JP2011241931A - Vibration control device - Google Patents

Abstract

The present invention provides a vibration isolator capable of improving the vibration isolation effect while ensuring durability and reducing the resonance magnification to suppress vibration amplification.
A first vibration isolation base, a first outer cylinder, a first connection portion, an elastic portion, a second connection portion, a second outer cylinder and a second vibration isolation base are arranged in series. Therefore, the composite spring constant can be reduced, the vibration isolation effect can be improved, and the durability of the first vibration isolation base 13 and the like can be prevented from being lowered. Further, the masses M1, M2 and the spring constants K1, K2, K3 are set so that a plurality of resonances generated at different frequencies are coupled and the plurality of resonances interfere with each other. The resonance magnification of the first resonance can be reduced. Thereby, amplification of vibration in the resonance region can be suppressed.
[Selection] Figure 2

Description

  The present invention relates to an anti-vibration device in which the vibration generating side and the vibration receiving side are anti-vibrated and connected to each other. The present invention relates to a vibration control device that can be suppressed.

  Conventionally, vibration isolators such as a torque rod and a suspension arm that mutually connect the vibration generation side and the vibration receiving side with vibration isolation have been used. As such an anti-vibration device, the anti-vibration device includes a rod portion (connecting member) made of a metal material and anti-vibration bushes (first bush and second bush) connected to both ends of the rod portion. A bushing is known in which a rubber-like elastic body (first vibration isolation base, second vibration isolation base) is interposed between an inner cylinder and an outer cylinder (Patent Document 1).

  However, in the vibration isolator disclosed in Patent Document 1, a vibration isolating bush (first bush) is attached to the engine side (vibration generating side), and a vibration isolating bush (second bushing) is mounted on the vehicle body side (vibration receiving side). ), The rod part may be twisted near the anti-vibration bush (second bush). When the rod portion is twisted, a large load acts on the vibration isolating bush (second bush), and vibrations in the bounce direction and the pitch direction may be transmitted to the vehicle body side.

  In order to prevent this, Patent Document 2 discloses a vibration isolator that includes a rod portion that connects the engine side (vibration generation side) and the vehicle body side (vibration receiving side) with each other in a vibration-proof manner. And what has a vehicle body side rod and the elastic body interposed between these rods is disclosed. In the vibration isolator disclosed in Patent Document 2, the elastic body is bent and deformed to prevent the rod portion from being twisted, and as a result, vibrations and load transmission to the vehicle body due to the twist can be reduced.

JP-A-8-74933 JP 2008-169865 A

  By the way, there is a vibration transmission characteristic as one of the important characteristics of the vibration isolator that vibration-proofly connects the vibration generating side and the vibration receiving side. The vibration transfer characteristic has a deep relationship with the resonance frequency of the vibration isolator, and the resonance frequency of the vibration isolator is mainly determined by the mass of the rod constituting the vibration isolator and the spring constant of the elastic body. Since the conventional vibration isolator disclosed in Patent Document 2 is simply for the purpose of preventing the rod portion from being twisted, the elastic body interposed between the engine side rod and the vehicle body side rod is the rod portion. It was provided at the longitudinal intermediate position or at the longitudinal end of the rod portion (paragraph 0019 of Patent Document 2). When the elastic body is provided at an intermediate position in the longitudinal direction of the rod portion, the mass of the engine side rod and the vehicle body side rod are the same size, and when the elastic body is provided at the longitudinal end portion of the rod portion, the engine The mass of either the side rod or the vehicle body side rod is almost zero. Thus, the mass of the engine side rod and the vehicle body side rod changes depending on the position where the elastic body is provided.

  However, these masses and the springs of the vibration isolating bush (first bush) attached to the engine side (vibration generating side) and the vibration isolating bush (second bush) attached to the vehicle body side (vibration receiving side). No relationship with the constant was specified. As a result, in the vibration isolator disclosed in Patent Document 2, it is difficult to arbitrarily determine the resonance frequency. Therefore, it is difficult to reduce the response magnification at a specific frequency and suppress the vibration amplification in the resonance region (the region on the lower frequency side than the frequency at which the response magnification is 0 dB).

  The present invention has been made to solve the above-described problems, and can improve the vibration isolation effect while ensuring the durability, and reduce the response magnification (resonance magnification) at the resonance frequency to reduce the vibration in the resonance region. It aims at providing the vibration isolator which can suppress amplification.

Means for Solving the Problems and Effects of the Invention

  In order to achieve this object, according to the vibration isolator of claim 1, the first vibration isolation base, the first outer cylinder, the connecting member, the second member are provided between the first inner cylinder and the second inner cylinder. The outer cylinder and the second vibration-proof base are arranged in series. Moreover, as for a connection member, the 1st connection part, the elastic part, and the 2nd connection part are arranged in series. As a result, the total combined spring constant of the vibration isolator can be reduced as compared with the spring constant of the elastic portion. Although the elastic modulus of the elastic part is larger than that of the first anti-vibration base and the second anti-vibration base, the composite spring constant of the anti-vibration device can be made smaller than the spring constant of the elastic part. is there. In addition, since it is not necessary to extremely reduce the spring constants of the first vibration isolation substrate and the second vibration isolation substrate, it is possible to prevent the durability of the first vibration isolation substrate and the second vibration isolation substrate from being lowered, and thus to prevent the vibration. This has the effect of ensuring the durability of the vibration device.

  The masses of the first outer cylinder, the first connecting portion, the second outer cylinder and the second connecting portion, and the spring constants of the first vibration isolating base, the second anti-vibration base and the elastic portion are a plurality of frequencies generated at different frequencies. Since resonance is coupled and a plurality of resonances are set to interfere with each other, it is generated by the mass of the first outer cylinder, the first connecting part, the second outer cylinder, and the second connecting part and the combined spring constant. The resonance magnification (response magnification at the resonance frequency) of the first resonance can be made lower than the resonance magnification when there is no interference. This has the effect of suppressing vibration amplification in the resonance region.

  As described above, according to the vibration isolator described in claim 1, the vibration isolation effect can be improved while ensuring durability, and the resonance magnification of the first resonance is reduced by interfering a plurality of resonances. Thus, there is an effect of suppressing vibration amplification in the resonance region.

  According to the vibration isolator of the second aspect, since the first vibration isolation base is set to have a spring constant smaller than that of the second vibration isolation base, the resonance frequency of the second resonance generated on the high frequency side. Can be shifted to the low frequency side. As a result, the second resonance can be made to strongly interfere with the first resonance. As a result, in addition to the effect of the first aspect, there is an effect that the resonance amplification factor of the first resonance can be further reduced to improve the suppression effect of vibration amplification in the resonance region.

  According to the vibration isolator of claim 3, since the total mass of the first connecting portion and the first outer cylinder is set larger than the total mass of the second connecting portion and the second outer cylinder, The resonance frequency of the second resonance generated on the high frequency side can be lowered and shifted to the low frequency side. As a result, the second resonance can be made to strongly interfere with the first resonance. As a result, in addition to the effect of the first or second aspect, there is an effect that the resonance amplification factor of the first resonance can be further reduced to improve the suppression effect of vibration amplification in the resonance region.

  According to the vibration isolator of the fourth aspect, since the elastic portion is made of a rubber-like elastic material, it is possible to prevent the elastic deformation direction from being limited. Thereby, in addition to the effect of any one of claims 1 to 3, it is possible to prevent the direction of the twisting that can be suppressed from being limited, and to reduce the vibration and load transmission to the vehicle body side caused by the twisting.

It is the fragmentary sectional view which cut and represented a part of vibration isolator in one embodiment of this invention. It is a schematic diagram of the vibration isolator represented by an equivalent circuit. It is the fragmentary sectional view which cut and represented a part of conventional vibration isolator. It is a figure which shows the vibration transmission characteristic of this invention product and a conventional product. It is a figure which shows the vibration transmission characteristic of this invention product and a conventional product.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is a partial sectional view showing a part of a vibration isolator 1 according to an embodiment of the present invention. In addition, in FIG. 1, the torque rod for motor vehicles is shown in figure and the state which cut | disconnected the 2nd bush 20 to the axial direction is represented.

  As shown in FIG. 1, the vibration isolator 1 includes a first bush 10 attached to an unillustrated engine side (vibration generating side) and a second bush 20 attached to a vehicle body side (vibration receiving side) not shown. And a connecting member 30 that connects the first bush 10 and the second bush 20 to each other, and is configured to be able to regulate displacement in the roll direction of the engine and displacement in the front-rear direction during acceleration.

  As shown in FIG. 1, the first bush 10 includes a first inner cylinder 11 attached to the engine side, a first outer cylinder 12 positioned on the outer peripheral side of the first inner cylinder 11, and the first inner cylinders. 11 and the 1st outer cylinder 12, and the 1st anti-vibration base | substrate 13 comprised from a rubber-like elastic material is provided.

  The first inner cylinder 11 is made of a metal material in a cylindrical shape, and is fastened and fixed to the engine side by a bolt through an insertion hole formed in the center. The second outer cylinder 12 is formed of a metal material into a cylindrical shape, and is configured integrally with a connecting member 30 (first connecting portion 31) described later, and is positioned on the outer peripheral side of the first inner cylinder 11 at a predetermined interval. To do. The first anti-vibration base 13 connects the first inner cylinder 11 and the first outer cylinder 12 over the entire circumference.

  The second bush 20 includes a second inner cylinder 21 attached to the vehicle body side, a second outer cylinder 22 positioned on the outer peripheral side of the second inner cylinder 21, and the second inner cylinder 21 and the second outer cylinder. And a second vibration isolating base 23 made of a rubber-like elastic material.

  The second inner cylinder 21 is formed of a metal material in a cylindrical shape, and is fastened and fixed to the vehicle body side with a bolt through an insertion hole formed in the center. The second outer cylinder 22 is formed of a metal material in a cylindrical shape, and is formed integrally with a connecting member 30 (second connecting portion 32) described later, and is positioned at a predetermined interval on the outer peripheral side of the second inner cylinder 21. To do. The second vibration isolation base 23 connects the second inner cylinder 21 and the second outer cylinder 22 over the entire circumference in the circumferential direction.

  The connecting member 30 is made of a metal material in a rod shape and is integrally formed with the first outer cylinder 12, and is formed of a metal material in a rod shape and integrated with the second outer cylinder 22. The second connecting portion 32 is configured to be vulcanized and bonded to the opposing surfaces of the first connecting portion 31 and the second connecting portion 32, and is formed of a rubber-like elastic material. 2 and an elastic portion 33 interposed in the connecting portion 32. While the elastic part 33 is made of a rubber-like elastic material, the first connecting part 31 and the second connecting part 32 are made of a metal material, so that the elastic modulus of the elastic part 33 is the first connecting part 31 and the second connecting part 32. It is set smaller than the elastic modulus of the connecting portion 32. The masses of the first outer cylinder 12, the first connecting part 31, the second outer cylinder 22, and the second connecting part 32, and the spring constants of the first vibration isolating base 13, the second anti-vibration base 23, and the elastic part 33 are as follows. A plurality of resonances generated at different frequencies are coupled so that the plurality of resonances interfere with each other.

  Next, an equivalent circuit of the vibration isolator 1 configured as described above will be described with reference to FIG. FIG. 2 is a schematic diagram of the vibration isolator 1 represented by an equivalent circuit. The spring constant of the first anti-vibration base 13 is K1, the total mass of the first outer cylinder 12 and the first connecting portion 31 is M1, the spring constant of the second anti-vibration base 23 is K2, and the second outer cylinder 22 and the second The total mass of the two connecting portions 32 is M2, and the spring constant of the elastic portion 33 is K3.

  The spring constant K3 of the elastic portion 33 is set larger than the spring constant K1 of the first vibration isolation base 13 and the spring constant K2 of the second vibration isolation base 23. Thereby, the small vibration from the engine side can be suppressed by the first vibration isolation base 13. When the change in the attitude of the engine, such as sudden start or sudden braking, is large, the displacement can be suppressed by the elastic portion 33 after the first vibration isolation base 13 is crushed, and the vibration can be converged at an early stage. Moreover, since the elastic part 33 is comprised from the rubber-like elastic material, it can prevent that the direction which elastically deforms is limited. Accordingly, it is possible to prevent the connection member 30 from being twisted, to prevent the direction of the twisting that can be suppressed from being limited, and to reduce vibration and load transmission to the vehicle body side due to the twisting.

  Here, the first anti-vibration base 13, the first outer cylinder 12, the first connecting part 31, the second anti-vibration base 23, the second outer cylinder 11, the second connecting part 32, and the elastic part 33 are arranged in series. Therefore, when the total combined spring constant of the vibration isolator 1 including the first vibration isolator base 13, the second anti-vibration base 23, and the elastic portion 33 is Kt, Kt is expressed by Expression (1). By dividing the numerator and denominator of equation (1) by K1 · K2, the combined spring constant Kt is expressed by equation (2).

  As described above, since the spring constant K3 of the elastic portion 33 is set to be larger than the spring constant K1 of the first vibration isolation base 13 and the spring constant K2 of the second vibration isolation base 23, K3 of the denominator of the equation (2). / K1 and K3 / K2 are greater than 1. As a result, since the denominator of the equation (2) becomes larger than 3, it is clear that the combined spring constant Kt is smaller than 1/3 of the spring constant K3 of the elastic portion 33. Therefore, the composite spring constant Kt can be made smaller than the spring constant K3 of the elastic portion 33 without making the spring constants K1 and K2 of the first vibration isolation base 13 and the second vibration isolation base 23 extremely small. 1 can be improved. Further, since it is not necessary to extremely reduce the spring constants of the first vibration isolation base 13 and the second vibration isolation base 23, the durability of the first vibration isolation base 13 and the second vibration isolation base 23 is prevented from being lowered. As a result, the durability of the vibration isolator 1 can be secured.

  Next, referring to FIG. 3 to FIG. 5, the effect of the vibration isolator 1 (hereinafter referred to as “the product of the present invention”) in the present embodiment is the conventional vibration isolator 100 (hereinafter referred to as the “conventional product”). This will be explained in comparison with First, the configuration of the conventional product will be described. FIG. 3 is a partial cross-sectional view of a conventional vibration isolator 100 (conventional product) cut away.

  As shown in FIG. 3, the conventional vibration isolator 100 includes a first bush 110 attached to an engine side (vibration generating side) (not shown) and a second bush attached to a vehicle body side (vibration receiving side) (not shown). The bush 120 and a connecting member 130 that connects the first bush 110 and the second bush 120 to each other are provided, and are configured to be able to regulate displacement in the roll direction of the engine and displacement in the front-rear direction during acceleration. .

  As shown in FIG. 3, the first bush 110 includes a first inner cylinder 111 attached to the engine side, a first outer cylinder 112 positioned on the outer peripheral side of the first inner cylinder 111, and the first inner cylinders. 111 and a first outer cylinder 112, and a first anti-vibration base 113 made of a rubber-like elastic material.

  The first inner cylinder 111 is made of a metal material in a cylindrical shape, and is fastened and fixed to the engine side by a bolt through an insertion hole formed in the center. The second outer cylinder 112 is formed of a metal material in a cylindrical shape, is configured integrally with a connecting member 130 described later, and is positioned on the outer peripheral side of the first inner cylinder 111 at a predetermined interval. The first vibration isolation base 113 connects the first inner cylinder 111 and the first outer cylinder 112 over the entire circumference in the circumferential direction.

  The second bush 120 includes a second inner cylinder 121 attached to the vehicle body side, a second outer cylinder 122 positioned on the outer peripheral side of the second inner cylinder 121, the second inner cylinder 121 and the second outer cylinder. And a second anti-vibration base 123 made of a rubber-like elastic material.

  The second inner cylinder 121 is formed of a metal material in a cylindrical shape, and is fastened and fixed to the vehicle body side with a bolt through an insertion hole formed in the center. The second outer cylinder 122 is formed of a metal material in a cylindrical shape, is configured integrally with a connecting member 130 described later, and is positioned on the outer peripheral side of the second inner cylinder 121 with a predetermined interval. The second vibration isolation base 123 connects the second inner cylinder 121 and the second outer cylinder 122 over the entire circumference in the circumferential direction.

  The connecting member 130 is formed of a metal material in a rod shape and is integrally formed with the first outer cylinder 112 and the second outer cylinder 122, and connects the first bush 110 and the second bush 120 to each other. The anti-vibration device 100 (conventional product) is different from the anti-vibration device 1 (invention product) in that the connecting member 130 does not include an elastic portion.

  Next, the vibration transmission characteristics of the product of the present invention and the conventional product will be described with reference to FIGS. FIG. 4 shows the first outer cylinders 12 and 112 (when the vibration is inputted to the first inner cylinders 11 and 111 (first bushes 10 and 110) of the present invention and the conventional product by a vibration device (not shown). FIG. 5 is a diagram showing vibration transmission characteristics of the first bushes 10 and 110. FIG. 5 shows the first inner cylinders 11 and 111 (first bushes 10 and 110) of the present invention and the conventional product by a vibration device (not shown). ) Is a diagram showing the vibration transmission characteristics of the second outer cylinders 22 and 122 (second bushes 20 and 120) when vibration is input to). 4 and 5, the horizontal axis represents frequency (unit: Hz), and the vertical axis represents response magnification (unit: dB). The vibration transmission characteristics of the product of the present invention (vibration isolation device 1) are indicated by solid lines, and the vibration transmission characteristics of the conventional product (vibration isolation device 100) are indicated by broken lines.

  On the vibration generating side, as shown in FIG. 4, the vibration transfer characteristic of the product of the present invention shows two resonances. The first resonance on the low frequency side shows the peak P1, the frequency (resonance frequency) at the peak P1 is a, and the response magnification (resonance magnification) at the peak P1 is R1. As the frequency becomes higher than the peak P1, the response magnification decreases, and the frequency of the zero cross point C1 at which the response magnification becomes 0 dB is b. The second resonance on the high frequency side shows the peak P2, the frequency (resonance frequency) at the peak P2 is c, and the response magnification (resonance magnification) at the peak P2 is R2.

  On the other hand, the vibration transfer characteristic of the conventional product shows only resonance at the peak P3. The frequency (resonance frequency) at the peak P3 is d, and the response magnification (resonance magnification) at the peak P3 is R3. As the frequency becomes higher than the peak P3, the response magnification decreases, and the frequency of the zero cross point C2 at which the response magnification becomes 0 dB is e. The frequency a (resonance frequency) of the peak P1 of the product of the present invention is lower than the frequency d (resonance frequency) of the peak P3 of the conventional product, and the response magnification R1 (resonance magnification) of the peak P1 of the present product is the peak of the conventional product. It is smaller than the response magnification (resonance magnification) of P3. Further, the frequency b of the zero cross point C1 of the present invention product is smaller than the frequency e of the zero cross point C2 of the conventional product.

  On the vibration receiving side, as shown in FIG. 5, the vibration transfer characteristic of the product of the present invention shows two resonances. The first resonance on the low frequency side shows the peak P4, the frequency (resonance frequency) at the peak P4 is f, and the response magnification (resonance magnification) at the peak P4 is R4. As the frequency becomes higher than the peak P4, the response magnification decreases, and the frequency of the zero cross point C3 at which the response magnification becomes 0 dB is g. The second resonance on the high frequency side shows the peak P5, the frequency (resonance frequency) at the peak P5 is h, and the response magnification (resonance magnification) at the peak P5 is R5.

  On the other hand, the vibration transfer characteristic of the conventional product shows only resonance at the peak P6. The frequency (resonance frequency) at the peak P6 is i, and the response magnification (resonance magnification) at the peak P6 is R6. The response magnification decreases as the frequency becomes higher than the peak P6, and the frequency of the zero cross point C4 at which the response magnification becomes 0 dB is j. The frequency f (resonance frequency) of the peak P4 of the present product is lower than the frequency i (resonance frequency) of the peak P6 of the conventional product, and the response magnification R4 (resonance magnification) of the peak P4 of the present product is the peak of the conventional product. It is smaller than the response magnification R6 (resonance magnification) of P6. Further, the frequency g at the zero cross point C3 of the product of the present invention is smaller than the frequency j of the zero cross point C4 of the conventional product.

  Here, the spring constant of the conventional first anti-vibration base 113 is K1, the spring constant of the second anti-vibration base 123 is K2, and the total mass of the first outer cylinder 112, the second outer cylinder 122, and the connecting member 130 is Assuming M (where M≈M1 + M2), the composite spring constant K of the conventional product is expressed by equation (3), and the resonance frequency ω (= i) is expressed by equation (4).

  On the other hand, in the product of the present invention, two resonances occur at different frequencies. As a result of the analysis, the first resonance (peak P4) occurs depending on the composite spring constant Kt and the masses M1 and M2, and the second resonance (peak P5) depends on the spring constants K1 and K3 and the mass M1. It was speculated that this would occur. As a result, the resonance frequency ω (= f) of the first resonance (peak P4) is expressed by equation (5), and the resonance frequency ω (= h) of the second resonance (peak P5) is expressed by equation (6). expressed.

  In the product of the present invention, the mass M1 of the first outer cylinder 12 and the first connection part 31, the mass M2 of the second outer cylinder 22 and the second connection part 32, the first vibration isolation base 13, the second vibration isolation base 23 and the elasticity. The spring constants K1, K2, and K3 of the portion 33 are set so that the first resonance and the second resonance interfere with each other by coupling the first resonance and the second resonance generated at different frequencies. Therefore, the resonance magnification R4 of the first resonance generated by the masses M1 and M2 of the first outer cylinder 12, the first connecting part 31, the second outer cylinder 22 and the second connecting part 32, and the combined spring constant kt, The resonance magnification R6 of the conventional product can be reduced.

  Here, in the vibration transfer characteristic (see FIG. 5), there is an anti-vibration effect in a frequency region (anti-vibration effect region) higher than the zero-cross point C3 (frequency g), and a lower frequency region (resonance) than the zero-cross point C3 (frequency g). Vibration is amplified in the region. As described above, in the product of the present invention, by causing the second resonance to interfere with the first resonance, the resonance magnification R4 of the first resonance can be made lower than the resonance magnification R6 in the conventional product (R4 <R6). ). As a result, vibration amplification in the resonance region can be suppressed.

  Further, by causing the second resonance to interfere with the first resonance, the zero-cross point C3 (frequency g) of the product of the present invention is shifted to the lower frequency side than the zero-cross point C4 (frequency j) of the conventional product. (G <j).

  As described above, according to the vibration isolator 1, by interfering with a plurality of resonances, the resonance magnification R4 of the first resonance can be reduced, and the amplification of vibrations in the resonance region can be suppressed.

  Further, as described above, the resonance frequency ω (= f) of the first resonance (peak P4) is expressed by the equation (5), and the resonance frequency ω (= h) of the second resonance (peak P5) is expressed by the equation. It is represented by (6). In equation (6), since the spring constant K1 of the first vibration isolation base 13 is included in the numerator, the spring constant K1 of the first vibration isolation base 13 is set smaller than the spring constant K2 of the second vibration isolation base 23. As a result, the resonance frequency ω (= h) of the second resonance (peak P5) can be reduced. Accordingly, the second resonance and the first resonance can be caused to interfere more strongly, and the resonance magnification R4 of the first resonance can be further reduced by the interaction of the resonance. As a result, vibration amplification in the resonance region can be further suppressed. Similarly, the zero cross point C3 (frequency g) can be further reduced by causing the second resonance and the first resonance to interfere more strongly.

  Moreover, in Formula (6), since the total mass M1 of the 1st connection part 31 and the 1st outer cylinder 12 is contained in the denominator, the total mass of the 1st connection part 31 and the 1st outer cylinder 12 is included. By setting M1 to be larger than the total mass M2 of the second connecting portion 32 and the second outer cylinder 22, the resonance frequency ω (= h) of the second resonance (peak P5) can be reduced. Thereby, the interference between the second resonance and the first resonance can be further strengthened, and the resonance magnification R4 of the first resonance can be further reduced by the interaction of the resonance. As a result, vibration amplification in the resonance region can be further suppressed. Similarly, the zero cross point C3 (frequency g) can be further reduced by making the interference between the second resonance and the first resonance stronger.

  As described above, according to the vibration isolator 1, by setting the spring constant K1 of the first vibration isolation base 13 to be smaller than the spring constant K2 of the second vibration isolation base 23, a plurality of resonances are strongly interfered with each other, The resonance magnification R4 of the first resonance can be further reduced to improve the effect of suppressing vibration amplification in the resonance region.

  Further, according to the vibration isolator 1, the total mass M1 of the first connecting portion 31 and the first outer cylinder 12 is set to be larger than the total mass M2 of the second connecting portion 32 and the second outer cylinder 22. As a result, a plurality of resonances can be caused to interfere strongly, and the resonance magnification R4 of the first resonance can be further reduced to improve the suppression effect of vibration amplification in the resonance region.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed.

  For example, the numerical values (for example, the number and size of each component) given in the above embodiment are merely examples, and other numerical values can naturally be adopted.

  In the said embodiment, although the case where the elastic part 33 was comprised from a rubber-like elastic material was demonstrated, it is not necessarily restricted to this, It is possible to employ | adopt another member and site | part. Examples of the other member include a member made of a synthetic resin having a smaller elastic modulus than the first connecting portion 31 and the second connecting portion 32. As other parts, by forming a notch in a part of the connecting member 30 in the longitudinal direction, or by reducing the thickness of a part of the connecting member 30 in the longitudinal direction, The part which made the elasticity modulus smaller than 2 connection part 32 can be mentioned.

  In the above embodiment, the case where the elastic portion 33 made of a rubber-like elastic material is bonded to the opposing surfaces of the first connecting portion 31 and the second connecting portion 32 has been described. However, the thickness of a part of the connecting member 30 in the longitudinal direction may be reduced, and a rubber-like elastic material may be bonded to the part and laminated in a planar shape. Also in this case, since the elastic modulus of the elastic part can be made smaller than that of the first connecting part 31 and the second connecting part 32, the same action can be obtained.

  In the above-described embodiment, the case where the connecting member is formed in a rod shape has been described. However, the present invention is not necessarily limited to this, and it is not necessarily limited to this. Other connecting members can be employed as required.

  In the above embodiment, the first vibration isolation base 13 is vulcanized and bonded to the first outer cylinder 12, and the second vibration isolation base 23 is vulcanized and bonded to the second outer cylinder 22. Although the case where the second outer cylinder 22 is configured integrally with the first connecting portion 31 and the second connecting portion 32 has been described, it is not necessarily limited to this configuration. For example, a metal sleeve separate from the first outer cylinder 12 and the second outer cylinder 22 can be used. In this case, an integrally vulcanized molded product is formed by vulcanizing and bonding the first vibration isolation base 13 and the second vibration isolation base 23 between the first inner cylinder 11 or the second inner cylinder 21 and the metal sleeve. Then, the metal sleeve of the integrally vulcanized molded product is press-fitted into the first outer cylinder 11 and the second outer cylinder 21. Thereby, the setting which raises the spring constant of the 1st anti-vibration base | substrate 13 or the 2nd anti-vibration base | substrate 23 can be performed.

  In the above embodiment, the case where the first vibration isolating substrate 13 and the second vibration isolating substrate 23 are not formed with slits or curling portions has been described. However, the present invention is not necessarily limited to this, and the first vibration isolating substrate is not limited thereto. It is possible to tune the spring characteristics by forming slits or curling portions in the 13 or the second vibration isolating base 23.

  Although a description is omitted in the above embodiment, a member on the vibration receiving side is provided by providing a dynamic damper on the connecting member 30 and making the natural frequency of the vibration isolator 1 different from the natural frequency of the member on the vibration receiving side. It is also possible to suppress the resonance. In this case, the dynamic damper is provided in the first connecting portion 31 or the second connecting portion 32, but the mass of the dynamic damper is added to the mass of the first connecting portion 31 or the second connecting portion 32, so that the first The first resonance and the second resonance are set to interfere with each other.

  In the above embodiment, the case where the first bush 10 and the second bush 20 are formed in a bottomless cylindrical shape has been described. However, the present invention is not necessarily limited thereto, and Japanese Patent Application Laid-Open No. 2005-23973 and the like. As disclosed, it may be formed in a bottomed cylindrical shape (a bowl shape).

  In the above-described embodiment, an automobile torque rod is exemplified as the vibration isolator 1. However, the present invention is not only applied to the torque rod but also suitably used for, for example, a suspension arm. Moreover, it is not limited to the object for motor vehicles, It can apply as an object for trains or other various connection rods.

1 vibration isolator 10 first bush 11 first inner cylinder 12 first outer cylinder 13 first vibration isolation base 20 second bush 21 second inner cylinder 22 second outer cylinder 23 second vibration isolation base 30 connecting member 31 first Connecting part 32 Second connecting part 33 Elastic part

Claims (4)

In a vibration isolator comprising a first bush attached to the vibration generating side, a second bush attached to the vibration receiving side, and a connecting member for connecting the first bush and the second bush to each other.
The first bush is
A first inner cylinder attached to the vibration generating side;
A first outer cylinder located on the outer peripheral side of the first inner cylinder and connected to the connecting member;
A first vibration isolating base interposed between the first inner cylinder and the first outer cylinder and made of a rubber-like elastic material;
The second bush is
A second inner cylinder attached to the vibration receiving side;
A second outer cylinder located on the outer peripheral side of the second inner cylinder and connected to the connecting member;
A second vibration isolating base interposed between the second inner cylinder and the second outer cylinder and made of a rubber-like elastic material;
The connecting member is
A first connecting portion connected to the first outer cylinder;
A second connecting portion connected to the second outer cylinder;
The elastic member is connected to the first connecting part and the second connecting part, and has an elastic modulus smaller than that of the first connecting part and the second connecting part and larger than that of the first anti-vibration base and the second anti-vibration base. With an elastic part,
The masses of the first outer cylinder, the first connecting part, the second outer cylinder and the second connecting part, and the spring constants of the first vibration isolating base, the second anti-vibration base and the elastic part have different frequencies. The vibration isolator is configured such that a plurality of resonances generated in the above are coupled so that the plurality of resonances interfere with each other.   The anti-vibration device according to claim 1, wherein the first anti-vibration base has a spring constant set smaller than that of the second anti-vibration base.   The total mass of the first connecting portion and the first outer cylinder is set to be larger than the total mass of the second connecting portion and the second outer cylinder. The vibration isolator described in 1.   The vibration isolator according to any one of claims 1 to 3, wherein the elastic portion is made of a rubber-like elastic material.

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