Double-sided film capacitor core hot pressing process and thermal pressure detection device

Abstract

The invention discloses a double-sided film capacitor core hot-pressing process and a hot pressure detection device. The hot-pressing process comprises the following steps: S1) winding a metallized film into capacitor cores through winding equipment, and orderly arranging the capacitor cores on an epoxy resin plate; s2) putting the core and the epoxy resin plate into an upper hot pressing plate and a lower hot pressing plate, and starting hot pressing according to the temperature, time and pressure corresponding to the thickness of the core body; s3) after the side surfaces of the core body are braided, metal spraying is carried out on non-braided-tape areas on the two end surfaces; or firstly braiding and then clamping, spraying metal on the braid-free areas on the two end surfaces, standing in a 110 DEG C oven for 10 hours, and dismounting the clamp. The hot-pressing temperature and the hot-pressing time are selected according to the thickness of the core body, so that the internal temperature and the surface temperature of the core body can be ensured to be consistent as much as possible, films are tightly attached, the core body cannot be pushed to be loose when the core body is fed into a braiding machine, the percent of pass reaches 99.8%, the stability of the capacity and the pressure resistance value is ensured, and the core body can pass a type experiment; the production time can be reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of capacitors, and in particular relates to a hot pressing process for a double-sided film capacitor core, and a hot pressing detection device. Background Art

[0002] In the field of metallized film capacitor technology, double-sided metallized film capacitors are widely used in various electronic devices due to their high voltage resistance, high dielectric constant, high insulation resistance, low dielectric loss factor, high temperature resistance and other characteristics. The stability of the capacitor's withstand voltage and capacity is closely related to the hot pressing process. The process is to flatten and shape the wound core through a hot pressing device to prepare for the subsequent process. The purpose of hot pressing is to use the film's heat shrinkage characteristics to squeeze out the air remaining between the dielectric layers during winding, and also evaporate the moisture attached to the core, improve the fit between the metal films, and prevent the core from being pushed and deformed during tape braiding (hot pressing is not tight), resulting in the deformation of the core and difficulty in shelling, and the capacitor capacity and withstand voltage values ​​are reduced.

[0003] At the same time, the patent with application number 202420255387.4 discloses a plastic film hot pressing device, including a frame, a support roller, a hot pressing plate, a mounting plate, a buffer spring and a driving cylinder, the support roller is rotatably connected to the frame, and the support roller is used to support the plastic film; the hot pressing plate is located above the support roller and is lifted and lowered on the frame, and the hot pressing plate is used to press the plastic film onto the support roller; the mounting plate is located directly above the hot pressing plate and moves up and down synchronously with the hot pressing plate, and the mounting plate is connected to the hot pressing plate through the buffer spring; the piston rod of the driving cylinder passes through the hot pressing plate and is connected to the mounting plate, and the driving cylinder is used to control the up and down movement of the hot pressing plate and the mounting plate.

[0004] However, in the implementation of relevant technologies, it was found that the traditional shaping process of the above-mentioned plastic film hot pressing device requires a hot pressing process and a heat shaping process to make the two metal films fit tightly together. However, this process causes the capacitor core to be heated for a long time during shaping, and the creepage distance of the shrinking end of the dielectric film is reduced, which increases the probability of the metal film falling over, reduces the contact effect with the gold spraying, and causes poor charging and discharging. At the same time, it also generates a large number of production hours and low production efficiency. Summary of the invention

[0005] In order to solve the problems raised in the above background technology, the present invention provides a double-sided film capacitor core process and a hot pressing detection device, which has the advantages of directly requiring fixed pressure and fixed temperature through the hot pressing process to make the two metal films fit tightly, thereby ensuring that the double-sided film capacitor core is not pushed and deformed during tape weaving, causing the core body to deform and difficult to be shelled, and the capacitor capacity and withstand voltage value to decrease. At the same time, it also has the advantages of reducing production hours and improving production efficiency.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a hot pressing process for a double-sided film capacitor core, characterized in that it includes the following steps: S1) winding a metallized film into a capacitor core through a winding device and then arranging it in order on an epoxy resin board; S2) placing the core and the epoxy resin board into upper and lower hot pressing plates, and starting the hot pressing equipment at the corresponding temperature, time and pressure according to the thickness of the core; S3) after the side of the core is taped, gold is sprayed on the non-taping areas of the two end surfaces; or first the tape is clamped, then gold is sprayed, and it is left to stand in a 110°C oven for 10 hours, and the clamp is removed.

[0007] The hot pressing device for the hot pressing process of the double-sided film capacitor core mentioned above is characterized in that it includes an upper hot pressing plate, a lower hot pressing plate and a core to be processed as the hot pressing body; an upper epoxy resin plate is bonded to the upper side of the core to be processed, and a lower epoxy resin plate is bonded to the lower side of the core to be processed; the upper hot pressing plate and the lower hot pressing plate are brought close to each other through a hydraulic pushing structure, and the core to be processed is pressed and processed under the action of temperature and pressure.

[0008] The above-mentioned double-sided film capacitor core hot pressing process detection device includes a thrust pointer meter and a lifting assembly, the bottom end of the thrust pointer meter is fixedly provided with a contact rod, the bottom end surface of the contact rod is fitted with a thrust rod, the bottom arc surface of the thrust rod is fitted with a hot-pressed core body, and the outer side of the core body is fitted with a tight box;

[0009] The lifting assembly comprises a sliding plate which moves up and down, and a connecting rod which is fixedly arranged with the thrust pointer gauge is fixedly arranged on the left side of the sliding plate.

[0010] Preferably, a thrust device main frame is provided through the right side of the interior of the sliding plate, and a base plate fixedly provided with the abutting box is fixedly provided at the bottom end of the thrust device main frame.

[0011] Preferably, an adjusting screw rod slidably arranged with the sliding plate runs through the top cross beam of the main frame of the thrust device, and the adjusting screw rod is rotatably arranged with the base plate.

[0012] Preferably, a vertical shaft fixed to the base plate is provided through the left side of the interior of the sliding plate, and a spring located between the crossbeam of the main frame of the thrust device and the sliding plate is sleeved on the outer side of the vertical shaft.

[0013] Preferably, a handle is fixedly provided at the top end of the adjusting screw rod, and a fixing frame fixedly provided with the base plate is fixedly provided at the end of the top crossbeam of the main frame of the thrust device.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The present invention selects the hot pressing temperature and hot pressing time according to the thickness of the core body, which can not only ensure that the internal temperature of the core body is as consistent as possible with its surface temperature, so that the films are closely fitted to each other, but also that the core body will not be pushed loose when it is placed on the taping machine. The qualified rate reaches 99.8%, ensuring the stability of the capacity and withstand voltage values, passing the type test, and reducing production hours and improving production efficiency.

[0016] 2. The present invention places the capacitor core body in a tight box after assembling the capacitor core body by hot pressing process of the double-sided film capacitor, and slides the sliding plate downward by rotating the screw rod along the pointer, and the sliding plate drives the thrust pointer to slide downward. During the sliding process, the contact rod at the bottom of the thrust pointer contacts the thrust rod, and the contact rod squeezes the push rod to squeeze the capacitor core body, and the value is read. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the detection component of the present invention;

[0018] Figure 2 It is a schematic diagram of the substrate structure of the present invention;

[0019] Figure 3 It is a schematic diagram of the arrangement of the capacitor core of the present invention in a detection state;

[0020] Figure 4 It is a schematic diagram of the pressure gauge connection structure of the detection assembly of the present invention.

[0021] Figure 5 It is a schematic diagram of the structure of the hot pressing assembly of the present invention.

[0022] In the figure: 1. base plate; 2. fixing frame; 3. thrust equipment main frame; 4. adjusting screw rod; 5. handle; 6. sliding plate; 7. vertical axis; 8. spring; 9. connecting rod; 10. thrust pointer; 11. contact rod; 12. thrust rod; 13. capacitor core body; 14. abutment box; 15. upper epoxy resin plate; 16. lower epoxy resin plate; 17. upper hot press plate; 18. lower hot press plate; 19. core to be processed; 20. scale. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] like Figures 1 to 5As shown, the present invention provides a double-sided film capacitor core hot pressing process, a hot pressing device, and a detection device. The hot pressing device and the detection device respectively include a hot pressing component and a detection component. The hot pressing component includes an upper hot pressing plate 17, a lower hot pressing plate 18 and a core 19 to be processed as a hot pressing body; the detection component includes a thrust pointer gauge 10, a contact rod 11 is fixedly provided at the bottom end of the thrust pointer gauge 10, a thrust rod 12 is fitted on the bottom end surface of the contact rod 11, a capacitor core body 13 is fitted on the bottom arc surface of the thrust rod 12, and a tight box 14 is fitted on the outer side of the capacitor core body 13; the rear side of the detection component also includes a lifting component; the lifting component includes a sliding plate 6 that moves up and down, and a connecting rod 9 fixed to the thrust pointer gauge 10 is fixed on the left side of the sliding plate 6.

[0025] Specifically, an upper epoxy resin plate 15 is bonded to the upper side of the core 19 to be processed, and a lower epoxy resin plate 16 is bonded to the lower side of the core 19 to be processed. The upper epoxy resin plate 15 and the lower epoxy resin plate 16 are bonded to the outer side of the core 19 to be processed after hot pressing.

[0026] Furthermore, the upper hot pressing plate 17 and the lower hot pressing plate 18 are brought closer to each other by a hydraulic pushing structure, and the air inside the core 19 to be processed can be discharged while they are closely fitted.

[0027] Furthermore, a thrust device main frame 3 is provided through the right side of the interior of the sliding plate 6 , and a base plate 1 fixedly provided with the abutting box 14 is fixedly provided at the bottom end of the thrust device main frame 3 .

[0028] It is worth noting that the top crossbeam of the thrust device main frame 3 is penetrated by an adjusting screw 4 slidably arranged with the sliding plate 6. When the adjusting screw 4 rotates, it drives the sliding plate 6 to slide up and down, and the adjusting screw 4 is rotatably arranged with the base plate 1.

[0029] It is worth noting that a vertical shaft 7 fixed to the base plate 1 is provided through the left side of the interior of the sliding plate 6, and a spring 8 located between the crossbeam of the thrust equipment main frame 3 and the sliding plate 6 is sleeved on the outer side of the vertical shaft 7. When the sliding plate 6 is squeezed downward, the spring 8 is squeezed, and when the sliding plate 6 slides upward, the reaction force of the spring 8 pushes the sliding plate 6 to slide upward. A scale 6 is provided through the left side of the sliding plate 6, and several groups of scale lines are provided on the outer side of the scale 20. When the adjusting screw 4 is adjusted downward, the sliding distance of the sliding plate 6 can be known by observing the overlapping scale lines between the arc sliding plate 6 and the measuring ruler 20.

[0030] It is worth mentioning that a handle 5 is welded and fixed to the top of the adjusting screw rod 4, and a fixing frame 2 fixed to the base plate 1 is fixed at the end of the top crossbeam of the thrust device main frame 3, and the fixing frame 2 is used to support the thrust device main frame 3.

[0031] Among them, the thrust pointer meter 10 is a prior art and will not be described in detail. At the same time, the present invention also includes a power supply, a controller, and a switch, which are not the main technical points of this patent and will not be described in detail. The "front, back, left, and right" perspectives of this device are as follows: Figure 1 The direction shown in the figure is used as the reference.

[0032] The present invention also discloses a double-sided film heat setting process based on the above-mentioned heat pressing device, and the specific steps are:

[0033] S1) winding the metallized film into a capacitor core by a winding device and then arranging the capacitor core in an orderly manner on an epoxy resin plate;

[0034] S2) placing the core and epoxy resin board into a hot pressing device, and starting the hot pressing device according to the temperature, time and pressure corresponding to Table 1 according to the thickness of the core;

[0035] S3) After the core body is taped on the side, gold is sprayed on the non-tape areas on both ends; or after the side is taped, gold is sprayed on the clamp, and it is left to stand in an oven at a specified temperature for the required time, and then the clamp is removed.

[0036] Table 1

[0037]

[0038]

[0039] Further, the process of step S2 is described in detail in combination with the structure of the hot pressing device as follows:

[0040] The staff's requirement for the core shape is that the flat capacitor uses a winding device to wind the metallized film into a capacitor core body 13, and then arranges the wound core 19 to be processed in order on the epoxy resin board 15 according to the size of the core body, selects the corresponding temperature, time, and pressure according to the thickness of the core body, and puts it into the hot pressing equipment.

[0041] For example: when the core thickness W (mm) is 2≤W≤9, the time and temperature are set to 115±5℃, 120S respectively, and the hot pressing-taping-gold spraying process is adopted for hot pressing;

[0042] For example: when the core thickness W (mm) is 9<W<20, the time and temperature are set to 115±5℃, 240S respectively, and the hot pressing-taping-gold spraying process is adopted for hot pressing;

[0043] Example: The core thickness W (m) is W ≥ 20, the time and temperature are set to 100 ± 5 ° C, 120S, and the hot pressing is carried out using the process route of hot pressing-taping-clamping-gold spraying;

[0044] Start the equipment and carry out hot pressing treatment;

[0045] After the hot pressing is completed, 10 hot pressed cores are drawn from each plan, and a special thrust gauge is used to detect the compression force of the extracted cores. At the same time, the same thrust gauge is used to detect the thrust size of the braiding machine. Then the capacitor core body 13 is placed on the top of the abutment box 14, and the handle 5 is turned. The handle 5 drives the adjusting screw 4 inside the main frame 3 of the thrust equipment to rotate. During the rotation process, the adjusting screw 4 drives the sliding plate 6 to slide downward. During the sliding process, the sliding plate 6 is welded and fixed to the sliding plate 6 through the connecting rod 9. The thrust pointer 10 on the other side drives the contact rod 11 at the bottom to slide downward, and the contact rod 11 squeezes the thrust rod 12 downward. Slide, the contact rod 11 at the bottom of the thrust pointer 10 contacts the thrust rod 12, the contact rod 11 squeezes the thrust rod 12 to squeeze the capacitor core body 13, the capacitor core body 13 presses downward against the box 14, and reads the value according to the moved position. The core is pressed tightly by hot pressing and put on the taping machine without pushing it loose. The hot pressing temperature is ≥120℃. If it exceeds 120℃, the end surface of the core will fall over, so 120℃ is the best choice; W>20mm, currently hot pressing alone cannot press it tightly, so hot pressing + clamping is used according to the original process. The test results can show that there is no obvious difference in the core completed by hot pressing, and it can pass the type test to ensure the stability of capacity and withstand voltage.

[0046] Processability verification:

[0047] According to the process parameters of the hot pressing process, the influencing factors such as hot pressing temperature, time, and pressure were selected, and verified one by one according to the influencing factors. A double-sided film product was selected to wind the double-sided film capacitor core according to the number of full plates; the wound double-sided film capacitor core was hot-pressed in batches according to the above influencing factors of hot pressing temperature / hot pressing time / hot pressing pressure and the corresponding numbers were recorded:

[0048] Table 2 Experiments with different hot pressing temperature / time / pressure

[0049]

[0050] The hot pressed cores were sampled from each scheme, and the compression force of the extracted cores was tested using a special thrust gauge. At the same time, the same thrust gauge was used to test the thrust of the taping machine. The verification data is shown in Table 3.

[0051] Table 3 Compressive force at different hot pressing temperatures

[0052]

[0053]

[0054] Table 4 Compressive force at different hot pressing times

[0055]

[0056] Table 5 Compressive force of different hot pressing pressures

[0057]

[0058]

[0059] After analyzing and comparing the data of the verification results of the core hot pressing pressure at different hot pressing temperatures / times / pressures, the following conclusions can be drawn:

[0060] 1. Press the core tightly by hot pressing and put it on the braiding machine without loosening it. The hot pressing temperature is ≥120℃. If it exceeds 120℃, the end surface of the core will fall over, so 120℃ is the best choice; W>20mm, hot pressing alone is not enough, so hot pressing + clamping is used according to the original process;

[0061] 2. According to the different core thickness, the hot pressing time needs to be adjusted: 2≤W≤9mm, time = 120S; 9<W<20mm, time = 240S; W≥20mm, time = 480S;

[0062] 3. Whether the hot pressing pressure is 8MPa or 10MPa, it cannot be pressed tightly. Too high pressure will damage the core, so hot pressing is carried out according to the original pressure of 8MPa.

[0063] Take 5 hot pressed cores from each scheme and do endurance and charge-discharge tests according to the corresponding voltage; see Table 6 for experimental data (120℃ / 240S / 8MPa)

[0064] Table 6:

[0065]

[0066]

[0067] Table 7 Experimental data (hot pressing 110℃ / 240S / 8MPa-upper clamp)

[0068]

[0069]

[0070] According to the above data, it can be concluded that the hot pressing process of the double-sided film capacitor core provided by the invention has no significant difference compared with the existing process route, and can pass type tests to ensure the stability of capacity and withstand voltage values.

[0071] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0072] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hot pressing process for double-sided film capacitor core, characterized in that The following steps are involved: S1) winding the metallized film into a capacitor core by a winding device and then arranging the capacitor core in an orderly manner on an epoxy resin plate; S2) Place the core and epoxy resin plate into the upper and lower hot pressing plates, and start hot pressing according to the temperature, time and pressure corresponding to the core thickness; S3) After taping the side of the core, spray gold on the two end surfaces without taping; or first tape and clamp, spray gold on the two end surfaces without taping and let it stand in a 110℃ oven for 10 hours, and then remove the clamp.

2. The hot pressing device for hot pressing of double-sided film capacitor core according to claim 1, characterized in that: The invention comprises an upper hot pressing plate (17) as a hot pressing body, a lower hot pressing plate (18) and a core to be processed (19); an upper epoxy resin plate (15) is bonded to the upper side of the core to be processed (19), and a lower epoxy resin plate (16) is bonded to the lower side of the core to be processed (19); a hydraulic pushing structure is provided between the upper hot pressing plate (17) and the lower hot pressing plate (18), so that the core to be processed (19) is pressed and processed.

3. A detection device for hot pressing process of double-sided film capacitor core according to claim 1, comprising a thrust pointer gauge (10) and a lifting assembly, wherein a contact rod (11) is fixedly arranged at the bottom end of the thrust pointer gauge (10), a thrust rod (12) is fitted on the bottom end surface of the contact rod (11), a core body (13) which has been hot pressed is fitted on the bottom arc surface of the thrust rod (12), and a tight box (14) is fitted on the outer side of the core body (13); The lifting assembly comprises a sliding plate (6) that moves up and down, and a connecting rod (9) that is fixedly arranged on the left side of the sliding plate (6) and is fixedly arranged with the thrust pointer gauge (10).

4. The detection device for hot pressing process of double-sided film capacitor core according to claim 3 is characterized in that: A thrust device main frame (3) is provided through the right side of the interior of the sliding plate (6), and a base plate (1) fixedly provided with the abutment box (14) is fixedly provided at the bottom end of the thrust device main frame (3).

5. The detection device for hot pressing process of double-sided film capacitor core according to claim 4 is characterized in that: An adjusting screw rod (4) slidably arranged with the sliding plate (6) passes through the top crossbeam of the thrust device main frame (3), and the adjusting screw rod (4) is rotatably arranged with the base plate (1).

6. The detection device for hot pressing process of double-sided film capacitor core according to claim 5, characterized in that: A vertical shaft (7) fixed to the base plate (1) is provided through the left side of the interior of the sliding plate (6), and a spring (8) located between the crossbeam of the thrust equipment main frame (3) and the sliding plate (6) is sleeved on the outer side of the vertical shaft (7).

7. The detection device for hot pressing process of double-sided film capacitor core according to claim 6, characterized in that: A handle (5) is fixedly provided at the top end of the adjusting screw rod (4), and a fixing frame (2) fixedly provided with the base plate (1) is fixedly provided at the end of the top crossbeam of the thrust device main frame (3).

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