A charging device for a forklift truck power battery pack

Abstract

The application relates to the technical field of battery charging equipment, and discloses a forklift power battery pack charging device which comprises a battery placing platform, a liftable fence protection module and a thermal runaway early warning module; the battery placing platform is electrically connected with an external charging pile and is used for charging the battery pack; the liftable fence protection module is arranged on the outer side of the battery placing platform and is used for isolating the battery placing platform from the external environment; the thermal runaway early warning module comprises a surface flaw detection unit which is used for detecting the surface microcracks of the battery pack. Through the arrangement of the thermal runaway early warning module, the surface cracks, swelling deformation and electrolyte volatilization concentration of the battery pack can be acquired in real time, and the risk value of the battery pack can be calculated based on the data, so that corresponding protection actions are triggered according to the risk value, the effective monitoring and protection of the charging process of the battery pack are realized, the occurrence of safety accidents such as short-circuit fire, thermal runaway and overcharge damage is effectively avoided, and the safety of the charging process is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery charging equipment, more particularly, it relates to a forklift power battery pack charging device. BACKGROUND

[0002] The current electric forklift is rapidly popularized in the fields of logistics and warehousing, manufacturing and the like, and the power battery thereof generally adopts a high-energy-density lithium iron phosphate battery pack. The industry generally adopts a "replacement type centralized charging" mode, and in a three-shift production scenario, 4-6 battery packs need to be replaced per day, and the single charging time is about 3.5-4.5 hours. However, common safety accidents in the charging process include short-circuit fire, over-heat runaway (battery surface temperature reaches 60-80℃), and over-charging damage. The existing protection scheme mainly relies on metal shell physical isolation, fuse over-current protection, and basic parameter monitoring, which is essentially a passive response type protection.

[0003] However, the traditional protection scheme adopts a passive mode such as metal shell physical isolation and fuse over-current protection, and lacks early monitoring capability for the progressive degradation of the battery interior (such as micro-crack expansion, micro-volatilization of electrolyte, and local swelling deformation); in addition, the traditional protection scheme generally starts the isolation means only after the appearance of open fire or thick smoke, and cannot prevent the triggering process of the thermal runaway chain reaction, and the single-stage over-charging protection based on a fixed threshold value is difficult to match the battery aging characteristics, ultimately resulting in frequent occurrence of accidents such as short-circuit fire, thermal runaway, and over-charging damage during charging.

[0004] Therefore, there is an urgent need for a forklift power battery pack charging device with a multi-stage protection system having early warning, dynamic regulation and active isolation. SUMMARY

[0005] The present application aims to provide a forklift power battery pack charging device to solve the above technical problems.

[0006] The present application solves the above existing technical problems by the following technical solutions:

[0007] The present application provides a forklift power battery pack charging device, comprising:

[0008] A battery placement platform is electrically connected to an external charging pile, used for carrying the battery pack and implementing charging;

[0009] A fence protection module is arranged on the outside of the battery placement platform in a liftable manner, used for forming a physical isolation barrier;

[0010] A thermal runaway early warning module comprises:

[0011] A surface flaw detection unit is used for detecting micro-cracks on the surface of the battery pack;

[0012] an inflation deformation detection unit for obtaining battery pack surface inflation data;

[0013] a volatile matter detection unit for detecting electrolyte volatile concentration;

[0014] a control module connected with the thermal runaway early warning module and the fence protection module, and configured to:

[0015] real-time receive crack area, deformation rate, and vapor concentration data;

[0016] calculate battery pack risk value based on the data through a preset algorithm;

[0017] when the risk value reaches a first threshold, reduce the charging current and increase the scanning frequency;

[0018] when the risk value reaches a second threshold, cut off the charging current and trigger an alarm;

[0019] when the risk value reaches a third threshold, cut off the charging, trigger an alarm, and control the fence protection module to rise to an isolation height.

[0020] Preferably, the surface detection unit adopts an ultrasonic probe, performs periodic full scanning when the risk value is below a safety threshold, and performs high-frequency local scanning on the crack area when the risk value exceeds the safety threshold.

[0021] Preferably, the inflation deformation detection unit adopts a laser displacement sensor, and marks an abnormal state when detecting that the deformation rate exceeds a preset abnormal inflation threshold.

[0022] Preferably, the volatile matter detection unit includes a negative pressure suction device and an electrolyte vapor sensor, increases the sampling frequency when the battery temperature exceeds a preset temperature, and has a function of automatically compensating the detection value according to the environmental humidity.

[0023] Preferably, the fence protection module includes a retractable fence assembly, a lifting drive assembly for driving the fence assembly to retract, a temperature sensor, and a smoke sensor, the temperature sensor and the smoke sensor are respectively used for detecting temperature and smoke data around the battery pack.

[0024] Preferably, the fence assembly is composed of four fence plates arranged in a rectangular layout, each fence plate includes a fixed part at the upper end and a retractable part at the lower end.

[0025] The lifting drive assembly includes a driving frame, two electric push rods and two telescopic rods arranged at the four corners of the fence plate, the driving frame is connected with the top ends of the electric push rods and the telescopic rods, the four fence plates are respectively arranged between the electric push rods and the telescopic rods in sliding mode, and the top of each fence plate is connected with the bottom of the driving frame.

[0026] Preferably, the fence plate has a composite layered structure, comprising: an outer layer of ceramic matrix composite, a middle layer of elastic stainless steel support layer, and an inner layer of ceramic fiber cloth and expanded graphite foil.

[0027] Preferably, the fence protection module further comprises a pressure sensor arranged on the battery placement platform, for detecting the pressure value on the battery placement platform.

[0028] The beneficial effects of the present application are:

[0029] The present application can obtain data such as surface cracks, swelling deformation and electrolyte evaporation concentration of the battery pack in real time by setting the thermal runaway early warning module, and calculate the risk value of the battery pack based on these data, so as to trigger corresponding protection actions according to the risk value, thereby realizing effective monitoring and protection of the battery pack charging process, effectively avoiding the occurrence of safety accidents such as short circuit fire, thermal runaway and overcharge damage, and improving the safety of the charging process.

[0030] At the same time, by setting the fence protection module, physical isolation can be quickly formed when the battery pack has an accidental thermal runaway, effectively preventing the spread of fire, and further improving the safety performance of the charging device. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a structural schematic diagram of a forklift power battery pack charging device provided by the present application;

[0032] Figure 2 is a structural schematic diagram of a forklift power battery pack charging device provided by the present application;

[0033] Figure 3 is a structural schematic diagram of a forklift power battery pack charging device provided by the present application;

[0034] Figure 4 is a structural schematic diagram of a forklift power battery pack charging device provided by the present application;

[0035] Figure 5 is a flowchart of the response of the control end of a forklift power battery pack charging device provided by the present application.

[0036] In the figure: 10, battery placement platform; 20, fence protection module; 201, fence plate; 202, electric push rod; 203, telescopic rod; 204, driving frame; 30, thermal runaway early warning module; 301, ultrasonic probe; 302, laser displacement sensor; 303, electrolyte vapor sensor; 40, charging pile. DETAILED DESCRIPTION

[0037] The subject matter described herein will now be discussed with reference to example implementations. It should be understood that the discussion of these implementations is merely meant to provide a better understanding of the subject matter described herein and that changes to the functions and arrangements of elements discussed can be made without departing from the scope of the content of this specification. Various examples can omit, substitute, or add various procedures or components as desired. Additionally, features described with respect to some examples can be combined in other examples.

[0038] Reference will be made to the drawings throughout the following description. Figures 1 to 5 A forklift power battery pack charging device, comprising: a battery placement platform 10, a thermal runaway early warning module 30, a liftable fence protection module 20, and a control module. Wherein the battery placement platform 10 is electrically connected with an external charging pile 40, mainly as a battery pack placement position, used for charging the battery pack, the top surface of the battery placement platform 10 is provided with a positioning groove matched with the battery pack.

[0039] The thermal runaway early warning module 30 evaluates the risk value of the current battery pack by obtaining the relevant data of the battery pack, and specifies the appropriate charging mode. It includes: a surface flaw detection unit, an expansion deformation detection unit, and a volatile matter detection unit. Wherein the surface flaw detection unit is used for detecting the microcracks on the surface of the battery pack, the surface flaw detection unit can be set as a 5MHz ultrasonic probe 301, and the scanning logic is: in normal mode, scan once every 5 minutes; and when the risk value is greater than the safety threshold, focus on the crack expansion area, and scan locally 3 times per second. The expansion deformation detection unit is used for obtaining the expansion data of the battery pack surface; the expansion deformation detection unit is a laser displacement sensor 302, which drives the laser displacement sensor 302 to move around the battery pack through the linear displacement member, so as to measure the concave-convex change of the battery pack surface, and the deformation rate calculation formula is: ; wherein, when V d >0.03mm / s is marked as abnormal expansion.

[0040] The volatile matter detection unit is used for detecting the volatile concentration of the electrolyte; including a negative pressure suction device and an electrolyte vapor sensor 303 connected with the negative pressure suction device, and the working logic is: in normal mode, sample once every 30 seconds; and when the temperature >45℃, start the negative pressure suction device, and the sampling frequency is increased to 2 times per second; in addition, the electrolyte vapor sensor 303 can automatically compensate the detection value according to the environmental humidity (compensation coefficient Kh=1-0.005H, H is the humidity percentage), realizing the concentration calibration function and ensuring the detection accuracy.

[0041] The control module is signal connected with the thermal runaway early warning module 30, and is configured to perform:

[0042] a. Real-time receive the crack area Ac , fusion deformation rate V d , vapor concentration C v data information;

[0043] b. According to the received data information, and according to the formula The risk value R of the current battery pack is calculated;

[0044] The design basis of the coefficient in the above risk value calculation formula is:

[0045] The exponential term amplifies the influence of the expansion rate (V d Every 0.01mm / s, R value increases by 12%)

[0046] The square root term weakens the interference of small cracks (A c When <2mm², the contribution rate is <10%)

[0047] c. Trigger the protection action (such as Figure 5 indicated) in stages:

[0048] When R (risk value) <60 (safety threshold R1), output normal charging current to the battery pack;

[0049] When 60 (safety threshold R1) <R (risk value) <80 (low risk threshold R2), reduce the charging current to 70% of the rated value, and start high-frequency scanning;

[0050] When 80 (low risk threshold R2) <R (risk value) <90 (high risk threshold R3), cut off the charging current and trigger the sound and light alarm;

[0051] Among them, the sound and light alarm can be an 85dB buzzer and a flashing indicator light, and a remote alarm function can also be added, which is pushed to the management platform through the 4G module.

[0052] When R (risk value) >90 (high risk threshold R3), cut off the charging, trigger the sound and light alarm, and control the battery placement platform to lift the battery pack to a preset height.

[0053] It should be noted that the selection basis of the parameters in the above risk value calculation formula is shown in the following table:

[0054]

[0055] The comparison and verification of the calculation model of the application and the traditional model are shown in the following table:

[0056]

[0057] The working process of the above scheme is as follows:

[0058] When charging the forklift power battery pack, first place the battery pack on the battery placement platform 10, and the battery placement platform 10 is electrically connected with the external charging pile 40, to ensure the smooth progress of the charging process. The thermal runaway early warning module 30 is started immediately, and the surface flaw detection unit, the swelling deformation detection unit and the volatile matter detection unit included in the thermal runaway early warning module 30 start to work, for monitoring the microcracks on the surface of the battery pack, the swelling data on the surface of the battery pack and the volatile concentration of the electrolyte respectively. The surface flaw detection unit performs a full scan every five minutes in the normal mode, to comprehensively detect potential cracks on the surface of the battery pack. When the risk value exceeds the safety threshold value, the ultrasonic probe 301 focuses on the crack propagation area, and performs a local scan three times per second, to timely find and respond to the crack propagation situation. The swelling deformation detection unit is driven by the linear displacement member, and moves around the battery pack, to accurately measure the concave-convex changes on the surface of the battery pack. When the deformation rate exceeds a preset value, such as 0.03 mm / s, it is marked as abnormal swelling, to prompt possible safety hazards. The volatile matter detection unit cooperates with the negative pressure suction device and the electrolyte vapor sensor 303, to monitor the volatile concentration of the electrolyte in real time. In the normal mode, sampling is performed every thirty seconds. When the temperature exceeds 45℃, the sampling frequency is increased to twice per second, to ensure that the change of the volatile concentration of the electrolyte can be quickly captured when the battery temperature rises.

[0059] The control module receives these monitoring data in real time, and calculates the risk value of the current battery pack according to a preset risk value calculation formula. According to the size of the risk value, the control module triggers corresponding protection actions in stages. For example, when the risk value is below the safety threshold value, the battery pack is normally charged; when the risk value is between the safety threshold value and the low risk threshold value, the charging current is reduced to a preset rated value, and high-frequency scanning is started to strengthen monitoring; when the risk value further rises to between the low risk threshold value and the medium risk value, the charging current is cut off, and an audible and light alarm is triggered to alert the operator; when the risk value exceeds the high risk threshold value, the charging is immediately cut off, the audible and light alarm is triggered, and the fence protection module 20 is controlled to rise to a preset height, to form physical isolation and prevent fire spreading.

[0060] Based on the above scheme, the thermal runaway early warning module 30 arranged in the application can acquire data such as the surface cracks of the battery pack, the swelling deformation and the volatile concentration of the electrolyte in real time, and calculate the risk value of the battery pack based on these data, so that corresponding protection actions are triggered in stages according to the size of the risk value, to realize effective monitoring and protection of the charging process of the battery pack, effectively avoid the occurrence of safety accidents such as short circuit fire, overheating runaway and overcharge damage, and improve the safety of the charging process.

[0061] Please refer to Figure 2 and Figure 3In order to realize the further isolation protection function after the battery pack accidental thermal runaway, the present application designs the fence protection module 20 to carry out the protection in the physical level, specifically:

[0062] The fence protection module 20 includes a retractable fence assembly, a lifting drive assembly for driving the fence assembly to retract, a temperature sensor and a smoke sensor, the temperature sensor and the smoke sensor are used for detecting the temperature and smoke data around the battery pack respectively, and transmitting the data to the control module in real time.

[0063] Specifically, the fence assembly is composed of four fence plates 201 arranged in a rectangular layout, and the height of the fence plate 201 when retracted is pre-set to 300mm. The fence plate 201 includes a fixed part at the upper end and a retractable part at the lower end, and the bottom end of the retractable part is fixed with the battery placing platform 10. The fixed part of the fence plate 201 is also provided with a safety glass observation window, which facilitates the staff to observe the internal situation of the fence assembly. The fixed part and the retractable part of the fence plate 201 are composed of three layers of materials, the outer layer is ceramic matrix composite material, which can resist direct impact of flame and not melt at high temperature; the middle layer is stainless steel sheet, which can provide elastic support for the overall structure; the inner layer is ceramic fiber cloth and expanded graphite foil, which can expand and fill the gap at high temperature to realize airtight isolation. In addition, the retractable part is corrugated to adapt to the subsequent extension action.

[0064] The lifting drive assembly includes two electric push rods 202, two telescopic rods 203 and a driving frame 204, the two electric push rods 202 and the two telescopic rods 203 are arranged at intervals at the four corners of the fence assembly, the four corners of the driving frame 204 are connected with the top ends of the electric push rods 202 and the telescopic rods 203 respectively, and the four fence plates 201 are respectively arranged in sliding mode between the electric push rods 202 and the telescopic rods 203, and the top of each fence plate 201 is connected with the bottom of the driving frame 204.

[0065] It should be noted that when the obtained temperature and smoke concentration data exceed the threshold value, the protection mode is triggered, and the control module controls the lifting drive assembly to drive the fence assembly to rise by a pre-set height, and when the lifting drive assembly drives the fence assembly to rise, the electric push rod 202 is elongated, which can make the driving frame 204 move upward, and the four fence plates 201 move upward together with the driving frame, and under the sliding limiting action of the telescopic rod 203, the fence plate 201 always maintains a stable rectangular enclosure, which includes the battery placing platform 10, after rising to the pre-set height, the pre-set height is generally set to 1800mm, at this time the fence plate 201 is much higher than the battery pack, even if the battery pack catches fire quickly, it can effectively isolate the fire from the outside.

[0066] Further, the fence protection module 20 further comprises six groups of pressure sensors evenly arranged on the battery placing platform 10, for detecting the pressure value on the battery placing platform 10. When it is detected that the pressure value of the battery placing platform 10 exceeds a threshold value, it is determined that someone stands on the battery placing platform 10, at this time, the fence protection module 20 is in a locked state, and the fence assembly will not be automatically driven to rise, so as to avoid causing harm to the staff.

[0067] Based on the above scheme, it can be known that, by further arranging the fence protection module 20, physical isolation can be quickly formed when the battery pack is accidentally out of control, the fire spreading is effectively prevented, and the safety performance of the charging device is further improved.

[0068] The embodiments of the present application are described above, but the present application is not limited to the specific embodiments described above, and the specific embodiments described above are only illustrative but not restrictive, and many forms can be made by those skilled in the art under the inspiration of the present application, which all belong to the protection of the present application.

Claims

1. A charging device for a forklift power battery pack, characterized in that, include: The battery placement platform is electrically connected to an external charging station and is used to support the battery pack and implement charging. The fence protection module can be raised and lowered and installed on the outside of the battery placement platform to form a physical isolation barrier; Thermal runaway early warning module, including: The surface flaw detection unit is used to detect microcracks on the surface of the battery pack. The surface flaw detection unit uses an ultrasonic probe to perform periodic full scanning when the risk value is lower than the safety threshold, and to perform high-frequency local scanning on the crack area when the risk value exceeds the safety threshold. An expansion deformation detection unit is used to acquire battery pack surface expansion data. The expansion deformation detection unit uses a laser displacement sensor, and when the detected deformation rate exceeds a preset abnormal expansion threshold, it is marked as an abnormal state. A volatile matter detection unit is used to detect the concentration of electrolyte volatilization. The volatile matter detection unit includes a negative pressure suction device and an electrolyte vapor sensor. When the battery temperature exceeds the preset temperature, the sampling frequency is increased, and the detection value is automatically compensated according to the ambient humidity. The control module is connected to the thermal runaway early warning module and the fence protection module via signal transmission, and is configured as follows: Real-time reception of crack area, deformation rate, and steam concentration data; The risk value of the battery pack is calculated based on the data using a preset algorithm. When the risk value reaches the first threshold, reduce the charging current and increase the scanning frequency; When the risk value reaches the second threshold, the charging current is cut off and an alarm is triggered. When the risk value reaches the third threshold, charging is cut off, an alarm is triggered, and the fence protection module is raised to the isolation height.

2. The forklift power battery pack charging device according to claim 1, characterized in that, The fence protection module includes a retractable fence assembly, a lifting drive assembly for driving the fence assembly to extend and retract, a temperature sensor, and a smoke sensor. The temperature sensor and the smoke sensor are used to detect temperature and smoke data around the battery pack, respectively.

3. A forklift power battery pack charging device according to claim 2, characterized in that, The fence assembly consists of four fence panels arranged in a rectangular layout. Each fence panel includes a fixed part at the top and a telescopic part at the bottom. The lifting drive assembly includes a drive frame and two electric push rods and two telescopic rods spaced apart at the four corners of the fence panel. The drive frame is connected to the top of the electric push rods and the top of the telescopic rods respectively. The four fence panels are slidably disposed between the electric push rods and the telescopic rods respectively, and their tops are all connected to the bottom of the drive frame.

4. A forklift power battery pack charging device according to claim 3, characterized in that, The fence panel has a composite layered structure, including: an outer ceramic matrix composite material, a middle elastic stainless steel support layer, and an inner ceramic fiber cloth and expanded graphite foil.

5. A forklift power battery pack charging device according to claim 4, characterized in that, The fence protection module also includes a pressure sensor installed on the battery placement platform to detect the pressure value on the battery placement platform.

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