Die-casting die processing method for producing negative plate and battery cover pressing plate by using semi-solid metal slurry

Abstract

The invention discloses a die-casting die machining method for producing a negative plate and a battery cover pressing plate through semi-solid metal slurry, a die is included, the die comprises an upper die body and a lower die body, the lower die body comprises at least two forming die bodies, the two forming die bodies are used for forming the negative plate and the battery cover pressing plate respectively, and a through channel is provided with a heat pipe structure. A condensation section of the heat pipe structure extends into the through channel of the lower die, a heat dissipation end of the heat pipe structure extends out of the lower die and is matched with a water cooling device, and the water cooling structure comprises a liquid cooling device wrapping the heat dissipation end; the two forming dies are provided with branch runners which are symmetrically arranged, each branch runner is of a groove structure, the two branch runners are connected with the same main runner, and the lower die is provided with an ejector pin; the upper mold is provided with a pressing mold, the pressing mold partially extends into the forming mold, and the upper mold is provided with a high-pressure injection channel; a plurality of concave filling grooves are formed in the peripheral wall of the forming die at intervals, and exhaust grooves communicated with the filling grooves are formed in the upper wall of the forming die in a concave mode.

Description

Technical Field

[0001] The present invention relates to the field of lithium battery processing, and particularly to a die-casting mold processing method for producing negative plates and battery cover pressing plates with semi-solid metal slurries. Background Art

[0002] In a battery structure, the negative plate (anode) and the battery cover pressing plate each play an important role.

[0003] The negative plate, also known as the anode, is a key component inside the battery. Its main functions include:

[0004] 1. The place where electrochemical reactions occur: The negative plate is one of the main sites of electrochemical reactions in the battery. During the discharge process, the materials on the negative plate will undergo chemical changes, releasing electrons and thus generating an electric current.

[0005] 2. Storage and release of electrical energy: The chemical properties of the negative plate enable it to convert chemical energy into electrical energy during discharge and vice versa. This process is crucial for the energy conversion efficiency of the battery.

[0006] 3. Ion conduction: During the charging and discharging process of the battery, the ions in the electrolyte need to move through the negative plate to balance the charge. The structure and materials of the negative plate affect the efficiency of ion conduction.

[0007] Although the battery cover pressing plate is not a core electrochemical reaction component of the battery, it plays an important role in the structural stability and safety of the battery. Specific functions include:

[0008] 1. Fixing the plates: The battery cover pressing plate is used to fix the plates inside the battery, ensuring their stability during battery operation and preventing displacement or damage of the plates caused by vibration or impact.

[0009] 2. Sealing and protection: The battery cover pressing plate is usually used together with the battery cover to seal the inside of the battery, preventing external air and moisture from entering the battery, thereby protecting the chemical components inside the battery from contamination.

[0010] 3. Heat dissipation management: During high-power operation, the battery generates a large amount of heat. The design of the battery cover pressing plate sometimes takes into account the heat dissipation requirements to help the battery dissipate heat better, ensuring that the battery operates within a safe temperature range and avoiding safety problems caused by overheating.

[0011] Among them, the pressing plate is generally arranged above the plate to achieve the functions of conduction and protection.

[0012] Existing battery pressure cover plates and negative plates are generally produced using two sets of molds. However, in actual use, due to material differences and temperature differences, there will be slight differences in the resistance between the two, which in turn affects the passage of current.

[0013] Therefore, the existing method generally uses a stamping forming method to form thin-walled negative plates and battery cover pressure plates. However, the existing design has the following problems:

[0014] 1. However, using a two-cavity structure, it is easy to have problems such as local wall decay.

[0015] 2. Due to the thin-wall problem of the product, there are often problems of insufficient local filling, which in turn affects the production qualification rate. Therefore, to solve the above problems, the injection pressure is generally increased.

[0016] 3. Because the wall thickness of the product is small, it is easy to have problems such as scratching during demolding, which in turn affects the surface of the product. At the same time, in actual design, the thickness of the product is small, but it should have a predetermined pressure-bearing capacity to ensure the stability of the lithium battery; at the same time, the decrease in temperature also affects the hot processing efficiency.

[0017] Among them, the defective products of the product are mainly composed of several factors. ① The fluid temperature of the semi-solid metal slurry, but this production factor is relatively easy to control; ② The cooling temperature after die-casting. The existing method generally uses liquid cooling, so its temperature drops relatively slowly. At the same time, affected by the stroke length, the stroke temperature is different, affecting the cooling effect, so it is easy to have problems such as local internal shrinkage.

[0018] 4. The products produced are of special-shaped structures. Therefore, using a stamping forming scheme, its process and stability are also low. Therefore, how to form two cavities in one mold simultaneously is the key to the design, which can ensure large-scale production; for this non-standard electrode plate and cover pressure plate, its shape is relatively complex. Therefore, the products formed by stamping are affected by stress. Without changing the material, its tolerance exceeds the predetermined value, and there is also a problem of non-unique wall thickness (that is, the wall thickness at some positions will become thinner under the action of stamping). Summary of the Invention

[0019] The main purpose of the present invention is to propose a die-casting mold processing method for producing negative plates and battery cover pressure plates with semi-solid metal slurry, aiming to achieve the production of two cavities in one mold, which can not only ensure the stable forming of the negative plates and battery cover pressure plates, but also facilitate demolding, and at the same time has good stability.

[0020] To achieve the above object, the present invention proposes a die-casting mold processing method for producing negative plates and battery cover pressure plates with semi-solid metal slurry, including:

[0021] A mold, the mold includes an upper mold and a lower mold.

[0022] The lower mold includes at least two forming molds, and the two forming molds are respectively used for forming a negative electrode plate and a battery cover pressing plate.

[0023] The lower mold is provided with at least one through channel, and the through channel is provided with a heat pipe structure. The condensation section of the heat pipe structure extends into the through channel of the lower mold, and the heat dissipation end of the heat pipe structure extends out of the lower mold and cooperates with a water cooling device. The water cooling structure includes a liquid cooling device that wraps the heat dissipation end.

[0024] The two forming molds are provided with symmetrically arranged branch flow channels. The branch flow channels are groove structures, and the two branch flow channels are connected to the same main flow channel. The lower mold is provided with ejector pins.

[0025] The upper mold is provided with a pressing mold, and a part of the pressing mold extends into the forming mold. The upper mold is provided with a high-pressure injection channel.

[0026] The outer peripheral wall of the forming mold is provided with a plurality of recessed filling grooves at intervals, and the upper wall of the forming mold is recessed with exhaust grooves communicating with the filling grooves.

[0027] The lower mold is provided with slidably arranged ejector pins, and the ejector pins are distributed in the filling grooves and the main flow channel.

[0028] The specific processing method includes:

[0029] S1: Select an aluminum alloy material with a yield strength of 200 mpa, a tensile strength of 370 mpa, and a hardness of 90 HB.

[0030] S2: Place the magnesium-aluminum alloy material in a furnace for melting to make it in a molten state, and the temperature of the furnace is controlled between 520°C and 650°C.

[0031] S3: Inject the molten aluminum alloy fluid into the main flow channel through the high-pressure injection channel of the upper mold with a first-stage pressure. The aluminum alloy fluid flows into the two branch flow channels, the forming mold, and the filling grooves in sequence.

[0032] S4: When the volume of the injected aluminum alloy fluid is equal to the sum of the volumes of the main flow channel, the branch flow channels, the forming mold, and the filling grooves,

[0033] The high-pressure injection channel injects a second-stage fluid with a volume of 1%-2% of the sum of the volumes with a second-stage pressure, and the second-stage pressure is more than twice the first-stage pressure.

[0034] The characteristics of the processing method of the mold are as follows: the main runner, branch runners, forming die and filling grooves are designed. When injecting into the main runner with the first-stage pressure, the pressure is constant, which can make the fluid evenly distributed, enable the aluminum alloy fluid to be evenly injected into the die casting cavity, and fully discharge the internal air through the exhaust grooves, avoiding problems such as bubble holes. At the same time, the injection of the aluminum alloy fluid with the second-stage pressure can further extrude the preliminary solution, further avoiding problems of bubbles and insufficient filling. Moreover, through the injection with the second-stage pressure, the quality of the product is effectively improved, and its yield strength, tensile strength and hardness are increased by 0.5%-1.5% compared with the material body; while ensuring the product quality, the structural strength is improved;

[0035] S5: The preliminary product in the die casting cavity is formed. At this time, the heat pipe structure and the lower die are at the same temperature and gradually decrease,

[0036] The mold stands still for 5-15S, the liquid cooling device is turned on, and the temperature of the heat pipe structure gradually decreases in the first cooling section at a temperature of 40°C / 5S;

[0037] When the temperature of the heat pipe structure drops below 250°C, the liquid cooling device gradually decreases in the second cooling section at 20°C / 5S.

[0038] The advantage of using the heat pipe structure is that it can switch from 40°C to 20°C 60%-80% faster than the existing liquid cooling devices. Through the predetermined interval (a temperature difference of about 20°C), the yield strength and tensile strength of the structure can be improved.

[0039] Through the double-stage cooling in step S5, the temperature can be effectively reduced. Its advantages are as follows: when the liquid cooling device is not turned on, the temperature of the heat pipe structure is consistent with that of the lower die, avoiding the temperature difference generated when injecting fluid in the existing cold mold, thereby reducing the time interval between two die casting formations, and then improving the processing efficiency;

[0040] At the same time, compared with the existing direct liquid cooling drive method, its heat dissipation efficiency is higher, and the heat dissipation efficiency of the heat pipe structure can be increased by more than 2 times;

[0041] At the same time, adopting the double-stage cooling method can optimize the microstructure and properties of the material, release the thermal stress and phase change stress in the formed cover plate at the same time, improve the structural stability, reduce the stress peak value, prevent deformation, and strengthen the strength of the cover pressing plate and the negative plate.

[0042] The first-stage pressure can be 30MPA, and the second-stage pressure can be 60MPA. Through the small feed amount of the second-stage pressure, the structural strength is improved, and through the two-stage cooling, the problem of internal stress is reduced. At the same time, the stress is mainly generated at the waste positions of the main runner and the filling groove, Description of the Drawings

[0043] Figure 1 is an exploded view of the upper mold and the lower mold;

[0044] Figure 2 is a plan view when the upper mold and the lower mold are separated;

[0045] Figure 3 is a three-dimensional schematic diagram of the lower mold;

[0046] Figure 4 is a sectional view of the mold at the position of the heat pipe structure;

[0047] Figure 5 is a schematic diagram of the heat pipe at the heat dissipation end;

[0048] Figure 6 is a schematic diagram of one of the ejector pins;

[0049] Figure 7 is a cross-section of the present invention Figure 1 ;

[0050] Figure 8 is a cross-section of the present invention Figure 2 ;

[0051] Figure 9 is a schematic diagram of a half-section view of the present invention with the upper mold and the lower mold hidden;

[0052] Figure 10 is a partially enlarged schematic diagram of the exhaust groove;

[0053] Figure 11 is a schematic diagram of the cooperation between the negative plate and the battery cover pressing plate.

[0054] In the figure,

[0055] 11 is the upper mold, 12 is the lower mold,

[0056] 21 is the forming mold, 22 is the pressing mold, 201 is the filling groove, 202 is the exhaust groove,

[0057] 3 is the through-channel, 31 is the heat pipe structure, 31a is the condensation section, 32b is the heat dissipation end, 32c is the liquid cooling device, 33d is the heat dissipation copper pipe,

[0058] 4 is the high-pressure injection channel, 41 is the main runner, 42 is the branch runner,

[0059] 5 is the ejector pin, 51 is the inclined surface, 52 is the guide hole, 53 is the cutting surface, 54 is the cutting edge, 55 is the non-circular block,

[0060] 61 is the bottom plate, 62 is the movable plate, 63 is the drag chain,

[0061] 7 is the scale,

[0062] 81 is the negative electrode plate, 82 is the battery cover pressing plate, and 83 is the filler. Specific embodiments

[0063] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0064] It should be noted that if there are directional indications (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial...) involved in the embodiments of the present invention, then the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0065] In addition, if there is a description involving "first" or "second" in the embodiments of the present invention, then the description of "first" or "second" is only for descriptive purposes and cannot be understood as indicating or implying its relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0066] As Figures 1 to 11 shown, a die-casting mold processing method for producing a negative electrode plate 81 and a battery cover pressing plate from semi-solid metal slurry includes:

[0067] A mold, the mold includes an upper mold 11 and a lower mold 12,

[0068] The lower mold 12 includes at least two forming molds 21, and the two forming molds 21 are respectively used for forming the negative electrode plate and the battery cover pressing plate.

[0069] The lower die 12 is provided with at least one through-channel 3 (since the product is mainly formed on the lower die, there is a reserved through-channel on the upper die, which is not actually used, realizing the structure of a single-sided cold die). The through-channel 3 is provided with a heat pipe structure 31 (this structure is a prior art, and there is currently no specific structural method for this structure and the die). The condensation section 31a of the heat pipe structure extends into the through-channel 3 of the lower die 12, and the heat dissipation end 32b of the heat pipe structure extends out of the lower die 12 and cooperates with a water cooling device. The water cooling structure includes a liquid cooling device 32c that wraps the heat dissipation end 32b;

[0070] The two forming dies 21 are provided with symmetrically arranged branch flow channels 42. The branch flow channels 42 are groove structures, and the two branch flow channels 42 are connected to the same main flow channel 41 (that is, the branch flow channels 42 generally include a product end and an injection end, and the injection end is connected to the high-pressure injection channel 4). The lower die 12 is provided with ejector pins 5;

[0071] The upper die 11 is provided with a pressing die 22. The pressing die 22 partially extends into the forming die 21. The upper die 11 is provided with a high-pressure injection channel 4 (generally, a temperature control device is also provided, such as a hot runner structure);

[0072] The outer peripheral wall of the forming die 21 is provided with a plurality of recessed filling grooves 201 at intervals, and the upper wall of the forming die 21 is recessed with exhaust grooves 202 communicating with the filling grooves 201;

[0073] The lower die 12 is provided with ejector pins 5 that are slidably arranged. The ejector pins 5 are distributed in the filling grooves 201 and the main flow channel 41;

[0074] The specific processing method includes:

[0075] S1: Select an aluminum alloy material with a yield strength of 200 mpa, a tensile strength of 370 mpa, and a hardness of 90 HB;

[0076] S2: Place the magnesium-aluminum alloy material in a furnace for melting to make it in a molten state, and the temperature of the furnace is controlled between 520 °C and 650 °C;

[0077] S3: Inject the molten aluminum alloy fluid into the main flow channel 41 through the high-pressure injection channel 4 of the upper die 11 by the first-stage pressure. The aluminum alloy fluid flows into the two branch flow channels 42, the forming die 21, and the filling grooves 201 in sequence;

[0078] S4: When the volume of the injected aluminum alloy fluid is equal to the sum of the volumes of the main flow channel 41, the branch flow channels 42, the forming die 21, and the filling grooves 201,

[0079] The high-pressure injection channel 4 injects a second-stage fluid with a volume of 1% - 2% of the sum of the volumes at the second-stage pressure, and the second-stage pressure is more than twice the first-stage pressure;

[0080] The characteristics of the processing method of this mold lie in the design of the main runner 41, branch runners 42, forming die 21, and filling grooves 201. When injecting into the main runner 41 at the first-stage pressure, the pressure is constant, which can make the fluid evenly distributed, enabling the aluminum alloy fluid to be evenly injected into the die-casting cavity. And through the exhaust groove 202, the internal air can be fully discharged, avoiding problems such as bubble holes. At the same time, by injecting the aluminum alloy fluid at the second-stage pressure, the preliminary solution can be further extruded, further avoiding problems of bubbles and insufficient filling. Moreover, through the injection at the second-stage pressure, the quality of the product is effectively improved. Its yield strength and tensile strength are increased by 0.5% - 1.5% compared with the material body. While ensuring the product quality, the structural strength is improved.

[0081] S5: The preliminary product in the die-casting cavity is formed. At this time, the heat pipe structure and the lower die 12 are at the same temperature and gradually decrease.

[0082] The mold stands still for 5 - 15S, the liquid cooling device 32c is turned on, and the temperature of the heat pipe structure gradually decreases in the first cooling section at a rate of 40°C / 5S.

[0083] When the temperature of the heat pipe structure drops below 250°C, the liquid cooling device 32c gradually decreases in the second cooling section at a rate of 20°C / 5S.

[0084] Through the two-stage cooling in step S5, the temperature can be effectively reduced. Its advantages are that when the liquid cooling device 32c is not turned on, the temperature of the heat pipe structure is the same as that of the lower die 12, avoiding the temperature difference generated when injecting fluid in the existing cold mold. Furthermore, the time interval between two die-casting formations can be reduced, thereby improving the processing efficiency.

[0085] At the same time, compared with the existing direct water-cooling drive method, its heat dissipation efficiency is higher, and the heat dissipation efficiency of the heat pipe structure can be increased by more than 2 times.

[0086] At the same time, adopting the two-stage cooling method can optimize the microstructure and properties of the material, release the thermal stress and phase change stress in the formed cover plate, improve the structural stability, reduce the stress peak value, prevent deformation, and strengthen the strength of the cover pressing plate and the negative plate.

[0087] The first-stage pressure can be 30MPA, and the second-stage pressure can be 60MPA. Through the small injection volume at the second-stage pressure, the structural strength is improved, and through the two-stage cooling, the problem of internal stress is reduced. At the same time, the stress is mainly generated at the waste positions of the main runner 41 and the filling groove 201, improving the product qualification rate.

[0088] Specifically, the lower mold 12 includes a bottom plate 61 and a forming mold 21 provided on the bottom plate. A movable plate 62 is provided below the bottom plate. The movable plate 62 is connected to the lower end of the ejector pin 5, and the movable plate 62 is connected to a driving device.

[0089] Specifically, the driving device is a telescopic motor or a drag chain 63 or a drag plate.

[0090] Specifically, when using a drag chain 63 or a drag plate, the upper end of the drag chain 63 or the drag plate is connected to the side wall of the upper mold 11, and a strip-shaped groove is provided at the lower end. The movable plate 62 is provided with a limit post that cooperates with the strip-shaped groove. When the upper mold 11 rises, it drives the limit post to rise, thereby realizing the rise of the movable plate 62, and then driving the ejector pin 5 to rise, so that the filling block rises under the action of the lifting drive, and then drives the product to rise, realizing the linkage of the mold and reducing the setting of the driving structure.

[0091] Specifically, the end of the filling groove 201 close to the forming mold 21 is an inclined surface 51. The setting of the inclined surface 51 can make the connection end between the product and the filler smaller, thereby facilitating the separation or cutting of the two.

[0092] Specifically, a guide hole 52 is provided at the position of the inclined surface 51. The guide hole 52 is provided with the ejector pin. The ejector pin is provided with a cutting surface 53 that fits the inclined surface 51, and a cutting edge 54 is provided at the inner end of the cutting surface 53;

[0093] When the mold is opened, the movable plate 62 rises. The cutting edge 54 generates pressure during the rising process, and separates or generates cutting marks on the connection end between the product and the filler through the cutting edge 54; the hardness of the cutting edge 54 is greater than the hardness of the casting;

[0094] The cutting edge 54 extends upward from the ejector pin or is provided at the top end of the ejector pin. The setting of the cutting edge 54 is adjusted according to the gap size between the product and the filling block.

[0095] The later cutting process is reduced. At the same time, during the mold opening process, the retention of the remaining temperature (for example, the mold opening temperature is 50 degrees - 100 degrees) can reduce the burrs or twist marks generated after cutting. When the hardness is relatively large, cutting marks can be selected, which is more convenient for later processing.

[0096] Specifically, the heat pipe structure is extruded and formed in the through-channel 3 or the heat pipe structure is formed in the through-channel 3 by secondary sintering. Different from the existing water-cooling channels, water-cooling requires the inlet and outlet to be respectively provided at both ends of the lower mold 12, which can effectively simplify the mold design and facilitate the removal of the product.

[0097] Specifically, a heat dissipation copper tube 33d is wound around the outer peripheral wall of the heat dissipation end 32b. The heat dissipation copper tube 33d has a hollow structure, and a water cooling channel is provided in the hollow structure. Both ends of the water cooling channel are connected to the liquid cooling device 32c. The arrangement of the heat dissipation copper tube 33d can improve the heat dissipation efficiency. At the same time, it reduces the temperature wear and improves the controllability of the heat dissipation temperature.

[0098] Specifically, the cutting edge 54 is adapted to the outer peripheral wall of the product. The guiding hole 52 is non-circular in shape, and a non-circular block 55 that matches the guiding hole 52 is provided at the rear end of the ejector pin. This ensures the sliding consistency of the ejector pin. At the same time, the cutting edge is adapted to the outer peripheral wall of the product, which facilitates the cutting of the connection end.

[0099] Specifically, the exhaust groove 202 is arranged in a long strip shape, and a scale 7 is provided on the exhaust groove 202. In the actual processing of this type of product, how to adjust the temperature, pressure, and filling amount has always been the key to the design. Especially after adopting the double-stage injection method, the debugging is more difficult. Therefore, by setting the scale 7 on the exhaust groove 202, the parameters can be continuously adjusted during the trial mold, so as to meet the processing of thin-walled products and avoid problems such as bubbles and stress.

[0100] This design is an excellent die-casting cold mold production model and has strong applicability to thin-walled products.

[0101] In the actual production embodiment, with the injection volume being v, when the parameters of the first-stage pressure, the second-stage pressure, the first cooling stage, and the second cooling stage remain unchanged, these parameters can be adjusted according to different products. The penetration point can be tested through the product and visually observed through the exhaust groove 202, which facilitates debugging and testing.

[0102] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A die-casting mold processing method for producing negative electrode plates and battery cover pressing plates using semi-solid metal slurry, characterized in that: include: A mold, comprising an upper mold and a lower mold, The lower mold includes at least two molding dies, and the two molding dies are used to mold the negative electrode plate and the battery cover pressing plate respectively. The lower mold is provided with at least one through channel, the through channel is provided with a heat pipe structure, the condensing section of the heat pipe structure extends into the through channel of the lower mold, the heat dissipation end of the heat pipe structure extends out of the lower mold and cooperates with a water cooling device, and the water cooling structure includes a liquid cooling device covering the heat dissipation end; The two molding dies are provided with symmetrically arranged branch flow channels, the branch flow channels are groove structures, the two branch flow channels are connected to the same main flow channel, and the lower die is provided with an ejector pin; The upper mold is provided with a pressing mold, the pressing mold portion extends into the forming mold, and the upper mold is provided with a high-pressure injection channel; The outer peripheral wall of the molding die is provided with a plurality of recessed filling grooves at intervals, and the upper wall of the molding die is provided with a recessed exhaust groove connected to the filling grooves. The lower mold is provided with ejector pins which are arranged in a sliding manner, and the ejector pins are distributed in the filling groove and the main channel; Specific processing methods include: S1: Aluminum alloy material is selected, with a yield strength of 200 MPa, a tensile strength of 370 MPa, and a hardness of 90 HB; S2: placing the magnesium-aluminum alloy material in a furnace for melting to make it molten, and the temperature of the furnace is controlled between 520°C and 650°C; S3: The molten aluminum alloy fluid is injected into the main channel through the high-pressure injection channel of the upper mold through the first stage of pressure, and the aluminum alloy fluid flows into the two branch flow channels, the forming mold, and the filling groove in sequence; S4: When the volume of the injected aluminum alloy fluid is equal to the sum of the volumes of the main channel, branch channel, forming die and filling groove, The high-pressure injection channel injects 1%-2% of the second-stage fluid by volume at a second-stage pressure, and the second-stage pressure is more than twice the first-stage pressure; S5: The initial product is formed in the die casting cavity. At this time, the heat pipe structure and the lower mold are at the same temperature and gradually decrease. The mold is stationary for 5-15 seconds, the liquid cooling device is turned on, and the temperature of the heat pipe structure is gradually reduced at 40°C / 5S in the first cooling section; When the temperature of the heat pipe structure drops below 250°C, the liquid cooling device gradually decreases the second cooling stage at 20°C / 5S.

2. The die-casting mold processing method for producing negative electrode plates and battery cover pressing plates using semi-solid metal slurry as claimed in claim 1, characterized in that: The lower mold comprises a bottom plate and a forming mold arranged on the bottom plate. A movable plate is arranged below the bottom plate. The movable plate is connected to the lower end of the ejector pin and is connected to a driving device.

3. The die-casting mold processing method for producing negative electrode plates and battery cover pressing plates using semi-solid metal slurry as claimed in claim 2, characterized in that: The driving device is a telescopic motor or a drag chain or a drag plate.

4. The die-casting mold processing method for producing negative electrode plates and battery cover pressing plates using semi-solid metal slurry as claimed in claim 3, characterized in that: When a drag chain or a pallet is used, the upper end of the drag chain or the pallet is connected to the side wall of the upper mold, and the lower end is provided with a strip groove, and the movable plate is provided with a limiting column matched with the strip groove.

5. The die-casting mold processing method for producing negative electrode plates and battery cover pressing plates using semi-solid metal slurry as claimed in claim 4, characterized in that: The end of the filling groove close to the forming die is an inclined surface.

6. The die-casting mold processing method for producing negative electrode plates and battery cover pressing plates using semi-solid metal slurry as claimed in claim 5, characterized in that: A guide hole is provided at the position of the inclined surface, the guide hole is provided with the ejector pin, the ejector pin and the inclined surface are matched to form a cutting surface, and the inner end of the cutting surface is provided with a cutting blade; When the mold is opened, the movable plate rises, and the cutting blade generates pressure during the rising process, and separates the connecting ends between the product and the filler or generates cutting marks through the cutting blade; the hardness of the cutting blade is greater than the hardness of the casting; The cutting blade extends upward from the ejector pin or is arranged at the top end of the ejector pin, and the arrangement of the cutting blade is adjusted by the size of the gap between the product and the filling block.

7. The die-casting mold processing method for producing negative electrode plates and battery cover pressing plates using semi-solid metal slurry as claimed in claim 1, characterized in that: The heat pipe structure is extruded and formed in the through-channel or the heat pipe structure is formed in the through-channel by secondary sintering.

8. The die-casting mold processing method for producing negative electrode plates and battery cover pressing plates using semi-solid metal slurry as claimed in claim 7, characterized in that: A heat dissipation copper tube is wound around the outer peripheral wall of the heat dissipation end. The heat dissipation copper tube is a hollow structure. The hollow structure is provided with a water cooling channel. Both ends of the water cooling channel are connected to a liquid cooling device.

9. The die-casting mold processing method for producing negative electrode plates and battery cover pressing plates using semi-solid metal slurry as claimed in claim 6, characterized in that: The cutting blade is adapted to the outer peripheral wall of the product, the guide hole is non-circular in shape, and a non-circular clamping block matching the guide hole is provided at the rear end of the ejector pin.

10. The die-casting mold processing method for producing negative electrode plates and battery cover pressing plates using semi-solid metal slurry as claimed in claim 1, characterized in that: The exhaust groove is arranged in a long strip shape and is provided with a scale.

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