Die design method and die convenient for off-line ring purpose and off-line die changing method

Abstract

The invention relates to a mold design method convenient for an offline ring purpose, a mold and an offline mold changing method. The mold design method mainly comprises the design of a mold body, a mold base and a mold mounting plate. And by setting a design reference on the mold mounting plate, the integrity, clearness and uniformity of the mold are ensured. The reference can be used for machining, positioning and measuring, and provides a unique size relation for each die holder in multi-station forming equipment. And a connecting structure of the mold mounting plate and the forming equipment is accurately mounted through the positioning holes and the locking holes. The design reference limits the moving freedom degree and the rotating freedom degree of the mold in two directions. Meanwhile, detailed design of the movable mold and the fixed mold is covered, the movable mold and the fixed mold comprise respective mounting plates, datum holes and matching holes, it is guaranteed that only one-time disassembly and assembly are needed when the mold is replaced, a new mold is adjusted in advance in an off-line mode, the mold replacement time is greatly shortened, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to a design technology and a design method for mutual exchange of mechanical parts in the field of mechanical manufacturing, and in particular to an off-line rapid mold change technology for multi-station molding equipment. Background Art

[0002] When changing the manufactured products of a multi-station cold heading machine, it is necessary to replace the mold used online with the mold to be processed. A set of molds for a multi-station cold heading machine consists of multiple pairs of movable and fixed molds for upsetting and shearing molds for cutting profiles. Replacing a set of molds and replacing all movable and fixed molds (including shearing molds) at the same time takes a long time, generally 4 to 6 hours. For large cold heading machines with many stations, the time required for mold replacement is even longer.

[0003] The development trend of cold heading products is towards multiple varieties, small batches and high precision. When producing multiple varieties and small batches, the work of changing molds is more frequent. The time consumed in changing molds and the adjustment quality of the molds after changing directly affect the subsequent production efficiency and production costs. Therefore, it is urgent to reduce the mold change time and improve the mold change quality.

[0004] At present, the rapid die change technology adopted is mainly from the perspective of process (time quota) or management (lean engineering), to reasonably arrange the operation smoothly and save operation time. However, the room for improvement of this technology in saving time is very limited, and there is a lack of technological innovation. On the other hand, the rapid die change device proposed in the cold heading machine accelerates the convenience and speed of online die change operation. As an auxiliary mechanism or tool, it has a certain effect on saving die change time. The main problem is that it is poor in practicality and universality, and it is difficult to promote and apply; as a more efficient and direct rapid die change technology, that is, offline die change technology, many companies are developing it, and its design ideas are still thinking from the perspective that two templates can be interchangeable, and the assembly adjustment is also stuck in the traditional interchangeable assembly and replacement of adjustment parts. There is a lack of innovative methods, and some patents also use this technical solution. Offline die change faces serious high "precision" design technology problems, which cannot be truly solved, applied and popularized. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a design method for a mold that is convenient for offline mold change, and also provides a mold designed by the above method, and a corresponding offline mold change method. A complete set of solutions is provided to effectively improve the production efficiency of the molding equipment.

[0006] In order to achieve the above-mentioned purpose, the purpose of the present invention is to provide a complete and rigorous design technology suitable for offline die changing of multi-station cold heading machines to solve the problem of die accuracy in order to address the technical problem of "precision" in the development of offline die changing.

[0007] The movable die and fixed die of the cold heading machine are installed on two different parts. Offline die change is to combine all the movable dies of the multi-station cold heading machine together, and also combine all the fixed dies together, as a whole (movable die assembly and fixed die assembly), and complete the assembly and adjustment outside the machine before the new product is upsetting. After the batch processing of the original product is completed, the original set of die assemblies used for processing is dismantled and taken out, and the other set of movable die assemblies and fixed die assemblies to be processed are respectively installed in the corresponding working positions, fixed and other components (such as the length of the ejector rod) are appropriately adjusted, and then the upsetting operation of the new product can be started.

[0008] Offline die change requires two sets of intermediate components for installing the die and connecting to the cold heading machine - die mounting plates, one set for the die for processing the current product, and the other set for the pre-assembly and adjustment of the product to be processed outside the machine. Most of the time for replacement and adjustment in die change overlaps with the processing time of the previous product, and only one overall removal and installation is required, which can save a lot of time for die change in the machine, and the economic benefits are very obvious.

[0009] The basic requirement for offline die change is that the two sets of dies can be exchanged, but interchangeability is far from meeting the "precision" requirement for offline die change. As a machine tool, such as a cold heading machine, it is required that the two sets of dies that are replaced during the processing reach the same precision, and the die mounting plates of the two sets of dies are required to achieve the same installation precision when installed in two parts of the cold heading machine. In other words, the two die mounting plates for the fixed die must be made "exactly the same", and the two die mounting plates for the movable die must also be "exactly the same", and the position after installation must be "exactly the same". The technical difficulty lies in "exactly the same". Otherwise, a slight difference will lead to a huge mistake, and the same processing conditions required cannot be achieved.

[0010] From a mechanical point of view, no matter what technology is used, there are more or less manufacturing errors and installation errors. Both of these errors contain reference errors, and the references involved are design references and process references.

[0011] To solve the mold accuracy of offline mold change, the first step is to solve the benchmark problem, followed by improving the manufacturing accuracy of parts and structures, and finally to correct errors through repair methods during assembly to further improve accuracy.

[0012] The present invention aims to ensure the design and manufacturing accuracy of parts during the design process, thus laying a foundation for the final quality assurance of mold change.

[0013] Improving accuracy lies in reducing errors, and the key is to reduce the errors caused by datum conversion, so that the design datum and process datum coincide with each other, and the errors caused by the misalignment of the datums of the parts in the whole process can be reduced to zero.

[0014] In the design process of the mold mounting plate, the selection of design datum should follow the principles of completeness, clarity and unity.

[0015] The so-called complete design datum means that the datums in the three directions of X / Y / Z can be fully reflected in the design drawing of the mold mounting plate. The datum position of the template design should be fully reflected on the corresponding components of the cold heading machine design of the molding equipment as the initial datum for assembly. The design datum of the movable mold mounting plate should obtain the corresponding structural elements on the slider, and the design datum of the fixed template should also have corresponding datum elements at the front end of the bed of the cold heading machine.

[0016] The so-called clear design reference means that the position of the design reference can be retained and exposed during the entire process of template use, which serves as the basis for overall alignment and adjustment.

[0017] The so-called unification is the unification of design datum and process datum. The process datum is divided into process datum, measurement datum, positioning datum and assembly datum in different manufacturing occasions. Specifically, the unification of datum requires that the design datum in three directions be clearly defined during the design, which can be directly used as the process datum, positioning datum and measurement datum during the processing process. It can be directly used during the processing of related surfaces. At this time, it is used as the overall datum to control the manufacturing quality of parts; during the assembly process, the design datum is also used as the assembly datum. The three-direction datum can be clearly shown in the structure, clarify the assembly relationship, and facilitate measurement and correction. At the same time, as a rough datum for precise assembly, it can be ground and repaired when necessary to ensure the consistency of the two mold mounting plates for offline mold change. Under the condition of ensuring consistency (within the allowable error range), the assembly precision datum (assembly positioning pin) is then established for the installation and positioning of the template during mold change, thereby ensuring accurate and rapid replacement of the template. For the same mold mounting plate, multiple disassembly and assembly ensure that the correct position remains unchanged.

[0018] For the other mold mounting plate, use the same method to adjust and repair the technical requirements. After meeting the specified technical requirements, establish the precise assembly reference and use two locating pins that are different from the previous template to determine the precise assembly position.

[0019] The design of two mounting plates constituting a paired set of molds, one movable mold mounting plate and the other fixed mold mounting plate, must also follow the principle of unified reference position.

[0020] The design of the mold mounting plate must ensure the benchmark requirements of the two interchangeable templates. The other mold mounting plate used in conjunction should also have the same benchmark requirements, that is, the benchmarks in the three directions of X / Y / Z. These three benchmarks can be directly used as process benchmarks, positioning benchmarks and measurement benchmarks during the processing. When they can be used for the processing of related surfaces, they can directly control the manufacturing quality of parts. At the same time, the benchmark selection of the matching mold (movable mold and fixed mold) mounting plate should have the same and same position design criteria, and the two should be marked in a mirror image (from the direction of the mold mounting surface). This facilitates the calibration of the matching templates and minimizes the errors between the two during the production process.

[0021] The simplest and most effective reference element is two holes on one side, which are located in the same straight line as the mold holes of each workstation.

[0022] The design of the mold holes at each workstation should follow the principles of relative independence and minimum cumulative error.

[0023] The position between each die hole is related to the key data of the forming operation quality and the operation of the mechanism. To ensure the dimensional accuracy and position accuracy between each other, an independent internal relationship is established during the design process, and at the same time, a unique connection is maintained with the datum (one link is connected to the design datum, rather than each station being directly connected to the design datum), which is conducive to the trimming and adjustment of the overall position under the condition of ensuring upsetting. The position design between each station follows the principle of minimum cumulative error, so that the cumulative error caused by manufacturing from the starting station to the final station is minimized.

[0024] The installation relationship between the mold base of each workstation and the mold mounting plate must follow the principle of precise adjustment.

[0025] The mold base of the mold must have a separate fine-tuning link when installed and connected to the mounting plate to correct the compensation adjustment of the manufacturing errors between the holes of adjacent stations and the adjustment of the relative centering requirements between the moving and fixed molds.

[0026] After adjusting to the precise position, the positioning pin is used to fix the position to ensure the accuracy of the installation of the matching mold. Similarly, the other set of matching movable and fixed molds also ensure the overall accuracy. Thus, the offline mold replacement technology of removing two sets of molds and replacing them with another set of molds can be implemented quickly and correctly. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the composition and assembly relationship of the movable mold group.

[0028] Figure 2 Schematic diagram of the general design of the movable mold mounting plate.

[0029] Figure 3 Schematic diagram of the standard design of the movable mold mounting plate.

[0030] Figure 4 Schematic diagram of the optimized design of the movable mold mounting plate.

[0031] Figure 5 Schematic diagram of the composition structure and assembly relationship of the fixed mold module.

[0032] Figure 6 Schematic diagram of the general design of the fixed mold mounting plate.

[0033] Figure 7 Schematic diagram of the standard design of the fixed mold mounting plate.

[0034] Figure 8 Schematic diagram of the structure and assembly relationship of the fixed mold module with peripheral support.

[0035] Fig. 9 Schematic diagram of the peripheral structure with peripheral support fixed template.

[0036] Fig.10 Schematic diagram of the standard design of a fixed formwork with peripheral supports.

[0037] In the figure: 1, slider, 2, movable mold mounting plate, 3, movable mold seat, 4, ejector sleeve, 5, die bushing, 6, die core, 7, core fixing screw, 8, locking nut, 9, movable mold seat fixing screw, 10, stud, 11, nut and anti-loosening washer, 111, movable mold plate connecting hole (bright hole), 112, movable mold seat connecting hole (screw hole), 113, movable mold last station core mounting hole, 114, movable mold third station core mounting hole, 115, movable mold second station core mounting hole, 116, movable mold first station core mounting hole, 117, movable mold first design reference hole (limiting one rotational degree of freedom), 118, movable mold second design reference hole (limiting two directions of movement freedom);

[0038] 21. First fixed mold mounting plate, 22. Fixed mold adjusting member, 23. Fixed mold seat, 24. Fixed mold fixing member, 211. First fixed mold plate connecting hole (bright hole), 212. First fixed mold seat connecting hole (screw hole), 213. First fixed mold last station mold core mounting hole, 214. First fixed mold third station mold core mounting hole, 215. First fixed mold second station mold core mounting hole, 216. First fixed mold first station mold core mounting hole, 217. First fixed mold shearing mold mounting hole, 218. First fixed mold first ejection fixed mold design reference hole (limit one rotational freedom), 219. First fixed mold second design reference hole (limit one rotational freedom), 220. First fixed mold third design reference hole (limit two directions of movement freedom);

[0039] 31. fixed die core, 32. second fixed die mounting plate, 33. core set screw, 34. ejector rod, 35. limit screw, 36. sliding sleeve, 37. intermediate sleeve, 38. bottom plate, 39. sleeve, 40. transition ejector rod, 43. side support plate, 44. bottom support plate, 45. wedge clamping block;

[0040] A0-movable template connection hole distance end face (length direction reference), A-movable template connection hole horizontal direction spacing, B0-movable mold hole center distance end face (reference), B-movable mold hole spacing, C-movable mold total length, D-movable mold thickness, H1-movable mold base connection hole spacing, H2-movable mold connection hole height direction spacing, H3-movable mold height, A'0-movable mold connection hole distance to the second design reference hole of the movable mold (design reference for limiting length direction movement), A1~A3-movable mold connection hole spacing Horizontal spacing, B'0-the size of the center of the movable die hole from the second design reference hole of the movable die (the reference for limiting the movement in the length direction), B1~B3-the spacing between the movable die holes, E-the length between the two design reference holes of the movable die plate, Ⅰ-the first hinge positioning hole of the movable die that is prefabricated at the upper left and lower right corners and assembled with the first set of movable die mounting plates, and then hinged and fixed with the slider to fix the movable die plate, Ⅱ-the second hinge positioning hole of the movable die that is prefabricated at the lower left and upper right corners and assembled with the second set of movable die mounting plates, and then hinged and fixed with the slider to fix the movable die plate;

[0041] A-optimal design - the size of the distance between the middle connecting hole of the moving mold (near) and the second design reference hole of the moving mold (the design reference for limiting the movement in the length direction); A-optimal design 1 - the distance between adjacent mold holes (moving mold installation holes) in the horizontal direction; A-optimal design 2 - the distance between two mold holes in the horizontal direction, that is, 2 times A-optimal design 1; B-optimal design - the size of the distance between the center hole of the moving mold installation (near) and the second design reference hole of the moving mold (the reference for limiting the movement in the length direction); B-optimal design - the horizontal distance between adjacent mold holes; B-optimal design 2 - the distance between two mold holes;

[0042] F0-fixed template connection hole distance end face (length direction reference), F-fixed template connection hole horizontal direction spacing, G0-fixed mold hole center distance end face (reference) size, G-fixed mold hole spacing, J-fixed template total length, D'-fixed template thickness, H'1-fixed mold base connection hole spacing H'2-fixed mold connection hole height direction spacing, H'3-fixed template height, F-optimal design fixed template (near) middle connection hole distance to the first fixed mold third design reference hole (design reference for limiting length direction movement); F1-spacing between adjacent mold holes (template mounting holes) in the horizontal direction, F2-spacing between 2 mold holes in the horizontal direction, i.e. 2 times F1; F3-spacing between 3 mold holes in the horizontal direction, i.e. 3 times A1; G-optimal design fixed mold installation (near) center hole distance to the first fixed mold third design reference hole (limit length direction movement reference); G1-horizontal spacing between adjacent mold holes; G2-2 mold hole spacing. K-the length from the third design reference hole of the first fixed mold to the second design reference hole of the first fixed mold (the solution when the length is the same as the distance from the movable mold positioning hole); K1-the length from the third design reference hole of the first fixed mold to the first design reference hole of the first fixed mold (the solution when the length is different from the distance from the movable mold positioning hole), Ⅰ'-the first hinged positioning hole of the fixed mold that is prefabricated in the upper left and lower right corners and assembled with the first set of fixed mold mounting plates, and then hinged and fixed to the bed, Ⅱ'-the second hinged positioning hole of the fixed mold that is prefabricated in the diagonal and assembled with the second set of fixed mold mounting plates, and then hinged and fixed to the bed, DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0044] Example 1.

[0045] This embodiment describes a mold design method that is convenient for offline mold change, mainly involving a movable mold module, and an offline mold change mold obtained by this design method, and also includes an offline mold change method of this movable mold module.

[0046] like Figure 1 The figure shows the composition and structure of the four-station (four-station design is used as an example) movable die set installed on the slide 1. The form used in the bolt cold heading machine and the nut cold heading machine is basically the same. This embodiment describes the design technology of the die base, the ejector sleeve and the movable die mounting plate of the stamping die installed in front of each station.

[0047] The movable mold mounting plate 2 and the mold part mounted thereon are used as the movable mold assembly, which is mounted on the front end surface of the slide block 1 of the cold heading machine through the movable mold mounting plate 2. Offline mold change is to correctly install and adjust the movable mold assembly to be processed outside the production machine. When the previous production task is completed, the existing movable mold assembly on the machine will be folded down and hoisted out of the machine. The movable mold assembly completed outside the machine will be hoisted into the corresponding position, aligned and installed, and tightened. There is no need to adjust the mold. If necessary, the ejection stroke will be appropriately adjusted.

[0048] Figure 2 The movable die mounting plate 2 shown in the figure connects the die bases of each station with the movable die base connecting holes 112. The integral installation on the cold heading machine slide block 1 uses the movable die plate connecting holes 111 located between and on both sides of the die core mounting holes (die holes). The large hole in the middle is the die hole, that is, the die core hole, and also the die core mounting hole. From the perspective of design and drawing, Figure 2 The structural elements of the movable mold mounting plate 2 are fully expressed, and the relevant dimensions are complete (the dimensions of the structural shape itself are not marked in the figure), which meets the design requirements. The marking contents of each part are as follows: A0-movable mold plate connection hole distance end face (length direction reference), A-movable mold plate connection hole horizontal direction spacing, B0-movable mold hole center distance end face (reference) size, B-movable mold hole spacing, C-movable mold plate total length, D-movable mold plate thickness, H1-movable mold seat connection hole spacing, H2-movable mold plate connection hole height direction spacing, H3-movable mold plate height.

[0049] Further analysis Figure 2 The datum for the design of up and down (height, Y direction) is the symmetrical center line of the mold holes at each station (each height dimension is marked symmetrically), and the datum for left and right (length, X direction) is the left end face. It is not clear in the thickness direction (Z direction), and can be an interchangeable datum between the front and back faces, so the datum is complete. During the processing, as long as the left end face is not changed during use, it can be used as the positioning datum, measurement datum and process datum in the length direction, and the design datum coincides with the process datum. As the symmetrical center line of the upper and lower datum, it theoretically exists, but it is hidden inside, invisible and intangible, and cannot be used directly in the processing process. Only the slender small plane below or above can be used as the positioning datum, measurement datum and process datum. Even in Figure 2 The dimension H0 between the symmetry centerline and the lower surface (or upper surface) is only to further clarify the reference, indicating the specific relative position, size and tolerance (actually the reference misalignment error) requirements between the upper (or lower) surface as the process reference in the Y direction and the design reference centerline. Obviously, the design reference in the Y direction does not coincide with the process reference. The error caused by the misalignment of the design reference affects the precision quality of the mold after manufacturing. If the accuracy requirements of the relevant dimensions are required to be guaranteed, the difficulty and cost of manufacturing will be increased.

[0050] In order to make the design datum coincide with the process datum, the structure and marking method of the movable mold mounting plate 2 are redesigned, such as Figure 3 As shown, A'0-the size of the movable template connection hole from the second design reference hole of the movable mold (the design reference for limiting the movement in the length direction), A1~A3-the horizontal spacing between the movable template connection holes, B'0-the size of the movable mold hole center from the second design reference hole of the movable mold (the reference for limiting the movement in the length direction), B1~B3-the spacing between the movable mold holes, E-the length between the two design reference holes of the movable template, Ⅰ-the first hinged positioning hole of the movable mold that is prefabricated at the upper left and lower right diagonals and assembled with the first set of movable mold mounting plates, and then aligned and fixed with the slider to fix the movable mold, Ⅱ-the second hinged positioning hole of the movable mold that is prefabricated at the lower left and upper right diagonals and assembled with the second set of movable mold mounting plates, and then aligned and fixed with the slider to fix the movable mold.

[0051] exist Figure 3 Two process holes are added to the design as the positioning holes for processing, namely the first design reference hole 117 of the movable mold and the second design reference hole 118 of the movable mold, to meet the precision guarantee requirements in processing. These two holes can be used for positioning in the rough processing, semi-finishing and finishing processes of the entire movable mold mounting plate 2. The positioning reference is unified with two holes on one side, the positioning is accurate, and the positioning method is simple. If combined with a combined fixture, the processing is more convenient. The positioning of the two holes on one side limits the six degrees of freedom of the workpiece. Both design reference holes are taken on the center line. One of the second design reference holes 118 of the movable mold limits the movement freedom of X and Y, and the other first design reference hole 117 of the movable mold limits the rotation freedom of Z. In the application process, the functions of these two reference holes cannot be confused. If confused, the requirement of reference coincidence is lost. For this reason, the diameters of the two holes can be made different to distinguish and prevent confusion. Figure 3 The design datum shown coincides with the process datum (positioning datum, measurement datum, process datum, and also assembly datum). The datum expressions in the three directions of X / Y / Z are complete, clear, and cannot be replaced. They can all be clearly displayed during the assembly process and serve as the basis for assembly alignment and adjustment. Figure 3 The design effect that meets the principles of complete, clear and coincident design benchmarks is significantly better than Figure 2 The design provides reliable guarantee for the processing quality of the moving mold mounting plate.

[0052] Next, let’s analyze Figure 2 and Figure 3 The advantages and disadvantages of the dimensional standard. This embodiment requires that the main holes of each mold hole system on the movable mold mounting plate 2 should be relatively independent, self-contained and reduce the cumulative error. Figure 2The four mold holes shown, the movable mold base connecting hole 112 where the movable mold base 3 is installed relative to the movable mold mounting plate 2, and the movable mold plate connecting hole 111 of the movable mold mounting plate 2 on the slider 1, the position of one of the holes is derived from the reference, that is, the second design reference hole 118 of the movable mold (the reference used is not the coincidence reference), and the other holes are marked with the center distance between adjacent holes, which can be considered to meet the requirements of independence and self-contained system. Figure 3 The four mold holes, the screw holes for the mold base to be installed relative to the mounting plate, and the mounting holes (light holes) for the mounting plate on the slider, one of which is derived from the coincidence reference (circular hole) that limits two degrees of freedom, meet the requirements of independence and self-contained system, and further establish a connection between its annotation system and the coincidence reference. The dimensions of each hole are not marked with adjacent spacing, but are directly established from the origin (hole) of the annotation system, that is, the movable mold plate connection hole 11 and the movable mold base connection hole 112 marked in the figure, and the dimensional relationship is established.

[0053] As we all know, the dimensional tolerance is related to the precision level of processing and the length of the processing size. The same processing level means the same processing difficulty; the longer the processing length, the larger the tolerance value, but the relationship with the processed length is not proportional. Taking the processing of the hole system with a 250 pitch of level 7 precision as an example, the tolerance is 0.046mm when the pitch is 250, and the tolerance is 0.063mm when the pitch is 500. The cumulative error caused by the two 250 hole pitches is 0.092, which is much larger than the tolerance of the same size. Figure 2 Although the hole system dimensioning averages the errors between holes, the cumulative error of the last hole relative to the first hole is (n-1) times the single tolerance. Figure 3 This is particularly evident in the case of a group of parts being assembled and where the alignment requirements between the relative holes are high.

[0054] As an optimization solution, Figure 4 As shown, each component is as follows Figure 3 The same, but the marked dimensions are as follows: A-optimal design of the size of the middle connecting hole of the movable mold (near) to the second design reference hole of the movable mold (the design reference for limiting the movement in the length direction); A-optimal 1-the distance between adjacent mold holes in the horizontal direction (movable mold mounting holes); A-optimal 2-the distance between 2 mold holes in the horizontal direction, that is, 2 times A-optimal 1; B-optimal design of the size of the center hole of the movable mold mounting (near) to the second design reference hole of the movable mold (the reference for limiting the movement in the length direction); B-optimal 1-the horizontal spacing size between adjacent mold holes; B-optimal 2-the spacing size between 2 mold holes.

[0055] The relationship between the hole system's own datum and the design datum is to select the middle hole or one of the two holes that are close to the design datum for marking, such as the marked dimensions A and B. Figure 4The cumulative error generated in each hole system is minimal, which can better ensure the coaxiality requirements between the corresponding holes during the assembly of two parts (such as the movable mold mounting plate and the slider).

[0056] The movable mold mounting plate of this structure does not contact other parts around, and has no special requirements. The surface roughness requirement is not high, and the dimensional accuracy requirement for length and width is not high. Its processing is used for positioning, which will affect the processing quality of other structural elements.

[0057] Example 2.

[0058] This embodiment describes a mold design method that is convenient for offline mold change, mainly involving a fixed mold module, and an offline mold change mold obtained by this design method, and also includes an offline mold change method of this fixed mold module.

[0059] Figure 5 The composition relationship and structural state of the fixed mold assembly shown in the figure include a first fixed mold mounting plate 21, a fixed mold adjusting member 22, a fixed mold seat 23 and a fixed mold fixing member 24.

[0060] The fixed die assembly of commonly used nut machines and some light-load cold heading machines adopts this structure. In addition to the mounting holes of the fixed die dies of each station with the same number as the movable die, there is also a shearing die hole for shearing the profile into the blank for upsetting. The length of the first fixed die mounting plate 22 is obviously longer than that of the movable die mounting plate 2, and the structure of the first fixed die mounting plate 22 is also obviously different from the composition and structure of the movable die mounting plate 2.

[0061] Figure 6 It is designed according to the conventional method. The dimensions in the figure include: F0-fixed template connection hole distance from the end face (length direction reference), F-fixed template connection hole horizontal distance, G0-fixed mold hole center distance from the end face (reference), G-fixed mold hole spacing, J-fixed template total length, D'-fixed template thickness, H'1-fixed mold base connection hole spacing H'2-fixed template connection hole height direction spacing, H'3-fixed template height.

[0062] The fixed die mounting plate structure used in the existing cold heading machine. It has four fixed die mounting holes, i.e., core mounting holes, and a shear die mounting hole. The hole spacing between these holes is the same; it also includes the first fixed die seat connection hole (screw hole) 212 for mounting the die, the first fixed die mounting plate mounting hole (light hole) 211, etc. The traditional fixed die mounting plate is installed by aligning and centering with the movable die, and fixed on the bed. During use, it is usually not disassembled. The mounting plate does not have high requirements for the benchmark, and there can be no benchmark. As long as the assembly requirements between the hole systems are guaranteed during processing, it is not reflected on the fixed die mounting plate.

[0063] The assembly relationship between the hole systems of these die holes on the cold heading machine must be consistent in the design. The fixed die is guaranteed by the hole system position on the bed structure. The hole system position on the bed corresponding to the fixed die must correspond to the hole system of the fixed die mounting plate; the hole system relationship on the movable die mounting plate 2 must correspond to the hole system relationship on the slider 1; the hole system relationship on the slider 1 must also correspond to the die hole system relationship on the bed. These relationships are determined by the assembly dimension chain calculation during design. In the length direction, the assembly dimension chain formed by the composition relationship between the bed cavity and the slider and the relationship between the bed cavity and the fixed die hole calculates the relationship, size and accuracy requirements with the reference hole system (which can be a die hole or other reference hole). Determine the position on the slider 1 and transfer it from the slider 1 to the movable die mounting plate 2; transfer it from the reference position on the bed to the fixed die mounting plate. The reference hole on the slider 1 is unified with the reference hole on the movable die mounting plate 2, and the reference hole on the bed must also be unified with the reference hole on the fixed die mounting plate. All the positioning holes at the four positions of slider 1 - movable mold mounting plate 2 - fixed mold mounting plate - bed are in a straight line, so that the benchmarks of the molding system components are all unified, and there is no misalignment error between the benchmarks, which simplifies the design, avoids the error caused by benchmark conversion, and is conducive to improving assembly accuracy. At the same time, process holes representing the benchmark are processed on slider 1, movable mold mounting plate 2, fixed mold mounting plate, and bed. These benchmarks should be clearly visible during the assembly process. As the initial benchmark for assembly, they can also play the role of supporting the template in assembly, which is convenient for the correct alignment of the mold hole position during assembly.

[0064] As a reasonable choice for the unified datum of the moving and fixed parts in the molding process, it is also one of the factors affecting the accuracy. The ideal datum should be derived from the same datum in the assembly dimension chain and the size should be shorter, which is conducive to reducing the datum error. Due to the different lengths of the movable mold mounting plate and the fixed mold mounting plate, the reasonable datum selection should not be on the side of the shear mold, but should be near the mold hole of the last station on the operating side.

[0065] Figure 7 yes Figure 6On the basis of, the optimized design obtained by the method of the present application, F0-fixed template connection hole distance end face (length direction reference), F-fixed template connection hole horizontal direction spacing, G0-fixed mold hole center distance end face (reference) size, G-fixed mold hole spacing, J-fixed template total length, D'-fixed template thickness, H'1-fixed mold base connection hole spacing H'2-fixed template connection hole height direction spacing, H'3-fixed template height, F-optimized design fixed template (near) middle connection hole distance first fixed mold third design reference hole (design reference for limiting length direction movement) size; F1-spacing between adjacent mold holes (template mounting holes) in the horizontal direction, F2-spacing between 2 mold holes in the horizontal direction, i.e. 2 times F1; F3-spacing between 3 mold holes in the horizontal direction, i.e. 3 times A1; G-optimized design fixed mold installation (near) center hole distance first fixed mold third design reference hole (limit length direction movement reference) size; G1-horizontal spacing size between adjacent mold holes; G2-2 mold hole spacing size. K-the length from the third design reference hole of the first fixed mold to the second design reference hole of the first fixed mold (the solution when the length is the same as the distance from the movable mold positioning hole); K1-the length from the third design reference hole of the first fixed mold to the first design reference hole of the first fixed mold (the solution when the length is different from the distance from the movable mold positioning hole), Ⅰ'-the first hinged positioning hole of the fixed mold that is prefabricated in the upper left and lower right corners and assembled with the first set of fixed mold mounting plates, and then hinged and fixed to the bed, Ⅱ'-the second hinged positioning hole of the fixed mold that is prefabricated in the diagonal and assembled with the second set of fixed mold mounting plates, and then hinged and fixed to the bed,

[0066] The third design reference hole 220 of the first fixed mold is selected near the fourth station. This design reference limits the freedom of movement in the X / Y directions. Another reference is the second design reference hole 219 of the first fixed mold, which limits the freedom of rotation around Z. It is selected outside the first station and is consistent with the second design reference hole 118 of the movable mold mounting plate. The first fixed mold first ejection mold design reference hole 218 can also be set outside the first fixed mold shear mold mounting hole 21. The first fixed mold second design reference hole 219 and the first fixed mold first ejection mold design reference hole 218 can be selected according to the situation, but it is ensured that they can be clearly seen during the assembly process. If necessary, both can be set.

[0067] The dimension marking requirements of other structural elements of the first fixed mold mounting plate 21 are the same as the design of the movable mold mounting plate in the embodiment.

[0068] Example 3.

[0069] This embodiment describes a mold design method that is convenient for offline mold changing, mainly involving a fixed mold module containing side plates and an inclined wedge structure, and an offline mold changing mold obtained by this design method, and also includes an offline mold changing method of this fixed mold module.

[0070] The mold mounting plates of the above two embodiments are installed on the slide block or the bed. When adjusted to the correct position, they are positioned by two positioning pins and fixed by fixing bolts to the position of the template and can be used. Figure 8 As shown, when the upsetting force of the cold heading machine for larger screws is very large, the expansion force of the fixed die during the upsetting process and the lateral force during shearing may cause the fixed die assembly to produce slight lateral movement, affecting the working performance of the cold heading machine and the quality of the product, and it is necessary to prevent the peripheral micro-movement.

[0071] Fig. 9 It indicates that the peripheral side surfaces of the fixed mold assembly are securely fixed by the side support plates 43 and the wedge-shaped clamping blocks 45, and the bottom surface is supported and adjusted by the adjustment blocks on the bottom support plate 44 to adjust the position accuracy in the height direction; the back has a bottom plate 38 to transitionally adjust the axial size and accuracy when the mold is closed.

[0072] The selection of the design basis of the second fixed die mounting plate 32 (also called the fixed die body on the cold heading machine) of this embodiment, the design of the die hole system and the connecting hole system are carried out with reference to Example 2, which conforms to the design criteria of the present invention.

[0073] The left and right sides of the second fixed mold mounting plate 32 of this embodiment are limited by the side support plate 43 and the wedge-shaped clamping block 45, and the bottom surface is supported, contacted and limited by the bottom support plate 44. The surface processing requirements of the left and right sides and the bottom surface of the second fixed mold mounting plate 32 during design must meet the requirements of matching, and are selected and determined according to the assembly method. Its size must be based on the theoretical size and increase the repair margin. When assembling a single piece, in order to meet the requirements of assembly accuracy and improve the rigidity after assembly, the assembly accuracy is guaranteed by the repair method. The repair method is to select a repair part that is easy to disassemble and has a simple structure. In the structure of this embodiment, the side plate is used as the repair part in the single piece production, which is small in size, easy to disassemble and carry, and can be disassembled and polished according to the requirements of matching.

[0074] It is particularly important to note that when changing molds offline, the side plates must not be ground during the alignment and installation of the fixed mold plate in this embodiment. The second fixed mold mounting plate 32 can only and must be ground. The fixed mold mounting plate is a repair part. The repair part to be repaired must be the fixed mold mounting plate, or the side support plate 43 is used for repair when the first fixed mold mounting plate is assembled, and the side support plate 43 is kept unchanged during the alignment of the second plate, and the fixed mold mounting plate is repaired. If the fixed mold mounting plate is not repaired, the technical requirements of offline mold change and rapid replacement of two sets of molds cannot be met.

[0075] When designing the second fixed mold mounting plate, sufficient grinding allowances should be left on the left and right sides and the bottom surface, while improving the surface processing accuracy and surface roughness. When designing, it is also necessary to consider reducing the amount of repair while achieving assembly accuracy, and select several important small planes on each surface for repair. The final design structure of the fixed mold plate is as follows: Fig.10As shown, where: F0-fixed template connection hole distance end face (length direction reference), F-fixed template connection hole horizontal spacing, G0-fixed mold hole center distance end face (reference) size, G-fixed mold hole spacing, J-fixed template total length, D'-fixed template thickness, H'1-fixed mold base connection hole spacing H'2-fixed template connection hole height direction spacing, H'3-fixed template height, F-optimal design fixed template (near) middle connection hole distance to the first fixed mold third design reference hole (design reference for limiting length direction movement); F1-spacing between adjacent mold holes (template mounting holes) in the horizontal direction, F2-spacing between 2 mold holes in the horizontal direction, i.e. 2 times F1; F3-spacing between 3 mold holes in the horizontal direction, i.e. 3 times A1; G-optimal design fixed mold installation (near) center hole distance to the first fixed mold third design reference hole (limit length direction movement reference); G1-horizontal spacing between adjacent mold holes; G2-2 mold hole spacing. K-the length from the third design reference hole of the first fixed mold to the second design reference hole of the first fixed mold (the solution when the length is the same as the distance from the movable mold positioning hole); K1-the length from the third design reference hole of the first fixed mold to the first design reference hole of the first fixed mold (the solution when the length is different from the distance from the movable mold positioning hole), Ⅰ'-the first hinged positioning hole of the fixed mold that is prefabricated in the upper left and lower right corners and assembled with the first set of fixed mold mounting plates, and then hinged and fixed to the bed, Ⅱ'-the second hinged positioning hole of the fixed mold that is prefabricated in the diagonal and assembled with the second set of fixed mold mounting plates, and then hinged and fixed to the bed,

Claims

1. A mold design method that facilitates offline mold change, including the design of a mold body, a mold base and a mold mounting plate, characterized in that: Based on the mold mounting plate, a design datum is determined thereon, and the design datum meets the following requirements: a) Integrity: The design drawing of the mold mounting plate can reflect the X / Y / Z datum, and the design datum can have corresponding structural elements on other components; b) Clarity: During the entire use of the mold mounting plate, the position of the design reference can be retained and exposed to facilitate overall alignment and adjustment; c) Uniformity: The design datum is unified with the processing technology datum of the mold mounting plate, and can be directly used as the process datum, positioning datum and measurement datum during the processing, and can be used as the assembly datum during the assembly process; A die base is designed for each die of the multi-station forming device, wherein the die base includes a connection structure for mounting on a die mounting plate; and the mounting position of each die base has a unique dimensional relationship relative to a design reference on the die mounting plate; The connection structure between the mold mounting plate and the slider or bed of the forming equipment is designed so that the design datum of the mold mounting plate is associated and unified with the corresponding datum of the slider or bed of the forming equipment.

2. The mold design method for facilitating offline mold change according to claim 1, characterized in that: The design datum of the mold mounting plate includes at least one datum element that limits the freedom of movement in two directions and at least one datum element that limits the freedom of rotation.

3. The mold design method for facilitating offline mold change according to claim 2, characterized in that: The reference element for limiting the freedom of movement in two directions is a hole, and the reference element for limiting the freedom of rotation is a hole or a plane; and when the reference element is a hole, the center line is colinear or parallel to the center lines of multiple mold holes on the mold mounting plate.

4. The mold design method for facilitating offline mold change according to claim 1, characterized in that: The connection structure between the mold mounting plate and the slider or bed of the forming equipment includes at least one connection hole for precise positioning and at least one connection hole for locking, and the center line of the multiple connection holes is colinear or parallel to the line formed by the design reference.

5. The mold design method for facilitating offline mold change according to any one of claims 1 to 4, characterized in that: The dimensions of all mold base mounting holes on the mold mounting plate are directly marked relative to the design reference, or a center marking point located in the middle of the mold hole center line is first determined relative to the design reference, and then marked based on the center marking point.

6. A mold that is easy to change molds offline by the design method according to any one of claims 1 to 5, comprising a movable mold assembly, including a slider, a movable mold mounting plate, a movable mold seat and a punching mold core, characterized in that: The movable mold mounting plate is provided with a movable mold plate connection hole for cooperating with the slider, a mold base connection hole for cooperating with the movable mold base, a mold core mounting hole for cooperating with the die core, and a first design reference hole and a second design reference hole; the first design reference hole and the second design reference hole are arranged at a position close to the edge of the joint surface between the movable mold mounting plate and the movable mold base, and the center line of the first design reference hole and the second design reference hole and the line connecting the plurality of mold core mounting holes are on the same straight line; The first design reference hole and the second design reference hole have different diameters, and the markings of the movable template connection hole, the mold base connection hole and the mold core mounting hole are derived based on the first design reference hole.

7. The mold for facilitating offline mold change according to claim 6, characterized in that: First, determine the movable template connection hole closest to the first design reference hole as the reference movable template connection hole, and mark the distance between the first design reference hole and the reference movable template connection hole, and then use the reference movable template connection hole as the second reference to directly mark the distance from the remaining movable template connection holes to the reference movable template connection hole; the mold base connection holes and mold core mounting holes are marked according to the above method.

8. The mold for facilitating offline mold change according to claim 6, characterized in that: First, determine the hole in the middle of multiple movable template connecting holes as the reference movable template connecting hole, and mark the distance between the first design reference hole and the reference movable template connecting hole. Then, use the reference movable template connecting hole as the second reference to directly mark the distance from the remaining movable template connecting holes to the reference movable template connecting hole. The mold base connecting hole and the mold core mounting hole are marked according to the above method.

9. The mold for facilitating offline mold change according to any one of claims 6 to 8, characterized in that: It also includes a fixed mold assembly, including a fixed mold mounting plate, a fixed mold adjusting part, a fixed mold seat and a fixed mold fixing part. The fixed mold mounting plate is designed to be arranged in coordination with the movable mold mounting plate, and also includes a third design reference hole. The third design reference hole is in the same straight line as the first design reference hole and the second design reference hole, and is separated from one of the design reference holes by a core mounting hole.

10. An off-line mold changing method using the mold according to claims 6-9, characterized in that: Two sets of mold mounting plates are needed to install the mold and connect with the molding equipment, one set is used for the mold for product processing, and the other set is used for the pre-assembly and adjustment of the product to be processed outside the machine, so that most of the time of replacement and adjustment in mold change overlaps with the processing time of the previous product, and only one overall dismantling and installation is required; wherein the fixed mold mounting plate or the movable mold mounting plate is provided with pairs of diagonally arranged hinge positioning holes; when the fixed mold mounting plate needs other supporting parts to be repaired during assembly, only the fixed mold mounting plate is repaired while the shape and size of the supporting parts remain unchanged.

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