JP2008180315A - Vibrationproof rubber member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibrationproof rubber member enabling a low dynamic-to-static modulus ratio without losing reinforcement properties and having excellent vibrationproof characteristics. <P>SOLUTION: In this vibrationproof rubber member, a vibrationproof rubber layer is interposed between an upper mounting device 1a and a lower mounting device 1b. A plate neodymium magnet 2 is installed on each of the upper mounting device 1a side and the lower mounting device 1b side. The neodymium magnets are so arranged parallel to each other that the same poles thereof are opposed to each other through the vibrationproof rubber layer 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an anti-vibration rubber member that can be widely used for an automobile bush, an engine mount, an anti-vibration member for industrial machinery, and the like.

  Anti-vibration rubber members used in automobile bushes, engine mounts, industrial machine anti-vibration members and the like are intended to reduce vibration and noise, and are usually metal fittings and rubber materials. And are integrally formed and used as a connecting member for various components such as a frame and an engine. The rubber material constituting the vibration isolating rubber member is desirably low in rigidity from the viewpoint of vibration and noise reduction. However, if the rigidity is too low, the steering stability of the automobile is adversely affected. For this reason, the anti-vibration rubber member is required to have a trade-off characteristic of reducing vibration and noise and ensuring steering stability.

  Here, vibration and noise are dynamic elements in a relatively high frequency region (100 Hz or more), while the support performance serving as an indicator of steering stability is a static spring constant (Ks) indicating support rigidity. ) Is better. On the other hand, the anti-vibration performance is a rubber having a small value of dynamic magnification (dynamic spring constant / static spring constant), which is a ratio between the static spring constant and the spring constant (dynamic spring constant (Kd)) when transmitting vibration. It is said that it is excellent as an anti-vibration rubber for automobiles.

Conventionally, various studies have been made to reduce the dynamic ratio. For example, the rubber composition contains carbon black having a large particle size, or the crosslinking agent (sulfur) is increased. As a result, the crosslink density of the rubber is increased to achieve a low dynamic magnification (see Patent Document 1).
JP-A-8-73658

  However, as described above, when the rubber composition contains carbon black having a large particle size, the elongation at break of the rubber is likely to be lowered, and the reinforcing property is deteriorated accordingly. On the other hand, when the crosslinking density is increased by increasing the amount of the crosslinking agent, there is a concern that the heat resistance is lowered.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vibration-isolating rubber member that achieves a low dynamic magnification without impairing reinforcement and the like and is excellent in vibration-isolating characteristics.

  In order to achieve the above object, the vibration isolating rubber member of the present invention is a vibration isolating rubber member in which an anti-vibration rubber layer is interposed between two upper and lower fixtures, the upper fixture side and the lower fixture side. A plate-like neodymium magnet is provided on each side of the fixture, and the same magnetic poles are arranged to face each other through the vibration-proof rubber layer.

  That is, the present inventors have a limit in achieving a reduction in dynamic magnification with a rubber composition and a composition without impairing reinforcing properties while aiming at further reduction in dynamic magnification of the vibration-proof rubber member. We thought that there was, and studied to achieve a low dynamic magnification in a manner different from the conventional method. In the course of the research, in the anti-vibration rubber member constituting the anti-vibration rubber layer between the upper and lower two attachments, between the upper attachment and the anti-vibration rubber layer, and between the lower attachment and the anti-vibration layer. Plate-like neodymium magnets are arranged in parallel between the rubber layers so that the same magnetic poles face each other through the anti-vibration rubber layer, and the repulsive force (magnetic force) between the same poles of the facing magnets. Was used to reduce the dynamic magnification of the anti-vibration rubber member. When a test was actually performed with such a configuration, when the static spring constant (Ks) accompanied by a large deformation was measured, the static spring constant was improved by the above repulsive force, and a large deformation was caused. When measuring the dynamic spring constant (Kd) not accompanied, the above-mentioned repulsive force effect was reduced, and as a result, it was found that high Ks and low Kd were achieved and a low dynamic magnification effect was obtained, and the present invention was achieved.

  The anti-vibration rubber member of the present invention has an anti-vibration rubber layer interposed between two upper and lower fixtures, each having a plate-like neodymium magnet on the upper fixture side and the lower fixture side. And are arranged so that the same magnetic poles face each other through the anti-vibration rubber layer. For this reason, the lowering of reinforcing properties and the like associated with achieving a low dynamic magnification is eliminated by the rubber composition and blend, and high Ks and low Kd are achieved by the magnetic force, thereby producing a low dynamic magnification effect.

  In particular, when the distance between the opposed neodymium magnets is set in the range of 5 to 20 mm, the low dynamic magnification effect can be obtained more favorably.

  Next, an embodiment of the present invention will be described.

  The anti-vibration rubber member of the present invention comprises, for example, as shown in FIG. 1, an anti-vibration rubber layer 5 interposed between an upper fixture 1a and a lower fixture 1b, and the upper fixture 1a. A plate-like neodymium magnet 2 is provided on each of the side and lower fixture 1b sides, and they are arranged in parallel so that the same magnetic poles face each other via the vibration-proof rubber layer 5 (in FIG. 1, N poles) The composition is that they are facing each other.

  As said fixture (upper fixture 1a and lower fixture 1b), what consists of raw materials which have rigidity, such as a metal, is normally used, for example, iron, copper, aluminum, magnesium, lead, tin, or these A material such as an alloy or stainless steel is used. Among these, iron is preferable because the magnetic force of the neodymium magnet 2 acts and the neodymium magnet 2 can be fixed (adhered) without an adhesive or the like.

  The rubber composition for forming the vibration proof rubber layer 5 is not particularly limited as long as it has vibration proof properties. For example, natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), isoprene. Rubber (IR), acrylonitrile butadiene rubber (NBR), carboxyl modified NBR, chloroprene rubber (CR), ethylene propylene rubber (EPM, EPDM), maleic acid modified EPM, butyl rubber (IIR), halogenated IIR, fluorine rubber (FKM) , Rubbers such as acrylic rubber and epichlorohydrin rubber are used singly or in combination of two or more. Of these, natural rubber is preferably used from the viewpoint of good vibration proofing properties. In addition, a reinforcing agent such as carbon black, a vulcanizing agent, a vulcanization accelerator, a lubricant, an auxiliary agent, a plasticizer, an antiaging agent, and the like are appropriately added to the rubber composition as necessary.

  And the anti-vibration rubber member of this invention can be manufactured as follows, for example. That is, first, the rubber composition for forming the vibration-proof rubber layer 5 is prepared by kneading. Next, a plate-like neodymium magnet 2 is attached to the upper fixture 1a and the lower fixture 1b so that the arrangement shown in FIG. 1 is obtained. In addition, when the material of the upper fixture 1a and the lower fixture 1b is a material which does not catch a magnet (material which a magnetic force does not act on), an adhesive is appropriately used when the neodymium magnet 2 is attached. . And the upper fixture 1a and the lower fixture 1b which stuck the said neodymium magnet 2 are arrange | positioned in a metal mold | die. At that time, as shown in FIG. 1, the neodymium magnet 2 needs to be arranged in parallel at a predetermined interval so that the same magnetic poles face each other. The shape, quantity, and magnetic pole of the neodymium magnet 2 are not particularly limited. Therefore, the entire facing surface of the upper fixture 1 a and the lower fixture 1 b may be the neodymium magnet 2. In FIG. 1, the N poles (positive electrodes) are opposed to each other, but the S poles (negative electrodes) may be opposed to each other. And the rubber composition obtained by the said preparation is inject | poured in the said metal mold | die (in the space between the upper fixture 1a and the lower fixture 1b), and it vulcanizes by heating (140-200 degreeC * 5) The anti-vibration rubber member as shown in FIG. 1 can be manufactured by removing the mold from the mold.

  The anti-vibration rubber layer 5 may be separately produced by press molding or the like. That is, the anti-vibration rubber layer 5 produced separately is adhered to the fixtures (1a, 1b) and the neodymium magnet 2 (adhered appropriately using an adhesive or the like), thereby providing an anti-vibration rubber as shown in FIG. You may manufacture a member.

  In the anti-vibration rubber member of the present invention obtained as described above, the distance d between the opposing neodymium magnets (the thickness of the anti-vibration rubber layer 5 between the magnets) is set in the range of 5 to 20 mm. This is preferable because the low dynamic magnification effect can be obtained better.

  The anti-vibration rubber member of the present invention is not limited to the shape shown in FIG. 1, and various types of vibration-proof rubber members may be used depending on the shape of the mold used at the time of manufacture and the shape of the fixture (1a, 1b). An anti-vibration rubber member can be manufactured. Specifically, the shape of the fixtures (1a, 1b) may be various shapes such as a cylindrical shape and a flat plate shape. Such a vibration-proof rubber member specifically includes bushes, engine mounts, etc. used in automobiles and transportation equipment (industrial transportation vehicles such as airplanes, forklifts, excavators, cranes, railway vehicles, etc.) It is suitably used as a vibration-proof member used in various machines such as motor mounts and industrial machines.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

  First, 100 parts by weight of natural rubber (hereinafter abbreviated as “parts”), 5 parts of zinc oxide, 1 part of stearic acid, 1 part of anti-aging agent (6PPD), 1 part of accelerator (CBS), sulfur A rubber composition (unvulcanized rubber) for forming the vibration-proof rubber layer 5 was prepared by kneading 2 parts with a kneader and a kneading roll machine. Next, an upper fixture 1a and a lower fixture 1b (both are made of iron and have a substantially disc shape of φ60 mm) are prepared. As shown in FIG. 1, disc-shaped neodymium magnets 2 (φ20 mm, Four pieces each having a thickness of 5 mm (made by Seiko Sangyo Co., Ltd.) were attached (attached by the magnetic force of the S pole surface). And as shown in FIG. 1, the upper fixture 1a and the lower fixture 1b are arrange | positioned in a metal mold | die so that the both neodymium magnet 2 sticking surfaces may oppose (distance d between the opposing neodymium magnets d: 15 mm), and the rubber composition prepared above was poured into the mold (the space between the upper fixture 1a and the lower fixture 1b) and vulcanized by heating (150 ° C. × 30 minutes). . As a result, a vibration-proof rubber layer 5 having a diameter of 50 mm was formed. Thereafter, this was removed from the mold to obtain an anti-vibration rubber member as shown in FIG.

[Comparative Example 1]
Without using a neodymium magnet, 30 parts of FT carbon black was added to the rubber composition for forming the vibration-insulating rubber layer 5 of Example 1 above. Otherwise, a vibration-proof rubber member was obtained in the same manner as in Example 1.

[Comparative Example 2]
Without using a neodymium magnet, 50 parts of FEF carbon black was further added to the rubber composition for forming the vibration-insulating rubber layer 5 of Example 1 above. Otherwise, a vibration-proof rubber member was obtained in the same manner as in Example 1.

[Comparative Example 3]
A neodymium magnet was not used. Otherwise, a vibration-proof rubber member was obtained in the same manner as in Example 1.

[Comparative Example 4]
Instead of using a neodymium magnet, an iron member (φ20 mm, thickness 5 mm) having the same shape was attached to the upper fixture 1a and the lower fixture 1b (adhesion with an adhesive). Otherwise, a vibration-proof rubber member was obtained in the same manner as in Example 1.

  Using the anti-vibration rubber members of Examples and Comparative Examples thus obtained, spring characteristics were measured and evaluated according to the following methods. The results are shown in Table 1 below.

[Spring characteristics]
The dynamic spring constant (Kd100) and the static spring constant (Ks) were measured according to JIS K 6394, respectively. Based on this value, the dynamic magnification (Kd100 / Ks) was calculated.

  From the above results, the example product is set in a region where the static spring constant is high using the repulsive force between the same poles of the magnets (N poles), and a low dynamic magnification is realized. It turns out that it is useful for the vibration proof rubber use of vehicles, such as a car.

  In contrast, in Comparative Examples 1 and 2, carbon black is contained in the rubber composition for forming the vibration-insulating rubber layer 5 in order to achieve a low dynamic magnification, but the static spring constant is set high. Therefore, it can be seen that there is a negative effect that the dynamic magnification increases with increasing the content. Moreover, the comparative example 3 product which did not use a neodymium magnet, and the comparative example 4 product which stuck the iron member of the same shape on the upper fixture 1a and the lower fixture 1b instead of the neodymium magnet are compared with an example product, It can be seen that the static spring constant is low.

It is sectional drawing which shows an example of the vibration proof rubber member of this invention.

Explanation of symbols

1a Upper fitting 1b Lower fitting 2 Neodymium magnet 5 Anti-vibration rubber layer

Claims (1)

  An anti-vibration rubber member in which an anti-vibration rubber layer is interposed between two upper and lower fixtures, and plate-like neodymium magnets are provided on the upper fixture side and the lower fixture side, respectively. An anti-vibration rubber member, wherein the same magnetic poles are arranged to face each other via a vibration rubber layer.

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