Power unit mounting structure

Abstract

To provide a power unit mounting structure that, in the event of a vehicle collision, tilts the power unit and moves it to the rear of the vehicle, thereby preventing the power unit from colliding with components located at the rear of the engine compartment. [Solution] The bracket 20 consists of a first bracket 21 and a second bracket 22. The vibration-damping bush 12A is formed in a cylindrical shape having a bolt through hole 12B extending in the vehicle width direction, and is sandwiched between the rear end of the first bracket 21 and the rear end 25 of the second bracket 22, and is supported by a bush bolt 22C that passes through the second bracket 22 and the bolt through hole 12B and is fastened to the first bracket 21. Between the second bolts 22A, 22B and the bush bolt 22C in the second bracket 22, a weak portion 23 is formed that bends in the longitudinal direction of the vehicle when subjected to an impact force of a predetermined value or more from the front of the vehicle.

Description

Technical Field

[0001] The present invention relates to a mounting structure of a power unit.

Background Art

[0002] Patent Document 1 describes a mounting structure of a power unit that can achieve both strength to suppress an input load from an engine and fracture strength required at the time of a vehicle collision. This mounting structure includes a torque rod connected to a bracket via a connecting bolt, and a stiffener that connects the bracket and the connecting bolt. The stiffener is formed to have lower rigidity than the bracket. Thereby, at the time of a vehicle collision, the low-rigidity stiffener is deformed and the collar of the torque rod falls, generating a bending stress due to a rotational moment on the rod portion of the torque rod. Then, by breaking a vulnerable portion with low rigidity of the torque rod by this bending stress, the impact absorption stroke can be lengthened.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional technology described in Patent Document 1, although the impact absorption performance can be improved by damaging the torque rod at the time of a vehicle collision and moving the power train backward, there is a risk that the power unit that has moved backward collides with auxiliary components and damages the auxiliary components.

[0005] The present invention aims to provide a power unit mounting structure that, in the event of a vehicle collision, tilts the power unit and moves it to the rear of the vehicle, thereby preventing the power unit from colliding with components located at the rear of the engine compartment. [Means for solving the problem]

[0006] The present invention relates to a mounting structure for a power unit comprising: a power unit whose upper ends at both ends in the vehicle width direction are supported by the vehicle body; a torque rod extending in the vehicle longitudinal direction; a cylindrical vibration-damping bush provided at the front end of the torque rod; and a bracket connecting the vibration-damping bush to the lower part of the central portion of the power unit in the vehicle width direction, wherein the bracket comprises a first bracket fixed to the power unit by a plurality of first bolts, and a second bracket extending in the vehicle longitudinal direction and fixed to the vehicle width direction side of the first bracket by a plurality of second bolts, wherein the vibration-damping bush is formed in a cylindrical shape having bolt through holes extending in the vehicle width direction, and is supported by bush bolts that are fastened to the first bracket through the second bracket and the bolt through holes while sandwiched between the rear end of the first bracket and the rear end of the second bracket, the second bolts are positioned away from the front of the vehicle from the bush bolts, and a weak portion is formed between the second bolts and the bush bolts in the second bracket that bends in the vehicle longitudinal direction when subjected to an impact force of a predetermined value or more from the front of the vehicle. [Effects of the Invention]

[0007] As described above, the present invention provides a power unit mounting structure that, in the event of a vehicle collision, tilts the power unit and moves it to the rear of the vehicle, thereby preventing the power unit from colliding with components located at the rear of the engine compartment. [Brief explanation of the drawing]

[0008] [Figure 1]Figure 1 is a bottom view of the front of a vehicle equipped with a power unit mounting structure according to one embodiment of the present invention. [Figure 2] Figure 2 is a perspective view of the torque rod and bracket of a power unit mounting structure according to one embodiment of the present invention. [Figure 3] Figure 3 is a plan view of the torque rod and bracket of a mounting structure for a power unit according to one embodiment of the present invention. [Figure 4] Figure 4 is a right side view of the torque rod and bracket of a mounting structure for a power unit according to one embodiment of the present invention. [Figure 5] Figure 5 is a bottom view of a vehicle equipped with a power unit mounting structure according to one embodiment of the present invention, after deformation caused by a collision at the front of the vehicle. [Figure 6] Figure 6 is a perspective view of a bracket for a power unit mounting structure according to one embodiment of the present invention. [Modes for carrying out the invention]

[0009] A power unit mounting structure according to one embodiment of the present invention comprises a power unit whose upper ends at both ends in the vehicle width direction are supported by the vehicle body, a torque rod extending in the vehicle longitudinal direction, a cylindrical vibration-damping bush provided at the front end of the torque rod, and a bracket connected to the vibration-damping bush and the lower part of the central part in the vehicle width direction of the power unit, wherein the bracket consists of a first bracket fixed to the power unit by a plurality of first bolts, and a second bracket extending in the vehicle longitudinal direction and fixed to the vehicle width direction side of the first bracket by a plurality of second bolts, the vibration-damping bush is formed in a cylindrical shape having bolt through holes extending in the vehicle width direction, and is supported by bush bolts that are fastened to the first bracket through the second bracket and the bolt through holes while sandwiched between the rear end of the first bracket and the rear end of the second bracket, the second bolts are positioned away from the front of the vehicle from the bush bolts, and a weak portion is formed between the second bolts and the bush bolts in the second bracket that bends in the vehicle longitudinal direction when subjected to an impact force of a predetermined value or more from the front of the vehicle. As a result, the power unit mounting structure according to one embodiment of the present invention can tilt the power unit and move it to the rear of the vehicle during a vehicle collision, thereby preventing the power unit from colliding with components located at the rear of the engine compartment. [Examples]

[0010] The following describes a mounting structure for a power unit according to one embodiment of the present invention, with reference to the drawings.

[0011] Figures 1 to 6 show a mounting structure for a power unit according to one embodiment of the present invention. In Figures 1 to 6, the vertical, horizontal, front-rear, and left-right directions are defined as the front-rear direction of the vehicle, the left-right direction of the vehicle (vehicle width direction), and the vertical direction of the vehicle (vehicle height direction).

[0012] First, let's explain the configuration. In Figure 1, a power unit 8 consisting of an engine 8A and a transmission 8B is installed at the front of the vehicle 1. The transmission 8B is connected to the left end of the engine 8A. The vehicle 1 includes a side panel 3 extending in the front-rear direction at the left end of the vehicle 1, a side panel 4 extending in the front-rear direction at the right end of the vehicle 1, and a dash panel 2 extending in the width direction behind the power unit 8. The space between the left and right side panels 3 and 4 and in front of the dash panel 2 constitutes the engine room 1A, and the power unit 8 is housed in the engine room 1A.

[0013] The upper left end of the power unit 8 in the vehicle width direction is supported by the side panel 3 by a mounting member 5, and the upper right end of the power unit 8 in the vehicle width direction is supported by the side panel 4 by a mounting member 6.

[0014] Vehicle 1 includes a torque rod 10 extending in the longitudinal direction of the vehicle, a vibration-damping bush 12A made of a cylindrical elastic body provided at the front end of the torque rod 10, and a bracket 20 connected to the vibration-damping bush 12A and the lower mounting surface 8C of the central part of the power unit 8 in the vehicle width direction. In this way, vehicle 1 supports the power unit 8 by a so-called pendulum-type mounting structure.

[0015] Here, the mounting surface 8C of the power unit 8 consists of a plane extending in the longitudinal direction of the vehicle at the left end of the rear end of the transmission 8B. The rear end of the torque rod 10 is fixed to the vehicle frame 1B by a bolt 14. The vehicle 1 also has a component 7 behind the left portion of the power unit 8 in the engine compartment 1A. Component 7 consists of, for example, fuel piping.

[0016] Here, when the vehicle 1 collides, the power unit 8 retreats (is pushed in) due to the collision load to absorb the impact. However, it is conceivable that the power unit 8 that has moved backward may collide with the component 7 and damage the component 7. Therefore, when the vehicle 1 collides, it is desirable to enable the power unit 8 to retreat and absorb the impact while suppressing the power unit 8 from colliding with the component 7.

[0017] Therefore, in this embodiment, as will be described in detail below, by making the components on the right side of the bracket 20 more fragile than the components on the left side, when the vehicle 1 collides, the right part (engine 8A) of the power unit 8 retreats and the left part (transmission 8B) advances, and the power unit 8 is rotated so as to suppress the power unit 8 from colliding with the component 7.

[0018] As shown in FIGS. 2, 3, and 4, a cylindrical vehicle body side mounting portion 13 and a bush 15 formed of a cylindrical elastic body fixed inside the vehicle body side mounting portion 13 are provided at the rear end portion of the torque rod 10. The vehicle body side mounting portion 13 at the rear end portion of the torque rod 10 is fixed to the vehicle body frame 1B by a bolt 14 passing through the center of the bush 15.

[0019] A cylindrical bracket mounting portion 12 and a cylindrical vibration isolation bush 12A fixed inside the bracket mounting portion 12 are provided at the front end portion of the torque rod 10.

[0020] The torque rod 10 includes a rod portion 11 that is continuous with the bracket mounting portion 12 at the front end portion and the vehicle body side mounting portion 13 at the rear end portion thereof, and the rod portion 11 extends in the vehicle longitudinal direction.

[0021] The bracket 20 comprises a first bracket 21 made of cast aluminum and a second bracket 22 made of sheet metal. Here, sheet metal refers to a plate-shaped metal. The first bracket 21 is fixed to the lower mounting surface 8C of the center of the power unit 8 in the vehicle width direction by a plurality of first bolts 21A, 21B, and 21C. The second bracket 22 extends in the vehicle longitudinal direction. The front end 24 of the second bracket 22 is fixed to the vehicle width direction side (right side) of the front end of the first bracket 21 by a plurality of second bolts 22A and 22B.

[0022] The vibration-damping bush 12A is formed in a cylindrical shape with a bolt through hole 12B extending in the vehicle width direction. The vibration-damping bush 12A is supported by a bush bolt 22C while sandwiched between the rear end of the first bracket 21 and the rear end 25 of the second bracket 22. The bush bolt 22C is fastened to the first bracket 21 by passing through the second bracket 22 and the bolt through hole 12B. Therefore, the rear end 25 of the second bracket 22 is fixed to the vehicle width direction side (left side) of the rear end of the first bracket 21 by the bush bolt 22C, with the vibration-damping bush 12A sandwiched between it and the first bracket 21.

[0023] The second bolts 22A and 22B are positioned away from the bushing bolt 22C, extending forward of the vehicle. In other words, the second bracket 22 has a shape that extends in the longitudinal direction of the vehicle. To put it another way, the front end 24 of the second bracket 22 where the second bolts 22A and 22B are located is away from the rear end 25 of the second bracket 22 where the bushing bolt 22C is located, extending forward of the vehicle.

[0024] Between the second bolts 22A and 22B and the bushing bolt 22C in the second bracket 22 (between the front end 24 and the rear end 25), a weak portion 23 is formed that bends in a way that causes it to buckle in the longitudinal direction of the vehicle when subjected to an impact force of a predetermined value or greater from the front of the vehicle.

[0025] The front end 24 of the second bracket 22 is located on the extension of the axis that runs through the left and right centers of the torque rod 10. The rear end 25 of the second bracket 22 is located to the right in the vehicle width direction of the front end 24.

[0026] The vulnerable portion 23 has an inclined surface 23B that is obliquely inclined with respect to the vehicle's longitudinal direction. Because the vulnerable portion 23 has an inclined surface 23B, the collision load applied to the front end 24 of the second bracket 22 from the rear acts to deform (shorten) the vulnerable portion 23 of the second bracket 22 in the vehicle's longitudinal direction.

[0027] The weak portion 23 has an opening 23A. The presence of the opening 23A reduces the rigidity of the weak portion 23.

[0028] Thus, the second bracket 22 can be deformed more easily in the longitudinal direction of the vehicle by collision load than the first bracket 21, and furthermore, by having a weak portion 23 with reduced rigidity due to the shape of the inclined surface 23B and the opening 23A, it can be reliably deformed in the longitudinal direction of the vehicle by collision load.

[0029] As shown in Figure 6, the opening 23A is formed on the axis of the first bolt 21C and has an opening area through which the tool 30 used to tighten the first bolt 21C passes. Of the three first bolts 21A, 21B, and 21C, the space along the extension of the heads of the first bolts 21A and 21B is outside the outer edge of the second bracket 22. Therefore, the first bolts 21A and 21B can be fastened without interfering with the second bracket 22.

[0030] As described above, in this embodiment, the bracket 20 consists of a first bracket 21 fixed to the power unit 8 by a plurality of first bolts 21A, 21B, and 21C, and a second bracket 22 extending in the vehicle longitudinal direction and fixed to the vehicle width side of the first bracket 21 by a plurality of second bolts 22A and 22B. The vibration-damping bush 12A is formed in a cylindrical shape having a bolt through hole 12B extending in the vehicle width direction, and is supported by a bush bolt 22C that passes through the second bracket 22 and the bolt through hole 12B and fastens to the first bracket 21 while sandwiched between the rear end of the first bracket 21 and the rear end 25 of the second bracket 22. The second bolts 22A and 22B are positioned away from the bush bolt 22C in the vehicle forward direction, and a weak portion 23 is formed between the second bolts 22A and 22B and the bush bolt 22C in the second bracket 22, which bends in the vehicle longitudinal direction when subjected to an impact force of a predetermined value or more from the front of the vehicle.

[0031] As a result, the second bracket 22 has lower rigidity than the first bracket 21, and as shown in Figure 5, the second bracket 22 can be deformed more easily in the longitudinal direction of the vehicle compared to the first bracket 21 during a collision with the vehicle 1.

[0032] Furthermore, since the portion of the second bracket 22 between the second bolts 22A and 22B and the bushing bolt 22C extends beyond a predetermined distance in the vehicle's longitudinal direction, the amount of deformation of the second bracket 22 during a collision with the vehicle 1 can be increased compared to the case where the second bracket 22 has a shorter shape in the vehicle's longitudinal direction.

[0033] Furthermore, during a collision with vehicle 1, the second bracket 22 buckles in the longitudinal direction at the weak point 23, becoming shorter. As a result, bracket 20 is displaced to the left, and the torque rod 10 connected to bracket 20 rotates to the left with the position of bolt 14 as the pivot point (see arrow C). In addition, the output shaft 8D of the power unit 8 tilts diagonally, with its right portion retracting (see arrow B) and its left portion moving forward (see arrow A). As a result, the rear surface 8E of the power unit 8 moves away from component 7, with its right portion retracting and its left portion moving forward. Therefore, component 7 can be protected. If the collision load acting on vehicle 1 is even greater, the power unit 8 may tilt diagonally and retract as a whole, causing not only the right portion but also the left portion of the rear surface 8E of the power unit 8 to retract. However, even in that case, the amount of retraction of the left portion of the rear surface 8E of the power unit 8 is smaller than that of the right portion, so component 7 can still be protected.

[0034] As a result, when vehicle 1 collides, the power unit 8 is tilted and moved to the rear of the vehicle, preventing it from colliding with component 7 located at the rear of engine compartment 1A.

[0035] Furthermore, in this embodiment, the vulnerable portion 23 has an inclined surface 23B that is obliquely inclined with respect to the vehicle's longitudinal direction.

[0036] This allows the rigidity of the weak point 23 to be adjusted by adjusting the length of the inclined surface 23B.

[0037] In this embodiment, the vulnerable portion 23 has an opening 23A.

[0038] This allows the rigidity of the weak point 23 to be adjusted by adjusting the size of the opening 23A.

[0039] Furthermore, in this embodiment, the opening 23A is formed on the axis of the first bolt 21C and has an opening area through which the tool 30 for tightening the first bolt 21C passes.

[0040] This allows the tightening of the first bolt 21C to be performed using the opening 23A, which reduces the rigidity of the weak part 23, thereby improving work efficiency.

[0041] While embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that modifications can be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims. [Explanation of Symbols]

[0042] 1 vehicle 1B Vehicle frame (vehicle body) 3, 4 Side panels (vehicle body) 8 Power Units 10 Torque Rod 12A Vibration-damping bushing 12B Bolt through hole 20 brackets 21 First bracket 21A, 21B, 21C First bolt 22 Second Bracket 22A, 22B Second bolt 22C bushing bolts 23 Vulnerable parts 23A opening 23B Slope 30 Tools

Claims

1. A mounting structure for a power unit comprising: a power unit whose upper ends in the vehicle width direction are supported by the vehicle body; a torque rod extending in the vehicle longitudinal direction; a cylindrical vibration-damping bush provided at the front end of the torque rod; and a bracket connecting the vibration-damping bush to the lower part of the central portion of the power unit in the vehicle width direction, The bracket comprises a first bracket fixed to the power unit by a plurality of first bolts, and a second bracket extending in the longitudinal direction of the vehicle and fixed to the side of the first bracket in the vehicle width direction by a plurality of second bolts. The vibration-damping bush is formed in a cylindrical shape having a bolt through hole extending in the vehicle width direction, and is sandwiched between the rear end of the first bracket and the rear end of the second bracket, and is supported by a bush bolt that passes through the second bracket and the bolt through hole and is fastened to the first bracket. The second bolt is positioned away from the bushing bolt and towards the front of the vehicle. A mounting structure for a power unit, characterized in that a weak portion is formed between the second bolt and the bushing bolt in the second bracket, which bends in a state that causes it to buckle in the longitudinal direction of the vehicle when subjected to an impact force of a predetermined value or more from the front of the vehicle.

2. The power unit mounting structure according to claim 1, characterized in that the weak portion has an inclined surface that is obliquely inclined with respect to the vehicle's longitudinal direction.

3. The mounting structure for a power unit according to claim 2, characterized in that the vulnerable portion has an opening.

4. The mounting structure for a power unit according to claim 3, characterized in that the opening is formed on the axis of the first bolt and has an opening area through which a tool for tightening the first bolt passes.

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