JP2012232743A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric vehicle that can prevent the damage of a battery unit, even if the collision is made from the side where a power unit is mounted, or even if the collision is made from the side where the power unit is not mounted.SOLUTION: The electric vehicle is provided with a battery unit side bracket fragile part 48 that breaks when a shock load more than the prescribed amount is applied between a power unit mounting bush 24 which is elastically supported by the power unit 16 of a battery unit side bracket 23, and a vehicle body mounting bush 26 which is elastically supported by a vehicle body when colliding at one end side in vehicle longitudinal direction or when colliding at the other end side in vehicle longitudinal direction, and is also provided with a deflection control means 51 to suppress deflection of the power unit mounting bracket only when the shock load is input from the one end of the vehicle body, and the battery unit side bracket fragile part is made to break by the shock load, wherein the shock load input from the one end when colliding at one end side in the vehicle longitudinal direction is smaller than the shock load input from the other end when colliding at the other end side in the vehicle longitudinal direction.

Description

  The present invention relates to an electric vehicle equipped with a power unit and a battery unit.

  In electric vehicles, in order to improve reliability, reduce costs, and shorten the development period, use the body of a vehicle equipped with an internal combustion engine to install a power unit composed of an electric motor or a battery unit that serves as a power source. May be installed. Specifically, as shown in Patent Document 1, the engine room formed at the front and rear end of the vehicle body is used as it is as a power unit room to mount the power unit, or under the floor of the cabin formed in the center of the vehicle body A battery unit is mounted.

Normally, a power unit of an electric vehicle is structured to be elastically supported on each part of a power unit room via a bracket protruding from each part of the power unit and a body mounting bush for elastic support provided at the tip of the bracket as in Patent Document 1. It has been carried out using a vehicle.
Unlike an internal combustion engine, an electric motor that constitutes a power unit generates high-frequency vibration during operation. Therefore, the battery unit side bracket that supports the end of the power unit on the battery unit side supports the power unit via the power unit mounting bush. The vibration structure is adopted to prevent the high frequency vibration of the power unit from being transmitted to the vehicle body.

  By the way, as described above, since the space for mounting the device is easily secured at the center and the end of the vehicle body as described above, the power unit and the battery unit are structurally mounted adjacent to each other. The layout is easy to be forced. In particular, the cruising distance of an electric vehicle largely depends on the electric capacity of the mounted battery, and there is a demand for mounting a battery as large as possible, so it is difficult to make a large gap between the adjacent power unit and the battery unit. It is.

  Therefore, the electric vehicle has a limited gap between the power unit and the battery unit. Therefore, the battery unit side bracket uses an arm member extending in the vehicle width direction through the end of the power unit on the battery unit side, and elastically supports both ends of the arm member on the vehicle body via the vehicle body mounting bush. A structure is used in which both sides of the intermediate portion of the member are elastically supported by the power unit via the power unit mounting bush so as to occupy less in the longitudinal direction of the vehicle body.

JP-A-8-310252

By the way, in the electric vehicle, when a collision load is input to one end of the vehicle body at the time of a collision from the side (one end side) on which the power unit is mounted, the power unit remains due to inertia, and only the vehicle body moves toward the battery unit. A behavior of forced displacement occurs.
At this time, the stress caused by the relative displacement between the vehicle body and the power unit concentrates on the portion between the power unit mounting bushes having a large support span at the battery unit side bracket. For this reason, the battery unit side bracket is broken from the same portion, and the action of displacing the power unit to the battery unit is suppressed.

However, the broken battery unit side bracket continues to be supported by the power unit.
For this reason, the broken part of the broken bracket part remains in the center in the vehicle width direction even after the broken part. In particular, since the distance (gap) between the power unit and the battery unit is small, the broken bracket part is directed to the battery unit as it is due to the forced displacement of the vehicle body.

  For this reason, the sharp fracture | rupture part of the fracture | ruptured bracket part collides with the edge part of a battery unit, and there exists a problem which damages a battery unit. In addition, the vehicle body mounting bush is not able to move freely due to the load from the power unit at this time, so it cannot escape and hits the end of the battery unit as it is, causing damage to the battery unit. .

In such a case, in the field of automobiles, a weak part is formed in the battery unit side bracket, and the battery unit side bracket is broken from a specific place.
However, in an electric vehicle, simply forming the weakened portion does not prevent the battery unit from being damaged.
This is because the behavior at the time of collision from the side where the power unit of the electric vehicle is not mounted (the other end side) is different from that at the time of collision from the side where the power unit is mounted (one end side). is there.

In other words, unlike a collision on the side where the power unit is mounted (one end side), an electric vehicle has a collision load on the other end of the vehicle body when a collision occurs from the side where the power unit is not mounted (the other end side). When input, a behavior occurs in which the power unit is forcibly displaced toward the battery unit due to inertia.
At this time, unlike the collision from the side (one end side) where the power unit is mounted, the battery unit side bracket is required to suppress breakage as much as possible and to prevent the power unit from approaching the battery unit.

  However, simply forming the fragile portion makes it easy for the battery unit side bracket to break even when a collision occurs from the side where the power unit is not mounted (the other end side). For this reason, conversely, at the time of a collision from the side where the power unit is not mounted, the power unit easily collides with the battery unit, and the battery battery unit is easily damaged.

  Accordingly, an object of the present invention is to provide an electric vehicle capable of suppressing damage to a battery unit even at the time of a collision from the side on which the power unit is mounted or at the time of a collision from the side where the power unit is not mounted. It is to provide.

  The invention according to claim 1 is mounted on the center in the front-rear direction of the vehicle body adjacent to the power unit, a power unit composed of equipment for driving the vehicle, a vehicle body on which the power unit is mounted on one end side in the vehicle front-rear direction, A battery unit serving as a power source for the vehicle and a plurality of brackets for attaching the power unit to the vehicle body. Each of the plurality of brackets has a vehicle body mounting bush, and is elastically supported by the vehicle body via the vehicle body mounting bush. The plurality of brackets include a battery unit side bracket that supports an end of the power unit on the battery unit side, and the battery unit side bracket has a power unit mounting bush and is elastically supported by the power unit via the power unit mounting bush. , Power unit mounting bush and body mounting bush A battery unit side bracket weakened part that breaks when an impact load of a predetermined level or more is applied at the time of a collision at one end in the vehicle longitudinal direction or at the other end in the vehicle longitudinal direction. The battery unit side bracket fragile portion is input from one end portion of the vehicle body at the time of a collision on one end side in the vehicle front-rear direction, having a deflection suppressing means for suppressing the deflection of the power unit mounting bush only when a load is input. The impact load is formed so as to break with an impact load smaller than the impact load input from the other end portion of the vehicle body at the time of a collision on the other end side in the longitudinal direction of the vehicle.

In the invention according to claim 2, when the deflection suppressing means allows the deflection of the power unit mounting bush when the impact load is input from the other end of the vehicle body, and when the impact load is input from the one end of the vehicle body Is constituted by a deflection limiting member that abuts between the power unit and the battery unit side bracket with rigid bodies.
According to the third aspect of the present invention, the lower side of the battery unit side bracket in the vicinity of the vehicle body mounting bushing facing the end of the battery unit has a protruding portion protruding toward the battery unit.

According to a fourth aspect of the present invention, the lower part of the vehicle body mounting bush of the battery unit side bracket is provided so as to wrap with the upper surface of the adjacent battery unit.
In the invention according to claim 5, the battery unit side bracket extends in the vehicle width direction, and the battery unit side bracket fragile portion is formed with a concave portion extending in the vertical direction on the side surface facing the power unit side of the battery unit side bracket. It was decided.

  According to the sixth aspect of the present invention, in addition to the battery unit side bracket, the bracket has an opposite side bracket that supports an end opposite to the battery unit, and the opposite side bracket has an attachment point to which the power unit is attached. It has an opposite side bracket weak part between the vehicle body mounting bush, and the opposite side bracket weak part breaks at an earlier stage than the battery unit side bracket weak part breaks at the time of collision on one end side in the vehicle longitudinal direction, The battery unit side bracket fragile portion at the time of a collision on the other end side in the vehicle longitudinal direction is formed so as to be broken at a load larger than the breaking load.

  According to the first aspect of the present invention, the battery unit side bracket can be quickly mounted on the vehicle body at the time of a collision from the side (one end side) on which the power unit is mounted due to the difference in the breaking characteristics of the battery unit side bracket weak part. The bush is broken while leaving a bracket portion having a short overall length, making it difficult for the power unit and the battery unit to collide. At this time, the bracket portion remaining on the vehicle body mounting bush is short, and the broken bracket portion can move freely and easily escape from the battery unit, so that the sharply broken portion of the broken bracket portion collides with the battery unit. prevent. In addition, since the vehicle body mounting bush can also move freely, the vehicle body mounting bush is prevented from colliding with the battery unit.

In particular, by having a deflection suppressing means, the battery unit side bracket can be broken without being affected by the elasticity of the power unit mounting bush at the time of a collision from the side (one end side) on which the power unit is mounted. You can finish up to the unit.
In addition, when a collision occurs from the side where the power unit is not mounted (the other end side), the bracket on the battery unit side is not broken and prevents the power unit from colliding with the battery unit by suppressing the displacement of the power unit to the battery unit. .

  Therefore, it is possible to suppress damage to the battery unit even at the time of a collision from the side where the power unit is mounted or at the time of a collision from the side where the power unit is not mounted. In particular, the same effect is effective for an electric vehicle in which the battery unit side bracket fragile portion having different breaking characteristics is used for the battery unit side bracket, and the gap between the battery unit and the power unit cannot be increased.

According to the invention of claim 2, this structure can be realized with a simple structure in which only a deflection limiting member is provided.
According to the third and fourth aspects of the present invention, the vehicle body mounting bush can easily ride on the upper surface of the battery unit.
According to the invention of claim 5, the groove-shaped concave portion formed on the side surface of the battery unit side bracket is bent in a direction in which the opening of the concave portion is likely to be broken during a collision from the side where the power unit is mounted. In the event of a collision from the side where the power unit is not mounted, stress is applied. On the other hand, bending is applied in the direction in which the opening is narrowed, making it difficult to break, so the collision from the side where the power unit is mounted is simple. It is possible to obtain a battery unit-side bracket weakened portion having a breaking characteristic required at the time of a collision from the side where the power unit is not mounted.

  According to the invention of claim 6, in cooperation with the battery unit side bracket weak part, at the time of a collision from the side (one end side) where the power unit is mounted and from the side (the other end side) where the power unit is not mounted. In both cases, the power unit can be made more difficult to collide with the battery unit, and the effect of suppressing damage to the battery unit can be enhanced.

The side sectional view showing the rear side in which the power unit and battery unit of the electric vehicle concerning one embodiment of the present invention are carried. The perspective view which shows the structure where the same power unit was mounted in the vehicle body. The top view which shows the support structure which supports each part of the power unit to a vehicle body. The disassembled perspective view which shows the rear bracket which comprises the support structure. The disassembled perspective view which shows the bracket which supports the edge part by the side of the battery unit of a power unit. The top view which shows the part to which the power unit of the bracket attaches, a weak part, and a bush for vehicle body attachment. The perspective view for demonstrating the position of the bush for vehicle body attachment. The perspective view which shows when a rear bracket fractures | ruptures by the impact load at the time of the collision from the side in which the power unit is mounted. The top view which similarly shows when a rear bracket fractures | ruptures. The side view which shows a time when a rear bracket similarly fractures | ruptures with a periphery apparatus and member. The side view which shows that the attitude | position of a power unit changes according to the fracture | rupture of the rear bracket. The perspective view which shows the front bracket fractured | ruptured after the rear bracket. The top view which shows the weak part which the front bracket fractured | ruptured. The perspective view which shows the bracket part which remains in the bush for vehicle body attachment after the same fracture | rupture. The side view explaining the behavior which the bush for vehicle body attachment after the fracture | rupture escapes from a battery unit. The side view explaining the behavior which the power unit after the fracture | rupture escapes from a battery unit. The side view explaining the behavior which suppresses the forced displacement of a power unit at the time of the collision from the side in which a power unit is not installed, without breaking a front bracket. The top view explaining the behavior of the weak part of the front bracket. The top view explaining the behavior which suppresses the forced displacement of a power unit at the time of a collision from the side in which a power unit is not installed, without breaking a rear bracket.

Hereinafter, the present invention will be described based on an embodiment shown in FIGS.
FIG. 1 shows a side sectional view of the rear side of an electric vehicle, in which 1 is a vehicle body. The vehicle body 1 has a luggage compartment 2 at the rearmost part in the front-rear direction and a passenger cabin 3 at the center in the front-rear direction. Reference numeral 4 denotes a pair of side frames (members forming the skeleton of the vehicle body 1) disposed on the lower surface of the vehicle body 1.
As shown in FIG. 2, two side frames 4 are arranged in parallel in the vehicle width direction at a predetermined interval, both of which are formed at the lower surface of the floor of the cabin 3 and at a point higher than the floor of the cabin 3. It passes through the lower surface of the floor of the cargo compartment 2 and extends in the vehicle longitudinal direction. In FIG. 1, 4 a indicates a rear portion passing under the cargo compartment 2. A space at the rear end of the vehicle body (one end side in the vehicle front-rear direction) formed under the floor of the cargo compartment 2 is defined as a power unit room 5. In addition, a space on the center side in the longitudinal direction of the vehicle body surrounded by the side frames 4 and 4 under the floor of the cabin 3 is a battery unit housing chamber 6. Specifically, as shown in FIG. 1, the battery unit housing chamber 6 is formed between the side frames 4, 4 that are continuous from the lower side of the rear seat 8 installed on the rear side of the cabin 3 to the lower side of the front seat 9 that is also installed on the front side. It is formed in a flat space. That is, the power unit room 5 and the battery unit accommodation chamber 6 have a layout adjacent to each other in the vehicle front-rear direction.

Among these, in the battery unit accommodation chamber 6, the battery unit 10 is accommodated so as to occupy the same space. A battery unit 10 serving as a power source of an electric vehicle has a box-shaped structure in which a large number of battery modules 12 are housed in a box-shaped housing container 11. The rear end of the battery unit 10 faces the power unit room 5.
As shown in FIG. 2, the power unit 16 is housed in the power unit room 5 together with a control unit 27 for controlling the power unit 16 and a mount frame 30 for mounting them.

Explaining the structure, the power unit 16 is formed by connecting an electric motor 17 and a speed reducer 18 in the vehicle width direction (lateral direction) and connecting a differential 19 to the speed reducer 18 as shown in FIG.
Of these, as shown in FIGS. 3 and 4, the support plate portion 17x projecting toward the rear side of the vehicle body of the electric motor 17 has an arm-shaped rear bracket 21 having a vehicle body mounting bush 20 at the tip (an opposite side bracket of the present application). Is equivalent). Specifically, as shown in FIGS. 3 and 4, the vehicle body mounting bush 20 includes a circular frame portion 20b formed at the front end of the rear bracket 21, and a cylindrical shape press-fitted into the frame portion 20b. The bush member 20a is combined. Then, the base end portion of the rear bracket 21 is fastened to the support plate portion 17x with the bolt nut 22, and the vehicle body mounting bush 20 at the front end is protruded to the rear side of the vehicle body.

  Further, a front bracket 23 (corresponding to the battery unit side bracket of the present application) extending in the vehicle width direction is provided in a casing portion facing the vehicle body front side of the electric motor 17 and the speed reducer 18. Specifically, as shown in FIGS. 2, 3, and 5, the front bracket 23 is connected to the side of the horizontally-mounted electric motor 17 and the speed reducer 18 that is the end of the power unit 16 on the battery unit side. One arm member extending in the width direction is used. A short cylindrical power unit mounting bush 24 is press-fitted on both sides of the intermediate portion of the arm member. The intermediate portions of the arm members are elastically supported on the support seats 17a and the support seats 18a formed on the casing portions of the electric motor 17 and the speed reducer 18 with the bolts 25 via the power unit mounting bushes 24, respectively. It is. In addition, vehicle body mounting bushings 26 are provided at both ends of the arm member protruding from the end of the electric motor 17 and the end of the speed reducer 18 respectively. Similarly to the rear bracket 21, the vehicle body mounting bush 26 has a structure in which a circular frame portion 26b formed at each end of the arm member and a cylindrical bush member 26a press-fitted into the frame portion 26b are combined. It has become.

As shown in FIG. 2, the control unit 27 includes an inverter device 28 a that varies the power supply frequency of the electric motor 17, a control device 28 that controls the inverter device 28 a according to the driving state of the vehicle, a DC / DC converter 29 a, and a charging device. The devices 29 are arranged in the vehicle width direction.
The mount frame 30 is a member that forms part of the vehicle body 1, and as shown in FIGS. 2 and 3, a pair of side frame portions 31 that extend in parallel to the rear side of the vehicle body 1 and the rear ends of the side frame portions 31. It has a substantially U shape having an end frame portion 32 connecting the portions. Among these, the pair of side frame portions 31 pass through the ends of the electric motor 17 and the speed reducer 18 and extend in the front-rear direction of the vehicle body 1, and the end frame portions 32 pass through the rear of the power unit 16 and extend in the vehicle width direction. ing. As shown in FIGS. 2 and 3, the mount frame 30 is connected to the skeleton of the power unit room 5 via the front mounting seat 34 provided at the end of the side frame portion 31 and the rear mounting seat 35 provided at the end frame portion 32. The bolts and nuts 37 are fastened to the lower parts of the rear parts 4a and 4a (side frames) and the lower part of the cross member part 36 formed between the rear parts 4a and 4a.

  As shown in FIGS. 1 and 2, the inverter device 28a and the control for controlling the inverter device 28a on the upper portion of the suspended mount frame 30, that is, on the side frame 31 and the end frame 32, according to the driving state of the vehicle. A device 28, a DC / DC converter 29a, and a charging device 29 are mounted. The power unit 16 is suspended below the mount frame 30, that is, below the side frame 31 and the end frame 32. Specifically, as shown in FIGS. 2 and 5, the power unit 16 is supported by bolt nuts 40 on a pair of mount brackets 39 in which the vehicle body mounting bushes 26 of the front bracket 23 are attached to the side frames 31. As shown in FIGS. 2 and 4, the vehicle body mounting bush 20 of the rear bracket 21 is supported by the mount bracket 41 attached to the center of the end frame portion 32 with a bolt nut 42, thereby mounting the frame 30. It is hung on.

  That is, each part of the power unit 16 such as the end on the battery unit side of the power unit 16 and the end on the opposite side is connected to the vehicle body 1 by the plurality of brackets 21 and 23 having the vehicle body mounting bushes 20 and 26 and the power unit mounting bush 24. Is elastically supported. Furthermore, a double vibration isolation structure is provided by providing the power unit mounting bush 24 to prevent high frequency vibrations from the electric motor 17 from being transmitted to the vehicle body 1 (high vibration absorption).

The front bracket 23 has a side where the power unit 16 of the vehicle body 1 is mounted (one end side in the vehicle front-rear direction) (a rear collision in this embodiment) and a side where the opposite power unit 16 is not mounted (vehicle). A device has been devised to prevent damage to the battery unit 17 both at the time of a collision at the other end in the front-rear direction) (front collision in this embodiment).
2, 3, and 5, each bracket portion 23 a between the power unit mounting bush 24 and the vehicle body mounting bush 26 of the front bracket 23 (indicated by the one-dot chain line α in FIG. 2). Position), the front bracket weakened portion 48 (battery unit side bracket weakened portion of the present application) having different breaking characteristics at the time of the collision on the side where the power unit 16 is mounted and on the side where the power unit 16 is not mounted. Equivalent to the above) is used.

  These front bracket fragile portions 48 have a normal characteristic of breaking when an impact load of a predetermined level or more is applied, and from the rear portion (one end side) of the vehicle body 1 at the time of collision on the side (one end side) on which the power unit 16 is mounted. The impact load that is input easily breaks, and the impact load that is input from the front portion (the other end side) of the vehicle body 1 at the time of collision on the side where the opposite power unit 16 is not mounted (the other end side) is not easily broken. The structure is used. Specifically, the front bracket fragile portion 48 has a structure in which a concave portion extending in the vertical direction, for example, a groove-shaped concave portion 49 is formed on the side surface of the bracket portion 23a facing the power unit 16 as shown in FIGS. It is used.

  When the vertical concave portion 49 that opens to the power unit 16 side is formed in this way, the vehicle body 1 is forced to the bracket portion 23a at the time of a collision from the side on which the power unit 16 is mounted (rear collision). Due to the behavior of being displaced, bending stress is applied from the direction in which the opening of the groove-shaped concave portion 49 is likely to be broken. Further, at the time of a collision from the side where the opposite power unit 16 is not mounted (frontal collision), the behavior that the power unit 16 is forcibly displaced by the collision causes a fracture that the opening of the groove-shaped recess 49 is narrowed. Bending stress is applied from the direction where it does not occur easily. Due to this difference, when the impact load P1 is input from the rear portion of the vehicle body 1 and the impact load P2 is input from the front portion of the vehicle body 1, the impact load P2 is applied in the event of a collision on the side where the power unit 16 is mounted. The front bracket 23 is ruptured with an extremely small impact load P1, and the front bracket 23 is not ruptured even with a large impact load P2 at the time of a collision on the side where the power unit 16 is not mounted. . Of course, the recess 49 may be a simple recess other than the groove shape as long as such control of breakage is possible.

  Due to the difference in breaking characteristics, the front bracket 23 is broken at the time of a collision from the side on which the power unit 16 is mounted (rear collision) leaving a short bracket portion 23b on the vehicle body mounting bush 26. (3 divisions). As a result, the bracket portion 23a released from the support of the power unit 16 escapes so as to avoid the battery unit 10, and the vehicle body mounting bush 26 rides on the battery unit 10 and escapes. ing. Further, at the time of a collision from the side where the power unit 16 is not mounted (frontal collision), the front bracket 23 is prevented from being broken as much as possible, and a behavior that makes it difficult to displace the power unit 16 to the battery unit 10 is obtained.

  At this time, the deflection of the power unit mounting bush 24 prevents the front bracket 23 from being broken during a collision from the side on which the power unit 16 is mounted (rear collision). In order to improve this, as shown in FIGS. 2, 3, 5, and 6, the front bracket 23 has a deflection suppressing portion 50 (which corresponds to the deflection suppressing means of the present application) that suppresses the deflection of the power unit mounting bush 24. ) Is provided. As shown in FIGS. 5 and 6, the deflection suppressing portion 50 is formed between the head that protrudes toward the battery unit 10 side of the bolt 25 that supports the front bracket 23 on the power unit 16 and the end portion of the power unit mounting bush 24. In addition, a circular washer 51 (made of a rigid body; corresponding to the deflection limiting member of the present application) having an outer diameter larger than that of the power unit mounting bush 24 is assembled.

  As shown by the solid line in FIG. 6, this washer 51 is normally kept away from the front bracket 23, and from the rear of the vehicle body (the side on which the power unit 16 is mounted) as shown in FIG. When the impact load P1 is input and the power unit mounting bush 24 is bent, the outer peripheral end of the washer 51 and the side of the front bracket 23 abut against each other. Further, the impact load P2 from the front part of the vehicle body (the side where the power unit 16 is not mounted) is bent as it is. Thus, only when an impact load at the time of collision from the side (one end side) on which the power unit 16 is mounted is input, the power unit 16 and the front bracket 23 are abutted with each other by rigid bodies, and the power unit mounting bush 24 is bent. The impact load P1 is concentrated in the concave portion 49. By controlling the deflection, the front bracket 23 is controlled to be broken until the front bracket 23 reaches the battery unit 10.

  Further, by providing the washer 51 on the surface of the front bracket 23 on the battery unit 10 side, the elasticity of the power unit mounting bush 24 is inhibited during a rear collision, and the elasticity of the power unit mounting bush 24 is not inhibited during a front collision. The break control in each mode such as the rear collision and the front collision at the front bracket 23 is preferably performed.

  On the other hand, as shown in FIG. 7, the position of the vehicle body mounting bush 26 is as close to the side frame portion 31 (mounting frame) as shown by the arrow H in order to make it easier to ride the vehicle body mounting bush 26 onto the battery unit 10, that is, It is positioned closer to the side frame 4. Thus, the end portion of the vehicle body mounting bush 26, specifically, the L portion where the lower portion from the axial center position and the lower portion from the upper surface of the battery unit 10 wraps below a predetermined value, specifically as much as possible. The vehicle body mounting bush 26 is easily mounted on the upper surface of the battery unit 10 while keeping the dimensions small.

  In addition, in order to make it easier for the vehicle body mounting bush 26 to ride on the battery unit 10, as shown in FIGS. 2, 5, 6, and 7, a slope portion 53 is provided below the vehicle body mounting bush 26. Is provided. Specifically, as shown in FIG. 7, the slope portion 53 is a frame portion 26 b that wraps with the end portion of the battery unit 10 among the end surface portions facing the end portions of the battery unit 10 of the frame portion 26 b that houses the bush member 26 a. A structure in which a protrusion 54 protruding toward the battery unit 10 is formed in the lower half of the battery is used. When the vehicle body mounting bush 26 comes into contact with the battery unit 10 due to the projecting portion 54 protruding in the arc shape, the projecting portion 54 comes into contact with the battery unit 10 first, and the vehicle body mounting bush 26 and the frame portion 26b are brought into contact with each other. Tilt forward more smoothly. Thus, the vehicle body mounting bush 26 and the frame portion 26b make it easy to ride on the battery unit 10.

  On the other hand, as shown in FIGS. 2, 3, and 4, the rear bracket 21 (corresponding to the bracket on the opposite side of the present application) is provided between the mounting point S (shown only in FIG. 3) to which the power unit 16 is attached and the vehicle body mounting bush 20. Further, a rear bracket weak portion 56 (corresponding to the opposite bracket weak portion of the present application) is provided. As shown in FIG. 3, the rear bracket weakened portion 56 is formed with an offset portion 57 formed by obliquely bending the middle portion of the rear bracket 21, so that the attachment point S to which the power unit 16 is attached and the vehicle body mounting bush 20. A structure with an offset is used. Due to the offset portion 57, the rear bracket 21 is easily broken due to a large bending moment in the offset portion 57 due to the forced displacement of the vehicle body 1 against a collision from the side where the power unit 16 is mounted. For the collision from the side where the power unit 16 is not mounted, the offset unit 57 is deformed in the extension direction due to the forced displacement of the power unit 16, and the breaking characteristic is not easily caused. ing. In other words, the rear bracket 21 also has a rupture characteristic that it is easy to break at the time of collision from the side where the power unit 16 is mounted and is not easily broken at the time of collision from the side where the power unit 16 is not mounted. It is. Note that F in FIG. 3 indicates an offset amount of the offset portion 57.

  Further, the rear bracket 21 is constituted by a frame-shaped frame 21a as shown in FIG. 4 in order to ensure required breaking characteristics and necessary rigidity strength, and the middle of the frame 21a with respect to the vehicle width direction. The rigidity strength is changed by offsetting, adding various ribs 58, increasing the rigidity strength of the mounting point S where the power unit 16 is attached and the point where the vehicle body mounting bush 20 is located, and decreasing the rigidity strength of the intermediate offset portion. Easy-to-use structure is used.

  Due to the structure of the rear bracket 21 and the setting of the offset portion 57, the rear bracket fragile portion 56 is in an earlier stage than the front bracket fragile portion 48 breaks against a collision from the side where the power unit 16 is mounted. For the collision on the side where the power unit 16 is not mounted, the fracture characteristic is given that the fracture is caused by a load larger than the impact load of the front bracket fragile portion 40, that is, the fracture is difficult. 1, 10, 11, and 17, 59 indicates a rear wheel connected to the differential 19 through a shaft (not shown).

The front bracket fragile portion 48 and the rear bracket fragile portion 56 make it difficult for the battery unit 10 to be damaged by a collision from the side where the power unit 16 is mounted or a collision from the side where the power unit 16 is not mounted. .
That is, the behavior at the time of a collision of an electric vehicle will be described with reference to FIGS.
Now, for example, it is assumed that another vehicle has collided with the rear end portion of the stopped electric vehicle from behind the electric vehicle (collision from the side on which the power unit 16 is mounted: rear collision).

At the time of this rear impact, the electric vehicle receives an impact load P1 of a predetermined value or more from the side (one end) on which the power unit 16 is mounted as indicated by the arrow in FIG. The impact load P <b> 1 is input to the rear mounting bracket 41 and the rear end of the side frame 4 near the collision location.
Here, the rear bracket 21 and the front bracket 23 have a concave portion 49 and an offset portion 57 as weak portions. At this time, the offset portion 57 is set to be most easily broken with respect to an impact load input from the rear portion of the vehicle body 1.

Therefore, as shown in FIGS. 8 to 10, the offset portion 57 of the rear bracket 21 is broken by a bending moment M (shown in FIG. 9) generated by the input impact load P1. As a result, first, the behavior that the front end side of the rear bracket 21 is detached from the vehicle body 1 occurs.
As a result, the power unit 16 loses support on the rear side of the vehicle body, and only supports the front side of the vehicle body. Then, the rear side of the power unit 16 is lowered with the front side as a fulcrum as shown in FIG. 11 (supported by the power unit mounting bush 24 and the vehicle body mounting bush 26a). Thus, the power unit 16 assumes an oblique posture in which the rear side is lowered.

  The side frame 4 and the mount frame 30 are forcibly displaced forward by the input impact load P1, while leaving the power unit 16 due to inertia, as indicated by the arrows in FIG. Then, bending stress is generated in each part of the front bracket 23 due to the behavior of the vehicle body mounting bush 26 that is forcibly displaced together with the side frame 4 and the power unit 16 that is to remain.

At this time, as shown in FIG. 6, the bracket portion 23a between the power unit mounting bush 24 and the vehicle body mounting bush 26 is formed with a concave portion 49 that is a fragile portion that specifies the fracture position. In addition, the recess 49 is formed in a direction that is easy to break with respect to the bending moment generated at this time.
For this reason, the front bracket 23 is displaced by the forcible displacement of the side frame 4 (mount frame 30) and abuts against the washer 51, the deflection of the power unit mounting bush 24 is limited, and the impact load P1 is efficiently transmitted to the recess 49. As shown in FIG. 13, the recess 49 is deformed in the direction of expanding the opening that is likely to be broken. Then, the bracket portion 23a breaks from the same portion. Thereby, as shown in FIG. 12, the front bracket 23 is quickly divided into three parts, that is, the intermediate part and the left and right sides.

By this division, the power unit 16 is detached from the vehicle body 1. Further, as shown in FIG. 14, the vehicle body mounting bush 26 and the broken bracket portion 23b remain on the side of the vehicle body 1 that is forcibly displaced.
At this time, as shown in FIG. 14, the bracket portion 23b remaining on the vehicle body mounting bush 26 has a short overall length and is free from the support of the power unit 16 so that it can move freely. The behavior which avoids the collision with the battery unit 10, such as riding on the upper surface of the battery unit 10 as indicated by the two-dot chain line, occurs.

Thereby, even if the broken bracket part 23 faces the battery unit 10, the sharp broken part 23 c at the tip of the bracket part 23 b can be prevented from colliding with the battery unit 10.
The vehicle body mounting bush 26 itself is also released from the support of the power unit 16 and can move freely, and thus rides on the upper surface of the battery unit 10. This behavior is shown in FIGS. 15 (a) to (c).

  The behavior of riding on the vehicle body mounting bush 26 will be described. As shown in FIG. 15 (b), when the vehicle body mounting bush 26, which is in a freely movable state as shown in FIG. 15 (a), approaches the end of the battery unit 10 due to the forced displacement of the side frame 4. As described above, the protruding portion 54 in the lower portion of the frame portion 26 b (lower side from the bolt insertion position) hits the upper portion of the end portion of the battery unit 10. Then, the vehicle body mounting bush 26 is pushed by the battery unit 10 and tilts (forward tilt).

Accordingly, the vehicle body mounting bush 26 is dragged from the end of the battery unit 10 to the upper surface. By this dragging, as shown in FIG. 15 (c), the vehicle body mounting bush 26 rides so as to slide on the upper surface of the battery unit 10 while being inclined, and avoids collision with the battery unit 10.
On the other hand, as shown in FIG. 16A, the power unit 16 detached from the vehicle body 1 has a high battery unit side (front side) and a low side on the opposite side (rear side). While facing the posture, it faces the battery unit 10 and avoids a collision with the battery unit 10.

That is, as shown in FIG. 16A, the power unit 16 has an inclined lower surface portion that hits the upper stage of the end portion of the battery unit 10. Then, an upward behavior is given to the power unit 16. Thereby, as shown in FIG. 16B, the power unit 16 is displaced so as to ride on the battery unit 10, thereby avoiding a collision with the battery unit 10.
Thereby, at the time of a collision on the side where the power unit 16 is mounted, the collision between the fracture portion 23c, the vehicle body mounting bush 26 and the power unit 16 and the battery unit 10 is suppressed.

Contrary to the above, for example, when the front part of a running electric vehicle collides with an object ahead (collision from the side where the power unit 16 is not mounted: front collision), the concave portion 49 and the offset part 57 prevents the power unit 16 and the battery unit 10 from colliding with each other.
The behavior at the time of this front collision will be described. At this time, the electric vehicle receives an impact load P2 of a predetermined value or more from the side (the other end) where the power unit 16 is not mounted, as indicated by an arrow in FIG.

Then, the power unit 16 is forcibly displaced toward the battery unit 10 due to inertia as indicated by an arrow in FIG.
Here, the rear bracket 21 and the front bracket 23 have a concave portion 49 and an offset portion 57 as fragile portions, but the concave portion 49 is set in a direction that is difficult to break against an impact load input from the front portion of the vehicle body 1. The offset portion 57 is set to be broken in a pulling direction that is more difficult to break than the concave portion 49.

  Therefore, even if the power unit 16 hits the front bracket 23 due to the forced displacement of the power unit 16 as shown in FIG. 18 and the impact load P2 is applied to the concave portion 49, the concave portion 49 is broken as shown in FIG. It only deforms in the direction of narrowing the difficult opening and does not break. Further, as shown in FIG. 19, the offset portion 57 is deformed in a direction in which the offset portion 57 is pulled straight and does not break. Due to this behavior, displacement of the power unit 16 to the battery unit 10 is suppressed.

  At the time of this front collision (when the collision load P2 is applied), the washer 51 that inhibits the displacement of the power unit mounting bush 24 at the time of the rear collision (when the collision load P1 is applied) Since the displacement of 24 is not hindered, the load applied from the power unit 16 to the front bracket 23 is suppressed by the bush 51. It is also delayed that the load is transmitted to the front bracket 23.

When an excessively large impact load P2 is input, the front bracket 23 is broken at the recess 49, and then the offset portion 57 of the rear bracket 21 is broken, so that the power unit 16 is directed toward the battery unit 10 as much as possible. suppress.
Thereby, at the time of a collision on the side where the power unit 16 is not mounted, the power unit 16 and the battery unit 10 do not collide.

  Therefore, the electric vehicle has a collision from the side where the power unit 16 is not mounted (at the time of a rear collision) due to a difference in breaking characteristics of the front bracket weak part 48, even at the time of a collision from the side where the power unit 16 is not mounted (at the time of rear collision). Even at the time of a front collision, it is possible to suppress damage to the battery unit 10 in consideration of each behavior. This is particularly effective for electric vehicles in which the gap between the battery unit 10 and the power unit 16 cannot be made large.

Moreover, the front bracket fragile portion 48, which is important for the relief of the breaking portion 23c and the vehicle body mounting bush 26, can be obtained simply by forming the recess 49 on the side surface of the front bracket 23 on the power unit side, so that the required breaking characteristics can be obtained. It is.
In addition, since the deflection of the power unit mounting bush 24 is limited by the washer 51 at the time of a collision from the side where the power unit is mounted, the front bracket 23 is connected to the battery unit without being affected by the elasticity of the power unit mounting bush 24. It can be broken before reaching 10. Moreover, since only the washer 51 is used for the deflection restriction, the structure is simple.

Furthermore, since the washer 51 is provided on the surface of the front bracket 23 on the battery unit side, it does not hinder delaying the load applied to the front bracket 23 by the elasticity of the power unit mounting bush 24 at the time of a front collision.
In addition, the vehicle body mounting bush 26 employs a structure that suppresses as much as possible the portion of the battery unit 10 that overlaps the lower portion from the upper surface, so that the vehicle body can be easily mounted in the event of a collision from the side on which the power unit 16 is mounted. The bush 26 can be ridden on the upper surface of the battery unit 10. In addition, since the projecting portion 54 protruding to the battery unit 10 is formed on the lower side of the vehicle body mounting bush 26, the vehicle body mounting bush 26 can be easily ridden on the upper surface of the battery unit 10. it can.

  In addition, the rear bracket 21 is formed with an offset portion 57 (rear bracket weak portion 56) having a different breaking characteristic than the concave portion 49 of the front bracket 23, thereby cooperating with the concave portion 49 (front bracket weak portion 48). In the event of a collision on the side where the power unit 16 is mounted, a behavior that allows the power unit 16 to sufficiently escape from the battery unit 10 is given, and in the case of a collision on the side where the power unit 16 is not mounted, the power unit 16 is further connected to the battery unit 10. Therefore, a further effect of preventing damage to the battery unit 10 can be exhibited.

  The present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the spirit of the present invention. For example, in one embodiment, an example of an electric vehicle in which a power unit is mounted on the rear end side of the vehicle body and a battery unit is mounted on the center side of the vehicle body is described. However, the present invention is not limited thereto, and for example, the power unit is mounted on the front end side of the vehicle body. And this invention may be applied to the electric vehicle which mounted the battery unit in the center side of the vehicle body.

  In one embodiment, a safety member may be further strengthened by providing a reinforcing member such as a metal plate on the power unit mounting side of the battery unit.

1 Car body 10 Battery unit 16 Power unit 21 Rear bracket (opposite bracket)
23 Front bracket (Battery unit side bracket)
24 Power unit mounting bush 26 Car body mounting bush 48 Front bracket weak part (Battery unit side bracket weak part)
49 Concave portion 51 Washer (deflection suppression means, deflection limiting member)
54 Projection 56 Rear bracket weak part (opposite bracket weak part)
57 Offset section

Claims (6)

A power unit composed of devices that drive the vehicle;
A vehicle body that mounts the power unit on one end side in the vehicle longitudinal direction;
A battery unit that is mounted adjacent to the power unit on the center side in the front-rear direction of the vehicle body and serves as a power source for the vehicle;
A plurality of brackets for attaching the power unit to the vehicle body;
With
Each of the plurality of brackets has a vehicle body mounting bush, and is elastically supported by the vehicle body via the vehicle body mounting bush.
The plurality of brackets include a battery unit side bracket that supports an end of the power unit on the battery unit side,
The battery unit side bracket has a power unit mounting bush, is elastically supported by the power unit via the power unit mounting bush, and the vehicle unit longitudinal direction is between the power unit mounting bush and the vehicle body mounting bush. It has a battery unit side bracket fragile portion that breaks when an impact load of a predetermined level or more is applied at the time of a collision on one end side or a collision on the other end side in the vehicle longitudinal direction, and only when an impact load is input from one end portion of the vehicle body, The battery unit side bracket weakened portion has a deflection suppressing means for suppressing deflection of the power unit mounting bush, and the impact load input from one end portion of the vehicle body at the time of a collision on one end side in the vehicle front-rear direction is Impact load input from the other end of the vehicle body at the time of a collision on the other end in the vehicle longitudinal direction Electric vehicle, characterized in that is formed so as to break with a smaller impact load.   The deflection suppressing means permits the deflection of the power unit mounting bush when an impact load is input from the other end portion of the vehicle body, and when the impact load is input from one end portion of the vehicle body, The electric vehicle according to claim 1, wherein the electric vehicle includes a deflection limiting member that abuts the battery unit side brackets with rigid bodies.   3. The lower side of the battery unit side bracket, which faces the end of the battery unit, in the vicinity of the vehicle body mounting bush has a protruding portion that protrudes toward the battery unit side. The described electric vehicle.   The lower part of the vehicle body mounting bush of the battery unit side bracket is provided so as to wrap with the upper surface of the adjacent battery unit. Electric car. The battery unit side bracket extends in the vehicle width direction,
The said battery unit side bracket weak part forms the recessed part extended in an up-down direction in the side surface which faces the said power unit side of the said battery unit side bracket, The any one of Claim 1 thru | or 4 characterized by the above-mentioned. The electric vehicle described in 1. In addition to the battery unit side bracket, the bracket has an opposite side bracket that supports an end opposite to the battery unit,
The opposite side bracket has an opposite side bracket weakened portion between a mounting point to which the power unit is attached and a vehicle body mounting bush,
The opposite-side bracket weak part breaks at an earlier stage than the battery unit-side bracket weak part breaks at the time of a collision at one end of the vehicle in the front-rear direction, and the battery unit at the time of the collision at the other end of the vehicle front-rear direction The electric vehicle according to any one of claims 1 to 5, wherein the side bracket fragile portion is formed to be broken at a load larger than an impact load at which the side bracket weak portion is broken.

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