JPH09240292A - Vibration damping device for power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accomplish reduction in weight and in a product cost. SOLUTION: A bracket 32 fixed in the front side part of the vehicle longitudinal direction of a power unit is formed of a steel plate and is formed into a plate shape by means of press molding, and a solid rod type connecting pin 34 is fixed in the bracket 32. A connecting plate part 32a provided with a curved shape in a plane vision and a curved plate part 32b, which constitute the bracket 32, are fixed so as to form a triangle in a plane vision with a body part 34d extended from the base end part 34b of the connecting pin 34 to the vehicle longitudinal direction side. In this way, when a vehicle longitudinal force is inputted from a mount insulator 30, the body part 34d receives the vehicle longitudinal force by means of compressive proof stress and tensile proof stress, so that deformation of the bracket 34 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolator for a power unit, which is disposed between a power unit mounted on a vehicle and a member on the vehicle body side to reduce vibration transmission from the power unit to the member on the vehicle body side.

[0002]

2. Description of the Related Art As a power unit anti-vibration device, for example, a device shown in FIG. 5 is known. FIG. 5 is a front view of the inside of the engine room, in which the engine 2 and the transmission 3 that form the power unit 1 are
It is arranged so as to extend in the vehicle width direction. A power unit vibration isolator 5 is provided between the vehicle body side member 4 that is disposed on the transmission 3 side and extends in the vehicle front-rear direction, and the vehicle front-rear direction front side portion 3a of the transmission 3. ing.

The anti-vibration device 5 includes a vehicle body side member 4
A mount insulator 6 attached to the lower part of the vehicle and a bracket 7 integrally provided with a connecting pin 7a attached to an elastic body inside the mount insulator 6 and fixed to the front side portion 3a of the transmission 3 via a bolt. Has been done.

The bracket 7 is a member made of cast metal, and is inserted into a plurality of connecting bolts for screwing the connecting bolts to the front side portion 3a of the transmission 3 after being carved into a predetermined external dimension. Secondary processing such as holes and screw holes for fixing the base ends of the connecting pins 7a is performed.

Even if a predetermined force is input by the relative movement between the vehicle body side member 4 and the engine 2 due to the vibration of the engine 2, the casting bracket 7 integrated with the connecting pin 7a has sufficient strength and rigidity. And the elastic body inside the mount insulator 6 absorbs the vibration, so that the vibration transmission to the vehicle body side member 4 is reduced.

[0006]

However, since the bracket 7 is formed by casting, it is difficult to reduce the weight of the vibration isolator 5. Further, as described above, in order to form the bracket 7, secondary processing must be performed after casting, which causes a problem in terms of product cost.

The present invention has been made by paying attention to the unsolved problem of the above-mentioned conventional example, and for a power unit which has the same function as that of the conventional device but can be reduced in weight and product cost. It is an object to provide a vibration isolation device.

[0008]

In order to achieve the above object, the invention according to claim 1 is a bracket fixed to a front side portion in a vehicle front-rear direction of a power unit mounted horizontally, and a bracket for the vehicle. The mount insulator is fixed to the vehicle body side member located on the outer side in the width direction, and the mount insulator in which the shaft center of the elastic body mounted inside is oriented in the vehicle width direction, and the pin tip end is mounted on the shaft center of the elastic body of the mount insulator. In a power unit vibration isolator including a connecting pin having a pin base end fixed to the bracket, the bracket is formed by press molding using a steel plate, and the power unit is formed in a shape along the front side of the power unit. A connecting plate part fixed via a plurality of fastening bolts and a front part of the vehicle continuously from the outside in the vehicle width direction of the connecting putt part. A plate base shape that is bent in a plan view with a bending plate portion that extends toward the base plate, the connecting pin is formed by a long member having a solid rod shape, and the pin base end is fixed to the connecting plate portion of the bracket. A portion, a pin tip portion located on the front side of the vehicle with respect to the portion, a pin distal end portion extending from the pin base end portion to the front side of the vehicle, and fixed to the bending plate portion of the bracket, and the connecting plate portion and the A shape including a bent plate portion and a pin body portion that forms a substantially triangular shape in a plan view is adopted.

According to the present invention, since the bracket has a plate material shape formed by press-molding a steel plate and the connecting pin having a solid rod shape is fixed to the bracket, the conventional device using a cast member is compared. Therefore, the weight of the vibration isolator can be reduced.

Further, when the force in the front-rear direction of the vehicle is input to the connecting pin and the bracket through the mount insulator, the pin body forming a substantially triangular shape in plan view with the connecting plate portion and the bent plate portion of the bracket. However, the bracket itself is prevented from being deformed by receiving the force due to its compressive strength and tensile strength.

According to a second aspect of the present invention, in the vibration isolator for a power unit according to the first aspect, the pin base end portion is formed as a flat plate pin base end portion by forging, and the flat plate shape is obtained. The pin base end portion is fixed to the connection plate portion of the bracket by welding, and the pin base end portion and the connection plate portion fixed by this welding are attached to the front side portion of the power unit via the fastening bolt. Fixed

According to the present invention, the edge portion of the fixed portion of the connecting pin formed as a flat plate by forging is fixed to the connecting plate portion of the bracket by welding, and the fixed portion is further connected to the power unit via the fastening bolt. It is fixed to the front part of the, and the fixing part of the connecting pin has a structure as if the wall thickness is thick, so even if the force in the vertical direction of the vehicle is input to the fixing part of the connecting pin via the mount insulator, The fixing strength of the connecting pin is sufficiently secured, and the rigidity of the bracket is improved.

Further, the invention according to claim 3 is the invention according to claim 1.
Alternatively, in the vibration isolator for a power unit described in 2, a reinforcing wall rising from the peripheral edge of the connecting plate portion toward the front of the vehicle is continuously formed up to the bending plate portion.

According to the present invention, the reinforcing wall prevents the bracket from being deformed even when a force in the front-rear direction of the vehicle is input to the bracket through the mount insulator.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a vibration isolator for a power unit according to the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a front view showing the inside of the engine room of the vehicle, and FIG. 2 is a plan view showing the inside of the engine room. In these figures, a power unit 20 is composed of an engine 22 mounted horizontally (in the vehicle width direction) and a transmission 24 integrally connected to the left side of the engine 22 in the vehicle width direction. .

The power unit 20 is supported by a member on the vehicle body side through a plurality of anti-vibration devices connected to both ends in the vehicle width direction and to the front and rear sides of the vehicle. These FIGS. 1 and 2
In FIG. 2, a device indicated by reference numeral 26 is a vibration isolator disposed between a front side portion 24 a of the transmission 24 and a vehicle body side member (vehicle body side member) 28. The vibration isolator 26 is a vehicle body side member. A mount insulator 30 fixed to the lower surface of the member 28, a bracket 32 fixed to the front side portion 24a of the transmission 24, a press-fit pin portion (pin tip portion) 34a at the tip end portion, and a base end side (pin base portion) are formed. The end portion) is composed of a connecting pin 34 fixed to the bracket 32.

The mount insulator 30 is shown in FIG.
And as shown in FIG. 4, a cylindrical outer cylinder member 30a,
A pair of flange portions 30b ₁ and 30b ₂ extending in opposite directions from the outer periphery of the outer tubular member 30a, and the outer tubular portion 30a.
A mount rubber (elastic body) 30c mounted by vulcanization adhesion inside, and an inner cylinder member 30d mounted at the axial center position of the mount rubber 30c. As shown in FIG. 3, a plurality of currants 30c ₁ are formed on the mount rubber 30c. Then, the pair of flange portions 30b ₁ and 30b ₂ have bolt insertion holes 30b ₃ and 3b.
0b ₄ are formed and these bolt insertion holes 30
Bolts 36 (see FIG. 1) inserted into b ₃ and 30 b ₄ from below are screwed into screw holes formed in the vehicle body side member 28 and tightened. As a result, the mount insulator 30 is fixed to the lower portion of the vehicle body side member 28.

Further, the bracket 32 is formed by press molding using a steel plate as a material, and as shown in FIG.
The rear surface 32a ₁ is provided with the transmission 2 so that the contact area with the front side portion 24a of the transmission 24 becomes large.
Connection plate part 3 formed in a shape along the front side part 24a of FIG.
2a and a bending plate portion 32b that continuously extends from the left side of the connecting plate portion 32a in the vehicle width direction toward the front side of the vehicle are formed as a plate material having a bending shape in plan view.

A reinforcing wall 32c is formed so as to rise from the peripheral edge of the connecting plate portion 32a toward the surface 32a ₂ side, and the reinforcing wall 32c extends to the bent plate portion 32b. A curved portion 32b ₁ having a curved surface that comes into contact with the outer peripheral surface of the connecting pin 34 described later is formed at the edge of the bent plate portion 32b. Further, the connecting plate portion 32a is formed with three bolt insertion holes 38a, 38b, 38c penetrating the front and back surfaces 32a ₁ , 32a ₂ .

The connecting pin 34 is formed of a solid rod-shaped elongated member, and as shown in FIG. 3, a body portion 34d.
A press-fit pin portion 34a having an outer diameter larger than the inner diameter of the inner tubular member 30d is formed at one end portion of the inner cylindrical member 30d, and a flat plate-shaped fixing portion (flat plate) is formed by forging at the other end side of the body portion 34d. Shaped pin base end portion) 34b is formed.

The body portion 34d is fixed to the fixed portion 34b.
Side first bending position 34c₁At an angle of about 45 °
Second bending position 3 on the press-fit pin portion 34a side after being bent
4c _TwoAt the bending position 34c₁Bending direction of
The shape is bent at an angle of about 45 ° in the opposite direction.
I have.

Further, between the second bending position 34c ₂ and the press-fitting pin portion 34a, a ring-shaped brim member 40 having an outer diameter larger than that of the outer cylinder member 30a of the mount insulator 30 is fitted. ing. Further, the fixed portion 34b
In the plate thickness direction, a bolt insertion hole 34e having the same hole diameter as that of the bolt insertion hole 38c formed in the connection plate portion 32a is formed.

Then, as shown in FIG.
The outer circumference of the body portion 34d of the curved portion 32b _{1 of the} bracket 32
After contact with the curved surface, in contact with the fixing portion 34b on the surface 32a ₂ of the connecting plate portion 32a, the bolt insertion holes 34e of the connecting pin 34, the farthest bolt insertion holes 38c from the reinforcing wall 32c of the bracket 32 Correspond. And
Areas indicated by reference numerals 42 and 44 in FIG. 3 and reference numeral 46 in FIG.
The connecting pin 34 and the bracket 32 are integrally fixed to each other by joining the region indicated by 48 by fillet welding. Here, as shown in FIG. 3, the body portion 34d of the connecting pin 34 is fixed to the connecting plate portion 32a and the bending plate portion 32b in a substantially triangular shape in plan view.

Further, the press-fitting pin portion 34a of the connecting pin 34
By press-fitting the press-fitting pin 36a into the inner cylinder member 30d of the mount insulator 30, the connecting pin 34 and the mount insulator 30 are integrally connected.

A vibration isolator 2 comprising the above-mentioned components
In order to arrange 6 between the front side portion 24a of the power unit 20 in the vehicle width direction and the vehicle body side member 28, as shown in FIG. 1, the reinforcing wall 32c is located above the vehicle and the connecting pin 34 is provided. The rear surface 32a _{1 of the} bracket 32 is attached to the transmission 2 while the fixing portion 34b of the
4 abutting on the front side portion 24a of each of the bolt insertion holes 38a, 3
8b and 38c are made to correspond to the unit side screw holes formed in the front side portion 24a. Then, the bolts 52 and 54 are inserted through the bolt insertion holes 38a and 38b and screwed into the unit side screw holes to be tightened. Further, the bolt 56 is also inserted into the bolt insertion hole 38c corresponding to the bolt insertion hole 34e, and is screwed into the unit side screw hole formed in the front side portion 24a to be tightened.

Further, the pair of flange portions 30b ₁ and 30b ₂ of the mount insulator 30 are brought into contact with the lower surface of the vehicle body side member 28 so that the flange portions 30b ₁ and 30b
Bolts 36 are inserted from below into the bolt insertion holes 34b ₃ and 34b ₄ of b ₂ , and these bolts 36 are screwed into the screw holes of the vehicle body side member 28 and tightened. As a result, the front side portion 24 a of the engine transmission 24 is supported by the vehicle body side member 28 via the vibration isolation device 26.

When the vibration of the power unit 20 is input to the mount insulator 30 via the bracket 32, the mount rubber 30c absorbs the vibration and reduces the transmission of the vibration to the vehicle body side member 28.

At this time, a predetermined force is input from the mount insulator 30 to the bracket 32 and the connecting pin 34 due to the relative movement of the vehicle body side member 28 and the engine 22 due to the vibration of the engine 22.
2 and the connecting pin 34 are required to have sufficient strength and rigidity to withstand the above-mentioned force.

When the force F _{1 in the} vehicle front-rear direction shown in FIG. 2 is input from the mount insulator 30 to the bracket 32 and the connecting pin 34 as the above-mentioned force, the connecting plate portion 32a and the bending plate portion 3 of the bracket 32 are used.
2b is fixed to the body portion 34d of the connecting pin 34 so as to have a triangular shape in a plan view, and receives the force F ₁ by the compressive strength and tensile strength of the body portion 34d extending in the front-rear direction of the vehicle. To prevent the bracket 32 from being deformed. Further, the reinforcing wall 32c extending in the vehicle width direction at the upper portion of the bracket 32 also receives the force F _{1 in} the front-rear direction of the vehicle and prevents the bracket 32 from being deformed.

On the other hand, as shown in FIG. 1, when the vertical force F ₂ of the vehicle is input to the mount insulator 30, the fixing portion 34b of the connecting pin 34 is formed as if the wall thickness is increased. Since it is integrated with the bracket 32, sufficient fixing strength and rigidity are secured even if the force F ₂ is input.

That is, the fixing portion 34b is formed in a flat plate shape, and the edge portion thereof is fixed to the bracket 34 by fillet welding in the areas indicated by reference numerals 46 and 48, and this fixing portion is further connected via the bolt 56 to the transmission. Two
4 is fixed to the front side portion 24a of the vehicle 4 and is fixed as if the wall thickness is increased.
_{Even if 2} is input, the strength of the fixed portion can be sufficiently secured.

Therefore, the vibration isolator 26 having the above structure is
Since the bracket 32 is formed by press molding using a steel plate as a material, the weight of the vibration isolator 26 can be reduced as compared with the conventional device using a cast member, and the complicated secondary machining work of the bracket 32 can be performed. Since it is not necessary, the unit cost of the device can be significantly reduced.

When the force F _{1 in} the longitudinal direction of the vehicle is input to the mount insulator 30, the bracket 3 is used.
2 connecting plate part 32a and bending plate part 32b
Is fixed to the body portion 34d of the connecting pin 34 so as to have a triangular shape in a plan view, and receives the force F ₁ due to the compression strength and the tensile strength of the body portion 34d to prevent the bracket 32 from being deformed. The reinforcing wall 32c extending in the vehicle width direction at the upper part of the bracket 32 also receives the force F ₁ to prevent the bracket 32 from being deformed, and therefore the strength and rigidity of the vibration isolator 26 can be sufficiently ensured.

When the vertical force F ₂ of the vehicle is input to the mount insulator 30, the connecting pin 34 is used.
The fixed portion 34b formed as a flat plate is fixed to the bracket 34 at the edge portion by fillet welding, and this fixed portion is further attached via the bolt 56 to the transmission 24.
Since it is fixed to the front side portion 24a of the connecting pin 34 as if it had been made thicker, it is possible to sufficiently secure the fixing strength of the connecting pin 34.

Although the above embodiments have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and the shape of the vibration isolator 26 may be within a range not departing from the gist of the present invention. For example, the same effects as those described above can be obtained.

[0037]

As described above, according to the first aspect of the present invention.
The power unit vibration isolator has a structure in which a bracket that is fixed to the front part of the power unit in the vehicle front-rear direction is formed into a plate shape by press forming using a steel plate, and a solid rod-shaped connecting pin is fixed to the bracket. Therefore, it is possible to reduce the weight of the anti-vibration device as compared with the conventional device using the cast member, and the complicated secondary processing work of the bracket becomes unnecessary, so that the unit cost of the device can be significantly reduced.

When force in the front-rear direction of the vehicle is input to the connecting pin and the bracket via the mount insulator, the pin body forming a substantially triangular shape in plan view with the connecting plate portion and the bent plate portion of the bracket. However, since the bracket is prevented from being deformed by receiving the force due to its own compressive strength and tensile strength, it is possible to sufficiently secure the strength and rigidity of the vibration damping device.

According to the power unit vibration isolation device of the second aspect, the effect of the first aspect can be obtained, and the edge of the fixing portion of the connecting pin formed as a flat plate by forging is connected to the bracket. It is fixed to the plate portion by welding, and this fixed portion is fixed to the front side portion of the power unit via a fastening bolt, and the fixing portion of the connecting pin is as thick as possible. As a result, even if the vertical force of the vehicle is input to the fixing portion of the connecting pin via the mount insulator,
It is possible to sufficiently secure the fixing strength of the connecting pin.

Further, according to the power unit vibration damping device of the third aspect, the effect of the first or second aspect can be obtained, and the force in the front-rear direction of the vehicle is input to the bracket through the mount insulator. , The reinforcing wall that extends from the peripheral edge of the connecting plate portion toward the front of the vehicle and is continuously formed up to the bending plate portion prevents the bracket from being deformed, so that the strength and rigidity of the vibration isolation device should be sufficiently ensured. You can

[Brief description of drawings]

FIG. 1 is a front view of an engine room showing a power unit and a vibration isolator according to the present invention.

FIG. 2 is a plan view of an engine room showing a power unit and a vibration isolator according to the present invention.

FIG. 3 is a plan view showing a vibration isolator for a power unit of the present invention.

FIG. 4 is a front view showing a vibration isolator for a power unit of the present invention.

FIG. 5 is a front view showing a conventional vibration damping device.

[Explanation of symbols]

20 Power Unit 22 Engine 24 Transmission 24a Front Side of Transmission (Front Side of Power Unit) 26 Vibration Isolator for Power Unit 28 Vehicle Side Side Member (Vehicle Side Member) 32 Bracket 30 Mount Insulator 30c Mount Rubber (Elastic Body) 32c Reinforcing Wall 32a Connection Plate part 32b Bending plate part 34 Connecting pin 34a Press-fitting pin (pin tip part of connecting pin) 34b Flat plate fixing part (flat plate pin base end part) 34d Connecting pin body part 46, 48 Fixing part and connecting plate part Welding area with 52, 54, 56 bolts (fastening bolts)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takahisa Hiraide 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd.

Claims (3)

[Claims] 1. A bracket fixed to a front side portion in a vehicle front-rear direction of a power unit mounted horizontally, and an elastic body fixed to a vehicle body side member positioned outside the bracket in a vehicle width direction and mounted inside. A vibration insulator for a power unit including a mount insulator whose axis is oriented in the vehicle width direction, and a connecting pin whose pin tip is attached to the axis of an elastic body of the mount insulator and whose pin base is fixed to the bracket. In the device, the bracket is formed by press molding using a steel plate as a material, and is formed into a shape along the front side portion of the power unit, and is fixed to the power unit via a plurality of fastening bolts; A plate material shape that is bent in a plan view and includes a bent plate portion that continuously extends from the outside in the vehicle width direction toward the front of the vehicle. And then, the formed by elongated solid member rod-shaped connecting pins, and the pin base end portion which is secured to the connecting plate portion of the bracket, and a pin tip positioned on the front side of the vehicle than this,
A pin body portion that extends from the pin base end portion to the front side of the vehicle and is fixed to the bending plate portion of the bracket, and that the connecting plate portion and the bending plate portion form a substantially triangular shape in a plan view. An anti-vibration device for a power unit, which has a shape provided with. 2. The pin base end portion is formed as a flat pin base end portion by forging, and the flat plate pin base end portion is fixed to the connecting plate portion of the bracket by welding, and The anti-vibration device for a power unit according to claim 1, wherein the pin base end portion and the connection plate portion that are fixed by welding are fixed to the front side portion of the power unit via the fastening bolt. 3. The vibration isolator for a power unit according to claim 1, wherein a reinforcing wall rising from the peripheral edge of the connecting plate portion toward the front of the vehicle is continuously formed up to the bending plate portion. .