Internal hex profile step-out profile screw finish-up forming negative mold

Abstract

This utility model relates to the field of fastener processing and discloses a female mold for final upsetting of an internal six-petal stepped irregular screw, including a female mold sleeve, a female mold core assembly, a pad, a screw locking sleeve, and a female mold ejector rod. The female mold core assembly includes a C-shaped ring locking sleeve and a first round insert, a second round insert, and a third round insert arranged coaxially from left to right within the C-shaped ring locking sleeve. The inner diameter of the first round insert matches the outer diameter of the step of the product and is used to form the head step of the product. The inner diameter of the second round insert matches the outer diameter of the rod of the product and is used to form the head step surface and the oil groove on it, as well as to bind the rod. The third round insert has a rod reduction cavity for forming the rod of the product. The hardness of the first round insert is greater than that of the second round insert, and the hardness of the second round insert is less than that of the third round insert. This utility model has the advantages of long service life and low replacement cost.

Description

Technical Field

[0001] This utility model relates to the field of fastener processing, and in particular to a final upset forming die for an internal six-petal stepped irregular screw. Background Technology

[0002] There is a type of internal hexagonal stepped irregular screw, as shown in the attached image. Figure 1 As shown, a preform is formed by cold heading using a preceding cold heading die, and then a final heading die is used to form the flange and step at the head, as well as the shrinkage of the rod, into a semi-finished product. Finally, it is finished by thread rolling. The currently used final heading die consists of a male die and a female die. The male die is used to form the inner six-petal hole at the head of the semi-finished product and the outer circular surface of the flange. The female die is used to form the step at the head of the flange and the shrinkage of the rod. The female die is shown in the attached figure. Figure 2 As shown, it mainly consists of a female mold sleeve 1, a first female mold core a, a second female mold core b, a pad block 6, a locking sleeve 7, and a female mold ejector rod 8. The first female mold core is located inside the tapered hole of the female mold sleeve, and the second female mold core is located inside the first female mold core. The first and second female mold cores are used together to form the head cylinder and rod part of the product. The existing final upsetting female mold has the following defects:

[0003] 1. Because the tail of the product needs to be tapered, the material of the second female mold core must be hard. Currently, the first female mold core is made of VA80 material with a hardness of HRA84-85, while the second female mold core is made of KG6 material with a hardness of HRA87-88. However, the head of the product has a large diameter, and there is an annular oil groove on the step, which is formed by a protruding ring at the end of the second female mold core. The contact area of ​​the protruding ring is small, while the force of forming the head is large. Therefore, if the hardness of the second female mold core is too high, the protruding ring is prone to breakage and fragmentation, resulting in a short mold life.

[0004] 2. When the second female mold core is damaged, the first female mold core needs to be removed and the second female mold core replaced. If the second female mold core is damaged multiple times, the original first female mold core can no longer be reliably pressed into the female mold sleeve (multiple pressing of the first female mold core will enlarge the mounting hole of the female mold sleeve). Therefore, the first female mold core also needs to be replaced, which increases the replacement cost.

[0005] Based on this, this application provides a final upsetting female mold for internal six-petal stepped irregular screws with a long service life, low replacement cost, and more reasonable design to solve the above problems. Utility Model Content

[0006] This utility model aims to solve the technical problems existing in the prior art. To this end, this utility model provides a final upset forming female mold for internal six-petal stepped irregular screws with a long mold service life, low replacement cost due to damage, and a more reasonable design.

[0007] The technical solution adopted by this utility model to solve its technical problem is:

[0008] A die for final upsetting a hexagonal stepped irregular screw is provided, comprising a die sleeve, a die core assembly disposed within the die sleeve, a pad disposed within the die sleeve to abut against the die core assembly, a locking sleeve screwed to the end of the die sleeve for locking the pad, and a die push rod penetrating the locking sleeve and the pad and extending into the die core; the die core assembly includes a C-ring locking sleeve and a first round insert, a second round insert, and a third round insert coaxially disposed from left to right within the C-ring locking sleeve, wherein: the inner diameter of the inner cavity of the first round insert matches the outer diameter of the step of the product, and is used to form the head step of the product; the inner diameter of the inner cavity of the second round insert matches the outer diameter of the rod of the product, and is used to form the head step surface of the product and the oil groove thereon, as well as to bind the rod; the third round insert has a rod reduction cavity for rod reduction forming of the product; the hardness of the first round insert is greater than the hardness of the second round insert, and the hardness of the second round insert is less than the hardness of the third round insert.

[0009] In some alternative embodiments, the first circular meson is made of VA80 material with a hardness of HRA84-85; the second circular meson is made of VA95 material with a hardness of HRA81-82; and the third circular meson is made of KG6 material with a hardness of HRA87-88.

[0010] In some optional embodiments, the end of the female mold sleeve away from the locking sleeve is provided with an installation hole whose inner diameter increases from the outside to the inside, and the C-type ring locking sleeve is a conical sleeve that matches the installation hole, and has a circular through hole inside for installing the first round spacer, the second round spacer and the third round spacer.

[0011] In some alternative embodiments, the C-ring locking sleeve is made of SKH9 material with a hardness of HRC58-60.

[0012] In some alternative embodiments, the end face of the second circular interferometer near the first circular interferometer is provided with a raised ring for forming an oil groove on the stepped surface of the product.

[0013] In some optional embodiments, the end face of the first circular meson near the second circular meson is evenly distributed with a plurality of first exhaust grooves, and the outer circular surface of the first circular meson is evenly distributed with a plurality of second exhaust grooves that communicate with the first exhaust grooves.

[0014] In some optional embodiments, the end face of the third circular spacer near the pad is evenly distributed with a plurality of third vent grooves, the end face of the C-shaped ring locking sleeve near the pad is provided with a plurality of fourth vent grooves corresponding to the third vent grooves, and the female mold sleeve is provided with a plurality of fifth vent grooves corresponding to the fourth vent grooves.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. The female mold core assembly designed in this utility model utilizes three round inserts of different hardness to achieve the head step and the oil groove forming and the rod shrinking forming. The oil groove is formed by the relatively soft second round insert, while the shrinking rod is formed by the relatively hard third round insert. This split structure can effectively improve the service life of the female mold core while ensuring the forming quality of the rod.

[0017] 2. The first, second, and third round inserts are press-fitted into the female mold sleeve by a C-ring locking sleeve, which facilitates the replacement of a damaged round insert and reduces replacement costs. When the round inserts are replaced multiple times, only the C-ring locking sleeve needs to be replaced. The replacement cost of the C-ring locking sleeve is lower than that of the traditional first female mold core. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0019] Figure 1 This is a flowchart of the product processing provided by this utility model;

[0020] Figure 2 This is a schematic diagram of the structure of the traditional internal six-petal-shaped stepped irregular screw final upsetting female mold;

[0021] Figure 3 This is a schematic diagram of the structure of the internal six-petal stepped irregular screw final upsetting female mold provided by this utility model;

[0022] Figure 4 This is a cross-sectional view of the C-type ring locking sleeve provided by this utility model;

[0023] Figure 5 yes Figure 4 Left view of the provided C-ring locking sleeve;

[0024] Figure 6 yes Figure 4 Right view of the provided C-ring locking sleeve;

[0025] Figure 7 yes Figure 3 The right view of the first circular meson provided;

[0026] Figure 8 yes Figure 7 A cross-sectional view of the first circular meson is provided;

[0027] Figure 9 This is a cross-sectional view of the second circular meson provided by this utility model;

[0028] Figure 10 This is a cross-sectional view of the third circular meson provided by this utility model;

[0029] Figure 11 yes Figure 10 The right view of the third circular meson provided.

[0030] The attached diagram lists the components represented by each number as follows:

[0031] 1—Female mold sleeve, 1.1—Fifth venting groove, 2—C-type ring locking sleeve, 2.1—Fourth venting groove, 3—First round insert, 3.1—First venting groove, 3.2—Second venting groove, 4—Second round insert, 4.1—Protruding ring, 5—Third round insert, 5.1—Third venting groove, 6—Padded block, 7—Locking sleeve, 8—Female mold ejector rod, a—First female mold core, b—Second female mold core. Detailed Implementation

[0032] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0034] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0035] Furthermore, the terms "first," "second," etc., used in this utility model are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. The terms "installed," "connected," and "joined" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0036] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0037] Example 1

[0038] As attached Figure 3 As shown, this embodiment provides a final upset forming female mold for an internal hexagonal stepped irregular screw, including a female mold sleeve 1, a female mold core assembly disposed within the female mold sleeve, a pad 6 disposed within the female mold sleeve to abut against the female mold core assembly, a locking sleeve 7 screwed to the end of the female mold sleeve for locking the pad, and a female mold ejector rod 8 penetrating the locking sleeve and the pad and extending into the female mold core, wherein:

[0039] The female mold core assembly includes a C-shaped ring locking sleeve 2 and a first circular insert 3, a second circular insert 4, and a third circular insert 5, which are coaxially arranged from left to right within the C-shaped ring locking sleeve, wherein:

[0040] The end of the female mold sleeve 1 away from the locking sleeve 7 is provided with an installation hole whose inner diameter increases from the outside to the inside. In this embodiment, the taper of the installation hole is preferably 6°.

[0041] As attached Figure 4 To be continued Figure 6 As shown, the C-shaped locking sleeve 2 is a tapered sleeve that matches the mounting hole. It has a circular through hole for installing the first circular insert 3, the second circular insert 4, and the third circular insert 5. In this embodiment, the C-shaped locking sleeve provides covering force for the first, second, and third circular inserts. After assembly, the four components are pressed into the mounting hole of the female mold sleeve. Preferably, the C-shaped locking sleeve in this embodiment is made of SKH9 material with a hardness of HRC58-60.

[0042] In this embodiment, the first, second, and third round inserts are press-fitted into the female mold sleeve using a C-ring locking sleeve, which facilitates the replacement of a damaged round insert and reduces replacement costs. When the round inserts are replaced multiple times, only the C-ring locking sleeve needs to be replaced, and the replacement cost of the C-ring locking sleeve is lower than that of the traditional first female mold core.

[0043] As attached Figure 3 Appendix Figure 7 To be continued Figure 9 As shown, the inner diameter of the first round bead 3 matches the outer diameter of the product's step, used to form the head step of the product; the inner diameter of the second round bead 4 matches the outer diameter of the product's rod, and its end face near the first round bead 3 is provided with a protruding ring 4.1 for forming oil grooves on the product's step surface, used to form the head step surface of the product and its oil grooves, as well as to bind the rod; the third round bead 5 has a rod-shrinking cavity for forming the rod of the product. Meanwhile, in this embodiment, the hardness of the first round bead 3 is greater than the hardness of the second round bead 4, and the hardness of the second round bead 4 is less than the hardness of the third round bead 5. Specifically, in one embodiment, the first round bead is made of VA80 material with a hardness of HRA84; the second round bead is made of VA95 material with a hardness of HRA81.5; and the third round bead is made of KG6 material with a hardness of HRA87.2.

[0044] This embodiment utilizes three round inserts of different hardness to achieve the head step and the oil groove forming on it, as well as the rod shrinking forming. The oil groove is formed by the relatively soft second round insert, while the shrinking rod is formed by the relatively hard third round insert. This split structure effectively improves the service life of the female mold core while ensuring the forming quality of the rod.

[0045] Preferred options are listed below. Figure 3 and attached Figure 7 As shown, the first circular insert 3 has multiple first venting grooves 3.1 evenly distributed on its end face near the second circular insert 4, and the outer circular surface of the first circular insert 3 has multiple second venting grooves 3.2 evenly distributed, which are connected to the first venting grooves 3.1. This design can discharge the air in the cavity through the first and second venting grooves during the cold forging process of the product head, ensuring the molding quality of the product head.

[0046] Preferred options are listed below. Figure 3 Appendix Figure 10 and attached Figure 11As shown, the end face of the third circular insert 5 near the pad has multiple third venting grooves 5.1 evenly distributed. The end face of the C-shaped ring locking sleeve 2 near the pad has multiple fourth venting grooves 2.1 corresponding to the third venting grooves 5.1. The female mold sleeve 1 has multiple fifth venting grooves 1.1 corresponding to the fourth venting grooves 2.1. This allows the air in the cavity to be discharged through the gap between the ejector pin and the cavity, the third venting grooves, the fourth venting grooves, and the fifth venting grooves during the rod retraction process, ensuring the molding quality of the rod.

[0047] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made using the content of this utility model specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A die for final upsetting of an internal hexagonal stepped irregular screw, comprising a die sleeve, a die core assembly disposed within the die sleeve, a pad disposed within the die sleeve for abutting the die core assembly, a locking sleeve screwed to the end of the die sleeve for locking the pad, and a die ejector rod penetrating the locking sleeve and the pad and extending into the die core; characterized in that: The female mold core assembly includes a C-shaped ring locking sleeve and a first circular insert, a second circular insert, and a third circular insert, coaxially arranged from left to right within the C-shaped ring locking sleeve, wherein: The inner diameter of the first circular cavity matches the outer diameter of the product's step, and is used to form the head step of the product; The inner diameter of the second circular cavity matches the outer diameter of the rod of the product, and is used to form the head step surface of the product and the oil groove thereon, as well as to bind the rod. The third circular spacer is provided with a rod-reduction cavity for rod-reduction forming of the product's rod portion; The hardness of the first circular meson is greater than that of the second circular meson, and the hardness of the second circular meson is less than that of the third circular meson.

2. The internal six-petal flower-shaped stepped irregular screw final upsetting die according to claim 1, characterized in that: The first circular meson is made of VA80 material with a hardness of HRA84-85; the second circular meson is made of VA95 material with a hardness of HRA81-82; and the third circular meson is made of KG6 material with a hardness of HRA87-88.

3. The internal six-petal stepped irregular screw final upsetting die according to claim 1, characterized in that: The female mold sleeve has an installation hole with an inner diameter that increases from the outside to the inside at one end away from the locking sleeve. The C-type ring locking sleeve is a tapered sleeve that matches the installation hole and has a circular through hole inside for installing the first round spacer, the second round spacer and the third round spacer.

4. The internal six-petal flower-shaped stepped irregular screw final upsetting die according to claim 3, characterized in that: The C-ring locking sleeve is made of SKH9 material with a hardness of HRC58-60.

5. The internal six-petal stepped irregular screw final upsetting die according to claim 1, characterized in that: The second circular interferometer has a raised ring on its end face near the first circular interferometer for forming an oil groove on the stepped surface of the product.

6. The internal six-petal flower-shaped stepped irregular screw final upsetting die according to claim 1, characterized in that: The first circular meson has a plurality of first exhaust grooves evenly distributed on the end face of the first circular meson near the second circular meson, and the outer circular surface of the first circular meson has a plurality of second exhaust grooves evenly distributed on the outer circular surface of the first circular meson that are connected to the first exhaust grooves.

7. The internal six-petal stepped irregular screw final upsetting die according to claim 1, characterized in that: The end face of the third circular insert near the pad has multiple third venting grooves evenly distributed. The end face of the C-shaped ring locking sleeve near the pad has multiple fourth venting grooves corresponding to the third venting grooves. The female mold sleeve has multiple fifth venting grooves corresponding to the fourth venting grooves.

Images