JP2004301196A - Vibration control rubber, and vibration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration control rubber, and a vibration control device for a vibrating body such as an engine to be installed on a vehicle or the like. <P>SOLUTION: This vibration control rubber comprises an outer cylinder provided with a flange that roughly perpendicularly overhangs upward, and an inner cylinder contained in the outer cylinder that directs the same axial direction as the outer cylinder. The flange of the outer cylinder is kept at a lower position than an upper end of the cylinder. A rubber elastic body is provided between an inner circumferential surface of the outer cylinder and a flange surface and an outer circumferential surface of the inner cylinder to be integrally vulcanization-bonded. A surface of the rubber elastic body held between a lower end of the inner cylinder and a lower end of the outer cylinder is recessed in curvature up to a lower surface of the flange or over it upward. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vibration damping rubber and a vibration damping device for attaching a vibration generator such as an engine to a body such as a vehicle.
[0002]
[Prior art]
Hereinafter, the present invention will be described by taking an engine as an example of a vibration generator. However, when an engine is mounted on a skeleton, it is required that the vibration generated by the engine be transmitted to an operator with a small amount. There is known a vibration isolator mainly made of rubber.
[0003]
As a conventional vibration isolator, one having a structure as shown in FIG. 4 (Patent Document 1) has been used. That is, a vibration isolating rubber B is mounted between the bracket 31 provided on the frame and the receiving bracket 32 with the bolts 33 and the nuts 34. The vibration isolating rubber B is opposed to a pair of upper and lower vibration isolating rubbers b1 and b2. It was used as FIG. 5 shows the anti-vibration rubber b1 alone, in which an inner cylinder 35 and an outer cylinder 37 with a flange 36 are opposed to each other, and a rubber elastic body 38 is formed by vulcanization bonding therebetween. A bracket 39 for mounting the engine is sandwiched between the flanges 36, 36 of the outer cylinder 37, and when vibration occurs, it is absorbed by the upper and lower rubber elastic bodies 38, 38.
[0004]
In such a vibration damping device, when absorbing the generated vibration, the rubber elastic bodies 38, 38 receive a compressive load from the vibrating mounting bracket 39. If it is not compressed, the support force of the bracket 39 is small and cannot be used. For this reason, the rubber elastic body 38, which is taller than the inner cylinder 35, is usually used. The rubber elastic body 38, 38 is compressed by this amount (38a) at the time of mounting to pre-compress the rubber elastic bodies 38, 38.
[0005]
[Patent Document 1] JP-A-8-326811
[0006]
However, there is still a point to be improved by such an improvement. In particular, when a rubber elastic body surface (hereinafter referred to as a fillet) 38p sandwiched between the lower end of the inner cylinder 35 and the lower end of the outer cylinder 37 of the vibration isolating rubbers b1 and b2 is used. , A tensile force is generated due to a difference in thermal expansion coefficient between the inner cylinder 35 and the outer cylinder 37 and the rubber elastic body 38, which acts on the rubber elastic body 38, and in particular, a tensile stress concentrates near the fillet 38p. , Resulting in poor durability.
[0007]
Therefore, in actual use, the lower end of the outer cylinder 37 is drawn (in the direction of the arrow) in the inner diameter direction in order to reduce the concentration of tensile stress. However, when the lower end of the outer cylinder 37 is squeezed in order to reduce the concentration of tensile stress, the number of working steps is increased and the cost is increased.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the above conventional technology, and has a special configuration in order to reduce the concentration of tensile stress on a rubber elastic body in the above-described vibration-isolating rubber and the vibration-isolating device. A rubber and a vibration isolator using the same are provided.
[0009]
[Means for Solving the Problems]
A first aspect of the present invention is an invention of an anti-vibration rubber, which includes an outer cylinder having a flange projecting at a substantially right angle on an upper part, and an inner cylinder which is accommodated in the outer cylinder and faces in the same axial direction as the outer cylinder. Vibration isolation by maintaining the flange of the outer cylinder at a lower position than the upper end of the inner cylinder, and integrating the rubber elastic body between the inner peripheral surface and the flange surface of the outer cylinder and the outer peripheral surface of the inner cylinder by vulcanization bonding The rubber is such that the surface of the rubber elastic body sandwiched between the lower end of the inner cylinder and the lower end of the outer cylinder is a curved portion that is recessed to a level equal to or higher than the lower surface of the flange.
[0010]
The second aspect of the present invention is an invention of an anti-vibration device using the anti-vibration rubber of the first invention, wherein the anti-vibration rubbers a1 and a2 of the first invention are used, and the lowermost ends of the anti-vibration rubbers a1 and a2. The anti-vibration rubbers A are configured to face each other, and the anti-vibration rubbers A are inserted between the brackets provided on the skeleton and the receiving brackets. A nut is screwed into the inserted bolt to compress the rubber elastic body of the vibration isolating rubber A, and the rubber elastic body sandwiched between the lower end of the inner cylinder and the lower end of the outer cylinder is fixed while being compressed. Things.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Here, focusing on the first invention, when the rubber elastic body is mounted on each bracket across the bracket for mounting the engine, the rubber elastic body is compressed and mounted. A concave curved portion is provided to be equal to or higher than the lower surface, and even when the rubber elastic body is compressed, such a fillet portion relaxes the tensile stress, and is usually oriented in the compression direction, and moreover, There is no wrinkle on the fillet surface, and there is no factor that reduces durability due to repeated use.
[0012]
More specifically, if the lower end of the outer cylinder is positioned lower than the lower end of the inner cylinder, the moving distance of the inner cylinder with respect to the compression is greater, and the compression force applied to the rubber elastic body can be increased. It is a thing. The amount of movement varies depending on the purpose of use and the size of the vibration isolating rubber, the relationship between the inner cylinder and the outer cylinder, and the like, but is usually 0.1 to 0. About three times is preferable. This is because the tensile stress acting on the fillet portion can be easily controlled, and the variation in durability can be reduced.
[0013]
It is preferable that the lower end of the inner cylinder be located between the lower end of the outer cylinder and the lower surface of the flange in relation to the fillet surface described above. Speaking of the fillet surface, it is a concave curved portion having a substantially arc shape, and the curvature on the inner cylinder side is preferably larger than the curvature of the outer cylinder. This is because the tensile stress acting on the fillet portion can be further reduced. In the pre-compression of the rubber elastic body, it is needless to say that the upper end of the rubber elastic body is located above the upper end of the inner cylinder, and the rubber elastic body in this portion can be compressed by the bracket.
[0014]
In the second invention, the vibration isolating rubbers are used to face each other, but the vibration generator mounting bracket sandwiched between the flanges is reliably supported by the rebound resilience of the pre-compression of the rubber elastic body. The resulting vibration is also absorbed by this. In the pre-compression of the rubber elastic body, the upper end of the rubber elastic body uses the vibration isolating rubber positioned above the upper end of the inner cylinder, so that it can be compressed to the upper end surface of the inner cylinder by the bracket and the fillet part The acting tensile force can be reduced, and the tensile stress at this portion can be reduced.
[0015]
【Example】
Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a sectional view of an anti-vibration rubber according to a first embodiment of the present invention. Reference numeral 1 denotes an outer cylinder, which is provided with a flange 2 projecting at a substantially right angle on an upper portion thereof. Reference numeral 3 denotes an inner cylinder which is housed in the outer cylinder 1 and faces in the same axial direction as the outer cylinder 1. Then, the flange 2 of the outer cylinder 1 is maintained at a position lower than the upper end of the inner cylinder 2, here slightly above the lower end of the inner cylinder 2, and the inner peripheral surface of the outer cylinder 1 and the surface of the flange 2 and the inner cylinder 3 The rubber elastic body 4 is integrated between the outer peripheral surfaces by vulcanization bonding.
[0016]
Characteristically, the surface 5p of the fillet 5 sandwiched between the lower end 3a of the inner cylinder 3 and the lower end 1a of the outer cylinder 1 is formed as a curved portion 6 that is recessed to the same level as or higher than the lower surface 2a of the flange 2. The curvature of the inner cylinder is larger than the curvature of the outer cylinder. Further, in this example, the lower end 1a of the outer cylinder 1 is positioned lower than the lower end 3a of the inner cylinder 3, and more specifically, the lower end 3a of the inner cylinder 3 is located below the lower surface 3a of the flange 3. It is located. In the rubber elastic body 4, the lower fillet 5 is made as described above, and further, an annular recess 4 a is formed around the inner cylinder 3 in the upper part, and subsequently, the upper part of the inner cylinder 3 is Also, a bulging portion 4b is formed in an annular shape further upward.
[0017]
Now, in such a vibration-proof rubber, since the rubber elastic body 4 is usually pre-compressed at the time of use, the inner cylinder 3 is used by being pressed from above. Therefore, the inner cylinder 3 must have a certain amount of movement, but the lower cylinder 1 has the lower end 1a positioned lower than the lower end 3a of the inner cylinder 3 so that the amount of movement is ensured. It is. When the inner cylinder 3 moves downward, a force acts in the pulling direction in the rubber elastic body 4, particularly near the fillet 5, but the surface 5 p of the fillet 5 is equal to or higher than the lower surface 2 a of the flange 2. Since the recessed curved portion 6 is formed, it does not work in the pulling direction but works only in the compression direction. For this reason, even if the rubber elastic body 4 is repeatedly deformed during use, cracking of the rubber elastic body from the fillet 5 does not occur. On the other hand, in the conventional anti-vibration rubber shown in FIG. 5, the fillet 5 is clearly in the tensile direction when used, and a crack is generated in the rubber elastic body from the portion where the fillet 5 is hung.
[0018]
Next, one example of the use of the vibration-proof rubber of the present invention is shown in FIG. Reference numeral 10 denotes a bracket fixed to the frame, and reference numeral 11 denotes a receiving bracket. A rubber elastic body 12 for vibration isolation is attached to the receiving bracket 11, and an engine mounting bracket 13 is sandwiched between the rubber elastic body 12 and the flange 3. The rubber elastic body 4 is fixed while compressing the rubber elastic body 4 by screwing a nut 15 to a bolt 14 inserted into the bolt. As described above, the amount of compression movement corresponds to the difference between the lower end 3a of the inner cylinder 3 and the lower end 1a of the outer cylinder 1, and the rubber elastic body 4 is compressed. Will be maintained on the compression side.
[0019]
FIG. 3 is a sectional view of a vibration isolator according to a second embodiment of the present invention. The feature of this vibration isolator is that two rubber isolators (a1 and a2) are used, and the fillet 5 side is opposed to form the rubber isolators A. Reference numeral 21 denotes a bracket provided on the frame, and the vibration-proof rubber A is inserted between receiving brackets 22 parallel to the bracket. In the vibration isolating rubber A, an engine mounting bracket 23 is sandwiched between the flanges 2 and 2, and a nut 25 is screwed into a bolt 24 that penetrates the brackets 21 and 22 and is inserted into the inner cylinder 3. The rubber elastic body 4 of the vibration-proof rubber A is mounted in a compressed state.
[0020]
The vibration-proof rubber A is as described in FIG. 2, and the rubber elastic body 4 is appropriately compressed and maintained, and the particularly problematic fillet part always maintains the compressed state. The compression force can be applied to cancel the tensile force and reduce the tensile stress applied to the fillet portion, and the durability of the vibration isolator itself has been improved.
[0021]
【The invention's effect】
The present invention is configured as described above. With respect to the vibration isolator, the engine mounting bracket is attached to the fixed bracket on the skeleton side via the vibration isolating rubber. It is to be mounted in a compressed state. As a result, the engine mounting bracket is pre-compressed in a direction opposite to the direction of the vibration load, and the vibration of the mounting bracket can be effectively absorbed.
[Brief description of the drawings]
FIG. 1 is a view showing a first rubber cushion according to the present invention.
FIG. 2 is a view showing an example of use of a vibration-proof rubber of the present invention.
FIG. 3 is a view showing a second vibration isolator of the present invention.
FIG. 4 is a diagram showing a conventional vibration isolator.
FIG. 5 is a view showing a conventional rubber cushion.
[Explanation of symbols]
1 ‥ outer cylinder,
1a ‥ Lower end of outer cylinder,
2 ‥ flange,
2a @ lower surface of flange,
3 ‥ inner cylinder,
3a ‥ Lower end of inner cylinder,
4 ‥ rubber elastic body,
4a @ annular depression,
4b bulge,
5 fillet,
5p fillet surface,
6 ‥ concave curved part,
21 ‥ Brackets provided on the skeleton,
22 ‥ bracket,
23 mm engine mounting bracket,
24 ‥ bolt,
25mm nut,
A. Anti-vibration rubber.

Claims (7)

The upper part consists of an outer cylinder with a flange projecting almost at a right angle, and an inner cylinder that fits in the outer cylinder and faces in the same axial direction as the outer cylinder.The flange of the outer cylinder is lower than the upper end of the inner cylinder. It is a vibration-proof rubber made by integrating a rubber elastic body by vulcanization bonding between the inner peripheral surface and the flange surface of the outer cylinder and the outer peripheral surface of the inner cylinder, and is sandwiched between the lower end of the inner cylinder and the lower end of the outer cylinder. A vibration-proof rubber, characterized in that the surface of the rubber elastic body is a curved portion that is recessed to a level equal to or higher than the lower surface of the flange. 2. The vibration damping rubber according to claim 1, wherein a lower end of the outer cylinder is located below a lower end of the inner cylinder. The anti-vibration rubber according to claim 1 or 2, wherein a lower end of the inner cylinder is located between a lower end of the outer cylinder and a lower surface of the flange. The anti-vibration rubber according to claim 1 or 3, wherein an upper end of the rubber elastic body is located above an upper end of the inner cylinder. 2. The vibration damping rubber according to claim 1, wherein a surface of the rubber elastic body sandwiched between a lower end of the inner cylinder and a lower end of the outer cylinder has a substantially arc shape. 6. The rubber cushion according to claim 5, wherein the curvature of the arc-shaped inner cylinder is larger than the curvature of the outer cylinder. An anti-vibration rubber A is formed by using the anti-vibration rubbers a1 and a2 according to claim 1 with the lowermost ends of the anti-vibration rubbers a1 and a2 facing each other, and the anti-vibration rubber is provided between a bracket provided on a body and a receiving bracket. Rubber A is inserted, and a nut is screwed into each bracket and a bolt inserted into the inner cylinder while sandwiching the vibration generator mounting bracket between the flanges to compress the rubber elastic body of the vibration isolating rubber A, and A vibration isolator characterized in that the surface of a rubber elastic body sandwiched between a lower end of a cylinder and a lower end of an outer cylinder is fixed while being compressed.

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