JP2007333029A - Torque rod - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress increase of the number of components and manufacturing man-hours of a device caused by providing a dynamic damper comprising a mass member and an elastic connection body, and to suppress more effectively each resonance phenomenon of sway vibration and rocking vibration respectively by the dynamic damper. <P>SOLUTION: In this torque rod 10, the elastic connection body 46 is molded integrally with the first rubber elastic body 26. Hereby, increase of the number of components and manufacturing man-hours of the torque rod 10 caused by providing the dynamic damper 44 comprising the mass member 48 and the elastic connection body 46 can be suppressed. In the torque rod 10, since the dynamic damper 44 is arranged on an elongation of the center axis C on the outer circumferential side of the first external cylinder part 14, the distance from the axial center S2 of the second external cylinder part 16 to the mass member 48 can be set sufficiently long, and the moment of inertia of the mass member 48 to the rocking vibration can be set sufficiently large. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a torque rod that elastically connects a power unit including an engine in a vehicle to the vehicle body side, and receives a torque reaction force or the like exerted on the vehicle body from the power unit as a load load.

  Conventionally, in vehicles such as automobiles, vibration transmission from the power unit including the engine, which is the main vibration source, to the vehicle body is suppressed to achieve excellent ride comfort, and various members attached to the vehicle body are protected from vibration. In order to achieve this, the power unit is supported by the vehicle body via an anti-vibration support mechanism. Such an anti-vibration support mechanism is generally composed of a plurality of mounting devices using rubber elastic bodies. As one type of such mounting devices, a torque reaction force exerted on the vehicle body from a power unit is mainly input as a load load. An engine torque rod (hereinafter simply referred to as “torque rod”) is known. For example, in the power unit support form such as the pendulum system that is often used in FF type (front engine / front drive type) automobiles, the torque rod elastically connects the outer periphery of the power unit off the torque roll shaft to the vehicle body. Thus, the amount of displacement of the power unit in the roll direction with respect to the vehicle body is limited in a buffering manner.

  As such a torque rod, for example, the one described in Patent Document 1 is known. The torque rod described in Patent Document 1 is provided with a small-diameter and large-diameter cylinder (outer cylinder member) at both ends of the rod body, respectively, and the pair of outer cylinder members has a small-diameter and large-diameter anti-vibration bush. Is arranged. Further, in this torque rod, a substantially ring-shaped mass member is disposed so as to surround the outer peripheral side in the longitudinal direction intermediate portion of the rod body, and this mass member and the rod body are constituted by a rubber elastic body (elastic coupling body). It is connected. Thus, when vibration (sway vibration) along the longitudinal direction of the rod body from the power unit is input, if the vibration frequency becomes equal to the resonance frequency of the torque rod, the rubber elastic body and the mass member function as a dynamic damper, and When the member resonates in the sway direction, the sway vibration level (resonance magnification) at the resonance frequency of the torque rod can be reduced by the inertial force.

By the way, in the torque rod as described above, in addition to the sway vibration, which is the main vibration input along with the displacement of the power unit in the roll direction, for example, the large-diameter outer cylinder member side is moved up and down with a small-diameter anti-vibration bush as the center. It is known that a rocking vibration (rocking vibration) is generated and a rocking vibration resonance phenomenon occurs at a frequency different from the resonance frequency of the sway vibration.
JP 2005-106293 A

  However, in the torque rod described in Patent Document 1, the mass member is disposed in the center portion in the longitudinal direction of the connecting rod, and the distance from the vibration isolating bush on the small diameter side to the mass member is relatively short. On the other hand, it is difficult to increase the moment of inertia of the mass member, and the resonance magnification of the rocking vibration cannot be efficiently reduced by the elastic coupling body and the mass member (dynamic damper) when the rocking vibration is input.

  Further, in the torque rod described in Patent Document 1, the elastic coupling body constituting a part of the dynamic damper is formed separately from the rubber elastic body (bush rubber) in the vibration isolating bush. Need to be molded as separate parts, the number of parts and the number of manufacturing steps are increased in order to provide a dynamic damper in the apparatus, leading to an increase in manufacturing cost.

  Further, in the torque rod described in Patent Document 1, when characteristics such as the spring constant of the bush rubber change with time, a phenomenon may occur in which the resonance frequency gradually changes with the change in the characteristics. At this time, since the damper rubber and the bush rubber are formed as separate bodies, the characteristic change of the elastic coupling body does not follow the characteristic change of the bush rubber, and the resonance frequency of the dynamic damper over time becomes the resonance of the torque rod itself. There is a risk of deviation from the frequency. As a result, the function of the dynamic damper deteriorates with time, and the resonance magnification cannot be reduced normally by the dynamic damper.

  The object of the present invention is to reduce the increase in the number of parts and the number of manufacturing steps of the apparatus by providing a dynamic damper composed of a mass member and an elastic coupling body in consideration of the above fact, and to suppress the resonance phenomenon of sway vibration and rocking vibration. The object is to provide a torque rod that can be effectively suppressed by a dynamic damper.

  In order to achieve the above object, a torque rod according to claim 1 of the present invention is a torque rod for elastically connecting a power unit including an engine to a vehicle body side, and is a first outer cylinder formed in a cylindrical shape. A connecting stay in which one end portion is joined to the outer peripheral portion of the first outer cylindrical member and the other end portion is joined to the outer peripheral portion of the second outer cylindrical member; A first mounting member disposed on the inner circumferential side of the first outer cylinder member and coupled to one of the power unit and the vehicle body, and disposed on an inner circumferential side of the second outer cylinder member and coupled to the other of the power unit and the vehicle body. The first mounting member is disposed between the first outer cylinder member and the inner peripheral surface of the first outer cylinder member and the outer peripheral surface of the first mounting member, and elastically connects the first outer cylinder member and the first mounting member. The first rubber elastic body, the inner peripheral surface of the second outer cylinder member, and the second mounting portion A second rubber elastic body disposed between the outer peripheral surface of the first rubber elastic body and elastically connecting the second outer cylinder member and the second mounting member; and the first rubber elastic body and the first rubber elastic body. It has the elastic coupling body which protruded to the outer peripheral side of 1 outer cylinder member, and the mass member which has a predetermined mass and was vulcanized-bonded to the outer peripheral part of the said elastic coupling body.

  The operation of the torque rod according to claim 1 of the present invention will be described below.

  In the torque rod according to claim 1, the elastic coupling body integrally formed with the first rubber elastic body projects toward the outer peripheral side of the first outer cylinder member, and the mass member having a predetermined mass is the outer circumference of the elastic coupling body. Since the elastic coupling body and the mass member arranged on the outer peripheral side of the first outer cylinder member are configured as a dynamic damper by being fixed to the part, the resonance frequency of the dynamic damper is a specific resonance frequency of the torque rod. If the resonance phenomenon occurs in the torque rod, the resonance phenomenon also occurs in the mass member of the dynamic damper, and the inertial force of the mass member causes the resonance frequency at the resonance frequency of the torque rod itself. The vibration level can be reduced.

  Here, since the elastic coupling body is integrally formed with the first rubber elastic body, the elastic coupling body is molded simultaneously with the molding of the first rubber elastic body on the inner peripheral side of the first outer cylinder member. Since the outer peripheral part of the connection body can be fixed to the mass member by vulcanization adhesion, it is possible to suppress an increase in the number of parts and manufacturing man-hours of the torque rod due to the provision of the dynamic damper composed of the mass member and the elastic connection body.

  Further, in the torque rod according to the first aspect, since the dynamic damper including the elastic coupling body and the mass member is disposed on the outer peripheral side of the first outer cylinder member, it follows the sway direction of the mass member generated when the sway vibration is input. As for the inertial force, the mass member is of the same level as the conventional torque rod arranged outside the connecting rod, and the level of resonance vibration along the sway direction can be effectively reduced by the inertial force of the mass member. .

  Further, in the torque rod according to the first aspect, when a rocking vibration that swings the first outer cylinder member around the second mounting member occurs, the distance from the second mounting member to the mass member is sufficiently long. The mass moment of inertia of the mass member with respect to the rocking vibration can be sufficiently increased, so that the level of resonance vibration along the rocking direction can be effectively reduced by the inertia force of the mass member.

  A torque rod according to a second aspect of the present invention is the vibration isolator according to the first aspect, wherein the elastic connection is made through a conduction hole penetrating the first outer cylinder member along a radial direction and through the conduction hole. And a joining portion for joining the body to the first rubber elastic body.

  The torque rod according to claim 3 of the present invention is the torque rod according to claim 1 or 2, wherein the elastic coupling body and the mass member are arranged on an extension line along a longitudinal direction of the coupling rod. Features.

A torque rod according to a fourth aspect of the present invention is the torque rod according to any one of the first to third aspects, wherein the inner and outer diameters of the first outer cylinder member are larger than the inner and outer diameters of the second outer cylinder member. Is also characterized by a large diameter.
The first mounting member is connected to the vehicle body side, and the second mounting member is connected to the power unit side.

  A torque rod according to a fifth aspect of the present invention is the torque rod according to any one of the first to fourth aspects, wherein the first mounting member is connected to the vehicle body side, and the second mounting member is connected to the power unit side. It is connected to.

  A torque rod according to a sixth aspect of the present invention is the torque rod according to any one of the first to fifth aspects, wherein the first rubber elastic body is formed of a rubber composition having a relatively low dynamic magnification. In addition, the second rubber elastic body is formed of a rubber composition having relatively high attenuation.

  As described above, according to the torque rod of the present invention, it is possible to suppress an increase in the number of parts and manufacturing man-hours of the apparatus by providing a dynamic damper composed of a mass member and an elastic coupling body, and resonance of sway vibration and rocking vibration. Each phenomenon can be effectively suppressed by a dynamic damper.

  Hereinafter, a torque rod according to an embodiment of the present invention will be described with reference to the drawings.

(Configuration of the embodiment)
1 and 2 show a torque rod according to an embodiment of the present invention. The torque rod 10 is a kind of mounting device that mounts a power unit including an engine in a vehicle on a vehicle body. For example, the torque rod 10 is interposed between a rear end portion of the power unit and the vehicle body, and torque torque of the power unit is reduced. Limiting the displacement of the power unit in the roll direction and the longitudinal direction of the vehicle body by force and inertial force.

  As shown in FIG. 1, the torque rod 10 includes a metal rod main body 12 that is elongated along one direction as a whole. The rod body 12 has a first outer cylinder portion 14 formed in a substantially annular shape on one end side (right side in FIG. 1) along the longitudinal direction thereof, and a first annular shape formed in a substantially annular shape on the other end side. Two outer cylinder portions 16 are formed. The first outer cylinder portion 14 has an inner diameter and an outer diameter larger than those of the second outer cylinder portion 16.

  The rod body 12 is integrally formed with a stay portion 18 between the first outer cylinder portion 14 and the second outer cylinder portion 16, and the stay portion 18 is in the form of an elongated rod along the longitudinal direction of the torque rod 10. The other end portion is joined to the outer peripheral portion of the second outer cylinder portion 16 and the other end portion is joined to the outer peripheral portion of the first outer cylinder portion 16. In the torque rod 10, the first outer cylinder portion 14, the stay portion 18, and the second outer cylinder portion 16 are integrally formed using a metal material such as an aluminum alloy as a raw material to constitute the rod body 12.

  1 and 2 represents the central axis of the torque rod 10, and this central axis C coincides with the longitudinal direction (arrow L direction) of the rod body 12. S1 and S2 represent the axial centers of the first outer cylindrical portion 14 and the second outer cylindrical portion 16, respectively. The direction along the axial centers S1 and S2 is the thickness direction of the torque rod 10 (in FIG. 2). Arrow T direction). Further, the following description will be made with the direction orthogonal to the longitudinal direction and the thickness direction of the torque rod 10 as the width direction (the direction of arrow W in FIG. 1).

  A first metal fitting 20 made of metal is disposed on the torque rod 10 on the inner peripheral side of the first outer cylinder portion 14. The first mounting bracket 20 has a substantially isosceles triangle cross-sectional shape along the direction perpendicular to the axis, and the longest bottom portion 22 of the three sides is located on the innermost side in the longitudinal direction within the first outer cylinder portion 14. The apex portion 21 that faces the bottom portion 22 is located on the outermost side in the longitudinal direction in the first outer cylinder portion 14. The first mounting bracket 20 is formed with a circular connection hole 24 penetrating in the thickness direction at the center thereof. Here, the first mounting bracket 20 is disposed such that the center point of the connection hole 24 is offset to the predetermined distance inward in the longitudinal direction with respect to the axis S1.

  In the torque rod 10, a first rubber elastic body 26 formed in a cylindrical shape as a whole is disposed between the first outer cylinder portion 14 and the first mounting bracket 20. The outer peripheral surface of the first rubber elastic body 26 is vulcanized and bonded to the inner peripheral surface of the first outer cylinder portion 14, and a part of the inner peripheral surface is attached to each of the pair of oblique sides 23 in the first mounting bracket 20. It is vulcanized and bonded. Thereby, the first outer cylinder portion 14 and the first mounting bracket 20 are elastically connected by the first rubber elastic body 26.

  As shown in FIG. 1, the first rubber elastic body 26 has an outer straight portion 27 penetrating in the thickness direction on the outer side in the longitudinal direction of the first mounting bracket 20, and the longitudinal length of the first mounting bracket 20. An inner straight portion 28 penetrating in the thickness direction is also formed on the inner side in the direction. The first rubber elastic body 26 is formed with a block-shaped main body portion 30 between one end side of the outer straight portion 27 and one end side of the inner straight portion 28, and the other end side and inner side of the outer straight portion 27. A block-shaped main body 30 is also formed between the other end side of the straight portion 28. The pair of main body portions 30 respectively extend from the inner peripheral surface of the first outer cylinder portion 14 to the first mounting bracket 20 side, and the end surfaces on the inner peripheral side are vulcanized and bonded to the pair of oblique sides 23 in the first mounting bracket 20. Has been.

  The pair of main body portions 30 extend so as to be substantially parallel to the normal direction of the pair of oblique sides 23, and are inclined symmetrically with respect to the longitudinal direction of the torque rod 10. Further, the first rubber elastic body 26 is formed with an outer stopper portion 31 so as to be opposed to the apex portion 21 of the first mounting bracket 20 via the outer straight portion 27, and the first rubber elastic body 26 via the inner straight portion 28. An inner stopper portion 32 is formed so as to face the bottom side portion 22 of the mounting bracket 20.

  As shown in FIG. 1, a second metal fitting 34 made of metal is arranged substantially coaxially on the inner peripheral side of the second outer cylinder portion 16 in the torque rod 10. The second mounting bracket 34 is formed in a columnar shape (pipe shape), and a circular connection hole 35 penetrating in the thickness direction is formed at the center thereof. In the torque rod 10, a cylindrical second rubber elastic body 36 is disposed between the outer peripheral surface of the second outer cylinder portion 16 and the inner peripheral surface of the second mounting bracket 34. The outer peripheral surface of the second rubber elastic body 36 is vulcanized and bonded to the inner peripheral surface of the second outer cylinder portion 16 over the entire circumference, and the inner peripheral surface of the second mounting bracket 34 extends over the entire circumference. Vulcanized and bonded to the outer peripheral surface. Thereby, the second outer cylinder portion 16 and the second mounting bracket 34 are elastically connected by the second rubber elastic body 36.

  In the torque rod 10 of the present embodiment, the rod body 12 is formed of a metal material such as an aluminum alloy. However, if the strength and formability can be ensured, the rod body 12 may be formed of another material such as a resin material. May be.

  As shown in FIG. 1, the torque rod 10 is integrally formed with a pedestal portion 38 at an end portion on the outer side in the longitudinal direction of the first outer cylinder portion 14, and an end face on the outer side in the longitudinal direction of the pedestal portion 38. Is a seating surface 40 made of a plane orthogonal to the longitudinal direction of the torque rod 10. The rod body 12 is provided with a circular conduction hole 42 penetrating between the inner peripheral surface of the first outer cylinder portion 14 and the center portion of the seat surface 40 along the central axis C.

  As shown in FIG. 2, a dynamic damper 44 is disposed on the seat surface 40 in the torque rod 10. The dynamic damper 44 includes an elastic coupling body 46 formed integrally with the first rubber elastic body 26 and a metal mass member 48 having a predetermined mass. The mass member 48 is formed in a plate shape having a substantially constant thickness, and is arranged so that the thickness direction thereof substantially coincides with the longitudinal direction of the torque rod 10. The elastic coupling body 46 is formed with a main body coupling portion 52 formed in a plate shape having a substantially constant thickness, and a joint portion 50 that protrudes from the center portion of the end surface on the inner side in the longitudinal direction is integrally formed. Yes. The joint portion 50 is inserted through the conduction hole 42 of the first outer cylinder portion 14, and the tip portion thereof is joined to the outer peripheral surface of the first rubber elastic body 26.

  The main body coupling portion 52 of the elastic coupling body 46 has an outer end surface that is vulcanized and bonded to the inner end surface of the mass member 48 along the longitudinal direction, and the outer side of the joint portion 50 at the inner end surface is added to the seat surface 40. Sulfur bonded. Accordingly, the mass member 48 is elastically connected to the seat surface 40 by the elastic connecting body 46. Note that a thin film-like covering portion may be integrally formed on the mass member 48 on the elastic coupling body 46, and this covering portion may be vulcanized and bonded so as to cover a surface portion other than the inner end face of the mass member 48. Thereby, when the mass member 48 is a material that easily generates rust, it is possible to effectively prevent the mass member 48 from generating rust without performing a rust prevention treatment.

  A method for manufacturing the torque rod 10 configured as described above will be described. When manufacturing the torque rod 10, first, the rod body 12, the first mounting bracket 20, and the mass member 48 are manufactured, and these are placed at predetermined positions in a vulcanization mold (not shown). Load as insert core. In this state, a hollow portion (first cavity) corresponding to the shape of the first rubber elastic body 26 and the elastic coupling body 46 is formed in the mold.

  Next, molten vulcanized rubber is injected into the first cavity through the first injection hole provided in the mold, and the first rubber elastic body 26 and the elastic coupling body 46 are vulcanized and molded at the same time. The elastic body 26 and the elastic coupling body 46 are vulcanized and bonded to the first outer cylinder portion 14, the first mounting bracket 20, and the mass member 48. At this time, if vulcanized rubber is injected into the space corresponding to the first rubber elastic body 26 in the first cavity, the vulcanized rubber passes through the conduction hole 42 and corresponds to the main body connecting portion 52 of the elastic connecting body 46. Since it also wraps around the space, the first rubber elastic body 26 and the elastic coupling body 46 can be vulcanized and formed at the same time by one injection operation.

  Instead of forming the conduction hole 42 in the first outer cylinder portion 14, a conduction groove is formed so as to cross the end surface portion along the thickness direction in the first outer cylinder portion 14, and the first through the conduction groove. The rubber elastic body 26 and the elastic coupling body 46 may be vulcanized and molded at the same time.

  Further, in the molding process different from the molding process of the first rubber elastic body 26 and the elastic coupling body 46, the second rubber elastic body 36 is vulcanized and molded using the second mounting bracket 34 as an insert core, and at the same time, the second rubber elasticity The body 36 is vulcanized and bonded to the outer peripheral surface of the second mounting bracket 34. The second rubber elastic body 36 and the second outer cylinder portion 16 are fitted into the second outer cylinder portion 16 by press-fitting the second rubber elastic body 36 vulcanized and bonded to the second mounting bracket 34 into the second outer cylinder portion 16. 2 Attach to the inner peripheral side of the outer cylinder part 16.

  However, as with the first rubber elastic body 26, the second rubber elastic body 36 is loaded at a predetermined position in the vulcanization molding mold with the second outer cylinder portion 16 and the second mounting bracket 34 as insert cores. In addition, by injecting a molten vulcanized rubber between the second outer cylinder portion 16 and the second mounting bracket 34, vulcanization and adhesion are performed simultaneously with the second outer cylinder portion 16 and the second mounting bracket 34. You may make it vulcanize-bond.

  Next, the optimum mode when the torque rod 10 configured as described above is attached to the vehicle and the optimum tuning of the rubber elastic bodies 26 and 36 will be described.

  In the torque rod 10, it is known that the dynamic vibration transmission characteristics change depending on whether the large-diameter first outer cylinder portion 14 or the small-diameter second outer cylinder portion 16 is attached to the power unit side.

  First, assuming that the dynamic damper 44 does not exist in the torque rod 10, the first rubber elastic body 26 and the second rubber elastic body have the mass of the torque rod 10 itself as a mass component in the region where the vibration frequency is 50 to 200 Hz. A resonance phenomenon of a rigid body mode having 36 as a spring component occurs, and the vibration transmissibility between the power unit and the vehicle body is greatly deteriorated. The resonance phenomenon of the rigid body mode can be divided into a low-order mode and a high-order mode. In the low-order mode, the first outer cylinder portion 14 side including the first rubber elastic body 26 having a low spring constant is relatively Since a phenomenon (resonance phenomenon) that greatly fluctuates automatically occurs, the vibration transmissibility on the first outer cylinder portion 14 side deteriorates. For this reason, it is not desirable to attach the first outer cylinder portion 14 to the vehicle body side in consideration of the frequency region of the low-order mode.

  On the other hand, when considering a higher frequency region (higher-order mode), a phenomenon (resonance phenomenon) in which the second outer cylindrical portion 16 side including the second rubber elastic body 36 having a high spring constant sways relatively greatly occurs. The vibration transmissibility on the second outer cylinder portion 16 side is deteriorated.

  Further, considering a higher frequency region than the rigid body mode, since one enters the vibration isolation region where the resonance magnification is less than 1, either one of the first outer cylinder portion 14 and the second outer cylinder portion 16 is relatively large. The shaking phenomenon does not occur, and the vibration transmissibility can be reduced by attaching the first outer cylinder portion 14 including the first rubber elastic body 26 having a relatively small spring constant to the vehicle body side.

  To summarize the above, it is desirable to attach the first outer cylinder portion 14 to the power unit side in the frequency region of 50 to 200 Hz, in which the low-order rigid body mode resonance of the torque rod 10 is a problem, and in the higher frequency region, It is desirable to attach the first outer cylinder portion 14 to the vehicle body side. Therefore, in the torque rod 10, if the dynamic damper 44 can solve the deterioration (increase) of the vibration transmissibility due to the low-frequency-side rigid body mode resonance, the first outer cylinder portion 14 including the first rubber elastic body 26 having a low spring constant is provided. By attaching to the vehicle body side, the vibration isolation region can be widened and the total vibration isolation effect can be increased.

  Based on the above conclusion, the first rubber elastic body 26 and the first rubber member 26 when the first outer cylinder portion 14 of the torque rod 10 having the dynamic damper 44 is attached to the vehicle body side and the second outer cylinder portion 16 is attached to the power unit side are used. (2) The optimum characteristics of the rubber elastic body 36 will be examined.

  First, the vibration input to the torque rod 10 when the torque rod 10 is applied to an FF side-mounted engine (power unit) suspended on the vehicle body by a pendulum system that has been frequently seen in recent years will be examined. In this case, the torque rod 10 has a longitudinal direction (arrow L direction) substantially coincided with the front-rear direction in the vehicle, and a thickness direction (axial direction of the outer cylinder portions 14, 16) is the left-right direction in the vehicle. The first mounting bracket 20 is connected to the vehicle body side via a fastening member such as a bolt that passes through the connection hole 24, and the second mounting bracket 34 is inserted through the connection hole 35. It is connected to the power unit side via a fastening member.

  At this time, it is considered that the torque rod 10 is arranged in a three-dimensional coordinate space, and the coordinate axis along the longitudinal direction L (vehicle longitudinal direction) of the torque rod 10 is along the X axis and along the width direction W (vehicle vertical direction). Assuming that the coordinate axis is the Z-axis and the axis along the thickness direction T (the vehicle left-right direction) is the coordinate Y-axis, the torque rod 10 mainly has longitudinal vibration along the X-axis and the Z-axis from the power unit side. Vertical vibration is input. At this time, the resonance phenomenon of the torque rod 10 becomes a problem in translation along the X and Z axes, rotation around the Y axis, and their coupled modes. Of these, resonance along the X-axis tends to appear as a relatively uncoupled mode and mainly generates sway vibrations, but translation along the Z-axis and rotation around the Y-axis always appear as coupled modes. On the low-order side of the rigid body mode, rocking vibration is generated around the axis S2 of the second outer cylinder portion 16.

  With respect to the sway vibration and the rocking vibration as described above, the second rubber elastic body 36 preferably has a smaller spring constant in the twisting direction and the twisting direction, and the rubber composition used is a second rubber elastic body. In order to suppress the resonance phenomenon in the second outer cylinder portion 16 including 36, it is preferable to use a NR / SBR rubber or the like having a relatively high attenuation.

  On the other hand, in the first rubber elastic body 26, the spring characteristic along the X axis is tuned (optimized) by adjusting the shape of the pair of body portions 30 according to the frequency and amplitude of the longitudinal vibration input from the power unit. The At this time, in order to suppress deterioration (rise) of the dynamic spring constant in the high frequency region, it is preferable to use a NR rubber or the like having a relatively low dynamic magnification.

  Further, in the torque rod 10, when an excessive load is input from the power unit along the vehicle front-rear direction and the input load is directed toward the rear side of the vehicle, the apex portion 21 of the first mounting bracket 20 is the first portion 21. The outer stopper portion 31 is pressed against the outer stopper portion 31 of the rubber elastic body 26 and compressed. Thereby, the outer side stopper part 31 makes a big elastic reaction force act on the 1st mounting bracket 20, and prevents the excessive displacement to the vehicle rear side of the 1st mounting bracket 20. FIG. On the other hand, when the input load is directed toward the front side of the vehicle, the bottom side portion 22 of the first mounting bracket 20 is pressed against the inner stopper portion 32 of the first rubber elastic body 26 to compress the inner stopper portion 32. Thereby, the inner side stopper part 32 makes a big elastic reaction force act on the 1st attachment bracket 20, and prevents the excessive displacement to the vehicle front side of the 1st attachment bracket 20. FIG. Therefore, even when a large inertial force acts on the power unit along the vehicle front-rear direction, or when the power unit generates a large torque reaction force, it is certain that the power unit is excessively displaced along the vehicle front-rear direction by the torque rod 10. To be prevented.

(Operation of the embodiment)
Next, the operation of the torque rod 10 according to the embodiment of the present invention configured as described above will be described.

  In the torque rod 10, an elastic coupling body 46 formed integrally with the first rubber elastic body 26 protrudes to the outer peripheral side of the first outer cylinder portion 14, and a mass member 48 having a predetermined mass is provided on the elastic coupling body 46. Since the elastic coupling body 46 and the mass member 48 disposed on the outer peripheral side of the first outer cylinder portion 14 are configured as the dynamic damper 44 by being fixed to the outer peripheral portion, the resonance frequency of the dynamic damper 44 is set to the torque rod. If the resonance is generated in the torque rod 10 in advance, the mass member 48 of the dynamic damper 44 is caused to resonate when the resonance phenomenon occurs in the torque rod 10. The vibration level at the resonance frequency of the torque rod itself can be reduced by the inertial force.

  Here, since the elastic coupling body 46 is integrally formed with the first rubber elastic body 26, the first rubber elastic body 26 is molded on the inner peripheral side of the first outer cylinder portion 14, and at the same time, the elastic coupling body 46 is Since the outer peripheral portion of the elastic coupling body 46 can be fixed to the mass member 48 by vulcanization adhesion, the number of parts of the torque rod 10 by providing the dynamic damper 44 composed of the mass member 48 and the elastic coupling body 46 can be increased. And the increase in manufacturing man-hours can be suppressed.

  In the torque rod 10, the dynamic damper 44 including the elastic coupling body 46 and the mass member 48 is disposed on the outer peripheral side of the first outer cylinder portion 14, so that the sway direction ( (= Longitudinal direction) The inertial force along the longitudinal direction) is almost the same as that of the conventional torque rod arranged outside the connecting rod, so that the resonance vibration along the sway direction is caused by the inertial force of the mass member 48. Can be effectively reduced.

  In the torque rod 10, when a rocking vibration that causes the first outer cylinder portion 14 to swing up and down about the axis S <b> 2 of the second outer cylinder portion 16 is generated, the dynamic damper 44 is moved to the first outer cylinder portion. 14 and on the extended line of the central axis C, the distance from the axial center S2 of the second outer cylinder portion 16 to the mass member 48 is made sufficiently long to prevent rocking vibration. Since the inertia moment of the mass member 48 can be sufficiently increased, the level of resonance vibration along the rocking direction can be effectively reduced by the inertia force of the mass member 48.

It is a side view which shows the structure of the torque rod which concerns on embodiment to this invention. It is sectional drawing along the II-II cutting line of the torque rod shown by FIG. It is side surface sectional drawing which shows the 1st outer cylinder part and dynamic damper in the torque rod shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Torque rod 12 Rod main body 14 1st outer cylinder part (1st outer cylinder member)
16 2nd outer cylinder part (2nd outer cylinder member)
18 Stay section (consolidated stay)
20 First mounting bracket (first mounting member)
26 First rubber elastic body 34 Second mounting bracket (second mounting member)
36 Second rubber elastic body 42 Conducting hole 44 Dynamic damper 46 Elastic coupling body 48 Mass member 50 Joint portion 52 Main body coupling portion (elastic coupling body)

Claims (6)

A torque rod for elastically connecting a power unit including an engine to the vehicle body side,
A first outer cylinder member and a second outer cylinder member each formed in a cylindrical shape;
A connecting stay having one end joined to the outer periphery of the first outer cylinder member and the other end joined to the outer periphery of the second outer cylinder member;
A first mounting member disposed on the inner peripheral side of the first outer cylinder member and connected to one of the power unit and the vehicle body;
A first mounting member disposed on the inner peripheral side of the second outer cylinder member and connected to the other of the power unit and the vehicle body;
A first rubber elastic body disposed between an inner peripheral surface of the first outer cylinder member and an outer peripheral surface of the first attachment member, and elastically connecting the first outer cylinder member and the first attachment member; ,
A second rubber elastic body disposed between the inner peripheral surface of the second outer cylindrical member and the outer peripheral surface of the second mounting member, and elastically connecting the second outer cylindrical member and the second mounting member; ,
An elastic coupling body integrally formed with the first rubber elastic body and projecting toward the outer peripheral side of the first outer cylinder member;
A mass member having a predetermined mass and vulcanized and bonded to the outer periphery of the elastic connector;
A torque rod characterized by comprising: A conduction hole penetrating the first outer cylinder member along the radial direction;
The torque rod according to claim 1, further comprising: a joint portion that joins the elastic coupling body to the first rubber elastic body through the conduction hole.   The torque rod according to claim 1 or 2, wherein the elastic coupling body and the mass member are arranged on an extension line along a longitudinal direction of the coupling rod.   The vibration isolator according to any one of claims 1 to 3, wherein an inner / outer diameter of the first outer cylinder member is formed larger than an inner / outer diameter of the second outer cylinder member.   The torque rod according to any one of claims 1 to 4, wherein the first mounting member is connected to a vehicle body side, and the second mounting member is connected to a power unit side.   The first rubber elastic body is formed of a rubber composition having a relatively low dynamic magnification, and the second rubber elastic body is formed of a rubber composition having a relatively high damping. The torque rod according to any one of 5.

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