JP2000120742A - Damping member and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent damping effect and vibration controlling effect by providing a spring in a rubber foamed body having low repellency. SOLUTION: This damping member is provided with a cylindrical rubber foamed body 2 having low repellency. The rubber foamed body 2 may be a cylindrical solid body, a hollow cylinder, or a solid square pole. A spring 1 is arranged within the rubber formed body 2. The expanding and contracting direction of the spring 1 is set to the same direction as the axial direction of the rubber foamed body 2. Since the rubber foamed body 2 has low repellency, it has viscosity and elasticity necessary for attaining the form restorability. Accordingly, a large vibration damping effect can be provided from the viscosity, and the restorability to the original form even if deformed can be provided by the elasticity. In addition to this, a large expansion ratio can be provided because of foaming, so that the expansion and contraction of the spring 1 is hardly disturbed. Thus, the spring 1 sufficiently functions, and the damping effect by the foamed body 2 and the vibration controlling effect by the spring 1 can be simultaneously provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping member which is used as a leg of a device or attached to a leg of a device to prevent vibration of the device from being transmitted to a floor and a method of manufacturing the same. It is.

[0002]

2. Description of the Related Art Conventionally, a vibration damping member such as rubber or a spring is sometimes attached to a leg of a device or a leg of the device so that vibration of the device or the like installed on the floor is not transmitted to the floor.

However, when rubber is used, the damping effect is large, the vibration of the device is reduced, and the vibration does not resonate. Therefore, it is not said that the vibration is amplified by the frequency.
The vibration isolation effect is small and the vibration is easily transmitted to the floor. In addition, even if a flexible material is used, it is very small, about 15% of the entire amount of deflection, and when it is bent, it becomes hard and vibration is easily transmitted to the floor. In addition, the spring constant of rubber is unexpectedly large, and when used with a spring, the spring must be designed in consideration of the spring constant of rubber, making it difficult to obtain the spring constant as designed. There is.

On the other hand, when a spring is used, on the contrary, the vibration-proofing effect is large, but the damping effect is small, and it is difficult for the vibration of the device or the like to stop. In addition, when the frequency of the vibration to be controlled is close to the resonance point, there is a problem unique to the spring that the vibration resonates and the vibration is amplified.

In view of the above, as a vibration damping member having both excellent damping effect and vibration damping effect, a combination of rubber and spring has been conventionally devised. For example, a vibration damping member in which a spring is embedded in a rubber column is considered. Although a vibration member and the like are known and satisfy both the damping effect and the vibration damping effect to some extent, the following problems have been pointed out.

As described above, since the expansion and contraction of rubber is extremely small (compression deformation tolerance is small) as compared with the expansion and contraction of a spring, it cannot be largely bent, and a sufficient amount of bending expected for a spring cannot be obtained. However, in order to secure a sufficient amount of deflection, the overall length must be long, the spring constant of the rubber will be added to the spring constant of the spring, making it difficult to design the spring. It was pointed out that the damping capacity was unexpectedly small and a sufficient damping effect could not be expected, and even if rubber and spring were combined, the advantages of both could not function effectively and complementarily, As a result, such a vibration damping member could not exhibit sufficient anti-vibration and damping effects as expected.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to develop a vibration damping member having both better damping effect and vibration damping effect than ever before, and to develop means for easily manufacturing such a vibration damping member. Is a problem to be solved by the present invention.

[0008]

According to a first aspect of the present invention, there is provided a vibration damping member characterized in that a spring (1) is provided in a rubber foam (2) having low resilience.

According to this, since the rubber foam (2) has a larger expansion and contraction rate than the conventional rubber material and has a very small spring constant, the spring (1) is contained in the rubber foam (2). When embedded is used, the spring (1) can be designed without considering the spring constant of the rubber foam (2). Moreover, in the case of the rubber foam (2), a large amount of bending can be obtained unlike conventional rubber, so that the same amount of bending as the bare spring (1) can be secured, and the spring (1) functions effectively. Become. Moreover, the rubber foam (2) having low resilience has a large damping effect. Therefore, both a damping effect and an anti-vibration effect are excellent, and a vibration damping member completely different from the conventional example can be obtained.

A second aspect of the present invention further restricts the vibration damping member according to the first aspect, wherein a through hole (3c) is formed in the rubber foam (2) in the spiral traveling direction of the spring (1). Is formed. "

In this case, the through hole (3c) in the rubber foam (2)
Due to the presence of the rubber foam (2), the rubber foam (2) is more easily flexed, and the effect of the spring (1) can be further exhibited.

[0013] Claim 3 relates to a method of manufacturing the vibration damping member, wherein "in a pre-foaming mold (4) having an inner size smaller than that of a final product,
Pre-foamed with spring (1), filled with resin (20) which is a material of rubber foam having low resilience, heated and pre-foamed, and then removed from pre-foaming mold (4)
(21) is placed in a mold (5) having the same internal dimensions as the product, and is heated and finally foamed. "

[0013] It is considered effective to make the rubber foam to improve the elasticity of the rubber. However, actually, a vibration damping member in which the foam rubber (2) and the spring (1) are integrated is manufactured. It is difficult to do. That is, the material resin of the liquid foamable rubber is poured while the spring is held in the mold,
When the mold is foamed by heating it and then removed from the mold after foaming, the shape of the rubber foam differs from the shape of the mold.
Shape and cannot be fixed. This is presumably because the heat transfer to the material resin becomes uneven due to the heat conduction of the internal spring and the like, and the degree of foaming partially differs.

Thus, in the present invention, it is possible to obtain a more uniform rubber foam (2) by performing foaming in two stages. Foam is homogeneous, so rubber foam
The shape of (2) is finished in a shape close to the cavity shape of the final mold (5), and does not become irregular.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to preferred embodiments. FIG. 1 is a diagram showing a vibration damping member of the present embodiment. In the figure, (2) is a cylindrical rubber foam having low resilience. Of course, the rubber foam (2) may be a solid cylinder, a cylinder or a solid prism, or a rubber foam (2).
In the case of a cylindrical body having a through hole (3c) formed therein, the forming direction of the through hole (3c) is formed in the axial direction, that is, in the spiral traveling direction of the spring (1). The through hole (3c) is 1 in the case of the embodiment shown in the figure.
Although it is a book, of course, the present invention is not limited to this, and a plurality of books may be formed.

(1) is a spring disposed in the rubber foam (2), and the spring (1) extends and contracts in the same direction as the axial direction of the rubber foam (2). Rubber foam (2)
At one end, a washer (3a) for inserting a screw on the device side when attaching the vibration damping member to the device etc. is attached, and at the other end, a metal plate (3b) serving as a bottom plate is attached. Installed.

The rubber foam (2) is a special material having low resilience, having viscosity and elasticity necessary for achieving shape resilience. Therefore, a large vibration damping ability is provided due to the viscosity, and even if it is deformed by elasticity, it has the ability to return to its original shape. In the case of the present invention, since it is foamed in addition to this, the expansion and contraction rate is large, and the spring (1)
Because it is hard to prevent the expansion and contraction of the spring, the spring works well,
The damping effect of the rubber foam (2) and the vibration damping effect of the spring (1) can be simultaneously obtained. Its mechanical properties are hardness (JIS-A): 25 to 65, tensile strength (MP
a): 6 to 16, elongation (%): 200 to 700, rebound resilience: 2 to 8. Incidentally, natural rubber has a rebound resilience of 40 to 90, and has a rebound resilience of 1/10 or less. This rubber foam (2) is formed mainly of norbornene rubber or butyl rubber.

In manufacturing the vibration damping member according to the present invention, first, as shown in FIG. 2A, a spring (1) is arranged in a pre-foaming mold (4) in which the inner space of the mold is smaller than the product. A resin (20) to be a material of a rubber foam is inserted. (4a) is a lid of the pre-foaming mold (4). The resin (20) used is clay-like and has the property of foaming and cross-linking when heated to form a low-rebound rubber foam (2). Here, FIG. 2 (B)
As shown in (2), after filling, the pre-foaming mold (4) is heated and foamed, but is not completely foamed by adjusting the degree of heating.

The pre-foamed product (21) is taken out of the pre-foaming mold (4) at a place where the pre-foaming and crosslinking have been performed to some extent, and as shown in FIG. 2 (C), a product having an internal space of the same shape as the final product. Put in mold (5). The pre-foamed body (21) removed from the pre-foaming mold (4) has a spring (1) embedded inside and does not conduct uniform heat, so the part where heat transfer is good is large. The swelling and, on the contrary, the place where heat transfer is poor are taken out of the pre-foaming mold (4) in a totally distorted shape due to insufficient swelling or a difference in the degree of progress of the crosslinking reaction.

(5a) is a lid of the product mold (5). After the pre-foam (21) having a distorted shape as a whole is loaded into the product mold (5) (if necessary, the washer (3a) and the metal plate (3b) are pre-formed into the product mold (5) The prefoamed body (21) may be completely foamed by heating as shown in FIG. 2 (D). In this case, the pre-foamed body (21) is heated in a state in which it is completely restrained in the cavity of the product mold (5), and the part where the foaming is delayed and the part where the crosslinking reaction is delayed gradually foam, The overall foaming rate becomes uniform. As a result, when the molded product is taken out of the product mold (5), the distortion of the pre-foamed body (21) is eliminated, and the molded product has a final shape close to the cavity shape of the product mold (5).

A washer (3a) and a metal plate (3b) are previously prepared in a product mold (5).
If it is loaded inside, the washer (3a) and the metal plate (3b) will adhere to both ends during the expansion process in the product mold (5). If the washer (3a) and the metal plate (3b) are not loaded in the product mold (5) in advance, the washer (3a) and the metal plate (3b) To complete it.

Since the foaming is performed in two stages as described above, heat is easily transmitted uniformly to each part of the material. Thereby, foaming is performed more uniformly, and a low-resilient rubber foam containing a spring having a desired shape can be obtained.

[0023]

As described above, in the present invention, a low rebound foam rubber is used, and a spring is buried in the inside, so that both a damping effect and an anti-vibration effect are excellent. The member could be developed and the means for producing such a damping member could be provided by two-stage foaming.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment.

FIG. 2 is a diagram for explaining manufacturing according to the embodiment.

[Explanation of symbols]

 (1) Spring (2) Rubber foam (3a) Washer (3b) Metal plate (bottom plate) (4) Pre-foam mold (4a) Lid of pre-foam mold (5) Product mold (5a) Product mold Mold lid (20) Clay-like resin used as material

Claims (3)

[Claims] 1. A vibration damping member characterized in that a spring is provided in a rubber foam having low resilience. 2. The vibration damping member according to claim 1, wherein a through hole is formed in the rubber foam body in a spiral traveling direction of the spring. 3. A pre-foaming mold having an inner size smaller than that of a final product is provided with a spring and a resin which is a material of a rubber foam having low resilience is filled therein, heated to pre-foam, and then pre-foamed. A method for manufacturing a vibration damping member, comprising: placing a pre-foamed body taken out of a foaming mold into a mold having the same size as a product and heating the foam to final foaming.