Vehicle

Abstract

This vehicle is provided with: a battery; a battery case that is fastened to a pair of vehicle body frames arranged separately from each other in the left-right direction, and that accommodates therein a battery; and an electrical component that is mounted on the battery case and at the front side. The battery case is provided with: a rear frame that is disposed at the rear side of the battery case and is stretched over the upper surfaces of the pair of vehicle body frames; and a cross member that is disposed along the left-right direction at the front side relative to the rear frame.

Description

vehicle

[0001] The present invention relates to a vehicle.

[0002] 2. Description of the Related Art In vehicles such as hybrid vehicles and electric vehicles, a battery pack for supplying electricity to a motor that serves as a drive source is provided under the luggage compartment behind the rear seats (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2021-27008

[0004] In such a battery pack, electrical components may be mounted on top of the battery case, and when electrical components are mounted on top of the battery case, it is necessary to protect the electrical components even in the event of a rear-end collision of the vehicle.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to protect electrical components mounted on the upper part of a battery case.

[0006] A vehicle according to one embodiment of the present invention comprises a battery, a battery case that is fastened to a pair of body frames that are spaced apart in the left-right direction and that houses the battery, and electrical components that are mounted on the front side of the battery case, and the battery case comprises a rear frame that is arranged on the rear side of the battery case and that spans the upper surfaces of the pair of body frames, and a cross member that is arranged in front of the rear frame and along the left-right direction.

[0007] According to the present invention, it is possible to protect the electrical components mounted on the upper part of the battery case.

[0008] 1 is a diagram showing an outline of the configuration of a vehicle. 2 is a diagram showing an example of how a battery pack is installed. 3 is a diagram showing the configuration of a battery pack. 4 is a top view of a lower case. 5 is a diagram showing a battery and a high-voltage unit housed in the lower case. 6 is a bottom view of the lower case. 7 is an exploded view of a battery cover. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 3. 9 is a cross-sectional view taken along line IX-IX in FIG. 3. 10 is a cross-sectional view taken along line X-X in FIG. 3. 11 is a diagram showing the configuration of a vehicle body. 12 is a diagram showing a vehicle body with a battery pack installed. 13 is a diagram showing a vehicle body with a battery pack installed with the cover removed. 14 is a diagram showing how an inverter is protected in the event of a rear-end collision. 15 is a diagram showing how an inverter is protected in the event of a rear-end collision. 16 is a diagram showing how an inverter is protected in the event of a rear-end collision. 17 is a diagram showing how an inverter is protected in the event of a rear-end collision. 18 is a diagram showing how an inverter is protected in the event of a rear-end collision. 19 is a diagram showing how an inverter is protected in the event of a rear-end collision.

[0009] 1. General Configuration of Vehicle> Fig. 1 is a diagram showing the general configuration of a vehicle 1. As shown in Fig. 1, the vehicle 1 is an electric vehicle or a hybrid vehicle equipped with a motor generator 2 (denoted as "M / G" in the figure) as a power source. The vehicle 1 includes the motor generator 2, a battery pack 3, an inverter 4, and a power transmission cable 5. The battery pack 3 includes a battery 11 and a high-voltage unit 12.

[0010] The motor generator 2 is a power source, such as a three-phase AC motor, that drives the vehicle 1. The motor generator 2 generates driving force using electricity (power) supplied from the battery 11 via the high-voltage unit 12, the inverter 4, and the power transmission cable 5, and transmits the driving force to the drive wheels to drive the vehicle 1. If the vehicle 1 is a hybrid vehicle, it will also be equipped with an engine as a power source.

[0011] The motor generator 2 is capable of generating electricity (power) by performing regenerative operation. The electricity generated by the regenerative operation of the motor generator 2 is supplied to the battery 11 via the inverter 4, the power transmission cable 5, and the high-voltage unit 12.

[0012] The inverter 4 converts the DC current supplied from the battery 11 into three-phase AC current and supplies it to the motor generator 2 via the power transmission cable 5. When the motor generator 2 performs regenerative operation, the inverter 4 converts the AC current supplied from the motor generator 2 into DC current and supplies it to the battery 11 via the power transmission cable 5.

[0013] The battery 11 is a so-called high-voltage secondary battery that stores electricity to be supplied to the motor generator 2. The battery 11 can be charged by regenerative operation of the motor generator 2. The battery 11 may also be charged by electricity supplied from an external device (not shown).

[0014] The high-voltage unit 12 includes a junction box and a monitoring unit. The junction box is provided with electronic components such as relays, fuses, and connectors. The monitoring unit is provided with electronic components such as sensors for monitoring the state of the battery 11. In the vehicle 1, a BCU (Battery Control Unit), which is a computer for controlling the operation of the battery 11, is provided separately from the battery pack 3, but the BCU may be included in the high-voltage unit 12.

[0015] The high voltage unit 12 is connected to the battery 11 via a cable (not shown). Therefore, the high voltage from the battery 11 is applied to the high voltage unit 12.

[0016] Fig. 2 is a diagram showing an example of installation of the battery pack 3. As shown in Fig. 2, the vehicle 1 is provided with a luggage compartment 7 behind the rear seats 6. The luggage compartment 7 can be opened and closed by a back door 8.

[0017] A battery pack 3 is mounted below the luggage compartment 7. A luggage compartment board 9 is provided above the battery pack 3, and luggage and the like can be placed on the luggage compartment board 9.

[0018] 2. Battery Pack Configuration Fig. 3 is a diagram showing the configuration of the battery pack 3. Fig. 4 is a top view of the lower case 14. Fig. 5 is a diagram showing the battery 11 and high-voltage unit 12 housed in the lower case 14. Fig. 6 is a bottom view of the lower case 14. Fig. 7 is an exploded view of the battery case cover 15. Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 3. Fig. 9 is a cross-sectional view taken along line IX-IX in Fig. 3. Fig. 10 is a cross-sectional view taken along line X-X in Fig. 3.

[0019] In the following description, the forward direction of the vehicle 1 will be referred to as the forward direction, the backward direction of the vehicle 1 as the backward direction, the direction facing right with respect to the forward direction of the vehicle 1 as the right direction, the direction facing left with respect to the forward direction of the vehicle 1 as the left direction, the vertically upward direction as the upward direction, and the vertically downward direction as the downward direction. The left-right direction may also be referred to as the width direction of the vehicle 1 or simply as the width direction.

[0020] 3 , the battery pack 3 includes a battery case 13. The battery 11 and the high-voltage unit 12 are housed inside the battery case 13. The battery case 13 is composed of a lower case 14 that is recessed and opens upward, and a battery case cover 15 that closes the opening of the lower case 14.

[0021] As shown in Figures 3 to 6, the lower case 14 includes a front frame 21, a rear frame 22, a left frame 23, a right frame 24, a battery case pan 25, a center frame 26, a stay 27, a left front bracket 28, a right front bracket 29, a left side bracket 30, a right side bracket 31, a center frame lower 32, a left side frame lower 33, a right side frame lower 34, a crash box 35, a front frame lower 36, and a rear frame lower 37.

[0022] The front frame 21 extends in the left-right direction. As shown in Fig. 8 , the front frame 21 is formed so that the cross section perpendicular to the longitudinal direction is generally in an inverted U shape, opening downward. In other words, the cross section of the front frame 21 is hat-shaped. The front frame 21 is formed with fastening holes 38a, 38b, 38c, and 38d for fixing the battery pack 3 to the vehicle body 100 (see Fig. 11 ).

[0023] A front bracket 20 is fastened to the front wall surface of the front frame 21. As shown in FIG. 8 , the front bracket 20 is attached so as to extend downward and forward from the front wall surface of the front frame 21. Two through holes are formed on the front side of the front bracket 20. When the battery pack 3 is attached to the vehicle body 100 (see FIG. 10 ), the front bracket 20 is fastened to the front cross member 103 by fastening parts (e.g., bolts and nuts) via the through holes.

[0024] The rear frame 22 is located rearward of the front frame 21 and is arranged parallel to and spaced apart from the front frame 21 in the front-to-rear direction. Note that "parallel" includes not only completely parallel but also approximately parallel, and this also applies hereinafter. Like the front frame 21, the rear frame 22 extends in the left-to-right direction and has a cross section perpendicular to the longitudinal direction that is approximately inverted U-shaped (hat-shaped). Fastening holes 38e, 38f, 38g, and 38h are formed in the rear frame 22 for fixing the battery pack 3 to the vehicle body.

[0025] The left frame 23 extends in the front-to-rear direction. As shown in Figure 9, the left frame 23 is formed so that a cross section perpendicular to the longitudinal direction is generally in an inverted U shape, opening downward. In other words, the left frame 23 has a hat-shaped cross section. A fastening hole 39a is formed in the left frame 23 rearward of the center in the front-to-rear direction. The fastening hole 39a is formed in a position facing a fastening hole 45a of a left bracket 45 (described later), and the fastening hole 39a and the fastening hole 45a are fastened together by a fastening portion 47a.

[0026] The right frame 24 is disposed to the right of the left frame 23 and is spaced apart from and parallel to the left frame 23 in the left-right direction. Like the left frame 23, the right frame 24 extends in the front-to-rear direction and has a generally inverted U-shaped (hat-shaped) cross section. A fastening hole 39b is formed in the right frame 24 rearward of the center in the front-to-rear direction. The fastening hole 39b is formed in a position facing a fastening hole 46a of a right bracket 46 (described later), and the fastening hole 39b and the fastening hole 46a are fastened together by a fastening portion 48a. The fastening portions 47a, 48a are, for example, bolts and nuts.

[0027] The upper end of the left frame 23 is joined to the left end of the front frame 21. The upper end of the right frame 24 is joined to the right end of the front frame 21. The lower end of the left frame 23 is joined to the left end of the rear frame 22. The lower end of the right frame 24 is joined to the right end of the rear frame 22. As a result, the front frame 21, rear frame 22, left frame 23, and right frame 24 are formed as a substantially rectangular frame as a whole. Furthermore, the front frame 21, rear frame 22, left frame 23, and right frame 24 have hat-shaped cross sections, which increases their rigidity.

[0028] 8 and 9, the battery case pan 25 is formed by bending a plate material to form a bottom surface 25a, and a front wall 25b, a rear wall 25c, a left side wall 25d, and a right side wall 25e that surround the bottom surface 25a. The bottom surface 25a, the front wall 25b, the rear wall 25c, the left side wall 25d, and the right side wall 25e form the battery case pan 25 in a recessed shape that is open at the top.

[0029] The bottom portion 25a is formed in a generally rectangular shape and extends horizontally (front-to-back and left-to-right directions). A front wall 25b is formed continuously with the upper end of the bottom portion 25a. The front wall 25b is formed so as to extend in the up-down and left-to-right directions. A rear wall 25c is formed continuously with the lower end of the bottom portion 25a. The rear wall 25c is formed so as to extend in the up-down and left-to-right directions. A left side wall 25d is formed continuously with the left end of the bottom portion 25a. The left side wall 25d is formed so as to extend in the up-down and front-to-back directions. A right side wall 25e is formed continuously with the right end of the bottom portion 25a. The right side wall 25e is formed so as to extend in the up-down and front-to-back directions. The battery case pan 25 may be formed by combining the bottom portion 25a, front wall 25b, rear wall 25c, left side wall 25d, and right side wall 25e, each made of a different plate material, by welding or the like.

[0030] The front wall 25b, rear wall 25c, left side wall 25d, and right side wall 25e each have a flange 25f formed continuously at the upper end thereof so as to extend outward. That is, the battery case pan 25 has the flange 25f formed on its outer edge. The flange 25f extends horizontally (in the front-to-rear and left-to-right directions). The front frame 21, rear frame 22, left frame 23, and right frame 24 are joined to the flange 25f from above.

[0031] The center frame 26 is joined to the upper surface of the bottom surface 25a of the battery case pan 25 so as to be centered in the left-right direction of the battery case pan 25 and aligned along the front-rear direction. As shown in Fig. 8 , the rear end of the center frame 26 abuts against the rear side wall 25c, and the front end extends forward from the center in the front-rear direction of the bottom surface 25a. As shown in Fig. 9 , the cross section of the center frame 26 perpendicular to the longitudinal direction is formed in an inverted U-shape (hat-shape), thereby increasing the rigidity of the center frame 26.

[0032] The stay 27 is joined to the upper surface of the bottom portion 25a at the center in the left-right direction of the battery case pan 25 so as to overlap the front end of the center frame 26. The front end of the stay 27 abuts the front side wall 25b and extends obliquely upward from the rear to the front. The stay 27 has an inverted U-shape (hat shape) perpendicular to the longitudinal direction, which increases its rigidity.

[0033] The left front bracket 28 is joined to the left front of the upper surface of the bottom surface portion 25a. The left front bracket 28 is made of a bent plate material so that the center portion is positioned substantially horizontal and higher than the upper surface of the bottom surface portion 25a. As shown in FIG. 5, the high-voltage unit 12 is attached to the center portion of the left front bracket 28.

[0034] The right front bracket 29 is joined to the right front of the upper surface of the bottom surface portion 25a. The right front bracket 29 is made of a bent plate material so that its center is positioned substantially horizontal and higher than the upper surface of the bottom surface portion 25a. As shown in FIG. 5, the high-voltage unit 12 is attached to the center of the right front bracket 29.

[0035] In this way, the high-voltage unit 12 is attached separately to the left front bracket 28 and the right front bracket 29. However, the high-voltage unit 12 may be attached collectively to only one of the left front bracket 28 and the right front bracket 29.

[0036] The left side bracket 30 is joined to the left rear of the upper surface of the bottom portion 25a. The left side bracket 30 is arranged to extend in the front-to-rear direction, and is made of a bent plate material so that its central portion is higher than the upper surface of the bottom portion 25a and is generally horizontal. The right side bracket 31 is joined to the right rear of the upper surface of the bottom portion 25a. The right side bracket 31 is arranged to extend in the front-to-rear direction, and is made of a bent plate material so that its central portion is higher than the upper surface of the battery case pan 25 and is generally horizontal. As shown in FIG. 9 , the battery 11 is attached so as to span the center of the left side bracket 30 and the right side bracket 31. Note that the illustration shows an example in which two stacks of multiple cells are provided as the battery 11.

[0037] As shown in Fig. 6, the center frame lower 32 extends in the front-rear direction at the center of the battery case pan 25 in the left-right direction and is joined to the underside of the bottom surface 25a. The left side frame lower 33 and the right side frame lower 34 are arranged parallel to the left and right of the center frame lower 32, extend in the front-rear direction, and are joined to the underside of the bottom surface 25a. As shown in Fig. 9, the center frame lower 32, the left side frame lower 33, and the right side frame lower 34 have a U-shaped (inverted hat) cross section perpendicular to the longitudinal direction, which increases their rigidity.

[0038] In this way, the rigidity of the upper part of the lower case 14 is increased by the front frame 21, rear frame 22, left frame 23, and right frame 24. In addition, the rigidity of the lower part of the lower case 14 is increased by the center frame 26, stays 27, center frame lower 32, left side frame lower 33, and right side frame lower 34.

[0039] The lower case 14 also prevents the battery case pan 25 from being crushed by external forces from the left and right direction by the front frame 21 and rear frame 22. Furthermore, the lower case 14 also prevents the battery case pan 25 from being crushed by external forces from the front and rear direction by the left frame 23, right frame 24, center frame 26, stays 27, center frame lower 32, left side frame lower 33, and right side frame lower 34.

[0040] The crash boxes 35 are joined from below to the central rear end of the bottom surface 25a so as to overlap the rear ends of the center frame lower 32, left side frame lower 33, and right side frame lower 34. As shown in FIG. 8 , the crash boxes 35 are composed of two plates 35a, 35b, and a separator member 35c. The front end of the plate 35a is joined to the vertical center of the rear wall 25c and extends downward and rearward from its front end to its rear end. The tip of the plate 35b is joined to the bottom surface 25a and the rear end of the center frame lower 32 and extends upward and rearward from its front end to its rear end. The separator member 35c has a structure including two separators connecting the plate members 35a and 35b, which are spaced apart in the vertical direction. The crash box 35 is formed by plate members 35a and 35b so that the cross section perpendicular to the left-right direction has a closed cross section (approximately rectangular), and its interior is reinforced by a separator member 35c to increase its strength.

[0041] 8, the front frame lower 36 is joined from below to the front flange 25f of the battery case pan 25. As a result, the front flange 25f of the battery case pan 25 is sandwiched between the front frame 21 and the front frame lower 36, further increasing the rigidity of the front portion of the lower case 14.

[0042] The rear frame lower 37 is joined from below to the rear flange 25f of the battery case pan 25. As a result, in the battery case pan 25, the rear flange 25f is sandwiched between the rear frame 22 and the rear frame lower 37, further increasing the rigidity of the rear portion of the lower case 14.

[0043] As shown in FIGS. 3 and 7, the battery case cover 15 includes a main cover 41, a left front cover 42, a service plug cover 43, an inverter unit 44, a left bracket 45, and a right bracket 46.

[0044] The main cover 41 includes a lower cover 51, a center frame upper 52, a first cover cross member 53, and a second cover cross member 54.

[0045] The lower cover 51 is formed in a shape such that the front left and front right portions are cut out of a substantially rectangular plate material. The length of the lower cover 51 in the front-to-rear direction is approximately the same as the distance between the front frame 21 and the rear frame 22 of the lower case 14, and the length of the lower cover 51 in the left-to-right direction is approximately the same as the distance between the left frame 23 and the right frame 24 of the lower case 14.

[0046] A through-hole 51a is formed in the lower cover 51 below the second cover cross member 54. A cooling duct 16 is connected to the through-hole 51a. The cooling duct 16 is a duct for sending air from the vehicle compartment into the battery case 13 and houses a cooling fan 17 therein. In addition, as shown in FIG. 10 , an in-case cooling duct 18 is provided inside the battery pack 3, extending from the through-hole 51a to below the battery 11.

[0047] When the cooling fan 17 operates, it draws in air from the air intake port 16a and sends the air through the cooling duct 16 to the in-case cooling duct 18. The air sent into the in-case cooling duct 18 passes through the in-case cooling duct 18 and is released from below the battery 11, as shown by the outline arrows in Fig. 10. The released air cools the battery 11 as it passes between the cells of the battery 11, as shown by the arrows in Fig. 10. The air that has been warmed by cooling the battery 11 is discharged from exhaust holes 51c formed in the lower cover 51, and is also discharged into the inverter case 62 when the inverter fan 63, described below, is operating.

[0048] A through hole 51b is formed in the lower cover 51 between the first cover cross member 53 and the second cover cross member 54. A smoke exhaust duct 19 is connected to the through hole 51b. One end of the smoke exhaust duct 19 is connected to the through hole 51b, and the other end is open to the outside of the vehicle. The smoke exhaust duct 19 is provided to exhaust smoke gases to the outside of the vehicle when the battery 11 emits smoke.

[0049] The upper center frame 52 is joined to the top surface of the lower cover 51 at the center in the left-right direction of the lower cover 51 so as to extend in the front-rear direction. The upper center frame 52 is formed so that its length in the front-rear direction is approximately the same as that of the lower cover 51. As shown in FIG. 8 , the upper center frame 52 spans between the front frame 21 and the rear frame 22.

[0050] The first cover cross member 53 is joined to the upper surface of the lower cover 51 so as to extend in the left-right direction near the center of the lower cover 51 in the front-rear direction. The first cover cross member 53 is formed so that its length in the left-right direction is approximately the same as that of the lower cover 51.

[0051] The second cover cross member 54 is joined to the upper surface of the lower cover 51 so as to be disposed parallel to and spaced apart from the first cover cross member 53 in the front-to-rear direction. The second cover cross member 54 is disposed rearward of the first cover cross member 53. Like the first cover cross member 53, the second cover cross member 54 is formed so that its length in the left-to-right direction is approximately the same as that of the lower cover 51.

[0052] As shown in Figure 9, the first cover cross member 53 and the second cover cross member 54 are bridged between the left frame 23 and the right frame 24. In addition, as shown in Figure 8, the first cover cross member 53 and the second cover cross member 54 are disposed directly above the battery 11.

[0053] The center frame upper 52, the first cover cross member 53 and the second cover cross member 54 have a cross section perpendicular to the longitudinal direction that is formed in a generally inverted U-shape (hat-shape), thereby increasing rigidity.

[0054] The first cover cross member 53 and the second cover cross member 54 have a thickness in the vertical direction greater than that of the center frame upper 52. Therefore, the first cover cross member 53 and the second cover cross member 54 are joined to the lower cover 51 so as to pass above the center frame upper 52.

[0055] The left front cover 42 is formed from a plate material in a generally rectangular shape so as to fit into the upper left notch of the lower cover 51. A through hole 42a is formed in the left front cover 42 at a position facing the service plug of the high-voltage unit 12 provided in the battery case 13. A service plug cover 43 is attached to cover the through hole 42a from above. The service plug cover 43 is formed from a plate material and is detachable from the left front cover 42.

[0056] The inverter unit 44 is formed in a generally rectangular shape so as to fit into the upper right notch of the lower cover 51. As shown in FIG. 10 , the inverter unit 44 includes an inverter 61, an inverter case 62, and an inverter fan 63.

[0057] The inverter 61 converts the DC voltage from the battery 11 into an AC voltage, for example, generating an AC voltage of 100 V. The AC voltage generated by the inverter 61 can be used as a power source for operating various electrical appliances via an outlet provided in the vehicle 1.

[0058] The inverter 61 is housed in an inverter case 62. The inverter case 62 is formed in a generally rectangular parallelepiped shape with a hollow interior. The front side of the inverter case 62 is disposed so as to rest on the front frame 21. Therefore, the inverter case 62 (inverter unit 44) is disposed at an angle so as to face upward toward the front.

[0059] A through hole is formed in the bottom surface of the inverter case 62 so as to communicate the internal space of the inverter case 62 with the internal space of the battery case 13. An inverter fan 63 is provided in the inverter case 62 near this through hole.

[0060] When the inverter fan 63 operates, it sucks in air stagnating in the internal space of the battery case 13 and sends it out to the inverter case 62. In the inverter unit 44, the inverter 61 is cooled by the air sent out to the inverter fan 63. The air heated by cooling the inverter 61 is discharged from an exhaust port 62a provided in front of the inverter case 62.

[0061] The left front cover 42 and the inverter unit 44 are fastened to the lower cover 51 and the upper center frame 52 with fastening parts (e.g., bolts and nuts). This gives the battery case cover 15 a generally rectangular shape as a whole. The battery case cover 15 is then fastened to the front frame 21, rear frame 22, left frame 23, and right frame 24 of the lower case 14 with fastening parts.

[0062] The left bracket 45 and the right bracket 46 are made of plate material and are formed into a generally triangular shape in top view. Fastening holes 45a, 45b, and 45c are formed in the left bracket 45 at positions corresponding to the corners of the generally triangle. Fastening holes 46a, 46b, and 46c are formed in the right bracket 46 at positions corresponding to the corners of the generally triangle.

[0063] The main cover 41 has a fastening hole 41a formed in a position facing the fastening hole 45b, and a fastening hole 41b formed in a position facing the fastening hole 46b. The left bracket 45 has the fastening hole 45a fastened to the fastening hole 39a of the left frame 23 by the fastening portion 47a, and the fastening hole 45b fastened to the fastening hole 41a of the main cover 41 by the fastening portion 47b. This fixes the left bracket 45 to the left frame 23 and the main cover 41. The right bracket 46 has the fastening hole 46a fastened to the fastening hole 39b of the right frame 24 by the fastening portion 48a, and the fastening hole 46b fastened to the fastening hole 41b of the main cover 41 by the fastening portion 48b. This fixes the right bracket 46 to the right frame 24 and the main cover 41.

[0064] The left bracket 45 and the right bracket 46 are not essential components, and may not be provided.

[0065] 3. Vehicle Body Configuration Next, a description will be given of the configuration of a vehicle body on which the battery pack 3 is mounted. It is assumed that the battery pack 3 is mounted on a plurality of different vehicle bodies. Here, an example of a vehicle body on which the battery pack 3 is mounted will be described.

[0066] Fig. 11 is a diagram showing the configuration of the vehicle body 100. Fig. 12 is a diagram showing the vehicle body 100 on which the battery pack 3 is mounted. Fig. 13 is a diagram showing the vehicle body 100 on which the battery pack 3 is mounted, with the battery case cover 15, cooling duct 16, and smoke exhaust duct 19 removed.

[0067] 11, 12, and 13, the vehicle body 100 includes a left main frame 101 and a right main frame 102. The left main frame 101 and the right main frame 102 are spaced apart in the left-right direction and extend along the front-rear direction.

[0068] A front cross member 103 and a rear cross member 104 are spanned between the left main frame 101 and the right main frame 102. The front cross member 103 and the rear cross member 104 are joined to the left main frame 101 and the right main frame 102 so as to be spaced apart in the front-to-rear direction and extend in the left-to-right direction. The front cross member 103 is disposed near the boundary between the rear seat 6 and the luggage compartment 7 in the front-to-rear direction. The rear cross member 104 is disposed approximately in the center of the luggage compartment 7 in the front-to-rear direction. The front cross member 103 has a cross section perpendicular to the longitudinal direction that is formed as a hollow, approximately rectangular, closed cross section, thereby enhancing its rigidity. The rear cross member 104 has a cross section perpendicular to the longitudinal direction that is formed as a hollow, approximately rectangular, closed cross section, thereby enhancing its rigidity.

[0069] A floor pan 105 is mounted between the left main frame 101 and the right main frame 102. The floor pan 105 is formed by bending a plate material into a concave shape that opens upward. A flange is formed on the outer edge of the floor pan 105, and the left main frame 101, the right main frame 102, and the front cross member 103 are joined to this flange. The rear cross member 104 is joined to the underside of the floor pan 105.

[0070] A left gusset 106 is joined to the joint between the left main frame 101 and the front cross member 103, reinforcing the joint between the left main frame 101 and the front cross member 103. Similarly, a right gusset 107 is joined to the joint between the right main frame 102 and the front cross member 103, reinforcing the joint between the right main frame 102 and the front cross member 103.

[0071] A suspension support member 108, to which a suspension abuts, is joined to the left main frame 101 forward of the rear cross member 104 in the front-to-rear direction. The suspension support member 108 is disposed so as to protrude leftward from the left main frame 101. The suspension support member 108 is also disposed so as to tilt upward as it extends leftward.

[0072] A suspension support member 109, to which the suspension abuts, is joined to the right main frame 102 forward of the rear cross member 104 in the front-to-rear direction. The suspension support member 109 is disposed so as to protrude to the right from the right main frame 102. The suspension support member 109 is also disposed so as to tilt upward as it extends to the right.

[0073] A rear skirt 110 is joined to the rear end of the floor pan 105. The rear skirt 110 is disposed so as to extend upward from the floor pan 105. A striker is attached to the center of the rear skirt 110 in the left-right direction, and the luggage compartment 7 is closed when the back door 8 engages with the striker.

[0074] A rear bumper beam 111 is joined to the rear ends of the left main frame 101 and the right main frame 102. The rear bumper beam 111 is arranged to extend in the left-right direction, with both ends joined to the left main frame 101 and the right main frame 102, respectively. Most of the rear bumper beam 111 is arranged rearward and spaced apart from the left main frame 101, the right main frame 102, the floor pan 105, and the rear skirt 110. The rear bumper beam 111 has greater strength than other components constituting the vehicle body 100, and reduces damage to the vehicle body 100 in a rear-end collision (including an offset collision).

[0075] In the vehicle body 100, the battery pack 3 is fastened to the left main frame 101, the right main frame 102, and the front cross member 103. When the battery pack 3 is fastened to the vehicle body 100, the left bracket 45 and the right bracket 46 are not provided on the battery pack 3 (they are removed).

[0076] The front cross member 103 (left gusset 106, right gusset 107) has fastening holes 112a, 112b spaced apart in the left-right direction on the left side and fastening holes 112c, 112d spaced apart in the left-right direction on the right side. The left main frame 101 has fastening holes 112e, 112f spaced apart in the front-rear direction on the rear side. The right main frame 102 has fastening holes 112g, 112h spaced apart in the front-rear direction on the rear side. These fastening holes 112a to 112h are located at positions corresponding to the fastening holes 38a to 38h formed in the battery pack 3, respectively.

[0077] Fastening hole 112a and fastening hole 38a are fastened together by fastening portion 113a. Similarly, fastening hole 112b and fastening hole 112h and fastening hole 38b and fastening hole 38h are fastened together by fastening portions 113b and 113h, respectively. Fastening portions 113e and 113g are formed by threads and nuts welded to extend upward from the top surfaces of left main frame 101 and right main frame 102. Fastening portions 113a, 113b, 113c, 113d, 113f, and 113h are formed by bolts and nuts, for example. Note that hereinafter, when fastening portions 113a to 113h are described without distinction, they will be referred to as fastening portions 113.

[0078] 14 to 19 are diagrams showing how the inverter 61 is protected during a rear-end collision. Figures 14 to 19 show the state of the vehicle 1 during a rear-end collision in chronological order.

[0079] As described above, the battery pack 3 is fastened so that the front frame 21 and the rear frame 22 span across the left main frame 101 and the right main frame 102. Therefore, as the upper surfaces of the left main frame 101 and the right main frame 102 are indicated by dashed lines in FIG. 14 , the front frame 21, the rear frame 22, and the battery case cover 15 of the battery pack 3 are located above the upper surfaces of the left main frame 101 and the right main frame 102. In addition, the inverter unit 44 (inverter 61) provided on the battery case cover 15 is also located above the upper surfaces of the left main frame 101 and the right main frame 102.

[0080] When the vehicle 1 collides from behind with a collision object 300 such as a tall vehicle or a large vehicle, the collision object 300 may run up onto the left main frame 101 and the right main frame 102 of the vehicle body 100. In this case, there is a risk that the collision object 300 may damage the inverter 61.

[0081] Therefore, in the vehicle 1, the rear frame 22, the first cover cross member 53 and the second cover cross member 54 reduce damage to the inverter 61 due to a collision with the colliding object 300.

[0082] When the vehicle 1 collides from behind with a collision object 300 that is higher than the upper surfaces of the left main frame 101 and the right main frame 102, as shown in Figure 15, the collision object 300 collides with the rear frame 22, which is the rearmost part of the battery pack 3 and is located higher than the upper surfaces of the left main frame 101 and the right main frame 102.

[0083] Thereafter, when the collision object 300 moves forward, the collision object 300 crushes the rear frame 22, as shown in Figure 16. At this time, the rear side of the battery pack 3 is pushed down together with the vehicle 1 by the collision object 300, and the rear side of the center frame upper 52 spanning the front frame 21 and the rear frame 22 is also pushed down.

[0084] As the collision object 300 subsequently moves further forward, it abuts against the second cover cross member 54, which is located forward and higher than the rear frame 22. As the collision object 300 moves further forward, the second cover cross member 54 is crushed by the collision object 300, as shown in FIG. 17 . At this time, the rear side of the second cover cross member 54 is crushed more than the front side (becomes lower in height), resulting in an overall downward tilt from front to rear. The rear side of the battery pack 3 is further pushed down by the collision object 300. Furthermore, as the collision object 300 runs up onto the vehicle 1, it tilts so that the front side faces diagonally upward.

[0085] Thereafter, as the colliding object 300 moves further forward, it abuts against the first cover cross member 53, which is located in front of the second cover cross member 54. Then, as the colliding object 300 moves further forward, the first cover cross member 53 is crushed by the colliding object 300, as shown in FIG. 18 . At this time, the rear side of the vehicle 1 is pressed downward, and since the colliding object 300 faces diagonally upward, the first cover cross member 53 is crushed less than the second cover cross member 54. Furthermore, as with the second cover cross member 54, the rear side of the first cover cross member 53 is crushed more than the front side (its height is reduced), and therefore an overall downward slope is formed from the front to the rear.

[0086] 19, when the first cover cross member 53 and the second cover cross member 54 are crushed in this manner, the vehicle 1 changes its posture and tilts along the upper surfaces of the rear frame 22, the first cover cross member 53, and the second cover cross member 54 (tilting at an angle close to the amount of deformation). As a result, when the colliding object 300 moves further forward, the colliding object 300 passes above the inverter unit 44, thereby protecting the inverter unit 44 (inverter 61).

[0087] This makes it possible to protect the inverter 61 mounted on the upper part of the battery case 13 in the vehicle 1 in the event of a rear-end collision.

[0088] 5. Modifications The above embodiment is merely an example of how the present invention can be implemented, and the implementation of the present invention is not limited to the above example, and various modifications are possible.

[0089] In the above embodiment, the battery case 13 is provided with two cross members, the first cover cross member 53 and the second cover cross member 54. However, the battery case 13 may have one cross member, or three or more cross members.

[0090] Furthermore, although the inverter 61 has been given as an example of an electrical component mounted on the upper portion of the battery case 13, an electrical component other than the inverter 61 may be used.

[0091] 6. Summary As described above, the vehicle 1 of the embodiment includes the battery 11, the battery case 13 fastened to a pair of body frames (left main frame 101, right main frame 102) spaced apart in the left-right direction and accommodating the battery 11, and electrical components (inverter 61) mounted on the front side of the battery case 13. The battery case 13 includes the rear frame 22 disposed rearward of the battery case 13 and spanning the upper part of the body frames, and cross members (first cover cross member 53, second cover cross member 54) disposed forward of the rear frame 22 and extending along the left-right direction. As a result, when a collision object 300 higher than the left main frame 101 and the right main frame 102 collides from behind, the collision object 300 collides with and destroys the rear frame 22, second cover cross member 54, and first cover cross member 53 in that order. Thereafter, when the colliding object 300 moves further forward, the battery pack 3 tilts to an angle close to the deformation amount of the rear frame 22, the first cover cross member 53, and the second cover cross member 54, thereby reducing the likelihood of the colliding object 300 colliding with the inverter 61. Therefore, the vehicle 1 can protect the electrical components (inverter 61) mounted on the upper part of the battery case 13.

[0092] A plurality of cross members (first cover cross member 53, second cover cross member 54) are provided spaced apart in the front-to-rear direction. That is, the vehicle 1 is provided with the first cover cross member 53 and the second cover cross member 54 as cover cross members. This makes it possible to make the final tilt of the battery pack 3 gentler when the colliding object 300 collides with the rear, further reducing the risk of the colliding object 300 colliding with the inverter 61.

[0093] The cross members (first cover cross member 53, second cover cross member 54) are disposed above the rear frame 22. This makes it possible to make the final tilt of the battery pack 3 gentle when the colliding object 300 collides from behind, and to prevent the colliding object 300 from colliding with the inverter 61.

[0094] The electrical components are arranged at an angle relative to the horizontal so that the more forward they are positioned, the higher they are. This further prevents the colliding object 300 from colliding with the inverter 61 when the colliding object 300 collides from behind.

[0095] REFERENCE SIGNS LIST 1 vehicle 3 battery pack 11 battery 13 battery case 22 rear frame 17 cooling fan 53 first cross member 54 second cross member 61 inverter

Claims

1. A vehicle comprising: a battery; a battery case that is fastened to a pair of body frames that are arranged spaced apart in the left-right direction and that houses the battery; electrical components that are mounted on the front side of the battery case; a rear frame that is arranged on the rear side of the battery case and that spans the upper surfaces of the pair of body frames; and a cross member that is arranged forward of the rear frame and along the left-right direction.

2. The vehicle according to claim 1, wherein the cross member is disposed above the rear frame.

3. A vehicle according to claim 1 or claim 2, wherein a plurality of the cross members are provided spaced apart in the longitudinal direction.

4. A vehicle according to claim 1 or claim 2, wherein the electrical components are arranged tilted relative to the horizontal so that the more forward they are positioned, the higher they are.

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