KR20240098607A - Side frame for battery case - Google Patents

Abstract

The present invention provides a side frame for a battery case made of different materials that can sufficiently protect battery cells from external shock while simultaneously achieving weight reduction and cost reduction. In one embodiment, the first side frame is formed to have an open cross section. A frame portion, a second frame portion disposed within the first frame portion to close an open cross-section of the first frame portion and coupled to the first frame portion, and the second frame portion centered on an intersection provided within the second frame portion. 2 A side frame of the battery case that extends to contact the inner surface of the frame portion, and the intersection portion includes a reinforcing portion having a shape that protrudes toward the first frame portion, and the first frame portion and the second frame portion are formed of different materials. provides.

Description

Side frame of battery case {SIDE FRAME FOR BATTERY CASE}

The present invention relates to a side frame of a battery case made of different materials that can sufficiently protect the battery cell from external shock while simultaneously achieving weight reduction and cost reduction compared to a single material.

For example, battery systems used in electric vehicles use various load-bearing members to protect internal battery cells.

A representative example is the side frame of a battery case. The side frame forms a side wall that divides the space in the battery case where the battery cell is mounted, and surrounds the battery cell to protect the battery cell from external shock.

Additionally, the side frame allows a mounting frame necessary to secure the battery case to the vehicle body to be mounted on the side.

Typically, side frames and battery cases are mostly manufactured using aluminum or aluminum alloy. This is because aluminum has advantages such as the lightness of the material itself and the freedom of forming, which allows for easy creation of side frames with complex cross-sections, for example, using an extrusion process.

However, despite the above-described advantages, aluminum or aluminum alloy is much more expensive than steel, and the extrusion process has a very low production yield, increasing costs.

(Patent Document 1) KR 2019-0131415 A

The purpose of the present invention is to provide a side frame for a battery case made of different materials that can sufficiently protect battery cells from external shock while simultaneously achieving weight reduction and cost reduction.

In order to achieve the above object, the present invention provides the following side frame of the battery case.

In one embodiment, the present invention includes a first frame portion formed to have an open cross section, a second frame portion disposed within the first frame portion to close the open cross section of the first frame portion and coupled to the first frame portion, and It extends to contact the inner surface of the second frame unit around an intersection provided inside the second frame portion, and the intersection portion includes a reinforcing portion having a shape that protrudes toward the first frame portion, and the first frame portion and the second frame portion provides side frames of the battery case formed of different materials.

In one embodiment, the second frame portion includes first and second transverse members spaced apart from each other in the height direction and spaced apart from each other in the width direction and connecting the first transverse member and the second transverse member. It may include a first longitudinal member and a second longitudinal member.

In one embodiment, the reinforcing portion includes a first reinforcing member extending to abut the first transverse member, a second reinforcing member extending to abut the second transverse member, and a second reinforcing member extending to abut the second longitudinal member. and a third reinforcing member, wherein the third reinforcing member may extend in a direction parallel to the first transverse member and the second transverse member around the intersection.

In one embodiment, the first reinforcing member and the second reinforcing member may be formed to be inclined toward the opposite side of the first frame portion at the intersection portion.

In one embodiment, the reinforcement part may be provided such that the height distance between the third reinforcement member and the first transverse member is equal to the height distance between the third reinforcement member and the second transverse member.

In one embodiment, the first transmission portion in contact with the first reinforcing member and the first transverse member and the second transmission portion in contact with the second reinforcing member and the second transverse member are located outside the first frame portion. can do.

In one embodiment, the second frame part may be formed so that a third transmission part in contact with the third reinforcing member and the second longitudinal member protrudes to the opposite side of the first frame part.

In one embodiment, the third reinforcing member may be provided so that the third transmission unit is located at the center of the second longitudinal member in the height direction.

In one embodiment, the second frame portion may have at least a portion of the first transverse member thicker than the remainder, and at least a portion of the second transverse member may have a thickness greater than the remainder. there is.

In one embodiment, the second frame portion is located at one end in the width direction and includes a 2-1 frame portion provided inside the first frame portion, a 2-2 frame portion connected to the 2-1 frame portion, and It consists of a 2-3 frame part connected to the 2-2 frame part, located at the other end in the width direction, and provided outside the first frame part, wherein the 2-1 frame part and the 2-3 frame part The thickness of the first transverse member and the second transverse member located in may be thicker than the thickness of the first transverse member and the second transverse member located in the 2-2 frame part.

In one embodiment, the first frame portion includes a first vertical member having a first height, a second vertical member spaced apart from the first vertical member by a first length and having a second height shorter than the first height, A third vertical member spaced apart from the second vertical member in the height direction by a second length from the first vertical member and having a third height shorter than the first height, one end of the first vertical member and the second A first horizontal member connecting one end of the vertical member, a second horizontal member connecting the other end of the first vertical member and one end of the third vertical member, and one end connected to the other end of the second vertical member to form a third length. It includes a third horizontal member extending in the width direction by a distance equal to that of the third horizontal member and a fourth horizontal member having one end connected to the other end of the third vertical member and extending in the width direction by a fourth length, and the other end of the third horizontal member and the third horizontal member. 4 An opening may be formed between the other ends of the horizontal members.

In one embodiment, the first frame portion includes a wall portion having the first height and a protrusion extending from the wall portion to one side in the width direction by the third length or the fourth length, and the opening portion is provided on one side of the protrusion. can be formed.

In one embodiment, the second frame portion may be disposed on at least the protrusion within the first frame portion to close the opening portion.

In one embodiment, the second frame part may be joined within the first frame part by mechanical bonding through a fixture or chemical bonding through an adhesive.

In one embodiment, the first frame part may be formed by bending a single plate, and the second frame part may be formed by extrusion.

In one embodiment, the second frame part may have a tapered structure in an inlet provided inside the first frame part.

In one embodiment, the inlet portion may be formed to be inclined so as to widen from one end surface of the first frame portion to the opposite side.

In one embodiment, the first frame part may be made of a heavy metal material with a specific gravity of 4 or more, and the second frame part may be made of a material with a lower specific gravity than the first frame part.

According to one embodiment of the present invention, by forming the side frame from a different material, the advantages of extruded materials and the advantages of rigid materials can be utilized equally, thereby achieving not only sufficient structural rigidity but also weight reduction and cost reduction. .

In addition, according to one embodiment of the present invention, a reinforcing structure that induces depression is formed inside the extruded material, thereby inducing internal depression as tensile stress is generated in the reinforcing structure, thereby maximizing impact resistance and shock absorption. can be obtained.

Figure 1 is a perspective view showing a battery case to which a side frame is applied according to an embodiment of the present invention.
Figure 2 is a perspective view showing a side frame according to an embodiment of the present invention.
Figure 3 is a cross-sectional view taken along line A-A' of the side frame according to an embodiment of the present invention shown in Figure 2.
FIG. 4(a) is a cross-sectional view of the second frame portion of FIG. 3, and FIG. 4(b) is a cross-sectional view of the second frame portion showing a collapsed state after receiving a load.
Figure 5 is a cross-sectional view of a side frame according to a second embodiment of the present invention.
Figure 6 is a cross-sectional view of a side frame according to a third embodiment of the present invention.
Figure 7 is a conceptual diagram showing the process of combining side frames according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the attached drawings. However, the spirit of the present invention is not limited to the presented embodiments, and those skilled in the art who understand the spirit of the present invention may add, change, or delete other components within the scope of the same spirit, or create other degenerative inventions or this invention. Other embodiments that are included within the scope of the inventive idea can be easily proposed, but it will also be said that this is included within the scope of the inventive idea of the present application. In addition, in this specification, terms such as 'upper', 'top', 'upper surface', 'lower', 'lower', 'lower surface', 'side', etc. are based on the drawings and are actually elements or components. It may vary depending on the direction in which it is placed.

In addition, throughout the specification, the fact that a certain configuration is 'connected' to another configuration includes not only the case where these configurations are 'directly connected', but also the case where they are 'indirectly connected' with another configuration in between. means that In addition, 'including' a certain component does not mean excluding other components, but may further include other components, unless specifically stated to the contrary.

In addition, components having the same function within the scope of the same idea shown in the drawings of each embodiment will be described using the same reference numerals.

Figure 1 is a perspective view showing a battery case to which a side frame is applied according to an embodiment of the present invention.

The battery case may include a first case (1) and a second case (2).

The first case 1 may include a base plate 20 and a side frame 10 surrounding the base plate 20. The base plate 20 of the first case 1 may function as a flooring material supporting battery cells, and the side frame 10 may form a side wall of the first case 1.

The base plate 20 and the side frame 10 may be joined to each other by welding or the like to become one piece. Accordingly, the first case 1 may have a space within a side frame that forms a closed cross-section around the base plate 20.

For example, at least one side frame 10 is provided to surround the base plate 20, and both ends of the side frame 10 are optionally or as necessary, corresponding ends of the other side frame 10. After contacting, they can be joined by welding, etc.

The second case 2 may be a simple flat plate or may include a body 3 with a hollow portion and a flange 4 formed at an end of the body 3. When the main body 3 has a hollow portion, the second case 2 can be manufactured by molding a material with appropriate strength into a predetermined shape using a press.

At this time, the main body 3 of the second case 2 covers the space of the first case 1 so that the first case 1 and the second case 2 are combined with each other, An accommodating space for accommodating battery cells may be formed inside.

The first case 1 and the second case 2 are combined, for example, by overlapping the flange 4 formed at the end of the main body 3 and the side frame 10 with a bolt (not shown). This can be done by bolting.

Meanwhile, when evaluating the performance of a battery case, it is important to evaluate side collisions. Evaluation of side impact is made by impacting the side of a side frame with a roughly square cross-section in the battery case with a cylinder made of a rigid body to withstand a certain level of impact load. If there is no contact between the side frame and the battery cell until a certain level of crash load is reached, the battery case is evaluated as satisfying the crash performance.

In the evaluation of side collisions, the deformation mode of the side frame can be largely divided into buckling mode at the beginning of the collision and bending mode at the end of the collision.

The initial collision is the first collision time of several milliseconds (msec), and at this time, concentrated deformation occurs in the side frame at the contact area with the rigid body. At the beginning of a collision, the horizontal member in the width direction (Y direction) of the cross-sectional structure of the side frame receives concentrated force, and when buckling occurs in the horizontal member, the buckling point becomes a plastic hinge and the horizontal member becomes structural. It loses its function as an absence.

In order to minimize such buckling and plastic hinge phenomena, the thickness of the material constituting the side frame must be thick. For example, aluminum is lighter than steel, so it can be designed to be thick, but steel has a lower thickness to reduce weight. Because it has no choice but to be thin, side frames made of steel become very vulnerable to buckling mode at the beginning of a collision.

For this reason, side frames made of steel are heavier and have lower performance than side frames made of aluminum or aluminum alloy.

When the buckling mode at the beginning of the collision as described above ends, the cross-sectional structure of the side frame rapidly collapses and the concentrated deformation changes into bending deformation of the entire side frame. In other words, it switches to a bending mode similar to the three-point bending of the side frame, and at this time, the role of the vertical member in the height direction (Z direction) becomes much larger than that of the horizontal member in the cross-sectional structure of the side frame.

In bending mode, the vertical member is subjected to maximum compression or tension, and thus the strength of the vertical member becomes an important factor. For example, side frames made of high-strength steel can have increased bending resistance and are advantageous for withstanding compressive or tensile stress that occurs in bending mode.

Due to the deformation characteristics of the side frame, the thickness of the horizontal member is important in the early stage of the collision, and the strength of the vertical member becomes an important factor in the late stage of the collision. However, there is no single material that satisfies both of the above two conditions.

Additionally, the conventional battery case is provided with a mounting frame coupled to one side of the side frame to secure the battery case to the vehicle body.

Here, the member that first contacts the rigid body at the beginning of the collision is the mounting frame, and if the side frame is designed to be sufficiently strong, the buckling mode at the beginning of the collision occurs in the mounting frame, not the side frame.

Conversely, if the mounting frame is stronger than the side frame, the buckling mode will occur in the side frame.

Accordingly, the mounting frame also requires mechanical consideration, such as the buckling mode at the beginning of a collision, but usually the mounting frame and side frame are manufactured separately and joined by welding, etc., so the mechanical balance between these mounting frames and side frames is not correct, resulting in battery case damage. is bound to have structural weaknesses.

Therefore, in the side frame of the battery case according to an embodiment of the present invention, different materials are applied to the horizontal and vertical members, and the mounting frame is integrated into the side frame to satisfy the mechanical characteristics required for the side frame. We want to maximize the efficiency of the structure.

FIG. 2 is a perspective view showing a side frame according to an embodiment of the present invention, FIG. 3 is a cross-sectional view taken along line A-A' of FIG. 2, and FIG. 4 is a cross-sectional view showing the second frame portion collapsing due to a compressive load.

The side frame 10 according to an embodiment of the present invention includes a first frame part 30, a second frame part 40, and a reinforcement part 50 provided inside the second frame part.

The first frame portion 30 may be formed by bending a single plate having a predetermined width and length several times to have, for example, a lying T-shaped cross section. Accordingly, the first frame portion 30 may have a hollow portion with an open cross section inside.

The first frame portion 30 has a first vertical member 31 having a first height H1 and is spaced apart from the first vertical member 31 by a first length L1 and has a first height H1. A second vertical member 32 having a shorter second height H2, and being spaced apart from the second vertical member 32 in the height direction and spaced apart from the first vertical member 31 by a second length L2. and includes a third vertical member 33 having a third height H3 shorter than the first height H1, and the first frame portion 30 has one end of the first vertical member 31 and A first horizontal member 34 connecting one end of the second vertical member 32, a second horizontal member connecting the other end of the first vertical member 31 and the other end of the third vertical member 33 ( 35), a third horizontal member 36 having one end connected to the other end of the second vertical member 32 and extending in the width direction by a third length L3, and at the other end of the third vertical member 33 It includes a fourth horizontal member 37, one end of which is connected and extending in the width direction by the fourth length L4. At this time, an opening 29 may be formed between the other end of the third horizontal member 36 and the other end of the fourth horizontal member 37.

The first frame portion 30 may be formed integrally by machining a single plate, such as metal. For example, the first frame portion 30 may be formed to have an open cross-section and a predetermined length by bending, roll forming, press forming, etc.

For example, the plate extends from one end in the width direction (-Y direction) by the third length L3 to form the third horizontal member 36, and then is rotated once in the first direction (counterclockwise in FIG. 3). It bends. Subsequently, it is lowered in the height direction (-Z direction) by the second height H2 to form the second vertical member 32, and then bent once in the second direction (clockwise in FIG. 3), which is opposite to the initial bending direction. do. The first horizontal member 34 is formed by extending in the width direction (-Y direction) for about a first length L1 and then bent once more in the second direction.

Subsequently, it is raised in the height direction (Z direction) by the first height H1 to form the first vertical member 31 and then bent once in the second direction. The second horizontal member 35 is formed by extending the second length L2 in the width direction (Y direction) and then bent once more in the second direction. Subsequently, it is lowered in the height direction (-Z direction) by the third height H3 to form the third vertical member 33, and then bent once in the first direction, which is the initial bending direction. Thereafter, the fourth length L4 is extended in the width direction (Y direction) to form the fourth horizontal member 37.

In this way, the method of extending to a predetermined length and then bending is repeated to form an open cross-section with a desired number of horizontal members 34 to 37 and vertical members 31 to 33, and then the plate is terminated at the other end.

Accordingly, the first frame portion 30 according to an embodiment of the present invention includes a wall portion 38 having a first height H1 and a third length L3 or It may include a protrusion 39 extending by 4 lengths L4. The wall portion 38 can be roughly divided into a first vertical member 31, a first horizontal member 34, a second vertical member 32, a second horizontal member 35, and a third vertical member 33. The protrusion 39 may be formed of a third horizontal member 36 and a corresponding fourth horizontal member 37.

The wall portion 38 corresponds to an existing side frame, while the protrusion 39 corresponds to an existing mounting frame. Ultimately, in the side frame 10 according to an embodiment of the present invention, the mounting frame is attached to the side frame. By integrating it into the frame, it can be formed as one piece with the side frame.

In addition, in the first frame portion 30, the third horizontal member 36 and the fourth horizontal member 37 are formed by adding the second height H2 and the third height H3 from the first height H1. They may be spaced apart from each other by the difference in height (H2+H3) and may have an open portion 29 between the end of the third horizontal member 36 and the end of the fourth horizontal member 37.

Accordingly, the protrusion 39 of the first frame portion 30 may include an opening 29, and the protrusion 39 and the opening 29 are positioned at a second height (H1) from the first height (H1). It has a height (H1-(H2+H3)) corresponding to the difference between the height (H2+H3) plus H2) and the third height (H3).

Here, the plurality of horizontal members 34 to 37 and the plurality of vertical members 31 to 33 are not necessarily formed completely horizontally or vertically and may have an inclination. Accordingly, the separation distance or height difference may vary.

Additionally, optionally, the first length (L1) and the second length (L2) are equal to each other, the second height (H2) and the third height (H3) are equal to each other, or the third length (L3) and the fourth height (L3) are equal to each other. The lengths L4 may be equal to each other. Meanwhile, as shown in FIGS. 3 and 4, the third height H3 may be longer than the second height H2 and may vary depending on the size of the space accommodating the battery cell.

The first frame portion 30 formed in this way may constitute the exterior of the side frame 10.

The second frame portion 40 according to an embodiment of the present invention is formed to have a predetermined length and may be formed of a pipe member of approximately rectangular cross-section with a certain height and a certain width. Accordingly, the second frame portion 40 may have a hollow portion with a closed cross-section inside.

The second frame portion 40 includes a first transverse member 41 and a second transverse member 43 spaced apart from each other in the height direction (Z direction), and a first transverse member 43 spaced apart from each other in the width direction (Y direction). It may include a first longitudinal member 42 and a second longitudinal member 44 connecting the first transverse member and the second transverse member.

The height of the second frame 40 corresponds to the height of the opening 29 of the first frame 30, and the width of the second frame 40 is equal to the height of the opening 29 of the first frame 30. It may correspond to a length (L1+L3) obtained by adding the first length (L1) of the first horizontal member 34 and the third length (L3) of the third horizontal member 36. Alternatively, the width of the second frame portion 40 is the second length L2 of the second horizontal member 35 of the first frame portion 30 and the fourth length of the fourth horizontal member 37 ( It may correspond to the length (L2+L4) plus L4).

Here, the second frame part 40 may be arranged in alignment with at least the protrusion 39 within the first frame part 30, and the open cross section of the first frame part, that is, the open part 29 By closing, the entire side frame 10 can be formed into a closed cross-section.

The second frame portion 40 formed and arranged in this way can constitute the interior of the side frame 10.

The reinforcement part 50 according to an embodiment of the present invention is provided inside the second frame part 40 and has an intersection part 50C. The intersection portion 50C may extend along a direction parallel to the second frame portion 40 in the longitudinal direction and may appear as a single point in the cross section of FIG. 3 .

The reinforcement portion 50 extends to contact the inner surface of the second frame portion 40 around the intersection portion 50C. At this time, the reinforcement portion 50 may have a shape in which the intersection portion 50C protrudes toward the first frame portion 30. For example, in the cross section of FIG. 3, the first frame portion 30 It may be shaped like an arrow pointing to the side.

The reinforcing portion 50 extends to abut the first reinforcing member 51 and the second transverse member 43, which extend to abut the first transverse member 41 of the second frame portion 40. It may include a second reinforcing member 52 and a third reinforcing member 53 extending to contact the second longitudinal member 44. At this time, the portion in contact with the first reinforcing member 51 and the first transverse member 41 may be referred to as a first transmission portion 51P, and the second reinforcing member 52 and the second transverse member 41 may be referred to as a first transmission portion 51P. The part where the members 43 come into contact can be called the second transmission part 52P, and the part where the third reinforcing member 53 and the second longitudinal member 44 come into contact with each other can be called the third transmission part 53P. can do. At this time, the reinforcement portion 50 according to an embodiment of the present invention may be configured such that the first transmission portion 51P and the second transmission portion 52P are located outside the first frame portion 30. . In other words, the first transmission part 51P and the second transmission part 52P may be located outside the protrusion 39 of the first frame part 30.

The third reinforcing member 53 according to an embodiment of the present invention may extend in a direction parallel to the first transverse member 41 and the second transverse member 43 around the intersection 50C. there is. Additionally, the first reinforcing member 51 and the second reinforcing member 52 may be formed to be inclined toward the opposite side of the first frame portion 30 at the intersection portion 50C. Accordingly, the reinforcement part 50 may have an arrow shape pointing toward the first frame part 30. At this time, the degree of inclination, that is, the inclination, of the first reinforcing member 51 and the second reinforcing member 52 may be different from each other, and may be provided symmetrically in the height direction.

That is, the reinforcing part 50 ensures that the impact applied from the side first passes through the third reinforcing member 53 and is transmitted to the intersection 50C in the shortest straight line distance along the third reinforcing member 53. It can be divided into the first reinforcing member 51 and the second reinforcing member 52 at the intersection 50C, thereby transferring the load to the first transverse member 41 and the second transverse member 43. It has a dispersing effect. At this time, due to the structural characteristics of the reinforcing part 50, the first reinforcing member 51 and the second reinforcing member 52 are subjected to tensile stress, which may induce internal depression.

In other words, when a compressive load occurs from the outside as shown in FIG. 4, the main compressive load is caused by the structure in which the second frame portion 40 protrudes outward from the first frame portion 30. 2 It is first transmitted to the middle member of the frame portion 40. At this time, the transmitted load propagates along the third reinforcing member 53 and branches off at the intersection 50C to apply tensile stress to the first transmission portion 51P and the second transmission portion 52P. . As a result, the second frame portion 40 is depressed from the first transmission portion 51P and the second transmission portion 52P toward the intersection portion 50C.

Accordingly, the reinforcing part 50 according to an embodiment of the present invention first generates a compressive load before the load is transmitted to the first frame part 30 provided adjacent to the space in which the battery cell is accommodated. The second frame portion 40 can absorb shock and induce internal collapse.

In this way, the reinforcing part 50 can form the interior of the second frame part 40, and can maximize impact resistance and shock absorption on the second frame part 40.

Meanwhile, depending on the size of the vehicle body or the required battery accommodation space, the battery case side frame 10 according to an embodiment of the present invention has the first frame portion 30 at a height (H2) of the second vertical member 32. ) and the height H3 of the third vertical member 33 may be formed differently, so the third reinforcing member 53 for transmitting the force received during the initial impact is the second vertical member 32 and the third vertical member 33. 3 Among the vertical members 33, it can be located closer to the one with a higher height. For example, in the first frame portion 30 according to an embodiment of the present invention, the height H3 of the third vertical member 33 is greater than the height H2 of the second vertical member 32. can be formed.

At this time, the reinforcing part 50 is such that the third reinforcing member 53 has a height spacing (I1) to the first transverse member 41 and a height spacing to the second transverse member 43. It can be provided to be the same. That is, the third reinforcing member 53 may be provided so that the third transmission portion 53P, which abuts the second longitudinal member 44, is located at the center of the second longitudinal member 44 in the height direction. there is. As a result, the compressive load from the outside can be propagated symmetrically through the first reinforcing member 51 and the second reinforcing member 52, and the first transmission unit 51P and the second transmission unit 52P It can be induced to generate the same tensile stress.

Below, a side frame of a battery case according to another embodiment of the present invention will be described, excluding parts that overlap with the parts described above and focusing on parts that are different.

Figure 5 is a cross-sectional view of a side frame of a battery case according to a second embodiment of the present invention.

The second frame portion 40 according to the second embodiment of the present invention is formed so that at least a portion of the first transverse member 41 is thicker than the remaining thickness, and at least the second transverse member 43 Some parts may be thicker than others. For example, the thickness of at least a portion of the first transverse member 41 and the second transverse member 43 may be formed to be 0.5 mm or more thicker than the remaining thickness.

Meanwhile, the second frame part 40 according to the second embodiment of the present invention is composed of a 2-1 frame part 40a, a 2-2 frame part 40b, and a 2-3 frame part 40c. It can be. More specifically, referring to FIG. 4, the 2-1 frame portion 40a is located at one end in the width direction (Y direction) and is provided inside the first frame portion 30, and the 2-2 frame The portion 40b is located in the central portion connected to the 2-1 frame portion 40a, and the 2-3 frame portion 40c is connected to the 2-2 frame portion 40b in the width direction ( It is located at the other end in the Y direction) and may be provided outside the first frame portion 30.

For example, the 2-1 frame portion 40a, the 2-2 frame portion 40b, and the 2-3 frame portion 40c partition the second frame portion 40 in the width direction. The 2-1 frame portion 40a may refer to a portion located on the wall 38 of the first frame portion 30, and the 2-2 frame portion 40b may refer to the portion located on the wall portion 38 of the first frame portion 30. It may refer to the portion from the protruding portion 39 of the first frame portion 30 passing through the intersection 50C, and the second-third frame portion 40c may refer to the remaining portion.

Here, since the 2-3 frame portion 40c receives concentrated force in the width direction (Y direction) following the initial collision, the transverse member needs to be designed to be thick to minimize the phenomenon of buckling and plastic hinge. there is. Furthermore, the 2-1 frame portion 40a needs to be designed with thick transverse members in order to absorb shock transmitted to the inner space in contact with the battery cell.

That is, the second frame portion 40 according to the second embodiment of the present invention includes the first transverse member 41 located in the 2-1 frame portion 40a and the 2-3 frame portion 40c. ) and the thickness of the second transverse member 43 may be formed to be thicker than the thickness of the first transverse member 41 and the second transverse member 43 located in the 2-2 frame portion 40b. Thereby, shock resistance and shock absorption can be maximized.

Figure 6 is a cross-sectional view of a side frame of a battery case according to a third embodiment of the present invention.

Here, the second frame part 40 has a third transmission part 53P, where the third reinforcing member 53 and the second longitudinal member 44 come into contact, protrudes to the opposite side of the first frame part 30. can be formed. That is, the third transmission part 53P protrudes outward so that the compressive load can be easily transmitted, and as shock and collision are first applied to the protruding third transmission part 53P, the third reinforcement first occurs. The load can be transmitted to the intersection 50C through the member 53. As a result, the internal collapse of the second frame unit 40 can be induced before the compressive load is transmitted to the first frame unit 30, thereby improving collision resistance.

Figure 7 is a conceptual diagram showing the process of combining side frames according to an embodiment of the present invention.

When assembling the side frame 10 according to an embodiment of the present invention, first move the separately molded first frame portion 30 and second frame portion 40 relative to each other in the width direction (Y direction). The second frame part 40 can be inserted into the protrusion 39 within the first frame part 30.

Subsequently, the third transverse member 36 of the first frame portion 30 and the first transverse member 41 of the second frame portion 40, and the fourth transverse member 37 of the first frame portion and the second An adhesive 15 may be interposed between the second transverse members 43 of the frame portion to bond them to each other. Additionally, an adhesive 15 may be interposed between the first vertical member 31 of the first frame portion 30 and the first longitudinal member 42 of the second frame portion 40 to bond them to each other.

This adhesive 15 is used not only for bonding between the first frame part 30 and the second frame part 40, but also for, for example, the first frame part 30 is made of steel and the second frame part 40 is made of aluminum. When formed, the effect of preventing corrosion caused by direct contact between these different materials can be obtained.

Meanwhile, in mass producing the side frame 10 of the battery case according to an embodiment of the present invention, the spacing dimension (H1-(H2+H3)) of the first frame portion 30 is changed to spring back (Spring Back). ), if produced lower than the specified number due to manufacturing tolerances, etc., a problem may occur in which the second frame portion 40 collides with the open cross section of the protrusion 39.

To this end, the second frame part 40 according to an embodiment of the present invention may have a tapered structure in which the inlet part 45 provided inside the first frame part 30 has a tapered structure. That is, the inlet portion 45 may correspond to the above-described 2-1 frame portion 40a, and when the first frame portion 30 and the second frame portion 40 are combined, the protrusion 39 ) may refer to the part that enters first into the side. More specifically, the inlet portion 45 may be formed to be inclined to widen from one end surface of the first frame portion 30 to the opposite side, and the inlet portion 45 may be formed at an angle to the first transverse member 41. It may include a first inclined surface 45a formed on and a second inclined surface 45b formed on the second transverse member 43. At this time, in FIG. 9, the first inclined surface 45a may form an inclined angle of approximately 5° in a counterclockwise direction with respect to the first transverse member 41, and the second inclined surface 45b may form the first inclined surface 45b. 2 An inclination angle of approximately 5° can be formed clockwise based on the transverse member 43.

As a result, when manufacturing the side frame 10 of the battery case according to an embodiment of the present invention, the problem of the second frame portion 40 colliding with the open end surface of the first frame portion 30 can be prevented. In addition, by ensuring smooth insertion and coupling even with slight manufacturing tolerances, the defect rate can be reduced and productivity can be increased.

In the side frame 10 according to an embodiment of the present invention described above with reference to FIGS. 2 to 7, the first frame portion 30 and the second frame portion 40 may be formed of different materials.

For example, the first frame portion 30 may be made of a heavy metal material with a specific gravity of 4 or more, such as steel. The second frame part 40 may be made of a material with a lower specific gravity than the first frame part 30.

Alternatively, the second frame portion 40 may be made of a material with a higher specific strength than the first frame portion 30.

More specifically, the first frame part 30 uses ultra-high strength steel of 1 GPa or higher, so that an optimal combination can be achieved to reduce the weight of the side frame 10 and, by extension, the battery case.

For example, the first frame portion 30 may be made of a plate such as 1470 Martensitic (MART) steel or 1180 CP (Complex Phase) steel with a thickness of about 0.5 mm to 1.5 mm produced by the present applicant.

Here, 1470 MART steel is a steel type with improved collision safety by having a tensile strength of more than 1,470 MPa and a yield strength of more than 1,050 MPa, and 1180 CP steel is a steel type with improved bending workability while guaranteeing a tensile strength of more than 1,180 MPa and a yield strength of more than 850 MPa. .

Additionally, the second frame portion 40 may be made of a material that can be formed by extrusion, for example, a light metal such as aluminum, an alloy thereof, plastic, or a composite material.

In this way, since the first frame portion 30 and the second frame portion 40 are formed of different materials, the first frame portion and the second frame portion are made of rivets (e.g. blind rivets) and screws (e.g. flow drill screws). They can be joined together through mechanical bonding through fixtures such as drill screws) and chemical bonding through adhesives (15) such as structural adhesives.

Of course, the joining method is not necessarily limited to the above-mentioned examples, and fasteners such as rivets or screws and adhesives such as structural adhesives 15 are combined to bond the first frame portion 30 and the second frame portion 40. It can be used for.

In this way, welding is no longer required to assemble the first frame portion 30 and the second frame portion 40, and the welding portion can be significantly reduced in the side frame 10 according to an embodiment of the present invention. There is an advantage in that this can be easily accomplished. In addition, since the inlet part has a tapered structure, during mass production, the defect rate due to manufacturing tolerances due to spring back can be reduced and productivity can be maximized.

Accordingly, in the side frame 10 according to an embodiment of the present invention, the second frame part 40 made of a lightweight material has an additional transverse member (i.e., a transverse member) within the first frame part 30 made of a high-strength material. It is possible to provide or at least add more thickness to the third and fourth horizontal members 36 and 37.

Additionally, in the side frame 10 according to an embodiment of the present invention, the second frame portion 40 made of a lightweight material surrounds the side portion of the battery case and the battery cell, thereby improving structural stability.

The side frame 10 according to an embodiment of the present invention includes a first frame portion 30 and a second frame portion 40 made of different materials, and lightweight materials are disposed in portions requiring thick horizontal members. In addition to placing high-strength materials in vertical members that require strength, there is an advantage in being able to implement a high-performance, low-cost, and highly efficient structure by integrating the mounting frame into the side frame.

As a result, buckling and plastic hinge phenomena can be prevented by thick horizontal members in the early stages of a collision, and bending deformation can be counteracted by high-strength vertical members in the later stages of a collision.

In addition, considering the role of the mounting frame that receives the initial impact, the horizontal member is extended to the position of the existing mounting frame and the outside is surrounded with high-strength material, so that the mechanical characteristics can be satisfied and the efficiency of the structure can be maximized with just the side frame. . In addition, by inserting reinforcing members into the interior of the horizontal member and having a structure in which the reinforcing members can disperse force, shock absorption and impact resistance can be maximized.

As described above, according to the present invention, by forming the side frame from different materials, the advantages of extruded materials and the advantages of rigid materials can be utilized equally, thereby achieving not only sufficient structural rigidity but also weight reduction and cost reduction.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention.

In this specification and drawings, the horizontal member of the first frame portion, the transverse member of the second frame portion, and the vertical member of the first frame portion and the longitudinal member of the second frame portion are used only for the purpose of distinguishing terms, and other terms are used. Please note that it does not have any technical meaning.

In the above, the present invention has been described focusing on the embodiments, but the present invention is not limited to the above-described embodiments, and may be modified and implemented by those skilled in the art without changing the technical spirit of the present invention as claimed in the claims. Of course.

1: 1st case 2: 2nd case
3: Body 4: Flange
10: Side frame 15: Adhesive
20: base plate 29: opening
30: first frame portion 31: first vertical member
32: second vertical member 33: third vertical member
34: first horizontal member 35: second horizontal member
36: third horizontal member 37: fourth horizontal member
38: wall portion 39: protrusion
40: 2nd frame part 40a: 2-1 frame part
40b: 2-2 frame part 40c: 2-3 frame part
41: first transverse member 42: first longitudinal member
43: second transverse member 44: second longitudinal member
45: Inlet 45a: First slope
45b: second slope 50: reinforcement portion
50C: Intersection 51: First reinforcing member
51P: first transmission part 52: second reinforcing member
52P: second transmission unit 53: third reinforcing member
53P: Third transmission unit

Claims (18)

A first frame portion formed to have an open cross section;
a second frame part disposed within the first frame part to close an open cross-section of the first frame part and coupled to the first frame part; and
a reinforcement portion that extends to contact the inner surface of the second frame portion around an intersection provided inside the second frame portion, and the intersection portion has a shape that protrudes toward the first frame portion;
Including,
A side frame of a battery case in which the first frame portion and the second frame portion are formed of different materials.
According to claim 1,
The second frame part,
a first transverse member and a second transverse member spaced apart from each other in the height direction; and
a first longitudinal member and a second longitudinal member spaced apart from each other in the width direction and connecting the first and second transverse members;
A side frame of a battery case containing a.
According to claim 2,
The reinforcement part,
a first reinforcing member extending to contact the first transverse member;
a second reinforcing member extending to contact the second transverse member; and
a third reinforcing member extending to abut the second longitudinal member;
Includes,
The third reinforcing member is,
A side frame of a battery case extending in a direction parallel to the first and second transverse members around the intersection.
According to claim 3,
The first reinforcing member and the second reinforcing member,
A side frame of a battery case formed to be inclined at the intersection toward a side opposite to the first frame portion.
According to claim 4,
The reinforcement part,
A side frame of a battery case wherein the third reinforcing member is provided so that the height-wise spacing to the first transverse member is the same as the height-direction spacing to the second transverse member.
According to claim 5,
A first transmission portion in contact with the first reinforcing member and the first transverse member and a second transmission portion in contact with the second reinforcing member and the second transverse member are located on the side of the battery case located outside the first frame portion. frame.
According to claim 3,
The second frame part,
A side frame of a battery case in which a third transmission portion, where the third reinforcing member and the second longitudinal member come into contact, is formed to protrude to an opposite side of the first frame portion.
According to claim 7,
The third reinforcing member is,
A side frame of a battery case wherein the third transmission part is positioned at the center of the second longitudinal member in the height direction.
According to claim 2,
The second frame part,
A side frame of a battery case wherein at least a portion of the first transverse member is formed to be thicker than the remaining thickness, and at least a portion of the second transverse member is formed to be thicker than the remaining thickness.
According to clause 9,
The second frame part,
A 2-1 frame part located at one end in the width direction and provided inside the first frame part, a 2-2 frame part connected to the 2-1 frame part, and a 2-2 frame part connected to the 2-2 frame part. It is located at the other end in the width direction and consists of a 2-3 frame part provided on the outside of the first frame part,
The thickness of the first transverse member and the second transverse member located in the 2-1 frame portion and the 2-3 frame portion is,
A side frame of a battery case formed to be thicker than the thickness of the first and second horizontal members located in the 2-2 frame portion.
According to claim 3,
The first frame part,
a first longitudinal member having a first height;
a second vertical member spaced apart from the first vertical member by a first length and having a second height shorter than the first height;
a third vertical member spaced apart from the second vertical member in the direction of height, spaced apart from the first vertical member by a second length, and having a third height shorter than the first height;
a first horizontal member connecting one end of the first vertical member and one end of the second vertical member;
a second horizontal member connecting the other end of the first vertical member and one end of the third vertical member;
a third horizontal member having one end connected to the other end of the second vertical member and extending in the width direction for a third length; and
a fourth horizontal member having one end connected to the other end of the third vertical member and extending in the width direction for a fourth length;
Including,
A side frame of a battery case in which an opening is formed between the other end of the third horizontal member and the other end of the fourth horizontal member.
According to claim 11,
The first frame part,
a wall portion having the first height; and
a protrusion extending from the wall portion to one side in the width direction by the third length or the fourth length;
Including,
A side frame of a battery case in which the opening is formed on one side of the protrusion.
According to claim 12,
The second frame part,
A side frame of a battery case disposed on at least the protrusion within the first frame portion and closing the opening portion.
According to claim 13,
The second frame part,
A side frame of a battery case that is joined within the first frame portion by mechanical bonding through a fixture or chemical bonding through an adhesive.
The method according to any one of claims 1 to 14,
The first frame part is formed by bending a single plate,
The second frame portion is a side frame of a battery case formed by extrusion.
The method according to any one of claims 1 to 14,
The second frame part,
A side frame of a battery case in which an inlet portion provided inside the first frame portion has a tapered structure.
According to claim 16,
The inlet part,
A side frame of a battery case that is inclined to widen from one end of the first frame side to the opposite side.
The method according to any one of claims 1 to 14,
The first frame part,
It is made of heavy metal material with a specific gravity of 4 or more.
The second frame part,
A side frame of a battery case made of a material with a lower specific gravity than the first frame portion.

Images