CN114643311A

CN114643311A - Forming method of cylindrical part

Info

Publication number: CN114643311A
Application number: CN202210246884.3A
Authority: CN
Inventors: 高锦张; 金志浩; 郑璐恺
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2022-03-14
Filing date: 2022-03-14
Publication date: 2022-06-21

Abstract

The invention discloses a method for forming a cylindrical part, which comprises the following steps: 1. determining the size of the target cylinder; 2. the first pass is processed to form a forming angle theta₁The path scheme is selected in the subsequent passes according to the value of the height-diameter ratio H/D; 3. if H/D is less than or equal to 0.5, an angle-variable straight path method is selected to calculate the incremental forming angle delta theta, and the forming angle theta is processed in the nth pass₁A round table of + (n-1) Δ θ, the forming height is D/2+ R; 4. if H/D is more than 0.5 and less than or equal to 1.0, an equal-height variable angle linear path method is selected to calculate the increment depth delta H and the increment forming angle delta theta, a straight wall with the height of (n-1) delta H is firstly processed in the nth pass, and then the forming angle theta is used₁Forming the circular truncated cone by the aid of the delta theta, wherein the sum of forming heights of the two paths is D + R; 5. and (4) processing the straight wall with the required depth H of the workpiece in the Nth step to obtain the target cylindrical part. The height-diameter ratio H/B of the prepared cylindrical part is less than or equal to 1.0, and the wall thickness distribution condition is good; the finished piece has high dimensional accuracy and flat bottom.

Description

Forming method of cylindrical part

Technical Field

The invention relates to a forming method, in particular to a forming method of a cylindrical part.

Background

In the actual production process, the cylindrical part is a common structural part in the sheet metal process, and when the cylindrical part is formed by adopting the traditional drawing process, the cylindrical part is easy to wrinkle and crack, the forming depth is greatly limited, the manufacturing cost is high, the period is long, and the method is not suitable for diversified development of the market. The plate incremental forming process utilizes the idea of layered manufacturing to form the blank point by point, can exert the plasticity of the blank to the maximum extent and saves the time and the cost for manufacturing a die. When the existing outer contour supporting method is adopted to process the cylindrical part, the area participating in deformation in the blank is limited, the phenomena of breakage and distortion are easy to occur, the bottom of the part is raised, the dimensional precision is not high, and a process fillet caused by processing a tool head is inevitably generated.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a method for forming a cylindrical part, which can form the cylindrical part with relatively uniform wall thickness and H/D (hydrogen/diameter) less than or equal to 1.0.

The technical scheme is as follows: the method for forming the cylindrical part comprises the following steps:

(1) determining the size of the target cylinder: the diameter D and the height H, wherein the ratio of height to height H/D is more than 0 and less than or equal to 1, the radius of the selected forming tool head is R (the selection range is 5mm-8mm), the selection of the axial feed quantity delta z in the forming process is required to meet the requirement that the delta z is 0.4mm-0.6mm, and the processing modes between adjacent passes are in forward and reverse alternation;

(2) the forming angle theta is processed in the first pass₁If H/D is less than or equal to 0.5, the height of the formed circular truncated cone is D/2+ R, and then a variable-angle linear path is adopted, namely step (3); if H/D is more than 0.5 and less than or equal to 1.0, the height of the formed circular truncated cone is D + R, and then a linear path with the same height and variable angle is adopted, namely step (4);

(3) when H/D is less than or equal to 0.5, the forming angle theta is processed in the nth (N is 2,3, …, N-1) pass₁A round table of + (n-1) Δ θ, formed to a height D/2+ R, where Δ θ ═ 90 ° - θ₁)/(N-1)；

(4) If H/D is more than 0.5 and less than or equal to 1.0, the nth (N is 2,3, …, N-1) pass firstly processes the straight wall with the height of (N-1) delta H, and then takes the forming angle theta as₁+ (N-1) Δ θ forming a circular truncated cone, the sum of the forming heights of the two paths being D + R, where Δ h ═ D + R)/(N-1) and Δ θ ═ 90 ° - θ₁)/(N-1)；

(5) And (4) processing the straight wall with the depth H in the Nth pass, and cutting off redundant materials to obtain the target cylindrical part.

Further, in step (3): the forming pass number N is in the range of 3-5; in the step (3): the number of forming passes N ranges from 5 to 7.

Further preferably, in step (3): the optimal selection of the number N of forming passes is 4; in the step (4): the optimum choice for the number of forming passes N is 6. If the number N of forming passes is too small, the phenomenon of uneven wall thickness even if the straight wall portion is broken occurs, and if the number N of forming passes is too large, the forming time is long, the sheet material is work-hardened, and the processing efficiency is low.

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: 1. a cylindrical part with the height-diameter ratio H/D less than or equal to 1.0 can be formed; 2. the blank has more parts participating in deformation, the reduction of the sheet material is easier to control by optimizing a forming path, the wall thickness condition of a target product is better, and the mechanical property is good; 3. the rapid incremental forming of the cylindrical parts with different sizes can be realized; 4. the processing cost is low, the forming efficiency is high, and the period is short; 5. the finished piece has high dimensional accuracy and smooth bottom, and does not generate a process fillet caused by processing a tool head.

Drawings

FIG. 1 is a schematic view of a variable angle linear forming path;

FIG. 2 is a schematic view of a contour varied angle linear forming path;

FIG. 3 is a pictorial view of the objective cylinder of example 1;

FIG. 4 is a wall thickness profile of the target cylinder of example 1;

FIG. 5 is a pictorial view of the objective cylinder of example 2;

FIG. 6 is a graph of the wall thickness profile of the target cylinder of example 2;

FIG. 7 is a pictorial view of a comparative example target cylinder;

FIG. 8 is a graph of comparative example target cylinder wall thickness distribution.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings.

Example 1:

the specific parameters of the target cylindrical part are as follows: the diameter D is 60mm, the height H is 30mm, a 1060 aluminum plate with the thickness of 1.5mm is selected as an original plate, a hemispherical tool head with the radius R of 6mm is selected, and the axial feed amount is 0.5 mm.

In example 1, H/D is 0.5 or less, and according to steps (2) and (3), a variable angle linear forming path is adopted as shown in fig. 1, a 4-pass forming path (N is 4) is designed, and a forming angle θ is formed in the first pass₁A round table with a height D/2+ R of 36mm at 60 °, calculated as Δ θ (90 ° - θ)₁) The forming angle theta is processed in the subsequent N (N is 2,3) th pass₁And (n-1) delta theta is (50+ n10) ° of the circular truncated cone, the forming height is D/2+ R is 36mm, the 4 th pass processes a straight wall with the depth H being 30mm, and redundant materials are cut off to obtain the target cylindrical part, as shown in fig. 3. The method comprises the following steps of cutting a workpiece along an axis, measuring wall thickness values corresponding to different forming depths, and drawing a wall thickness curve distribution diagram, wherein as shown in fig. 4, the wall thickness distribution of a formed target workpiece is relatively uniform, the wall thickness values are all more than 0.5mm, the size is accurate, the surface quality is good, the bottom is smooth, and no process fillet exists.

Example 2:

the specific parameters of the target cylindrical part are as follows: the diameter D is 60mm, the height H is 60mm, a 1060 aluminum plate with the thickness of 2.0mm is selected as an original plate, a hemispherical tool head with the radius R of 7mm is selected, and the axial feed amount is 0.5 mm.

In example 2, H/D is not more than 1.0, the contour angle linear forming path is adopted according to steps (2) and (4), as shown in fig. 1, 6 passes of forming path are designed (N is 6), and the forming angle θ is formed in the first pass₁A round table having a height D + R of 67mm and an angle of 60 ° was calculated, where Δ h (D + R)/(N-1) is 13.4mm, and Δ θ (90 ° - θ)₁) The vertical wall with the height of (N-1) delta h of 13.4(N-1) mm is firstly processed in the subsequent N (N is 2,3,4,5) pass, and then the forming angle is theta₁And (4) forming the circular truncated cone part in a plus (n-1) delta theta (54+ n6) degree, forming the sum of the forming heights of the two paths to be 67mm, processing a straight wall with the depth H being 60mm in the 6 th pass, and cutting off redundant materials to obtain the target cylindrical part, wherein the target cylindrical part is shown in fig. 5. Cutting the workpiece along the axis, measuring the wall thickness values corresponding to different forming depths, and drawing a wall thickness curve distribution diagram, as shown in FIG. 6, wherein the forming depth can be seen from the diagramThe wall thickness of the produced target workpiece is distributed relatively uniformly, the wall thickness value is more than 0.5mm, the size is accurate, the surface quality is good, the bottom is smooth, and no process fillet exists.

In the comparative example: the specific parameters of the target cylindrical part are as follows: the diameter D is 60mm, the height H is 60mm, and the fillet r is 12 mm; the 1060 aluminum plate with the thickness of 2.0mm is selected as an original plate, the hemispherical tool head with the radius R being 7mm is selected, and the axial feeding amount is 0.5 mm. In the comparative example, a 7-pass outer contour support progressive forming method is adopted, as shown in fig. 7, a workpiece is cut along an axis, wall thickness values corresponding to different forming depths are measured, and a wall thickness curve distribution diagram is drawn, as shown in fig. 8. Compared with the comparative example, the forming technology of the invention has the advantages that compared with the prior art, the formed part has no process fillet, the bottom of the formed part does not have a bulge phenomenon, the side wall is better in verticality and high in size precision, compared with the wall thickness distribution diagrams of the two parts, the part in the example 2 is better in wall thickness distribution, the average wall thickness value of the part is much higher than that of the part in the comparative example, and the mechanical property is better.

In conclusion, the forming method can be used for quickly forming the cylindrical part with the height-diameter ratio H/B of 0.5 and 1.0, and then the target part with relatively good wall thickness of the straight wall part is ensured to be obtained by adopting a residual material cutting process according to the height required by the target part.

Claims

1. A method of forming a cylindrical member, comprising the steps of:

(1) determining the size of the target cylinder: the diameter D and the height H, wherein the ratio of the height to the height H is more than 0 and less than or equal to 1, the radius of the selected forming tool head is R, and the axial feed amount delta z in the forming process is obtained;

(2) the first processing step produces a forming angle theta₁If H/D is less than or equal to 0.5, the height of the formed circular truncated cone is D/2+ R, and then a variable-angle linear path is adopted, namely step (3); if H/D is more than 0.5 and less than or equal to 1.0, the height of the formed circular truncated cone is D + R, and then a linear path with the same height and variable angle is adopted, namely step (4);

(3) when H/D is less than or equal to 0.5, the forming angle theta is processed in the nth (N is 2,3, …, N-1) pass₁A round table of + (n-1) Delta theta formed at a height ofD/2+R；

2. The method of forming a cylindrical member according to claim 1, wherein in the step (1): the radius R of the selected forming tool head ranges from 5mm to 8mm, the axial feed amount delta z in the forming process is required to meet the requirement that the delta z is 0.4mm to 0.6mm, N is the number of forming passes, and the processing modes between adjacent passes are in forward and reverse alternation.

3. The method of forming a cylindrical member according to claim 1, wherein in steps (3), (4): theta is a value of₁＝60°。

4. A method of forming a cylindrical member according to claim 1, wherein in step (3), the number of forming passes N is in the range of 3 to 5.

5. A method of forming a cylindrical member according to claim 1, wherein in step (4), the number of forming passes N is in the range of 5 to 7.