JP2012241730A - Vibration prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration prevention device in which durability can be improved while suppressing the generation of rubbing noise.SOLUTION: A third leg member 32 positioned between a pair of main leg members 31 is connected between an outer peripheral surface of an inner tubular member 1 and an inner peripheral surface of an outer tubular member 2. Therefore, even if relatively large displacement (e.g., rolling displacement of an engine) is inputted between the inner tubular member 1 and the outer tubular member 2, the generation of rubbing noise can be suppressed. A third leg connecting surface portion 13 of the inner tubular member 1 is formed while being curved in a concave circular-arc shape toward a direction away from the outer tubular member 2. Therefore, the occurrence of cracking can be suppressed by distributing stress of the third leg member 32. As a result, durability can be improved.

Description

  The present invention relates to a vibration isolator, and more particularly to a vibration isolator capable of improving durability while suppressing generation of a rubbing sound.

  As an example of an anti-vibration device that supports the engine in a vehicle, a pair of rubber cylinders between the outer peripheral surface of the inner cylinder member and the inner peripheral surface of the outer cylinder member, which are located on both sides of the inner cylinder member. The thing of the structure connected by a leg member is known (patent documents 1-4).

  This type of vibration isolator is shown in FIG. FIG. 12A is a front view of a conventional vibration isolator 800. FIG. The vibration isolator 800 connects the inner cylindrical member 810 and the outer cylindrical member 820 made of a metal material, and the outer peripheral surface of the inner cylindrical member 810 and the inner peripheral surface of the outer cylindrical member 820 and from a rubber-like elastic body. A pair of leg members 830, and a stopper member 840 protruding from the inner peripheral surface of the outer cylinder member 820.

  In this vibration isolator 800, when the engine is displaced in the roll direction due to turning of the vehicle or the like with the tip of the stopper member 840 in contact with the outer peripheral surface of the inner cylindrical member 810, the outer peripheral surface of the inner cylindrical member 810 and the stopper member A rubbing sound is generated between the tip of 840 and becomes an abnormal sound. Accordingly, the applicant of the present application has come up with a vibration isolator 900 having a structure in which the tip of the portion corresponding to the stopper member 840 is connected to the outer peripheral surface of the inner cylinder member 810 to form the third leg member 940 (not yet filed at the time of filing this application). Known). FIG. 12B is a front view of the vibration isolator 900.

Japanese Patent No. 2976968 JP 2005-249062 A JP 2005-172242 A

  However, in the above-described vibration isolator 900, the rubber volume of the third leg member 940 increases as compared with the stopper member 840 of the vibration isolator 800, and therefore the direction in which the third leg member 940 is compressed (FIG. 12B). A large strain is generated in the third leg member 940 when the inner cylinder member 810 is displaced downward). For this reason, the third leg member 940 is cracked, resulting in a deterioration in durability.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vibration isolator capable of improving durability while suppressing generation of rubbing noise.

Means for Solving the Problems and Effects of the Invention

  According to the vibration isolator of claim 1, in the structure in which the outer peripheral surface of the inner cylinder member and the inner peripheral surface of the outer cylinder member are connected by the pair of main leg members, Since the third leg member located at is connected between the outer peripheral surface of the inner cylinder member and the inner peripheral surface of the outer cylinder member, a relatively large displacement (for example, between the inner cylinder member and the outer cylinder member) Even when the engine roll displacement) is input, there is an effect that generation of rubbing noise can be suppressed.

  Further, the outer peripheral surface of the inner cylinder member is formed such that at least a portion to which the third leg member is connected is curved in an arc shape with the arc center located on the opposite side to the axis of the inner cylinder member when viewed in the axial direction. Therefore, the stress of the third leg member can be dispersed to suppress the generation of cracks, and as a result, the durability can be improved.

  That is, in the configuration in which the outer peripheral surface to which the third leg member among the outer peripheral surfaces of the inner cylindrical member is connected is curved in a convex arc shape toward the outer cylindrical member in the axial direction view, the third leg member is In a state where the inner cylinder member is displaced in the compressing direction, a stress is applied to a part of the third leg member (that is, a part in the vicinity of the outer peripheral surface of the inner cylinder member and the central part in the width direction of the third leg part). concentrate.

  On the other hand, in claim 1, the outer peripheral surface of the inner cylinder member to which the third leg member is connected is curved in an arc shape with the arc center located on the side opposite to the axis of the inner cylinder member. In the vicinity of the outer peripheral surface of the member, the stress of the third leg member can be dispersed and the stress can be reduced from being concentrated in the center portion in the width direction. As a result, the occurrence of cracks can be suppressed and durability can be improved.

  According to the vibration isolator of the second aspect, in addition to the effect of the vibration isolator of the first aspect, the main leg connecting surface portion, which is the outer peripheral surface of the inner cylinder member and to which the main leg member is coupled, and the third Since the intermediate surface portion located between the third leg connecting surface portion to which the leg member is connected is exposed to the outside, the main leg member and the third leg member can be separated. Thereby, even if a crack occurs in the third leg member, there is an effect that the crack can be prevented from proceeding to the main leg member. Further, according to claim 2, even when the intermediate surface portion is covered with the rubber film connected to the main leg member and the third leg member, the thickness dimension of the rubber film is about 2 mm or less. The rubber film can be a portion that does not contribute to the progress of cracks. That is, even if a crack occurs in the third leg member, the crack can be prevented from progressing to the main leg member.

  According to the vibration isolator according to claim 3, in addition to the effect of the vibration isolator according to claim 2, the third leg member is recessed on the side surface facing the space between the pair of main leg members. And a pair of leg recesses connected to the intermediate surface portion of the inner cylinder member or the rubber film, so that the stress of the third leg member is dispersed in the vicinity of the outer peripheral surface (third leg connection surface portion) of the inner cylinder member. There is an effect that it is possible to reduce the concentration of stress in the central portion in the width direction. Further, since the deformability of the third leg member in the vicinity of the outer peripheral surface (third leg connecting surface portion) of the inner cylinder member can be secured by the pair of leg recesses, the strain concentration portion is shifted to the outer cylinder member side accordingly. There is an effect that can be. As a result, the occurrence of cracks can be suppressed and durability can be improved.

  According to the vibration isolator of Claim 4, in addition to the effect which the vibration isolator of any one of Claim 1 to 3 shows, an inner cylinder member is an outer peripheral surface part to which a 3rd leg member is connected. And a pair of inner cylinder recesses positioned on both sides in the width direction of the third leg member, so that the area of the outer peripheral surface of the inner cylinder member (that is, the area of the connection surface to which the third leg member is connected) ) Can be increased. Therefore, in the vicinity of the outer peripheral surface of the inner cylinder member, there is an effect that the stress of the third leg member can be dispersed and the effect of reducing the stress concentration at the central portion in the width direction can be further exhibited. As a result, the occurrence of cracks can be suppressed and the durability can be further improved.

  In addition, in this way, by increasing the area of the outer peripheral surface of the inner cylinder member (that is, the area of the connection surface to which the third leg member is connected) by the pair of inner cylinder recesses, it acts on the connection surface accordingly. As a result, the connection state between the outer peripheral surface of the inner cylinder member and the third leg member can be easily maintained.

(A) is a front view of the vibration isolator in 1st Embodiment of this invention, (b) is sectional drawing of the vibration isolator in the Ib-Ib line | wire of Fig.1 (a). It is the partial expanded front view which expanded a part of vibration isolator shown to Fig.1 (a) partially. (A) is a front view of the vibration isolator in 2nd Embodiment, (b) is sectional drawing of the vibration isolator in the IIIb-IIIb line | wire of Fig.3 (a). It is the partial expanded front view which expanded a part of vibration isolator shown to Fig.3 (a) partially. (A) is a front view of the vibration isolator in 3rd Embodiment, (b) is sectional drawing of the vibration isolator in the Vb-Vb line | wire of Fig.5 (a). FIG. 6 is a partially enlarged front view in which a part of the vibration isolator shown in FIG. It is a characteristic view which shows the result of having analyzed the relationship between the displacement of an inner cylinder member and the largest principal distortion generate | occur | produced in a 3rd leg member by numerical calculation. It is an analysis figure which shows strain distribution of the vibration isolator analyzed by numerical calculation. It is an analysis figure which shows strain distribution of the vibration isolator analyzed by numerical calculation. It is a front view of the vibration isolator in 4th Embodiment. It is a front view of the vibration isolator in 5th Embodiment. (A) is a front view of the conventional vibration isolator, (b) is a front view of the vibration isolator which becomes the foundation of this application.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Fig.1 (a) is a front view of the vibration isolator 100 in 1st Embodiment of this invention, FIG.1 (b) is a cross section of the vibration isolator 100 in the Ib-Ib line | wire of Fig.1 (a). FIG. FIG. 2 is a partially enlarged front view in which a part of the vibration isolator 100 shown in FIG.

  As shown in FIGS. 1 and 2, a vibration isolator 100 is a vibration isolator for supporting and fixing an automobile engine and preventing transmission of the engine vibration to a vehicle body frame, and is attached to the engine side. An inner cylinder member 1, an outer cylinder member 2 attached to the vehicle body side, and an antivibration base 3 that connects the inner cylinder member 1 and the outer cylinder member 2 and is made of a rubber-like elastic body.

  The vibration isolator 100 supports the engine on the vehicle body in the state shown in FIG. That is, the vibration isolator 100 supports the engine on the vehicle body in such a direction that the action direction of gravity coincides with the vertical direction in FIG. Therefore, in the vibration isolator 100, the inner cylinder member 1 is displaced by a predetermined amount downward in FIG. 1A due to the weight of the engine, and the third leg member 32 is compressed between the inner cylinder member 1 and the outer cylinder member 2. The engine is supported on the vehicle body in a deformed state (so-called 1 W state).

  The inner cylinder member 1 is a member formed in a cylindrical shape from an aluminum alloy, and a through hole 11 having a circular cross section is formed through the axial center O at a substantially central portion of the inner cylinder member 1. Bolts for fastening and fixing the inner cylinder member 1 to engine-side parts are inserted into the through holes 11. The outer cylinder member 2 is a member formed in a cylindrical shape from a steel material, and surrounds the outer peripheral side of the inner cylinder member 1 and is disposed in a state where the axis O is substantially coincident with the inner cylinder member 1.

  In addition, the cross-sectional shape which cut | disconnected the inner cylinder member 1 and the outer cylinder member 2 by the plane perpendicular | vertical to the axial center O is made into the same shape along the axial center O (namely, in any location on the axial center O). . Therefore, such a cross-sectional shape coincides with the shape when viewed in the direction of the axial center O shown in FIGS. Moreover, the material of both the members 1 and 2 is an illustration, and steel material may be employ | adopted for the inner cylinder member 1, and steel material may be each employ | adopted for the outer cylinder member 2, or other materials (for example, resin material etc.), respectively. ) May be adopted.

  Here, the inner cylinder member 1 has a pair of main leg connecting surface portions 12 whose outer peripheral surfaces are arranged to face each other with the axis O interposed therebetween, and one end side of the pair of main leg connecting surface portions 12 (FIG. 1 ( a) Third leg connecting surface portion 13 located on the lower side), and stoppers that are positioned with the axis O between the third leg connecting surface portion 13 and are connected to the pair of main leg connecting surface portions 12 at both ends. It is comprised from the surface part 14 and a pair of intermediate surface parts 15 which are located between the main leg connection surface part 12 and the 3rd leg connection surface part 13, and are connected to them.

  The outer cylinder member 2 is formed in an oval shape when viewed in the direction of the axis O, and the inner peripheral surface corresponding to the oval straight line portion is the third leg connecting surface portion 13 of the inner cylinder member 1 and The stopper surface portions 14 are arranged in opposite directions.

  The anti-vibration base 3 is made of a rubber-like elastic body, and is a member that is vulcanized and bonded to the outer peripheral surface of the inner cylindrical member 1 and the inner peripheral surface of the outer cylindrical member 2. A main leg member 31, a third leg member 32 positioned between the pair of main leg members 31, and a lower covering member 33 and an upper covering member 34 that cover the inner peripheral surface of the outer cylinder member 2. .

  The main leg member 31 is formed in a substantially rectangular shape (that is, a straight line in which both side surfaces are substantially parallel) when viewed from the axial center O direction, and one end side in the longitudinal direction is the main leg connecting surface in the outer peripheral surface of the inner cylinder member 1. In addition to being connected to the portion 12, the other end in the longitudinal direction is connected to the inner peripheral surface of the portion of the outer cylinder member 2 that is arcuate as viewed in the axial center O direction.

  Here, as the pair of main leg connecting surface portions 12 of the inner cylinder member 1 moves from the third leg connecting surface portion 13 toward the stopper surface portion 14, the distance between the opposing surfaces as viewed in the direction of the axial center O (FIG. It is formed in an inverted C shape whose width (direction width) gradually increases. On the other hand, the pair of main leg members 31 are connected to the main leg connecting surface portion 12 in a direction in which the longitudinal direction is substantially vertical, and are formed in a substantially C shape when viewed in the axial center O direction.

  A rubber film that covers the stopper surface portion 14 of the inner cylinder member 1 with a certain thickness is connected to one end side in the longitudinal direction of the main leg member 31. The stopper surface portion 14 of the inner cylinder member 1 is formed such that the shape in the direction of the axis O is curved in a convex arc shape toward the inner peripheral surface of the outer cylinder member 2.

  The third leg member 32 is formed in a substantially rectangular shape in the axial center O direction (that is, a straight line in which both side surfaces are substantially parallel), and one end side in the longitudinal direction is the third leg in the outer peripheral surface of the inner cylinder member 1. While being connected to the connection surface portion 13, the other end in the longitudinal direction is connected to the inner peripheral surface of the portion of the outer cylinder member 2 that is linear when viewed in the axial center O direction.

  Here, the third leg connecting surface portion 13 of the inner cylinder member 1 is formed to be curved in an arc shape in which the center of the arc is located on the side opposite to the axis O of the inner cylinder member 1 when viewed in the direction of the axis O. . That is, the inner cylinder member 1 is formed such that the outer peripheral surface portion to which the third leg member 32 is connected is recessed in a shape that is concave from the inner peripheral surface of the outer cylinder member 2 toward the axis O of the inner cylinder member 1. Is done.

  Moreover, as for the inner cylinder member 1, the intermediate surface part 15 located between the main leg connection surface part 12 and the 3rd leg connection surface part 13 is exposed outside. That is, one end side in the longitudinal direction of the main leg member 31 and one end side in the longitudinal direction of the third leg member 32 are not connected to the intermediate surface portion 15 of the inner cylinder member 1, but the main leg connecting surface portion 12 and the third leg connection. Only the surface portion 13 is connected.

  The lower covering member 33 and the upper covering member 34 are members that cover the inner peripheral surface of the outer cylinder member 2, and the lower covering member 33 includes the other end side in the longitudinal direction of the main leg member 31 and the third leg member 32. To the other end in the longitudinal direction. Further, the upper covering member 34 is connected to the other end in the longitudinal direction of the pair of main leg members 31, and receives the stopper surface portion 14 of the inner cylinder member 1, thereby exerting a buffering action during the stopper function.

  The radius of the portion where the lower covering member 33 and the other end in the longitudinal direction of the third leg member 32 are continuous is such that the one end in the longitudinal direction of the third leg member 32 is the third leg connecting surface portion when viewed in the direction of the axis O. The value is set to a value sufficiently larger than the radius of the portion connected to 13 (5 or more times in the present embodiment). As a result, the third leg member 32 has a larger width dimension (the width in the left-right direction in FIG. 1A) at the other end in the longitudinal direction.

  Since the members 31 to 34 are configured as described above, the first anti-vibration base 3 has a first straight portion 41 formed as a space between the main leg member 31 and the upper covering member 34. A pair of second straight portions 42 formed as a space between the main leg member 31 and the third leg member 32 are formed penetrating in the direction of the axis O. .

  As described above, according to the vibration isolator 100 in the present embodiment, in the structure in which the outer peripheral surface of the inner cylindrical member 1 and the inner peripheral surface of the outer cylindrical member 2 are connected by the pair of main leg members 31, Since the third leg member 32 positioned between the pair of main leg members 31 is connected between the outer peripheral surface of the inner cylindrical member 1 and the inner peripheral surface of the outer cylindrical member 2, for example, the roll displacement of the engine is reduced. Even if it is input, the generation of a rubbing sound can be suppressed.

  Further, the outer peripheral surface of the inner cylinder member 1 has an arc on the side opposite to the axis O of the inner cylinder member 1 when the third leg connecting surface portion 13 to which the third leg member 32 is connected is viewed in the direction of the axis O. Since the center is curved in a circular arc shape, the stress of the third leg member 32 can be dispersed to suppress the occurrence of cracks, and as a result, the durability can be improved.

  That is, the third leg connecting surface portion 13 of the inner cylinder member 1 has, for example, an arc shape (outer cylinder member 2) whose arc center is located on the same side as the axis O of the inner cylinder member 1 when viewed in the direction of the axis O. (See FIG. 12 (b)), the third leg member 32 is in a 1W state in which the inner cylinder member 1 is displaced in the direction in which the third leg member 32 is compressed or more. Is compressed and deformed, a part of the third leg member 32 (that is, in the vicinity of the third leg connecting surface portion 13 of the inner cylinder member 1 and in the width direction of the third leg member 32 (FIG. 1 (a) and Stress concentrates in the left and right direction in FIG.

  On the other hand, the third leg connecting surface portion 13 of the inner cylinder member 1 is curved in an arc shape in which the arc center is located on the side opposite to the axis O of the inner cylinder member 1, thereby In the vicinity of the tripod connecting surface portion 13, the stress of the third leg member 32 can be dispersed to reduce the concentration of stress in the central portion in the width direction (the left and right directions in FIGS. 1A and 2). As a result, it is possible to suppress the occurrence of cracks in the third leg member 32 and improve durability.

  As described above, in the third embodiment, the stress is easily concentrated on the third leg member 32 in the vicinity of the third leg connecting surface portion 13, and even if a crack occurs at this stress concentration location, Since the intermediate surface portion 15 of the cylindrical member 1 is exposed to the outside, the one end side in the longitudinal direction of the main leg member 31 and the one end side in the longitudinal direction of the third leg member 32 can be separated. Proceeding to the main leg member 31 can be prevented.

  Next, the vibration isolator 200 according to the second embodiment will be described with reference to FIGS. 3 and 4. In the first embodiment, the case where both side surfaces of the third leg member 32 are formed to be flat has been described. However, the third leg member 232 according to the second embodiment has a pair of leg recesses on both side surfaces. 232a is set. In addition, the same code | symbol is attached | subjected about the part same as 1st Embodiment, and the description is abbreviate | omitted.

  3A is a front view of the vibration isolator 200 according to the second embodiment, and FIG. 3B is a cross-sectional view of the vibration isolator 200 taken along the line IIIb-IIIb in FIG. 3A. . FIG. 4 is a partially enlarged front view in which a part of the vibration isolator 200 shown in FIG.

  As shown in FIGS. 3 and 4, in the vibration isolator 200 according to the second embodiment, a leg recess 232 a is provided in the third leg member 232 of the vibration isolating base 203. The leg recess 232a is a substantially semicircular recess formed by being curved in an arc shape when viewed in the direction of the axis O, and is formed on both side surfaces of the third leg member 232 (a space between the pair of main leg members 31). And are smoothly connected to the intermediate surface portion 15 of the inner cylinder member 1.

  As a result, in the vicinity of the third leg connecting surface portion 13 of the inner cylindrical member 1, the stress of the third leg member 232 is dispersed, and the stress is concentrated in the central portion in the width direction (the left and right directions in FIGS. 3A and 4). Can be reduced.

  Further, since the deformability of the third leg member 232 in the vicinity of the third leg connecting surface portion 13 of the inner cylinder member 1 can be ensured by the pair of leg recesses 232a, the strain concentration portion correspondingly becomes the outer cylinder member 2 side ( The other end of the third leg member 232 in the longitudinal direction can be shifted to the lower side of FIGS. 3A and 4. Since the rubber volume (volume) is increased by the lower covering member 33 on the other end side in the longitudinal direction of the third leg member 232, the occurrence of cracks is suppressed by shifting the strain concentration portion to the portion side. Thus, the durability can be improved.

  The radius of the leg recess 232a is preferably set in the range of 5% to 35% of the width dimension of the third leg member 232 (the width in the horizontal direction in FIGS. 3A and 4). Further, the cross-sectional shape obtained by cutting the vibration isolation leg 230 along a plane perpendicular to the axis O is the same along the axis O (that is, at any location on the axis O). Therefore, such a cross-sectional shape coincides with the shape when viewed in the direction of the axial center O shown in FIGS.

  Next, with reference to FIG. 5 and FIG. 6, a vibration isolator 300 according to the third embodiment will be described. In the first embodiment, the case has been described in which the third leg connecting surface portion 13 of the inner cylinder member 1 is formed into a shape that is curved by one arc and does not have unevenness. However, the inner cylinder in the third embodiment The third leg connecting surface 313 of the member 301 is formed in a shape in which a plurality of recesses (inner cylinder recesses 313a) are provided in one arc. In addition, the same code | symbol is attached | subjected about the part same as 1st Embodiment, and the description is abbreviate | omitted.

  Fig.5 (a) is a front view of the vibration isolator 300 in 3rd Embodiment, FIG.5 (b) is sectional drawing of the vibration isolator 300 in the Vb-Vb line | wire of Fig.5 (a). . FIG. 6 is a partially enlarged front view in which a part of the vibration isolator 300 shown in FIG.

  As shown in FIGS. 5 and 6, in the vibration isolator 300 according to the third embodiment, a pair of inner cylinder recesses 313 a is provided in the third leg connection surface portion 313 of the inner cylinder member 301. The inner cylinder recess 313a is a substantially semicircular recess formed by being curved in an arc shape when viewed in the direction of the axis O, and is set at both ends of the third leg connecting surface portion 313, respectively, and the inner cylinder member 1 to the intermediate surface portion 15 smoothly.

  The third leg member 332 of the anti-vibration base 303 is a third leg connecting surface portion 313 of the inner cylinder member 301 with one end side in the longitudinal direction (vertical direction in FIG. 5A) exposing the intermediate surface portion 15 to the outside. Thus, it is connected to a range including the inner cylinder recess 313a.

  Thereby, the area of the 3rd leg connection surface part 313 of the inner cylinder member 301 (namely, the area of the connection surface to which the longitudinal direction one end side of the 3rd leg member 332 is connected) can be increased. Therefore, in the vicinity of the third leg connecting surface portion 313 of the inner cylinder member 301, the stress of the third leg member 332 is dispersed, and the stress is concentrated in the central portion in the width direction (the left and right directions in FIGS. 5A and 6). Can be reduced. As a result, the occurrence of cracks can be suppressed and durability can be improved.

  Further, in this way, by setting the pair of inner cylinder recesses 313a in the third leg connecting surface portion 313, the area of the connecting surface to which the third leg member 332 is connected (that is, the vulcanization adhesion area) is increased. be able to. Accordingly, since the stress acting on the third leg connecting surface portion 313 can be suppressed accordingly, the connection between the third leg connecting surface portion 313 of the inner cylinder member 301 and one end side in the longitudinal direction of the third leg member 332 is possible. The state can be easily maintained. In other words, it is possible to prevent the longitudinal end of the third leg member 332 from completely separating from the third leg connecting surface portion 313 of the inner cylinder member 301.

  The radius of the inner cylindrical recess 313a is in the range of 5% to 35% of the width-direction dimension of the third leg member 332 (FIG. 5 (a) and the horizontal width in FIG. 6) (that is, the leg in the second embodiment). It is preferable to set it to be equivalent to the case of the recess 232a. Further, the cross-sectional shape obtained by cutting the inner cylinder member 301 along a plane perpendicular to the axis O is the same along the axis O (that is, at any location on the axis O). Therefore, such a cross-sectional shape coincides with the shape when viewed in the direction of the axial center O shown in FIGS.

  Next, with reference to FIG. 7 to FIG. 9, the result of analyzing the strain characteristics of the vibration isolation devices 100 to 300 described in the first to third embodiments will be described. FIG. 7 is a characteristic diagram showing the relationship between the displacement of the inner cylindrical member 1,301 analyzed by numerical calculation and the maximum principal strain generated in the third leg members 32, 232, 332. As shown in FIG.

  The characteristic diagram shows the result of modeling the vibration isolators 100 to 300, 900 and analyzing them by numerical calculation (finite element method analysis). The horizontal axis represents the displacement value of the inner cylindrical member 1,301, and the vertical axis Represents the value of the maximum principal strain [%] generated in the third leg members 32, 232, 332, respectively. The characteristic L1 is the vibration isolator 100 in the first embodiment (see FIG. 1), the characteristic L2 is the vibration isolator 200 in the second embodiment (see FIG. 3), and the characteristic L3 is the third. This corresponds to the vibration isolator 300 (see FIG. 5) in the embodiment.

  Here, the direction of displacement of the horizontal axis is the no-load state (that is, the state shown in FIGS. 1A, 3A, and 5A) as the origin, and the inner cylinder member 1 from the origin position. , 301 compresses the third leg members 32, 232, 332 in the longitudinal direction (for example, the vertical direction in FIG. 1A) between the third leg connecting surface portions 13, 313 and the inner peripheral surface of the outer cylinder member 2. This corresponds to the direction of deformation (ie, downward in the direction of gravity when mounted on the vehicle, for example, downward in FIG. 1A).

  Further, the horizontal axis displacement X1 compresses the length of the third leg members 32, 232, and 332 in the longitudinal direction (for example, the vertical direction in FIG. 1A) to 75% with respect to the unloaded state (that is, the inner cylinder). The value of the displacement of the inner cylinder member 1,301 is defined as 75% of the facing distance between the third leg connecting surface portions 13, 313 of the member 1 and the inner peripheral surface of the outer cylindrical member 2). Corresponding to Further, the displacement X2 corresponds to 50%.

  For comparison, in the characteristic diagram, as a conventional product, the relationship between the displacement of the inner cylindrical member 810 in the vibration isolator 900 (see FIG. 10) and the maximum principal strain generated in the third leg member 940 is shown as a characteristic L4. As shown. Since the direction of displacement and the displacements X1 and X2 are the same as those of the vibration isolators 100 to 300, the description thereof is omitted.

  As shown in FIG. 7, in the displacement range up to the displacement X1, there is a large difference in the value of the maximum principal strain between the vibration isolator 900 (characteristic L4) and the vibration isolator 100 to 300 (characteristics L1 to L3). It has almost the same characteristics.

  In a displacement range larger than the displacement X1, the increase rate of the maximum principal strain in the vibration isolation devices 100 to 300 is smaller than the increase rate of the maximum principal strain in the vibration isolation device 900. The value of the maximum principal strain in the vibration isolator 100 to 300 is approximately 30% to 35% smaller than the value of the maximum principal strain. Thereby, the effect by the 3rd leg connection surface part 13,313 (inner cylinder recessed part 313a) and the leg recessed part 232a of the inner cylinder member 1,301 is confirmed.

  Further, in a displacement range larger than the displacement X1, the value of the maximum principal strain in the vibration isolation devices 200 and 300 is smaller than the value of the maximum principal strain in the vibration isolation device 100. For example, in the displacement X2, the vibration isolation device With respect to the value of the maximum principal strain at 100, the value of the maximum principal strain in the vibration isolators 200 and 300 is about 5% smaller. Thereby, the effect by having set the inner cylinder recessed part 313a and the leg recessed part 232a with respect to the inner cylinder member 1 and the 3rd leg member 32 of the vibration isolator 100 is confirmed.

  8 and 9 are analysis diagrams showing strain distributions of the vibration isolation devices 100 to 300 and 900 analyzed by numerical calculation.

  The analysis diagram shows the result of modeling the vibration isolators 100 to 300, 900 and analyzing them by numerical calculation (finite element method analysis). The inner cylinder members 1, 301, 810 are displaced up to the displacement X2 (see FIG. 7). The magnitude of the maximum principal strain [%] in the displaced state is illustrated by color shading. In the analysis diagram, the higher the darkness of the color, the greater the maximum principal strain.

  The analysis diagrams of FIGS. 8A and 8B are the vibration isolator 100 according to the first embodiment and the vibration isolator 200 according to the second embodiment shown by the characteristics L1 and L2 in FIG. 9 (a) and 9 (b) show the vibration isolator 300 in the third embodiment shown by the characteristics L3 and L4 in FIG. 7 and the anti-vibration apparatus for comparison. 900 respectively. In FIG. 8 and FIG. 9, the reference numerals are omitted.

  As shown in FIG. 9 (b), in the vibration isolator 900 (see FIG. 12 (b)), the maximum principal strain is located at the substantially central portion in the width direction of the third leg member 940 and in the vicinity of the outer peripheral surface of the inner cylindrical member 810. The big part of is concentrated. Therefore, a crack is generated at the strain concentrated portion, and the crack progresses, thereby causing the third leg member 940 to break.

  On the other hand, in the vibration isolator 100 (see FIG. 1), the third leg connecting surface portion 13 of the inner cylinder member 1 is curved in a concave arc shape in a direction away from the outer cylinder member 2. In the vicinity of the third leg connecting surface portion 13 of the inner cylinder member 1, portions where the maximum main strain of the third leg member 32 increases are dispersed, and concentration in the center portion in the width direction is reduced.

  In the vibration isolator 200 (see FIG. 4), since the pair of leg recesses 232a is provided in the third leg member 232, the portion where the maximum main strain increases is compared with the case of the vibration isolator 100, It is separated from the vicinity of the third leg connecting surface portion 13 of the inner cylinder member 1 to the outer cylinder member 2 side (shifted downward in FIG. 8 (b)), and in the vicinity of the third leg connecting surface portion 13 of the inner cylinder member 1, the maximum main The strain is reduced.

  Further, in the vibration isolator 300 (see FIG. 5), since the pair of inner cylinder recesses 313a are formed in the third leg connecting surface portion 313 of the inner cylinder member 301, the portion where the maximum main strain increases is prevented. Compared to the case of the vibration device 100, the inner cylinder member 301 is separated from the vicinity of the third leg connecting surface portion 313 toward the outer cylinder member 2 (shifted downward in FIG. 9A), and the third of the inner cylinder member 301 is moved. In the vicinity of the leg connecting surface portion 313, the maximum principal strain is reduced.

  In an actual product, the inner cylinder member 1 or the like may have a dimensional tolerance and may be formed smaller than the vulcanization mold, and the vulcanization mold may be worn. Therefore, when there is a gap between the intermediate surface portion 15 such as the inner cylinder member 1 and the vulcanization mold, the intermediate surface portion 15 may be covered with a rubber film and not completely exposed to the outside. is there. In this numerical calculation, in consideration of this, in addition to the model in which the intermediate surface portion 15 is completely exposed to the outside, the intermediate surface portion 15 such as the inner cylinder member 1 is covered with a rubber film having a thickness of 2 mm. This model was also analyzed and compared (see FIGS. 8 and 9). As a result, it was confirmed that the rubber film having a thickness of 2 mm or less has no influence on the analysis result.

  Next, a vibration isolator 400 according to the fourth embodiment will be described with reference to FIG. In the first embodiment, the case where the outer cylinder member 2 is formed in an oval shape when viewed from the axial center O direction has been described. However, the outer cylindrical member 402 according to the fourth embodiment has a circular shape when viewed from the axial center O direction. Formed. In addition, the same code | symbol is attached | subjected about the part same as 1st Embodiment, and the description is abbreviate | omitted.

  FIG. 10 is a front view of the vibration isolator 400 according to the fourth embodiment. As shown in FIG. 10, the outer cylinder member 402 in the fourth embodiment is formed in a circular shape when viewed in the direction of the axis O, and is centered on the inner cylinder member 1 while surrounding the outer peripheral side of the inner cylinder member 1. Arranged so that O substantially matches.

  In addition, the vibration isolating base 403 has a longer longitudinal dimension (the vertical direction in FIG. 10) of the third leg member 432 along with a change in the shape of the outer cylinder member 402, and the lower covering member 433 and the upper covering member. Only the point that the thickness dimension of 434 (the vertical dimension in FIG. 10) is increased is different from the anti-vibration substrate 3 in the first embodiment.

  Thus, even when the outer cylinder member 402 is formed in a circular shape when viewed in the direction of the axis O, the same effects as those of the vibration isolator 100 according to the first embodiment can be obtained. In particular, according to the vibration isolator 400 in the present embodiment, the longitudinal dimension of the third leg member 432 can be increased, and the other end side in the longitudinal direction of the third leg member 432 (lower side in FIG. 10). Since the rubber volume can be increased by the lower covering member 433, the occurrence of cracks in the third leg member 432 can be suppressed, and the durability can be further improved.

  Next, a vibration isolator 500 according to the fifth embodiment will be described with reference to FIG. The vibration isolator 500 according to the fifth embodiment is formed by combining the vibration isolator 200 according to the second embodiment and the vibration isolator 300 according to the third embodiment. In addition, the same code | symbol is attached | subjected about the part same as said each embodiment, and the description is abbreviate | omitted.

  FIG. 11 is a front view of a vibration isolator 500 according to the fifth embodiment. As shown in FIG. 11, the vibration isolator 500 according to the fifth embodiment is formed by adding the leg recess 232a according to the second embodiment to the vibration isolator 300 according to the third embodiment. That is, in the vibration isolator 300 according to the third embodiment, both side surfaces of the third leg member 332 are formed to be flat, whereas in the vibration isolator 500 according to the fifth embodiment, the third leg member 532 is A pair of leg recesses 232a in the second embodiment is set on both side surfaces. The vibration isolator 500 is the same as the vibration isolator 300 except for the presence or absence of the leg recess 232a.

  According to the vibration isolator 500 in the fifth embodiment, the effects exerted by the vibration isolator 200 in the second embodiment and the vibration isolator 300 in the third embodiment can be exhibited synergistically. As a result, the occurrence of cracks in the third leg member 532 can be suppressed, and the durability can be further improved.

  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.

  The numerical values given in the above embodiments are merely examples, and other numerical values can naturally be adopted. Moreover, the magnitude relationship of each structure is an example, and it is naturally possible to employ other relationships.

  In each of the above-described embodiments, the case where the inner cylindrical members 1 and 301 are formed in the same cross-sectional shape along the axis O direction has been described. However, the present invention is not necessarily limited to this, for example, radially outward A bulging portion that bulges toward the center may be provided in the center of the inner cylinder member 1, 301 in the direction of the axis O.

  In each of the above embodiments, the case where the intermediate surface portion 15 of the inner cylinder member 1, 301 is exposed to the outside has been described. However, the present invention is not necessarily limited to this, and the main leg member 31 and the third leg member 32, A part or all of the intermediate surface portion 15 may be covered with a rubber film continuous to 232, 332, 432, and 532.

  However, when the entire intermediate surface portion 15 is covered with the rubber film, the thickness dimension of the rubber film (the distance from the outer peripheral surface of the intermediate surface portion 15 to the surface of the rubber film) is preferably about 2 mm or less. By setting the thickness dimension of the rubber film to approximately 2 mm or less, the rubber film can be a portion that does not follow the elastic deformation of the third leg members 32, 232332, 432, 532, etc. and does not contribute to the progress of the crack. Therefore, even if a crack occurs in the third leg member 32 or the like, the crack can be prevented from progressing to the main leg member 31.

  On the other hand, by allowing the intermediate surface portion 15 to be covered with the rubber film in this way, the dimensional tolerance when manufacturing the vulcanizing mold can be made moderate, and the manufacturing cost can be reduced. Even if the part corresponding to the intermediate surface portion 15 is worn with the use of the vulcanization mold, the vulcanization mold can be worn, so that the lifetime of the vulcanization mold is extended and the manufacturing cost is reduced. Can be achieved.

100, 200, 300, 400, 500 Antivibration device 1,301 Inner cylinder member 12 Main leg connecting surface portion 13,313 Third leg connecting surface portion 313a Inner cylinder recess 15 Intermediate surface portion 2,402 Outer cylinder member 31 Main leg Members 32, 232, 332, 432, 532 Third leg member 232a Leg recess 42 Second straight part (space between main leg member and third leg member)

Claims (4)

A cylindrical inner cylinder member, an outer cylinder member that surrounds the outer peripheral side of the inner cylinder member, and between the outer peripheral surface of the inner cylinder member and the inner peripheral surface of the outer cylinder member that are located across the inner cylinder member And a pair of main leg members made of a rubber-like elastic body,
A third leg member that is located between the pair of main leg members and connects between the outer peripheral surface of the inner cylinder member and the inner peripheral surface of the outer cylinder member and made of a rubber-like elastic body;
An outer peripheral surface to which at least the third leg member is connected among the outer peripheral surfaces of the inner cylindrical member is curved in an arc shape in which an arc center is located on the opposite side to the axial center of the inner cylindrical member when viewed in the axial direction. An anti-vibration device characterized by being formed.   An outer peripheral surface of the inner cylinder member is an intermediate surface portion located between a main leg connecting surface portion to which the main leg member is connected and a third leg connecting surface portion to which the third leg member is connected. 2. The rubber film according to claim 1, wherein the intermediate surface portion is exposed to the main leg member and the third leg member and is covered with a rubber film having a thickness of about 2 mm or less. Anti-vibration device.   The third leg member is provided with a pair of leg recesses that are recessed in the side surfaces facing the space between the pair of main leg members and that are continuous with the intermediate surface portion of the inner cylinder member or the rubber film. The vibration isolator according to claim 2 characterized by the above-mentioned.   The said inner cylinder member is provided with a pair of inner cylinder recessed part respectively located in the width direction both sides of the said 3rd leg member while being recessedly provided in the outer peripheral surface part to which the said 3rd leg member is connected. Item 4. The vibration isolator according to any one of Items 1 to 3.