Electric road vehicle structure and method for protecting the electrical unit

Abstract

An electric road vehicle structure is envisaged, comprising the following: a transverse element positioned as a bridge between side frames in the front section of the vehicle, a motor suspended beneath the transverse element, a tub fixed to an upper surface of the transverse element, and an electrical unit for driving the motor, fixed to the tub. A leading edge of the electrical unit is located in front of a leading edge of the transverse element, and the tub has a leading edge extending forward of the electrical unit over a width thereof.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a structure of an electric road vehicle driven by an electric motor. More specifically, the present disclosure relates to a structure of an electric road vehicle in which left and right front side frames extending substantially in vehicle longitudinal directions are provided on both left and right sides inside an engine compartment located in a front part of the vehicle, a cross member extending in vehicle width directions is interposed between the left and right front side frames as a bridge, an electric unit is placed on the cross member, and a vehicle drive motor to which electric power is supplied from the electric unit is suspended under the cross member. Furthermore, the invention relates to a method for protecting an electric unit upon a frontal collision of the vehicle. GENERAL STATE OF THE ART

[0002] Conventionally, electric road vehicles are known which are configured such that an engine compartment is formed in a front part of the vehicle, left and right front side frames extending substantially in vehicle longitudinal directions are provided on both left and right sides of the engine compartment, an electric motor is arranged between the pair of left and right front side frames, and left and right wheels are driven by the electric motor as a power source.

[0003] DE 10 2009 040 896 A1 and DE 10 2011 113 198 A1 disclose such electric road vehicles. DE 10 2009 040 896 A1 discloses an electric road vehicle in which left and right front side frames extending substantially in the vehicle longitudinal directions are provided on both left and right sides inside an engine compartment, a cross member extending in the vehicle width direction is interposed between the left and right front side frames as a bridge, and a vehicle drive motor is suspended under the cross member.

[0004] In DE 10 2009 040 896 A1, when an electrical unit including an inverter is placed on the cross member, some parts, including a radiator, move rearward when a frontal collision of the vehicle occurs, and these rearward-moving parts collide with the electrical unit and damage it. Consequently, there is room for improvement.

[0005] DE 10 2011 113 198 A1 discloses an electric road vehicle in which a cross member is inserted as a bridge in vehicle width directions by means of support members between left and right front side frames inside an engine compartment, a vehicle drive motor is supported under the cross member, the cross member is formed in a rectangular cylindrical container having a bottom at one end and open at the other, upper, end, and an electric unit including an inverter is housed in the cross member.

[0006] However, since the transverse element in DE 10 2011 113 198 A1 is shaped like a container, its mass becomes excessively large. Consequently, there is room for improvement.

[0007] Furthermore, DE 10 2016 105 972 A1 shows an electric vehicle with a holding mechanism having a holding plate for holding an electronic device and a leg portion supporting two long sides of the holding plate.

[0008] An electric road vehicle structure with a hull whose front edge is a vertically rising wall section is disclosed in CN 1 04 999 896 A. SUMMARY OF REVELATION

[0009] Thus, an object of the present disclosure is to provide an electric road vehicle structure capable of protecting an electric unit by catching a rearward moving part (or parts) located in front by means of a pan when a frontal collision of the vehicle occurs.

[0010] According to one aspect of the present disclosure, an electric road vehicle structure is provided, comprising: a cross member interposed between side frames in a front part of the vehicle as a bridge; an electric motor suspended below the cross member; a tub fixed to an upper surface of the cross member; and an electric unit for driving the electric motor, fixed on the tub. A front edge of the electric unit is located forward of a front edge of the cross member. The tub has a front edge located forward of the electric unit across a width thereof.

[0011] The electrical unit may be connected to an inverter to convert high voltage DC power supplied from a main battery into three-phase AC power, a junction box having a relay circuit therein, etc.

[0012] According to this structure, since the front edge of the tray is located in front of the electrical unit housing in a plan view across its width, a rearward-moving part(s) can contact the front edge of the tray before other components when a frontal collision of the vehicle occurs, and thus the rearward-moving part(s) can be absorbed. Consequently, the electrical unit can be protected by the front edge of the tray.

[0013] The front edge of the tub may be a wall section that rises substantially vertically.

[0014] According to this structure, since the rearward moving part(s) are securely caught by the front edge of the wall-like tray rising substantially vertically from the lower surface thereof, the electric unit can be more effectively protected.

[0015] A longitudinal dimension (in the vehicle's longitudinal direction) of the tray is greater than a longitudinal dimension (in the vehicle's longitudinal direction) of the cross member. The longitudinal dimension of the electrical unit in the vehicle's longitudinal direction is greater than the longitudinal dimension of the cross member in the vehicle's longitudinal direction. The tray may have fastening pieces at locations in front of the cross member and behind the cross member, which are aligned with fastening receptacles provided on a lower part of the electrical unit.

[0016] The tray may include a first lower portion secured to the upper surface of the cross member, and a second lower portion formed continuously from a front portion of the first lower portion and located higher than the first lower portion. The mounting receptacles may be provided on the second lower portion.

[0017] According to this structure, since the bottom surface of the tub is formed in the stepped structure with the first lower part and the second lower part, the bottom surface of the tub can be reinforced.

[0018] According to a further aspect, a method for protecting an electrical unit of an electric vehicle in a frontal collision is provided, comprising the following steps: Forming a bridge between side frames in a front part of a vehicle by means of a cross member; Hanging an electric motor under the cross member; Mounting a tray to an upper surface of the cross member; and Mounting an electrical unit to drive the electric motor on the tub, Positioning a front edge of the electrical unit in front of a front edge of the cross member, and Forming the trough with a front edge located across a width thereof in front of the electrical unit.

[0019] Preferably, the front edge of the tub is formed by a wall part which rises substantially vertically. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view illustrating an electric road vehicle structure of the present disclosure. Fig. 2 is a front view of the electric road vehicle structure. Fig. 3 is a plan view of the electric road vehicle structure. Fig. 4 is a rear view of the electric road vehicle structure. Fig. 5 is a vertical cross-sectional view of an essential part showing a coupling structure of a bus bar. Fig. 6 is a perspective view of a tub. Fig. 7 is an exploded view illustrating a mounting structure of an electric unit to the tub. Fig. Figure 8 is a plan view showing the electrical unit attached to the tub. DETAILED DESCRIPTION OF REVELATION

[0020] The task of catching rearward-moving parts located in front of it by means of a tray to protect an electrical unit when a vehicle is involved in a frontal collision is fulfilled by an electric road vehicle having the following structure: The structure includes left and right front side frames extending substantially in vehicle longitudinal directions on both left and right sides inside an engine compartment located in a front part of the vehicle. A cross member extending in vehicle width directions is interposed between the left and right front side frames as a bridge. An electric unit is placed on the cross member, and a vehicle drive motor, to which electric power is supplied from the electric unit, is suspended under the cross member. A longitudinal dimension of the electric unit is larger than a longitudinal dimension of the cross member, and a front edge of a housing of the electric unit, when installed, is located forward of a front edge of the cross member.A tray having a lower surface providing a fixed portion for a lower portion of the electrical unit is attached to an upper surface of the cross member. The tray has a front edge that, in a plan view across its width, is located forward of a front edge of the electrical unit housing. [Embodiment]

[0021] Hereinafter, an embodiment of the present disclosure will be described in detail based on the accompanying drawings. In the figures, an arrow F indicates "forward" or "front" in the vehicle longitudinal directions, and an arrow R indicates "rearward" or "backward" in the vehicle longitudinal directions.

[0022] The drawings represent the electric road vehicle structure, where Fig. 1 is a perspective view of the electric road vehicle structure, Fig. 2 a front view of Fig. 1 represents, Fig. 3 a plan view of Fig. 1 and Fig. 4 a rear view of Fig. 1 represents.

[0023] In Fig. 1 to 4, an engine compartment 1 is arranged in a front part of the vehicle. In detail, a lower instrument panel is provided rising from a front end of a floor panel, the engine compartment 1 is defined as being in front of the lower instrument panel, and a cabin is defined as being behind the lower instrument panel.

[0024] Left and right front side frames 2, which extend substantially in the vehicle longitudinal directions, are provided on both left and right sides inside the engine compartment 1.

[0025] As in Fig. 3 and Fig. 4, each front side frame 2 is a vehicle body reinforcement element in which a substantially closed cross-section 5 (see Fig. 4) extending substantially in the vehicle longitudinal directions, is formed by firmly joining upper and lower flange parts of a front side frame outside 3 and a front side frame inside 4.

[0026] As in Fig. As shown in Figures 1 to 4, an insertion plate 6 for attaching a crash absorber is provided at a front end of each front side frame 2, and the crash absorber is fixed to the insertion plate 6 by a fixing plate. A bumper reinforcement extending in the vehicle width direction is fixed between the front ends of the left and right crash absorbers.

[0027] As in Fig. 1 and Fig. As shown in Figure 3, suspension brackets 7 are attached to an upper surface of the front side frame 4 inside the front side frame 2 using bolts. A cross member 8 is interposed as a bridge between the pair of left and right front side frames 2 by attaching the cross member 8, which extends in the vehicle width directions, to the left and right suspension brackets 7.

[0028] As in Fig. 1 and Fig. As shown in Figure 3, a battery support arm 9 is provided on the left side of the vehicle, immediately behind the suspension bracket 7. The battery support arm 9 has an inverted L-shape in a front view of the vehicle. This battery support arm 9 is attached to the front side frame 4 at a substantially vertical portion thereof.

[0029] On the other hand, a battery support projection 7a extending substantially upward is formed integrally with the suspension bracket 7 on the left side of the vehicle. As shown in Fig. 2 and Fig. As shown in Figure 3, a battery 11 is placed on the battery support protrusion 7a and the battery support arm 9 through a battery tray 10. At an intermediate portion of the battery tray 10 in the vehicle longitudinal direction, a battery terminal 12 couples upper ends of inner and outer portions of the battery tray 10 in the vehicle width direction. In this embodiment, the battery 11 may be a 12V lead-acid battery, but is not limited thereto.

[0030] Fig. Figure 5 is a vertical cross-sectional view of an essential part of the electric road vehicle structure. As shown in this figure, the cross member 8 is formed by molding so that it has a substantially gate-like shape in this cross section, including an upper wall 8a, a front wall 8b, a rear wall 8c, and a plurality of reinforcing ribs 8d. Moreover, an upper surface of the upper wall 8a of the cross member 8 is flat. As shown in Fig. 2, central parts of the front wall 8b and the rear wall 8c extend downward in the vehicle width direction to have a downwardly convex and arcuate shape with respect to both ends of the walls in the vehicle width direction. As shown in Fig. 2, recesses or notches 8e which are substantially open downward are formed at two, left and right, locations in an intermediate part of the front wall 8b of the cross member 8 in the vehicle width directions.

[0031] As in Fig. 2, a motor unit 15 is suspended under the cross member 8 by using left and right support devices 13 and 14 provided at positions substantially corresponding to the recesses 8e of the cross member 8.

[0032] As shown in this figure, the motor unit 15 is an integrated unit of a three-phase AC motor 16 (hereinafter simply referred to as “the motor 16”) for driving the vehicle, which is located on the right side of the vehicle, a transmission 17 located on the left side of the vehicle and constituting a gear transmission mechanism, a blocking member 18 for blocking an opening formed on the right side of a motor casing 16a, and a blocking member 19 for blocking an opening formed on the left side of a housing 17a of the transmission 17.

[0033] As in Fig. 2, a flange part 16b provided on the left side of the motor casing 16a and a flange part 17b provided on the right side of the gearbox 17 are fastened to each other with bolts 20.

[0034] Here, on the left side of the vehicle, an upper part of the blocking member 19 and a lower part of the support device 13 are attached with bolts inserted inward in the vehicle width direction, and on the right side of the vehicle, an upper part of the blocking member 18 and a lower part of the support device 14 are attached with bolts inserted rearward in the vehicle longitudinal direction. Thus, the engine 16 is suspended under the cross member 8.

[0035] Fig. 6 is a perspective view of the tub, Fig. Fig. 7 is an exploded view showing a mounting structure of the electric unit to the tub, and Fig. Figure 8 is a plan view showing the electrical unit attached to the tub.

[0036] As also in Fig. 2 by way of a front view, a left pan 21 as the pan is fixed to an upper surface of the cross member 8 at a substantially central portion in the vehicle width direction. An inverter 30 is placed on the left pan 21, and a terminal box 40 is placed on the inverter 30. An electrical unit E1 includes the inverter 30 and the terminal box 40.

[0037] Moreover, as in Fig. As shown in Figure 2, a right pan 22, which is the pan, is attached to the right side in the vehicle width direction of the left pan 21 on the cross member 8. A charger 50 is placed on the right pan 22, and a DC-DC converter 60 is placed on the charger 50. An electrical unit E2 includes the charger 50 and the DC-DC converter 60.

[0038] The inverter 30 is a high-voltage component for converting high-voltage direct current power (e.g., about 300V) supplied from a main battery (not shown) arranged under the floor board into three-phase alternating current power and for supplying the converted alternating current power to the motor 16, and is provided with an inverter circuit.

[0039] The junction box 40 includes terminals used when electrical lines are coupled, branched, and switched, and a so-called “junction box” for protecting the terminals, and has a relay circuit.

[0040] The charger 50 is used to charge the main battery using electrical power input from an external power source and includes a charging circuit. The charger 50 is connected to the main battery via electrical power cables (not shown). The DC-DC converter 60 is a converter for converting the high voltage to a low voltage (e.g., approximately 12V) for powering onboard instruments.

[0041] As in Fig. 3 and Fig. 5, the longitudinal dimensions of the electrical units E1 and E2 are larger than the longitudinal dimensions of the cross element 8. As shown in Fig. 3 and Fig. 5, there are front edges of the housings of the electrical units E1 and E2, ie front edges of an inverter housing 31, a terminal box housing 41 (see Fig. 5), a charger housing 51 and a converter housing 61 (see Fig. 2) of the DC-DC converter 60, when installed, in front of the front wall 8b as a front edge of the cross member 8.

[0042] As in Fig. 6 and Fig. 7, a left pan 21 includes a first lower part 21a contacting and fixed to the upper surface of the cross member 8, a second lower part 21b formed continuously from a front part of the first lower part 21a and located higher than the first lower part 21a, and left and right third lower parts 21c formed continuously from left and right rear parts of the first lower part 21a and located substantially at the same height as the second lower part 21b. The first lower part 21a is fixed to the upper surface of the cross member 8 using a plurality of bolts 23, and the inverter 30 under the electric unit E1 is hinged to fastening parts 24 of the second lower part 21b and the third lower parts 21c using bolts 25.That is, the first lower part 21a, the second lower part 21b and the third lower parts 21c are lower surfaces that provide a fixed part of the inverter 30 under the electric unit E1.

[0043] As in Fig. 5 to 8, the left pan 21 has, in plan view, a front edge 21d located across its width in front of the front edge of the inverter housing 31 and the front edge of the terminal box housing 41. The front edge 21d is formed in a wall shape that rises substantially vertically from the second lower part 21b as the lower surface.

[0044] As in Fig. 6 to 8, the left pan 21 integrally forms left and right side walls 21e rising from both left and right outer ends in the vehicle width direction of the first lower part 21a and the second lower part 21b, and a rear wall 21f rising substantially upward between the third lower parts 21c so as to couple the third lower parts 21c.

[0045] Moreover, as in Fig. As shown in Figure 6, the first lower part 21a of the left pan 21 is provided with a plurality of upwardly convex ridges 21g extending substantially parallel to each other in the vehicle longitudinal direction. The ridges 21g are separated from each other in the vehicle width direction. In contrast, the second lower part 21b is provided with a plurality of downwardly convex ridges 21h extending substantially parallel to each other in the vehicle longitudinal direction. The ridges 21h are separated from each other in the vehicle width direction. The stepped structure of the first lower part 21a and the second lower part 21b and the structure of the ridges 21g and 21h reinforce the lower surface of the left pan 21.

[0046] As in Fig. 6 and Fig. 7, the tray comprises a first lower part 22a contacting and fixed to the upper surface of the cross member 8, and a second lower part 22b formed continuously from a front part of the first lower part 22a and located higher than the first lower part 22a.

[0047] The right pan 22 integrally forms left and right side walls 22c rising from both left and right ends of the first lower part 22a and the second lower part 22b, attachment pieces 22d and 22e extending substantially horizontally outward in the vehicle width direction from an upper end of the side wall 22c on the right side in the vehicle width direction, a standing wall 22f standing upright in a rear left corner part of the first lower part 22a, an attachment piece 22g extending substantially horizontally and obliquely rearward from an upper end of the standing wall 22f, and a rear wall 22h formed by being bent substantially downward from a rear end of the first lower part 22a.

[0048] Moreover, the right tub 22 also integrally forms a vertical wall 22i extending substantially upward from a front end of the second lower part 22b, a fixing piece 22j extending substantially horizontally and forward of an upper end of the vertical wall 22i, and front walls 22k extending substantially upward from a front end of the fixing piece 22j.

[0049] The first lower part 22a is fixed to the upper surface of the cross member 8 using a plurality of bolts 26. The mounting pieces 22d, 22e, 22g, and 22j are located at substantially the same height. The charger 50 under the electrical unit E2 is attached by bolts 28 to mounting parts 27 formed in the respective mounting pieces 22d, 22e, 22g, and 22j.

[0050] The front wall 22k of the right pan 22 is a wall located in front of the front edge of the charger housing 51 and the front edge of the converter housing 61 in plan view.

[0051] In this embodiment, the left pan 21 and the right pan 22 may comprise a rigid member (e.g., a steel plate having a thickness of about 2.5 mm), but are not limited thereto.

[0052] As in Fig. 5, the housing 31 of the inverter 30, which forms one of the electrical units E1 and E2 (in this case E1), and the housing 41 of the junction box 40 are stacked substantially vertically, so that the inverter housing 31 is located below the junction box housing 41.

[0053] As in Fig. 2, the housing 51 of the charger 50 constituting the other electrical unit E2 and the housing 61 of the DC-DC converter 60 are stacked substantially vertically, so that the charger housing 51 is located below the converter housing 61.

[0054] As in Fig. 5 and Fig. 8, the inverter case 31 is formed in a box shape having an upper wall 31a, a lower wall 31b, a front wall 31c, a rear wall 31d, and left and right side walls 31e, and a partition wall 31f for forming a space 33 communicating with a rear opening 32 is formed integrally with the inverter case 31.

[0055] Furthermore, as shown in these figures, the inverter housing 31 includes a plurality of mounting recesses 31g extending substantially forward from the bottom of the front wall 31c, and a plurality of mounting recesses 31h extending substantially rearward from the bottom of the rear wall 31d. As shown in Fig. 5, the fastening receptacles 31g and 31h are respectively fixedly attached to the second lower part 21b and the third lower parts 21c of the left tub 21 using the bolts 25.

[0056] Moreover, as in Fig. 5, a busbar insertion hole 31i is formed in the upper wall 31a of the inverter case 31 so that it communicates with the space 33, and, as shown in Fig. 5 and Fig. 8, the rear opening 32 is removably covered with a cover member 29 using bolts 34.

[0057] Moreover, as in Fig. 1, a plurality of mounting recesses 31j are formed integrally with the inverter case 31 so as to protrude substantially outwardly from upper parts of the inverter case 31.

[0058] It should be noted that the inverter housing 31 is preferably formed by die-casting aluminum.

[0059] As in Fig. 5, the junction box housing 41 is also preferably formed by die-casting aluminum and is formed by striking a box base body 42 and a bottom surface 43 located below the box base body 42 using a plurality of bolts 44.

[0060] As shown in this figure, the box main body 42 includes an upper wall 42a, a front wall 42b, a rear wall 42c, and left and right side walls 42d, where an upper opening 45, a lower opening 46, and a rear opening 47 are formed.

[0061] The upper opening 45 is detachably covered with a cover member 49 by means of bolts 48, and a busbar insertion hole 43a aligned with the busbar insertion hole 31i of the inverter case 31 is formed in the lower surface 43.

[0062] As in Fig. 1 and Fig. As shown in Figure 5, a plurality of mounting recesses 43b corresponding to the mounting recesses 31j of the inverter housing 31 are integrally formed in the lower surface 43 and project substantially outward. The mounting recesses 43b of the terminal box housing 41 are placed on the mounting recesses 31j of the inverter housing 31, and these recesses 31j and 43b are secured using a plurality of bolts 35.

[0063] As in Fig. As shown in Figure 5, the bolts 35 that attach the inverter housing 31 to the junction box housing 41 are thicker and larger in shear force than the bolts 25 that attach the inverter housing 31 to the left pan 21. In this embodiment, the bolts 35 may be, but are not limited to, M10, while the bolts 25 may be, but are not limited to, M8.

[0064] As in Fig. As shown in Figure 5, a conductive part inside the terminal box 40 is coupled to a conductive part inside the inverter casing 31 by means of a bus bar 36 made of copper bars. This bus bar 36 is wired through the lower surface 43 and the space 33 via the upper and lower bus bar insertion holes 43a and 31i, and the periphery of the wired part is covered with an insulating member 37.

[0065] As in Fig. 7 and Fig. As shown in Figure 8, the charger housing 50 is formed in a box shape including a top wall (not shown), a bottom wall 51b, a front wall 51c, a rear wall 51d, and left and right side walls 51e. The charger housing 51 integrally forms a plurality of mounting recesses 51f projecting substantially outwardly from a lower portion of the charger housing 51. These mounting recesses 51f are fixedly coupled to the respective mounting pieces 22d, 22e, 22g, and 22j of the right tray 22 using the bolts 28.

[0066] As in Fig. 1, Fig. 2 and Fig. 4, the charger case 51 further integrally forms a plurality of mounting recesses 51g projecting substantially outwardly from an upper part of the charger case 51, and a plate 53 is fixed to the mounting recesses 51g using bolts 52.

[0067] The plate 53 has a plurality of lower fastening pieces 53a and a plurality of upper fastening pieces 53b. The lower fastening pieces 53a are fixed to the fastening receptacles 51g of the charger housing 51, respectively. A plurality of fastening receptacles 61a, which protrude substantially outwardly from the converter housing 61 of the DC-DC converter 60, are fixedly attached to the upper fastening pieces 53b using bolts 54, respectively.

[0068] As in Fig. 4, a rear surface of the housing 51 of the charger 50 and a rear surface of the rear wall 22h of the right tub 22 are mutually coupled by a coupling element 55. The inverter 30 and the DC-DC converter 60, among the group of the inverter 30, the junction box 40, the charger 50, and the DC-DC converter 60, which constitute the electrical units E1 and E2, are electrical components that require cooling by means of a coolant.

[0069] As in Fig. 1 to 3, a pair of ports (an inlet and an outlet) 38 for supplying and discharging the coolant to and from a water cooling jacket (not shown) inside the inverter case 31 are provided on the side wall 31e located substantially outward in the vehicle width direction in the inverter case 31 at a position as far forward as possible in the vehicle longitudinal direction. Moreover, a pair of ports (an inlet and an outlet) 62 and 63, which supply and discharge the coolant from a water cooling jacket (not shown) inside the inverter case 31, are provided to a front side of the upper wall in the converter case 61 of the DC-DC converter 60.

[0070] As in Fig. 3 and Fig. 4, coupling parts 70 of the electric power cables 71 and 72 for supplying electric power from the main battery (not shown) to the rear left side of the junction box case 41 are provided in the junction box 40.

[0071] As in Fig. 3 and Fig. 4, a coupling part 76 of the three-phase cables 73, 74 and 75, which supply three-phase alternating current electric power converted into three-phase alternating current by the inverter 30 to the motor 16 under the cross member 8, is provided to the rear right side of the terminal box case 41 in the terminal box 40.

[0072] As in Fig. 5, upper ends of the three-phase cables 73 are substantially perpendicular to the coupling part 76. Connection terminals 78 are provided at the tip ends of the cable main bodies, which are inserted into the terminal box case 41 through a sealing member 77, and these connection terminals 78 are coupled to horizontal parts at an upper end of the bus bar 36 by means of bolts 79.

[0073] As in Fig. 4 and Fig. As shown in Figure 5, the three-phase cables 73, 74, and 75 extend substantially downward, smoothly bent from their upper ends to their lower ends. The lower ends of the three-phase cables 73, 74, and 75 are held by a coupling member 80 on the rear side of the motor enclosure 16a so that they are substantially perpendicular to the coupling member 80.

[0074] In Fig. 5, although only one of the three-phase cables 73, 74, and 75 is shown, the remaining two cables have a similar structure for elements 78, 79, 36, 37, 43a, and 31i. In addition, the structures for elements 78, 79, 36, 37, 43a, and 31i at the upper ends of the two electrical power cables 71 and 72 are also similar to the structures of Fig. 5.

[0075] It should be noted that 90 drive shafts in Fig. 1 to 4 and 91 a lower suspension bracket of the engine unit 15 in Fig. 3 indicates.

[0076] As described above, the electric road vehicle structure of the embodiment includes the left and right front side frames 2, which extend substantially in the vehicle longitudinal direction, on both left and right sides inside the engine compartment 1 located in the front part of the vehicle. The cross member 8, which extends in the vehicle width direction, is interposed between the left and right front side frames 2 as a bridge. The electric unit E1 is placed on the cross member 8, and the motor 16 for driving the vehicle, to which electric power is supplied from the electric unit E1, is suspended under the cross member 8. In this electric road vehicle structure, the longitudinal dimension of the electric unit E1 is larger than the longitudinal dimension of the cross member 8.The front edge of the housing of the electrical unit E1 (see the inverter housing 31 and the terminal box housing 41), if installed, is located in front of the front edge of the cross member 8. The tray (the left tray 21) having the lower surface (see the first lower part 21a and the second lower part 21b) providing the fixed part below the electrical unit E1 is fixed to the upper surface of the cross member 8. The tray (the left tray 21) has a front edge 21d which, in plan view across its width, is located in front of a front edge of the housing of the electrical unit E1 (see . Fig. 1, Fig. 2 and Fig. 5).

[0077] According to this structure, since the front edge 21d of the pan (the left pan 21) is located in front of the electric unit E1 casing (the inverter casing 31 and the terminal box casing 41) in plan view across its width, the rearward moving part(s) touches the front edge 21d of the pan (the left pan 21) in front of other components when a frontal collision of the vehicle occurs, thereby catching the rearward moving part(s). Consequently, the electric unit E1 can be protected by the front edge 21d of the pan (the left pan 21).

[0078] In one embodiment of the present disclosure, the front edge 21d of the tub (the left tub 21) is formed in the wall shape that rises substantially vertically from the lower surface (the second lower part 21b) (see Fig. 5).

[0079] According to this structure, since the rearward moving part(s) can be safely caught by the front edge 21d of the wall-like tray (the left tray 21) rising substantially vertically from the lower surface, the electric unit E1 can be more effectively protected.

[0080] In one embodiment of the present disclosure, the lower surface of the tray (the left tray 21) includes the first lower part 21a, which contacts and is fixed to the upper surface of the cross member 8, and the second lower part 21b, which is continuously formed from the front part of the first lower part 21a and is located higher than the first lower part 21a, and to which the lower part of the electric unit E1 (in this embodiment, the lower part of the inverter case 31) is fixed (see Fig. 5).

[0081] According to this structure, since the lower surface of the tub (the left tub 21) is formed in the stepped structure with the first lower part 21a and the second lower part 21b, the lower surface of the tub (the left tub 21) can be reinforced.

[0082] Regarding the correspondence of the structure of the present disclosure and the structure of this embodiment, the electric unit casing of the present disclosure corresponds to the inverter casing 31 and the terminal box casing 41 of this embodiment, the tray corresponds to the left tray 21, and the bottom surface of the tray corresponds to the first lower part 21a and the second lower part 21b; however, the present disclosure is not limited to the structure of this embodiment.

[0083] As described above, the present disclosure is useful for the electric road vehicle structure in which the left and right front side frames extending substantially in the vehicle longitudinal direction are provided on both left and right sides inside the engine compartment located in a front part of the vehicle, the cross member extending in the vehicle width direction is interposed between the left and right front side frames as a bridge, the electric unit is placed on the cross member, and the vehicle drive motor to which electric power is supplied from the electric unit is suspended under the cross member. LIST OF REFERENCE SYMBOLS 1 engine compartment 2 front frames 8 Cross element 16 Engine 21 left tub (tub) 21a first lower part (lower surface) 21b second lower part (lower surface) 21d leading edge 31 Inverter housing (electrical unit housing) 41 Junction box housing (housing of electrical unit) E1 electrical unit

Claims

[1] Electric road vehicle structure, comprising: a cross member (8) inserted between side frames (2) in a front part of a vehicle as a bridge; an electric motor (16) suspended under the cross member (8); a tray (21, 22) fixed to an upper surface of the cross member (8); and an electrical unit (E1) for driving the electric motor (16) which is fixed on the tub (21, 22), wherein a front edge of the electrical unit (E1) is located in front of a front edge (8b) of the transverse element (8), wherein the trough (21, 22) has a front edge (21d) which is located across a width thereof in front of the electrical unit (E1), wherein a longitudinal dimension of the trough (21, 22) is greater than a longitudinal dimension of the transverse element (8) and wherein the longitudinal dimension of the electrical unit (E1) in the vehicle longitudinal direction is greater than the longitudinal dimension of the transverse element (8) in the vehicle longitudinal direction. [2] An electric road vehicle structure according to claim 1, wherein the front edge (21d) of the tub (21, 22) is a wall part which rises substantially vertically. [3] An electric road vehicle structure according to any preceding claim, wherein the pan (21, 22) comprises a first lower part (21a) hinged to the upper surface of the cross member (8) and a second lower part (21b) formed continuously from a front part of the first lower part (21a) and located higher than the first lower part (21a). [4] An electric road vehicle structure according to any one of the preceding claims, wherein the tray (21, 22) comprises fastening pieces (22d, 22e, 22g, 22j) aligned with fastening receptacles (51f) provided on a lower part of the electric unit (E1) at locations in front of the cross member (8) and behind the cross member (8). [5] An electric road vehicle structure according to claim 4, wherein the mounting receptacles (31g, 31h) are provided on the second lower part (21b). [6] A method for protecting an electrical unit (E1) of an electric vehicle in a frontal collision, comprising the following steps: Forming a bridge between side frames (2) in a front part of a vehicle by means of a cross member (8); Suspending an electric motor (16) under the cross member (8); Mounting a tray (21, 22) on an upper surface of the cross member (8); and Mounting an electrical unit (E1) for driving the electric motor (16) on the tub (21, 22), Positioning a front edge of the electrical unit (E1) in front of a front edge (8b) of the cross element (8), Forming the trough (21, 22) with a front edge (21 d) which is located across a width thereof in front of the electrical unit (E1) Forming the trough (21, 22) with a longitudinal dimension of the trough (21, 22) which is greater than a longitudinal dimension of the transverse element (8), and Forming the electrical unit (E1) with a longitudinal dimension in the vehicle longitudinal direction that is greater than the longitudinal dimension of the cross member (8) in the vehicle longitudinal direction. [7] Method according to claim 6, wherein the front edge (21d) of the trough (21, 22) is formed by a wall part which rises substantially vertically.

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