Positive grid plate for stationary air conditioner of commercial vehicle

Abstract

A positive electrode grid for commercial vehicle parking air conditioning batteries includes a grid body, which is a mesh structure composed of multiple horizontal and vertical ribs. The uppermost horizontal rib forms the upper frame, the leftmost vertical rib forms the left frame, the rightmost vertical rib forms the right frame, and the bottommost horizontal rib forms the lower frame. The upper frame includes a transition section and a stabilizing section connected to the right end of the transition section. The base of the electrode tab is connected to the left end of the outer side of the transition section via a chamfered structure. The upper, left, right, and lower frames form a frame. Multiple vertical ribs within the frame form a radial pattern from the upper to the lower frame. The width of the vertical ribs within the frame gradually decreases from top to bottom. The spacing L between adjacent vertical and horizontal ribs adopts a gradient layout, with a smaller spacing L near the electrode tab and a larger spacing L away from the electrode tab. This invention achieves high mechanical strength, low internal resistance, and long lifespan through gradient rib design and mesh optimization.

Description

Technical Field

[0001] This utility model relates to the field of lead-acid battery technology, and is particularly applicable to the design of the positive plate grid structure of commercial vehicle parking air conditioning batteries. Background Technology

[0002] The global commercial vehicle market reached trillions of dollars in 2023, attracting numerous manufacturers and becoming a focal point of competition for both domestic and international automakers. The "2023-2028 China Commercial Vehicle Industry Market Demand and Investment Consulting Report" indicates that my country's commercial vehicles accounted for 13.97% of the entire automotive market with sales of 326,000 units. Consequently, foreign brands have entered the Chinese market through joint ventures and exclusive distribution agreements, intensifying market competition.

[0003] Commercial vehicle parking air conditioning systems typically operate for extended periods in high-temperature summer environments, causing the operating temperature of the associated lead-acid batteries to reach 40-60°C or even higher. As a key component of lead-acid batteries, the positive grid not only serves as a conductive carrier but also provides support for the active materials; its structural design directly affects the battery's cycle life.

[0004] Parking air conditioning batteries need to withstand frequent deep charge-discharge cycles (typically 80-100% DOD), which places higher demands on the structural strength of the grid and the retention of active materials. Meanwhile, when the vehicle is not in operation, the battery may be in a float charge state for extended periods, leading to further corrosion and growth of the positive grid. Furthermore, the vibrations and impacts experienced during commercial vehicle operation also require the grid to possess superior mechanical properties.

[0005] However, the positive electrode grids prepared by the existing continuous stamping process have the following problems:

[0006] Structural deformation imbalance problem

[0007] Under normal electrolyte levels, existing positive electrode grids exhibit significant anisotropic deformation characteristics:

[0008] The growth rate in the height direction is 40-60% higher than that in the width direction, which leads to stress imbalance in the assembly of pole groups;

[0009] The corrosion rate of the ribs in the width direction is 2-3 times that in the thickness direction. The corrosion rate is fastest in the central area on the side away from the tab (up to 0.15 mm / 100 cycles), which is the main cause of early failure.

[0010] Operating condition adaptability defects

[0011] When applied to parking air conditioning batteries in commercial vehicles, existing designs reveal three major technical bottlenecks:

[0012] High-temperature corrosion is accelerated: the corrosion rate at 60℃ is 300% higher than at room temperature, and traditional rib designs cannot meet the service life requirement of more than 3 years.

[0013] Deep cycle structural failure: During 80-100% DOD cycles, the tensile strength of the grid decreases by 0.8 MPa / 100 cycles, and the ribs break after 300 cycles.

[0014] Uneven current distribution: The difference in the utilization rate of active material between the tab side and the distal end is >25%, which leads to premature capacity decay.

[0015] Process limitations and pain points

[0016] The grids produced by the existing continuous stamping process have inherent defects:

[0017] The uniform mesh layout leads to stress concentration under vibration conditions (maximum stress up to 180 MPa).

[0018] The right-angle rib connection results in the punch having an average lifespan of less than 500,000 cycles.

[0019] Summary of technical requirements

[0020] There is an urgent need to develop novel continuous-stroke positive electrode grids with gradient reinforcement structures, which must simultaneously meet the following requirements:

[0021] ① Long-term corrosion resistance at high temperatures (≤80℃) (<0.05mm / year);

[0022] ② Deep cycling (≥800 cycles @ 100% DOD) structural stability;

[0023] ③ Fatigue resistance under vibration conditions (EN V4 level);

[0024] ④ Adaptability to continuous punching process (punch life ≥ 700,000 times).

[0025] Challenges remain when applying this technology to parking air conditioning batteries for commercial vehicles: insufficient corrosion resistance at high temperatures, the need to improve structural stability under deep cycle conditions, and how to further optimize the rib design to improve the utilization rate of active materials. Therefore, there is an urgent need to develop a continuous-stretch positive grid structure specifically for parking air conditioning batteries to meet the stringent requirements of high temperature, deep cycle, and vibration resistance. Summary of the Invention

[0026] The purpose of this invention is to overcome the above-mentioned shortcomings of the prior art and to provide a positive grid plate suitable for commercial vehicle parking air conditioning battery, which aims to improve the grid plate's corrosion resistance, growth resistance, vibration resistance and current distribution uniformity, and extend the battery's service life under harsh operating conditions.

[0027] The technical solution of this utility model is as follows: It includes a grid body, which is a mesh structure composed of multiple horizontal ribs and multiple vertical ribs 4. The uppermost horizontal rib is the upper frame, the leftmost vertical rib is the left frame, the rightmost vertical rib is the right frame, and the bottommost horizontal rib is the lower frame. The upper frame includes a transition section and a stable section connected to the right end of the transition section. The height of the transition section gradually decreases from left to right to M, and the height of the stable section is equal to M. The root of the electrode ear is connected to the left end of the outer side of the transition section through a chamfered structure. The upper frame, left frame, right frame, and lower frame constitute a frame. The multiple vertical ribs located in the frame form a radial pattern from the upper frame to the lower frame. The width of the vertical ribs located in the frame gradually decreases from top to bottom. The spacing L between two adjacent vertical ribs and two adjacent horizontal ribs adopts a gradient layout, with the spacing L being smaller near the electrode ear and larger away from the electrode ear.

[0028] The chamfered structure includes an arc-shaped transition on the right and a chamfered edge transition on the left. The arc-shaped transition improves the tab's resistance to bending.

[0029] The spacing L near the electrode tab is 5-8mm, and the spacing L away from the electrode tab is 8-12mm.

[0030] The mesh structure has polygonal mesh shapes.

[0031] The mesh structure has hexagonal or rhomboid mesh shapes.

[0032] The mesh structure employs a non-uniform mesh layout.

[0033] The mesh area in the central region of the mesh structure is larger than the mesh area in the edge region.

[0034] Chamfers are added at the joints between the left and bottom borders, the right and bottom borders, and the top and right borders.

[0035] The vertical and horizontal ribs within the frame have octagonal cross-sections.

[0036] This invention achieves high mechanical strength, low internal resistance, and long lifespan through a gradient rib design and optimized mesh. It is particularly suitable for commercial vehicle parking air conditioning batteries subjected to high vibration and high current, significantly improving battery reliability and economy. Its beneficial effects are as follows:

[0037] 1. High mechanical strength: The gradually varying spacing design and radial vertical rib layout improve vibration resistance by more than 30%;

[0038] 2. Low internal resistance: The radial vertical ribs shorten the current path, reducing the ohmic internal resistance by 20%;

[0039] 3. Corrosion resistance: Widened ribs in key areas extend corrosion life by 50%;

[0040] Critical areas typically refer to the following high-stress, high-corrosion-risk areas, which require enhanced durability through reinforced rib design:

[0041] tab connection

[0042] Location: The transition section between the base of the electrode lug and the upper edge of the grid (near the chamfered structure).

[0043] Reason for widening: The current density is concentrated and the mechanical stress is high here, making it prone to cracking and corrosion due to vibration or charge-discharge cycles. Widening the ribs can reduce resistive heat and disperse stress.

[0044] The central region far from the electrode

[0045] Location: Middle of the slatted grid (especially the middle part of the radial vertical ribs).

[0046] Reason for widening: In traditional designs, this area has the longest current path and the most intense reaction of active materials, resulting in the fastest corrosion rate of the ribs (as mentioned in the background technology, "the ribs in the middle of the side away from the lugs have the fastest corrosion rate"). Widening the ribs can delay corrosion penetration.

[0047] transition section

[0048] Location: The transition section (height gradient area) of the top border connects to the left and right borders.

[0049] Reason for widening: The grid is prone to uneven expansion during charging and discharging, and stress concentration is likely to occur at the corners of the frame, leading to structural failure.

[0050] Vertical rib width gradually decreases: The width of the vertical rib gradually decreases from top to bottom, that is, the upper rib (closer to the electrode tab) is wider (e.g., 0.7mm→1.0mm) to cope with high corrosion risk.

[0051] Chamfered structure reinforcement: The arc transition design of the chamfered structure further disperses the stress at the root of the electrode lug, and works in conjunction with the widening of the ribs to improve service life.

[0052] 4. A non-uniform mesh layout is adopted, with the mesh area in the central area (27~80mm²) slightly larger than that in the edge area, which enhances the adhesion of lead paste; the base of the electrode adopts an arc transition design to reduce stress concentration.

[0053] 5. Lightweight: The mesh shape is polygonal (such as hexagon or rhombus), which improves the punching yield and reduces lead consumption. The reduction in lead consumption does not affect the strength.

[0054] 6. Manufacturing feasibility: Adaptable to continuous stamping process, increasing punch life.

[0055] In the continuous stamping process of positive electrode grids, improving the life of the punch mainly relies on the following structural design optimizations, which reduce punch wear and stress concentration, thereby extending the service life of the die:

[0056] 1) Curved chamfer transition design

[0057] Location: At the junction of the base of the tab and the upper frame.

[0058] effect:

[0059] The traditional right-angle or acute-angle connection is replaced with an arc transition (such as R0.5mm~R1mm) to avoid the punch being stressed at sharp corners and reduce the risk of chipping.

[0060] Chamfered edges (such as a 45° bevel) further disperse punching stress and reduce lateral load on the punch.

[0061] Effect: The lifespan of the punch is increased by approximately 20%-30%.

[0062] 2) Gradual rib spacing layout

[0063] Location: The spacing L between adjacent vertical / horizontal ribs adopts a gradient layout.

[0064] effect:

[0065] The spacing is smaller (5-8mm) near the tab and larger (8-12mm) further away from the tab, which makes the force distribution of the punch more even and avoids rapid wear caused by local dense punching.

[0066] The gradient design reduces the instantaneous impact force during punching, thus lowering the probability of punch fatigue fracture.

[0067] Effect: Increases the lifespan of the punch by 15%-20%.

[0068] 3) Polygonal mesh shapes (hexagonal / rhomboid)

[0069] Location: Mesh design.

[0070] effect:

[0071] Polygonal mesh (such as hexagonal) has corner angles greater than 90° (such as 120°), which reduces the wear of the punch at the sharp corners compared to traditional square mesh.

[0072] The long axis of the diamond-shaped mesh can be arranged along the stamping direction to reduce stamping resistance.

[0073] Effects: Punch life is increased by 10%-15%, and punching yield is improved.

[0074] 4) Gradual width design of stiffeners

[0075] Location: The width of the vertical ribs gradually decreases from top to bottom (1.0mm on the far side → 0.7mm on the far side).

[0076] effect:

[0077] Wider ribs (such as on the tab side) provide higher structural strength and allow punches to use larger fillet radii (such as R0.2mm→R0.3mm), reducing stress concentration.

[0078] Gradual width prevents the punch from wearing out continuously at a single size, thus dispersing the wear area.

[0079] Effect: The lifespan of the punch is extended by more than 10%.

[0080] 5) Non-uniform mesh layout

[0081] Location: The mesh area in the central region is larger than that in the edge region.

[0082] effect:

[0083] The large mesh size (70mm²) in the center area reduces the number of punching operations, while the small mesh size (40mm²) in the edge area ensures strength, balances the punch load, and avoids localized high-frequency wear caused by uniform punching across the entire board.

[0084] Effect: Overall mold life is increased by 15%-25%.

[0085] 6) Adaptability to continuous stamping process:

[0086] This invention significantly reduces the instantaneous impact force and localized wear of the punch by using designs such as curved chamfers, gradual spacing, and polygonal mesh. Tests show that, under the same production conditions, the punch life is increased from 500,000 cycles in the traditional design to over 700,000 cycles, while the punching yield is increased from 92% to 97%. Attached Figure Description

[0087] Figure 1 This is a schematic diagram of the overall structure of the plate grid of this utility model;

[0088] Figure 2 yes Figure 1 Side view;

[0089] Figure 3 This is an enlarged view of part A of the grid of this utility model;

[0090] Figure 4 This is an enlarged view of part B of the plate grid of this utility model. Detailed Implementation

[0091] Figure 1 , 2In the design, the main body of the grid (referred to as the grid) 9 is a mesh structure with a thickness of D. The top, left, right, and bottom borders form the frame 5. Multiple vertical ribs 4 within the frame form a radial pattern from the top to the bottom border. The width of the vertical ribs 4 gradually decreases from top to bottom. The spacing L between adjacent vertical and horizontal ribs adopts a gradient layout, with smaller spacing L near the tabs and larger spacing L further away from the tabs. The mesh 7 of the mesh structure is rhomboid in shape. The top border includes a transition section 3 and a stable section 1 connected to the right end of the transition section. The height of the transition section 3 gradually decreases from left to right to M, and the height of the stable section is equal to M. The base of the tab 2 is connected to the left end of the outer side of the transition section via a chamfered structure. Chamfers are provided at the connections between the left and bottom borders, the right and bottom borders, and the top and right borders to reduce burrs and flash. The vertical and horizontal ribs within frame 5 have octagonal cross-sections. Their functions are: firstly, the punch is less prone to wear during punching and less prone to stretching after rolling; secondly, the metallographic structure of the grid is dense and more corrosion resistant.

[0092] Figure 3 In the middle section, the inner surface of the left end of the bottom border is connected to the inner surface of the bottom end of the left border by a rounded corner R6, and the outer surface of the left end of the bottom border is connected to the bottom end of the left border by rounded corners R3 and R1. The width of the bottom border L4 is less than the width of the left border L3.

[0093] Figure 4 In the middle, the inner right side of the top frame is connected to the inner top side of the right frame by a rounded corner R6, and the outer right side of the top frame is connected to the top surface of the right frame by rounded corners R3 and R1. The width of the top frame L6 is less than the width of the left frame L5.

[0094] The features of this utility model are as follows:

[0095] 1. Gradient ribs + radial composite layout

[0096] The design achieves dual optimization through a gradient width of vertical ribs (0.7mm on the tab side → 1.0mm on the edge side) and a radial arrangement:

[0097] 2. Improved mechanical strength: The widened side ribs of the electrode lugs resist vibration, and the radial layout disperses stress, with a vibration deformation rate of <0.3%;

[0098] 3. Balanced current distribution: Shortening the current path from the tab to the edge reduces ohmic internal resistance by 20% and increases cycle life by 167%.

[0099] 4. Non-uniform mesh topology optimization

[0100] A differentiated design is adopted, featuring a large mesh size (70mm²) in the central area and a small mesh size (40mm²) in the edge area, to simultaneously address:

[0101] Lead paste adhesion: The dense mesh at the edges enhances the encapsulation of active materials, and the cycle capacity retention rate is ≥80%;

[0102] 5. Lightweight: The central open mesh reduces weight by 15%, and the lead consumption is reduced without sacrificing strength (structural reinforcement is achieved through hexagonal mesh).

[0103] 6. Innovation in adaptability of continuous stamping process

[0104] The synergistic design of curved chamfers (R0.5-1mm), gradient spacing (5-12mm), and polygonal mesh (120° inner angle) increases punch life by 40% and yields a 97% yield, breaking through the bottleneck of traditional grid mass production.

[0105] Taking the parking air conditioner battery of a commercial vehicle as an example:

[0106] Grid dimensions (grid width * grid height * total height): 141.5mm * 118mm * 137mm, thickness 0.9mm;

[0107] Horizontal rib width: 0.75mm (0.8mm in pinch roller area), spacing 6mm on the ear side and 10mm on the edge side;

[0108] Vertical rib width: 0.7mm on the far side and 1.0mm on the side furthest away;

[0109] Mesh area: 70mm² in the center area and 40mm² in the edge area.

[0110] Tests have verified that the positive electrode grid designed using this invention can achieve more than 800 charge-discharge cycles under standard test conditions (25℃ ambient temperature, 100% discharge depth cycling) (compared to 300 cycles for traditional similar products), with a cycle capacity retention rate of ≥80%. Furthermore, under the highest V4 vibration resistance level test according to European standard EN50342-2015, the grid structure remains intact without breakage, and the rib deformation rate is <0.3%. Even when vehicles are driven for extended periods in harsh road conditions, it ensures stable power supply to the parking air conditioning battery, solving the failure problems of traditional grids caused by vibration, such as breakage and deformation.

Claims

1. A positive electrode grid for a commercial vehicle parking air conditioning battery, characterized in that: The main body of the plate grid (9) is a mesh structure composed of multiple horizontal ribs (6) and multiple vertical ribs (4). The horizontal ribs on the uppermost side are the upper frame, the vertical ribs on the leftmost side are the left frame, the vertical ribs on the rightmost side are the right frame, and the horizontal ribs on the bottommost side are the lower frame. The upper frame includes a transition section (3) and a stable section (1) connected to the right end of the transition section. The height of the transition section (3) gradually decreases from left to right to M, and the height of the stable section is equal to M. The root of the pole lug (2) is connected to the left end of the outer side of the transition section through a chamfered structure. The upper frame, left frame, right frame, and lower frame form a frame (5). The multiple vertical ribs (4) inside the frame form a radial pattern from the upper frame to the lower frame. The width of the vertical ribs (4) inside the frame gradually decreases from top to bottom. The spacing L between two adjacent vertical ribs and two adjacent horizontal ribs adopts a gradient layout. The spacing L is small near the pole lug and large away from the pole lug.

2. The positive electrode grid of a commercial vehicle parking air conditioning battery according to claim 1, characterized in that: The chamfered structure includes an arc-shaped transition on the right and a chamfered edge transition on the left.

3. The positive electrode grid of a commercial vehicle parking air conditioning battery according to claim 1, characterized in that: The spacing L near the electrode tab is 5-8mm, and the spacing L away from the electrode tab is 8-12mm.

4. The positive electrode grid of a commercial vehicle parking air conditioning battery according to claim 1, characterized in that: The mesh structure has polygonal mesh shapes.

5. The positive electrode grid of a commercial vehicle parking air conditioning battery according to claim 1, characterized in that: The mesh (7) of the mesh structure is hexagonal or rhomboid in shape.

6. The positive electrode grid of a commercial vehicle parking air conditioning battery according to claim 1, characterized in that: The mesh (7) of the mesh structure adopts a non-uniform mesh layout.

7. The positive electrode grid of a commercial vehicle parking air conditioning battery according to claim 1, characterized in that: The mesh area in the central region of the mesh structure is larger than the mesh area in the edge region.

8. The positive electrode grid of a commercial vehicle parking air conditioning battery according to claim 1, characterized in that: Chamfers are added at the joints between the left and bottom borders, the right and bottom borders, and the top and right borders.

9. The positive electrode grid of a commercial vehicle parking air conditioning battery according to claim 1, characterized in that: The cross-sections of the vertical and horizontal ribs within the frame (5) are octagonal.

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