A hot stamping die with variable cross-sectional area of ​​conformal cooling channel

Abstract

The present invention provides a hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel, comprising an upper die and a lower die; a product to be processed is placed between the upper die and the lower die; the lower surface shape of the upper die and the upper surface shape of the lower die match the shape of the product to be processed after forming; the upper die comprises an upper die body, an upper die water dividing block fixing plate and an upper die water dividing block; the upper die body is connected to the upper die water dividing block fixing plate; the upper die water dividing block is placed in the first diversion cavity of the upper die body; the upper die water dividing block is connected to the upper die water dividing block fixing plate; a stud and a guide column are provided on the upper die water dividing block; and a mounting hole and a guide hole matching the same are provided on the upper die water dividing block fixing plate. In the present invention, the distance from the lower surface of the water dividing block to the upper surface of the diversion cavity is adjusted by controlling the depth of the nut screwed into the stud on the water dividing block, and a plurality of water dividing blocks are provided, each of which can be adjusted individually to change the cooling rate of different positions of the die, realize uniform cooling of the die as a whole, and effectively improve the quality of the formed part.

Description

Technical Field

[0001] The invention relates to the technical field of hot stamping forming, and in particular to a hot stamping die with a variable cross-sectional area of ​​a conformal cooling pipe. Background Art

[0002] Molds are widely used in punching, extrusion, pressure casting, and forming processes of plastics and rubber. It is a tool that forms a blank into a specific shape and size under the action of external force. Most of the products used in daily life and industrial production are produced through mold technology. For molds, their cooling system plays a vital role. Molds with high cooling efficiency and fast cooling speed can greatly shorten the production cycle, thereby greatly improving production efficiency; because most of the problems in the production process are caused by the inconsistent cooling speed of various parts of the blank during the cooling process, such as uneven product thickness, product rupture, and local excessive thickness and wrinkling of the product. In order to ensure the quality of the product, the general solution is to set a cooling pipe inside the mold to control the temperature of the mold and the product by the flow of water inside the mold.

[0003] With the development of science and technology, the strength of the original cold stamped parts can no longer meet the requirements of the automotive industry. In order to meet the automotive industry's requirements for lightweight and safety, more and more high-strength steels and ultra-high-strength steels are used in automobile body manufacturing. At present, the main forming method of high-strength steel and ultra-high-strength steel is hot stamping, that is, the blank is heated to complete austenitization, and then stamped and quenched to achieve the transformation of the blank structure from austenite to martensite. In the entire hot stamping process, the quenching and cooling stage plays a decisive role. If the cooling speed is too slow or uneven, it will affect the strength of the formed part and cause the formed part to be scrapped. In order to make the cooling speed of the blank meet the critical quenching speed, the most common method is to arrange cooling pipes in the mold, use cooling water to cool the mold, and transfer the heat of the formed part in the mold through the cooling pipe, thereby achieving cooling quenching.

[0004] Limited by the processing method, the most common mold flow channel is obtained by drilling. The flow channel obtained by drilling is generally a straight flow channel. For complex molded parts, the mold is usually composed of several parts, but even so, the pipeline layout inside the mold cannot fully meet the cooling requirements. And because the pipeline is a straight line, when the flow direction of the pipeline needs to change, the transition between the two pipelines is very uneven, which is not conducive to the flow of cooling water in the pipeline and affects the cooling performance.

[0005] Due to changes in production conditions or defects in formed parts, the water channels of the mold cooling system need to be debugged. However, the water channels of the current molds are basically fixed and cannot be changed. If the water channels need to be adjusted, the mold can only be redesigned and the water channels rearranged. Not only will it affect production efficiency, but it will also inevitably cause waste of materials. In addition, after a period of use, due to the continuous alternation of hot and cold and the influence of the use environment, some impurities such as iron filings and oil stains will inevitably be generated in the water channels. If the impurities in the water channels cannot be cleaned in time, it will not only affect the heat exchange between the mold and the cooling water, but it may also cause blockage of the cooling pipes and damage to the cooling pipes.

[0006] In summary, there is an urgent need for a hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel to solve the problems existing in the prior art. Summary of the invention

[0007] The present invention aims to provide a hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel, so as to solve the problems of uneven cooling in the die, insufficient cooling rate and difficulty in cleaning the cooling channel.

[0008] To achieve the above object, the present invention provides a hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel, comprising an upper die and a lower die; a product to be processed is placed between the upper die and the lower die; the lower surface shape of the upper die and the upper surface shape of the lower die match the shape of the product to be processed after forming;

[0009] The upper mold includes an upper mold body, an upper mold water dividing block fixing plate and an upper mold water dividing block; the upper mold body is connected to the upper mold water dividing block fixing plate; the upper mold water dividing block is placed in the first diversion cavity of the upper mold body, and the gap between the upper mold water dividing block and the first diversion cavity forms a cooling channel; the upper mold water dividing block is connected to the upper mold water dividing block fixing plate;

[0010] The upper mold water dividing block is provided with studs and guide columns; the upper mold water dividing block fixing plate is provided with mounting holes and guide holes; the guide columns match the guide holes, the studs pass through the mounting holes and are connected with nuts, and the distance from the lower surface of the upper mold water dividing block to the upper surface of the first diversion cavity of the upper mold body is adjusted by controlling the screwing depth of the nuts.

[0011] Furthermore, there are multiple first diversion cavities in the upper mold body, and the multiple first diversion cavities are distributed along the length direction of the upper mold body; the number of upper mold water diversion blocks corresponds to the number of first diversion cavities.

[0012] Furthermore, a groove is formed on the upper mold water dividing block fixing plate, and the groove is connected to the first diversion cavity; a cooling water inlet and a cooling water outlet are respectively provided on both sides of the upper mold water dividing block fixing plate, and the cooling water inlet and the cooling water outlet are connected to the groove.

[0013] Furthermore, the lower mold includes a lower mold body, a lower mold water diversion block fixing plate and a lower mold water diversion block; the lower mold body is connected to the lower mold water diversion block fixing plate; the lower mold water diversion block is placed in the second diversion cavity of the lower mold body, and the gap between the lower mold water diversion block and the first diversion cavity forms a cooling pipe; the lower mold water diversion block is connected to the lower mold water diversion block fixing plate.

[0014] Furthermore, the structure of the lower mold water dividing block fixing plate is the same as that of the upper mold water dividing block fixing plate; the structure of the lower mold water dividing block is the same as that of the upper mold water dividing block.

[0015] Furthermore, there are multiple second diversion cavities in the lower mold body, and the multiple second diversion cavities are distributed along the length direction of the lower mold body; the number of lower mold water diversion blocks corresponds to the number of second diversion cavities.

[0016] Furthermore, the first diversion cavity is a conformal cavity, and the thickness of each point on the bottom surface of the first diversion cavity is equal.

[0017] Furthermore, the second flow distribution cavity is a conformal cavity, and the thickness of each point on the bottom surface of the second flow distribution cavity is equal.

[0018] The application of the technical solution of the present invention has the following beneficial effects:

[0019] (1) In the present invention, the distance from the lower surface of the water divider to the upper surface of the diverter cavity is adjusted by controlling the depth of the nut screwed into the stud on the water divider, that is, the cross-sectional area of ​​the mold cooling pipeline is changed. There are multiple water dividers, each of which can be adjusted individually to change the cooling rate of different positions of the mold, achieve uniform cooling of the entire mold, effectively improve the quality of the formed part and improve the adaptability of the mold, and can adapt to different production conditions.

[0020] (2) In the present invention, the water dividing block is connected to the water dividing block fixing plate by nuts and studs, and is easy to assemble and disassemble. When the mold is used for a long time and the pipeline is blocked, the water dividing block can be disassembled and the inside of the cooling pipeline can be cleaned. Since the water dividing block is processed separately, when the water dividing block is damaged, only the damaged water dividing block needs to be replaced separately, and the later maintenance is simple and the cost is low.

[0021] (3) For complex and large parts, integrated molds can be used. Reducing unnecessary mold segmentation and splicing can increase the mold life and cooling rate.

[0022] (4) The mold is easy to manufacture. The upper and lower mold bodies, the water divider fixing plate and the water divider can be manufactured separately. The upper mold body and the lower mold body are made of high-quality mold materials; the water divider fixing plate and the water divider can be made of ordinary materials. It only needs to consider their heat transfer coefficient and perform anti-rust treatment on them. To a large extent, it can shorten the mold manufacturing time and reduce the mold manufacturing cost.

[0023] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 It is a structural schematic diagram of the formed part involved in the present invention;

[0026] Figure 2 It is a schematic diagram of the structure of a hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel;

[0027] FIG3( a ) is a front view of a hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel;

[0028] FIG3( b ) is a left side view of FIG3( a );

[0029] FIG3( c ) is a top view of FIG3( a );

[0030] Figure 4 for Figure 2 Schematic diagram of the structure of the fixed plate of the middle and upper mold water dividing block;

[0031] Figure 5 for Figure 2 Schematic diagram of the structure of the fixed plate of the middle and lower mold water distribution block;

[0032] Figure 6 for Figure 2 Schematic diagram of the structure of the middle upper mold body and the upper mold water dividing block;

[0033] Figure 7 for Figure 2 Schematic diagram of the structure of the middle and lower mold body and the lower mold water dividing block;

[0034] FIG8( a ) is a schematic diagram of the cross-sectional structure of the conformal cooling pipe before the cross-sectional area changes;

[0035] FIG8( b ) is a schematic diagram of the cross-sectional structure of the conformal cooling pipe after the cross-sectional area changes;

[0036] Among them, 1. upper mold body, 1.1. first diversion cavity, 2. upper mold water diversion block fixing plate, 2.1. mounting hole, 2.2. guide hole, 2.3. groove, 2.4. cooling water inlet, 2.5. cooling water outlet, 3. upper mold water diversion block, 3.1. stud, 3.2. guide column, 4. nut, 5. lower mold body, 5.1. second diversion cavity, 6. lower mold water diversion block fixing plate, 7. lower mold water diversion block, 8. formed product, 9. upper mold cooling pipe, 10. lower mold cooling pipe. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0038] Embodiment 1:

[0039] See also Figure 1 to Figure 8(b) , a hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel, this embodiment is applied to the processing and production of automobile parts, and in this embodiment, a long strip automobile part with a wavy cross-section is selected as the formed product 8, such as Figure 1 shown.

[0040] A hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel, comprising an upper die and a lower die; a product to be processed is placed between the upper die and the lower die; the lower surface shape of the upper die and the upper surface shape of the lower die match the shape of the product to be processed after forming;

[0041] The upper mold includes an upper mold body 1, an upper mold water dividing block fixing plate 2 and an upper mold water dividing block 3; the upper mold body 1 is connected to the upper mold water dividing block fixing plate 2; the upper mold water dividing block 3 is placed in the first diversion cavity 1.1 of the upper mold body, and the gap between the upper mold water dividing block 3 and the first diversion cavity 1.1 forms a cooling channel; the upper mold water dividing block 3 is connected to the upper mold water dividing block fixing plate 2; by injecting cooling water into the cooling channel, the heat in the mold is brought to the outside for heat exchange, thereby realizing cooling and quenching.

[0042] The upper mold water divider block 3 is provided with a stud 3.1 and a guide column 3.2; the upper mold water divider block fixing plate 2 is provided with a mounting hole 2.1 and a guide hole 2.2; the guide column 3.2 matches the guide hole 2.2, and the guide column 3.2 is always perpendicular to the upper mold water divider block fixing plate 2; in this example, the guide column 3.2 and the guide hole 2.2 are both square in shape; the stud 3.1 passes through the mounting hole 2.1 and is connected with a nut 4, and the distance from the lower surface of the upper mold water divider block 3 to the upper surface of the first diversion cavity 1.1 of the upper mold body 1 is adjusted by controlling the screwing depth of the nut 4. Due to the complex shape of the mold, the heat transfer speed of each part is inconsistent. By adjusting the distance between the water divider block in the mold and the mold body, the cross-sectional area of ​​the cooling pipe can be changed to achieve uniform cooling of the parts, ensure uniform organization of each part of the formed part, and improve the performance of the formed part.

[0043] The lower mold includes a lower mold body 5, a lower mold water dividing block fixing plate 6 and a lower mold water dividing block 7; the lower mold body 5 is connected to the lower mold water dividing block fixing plate 6; the lower mold water dividing block 7 is placed in the second diversion cavity 5.1 of the lower mold body 5, and the gap between the lower mold water dividing block 7 and the first diversion cavity 1.1 forms a cooling pipe; the lower mold water dividing block 7 is connected to the lower mold water dividing block fixing plate 6.

[0044] like Figures 4 to 7 As shown, the structure of the lower mold water block fixing plate 6 is the same as that of the upper mold water block fixing plate 2; the structure of the lower mold water block 7 is the same as that of the upper mold water block 3. The upper mold water block 3 and the lower mold water block 7 are both split, which is convenient for processing and later maintenance and replacement.

[0045] The upper mold body 1 and the lower mold body 5 are integral, and the cooling pipe is processed and formed inside them. The integral structure can meet the mechanical requirements and cooling requirements of stamping and ensure the efficiency of the cooling and quenching process.

[0046] There are six first diversion cavities 1.1 in the upper mold body 1, and the six first diversion cavities 1.1 are distributed along the length direction of the upper mold body 1; the number of upper mold water diversion blocks 3 corresponds to the number of first diversion cavities 1.1. There are six second diversion cavities 5.1 in the lower mold body 5, and the six second diversion cavities 5.1 are distributed along the length direction of the lower mold body 5; the number of lower mold water diversion blocks 7 corresponds to the number of second diversion cavities 5.1. Each upper mold water diversion block 3 or lower mold water diversion block 7 can be adjusted individually; the cross-sectional area of ​​each cooling channel can be adjusted individually to achieve control of the cooling rate of different parts of the workpiece.

[0047] The first flow-dividing cavity 1.1 is a conformal cavity, and the thickness of each point on the bottom surface of the first flow-dividing cavity 1.1 is equal. The second flow-dividing cavity 5.1 is a conformal cavity, and the thickness of each point on the bottom surface of the second flow-dividing cavity 5.1 is equal.

[0048] like Figure 4 As shown, a groove 2.3 is formed on the upper mold water dividing block fixing plate 2, and the groove 2.3 is connected to the first diversion chamber 1.1; a cooling water inlet 2.4 and a cooling water outlet 2.5 are respectively provided on both sides of the upper mold water dividing block fixing plate 2, and the cooling water inlet 2.4 and the cooling water outlet 2.5 are connected to the groove 2.3; the cooling water inlet 2.4 and the cooling water outlet 2.5 are located on both sides of the upper mold water dividing block fixing plate 2, which can ensure the uniformity of the cooling water flow rate in different cooling pipes, so that the cooling speed of the entire workpiece maintains a high consistency, thereby improving the quality of the formed part.

[0049] The groove 2.3 is used to realize the diversion of cooling water, evenly distribute the cooling water from the cooling water inlet 2.4 to each cooling pipe and ensure the speed of cooling water in each pipe is consistent, so as to realize uniform cooling of the mold and improve cooling efficiency.

[0050] Since the cooling pipe does not have high requirements for sealing performance, a transition fit can be used to achieve a tight fit, or sealing materials can be used to fill the gap between the water divider block and the mold body. Since the water divider block is manufactured separately, if the water divider block is worn or damaged, it is very easy to repair and replace it.

[0051] The cross-sectional changes of the upper mold cooling pipe 9 and the lower mold cooling pipe 10 before and after the water dividing block is adjusted are shown in Figure 8(a) and Figure 8(b). After the nuts fixing the water dividing block are adjusted and the distance between the water dividing block and the water dividing block fixing plate is changed to adjust the cooling pipe, the cross-sectional area of ​​the cooling pipe can be greatly changed, which can better meet the requirements of different production conditions and improve the applicability of the mold.

[0052] The hot stamping die needs to use water as a cooling medium to cool the die, so as to achieve quenching cooling of the sheet material, so the die needs to be rust-proofed to ensure that the die does not rust during its working cycle. The present invention needs to perform rust-proofing on the parts after the processing of each part is completed. Since the water divider is not a major force-bearing part, its thermodynamic properties can be given priority when selecting the material of the water divider, and the strength of the water divider material does not need to be too high. For the water divider fixing plate, since it is not in direct contact with the cooling water, the cooling effect on the entire mold is small, so its thermodynamic properties can be ignored when selecting the material, and only its strength requirements need to be considered during design.

[0053] The present invention has outstanding advantages for parts with complex shapes. For complex parts, it is very difficult to process the accompanying cooling pipes. With the present invention, the cooling grooves are first processed on the main part of the mold, and after the cooling grooves are processed, the cross-sectional area of ​​the cooling pipes at different positions of the mold and the center distance of the cooling pipes can be controlled by adjusting the position of the water dividing block, thereby achieving uniform cooling of the mold and improving the cooling efficiency of the mold.

[0054] The structure of the hot stamping die for the variable-section cooling conformal pipe of the present invention solves the problems that the hot stamping die for complex parts and large parts needs to cut and process complex cooling pipes, the processing is difficult, and the cross-sectional area of ​​the cooling pipe and the center distance of the cooling pipe cannot be adjusted after assembly, so that the mechanical properties and precision of the formed parts are significantly improved; the water dividing block of the mold is waterproofed and can be replaced separately, which greatly improves the service life of the mold and has important practical value.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel, characterized in that: It comprises an upper die and a lower die; the product to be processed is placed between the upper die and the lower die; the shape of the lower surface of the upper die and the shape of the upper surface of the lower die match the shape of the product to be processed after forming; The upper mold comprises an upper mold body (1), an upper mold water dividing block fixing plate (2) and an upper mold water dividing block (3); the upper mold body (1) is connected to the upper mold water dividing block fixing plate (2); the upper mold water dividing block (3) is placed in a first diversion cavity (1.1) of the upper mold body, and a gap between the upper mold water dividing block (3) and the first diversion cavity (1.1) forms a cooling channel; the upper mold water dividing block (3) is connected to the upper mold water dividing block fixing plate (2); The upper mold water dividing block (3) is provided with a stud (3.1) and a guide column (3.2); the upper mold water dividing block fixing plate (2) is provided with a mounting hole (2.1) and a guide hole (2.2); the guide column (3.2) matches the guide hole (2.2); the stud (3.1) passes through the mounting hole (2.1) and is connected with a nut (4); and the distance from the lower surface of the upper mold water dividing block (3) to the upper surface of the first diversion cavity (1.1) of the upper mold body (1) is adjusted by controlling the screwing depth of the nut (4); The upper mold water dividing block fixing plate (2) is provided with a groove (2.3), and the groove (2.3) is connected to the first diversion cavity (1.1); cooling water inlets (2.4) and cooling water outlets (2.5) are respectively provided on both sides of the upper mold water dividing block fixing plate (2), and the cooling water inlets (2.4) and cooling water outlets (2.5) are connected to the groove (2.3); The first flow distribution cavity (1.1) is a conformal cavity, and the thickness of each point on the bottom surface of the first flow distribution cavity (1.1) is equal.

2. The hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel according to claim 1, characterized in that: There are a plurality of first diversion cavities (1.1) in the upper mold body (1), and the plurality of first diversion cavities (1.1) are distributed along the length direction of the upper mold body (1); and the number of upper mold water diversion blocks (3) corresponds one to one to the number of first diversion cavities (1.1).

3. The hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel according to claim 2, characterized in that: The lower mold comprises a lower mold body (5), a lower mold water dividing block fixing plate (6) and a lower mold water dividing block (7); the lower mold body (5) is connected to the lower mold water dividing block fixing plate (6); the lower mold water dividing block (7) is placed in the second flow dividing cavity (5.1) of the lower mold body (5), and the gap between the lower mold water dividing block (7) and the second flow dividing cavity (5.1) forms a cooling channel; the lower mold water dividing block (7) is connected to the lower mold water dividing block fixing plate (6).

4. The hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel according to claim 3, characterized in that: The structure of the lower mold water divider block fixing plate (6) is the same as that of the upper mold water divider block fixing plate (2); and the structure of the lower mold water divider block (7) is the same as that of the upper mold water divider block (3).

5. The hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel according to claim 3, characterized in that: There are a plurality of second flow diversion chambers (5.1) in the lower mold body (5), and the plurality of second flow diversion chambers (5.1) are distributed along the length direction of the lower mold body (5); and the number of the lower mold water diversion blocks (7) corresponds one to one to the number of the second flow diversion chambers (5.1).

6. The hot stamping die with a variable cross-sectional area of ​​a conformal cooling channel according to claim 5, characterized in that: The second flow distribution cavity (5.1) is a conformal cavity, and the thickness of each point on the bottom surface of the second flow distribution cavity (5.1) is equal.

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