JP3016454B2 - Vehicle power unit mounting structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power unit mount structure for a vehicle, and more particularly to a power unit mount structure for a vehicle, which reduces an impact acting on an occupant in the event of a vehicle collision.

[0002]

2. Description of the Related Art A power unit of an automobile is elastically supported on a vehicle body via an engine mount. When the automobile collides with an obstacle in front of the automobile, a time lapse from the occurrence of the collision and a deceleration acting on the passenger compartment are reduced. It is known that the relationship becomes a characteristic as shown by a virtual line in FIG. 7 according to the embodiment. still,
The time integral sum of the characteristic line corresponds to the collision speed and correlates with the collision energy. That is, in the first half of the first half of the collision, as shown in FIGS. 8 and 9, the vehicle body B and the power unit E behave independently via the spring system S of the engine mount and are decelerated. Although it becomes relatively high, when the spring system S of the engine mount is fully extended in the latter half of the first half of the collision, the vehicle body B and the power unit E are decelerated as shown in FIG. Speed decreases. In the late stage of the collision, the power unit E stops moving forward due to the obstacle, and as shown in FIGS. 11 and 12, the collapse of the front part of the vehicle body progresses and the resistance increases, so that the deceleration of the vehicle body suddenly increases and peaks. Reach.

An occupant in a vehicle cabin is restrained to a certain extent by a vehicle body with a seat belt or an airbag, but is not integrated with the vehicle body. Therefore, the occupant is displaced forward relative to the vehicle body, and deceleration of the vehicle body is reduced. At approximately the peak, the relative speed of the occupant to the vehicle body is maximized, and the head and chest are damaged. Conventionally, various measures have been taken to reduce the impact received by the occupant in the event of a collision, such as improving the collapse pattern and spring constant of the front frame at the front of the vehicle body and strengthening the vehicle body frame that forms the cabin. It is being taken. Conventionally, when setting the collapse pattern of the front part of the vehicle body, it has been performed to add a power unit as a rigid body of a predetermined size, but the technology to improve the impact at the time of collision by adding the mass of the power unit is Not proposed at all.

On the other hand, as an engine mount for supporting a power unit on a vehicle body, a rubber mount has been generally applied in the past, but in recent years, a liquid-sealed rubber mount has been widely put into practical use.
As described in Japanese Unexamined Patent Publication No. 2, various active engine mounts capable of variably controlling a damping force by electric control have been proposed and put into practical use. In addition, for example,
As described in Japanese Patent No. 164638, a normal engine mount is provided with a roll stopper for restricting rolling of the power unit. However, conventionally, in an engine mount of a power unit in which a roll axis is directed in a vehicle width direction,
Roll stoppers are provided at least on both front and rear sides of the engine mount, and in a power unit engine mount having a roll axis oriented in the front-rear direction, roll stoppers are provided on at least left and right sides of the engine mount.

[0005]

Generally, in a conventional vehicle, as shown in FIG. 7, since the deceleration of the vehicle body decreases in the latter half of the first half of the collision, the peak value of the deceleration in the latter half of the collision becomes higher. Therefore, the relative speed of the occupant to the vehicle body increases, the impact acting on the occupant from the vehicle body or seat belt increases, and the timing of restraining the occupant by the seat belt or air bag is delayed, so that the seat belt or air bag is effective. There is a problem such as a decrease in the performance. SUMMARY OF THE INVENTION An object of the present invention is to provide a power unit mounting structure for a vehicle that can effectively utilize the mass of the power unit to reduce the impact acting on an occupant during a collision.

[0006]

According to a first aspect of the present invention, there is provided a power unit mounting structure for a vehicle, comprising: a fixed portion fixed to a vehicle body; a support portion for supporting the power unit; and a mount rubber mounted between the fixed portion and the support portion. A power unit mount structure for a vehicle having elastic support means including: a stopper for restricting movement of the support portion, wherein the power unit is easily displaced forward and rearward with respect to the vehicle body in the event of a vehicle collision. It is configured to be difficult to perform.

According to a second aspect of the present invention, in the vehicle power unit mounting structure, the stopper is provided only on the rear side of the support portion in the structure of the first aspect. According to a third aspect of the present invention, there is provided a power unit mounting structure for a vehicle according to the first aspect, wherein the stopper is provided on both front and rear sides of a support portion, and rubber members integrated with or separately from a mount rubber are provided at front and rear portions of the support portion. The front rubber member is softer than the rear rubber member. According to a fourth aspect of the present invention, there is provided a power unit mount structure for a vehicle according to the first aspect, wherein the stopper is provided on both front and rear sides of the support portion, and the front stopper has lower rigidity than the rear stopper.

[0008]

In the power unit mounting structure for a vehicle according to the first aspect, a stopper for restricting the movement of the support portion is provided, and the power unit is easily displaced forward and rearward with respect to the vehicle body at the time of collision of the vehicle. With this configuration, the power unit easily behaves independently of the vehicle body in the first half of the collision, so that the deceleration of the vehicle body is greater than when the power unit and the vehicle body behave integrally. As a result, the deceleration in the late stage of the collision can be reduced, and the peak of the deceleration can be advanced to reduce the impact on the occupant. Furthermore, the forward movement of the vehicle body is more likely to be restrained via the power unit when the power unit stops moving forward in the late stage of the collision, so that the deceleration of the vehicle body is promoted and the timing of the peak of the deceleration of the vehicle body is advanced. That is, the occupant begins to be restrained by the seat belt or the like at an early stage after the start of the collision, and is restrained over time, so that the impact is reduced.

According to the second aspect of the present invention, by providing the stopper only on the rear side of the support portion, the forward movement of the vehicle body can be restrained via the power unit in the late stage of the collision, and the deceleration of the vehicle body can be promoted. In claim 3, the stopper is provided on both front and rear sides of the support portion, a rubber member integrated with or separate from a mount rubber is provided on each of a front portion and a rear portion of the support portion, and a front rubber member is a rear rubber member. With a softer configuration, the degree of constraint when the power unit is displaced forward with respect to the vehicle body can be set to be weaker than the degree of constraint when displaced backward. 5. The restraint degree when the power unit is displaced forward with respect to the vehicle body by providing the stopper on both front and rear sides of the support portion and configuring the front stopper with lower rigidity than the rear stopper. Can be set to be weaker than the degree of constraint when displacing rearward.

[0010]

As described above, the following effects can be obtained. According to the power unit mount structure for a vehicle according to the first aspect, since the power unit easily behaves independently of the vehicle body in the first half of the collision, the deceleration of the vehicle body is reduced as compared with the case where the power unit and the vehicle body behave integrally. growing. As a result, the deceleration in the late stage of the collision can be reduced, and the timing of the peak of the deceleration can be advanced to reduce the impact on the occupant. Furthermore, the forward movement of the vehicle body is more likely to be restrained via the power unit when the power unit stops moving forward in the late stage of the collision, so that the deceleration of the vehicle body is promoted and the timing of the peak of the deceleration of the vehicle body is advanced. That is, the occupant begins to be restrained by the seat belt or the like at an early stage after the start of the collision, and is restrained over time, so that the impact is reduced.

According to the second aspect, by providing the stopper only on the rear side of the support portion, the forward movement of the vehicle body can be restrained via the power unit in the late stage of the collision, and the deceleration of the vehicle body can be promoted. According to claim 3, the stopper is provided on both front and rear sides of the support portion, a rubber member integral with or separate from the mount rubber is provided on each of the front and rear portions of the support portion, and the front rubber member is connected to the rear rubber. Since the power unit is configured to be softer than the member, the degree of constraint when the power unit is displaced forward with respect to the vehicle body can be set to be weaker than the degree of constraint when displaced backward. According to the fourth aspect, the stopper is provided on both front and rear sides of the support portion, and the front stopper is configured to have lower rigidity than the rear stopper, so that the power unit is restrained when displaced forward with respect to the vehicle body. The degree can be set to be weaker than the degree of constraint when displacing backward.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a power unit mounting device of an FF type automobile.
Hereinafter, the power unit mounting device is abbreviated as an engine mounting device, and the front, rear, left and right are defined based on the front, rear, left and right of the vehicle. As shown in FIG. 1 and FIG.
With respect to the vehicle body structure at the front of the vehicle, wheel aprons 3 are provided on both left and right sides of the engine room 2, and a pair of left and right front frames 4 are provided at lower ends of the left and right wheel aprons 3.
The front ends of the left and right front frames 4 are connected by a first cross member 5, and the rear end of the front frame 4 is connected to a cross section 7 having a closed cross section at the lower end of a dash lower panel 6. A suspension cross member 8 is provided between the rear portions of the left and right front frames 4 and connected to each other.
A center member 9 is provided between the first cross member 5 and the first cross member 5 at a position slightly to the left of a substantially central portion in the vehicle width direction.

A power unit 10 is disposed in the engine room 2. The power unit 10 includes a first engine mount device 11 provided substantially at the center of the suspension cross member 8 in the left-right direction, and a portion near the front end of the center member 9. Engine mount device 12 provided in the vehicle
A third engine mount device 13 provided at a substantially central portion of the right front frame 4 in the front-rear direction, and a fourth engine mount device 14 provided at a substantially central portion of the left front frame 4 in the front-rear direction. It is elastically supported on the vehicle body via two engine mount devices.

The first to third engine mounting devices 11
As shown in FIGS. 3 to 5, basically, a rubber mount rubber 15, a holder member 16, a partition for partitioning the inside of the holder member 16 into a main chamber and a sub-chamber, A liquid-filled type engine mounting device having a general configuration including an orifice formed in the main body and the working fluid filled in the main chamber and the sub-chamber, which attenuates the vibration of the power unit 10. is there. As shown in FIG. 1, the fourth engine mount device 14 is a cylinder-type engine mount device having a general configuration that attenuates the vibration of the power unit 10 via a left-right-facing cylindrical rubber member.

Hereinafter, the third engine mount device 13 having a configuration unique to the present invention will be described in detail. As shown in FIGS. 3 to 5, the third engine mount device 13 is fixed to the front frame 4 via a pair of fixing bracket members 17 fixed to the front and rear portions of the holder member 16, respectively. At the same time, a substantially disk-shaped mounting bracket is fixed to the upper end of a mount rubber 15 fixed to the wheel house 19 via a fixing bracket member 18 fixed to the right part of the holder member 16 and protruding upward from the holder member 16. 2
0, a bolt 21 is erected at the center of the mounting bracket 20, and a support bracket 22 on the power unit 10 side extending to the right from the power unit 10 is fastened to the mounting bracket 20 via the bolt 21. Vibration from the power unit 10 is transmitted to the mount rubber 15 via the mounting bracket 20, and the mount rubber 15 and the holder member 16
Damped through the working fluid within.

Next, in order to allow the power unit 10 to move forward in the event of a head-on collision and to restrict the rearward movement as much as possible, a locking portion 24 extending rearward is formed at the rear end of the mounting bracket 20. At the rear of the mount rubber 15, a buffer portion 25 surrounding the locking portion 24 is formed.
A substantially U-shaped stopper member 26 is fixed to a rear portion of the upper end of the holder member so as to cover the buffer portion 25 with a predetermined gap, and a support bracket 27 extending forward is fixed to a front portion of the holder member 16. A support plate 28 extending to the right is fixed to the upper end of 26, and a partially annular reinforcing member 29 is provided on the outer peripheral side of the right part of the mount rubber 15 so as to be substantially concentric with the mount rubber 15 and inclined forward and downward. The front and rear ends of the reinforcing member 29 are connected to the right portion of the support plate 28 and the front of the support bracket 27 via bolts 30 and 31, respectively, and the front half of the reinforcing member 29 is positioned lower than the mounting bracket 20. Are located in

Next, the third engine mounting device 13
The operation of will be described. In the third engine mount device 13, the roll of the power unit 10 is regulated by the stopper 24 abutting on the stopper member 26 via the buffer 25. When the vehicle 1 collides with an obstacle ahead in a frontal collision or the like, the forward movement of the power unit 10 with respect to the vehicle body is allowed against a relatively small restraining force by the four mount rubbers 15, so that the vehicle 1 In, the vehicle body and the power unit 10 behave almost independently. Most of the vehicle body including the passenger compartment is decelerated by the collision load acting on the front frame 4, but the connection between the vehicle body and the power unit 10 is strong as in a conventional engine mount device, and these are integrally formed. 7, the deceleration of the vehicle body in the first half of the collision becomes smaller as indicated by the phantom line in FIG. The timing of the peak of the speed is also delayed.

However, the third engine mounting device 1
According to 3, since the locking portion 24 and the stopper member 26 are not provided at the front portion of the third engine mount device 13, the connection between the vehicle body and the power unit 10 in the first half of the collision is weak, and the vehicle body and the power unit 10 are substantially independent. Therefore, the deceleration of the vehicle body in the first half of the collision increases. As a result, as shown by a solid line in FIG. 7, the deceleration of the vehicle body in the early stage of the collision increases, and the deceleration of the vehicle body in the latter period of the collision decreases. In the late stage of the collision, the power unit 10 is in a stopped state, the collapse of the front part of the vehicle body progresses, and the resistance increases, so that the vehicle body is rapidly decelerated. If
In the late stage of the collision, the locking portion 24 comes into contact with the stopper member 26 via the buffer portion 25, so that the rearward movement of the power unit 10 with respect to the vehicle body, that is, the forward movement of the vehicle body with respect to the power unit 10, is restricted. The time of occurrence will be hastened.

In summary, the deceleration of the vehicle body in the early stage of the collision is promoted, the deceleration in the late stage of the collision is reduced, and the timing of the peak of the deceleration is advanced. Therefore, in the event of a collision, the occupant begins to be restrained by the vehicle body with a seatbelt or airbag from an early stage, and slowly decelerates over time. The properties are further improved. The third
In the engine mount device 13, by providing the reinforcing member 29 having a simple configuration, the rearward deformation of the stopper member 26 can be prevented, and the rearward movement of the power unit 10 can be more reliably restricted.

As described above, with the third engine mount device 13 having a simple structure, the impact at the time of a head-on collision can be reduced without providing a separate shock absorbing member or the like on the vehicle body side, thereby increasing the weight of the vehicle body. Therefore, the safety of the occupant can be further improved. In this embodiment, the reinforcing member 29 is used.
To prevent the rearward deformation of the stopper member 26, but the stopper member 26 may be made thicker, or a reinforcing bracket may be provided on the rear side of the stopper member 26,
Its strength and rigidity may be increased.

Next, the third engine mounting device 13
A description will be given of a modified example in which the configuration is partially changed.
The same members as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 6, in the third engine mount device 33, the support plate 28, the reinforcing member 29, and the support bracket 27 are omitted, and the locking unit is used to more effectively prevent the power unit 10 from rolling. A locking portion 34, a buffer portion 35, and a stopper member 36 having the same configuration as the 24, the buffer portion 25, and the stopper member 26 are provided on the front portion of the third engine mount device 33 symmetrically in the front-rear direction. An upright reinforcing rib 37 is fixed to the center of the rear side of the stopper member 26 in the width direction. The stopper member 36 has sufficient strength and rigidity to regulate the roll of the power unit 10. Is the reinforcing rib 3
7, the strength and strength of the stopper member 36
The rigidity is set high.

In the third engine mount device 33,
As in the above-described embodiment, the power unit 10 is easily displaced forward with respect to the vehicle body in the event of a collision, but is less likely to be displaced rearward. Will be further improved. Further, as a modified example, the third engine mount device 3 shown in FIG.
3, the reinforcing ribs 37 are omitted, at least the strength and rigidity of the stopper member 26 are set high, the hardness of the front buffer portion 35 is set relatively soft, and the hardness of the rear buffer portion 25 is set. By setting the hardness relatively high, the forward movement of the power unit 10 during a collision may be allowed to some extent, and the backward movement may be restricted. Alternatively, the distance between the front locking portion 34 and the stopper member 36 is set relatively long, and the distance between the rear locking portion 24 and the stopper member 26 is set relatively short. The strength and rigidity of the power unit 10 may be set high to allow the power unit 10 to move forward to some extent and restrict the movement of the power unit 10 to the rear.

Incidentally, as the first engine mount device 11, an engine mount device having the same configuration as the third engine mount devices 13 and 33 may be employed. In the second engine mount device 12, as shown in FIG.
Since the stopper member 38 for regulating the roll of the power unit 10 is provided only at the front portion of the second engine mount device 12, the stopper member 38 can be made thin or a bead that promotes forward deformation of the stopper member 38 can be provided. Holes and notches to form stopper members 3
When an excessive load is applied to the front of the stopper 8, the stopper member 38 may be relatively easily deformed forward. Further, as the fourth engine mount device 14, an engine mount device having a symmetrical configuration with the third engine mount devices 13 and 33 may be employed. In addition, a simple rubber engine mount device may be adopted as the engine mount devices 11 to 13 and 33.

[Brief description of the drawings]

FIG. 1 is a plan view of a front portion of a vehicle body.

FIG. 2 is a cross-sectional view of a front part of a vehicle body.

FIG. 3 is a front view of a third engine mount device.

FIG. 4 is a side view of a third engine mount device.

FIG. 5 is a plan view of a third engine mount device.

FIG. 6 is a side view of a third engine mount device according to a modification.

FIG. 7 is a characteristic diagram of deceleration of a vehicle body at the time of a collision of an automobile.

FIG. 8 is a mechanism diagram of a front structure of a vehicle before a collision.

FIG. 9 is a mechanism diagram of a front structure of an automobile at the time of starting a collision.

FIG. 10 is a mechanism diagram of a front structure of an automobile in a first half of a collision.

FIG. 11 is an initial mechanism diagram of the front structure of the vehicle in the late stage of the collision.

FIG. 12 is a mechanism diagram of the front structure of the automobile at a late stage of the collision.

[Explanation of symbols]

 13 Third engine mounting device 15 Mount rubber 16 Holder member 17 Bracket member 24 Locking portion 25 Buffering portion 26 Stopper member 34 Locking portion 35 Buffering portion 36 Stopper member 37 Reinforcing rib

Continuation of front page (56) References JP-A-63-43043 (JP, A) JP-A-4-50745 (JP, U) JP-A-3-17338 (JP, U) JP-A-64-12948 (JP , U) Japanese Utility Model Showa 62-136646 (JP, U) Japanese Utility Model Showa 63-168340 (JP, U) Japanese Utility Model Showa 61-202729 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) B60K 5/12

Claims (4)

(57) [Claims] 1. A power unit mounting structure for a vehicle, comprising: a fixed portion fixed to a vehicle body; a support portion for supporting a power unit; and elastic support means including mount rubber mounted between the fixed portion and the support portion. A power unit mounting structure for a vehicle, comprising a stopper for restricting the movement of the support portion, wherein the power unit is easily displaced forward and hardly rearward with respect to the vehicle body in the event of a vehicle collision. 2. The power unit mounting structure for a vehicle according to claim 1, wherein the stopper is provided only on a rear side of a support portion. 3. The stopper is provided on both front and rear sides of a support portion, and rubber members integral with or separate from a mount rubber are provided on a front portion and a rear portion of the support portion, respectively, and a front rubber member is separated from a rear rubber member. The power unit mount structure for a vehicle according to claim 1, wherein the power unit mount structure is also soft. 4. The power unit mount structure for a vehicle according to claim 1, wherein the stopper is provided on both front and rear sides of the support portion, and the front stopper has a lower rigidity than the rear stopper.