Upsetting die

Abstract

The utility model relates to the technical field of forging, and particularly discloses an upsetting die which is characterized in that a first cavity of an upper die and a second cavity of a lower die define a cavity. The guide structure comprises a first guide part and a second guide part, the first guide part is arranged on the upper die, and the second guide part is arranged on the lower die. When the upper die and the lower die are buckled, a bar is arranged between the upper die and the lower die, the first guide part and the second guide part are in clearance fit and can slide relatively, and accurate positioning between the upper die and the lower die is ensured. And then the upper die is stamped, the wall face of the seam after the upper die and the lower die are closed is kept smooth, and the bar is upset into a target blank with the shape consistent with that of the cavity. In the upsetting process, the target blank is located in the cavity all the time, the upper die and the lower die limit the appearance of the target blank, it is guaranteed that the target blank is machined into the target shape, the double-drum-degree phenomenon is effectively reduced, and the target blank is smooth in appearance, free of flash and collapse and good in size consistency.

Description

Technical Field

[0001] The utility model relates to the technical field of forging, in particular to a upset forging die. Background Art

[0002] For some shaft neck forgings, due to their large height-to-diameter ratio, the height-to-diameter ratio of the blank required for die forging is also large. The circumferential surface of the blank designed conventionally has a risk of folding during die forging, thus affecting the final forming quality of the product.

[0003] Currently, the commonly used blank making method is: using the method of free forging upset without a die to make a blank with a bulge on the circumferential surface. However, for some bar materials with a large height-to-diameter ratio, forging defects of double bulges will appear on the circumferential surface of the blank after free forging upset. For some blanks with poor surface quality (such as remelted and ground blanks), the double bulge phenomenon is more serious after free forging upset, and even local folding or skewing of the blank may occur; for blanks with even worse surface quality and low consistency of external dimensions, the forming quality of free forging upset is even worse.

[0004] Therefore, there is an urgent need for an upset forging die to solve the above problems. Summary of the Utility Model

[0005] The purpose of the utility model is to provide an upset forging die. By placing a bar material with a large height-to-diameter ratio in the die for upset forging, it is ensured that the forming quality of the blank is better, the appearance is smooth without burrs, and the dimensional consistency is good.

[0006] To achieve the above purpose, the utility model adopts the following technical solutions:

[0007] The utility model provides an upset forging die for processing a bar material with a large height-to-diameter ratio into a target blank. The upset forging die includes:

[0008] An upper die, a first chamber with an opening on one side is formed inside the upper die;

[0009] A lower die, a second chamber with at least one opening on one side is formed inside the lower die;

[0010] A guiding structure, including a first guiding part and a second guiding part which cooperate with each other. The first guiding part is arranged on the upper die, and the second guiding part is arranged on the lower die. When the upper die and the lower die are buckled, the first guiding part and the second guiding part are in clearance fit and can slide relative to each other. The first chamber and the second chamber enclose a forming cavity, the bar material is arranged in the forming cavity, and the shape of the forming cavity after upset forging is consistent with the shape of the target blank.

[0011] Optionally, the upper mold includes a first circular base and a first annular plate which are coaxially arranged, the first annular plate is connected to the outer edge of the first circular base, and the first guide portion is a partial outer wall of the first annular plate;

[0012] The lower mold includes a coaxially arranged second circular base and a second annular plate. The center of the second circular base is hollowed out to form the second chamber. A clearance step is formed between the top surface of the second circular base and the inner wall of the second annular plate. The first annular plate is inserted into the clearance step, and part of the inner wall of the second annular plate forms the second guide portion.

[0013] Optionally, the inner wall of the first annular plate and the inner wall of the second circular base together form a waist-drum-shaped curved surface, and the waist-drum-shaped curved surface fits with the peripheral side wall of the target blank.

[0014] Optionally, the upper die and the lower die are separated at a middle position in the height direction of the target blank, and the contact surface between the first annular plate and the second circular base is located in the same plane as the cross section with the largest diameter of the target blank.

[0015] Optionally, the center of the second circular base is hollowed out to form a through hole, and two openings are formed on opposite sides of the second chamber.

[0016] Optionally, a limiting convex portion is provided on a side of the first circular base close to the first cavity, and the limiting convex portion abuts against the top of the target blank.

[0017] Optionally, a first groove is provided on the outer side of the upper mold, and a second groove is provided on the outer side of the lower mold, and the first groove and the second groove are used to be clamped by a robot.

[0018] Optionally, a gap between the first guide portion and the second guide portion is Br, and a value range of the gap Br is 0.5 mm-1.0 mm.

[0019] Optionally, along the height direction of the upsetting die, the height of the first guide portion is H, and the value range of the height H is H≥15.0 mm.

[0020] Optionally, the volume margin coefficient of the upsetting die is r, r=V1 / V2, and the value range of the volume margin coefficient r is 1.01-1.03;

[0021] Among them, the volume of the cavity is V1, and the volume of the target blank is V2.

[0022] The beneficial effects of the utility model are:

[0023] The utility model provides an upset forging die, comprising an upper die, a lower die and a guide structure, wherein a first cavity of the upper die and a second cavity of the lower die enclose a cavity. The guide structure comprises a first guide portion and a second guide portion that cooperate with each other, wherein the first guide portion is arranged on the upper die, and the second guide portion is arranged on the lower die. When the upper die is buckled with the lower die, a bar is placed between the upper die and the lower die, and the first guide portion and the second guide portion are clearance-matched and can slide relatively, thereby ensuring accurate positioning between the upper die and the lower die. Afterwards, the upper die is punched, and the wall surface at the joint after the upper die and the lower die are closed is kept smooth, and the bar is upset into a target blank that is consistent with the shape of the cavity. During the upsetting process, the target blank is always located in the cavity, and the upper die and the lower die restrict the shape of the target blank, thereby ensuring that the target blank is processed into a target shape, effectively reducing the occurrence of the double-drum phenomenon, and the appearance of the target blank is smooth, without burrs or collapse, and the size consistency of the target blank is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of an upsetting die (before upsetting) in an embodiment of the utility model;

[0025] Figure 2 It is a structural schematic diagram of the upsetting die (after upsetting) in the embodiment of the utility model.

[0026] In the figure:

[0027] 10. Bar stock; 11. Target blank;

[0028] 100, upper mold; 110, first circular base; 111, limiting convex portion; 120, first annular plate; 121, first guide portion; 122, first groove;

[0029] 200, lower mold; 210, second circular base; 220, second annular plate; 221, second guide portion; 222, second groove; 230, clearance step; 2301, contact surface. DETAILED DESCRIPTION

[0030] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0032] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected" and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0033] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present utility model and cannot be construed as a limitation on the present utility model.

[0034] As Figure 1 and Figure 2 shown, this embodiment provides a upsetting die for processing a bar 10 with a large height-to-diameter ratio into a target blank 11. The upsetting die includes an upper die 100, a lower die 200 and a guiding structure. Among them, a first chamber with an opening on one side is formed inside the upper die 100, and a second chamber with at least one opening on one side is formed inside the lower die 200. The guiding structure includes a first guiding portion 121 and a second guiding portion 221 that cooperate with each other. The first guiding portion 121 is provided on the upper die 100, and the second guiding portion 221 is provided on the lower die 200.

[0035] When the upper die 100 and the lower die 200 are buckled, the lower die 200 is placed on the workbench, the first guide portion 121 and the second guide portion 221 are in clearance fit and can slide relative to each other, the first cavity and the second cavity surround the mold cavity, and the bar 10 is set in the mold cavity. At this time, the upper die 100 and the lower die 200 are in contact with the bar 10 at the same time. Through the arrangement of the first guide portion 121 and the second guide portion 221, when the upper die 100 and the lower die 200 are closed, the upper die 100 can be buckled with the lower die 200 along the first direction (the first direction is the axial direction of the upsetting die, and also the axial direction of the upper die 100 and the lower die 200), ensuring accurate positioning between the upper die 100 and the lower die 200. Then, the upper die 100 is punched with an upset punch to make the upper die 100 approach the lower die 200. After the upper die 100 and the lower die 200 are closed, the wall surface at the joint remains flush, that is, the outside of the cavity is a smooth interface, and then the bar 10 with a large aspect ratio is upset into a target blank 11 that is consistent with the shape of the cavity. Finally, the upper die 100 and the lower die 200 are separated, and the target blank 11 is taken out of the lower die 200, and the processing of the target blank 11 is completed.

[0036] In this upsetting process, since the target blank 11 is located in the cavity, the upper die 100 and the lower die 200 can limit the shape of the target blank 11. As long as the volume of the cavity is sufficient, the target blank 11 can be processed into the target shape, effectively reducing the occurrence of the double-drum phenomenon, and the appearance of the target blank 11 is smooth without flash and collapse. At the same time, because each target blank 11 is upset using the same upsetting die, the size of each target blank 11 can be kept consistent.

[0037] As an optional solution, the upper mold 100 in this embodiment includes a first circular base 110 and a first annular plate 120 which are coaxially arranged, the first annular plate 120 is connected to the outer edge of the first circular base 110, and the first annular plate 120 is flush with the outer wall surface of the first circular base 110, and the first annular plate 120 and the first circular base 110 jointly enclose a first chamber. Exemplarily, the first circular base 110 and the first annular plate 120 are an integral structure. The lower mold 200 includes a second circular base 210 and a second annular plate 220 which are coaxially arranged, the center of the second circular base 210 is hollowed out to form a second chamber, a clearance step 230 is formed between the top surface of the second circular base 210 and the inner wall of the second annular plate 220, and the clearance step 230 is for the first annular plate 120 to be inserted, a part of the outer wall of the first annular plate 120 forms a first guide portion 121, and a part of the inner wall of the second annular plate 220 forms a second guide portion 221. When the upper die 100 and the lower die 200 are buckled, the first guide portion 121 and the second guide portion 221 can be used for guidance and positioning, so as to ensure that the upper die 100 is inserted into the lower die 200 along the first direction, accurately positioned, and avoid forging deviation.

[0038] Further, the gap between the first guiding portion 121 and the second guiding portion 221 is Br, and the value range of the gap Br is 0.5 mm - 1.0 mm. For example, the gap Br can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1.0 mm. By providing the gap Br between the first guiding portion 121 and the second guiding portion 221, the upper die 100 and the lower die 200 can be prevented from being locked, which helps the target blank 11 to be demolded. It should be noted that the gap Br not only exists before the upset forging of the bar 10, but also exists between the upper die 100 and the lower die 200 after the upset forging of the bar 10, but the gap Br is smaller and is not shown in the figure. Figure 2 Further, along the height direction of the upset forging die, the height of the first guiding portion 121 is H, and the value range of the height H is H ≥ 15.0 mm. Exemplarily, the height H can be 15.0 mm, 16.0 mm, 17.0 mm, 18.0 mm, 19.0 mm, 20.0 mm. It should be noted that the height H of the first guiding portion 121 should not be too small, otherwise the upset forging die has a risk of cracking and a short service life.

[0039] Optionally, in this embodiment, a through hole is formed by hollowing out the center of the second circular base 210, and two openings are formed on opposite sides of the second chamber. That is, when the bar 10 is inserted into the second chamber, the bottom end of the bar 10 will contact the workbench, and at this time, the material used for the lower die 200 can be relatively reduced, saving costs. Of course, in other embodiments, the center of the second circular base 210 may not be completely hollowed out to form a through hole, and an opening may be formed on one side where the second annular plate 220 is provided to communicate with the second chamber.

[0040] Continue to refer to Figure 2 , in this embodiment, the target blank 11 is integrally waist-shaped, that is, starting from the bottom of the target blank 11, the diameter of the cross-section gradually increases along the height direction of the target blank 11 until reaching the middle position in the height direction of the target blank 11 where the diameter of the target blank 11 is the largest, and then the diameter of the cross-section gradually decreases along the height direction of the target blank 11 until the diameter of the top cross-section of the target blank 11 is the same as the diameter of the bottom cross-section, so as to form an outwardly convex arc surface on the circumferential side wall of the target blank 11. The inner wall of the first annular plate 120 and the inner wall of the second circular base 210 together form a waist-shaped arc surface, and the waist-shaped arc surface fits with the circumferential side wall of the target blank 11. Here, the waist-shaped arc surface refers to an arc surface that is recessed from the middle position of the height of the upset forging die to both sides, and the recessed direction of the waist-shaped arc surface is perpendicular to the first direction. That is to say, half of the circumferential side wall of the target blank 11 is restricted by the upper die 100, and the other half is restricted by the lower die 200.

[0041] Further, in this embodiment, the upper die 100 and the lower die 200 are selected to be parted at the middle position in the height direction of the target blank 11. The contact surface 2301 between the first annular plate 120 and the second circular base 210 is in the same plane as the cross-section with the largest diameter of the target blank 11. That is to say, half of the target blank 11 after upsetting is located in the first chamber, and the other half is located in the second chamber. Selecting the parting position at the cross-section with the largest diameter of the target blank 11 is to ensure the smooth demolding of the target blank 11.

[0042] Optionally, in this embodiment, the volume allowance coefficient of the upsetting die is r, r = V1 / V2, and the value range of the volume allowance coefficient r is 1.01 - 1.03; where, the volume of the cavity is V1, and the volume of the target blank 11 is V2. For example, the volume allowance coefficient r can be 1.01, 1.02, or 1.03. By setting the volume allowance coefficient, the bar stock 10 will not completely fill the cavity during upsetting, and there is still a small space in the cavity, thereby avoiding cracking of the upsetting die and also avoiding burrs or flash on the surface of the target blank 11 formed after upsetting the bar stock 10, which helps to ensure the smooth outer surface of the target blank 11 and high product quality.

[0043] Further, a limiting convex portion 111 is provided on one side of the first circular base 110 close to the first chamber, and the limiting convex portion 111 abuts against the top of the bar stock 10 or the target blank 11. By providing the limiting convex portion 111, on the one hand, it is to upset the bar stock 10 into the target blank 11 with the target shape; on the other hand, it can also play a certain limiting effect on the bar stock 10 to prevent the position of the bar stock 10 from shifting during the upsetting process.

[0044] Optionally, a first groove 122 is provided on the outer side of the upper die 100 in this embodiment, and a second groove 222 is provided on the outer side of the lower die 200. The first groove 122 and the second groove 222 are the clamping ports of the manipulator. By providing the first groove 122 and the second groove 222, the upper die 100 and the lower die 200 are easily clamped by the manipulator, preventing the upper die 100 and the lower die 200 from slipping off the manipulator. More preferably, anti-slip lines can also be engraved on the bottom walls of the first groove 122 and the second groove 222 to further improve the reliability of the manipulator clamping the upper die 100 and the lower die 200.

[0045] Obviously, the above embodiments of the present invention are only examples for clearly explaining the present invention, and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An upsetting die for processing a bar (10) with a large aspect ratio into a target blank (11), characterized in that: The upsetting die comprises: An upper mold (100), wherein the inner side of the upper mold (100) forms a first cavity with one side open; A lower mold (200), wherein the inner side of the lower mold (200) forms a second cavity with at least one side open; The guide structure comprises a first guide portion (121) and a second guide portion (221) which cooperate with each other, wherein the first guide portion (121) is arranged on the upper die (100), and the second guide portion (221) is arranged on the lower die (200); when the upper die (100) and the lower die (200) are engaged, the first guide portion (121) and the second guide portion (221) are loosely matched and can slide relative to each other; the first chamber and the second chamber surround a mold cavity; the bar (10) is arranged in the mold cavity; and after upsetting, the shape of the mold cavity is consistent with the shape of a target blank (11).

2. The upsetting die according to claim 1, characterized in that: The upper mold (100) comprises a first circular base (110) and a first annular plate (120) which are coaxially arranged, the first annular plate (120) being connected to the outer edge of the first circular base (110), and the first guide portion (121) being a portion of the outer wall of the first annular plate (120); The lower mold (200) comprises a second circular base (210) and a second annular plate (220) which are coaxially arranged. The center of the second circular base (210) is hollowed out to form the second chamber. A clearance step (230) is formed between the top surface of the second circular base (210) and the inner wall of the second annular plate (220). The first annular plate (120) is inserted into the clearance step (230). Part of the inner wall of the second annular plate (220) forms the second guide portion (221).

3. The upsetting die according to claim 2, characterized in that: The inner wall of the first annular plate (120) and the inner wall of the second circular base (210) together form a waist-drum-shaped curved surface, and the waist-drum-shaped curved surface is in contact with the peripheral side wall of the target blank (11).

4. The upsetting die according to claim 3, characterized in that: The upper die (100) and the lower die (200) are separated at the middle position in the height direction of the target blank (11), and the contact surface (2301) between the first annular plate (120) and the second circular base (210) is located in the same plane as the cross section with the largest diameter of the target blank (11).

5. The upsetting die according to claim 2, characterized in that: The center of the second circular base (210) is hollowed out to form a through hole, and two openings are formed on opposite sides of the second chamber.

6. The upsetting die according to claim 2, characterized in that: A limiting convex portion (111) is provided on one side of the first circular base (110) close to the first chamber, and the limiting convex portion (111) abuts against the top of the target blank (11).

7. The upsetting die according to claim 1, characterized in that: A first groove (122) is provided on the outer side of the upper mold (100), and a second groove (222) is provided on the outer side of the lower mold (200). The first groove (122) and the second groove (222) are used for being clamped by a robot.

8. The upsetting die according to claim 1, characterized in that: A gap between the first guide portion (121) and the second guide portion (221) is Br, and a value range of the gap is 0.5 mm-1.0 mm.

9. The upsetting die according to claim 1, characterized in that: Along the height direction of the upsetting die, the height of the first guide portion (121) is H, and the value range of the height H is H≥15.0 mm.

10. The upsetting die according to claim 1, characterized in that: The volume margin coefficient of the upsetting die is r, r=V1 / V2, and the value range of the volume margin coefficient r is 1.01-1.03; The volume of the cavity is V1, and the volume of the target blank (11) is V2.

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