CN217223435U

CN217223435U - Cold forging die

Info

Publication number: CN217223435U
Application number: CN202220381573.3U
Authority: CN
Inventors: 李丽英; 周学良; 张嘉芸; 丁建华; 郑召龙; 黄裕文
Original assignee: Futaihua Industry Shenzhen Co Ltd
Current assignee: Futaihua Industry Shenzhen Co Ltd
Priority date: 2022-02-24
Filing date: 2022-02-24
Publication date: 2022-08-19
Anticipated expiration: 2032-02-24

Abstract

The application provides a cold forging die, including die block and drift. The bottom die is provided with a die cavity. The punch is provided with a top wall, a bottom wall and a side wall connected between the top wall and the bottom wall, the direction from the top wall to the bottom wall is defined as a preset direction, a plurality of depressions penetrating through the bottom wall and the top wall along the preset direction are arranged on the side wall, connecting parts are formed between adjacent depressions by the side wall, a first working belt is formed by the bottom depressions of the partial depressions close to the bottom wall, a second working belt is formed by the partial depressions of the connecting parts close to the bottom wall, and the length of the first working belt is larger than that of the second working belt; a first R angle is formed between the first working band and the bottom wall, a second R angle is formed between the second working band and the bottom wall, the radius of the first R angle is defined as R1, the radius of the second R angle is defined as R2, and R1 is larger than R2. The problem of severe corner collapse of the bottom R corner of the forged piece is improved by arranging the first working belt and the second working belt on the punch and adjusting the size of the first R corner and the second R corner.

Description

Cold forging die

Technical Field

The present application relates to a cold forging press mold.

Background

The cold forging and pressing technology is a forming and processing technology below the metal recrystallization temperature, and is forging carried out under the condition that a blank is not heated, so that the blank is formed into a cavity structure. Specifically, the blank is cut into a required preset size to obtain a blanking piece, then the blanking piece is placed in a cavity of a lower die in a forging die, and a punch forges the blanking piece under strong pressure and speed, so that metal is extruded in the cavity to form a forging piece with a groove.

In some applications, to increase the structural strength of the forged part, a plurality of ribs may be embossed into the inner wall of the groove of the forged part. However, in the process of forging and pressing the blanking piece, the material at the reinforcing rib of the forging piece has higher fluidity than other positions, so that the severe corner collapse phenomenon occurs at the R corner at the bottom of the forging piece, the depth of the corner collapse can reach 3.1mm, and the subsequent operation on the forging piece is influenced.

SUMMERY OF THE UTILITY MODEL

In view of the above, the present application provides a cold forging die to solve the above problems.

The application provides a cold forging die, including die block and drift. The bottom die is provided with a die cavity. The punch is movably arranged in the cavity and provided with a top wall, a bottom wall and a side wall connected between the top wall and the bottom wall, the direction from the top wall to the bottom wall is defined as a preset direction, a plurality of depressions penetrating through the bottom wall and the top wall along the preset direction are arranged on the side wall, a connecting part is formed between every two adjacent depressions by the side wall, the bottom of the depression close to the bottom wall is recessed inwards to form a first working belt, the connecting part close to the bottom wall is recessed inwards to form a second working belt, and the length of the first working belt is larger than that of the second working belt in the preset direction; a first R angle is formed between the first working band and the bottom wall, a second R angle is formed between the second working band and the bottom wall, the radius defining the first R angle is R1, the radius defining the second R angle is R2, and R1 > R2.

In some embodiments, the depth of the first operating band is equal to the depth of the second operating band.

In some embodiments, the first working band has a depth of 0.1mm to 0.2 mm.

In some embodiments, the difference between r1 and r2 is greater than 1 mm.

In some embodiments, the bottom mold comprises a mold plate and a top block, the mold cavity is located on the mold plate, the mold plate is provided with a receiving hole at the bottom of the mold cavity, the receiving hole is communicated with the mold cavity, the top block is received in the receiving hole, and the top surface of the top block is flush with the bottom of the mold cavity.

In some embodiments, the cavity has an inner diameter D1, and the receiving hole has an inner diameter D2, D1 > D2.

In some embodiments, a third R-angle is formed between the bottom and inner side walls of the cavity, the third R-angle is defined by a radius R3, and a difference between D1 and D2 is greater than or equal to 2 times R3.

In some embodiments, a driving source is further provided on a side of the top block facing away from the punch.

In some embodiments, the cold forging die further comprises a backing plate and a clamping plate through which the top wall of the punch is secured to the backing plate.

In some embodiments, the cold forging die further comprises a base, the base has an accommodating hole for accommodating the bottom die, the base is further provided with a plurality of guide posts, the clamping plate is further provided with a plurality of first through holes for the guide posts to pass through, and the base plate is provided with a plurality of second through holes which are collinear with the first through hole central axis and are used for the guide posts to pass through.

In the application, when the punch forges the blank, the first working band and the second working band can slow down the upward extrusion flowability of the blank in the cavity, so that the blank can be fully filled at the bottom of the cavity; the provision of the first working band having a length greater than the length of the second working band and the radius R1 of the first R-corner being greater than the radius R2 of the second R-corner limits the flow of the billet at the first working band, ensuring as much as possible the consistency of the flow rate through the recesses and connections as the billet flows towards the top wall of the punch, to ameliorate the problem of severe collapse of the R-corner of the bottom of the forged part.

Drawings

Fig. 1 is a schematic structural view of a cold forging die according to an embodiment of the present disclosure.

Fig. 2 is a schematic structural view of a swage in one embodiment.

Fig. 3 is a schematic structural diagram of a punch in the cold forging die in the embodiment shown in fig. 1.

Fig. 4 is a schematic structural diagram of a part of the punch in the embodiment shown in fig. 3.

FIG. 5 is an exploded view of the cold forging die of the embodiment shown in FIG. 1.

FIG. 6 is a cross-sectional view taken along line VI-VI of the cold forging die of the embodiment shown in FIG. 1.

Description of the main elements

Cold forging die 100

Upper die 10

Backing plate 11

Second through hole 111

Splint 12

The first through hole 121

Punch 13

Top wall 131

Side wall 132

Recess 1321

Connecting part 1322

First work zone 1323

Second work zone 1324

Bottom wall 133

Lower die 20

Bottom die 21

Template 211

Mold cavity 2111

Receiving hole 2112

Top block 212

Base 22

Receiving hole 221

Guide post 23

First R angle A1

Second R angle A2

Third R angle A3

Forged part 200

Groove 210

Tendon position 220

The following detailed description will further describe the present application in conjunction with the above-described figures 1-6.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

To further explain the technical means and effects of the present application for achieving the intended purpose, the following detailed description is made in conjunction with the accompanying drawings and embodiments.

Referring to fig. 1 and 2, a cold forging die 100 according to an embodiment of the present invention includes an upper die 10 and a lower die 20. The upper die 10 includes a backing plate 11, a clamping plate 12, and a punch 13. The clamping plate 12 is fixedly connected with the backing plate 11, and the punch 13 is clamped on the clamping plate 12 and is fixedly connected with the backing plate 11. The lower mold 20 includes a bottom mold 21, the bottom mold 21 has a cavity 2111 for receiving the billet, and under the driving of an external force, the punch 13 moves into the cavity 2111 and forges the billet (not shown) to obtain a forged part 200 having a groove 210, and the forged part 200 is further protruded with a plurality of rib positions 220 on the inner wall of the groove 210 to improve the structural strength of the forged part 200.

To ensure the need for subsequent CNC machining of the forging 200, it is necessary to ensure that the depth of the roll off of the bottom of the forging 200 forming the R-corner is less than 0.9 mm.

Referring to fig. 3 and 4, the punch 13 has a top wall 131, a bottom wall 133, and a side wall 132 connected between the top wall 131 and the bottom wall 133. The bottom wall 133 is used to forge the blank. The direction from the top wall 131 to the bottom wall 133 is defined as a predetermined direction S, a plurality of recesses 1321 are formed in the side wall 132 to penetrate through the top wall 131 and the bottom wall 133 along the predetermined direction S, and the plurality of recesses 1321 correspond to the plurality of ribs 220 of the forging member 200. Side walls 132 define a junction 1322 between adjacent recesses 1321, a bottom recess of a portion of recess 1321 adjacent bottom wall 133 forming first working band 1323, and a first R-angle a1 between the portion of first working band 1323 and bottom wall 133 defining a first R-angle a1 having a radius R1. Portions of connector portion 1322 adjacent bottom wall 133 are recessed to form second working band 1324. The length L1 of the first working tape 1323 is greater than the length L2 of the second working tape 1324 in the preset direction S. A second R-angle A2 is formed between a portion of second working band 1324 and bottom wall 133, and a radius of second R-angle A2 is defined as R2, and R1 > R2.

The provision of the first working band 1323 and the second working band 1324 may slow the upward flow of the billet as it is extruded so that the billet may be fully filled in the bottom of the cavity 2111 as it is being forged. Further by limiting the length of the first 1323 and second 1324 bands and the first a1 and second a2 angles to ensure a consistent flow rate as the billet flows through the recess 1321 and the attachment 1322 during forging, the problem of severe starvation of the forging press 200 resulting in a deeper draft angle is ameliorated, thereby allowing for a fuller bottom R angle of the forging press 200.

In some embodiments, the depth of the first working band 1323 and the depth of the second working band 1324 are the same to ensure consistency of the thickness of the forging 200 at the first working band 1323 and the second working band 1324 as the blank is forged.

Referring to fig. 2, 3 and 4, in some embodiments, the depth H of the first working band 1323 is 0.1mm to 0.2mm, and the depth H of the first working band 1323 and the second working band 1324 is within this range to improve severe bottom collapse of the forging 200.

Referring to fig. 2, 3 and 4, in some embodiments, the difference between R1 and R2 is greater than 1mm and the difference between R1 and R2 is within the range such that the first R angle a1 and the second R angle a2 engage the corresponding first working band 1323 and second working band 1324 to allow the billet to substantially fill the bottom of the cavity 2111 and to improve the phenomenon of corner collapse due to the missing material at the bottom of the forged part 200 under the forging of the punch 13. In some embodiments, the length L1 of first working band 1323 is 40mm, the length L2 of second working band 1324 is 10mm, the radius of first R angle a1 is R3 (i.e., 3mm), and the radius of second R angle a2 is R1 (i.e., 1 mm). Under the conditions, the collapse depth of the R corner at the bottom of the forged piece 200 is within 0.5mm through batch production verification. This shows that the first working band 1323, the second working band 1324 and the first R angle A1 and the second R angle A2 are arranged, so that the problem that the blank forged by the punch 13 seriously collapses the bottom R angle of the forged part 200 is solved, and the production requirement is met.

Referring to fig. 5, the lower mold 20 further includes a base 22, the base 22 has a receiving hole 221 for receiving the bottom mold 21, and the bottom mold 21 is detachably mounted in the receiving hole 221 so as to facilitate replacement of bottom molds 21 with different specifications or types according to production requirements.

Referring to fig. 5 and 6, the bottom mold 21 includes a mold plate 211 and a top block 212, the cavity 2111 is disposed on the mold plate 211, the mold plate 211 has a receiving hole 2112 at the bottom of the cavity 2111, the receiving hole 2112 is communicated with the cavity 2111 and has a collinear central axis, the top block 212 is received in the receiving hole 2112, the top surface of the top block 212 is flush with the bottom of the cavity 2111, and the outer sidewall of the top block 212 contacts the inner wall of the receiving hole 2112. Compared with the integral structure of the die plate 211 and the ejector block 212, the detachable combination of the ejector block 212 and the die plate 211 enables the ejector block 212 to transfer the acting force applied to the die plate 211 when the punch 13 forges the blank, so that the service life of the die plate 211 is prolonged, and the damage of the die plate 211 caused by the fact that the acting force of the punch 13 forging the blank is completely applied to the die plate 211 is avoided.

Referring to fig. 5 and 6, in some embodiments, the inside diameter defining the cavity 2111 is D1 and the inside diameter defining the receiving hole 2112 is D2, where D1 > D2, to ensure that the bottom of the forge element 200 forms an R-angle when a billet is placed in the bottom of the cavity 2111.

Referring to fig. 5 and 6, in some embodiments, the mold plate 211 forms a third R-angle A3 between the bottom and inner side walls of the cavity 2111, defining a third R-angle A3 having an arc radius R3 and a difference between D1 and D2 greater than or equal to 2 times R3. When the punch 13 is driven by external force to forge the blank, the punch 13 generates a force on the bottom of the cavity 2111, and the force applied to the die plate 211 at the bottom of the cavity 2111 is gradually increased along with the movement of the punch 13, wherein the force applied to the die plate 211 at the third R angle a3 is the largest. In some embodiments, when the value of D1 is fixed, as the difference between D1 and D2 is gradually reduced to 2 times R3, the value of D2 is maximized, and the outer diameter of the top block 212 is increased to match the size of the receiving hole 2112, a large portion of the force applied to the cavity 2111 by the punch 13 when forging the blank is transferred to the top block 212, so that the force applied to the third R angle A3 is reduced, that is, the possibility of cracking at the third R angle A3 is reduced, and the service life of the bottom die 21 is prolonged. If the difference between D1 and D2 is too small, the magnitude of the third R angle A3 required for production cannot be satisfied.

In some embodiments, D1 is 201mm, D2 is 160mm, and R3 has a value of R4 (i.e. 4mm), and through multiple production verifications, compared with the above-mentioned values of D1 and D2, the value of D2 is adjusted from 160mm to 193mm under the same value of D1, and the third R angle A3 on the template 211 is not easy to crack, that is, the value of D2 is increased to improve the service life of the template 211.

Referring to fig. 2 and 6, in some embodiments, a driving source (not shown) is further provided on a side of the top block 212 facing away from the punch 13. After the punch 13 forges the blank to obtain the forging part 200, the driving source drives the ejector block 212 to move, and the ejector block 212 simultaneously pushes the forging part 200 to move so as to push the forging part 200 out of the cavity 2111, thereby facilitating the taking out of the forging part 200. In some embodiments, the drive source is a cylinder.

In some embodiments, the base 22 further has a plurality of guide posts 23, the clamping plate 12 further has a plurality of first through holes 121 for the guide posts 23 to pass through, and the backing plate 11 has a plurality of second through holes 111 collinear with the central axis of the first through holes 121 for the guide posts 23 to pass through, so that the punch 13 can precisely move toward the cavity 2111 and forge the blank.

The cold forging die 100 provided by the present application may be applied to a blank formed of any material, such as aluminum, aluminum alloy, copper, low carbon steel, or medium carbon steel.

The process of forming the forged part 200 from a billet will be described in detail by the following steps.

S1, cutting the blank into required diameters to obtain a pre-material part.

Specifically, a bar-shaped blank is cut into a plurality of pie-shaped pre-material pieces by a sawing machine. In some embodiments, to remove the oxide layer (or macrocrystalline layer) from the surface of the preform, the CNC machine further mills the preform to remove the oxide layer from the surface of the preform.

And S2, annealing the expected piece to obtain a processed piece.

And (4) placing the predicted piece in the S1 into an annealing furnace, slowly heating to a certain temperature, keeping the temperature for a period of time, cooling to room temperature, and taking out. If the pre-material piece is aluminum, the pre-material piece is placed in an annealing furnace, the temperature is raised to 400 ℃, and the temperature is kept for 2 hours. The hardness of the preform can be reduced by the annealing treatment, and the life of the cold forging die 100 and the smoothness of the material flow during cold forging can be ensured in the subsequent treatment process.

And S3, carrying out primary forging and pressing on the processed part to obtain a blanking part.

The round processed piece in the die is forged to the square blanked piece by cold forging. This step can be realized by an oil press.

In some embodiments, the blanking piece is further subjected to deburring treatment so as to solve the problem that burrs are mixed in a subsequent forged product to cause an interlayer due to the burrs on the blanking piece in the subsequent forging process. And chamfering treatment is carried out after deburring the blanking piece so as to further ensure the smoothness of material flow in the subsequent forging and pressing process.

And S4, carrying out secondary forging and pressing on the blanking piece to obtain a forged piece 200.

The blanking member in S3 is accommodated in the cavity 2111 and positioned on the top block 212, lubricating oil is uniformly applied to the cavity 2111 of the punch 13 and the die plate 211 and the blanking member, and the punch 13 is driven by an oil press to forge the blanking member, so that the forged member 200 having the groove 210 is obtained.

In the present application, when the punch 13 forges the blank, the first working band 1323 and the second working band 1324 can slow down the upward fluidity of the blank extruded in the cavity 2111, so that the blank can be sufficiently filled in the bottom of the cavity 2111; the provision of the first working band 1323 having a length greater than the second working band 1324 and the radius R1 of the first R-angle a1 being greater than the radius R2 of the second R-angle a2 limits the flow of the billet at the first working band 1323, ensuring as much as possible the consistency of the flow rate through the recesses 1321 and the abutments 1322 as the billet flows toward the top wall 131 of the punch 13, to ameliorate the problem of severe corner collapse of the R-angle of the bottom of the forged part 200.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present application and not for limiting, and although the present application is described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present application without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A cold forging die, comprising:

the bottom die is provided with a cavity;

the punch is movably arranged in the cavity and provided with a top wall, a bottom wall and a side wall connected between the top wall and the bottom wall, the direction from the top wall to the bottom wall is defined as a preset direction, a plurality of depressions penetrating through the bottom wall and the top wall along the preset direction are arranged on the side wall, a connecting part is formed between every two adjacent depressions by the side wall, the bottom of the depression close to the bottom wall is recessed inwards to form a first working belt, the connecting part close to the bottom wall is recessed inwards to form a second working belt, and the length of the first working belt is larger than that of the second working belt in the preset direction; a first R angle is formed between the first working band and the bottom wall, a second R angle is formed between the second working band and the bottom wall, the radius defining the first R angle is R1, the radius defining the second R angle is R2, and R1 > R2.

2. The cold forging die of claim 1, wherein the depth of the first working band is equal to the depth of the second working band.

3. The cold forging die of claim 1, wherein the first working band has a depth of 0.1mm to 0.2 mm.

4. The cold forging die of claim 1, wherein the difference between r1 and r2 is greater than 1 mm.

5. The cold forging die of claim 1, wherein the bottom die comprises a die plate and an top block, the cavity is located on the die plate, the die plate is provided with a receiving hole at the bottom of the cavity, the receiving hole is communicated with the cavity, the top block is received in the receiving hole, and the top surface of the top block is flush with the bottom of the cavity.

6. The cold forging die of claim 5, wherein the cavity has an inner diameter D1, the receiving hole has an inner diameter D2, and D1 > D2.

7. The cold forging die of claim 6, wherein a third R-angle is formed between the bottom and the inner sidewall of the cavity, the radius defining the third R-angle being R3, and the difference between D1 and D2 being greater than or equal to 2 times R3.

8. The cold forging die of claim 5, wherein a drive source is provided on a side of the top block facing away from the punch.

9. The cold forging die of claim 1, further comprising a backing plate and a clamping plate, wherein said top wall of said punch is secured to said backing plate through said clamping plate.

10. The cold forging die of claim 9, further comprising a base having a receiving hole for receiving the bottom die, wherein the base further has a plurality of guide posts, wherein the clamping plate further has a plurality of first through holes for the guide posts to pass through, and wherein the backing plate has a plurality of second through holes collinear with a central axis of the first through holes for the guide posts to pass through.