CN117723367A - Gear ring-containing plate forming limit test die and application method thereof - Google Patents

Abstract

The invention relates to a plate forming limit test die with a gear ring and a use method thereof, wherein the die comprises a blank holder and a female die, the end face of one side of the blank holder, which faces the female die, is annularly provided with the gear ring, the section of the gear ring is in an isosceles trapezoid shape, and the width of the isosceles trapezoid, which is close to the bottom plate of the female die, is smaller than the width of the bottom plate, which is far away from the female die; the using method comprises the following steps: placing a metal sheet sample between a female die and a blank holder containing a gear ring; starting a blank pressing oil cylinder to enable the gear ring to be in contact with the metal plate sample, enabling the metal plate sample to be in contact with the female die, and forming a proper blank pressing force and keeping; and starting a punch cylinder to enable the punch to penetrate through the gear ring to perform forming limit test on the sheet metal sample. Compared with the prior art, the invention can carry out forming limit test on the thick metal plate, and can keep the thick metal plate sample uniformly stressed and firmly clamped in the test process.

Description

A plate forming limit test mold containing a ring gear and its use method

Technical field

The invention relates to the technical field of metal plate forming limit testing, and in particular to a plate forming limit testing mold containing a ring gear and a method of using the same.

Background technique

The forming ultimate performance of the plate is an important parameter to measure the plastic mechanical properties of the plate. It directly reflects the maximum deformation ability of the plate before tensile instability. Among them, the Forming Limit Diagram (FLD) is the most important basis for judging the forming limit of sheet metal. Especially when combined with finite element numerical simulation technology, it is accurate, fast and intuitive. Therefore, many commercial finite element software will form The limit diagram serves as the main basis for predicting the fracture limit during stamping process and mold design. Obtaining an accurate material forming limit diagram is an important prerequisite to ensure that the analysis results are accurate and credible. The accurate forming limit diagram needs to be obtained through experiments.

At this stage, various steel companies only consider the FLD of thin plates (thickness less than 3mm) when researching and establishing plate databases. FLD forming tests of thick plates have not yet achieved reasonable and accurate measurements and tests. In actual production, many thick plates require stamping and stamping simulation work. Accurate thick plate FLD curves can ensure the accuracy of stamping simulation and improve production efficiency.

The sheet metal forming limit test obtains the forming limit of the material through the ball head bulging test. During the ball head bulging process, it is necessary to ensure that the sample is pressed by the blank holder and the die in the blank holder area and does not flow toward the center. The traditional sheet metal forming limit test The mold mainly sets draw beads on the blank holder or directly increases the blank holder force to prevent the sample from flowing to the center. The traditional forming limit test mold is mainly designed for thin plates (thickness less than 3mm). For plates with a thickness greater than 3mm, It is difficult to press the sample through the drawbead, and the sample will flow toward the center, so the forming limit of the sheet cannot be obtained.

Contents of the invention

The purpose of the present invention is to provide a plate forming limit test mold containing a ring gear and a method of using the same.

The object of the present invention can be achieved through the following technical solutions: a sheet metal forming limit test mold containing a ring gear, including a blank holder and a die. The end ring of the blank holder is provided with a ring gear on one side facing the die. , the cross-section of the ring gear is an isosceles trapezoid, and the width of the bottom plate on the side of the isosceles trapezoid close to the die is smaller than the width of the bottom plate on the side away from the die.

Preferably, the concentric ring on the end surface of the blank holder is provided with a plurality of ring gears.

Further preferably, the height of the ring gear located on the outer ring is higher than that of the inner ring.

Preferably, the tooth height and angle of the ring gear are determined according to the thickness and hardness of the sheet material.

The specific method can be: combined with finite element calculation, there is a linear relationship between the height of the ruler and the thickness of the sheet. Assume that the tooth height is H, the thickness of the sheet is T, H=αT, and the value of α ranges from 0.15 to 0.4.

Further preferably, the distance between adjacent ring gears is 7 to 9 mm.

Preferably, the width of the base plate on the side of the ring gear close to the die is 0.1 to 0.3 mm.

Preferably, the angle between two waists of the isosceles trapezoid is 60 to 120°.

Further preferably, the angle between two waists of the isosceles trapezoid is 85° to 95°.

More preferably, the angle between the two sides of the isosceles trapezoid is 90°.

Preferably, the ring gear protrudes toward the die side, and the protrusion height is 1 to 1.5 mm.

Preferably, the blank holder is arranged on the blank holder cylinder, a punch is provided on the inside of the blank holder, and the punch is arranged on the punch cylinder.

Preferably, the female mold is installed on a fixed frame.

Preferably, the material of the ring gear is SKD11.

A method of using a plate forming limit test mold containing a ring gear, including the following steps:

Place the metal plate sample between the die and the blank holder containing the toothed gear;

Start the blank holder cylinder to make the ring gear contact with the metal plate sample, and the metal plate sample also contact with the die, and form and maintain appropriate blank holder force;

Start the punch cylinder to make the punch pass through the ring gear to perform the forming limit test on the metal sheet sample.

Preferably, the blank holder force is 500-1000KN.

Preferably, the thickness of the metal plate sample is not less than 3 mm.

Further preferably, the thickness of the metal plate sample is 3 to 6 mm.

In the present invention, the metal plate sample of the ring gear is stressed in advance.

During the actual test process, the ring gear on the blank holder of the present invention can bite into the sheet material, and can "pin" the sheet material to prevent it from flowing toward the center, ensuring that the center of the sheet material can be broken by the punch upward, thereby obtaining accurate and effective results. Forming limit data. If the sheet metal flows toward the center, the sheet metal may not break within the extreme stroke of the punch, and the forming limit data of the sheet metal cannot be obtained.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention ensures the force bearing of metal sheet forming limit test specimens and makes the force bearing more reliable;

2. The present invention ensures that the metal sheet forming limit test sample is evenly stressed in the blank holder area, can bite the sheet material and prevent it from flowing toward the center, and can ensure that the FLD test of the metal sheet is more accurate;

3. The mold of the present invention can perform forming limit testing on thick metal plates. During the test process, the metal thick plate samples can be kept evenly stressed and firmly clamped.

Description of the drawings

Figure 1 is an assembly diagram of the plate forming limit test mold containing a ring gear according to the present invention;

Figure 2 is a schematic structural diagram of the punch;

Figure 3 is a schematic structural diagram of the blank holder;

Figure 4 is a schematic structural diagram of the ring gear.

Figure 5 is a schematic structural diagram of the die;

In the picture: 1-blanking ring, 11-ring gear, 2-die, 3-blanking cylinder, 4-punch, 5-punch cylinder, 6-fixing frame, 7-metal plate sample.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention and provides detailed implementation modes and specific operating procedures. However, the protection scope of the present invention is not limited to the following embodiments.

Example 1

A sheet metal forming limit test mold containing a ring gear includes a blank holder ring 1 and a concave die 2 arranged above the blank holder ring 1.

Among them, the edge ring of the blank holder 1 is provided with a ring gear 11 on the side facing the die 2. The cross section of the ring gear 11 is an isosceles trapezoid. The width of the bottom plate (upper bottom plate) of the isosceles trapezoid close to the die 2 is smaller than that of the side away from the die. The width of the 2-side bottom plate (lower bottom plate), that is, the tooth shape of the ring gear 11, has a structure of small at the top and large at the bottom.

Example 2

Referring to FIG. 1 , this embodiment provides a tool for testing the forming limit of thick metal plates.

Metal plate sample 7 is a laboratory sample, and the forming limit test tooling consists of a punch 4 (as shown in Figure 2), a blank holder 1 (as shown in Figure 3) containing a ring gear 11, and a die 2 (as shown in Figure 5). Supporting organization composition.

The die 2 of the forming limit test tooling is installed on the fixed frame 6, the blank holder 1 containing the ring gear 11 is installed on the blank holder cylinder 3, and the punch 4 is installed on the punch cylinder 5; the metal plate test Sample 7 is placed between the die 2 and the blank holder ring 1 containing the ring gear 11 according to the test requirements, and is in contact with the ring gear 11 of the blank holder ring 1 containing the ring gear 11; start and adjust the blank holder cylinder 3 to move upward to make the ring gear 11 is in contact with the metal plate sample 7, and the metal plate sample 7 is also in contact with the die 2, and forms an appropriate blank holder force and maintains it, starts the punch cylinder 5 to move upward to perform the forming limit test; after the test is completed, start the adjustment The blank holder cylinder 3 moves downward to separate the blank holder ring 1 containing the ring gear 11 from the metal plate sample 7, and starts the punch cylinder 5 to move downward to separate the punch 4 from the metal plate sample 7 and make the metal The plate sample 7 is separated from the die 2; take out the sample for further research.

In this embodiment, the blank holder cylinder 3, the punch cylinder 5, and the fixing frame 6 are existing equipment, and their movements will not be described again.

Example 3

A tooling for extreme testing of metal thick plate forming. There are two concentric ring gears 11 on the blank holder ring 1. As shown in Figure 4, the tooth height of the ring gear 11 located on the outer ring is 1.2mm, and the tooth top width is is 0.25mm, the tooth height of the ring gear 11 located in the inner ring is 1mm, the tooth top width is 0.2mm, and the distance between the tooth top centers of adjacent ring gears 11 is 8mm. The angles of the two ring gears 11 are both 90°. The rest is the same as Example 2.

The above description of the embodiments is to facilitate those of ordinary skill in the technical field to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without inventive efforts. Therefore, the present invention is not limited to the above embodiments. Based on the disclosure of the present invention, improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims (10)

1. The utility model provides a board shaping limit test mould that contains ring gear, its characterized in that includes blank holder (1) and die (2), blank holder (1) are equipped with ring gear (11) in the one side terminal surface ring towards die (2), and the cross-section of ring gear (11) is isosceles trapezoid, and isosceles trapezoid is close to die (2) side bottom plate width and is less than and keeps away from die (2) side bottom plate width.

2. The plate forming limit test die with the gear ring according to claim 1, wherein a plurality of gear rings (11) are arranged on concentric rings of the end face of the blank holder (1).

3. The sheet metal forming limit test die with the ring gear according to claim 2, wherein the ring gear (11) located at the outer ring is higher than the ring gear (11) located at the inner ring.

4. The gear ring-containing sheet material forming limit test die according to claim 2, wherein the interval between adjacent gear rings (11) is 7 to 9mm.

5. The plate forming limit test die with the gear ring according to claim 1, wherein the width of the side bottom plate of the gear ring (11) close to the female die (2) is 0.1-0.3 mm.

6. The gear ring-containing sheet material forming limit test die according to claim 1, wherein an included angle between two waists of the isosceles trapezoid is 60-120 °.

7. The plate forming limit test die with the gear ring according to claim 1, wherein the gear ring (11) protrudes toward the female die (2) side with a protruding height of 1 to 1.5mm.

8. The plate forming limit test die with the gear ring according to claim 1, wherein the blank holder (1) is arranged on a blank holder cylinder (3), a punch (4) is arranged on the inner side of the blank holder (1) in a penetrating manner, and the punch (4) is arranged on a punch cylinder (5).

9. The plate forming limit test die with the gear ring according to claim 1, wherein the female die (2) is mounted on a fixing frame (6).

10. A method of using the gear ring-containing sheet material forming limit test die set forth in any one of claims 1 to 9, comprising the steps of:

placing a metal sheet sample (7) between the female die (2) and the blank holder (1) containing the gear ring (11);

starting the blank pressing cylinder (3) to enable the gear ring (11) to be in contact with the metal plate sample (7), enabling the metal plate sample (7) to be also in contact with the female die (2), and forming a proper blank pressing force and keeping;

and starting the punch cylinder (5) to enable the punch (4) to penetrate through the gear ring (11) to perform forming limit test on the sheet metal sample (7).