DE102016222094B4 - Battery housing for a traction battery of an electrically powered vehicle - Google Patents

Abstract

Battery housing of a traction battery of an electrically operated vehicle, with a housing base (3) which has at least one housing base base (5) and a cooling embossment (7) which is raised towards the interior of the housing by an embossing height (a) and which has a coolant channel on the outside of the housing ( 11) of an external cooling system and on which at least one battery module (1) rests in a heat-conducting manner inside the housing, the battery module (1) having a mounting section (13) for fastening, which has at least one clamping unit (15) on the housing base base (5) can be clamped, which clamping unit (15) has a screw bolt (17) and a screw dome (19) fixed to the housing, the battery module (1) being clamped between a bolt head (16) of the screw bolt (17) and the screw dome (19) in the clamped state , characterized in that the screw dome (19) has a stop element (25) which can be adjusted in stroke between a non-use position (N) and a support position (S), that the stop element (25) in the non-use position (N) has a free tolerance gap (37). a bottom support surface (39) of the battery module mounting section (13), and that when the battery module (1) is tightened, the stop element (25) uses up the tolerance gap (37) until it comes into contact with the bottom support surface (39) of the battery module. Mounting section (13) is stroke-adjustable, so that in the clamped state the battery module mounting section (13) is clamped between the bolt head (16) and the stop element (25) of the screw dome (19), so that the screw dome (19) has at least a first thread ( 12), which can be brought into threaded engagement with the screw bolt (17) and has a first gear direction, and that the battery module (1) has a second thread (27) which has a thread direction that is the same as the first thread (12) and a is an open internal thread at the bottom, which is bounded upwards in the vertical direction by a blind hole bottom into which a mounting shaft (43) opens, through which the screw bolt (17) is guided, and that the blind hole bottom forms the bottom-side support surface (39), and that the stop element (25) is a stop sleeve which is in threaded engagement with the second thread (27) on the outer circumference and has a driver (29) on the inside which is in a detachable drive connection with the screw bolt (17) guided through the stop sleeve (25).

Description

The invention relates to a battery housing of a traction battery of an electrically operated vehicle according to the preamble of patent claim 1.

The traction battery of an electrically powered vehicle has battery cells, each of which is combined as a cell network in cuboid battery modules. A number of such battery modules can be arranged in a battery box, which is positioned, for example, under a rear seat of a vehicle or in a center tunnel of the vehicle. The battery modules may be cooled by an external cooling system located outside the battery case or by an internal cooling system located inside the battery case to achieve better operability.

In a battery housing, a housing base has at least one housing base base and a cooling embossment which is raised by an embossing height towards the housing interior. The cooling embossment formed in the housing base delimits a coolant channel on the outside of the housing of an external cooling system. Inside the housing, at least one battery module rests on the raised cooling embossing in a heat-conducting manner. The battery module is not attached directly to the top of the cooling embossing, but rather is clamped to the base of the housing via at least one clamping unit. The clamping unit consists of a screw bolt and a screw dome formed on the base of the housing. When clamped, the battery module is firmly clamped between the bolt head of the screw bolt and the screw dome. The screw dome, which is offset laterally from the cooling embossing, provides a load path through which forces can be introduced into the housing base when the battery module is subjected to mechanical stress, thereby bridging and relieving the cooling embossing.

Due to manufacturing and/or component tolerances, there is the problem that the battery module may not rest on the entire surface of the cooling embossing, but is instead supported solely on the screw dome. This creates air gaps between the battery module and the cooling embossing, which impairs the heat conduction between the battery module and the bottom-side cooling embossing of the battery housing. The solution so far has been a thermal paste, which is used to fill the air gaps between the battery module and the cooling embossing on the bottom. However, this leads to an increased component weight of the traction battery, increased costs and reduced cooling efficiency.

From the DE 10 2013 021 651 A1 a generic battery housing of a traction battery of an electrically operated vehicle is known. From the DE 20 2005 009 017 U1 and from the US 2005/0025566 A1 Tolerance compensation arrangements are known.

The object of the invention is to provide a battery housing of a traction battery with an external cooling system, in which, compared to the prior art, perfect battery cooling is possible in a simple and weight-reduced manner, with the cooling efficiency being increased and the manufacturing costs being reduced.

The task is solved by the features of patent claim 1. Preferred developments of the invention are disclosed in the subclaims.

According to claim 1, the screw dome additionally has a stop element which can be adjusted in stroke between a non-use position and a support position. In the non-use position, the stop element is spaced from a bottom support surface of the battery module mounting section via a free tolerance gap. When clamping the battery module, the stop element is adjusted in stroke, using up the tolerance gap, until it comes into contact with the bottom support surface of the battery module mounting section. In this way, in the clamped state, the battery module mounting section is reliably clamped between the bolt head and the stroke-adjustable stop element of the screw dome. In addition, component and/or manufacturing tolerances can be compensated for due to the stroke adjustability of the stop element. This ensures, on the one hand, a heat-conducting contact between the battery module and the cooling embossing on the bottom and, on the other hand, ensures a force-transmitting connection of the battery module to the screw dome.

The stroke adjustment of the stop element can preferably be carried out until it comes into contact with the bottom support surface of the battery module mounting section in such a way that the battery module does not lift off from the cooling embossing (forming a heat-insulating air gap), but still remains in heat-conducting contact with it. This ensures that no gaps form between the battery module and the cooling embossing when the battery module is tightened.

In a preferred technical implementation, the screw dome has a first thread (i.e. an internal thread), which is in thread engagement with the screw bolt can be brought and has a first thread direction (for example a right-hand thread). The above-mentioned stroke adjustment of the stop element can preferably be realized by the following design features: The battery module has a second thread which has a thread direction that is the same as the first thread. The stop element is designed as a stop sleeve. This is in threaded engagement with the above-mentioned second thread on the outside circumference and has a driver on the inside. The driver is in a detachable drive connection with the screw bolt guided through the stop sleeve. The drive connection is preferably a friction connection that releases when a torque is exceeded.

The clamping unit specified above results in a tightening process described below: When the screw bolt is screwed in, the driver formed on the stop sleeve first causes a rotary coupling between the screw bolt and the stop sleeve. This means that the stop sleeve (in the opposite direction to the screw bolt) is adjusted to its supporting position. When the support position is reached (i.e. when it stops on the battery module), the drive connection is released, so that the screw bolt is now screwed further into the screw dome in a rotationally decoupled manner from the stop sleeve. The detachable drive connection is designed in such a way that the battery module does not lift off from the cooling embossing, but rather remains in heat-conducting contact with it.

According to the invention, the second thread is designed independently of the screw dome on the battery module, namely as an internal thread. It is important that the second thread remains non-rotatable during the tightening process and is in threaded engagement with the stop sleeve.

In order to ensure proper assembly of the battery module on the housing base, it is important that the embossing height between the top of the housing base base and the top of the cooling embossing is larger than the gap dimension of the tolerance gap between the stop element in the non-use position and the support surface on the bottom of the battery module assembly section.

The invention and its advantageous training and further developments as well as their advantages are explained in more detail below with reference to drawings.

• 1 in einer Teilseitenansicht ein erstes nicht von der Erfindung umfasstes Vergleichsbeispiel, bei dem zwei Batteriemodule über Spanneinheiten auf dem Gehäuseboden eines Batteriegehäuses einer Traktionsbatterie montiert sind;
• 2 bis 4 Ansichten, die einen Montagevorgang zur Befestigung eines Batteriemoduls am Gehäuseboden veranschaulichen;
• 5 in einer Ansicht entsprechend der 4 ein zweites nicht von der Erfindung umfasstes Vergleichsbeispiel;
• 6 in einer Ansicht entsprechend der 4 gemäß einem Ausführungsbeispiel; und
• 7 ein nicht von der Erfindung umfasstes Vergleichsbeispiel.

Show it:

• 1 in a partial side view a first comparative example not covered by the invention, in which two battery modules are mounted via clamping units on the housing base of a battery housing of a traction battery;
• 2 until 4 Views illustrating an assembly process for attaching a battery module to the housing base;
• 5 in a view corresponding to the 4 a second comparative example not covered by the invention;
• 6 in a view corresponding to the 4 according to one embodiment; and
• 7 a comparative example not covered by the invention.

With a view to a simpler understanding of the invention, reference is first made to a battery housing of a traction battery of an electrically operated vehicle known from the prior art, as is partly shown in the 7 is shown. In the 7 an only partially indicated cuboid battery module 1 is shown, which is constructed from individual battery cells, not shown. The battery module 1 is mounted on a housing base 3 of the battery housing by means of a clamping unit 15. Like from the 7 As can be seen further, the housing base 3 has a housing base base 5 and a cooling embossing 7 that is raised to the side of it in the direction of the housing interior by an embossing height a. The cooling stamp 7, together with a cover plate part 9, delimits a coolant channel 11 on the outside of the housing, which is part of an external cooling system.

That in the 7 Battery module 1 shown also has a mounting section 13, which is clamped to the housing base base 5 via the clamping unit 15. The clamping unit 15 consists of 7 consisting of a screw bolt 17 with a bolt head 16 and a screw dome 19, which is attached to the housing base base 5 with the aid of a mounting bracket 21. By means of the clamping unit 15, a load path is provided laterally outside the cooling embossment 7, via which forces are introduced into the housing base 3 when the battery module 1 is subjected to mechanical stress, namely by bridging or relieving the cooling embossment 7.

In the 7 an installation situation is shown in which, due to manufacturing and/or component tolerances, the battery module 1 is supported solely on the screw dome 19 and is lifted off the cooling stamp 7 by a heat-insulating air gap 23. To increase the thermal conductivity (i.e. the cooling efficiency), it is therefore advisable to fill the heat-insulating air gap 23 with, for example, a thermal paste.

In contrast to that in the 7 The prior art shown is in the 1 until 6 The screw dome 19 of the clamping unit 15 is additionally assigned a height-adjustable stop element 25, which is implemented as a stop sleeve. In addition, the screw dome thread 12, which is in threaded engagement with the screw bolt 17, is coaxially extended on its side facing the battery module 1 with a second screw dome thread 27 ( 2 until 4 ). In the 2 until 4 the second screw dome thread 27 is realized as an internal thread which has a second gear direction that runs in the opposite direction with respect to the screw dome thread 12. By way of example, the first screw dome thread 12 can be a right-hand thread, while the second screw dome thread 27 is a left-hand thread. The stop sleeve 25 is formed on the outside circumference in threaded engagement with the second screw dome thread 27 and on the inside with a driver 29. The driver 29 formed on the inside of the stop sleeve 25 is in a releasable frictional connection with the screw bolt 17 guided through the stop sleeve 25.

Based on 2 until 4 the assembly of one of the battery modules 1 on the housing base 3 of the battery housing is illustrated: First of all, according to 2 the battery module 1 is placed loosely on the top 31 of the cooling stamp 7. The stop sleeve 25 is screwed into the second screw dome thread 27 up to its non-use position N, with its stop flange 33 almost in contact with the top end face 35 of the screw dome 19. The stop flange 33 of the stop sleeve 25 is in the 2 spaced by a free tolerance gap 37 from a bottom support surface 39 of the battery module mounting section 13.

Then according to the 3 the screw bolt 17 inserted into the mounting shaft 43 of the battery mode 1 is screwed into the screw dome 19 on the bottom. When screwing the screw bolt 17 into the first screw dome thread 12, the stop sleeve 25 is in frictional connection (and therefore rotationally coupled) with the screw bolt 17 via its driver 29. The stop sleeve 25 is therefore adjusted upwards (in the opposite direction to the screw bolt 17), namely using up the tolerance gap 37 to its support position S ( 4 ). In the support position S, the stop sleeve 25 with its stop flange 33 is in contact with the bottom support surface 39 of the battery module 1.

The frictional connection between the driver 29 of the stop sleeve 25 and the screw bolt 17 is dimensioned such that when the support position S is reached, the frictional connection is released without lifting the battery module 1 from the top 31 of the cooling stamp 11. In the further screwing process, the screw bolt 17 is screwed further into the screw dome 19 in a rotationally decoupled manner from the stop sleeve 25. In this way (in contrast to 7 ) ensures that the battery module 1 in the clamped state, on the one hand, still rests in a heat-conducting manner on the top 31 of the cooling stamp 7 and, on the other hand, a force-transmitting load path is still provided via the clamping unit 15.

In the 5 A comparative example not covered by the invention is shown, in which the second screw dome thread 27 is no longer realized as an internal thread, but rather as an external thread on the screw dome 19. The inner circumference of the stop sleeve 25 points in the 5 a top-side smooth cylindrical section in which the driver 29 is formed. The top smooth cylindrical section of the inner circumference of the stop sleeve 25 merges downwards into a stepped, larger-diameter internal thread which is in threaded engagement with the second screw dome thread 27, which is in the 5 is designed as an external thread on the screw dome 19. By way of example, the first screw dome thread 12 is a right-hand thread and the second screw dome thread 27 is a left-hand thread.

In the 6 An exemplary embodiment is shown in which the second thread 27 (in contrast to the previous figures) is no longer formed directly on the screw dome 19, but rather is formed as an internal thread on the battery module mounting section 13. Like from the 5 As can be seen, the second thread 27 is an internal thread that is open at the bottom and is limited in the vertical direction by a blind hole bottom into which a mounting shaft 43 opens, through which the screw bolt 17 is guided. The blind hole bottom corresponds to the bottom support surface 39 of the battery module 1.

In contrast to the first and second exemplary embodiments, in the 6 the screw dome thread 12 and the second thread 27 are not designed in opposite directions to one another, but rather both threads 12, 27 have the same direction.

In the 1 until 7 the screw dome 19 is mounted directly on the housing base 3. However, the invention is not limited to such a bottom-side installation of the screw dome 19. The only important thing is that the screw dome 19 remains positioned in a rotationally and stationary manner during the screwing process. For example, the screw dome 19 can also be attached to the mounting console 21 independently of the housing base 3.

Reference symbol list

1

Battery module

3

Case back

5

Caseback base

7

Cool stamping

9

Cover plate parts

11

Coolant channel

12

first thread

13

Battery module assembly section

15

Clamping unit

17

screw bolt

19

screw dome

21

Mounting console

23

gap

25

Stop element, stop sleeve

27

second thread

29

taker

31

Top of the cooling stamp

33

stop flange

35

upper face of the screw dome

37

Tolerance gap

39

Bottom support surface of the battery module 1

43

Mounting shaft

a

embossing height

N

Non-use position

S

Support position

Claims (4)

Battery housing of a traction battery of an electrically operated vehicle, with a housing base (3) which has at least one housing base base (5) and a cooling embossment (7) which is raised towards the interior of the housing by an embossing height (a) and which has a coolant channel on the outside of the housing ( 11) of an external cooling system and on which at least one battery module (1) rests in a heat-conducting manner inside the housing, the battery module (1) having a mounting section (13) for fastening, which has at least one clamping unit (15) on the housing base base (5) can be clamped, which clamping unit (15) has a screw bolt (17) and a screw dome (19) fixed to the housing, the battery module (1) being clamped between a bolt head (16) of the screw bolt (17) and the screw dome (19) in the clamped state , characterized in that the screw dome (19) has a stop element (25) which can be adjusted in stroke between a non-use position (N) and a support position (S), that the stop element (25) in the non-use position (N) has a free tolerance gap (37). a bottom support surface (39) of the battery module mounting section (13), and that when the battery module (1) is tightened, the stop element (25) uses up the tolerance gap (37) until it comes into contact with the bottom support surface (39) of the battery module. Mounting section (13) is stroke-adjustable, so that in the clamped state the battery module mounting section (13) is clamped between the bolt head (16) and the stop element (25) of the screw dome (19), so that the screw dome (19) has at least a first thread ( 12), which can be brought into threaded engagement with the screw bolt (17) and has a first gear direction, and that the battery module (1) has a second thread (27) which has a thread direction that is the same as the first thread (12) and a is an open internal thread at the bottom, which is bounded upwards in the vertical direction by a blind hole bottom into which a mounting shaft (43) opens, through which the screw bolt (17) is guided, and that the blind hole bottom forms the bottom-side support surface (39), and that the stop element (25) is a stop sleeve which is in threaded engagement with the second thread (27) on the outer circumference and has a driver (29) on the inside which is in a detachable drive connection with the screw bolt (17) guided through the stop sleeve (25). Battery housing Claim 1 , characterized in that the stroke adjustment of the stop element (25) until it comes into contact with the bottom support surface (39) of the battery module mounting section (13) takes place in such a way that the battery module (1) does not lift off from the cooling embossment (7), but rather in heat-conducting contact remains. Battery housing Claim 1 or 2 , characterized in that when the screw bolt (17) is screwed into the first screw dome thread (12), the screw bolt (17) takes the stop sleeve (25) with it, whereby the stop sleeve (25) moves from its non-use position (N) to its support position ( S) the stroke is adjusted, using up the tolerance gap (37), and that when the support position (S) is reached, the drive connection is released, so that the screw bolt (17) is rotationally decoupled from the stop sleeve (25) further into the screw dome (19). is screwed in. Battery housing according to one of the preceding claims, characterized in that the embossing height (a) between the top of the housing base base (5) and the top of the cooling embossing (7) is larger than the gap dimension of the tolerance gap (37) between the in the non-use position (N) located stop element (25) and the bottom support surface (39) of the battery module mounting section (13).

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