Forming die and method for manufacturing narrow-diameter material strip into plug-in type melt

Abstract

The invention relates to a forming die for manufacturing a narrow-diameter material belt into a plug-in type melt. The forming die comprises a lower die base, a lower die base and a lower die base, an upper die holder; and the forming die head is designed to be capable of sequentially pressing the narrow-diameter part of the narrow-diameter material belt from the middle pressing punch to the two sides in the length direction when the upper die base descends relative to the lower die base, bending the body part and bending the two ends of the material belt. Compared with the prior art, the forming die allows forming operation to be carried out on the material belt with the narrow-diameter part. The invention further relates to a method for manufacturing the strip with the narrow diameter into the plug-in type melt by using the forming die.

Description

Technical Field

[0001] The present invention relates to the field of machining, and in particular to a forming die for making a plug-in melt from a strip with a narrow diameter and a manufacturing method for machining a strip with a narrow diameter using the forming die to make a plug-in fuse melt. Background Art

[0002] A fuse is a simple and effective protective electrical appliance, mainly used for overload protection and short-circuit protection. A fuse mainly consists of a melt and an insulating tube for installing the melt. When in use, the melt is connected in series to the circuit to be protected. When a short-circuit fault occurs in the circuit, the melt instantaneously fuses to break the circuit and play a protective role. For the melt, its manufacturing process usually involves many processes for forming the melt of the fuse, such as feeding, cutting, blanking, etc. However, in the prior art, the processing procedures for melt forming are usually carried out separately in the devices for each process. Therefore, there are defects such as a large occupied space and low production efficiency caused by the disordered distribution of each device and the material transportation between each device.

[0003] As a solution, the inventors of the present application have proposed a forming die for making a melt strip into a melt for a fuse, which is disclosed in the Chinese Utility Model Patent CN 219899913U. The forming die includes a lower die base located below the lower template and an upper die base located above the stripping back plate. The two sides of the lower die base are provided with outer guide columns extending vertically into the upper die base, and the upper die base is configured to be guided along the vertical direction relative to the lower die base by means of an outer guide sleeve fixedly connected thereto and sleeved on the outer periphery of the outer guide column so as to press down and rise. On the upper surface of the lower die base, there are also provided a pair of positioning members, for example, each positioning member is located on both sides of two trimming edges to ensure that the melt strip is in place on the upper surface of the lower die base. Subsequently, the melt strip can be fed to the pair of positioning members and ensured to be adapted to the positioning members in the width direction. The upper die base guided along the vertical direction relative to the lower die base by the outer guide column will perform successive bending, trimming, folding, and punching narrow diameter operations on the melt strip positioned by the pair of positioning members. During the pressing down, by overcoming the elastic force of the pressure spring, the predetermined gap between the fixing plate and the stripping back plate is gradually reduced to successively form the melt strip. For example, the successive forming processes of the melt strip can be realized by the combined action of the pressure spring accommodated in the pressure spring hole and the ejector spring located in the upper die base.

[0004] The inventors of the present application found that although the above-mentioned forming die can integrate multiple successive operation steps for making a melt strip into a melt in a single die, thereby allowing a single die to be used to make a melt strip into a melt for a fuse. However, it is found in practice that the forming die using the above-mentioned patented technology still has the following deficiencies:

[0005] 1. The processing object of the above-mentioned forming die is a slender and solid melt strip, which makes the forming die need to integrate multiple technological steps such as bending, trimming, folding, and punching narrow diameters in sequence, making the design of the forming die itself complex, the manufacturing process cumbersome, and the cost still relatively high.

[0006] 2. Most traditional fuses adopt bolt connection, so the bending degree on both sides is very limited. With the development of the fuse industry, plug-in fuses have been proposed for use in different application environments. The melt of the plug-in fuse includes a body and pins bent outwards from both sides of the body for a considerable length, and the paired pins are used for welding installation later. The above-mentioned forming die cannot be used to manufacture such plug-in fuses with pins.

[0007] Therefore, there is a technical need in the related technical field to provide a forming die with a simplified structure and a wide application scope, which can improve the manufacturing efficiency and reduce the manufacturing cost. Summary of the Invention

[0008] Therefore, the task of the present invention is to provide a forming die and method to at least partially overcome the above-mentioned disadvantages of the prior art.

[0009] According to one aspect of the present invention, there is provided a forming die for making a plug-in melt from a strip with narrow diameters, wherein the strip with narrow diameters includes multiple groups of narrow diameter portions arranged at intervals between its opposite ends and a body portion between adjacent narrow diameter portions, and includes: a lower die base on which a female die is placed, wherein the female die includes a top surface arranged at the uppermost position in the vertical direction and a plurality of bending grooves arranged in an alternating manner with these top surfaces; an upper die base arranged vertically above the lower die base, wherein the upper die base is configured to be guided to descend and ascend vertically relative to the lower die base via a plurality of outer guide columns biased by return springs; a forming die head located above the female die, which includes: a fixing plate fixedly connected to the upper die base; a plurality of pressure punches accommodated therein and displaceable along the height direction relative to the fixing plate, wherein the pressure punches are designed to be at least partially aligned with the top surface along the height direction; a plurality of bending punches arranged in an alternating manner with these pressure punches, wherein the bending punches are designed to be at least partially aligned with the bending grooves along the height direction; and a folding punch located on the outermost side; wherein, the forming die is designed such that during the descent of the upper die base relative to the lower die base, it can successively press the narrow diameter portions of the strip with narrow diameters, bend the body portions, and fold the two ends of the strip along the length direction starting from the central pressure punch towards both sides.

[0010] Compared with the prior art, the forming die structure according to the present invention is significantly simplified and allows the forming operation of the strip with a narrow diameter portion. During the forming process, the blank holder punch and the bending punch arranged alternately therewith are allowed to work in sequence to complete blank holding and bending, while ensuring that the narrow diameter portion of the strip with a narrow diameter portion will not be adversely affected during the forming operation, ensuring that the quality of the obtained plug-in melt meets the technical requirements of the fuse.

[0011] According to a preferred aspect of the present invention, the number of the blank holder punches is the same as the number of the top surfaces in the female die, and the number of the bending punches is the same as the number of the bending grooves.

[0012] According to a preferred aspect of the present invention, it includes a centrally arranged first blank holder punch closest to the top surface in the height direction and second, third, fourth, fifth, and sixth blank holder punches arranged at intervals in the length direction, wherein the distances of these blank holder punches from the top surface gradually increase.

[0013] According to a preferred aspect of the present invention, it further includes a pair of bending punches located on both sides of the first blank holder punch in the length direction, wherein the height of the bending punches in the height direction is less than that of the first blank holder punch, and a pair of bending punches respectively assigned to the second, third, fourth, fifth, and sixth blank holder punches in the length direction, wherein the heights of these pairs of bending punches in the height direction are less than those of the second, third, fourth, fifth, and sixth blank holder punches to which they are assigned.

[0014] According to a preferred aspect of the present invention, it further includes a spring fixing seat arranged on the side of the upper die base facing away from the fixed plate, wherein a plurality of spring fixing holes are provided in the spring fixing seat, and a set of compression springs and pressure rods are arranged in the spring fixing holes, and the set of compression springs and pressure rods are assigned to the blank holder punches, bending punches, and bending punches.

[0015] According to a preferred aspect of the present invention, the pair of bending punches are inclined relative to the blank holder punch located therebetween, so that the pointed portion of the bending punch has a spacing relative to the lowermost end of the blank holder punch.

[0016] According to a preferred aspect of the present invention, the bending groove is designed to have a depth and a side length, and the spacing between the bending punch and the blank holder punch is designed to be 0.9 to 1.1 times the side length of the bending groove to which it is assigned.

[0017] According to a preferred aspect of the present invention, the longitudinal axis of the bending punch is designed to have an angle of 3 to 5 degrees relative to the longitudinal axis of the blank holder punch located therebetween.

[0018] According to another aspect of the present invention, there is also provided a method for manufacturing a plug-in melt from a strip with a narrow diameter using a forming die, wherein the forming die is the above-mentioned forming die, and it includes the following steps: Step 1. Adjust the position of the female die along the length direction according to the strip with a narrow diameter of a selected length, so that the narrow diameter part in the strip with a narrow diameter corresponds one-to-one with the top surface of the female die, and wherein a plurality of body parts correspond one-to-one with the bending grooves of the female die; Step 2. Lower the upper die base and the forming die head, so that the centrally arranged pressure punch first contacts the narrow diameter part and presses it against the top surface of the female die; Step 3. The bending punches on both sides of the centrally arranged pressure punch perform a bending operation on the body part located at the bending groove of the female die to form a V-shaped bend of the plug-in melt; Step 4. Successively use the second, third, fourth, fifth, and sixth pressure punches to contact the corresponding narrow diameter parts and press them against the top surface of the female die, and synchronously use the paired bending punches assigned to the second, third, fourth, fifth, and sixth pressure punches to perform a bending operation on the body part located at the bending groove of the female die to form a plurality of V-shaped bends of the plug-in melt; Step 5. Use the bending punches outside the sixth pressure punch to form the paired bending parts of the plug-in melt; Step 6. The return spring automatically raises the upper die base and the fixing plate to automatically return to the state of preparing for the next forming operation.

[0019] According to a preferred aspect of the present invention, wherein step 3 further includes: during the downward movement of the upper die base, the bending punch abuts against the body part of the strip and deflects and approaches the pressure punch located therebetween under the combined action of the force and the bending groove until substantially all of the body part of the strip between the bending punch and the bending groove closely adheres to the side length of the bending groove.

[0020] Part of the other features and advantages of the present invention will be obvious to those skilled in the art after reading this application, and the other part will be described in combination with the drawings in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, wherein:

[0022] Figure 1 is a plan view of a strip with a narrow diameter that can be used for the forming die of the present invention;

[0023] Figure 2 is made of Figure 1 the strip with a narrow diameter shown in;

[0024] Figure 3 is a front view of the forming die according to the present invention, wherein the forming die is in an open position to allow the insertion of a strip with a narrow diameter;

[0025] Figure 4 is Figure 3 a perspective view of the molding die in

[0026] Figure 5 is Figure 3 a perspective view of the molding die in , where it is from another perspective;

[0027] Figure 6 is Figure 3 a perspective view of the molding die in , where it is from yet another perspective;

[0028] Figure 7 is Figure 3 a top view of the molding die in ;

[0029] Figure 8 is a front view of the molding die according to the present invention, where some components are removed to better show the internal structure and details;

[0030] Figure 9 is Figure 8 a top view of the molding die in ;

[0031] Figure 10 is Figure 8 a perspective view of the molding die in ;

[0032] Figure 11 is a perspective view of the molding die according to the present invention, where more components are removed to better show the internal structure and details;

[0033] Figure 12 is Figure 11 a top view of the molding die in ;

[0034] Figure 13 is Figure 11 a front view of the molding die in ;

[0035] Figure 14 is Figure 11 a perspective view of the molding die from another perspective in ;

[0036] Figure 15 is Figure 3 a state diagram of the molding die when it is in the open position, where the initial state of the bending punch is schematically shown locally;

[0037] Figure 16 is Figure 15 an enlarged view of the locally schematic part in , where more details are shown;

[0038] Figure 17 is Figure 3 a state diagram of the molding die when it is in the bending position, where the working bending punch is schematically shown locally.

[0039] Description of the reference numerals:

[0040] 10. Tape with a narrow diameter; 11. Body part; 12. Narrow diameter part; 20. Plug-in melt

[0041] 21. Bending part; 100. Forming die; 101. Spring fixing seat; 101A. Compression spring

[0042] 101B. Pressing rod; 102. Upper die holder; 103. Fixed plate; 103A. Guide groove

[0043] 104A. First blank holding punch; 104B. Second blank holding punch; 104C. Third blank holding punch

[0044] 104D. Fourth blank holding punch; 104E. Fifth blank holding punch; 104F. Sixth blank holding punch

[0045] 105A. First bending punch; 105B. Second bending punch; 105C. Third bending punch

[0046] 105D. Fourth bending punch; 105E. Fifth bending punch

[0047] 106. Female die; 106A. Top surface; 106B. Bending groove

[0048] 107. Lower die holder; 108. Outer guide pillar; 108A. Outer sleeve

[0049] 109. Support; 110. Bending punch; 200. Forming die head

[0050] X. Length direction; Y. Width direction; Z. Height direction

[0051] D. Depth of the bending groove; L. Side length of the bending groove; d. Spacing Detailed implementation manners

[0052] Now referring to the accompanying drawings, a schematic solution of the forming die disclosed in the present invention will be described in detail. Although the accompanying drawings are provided to present some embodiments of the present invention, the drawings do not have to be drawn according to the dimensions of the specific implementation manners, and some features may be enlarged, removed or partially sectioned to better show and explain the disclosure of the present invention. Some components in the drawings may be adjusted in position according to actual needs without affecting the technical effects. The phrase "in the drawings" or similar terms appearing in the specification do not have to refer to all the drawings or examples.

[0053] Certain directional terms used hereinafter to describe the accompanying drawings, such as "inner", "outer", "above", "below" and other directional terms, will be understood to have their normal meanings and refer to those directions involved when normally viewing the accompanying drawings. Unless otherwise specified, the directional terms described in this specification are generally in accordance with the conventional directions understood by those skilled in the art.

[0054] The terms "first", "the first", "second", "the second" and their similar terms used in the present invention do not denote any order, quantity or importance in the present invention, but are used to distinguish one component from other components.

[0055] In Figure 1 is shown a strip 10 with a narrow diameter for a molding die 100 that can be used in the present invention, wherein the strip 10 is generally designed as a plate-shaped member made of a material such as copper or a copper-silver alloy having good ductility and electrical conductivity, and the thickness range of the plate-shaped member is, for example, from 0.1 mm to 2 mm.

[0056] The strip known for making the fuse melt is generally designed as a long strip-shaped solid structure, wherein in the molding die, the strip is generally first formed and bent, and then a narrow diameter of a predetermined size is punched out on the bent strip by a narrow-diameter punch, so as to avoid an adverse effect of the bending process on the size of the punched narrow diameter, and further an adverse effect on performance parameters such as the current-carrying capacity or the magnitude of the cut-off current of the obtained fuse melt. Although such a manufacturing process and molding die are feasible in production, there are still deficiencies such as complicating the design of the molding die, simplifying the production of the melt, making the manufacturing process cumbersome and having a still relatively high cost.

[0057] Different from the known long strip-shaped solid strip, the strip 10 with a narrow diameter for the molding die 100 in the present invention includes a plurality of groups of narrow-diameter portions 12 spaced apart from each other between its opposite ends, and these narrow-diameter portions 12 are prefabricated before the strip 10 is placed into the molding die 100 for subsequent forming processing. As Figure 1 shown, by way of example, the strip 10 with a narrow diameter shown in Figure 1 is from Figure 1From the leftmost end to the rightmost end, 10 groups of narrow-diameter portions 12 (framed by dashed lines) are arranged at equal intervals, and adjacent narrow-diameter portions 12 are connected by the body portion 11 that is not subjected to the punching operation. Such a design is advantageous in that the narrow-diameter size of the melt 20 formed using the narrow-diameter strip 10 can be designed to be larger, that is, the narrow-diameter size / hole size ratio can be made smaller, which effectively improves the current-carrying capacity of the melt 20. At the same time, due to the saving of the contact resistance part, the designed current density of the melt 20 can be improved to a certain extent, so as to meet the low-multiple protection requirements of automotive fuses, especially obvious at the fault current level of 1.5 kA to 3 kA, and can better meet the performance matching design of automotive fuses and relays.

[0058] It should be noted that although the narrow-diameter portion 12 with a design of 10 groups of circular through-holes is shown in Figure 1 , those skilled in the art know that the narrow-diameter portion 12 can be designed into various narrow-diameter structures as required according to actual needs, such as several diamond-shaped holes, other special-shaped holes or combinations of various holes being spaced apart. At the same time, the size or distance of the body portion 11 between adjacent narrow-diameter portions 12 can also be set flexibly.

[0059] In Figure 2 , a plug-in melt 20 prepared according to the intention of the present invention is shown. As clearly shown in Figure 2 , compared with the narrow-diameter strip 10 before forming, in the plug-in melt 20, the corresponding parts of the body portion 11 in the strip 10 have been bent into a plurality of (here 9) V-shaped bends, and these V-shaped bends are symmetrically distributed with respect to the central V-shaped bend. Preferably, the angles of each of the plurality of (here 9) V-shaped bends are formed to be approximately 85 - 100 degrees. Among them, the 10 groups of narrow-diameter portions 12 in the plug-in melt 20 are basically unchanged or unaffected during the bending or forming process. At the same time, the plug-in melt 20 also includes bending portions 21 connected to both ends thereof and bent outward perpendicular to the length direction by a certain height.

[0060] In use, the above-mentioned plug-in fuse element 20 can be received in a fuse tube (not shown) filled with insulating materials such as quartz sand, etc., and the bent portions 21 at both ends can extend out from both ends of the fuse tube and form pins for welding or plugging with electrical components by means of the bent portions 21 that are bent outward by a certain height perpendicular to the length direction. Here, the material of the fuse tube can be high-strength ceramics. In other embodiments, the material of the fuse tube can also be glass, reinforced resin or other insulating materials. Thus, different from the bolt connection used in the prior art, the fuse with the plug-in fuse element 20 according to the present invention can be detachably installed by plugging through the bent portions 21 at both ends, with simple operation and convenient installation. In addition, since the extending direction of the bent portions 21 at both ends intersects with the length direction of the fuse tube or the fuse element 20, this saves space in the length direction of the fuse tube extension.

[0061] It should be noted that the fuse with the above-mentioned plug-in fuse element 20 according to the present invention is not only used in the field of new energy vehicles, but also can be applied to fields such as traditional power generation, power transmission and distribution, metallurgy, mining, electrochemistry, communication, new energy wind power generation and energy storage, rail transit, ships, etc.

[0062] In Figures 3 to 14 FIG. shows an exemplary forming die 100 according to the present invention.

[0063] As Figures 3 to 14 shown in FIG., the forming die 100 includes, from bottom to top: a lower die base 107 generally designed as a long plate shape with locally chamfered corners at four corners, preferably made of stainless steel, and the lower die base 107 serves as a base for placing the female die 106 and the supports 109 symmetrically arranged on both sides of the female die 106 along the X direction. As Figure 3 and Figure 5 clearly shown in FIG., the female die 106 includes a top surface 106A arranged at the uppermost position in the vertical direction and a plurality of bending grooves 106B arranged alternately with these top surfaces 106A. The top surface 106A is used to press the narrow diameter portion 12 of the strip material 10 against it to protect it during the blank holding operation to be described below, and these bending grooves 106B are used to form or bend the body portion 11 of the strip material 10 into a V-shaped bend with an included angle of approximately 85 - 100 degrees as shown in Figure 2 FIG. during the bending operation to be described below. At the same time, the supports 109 on both sides of the female die 106 are used to place a strip material 10 of a predetermined length flat on the female die 106 in a preset posture and ensure that it does not displace along the length direction (i.e., the X direction) during the forming operation.

[0064] Further, four mutually parallel outer guide pillars 108 extending vertically along the height direction (Z direction) are respectively provided at four corner portions of the lower die base 107. An outer sleeve 108A is sleeved on the upper end of the outer guide pillar 108 along the height direction, and an upper die base 102 located vertically above the lower die base 107 is fixedly connected to the top end of the outer sleeve 108A. The upper die base 102 and the lower die base 107 are substantially the same in size and shape, and a pneumatic or electric actuating cylinder (not shown) for pressing it downward along the height direction (Z direction) toward the lower die base 107 is provided on the side of the upper die base 102 facing away from the lower die base 107. When the actuating cylinder operates, the upper die base 102 will be pressed downward along the height direction (in the Z direction in Figure 3 toward the lower die base 107 under the guidance of the cooperation of the four outer guide pillars 108 and the outer sleeve 108A with a matching shape. Thus, during the pressing of the upper die base 102, by means of the outer guide pillars 108 and the outer sleeve 108A with a matching shape that also extends along the height direction (Z direction), only the outer guide pillars 108 and the upper die base 102 fixedly connected to the outer sleeve 108A are allowed to descend or subsequently reset along the height direction (Z direction).

[0065] To realize the reset of the upper die base 102, a reset spring (not shown) capable of storing energy by biasing during pressing is provided in the vertically extending outer sleeve 108A. Here, the reset spring can, for example, be sleeved on the outside of the vertically extending outer guide pillar 108 and clamped between the outer sleeve 108A and the lower die base 107. Thus, after the pressing operation is completed, by means of the elastic potential energy stored in the reset spring, the upper die base 102 can be automatically reset to its initial position. That is, the upper die base 102 can be guided by the four outer guide pillars 108 that can be biased by the reset spring shown in Figure 3 to descend and rise vertically relative to the lower die base 107.

[0066] As Figures 3 - 5 shown, the forming die 100 of the present invention further includes a forming die head 200 provided directly above the female die 106. Here, the forming die head 200 includes a fixing plate 103 fixedly connected to the upper die base 102 directly above the female die 106, a plurality of blank holding punches that can be displaced along the height direction relative to the fixing plate 103 and are accommodated therein, a plurality of bending punches arranged alternately with these blank holding punches, and a bending punch 110 located on the outermost side. Specifically, the forming die head 200 shown in Figure 3 has the same number of blank holding punches as the top surface 106A of the female die 106 (where the number of groups of the narrow diameter portions 12 is also the same, here it is 10) (where the reference numerals 104A to 104F only partially indicate these blank holding punches). It should be noted that since the blank holding punches and the bending punches are both symmetrically arranged with respect to the length direction X direction, so in Figure 3Only the multiple blanking punches and bending punches located on the left side are shown. Those skilled in the art can understand that Figure 3 on the right side of Figure 3 there are also multiple blanking punches and bending punches arranged in an interleaved manner, and their arrangement is the same as or symmetric to the arrangement shown on the left side in

[0067] Among them, in Figure 3 along the length direction, at the central position of the forming die head 200, there is a first blanking punch 104A closest to the top surface 106A in the height direction (Z direction), and on both sides of the first blanking punch 104A in the length direction X direction, there are paired first bending punches 105A for subsequently forming a V-shaped bend. The height of these paired first bending punches 105A in the height direction Z direction is slightly less than that of the first blanking punch 104A and is at least partially aligned with the bending groove 106B located below it. In Figure 3 along the length direction X direction, adjacent to the first bending punch 105A, there is a second blanking punch 104B with a height slightly less than that of the first bending punch 105A, which is designed to subsequently cooperate with the top surface 106A to press against the corresponding narrow-diameter portion 12 of the strip 10 with a narrow diameter. On both sides of the second blanking punch 104B, there are paired second bending punches 105B for subsequently forming a V-shaped bend. The height of these paired second bending punches 105B in the height direction is slightly less than that of the second blanking punch 104B and is at least partially aligned with the bending groove 106B located below it.

[0068] As Figure 3 shown, according to the same arrangement method, along Figure 3In the length direction, third blanking punches 104C, fourth blanking punches 104D, fifth blanking punches 104E, and sixth blanking punches 104F are further arranged at intervals along the length direction outward. Here, the distances of these blanking punches from the top surface 106A in the height direction Z are gradually increasing. Further, as paired bending punches belonging to the second blanking punch 104B, third blanking punch 104C, fourth blanking punch 104D, fifth blanking punch 104E, and sixth blanking punch 104F, multiple pairs of third bending punches 105C, fourth bending punches 105D, and fifth bending punches 105E are arranged alternately between the third blanking punch 104C, fourth blanking punch 104D, fifth blanking punch 104E, and sixth blanking punch 104F. Among them, the heights of these paired third bending punches 105C, fourth bending punches 105D, and fifth bending punches 105E in the height direction are each less than those of the third blanking punch 104C, fourth blanking punch 104D, fifth blanking punch 104E, and sixth blanking punch 104F to which they belong. Finally, two bending punches 110 for bending the strip 10 with a narrow diameter are symmetrically arranged on the outermost sides of the forming die head 200 in the length direction (X direction).

[0069] In Figures 7 to 10 shows the arrangement of these blanking punches in the forming die head 200, multiple bending punches arranged alternately with these blanking punches, and the outermost bending punch 110 in the fixing plate 103. Multiple guide grooves 103A extending in the height direction are arranged in the fixing plate 103 corresponding to the positions of these punches, so as to allow these punches to be displaceably accommodated in the fixing plate 103 in the height direction relative to the fixing plate 103. Especially as Figure 8 and 10 clearly show, for the punches located in the guide grooves 103A of the fixing plate 103, corresponding pressure rods 101B are assigned to each punch. These pressure rods 101B will be put into work in sequence during the following bending operation, so as to allow the strip 10 with a narrow diameter to be blanked, bent, and bent in sequence, while ensuring that the narrow diameter portion 12 of the strip 10 with a narrow diameter will not be adversely affected during the forming operation.

[0070] As Figures 3 to 6 shows, in order to accommodate the pressure rods 101B on the back sides of these punches, a spring fixing seat 101 is also provided on the side of the upper die base 102 facing away from the fixing plate 103. Among them, preferably as Figure 7As shown, a plurality of spring fixing holes corresponding to the positions of the pressure rods 101B on the back side of the punch are provided in the spring fixing seat 101. These spring fixing holes can be designed as blind holes open on one side, for example. One end of the pressure rod 101B is located at the closed end of the blind hole, and the other end is operatively connected to its assigned punch through the open side or end of the blind hole.

[0071] As shown in Figure 15 and 16 Compression springs 101A are correspondingly arranged in the spring fixing holes corresponding to the positions of the pressure rods 101B in the spring fixing seat 101. That is, for each blanking punch and the bending punches arranged alternately therewith, a pressure rod 101B and a compression spring 101A operatively connected thereto are respectively assigned, so that during the pressing down of the forming die head 200, the blanking punch or the bending punch that has already abutted against the top surface 106A or the bending groove 106B in the female die 106 will not affect the continuous pressing down of the blanking punch or the bending punch that has not yet abutted. Furthermore, it is allowed that the blanking punch and the bending punches arranged alternately therewith are sequentially put into work to complete blanking and bending, while ensuring that no adverse effect is caused to the narrow diameter portion 12 of the strip 10 with a narrow diameter during the forming operation.

[0072] Especially as shown in Figure 15 and 16 Taking the centrally arranged first blanking punch 104A and the first bending punches 105A on both sides thereof as an example, the bending groove 106B generally in a V shape or a triangular shape below it has a depth marked as D and a side length marked as L in Figure 15 . Correspondingly, as shown in Figure 16 , when the forming die head 200 is in the initial position or the non-pressed-down position shown in Figure 15 , different from the existing molds, the first bending punches 105A on both sides of the first blanking punch 104A are inclinedly arranged relative to the first blanking punch 104A, so that the bending tip portions of the first bending punches 105A have a spacing d relative to the lowermost end of the first blanking punch 104A in the height direction Z, for example. The spacing d is designed to be, for example, 0.9 to 1.1 times the side length L of the bending groove 106B. As a result, the longitudinal axes of the first bending punches 105A on both sides of the first blanking punch 104A have an included angle of about 3 - 5 degrees, preferably 4 degrees, relative to the longitudinal axis of the first blanking punch 104A itself.

[0073] The inventors of the present invention have found that when bending the strip 10 with a narrow diameter, if multiple bending punches without a height difference between each other are simultaneously abutted against the bending groove 106B for bending, there will be a deficiency in which multiple body portions 11 simultaneously perform side-pulling deformation on the strip 10, thereby increasing the probability of defective products. At the same time, when the bending punch performs a bending operation on the body portion 11, the bending force will inevitably be conducted from the body portion 11 to the narrow diameter portion 12 of the strip 10 and thus have a substantial impact on the pre-formed narrow diameter portion 12.

[0074] Not being limited to theory, the inventors believe that before performing a bending operation on the body portion 11, the narrow diameter portion 12 near the body portion 11 can be pre-pressed, that is, it is immovably protected along the length direction by means of the pressing of the pressing punch and the top surface 106A, thereby basically blocking the force conduction from the bent body portion 11 to the pressed narrow diameter portion 12, and thus ensuring that the narrow diameter portion 12 near the body portion 11 is not affected by the bending operation. Further, by first performing a pressing protection operation on the center position of the strip 10 with a narrow diameter by the first pressing punch 104A, and then sequentially performing bending operations on multiple body portions 11 of the strip 10 with a narrow diameter from the inside to the outside. In this way, the side-pulling deformation operation that will increase the defective product rate is not simultaneously applied to multiple body portions 11 of the strip 10 with a narrow diameter, and while not affecting the production efficiency, it is beneficial to ensure the yield rate of the manufactured finished products.

[0075] Further, the inventors have also found that by means of the first pressing punch 104A and the first bending punches 105A on both sides thereof which are slightly inclined relative to each other, compared with the prior art in which the two are usually designed without an included angle or with parallel longitudinal axes, such a design allows the first bending punch 105A to first contact Figure 1 the body portion 11 of the strip 10 shown in. As the forming die head 200 continues to descend, the body portion 11 of the strip 10 between the first bending punch 105A and the bending groove 106B will be closely attached to the side length of the bending groove 106B from top to bottom as the first bending punch 105A deflects and approaches the first pressing punch 104A. Here, since the distance d between the bending tip portion of the first bending punch 105A and the first pressing punch 104A is designed to be, for example, 0.9 to 1.1 times the side length L of the bending groove 106B, this ensures that when the tip of the first bending punch 105A Figure 17 is abutted against the lowest point of the bending groove 106B as shown, the body portion 11 of the strip 10 between the first bending punch 105A and the bending groove 106B is basically all closely attached to the side length L of the bending groove 106B, thereby forming Figure 2 the V-shaped bend shown in.

[0076] It is believed that, compared with the prior art, the tensile force or stress generated by the V-shaped bend formed in this way on the strip 10 is significantly reduced, thereby reducing the influence of the bending operation applied to the narrow-diameter portion 12 near the main body portion 11 to a smaller extent.

[0077] Next, in combination with Figures 8 to 13 to describe the use of the molding die 100 of the present invention to Figure 1 perform a molding operation on the strip 10 with a narrow diameter in Figure 2 to manufacture the plug-in melt 20 shown in

[0078] When it is necessary to produce a plug-in melt 20 of a certain predetermined length, taking a low-voltage fuse as an example here, for example, it is necessary to manufacture a strip 10 with a narrow diameter having a length of about 100 millimeters, where, for example Figure 1 as shown, the strip 10 with a narrow diameter is provided with 10 groups of narrow-diameter portions 12 and a plurality of main body portions 11 arranged alternately therewith, which will subsequently be bent by a bending punch.

[0079] First, perform step 1, in which the position of the supports 109 on both sides of the female die 106 in the X direction of the elongation direction is first adjusted according to the strip 10 with a narrow diameter of the selected length, so that the 10 groups of narrow-diameter portions 12 in the strip 10 resting on the two supports 109 correspond one-to-one to the position of the top surface 106A of the female die 106, and a plurality of main body portions 11 correspond one-to-one to the position of the bending groove 106B in the female die 106.

[0080] Subsequently, enter step 2, and then start the actuating cylinder on the back side of the upper die holder 102 of the molding die 100 to drive the upper die holder 102 and the molding die head 200 with the fixing plate 103 fixedly connected thereto to be lowered controllably under the guidance of the outer guide post 108, which thereby drives the plurality of pressure punches connected to the molding die head 200 to also be lowered.

[0081] Since the first pressure punch 104A at the central position of the molding die head 200 is located at the lowest position in the Z direction of the height direction (here, as an example, the first pressure punch 104A extends beyond the first bending punch 105A by about 0.1 - 1.5 millimeters along the height direction), during the pressing of the upper die holder 102 and the molding die head 200, the first pressure punch 104A at the central position of the molding die head 200 first contacts the corresponding narrow-diameter portion 12 of the strip 10 with a narrow diameter and presses it against the top surface 106A of the female die 106.

[0082] Then, proceed to Step 3. At this time, as the upper die base 102 and the forming die head 200 continue to descend, the first bending punches 105A located on both sides of the first blanking punch 104A in the length direction in the forming die head 200 come into contact with the body portion 11 of the narrow-diameter strip 10 at the corresponding bending grooves 106B of the female die 106 to perform a bending operation to form Figure 2 the V-shaped bend of the plug-in melt 20 shown in Figure 16 and 17 As shown, before the first bending punches 105A on both sides come into contact with the body portion 11 of the strip 10, there is a certain distance d between the first bending punches 105A and the first blanking punch 104A. The distance d is designed to be, for example, 0.9 to 1.1 times the side length L of the bending groove 106B. As the forming die head 200 continues to descend, the first bending punches 105A will abut against the body portion 11 of the strip 10 and thus deflect and approach the first blanking punch 104A located therebetween along the Figure 16 arrow shown in Figure 17 As a result, the body portion 11 of the strip 10 between the first bending punches 105A and the bending groove 106B will closely adhere to the side length L of the bending groove 106B from top to bottom as it deflects and approaches. Furthermore, when the tip of the first bending punch 105A Figure 2 abuts against the lowest point of the bending groove 106B as shown, the body portion 11 of the strip 10 between the first bending punches 105A and the bending groove 106B is substantially entirely closely adhered to the side length L of the bending groove 106B, thereby forming

[0083] Figure 2 the V-shaped bend shown in

[0083] Figure 2 During this period, since the corresponding narrow-diameter portion 12 of the narrow-diameter strip 10 between the two first bending punches 105A has been pressed between the first blanking punch 104A and the top surface 106A, the narrow-diameter portion 12 between the two body portions 11 is substantially not affected by the side pulling force.

[0083] Next, step 4 is entered. Subsequently, the pressure rod 101B and the compression spring 101A located behind the first bending punch 105A are compressed and retracted, so that the first bending punch 105A which has abutted against the bending groove 106B does not interfere with the downward movement of the second blank holding punch 104B arranged adjacent thereto. As a result, the narrow diameter portion 12 located on one side of the bent V-shaped bend is then pressed between the second blank holding punch 104B and the corresponding top surface 106A and is ready for the subsequent bending operation on the body portion 11 located outside thereof. Next, the body portion 11 of the narrow-diameter strip 10 on the bending groove 106B is continuously bent by means of the second bending punch 105B located outside the second blank holding punch 104B to form more V-shaped bends in the plug-in melt 20. During the bending operation, since the corresponding narrow diameter portion 12 of the narrow-diameter strip 10 between the first bending punch 105A and the second bending punch 105B has been pressed between the second blank holding punch 104B and the top surface 106A, the narrow diameter portion 12 between the two body portions 11 is substantially not affected by the side pulling force.

[0084] Then step 4 is repeated, and the body portion 11 of the narrow-diameter strip 10 is continuously bent by alternately using the third blank holding punch 104C, the third bending punch 105C, the fourth blank holding punch 104D, the fourth bending punch 105D, the fifth blank holding punch 104E, and the fifth bending punch 105E to form more V-shaped bends. During this period, due to the arrangement of the pressure rod 101B, the operations of these blank holding punches and bending punches do not affect and interfere with each other, and reliably ensure that the narrow diameter portion 12 near the body portion 11 is protected from the side pulling force before the bending operation on the body portion 11.

[0085] Then step 5 is entered. Subsequently, the narrow-diameter strip 10 is pressed against the female die 106 by means of the sixth blank holding punch 104F, and then the paired bending portions 21 of the plug-in melt 20 are formed by means of the bending punch 110 outside the sixth blank holding punch 104F. At this time, the forming die head 200 will abut against a limit member (not shown) and be at the lower dead point of its downward stroke and cannot continue to move downward. Thus, Figure 2 All the forming operations of the plug-in melt 20 shown in

[0086] After the plug-in melt 20 is manufactured, the spring sleeved outside the outer guide post 108 automatically moves the upper die base 102 and the forming die head 200 with the fixing plate 103 upward to the initial position. At this time, the operator can take out the formed plug-in melt 20. Of course, the formed plug-in melt 20 can also be blown out or picked out by means of blowing or a manipulator, and then placed into the next strip of material 10 with a narrow diameter to be formed. In short, after the down pressing forming is completed, the forming die 100 automatically returns to the state where the next forming operation can be carried out without any intervention from the operator.

[0087] It should be understood that although this specification is described according to each embodiment, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0088] The above are only the schematic specific embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A forming die for making a plug-in melt from a strip with narrow diameters, wherein the strip with narrow diameters includes multiple groups of narrow diameter parts arranged at intervals between its opposite ends and a body part located at adjacent narrow diameter parts, and is characterized in that, Comprising: A lower die base, in which a female die is placed, and the female die includes a top surface arranged at the uppermost position in the vertical direction and a plurality of bending grooves arranged alternately with these top surfaces; An upper die base arranged above the lower die base in the vertical direction, and the upper die base is configured to be guided to descend and ascend vertically relative to the lower die base via a plurality of outer guide pillars biased by return springs; A forming die head located above the female die, which includes: A fixing plate fixedly connected to the upper die base; A plurality of blank holding punches accommodated therein so as to be displaceable in the height direction relative to the fixing plate, and the blank holding punches are designed to be at least partially aligned with the top surface in the height direction; A plurality of bending punches arranged alternately with these blank holding punches, and the bending punches are designed to be at least partially aligned with the bending grooves in the height direction; and A bending punch located at the outermost side; Wherein, the forming die is designed such that during the descent of the upper die base relative to the lower die base, the narrow diameter portion of the narrow-diameter strip can be successively blank-held from the central blank holding punch to both sides in the length direction, the body portion can be bent, and the two ends of the strip can be bent.

2. The molding die according to claim 1, characterized in that, Wherein the The number of blank holding punches is the same as the number of top surfaces in the female die, and the number of bending punches is the same as the number of bending grooves.

3. The molding die according to claim 2, wherein Including a centrally arranged first blank holding punch having the closest distance to the top surface in the height direction and second, third, fourth, fifth, and sixth blank holding punches arranged at intervals in the length direction, and the distances of these blank holding punches from the top surface gradually increase.

4. The molding die according to claim 3, characterized in that, It further includes pairs of bending punches located on both sides of the first blank holding punch in the length direction, wherein the height of the bending punches in the height direction is less than that of the first blank holding punch, and pairs of bending punches respectively assigned to the second, third, fourth, fifth, and sixth blank holding punches in the length direction, and the heights of these pairs of bending punches in the height direction are less than those of the second, third, fourth, fifth, and sixth blank holding punches to which they are assigned.

5. The molding die according to claim 1, characterized in that, It further includes a spring fixing seat arranged on the side of the upper die base facing away from the fixing plate, and a plurality of spring fixing holes are provided in the spring fixing seat, and a set of compression springs and pressure rods are provided in the spring fixing holes, and the set of compression springs and pressure rods are assigned to the blank holding punches, bending punches, and bending punches.

6. The molding die according to claim 4, characterized in that The paired bending punches are inclined relative to the blank holding punch located therebetween, so that the pointed part of the bending punch has a distance from the lowermost end of the blank holding punch.

7. The molding die according to claim 6, wherein Wherein the bending groove is designed to have a depth and a side length, and the distance between the bending punch and the blank holding punch is designed to be 0.9 to 1.1 times the side length of the assigned bending groove.

8. The molding die according to claim 6, wherein, Wherein the longitudinal axis of the bending punch is designed to have an angle of 3 to 5 degrees with respect to the longitudinal axis of the blank holding punch located therebetween.

9. A method for making a plug-in melt from a strip with a narrow diameter using a forming die, wherein the forming die is the forming die according to any one of claims 1 to 8, characterized in that Including the following steps: Step 1. Adjust the position of the female die in the length direction according to the selected length of the narrow-diameter strip, so that the narrow diameter portion in the narrow-diameter strip corresponds to the position of the top surface of the female die one by one, and a plurality of body portions correspond to the position of the bending grooves of the female die one by one; Step 2. Lower the upper die holder and the forming die head, so that the centrally arranged blank holder punch first contacts the narrow diameter portion and presses it against the top surface of the female die; Step 3. The bending punches located on both sides of the centrally arranged blank holder punch perform a bending operation on the body portion located at the bending groove of the female die to form a V-shaped bend of the plug-in melt; Step 4. Successively use the second, third, fourth, fifth, and sixth blank holder punches to contact the corresponding narrow diameter portions and press them against the top surface of the female die, and synchronously use the paired bending punches assigned to the second, third, fourth, fifth, and sixth blank holder punches to perform a bending operation on the body portion located at the bending groove of the female die to form multiple V-shaped bends of the plug-in melt; Step 5. Form the paired bending portions of the plug-in melt by means of the bending punch outside the sixth blank holder punch; Step 6. The return spring automatically raises the upper die holder and resets it, and the fixing plate is lifted to automatically return to the state of preparing for the next forming operation.

10. The method according to claim 9, wherein step 3 further comprises: During the downward movement of the upper die holder, the bending punches abut against the body portion of the strip and deflect and approach the blank holder punch located therebetween under the combined action of the force and the bending groove until the body portion of the strip between the bending punches and the bending groove is substantially completely pressed against the side length of the bending groove.

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