A punch two-stage lower hollow knife mold and its mold repair method

Abstract

The present invention relates to a punch two-stage lower hollow knife mold and a mold repair method thereof, wherein the mold includes a punch having a foreman on the discharge side, and the outer side surface of the foreman is sequentially provided with a second-stage lower hollow knife, a first-stage lower hollow knife, a working belt and an upper hollow knife along the discharge direction, forming a stepped structure; the outer side surface of the first-stage lower hollow knife protrudes from the outer side surface of the second-stage lower hollow knife; the outer side surface of the working belt protrudes from the outer side surfaces of the first-stage lower hollow knife and the upper hollow knife. This solution deepens the existing lower hollow knife structure and adds an extra stage of lower hollow knife. The deepening of the lower hollow knife can increase the welding material storage space, increase the welding force, reduce the pressure of the mold extrusion, reduce energy consumption, and the equipment does not need to work overload, effectively improving the surface quality of the profile; and the addition of an extra stage of lower hollow knife can ensure that the working belt will not be excessively deformed or damaged, thereby ensuring the profile forming effect; and it is more convenient to repair the mold and adjust the flow distribution and other issues.

Description

Technical Field

[0001] The invention belongs to the technical field of profile extrusion dies, and in particular relates to a punch two-stage lower hollow knife die and a die repair method thereof. Background Art

[0002] In the existing extrusion die design and production, the lower hollow knife (also known as the buckle) of the punch (also known as the upper die) is a common structure of the through die. Its function is to bear the mold cavity, ensure the strength of the working belt and control the flow rate. For example, the Chinese invention patent application publication number CN108114997A mentioned (the patent is attached) Figure 4 in the “lower air knife 13”); or Figure 1 As shown, the existing lower blade A3 has only one level. This structure is relatively mature and stable, applicable to all through-die extrusion dies. If the lower blade is too deep, the working zone of the die head (also known as the core) will be insufficiently strong, causing excessive deformation during die pressing, affecting profile formation and, in severe cases, even causing the die working zone to collapse. Therefore, the existing lower blade depth is not too deep to ensure the strength of the working zone. However, a shallow lower blade depth can also cause various problems, especially for dies with large die heads. For example, the lower blade has less material storage, resulting in higher extrusion pressure, which can reduce the mold surface quality and easily lead to various defects. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a two-stage hollow knife mold under the punch and a mold repair method thereof, so as to solve the dilemma that if the hollow knife under the punch is too deep, the working belt strength is insufficient, which affects the profile forming, while if it is too shallow, the pressure is too high, which causes defects on the profile surface. By optimizing the structure, the pressure of the mold extrusion is reduced, the energy consumption is reduced, the profile forming effect and surface quality are effectively improved, and the design and adjustment of the mold are more convenient.

[0004] According to the technical solution of the present invention, the present invention provides a punch two-stage lower hollow knife mold, including a punch, the punch having a foreman on the discharge side, and the outer side surface of the foreman is sequentially provided with a secondary lower hollow knife, a primary lower hollow knife, a working belt and an upper hollow knife along the discharge direction to form a stepped structure; the outer side surface of the primary lower hollow knife protrudes from the outer side surface of the secondary lower hollow knife; the outer side surface of the working belt protrudes from the outer side surfaces of the primary lower hollow knife and the upper hollow knife.

[0005] In some embodiments, a working belt additional groove is opened on the side of the working belt, an upper empty knife additional groove is opened on the upper empty knife, and a material guide groove is opened on the side of the first-level lower empty knife and the second-level lower empty knife. The material guide groove, the working belt additional groove and the upper empty knife additional groove are connected in the discharge direction.

[0006] Furthermore, the working belt additional groove is a C-shaped nail position groove, and the shape of the upper hollow knife additional groove corresponds to the working belt additional groove.

[0007] Furthermore, the foreman is located in the center of the punch, and the punch has diversion holes that penetrate along the discharge direction, and diversion bridges are formed between the diversion holes.

[0008] Furthermore, it also includes a die that matches the punch, the die has a recessed welding chamber on the feeding side, and the welding chamber has a die hole that passes through along the discharge direction; after the punch and the die are docked and installed, the foreman is located in the die hole, and a gap for profile forming is formed between the working belt and the die hole, and the gap is the same as the cross-sectional shape of the profile.

[0009] In some embodiments, the outer side of the profile has several protruding structures, and the die hole has a forming groove corresponding to the protruding structure; the welding chamber has a protruding flow-blocking strip on the feeding side, the flow-blocking strip is located in the peripheral area of ​​the forming groove, and the flow-blocking strip is arranged close to the edge of the die hole.

[0010] In some embodiments, the outer side surface of the working belt is rectangular, the width of the working belt at the short side of the rectangle is greater than the width of the working belt at the long side of the rectangle, and / or the depth of the secondary lower empty knife at the short side of the rectangle is less than the depth of the secondary lower empty knife at the long side of the rectangle.

[0011] In some embodiments, the inner side wall of the profile produced by the two-stage lower hollow knife mold of the punch has more than one protruding thick point, and the shapes of the working belt, the first-stage lower hollow knife, and the upper hollow knife all correspond to the inner side wall of the profile, and the side surface of the second-stage lower hollow knife adopts a flat plane or curved surface at the position corresponding to the thick point.

[0012] Preferably, the distance difference between the outer side surface of the secondary lower air knife and the outer side surface of the working belt is 7mm to 8mm, the distance difference between the outer side surface of the primary lower air knife and the outer side surface of the working belt is 5mm, and the width of the primary lower air knife is 8mm.

[0013] According to the technical solution of the present invention, the present invention also provides a mold repair method, which is used for the two-stage lower hollow knife mold of the punch of the present invention, which includes: when repairing the mold, adjusting the depth and / or width of the first-stage lower hollow knife and / or the second-stage lower hollow knife, thereby adjusting the distribution of flow rate and flow rate.

[0014] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0015] 1. The two-stage lower hollow knife mold of the punch and the mold repair method thereof of the present invention further develop and improve the currently common punch lower hollow knife structure, which is equivalent to deepening the depth of the lower hollow knife and adding one more level of lower hollow knife; deepening the lower hollow knife can increase the welding storage space of the foreman's lower hollow knife, increase the welding force, reduce the pressure of the mold extrusion, reduce energy consumption, and the equipment does not need to work under overload, thereby effectively improving the surface quality of the profile; and adding one more level of lower hollow knife can solve the problem of the strength of the punch working belt that may be caused by deepening the lower hollow knife, ensure that the working belt will not be excessively deformed or damaged, and ensure the profile forming effect.

[0016] 2. The two-stage lower hollow knife mold of the punch and the mold repair method thereof of the present invention are particularly suitable for profiles with structures such as nail positions. Because the depth of the lower hollow knife is deepened, the additional grooves corresponding to the structures such as the nail positions on the punch and the material guide groove structure will be easier to feed through the diversion hole. Compared with the existing mold structure, the extrusion pressure can be further reduced and the profile forming rate can be improved.

[0017] 3. The punch two-stage lower hollow knife mold and its mold repair method of the present invention are innovatively provided with a two-stage lower hollow knife structure on the punch, which can make mold design more convenient for adjusting flow distribution and other issues during subsequent mold repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural diagram of the punch head part in the prior art.

[0019] Figure 2 It is a structural schematic diagram of the punch head part of the present invention.

[0020] Figure 3 It is a schematic diagram of the three-dimensional structure of the male mold according to one embodiment of the present invention.

[0021] Figure 4 yes Figure 3 A schematic diagram of the three-dimensional structure of the punch from another perspective.

[0022] Figure 5 It is a schematic diagram of the top structure of the punch according to another embodiment of the present invention.

[0023] Figure 6 is with Figure 5 Schematic diagram of the top view structure of the die corresponding to the punch shown.

[0024] Figure 7 yes Figure 5 、 Figure 6 The cross-sectional structure diagram of the punch and die after docking and installation is shown.

[0025] Figure 8 It is a schematic diagram of the three-dimensional structure of a male mold according to another embodiment of the present invention.

[0026] Figure 9 It is a schematic diagram of the three-dimensional structure of a male mold according to another embodiment of the present invention.

[0027] Figure 10 yes Figure 9 The illustrated embodiment is a schematic diagram of a partial structure of the punch and die after docking and installation.

[0028] Description of reference numerals in the accompanying drawings:

[0029] A1, existing upper air knife;

[0030] A2, existing working belt;

[0031] A3, existing lower empty knife;

[0032] 1. Punch;

[0033] 2. Foreman;

[0034] 3. Second level air knife;

[0035] 4. Level 1 empty knife;

[0036] 5. Work belt;

[0037] 6. Aerial Knife;

[0038] 7. Additional slots for working belt;

[0039] 8. Additional slot for upper air knife;

[0040] 9. Feed chute;

[0041] 10. Diversion hole;

[0042] 11. Diversion bridge;

[0043] 12. Concave die;

[0044] 13. Welding room;

[0045] 14. Die hole;

[0046] 15. Molding groove;

[0047] 16. Flow control zone. DETAILED DESCRIPTION

[0048] The present invention provides a punch two-stage lower hollow knife mold and a mold repair method thereof, which solves the dilemma in existing extrusion molds that if the hollow knife under the punch is too deep, the working zone strength is insufficient, which affects the forming of the profile, while if it is too shallow, the pressure is too high, which causes defects on the surface of the profile. The invention reduces the extrusion pressure of the mold and energy consumption through structural optimization, effectively improves the profile forming effect and surface quality, and is more convenient for mold design and adjustment.

[0049] See also Figure 2A punch-type two-stage lower hollow blade die, according to one embodiment of the present invention, is a profile extrusion die. Similar to the prior art, it comprises a punch 1 with a head 2 on the discharge side. One of the main improvements of the present invention is that the outer side of the head 2 is sequentially arranged along the discharge direction with a second lower hollow blade 3, a first lower hollow blade 4, a working belt 5, and an upper hollow blade 6, forming a stepped structure. This is equivalent to adding an additional lower hollow blade to the existing lower hollow blade structure, hence the name "punch-type two-stage lower hollow blade" structure. In this stepped structure, the outer side of the first lower hollow blade 4 protrudes beyond the outer side of the second lower hollow blade 3, and the outer side of the working belt 5 protrudes beyond the outer sides of the first lower hollow blade 4 and the upper hollow blade 6. In other words, the outer side of the working belt 5 is the outermost, highest step in the stepped structure, with the upper hollow blade 6, the first lower hollow blade 4, and the second lower hollow blade 3 located on either side of it, with the step height gradually decreasing. Optionally, the outer side of the upper hollow blade 6 protrudes beyond (is higher than) the first lower hollow blade 4 and the second lower hollow blade 3. Between the secondary lower hollow knife 3 and the cylindrical main body of the punch 1, that is, the root position of the foreman 2, there is an inclined surface (for example, about 10 degrees) which plays a transition role.

[0050] See also Figure 3 、 Figure 4 In a specific embodiment, a working belt additional groove 7 is provided on the side of the working belt 5, an upper hollow knife additional groove 8 is provided on the upper hollow knife 6, and a feed groove 9 is provided on the side of the first-level lower hollow knife 4 and the second-level lower hollow knife 3. The feed groove 9, the working belt additional groove 7, and the upper hollow knife additional groove 8 are interconnected in the discharge direction. The working belt additional groove 7 is, for example, a C-shaped nail position groove, which is used to form a screw position on the inner side of the profile tube wall. The shape of the upper hollow knife additional groove 8 corresponds to the working belt additional groove 7, that is, it is slightly wider than the outline of the working belt additional groove 7. The feed groove 9 is set to pass through the range of the first-level lower hollow knife 4 and the second-level lower hollow knife 3. In other words, the first-level lower hollow knife 4 is only provided on both sides of the feed groove 9, and there is no "two-level lower hollow knife" stepped structure in the feed groove 9. The feed groove 9 is inclined on the side close to the cylindrical main part of the punch 1, which serves as a transition.

[0051] More specifically, see Figures 5 to 7 , the foreman 2 is located in the center of the punch 1, and the punch 1 has a diversion hole 10 that runs through in the discharge direction. There are multiple diversion holes 10 arranged around the foreman 2, and there are diversion bridges 11 between the diversion holes 10. It also includes a die 12 that matches the punch 1, and the die 12 has a concave welding chamber 13 on the feeding side. The welding chamber 13 has a die hole 14 that runs through in the discharge direction; after the punch 1 and the die 12 are docked and installed, the foreman 2 is located in the die hole 14, and a gap for profile forming is formed between the working belt 5 and the die hole 14. The gap has the same cross-sectional shape as the profile. The raw material of the profile (such as an aluminum bar) is placed on the feeding side end face of the punch 1 ( Figure 7The aluminum material (on the left side of the center) is extruded and, under the action of the diversion bridge 11, is diverted to multiple diversion holes 10. Then, as extrusion progresses, the aluminum material moves toward the die 12, converges and welds at the bottom of the welding chamber 13, and passes through the gap between the working belt 5 and the die hole 14, resulting in a long strip of profile with a cross-sectional shape identical to the gap. The profile can be, for example, a tubular with a hollow structure, but this is not limited to this. All extrusion dies with a die head 2 can adopt the solution of the present invention.

[0052] More preferably, Figure 6 、 Figure 7 As shown, the outer side of the profile has a number of raised structures, such as a groove structure, a cantilever structure, etc. located on the outer side, and the die hole 14 has a molding groove 15 corresponding to the raised structure. The welding chamber 13 has a raised flow blocking strip 16 on the feeding side. The flow blocking strip 16 is located in the peripheral area of ​​the molding groove 15, such as on both sides of the molding groove 15 and / or between adjacent molding grooves 15, and the flow blocking strip 16 is set close to the edge of the die hole 14. The flow blocking strip 16 is equivalent to forming a certain height of the enclosure next to the die hole 14. The aluminum material needs to cross the flow blocking strip 16 before entering the die hole 14. Therefore, the flow rate of the aluminum material at the flow blocking strip 16 is slowed down, so that more aluminum material can be filled into the molding groove 15, and the flow rate and flow rate at the molding groove 15 and the rest of the parts are matched, so that a more ideal profile forming effect can be obtained.

[0053] See also Figure 8 In another embodiment, the width of the working belt 5 is different at different places, which can also play a role in adjusting the forming effect. For example, the inner side of the cavity structure of the profile is rectangular, and the outer side of the working belt 5 is also rectangular. Since the wall thickness of the short side of the rectangular profile is thicker than the wall thickness of the long side, the width of the working belt 5 at the short side of the rectangle is greater than the width of the working belt 5 at the long side of the rectangle. The depth of the secondary lower hollow knife 3 at the short side is less than the depth of the secondary lower hollow knife 3 at the long side; the primary lower hollow knife 4 runs along the inner side of the cavity structure of the profile to ensure the strength of the working belt 5, and the secondary lower hollow knife 3 can be set to different depths according to the thickness of the profile, especially, for example Figure 9 、 Figure 10In the illustrated embodiment, the inner sidewall of the cavity of the profile produced by the two-stage lower hollow knife mold of the punch has one or more thick points protruding inward (i.e., there are one or more sections with different wall thicknesses on one side wall of the profile). For this profile structure, preferably, the shapes of the working belt 5, the first-stage lower hollow knife 4, and the upper hollow knife 6 all correspond to the inner sidewall of the profile (with groove structures corresponding to the thick points), while the side surface of the second-stage lower hollow knife 3 adopts a flat plane or curved surface consistent with the surrounding area at the position corresponding to the thick point (without the groove structure corresponding to the thick point); in other words, The first-level lower hollow knife 4 can be set to accommodate the uneven surface of the profile, while the second-level lower hollow knife 3 passes through one surface. There is no need to make the second-level lower hollow knife 3 uneven and complicated due to multiple thick spots. This makes processing more convenient and quick. At the same time, the second-level lower hollow knife 3 passes through one surface, which in turn reduces the depth of the lower hollow knife at the thick spot position, thereby slowing down the flow rate at the thick spot position. In this way, these thick spot positions no longer need to set a height difference on the working belt to balance the flow rate, directly avoiding defects such as shadowing and color difference on the profile surface caused by too many height differences in the working belt.

[0054] In a specific embodiment, based on the outer side of the working belt 5, the distance difference between the outer side of the secondary lower air knife 3 and the outer side of the working belt 5 (or the depth of the secondary lower air knife 3) is 7mm to 8mm, the distance difference between the outer side of the primary lower air knife 4 and the outer side of the working belt 5 is 5mm (or the depth of the primary lower air knife 4), and the width (or height, referring to the length along the discharge direction) of the primary lower air knife 4 is 8mm. This preferred size design is suitable for Figures 3 to 8 The embodiment shown and similar molds can achieve good results.

[0055] In summary, in the existing technical solution, there is only one level of hollow knife under the punch. This solution deepens the depth of the hollow knife under the punch and adds one more level of hollow knife to form a two-level hollow knife structure. The depth of the hollow knife under the existing technology is generally 2-3mm deep. This solution is preferably changed to 7-8mm deep, and at the same time, a lower hollow knife with a height of 8mm and a depth of 5mm is added. Deepening the hollow knife under the punch can increase the welding storage space of the hollow knife under the foreman, increase the welding force, reduce the pressure of mold extrusion, reduce energy consumption, and the equipment does not need to work under overload, which effectively improves the surface quality of the profile; and adding one more level of hollow knife under the punch can solve the problem of the strength of the punch working belt caused by deepening the hollow knife. In particular, for profiles with structures such as screw positions, a material guide groove is provided at the corresponding position of the foreman's lower hollow knife. The material guide groove is not a two-stage lower hollow knife, but only a two-stage lower hollow knife structure is made on the large surface outside the material guide groove. After the depth of the lower hollow knife is deepened, it is easier to feed the diversion hole for structures such as nail positions, which helps to improve the profile forming rate and avoid problems such as insufficient aluminum material and difficulty in complete forming at protruding nail positions and other structures.

[0056] Furthermore, the mold structure of this solution also facilitates subsequent mold repair. Mold repair, also known as die correction, is a crucial step in the design and use of extrusion dies. It is typically performed when the extrusion molding results are unsatisfactory, adjusting the actual mold and / or die design. Existing mold repair methods include blocking, accelerating, expanding or reducing the die hole size, honing and polishing, and surface nitriding. This solution, with its two-stage lower air knife structure, also provides a new, more flexible, and convenient method for mold repair.

[0057] Therefore, based on the two-stage hollow knife mold of the punch described in the present invention, the present invention also provides a mold repair method, which includes: when repairing the mold, adjusting the depth and / or width of the first-stage hollow knife 4, so as to adjust the distribution of flow rate and flow rate. For example, if you want to increase the flow rate or flow rate at a certain place, reduce the depth or width of the first-stage hollow knife 4 at that place to obtain a larger feeding and storage space. More specifically, for example, when repairing the mold at present, it is often encountered that the profile extrusion molding effect is not ideal due to the slow flow rate at the bottom of the diversion bridge and the unbalanced flow rate at other positions of the mold. For this situation, the existing mold repair methods include: Figure 1 In the existing structure shown, the welding iron block at the lower hollow blade A3 blocks the large surface or the diversion bridge surface is milled down. These mold repair methods require the mold to be sent back to the workshop for welding or milling operations, which is time-consuming and labor-intensive. However, when the mold structure of the mold with this solution encounters the same problem, the mold repairer only needs to use a grinding gun to mill off a part of the first-level lower hollow blade 4 at the bottom of the diversion bridge. Other flow rate imbalance problems can also be solved by adjusting the depth and / or width of the first-level lower hollow blade 4 in this way, thereby adjusting the flow rate distribution more flexibly and conveniently.

Claims

1. A two-stage punch lower hollow knife mold, comprising a punch (1), wherein the punch (1) has a head (2) on the discharge side, characterized in that: The outer side surface of the foreman (2) is provided with a secondary lower hollow knife (3), a primary lower hollow knife (4), a working belt (5) and an upper hollow knife (6) in sequence along the discharge direction, forming a stepped structure; the outer side surface of the primary lower hollow knife (4) protrudes from the outer side surface of the secondary lower hollow knife (3); the outer side surface of the working belt (5) protrudes from the outer side surfaces of the primary lower hollow knife (4) and the upper hollow knife (6); A working belt additional groove (7) is provided on the side of the working belt (5), an upper hollow knife additional groove (8) is provided on the upper hollow knife (6), and a material guide groove (9) is provided on the side of the first-level lower hollow knife (4) and the second-level lower hollow knife (3), wherein the material guide groove (9), the working belt additional groove (7) and the upper hollow knife additional groove (8) are interconnected in the discharge direction; The foreman (2) is located at the center of the punch (1), and the punch (1) has a diversion hole (10) extending along the discharge direction, and a diversion bridge (11) is formed between the diversion holes (10); It also includes a die (12) matching the male die (1), the female die (12) having a recessed welding chamber (13) on the feeding side, and a die hole (14) extending through the welding chamber (13) along the discharge direction; after the male die (1) and the female die (12) are docked and installed, the foreman (2) is located in the die hole (14), and a gap for profile forming is formed between the working belt (5) and the die hole (14), and the gap has the same cross-sectional shape as the profile.

2. The punch two-stage lower hollow knife mold according to claim 1, characterized in that: The working belt additional groove (7) is a C-shaped nail position groove, and the shape of the upper hollow knife additional groove (8) corresponds to the working belt additional groove (7).

3. The punch two-stage lower hollow knife mold according to claim 1, characterized in that: The outer side surface of the profile has a plurality of protruding structures, and the die hole (14) has a forming groove (15) corresponding to the protruding structures; the welding chamber (13) has a protruding flow-blocking strip (16) on the feeding side surface, and the flow-blocking strip (16) is located in the peripheral area of ​​the forming groove (15), and the flow-blocking strip (16) is arranged close to the edge of the die hole (14).

4. The punch two-stage lower hollow knife mold according to any one of claims 1 to 3, characterized in that: The outer side surface of the working belt (5) is rectangular, the width of the working belt (5) at the short side of the rectangle is greater than the width of the working belt (5) at the long side of the rectangle, and / or the depth of the secondary lower air knife (3) at the short side of the rectangle is less than the depth of the secondary lower air knife (3) at the long side of the rectangle.

5. The punch two-stage lower hollow knife mold according to any one of claims 1 to 3, characterized in that: The inner side wall of the profile produced by the two-stage lower hollow knife mold of the punch has more than one protruding thick point, the shapes of the working belt (5), the first-stage lower hollow knife (4), and the upper hollow knife (6) all correspond to the inner side wall of the profile, and the side surface of the second-stage lower hollow knife (3) adopts a flat plane or curved surface at the position corresponding to the thick point.

6. The punch two-stage lower hollow knife mold according to any one of claims 1 to 3, characterized in that: The distance difference between the outer side surface of the secondary lower air knife (3) and the outer side surface of the working belt (5) is 7 mm to 8 mm, the distance difference between the outer side surface of the primary lower air knife (4) and the outer side surface of the working belt (5) is 5 mm, and the width of the primary lower air knife (4) is 8 mm.

7. A mold repair method, characterized in that: It is used for the punch two-stage lower hollow knife mold as described in any one of claims 1 to 6, which includes: when repairing the mold, adjusting the depth and / or width of the first-stage lower hollow knife (4) and / or the second-stage lower hollow knife (3), thereby adjusting the distribution of flow rate and flow rate.

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