JP7636857B2 - Vehicle Structure - Google Patents

Description

The present invention relates to vehicle structures such as automobiles.

As a specific example of a vehicle structure, there is a vehicle in which an electricity storage unit such as a battery is mounted on the floor of the vehicle or below the floor, for example, in the space below a vehicle seat (for example, Patent Documents 1 and 2). With such a configuration, the electricity storage unit can be mounted in the vehicle with space efficiency.
In the vehicle structure described above, a subframe serving as a front suspension member is often disposed on the vehicle front side of the power storage unit. This subframe is, for example, a generally rectangular frame in plan view, and a pair of left and right lower arms supporting the front wheels are attached to the left and right sides of the subframe. The subframe itself is attached to a side member (front side member) serving as a vehicle body structural member.

On the other hand, if the vehicle is, for example, an electric vehicle, it is necessary to mount vehicle equipment units such as an electric compressor for air conditioning, an electric heater, and other electric and electronic devices on the vehicle. As one method for this, for example, Patent Document 3 describes mounting the vehicle equipment unit so that it is placed in the inner space of the subframe. With this configuration, the vehicle equipment unit can be mounted on the vehicle in a space-efficient manner by utilizing the subframe.

However, there is room for improvement in the above-mentioned conventional technology, as described below.

That is, a case will be considered in which a vehicle front collision occurs and a collision load is input to the front portion of the vehicle from the front side of the vehicle.
First, when the barrier (object of collision) is wide and most of the collision load acts on the side members, the side members exert their impact resistance and impact absorption properties.
However, in contrast to this, there is a case where the barrier is narrow, for example, pole-shaped, and the collision load during a frontal collision does not act on the side member but acts directly on the front part of the subframe. In this case, when the front part of the subframe is bent and deformed toward the rear of the vehicle due to the collision load, the vehicle equipment unit is also likely to move significantly backward toward the rear of the vehicle. For this reason, there is a risk that the vehicle equipment unit will collide with the power storage unit located on the rear side of the subframe, causing the power storage unit to be severely damaged. In order to improve the protection performance of the power storage unit, it is desirable to appropriately prevent or suppress such a situation.

JP 2001-97048 A JP 2021-133873 A JP 2010-228633 A

The present invention was conceived in light of the above-mentioned circumstances, and aims to provide a vehicle structure that allows the vehicle equipment unit to be mounted rationally to a subframe located on the vehicle front side of the power storage unit, and that can improve the protection performance of the power storage unit in the event of a frontal collision of the vehicle compared to conventional methods.

To solve the above problems, the present invention provides the following technical solutions:

The vehicle structure provided by the present invention comprises an electricity storage device unit mounted on the floor of the vehicle or below it, a subframe that is generally rectangular in plan view and is attached to a vehicle body component at the front of the vehicle so as to be located forward of the electricity storage device unit, and in which a front frame member and a rear frame member that extend in the vehicle width direction with a gap in the vehicle fore-and-aft direction are connected via a pair of left and right side frame members that extend in the vehicle fore-and-aft direction with a gap in the vehicle width direction, and a vehicle structure that is attached to the subframe so as to be located between the pair of side frame members in the vehicle width direction. A vehicle structure comprising both equipment units, and the vehicle equipment units comprise at least two vehicle equipment units whose front side is connected to the front frame member and whose rear side is connected to the rear frame member so as to bridge and connect the front frame member and the rear frame member, and the two vehicle equipment units extend in an inclined position relative to the vehicle longitudinal direction in a plan view, and the front sides of the two vehicle equipment units are set to form a forward-facing shape with a greater mutual distance in the vehicle width direction than the rear sides.

According to this configuration, the following effects can be obtained.
That is, the two vehicle equipment units are in a forward-opening shape in plan view, extending at an angle with respect to the vehicle front-rear direction, and are generally V-shaped with a forward opening in plan view. Therefore, even if a frontal collision of the vehicle occurs and a narrow barrier (collision object) such as a pole collides with a portion of the front frame member of the front part of the subframe that corresponds to the region near the center in the vehicle width direction, and a large collision load is input to this portion, the two vehicle equipment units can be prevented from directly receiving most of the collision load. According to the present invention, it is possible to make a state in which a barrier or a collision load from the barrier acts on the mutual region between the two vehicle equipment units, and to prevent the two vehicle equipment units from being directly and strongly pushed toward the rear side of the vehicle by the barrier. As a result, the two vehicle equipment units are prevented from significantly retreating toward the electric storage device unit, and the electric storage device unit is appropriately prevented from receiving a large collision load.
In addition, even if a collision load is directly applied to the front of the vehicle equipment unit from the front side of the vehicle, since the vehicle equipment unit is inclined with respect to the front-rear direction of the vehicle in a plan view, the collision load acts as a rotational force that moves the front side of the vehicle equipment unit backward. In other words, even if a collision load is directly applied to the front of the vehicle equipment unit, the entire vehicle equipment unit is prevented from moving backward significantly toward the rear of the vehicle.
As a result, it is possible to appropriately prevent or suppress the vehicle equipment unit from moving backward inappropriately when a frontal collision of the vehicle occurs, thereby improving the protection performance of the power storage device unit.
In addition, the two vehicle equipment units can be mounted on the vehicle using the subframe in a space-efficient manner.
As a means for improving the protection performance of the power storage device unit, there is no need or little need to increase the thickness of the subframe or to provide additional large reinforcing members, etc. Therefore, it is possible to suppress increases in manufacturing costs and weight and to improve productivity.
The two vehicle equipment units also have the function of increasing the rigidity of the entire subframe. Therefore, when the subframe is used as a suspension frame that constitutes a front suspension, the increased rigidity of the suspension frame can be expected to have the effect of improving the handling stability of the vehicle.

In the present invention, preferably, the front portions of each of the two vehicle equipment units are connected to or near a pair of left and right cross joints of the subframe where regions near both ends in the vehicle width direction of the front frame member and each of the pair of lateral frame members cross and join, and the rear portions of each of the two vehicle equipment units are connected to regions near the center in the vehicle width direction of the rear frame member.

According to this configuration, the following effects can be obtained.
That is, when a frontal collision of the vehicle occurs and, for example, a collision load from a narrow barrier (collision target) travels through the area between the two vehicle equipment units, most of the collision load is received at the connection point between the rear of the vehicle equipment unit and the area of the rear frame member of the subframe near the center in the vehicle width direction. The rear of the two vehicle equipment units are disposed close to each other and are both connected to the rear frame member, so that it is possible to increase the strength of this portion. On the other hand, the front of the two vehicle equipment units are connected to a pair of cross joints, which are high-strength portions of the subframe, or to their vicinity. Therefore, even if the two vehicle equipment units receive a tensile load toward the rear side of the vehicle, this is preferable for ensuring durability against the tensile load. As a result, it is possible to more reliably prevent the collision load from being input to the power storage unit located on the rear side of the subframe.

Other features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment of the invention, taken in conjunction with the accompanying drawings.

1 is a schematic bottom view of a main portion showing an example of a vehicle structure according to the present invention. 2 is a schematic side view of a main part of the vehicle structure shown in FIG. FIG. 2 is a schematic cross-sectional view of a main part taken along line III-III of FIG. FIG. 2 is a schematic exploded bottom view of the main part of FIG. 1 . FIG. 2 is a schematic perspective view showing a subframe used in the vehicle structure shown in FIG. 1 . 6A is a schematic end view of a main part taken along line VIa-VIa in FIG. 5, and FIG. 6B is a schematic end view of a main part taken along line VIb-VIb in FIG. FIG. 6 is a bottom view of the subframe shown in FIG. 5 . FIG. 6 is a plan view of the subframe shown in FIG. 5 . FIG. 2 is a bottom view for explaining the operation of the vehicle structure shown in FIG. 1 . 1A and 1B are schematic bottom views showing comparative examples 1 and 2 of the present invention.

The preferred embodiment of the present invention will be described in detail below with reference to the drawings.

1 to 4 show an example of a vehicle structure A to which the present invention is applied. The vehicle structure A of the present embodiment is, for example, a cab-over type vehicle 1 that is applied to a battery electric vehicle (BEV).
This vehicle structure A includes a pair of left and right side members 3 (shown with a halftone dot pattern in Figs. 1 and 4), an electricity storage device unit 6, a pair of left and right lower arms 4 (shown with light ink in Figs. 4, 7 and 8) that suspend the front wheels 9 as members constituting the front suspension FS, and a subframe 5 as a suspension member. The vehicle structure A also includes two vehicle equipment units 7a, 7b attached to the subframe 5.

The pair of side members 3 correspond to an example of the "vehicle body structural member at the front of the vehicle" as referred to in the present invention, and are positioned at a distance in the vehicle width direction, and extend in the vehicle longitudinal direction from near the front end of the vehicle 1 toward the rear of the vehicle. As shown in FIG. 3, each side member 3 is constructed using a member with a hat-shaped cross section that is open at the top. Although detailed illustration and description are omitted, each side member 3 is joined to the underside of the floor section 10 (floor panel section). A front bumper reinforcement 83 is connected to the front ends of the pair of side members 3. The floor section 10 has
An opening 10a for maintenance purposes is provided.

As shown in FIG. 4, this vehicle structure A includes cross members 80a, 80b that bridge the pair of side members 3, a pair of inclined beam members 81, a pair of left and right rockers 19 that are located on the outer side of the pair of side members 3 in the vehicle width direction and extend in the vehicle front-rear direction, and a torque box 82. The rockers 19 are members that form the lower edge of the side door opening (not shown) on the side of the vehicle 1.

The storage unit 6 includes a unit body 60 including a battery as a storage device. The unit body 60 includes a flange-shaped or leg-shaped mounting portion 61 that protrudes outward in the vehicle width direction. A single or multiple divided panel-shaped bracket 63 is connected between the side member 3 and the rocker 19. The mounting portion 61 of the storage unit 6 is connected to the bracket 63 using multiple fastening portions 62 using bolts or the like, and the storage unit 6 is mounted to the side member 3 via the bracket 63 (and also to the rocker 19). With this mounting, the storage unit 6 is mounted below the floor portion 10. In the present invention, the storage unit 6 may be mounted on the floor portion 10, unlike the present embodiment.

The lower arm 4 is a member that supports the front wheel 9 and has its base end, which is the part on the inside in the vehicle width direction, rotatably supported by the subframe 5 (see Figures 5, 7, 8, etc.). More specifically, the tip end, which is the part on the outside in the vehicle width direction of the lower arm 4, is provided with an attachment hole 48 for a ball joint 49, and a knuckle for the front wheel (not shown) is attached to this part to support the front wheel 9. The front and rear parts of the base end of the lower arm 4 are provided with connecting parts J1, J2 made of rubber bushings 47a, 47b, etc., for connecting these parts to the subframe 5. The tip side of the lower arm 4 can be swung up and down in the height direction around these connecting parts J1, J2.

The subframe 5 is a generally rectangular frame in plan view, and includes a front frame member 50, a rear frame member 51, and a pair of left and right side frame members 52. The front frame member 50 and the rear frame member 51 are members that extend in the vehicle width direction at a distance in the vehicle front-rear direction. The pair of left and right side frame members 52 extend in the vehicle front-rear direction at a distance in the vehicle width direction, and connect the front frame member 50 and the rear frame member 51 near both ends in the vehicle width direction. These members are connected, for example, by welding. A connection portion J1 for the lower arm 4 is provided at both ends in the vehicle width direction of the front frame member 50, and a connection portion J2 is provided at the rear end of the side frame member 52. A steering gear box (not shown) is attached to the front frame member 50.

The subframe 5 is fixedly attached to the undersides of the pair of side members 3 so as to be located on the vehicle front side of the power storage device unit 6. As an attachment means, for example, a means is adopted in which an upwardly convex bracket portion 53 is provided to protrude from the upper surface portion of the front frame member 50, and a bolt fastening portion 54 having a bolt insertion hole is provided on the rear frame member 51. As shown in Fig. 2, the upper portion of the bracket portion 53 and the bolt fastening portion 54 are fastened to the underside portion of the side member 3 using bolts 88a, 88b.
The reference numeral 18 in FIG. 2 denotes a dash panel that divides the front of the vehicle compartment. In the front of the vehicle 1, the area forward of the dash panel 18 corresponds to a crushable zone for absorbing impact in the event of a frontal collision of the vehicle 1, and the area rearward of this corresponds to a non-crushable zone.

The two vehicle equipment units 7a and 7b are units including vehicle equipment 70a and 70b, respectively. In this embodiment, the vehicle equipment 70a and 70b are configured as units attached to appropriately bent metal plate-like support members 71a and 71b.
Vehicle equipment 70a and 70b are, for example, an electric compressor and an electric heater for air conditioning, and in this embodiment, vehicle equipment 70a is attached to the upper side of support member 71a, while vehicle equipment 70b is attached to the lower side of support member 71b.
Unlike the present embodiment, the vehicle equipment units 7a, 7b may not include the relatively large support members 71a, 71b, and may be substantially composed of only the vehicle equipment 70a, 70b. Also, the vehicle equipment 70a, 70b may be provided with small pieces of bolt-fastening members.

The vehicle equipment units 7a, 7b are attached to the subframe 5 and are located between a pair of side frame members 52 in the vehicle width direction, and bridge and connect the front frame member 50 and the rear frame member 51. They are also configured in a generally V-shape with an open front when viewed from above. More specifically, they are configured as follows:

That is, as shown in Figures 5 to 8, the subframe 5 has front bracket portions 55a, 55b and a rear bracket portion 55c for mounting vehicle equipment. The rear bracket portion 55c is shared for mounting the rear portions of both vehicle equipment units 7a, 7b.

The subframe 5 is provided with a pair of left and right cross joints 57 formed by joining regions near both ends in the vehicle width direction of the front frame member 50 and regions near the front ends of the lateral frame members 52. The front bracket portions 55a, 55b are provided at the inner corners of the cross joints 57.
The means for providing the front bracket parts 55a, 55b may be, for example, a means for overlapping and welding a metal plate corresponding to the main body of the front bracket parts 55a, 55b to the lower flange part 50a of the front frame member 50. Preferably, the front bracket parts 55a, 55b are welded to both the front frame member 50 and the lateral frame member 52 so as to straddle them, thereby increasing the strength of the cross joint part 57. This also increases the strength of the area around the connecting part J1.

On the other hand, as shown in FIG. 5, the underside of the rear frame member 51 of the subframe 5 has a shape in which the region near the center in the vehicle width direction is curved upward more than both sides. In this embodiment, a metal member equivalent to the main body of the rear bracket portion 55c is welded to the underside of the region near the center in the vehicle width direction of the rear frame member 51, thereby providing the rear bracket portion 55c for mounting vehicle equipment. The presence of this rear bracket portion 55c increases the rigidity of the rear frame member 51.

The front parts of the support members 71a, 71b of the two vehicle equipment units 7a, 7b are connected to the front bracket parts 55a, 55b by bolts 89, and are connected to the pair of left and right cross joint parts 57 or their vicinity. The rear parts of the support members 71a, 71b are connected to the rear bracket part 55c by bolts 87.
As a result, the two vehicle equipment units 7a, 7b extend in a tilted position relative to the vehicle longitudinal direction in a plan view (a tilted position at appropriate tilt angles α1, α2 relative to the center line CL extending in the vehicle longitudinal direction in FIG. 7), and the front sides of the two vehicle equipment units 7a, 7b are wider than the rear sides in the vehicle width direction (approximately a V-shape with a front opening in a plan view). Preferably, the tilt angles α1, α2 are approximately the same. The height of the two vehicle equipment units 7a, 7b is such that they overlap the front frame member 50 and the rear frame member 51 of the subframe 5 in a front view of the vehicle.

Next, we will explain the operation of the vehicle structure A described above.

First, a frontal collision of the vehicle 1 occurs, and as shown in Fig. 9, a collision load F may be input to the front of the vehicle 1. Here, if the barrier B, which is the collision target, is, for example, a narrow pole-like shape and collides with an area of the front of the vehicle 1 that is approximately near the center in the vehicle width direction, the collision load F at that time is input to an area of the front frame member 50 of the subframe 5 that is approximately near the center in the vehicle width direction, and this area is deformed or displaced so as to retreat toward the rear of the vehicle. In contrast, as described above, the two vehicle equipment units 7a, 7b are set to have an approximately V-shape with an open front when viewed from the top, so that the collision load F is prevented from directly acting on the vehicle equipment units 7a, 7b as it is. Therefore, the vehicle equipment units 7a, 7b are prevented from retreating significantly toward the rear of the vehicle due to the collision load F. In addition, even if a collision load F is directly input to the front of the vehicle equipment units 7a, 7b from the front side of the vehicle, the vehicle equipment units 7a, 7b are inclined with respect to the front-rear direction of the vehicle in a plan view, so that the collision load F acts as a rotational force that moves the front side of the vehicle equipment units 7a, 7b backward. Therefore, even if the collision load F is directly input to the front of the vehicle equipment units 7a, 7b, the entire vehicle equipment units 7a, 7b are prevented from moving backward significantly toward the rear side of the vehicle, and it is possible to avoid a collision with the electricity storage device unit 6.
For this reason, when a frontal collision occurs in the vehicle 1, the collision load F is appropriately prevented or suppressed from acting on the power storage device unit 6 via the vehicle equipment units 7a, 7b. Therefore, the protection performance of the power storage device unit 6 can be improved.

10(a) and 10(b) show comparative examples 1 and 2 of the present invention.
In Comparative Example 1, the two vehicle equipment units 7 are not inclined relative to the vehicle longitudinal direction and are arranged parallel to each other in the vehicle width direction. In Comparative Example 2, the two vehicle equipment units 7 are arranged parallel to each other in the vehicle longitudinal direction.
In both of Comparative Examples 1 and 2, when a collision load Fa is input to the front frame member 50 of the subframe 5, the two vehicle equipment units 7 are likely to be significantly pushed backward toward the rear of the vehicle by the collision load Fa. In this case, the power storage device unit 6 is likely to be damaged due to the large load received through the two vehicle equipment units 7.
In contrast, the vehicle structure A of the present embodiment can appropriately eliminate such concerns.

In addition, in the event of a frontal collision of the vehicle 1, if the narrow barrier B or the collision load F from the barrier B travels through the area between the two vehicle equipment units 7a, 7b, most of the collision load F is received at the connection point between the rear of the vehicle equipment units 7a, 7b and the area of the rear frame member 51 near the center in the vehicle width direction. Here, this point is reinforced by the rear bracket part 55c as a reinforcing member, and the vehicle equipment units 7a, 7b are attached close to each other to increase the strength, so that it is possible to ensure a preferable strength for receiving the collision load F. On the other hand, the front parts of the two vehicle equipment units 7a, 7b are connected to a pair of cross joints 57, which are high-strength parts of the subframe 5. Therefore, even if the two vehicle equipment units 7a, 7b receive a tensile load toward the rear of the vehicle, it is preferable to ensure durability against this tensile load. This more reliably prevents the two vehicle equipment units 7a, 7b from moving backward too far toward the rear of the vehicle, and more reliably prevents the collision load F from being input to the power storage unit 6 via the two vehicle equipment units 7a, 7b.

The front and rear portions of the base end of the lower arm 4 are connected to the subframe 5 via connecting portions J1, J2, and the periphery of the connecting portion J1 is reinforced by front bracket portions 55a, 55b. In addition, the vehicle equipment units 7a, 7b are connected to the front bracket portions 55a, 55b. Therefore, the rigidity of the subframe 5 against the lateral force LF1 input from the front wheel 9 and the lower arm 4 to the connecting portion J1 is effectively increased.
Of the subframe 5, the rear frame member 51 located on the vehicle widthwise inward side of the connecting part J2 is reinforced by the rear bracket part 55c and the vehicle equipment units 7a, 7b connected to this rear bracket part 55c. Therefore, the rigidity of the subframe 5 against the lateral force LF2 input from the front wheels 9 and the lower arm 4 to the connecting part J2 is also effectively increased.
As a result, the handling stability of the vehicle 1 is improved.

In the vehicle structure A of this embodiment, there is no need or little need to increase the thickness of various parts of the subframe 5 or to provide additional, large reinforcing members as a means for improving the protective performance of the power storage unit 6 in the event of a frontal collision of the vehicle 1. This makes it possible to suppress increases in the manufacturing costs and weight of the vehicle 1 and to improve productivity.

The present invention is not limited to the above-described embodiment. The specific configuration of each part of the vehicle structure according to the present invention can be freely designed and modified within the intended scope of the present invention.

In the above embodiment, the vehicle 1 is a battery electric vehicle (BEV), but the present invention is also applicable to other electric vehicles, hybrid vehicles, etc., and further to other vehicles such as hydrogen vehicles, internal combustion engine vehicles, etc. Therefore, the vehicle equipment unit is not limited to the above-mentioned electric compressor and electric heater unit for air conditioning, and can be various other equipment units, such as an ESU (equipment that integrates charging, power conversion, power distribution, etc.).
The type of vehicle is not limited to the cab-over type, and the present invention can be applied to various other types of vehicles.

The subframe may have at least two vehicle equipment units arranged in a planar, forward-spreading shape as intended by the present invention, and further vehicle equipment units other than these may be attached to the subframe.
The power storage device unit is not limited to a unit having a battery as the power storage device, but may be a unit having a capacitor, for example.
The vehicle body structural members referred to in the present invention are not limited to a pair of left and right side members, and the subframe may be attached to a vehicle body structural member other than the side members.
The subframe does not have to correspond to a suspension frame.
As a means for connecting the various parts of the vehicle structure according to the present invention, it is of course possible to use other means such as fastening means other than bolt fastening or welding as appropriate.

A Vehicle structure 1 Vehicle 10 Floor portion 3 Side member (vehicle body component)
Reference Signs List 4: Lower arm 5: Subframe 50: Front frame member 51: Rear frame member 52: Side frame member 57: Intersection joint 6: Electricity storage device units 7a, 7b: Vehicle equipment unit

Claims (2)

an electricity storage device unit mounted on or below a floor portion of a vehicle;
a subframe having a generally rectangular frame shape in plan view, the subframe being attached to a vehicle body constituent member at a front part of the vehicle so as to be located forward of the power storage device unit, and in which a front frame member and a rear frame member extending in the vehicle width direction with a gap therebetween are connected via a pair of left and right lateral frame members extending in the vehicle front-rear direction with a gap therebetween;
a vehicle equipment unit attached to the subframe so as to be located between the pair of lateral frame members in a vehicle width direction;
A vehicle structure comprising:
the vehicle equipment units include at least two vehicle equipment units each having a front side connected to the front frame member and a rear side connected to the rear frame member so as to bridge and connect the front frame member and the rear frame member,
This vehicle structure is characterized in that, in a plan view, these two vehicle equipment units extend at an angle relative to the fore-and-aft direction of the vehicle, and the front sides of the two vehicle equipment units are configured to form a forward-flared shape with a greater mutual distance in the vehicle width direction than the rear sides. 2. A vehicle structure according to claim 1,
a front portion of each of the two vehicle equipment units is connected to a pair of left and right cross joint portions or their vicinities at which regions of the front frame member near both ends in a vehicle width direction of the subframe and the pair of lateral frame members cross and are joined,
A vehicle structure, wherein a rear portion of each of the two vehicle equipment units is connected to a region of the rear frame member near a center in a vehicle width direction.

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