JP5121750B2 - Vibration isolator and its mounting structure - Google Patents

Description

  The present invention relates to a vibration isolating device enclosing a vibration damping liquid and a mounting structure thereof, and in particular, a technique for realizing a reduction in the installation space of the device without reducing the vibration isolating and damping functions against input vibration. This is a proposal.

  The inner peripheral surface of one end portion of the cylindrical member is liquid-tightly connected to the outer peripheral surface of the core member with a rubber elastic body, and the other end of the cylindrical member is liquid-tightly sealed with a diaphragm. A liquid chamber formed by enclosing a liquid in a space partitioned by a member is divided into two in the axial direction of the cylindrical member by a partition member, and is divided into a liquid chamber and a sub liquid chamber, and both the liquid chambers Various types of liquid-sealing vibration isolator that communicates with each other through a restriction passage have been proposed and are in use.

  Such a liquid seal vibration isolator is, for example, elastic deformation of a rubber elastic body, vibration between the main liquid chamber and the sub liquid chamber for vibration input such as engine vibration to the core member, Excellent vibration-proofing and vibration-damping functions can be achieved by the flow through the restricted passage.

  By the way, in recent years, without reducing various functions of such a liquid seal vibration isolator, in other words, without substantially changing the volume of the rubber elastic body, the volume of the liquid chamber, etc., the vibration isolator has a smaller space. For example, in a small FF vehicle, when the liquid seal vibration isolator is applied as a main engine mount, the vibration isolator is mounted on the right side of the vehicle body in the engine room. In this case, it is essential to avoid interference between the lower portion of the vibration isolator and a vehicle body side member such as a tire housing.

  In order to adapt to the conditions on the vehicle side, when reducing the contour size of the vibration isolator, particularly the lower part, it is usually necessary to reduce the volume of the liquid chamber of the vibration isolator. In addition to reducing the volume of the main and sub liquid chambers, the size of the restriction passage will be reduced. For example, the flow passage volume of the restriction passage will be attenuated due to liquid column resonance, etc. It becomes difficult to ensure, and the various functions as expected of the liquid seal vibration isolator cannot be sufficiently performed.

  In this regard, Patent Document 1 discloses a negative pressure introduction type liquid seal vibration isolator, in which the negative pressure working chamber is efficiently and compactly arranged in a limited space to determine the axial dimension of the liquid seal vibration isolator. A technique for reducing the size is described.

JP 2002-81491 A

  However, in the prior art described in Patent Document 1, since the outer cylinder configuration or structure itself is not specially changed, the liquid seal vibration isolator is used in the engine room of a small FF vehicle. Thus, when installing in a lower area of the installation space of the vibration isolator in a space where a vehicle body side member such as a tire housing projects obliquely downward, the axial dimension of the vibration isolator itself can be reduced. However, in order to prevent interference with the vehicle body side member, it is inevitable to install the vibration isolator up to a relatively high level in the engine room. For this reason, for example, it is arranged at a predetermined position. When connecting the core member to the engine to be connected, and connecting the cylindrical member to the vehicle body side, the size and weight of each connecting bracket must be increased, and the required strength The strength of the joint portion racquet in order to ensure, for example, there is a problem such that it is forced to increase the thickness, and the like.

  This invention makes it a subject to solve such a problem which conventional technology has, and the object is that the lower region of the installation space of the vibration isolator, such as in the engine room, Provided is a vibration isolator capable of reducing the installation space, and a mounting structure thereof, which can be disposed in close proximity to the bottom of the pressed space even when the vehicle body side member is narrowed by the protrusion. It is in.

  In the vibration isolator of the present invention, one of the rigid members connected to each of the vibration generation side member and the transmission side member is a core member located on the upper side, and the other is located on the lower side. As the cylindrical member, the inner peripheral surface of the upper end portion of the cylindrical member is liquid-tightly connected to the outer peripheral surface of the core member by a rubber elastic body, and the lower end of the cylindrical member is liquid-tightly sealed with a diaphragm, At least a diaphragm, a cylindrical member that may be covered with rubber, and a rubber elastic body, sometimes in addition to these, a core member that is exposed from the rubber elastic body, and is filled with liquid The liquid chamber is divided into two in the axial direction of the cylindrical member by a partition member, and is divided into a main liquid chamber and a sub liquid chamber, and both the liquid chambers are communicated by a restriction passage, At least in the circumferential direction In one place, for example, within the angle range of less than 180 ° around the central axis of the core member, within the vertical cross section including the central axis, the lower end portion of the cylindrical member is moved relative to the upper end portion of the cylindrical member. And stepping down toward the inside of the liquid chamber, for example, in a form perpendicular to the central axis, or in a form oblique to the central axis, and the step-down amount of the step-down portion, that is, the liquid chamber The amount of intrusion in the inner direction is made larger than the step-down amount in the portion opposite to the central axis.

Here, “at least one place in the circumferential direction of the tubular member” means a circumferential region corresponding to at least one side when the out-of-plane contour shape of the tubular member is a polygon. When the shape is circular, it means a circumferential region corresponding to an angle range of less than 180 °.
In addition, here, as described above, the “step-down amount” is positive as the amount of entering the liquid chamber in the inner direction. For example, when protruding in the outer direction of the liquid chamber, the amount of entering is negative. Here, the value is on the smaller side.

Accordingly, in this case, in the cylindrical member having a cylindrical shape as a whole, the outer contour shape of the bottom surface of the lower end portion thereof may be substantially D-shaped.
In addition, here, in the vertical cross section of the cylindrical member, one side of the lower end portion of the cylindrical member sandwiching the core member central axis may be a chamfered inclined surface where the lower end greatly approaches the central axis. .

  In such a vibration isolator, the cylindrical member has an out-of-plane contour shape that is circular or polygonal, and the center axis of the lower end portion of the cylindrical member is the center axis of the core member and the upper end portion of the cylindrical member. On the other hand, it is preferable to offset the small step-down amount in accordance with the step-down amount on the large amount side in order to simplify the structure of the cylindrical member and facilitate manufacture.

  Preferably, the basic shape of the cylindrical member is such that the out-of-plane contour size of the cylindrical member is smaller at the lower end portion of the cylindrical member than the upper end portion of the cylindrical member via a stepped portion. At least at one place in the circumferential direction of the cylindrical member, the step-down portion is stepped down toward the inside of the liquid chamber with respect to the upper end portion of the cylindrical member within a vertical cross section including the central axis of the core member. The step-down amount is made larger than the step-down amount at the portion opposite to the central axis of the core member.

  In the vibration isolator mounting structure of the present invention, the side with the large step-down amount of the lower end portion of the tubular member of any one of the above-described vibration isolator is on the outside of the vehicle, that is, the protruding side of the vehicle body side member. It is attached to the car body in a directed posture.

  In the liquid seal vibration isolator of the present invention, the vibration inputted thereto is vibrated based on the deformation of the rubber elastic body and the flow of the sealed liquid through the restricted passage between the main liquid chamber and the sub liquid chamber. It is possible to effectively dampen and attenuate the transmission side member.

  In addition, here, at least at one place in the circumferential direction of the cylindrical member, the lower end portion of the cylindrical member is stepped down toward the inside of the liquid chamber with respect to the upper end portion of the cylindrical member over a predetermined angle range, And since the step-down amount of this step-down part is made larger than the step-down amount at the part opposite to the central axis of the core member, the installation space such as the engine room where the projecting part of the vehicle body side member exists exists. When the vibration isolator is provided, the lower end portion of the cylindrical member is arranged so that the side with the large step-down amount faces the protruding portion on the vehicle body side. Can be effectively prevented from interfering with the vehicle body side protruding portion, and as a result, the vibration isolator is disposed sufficiently close to the bottom of the installation space even when the vehicle body side protruding portion exists. Setting Therefore, it is possible to arrange the vibration isolator close to the bottom of the installation space, as well as being able to arrange it properly in a small space where the lower area of the installation space is narrow. By doing so, the installation level of the apparatus can be effectively reduced as compared with the prior art.

  Accordingly, it is possible to reduce the size and weight of the connection bracket for connecting each of the core member and the cylindrical member of the vibration isolator to either the vibration generation side member or the vibration transmission side member. It is possible to eliminate an increase in bracket strength under the shortening of the moment arm or the like.

  By the way, in this device, the decrease in the volume of the liquid chamber accompanying the formation of the portion with the large step-down amount at the lower end portion of the cylindrical member does not face the vehicle body side protruding portion, in other words, interferes with the vehicle body side member. The volume of the rubber elastic body and the volume of the liquid chamber, especially the volume of the main liquid chamber, which has an influence on the basic performance of the vibration isolator, can be compensated by supplementing at other parts in the circumferential direction of the cylindrical member without fear. It is ensured as before, and the liquid seal vibration isolator can exhibit the same vibration isolation and vibration damping functions as those of the prior art.

Here, the out-of-plane contour shape of the cylindrical member can be a circular shape as well as a polygonal shape, and in any of these, as expected with respect to the input vibration in the central axis direction. The anti-vibration and damping function can be exhibited.
In addition to this, when the center axis of the lower end portion of the cylindrical member is offset from the center axis of the core member and the upper end portion of the cylindrical member to the side with the smaller step-down amount, a restriction passage is formed. The partition member thus formed can be formed in an annular shape or the like, and the partition member or the like used in the conventional vibration isolator can be diverted, so that an increase in device cost can be effectively suppressed.

  Further, the basic form of the cylindrical member is such that the planar contour dimension of the cylindrical member is reduced at the lower end portion of the cylindrical member through the step portion with respect to the upper end portion of the cylindrical member. At least at one place in the circumferential direction of the cylindrical member, the lower end portion of the cylindrical member is directed toward the inner side of the liquid chamber with respect to the upper end portion of the cylindrical member within a vertical cross section including the central axis of the core member. The step including the stepped portion and stepping down beyond the stepped portion, and including the stepped portion including the existing stepped portion at the portion opposite to the central axis of the core member. Also when the amount is larger than the down amount, it is possible to arrange the vibration isolator and the optimum position while avoiding interference with the vehicle body side protruding portion, as in the case of the structure in which the center is offset.

  Furthermore, according to any one of the above-described vibration isolator, according to the vibration isolator mounting structure, which is attached to the automobile body in a posture in which the side with the large step-down amount of the lower end portion of the cylindrical member faces the outside of the vehicle body, Mainly, the anti-vibration device has sufficient functions as expected, while the step-down portion sufficiently prevents the vibration-proof device from interfering with the vehicle body side protruding part such as a tire housing provided on the outside of the vehicle body. Can be demonstrated.

  As a result, the vibration isolator can be disposed sufficiently close to the bottom of the required installation space, thereby greatly reducing the installation level of the vibration isolator compared to the prior art. Therefore, it is possible to realize a light weight and a small size of the bracket for connecting the vibration isolator to the vibration generating side member and the vibration transmitting side member.

1 is a vertical sectional view showing an embodiment of the present invention together with a conventional technique. It is a comparison figure which shows the height of an apparatus installation level. It is a vertical sectional view showing other embodiments with the prior art.

  FIG. 1A is a vertical sectional view including a central axis of a core member, showing an embodiment of a vibration isolator according to the present invention, and FIG. 1B is shown for comparison, before taking countermeasures. It is the same sectional drawing of a conventional device.

In the figure, reference numeral 1 denotes the bottom of the installation space for the vibration isolator, and reference numeral 2 denotes the vehicle body side protruding portion that protrudes into the installation space.
Reference numerals 3 and 4 each denote a rigid member, and each of an upper core member and a lower cylindrical member connected to either a vibration generating member or a vibration transmitting member.

In the illustrated vibration isolator, the inner peripheral surface of the upper end portion 4a of the cylindrical member 4 positioned on the lower side is liquid-tightly connected to the outer peripheral surface of the core member 3 positioned on the upper side by a rubber elastic body 5. At the same time, the lower end of the cylindrical member 4 is liquid-tightly sealed with a diaphragm 6 mainly composed of rubber, and at least the diaphragm 6 and the rubber elastic body 5 in the figure are lined with the same kind of rubber. The liquid-tight 7 that is partitioned by the lower end portion 4b of the cylindrical member 4 and the rubber elastic body 5 and encloses the liquid is divided into two in the axial direction of the cylindrical member 4 by the partition member 8, and the main liquid The chamber 7a is divided into a sub liquid chamber 7b, and the two liquid chambers 7a and 7b are communicated with each other through a restriction passage 9, which is integrally formed with the partition member 8 in the drawing.
Of course, the restriction passage 9 can be formed separately from the partition member 8.

  In the liquid seal vibration isolator having such a structure, input vibration from, for example, an automobile engine to which the core member 3 is connected is selected under the rubber elastic body volume and the liquid chamber volume selected in advance. It is damped and attenuated by deformation, and is damped by liquid column resonance, flow resistance, etc. accompanying the flow of the sealed liquid through the restriction passage 9 between the main liquid chamber 7a and the sub liquid chamber 7b. As a result, transmission of engine vibration to the tubular member 4 and thus to the vehicle body as a vibration transmission side member is effectively prevented.

  By the way, here, as shown in FIG. 1B, the basic shape of the cylindrical member 4 whose outer contour shape can be circular or polygonal, the outer contour dimension of the cylindrical member is a cylindrical member. The lower end portion 4b of the cylindrical member 4 is smaller than the upper end portion 4a of the cylindrical member 4 via the stepped portion 10, and at least one location in the circumferential direction of the cylindrical member 4, for example, the center of the core member Within the angle range of less than 180 ° around the axis x, or at one or two sides of the cylindrical member 4 having a polygonal shape, in the vertical cross section including the central axis x, the cylindrical member As shown in FIG. 1A, the lower end portion 4 b includes the step portion 10 toward the inner side of the liquid chamber 7 with respect to the upper end portion 4 a of the cylindrical member 4, and exceeds the step portion 10. Step down and step down part 1 The total step-down amount δ of the opposite portion of the central axis x, is greater than the step down amount γ which also includes an existing step portion 10.

  In this case, in order to make the total step-down amount δ of the step-down portion 11 larger than the step amount α of the step portion 10 of the original cylindrical member 4, the liquid chamber 7 has a predetermined volume. Normally, as shown in the figure, the step-down amount γ at the opposite side of the center axis x is made smaller than the step amount α, whereby the center axis x1 of the lower end portion 4b of the cylindrical member 4 is As shown in FIG. 1 (a), the core member 3 and the central axis x of the cylindrical member upper end portion 4a are offset to the side where the step-down amount is small.

  Therefore, when the total step-down amount δ is particularly increased and the volume of the liquid chamber 7 is secured in the same manner, the cylindrical member lower end portion 4b on the opposite side of the central axis line x is formed at the upper end of the cylindrical member 4. The portion 4a may protrude toward the offset side of the central axis line x1, which means that the basic form of the tubular member 4 is such that the lower end portion 4b of the tubular member 4 is as shown in FIG. This is more often caused when the step portion 10 has the same size as the outer contour size of the upper end portion 4a without the step portion 10 interposed.

  And if it is set as the anti-vibration apparatus comprised as mentioned above, because of the formation of the step-down part 11 to the lower end part 4b of the cylindrical member 4, the vehicle body side protrusion part 2 of the lower end part of an anti-vibration apparatus and As shown in FIG. 2, the vibration isolator can be disposed closer to the bottom 1 of the installation space, for example. In connecting the core member 3 of the vibration isolator to the engine whose arrangement position is specified in advance and the cylindrical member 4 to the bottom 1 of the installation space via the connecting bracket, the engine side bracket EB In addition, any of the body side brackets (not shown) can be made small and lightweight, and the functions expected of the vibration isolator can be sufficiently developed without the need to increase the strength of the brackets. It can be.

  FIG. 2 shows the invention device of FIG. 1 (a) and the conventional device of FIG. 1 (b) superimposed on the basis of the bottom 1 of the installation space and the vehicle body side protruding portion 2. The device is indicated by a solid line, and the conventional device is indicated by a virtual line.

FIG. 3 (a) is a diagram showing another embodiment, which is about FIG. 1 (a) in order to prevent interference between the lower end portion 4b of the tubular member 4 and the vehicle body side protruding portion 2. FIG. As described above, the total step-down amount δ of the step-down portion 11 facing the outside of the vehicle body is determined from the step amount α of the original step portion 10 of the cylindrical member 4 shown in FIGS. 1 (b) and 3 (b). so as to be larger, is also greater than the step down amount γ of the opposite side portions of the center axis x, for example, the outer diameter a ^phi of the tubular member lower end portion 4b of the outer contour can be circular, FIG. 3 The liquid chamber volume is increased by increasing the diameter by twice the amount of offset of the central axis x2 with respect to the central axis x as compared to the lower end outer diameter ^Bφ of the original cylindrical member shown in (b). Accordingly, the volume of the restriction passage 9 is increased.

According to this, the installation level of the vibration isolator is the same as that of the prior art shown in FIG. 3B, but the length of the restriction passage 9 is lengthened to enhance the vibration damping function by liquid column resonance. In addition, the deterioration durability of the liquid can be increased under an increase in the amount of the sealed liquid.
However, when further improvement of the vibration isolation performance is not expected, it is preferable to select a decrease in the installation level of the vibration isolation device as shown in FIG.

  As shown in the figure, the vibration isolator described above has a posture in which the side of the lower end portion 4b of the tubular member 4 having the large step-down amount is directed toward the outside of the vehicle, in other words, toward the vehicle body side protruding portion 2. According to the mounting structure of the present invention attached to the above, it is possible to realize the reduction in size and weight of various connecting brackets as described above on the condition that the mode shown in FIG. .

DESCRIPTION OF SYMBOLS 1 Bottom 2 Car body side protruding part 3 Upper side core member 4 Lower side cylindrical member 4a Upper end part 4b Lower end part 5 Rubber elastic body 6 Diaphragm 7 Liquid chamber 7a Main liquid chamber 7b Sub liquid chamber 8 Partition member 9 Limiting passage 10 Step difference Part 11 Step down portion x, x1, x2 Center axis δ, γ Step down amount α Step amount

Claims (4)

One of the rigid members connected to each of the vibration generation side member and the transmission side member is a core member positioned on the upper side, and the other is a cylindrical member positioned on the lower side. The inner peripheral surface of the upper end portion of the member is liquid-tightly connected to the outer peripheral surface of the core member by a rubber elastic body, and the lower end of the cylindrical member is liquid-tightly sealed with a diaphragm, and at least the diaphragm and the cylindrical shape The liquid chamber divided by the member and the rubber elastic body and filled with the liquid is divided into two in the axial direction of the cylindrical member by the partition member, and divided into the main liquid chamber and the sub liquid chamber, and those An anti-vibration device that allows both liquid chambers to communicate with each other through a restriction passage,
In at least one place in the circumferential direction of the cylindrical member, in a vertical cross section including the central axis of the core member, the lower end portion of the cylindrical member is directed toward the inside of the liquid chamber with respect to the upper end portion of the cylindrical member. An anti-vibration device in which the step-down amount of the step-down portion is made larger than the step-down amount in the portion opposite to the central axis of the core member.   The cylindrical member has an out-of-plane contour shape that is circular or polygonal, and the center axis of the lower end portion of the cylindrical member has a smaller step-down amount than the center axis of the core member and the upper end portion of the cylindrical member. The anti-vibration device according to claim 1, wherein the anti-vibration device is offset.   The basic shape of the tubular member is such that the out-of-plane contour dimension of the tubular member is made smaller at the lower end portion of the tubular member than the upper end portion of the tubular member via a stepped portion. The lower end portion of the cylindrical member is stepped down toward the inner side of the liquid chamber with respect to the upper end portion of the cylindrical member in a vertical cross section including the central axis of the core member at at least one location in the circumferential direction of the member. In addition, the step-down amount of the step-down portion is greater than the step-down amount at the portion opposite to the central axis of the core member.   The vibration isolator mounting structure according to any one of claims 1 to 3, wherein the vibration isolator is attached to an automobile body in a posture in which a side with a large step-down amount at a lower end portion of the cylindrical member is directed toward the outside of the vehicle. Device mounting structure.

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