner layer, i.e., the inner peripheral surface of the insertion hole. It is possible to favorably prevent the lubricant between the stabilizer bar from disappearing.

The second aspect of the present invention is effective when applied to a rubber elastic body in which a lubricant is blended in an amount of 10% by mass or more.
In addition, since the through hole provided in the intermediate plate is mainly intended to perform the above-described function, in the second aspect, a single large through hole is not provided, but a large number of small holes are provided. It is desirable to provide the openings in a distributed manner.

In the case where a single large through hole is provided, the spring rigidity of the rubber elastic body in the twisting direction and the direction perpendicular to the axis is lowered at the portion where the through hole is provided.
Further, the lubricant contained in the outer rubber layer is hardly supplied evenly inward in the radial direction from the outer rubber layer to the inner rubber layer in the axial direction.
On the other hand, by providing a large number of small through-holes in a dispersed manner, it is possible to effectively prevent a decrease in spring rigidity in the twisting direction and the direction perpendicular to the axis of the rubber elastic body, and from the rubber outer layer to the rubber. It becomes possible to supply the lubricant uniformly through the through-holes over a wide range in the axial direction toward the inner layer.

In this sense, according to the second aspect of the present invention, the through hole made up of small holes having a maximum diameter of 1 mm or more and 5 mm or less is defined as the interval between the adjacent small holes (distance of the portion that is not a through hole). It is desirable that a large number of 30 or more is dispersedly formed at a small interval in which the interval is between 0.5 mm and 3 mm.
Here, if the size of the maximum diameter portion is smaller than 1 mm, the rubber does not get stuck in the small holes at the time of molding, which may hinder the anchor effect and supply of the lubricant to the inside in the radial direction, and if the size of the maximum diameter portion exceeds 5 mm This will affect the spring stiffness.
Further, if the interval is smaller than 0.5 mm, there is a problem in the strength of the intermediate plate, and if it is larger than 3 mm, it becomes difficult to uniformly supply the lubricant radially inward.

  Next, according to a third aspect of the present invention, a plurality of through holes are provided in the flange portion of the intermediate plate, and the rubber flange portions provided at both ends of the rubber elastic body are communicated with the inside and outside in the axial direction through the through holes. Therefore, according to the third aspect, the restraining action of the intermediate plate against the rubber flange portions and the seal lips at both axial end portions of the bushing body can be further enhanced, and the seal lip portion of the seal lip portion can be prevented from being displaced in the twisting direction of the stabilizer bar. It is possible to further improve the followability, and to more reliably prevent the above-mentioned mouth opening phenomenon and the intrusion of muddy water, pebbles and the like into the gap caused by the phenomenon.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, reference numeral 10 denotes a stabilizer bush, which has an insertion hole 12 having a circular cross-section passing through in the axial direction in the central portion in the radial direction, into which a metal stabilizer bar 14 is inserted, and in that state is made of metal. The rigid bar 16 is fixed to the vehicle body 18, and the stabilizer bar 14 is elastically supported by the vehicle body 18.

  As shown in FIG. 3, the stabilizer bush 10 includes a bush main body 19 made of a rubber elastic body, a seal lip 20 formed of the same rubber elastic body, and integrally formed with the bush main body 19, and the bush main body 19 and the vehicle body 18. And a plate-like pedestal member 22 interposed therebetween.

In the present embodiment, the rubber elastic body constituting the bush main body 19 and the seal lip 20 is self-lubricating.
Specifically, the rubber elastic body constituting the bush main body 19 and the seal lip 20 contains a lubricant, and the contained lubricant exudes to the surface including the inner peripheral surface of the insertion hole 12 during use. . The lubricant that has oozed into the inner peripheral surface of the insertion hole 12 reduces the frictional resistance between the inner peripheral surface of the insertion hole 12 and the outer peripheral surface of the stabilizer bar 14, and the sliding resistance of the stabilizer bar 14 with respect to the stabilizer bush 10 decreases. I'm damned.

  This rubber elastic body (self-lubricating rubber) having lubricity is conventionally known, and the rubber elastic body is self-lubricated by containing silicon oil or other lubricants in the rubber elastic body.

  This self-lubricating rubber is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-292678, Japanese Patent Application Laid-Open No. 2006-206788, and the former uses an α-olefin wax having a double bond at the molecular chain end as a lubricant. In the latter, an unsaturated fatty acid amide or a polyethylene glycol type surfactant is used as a lubricant.

As shown in FIG. 2, the bush main body 19 has a cylindrical shape as a whole, and rubber flange portions 24 projecting radially outward are formed along the circumferential direction at both axial end portions. Yes.
As shown in FIG. 1, the seal lip 20 formed integrally with the bushing main body 19 is a portion that elastically fits to the outer peripheral surface of the stabilizer bar 14 to form a sealing action. It has a cylindrical shape with a circular cross section protruding in the direction.
In this embodiment, the seal lip 20 is provided on both the one end side and the other end side of the bush body 19 in the axial direction.

2 and 3, that is, before the stabilizer bar 14 is inserted, the seal lip 20 has a tapered shape that shifts inward in the radial direction from the root side to the tip side, that is, the axial center of the stabilizer bar 14. It has a tapered shape approaching the position (strictly, the center position of the insertion hole 12).
In addition, an inflection portion 26 is provided in the intermediate portion in the axial direction, and the first portion 28 on the root side and the second portion 30 on the distal end side of the inflection portion 26 have a tapered shape.
The second portion 30 is a portion that substantially performs a sealing action, and the first portion 28 functions as a support portion that elastically supports the second portion 30.

The inclination angle of the second portion 30 is steeper than the inclination angle of the first portion 28. That is, the second portion 30 has a shape that rises at a steep angle from the tip to the inflection portion 26.
Further, a protrusion 32 that protrudes toward the stabilizer bar 14 is formed at the tip and the inner peripheral side of the second portion 30.

The entire seal lip 20 has a smaller inner diameter than the insertion hole 12.
When the stabilizer bar 14 is inserted through the insertion hole 12, the seal lip 20 is elastically expanded and deformed radially outward as shown in FIG.
Specifically, when the stabilizer bar 14 is inserted, the distal end portion of the second portion 30 is elastically expanded and deformed by the outer peripheral surface thereof, and the entire seal lip 20 including the first portion 28 is expanded and deformed accordingly. Based on the elastic force accumulated by the deformation, the tip of the second portion 30 is brought into elastic contact with the outer peripheral surface of the stabilizer bar 14 to perform a sealing action.

As shown in FIG. 2, the stabilizer bush 10 is provided with an axial cut 34.
The cut 34 extends from the outer peripheral surface of the bush body 19 and the seal lip 20 to the inner peripheral surface, that is, the insertion hole 12.
The stabilizer bush 10 is fitted to the stabilizer bar 14 of FIG. 1 in the direction perpendicular to the axis so as to open the slit 34.

The pedestal member 22 is harder than the rubber elastic body, specifically a resin member here, and has an insertion hole 36 (see FIG. 3) in the center thereof in plan view, and further below it. A recess 38 is provided on the side.
The bush body 19 is provided with a downward insertion protrusion 40, and the insertion protrusion 40 is inserted downward with respect to the base member 22 in the insertion hole 36. A head 42 formed at the tip of the insertion protrusion 40 is accommodated in the recess 38.

The head portion 42 has a larger diameter than the insertion hole 36, and the insertion protrusion 40 inserted into the insertion hole 36 is secured to the base member 22 by the head portion 42.
Here, the insertion hole 36, the recess 38, the insertion protrusion 40, and the head 42 all have a circular planar shape.

The bracket 16 has a gate shape as a whole as shown in FIG.
The bracket 16 has a stabilizer bush 10, specifically, an outer fitting portion 44 fitted and fitted to the outer peripheral surface of the bush body 19 from the outside in the radial direction, and a fixing portion 46 bent from both ends in the circumferential direction. The fixing portion 46 is fixed to the vehicle body 18 in a state where the outer fitting portion 44 is elastically fitted to the outer peripheral surface of the bush body 19 in the stabilizer bush 10, specifically, the outer peripheral surface of the portion between the pair of rubber flange portions 24. It has come to be.

As shown in FIG. 3, an intermediate plate 48 is embedded in the bush body 19. Here, the intermediate plate 48 is integrally fixed to the rubber elastic body of the bush body 19 by vulcanization adhesion.
The intermediate plate 48 has higher rigidity than the rubber elastic body, has a circular cylindrical shape as a whole, and has flange portions 50 projecting radially outward at both end portions in the axial direction. The flange 50 is embedded in the bush main body 19 in a state where the flange 50 is positioned in the rubber flange 24 of the bush main body 19.

In the present embodiment, the intermediate plate 48 is made of a resin (here, PA (polyamide) 66 resin containing 30% glass fiber). However, it can be made of metal such as iron or aluminum alloy, or can be made of other materials.
The intermediate plate 48 is divided in the circumferential direction at a position corresponding to the cut 34 of the bush main body 19 shown in FIG.

In the present embodiment, the shape of the intermediate plate 48 and the embedded position in the bushing body 19 are determined as follows.
That is, the radial thickness of the inner rubber layer 52 located on the inner peripheral side of the bush body 19, that is, on the side of the stabilizer bar 14 is thinner than the radial thickness of the outer rubber layer 54 located on the outer peripheral side. In such a state, the shape and the embedding position of the intermediate plate 48 are determined so that the inner peripheral position of the intermediate plate 48 is positioned radially inward from the outer peripheral position of the root of the seal lip 20 on the bushing body 19 side. It has been.

Actually, in this embodiment, the thickness of the rubber inner layer 52 is 1.5 mm with respect to the thickness of the rubber outer layer 54 in the radial direction (thickness in the upper portion in the drawing from the intermediate plate 48).
Here, the thickness of the intermediate plate 48 is 1.2 mm, the thickness of the root of the seal lip 20 on the bushing body 19 side is 3 mm, and the inner rubber layer 52 is thinner than the seal lip 20. It has become.

  In this embodiment, as a result of the intermediate plate 48 being embedded in the bushing body 19 so as to reduce the thickness of the rubber inner layer 52, the intermediate plate 48 changes the movement of the bushing body 19 and the seal lip 20 in the twisting direction of the stabilizer bar 14. Acts as a restraining member to follow the movement of

  Specifically, as shown in FIG. 4, when the stabilizer bar 14 is moved in a direction indicated by an arrow P in the drawing, the rubber inner layer 52 is thin and the rubber inner layer 52 spring is hard. The inner layer 52 cannot absorb the twisting motion of the stabilizer bar 14 due to its own elastic deformation, and when the stabilizer bar 14 is twisted, the bushing body 19 follows this and integrally moves with the stabilizer bar 14 in the same direction. You can exercise.

At this time, the seal lip 20 is also displaced in the twisting direction as a whole following the twisting motion of the stabilizer bar 14. As a result, a gap S as shown in the enlarged view of FIG. 9 is prevented from occurring between the seal lip 20 and the stabilizer bar 14.
In other words, without causing the so-called opening phenomenon, the seal lip 20 is in close contact with the outer peripheral surface of the stabilizer bar 14 over the entire circumference, and the state between the stabilizer bar 14 and the insertion hole 12 is well sealed. Hold on.

  As described above, in the stabilizer bush 10 of the present embodiment, the thickness of the rubber inner layer 52 positioned on the inner side of the intermediate plate 48, that is, the thickness of the rubber inner layer 52 on the inner side of the intermediate plate 48 that directly contacts the stabilizer bar 14. When the force in the twisting direction is input to the stabilizer bar 14, the stabilizer bush 10 is sealed lip by the hard spring characteristic of the rubber inner layer 52, that is, by the restraining action by the intermediate plate 48. 20 and the stabilizer bar 14 can be integrally displaced in the twisting direction.

  As a result, when the stabilizer bar 14 is displaced relative to the stabilizer bush 10 in the direction of twisting, the phenomenon of opening of the opening at the axial end of the insertion hole 12, that is, the phenomenon of generating the gap S is effective. It is possible to effectively prevent the intrusion of muddy water, sand or the like into the interior of the stabilizer bush 10 through the gap, specifically the inside of the insertion hole 12, and the stabilizer bush 10 is worn or worn by the invading sand or the like. Alternatively, it is possible to satisfactorily prevent the generation of abnormal noise.

  In the present embodiment, flange portions 50 are provided at both axial ends of the intermediate plate 48, whereby the rigidity of the intermediate plate 48 in the twisting direction can be increased, and the bushing body 19 and the seal lip 20 can be improved. The restraining force in the twisting direction can be increased, and the stabilizer bush 10 can be made to follow the displacement of the stabilizer bar 14 in the twisting direction better, and the phenomenon of the mouth opening can be more effectively prevented.

  Further, the intermediate plate 48 has an inner peripheral position positioned radially inward from an outer peripheral position of the root of the seal lip 20 on the bushing body 19 side, so that the phenomenon of opening of the seal lip 20 itself is increased. Can be more effectively prevented.

  In the present embodiment, the intermediate plate 48 embedded in the bushing body 19 also has a function of hardening the spring characteristics in the direction perpendicular to the axis, thereby producing an effect of improving steering stability.

Next, FIGS. 5 to 7 show other embodiments of the present invention.
In this example, a self-lubricating rubber containing a lubricant in a large amount of 10% by mass or more, specifically, 30% by mass is used as the rubber elastic body.
Specific blending contents are as shown below (each blending agent in the following blending contents indicates an addition ratio relative to the rubber polymer).
This blending content is disclosed in JP-A-2006-206788 as an example of blending.
NR: 20 parts by mass BR: 80 parts by mass α-olefin wax A: 30 parts by mass Carbon black: 80 parts by mass Vulcanizing agent (sulfur): 4 parts by mass Vulcanization accelerator: 1 part by mass Zinc oxide: 5 parts by mass Naphthene System oil: 3 parts by weight Stearic acid: 1 part by weight Anti-aging agent: 2 parts by weight α-olefin wax A is an α-olefin wax having a double bond at one end of a linear hydrocarbon, manufactured by Nippon Seiwa Co., Ltd. The distribution peak of the carbon number is 20, and the melting point is 38 ° C.

As shown in FIG. 7, the intermediate plate 48 has a notch 60 extending over the entire length in the axial direction at a predetermined portion in the circumferential direction, and has a flexible portion 62 at a portion opposed to the axial perpendicular direction. is doing.
The flexible portion 62 has a window portion 64 having a single large opening, and the formation of the window portion 64 reduces the rigidity of the flexible portion 62 with respect to the other portions, thereby providing flexibility. Has been granted.

The intermediate plate 48 can be elastically deformed in the direction in which the opening width in the circumferential direction of the cutout portion 60 is increased by the flexible deformation of the flexible portion 62.
The intermediate plate 48 is embedded in the rubber elastic body with the notch 60 positioned at the cut 34 in FIG.
Note that the intermediate plate 48 has a notch 60 and is embedded in the rubber elastic body in a state in which the notch 60 coincides with the cut 34 in the first embodiment shown in FIGS. Is the same.

In the intermediate plate 48, each of the pair of flange portions 50 is cut out at the position of the flexible portion 62. In the figure, reference numeral 66 denotes a notch portion of the flange portion 50.
In this embodiment, the intermediate plate 48 includes a cutout portion 60 and a flexible portion 62, so that the upper half of the first half-cylindrical portion 68-1 and the lower half of the half-tubular portion 68- in the drawing. It is divided into two.

  A plurality of through-holes 72 made up of small holes are provided in the respective cylindrical wall portions 70 of the semi-cylindrical portions 68-1 and 68-2, and as shown in FIG. The rubber inner layer 52 and the rubber outer layer 54 are in communication with each other. That is, the inside of each through hole 72 is filled with rubber, and the rubber inner layer 52 and the rubber outer layer 54 are connected to each other by the rubber filled in the through hole 72.

In this example, the through-holes 72 made up of these small holes have the same size, and here, a circular hole of φ2.5 mm is formed.
Here, a large number of through-holes 72 are formed in a number of 35 for each of the cylindrical wall portions 70 of the semi-cylindrical portions 68-1 and 68-2.
These through-holes 72 are arranged in a vertically symmetrical shape and symmetrical positions in the drawing with the semi-cylindrical portions 68-1 and 68-2, and the number of through-holes 72 is 70 in the entire intermediate plate 48.

The through-holes 72 are located between the through-holes 72 adjacent to each other in the vertical and horizontal directions (that is, located closest) in each of the semi-cylindrical portions 68-1 and 68-2 (through-holes 72). Are formed at small intervals of 3 mm or less.
The through-holes 72 are uniformly distributed over most of the cylindrical wall portions 70 of the semi-cylindrical portions 68-1 and 68-2 (occupying at least each cylinder). It is desirable that the wall portion 70 is uniformly distributed over most of 40% or more of the wall portion 70).
Although the through hole 72 is a circular hole here, the through hole 72 may be formed in other shapes, for example, a square shape or other shapes.

In this embodiment, each of the pair of flange portions 50 is also provided with a plurality of through holes 74 penetrating in the axial direction. The rubber flange 24 is connected to the inside and outside in the axial direction by the rubber filled in and filled in the through holes 74.
In this embodiment, for each of the semi-cylindrical portions 68-1 and 68-2, a large number of 30 or more through holes 72 and a large number of 60 or more as the whole intermediate plate 48 are formed. Is desirable.

According to this embodiment, the rubber outer layer 54 is formed by the plurality of through holes 72 provided in each cylindrical wall portion 70 of the first half cylindrical portion 68-1 and the second half cylindrical portion 68-2 in the intermediate plate 48. And the inner rubber layer 52 are connected to each other, so that the intermediate plate 48 is not bonded to the bushing body 19, but the intermediate plate 48 is caused by the anchor effect of the rubber embedded in the through hole 72. It is possible to satisfactorily prevent the bush body 19 from slipping.
As a result, the above-described restraining action by the intermediate plate 48 and the effect of increasing the spring stiffness of the rubber elastic body by the intermediate plate 48 in the above-described twisting direction and the direction perpendicular to the axis can be exhibited well.

The plurality of through holes 72 provided in the intermediate plate 48 also have the following function.
That is, the lubricant exuding on the inner peripheral surface of the insertion hole 12 of the rubber inner layer 52 in contact with the outer peripheral surface of the stabilizer bar 14 is gradually lost due to rubbing by the stabilizer bar 14.

  If the lubricant is lost at the portion in contact with the surface of the stabilizer bar 14 in this way, the stabilizer bar 14 can not smoothly rotate with respect to the inner peripheral surface of the insertion hole 12 but also increases in frictional resistance generated there. An abnormal noise is generated.

The lubricant contained in the rubber inner layer 52 is gradually supplied to the inner peripheral surface of the insertion hole 12, but in this embodiment, the thickness of the rubber inner layer 52 in the direction perpendicular to the axis is thin, and the rubber inner layer 52 The amount of lubricant contained is not much compared to the amount contained in the entire bush body 19.
However, in this embodiment, since a plurality of through holes 72 are provided in the intermediate plate 48, the lubricant contained in the rubber outer layer 54 also passes through the through holes 72 to the rubber inner layer 52 and further to the outer periphery of the stabilizer bar 14. It is continuously supplied to the inner peripheral surface of the insertion hole 12 in contact with the surface.
As a result, a lubricant film can always be formed and held between the outer peripheral surface of the stabilizer bar 14 and the inner peripheral surface of the rubber inner layer 52, that is, the inner peripheral surface of the insertion hole 12. It is possible to satisfactorily prevent the lubricant between the bush body 19 and the stabilizer bar 14 from disappearing.

In this embodiment, since the through holes 72 are mainly intended to perform the above-described function, a large number of through holes 72 made up of small holes are dispersed instead of providing a single large through hole. It is provided.
In the case where a single large through hole is provided, the spring rigidity of the rubber elastic body in the twisting direction and the direction perpendicular to the axis is lowered at the portion where the through hole is provided.
Further, the lubricant contained in the rubber outer layer 54 is difficult to be supplied evenly inward in the radial direction from the rubber outer layer 54 to the rubber inner layer 52 in the axial direction.

  On the other hand, in the present embodiment, a large number of through-holes 72 made of small holes are provided in a dispersed manner, so that it is possible to effectively prevent a decrease in spring rigidity in the twisting direction and the axis-perpendicular direction in the bushing body 19, and It becomes possible to supply the lubricant uniformly through the through holes 72 over a wide range in the axial direction from the rubber outer layer 54 toward the rubber inner layer 52.

  In the present embodiment, a plurality of through holes 74 are also provided in the flange portion 50 of the intermediate plate 48, and the rubber flange portions 24 provided at both ends of the bushing body 19 are communicated with the inside and outside in the axial direction through the through holes 74. According to this embodiment, the restraining action of the intermediate plate 48 on the rubber flange portions 24 and the seal lips 20 at both axial ends of the bush body 19 can be further enhanced, and the stabilizer bar 14 can be The followability of the seal lip 20 can be further improved with respect to the displacement, and it is possible to more surely prevent the above-described opening phenomenon and further intrusion of muddy water, pebbles and the like into the gap S caused by the phenomenon. .

Although the embodiment of the present invention has been described in detail above, this is merely an example.
For example, in the above-described embodiment, the seal lip 20 is provided on both the one end side and the other end side in the axial direction of the bush body 19, but in some cases, this seal lip 20 is provided only on one end side in the axial direction. It is also possible (especially when a lateral displacement stopper for preventing relative movement in the axial direction between the stabilizer bar 14 and the stabilizer bush 10 is attached to the stabilizer bar 14 on the other end side).
In addition, this invention can be comprised in the form which added various change in the range which does not deviate from the meaning.

It is a figure which shows the stabilizer bush which is one Embodiment of this invention in the stabilizer bar insertion state. It is the perspective view which isolate | separated and showed the stabilizer bush and bracket of FIG. It is sectional drawing which shows the stabilizer bush of FIG. 1 in the state before stabilizer bar insertion. It is operation | movement explanatory drawing of the embodiment. It is a longitudinal cross-sectional view which shows the stabilizer bush of other embodiment in the state before stabilizer bar insertion. It is a cross-sectional view of the stabilizer bush of the embodiment. It is the figure which showed the intermediate | middle board shown in FIG.5 and FIG.6 alone. It is the perspective view which showed the conventional stabilizer bush with the bracket. It is explanatory drawing of the problem of the conventional stabilizer bush.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Stabilizer bush 12 Insertion hole 14 Stabilizer bar 16 Bracket 18 Car body 19 Bush body 20 Seal lip 48 Intermediate plate 50 Flange part 52 Rubber inner layer 54 Rubber outer layer 60 Notch part 62 Flexible part 64 Window part 72, 74 Through-hole

Claims (3)

(B) A bush body composed of a cylindrical rubber elastic body, having an axially penetrating insertion hole through which a stabilizer bar is inserted in the central portion in the radial direction, and rubber flange portions at both axial end portions; (B) Projecting outward in the axial direction from the axial end face of the bushing body and the periphery of the insertion hole, and elastically fitting to the outer peripheral surface of the stabilizer bar to perform a sealing action, before insertion of the stabilizer bar And a seal lip made of a tapered rubber elastic body that decreases in diameter radially inward toward the tip end in the axial direction, and the bracket is inserted into the insertion hole through the insertion hole. A stabilizer bush that is fixed to the vehicle body and elastically supports the stabilizer bar on the vehicle body, and has a cylindrical shape and a rubber having flange portions projecting radially outward at both ends in the axial direction Than sex body buried intermediate plate of high rigidity in the bush body,
In the intermediate plate, the radial thickness of the rubber inner layer located on the inner peripheral side of the bush main body is thinner than the thickness of the rubber outer layer located on the outer peripheral side of the intermediate plate, and the intermediate plate The stabilizer bush is embedded in the bush body so that the inner peripheral position of the seal lip is positioned radially inward from the outer peripheral position of the root on the bush body side of the seal lip. In claim 1, the cylindrical intermediate plate is provided with a notch portion in a predetermined portion in the circumferential direction over the entire length in the axial direction, and a portion facing the notch portion in the direction perpendicular to the axis, It is set as the flexible part provided with the window part of the opening shape formed between the both ends of an axial direction, and the part between these flexible parts and a notch part of this intermediate plate is 1st and 2nd semi-cylinder shape Part of
The rubber elastic body has a self-lubricating property containing a lubricant therein, and the intermediate plate is non-adhered to the rubber elastic body,
A plurality of through-holes connecting the outer rubber layer and the inner rubber layer are provided in each cylindrical wall portion of the first semi-cylindrical portion and the second semi-cylindrical portion of the intermediate plate, A stabilizer bush, wherein a through hole is filled with the rubber elastic body.   In Claim 2, The said flange part of the said intermediate plate is provided with the some through-hole which connects the said rubber flange part to the inside and outside of an axial direction, and this through-hole is filled with the said rubber elastic body. A stabilizer bush characterized by

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