JP2013124746A - Bush for suspension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bush for suspension with a simple structure.SOLUTION: The bush for suspension includes an inner cylinder 11 formed of metal, an outer cylinder 15 formed of elastic material, an intermediate cylinder 14 formed of resin containing lubricating agent sandwiched between the inner cylinder 11 and the outer cylinder 15, and fitting parts 14a, 15a for restricting the relative rotation between the intermediate cylinder 14 and the outer cylinder 15. The fitting parts 14a, 15a are formed of the outer periphery of the intermediate cylinder 14 and the inner periphery of the outer cylinder 15.

Description

  The present invention relates to a sliding bush for a suspension.

Some vehicles have a bush applied to the suspension.
FIG. 4 is a perspective view showing a swing type suspension arm 1 of a double wishbone type suspension mounted on a vehicle. As shown in FIG. 4, the suspension arm 1 is attached to a pair of front and rear vehicle bodies on the left side in the drawing. It has a portion 1a and a wheel side mounting portion 1b on the right side in the figure. Although the suspension arm 1 is an upper arm, a lower arm is provided below the suspension arm 1 with a substantially similar structure.

A mounting hole 2 for mounting a bush is formed in each vehicle body side mounting portion 1a.
The upper end of the upright (including the axle and the hub) 5 is connected to the lower side of the wheel side mounting portion 1b, and the wheel side mounting portion of the lower arm is connected to the lower end of the upright 5, and the wheel rotates in the upright 5 It is supported freely.

The bushing is disposed in the mounting hole 2 by press fitting or the like, and is connected to a suspension member connected to a side frame (not shown).
The bush is formed by press-fitting or vulcanizing and bonding rubber between a metal inner cylinder and an outer cylinder. When the suspension arm 1 is attached to a suspension member (not shown), the bush is press-fitted into the vehicle body side attachment portion 1a.
With this configuration, the bush has a function of following the positioning and vertical movement of the suspension mechanism, and a function of buffering the input from the wheels via the suspension mechanism and preventing vibration.

Such a bush structure is disclosed in, for example, Patent Document 1.
As shown in FIG. 5, the bush 100 disclosed in Patent Document 1 includes a first cylindrical fitting 110 through which the rotary shaft member 200 is inserted, and a second cylinder fitted to the vehicle body side mounting portion of the suspension arm. And a rubber elastic body 150 interposed between the first tubular fitting 110 and the second tubular fitting 120.

  This technique increases the press-fitting rate of the rubber elastic body 150 by making the outer diameter of a part of the rubber elastic body 150 press-fitted into the second cylindrical metal fitting 120 larger than the inner diameter of the mounting portion on the vehicle body. Even when a large load is received from the side mounting portion and the torsion angle of the rubber elastic body 150 increases, slipping between the rubber elastic body 150 and the second cylindrical metal fitting 120 is suppressed, and the durability of the rubber elastic body 150 is improved. It can be secured.

JP 2000-249180 A

  By the way, a so-called sliding bush using a sliding bearing has been developed for the suspension device bush in order to ensure smoother followability to the vertical movement of the suspension mechanism. As this sliding bush, the structure shown in FIG. 6 can be considered.

As shown in FIG. 6, the sliding bush type bush 300 includes a first cylindrical fitting 310, a resin member 340, a third cylindrical fitting 330, a rubber elastic body 350, and a second cylinder from the rotation axis toward the outside. And a metal fitting 320.
The first tubular fitting 310 is inserted through the rotary shaft member 400 on the inner side, and the outer periphery thereof is in contact with the inner periphery of the resin member 340.

The resin member 340 is formed symmetrically on one end side and the other end side in the axial direction, is formed in a cylindrical shape having flange portions on one end and the other end, and contains a lubricant in the resin. Yes.
The resin member 340 and the first cylindrical fitting 310 disposed in contact with the inner periphery of the resin member 340 slide smoothly with the lubricant contained in the resin member 340 and rotate relatively.

The third cylindrical fitting 330 is disposed on the outer periphery of the resin member 340, and a rubber elastic body 350 is vulcanized and bonded to the outer periphery thereof. The third tubular fitting 330 is disposed as a metal member having good compatibility between rubber and resin because it is difficult to reliably bond rubber and resin due to a difference in thermal expansion coefficient.
The second cylindrical fitting 320 is fitted into the vehicle body side attachment portion of the suspension arm, and the rubber elastic body 350 is press-fitted therein.

That is, the bush 300 can be said to have a structure in which a resin member 340 and a third cylindrical fitting 330 are added in order from the inside between the rubber elastic body of the so-called rubber bush shown in FIG. 5 and the first cylindrical fitting.
Therefore, the structure of the bush as shown in FIG. 6 is complicated.

  The present invention has been made in view of such a problem, and an object thereof is to provide a suspension bush having a simple structure.

(1) In order to achieve the above object, the suspension bush of the present invention includes an inner cylinder formed of metal, an outer cylinder formed of an elastic material, and the inner cylinder and the outer cylinder. An intermediate cylinder formed of a resin containing a lubricant, and a fitting portion that regulates relative rotation between the intermediate cylinder and the outer cylinder is an outer periphery of the intermediate cylinder and an inner periphery of the outer cylinder It is characterized by being formed.
(2) It is preferable that the intermediate cylinder is press-fitted into the outer cylinder.

  (3) The fitting portion includes a key groove and a contact portion that contacts the key groove, and the key groove is formed on one of the outer periphery of the intermediate tube and the inner periphery of the outer tube, The part is preferably formed on the other of the outer periphery of the intermediate tube and the inner periphery of the outer tube.

  (4) Further, the fitting portion restricts relative rotation between the intermediate cylinder and the outer cylinder by serration coupling, and an inner peripheral serration is formed on the outer periphery of the intermediate cylinder, and on the inner periphery of the outer cylinder It is preferable that an outer peripheral serration corresponding to the inner peripheral serration is formed.

  According to the suspension bush of the present invention, the fitting portion restricts the relative rotation between the intermediate cylinder and the outer cylinder. The relative rotation is restricted by the part. Since this fitting part is formed in the outer periphery of an intermediate cylinder, and the inner periphery of an outer cylinder, it can suppress relative rotation, without adhering and fixing an intermediate cylinder and an outer cylinder. Therefore, the relative rotation between the intermediate cylinder and the outer cylinder can be suppressed without requiring a metal member to be an adhesive substrate made of an elastic material such as rubber, and the structure can be simplified.

BRIEF DESCRIPTION OF THE DRAWINGS The whole structure of the suspension bush concerning one Embodiment of this invention is shown, (a) is the sectional side view, (b) is II sectional view taken on the line of (a). It is an exploded view of the bush for suspension concerning one embodiment of the present invention. It is sectional drawing for demonstrating the bush for suspension concerning a modification. It is a perspective view which shows the structure of the suspension arm to which the bush for suspension is applied. It is a sectional side view which shows the structure of the conventional rubber bush. It is a sectional side view which shows the structure of the conventional sliding bush.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<One Embodiment>
First, the structure of a suspension bush according to an embodiment will be described. The suspension bush according to the present embodiment is press-fitted into the vehicle body side attachment portion of the suspension arm when a suspension arm such as a truck upper arm is attached to the suspension member.

  As shown in FIG. 1A, the bush 10 includes an inner cylinder 11, an end washer 16 disposed on the other end side of the inner cylinder 11, an outer cylinder 15, and the inner cylinder 11 and the outer cylinder 15. And an intermediate cylinder 14 interposed therebetween. The cylinder axes of the inner cylinder 11, the intermediate cylinder 14 and the outer cylinder 15 and the axis of the end washer 16 are arranged concentrically and are arranged so as to coincide with the rotation axis. FIG. 1A is a side sectional view of the bush 100 in a state where it is press-fitted into a vehicle body side attachment portion of a suspension arm (not shown), with the right side as one end and the left side as the other end, and a rotation axis. The inside and outside are defined based on

The inner cylinder 11 is formed of metal in a cylindrical shape. The inner cylinder 11 is inserted with a bolt 20 that functions as a rotating shaft member, and rotates integrally with the bolt 20.
The inner cylinder 11 has a flange part 11a, a cylinder part 11b, and a crimping part 11d, and these flange part 11a, cylinder part 11b, and crimping part 11d are integrally formed.

The flange portion 11a is formed at one end portion of the inner cylinder 11, and extends along a direction orthogonal to the rotation axis.
The cylinder part 11b is formed between both ends of the inner cylinder 11, and extends in a cylindrical shape along the rotation axis.
The caulking portion 11d is a portion that is the other end portion of the inner cylinder 11 and protrudes from the other end portion of the cylinder portion 11b.
The end washer 16 has an inner hole crimped to the caulking portion 11d and extends along a direction perpendicular to the rotation axis.

  The outer cylinder 15 is formed of a rubber material (elastic material) in a cylindrical shape. The outer periphery of the outer cylinder 15 is in pressure contact with a vehicle body side mounting portion (not shown), and the inner periphery of the outer cylinder 15 is in pressure contact with the outer periphery of the intermediate cylinder 14. In addition, the outer cylinder 15 of Fig.1 (a) has shown what was elastically deformed.

  The inner side of one end of the outer cylinder 15 is in pressure contact with the outer side surface of the other end of the flange portion 11 a and the other end side surface of the front end of the flange portion 11 a, and the inner side of the other end of the outer cylinder 15 is outside the end of the end washer 16. The side surface is pressed against one end side surface of the end of the end washer 16.

The intermediate cylinder 14 is a cylinder formed of a resin containing a lubricant. The outer periphery of the intermediate cylinder 14 is adjacent to the inner periphery of the outer cylinder 15, and the inner periphery of the intermediate cylinder 14 is adjacent to the outer periphery of the cylinder portion 11b. The length of the intermediate cylinder 14 in the rotation axis direction is set to be slightly shorter than the length of the cylinder portion 11b in the rotation axis direction.
One end of the intermediate cylinder 14 abuts on the inner surface of the other end of the flange portion 11 a, and the other end of the intermediate cylinder 14 abuts on the inner surface of one end of the end washer 16.

  As the resin containing the lubricant used for the intermediate cylinder 14, for example, a liquid or semi-solid lubricant solidified with a resin material can be used. What was comprised from the polyolefin resin with affinity to an agent can be used.

Next, the bush 10 will be described with reference to FIG. 1B showing a cross-sectional view taken along the line II of FIG.
As shown in FIG. 1 (b), the bush 10 includes a cylindrical portion 11b, an intermediate cylinder 14 having a convex portion (contact portion) 14a, and a concave portion (key groove) 15a from the rotational axis toward the outside. The outer cylinder 15 which has is arrange | positioned in order. Further, the cylinder portion 11b and the intermediate cylinder 14 are adjacent to each other, and the intermediate cylinder 14 and the outer cylinder 15 are adjacent to each other.

  The convex portion 14a is a convex portion formed on the outer periphery of the intermediate cylinder 14, and extends from one end of the intermediate cylinder 14 to the other end along the rotational axis direction. Here, the convex part 14a shows what has a pair of surface parallel to the radial direction of the intermediate cylinder 14, and a surface orthogonal to the radial direction of the intermediate cylinder 14. FIG. 1B illustrates an example in which four protrusions 14a are formed on the outer periphery of the intermediate cylinder 14 every 90 degrees, such as a spline shaft. It is not limited to.

  The recess 15 a is a concave portion formed on the inner periphery of the outer cylinder 15, and extends along the rotational axis direction from one end of the outer cylinder 15 to the other end. Here, the concave portion 15 a has a pair of surfaces parallel to the radial direction of the outer cylinder 15 and a surface orthogonal to the radial direction of the outer cylinder 15. 1B illustrates an example in which four recesses 15a are formed on the outer periphery of the outer cylinder 15 every 90 degrees, but the positions and the number of the recesses are not limited to this.

  These concave portions 15a are formed at locations corresponding to the convex portions 14a. In other words, the convex portion 14a is formed at a location corresponding to the concave portion 15a. That is, when a force that relatively rotates the intermediate cylinder 14 and the outer cylinder 15 is applied, a surface parallel to the radial direction of the intermediate cylinder 14 included in the convex portion 14a and a surface parallel to the radial direction of the outer cylinder 15 included in the concave portion 15a. The force that presses and acts on.

Therefore, the convex portion 14 a and the concave portion 15 a function as a fitting portion that restricts relative rotation between the intermediate cylinder 14 and the outer cylinder 15.
The outer periphery of the intermediate cylinder 14 is in pressure contact with the inner periphery of the outer cylinder 15, and the convex portion 14a is in pressure contact with the concave portion 15a. For this reason, the convex part 14a is a part contact | abutted to the recessed part 15a.

Next, the structure of the bush 10 will be described with reference to FIG. 2 that shows exploded components of the bush 10 that are not press-fitted into the vehicle body mounting portion. In FIG. 2, reference numerals corresponding to the configuration of the bush 10 after press-fitting shown in FIG.
The bush 10 includes an intermediate cylinder 14, an outer cylinder 15, an inner cylinder 11, and an end washer 16.

An intermediate portion 15 b that is an outer periphery between both end portions of the outer cylinder 15 is formed linearly along the extending direction of the recess 15 a formed on the inner periphery of the outer cylinder 15.
Moreover, the protrusion part 11c is a part corresponding to the above-mentioned caulking part 11d, and is a part protruding along the cylinder axis from the other end part of the cylinder part 11b.

The outer diameter a of the intermediate cylinder 14 is set to be slightly larger than the inner diameter b of the outer cylinder 15, and the outer diameter c of the protruding portion 11 c is set to be slightly smaller than the inner diameter d on one end side of the end washer 16.
Further, the length A of the intermediate cylinder 14 in the cylinder axis direction is set slightly shorter than the length B of the cylinder part 11b in the cylinder axis direction, and is longer than the length C of the cylinder part 11b and the protruding part 11c in the cylinder axis direction. Also, the length D of the outer cylinder 15 in the cylinder axis direction is set longer.

Hereinafter, the assembly process of the bush 10 will be described.
First, the intermediate cylinder 14 is press-fitted into the outer cylinder 15. In this case, the convex portion 14 a formed on the outer periphery of the intermediate tube 14 is press-fitted so as to slide in the concave portion 15 a formed on the inner periphery of the outer tube 15, and one end of the intermediate tube 14 is connected to one end of the outer tube 15. Press fit until they match. Since the outer diameter a of the intermediate cylinder 14 is set to be slightly larger than the inner diameter b of the outer cylinder 15 and the outer cylinder 15 is formed of a rubber material, the intermediate cylinder 14 is assembled while being press-fitted into the outer cylinder 15. It is.

Then, the inner cylinder 11 is fitted inside the intermediate cylinder 14 press-fitted into the outer cylinder 15.
When the inner cylinder 11 is fitted inside the intermediate cylinder 14, the end washer 16 is compressed from the other end side of the outer cylinder 15 until one end contacts the other end of the cylinder portion 11b. When this compression is completed, the protruding portion 11c is positioned with a small gap inside the inner periphery of the end washer 16.

Then, the diameter of the protruding portion 11c is increased in a tapered shape from the other end side and crimped with the end washer 16. The crimped protrusion 11c is deformed and formed in the above-described crimped portion 11d.
In this way, the bush 10 is assembled. The assembled bush 10 is press-fitted and attached to the vehicle body side attachment portion of the suspension arm.

The suspension bush according to the embodiment of the present invention is configured as described above.
For this reason, if there is a road surface input to the wheel, the suspension arm rotates about the vehicle body side mounting portion in conjunction with the vertical movement of the suspension mechanism. In this case, the outer cylinder 15 whose outer periphery is adjacent to the vehicle body side mounting portion and the intermediate cylinder 14 adjacent to the outer cylinder 15 rotate integrally with respect to the inner cylinder 11 adjacent to the bolt 20 that functions as a rotating shaft member. To do.

  That is, the intermediate cylinder 14 and the outer cylinder 15 whose relative rotation is restricted by the convex portion 14a and the concave portion 15a functioning as a fitting portion rotate integrally. Since the outer periphery of the inner cylinder 11 is adjacent to the inner periphery of the intermediate cylinder 14 containing the lubricant, the rotation is smoothly realized by sliding the inner periphery of the intermediate cylinder 14 and the outer periphery of the inner cylinder 11.

  Therefore, since the convex portion 14a and the concave portion 15a function as a fitting portion that restricts the relative rotation between the intermediate cylinder 14 and the outer cylinder 15, a force that relatively rotates the intermediate cylinder 14 and the outer cylinder 15 is applied. However, the relative rotation is restricted by the convex portion 14a and the concave portion 15a. Since this convex part 14a is formed in the outer periphery of the intermediate | middle cylinder 14, and the recessed part 15a is formed in the inner periphery of the outer cylinder 15, it can suppress relative rotation, without adhering and fixing the intermediate | middle cylinder 14 and the outer cylinder 15. FIG. it can. Thereby, the relative rotation of the intermediate cylinder 14 and the outer cylinder 15 can be suppressed without requiring a metal member to be an adhesive substrate of rubber material, and the structure of the bush 10 can be simplified.

Moreover, since the integrally formed inner cylinder 11 has the flange portion 11a, it is not necessary to provide a separate washer on one end side of the bush 10, and the structure of the bush 10 can be simplified.
By simplifying the structure of the bush 10, the manufacturing cost can be suppressed by reducing the assembly process of the bush 10 and simplifying the components.

Further, since the relative rotation between the intermediate cylinder 14 and the outer cylinder 15 is restricted by the convex portion 14a and the concave portion 15a, the outer cylinder 15 can be prevented by preventing slipping on the inner peripheral surface of the outer cylinder 15 formed of a rubber material. The durability of can be improved. For this reason, it contributes to the life extension of the bush 10.
Further, since the intermediate portion 15b is formed linearly along the extending direction of the recess 15b, the thickness of the rubber material between the intermediate portion 15b and the recess 15b can be ensured uniformly.

  Further, since the length A in the cylinder axis direction of the intermediate cylinder 14 is set to be slightly shorter than the length B in the cylinder axis direction of the cylinder part 11b, the sealing performance due to the deformation of the outer cylinder 15 formed from a rubber material. Can be secured.

  For example, in a vehicle such as a truck, an engine is provided between the left and right front wheels. Therefore, it is difficult to secure the length of the suspension arm in the vehicle left-right direction, and a large load is input to the bush. In particular, the engine or the engine peripheral device is often disposed near the upper arm rather than the lower arm of the suspension arm, and it is difficult to ensure the length of the upper arm. The shorter the arm length, the larger the rotation angle corresponding to the vertical movement of the suspension mechanism. Therefore, a large load and a large rotation angle are required for the bush attached to the upper arm of the truck. The bush 10 of the present invention is preferably attached to the vehicle body side attachment portion of the upper arm of such a truck.

[Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
In the above-described embodiment, the fitting portion is configured by the convex portion formed in the intermediate cylinder and the concave portion formed in the outer cylinder. However, the present invention is not limited thereto, and the concave portion formed in the intermediate cylinder A fitting part may be constituted by a convex part formed in the outer cylinder.

  Moreover, you may use what restrict | limits the relative rotation of the intermediate | middle cylinder 14A and the outer cylinder 15A by serration coupling as a fitting part like the bush 10A shown in FIG. The inner cylinder 11A has the same structure as the above-described inner cylinder. In this case, a corrugated inner peripheral serration is formed on the outer periphery of the intermediate cylinder 14A, and an outer peripheral serration having a shape corresponding to the inner peripheral serration is formed on the inner periphery of the outer cylinder 15A.

  Moreover, in the assembly of the bush, the outer diameter of the intermediate cylinder of rubber material is set to be slightly larger than the inner diameter of the outer cylinder, and the intermediate cylinder is shown to be assembled while being press-fitted into the outer cylinder. However, the outer diameter of the intermediate cylinder and the inner diameter of the outer cylinder are set equal to each other, or the outer diameter of the intermediate cylinder is set to be slightly smaller than the inner diameter of the outer cylinder, and the intermediate cylinder slides into the outer cylinder and is incorporated. May be. In this case, when the assembled bush is press-fitted into the vehicle body side mounting portion, the inner circumference of the outer cylinder comes into pressure contact with the outer circumference of the intermediate cylinder as the outer cylinder of the rubber material is compressed and deformed.

  The suspension bush according to the present invention can be applied not only to medium-sized or large-sized automobiles such as trucks but also to small-sized automobiles such as passenger cars.

DESCRIPTION OF SYMBOLS 1 Suspension arm 1a Car body side attaching part 1b Wheel side attaching part 2 Mounting hole 5 Upright 10 Bush 11 Inner cylinder 11a Flange part 11b Tube part 11c Projection part 11d Caulking part 14 Intermediate cylinder 14a Convex part (contact part)
15 outer cylinder (rubber)
15a Concave part (key groove)
15b Intermediate part 16 End washer 20 Bolt

Claims (4)

An inner cylinder made of metal,
An outer cylinder made of an elastic material;
Having an intermediate cylinder interposed between the inner cylinder and the outer cylinder and formed of a resin containing a lubricant;
A suspension bush, wherein a fitting portion for restricting relative rotation between the intermediate cylinder and the outer cylinder is formed on an outer periphery of the intermediate cylinder and an inner periphery of the outer cylinder. The suspension bush according to claim 1, wherein the intermediate cylinder is press-fitted into the outer cylinder. The fitting portion includes a key groove and an abutting portion that abuts on the key groove,
The keyway is formed on one of the outer periphery of the intermediate tube and the inner periphery of the outer tube,
The suspension bush according to claim 1, wherein the contact portion is formed on the other of the outer periphery of the intermediate cylinder and the inner periphery of the outer cylinder. The fitting portion regulates relative rotation between the intermediate cylinder and the outer cylinder by serration coupling,
An inner peripheral serration is formed on the outer periphery of the intermediate cylinder,
The suspension bush according to claim 1 or 2, wherein an outer peripheral serration corresponding to the inner peripheral serration is formed on an inner periphery of the outer cylinder.

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