阅读说明：本技术 一种犁形螺栓加工方法及加工模具 (Machining method and machining die for plow-shaped bolt ) 是由 燕存露 王萍 于 2020-04-08 设计创作，主要内容包括：本发明公开了一种犁形螺栓加工方法,包括：对待加工线材进行冷镦挤压缩径以形成圆柱状的杆部,所述杆部包括第一杆部和第二杆部,所述第一杆部的直径大于所述第二杆部的直径；沿所述第一杆部贴合所述第二杆部的一端以预设长度束四方以形成四方部,且在所述束四方时对所述四方部的周部进行泄压操作；挤压与所述四方部相邻的所述第一杆部的剩余段形成头部。本发明还公开一种应用上述犁形螺栓加工方法的犁形螺栓加工模具。本发明所提供的犁形螺栓加工方法及加工模具提高了犁形螺栓的成型质量,简化了加工工艺,同时能够有效避免加工模具损坏。(The invention discloses a plow-shaped bolt processing method, which comprises the following steps: performing cold heading, extruding and reducing diameter of a wire to be processed to form a cylindrical rod part, wherein the rod part comprises a first rod part and a second rod part, and the diameter of the first rod part is larger than that of the second rod part; binding one end of the second rod part along the first rod part to form a square part in a preset length, and performing pressure relief operation on the periphery of the square part during binding; and extruding the remaining section of the first rod part adjacent to the square part to form a head part. The invention also discloses a plow-shaped bolt processing die applying the plow-shaped bolt processing method. The processing method and the processing die for the plow-shaped bolt improve the forming quality of the plow-shaped bolt, simplify the processing technology and simultaneously effectively avoid the damage of the processing die.)

1. A plow bolt machining method is characterized by comprising the following steps:

the wire rod processing method comprises the following steps that a wire rod to be processed is subjected to cold heading, extrusion and diameter reduction to form a cylindrical rod part, wherein the rod part comprises a first rod part (4) and a second rod part (5), and the diameter of the first rod part (4) is larger than that of the second rod part (5);

binding one end of the second rod part (5) along the first rod part (4) to form a square part (6) in a preset length, and performing pressure relief operation on the periphery of the square part (6) in the process of binding the square part;

-pressing the remaining section of the first stem (4) adjacent to the square (6) to form a head (7).

2. The plow bolt processing method of claim 1, wherein the step of cold heading, pressing and reducing the diameter of the wire material to be processed to form a cylindrical rod portion comprises: and carrying out closed type positive extrusion reducing on the wire to be processed, wherein the positive extrusion refers to an extrusion mode that extrusion force is vertical to the outer surface of the wire to be processed.

3. The plow bolt process of claim 1 wherein the pressure relief operation comprises venting and draining oil.

4. A plow-bolt machining method as defined in claim 3, wherein the step of pressing the remaining segment of the first shank (4) adjacent to the square portion (6) to form a head (7) comprises:

the first rod part (4) and the second rod part (5) are extruded centripetally by adopting segmented membrane kernels which are uniformly separated along the circumferential direction of the first rod part (4), and the first rod part (4) and the second rod part (5) are extruded in a segmented mode.

5. A plow bolt machining die for applying the plow bolt machining method according to claim 1, comprising:

the wire cutting machine comprises a first die (1) for extruding a wire to be processed to form a rod part, a second die (2) for extruding the first rod part (4), a square beam part and a third die (3) for processing and shaping the head part (7) and the square part (6);

the first die (1) is provided with a first compression hole (11) and a second compression hole (12) which are coaxially arranged, and the diameter of the first compression hole (11) is larger than that of the second compression hole (12);

the second die (2) is provided with a pressure relief hole (21) for pressure relief.

6. The plow-shaped bolt processing die of claim 5, wherein the second die (2) is provided with a square hole (22) for binding a square, and the pressure relief hole (21) is arranged at a position corresponding to the corner angle of the square hole (22) and the second die (2).

7. The plow-shaped bolt processing die of claim 6, wherein the third die (3) comprises an outer die (31) provided with a through hole and a film core (32) arranged in the through hole and used for extruding and forming the head part (7), the square part (6) and the second rod part (5), and the film core (32) is a segmented film core evenly divided along the circumferential direction of the first rod part (4).

8. The plow bolt processing die of claim 7, wherein the membrane core (32) is arranged in blocks along the transition between the square part (6) and the second rod part (5), and further comprising a pre-stress ring (33) arranged on the periphery of the block-type membrane core and used for gathering and pre-tightening the block-type membrane core, wherein the pre-stress ring (33) is in interference fit with the block-type membrane core.

9. The plow bolt processing die of claim 7, wherein the segmented die core comprises a first subshell located at the periphery of the head (7) and the square part (6) and arranged in segments along the circumferential direction of the head (7) and the square part (6) to be spliced into a cylindrical shape, and a second subshell located at the periphery of the second rod part (5) and arranged adjacent to the first subshell and arranged in a cylindrical shape.

10. The plow bolt machining die of claim 9, wherein the number of the first subshells is four, and the four first subshells are arranged in blocks along corners of the square portion (6).

Technical Field

The invention relates to the technical field of machining, in particular to a machining method of a plow-shaped bolt. The invention also relates to a machining die for the plow-shaped bolt.

Background

The plow-shaped bolt comprises a rod part, an end part and a square part for transitionally connecting the rod part and the end part; the plow-shaped bolt has better performance than a standard fastener, is usually used for fixing a scraper knife of a land leveler and the like of engineering machinery, and has good fixing effect and large using amount. Because the deformation of the head is large when the bolt is formed, the red forging process is adopted at present, and the red forging process is easy to form but has certain defects, such as defects of an outer layer structure of a blank, such as oxide skin, decarburization, recarburization and the like, caused by chemical change; and defects caused by abnormal changes of internal tissue structures, such as over-burning, overheating, lack of heat penetration and the like; and cracks caused by excessive stress due to uneven temperature distribution in the blank. In addition, the efficiency of the red forging is low, and the rod part is easy to expand when the short rod piece is formed by the red forging, so that the working procedure of grinding the billet diameter is required to be added, and the cost is increased. Therefore, the prior plow-shaped bolt is partially formed by a cold heading process and formed by cold heading, but the cold heading step is not standard, so that the machining is difficult and the die is easy to crack.

How to improve the processing technology of the plow-shaped bolt and improve the forming quality becomes a technical problem to be solved by the technical personnel in the field.

Disclosure of Invention

The invention aims to provide a plow-shaped bolt processing method and a plow-shaped bolt processing die, which improve the processing technology of the plow-shaped bolt, improve the molding quality of the plow-shaped bolt and reduce the damage of the processing die.

In order to achieve the above object, the present invention provides a method for machining a plow-shaped bolt, comprising:

performing cold heading, extruding and reducing diameter of a wire to be processed to form a cylindrical rod part, wherein the rod part comprises a first rod part and a second rod part, and the diameter of the first rod part is larger than that of the second rod part;

binding one end of the second rod part along the first rod part to form a square part in a preset length, and performing pressure relief operation on the periphery of the square part during binding;

and extruding the remaining section of the first rod part adjacent to the square part to form a head part.

Optionally, the step of performing cold heading, extrusion and diameter reduction on the wire rod to be processed to form the cylindrical rod portion is: and carrying out closed type positive extrusion reducing on the wire to be processed, wherein the positive extrusion refers to an extrusion mode that extrusion force is vertical to the outer surface of the wire to be processed.

Optionally, the pressure relief operation comprises venting and draining.

Optionally, the step of pressing the remaining segment of the first stem portion adjacent to the square portion to form a head portion comprises:

and extruding the first rod part and the second rod part centripetally by adopting segmented membrane kernels which are uniformly separated along the circumferential direction of the first rod part, and extruding and molding the first rod part and the second rod part in a segmented manner.

The invention also provides a plow-shaped bolt processing die, and the plow-shaped bolt processing method comprises the following steps:

the first die is used for extruding a wire to be processed to form the rod part, the second die is used for extruding the first rod part, the second die is used for bundling four sides, and the third die is used for processing and shaping the head part and the four sides;

the second die is provided with a pressure relief hole for pressure relief.

Optionally, the second mold is provided with a square hole for bundling four directions, and the pressure relief hole is provided at a position corresponding to an edge of the square hole and the second mold.

Optionally, the third mold includes an outer mold having a through hole and a film core disposed in the through hole to extrude the head portion, the square portion and the second rod portion, and the film core is a segmented film core evenly divided along the circumferential direction of the first rod portion.

Optionally, the membrane kernel is arranged in a blocking manner along a transition portion of the square portion and the second rod portion, and the membrane kernel further comprises a pre-stressed ring which is arranged on the periphery of the segmented membrane kernel and used for gathering and pre-tightening the segmented membrane kernel, and the pre-stressed ring is in interference fit with the segmented membrane kernel.

Optionally, the segmented mold insert includes a first sub-shell located at the periphery of the head and the square portion and arranged in a segmented manner along the circumferential direction of the head and the square portion to be spliced into a cylindrical shape, and a second sub-shell located at the periphery of the second rod portion and arranged adjacent to the first sub-shell and in a cylindrical shape.

Optionally, the number of the first sub-housings is specifically four, and the four first sub-housings are arranged along corners of the square portion in a blocking manner.

Compared with the prior art, the processing method of the plow-shaped bolt provided by the invention adopts a cold heading mode, so that the quality defect caused by red beating forming is effectively avoided; in order to avoid the cracking of the die, the wire to be processed is firstly processed and compressed into a first rod part and a second rod part with different diameters, the diameter of the second rod part is smaller and serves as a screw rod, the diameter of the first rod part is relatively larger and is used for upsetting and forming the head part and the square part of the plow-shaped bolt, the lengths and the diameters of the first rod part and the second rod part can be confirmed according to the size of the plow-shaped bolt to be processed, and the length of the first rod part is ensured to be not less than the sum of the lengths of the head part and the square part. The four sides are bundled through a section of the first rod part close to the second rod part, pressure relief is carried out while the four sides are bundled, gas and oil in a die are discharged, die cracking is avoided, the rest part of the first rod part is extruded to form a head, processing of the plow-shaped bolt is completed, and film kernel cracking of the processing die caused by stress concentration during integral extrusion is avoided through sectional type processing of the head and the four sides. The plow-shaped bolt processing die provided by the invention is suitable for the processing method and has the same beneficial effects.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a flow chart of a plow bolt machining method according to an embodiment of the present invention;

FIG. 2 is a schematic view of a first mold according to an embodiment of the present invention;

FIG. 3 is a front view of a second mold provided in accordance with an embodiment of the present invention;

FIG. 4 is a side view of a second mold provided in accordance with an embodiment of the present invention;

FIG. 5 is a schematic view of a third mold according to an embodiment of the present invention;

fig. 6 is a diagram of a processing sample corresponding to the plow-shaped bolt processing method provided by the embodiment of the invention.

Wherein:

1-a first mould, 11-a first compression hole, 12-a second compression hole, 2-a second mould, 21-a pressure relief hole, 22-a square hole, 3-a third mould, 31-an outer mould, 32-a membrane core, 33-a pre-stress ring, 4-a first rod part, 5-a second rod part, 6-a square part and 7-a head part.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 to 6, fig. 1 is a flowchart of a plow bolt machining method according to an embodiment of the present invention, fig. 2 is a schematic view of a first mold according to an embodiment of the present invention, fig. 3 is a front view of a second mold according to an embodiment of the present invention, fig. 4 is a side view of the second mold according to an embodiment of the present invention, fig. 5 is a schematic view of a third mold according to an embodiment of the present invention, and fig. 6 is a machining sample diagram corresponding to the plow bolt machining method according to an embodiment of the present invention.

The invention particularly provides a plow-shaped bolt processing method suitable for a cold heading process, aiming at reducing the processing cost of the plow-shaped bolt and avoiding the low molding quality of the plow-shaped bolt caused by uneven distribution of the interior of a blank in the red forging process.

The method specifically comprises the following three steps: and step S1, performing cold heading extrusion and diameter reduction on the wire to be processed to form a cylindrical rod part, filling the wire to be processed into a certain die, and extruding by using the die, so that the side wall of the wire to be processed is extruded and deformed by the die, and the diameter of the wire to be processed is reduced. The formed shank comprises in particular a first shank 4 of smaller diameter and a second shank 5 of larger diameter, wherein the second shank 5 is intended to act as the shank portion of a plow bolt, generally longer than the first shank 4, and the first shank 4 is intended to be subsequently upset to form the square 6 and head 7 of the plow bolt.

Step S2 is to extrude and bundle the square of the preset length of the adjacent portion of the first rod 4 and the second rod 5, wherein the bundle the square is to adopt a die with a square hole 22 in cross section to extrude and restrain the preset length of the first rod 4, and then to further extrude to form the square 6, because the square 6 is the head 7 and the screw transition section of the plow bolt, and the bundle the square is to extrude the adjacent portions of the first rod 4 and the second rod 5 on the first rod 4, the extruded length is adjusted according to the specification of the plow bolt, that is, the length of the square 6; in order to avoid excessive cracking of the first rod 4 by the die pressure while the die is being crimped, crimping is accompanied by a pressure relief operation, which is mainly for the crimping die.

And finally, in step S3, when the square part 6 is formed by the square-binding hole 22, the end of the first rod 4 far away from the second rod 5 or the screw is not extruded, the remaining section is mainly used for processing and forming the head 7 of the plow bolt, the round head 7 with two convex surfaces can be formed by extruding the remaining section, and the head 7 can be upset into a proper shape as required.

In the above embodiment, step S1 is to perform cold heading extrusion diameter reduction on the wire rod to be processed to form the rod portion, and generally, closed forward extrusion diameter reduction is adopted, where closed forward extrusion diameter reduction is to perform circumferential sealing on the wire rod to be processed and apply a pressure perpendicular to the outer surface, that is, the side surface, to perform compression, so as to improve the uniformity of compression of the wire rod to be processed, so that each section of the rod portion has the same or similar mechanical properties, and thus, the forming quality of the plow bolt is improved.

The pressure relief operation in step S2 specifically refers to discharging gas or oil in the strand square die from the die, and a pressure relief hole 21 and the like may be formed in the side wall of the strand square die in advance, so that when the strand square die extrudes a local section of the first rod portion 4, air or grease having a lubricating and cooling effect in the die can be discharged from the strand square die, thereby avoiding the die cracking caused by the reaction force of the wire rod to be processed and the excessive pressure of the gas or grease in the strand square process.

More specifically, the segmented membrane kernel segmented extrusion is used in upsetting the head portion 7 and the square portion 6. For example, the segmented membrane kernel is four segments evenly divided along the circumference of the first rod part 4, the four segments are spliced to form a complete shell shape, the first rod part 4 and the second rod part 5 are segmented and extruded to avoid stress concentration, the segmented extrusion can adopt a mode of separating the segmented membrane kernel along the transition part of the first rod part 4 and the second rod part, namely the membrane kernel 32 can comprise eight segments, the four segments are spliced to form a cylindrical first sub-shell for extruding the head part 7 and the four square parts 6, and the four segments are spliced to form a second sub-shell for extruding the second rod part 5. Therefore, the first rod part 4 and the second rod part 5 are extruded by utilizing different parts of the membrane core 32, and stress concentration and cracking of the transition part of the membrane core 32 caused by one-time extrusion of the integral membrane core 32 to the two parts are avoided. Particularly, the second sub-shell can be arranged in a circumferential block mode, and can also be a cylindrical integrated shell, so that the processing and forming are convenient.

The invention also discloses a plow bolt processing die applying the plow bolt processing method, and the plow bolt processing die comprises three parts: a first die 1 for extruding a wire to be processed to form a rod part including a first rod part 4 and a second rod part 5; a second die 2 for extruding and extruding one end of the first rod part 4 close to the second rod part 5; and a third die 3 for finishing the shaped head 7 and the square 6.

Referring to fig. 2 to 5, in order to form the first rod portion 4 and the second rod portion 5, the first mold 1 is an integral piece, the first mold 1 is provided with a compression hole for accommodating and compressing a wire to be processed, the compression hole includes a first compression hole 11 and a second compression hole 12 coaxially provided, a diameter of the first compression hole 11 is larger than a diameter of the second compression hole 12, when the wire to be processed enters from the first compression hole 11, the first compression hole 11 pre-compresses the wire, then the wire gradually enters the second compression hole 12, the wire is compressed by the second compression hole 12 to form the second rod portion 5, and a portion of the wire to be processed located in the first compression hole 11 forms the first rod portion 4; the diameters and lengths of the first compression hole 11 and the second compression hole 12 are set with reference to the specification of the plow-shaped bolt to be processed, and the first dies 1 of different specifications are used for producing plow-shaped bolts of different models.

Through set up the confined compression hole of circumference on the whole piece for when the wire rod removed in the compression hole, the lateral wall of compression hole was waited to process wire rod week portion and is exerted the positive extrusion force of perpendicular its surface, helped improving the shaping quality of pole portion. The first compression hole 11 and the first compression hole 11 are generally smoothly connected in transition, for example, the transition section of the first compression hole 11 and the second compression hole 12 is uniformly tapered along the direction from the first compression hole 11 to the second compression hole 12.

The second die 2 is provided with a square hole 22 which is used for binding square and has a square cross section, when binding square, a wire to be processed needs to pass through the square hole 22 from one end of the second rod part 5 until a preset length section of the first rod part 4 passes through the square hole 22, because the binding square is directed at a partial section of the first rod part 4 and not directed at the second rod part 5, the size of the square hole 22 is larger than the diameter of the second rod part 5 and smaller than the diameter of the first rod part 4, that is, the square hole 22 of the second die 2 only plays a role in compressing the first rod part 4 and does not play a role in compressing the second rod part 5; in order to avoid the second mold 2 from cracking in four directions, the second mold 2 is provided with pressure relief holes 21, the pressure relief holes 21 can be specifically opened at positions corresponding to the edges and corners of the second mold 2 and the four directions 6, the pressure relief holes 21 are symmetrically opened on the second mold 2, and the pressure relief holes 21 are usually opened at the positions corresponding to the four edges and corners, so that gas and grease in the mold are discharged, and the risk of cracking of the second mold 2 is reduced. Obviously, the relief holes 21 may be opened not only at the corresponding locations of the corners of the second mold 2 and the square portions 6. The relief hole 22 may be opened in the second mold 2 at a position corresponding to the side surface of the square portion 6.

The third die 3 is also provided with a through hole for accommodating and compressing the wire rod to be processed after being bundled into four directions, and the specification and the size of the through hole are correspondingly matched with the specification of the wire rod to be processed, such as a through hole section with a smaller diameter and corresponding to the second rod part 5 (the screw rod of the plow-shaped bolt), a square through hole section with a larger diameter and the like. The third die 3 comprises, in contrast, an outer die 31 arranged in the above-mentioned through hole and a membrane core 32 for extrusion forming the head 7 and thus for further processing of the four sides 6. The film kernel 32 adopts the circumference segmentation formula film kernel, also is that the film kernel 32 includes a plurality of subshells, and a plurality of subshells set up in above-mentioned through-hole, and can splice the shell form that forms and be used for extrudeing head 7 and square part 6 along the circumference of first pole portion 4, if adopt four subshells to splice into the first subshells that are used for extrudeing and form head 7 and square part 6, four subshells divide the piece setting along the edges and corners of square part 6, have reduced the stress concentration of edges and corners.

In order to avoid stress concentration of the membrane kernel 32 at the transition position of the first rod part 4 and the second rod part 5, and the membrane kernel 32 is cracked, the membrane kernel 32 is not only divided into two parts in the circumferential direction, but also divided into two parts in the axial direction of the first rod part 4, and a single membrane kernel subshell is divided into two parts at the transition position of the first rod part 4 and the second rod part, wherein one part is used for being spliced with the circumferentially corresponding subshell to form a first subshell which further extrudes the square part 6 and the head part 7, and the other part is spliced with the circumferentially corresponding subshell to form a cylindrical second subshell which extrudes the second rod part 5.

Furthermore, the plurality of sub-shells of the segmented membrane kernels are limited through the through holes of the outer die 31, and are bound by the aid of the pre-stressed ring 33 to form a complete shell, the plurality of sub-shells are fixed into the complete shell along the circumferential direction by the pre-stressed ring 33, and the pre-stressed ring 33 is in interference connection with the sub-shells of the segmented membrane kernels. The wire rod to be processed after being processed by the second die 2 is only required to be driven into the film core 32 shell from one end of the second rod part 5, so that the tail end of the first rod part 4 is completely immersed into the film core 32 shell, the head part 7 and the square part 6 are processed and formed, and the cold heading processing of the plow-shaped bolt is completed. The membrane kernel 32 is arranged in a blocking mode along the circumferential direction and the axial direction of the plow-shaped bolt, so that the forming of the head part 7 of the plow-shaped bolt is facilitated, the stress concentration of the membrane kernel 32 at the transition part of the square part 6 and the head part 7 is avoided, and the damage to the membrane kernel 32 and the third mold 3 is effectively avoided. The shape of the plow-shaped bolt after being processed by each step or each die is shown in fig. 6.

In another embodiment, the blocking mold core of the third mold 3 adopts a mode that a part for extruding the head 7 is blocked and a part for binding four sides is integrally arranged. In other words, the mold core 32 includes a first sub-shell and a second sub-shell which are adjacently disposed, the first sub-shell is divided into four pieces along the circumferential direction of the head 7, and the four pieces of first sub-shells are spliced to form a shell for extruding the head 7; the second sub-housing is an integral cylindrical housing, and the inner wall of the cylindrical housing is square and is used for extruding to form a square part 6. The first sub-housing and the second sub-housing are disposed adjacently, and the transition point between the first sub-housing and the second sub-housing is smoothly disposed, in this case, the pre-stressed ring 33 is disposed on the periphery of the first sub-housing.

Particularly, the first sub-housing is arranged along the corresponding edge of the square part 6 in a blocking manner, so that the stress concentration of the mold core 32 at the edge is reduced.

It is noted that, in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity from another entity without necessarily requiring or implying any actual such relationship or order between such entities.

The plow-shaped bolt processing method and the plow-shaped bolt processing mold provided by the invention are described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.