A hot upsetting forming die and forming method for titanium alloy hexagonal parts

Abstract

The invention discloses a hot upsetting forming die and a forming method for a titanium alloy hexagonal internal part, and relates to the technical field of die equipment and screw manufacturing and processing. The upper die part comprises an upper die core, and the central position of the bottom die surface of the upper die core is provided with a hexagonal internal die core; the lower die part comprises a lower die body, and a die cavity is provided in the lower die body, and a push rod is inserted into the lower end of the die cavity, and a T-shaped alloy screw head die groove is provided at the upper end of the die cavity, and the upper end head die groove of the T-shaped alloy screw head die groove adopts a conical cylinder structure; the upper end of a titanium alloy blank is heated and then put into the lower die body, and the heated part of the upper end of the titanium alloy blank is located in the upper end head die groove, and under the punching action of a punch press, the upper die core punches the upper end of the titanium alloy blank into a frustum body, and at the same time, the hexagonal internal die core punches out a hexagonal opening on the frustum body, so as to punch the titanium alloy blank into a titanium alloy screw; the upper die part is lifted, and under the limiting action of the upper end head die groove on the frustum body, the upper die core and the hexagonal internal die core are quickly separated from the frustum body.

Description

Technical Field

[0001] The invention relates to the technical field of mold equipment and screw manufacturing and processing, and in particular to a hot upsetting molding mold and a molding method for a titanium alloy hexagonal internal part. Background Art

[0002] Titanium alloy hexagon socket head bolts have the advantages of light weight, high strength, and the wrenching position is designed inside the bolt head, which is convenient for installation and saves assembly space compared with traditional external hexagon bolts. Therefore, they are used in large quantities in the aerospace field. At present, most of the connection methods used in my country at this stage are connected by ordinary external hexagon bolts. If the assembly space is small and the bolts require high strength, ordinary internal hexagons cannot be used. Therefore, the development of titanium alloy internal hexagon bolts will play a very important role in ensuring the needs of aerospace and other fields and solving the problem of high connection strength of small space parts.

[0003] Public document CN104668416A discloses a cold heading forming method for a deep hole in a bolt head: a specific scheme: the following steps are sequentially performed: step 1, extruding the bolt head through a first stamping die to obtain a tapered concave hole in the middle of the bolt end face and the size and depth of the concave hole; step 2, further stamping the concave hole of the bolt in step 1 through a second stamping die to further deepen the concave hole to form a set required depth and shape, and at the same time, extruding the bolt head into the outline and size set by the die; step 3, through a third stamping die, the concave hole of the bolt in step 2 is further stamped downward through a punch, so that the periphery of the concave hole of the bolt head extends upward according to the requirements of the third stamping die to form the set specifications and requirements; step 4, through a fourth stamping die, the inner wall of the concave hole of the bolt processed in step 3 is squeezed out with a set pattern, and at the same time, the bolt head is extruded by the fourth stamping die into the set required outline, shape and size, that is, the entire processing process is completed.

[0004] The above technical solution is the basic structural principle of ordinary bolt stamping. However, the above solution adopts the cold forging forming method. In addition, the deep hole processing on the bolt head is a round hole, so there is no problem of adhesion between the stamping rod and the bolt. If hot forging is used and the deep hole is a complex structure, the stamping rod and the bolt will inevitably have the problem of adhesion. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a hot upsetting forming die and forming method for a titanium alloy hexagonal part, so as to solve the problem that the part sticks to the die core after hot upsetting and improve the production efficiency of the part.

[0006] The present invention is achieved through the following technical solutions:

[0007] A hot upsetting forming die for titanium alloy hexagonal parts, comprising an upper die part and a lower die part, wherein the upper die part comprises an upper die core, and a hexagonal die core is arranged at the center of the bottom die surface of the upper die core;

[0008] The lower mold part includes a lower mold body, a mold cavity is arranged in the lower mold body, a push rod is inserted in the lower end of the mold cavity, a T-shaped alloy screw head mold groove is arranged in the upper end of the mold cavity, and the upper end mold groove of the T-shaped alloy screw head mold groove adopts a cone cylinder structure;

[0009] After heating the upper end of the titanium alloy blank, put it into the lower die body, the heated part of the upper end of the titanium alloy blank is in the upper end die groove, and under the punching action of the punch press, the upper die core punches the upper end of the titanium alloy blank into a frustum body, and at the same time, the hexagonal die core punches out a hexagonal opening on the frustum body, and punches the titanium alloy blank into a titanium alloy screw;

[0010] The upper mold part is lifted, and under the limiting effect of the upper end mold groove on the frustum ejector body, the upper mold core and the hexagonal mold core are quickly separated from the frustum ejector body.

[0011] Furthermore, the upper mold part also includes an upper mold plate and a fixed sleeve, the fixed sleeve sets the upper mold core sleeve on the upper mold plate, and the upper mold plate is connected to the telescopic arm of the punch press.

[0012] Furthermore, the upper mold part also includes a guide sleeve, the upper end of the guide sleeve is fixedly mounted on the upper mold plate, and the lower end of the guide sleeve can be guided and docked with the upper end of the lower mold body.

[0013] Furthermore, the lower mold part also includes a lower template, the bottom end of the lower template is connected to the lower template by bolts, and the lower template is installed on the workbench of the punch press.

[0014] Furthermore, the cone structure height of the upper end die groove is h, the cone bottom circle diameter is D, and the cone top circle diameter is d;

[0015] The expansion coefficient of titanium alloy is α,

[0016] The punching time of the punch press is S2.

[0017] Then, △L=α×△T×D;

[0018] △T=T1-T2;

[0019] T2=kS+T1;

[0020] C = (Dd) / h;

[0021] Among them, △L is the shrinkage of titanium alloy, △T is the temperature change of titanium alloy, T1 is the temperature value of titanium alloy after heating, k is the constant of the linear function of temperature change of titanium alloy within a period of time, S is the cooling time of titanium alloy, T2 is the temperature value of titanium alloy after cooling on the punch press for a period of time T, and C is the taper of the cone structure;

[0022] After the titanium alloy blank is punched into a titanium alloy screw with a hexagonal socket, it undergoes a punching time S2; when S=S2, then T2=kS2+T1; the frustum body is cooled after being punched, and when the bottom circle diameter △D=D-△L≈d after the frustum body 11 is cooled after a punching time S2, the frustum body can be ejected from the conical cylinder structure, and the titanium alloy screw is ejected from the lower mold body under the action of the ejector rod.

[0023] Furthermore, an air cooling nozzle is provided at the position of the upper end mold groove, and cold air is sprayed to the frustum body in the upper end mold groove through the air cooling nozzle to cool it down.

[0024] The present invention is achieved by another technical solution as follows:

[0025] A hot upsetting method for a titanium alloy hexagonal socket part comprises the following steps:

[0026] Step 1: First, the titanium alloy raw material is processed into a titanium alloy blank before hot upsetting by a lathe;

[0027] Step 2: Install the upper mold part on the telescopic arm of the punch press; install the lower mold part on the workbench of the punch press;

[0028] Step 3, heating the head of the titanium alloy blank, placing the heated titanium alloy blank into the lower die body through a manipulator, the heating part of the upper end of the titanium alloy blank is in the die groove of the T-shaped alloy screw head, and under the punching action of the punch press, the upper die core punches the upper end of the titanium alloy blank into a frustum body, and at the same time, the hexagonal die core punches out a hexagonal opening on the frustum body, and punches the titanium alloy blank into a titanium alloy screw;

[0029] Step 4: The punch press controls the telescopic arm to lift the upper die part, and under the limiting effect of the cone structure on the frustum of the cone, the upper die core and the hexagonal die core are quickly separated from the frustum of the cone;

[0030] Step 5: The punched frustum body is rapidly cooled in the conical cylinder structure. When the frustum body shrinks and the bottom circle diameter △D of the frustum body is equal to D-△L≈d, the frustum body can be ejected from the conical cylinder structure, and the titanium alloy screw is ejected from the lower mold body under the action of the ejector rod 7;

[0031] Step 6: Take away the titanium alloy screw through the robot and cyclically stamp out the next titanium alloy blank.

[0032] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0033] 1. The hot upsetting forming die and forming method of titanium alloy hexagonal parts of the present invention solve the industry problem that the parts stick to the mold core after hot upsetting, and the processing route is short and the efficiency is improved;

[0034] 2. The hot upsetting forming die and forming method of a titanium alloy hexagonal part of the present invention can form the hexagonal part of the part head in one go, thereby improving the strength of the part. In the traditional processing direction, several lathes are required to remove the waste accumulated at the bottom of the hexagonal part. At this time, the metal flow line of the head is cut off, which will reduce the strength of the bolt head.

[0035] 3. The hot upsetting forming die and forming method of a titanium alloy hexagonal internal part of the present invention use a small number of dies, thus saving manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0037] Figure 1 It is a schematic structural diagram of the titanium alloy blank of the present invention.

[0038] Figure 2 This is a schematic diagram of the structure of a semi-finished titanium alloy hexagonal part processed by traditional methods.

[0039] Figure 3 Schematic diagram of the drilling structure of semi-finished titanium alloy hexagonal parts processed by traditional method.

[0040] Figure 4 Schematic diagram of a semi-finished titanium alloy hexagonal socket part that is punched using a traditional method.

[0041] Figure 5 This is a schematic diagram of the structure of a finished titanium alloy hexagonal part processed by a traditional method.

[0042] Figure 6 Schematic diagram of traditional hot upsetting die stamping Figure 1 .

[0043] Figure 7 Schematic diagram of traditional hot upsetting die stamping Figure 2 .

[0044] Figure 8 Schematic diagram of the traditional hexagonal punching die structure Figure 1 .

[0045] Fig. 9 Schematic diagram of the traditional hexagonal punching die structure Figure 2 .

[0046] Fig.10 Schematic diagram of the hot upsetting die structure of the present invention Figure 1 .

[0047] Fig.11 Schematic diagram of the hot upsetting die structure of the present invention Figure 2 .

[0048] Fig.12 Schematic diagram of the hot upsetting die structure of the present invention Figure 3 .

[0049] Fig.13 It is a structural schematic diagram of the lower mold body of the present invention.

[0050] Fig.14 This is a schematic diagram of the finished structure of the titanium alloy screw of the present invention.

[0051] Fig.15 This is a schematic diagram of the cooling process of the titanium alloy blank of the present invention.

[0052] Fig.16 It is a schematic diagram of the gap between the cone-shaped body and the upper end die groove after cooling during the stamping process of the titanium alloy blank of the present invention.

[0053] Marks and corresponding parts names in the attached drawings:

[0054] 1-upper mold part, 2-lower mold part, 3-upper mold core, 4-hexagonal mold core, 5-lower mold body, 6-mold cavity, 7-elevator, 8-T-type alloy screw head mold groove, 9-upper end head mold groove, 10-titanium alloy blank, 11-conical body, 12-hexagonal mouth, 13-titanium alloy screw, 14-upper template, 15-fixing sleeve, 16-guide sleeve, 17-lower template, 18-bolt, 19-fixing cover. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0056] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0057] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "inside", "outside", etc. appear to indicate the orientation or position relationship, it is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0058] In the description of the present invention, unless otherwise clearly specified and limited, if the term "connection" or the like appears to indicate the connection relationship between components, the term should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two components or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] Example 1

[0060] like Figure 1-16 As shown, the present invention is a titanium alloy hexagonal parts hot upsetting forming die, such as Figure 1-9 As shown in the figure, the traditional method of processing the head forming process of titanium alloy hexagonal parts is:

[0061] Several turnings → upsetting → several turnings → upsetting → several turnings.

[0062] First, the titanium alloy raw material is turned into a blank before hot forging (such as Figure 1 As shown), then install the traditional hot upsetting die on the punch press (as shown Figure 6-7 As shown), the head of the titanium alloy blank 10 is heated and placed in the lower die body 5, and the punch press is started to close the upper die to the lower die to hot-forge the semi-finished bolt head to complete the forming ( Figure 2 As shown), and then several times the hot-forged semi-finished parts are drilled in the middle of the head (as shown Figure 3 As shown), and then install another set of molds (as shown Figure 8-9 As shown), put the semi-finished parts with pre-drilled holes into the lower die, and tighten the fixing cover 19 (as shown Fig. 9 As shown), the purpose is to prevent the part from sticking to the mold core, start the punch press to close the mold to the lower mold part head to complete the molding (as shown Figure 4 As shown, the punch press returns to its original position, the fixed cover 19 is unscrewed, and the parts are ejected through the ejector 7 to obtain a titanium alloy screw with a hexagonal head (as shown in FIG. Figure 4As shown in the figure), since this process is cold heading, there will be excess waste accumulated in the hexagon socket 12 of the head of the part. It is necessary to remove the excess waste in the hexagon socket 12 of the head several times to obtain a qualified product (such as Figure 5 as shown).

[0063] The present invention improves the above-mentioned forming mold and process, and the hot upsetting forming process of titanium alloy hexagonal parts is: lathing → upsetting.

[0064] like Figure 9-16 As shown, it specifically includes an upper mold part 1 and a lower mold part 2. The upper mold part 1 includes an upper mold core 3. The center position of the bottom mold surface of the upper mold core 3 is provided with an inner hexagonal mold core 4.

[0065] The lower mold part 2 includes a lower mold body 5, a mold cavity 6 is provided in the lower mold body 5, a push rod 7 is inserted at the lower end of the mold cavity 6, and a T-shaped alloy screw head mold groove 8 is provided at the upper end of the mold cavity 6. The T-shaped alloy screw head mold groove 8 is made of cemented carbide material and is embedded in the upper end of the mold cavity 6 to form a T-shaped stamping model cavity. The upper end head mold groove 9 of the T-shaped alloy screw head mold groove 8 adopts a conical cylinder structure; the conical cylinder structure is larger at the lower end and smaller at the upper end.

[0066] When stamping and manufacturing the titanium alloy screw 13, the upper end of the titanium alloy blank 10 is heated and then placed in the lower die body 5, and the heated portion of the upper end of the titanium alloy blank 10 is located in the upper end die groove 9. Under the stamping action of the punch press, the upper die core 3 stamps the upper end of the titanium alloy blank 10 into a frustum-shaped body 11, and at the same time, the inner hexagonal die core 4 stamps out an inner hexagonal opening 12 on the frustum-shaped body 11, and the titanium alloy blank 10 is stamped into a titanium alloy screw 13;

[0067] The upper die part 1 is lifted, and under the limiting effect of the upper end die groove 9 on the frustum body 11, the upper die core 3 and the inner hexagonal die core 4 are quickly separated from the frustum body 11. The shape and structure of the frustum body 11 at the end of the titanium alloy screw 13 just formed by stamping are the same as the upper end die groove 9, that is, the lower end is large and the upper end is small, so when the frustum body 11 is just stamped, the frustum body 11 cannot be taken out from the upper end die groove 9.

[0068] The upper mold part 1 further comprises an upper mold plate 14 and a fixing sleeve 15. The fixing sleeve 15 sleeves the upper mold core 3 on the upper mold plate 14. The upper mold plate 14 is connected to the telescopic arm of the punch press.

[0069] The upper mold part 1 further includes a guide sleeve 16, the upper end of which sleeves the fixing sleeve 15 on the upper mold plate 14, and the lower end of which sleeve can be guided and docked with the upper end of the lower mold body 5. On the one hand, the upper end of the guide sleeve 16 is connected to the upper mold plate 14 by bolts 18, connecting the fixing sleeve 15 to the upper mold plate 14, and on the other hand, the lower end of the guide sleeve 16 cooperates with the lower mold body 5 to play a guiding role, which is convenient for stamping operation.

[0070] The lower mold part 2 also includes a lower mold plate 17, the bottom end of which is connected to the lower mold plate 17 by bolts 18, and the lower mold plate 17 is then installed on the workbench of the punch press.

[0071] The cone structure height of the upper end die groove 9 is h, the bottom circle diameter of the cone is D, and the top circle diameter of the cone is d;

[0072] The expansion coefficient of titanium alloy is α,

[0073] The punching time of the punch press is S2, and S2 can also be regarded as the cooling time after the titanium alloy screw 13 is punched. Because the total time of the entire titanium alloy screw 13 punching process, the loading and unloading of the robot, the telescopic arm extension and retraction process of the punch press, and the ejection process of the ejector 7 are very short compared to the cooling time of the titanium alloy screw 13, they can be ignored. The punching time of the punch press is S2, which is the cooling time of the titanium alloy screw 13 after being punched.

[0074] Then, △L=α×△T×D;

[0075] △T=T1-T2;

[0076] T2=kS+T1;

[0077] like Fig.15 As shown in the figure, the temperature change curve of titanium alloy over time. For a titanium alloy at 500℃, under indoor temperature environment, the relationship curve between temperature and time can be roughly described as follows: Initial stage: the titanium alloy starts to cool from 500℃, and the temperature drops rapidly. Intermediate stage: As the titanium alloy exchanges heat with the indoor environment, the temperature drop rate gradually slows down. Final stage: The temperature of the titanium alloy gradually approaches the indoor temperature, and finally stabilizes at the same temperature as the indoor environment.

[0078] During the whole process, the speed of temperature drop will be affected by many factors such as the thermal conductivity, specific heat capacity, indoor temperature and heat exchange conditions of titanium alloy. Since the specific values ​​of these factors are unknown, it is impossible to give an accurate temperature-time curve. But in general, the curve will show a trend of rapidly dropping from high temperature, then gradually slowing down, and finally stabilizing.

[0079] The curve in the initial stage of cooling of titanium alloy can basically be seen as a straight line, such as Fig.15 As shown, the linear function T2=kS+T1; the portion where this function basically overlaps with the change curve can be regarded as the stage where the temperature drops rapidly, and the cooling time of the titanium alloy screw 13 of the present invention also occurs in this overlapping stage, so the cooling process of the titanium alloy screw 13 is regarded as the linear function T2=kS+T1.

[0080] C = (Dd) / h;

[0081] Among them, △L is the shrinkage of titanium alloy, △T is the temperature change of titanium alloy, T1 is the temperature value of titanium alloy after heating, k is the constant of the linear function of temperature change of titanium alloy within a period of time, S is the cooling time of titanium alloy, T2 is the temperature value of titanium alloy after cooling on the punch press for a period of time T, and C is the taper of the cone structure;

[0082] After the titanium alloy blank 10 is punched into a titanium alloy screw 13 with a hexagonal socket 12, a punching time S2 is passed; when S=S2, T2=kS2+T1; the frustum body 11 is cooled after being punched, and the bottom circle diameter △D of the frustum body 11 is △D=D-△L≈d, △D is basically consistent with the size of d, and the difference is within the range of ±0.1mm. The frustum body 11 can be ejected from the conical cylinder structure, and the titanium alloy screw 13 is ejected from the lower mold body 5 under the action of the ejector rod 7. △D is the bottom circle diameter of the frustum body 11 after cooling after a punching time S2.

[0083] By collecting the above-mentioned values, we can design the taper of the conical cylinder structure according to the manufacturing dimensions of the conical cone body 11, and control the stamping frequency according to the taper of the conical cylinder structure, so as to accurately control the time for removing the titanium alloy screw 13 and improve the production efficiency of the titanium alloy screw 13.

[0084] The upper die groove 9 is provided with an air cooling nozzle, through which cold air is sprayed to cool the frustum body 11 in the upper die groove 9. The air cooling nozzle can realize rapid cooling of the titanium alloy screw 13, thereby improving the production efficiency of the titanium alloy screw 13.

[0085] like Figure 10-14As shown, the process flow of the hot upsetting forming die for titanium alloy hexagonal parts and stamping titanium alloy screw 13 of the present invention is as follows: first, the titanium alloy raw material is processed into a titanium alloy blank 10 before hot upsetting by a lathe; the upper die part 1 is correspondingly installed on the telescopic arm of the punch press; the lower die part 2 is correspondingly installed on the workbench of the punch press; the head of the titanium alloy blank 10 is heated, and the heated titanium alloy blank 10 is placed in the lower die body 5 by a manipulator, and the upper end heating part of the titanium alloy blank 10 is located in the T-shaped alloy screw head die groove 8, and under the punching action of the punch press, the upper die core stamps the upper end of the titanium alloy blank 10 into a cone body 11, and at the same time, the inner hexagonal die core 4 is in the cone A hexagonal socket 12 is punched out on the body 11, and the titanium alloy blank 10 is punched into a titanium alloy screw 13; the punch press controls the telescopic arm to lift the upper mold part 1, and under the limiting effect of the conical cylinder structure on the frustum body 11, the upper mold core 3 and the hexagonal mold core 4 are quickly separated from the frustum body 11; the frustum body 11 after punching is quickly cooled in the conical cylinder structure, and when the frustum body 11 shrinks and the bottom circle diameter △D=D-△L≈d of the frustum body 11, the frustum body 11 can be ejected from the conical cylinder structure, and the titanium alloy screw 13 is ejected from the lower mold body 5 under the action of the ejector rod 7; the titanium alloy screw 13 is taken away by the robot, and the next titanium alloy blank 10 is punched in a cycle.

[0086] The ingenuity of the design of the present invention is that the lower mold body 5 (such as Fig.13 As shown in the structural analysis, the cavity of the lower mold body 5 adopts a reverse taper design, and the size of the opening is smaller than the bottom size. Because the part is formed by heating and upsetting the head, when the raw material blank is squeezed into the lower mold cavity by the pressure of the punch press, the temperature of the part is high, the fluidity of the raw material is good, and the head of the part and the lower mold are almost fitted (as shown in the figure). Fig.11 As shown in the figure, the punch press returns to its original position instantly, and the upper die core 3 is also pulled out with the punch press. Because the part is stuck in the lower die by the inverted cone structure at this time, the part will not be lifted up by the upper die core 3 and stuck on the upper die core 3. After the upper die core 3 is pulled out, the temperature of the part head cools down rapidly. Due to the principle of thermal expansion and contraction, after the part head cools down, there will be a gap between the head (cone body 11) and the upper end die groove 9 (as shown in the figure). Fig.16 As shown in the figure), the parts can be easily taken out by the ejector 7.

[0087] By comparing the processing flow of the mold designed by the present invention with the traditional processing flow,

[0088] Advantages of this patent: 1. Short processing route, improved efficiency; 2. The hexagon socket 12 of the part head is formed in one go, which improves the strength of the part. The traditional processing direction requires several lathes to remove the waste accumulated at the bottom of the hexagon socket. At this time, the metal flow line of the head is cut off, which will reduce the strength of the bolt head. 3. Fewer molds are used, saving manufacturing costs.

[0089] Example 2

[0090] like Figure 10-14 As shown, a hot upsetting method for a titanium alloy hexagon socket part comprises the following steps:

[0091] Step 1: First, the titanium alloy raw material is processed into a titanium alloy blank 10 before hot upsetting by a lathe;

[0092] Step 2: Install the upper mold part 1 on the telescopic arm of the punch press; install the lower mold part 2 on the workbench of the punch press;

[0093] Step 3, heating the head of the titanium alloy blank 10, and placing the heated titanium alloy blank 10 into the lower die body 5 through a manipulator, the upper heated portion of the titanium alloy blank 10 is located in the T-shaped alloy screw head die groove 8, and under the punching action of the punch press, the upper die core 3 punches the upper end of the titanium alloy blank 10 into a frustum body 11, and at the same time, the hexagonal die core 4 punches out a hexagonal opening 12 on the frustum body 11, and punches the titanium alloy blank 10 into a titanium alloy screw 13;

[0094] Step 4: The punch press controls the telescopic arm to lift the upper mold part 1. Under the limiting effect of the cone structure on the frustum body 11, the upper mold core 3 and the hexagonal mold core 4 are quickly separated from the frustum body 11.

[0095] Step 5, the stamped frustum body 11 is rapidly cooled in the conical cylinder structure. When the frustum body 11 shrinks and the bottom circle diameter △D of the frustum body 11 is equal to D-△L≈d, the frustum body 11 can be ejected from the conical cylinder structure, and the titanium alloy screw 13 is ejected from the lower mold body 5 under the action of the ejector rod 7;

[0096] Step 6: Take away the titanium alloy screw 13 (such as Fig.14 As shown), the next titanium alloy blank 10 is punched out in a cycle.

[0097] The titanium alloy screw 13 (such as Fig.14 As shown, the outer ring of the cone body 11 has a certain taper, and the conventional titanium alloy screw (such as Figure 5 As shown), the cone body 11 is a cylindrical structure of equal diameter. The titanium alloy screw 13 made by the present invention has no difference in use function from the traditional titanium alloy screw, but has a slight difference in appearance. The hexagonal socket 12 is formed by hot upsetting, and the structural strength of the titanium alloy screw 13 is stronger.

[0098] The ingenuity of the design of the present invention is that the lower mold body 5 (such as Fig.13As shown in the structural analysis, the cavity of the lower mold body 5 adopts a reverse taper design, and the size of the opening is smaller than the bottom size. Because the part is formed by heating and upsetting the head, when the raw material blank is squeezed into the lower mold cavity by the pressure of the punch press, the temperature of the part is high, the fluidity of the raw material is good, and the head of the part and the lower mold are almost fitted (as shown in the figure). Fig.11 As shown in the figure, the punch press returns to its original position instantly, and the upper die core 3 is also pulled out with the punch press. Because the part is stuck in the lower die by the inverted cone structure at this time, the part will not be lifted up by the upper die core 3 and stuck on the upper die core 3. After the upper die core 3 is pulled out, the temperature of the part head cools down rapidly. Due to the principle of thermal expansion and contraction, after the part head cools down, there will be a gap between the head (cone body 11) and the upper end die groove 9 (as shown in the figure). Fig.16 As shown in the figure), the parts can be easily taken out by the ejector 7.

[0099] By comparing the processing flow of the mold designed by the present invention with the traditional processing flow,

[0100] Advantages of this patent: 1. Short processing route, improved efficiency; 2. The hexagon socket 12 of the part head is formed in one go, which improves the strength of the part. The traditional processing direction requires several lathes to remove the waste accumulated at the bottom of the hexagon socket. At this time, the metal flow line of the head is cut off, which will reduce the strength of the bolt head. 3. Fewer molds are used, saving manufacturing costs.

[0101] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A hot upsetting die for titanium alloy hexagon socket parts, comprising an upper die part (1) and a lower die part (2), characterized in that: The upper mold part (1) comprises an upper mold core (3), and a hexagonal mold core (4) is provided at the center of the bottom mold surface of the upper mold core (3); The lower mold part (2) comprises a lower mold body (5), a mold cavity (6) is provided in the lower mold body (5), a push rod (7) is inserted at the lower end of the mold cavity (6), a T-shaped alloy screw head mold groove (8) is provided at the upper end of the mold cavity (6), and the upper end mold groove (9) of the T-shaped alloy screw head mold groove (8) adopts a conical cylinder structure; The upper end of the titanium alloy blank (10) is heated and then placed in the lower die body (5), the heated portion of the upper end of the titanium alloy blank (10) is located in the upper end die groove (9), and under the punching action of the punch press, the upper die core (3) punches the upper end of the titanium alloy blank (10) into a frustum-shaped body (11), and at the same time, the hexagonal die core (4) punches out a hexagonal opening (12) on the frustum-shaped body (11), thereby punching the titanium alloy blank (10) into a titanium alloy screw (13); The upper mold part (1) is lifted, and under the limiting effect of the upper end mold groove (9) on the frustum-shaped body (11), the upper mold core (3) and the hexagonal mold core (4) are quickly separated from the frustum-shaped body (11); The cone structure height of the upper end die groove (9) is h, the cone bottom circle diameter is D, and the cone top circle diameter is d; The expansion coefficient of titanium alloy is α, The punching time of the punch press is S2. Then, △L=α×△T×D; △T=T1-T2; T2=kS+T1; C = (Dd) / h; Among them, △L is the shrinkage of titanium alloy, △T is the temperature change of titanium alloy, T1 is the temperature value of titanium alloy after heating, k is the constant of the linear function of temperature change of titanium alloy within a period of time, S is the cooling time of titanium alloy, T2 is the temperature value of titanium alloy after cooling on the punch press for a period of time T, and C is the taper of the cone structure; After the titanium alloy blank (10) is punched into a titanium alloy screw (13) with a hexagonal socket (12), a punching time S2 is passed; when S=S2, then T2=kS2+T1; the frustum body (11) is cooled after being punched, and when the bottom circle diameter △D of the frustum body (11) after being cooled after a punching time S2 is △D=D-△L≈d, the frustum body (11) can be ejected from the conical cylinder structure, and the titanium alloy screw (13) is ejected from the lower mold body (5) under the action of the ejector rod (7).

2. The hot upsetting forming die for titanium alloy hexagon socket parts according to claim 1, characterized in that: The upper mold part (1) further comprises an upper mold plate (14) and a fixed sleeve (15), wherein the fixed sleeve (15) sleeves the upper mold core (3) on the upper mold plate (14), and the upper mold plate (14) is connected to the telescopic arm of the punch press.

3. The hot upsetting forming die for titanium alloy hexagon socket parts according to claim 2, characterized in that: The upper mold part (1) further comprises a guide sleeve (16), the upper end of which sleeves the fixing sleeve (15) onto the upper mold plate (14), and the lower end of which sleeve can be guided to dock with the upper end of the lower mold body (5).

4. The hot upsetting forming die for titanium alloy hexagon socket parts according to claim 1, characterized in that: The lower mold part (2) also includes a lower mold plate (17), the bottom end of the lower mold plate (17) is connected to the lower mold plate (17) by bolts (18), and the lower mold plate (17) is mounted on the workbench of the punch press.

5. The hot upsetting forming die for titanium alloy hexagon socket parts according to claim 1, characterized in that: An air cooling nozzle is provided at the position of the upper end mold groove (9), and cold air is sprayed toward the cone-shaped body (11) in the upper end mold groove (9) through the air cooling nozzle to cool it down.

6. A hot upsetting method for titanium alloy hexagonal parts, characterized in that: A hot upsetting forming die for a titanium alloy hexagon socket part according to any one of claims 1 to 5, comprising the steps of: Step 1: First, the titanium alloy raw material is processed into a titanium alloy blank (10) before hot upsetting by a lathe; Step 2: Install the upper mold part (1) on the telescopic arm of the punch press; and install the lower mold part (2) on the workbench of the punch press; Step 3, heating the head of the titanium alloy blank (10), placing the heated titanium alloy blank (10) into the lower die body (5) through a robot, the upper heated portion of the titanium alloy blank (10) being located in the T-shaped alloy screw head die groove (8), and under the punching action of the punch press, the upper die core (3) punches the upper end of the titanium alloy blank (10) into a frustum-shaped body (11), and at the same time, the hexagonal die core (4) punches out a hexagonal opening (12) on the frustum-shaped body (11), thereby punching the titanium alloy blank (10) into a titanium alloy screw (13); Step 4: The punch press controls the telescopic arm to lift the upper die part (1), and under the limiting effect of the conical cylinder structure on the frustum body (11), the upper die core (3) and the hexagonal die core (4) are quickly separated from the frustum body (11); Step 5, the pressed cone-shaped body (11) is rapidly cooled in the cone-shaped cylinder structure. When the cone-shaped body (11) shrinks and the bottom circle diameter △D of the cone-shaped body (11) is equal to D-△L≈d, the cone-shaped body (11) can be ejected from the cone-shaped cylinder structure, and the titanium alloy screw (13) is ejected from the lower mold body (5) by the action of the ejector rod (7); Step 6: The titanium alloy screw (13) is removed by a robot arm, and the next titanium alloy blank (10) is punched in a cycle.

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