Solid electrolytic capacitor tantalum block forming mold and forming method thereof

Abstract

The application discloses a solid electrolytic capacitor tantalum block forming die and a forming method thereof, and belongs to the technical field of solid electrolytic capacitor manufacturing. The die comprises a die base, a die body, a limiting stopper, a left pressing die, a right pressing die, a front pressing die and an upper pressing die. The die body is arranged on the base. A positioning groove A is formed in one side of the die body, and a positioning groove B is formed in the lower part of the positioning groove A. The limiting stopper is arranged in the positioning groove B. The left pressing die and the right pressing die are symmetrically arranged and are both in sliding connection with the positioning groove A and the limiting stopper. The front pressing die is in sliding connection with the die body and is arranged on one side of the die body which is provided with the positioning groove A. The upper pressing die is arranged directly above the limiting stopper. The die body, the front pressing die, the limiting stopper and the base are all provided with blanking channels in correspondence. The anode core adopts a lower discharging mode, which can not only reduce equipment investment or labor cost, but also improve the production efficiency of the anode core.

Description

Technical Field

[0001] This invention relates to a tantalum block forming mold for solid electrolytic capacitors and its forming method, belonging to the field of solid electrolytic capacitor manufacturing technology. Background Technology

[0002] In the manufacturing process of solid electrolytic capacitors, tantalum powder needs to be pressed into an anode tantalum core with a certain mechanical strength using a molding die. With the increasing demands on complete equipment, the electrical performance parameters of the products are becoming more stringent. If the surface of the molded anode tantalum core has scratches or damaged pores, it will negatively impact the consistency of the electrical performance parameters and the reliability of the manufactured solid electrolytic capacitors.

[0003] Chinese patent document CN204035554U discloses a forming mold for a vertical processing equipment for tantalum blocks. In use, a tantalum wire is inserted through a through-hole in the upper mold, and the lower mold extends into the mold cavity. A powder-dispensing mechanism fills the mold cavity with tantalum powder. The upper and lower molds, under the action of a servo motor, press the tantalum powder into regular cuboids or cylinders. During the pressing process, the tantalum wire is inserted into the tantalum block, and the pressed tantalum block is ejected from the mold cavity by the lower mold. This forming mold provides high pressing pressure and uniform density of the tantalum block during pressing. The vertical pressing process eliminates the V-shaped cracks around the tantalum wire formed during horizontal pressing, which is highly beneficial for improving product quality and ensuring product reliability. Furthermore, the mold cavity opening mechanism can control the moving slider to adjust the size of the mold cavity. When the tantalum block is ejected from the mold cavity by the lower mold, the moving slider moves backward, thus enlarging the mold cavity and preventing the tantalum block surface from contacting and rubbing against the mold cavity surface, which would otherwise cause a shiny appearance.

[0004] However, when the lower mold ejects the tantalum block from the mold cavity, it is necessary to manually or with equipment remove the tantalum block from the lower mold. This not only increases labor costs or equipment investment, but also adds extra steps and prolongs the lower mold reset time, resulting in reduced tantalum block production efficiency. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a solid electrolytic capacitor tantalum block forming mold and its forming method.

[0006] This invention is achieved through the following technical solution:

[0007] A tantalum block forming mold for solid electrolytic capacitors includes a mold base, a mold body, a limiting block, a left pressing mold, a right pressing mold, a front pressing mold, and an upper pressing mold. The mold body is mounted on the base. A positioning groove A is formed on one side of the mold body, and a positioning groove B is formed at the lower part of the positioning groove A. The limiting block is located in the positioning groove B. The left pressing mold and the right pressing mold are symmetrically arranged and are slidably connected to the positioning groove A and the limiting block, respectively. The front pressing mold is slidably connected to the mold body and is located on the side of the mold body where the positioning groove A is located. The upper pressing mold is located directly above the limiting block. The mold body, the front pressing mold, the limiting block, and the base are provided with corresponding material feeding channels.

[0008] Four sliding rods are arranged side by side on the side of the mold body near the front mold. The four sliding rods pass through the front mold and are slidably connected to it. Two of the four sliding rods pass through the limiting block.

[0009] The mold body has a vertically formed blanking groove A on the bottom surface of the positioning groove A, and the front die has a vertically formed blanking groove B at a position corresponding to the blanking groove A.

[0010] A tantalum block collection box is provided on the lower side of the base.

[0011] The bottom surface of the positioning groove A is the first side surface. When the front mold is in the closed state, the distance between it and the first side surface is l1, and when the front mold is in the open state, the distance between it and the first side surface is l2, and l1 < l2 ≤ 1.2l1.

[0012] The first side, the limiting block, the left pressure mold, the right pressure mold, the front pressure mold, and the upper pressure mold form a mold cavity for pressing tantalum blocks when the mold is closed.

[0013] The mold cavity is in the shape of a cuboid or other polyhedron.

[0014] The limiting block is provided with a material discharge groove C, and the width of the positioning groove B extending from the limiting block is d1, and l1<d1≤3l1.

[0015] The width of the mold body is d2, and 5l1 < d2.

[0016] The upper die is provided with a vertical through hole A.

[0017] A method for forming a tantalum block mold for a solid electrolytic capacitor includes the following steps:

[0018] Step 1: The left mold, right mold, and front mold close from the standby position, forming a mold cavity with an upper opening together with the mold body and the limiting block;

[0019] Step 2: Fill the mold cavity with tantalum powder;

[0020] Step 3: Pass one end of the tantalum wire through the through hole A on the upper die and insert it into the tantalum powder in the die cavity. Then, move the upper die down and press it onto the die body and the front die to close the die cavity.

[0021] Step 4: The left and right die move a certain distance toward each other, squeezing the tantalum powder inward to form the anode core;

[0022] Step 5: Cut the tantalum wire, and return the upper die and the front die to the standby position;

[0023] Step Six: The left and right die pushes the anode core into the discharge channel;

[0024] Step 7: Repeat steps 1 to 6 to complete the tantalum block forming process one by one.

[0025] The beneficial effects of this invention are as follows: When the left, right, front, and upper molds are closed, they cooperate with the mold body and limiting blocks to press tantalum powder into an anode core. Then, the upper and front molds retract to the standby position to release the anode core. This significantly reduces the friction between the anode core and the forming mold during the process of the left and right molds pushing the anode core into the discharge channel. This solves the problems of surface scratches and pore damage on the anode core of solid electrolytic capacitors, which is beneficial for extracting the capacitance of the anode core and improves the consistency of electrical parameters and reliability of the prepared solid electrolytic capacitor. After the left and right molds push the anode core into the discharge channel, the anode core undergoes free fall under its own weight, realizing automatic anode core unloading. Using this unloading method, no additional equipment or manual labor is required for anode core unloading except for the forming mold, which can reduce equipment investment or labor costs and improve the production efficiency of anode cores. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure during the pressing of an anode core according to the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of the mold body of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of the limiting block of the present invention;

[0030] Figure 5 This is a schematic diagram of the structure of the left compression mold of the present invention;

[0031] Figure 6 This is a schematic diagram of the right pressure mold of the present invention.

[0032] In the diagram: 1-base, 2-mold body, 20-positioning groove A, 21-positioning groove B, 22-feeding groove A, 3-limiting block, 30-feeding groove C, 4-left pressure mold, 5-right pressure mold, 6-front pressure mold, 60-feeding groove B, 7-upper pressure mold, 70-through hole A, 8-tantalum wire, 9-first side, 10-anode core, 11-feeding channel, 12-sliding rod. Detailed Implementation

[0033] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0034] like Figures 1 to 6As shown, the solid electrolytic capacitor tantalum block forming mold of the present invention includes a mold base 1, a mold body 2, a limiting block 3, a left pressing mold 4, a right pressing mold 5, a front pressing mold 6, and an upper pressing mold 7. The mold body 2 is mounted on the base 1. A positioning groove A20 is opened on one side of the mold body 2, and a positioning groove B21 is opened at the lower part of the positioning groove A20. The limiting block 3 is installed in the positioning groove B21. The left pressing mold 4 and the right pressing mold 5 are symmetrically arranged and are slidably connected to the positioning groove A20 and the limiting block 3. The front pressing mold 6 is slidably connected to the mold body 2 and is located on the side of the mold body 2 where the positioning groove A20 is machined. The upper pressing mold 7 is located directly above the limiting block 3. The mold body 2, the front pressing mold 6, the limiting block 3, and the base 1 are respectively machined with material discharge channels 11. In use, both the left die 4 and the right die 5 are located within the U-shaped groove formed by the top surface of the limiting block 3, the bottom surface of the positioning groove A20, and the side surface of the positioning groove A20, and are slidably connected to this U-shaped groove. The sides of the left die 4 and the right die 5 that are away from the mold body 2 are coplanar with the sides of the limiting block 3 that are away from the mold body 2. When the front die 6 is closed, it fits against the left die 4, the right die 5, and the limiting block 3. The positioning groove B21 positions the limiting block 3, and the positioning groove A20, in conjunction with the limiting block 3, positions the left die 4 and the right die 5, ensuring the relative positional accuracy between the limiting block 3 and the left die 4 and the right die 5. When the left die 4, right die 5, front die 6, and upper die 7 are closed, they cooperate with the die body 2 and the limiting block 3 to press the tantalum powder into an anode core 10 (i.e., a tantalum block). Then, the upper die 7 and front die 6 retract to the standby position to release the anode core 10. This significantly reduces the friction between the anode core 10 and the forming die during the process of pushing the anode core 10 into the material discharge channel 11 by the left die 4 and right die 5. This solves the problem of surface scratches and pore damage to the anode core 10 of the solid electrolytic capacitor, which is beneficial for the extraction of the capacitance of the anode core 10 and improves the consistency of the electrical parameters and the reliability of the solid electrolytic capacitor. When the left die 4 and the right die 5 push the anode core 10 into the discharge channel 11, the anode core 10 will fall freely under its own weight, thus realizing the automatic discharge of the anode core 10. With this discharge method, apart from the forming mold, there is no need to add additional equipment or manpower to discharge the anode core 10, which can reduce equipment investment or labor costs and improve the production efficiency of the anode core 10.

[0035] Four sliding rods 12 are installed side by side on one side of the mold body 2 near the front mold 6. The four sliding rods 12 pass through the front mold 6 and are slidably connected to it. Two of the four sliding rods 12 pass through the limiting block 3. The slidable connection between the front mold 6 and the four sliding rods 12 can improve the movement stability of the front mold 6.

[0036] The mold body 2 has a vertically formed blanking groove A22 on the bottom surface of the positioning groove A20, and the front mold 6 has a vertically formed blanking groove B60 at a position corresponding to the blanking groove A22.

[0037] A tantalum block collection box is placed on the lower side of the base 1. During use, the length and width dimensions of the material feeding channel 11 are larger than those of the anode core 10. The upper section of the material feeding channel 11 is formed by the material feeding grooves B60 and A22 in the mold-open state, the middle section is the material feeding groove C30, and the lower section is the material feeding port opened on the mold base 1. The manufactured anode cores 10 are collected uniformly through the tantalum block collection box.

[0038] The bottom surface of the positioning groove A20 is the first side surface 9. The distance between the front die 6 and the first side surface 9 is l1 when the die is closed, and l2 when the die is open, where l1 < l2 ≤ 1.2l1. By increasing the distance between the front die 6 and the die body 2 when the die is open, the surface friction force generated during the process of the left die 4 and right die 5 pushing the anode core 10 into the discharge channel 11 is reduced. This solves the problem of surface scratches and pore damage to the anode core 10 of the solid electrolytic capacitor, which is beneficial for the extraction of capacitance from the anode core 10 and improves the consistency of electrical parameters and reliability of the prepared solid electrolytic capacitor. By limiting the distance l2 between the front mold 6 and the first side 9 in the mold-opening state to between l1 and 1.2l1, the anode core 10 can be released after it is formed, which can significantly reduce the friction between the anode core 10 and the forming mold when it moves. At the same time, the travel of the front mold 6 can be limited to a small range, which can prevent the front mold 6 from closing and opening for too long, thus helping to improve the efficiency of the forming mold in making the anode core 10.

[0039] The first side 9, the limiting block 3, the left pressing mold 4, the right pressing mold 5, the front pressing mold 6 and the upper pressing mold 7 form a mold cavity for pressing tantalum blocks when the mold is closed.

[0040] The mold cavity is in the shape of a cuboid or other polyhedron.

[0041] The limiting block 3 is machined with a material discharge groove C30, and the width of the limiting block 3 extending out of the positioning groove B21 is d1, where l1 < d1 ≤ 3l1. For example... Figure 1As shown, the width of the limiting block 3 refers to the dimension of the limiting block 3 in the length direction of the slide bar 12. The width d1 of the limiting block 3 is limited to between l1 and 3l1 to limit the amount of tantalum powder filling in the mold cavity in step two within the required range, so as to ensure that the dimensions and mechanical properties of the anode core 10 pressed by the molding die meet the requirements. If the width of the limiting block 3 is too small, the amount of tantalum powder in the mold cavity in step two will be too small. Although it can still ensure that the size of the anode core 10 pressed by the molding die meets the requirements, the tantalum powder that makes up the anode core 10 is too loose and its mechanical properties do not meet the requirements. If the width of the limiting block 3 is too large, the amount of tantalum powder in the mold cavity in step two will be too large. Although it can ensure that the mechanical properties of the anode core 10 pressed by the molding die meet the requirements, on the one hand, it is difficult to ensure that the size of the anode core 10 meets the requirements. On the other hand, if the size of the anode core 10 meets the requirements, the pressure of the left mold 4, right mold 5, front mold 6 and upper mold 7 on the tantalum powder will increase significantly, resulting in a decrease in the stability of the molding die.

[0042] The width of the mold body 2 is d2, and 5l1 < d2. The width of the mold body 2 refers to the dimension of the mold body 2 in the length direction of the slide bar 12. 5l1 < d2 ensures that the strength and rigidity of the mold body 2 meet the requirements.

[0043] The upper die 7 has a vertically machined through hole A70.

[0044] A method for forming a tantalum block mold for a solid electrolytic capacitor includes the following steps:

[0045] Step 1: The left mold 4, right mold 5 and front mold 6 close from the standby position to form a mold cavity with an upper opening, together with the mold body 2 and the limiting block 3.

[0046] Step 2: Fill the mold cavity with tantalum powder;

[0047] Step 3: Pass one end of the tantalum wire 8 through the through hole A70 on the upper die 7 and insert it into the tantalum powder in the mold cavity. Then, the upper die 7 moves down and presses against the mold body 2 and the front die 6 to close the mold cavity.

[0048] Step 4: The left die 4 and the right die 5 move a certain distance toward each other, squeezing the tantalum powder inward to form the anode core 10;

[0049] Step 5: Cut the tantalum wire 8, and return the upper die 7 and the front die 6 to the standby position;

[0050] Step 6: The left die 4 and the right die 5 push the anode core 10 into the discharge channel 11; or the right die 5 alone can be used to push the anode core 10 into the discharge channel 11.

[0051] Step 7: Repeat steps 1 to 6 to complete the tantalum block forming process one by one.

[0052] Specifically, the left die 4, right die 5, front die 6 and upper die 7 are moved by drive mechanisms, which are linear modules or electric cylinders, etc.

[0053] Compared with the prior art of the patent with publication number CN204035554U, entitled "A Forming Mold for Vertical Processing Equipment of Tantalum Blocks", this application has the following differences:

[0054] In existing technology, the mold cavity is actually formed by a portion of the hole wall on the intermediate mounting plate and the forming surface on the movable slider. When the upper and lower molds extrude tantalum powder, the tantalum block expands outward radially or laterally and fits tightly against the inner wall of the mold cavity. In this case, even if the cylinder drives the movable slider to move backward through the mold cavity opening mechanism to enlarge the mold cavity, the tantalum block will still fit tightly against a portion of the hole wall on the intermediate mounting plate, resulting in a relatively large frictional force between them. When the lower mold ejects the tantalum block from the mold cavity, the surface of the tantalum block is prone to scratches and pore damage, which will adversely affect the consistency of the electrical performance parameters and the reliability of the manufactured capacitor.

[0055] In contrast, this application uses a different method. After the molding die presses the tantalum powder into the anode core 10, the upper die 7 and the front die 6 retract to the standby position, so that the anode core 10 is in a relaxed state relative to the die body 2 and the limiting block 3. Therefore, during the process of the left die 4 and the right die 5 pushing the anode core 10 into the material discharge channel 11, the friction between the anode core 10 and the molding die can be significantly reduced, thereby solving the problem of surface scratches and pore damage of the anode core 10 of the solid electrolytic capacitor. This is beneficial to the extraction of the capacitance of the anode core 10 and improves the consistency of the electrical parameters and the reliability of the solid electrolytic capacitor.

Claims

1. A mold for forming tantalum blocks for solid electrolytic capacitors, characterized in that: The mold includes a mold base (1), a mold body (2), a limiting block (3), a left pressure mold (4), a right pressure mold (5), a front pressure mold (6), and an upper pressure mold (7). The mold body (2) is mounted on the base (1). A positioning groove A (20) is provided on one side of the mold body (2), and a positioning groove B (21) is provided at the lower part of the positioning groove A (20). The limiting block (3) is located in the positioning groove B (21). The left pressure mold (4) and the right pressure mold (5) are symmetrically arranged and are slidably connected to the positioning groove A (20) and the limiting block (3). The front pressure mold (6) is slidably connected to the mold body (2) and is located on the side of the mold body (2) where the positioning groove A (20) is provided. The upper pressure mold (7) is located directly above the limiting block (3). The mold body (2), the front pressure mold (6), the limiting block (3), and the base (1) are provided with corresponding material discharge channels (11). The bottom surface of the positioning groove A (20) is the first side surface (9); The first side (9), the limiting block (3), the left pressing mold (4), the right pressing mold (5), the front pressing mold (6) and the upper pressing mold (7) form a mold cavity for pressing tantalum blocks in the mold closed state. The upper pressing mold (7) and the front pressing mold (6) return to the standby position. The left pressing mold (4) and the right pressing mold (5) push the anode core (10) to the material discharge channel (11). The upper die (7) is vertically provided with a through hole A (70), and one end of the tantalum wire (8) is passed through the through hole A (70) on the upper die (7).

2. The tantalum block forming mold for solid electrolytic capacitors as described in claim 1, characterized in that: Four sliding rods (12) are arranged side by side on one side of the mold body (2) near the front mold (6). The four sliding rods (12) pass through the front mold (6) and are slidably connected to the front mold (6). Two of the four sliding rods (12) pass through the limiting block (3).

3. The tantalum block forming mold for solid electrolytic capacitors as described in claim 1, characterized in that: The mold body (2) has a vertically formed blanking groove A (22) on the bottom surface of the positioning groove A (20), and the front mold (6) has a vertically formed blanking groove B (60) at the position corresponding to the blanking groove A (22). A tantalum block collection box is provided on the lower side of the base (1).

4. The tantalum block forming mold for solid electrolytic capacitors as described in claim 1, characterized in that: The distance between the front mold (6) and the first side surface (9) when the mold is closed is: The distance between the front die (6) and the first side (9) when the die is in the open state is ,and .

5. The tantalum block forming mold for solid electrolytic capacitors as described in claim 1, characterized in that: The mold cavity is in the shape of a cuboid or other polyhedron.

6. The tantalum block forming mold for solid electrolytic capacitors as described in claim 1, characterized in that: The limiting block (3) is provided with a material discharge groove C (30), and the width of the positioning groove B (21) extending from the limiting block (3) is... ,and .

7. The tantalum block forming mold for solid electrolytic capacitors as described in claim 1, characterized in that: The width of the mold body (2) is ,and .

8. A method for forming a tantalum block molding die for a solid electrolytic capacitor as described in any one of claims 1 to 7, characterized in that: Includes the following steps: Step 1: The left mold (4), right mold (5) and front mold (6) close from the standby position to form a mold cavity with an upper opening, together with the mold body (2) and the limiting block (3); Step 2: Fill the mold cavity with tantalum powder; Step 3: Pass one end of the tantalum wire (8) through the through hole A (70) on the upper die (7) and insert it into the tantalum powder in the mold cavity. Then, the upper die (7) moves down and presses on the mold body (2) and the front die (6) to close the mold cavity. Step 4: The left die (4) and the right die (5) move a certain distance toward each other and squeeze the tantalum powder inward to form the anode core (10). Step 5: Cut the tantalum wire (8), and return the upper die (7) and the front die (6) to the standby position; Step 6: The left die (4) and the right die (5) push the anode core (10) into the discharge channel (11). Step 7: Repeat steps 1 to 6 to complete the tantalum block forming process one by one.

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