CN108520931A - battery box - Google Patents

Abstract

The invention discloses a battery pack box, which is integrally formed by molten aluminum casting, and is characterized in that it includes an inwardly recessed shell, and the bottom surface of the shell includes several crisscross reinforcing ribs, and the bottom surface of the shell is criss-crossed. The middle position is provided with a partition that divides the bottom surface of the housing into two. The purpose of the present invention is to provide a reasonably designed battery pack box, adjust the original preparation method and its internal structure, speed up the production speed of the battery pack box and improve its yield.

Description

battery box

technical field

The invention belongs to the technical field of power battery packs for new energy vehicles, in particular to a battery pack box for new energy vehicles.

Background technique

At present, new energy vehicles are developing rapidly and their use is becoming more and more common. New energy vehicles generally use power battery packs as the power source, and the battery pack box is mainly equipped with battery modules, electrical components, upper casings and other parts. It can be seen that the battery pack box is the main bearing and sealing structure of the power battery pack.

The battery pack box of the existing new energy vehicle power battery pack adopts a sheet metal welding structure. The material is generally a steel plate with a thickness of 1-2mm. Welded joints are sealed with sealant. The installation points on the battery pack box for the upper shell, battery module and electrical components require welding nuts or sheet metal brackets. The surface of the battery pack box needs to be treated with anti-rust spray paint after welding.

The battery pack box of the above-mentioned sheet metal welding structure has the following problems:

(1) The battery pack box is made by bending forming and tailor welding process, the consistency is poor, and the battery module and electrical components are prone to assembly defects, which cannot meet the needs of mass production.

(2) The battery pack box and the left and right rear hangers are integrally welded. When the power battery pack is disassembled and maintained, the rear hanger interferes with the rear suspension of the chassis. Install the rear suspension after loading the vehicle, and the vehicle needs to re-adjust the four-wheel alignment. The battery pack has the problems of difficulty in disassembly and assembly, and high cost of maintenance man-hours.

(3) There are multiple welds on the joint surface of the battery pack box and the upper case, the flatness is not good, and the sealing reliability of the joint surface of the upper and battery pack boxes is poor.

(4) There is local welding deformation on the mating surface of the battery pack box and the electrical connector, and the sealing reliability of the connector is poor after installation.

(5) The battery pack box adopts a sheet metal welding structure, the structure process is complex, and the cost of parts is high.

(6) The bottom of the battery pack box is a flat sheet metal structure. In order to effectively reduce the risk of impact damage caused by road gravel to the bottom of the power battery pack, it is usually necessary to add sheet metal reinforcements for the battery pack box to enhance the strength of the battery pack box and rigidity, making the overall weight of the battery pack box too large, which does not meet the lightweight design requirements of new energy vehicles.

However, Chinese patent CN201621071957.6 discloses a vehicle battery pack lower case structure, a battery pack case and a battery pack. The vehicle battery pack lower case structure includes a lower case with an upper opening. The bottom is provided with a concave-convex structure, and the concave-convex structure includes a plurality of bosses and a plurality of grooves arranged alternately. In the lower casing structure of the vehicle battery pack of the present invention, the bottom of the lower casing is provided with a concave-convex structure, and the concave-convex structure includes a plurality of bosses and a plurality of grooves arranged alternately, which is flat compared to the bottom of the existing lower casing. The lower casing of the sheet metal structure, without increasing the thickness of the casing material, the lower casing with the concave-convex structure at the bottom can enhance the strength and rigidity of the lower casing, effectively reducing the impact of road gravel on the bottom of the power battery pack The risk of impact damage can be achieved, and the high-strength and lightweight design requirements of the battery pack can be realized, and the vibration and impact test requirements of the power battery pack can be met.

The above-mentioned patent still adopts a sheet metal structure, and its manufacturing process generally includes cutting, punching, bending and forming, etc. These methods are slow in processing and low in yield. For this reason, our company adjusts the material and manufacturing process of the lower shell of the battery pack, that is, the battery pack box. The battery pack box is integrally formed in the form of aluminum liquid casting, and its internal structure is adjusted to increase the mechanical strength of the aluminum battery pack box. performance.

Contents of the invention

The purpose of the present invention is to provide a reasonably designed battery pack box, adjust the original preparation method and its internal structure, speed up the production speed of the battery pack box and improve its yield.

To achieve the above object, the present invention provides the following technical solutions:

The battery pack box is integrally formed by molten aluminum casting, and is characterized in that it includes an inwardly recessed shell, and the bottom surface of the shell includes several criss-cross reinforcing ribs, and a spacer is provided in the middle of the bottom surface of the shell. The spacer divides the bottom surface of the housing into three through two partitions.

The battery pack case according to an embodiment of the present invention can be further configured such that connecting plates distributed longitudinally are arranged between the two partition plates of the partition portion.

According to yet another embodiment of the present invention, the battery pack box can be further configured such that the reinforcing ribs include longitudinal reinforcing ribs distributed longitudinally and transverse reinforcing ribs distributed transversely, wherein the longitudinal reinforcing ribs include main longitudinal reinforcing ribs and secondary longitudinal reinforcing ribs. The number of the longitudinal reinforcement main reinforcement is 3, and two longitudinal reinforcement secondary reinforcements are arranged between every two adjacent longitudinal reinforcement main reinforcements.

According to yet another embodiment of the present invention, the battery pack box can be further configured such that the longitudinal reinforcing rib penetrates through the two partitions, and a connecting plate is arranged above the main longitudinal reinforcing rib passing through the two partitions, and the connecting plates are all directed towards the shell. The inner walls on the left and right sides of the body are extended to form a reinforcing part of the connecting plate.

According to yet another embodiment of the present invention, the battery pack box can be further configured such that the bottom surface of the housing can be divided into a left area, a spacer area and a right area, wherein the reinforcement ribs at the four corners of the left area and the right area are criss-crossed. There is a reinforcement block, and the top surface of the reinforcement block is higher than the top surface of the reinforcement rib, and a vertically arranged hollow tube is arranged at the junction of the connecting plate and the longitudinal reinforcement main rib.

The battery pack case according to yet another embodiment of the present invention can be further configured such that a mounting groove around the outer edge of the casing is formed by extending outward on the outer edge of the casing, and a left front Boss, the installation groove at the left rear of the housing is also extended outwards with a left rear boss, while the installation groove at the right front of the housing is extended outwards with a right front boss, and the installation groove at the right rear of the housing is also extended outwards The extension is provided with a right rear boss.

The battery pack case according to yet another embodiment of the present invention may be further configured such that the installation groove is provided with several installation holes that are recessed downwards and do not penetrate through the installation groove.

The battery pack case according to yet another embodiment of the present invention may be further configured such that through holes are provided on the left front boss, the left rear boss, the right front boss, and the right rear boss.

The battery pack case according to yet another embodiment of the present invention may further be provided with several longitudinal reinforcing ribs arranged longitudinally on the back of the casing, and the longitudinal reinforcing ribs are separated by two spacer strips on the back of the casing. Left, center and right areas.

According to yet another object of the present invention, the method for preparing the battery pack box includes the following steps;

S1. Prepare the sand core, design the inner sand core according to the inwardly concave structure of the battery pack box, and coat the refractory material on the outside;

S2. Fix the inner sand core, coat the core of the outer mold of the battery pack case with refractory material, and then fix the inner sand core coated with refractory material into the outer mold;

S3. Pouring molten aluminum, and pouring the molten aluminum into the mold through a low-pressure pouring tool at low pressure to obtain a casting blank for the battery pack case;

S4, solid solution blank, solid solution aging treatment is performed on the rough casting of the battery pack box shell;

S5, taking out the cast shell from the cavity of the mould, and wait until it is completely cooled;

S6. Cleaning, precision machining and inspection of the outer side of the battery pack case to obtain the finished product of the integrated battery pack case.

The method for preparing a battery pack according to yet another embodiment of the present invention can be further set such that in step S3, the temperature of the molten aluminum is controlled at 720-735°C, and the filling pressure of the molten aluminum is controlled at 0.33-0.35 MPa, The boost pressure during pressure holding is controlled at 0.42-0.46MPa, the time for holding pressure in step S3 is controlled at 180-280s, and the time for cooling in step S4 is controlled at 60-100s.

According to another embodiment of the present invention, the method for preparing a battery pack can be further set such that in step S3, the temperature of the molten aluminum is controlled at 735°C, and the filling pressure of the molten aluminum is controlled at 0.36 MPa, and the The supercharging pressure is controlled at 0.46MPa, the pressure holding time in S3 step is controlled at 210s, and the cooling time in S4 step is controlled at 90s.

Compared with the prior art, the beneficial effects of the present invention are as follows:

1. The battery pack box provided by the present invention is casted by molten aluminum. Compared with the original sheet metal processing procedure, the processing speed is fast and the yield rate is high;

2. The reinforcement ribs provided on the bottom surface of the battery pack case provided by the present invention and the reinforcement ribs at the spacer both play a positive role in improving the mechanical properties of the battery pack case itself, increasing the compression and torsion resistance of the case;

3. The partition structure in the middle of the battery pack case provided by the present invention not only divides the battery pack case into two, but also divides it into three areas, namely the left area, the right area and the partition area, which facilitates the installation of the battery pack , and isolate the different areas of the battery pack, playing a certain protective role;

4. The mounting grooves and mounting holes formed on the outer edge of the battery pack box shell provided by the present invention make it easy to install with the upper shell, while the design of the left front boss, left rear boss, right front boss, and right rear boss is The package box and its cover are combined to play a good role in fixing;

5. The longitudinal reinforcing ribs provided on the back of the battery pack box shell provided by the present invention further strengthen the structural stability of the shell, and at the same time leave intervals to enhance the effect of ventilation and heat exchange.

Description of drawings

Fig. 1 is the schematic diagram of the battery pack case provided by the present invention;

Fig. 2 is the front view of the battery pack case provided by the present invention;

Fig. 3 is a top view of the battery pack box provided by the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The structural diagrams of the battery pack box provided in Figures 1 to 3 are integrally formed by molten aluminum casting, and are characterized in that they include an inwardly recessed shell 10, and the bottom surface 11 of the shell includes several criss-crossing reinforcing ribs 2 A spacer 12 is provided at a middle position of the bottom surface of the housing 11 , and the spacer portion 12 divides the bottom surface of the housing 11 into three through two partitions 121 .

Connecting plates 122 distributed longitudinally are arranged between the two partition plates 121 of the partition portion 12 .

The ribs 2 include longitudinally distributed longitudinal ribs 21 and transversely distributed transverse ribs 22, wherein the longitudinal ribs 21 include longitudinally reinforced main ribs 211 and longitudinally reinforced secondary ribs 212, and the number of longitudinally reinforced main ribs 211 There are 3 longitudinal reinforcement ribs 212 arranged between every two adjacent longitudinal reinforcement main ribs 211 .

The longitudinal reinforcing rib 21 runs through the two partitions 121, and a connecting plate 122 is arranged above the main longitudinal reinforcing rib 211 passing through the two partitions 121, and the connecting plate 122 extends toward the inner walls of the left and right sides of the casing 10 to form The connecting plate reinforcement part 123 .

The bottom surface of the housing 11 can be divided into a left area 111, a spacer area 112 and a right area 113, wherein reinforcing blocks 3 are arranged at the four corners of the left area 111 and the right area 113 where the reinforcing ribs 2 criss-cross, and the The top surface of the reinforcing block 3 is higher than the top surface of the reinforcing rib 2 , and a vertically arranged hollow tube 124 is provided at the junction of the connecting plate 122 and the longitudinal main reinforcing rib 211 .

The outer edge of the housing 10 is extended outward to form a mounting groove 4 around the outer edge of the housing 10, and the mounting groove 4 on the left front of the housing 10 is extended outwardly with a left front boss 41, in the housing 10 The mounting groove 4 at the left rear is also extended outwards with a left rear boss 42, while the mounting groove 4 at the right front of the housing 10 is extended outwards with a right front boss 43, and the mounting groove 4 at the right rear of the housing 10 also faces The outer extension is provided with a right rear boss 44, wherein the installation groove 4 is provided with several installation holes 45 that are sunken downwards and do not penetrate the installation groove 4. In the left front boss 41, left rear boss 42, right front Through holes 46 are all arranged on the boss 43 , and the right rear boss 44 .

On the back of the casing 10 are also provided several longitudinal reinforcing ribs 5 arranged longitudinally, and the longitudinal reinforcing ribs 5 are divided into three regions of left, middle and right by two spacer strips 51 on the back of the casing 10 .

At the same time, the method for preparing the battery pack box is characterized in that it comprises the following steps;

S1. Prepare the sand core, design the inner sand core according to the inwardly concave structure of the battery pack box, and coat the refractory material on the outside;

S2. Fixing the inner sand core, coating the core of the outer mold of the battery pack case 10 with a refractory material, and then fixing the inner sand core coated with the refractory material into the outer mold;

S3. Pouring the aluminum liquid, performing low-pressure pouring of the smelted aluminum liquid into the mold through a low-pressure pouring tool to obtain the rough casting of the battery pack case shell 10;

S4, solid solution blank, solid solution aging treatment is carried out on the blank of the casting of the battery pack case 10;

S5, taking out the cast shell 10 from the cavity of the mould, and wait until it is completely cooled;

S6 , cleaning the outside of the battery pack case 10 , precision machining and inspection to obtain the finished product of the integrated battery pack case 10 .

In the S3 step, the temperature of the molten aluminum is controlled at 720-735°C, and the filling pressure of the molten aluminum is controlled at 0.33-0.35MPa, and the pressurization pressure at the time of holding pressure is controlled at 0.42-0.46MPa. The time for holding the medium pressure is controlled at 180-280s, and the time for cooling in step S4 is controlled at 60-100s.

Preferably, in step S3, the temperature of the molten aluminum is controlled at 735°C, and the filling pressure of the molten aluminum is controlled at 0.36MPa, the pressurization pressure during pressure holding is controlled at 0.46MPa, and the time of holding pressure in step S3 is controlled At 210s, the cooling time in step S4 is controlled at 90s.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (10)

1. battery pack box uses the casting integrated molding of molten aluminum, which is characterized in that including the shell being recessed inwardly, the shell Bottom surface includes several crisscross reinforcing ribs, and the housing bottom surface centre position is provided with spacer portion, and the spacer portion is logical Two partition boards are crossed by housing bottom surface one dividing into three.

2. a kind of battery pack box according to claim 1, which is characterized in that be provided between two partition boards of spacer portion and be in The connecting plate of genesis analysis.

3. a kind of battery pack box according to claim 2, which is characterized in that the reinforcing rib includes in the vertical of genesis analysis To reinforcing rib and laterally distributed cross reinforcing, wherein the waling includes longitudinally reinforced main reinforcement and longitudinal direction Reinforce time muscle, the longitudinally reinforced main reinforcement quantity is 3, and 2 longitudinal directions are disposed between the adjacent longitudinally reinforced main reinforcement of each two Reinforce time muscle.

4. a kind of battery pack box according to claim 3, which is characterized in that the waling runs through two partition boards, And connecting plate is being provided with above longitudinally reinforced main reinforcement between two partition boards, and connecting plate prolongs to the inner wall at left and right sides of shell Spread is at connecting plate strengthening portion.

5. a kind of battery pack box according to claim 4, which is characterized in that the housing bottom surface can be divided into left area, interval Area of portion and You Qu, wherein the crisscross place of quadrangle reinforcing rib in the Zuo Qu and right area is provided with reinforcement block, and the reinforcement The top surface of block is higher than the top surface of the reinforcing rib, and is provided with vertical cloth at the connecting plate and the position of longitudinally reinforced main reinforcement handing-over The hollow tube set.

6. a kind of battery pack box according to claim 5, which is characterized in that extend outward shape in the shell outer edge At one around the outer peripheral mounting groove of shell, and extends outward in the mounting groove of shell left front and is provided with left front boss, Mounting groove in shell left back also extends outward is provided with left back boss, while extension is set the mounting groove of shell right front outward It is equipped with right front boss, the mounting groove in shell right back also extends outward is provided with right rear boss, wherein being set on the mounting groove Several are set to lower recess and do not run through the mounting hole of mounting groove, the left front boss, left back boss, right front boss, it is right Through hole is respectively provided on rear boss.

7. a kind of battery pack box according to claim 1 to 6 any one, which is characterized in that also set up in back side of shell It is in longitudinally arranged longitudinal reinforced rib to have several, and the longitudinal reinforced rib is by two intervallums separation positioned at back side of shell For the region of left, center, right three.

8. a kind of preparation method of battery pack box according to claim 7, which is characterized in that include the following steps;

S1, sand core is prepared, according to sand core in the structure design being recessed inwardly in battery pack box, and in its outer coating refractory material；

The core of battery pack box shell outer mold is applied refractory material, then will be coated with sand in refractory material by sand core in S2, fixation Core is fixed in outer mold；

S3, molten aluminum is poured, the molten aluminum of melting is poured tool by low pressure carries out low-pressure casting acquisition battery pack box into mold Shell casting blank；

S4, solid solution blank, fixation rates are carried out to battery pack box shell casting blank；

S5, by the shell cast by being taken out in the cavity of mold, until completely cooling；

S6, battery pack box hull outside is cleared up, precision machinery processing and examine obtain integral battery packet box shell at Product.

9. a kind of preparation method of battery pack box according to claim 8, which is characterized in that the temperature of molten aluminum in S3 steps Degree control is at 720-735 DEG C, and mold filling pressure when aluminum liquid filling type controls the boost pressure control in 0.33-0.35MPa, pressurize System is in 0.42-0.46MPa, and the time control of pressurize is in 180-280s, the cooling time control in S4 steps in S3 steps In 60-100s.

10. a kind of preparation method of battery pack box according to claim 9, which is characterized in that the molten aluminum in S3 steps Temperature is controlled at 735 DEG C, and the Pressure control that mold filling pressure when aluminum liquid filling type is controlled in 0.36MPa, pressurize exists 0.46MPa, the time control of pressurize is in 210s in S3 steps, and cooling time control is in 90s in S4 steps.