Vehicle structure

Abstract

To provide a vehicle structure that can simply and rationally receive rotation moment generated by a motor unit at the time of turning or acceleration of a vehicle and appropriately ensure fitting strength of the motor unit and vehicle strength.SOLUTION: A vehicle structure A in which the center of gravity G of a motor unit 2 is shifted toward one side in a vehicle width direction from the vehicle-width direction center CL of a vehicle V includes a reinforcement frame unit 5 in which first and second vertical members 51, 52 are connected by a lateral member 53 bridging therebetween. A specific bracket 3a for mounting the motor unit 2 and the first vertical member 51 are located to match or be close to the center of gravity G of the motor unit 2 in the vehicle width direction. The specific bracket 3a is attached to the first vertical member 51 or the lateral member 53. The second vertical member 52 is shifted toward the other side in the vehicle width direction from the vehicle-width direction center CL of the vehicle V as viewed from the vehicle bottom. A lateral rod mounting reinforcement member 42 is connected to the second vertical member 52.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to vehicle structures such as automobiles. [Background technology]

[0002] A specific example of a vehicle structure is described in Patent Document 1. In the vehicle structure described in the document, a motor unit used in electric vehicles, hybrid electric vehicles, etc. is attached to the underside of a floor of the vehicle. The motor unit has a motor section and a gear section, and is configured such that output from the motor section can be transmitted to a pair of left and right drive shafts via the gear section. In this vehicle structure, the roll center of the vehicle is set to be located above the center of gravity of the motor unit, which makes it possible to suppress roll when the vehicle turns.

[0003] However, the above-mentioned conventional techniques still have room for improvement, as described below.

[0004] That is, since the motor unit is a motor unit and a gear unit assembled integrally, the overall shape of the motor unit is usually asymmetric. Therefore, even if the motor unit is disposed at approximately the center of the vehicle in the vehicle width direction, the center of gravity of the motor unit is not at the center of the vehicle width direction when viewed from the bottom of the vehicle, and is often disposed offset to one side in the vehicle width direction from the center of the vehicle width direction. Here, if the center of gravity of the motor unit is disposed offset in this manner, a large rotational moment acts on the part supporting the motor unit when the vehicle turns or accelerates, and a large stress is generated in this part. In order to appropriately and sufficiently ensure the mounting strength (rigidity) of the motor unit and the strength of the vehicle body, it is desired to adopt an appropriate measure against the above-mentioned rotational moment, but in the past, no measures that can meet such a demand have been taken. One possible solution to the above problem is to position the center of gravity of the motor unit so that it coincides with the center of the vehicle width direction. However, simply adopting such a solution may result in an asymmetrical arrangement of the motor unit's parts for connecting the pair of left and right drive shafts, which may result in a problem in which it becomes impossible to use drive shafts with the same overall length as the pair of left and right drive shafts. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP2008-81010A [Patent Document 2] Patent Publication No. 2021-30978 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention was devised in light of the circumstances described above, and has as its objective the provision of a vehicle structure that can rationally receive the rotational moment generated by the motor unit when the vehicle turns or accelerates using simply configured means, and that can appropriately ensure the mounting strength of the motor unit and the strength of the vehicle body. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides the following technical solutions.

[0008] The vehicle structure provided by the present invention comprises a motor unit having a motor section and a gear section, and an output from the motor section can be transmitted to a pair of left and right drive shafts via the gear section, a motor unit bracket for mounting the motor unit to a vehicle body, and a lateral rod mounting reinforcement member having one end connected to a bracket section for a lateral rod provided on the vehicle body and extending in the vehicle width direction in a bottom plan view of the vehicle, the center of gravity of the motor unit being disposed offset from the center of the vehicle width direction to one side in the vehicle width direction in a bottom plan view of the vehicle, the vehicle structure further comprising first and second vertical members fixed to the underside of a floor section of the vehicle and arranged at a distance from each other in the vehicle width direction, and a first and second vertical members arranged at a distance from each other in the vehicle width direction, and a reinforcing frame portion having at least one transverse member joined to the first and second vertical members so as to bridge and connect them, and the bracket for the motor unit comprises a specific bracket positioned to coincide with or be close to the center of gravity of the motor unit in the vehicle width direction, the first vertical member is positioned to coincide with or be close to the center of gravity of the motor unit in the vehicle width direction, and the specific bracket is attached to the first vertical member or the transverse member, the second vertical member is positioned offset from the center of the vehicle width direction to the other side in the vehicle width direction when viewed from the bottom of the vehicle, and the other end of the lateral rod mounting reinforcement member is connected to the second vertical member.

[0009] According to this configuration, the following effects can be obtained. First, a reinforcing frame is used as a means for increasing the mounting strength of the motor unit, and this reinforcing frame is configured by bridging first and second vertical members arranged at a distance in the vehicle width direction with at least one horizontal member, making it possible to make a high-strength portion despite its simple configuration. In the present invention, the motor unit is connected to such a reinforcing frame, so that the mounting strength of the motor unit and the strength of the vehicle body can be effectively improved. Secondly, the specific bracket supporting the motor unit and the first vertical member of the reinforcing frame are both positioned to coincide with or be close to the center of gravity of the motor unit in the vehicle width direction, while the specific bracket is attached to the first vertical member or the horizontal member. Therefore, the rotational moment caused by the deviation of the center of gravity of the motor unit when the vehicle turns or accelerates does not act as a large load on any of the specific bracket, the first vertical member or the horizontal member, and this load can be effectively borne by each of the above-mentioned parts. This makes it possible to more appropriately improve the mounting strength of the motor unit and the strength of the vehicle body. Thirdly, the second vertical member of the reinforcing frame is more susceptible to the rotational moment of the motor unit than the first vertical member, but the lateral rod mounting reinforcement member, which has high mounting strength, is connected to this second vertical member. This increases the strength of the second vertical member against the rotational moment. As a result, the mounting strength of the motor unit and the strength of the vehicle body are further improved. Fourthly, according to the present invention, it is possible to use symmetrical drive shafts with the same overall length for the pair of left and right drive shafts. Also, the parts for mounting the motor unit and reinforcing it do not need to be very large in construction. This is therefore preferable in terms of not impairing the productivity of the entire vehicle, reducing manufacturing costs, and making the vehicle lighter.

[0010] Other features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2A is a schematic bottom view of a main portion showing an example of a vehicle structure according to the present invention, and FIG. 2B is a schematic cross-sectional view taken along line Ib-Ib in FIG. [Diagram 2] 1(a) is a schematic bottom view of the main part in a state where some of the components in FIG. 1(a) are not shown, and (b) is a schematic exploded bottom view of the main part of (a). [Diagram 3] FIG. 2 is a schematic cross-sectional view in which some of the components in FIG. 1(b) are omitted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0013] The vehicle structure A shown in Figures 1 to 3 comprises a pair of left and right first and second side members (rear side members) 10A, 10B (dot patterned parts), a motor unit 2 (light grey part) as a traction motor system, brackets 3a to 3c for the motor unit, a de Dion tube 40 that connects and supports a pair of left and right wheels (rear wheels) 9a, 9b, a lateral rod 41, a lateral rod mounting reinforcement member 42, and a reinforcement frame portion 5.

[0014] The first and second side members 10A, 10B are members extending in the vehicle front-rear direction with a gap between them in the vehicle width direction, are components of the vehicle body 1, and are formed, for example, using a member with a hat-shaped cross section. These first and second side members 10A, 10B are joined to the underside of a floor portion 19 (floor panel portion) of the vehicle V. In addition, first and second floor cross frames 11, 12 and a lower back frame 13 extending in the vehicle width direction as components of the vehicle body 1 are connected to bridge between the first and second side members 10A, 10B.

[0015] The motor unit 2 has a motor section 20 and a gear section 21, and is configured such that output from the motor section 20 can be transmitted to a pair of left and right drive shafts 28 via the gear section 21. The motor section 20 includes an inverter that receives power from a drive battery (not shown) separately mounted on the vehicle V, and a motor whose rotation is controlled by the inverter. The gear section 21 includes a reduction gear. The members that make up the motor section 20 and the gear section 21 are housed in a common housing case 22, and the entire assembly is unitized.

[0016] The motor unit brackets 3a to 3c are members for mounting the motor unit 2 to the vehicle body 1 with the motor unit 2 disposed on the underside of the floor portion 19 of the vehicle V. The bracket 3a corresponds to an example of a "specific bracket" as defined in the present invention, and is intended to be mounted to the reinforcing frame portion 5. However, details thereof will be described later (hereinafter, bracket 3a will be appropriately referred to as "specific bracket 3a"). The other two brackets 3b, 3c have their rear ends connected to both left and right sides of the motor unit 2 via fastening members 80, 81 such as bolts to support those sides, and their front ends connected to the first floor cross frame 11 via fastening members 82, 83. Alternatively, the front ends of brackets 3b, 3c can be indirectly connected to the first floor cross frame 11 (such as by sandwiching another separate member therebetween).

[0017] In the bottom view of the vehicle, the center of gravity of the motor unit 2 is offset by an appropriate dimension La to one side in the vehicle width direction (the wheel 9a side, the first side member 10A side) from the vehicle width center CL of the vehicle V. This is because the pair of left and right drive shafts 28 connected to the motor unit 2 have the same overall length, and because the motor unit 2 is not symmetrical, and its center of gravity G is offset from the center of the connection points of the pair of drive shafts 28.

[0018] In this embodiment, a De Dion suspension, which is one of the axle suspension systems, is used as the rear suspension. In other words, the pair of wheels 9a, 9b are connected and supported by a De Dion tube 40, and are driven to rotate by receiving rotational torque from a pair of drive shafts 28. The lateral rods 41 are used to detect the force of the wheels 9a, 9b against lateral forces. This member is for regulating the position in the vehicle width direction, and is attached so as to connect a bracket portion 43 for the lateral rod joined to the lower portion of the first side member 10A and a bracket portion 40a joined to the de Dion tube 40 to each other. One end portion 42a of a lateral rod mounting reinforcing member 42 extending in the vehicle width direction in a bottom view of the vehicle is connected to the bracket portion 43. The other end portion 42b of this reinforcing member 42 is connected to a second vertical member 52 of the reinforcing frame portion 5 as described later.

[0019] The reinforcing frame portion 5 is a reinforcing portion used for mounting the motor unit 2, and includes first and second vertical members 51, 52 fixed to the underside of the floor portion 19, and a horizontal member 53 joined thereto. In the drawing, only one horizontal member 53 is provided, but a configuration in which a plurality of horizontal members 53 are provided may also be used. The first and second vertical members 51, 52 are arranged side by side at intervals in the vehicle width direction, and extend in the vehicle front-rear direction so as to bridge and connect between the second floor cross frame 12 and the lower back frame 13. The first and second vertical members 51, 52 are formed, for example, using hat-shaped cross-section members, similar to the first and second side members 10A, 10B. The first and second vertical members 51, 52 are arranged such that their vehicle width center substantially coincides with the vehicle width center CL of the vehicle V.

[0020] 2 and 3, in this embodiment, the horizontal member 53 of the reinforcing frame portion 5 is provided with a rubber bushing 53a (a member in which rubber is interposed between a metallic outer tube and an inner tube). This horizontal member 53 has a shape extending in the vehicle width direction when viewed from the bottom of the vehicle, and both left and right ends thereof are attached to the first and second vertical members 51, 52 via fastening members 84 such as bolts, thereby bridging and connecting the first and second vertical members 51, 52.

[0021] A particular bracket 3a of the motor unit 2 has its front end connected to the motor unit 2 via a fastening member 85, and a portion of its rear end connected to a rubber bushing 53a of the cross member 53 of the reinforcing frame portion 5 via a fastening member 86. Here, the first vertical member 51 of the reinforcing frame portion 5 and the region near the front end of the specific bracket 3a are positioned to coincide (overlap) with the center of gravity G of the motor unit 2 in the vehicle width direction. On the other hand, the connecting portion between the specific bracket 3a and the rubber bush 53a is positioned to substantially coincide with the vehicle width center CL of the vehicle V in the vehicle width direction (in the illustrated embodiment, the connecting portion is positioned slightly offset toward one side in the vehicle width direction (the wheel 9a side, the first side member 10A side) from the vehicle width center CL of the vehicle V).

[0022] The second vertical member 52 of the reinforcing frame portion 5 is disposed offset toward the other vehicle width direction side (the wheel 9b side, the second side member 10B side) from the vehicle width direction center CL of the vehicle V in a bottom view of the vehicle. The other end portion 42b of the lateral rod mounting reinforcing member 42 is connected to the second vertical member 52.

[0023] Next, the operation of the above-mentioned vehicle structure A will be described.

[0024] First, the reinforcing frame portion 5 is used as a means for increasing the mounting strength of the motor unit 2. As described above, the reinforcing frame portion 5 is configured such that the first and second vertical members 51, 52, which are connected as a bridge between the high-strength second floor cross frame 12 and the lower back frame 13 and extend in the fore-aft direction of the vehicle, are connected to each other in the vehicle width direction via the horizontal member 53. Therefore, the reinforcing frame portion 5 can be made to have a high strength while having a relatively simple and compact configuration. In this embodiment, the motor unit is mounted and supported using such a reinforcing frame portion 5, so that it is possible to appropriately improve the mounting strength of the motor unit 2 and the strength of the vehicle body. do.

[0025] The specific bracket 3a supporting the motor unit 2 and the first vertical member 51 of the reinforcing frame portion 5 are both positioned to coincide with the center of gravity G of the motor unit 2 in the vehicle width direction. The specific bracket 3a is attached to a rubber bush 53a of the horizontal member 53, and its attachment position is positioned to coincide approximately with the center CL of the vehicle V in the vehicle width direction, and is not far from the center of gravity G in the vehicle width direction. Therefore, the rotational moment M (see FIG. 1(a)) caused by the deviation of the center of gravity G of the motor unit 2 when the vehicle V turns or accelerates does not act as a large load on either the specific bracket 3a or the horizontal member 53, and this load can be effectively borne by each of the above-mentioned portions. As a result, the mounting strength of the motor unit 2 and the strength of the vehicle body can be improved more appropriately.

[0026] The second vertical member 52 of the reinforcing frame portion 5 is disposed slightly away from the center of gravity G of the motor unit 2 in the vehicle width direction, and is therefore more susceptible to the effect of the rotational moment M of the motor unit 2 than the first vertical member 51. However, the lateral rod mounting reinforcement member 42, which has high installation strength, is connected to the second vertical member 52. Therefore, the second vertical member 52 has high strength against the rotational moment M, which is more preferable for improving the installation strength of the motor unit 2 and the vehicle body strength.

[0027] In addition, according to this embodiment, the pair of left and right drive shafts 28 are symmetrical and have the same overall length, making it possible to reduce the cost of the parts. Also, the entire mounting structure of the motor unit 2 does not need to be a very large-scale structure. This is therefore preferable in terms of not worsening the overall productivity of the vehicle V, suppressing manufacturing costs, and reducing the weight of the vehicle V.

[0028] The present invention is not limited to the above-described embodiment, and the specific configuration of each part of the vehicle structure according to the present invention can be freely designed and modified in various ways within the intended scope of the present invention.

[0029] In the embodiment described above, the specific bracket 3a is attached to the horizontal member 53, but it is also possible to configure it to be attached to the first vertical member 51 instead. In the above embodiment, the specific bracket 3a and the first vertical member 51 are arranged to coincide with the center of gravity G of the motor unit 2 in the vehicle width direction, but this is not limited to the above. Instead of such a configuration, the specific bracket 3a and the first vertical member 51 may be arranged closer to the center of gravity G of the motor unit 2 in the vehicle width direction. The present invention is applicable to any type of vehicle (such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV)). There are no limitations on the specific configurations of the motor and gear parts of the motor unit. [Explanation of symbols]

[0030] A. Vehicle Structure CL Vehicle width center V Vehicle G Center of gravity (motor unit) 1. Vehicle body 2 Motor unit 20 Motor section 21 Gear section 28 Drive shaft 3a Specific bracket 41 Lateral Rod 42 Lateral rod mounting reinforcement member 43 Bracket part for lateral rod 5 Reinforcement frame 51,52 First and second vertical members 53 Horizontal member 9a,9b wheels

Claims

[Claim 1] a motor unit including a motor section and a gear section, and an output from the motor section can be transmitted to a pair of left and right drive shafts via the gear section; a motor unit bracket for mounting the motor unit to a vehicle body; a lateral rod mounting reinforcement member having one end connected to a bracket portion for a lateral rod provided on the vehicle body and extending in a vehicle width direction in a bottom view of the vehicle; It is equipped with A vehicle structure in which a center of gravity of the motor unit is disposed offset from a center of the vehicle in a vehicle width direction to one side in the vehicle width direction when viewed from the bottom of the vehicle, a reinforcing frame portion fixed to the underside of a floor portion of the vehicle and including first and second vertical members arranged at an interval in the vehicle width direction, and at least one horizontal member joined to the first and second vertical members so as to bridge and connect the first and second vertical members, The bracket for the motor unit includes a specific bracket that is disposed in a position that coincides with or is close to the center of gravity of the motor unit in the vehicle width direction, the first vertical member is disposed so as to coincide with or be close to a center of gravity of the motor unit in a vehicle width direction, and the specific bracket is attached to the first vertical member or the horizontal member; A vehicle structure characterized in that the second vertical member is positioned offset from the center of the vehicle in the vehicle width direction toward the other side in the vehicle width direction when viewed from the bottom of the vehicle, and the other end side of the lateral rod mounting reinforcement member is connected to the second vertical member.

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