JP2006283870A - Torque rod - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque rod capable of substantiating good isolation of vibration by maintaining a spring constant of a rubber elastic body low at the time of idling and accelerating, while positively regulating displacement within a tolerance limit upon inputting a large load, without increasing its size. <P>SOLUTION: The torque rod 22 having a small bush 26, a large bush 28, and a connecting body 30 is provided with: a first rubber stopper part 64 working as a stopper on the large bush 28 at the time of acceleration; a window part 66 provided on an outer cylinder 40 with an opened shape for having the first rubber stopper part 64 penetrating therethrough to protrude therefrom; and an abutting part 72 provided on the connecting body 30 for contacting with the first rubber stopper part 64. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a torque rod that is interposed between an engine side and a body side of a vehicle, regulates displacement in the roll direction and forward / backward direction of the engine, and also performs vibration isolation between the engine side and the body side. .

In a conventional vehicle, a torque rod having a small bush and a large bush having elasticity at both ends and a rigid connecting body for connecting the small bush and the large bush is provided across the engine side and the body side of the vehicle. The torque rod receives torque from the engine and restricts the displacement in the roll direction and the displacement in the front-rear direction of the engine.
The torque rod also has a function of vibration isolation between the engine side and the body side.

FIG. 9 shows an example of a conventionally known torque rod (the following Patent Document 1).
In the figure, 200 and 202 are a small bush and a large bush having rigid inner cylinders 204 and 206, outer cylinders 208 and 210, and rubber elastic bodies 212 and 214 for elastically connecting them in the radial direction, respectively, and a connecting rod (connecting body). 216 are connected to each other.

In this torque rod, the small bush 200 is usually elastically coupled to the engine side and the large bush 202 is elastically coupled to the body side. Regulates longitudinal displacement.
Further, vibration insulation is performed between the engine side and the body side based on the elasticity of the rubber elastic bodies 212 and 214.

By the way, in this kind of torque rod, while maintaining a low elastic constant of the rubber elastic body during idling and acceleration, vibration insulation is satisfactorily performed.On the other hand, when a large input is applied and the displacement reaches a set allowable limit, the torque rod exceeds that. It is required to prevent displacement.
Therefore, this type of torque rod is provided with a rubber stopper portion, and excessive displacement is regulated by the stopper action of the rubber stopper portion.

FIG. 10 shows a conventional example of a torque rod provided with this kind of rubber stopper (Patent Document 2 below).
In the torque rod shown in the drawing, the rubber elastic body 214 on the large bush 202 side has a pair of rubber legs 218, and a pair of through-holes (recesses) 220 are provided in front of and behind the rubber legs 218. , 222 are provided.
The outer cylinder 210 has a rubber stopper portion 224 on the acceleration side, that is, a rubber stopper portion 224 that contacts the inner cylinder 206 and the rubber elastic body 214 during acceleration and protrudes toward the inner cylinder 206. It is provided integrally.

By the way, in the torque rod shown in FIG. 10, it is desirable to lower the spring constant of the rubber elastic body 214, that is, the rubber leg 218, in order to satisfactorily isolate the vibration during idling.
However, when the spring constant is lowered, the stopper contact at the time of acceleration is accelerated, that is, when the inner cylinder 206 and the rubber leg 218 are displaced upward in the figure, the rubber stopper portion 224 is quickly moved to the inner cylinder 206 and the rubber elastic body 214. I hit the side.

In addition, the protrusion height of the rubber stopper portion 224 is not sufficiently high, that is, the thickness of the rubber in the vertical direction in the drawing is not sufficiently thick, so that the entire spring is accompanied by the elastic deformation of the rubber stopper portion 224 after hitting the stopper. The rise of the characteristics becomes abrupt, and the spring constant after hitting the stopper is abruptly increased.
As a result, a loud noise in the passenger compartment during acceleration is promoted.

As countermeasures, a large stopper clearance is provided between the inner cylinder 206 and the rubber elastic body 214 and the rubber stopper portion 224, and the protrusion height of the rubber stopper portion 224, that is, the thickness of the rubber stopper portion 224 in the vertical direction in the figure is sufficient. Although it is conceivable to increase the thickness, in the case of the torque rod shown in FIG.
However, it is possible to increase the overall diameter of the large bushing 202 to increase the stopper clearance and increase the protruding height of the rubber stopper portion 224. However, if this is done, the large bushing 202 and thus the torque can be increased. The entire rod becomes large, and there is a problem that the torque rod cannot be assembled due to the assembly space.

JP-A-57-191129 JP 2004-316798 A

  The present invention is based on the above circumstances, and while maintaining a low spring constant of the rubber elastic body when idling and accelerating, it can satisfactorily isolate the vibration, while ensuring that the displacement is below the allowable limit when a large load is input. The purpose of the present invention is to provide a torque rod that can be regulated in the above-described manner and that can be realized without increasing the size.

  Thus, according to the first aspect of the present invention, there are provided a small bush and a large bush at both ends having elasticity, and a rigid connecting body for connecting them. A rubber elastic body elastically connected in a radial direction, and the outer cylinder is press-fitted into a cylindrical press-fit portion provided in the connection body and assembled to the connection body, In the torque rod that is interposed between the body side and receives torque from the engine and restricts displacement in the roll direction of the engine, the large bush has a first rubber stopper portion that acts as a stopper during acceleration. An opening shape is provided so as to project radially from the inner cylinder side toward the outer cylinder side, and the outer cylinder has the first rubber stopper portion protruding from the inside to the outside of the outer cylinder. There is a window The coupling body is provided with a rigid contact portion that is elastically deformed by contacting the first rubber stopper portion at a position spaced from the window portion in the protruding direction of the first rubber stopper portion. Features.

  According to a second aspect of the present invention, in the first aspect, the large bush has locations on both sides in the circumferential direction of the window portion of the outer cylinder at a position between the inner cylinder and the window portion of the outer cylinder. A bridge-shaped second rubber stopper portion to be bridged is provided separately from the rubber elastic body, and the first rubber stopper portion is integrally formed with the second rubber stopper portion. .

  According to a third aspect of the present invention, in the second aspect of the present invention, the second rubber stopper portion is formed so as to form a gap with respect to the inner cylinder and the rubber elastic body.

  According to a fourth aspect of the present invention, in any one of the second and third aspects, the bridge-shaped second rubber stopper portion is elastically deformed by a predetermined amount by the first rubber stopper portion being in contact with the contact portion. It also serves as a third rubber stopper portion that comes into contact with the outer cylinder and serves as a stopper.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a portion around the window portion of the coupling body is formed in a bag shape, and the contact portion is configured at the bottom portion of the bag. It is characterized by.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the connection body is formed by superposing and joining two plate bodies that are symmetrical to each other, and each plate body includes the large bush. Each half of the cylindrical press-fitting portion for press-fitting each outer cylinder is formed.

Effects and effects of the invention

  As described above, according to the present invention, the first rubber stopper portion that acts as a stopper at the time of acceleration is provided so as to protrude from the inner cylinder side of the large bush toward the outer cylinder side, and the first rubber stopper portion is provided on the outer cylinder. An opening-shaped window portion is provided that penetrates and protrudes from the inner side of the outer cylinder to the outer side, and a rigid contact portion that acts as a stopper by abutting the first rubber stopper portion on the outer side of the window portion is connected. According to the present invention, it is possible to increase the stopper clearance without particularly increasing the diameter of the large bush, and to increase the protrusion height of the first rubber stopper portion that acts as a stopper during acceleration. In addition, the stopper contact can be delayed and the initial spring characteristics after the stopper contact, that is, at the time of the stopper action, can be kept low.

Thereby, the spring constant at the time of acceleration can be kept low, vibration insulation can be performed satisfactorily, and the generation of a booming noise at the time of acceleration can be suppressed well.
In addition, the spring constant of the rubber elastic body itself can be kept low as the stopper contact can be delayed, that is, the change amount of the cylinder and the rubber elastic body until the stopper hits can be increased. Therefore, vibration isolation during idling can be performed well.

On the other hand, when a large load is input, a large compressive elastic deformation of the first rubber stopper portion can generate a large resistance force against the displacement, and it is possible to reliably prevent a large displacement from exceeding the allowable limit. It becomes.
In the present invention, the above effect can be realized by providing an opening-shaped window portion in the rigid outer cylinder of the large bush, and projecting the first rubber stopper portion outside through the window portion. This is because a rigid contact surface is formed on the connecting body located on the outer side, and the stopper action is performed by the contact of the first rubber stopper portion thereto.

  According to a second aspect of the present invention, the rubber-like elastic body includes a bridge-shaped second rubber stopper portion that bridges portions on both sides in the circumferential direction of the window portion of the outer cylinder at a position between the window portion of the outer cylinder and the inner cylinder. It is provided separately and the first rubber stopper portion is integrally formed with the second rubber stopper portion. According to the second aspect, the stopper action can be performed in two stages. It is possible to maintain the spring constant until reaching the first stage stopper action as compared with the case where such a second rubber stopper is not provided, and the spring constant at idling can be lowered more effectively. As a result, it is possible to further improve the vibration insulation performance during idling.

Here, the second rubber stopper portion can be formed in a state in which a gap is formed between the inner cylinder and the rubber elastic body.
In this case, the second rubber stopper portion having a bridge shape is brought into contact with the outer cylinder along with the displacement of the inner cylinder and the rubber elastic body after the first rubber stopper section comes into contact with the abutting portion and elastically deforms by a predetermined amount. It can be made to work as a third rubber stopper portion that comes into contact with and acts as a stopper (claim 4).

According to the fourth aspect of the present invention, the large bush has the first rubber stopper portion, the second rubber stopper portion, and the third rubber stopper portion, so that the stopper action can be performed in three stages.
In this case, the spring constant until the deformation allowable limit is reached can be reduced overall and effectively, and a low spring constant can be maintained in the region before the deformation allowable limit is reached, so that vibration isolation is improved. The effect which can be performed is acquired.

In this invention, the part around the said window part in a connection body can be formed in a bag shape, and the said contact part can be comprised in the bottom part of the bag (Claim 5).
Further, the connecting body can be constituted by overlapping two plates having symmetrical shapes with each other (Claim 6). In this case, the bag-like portion, that is, the first rubber stopper portion can be easily contacted. The part can be formed.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, 10 is a suspension member (body) of a vehicle, and 12 is an engine elastically supported on the suspension member 10 via a left engine mount 14 and a right engine mount 16.
However, the engine mounts 14 and 16 support the weight of the entire power unit 20 formed by assembling the engine 12 and the transmission 18.

Reference numeral 22 denotes a torque rod interposed between the center frame 24 of the suspension member 10 and the lower part of the engine 12, and includes a small bush 26 having elasticity, a large bush 28, and a rigid connecting body 30 for connecting them in the front-rear direction. It consists of.
The torque rod 22 has a small bush 26 elastically coupled to the engine 12 and a large bush 28 elastically coupled to the center frame 24 of the suspension member 10.
Here, an inner cylinder 34 described later is fixed to the engine 12 on the small bush 26 side, and an inner cylinder 42 is fastened and fixed to the center frame 24 of the suspension member 10 with bolts and nuts on the large bush 28 side.

The configuration of the torque rod 22 is specifically shown in FIGS.
In these figures, the small bush 26 has a metal-made rigid outer cylinder 32 and inner cylinder 34 and a cylindrical rubber elastic body 36 therebetween.
Here, the outer cylinder 32 is configured integrally with the connecting body 30.
The inner cylinder 34 and the rubber elastic body 36 are integrally vulcanized and bonded, and the integrally vulcanized product is press-fitted in the axial direction into the outer cylinder 32 and assembled.

On the other hand, the large bush 28 has a metal and rigid outer cylinder 40, an inner cylinder 42, and a rubber elastic body 44 that is integrally fixed thereto by vulcanization adhesion. The outer cylinder 40 is integrated with the connecting body 30. It is press-fitted in the axial direction and assembled into a cylindrical press-fit portion 41 configured as described above.
On the large bush 28 side, the rubber elastic body 44 extends from the inner cylinder 42 toward the outer cylinder 40 and has a pair of elastic legs 46 that elastically connect the inner cylinder 42 and the outer cylinder 40. .
The rubber elastic body 44 also has a thin covering portion 62 that covers the outer peripheral surface of the inner cylinder 42 as shown in FIGS. 3 and 4.

Before and after these elastic legs 46, a pair of straight portions (recesses) 48, 50 penetrating in the axial direction are formed.
A speed reduction rubber stopper 52 is provided with a straight portion 50 on the front side of the vehicle.
This rubber stopper portion 52 is integrally vulcanized and bonded to the outer cylinder 40.

In this embodiment, as shown in FIG. 3, the rigid connecting body 30 is made of a pair of metal plates 30-1 and 30-1 that are symmetrical to each other and are overlapped and joined together in FIG. Configured.
Each of the plate bodies 30-1 and 30-1 includes a pair of plate-like portions 60-1 and 60-1, half portions 32-1 and 32-1 of the outer cylinder 32 in the small bush 26, and further, Half portions 41-1 and 41-1 of a circular press-fit portion 41 on the large bush 28 side are formed.

The connecting body 30 also has flanges 38, 56 on the outer circumferences on the small bush 26 side and the large bush 28 side, and half portions 38-1, 38-1 and 56-1, 56- of each of them. 1 is integrally formed on each of the plate bodies 30-1 and 30-1.
The connecting body 30 is provided with a through hole 58 between the small bush 26 and the large bush 28, that is, at a portion connecting them.

As shown in FIGS. 3 and 4, the large bush 28 has a first rubber stopper portion 64 that acts as a stopper during acceleration from the inner cylinder 42 side toward the outer cylinder 40 side and in the rearward direction of the vehicle (see FIG. 3). The outer cylinder 40 is provided with a first rubber stopper 64 extending from the inside to the outside of the outer cylinder 40 as shown in detail in FIG. An opening-shaped window 66 for projecting is provided.
Further, the connecting body 30 is provided with a bag-like portion 68 outside the window portion 66.
The space inside the bag-like portion 68 is a stopper working space 70 of the first rubber stopper portion 64, and the bottom portion of the bag-like portion 68 extends in the protruding direction of the first rubber stopper portion 64 from the window portion 66. The first rubber stopper portion is brought into contact with the separated position to form an abutting portion 72 for elastic deformation.

Here, as shown in FIG. 5B, the first rubber stopper portion 64 is formed with a protruding height such that the tip protrudes slightly outward from the window portion 66. However, the protruding height of the tip portion may be the protruding height up to the same position as the outer peripheral position of the outer cylinder 40 (strictly speaking, the outer peripheral position of the upper and lower portions of the window 66 of the outer cylinder 40 in the figure). it can. Alternatively, it can be made to protrude larger than this.
Further, as shown in FIG. 6, a stopper clearance C < _b > ₂ is formed between the tip of the first rubber stopper portion 64 and the abutting portion 72 formed from the bottom portion of the bag-like portion 68.

The large bush 28 also has a bridge-shaped first bridge that bridges both sides in the circumferential direction of the window 66, that is, the left and right sides in FIG. 6, at a position between the inner cylinder 42 and the window 66 of the outer cylinder 40. Two rubber stoppers 74 are provided.
The first rubber stopper portion 64 is formed integrally with the second rubber stopper portion 74.

Here between the inner cylinder 42 and the rubber elastic body 44 side and the second rubber stopper 74, the stopper clearance C ₁ as shown in FIG. 6 are formed.
Here stopper clearance C ₁ is a small size in comparison with the stopper clearance C ₂ above.
As shown in FIGS. 3 and 5, the second stopper portion 74 is integrally provided with a third rubber stopper portion 76 that protrudes larger in the axial direction than the window portion 66.

Next, the operation of the torque rod of this embodiment will be described.
In the torque rod 22 of the present embodiment, FIG. 6 initially as shown in (I) Large bushing 28 has a second rubber stopper 74 and the inner cylinder 42 and the rubber elastic body 44 at a stopper clearance C ₁ Are in a separated state.
Note first rubber stopper 64 naturally this time also is in a state of relative contact portion 72 spaced from each other at a stopper clearance C _2.

In this state, when vibration is input to the torque rod 22 and the vibration is slight vibration, only the rubber elastic body 44 is elastically deformed, and the fine vibration is absorbed by the elastic deformation of the rubber elastic body 44 to be vibration-insulated. .
8 in K ₁ represents a spring constant of the time.

On the other hand, when the inner cylinder 42 is relatively displaced in the right direction in FIG. 7 relative to the outer cylinder 40 during acceleration, the inner cylinder 42 (strictly speaking, the inner cylinder 42 and the rubber elastic body 44 side, hereinafter simply referred to as the inner cylinder). 7) is in contact with the second stopper portion 74 as shown in FIG. 7 (II), and the second rubber stopper portion 74 is elastically deformed integrally with further displacement in the same direction. Let
This point stopper function of the second rubber stopper 74 occurs, the spring constant of that time will be shown in FIG. 8 K _2.
The spring constant K ₂ as shown in FIG. 8 is greater than the spring constant K _1, the inner cylinder 42 therefore restraining force is increased for further displacement by abutting the second rubber stopper 74.

When the displacement of the inner cylinder 42 is further increased, as shown in FIG. 7 (III), the first rubber stopper portion 64 comes into contact with the contact portion 72. This time, the first rubber stopper portion 64 acts as a stopper. Eggplant. The spring constant of the time is the K ₃ in FIG.
At this time, the third rubber stopper portion 76 integrally formed with the second rubber stopper portion 74 is still separated from the outer cylinder 40. However, when the inner cylinder 42 is further greatly displaced in the right direction in the drawing, Next to the first rubber stopper 64, the third rubber stopper 76 comes into contact with the outer cylinder 40 (position IV in FIG. 8), where the resistance force against the displacement of the inner cylinder 42 increases rapidly. Thus, the stopper 42 prevents the inner cylinder 42 from being greatly displaced beyond the allowable limit.

According to the present embodiment as described above, the stopper bushing can be made large without particularly increasing the diameter of the large bush 28, and the protruding height of the first rubber stopper portion 64 that serves as a stopper during acceleration is increased. In addition, the stopper contact can be delayed and the initial spring characteristics after the stopper contact, that is, at the time of the stopper action, can be kept low, and vibration insulation during acceleration can be performed well.
In addition, since the contact with the stopper can be slowed, the spring constant of the rubber elastic body 44 itself can be kept low, and therefore vibration isolation during idling can be performed well.
On the other hand, when a large load is input, a large compressive elastic deformation of the first rubber stopper portion 64 can generate a large resistance force against the displacement and reliably prevent a large displacement from exceeding an allowable limit. can do.

In the present embodiment, the bridge-shaped second rubber stopper portion 74 and the third rubber stopper portion 76 are provided. As a result, the large bush 28 is provided with the first rubber stopper portion 64, the second rubber stopper portion 74, and the third rubber stopper. By having the portion 76, the stopper action can be performed in three stages.
As a result, the spring constant until the allowable deformation limit is reached can be reduced overall and effectively, and a low spring constant can be maintained in the region before the allowable deformation limit is reached, and vibration isolation is improved. The effect which can be performed is acquired.

Although the embodiment of the present invention has been described in detail above, this is merely an example.
For example, the plate body 30-1 constituting the connecting body 30 can be made of resin depending on circumstances.
In the above embodiment, the second rubber stopper portion 74 is provided and the first rubber stopper portion 64 is formed integrally therewith. However, in some cases, the second rubber stopper portion 74 is omitted, and the rubber that is the main rubber portion. The first rubber stopper portion 64 may be integrally formed with the elastic body 44 or the inner cylinder 42 depending on circumstances, and the present invention can be configured in various modifications without departing from the spirit of the present invention. is there.

It is a figure which shows the torque rod of one Embodiment of this invention with an engine and a suspension member. It is a perspective view of the torque rod of the embodiment. It is side surface sectional drawing of the torque rod of the same embodiment. It is a plane sectional view of the torque rod of the embodiment. It is a figure of the big bush in the torque rod of the embodiment. It is a principal part enlarged view of FIG. It is operation | movement explanatory drawing of the torque rod of the embodiment. It is a figure which shows the spring characteristic of the torque rod of the embodiment. It is a figure which shows an example of a conventionally well-known torque rod. It is a figure of the conventional torque rod different from FIG.

Explanation of symbols

22 Torque rod 26 Small bush 28 Large bush 30 Connecting body 32, 40 Outer cylinder 41 Press-fit part 34, 42 Inner cylinder 36, 44 Rubber elastic body 48 Straight part 64 First rubber stopper part 66 Window part 68 Bag-like part 72 Contact Part 74 Second rubber stopper part 76 Third rubber stopper part

Claims (6)

A small bush and a large bush at both ends having elasticity, and a rigid coupling body for connecting them, and the large bush includes a rigid inner cylinder and an outer cylinder and a rubber elastic body for elastically coupling them in the radial direction The outer cylinder is press-fitted into a cylindrical press-fit portion provided in the coupling body and assembled to the coupling body, and is interposed between the engine side and the body side of the vehicle. In the torque rod that receives the torque from the engine and regulates the displacement of the engine in the roll direction,
The large bush is provided with a first rubber stopper portion that acts as a stopper during acceleration so as to project radially from the inner cylinder side toward the outer cylinder side, and the outer cylinder includes the first rubber stopper portion. An opening-shaped window portion is provided to project the rubber stopper portion from the inside to the outside of the outer cylinder and project, and the connecting body is spaced apart from the window portion in the projecting direction of the first rubber stopper portion. A torque rod characterized in that a rigid contact portion for elastically deforming the first rubber stopper portion by contacting the first rubber stopper portion is provided.   2. The bridge-shaped first bridge according to claim 1, wherein the large bush is bridged at positions between the inner cylinder and the window of the outer cylinder at positions on both sides in the circumferential direction of the window of the outer cylinder. 2. A torque rod, wherein a second rubber stopper is provided separately from the rubber elastic body, and the first rubber stopper is formed integrally with the second rubber stopper.   The torque rod according to claim 2, wherein the second rubber stopper portion is formed in a state of forming a gap with respect to the inner cylinder and the rubber elastic body.   4. The bridge-shaped second rubber stopper portion according to claim 2, wherein the first rubber stopper portion abuts against the outer cylinder after the first rubber stopper portion abuts against the abutting portion and elastically deforms by a predetermined amount. A torque rod characterized in that it also functions as a third rubber stopper portion that acts as a stopper.   In any one of Claims 1-4, the part around the said window part in the said connection body is formed in the bag shape, and the said contact part is comprised by the bottom part of this bag, It is characterized by the above-mentioned. Torque rod.   6. The connection body according to claim 1, wherein the connecting body is formed by superposing and joining two plate bodies having symmetrical shapes to each other, and each outer cylinder press-fitting cylinder in the large bush is attached to each plate body. A torque rod, wherein each half of the press-fitting portion of the shape is formed.

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