JP3502234B2 - Stabilizer bush - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stabilizer bush for holding a stabilizer bar of a vehicle.

[0002]

2. Description of the Related Art As shown in FIG. 10, a stabilizer bush is generally made of a thick-walled tubular rubber elastic body 1, and a stabilizer bar S of a vehicle is inserted and held in the tube. The rubber elastic body 1 has a top surface that is a flat surface, and a flange 1 that extends radially inward from both end edges in the axial direction.
1 and the outer peripheral surface between these flanges 11 is approximately U.
It is designed so as to be held in the character-shaped bracket 4. The bracket 4 is fixed to a vehicle body (not shown) by inserting bolts into the mounting holes 41 at both ends.

[0003]

The rubber elastic body 1 is
It is usually made of natural rubber material. However, in this case, when the vehicle starts or when the operating angle of the stabilizer bar S is large, the inner peripheral surface of the rubber elastic body 1 and the stabilizer bar S are suddenly displaced relative to each other, and abnormal noise is generated. was there. Therefore, there is one in which the rubber elastic body 1 is made of a highly slidable rubber to reduce the sliding resistance with the stabilizer bar S and suppress the abnormal noise. However, FIG.
When the rubber elastic body 1 slides sideways and comes into contact with the curved portion S1 of the stabilizer bar S, the lateral force applied from the stabilizer bar S causes the rubber elastic body 1 to be laterally displaced with respect to the bracket 4, as shown in FIG. There is. This is because the friction coefficient between the rubber elastic body 1 and the bracket 4 or the vehicle body that comes into contact with the rubber elastic body 1 is small. Therefore, in order to prevent this, it is considered to provide a lateral deviation prevention stopper adjacent to the rubber elastic body 1. However, there is a problem that the number of parts increases and the cost increases.

On the other hand, there is known a stabilizer bush in which a sliding surface made of a resin material is provided on the inner peripheral surface of a rubber elastic body (for example, Japanese Utility Model Laid-Open No. 63-39011 and Japanese Patent Laid-Open No. 6-39011).
3-57310, etc.). However, since the resin material has higher rigidity than rubber, the spring of the entire stabilizer bush becomes high, and if the rubber elastic body is softened in order to obtain desired spring characteristics, there is a problem that durability is reduced. Further, if sand enters between the sliding surface and the stabilizer bar, there is a risk that the sand may be worn or noise may be generated.

Therefore, an object of the present invention is to provide a stabilizer bush which can prevent the generation of abnormal noise and lateral displacement, and is free from the risk of cost increase due to an increase in the number of parts, and which has good spring characteristics and durability. Especially.

[0006]

The stabilizer bush of the present invention is a bracket in which a stabilizer bar is inserted and held in a cylinder of a rubber elastic body formed in a cylindrical shape, and an outer peripheral surface of the rubber elastic body is attached to a vehicle body. The rubber elastic body is configured to be held, and at least a part including an inner peripheral portion in contact with the stabilizer bar is made of highly slidable rubber . The high-sliding rubber is a rubber that is
Rubber (NR), natural rubber (NR) and butadiene rubber (B
R) blend rubber (NR / BR) and butyl rubber
(IIR or Cl-IIR),
To blend oleic acid amide with the base rubber
Higher slidability and rubber elasticity
The rubber that forms the base of the body is made of natural rubber (NR), natural rubber
Rubber (NR) and butadiene rubber (BR) blend rubber
(NR / BR) and butyl rubber (IIR or Cl-
IIR) (Claim 1).

According to the above configuration, the rubber elastic body is
Since the inner peripheral portion, through which the stabilizer bar is inserted and held, is made of highly slidable rubber, the sliding resistance of the stabilizer bar is reduced, and the generation of abnormal noise is suppressed. Further, since the base portion of the rubber elastic body is made of the conventional rubber material, the frictional resistance with the bracket is increased, and the lateral displacement is unlikely to occur. Therefore, it is possible to prevent the cost increase due to the increase in the number of parts, and since the resin material is not used, the spring characteristics and the durability are good. In addition, the adhesive strength is improved, and the above fatty acid amide
It is possible to prevent the rubber elastic body from moving to the base side.

[0008]

[0009]

[0010]

The rubber forming the base of the rubber elastic body is
Butyl rubber is more preferable (Claim 2), and the effect of preventing migration of higher fatty acid amide at high temperature is high.

The rubber elastic body comprises, for example, a cylindrical base rubber and a cylindrical highly slidable rubber laminated on the inner circumference thereof (claim 3 ).

An axial edge of the highly slidable rubber may extend outward in the radial direction to cover the axial end surface of the base rubber (claim 4 ). At this time, since the end surface of the rubber elastic body is made of highly slidable rubber, generation of abnormal noise due to contact of the stabilizer bar with the end surface is suppressed.

[0014]

1 (a) and 1 (b) show an embodiment of a stabilizer bush of the present invention. In the figure, reference numeral 1 denotes a thick-walled tubular rubber elastic body which constitutes a stabilizer bush, and the rubber elastic body 1 has a cylindrical highly slidable rubber 3 on the inner circumference of a tubular base rubber 2 serving as a base. Are laminated. The base rubber 2 is formed into a substantially U-shaped cross section having a top surface as a flat surface, and outer peripheral edges of both end portions thereof are radially extended to form a flange 21. And these flanges 21
The outer peripheral surface between the two is fixed to the vehicle frame by bolts U
It is designed to be held by a character-shaped mounting bracket (not shown).

The base rubber 2 is made of various rubber materials generally used as stabilizer bush materials. Specifically, natural rubber (NR), butadiene rubber (BR), isoprene rubber (IR), styrene butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), ethylene propylene diene copolymer rubber (EPDM) ), Butyl rubber (IIR), chlorinated butyl rubber (Cl-IIR), and blend rubbers thereof can be used.

The high slidability rubber 3 is obtained by adding a higher fatty acid amide to a base rubber to give high slidability. The base rubber here is not particularly limited, but examples thereof include natural rubber (NR), butadiene rubber (BR), isoprene rubber (IR), styrene butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber ( NBR), ethylene propylene diene copolymer rubber (EPDM), butyl rubber (IIR), chlorinated butyl rubber (Cl-IIR), and blend rubbers thereof can be used.

In the highly slidable rubber 3, the higher fatty acid amide compounded in the base rubber functions as a lubricant by blooming from the base rubber at the time of use and improves the slidability. Specific examples of higher fatty acid amides include, for example, oleic acid amide, palmitic acid amide,
12 carbon atoms such as stearic acid amide and erucic acid amide
.About.22 saturated / unsaturated fatty acid amides. The compounding amount of the higher fatty acid amide in the base rubber is usually 5 to 20.
The content is preferably in the range of wt%, and if the blending amount is less than 5 wt%, it is difficult to sufficiently maintain the sliding resistance reducing effect. Further, if the blending amount exceeds 20% by weight, the physical properties of rubber may be adversely affected.

The high slidability rubber 3 is made by mixing the base rubber and the higher fatty acid amide at a predetermined mixing ratio. At this time, generally known additives, for example, vulcanizing agent, vulcanization accelerator,
Vulcanization aids, processing aids and the like can be used. Examples of the vulcanizing agent include sulfur, peroxides, metal oxides, polyamines and the like, and are usually used in the range of 0.1 to 10% by weight. As the vulcanization accelerator, sulfenamide-based, thiazole-based, thiuram-based, dithiocarbamate salts, xanthogenates and the like are usually used in the range of 0.1 to 10% by weight. As the vulcanization aid, zinc oxide or the like is usually used, and the compounding amount thereof is usually in the range of 3 to 15% by weight. As processing aids, fatty acids such as stearic acid and fatty oils are used.

When manufacturing the stabilizer bush having the above structure, first, one of the base rubber 2 and the highly slidable rubber 3 is molded and vulcanized or semi-vulcanized, and then the other is placed in the mold. One may be injected and vulcanization molded. Of course, each rubber may be formed into a predetermined shape and then bonded.

Here, the combination of the base rubber 2 and the high-sliding rubber 3 is not particularly limited, but the rubber as the base material of the high-sliding rubber 3 and the SP value (solubility parameter) of the base rubber 2 When the difference is 0.5 or less, the bondability between the two is improved. Normally, if the rubber that is the base material of the high slidability rubber 3 is the same as or similar to the base rubber 2, S
Although the P values are almost the same and good bondability is obtained, the same effect can be obtained by selecting a rubber material having a similar SP value even if the materials are not necessarily similar materials.

Further, the high-sliding rubber 3 gives slidability by blooming of the higher fatty acid amide from the inside of the stabilizer bush when the stabilizer bush is used. However, depending on the combination of the base rubber 2 and the high-sliding rubber 3, May cause the bloomed higher fatty acid amide to migrate to the base rubber 2 side. In order to avoid this shift, the base rubber 2 and the high slidability are set so that the difference in SP value between the fatty acid amides in the base rubber 2 and the high slidability rubber 3 is 1.5 or more, preferably 2 or more. It is desirable to select rubber 3.

Specifically, for example, natural rubber (NR),
Blend rubber (NR / BR) of natural rubber (NR) and butadiene rubber (BR) and butyl rubber (IIR or Cl-IIR) have similar SP values (SP
Value: about 8), the rubber as the base material of the highly slidable rubber 3 and the base rubber 2 are selected from the above rubber materials, and when oleic acid amide having an SP value of about 10 is used as the higher fatty acid amide, the bondability is improved. It is a combination that is excellent in and that higher fatty acid amide does not easily migrate.

Here, with respect to the migration of higher fatty acid amide, if a rubber material having a low gas permeability is used as the base rubber 2, the suppressing effect can be further enhanced. Specifically, the gas permeability is 1 × 10 ^-10 cm ³ · cm / cm ² · s
It is preferable to use a rubber material having an ec · cmHg or less, for example, butyl rubber (IIR or Cl-IIR), and a remarkable effect is particularly seen when used at a high temperature.

According to the above construction, the inner peripheral portion of the stabilizer bush for holding the outer periphery of the stabilizer bar is made of the highly slidable rubber 3, so that the sliding resistance of the stabilizer bar is reduced, and the stabilizer bar is reduced when starting. It is possible to prevent abnormal noise from being generated when largely displaced. Further, since the base rubber 2 of the stabilizer bush that contacts the bracket and the vehicle body is made of a normal rubber material, the frictional resistance between them is large, and lateral displacement from the bracket is unlikely to occur even when a lateral force is applied. Therefore, since it is not necessary to install a lateral displacement prevention stopper or the like, it is possible to reduce the number of parts and costs, and since a resin material is not used, spring characteristics and durability are excellent.

FIG. 2 shows a second embodiment of the present invention. In the present embodiment, the rubber elastic body 1 is configured by laminating the base rubber 2 having a substantially rectangular cross section on the upper surface of the substantially slidable rubber 3 having a substantially cylindrical shape. In this embodiment, the fitting portion of the rubber elastic body 1 with the bracket is made of the highly slidable rubber 3
Since it is composed of, the frictional resistance when assembled to the bracket is reduced, and the assembling property is improved. The rubber elastic body 1
Since the upper end portion that comes into contact with the vehicle body is made of the base rubber 2 which is a normal rubber material, the frictional resistance at this portion is sufficiently large and the occurrence of lateral displacement is suppressed. In this way, the shapes of the highly slidable rubber 3 and the base rubber 2 may be changed as necessary.

FIG. 3 shows a third embodiment of the present invention.
In the present embodiment, the axially opposite end edges 31 of the highly slidable rubber 3 in the first embodiment are extended radially outward to cover the surface of the base rubber 2. According to the present embodiment, since both end surfaces of the rubber elastic body 1 are made of highly slidable rubber, it is possible to prevent abnormal noise from occurring when the stabilizer bar comes into contact with the end surfaces.

FIG. 4 shows a fourth embodiment of the present invention.
In the present embodiment, convex portions 32 having a T-shaped cross section that project into the base rubber 2 are provided at a plurality of locations on the outer peripheral surface of the highly slidable rubber 3 in the first embodiment. Here, a total of four convex portions 32 are provided at upper and lower symmetrical positions of the highly slidable rubber 3, and the tip ends reach the outer surface of the base rubber 2 (FIG. 4A). According to the present embodiment, the plurality of convex portions 3
Since the joining force between the high-sliding rubber 3 and the base rubber 2 is improved by 2, it is advantageous when the base rubber of the high-sliding rubber 3 and the base rubber 2 are not the same type of rubber.

FIG. 5 shows the fifth embodiment of the present invention.
In the present embodiment, the cross-sectional shape of the highly slidable rubber 3 in the first embodiment is gear-shaped (FIG. 5).
(A)). At this time, the teeth of the gear may be fan-shaped as shown in FIG. Also according to the present embodiment, the same effect as that of the fourth embodiment can be obtained.

FIG. 6 shows a sixth embodiment of the present invention.
In the present embodiment, the outer peripheral surface 33 of the highly slidable rubber 3 in the first embodiment is roughened to make it rough, and then bonded to the base rubber 2. According to this embodiment,
By increasing the bonding area between the two, the effect of increasing the bonding strength can be obtained.

[0030]

【Example】

Example 1 The relationship between the combination of the base rubber 2 and the high-sliding rubber 3 and the migration of higher fatty acid amide and the adhesive strength was investigated. Various rubber materials having the compositions shown in Table 1 were used as the base rubber 2, and NR / BR rubber containing oleic acid amide was used as the highly slidable rubber 3, and a test for a round bar dumbbell shape shown in FIG. 7B was performed. A piece P was produced. The test piece P is such that the left half of the figure is the high-sliding rubber 3 and the right half is the base rubber 2. After molding the high-sliding rubber 3, the base rubber 2 is injected, It is formed by vulcanization.

The test piece was allowed to stand at 23 ° C. for 14 days, and the amount of oleic acid amide transferred from the highly slidable rubber 3 to the base rubber 2 was measured. The amount (% by weight) of oleic acid amide in the base rubber 2 was measured at the portions 3 mm, 6 mm, and 9 mm away from the joint interface with the highly slidable rubber 3, and the results are shown in FIG.
It is shown in (a). In the figure, ◯, Δ, and □ indicate ◯: 3 mm from the interface, Δ: 6 mm from the interface, □: amount of oleic acid amide at a position 9 mm away from the interface, respectively.

The adhesive strength was measured by carrying out a tensile test using the above test piece at a tensile speed of 50 mm / min. The results are also shown in FIG. In the figure, ●, ▲,
▼: ●: High sliding rubber vulcanization time 1.5 minutes (T ₉₀ ) ^{* 1} ▲: High sliding rubber vulcanization time 3 minutes (T _90X1.5 ) ^{* 2} ▼: Each rubber material alone * 1) T ₉₀ : ΔV 229% * 2) _Indicates T _90X1.5 : ΔV 225%.

[0033]

[Table 1] * 3) Nox cellar M-60P 0.6 parts by weight Nox cellar PX-P 1.2 parts by weight Parnock RP 1.2 parts by weight * 4) Nox cellar TET 2.0 parts by weight Nox cellar TS 1.0 parts by weight (both Ouchi Shinko Chemical Industry Co., Ltd., trade name) * 5) Cyclohexyl benzothiazole sulfenamide

As is clear from the figure, the greater the difference in SP value between the base rubber 2 and the oleic acid amide, the smaller the migration amount of oleic acid amide, and the difference in SP value is 1.
If it is 5 or more, it is considered that a clear effect can be obtained. S
When the difference in P value is 2 or more, the transfer amount becomes almost 0. Also,
The adhesive strength is highest when the same NR / BR rubber is used as the base rubber of the high slidability rubber 3 as the base rubber 2, and it can be seen that the bonding force can be improved by using the same material.

Example 2 Next, the base rubber 2 is shown in Table 2.
The IIR rubber having the composition shown in Table 1 and the NR / BR rubber having the same composition as that used in Example 1 (see Table 1) contain the oleic acid amide having the same composition as in Example 1 as the highly slidable rubber 3. Using NR / BR rubber, a stabilizer bush having the shape shown in FIG. 8A was manufactured.

The obtained stabilizer bush was left standing at 80 ° C. for 72 hours, and the amount of oleic acid amide transferred from the highly slidable rubber 3 to the base rubber 2 under high temperature conditions was examined.
3 mm from the joint interface with the high slidability rubber 3 and 6 respectively
The amount (% by weight) of oleic acid amide in the base rubber 2 was measured at a portion separated by mm, and the result is shown in FIG. 8B with the gas permeability as the horizontal axis. In addition, the measurement of gas permeability,
It was performed under the conditions of an ambient temperature of 25 ° C. using nitrogen gas. In the figure, ○ and △ show the results when IIR rubber, ● and ▲ use NR / BR rubber, respectively, ○ and ●: 3 mm from the interface △, ▲: olein at a position 6 mm away from the interface, respectively The amount of acid amide is shown.

[0037]

[Table 2] * 5) Cyclohexyl, benzothiazole, sulfenamide * 6) Noxcellar TTCU 4.0 parts by weight Noxcellar TT 2.0 parts by weight Noxcellar DM 1.0 parts by weight (both manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

As is apparent from the figure, I was used as the base rubber 2.
When IR rubber was used, the amount of transfer was almost 0, and it can be seen that there was almost no transfer even under high temperature conditions. On the other hand, when NR / BR rubber is used, as shown in FIG. 7, almost no migration is observed at room temperature, but the migration amount increases at high temperature, and it is considered to be used at high temperature. It is more preferable to use a rubber material having a low gas permeability, especially a rubber material having a gas permeability of 1 × 10 ⁻¹⁰ cm ³ · cm / cm ² · sec · cmHg or less. When the IIR rubber was used and the adhesive strength was measured by the same method as in Example 1, the adhesive strength was 550 N / cm ² .
Good results have been obtained.

FIG. 9 shows the positional relationship of various rubber materials with the gas permeability as the horizontal axis and the SP value as the vertical axis.
From the figure, for example, when the base material of the high slidability rubber 3 is NR / BR rubber, in order to improve the adhesiveness, the base rubber 2 is S
NR rubber, NR / BR rubber with similar P value, and II
It is preferable to use R rubber, and the difference in SP value between NBR rubber and EPDM rubber is slightly large. On the other hand, in order to prevent migration of higher fatty acid amide which is a lubricant, IIR rubber, NB
R rubber is preferable because it has lower gas permeability than other rubber materials. Therefore, when IIR rubber is used as the base rubber 2,
It can be seen that it is possible to achieve both improved adhesiveness and prevention of migration at high temperatures.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, (a) is an axial sectional view of a stabilizer bush, and (b) is a lateral sectional view of the stabilizer bush.

2A and 2B show a second embodiment of the present invention, in which FIG. 2A is an axial sectional view of a stabilizer bush, and FIG. 2B is a lateral sectional view of the stabilizer bush.

FIG. 3 shows a third embodiment of the present invention, in which (a) is an axial sectional view of a stabilizer bush and (b) is a lateral sectional view of the stabilizer bush.

4A and 4B show a fourth embodiment of the present invention, in which FIG. 4A is a plan view of a stabilizer bush, FIG. 4B is an axial sectional view of the stabilizer bush, and FIG. 4C is a side sectional view of the stabilizer bush. Is.

5A and 5B show a fifth embodiment of the present invention, in which FIG. 5A is a sectional view in the axial direction of a stabilizer bush, FIG. 5B is a sectional view in the side direction of the stabilizer bush, and FIG. It is a figure which shows the other example of the cross-sectional shape.

FIG. 6 shows a sixth embodiment of the present invention, (a) is an axial sectional view of a stabilizer bush, and (b) is a lateral sectional view of the stabilizer bush.

7 (a) is a diagram showing the results of measuring the amount of oleic acid amide transferred and adhesive strength in Example 1, and FIG. 7 (b) is a schematic sectional view of a test piece.

8A is an axial cross-sectional view of a stabilizer bush produced in Example 2, and FIG. 8B is a diagram showing the relationship between gas permeability and the transfer amount of oleic acid amide.

FIG. 9 is a diagram showing gas permeability and SP value of various rubber materials.

FIG. 10 is a perspective view showing a state in which a conventional stabilizer bush is assembled to a stabilizer bar.

FIG. 11 is a partial cross-sectional view showing a state in which a conventional stabilizer bush is assembled to a stabilizer bar.

[Explanation of symbols]

1 rubber elastic body 2 Base rubber 21 flange 3 High sliding rubber 31 Both edges 32 convex 33 outer peripheral surface 4 bracket S stabilizer bar S1 bending part

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-129463 (JP, A) JP-A-6-234886 (JP, A) JP-A-4-25629 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) F16F 1/38 F16F 15/08

Claims (4)

(57) [Claims] 1. A stabilizer bush in which a stabilizer bar is inserted and held in a tube of a rubber elastic body formed in a tubular shape, and an outer peripheral surface of the rubber elastic body is held by a bracket attached to a vehicle body. , Of the rubber elastic body,
At least a part including an inner peripheral portion in contact with the stabilizer bar is made of highly slidable rubber, and the highly slidable rubber is provided.
However, the base rubber is natural rubber (NR), natural rubber
(NR) and butadiene rubber (BR) blend rubber (N
R / BR), and butyl rubber (IIR or Cl-I
(IR) and add rubber to the base material.
High slidability was imparted by incorporating in-acid amide
A rubber that is also a constituent of the base of the rubber elastic body
Natural rubber (NR), natural rubber (NR) and butadiene
Blend rubber (NR / BR) of rubber (BR), and
A stabilizer bush selected from butyl rubber (IIR or Cl-IIR) . 2. The rubber forming the base of the rubber elastic body is
The stabilizer bush according to claim 1, which is butyl rubber.
U. 3. The rubber elastic body and a cylindrical base rubber
A contract made of cylindrical high-sliding rubber laminated on the inner circumference of the
The stabilizer bush according to claim 1 or 2. 4. A radial edge of the high-sliding rubber is formed in the radial direction.
Extend outward and cover the axial end surface of the base rubber.
The stabilizer bush according to claim 3.