Vehicle incorporating a deformable front frame structure

Abstract

A vehicle, including: an electric motor operatively connected to at least one driving wheel of the vehicle, and a frame structure including first and second side members extending in a longitudinal direction along opposite sides of the vehicle and at least one cross member extending in a transversal direction of the vehicle and being connected to the first and second side members, wherein the electric motor is supported by the frame structure such that the electric motor is arranged in a front portion of the vehicle in association with a pair of front wheels of the vehicle, and wherein each of the side members, at least along a deformable section thereof, is configured to deform by bending in an inwards and/or outwards transversal direction when compressed by a longitudinally directed force exceeding a threshold value, such as in case the vehicle is subject to a sufficiently energetic frontal collision.

Claims

1. A vehicle, comprising: an electric motor operatively connected to at least one driving wheel of the vehicle, and a frame structure comprising first and second side members extending in a longitudinal direction along opposite sides of the vehicle and at least one cross member extending in a transversal direction of the vehicle and being connected to the first and second side members, wherein the electric motor is supported by the frame structure in association with a pair of front wheels of the vehicle, wherein each of the side members, at least along a deformable section thereof, is configured to deform by bending in an inwards and/or outwards transversal direction when compressed by a longitudinally directed force exceeding a threshold value when the vehicle is subject to a sufficiently energetic frontal collision, wherein a first cross member extends between the first and second side members at the deformable section thereof, wherein the electric motor is supported by the first cross member, wherein the first cross member is mounted to at least one of the side members via a mounting arrangement comprising an elongated fastening element extending in a direction that exhibits a substantial 90 angle in relation to the transversal direction of the vehicle, wherein the fastening element extends through a first hole in the cross member and a second hole in the corresponding side member, and wherein at least one of the first and second holes, at least in the transversal direction, is substantially larger/wider than a diameter of the fastening element so as to allow at least an initial bending deformation of the side member without pressing the fastening element onto an edge of the larger/wider hole.

2. The vehicle according to claim 1, wherein a resilient material is arranged between the first cross member and the first and second side members so as to eliminate or reduce transfer of vibrations.

3. The vehicle according to claim 1, wherein the elongated fastening element is provided with a screw head.

4. The vehicle according to claim 3, wherein the mounting arrangement is provided with a bushing arrangement comprising first and second annular parts arranged circumferentially around the fastening element, wherein the first annular part is arranged between the screw head and any of the side member or the first cross member, and wherein the second annular part is arranged between the side member and the first cross member.

5. The vehicle according to claim 4, wherein the bushing arrangement comprises a third annular part extending between and connecting the first and second annular parts, preferably the first, second and third annular parts form one integral unit.

6. The vehicle according to claim 5, wherein the first and second annular parts of the bushing arrangement protrudes outwardly in a radial direction of the fastening element so as to form a recess along and around the third annular part.

7. The vehicle according to claim 6, wherein a side of an edge of the first or the second hole is adapted to fit into the recess along and partly around the third annular part of the bushing arrangement.

8. The vehicle according to claim 1, wherein the elongated fastening element extends through the hole in the side member and is fixed into the hole of the first cross member.

9. The vehicle according to claim 8, wherein the hole in the side member is substantially larger/wider in the transversal direction than the diameter of the fastening element.

10. The vehicle according to claim 9, wherein the hole in the side member is larger/wider at an inside of the fastening element.

11. The vehicle according to claim 1, wherein the larger/wider hole provides a space transversally inside and/or outside of the elongated fastening element, wherein said space is adapted to receive a part of the mounting arrangement when the side member is moved in relation to the cross member in the transversal direction.

12. The vehicle according to claim 1, wherein the vehicle comprises a transmission unit operatively connected to the electric motor, wherein also the transmission unit is supported by the first cross member.

13. The vehicle according to claim 1, wherein the electric motor is operatively connected to at least one of the front wheels.

14. The vehicle according to claim 1, wherein the vehicle is a passenger car comprising a passenger compartment, wherein the first cross member is located in front of the passenger compartment.

15. A vehicle, comprising: a motor operatively connected to at least one driving wheel of the vehicle, and a frame structure comprising first and second side members extending in a longitudinal direction along opposite sides of the vehicle and at least one cross member extending in a transversal direction of the vehicle and being connected to the first and second side members, wherein the motor is supported by the frame structure in association with a pair of front wheels of the vehicle, wherein each of the side members, at least along a deformable section thereof, is configured to deform by bending in an inwards and/or outwards transversal direction when compressed by a longitudinally directed force exceeding a threshold value when the vehicle is subject to a sufficiently energetic frontal collision, wherein a first cross member extends between the first and second side members at the deformable section thereof, wherein the motor is supported by the first cross member, wherein the first cross member is mounted to at least one of the side members via a mounting arrangement comprising an elongated fastening element extending in a direction that exhibits a substantial 90 angle in relation to the transversal direction of the vehicle, wherein the fastening element extends through a first hole in the cross member and a second hole in the corresponding side member, and wherein at least one of the first and second holes, at least in the transversal direction, is substantially larger/wider than a diameter of the fastening element so as to allow at least an initial bending deformation of the side member without pressing the fastening element onto an edge of the larger/wider hole.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the description of the invention given below, reference is made to the following figures, in which:

(2) FIG. 1 shows, in a schematic view, some parts of a front portion of a vehicle, including connections between a cross member and side members, according to an embodiment of the invention.

(3) FIGS. 2-4 show, in a schematic view, a magnified view of one of the cross memberside member connections of FIG. 1 and a sequence indicating how the side member bends in the event of a frontal collision.

(4) FIG. 5 shows, in a schematic cross sectional view, a first example of a mounting arrangement for connecting the cross member to the side member.

(5) FIG. 6 shows, in a schematic cross sectional view, a second example of a mounting arrangement for connecting the cross member to the side member.

DETAILED DESCRIPTION

(6) The invention will now be described with reference to FIGS. 1-6. All figures are more or less schematic and intended to disclose the principle rather than the exact design that may differ depending on the application.

(7) FIG. 1 shows a top view of a front portion of a passenger vehicle 1. A passenger compartment (not shown) is located to the right. The figure is schematic and shows only a few parts of the front portion. The vehicle 1 is provided with a frame structure including first and second side members 2, 3 extending in a longitudinal direction along opposite sides of the vehicle 1. The frame structure further includes first and second cross members 4, 5 extending in a transversal direction of the vehicle 1 and being connected to the first and second side members 2, 3. The second cross member 5 is arranged at the very front of the frame structure and may be referred to as a bumper beam.

(8) The vehicle 1 is provided with an electric motor 6 operatively connected via drive means 7a, 7b to front driving wheels 8a, 8b for propelling the vehicle 1. The electric motor 6 is supported by and arranged on an underside of the first cross member 4.

(9) Each of the side members 2, 3 is provided with a particular deformable section that exhibits some extension in the longitudinal direction. Along this deformable section each side member 2, 3 is configured to deform by bending at pre-determined bending lines in an inwards or outwards transversal direction when compressed by a longitudinally directed force exceeding a threshold value, such as in case the vehicle 1 is subject to a sufficiently energetic frontal collision. At a specific bending line the side member 2, 3 is intended to bend outwards, at another bending line the side member 2, 3 is intended to bend inwards. The purpose of the deformable section is to absorb collision energy in the event of a (frontal) collision. Bending deformation structures are known as such.

(10) The deformable section is located in the same longitudinal zone of the vehicle as the front wheels 8a, 8b, etc. (and extends in this example somewhat rearwards as indicated in FIGS. 3-4). The first cross member 4 thus extends between and is connected to the first and second side members 2, 3 at the deformable section thereof.

(11) The first cross member 4 is mounted to the first and second side members 2, 3 via first and second mounting arrangements 10, 11, respectively. Each mounting arrangement 10, 11 includes first and second elongated fastening elements in the form of bolts 12, 13 extending in a vertical direction and thus exhibiting an angle of around 90 in relation to the transversal direction of the vehicle 1. FIGS. 1-4 show only the screw heads of the bolts 12, 13.

(12) The two mounting arrangements 10, 11 are in this example identical (but mirror-inverted). The first and second bolts 12, 13 form part of two separate mounting sub-arrangements, which are structured in a principally similar manner but may differ in specific design depending on the position of the bending lines etc. as described previously. In the following, focus is set on the first bolt 12, i.e. the first mounting sub-arrangement. It is assumed that the side members 2, 3 do not bend at the second bolt 13.

(13) The first bolt 12, 12, 12 extends through a first hole 15, 15 in the first cross member 4 and a second hole 16, 16, 16 in the corresponding side member (see FIGS. 5-6). In the examples shown here, the first hole 15, 15 has a diameter corresponding to that of the first bolt 12, 12, 12, see FIGS. 5-6 and further explanations below. The first bolt 12, 12, 12 is fixed in relation to the first cross member 4.

(14) In contrast, the second hole 16, 16, 16 is in this example elongated in the transversal direction and is substantially larger/wider than a diameter of the first bolt 12, 12, 12 so as to allow at least an initial bending deformation of the side member 2 without pressing the first bolt 12, 12, 12 onto an edge of the larger/wider second hole 16, 16, 16.

(15) FIGS. 2-4 show a magnified view of the connection between the first cross member 4 and the first side member 2 of FIG. 1 in a sequence schematically indicating how the side member 2 bends and how the mounting arrangement 10 principally works in the event of a frontal collision. The elongated second hole 16 is indicated in FIGS. 2-4.

(16) The second mounting sub-arrangement including the second bolt 13 is not paid any attention to here. In a real case some deformation involving the second bolt 13 would take place of course, but this has no particular influence on the principal behaviour of the structure at the first bolt 12.

(17) As shown in FIG. 2, the first bolt 12 is arranged at a bending line, indicated by arrow 18, where the side member 2 is configured to bend outwards, away from a longitudinal centreline of the vehicle 1, when compressed in the event of a frontal collision. The bolt 12 is located in its normal position in the hole 16, i.e. at the outer edge of the transversally elongated hole 16.

(18) In FIG. 3, the side member 2 has initiated its bending deformation in the outwards direction, i.e. the side member 2 has moved outwardly sideways in relation to the first cross member 4 and thus to the bolt 12 that is fixed to the first cross member 4. The friction of the mounting arrangement has been overcome and the bolt is now located at the inner edge of the transversally elongated hole 16. At this point, the parts involved in the bending deformation have achieved a considerable velocity and momentum.

(19) FIG. 4 shows the next phase of the deformation process where the forces have become sufficient to break parts of the frame structure and decouple the side member 2 from the first cross member 4. This is indicated by the fracture 20 in the first cross member 4. The side member 2 is now free to continue its deformation at the bend line 18. This is only a schematic example and it is of course possible to design the system so that other parts breaks or collapses when subject to the developed forces.

(20) FIGS. 5 and 6 show in schematic cross sectional side views a first and second example of a mounting arrangement for connecting the first cross member 4 to the side member 2. Both examples are in line with what is shown in FIGS. 2-4, i.e. the bolt 12, 12 is fixed to the first cross member 4, the larger/wider hole is arranged in the side member 2, the side member 2 is intended to bend as indicated by arrow 18 outwards (away from the other side member 3 located somewhere to the right in relation to FIGS. 5 and 6).

(21) As shown in FIG. 5, a bolt 12 with screw head is inserted through holes 16 and 15 and is secured at underside of the first cross member 4 by means of a nut 14. As can be seen in FIG. 5, a space is provided at the side, the right side in FIG. 5, of the bolt 12 allowing the side member 2 to be moved in relation to the cross member 4, towards the left in FIG. 5, without pressing the bolt 12 onto any edge of the hole 16 in the side member 2. Only a friction threshold in the mounting arrangement must be exceeded for this relative motion.

(22) The example shown in FIG. 6 is principally similar to the example shown in FIG. 5. One difference is that the bolt 12 is fixed by threading into the first cross member 4. A further difference is that the mounting arrangement includes a bushing arrangement 21 made of a resilient material.

(23) The bushing arrangement 21 forms in this case a single annular integral unit arranged circumferentially around the bolt 12. The bushing arrangement 21 includes a first part 21a arranged between the screw head and, in this case, the upper side of the side member 2, and a second part 21b arranged between, in this case, the lower side of the side member 2 and the upper side of the first cross member 4. The side member 2, more specifically a part of the side member 2 close to the left edge of the hole 16, is clamped between the first and second parts 21a, 21b of the bushing arrangement 21.

(24) The bushing arrangement further includes a third annular part 21c extending between and connecting the first and second annular parts 21a, 21b. The first and second annular parts 21a, 21b protrude outwardly in a radial direction of the bolt 12 so as to form a recess along and around the third annular part 21c. A side of the edge of the hole 16 in the side member 2 is adapted to fit into the recess along and partly around the third annular part 21c of the bushing arrangement 21.

(25) The bushing arrangement 21 eliminates or reduces the transfer of vibrations from the first cross member 4 to the side member 2. The electric motor 6 and any transmission coupled to the motor can generate vibrations that, if transferred to the first cross member 4 and further to the side members 2 and the rest of the frame structure, may produce disturbing noise in the passenger compartment.

(26) The bushing arrangement 21 is also useful for producing a reasonable level of friction in the mounting arrangement; not too high friction so that the first cross member 4 locks the side member 2 and prevents its initial transversal bending movement, and not too low friction so that the side member 2 may move in relation to the first cross member 4 during normal operation of the vehicle. As can be understood from FIG. 6 and the information above, the side member 2 is placed in the bushing recess between the first and second annular parts 21a, 21b of the bushing arrangement 21 during the initial bending deformation. With reference to FIG. 6, the side member is moved/slided to the left so that the space in the hole 16 becomes positioned on the left side of the bolt 12. There is no direct contact between the (metallic) side member 2 and (metallic) first cross member 4 at the mounting arrangement during this movement.

(27) The hole 16 in FIG. 6 is somewhat larger In the longitudinal direction than the hole 16 in FIG. 5 in order to fit around both the fastening element 12 and the third part 21c of the bushing 21. The hole 16 in FIG. 6 may be wider than the hole 16 in FIG. 5 to allow more room for the fastening element 12 and the (third part 21c) of the bushing 21.

(28) The example shown in FIG. 5 may exhibit a too high friction if all parts are made of metal and the nut 14 is tightly tightened. Further, this principal example lacks any vibration insulation.

(29) The mounting arrangement shown in FIG. 6 may be provided with a washer below the screw head and/or with an inner annular insert (radially inside of the bushing 21) that provides some play around the bolt 12 in order to provide some tolerances for fitting the bolt 12 into the hole 15 during manufacture. Such an insert may be provided with a flange at the upper end that can rest onto the first annular part 21a of the bushing arrangement 21 so as to hold the insert in place. Such a flange may also function as a washer.

(30) As an alternative to what is shown in FIGS. 5 and 6 the bolt 12, 12 may be placed closer to a centre position in the opening 16, 16, i.e. there may be a free space on both sides of the bolt to allow for bending deformation in both directions.

(31) A further alternative is that the hole 16, 16 is open all the way to an end portion of the component it is provided on so that only friction in the mounting arrangement needs to be overcome to completely decouple the side member 2 from the first cross member 4.

(32) The invention is not limited by the embodiments described above but can be modified in various ways within the scope of the claims.