Ultrasonic-assisted granular medium plate forming device and method

Abstract

The invention discloses an ultrasonic-assisted particle medium plate forming device and method, and relates to the field of metal plate flexible medium forming, and the ultrasonic-assisted particle medium plate forming device comprises a base, a female die, a guide column, a particle supporting top end, a particle supporting base and a male die. In the forming process of the plate, the pressure of the rigid die and the opposite acting force of the particle media are borne at the same time, the ultrasonic vibration device is kept in an open state to avoid gaps between the particle media, and the volume of the space where the particle media are located changes along with movement of the male die to ensure that the particle media are tightly attached to the surface of the plate; and meanwhile, the ultrasonic vibration is also beneficial to eliminating residual stress generated in the forming process of the plate, uniform thickness distribution of the formed plate is ensured, the plate is in a pressed state in the thickness direction, and the plate is completely attached to the surface of the male die, so that the forming quality of the plate is improved.

Description

Technical Field

[0001] The invention relates to the field of flexible medium forming of metal plates, and in particular to an ultrasonically assisted granular medium plate forming device and method. Background Art

[0002] The use of metal sheets in the manufacturing field is becoming more and more widespread, and certain requirements are put forward for the forming quality, stress concentration, and local thinning rate of sheet metal parts. Metal sheet forming is usually carried out by rigid die forming, hot forming, multi-pass forming, sheet liquid filling forming, etc. The sheet is usually placed on the mold, and then the forming load is performed, so that the sheet is deformed under the action of pressure, and finally fits with the concave die to complete the forming of the sheet. In the above methods, the use of rigid die forming is prone to stress concentration and local excessive thinning of the sheet; hot forming and multi-pass forming will cause problems such as high energy consumption and high manufacturing costs; sheet liquid filling forming puts forward certain requirements for sealing, and at the same time, the cost of hydraulic equipment is high and the control is difficult. The above methods are currently commonly used methods in sheet metal forming, but the forming process is mostly simple unidirectional drawing, which cannot effectively avoid the problems of stress concentration and local excessive thinning of the sheet during the forming process. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides an ultrasonically assisted granular medium sheet forming device and method. In the present invention, the sheet is subjected to the pressure of the rigid mold and the reverse force of the granular medium during the forming process. The ultrasonic vibration device remains in an open state to avoid gaps between the granular media, and the spatial volume of the granular medium changes with the movement of the punch to ensure that the granular medium and the surface of the sheet are closely fitted. At the same time, the ultrasonic vibration also helps to eliminate the residual stress generated by the sheet during the forming process, ensuring that the thickness of the sheet is evenly distributed after forming, so that the sheet is under pressure in the thickness direction, and the sheet is completely fitted with the surface of the punch, thereby improving the sheet forming quality.

[0004] The present invention achieves the above technical objectives through the following technical means.

[0005] An ultrasonically assisted granular medium sheet forming device comprises a base, a die, guide posts, a particle support top, a particle support base and a punch; the base is a hollow structure, a particle support base is arranged below the base, one end of a plurality of guide posts is mounted on the particle support base, the other end of the guide posts passes through the particle support top, a spring is mounted on the guide posts, and the spring is placed between the particle support top and the particle support base, a transducer is arranged on the particle support base, and the transducer is connected to an ultrasonic generator through a wire; the die is arranged on a step hole on the inner side of the base, a sheet is arranged on the die, and the punch cooperates with the die to form the sheet; the space between the upper end surface of the particle support top and the sheet is filled with granular medium.

[0006] In the above solution, the transducer is mounted on the particle support base via an ultrasonic device fixing plate.

[0007] In the above solution, the outer ring of the plate is clamped by a pressure ring.

[0008] In the above solution, a sealing ring is provided on the outer ring of the top end of the particle support.

[0009] In the above solution, the pressure ring is connected to the base through a second bolt.

[0010] The forming method of the ultrasonic assisted granular medium sheet forming device, during the sheet forming process, is simultaneously subjected to the pressure of the punch and the die and the reverse force of the granular medium, and specifically comprises the following steps:

[0011] Step 1: Assemble the forming device, place the sheet between the die and the punch, and press it with the blank holder;

[0012] Step 2: Turn on the ultrasonic generator to eliminate the gaps between the granular media. The punch moves downward to contact the plate. The volume of the space where the granular media is located changes with the movement of the punch, ensuring that the granular media fits tightly against the plate, forcing the plate to deform under the action of external force and fit with the punch under the reaction force of the granular media to complete the forming of the plate.

[0013] In the above scheme, the forming height, maximum thinning rate and maximum principal strain of the sheet after forming are measured.

[0014] In the above scheme, the particle size of the granular medium is 0.5mm to 2.0mm.

[0015] In the above scheme, the front end of the punch is a spherical structure, and the radius R1 of the ball head is 15mm to 60mm.

[0016] In the above solution, the plate has a thickness of 1 mm to 5 mm and a diameter D2 of 140 mm to 180 mm.

[0017] Beneficial effects:

[0018] 1. The present invention aims at the problem that rigid die forming is widely used at present, but the plate is easily excessively thinned and stress concentrated in the manufacturing process. By adding granular medium under the plate during the rigid die forming process, a force is applied to the plate in the opposite direction to promote the forming of the plate. At the same time, the volume of the space where the granular medium is located can be flexibly adjusted, and ultrasonic vibration is used to assist the forming of the granular medium plate, eliminating the gap between the granular medium, removing the residual stress generated by the plate during the forming process, and improving the forming quality of the plate. The method of the present invention has the advantages of convenient operation, safe test, high efficiency, low cost, green and pollution-free, and low noise.

[0019] 2. In the present invention, the plate is subjected to the pressure of the rigid mold and the reverse force of the granular medium during the forming process. The ultrasonic vibration device is kept in an open state to avoid gaps between the granular media, and the spatial volume of the granular medium changes with the movement of the punch to ensure that the granular medium and the surface of the plate fit closely. At the same time, the ultrasonic vibration also helps to eliminate the residual stress generated by the plate during the forming process, ensuring that the thickness of the plate is evenly distributed after forming, so that the plate is under pressure in the thickness direction, and the plate is completely in contact with the surface of the punch, thereby improving the forming quality of the plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of an ultrasonic-assisted granular medium sheet forming device;

[0021] Figure 2 for Figure 1 Schematic diagram of the transducer, spring, guide post, particle support top and particle support base;

[0022] Figure 3 for Figure 1 Schematic diagram of the structure of the punch involved in;

[0023] Figure 4 for Figure 1 Schematic diagram of the structure of the die involved.

[0024] Reference numerals:

[0025] 1-first bolt; 2-base; 3-sealing ring; 4-blank pressing ring; 5-second bolt; 6-plate; 7-die; 8-granular medium; 9, granular support top; 10-spring; 11-guide column; 12-transducer; 13-ultrasonic generator; 14-ultrasonic equipment fixing plate; 15-granular support base; 16-punch. DETAILED DESCRIPTION

[0026] Combined with Figure 1-4As shown, an ultrasonic-assisted granular medium sheet forming device includes a base 2, a die 7, a guide column 11, a particle support top 9, a particle support base 15 and a punch 16; the base 2 is a hollow structure, and a particle support base 15 is arranged below the base 2, and one end of several guide columns 11 is installed on the particle support base 15, and the other end of the guide column 11 passes through the particle support top 9, and a spring 10 is installed on the guide column 11, and the spring 10 is placed between the particle support top 9 and the particle support base 15, and a transducer 12 is arranged on the particle support base 15, and the transducer 12 is connected to the ultrasonic generator 13 through a wire; the die 7 is arranged on the inner side step hole of the base 2, and a plate 6 is arranged on the die 7, and the punch 16 cooperates with the die 7 to form the plate 6; the space between the upper end surface of the particle support top 9 and the plate 6 is filled with granular medium 8.

[0027] A method for ultrasonically assisted granular medium sheet forming, in which the sheet is subjected to pressure from a rigid die and a reverse force from a granular medium during the forming process, an ultrasonic vibration device is kept turned on to avoid gaps between the granular medium, and the volume of the space where the granular medium is located changes with the movement of the punch to ensure that the granular medium and the surface of the sheet fit closely, while ultrasonic vibration also helps to eliminate the residual stress generated by the sheet during the forming process, so that the sheet is under pressure in the thickness direction, and the sheet is accurately and completely fitted with the punch surface. The method for implementing granular medium assisted sheet forming includes the following steps performed in sequence:

[0028] 1) Install the sealing ring 3 in the sealing groove of the particle support top 9 to ensure that the sealing ring 3 remains in the predetermined position during the forming process and has good air tightness;

[0029] 2) Fix the ultrasonic device fixing plate 14 to the particle support base 15 by means of the first bolt 1, and install the transducer 12 on the ultrasonic device fixing plate 14 to ensure that the transducer 12 does not change in displacement during the forming process;

[0030] 3) Fix the four guide columns 11 on the particle support base 15 through their own threads to ensure that the installation heights of the four guide columns are consistent, install the spring 10 on the guide column 11, and finally install the particle support top 9 on the spring 10 and the guide column 11 to ensure that the upper surface of the particle support top 9 is in a horizontal state;

[0031] 4) Install the installed particle support assembly into the inner hole of the base 2, install the die 7 on the upper platform of the base 2, pour the particle medium 8 onto the die 7 and the particle support top 9, and ensure that the height of the particles 8 does not exceed the upper surface of the die 7;

[0032] 5) Place the plate 6 in the middle of the upper surface of the die 7, fix the blank holder 4 to the base 2 through the second bolt 5, and complete the construction of the equipment;

[0033] 6) Turn on the ultrasonic generator 13 to eliminate the gap between the granular media 8. The punch 16 moves downward to contact the plate 6. The volume of the space where the granular medium 8 is located changes with the movement of the punch 16, ensuring that the granular medium 8 is tightly fitted to the plate 6, forcing the plate 6 to deform under the action of external force and fit with the punch 16 under the reaction force of the granular medium 8 to complete the forming of the plate. Measure the forming height, maximum thinning rate, and maximum principal strain of the plate 6 after forming.

[0034] As shown in Appendix 1, it is suitable for granular medium-assisted sheet forming with a particle size d of 0.5mm to 2.0mm.

[0035] During the granular medium-assisted sheet forming process, the ultrasonic generator must always be kept in an open state to ensure that there are no large gaps between the particles during the forming process.

[0036] It is suitable for forming spherical parts. The head of the punch 16 is a spherical structure, and the radius R1 of the spherical head is 15mm to 60mm.

[0037] In the process of realizing the granular medium-assisted sheet forming, the punch 16 should always be kept in the middle of the sheet without any left or right deviation, and the pressure applied when the punch is pressed down should be loaded in a linear manner.

[0038] In the process of realizing the granular medium-assisted plate forming, it is ensured that the plate does not move left and right. The thickness T of the plate 6 is 1 mm to 5 mm, and the diameter D2 of the blank is 140 mm to 180 mm.

[0039] Table 1 Particle size, die radius and groove inner hole size required for plates of different thicknesses

[0040]

Claims

1. An ultrasonic assisted granular medium sheet forming device, It is characterized in that The invention comprises a base (2), a concave mold (7), a guide column (11), a particle support top (9), a particle support base (15) and a convex mold (16); the base (2) is a hollow structure, a particle support base (15) is arranged below the base (2), one end of a plurality of guide columns (11) are installed on the particle support base (15), the other end of the guide column (11) passes through the particle support top (9), a spring (10) is installed on the guide column (11), and the spring (10) is placed on the particle support Between the top (9) and the particle support base (15), a transducer (12) is arranged on the particle support base (15), and the transducer (12) is connected to the ultrasonic generator (13) through a wire; the die (7) is arranged on the inner step hole of the base (2), a plate (6) is arranged on the die (7), and the convex die (16) cooperates with the die (7) to shape the plate (6); and a granular medium (8) is filled between the upper end surface of the particle support top (9) and the plate (6).

2. The ultrasonic assisted granular medium sheet forming device according to claim 1, It is characterized in that The transducer (12) is mounted on a particle support base (15) via an ultrasonic device fixing plate (14).

3. The ultrasonic assisted granular medium sheet forming device according to claim 1, It is characterized in that The outer ring of the plate (6) is clamped by a pressure ring (4).

4. The ultrasonic assisted granular medium sheet forming device according to claim 1, It is characterized in that The outer ring of the particle support top end (9) is provided with a sealing ring (3).

5. The ultrasonic assisted granular medium sheet forming device according to claim 1, It is characterized in that The pressure ring (4) is connected to the base (2) via a second bolt (5).

6. A forming method according to any one of claims 1 to 5, comprising: It is characterized in that The sheet material (6) is subjected to pressure from the male die (16) and the female die (7) and a reverse force from the granular medium (8) during the forming process, which specifically includes the following steps: Step 1: Assemble the forming device, place the plate (6) between the concave die (7) and the convex die (16), and press it tightly with the blank holder (4); Step 2: Turn on the ultrasonic generator (13) to eliminate the gap between the granular media (8), and the punch (16) moves downward to contact the plate (6). The volume of the space where the granular media (8) is located changes with the movement of the punch (16), ensuring that the granular media (8) and the plate (6) are tightly fitted, forcing the plate (6) to deform under the action of external force, and fit with the punch (16) under the reaction force of the granular media (8) to complete the forming of the plate (6).

7. The forming method according to claim 6, It is characterized in that The forming height, maximum thinning rate and maximum principal strain of the formed sheet (6) are measured.

8. The forming method according to claim 6, It is characterized in that The particle size of the granular medium (8) is 0.5 mm to 2.0 mm.

9. The forming method according to claim 6, It is characterized in that The front end of the punch (16) is a spherical structure, and the ball head radius R 1 It is 15mm~60mm.

10. The forming method according to claim 6, It is characterized in that The plate (6) has a thickness of 1 mm to 5 mm and a diameter D 2 It is 140mm~180mm.

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