阅读说明：本技术 一种磁流变多孔软模及板材成形装置 (Magnetorheological porous soft die and plate forming device ) 是由 相楠 田轩赫 孙依露 李银柱 皇涛 陈拂晓 于 2021-04-28 设计创作，主要内容包括：本发明涉及一种磁流变多孔软模及板材成形装置。磁流变多孔软模,包括：弹性基体,具有孔隙；磁性颗粒,一体成型在弹性基体内,磁性颗粒在弹性基体内分散布置且处于孔隙外部；弹性基体包括至少两个成形段；所有的成形段内均具有所述的孔隙,至少一个成形段的孔隙率大于其余各成形段的孔隙率,以使孔隙率大的成形段的弹性模量小于孔隙率小的成形段的弹性模量；或者至少一个成形段内具有所述的孔隙且至少一个成形段内未具有所述的孔隙,以使具有孔隙的成形段的弹性模量小于未具有孔隙的成形段的弹性模量。通过上述结构的设计,使得坯料与异形凹模完全接触时,整个坯料的受力较为均匀,避免了坯料在成形较深部分时因成形力过大而导致破裂。(The invention relates to a magnetorheological porous soft die and a plate forming device. A magnetorheological porous soft mold comprising: an elastomeric matrix having pores; the magnetic particles are integrally formed in the elastic matrix, and the magnetic particles are dispersedly arranged in the elastic matrix and are positioned outside the pores; the elastomeric matrix includes at least two forming sections; all the forming sections are provided with the pores, and the porosity of at least one forming section is larger than that of the rest forming sections, so that the elastic modulus of the forming section with high porosity is smaller than that of the forming section with low porosity; or at least one forming section has said apertures therein and at least one forming section does not have said apertures therein, such that the modulus of elasticity of the forming section with apertures is less than the modulus of elasticity of the forming section without apertures. Through the design of the structure, when the blank is completely contacted with the special-shaped female die, the stress of the whole blank is uniform, and the blank is prevented from being broken due to overlarge forming force when the blank is formed at a deeper part.)

1. Magnetorheological porous soft mold (6), characterized in that it comprises:

an elastomeric matrix having pores (11);

magnetic particles (10) integrally formed in the elastic matrix, wherein the magnetic particles (10) are dispersedly arranged in the elastic matrix and are positioned outside the pores (11);

the elastomeric matrix includes at least two forming sections;

all the forming sections are provided with the pores (11), and the porosity of at least one forming section is larger than that of the rest forming sections, so that the elastic modulus of the forming section with high porosity is smaller than that of the forming section with low porosity; or at least one forming section has said apertures (11) therein and at least one forming section does not have said apertures (11) therein, such that the modulus of elasticity of the forming section with apertures (11) is less than the modulus of elasticity of the forming section without apertures (11).

2. The soft magnetorheological porous mold (6) according to claim 1, wherein the volume fraction of the magnetic particles (10) in each shaping segment is the same.

3. The soft magnetorheological porous mold (6) according to claim 2, wherein the magnetic particles (10) have a volume fraction of 25 to 30%.

4. The soft magnetorheological porous mold (6) according to claim 1, 2 or 3, wherein the pores (11) in the same forming section are the same size when the pores (11) are provided in all the forming sections.

5. The magnetorheological porous soft mold (6) according to claim 4, wherein the size of the pores (11) of the shaping segment with high porosity is greater than or equal to the size of the pores (11) of the shaping segment with low porosity.

6. The soft magnetorheological porous mold (6) according to claim 1, 2 or 3, wherein the elastomeric matrix is a rubber matrix.

7. The magnetorheological porous soft mold (6) according to claim 6, wherein the rubber matrix is a polyurethane rubber matrix or a silicone rubber matrix.

8. The soft magnetorheological porous mold (6) according to claim 1, 2 or 3, wherein the magnetic particles (10) are ferromagnetic particles.

9. The magnetorheological porous soft mold (6) according to claim 8, wherein the ferromagnetic particles have a particle size of 1 to 5 μm.

10. The plate forming device comprises a female die (3), a coil (4), a magnetorheological porous soft die (6), a containing frame (7) and a plunger (8), wherein the female die (3) and the containing frame (7) are arranged in a right-faced mode, the heads of the magnetorheological porous soft die (6) and the plunger (8) are positioned in an inner cavity of the containing frame (7), and the coil (4) is sleeved on the outer side walls of the containing frame (7) and the female die (3).

Technical Field

The invention relates to a magnetorheological porous soft die and a plate forming device.

Background

The special-shaped thin-wall shell part is a plate part commonly used in the fields of aviation, aerospace, automobiles and the like which have urgent requirements on equipment light weight. At present, common methods for processing such parts include rigid male and female die stamping, soft die forming, and the like. Compared with a rigid convex-concave die stamping forming method, the soft die forming method is simpler, can avoid the problem that the rigid convex-concave die is easy to crack in forming, and is widely applied at present.

The Chinese patent with the publication number of CN103273644B discloses a plate soft mold forming device based on a magnetorheological elastomer, which comprises a plunger, a coil, a containing frame, the magnetorheological elastomer and a female mold, wherein the upper end surface of the female mold is provided with a female mold cavity, the containing frame and the female mold are arranged opposite to each other up and down, the containing frame is sleeved outside the plunger, the head of the plunger is positioned in the inner cavity of the containing frame, the magnetorheological elastomer is filled in the inner cavity formed by the lower surface of the plunger and the inner wall of the containing frame, and the coil is sleeved on the outer side walls of the containing frame and the female mold.

In the forming process, because the elastic modulus of the magnetorheological elastomer is the same everywhere, when parts with different cavity depths are formed, the mold is firstly attached to the shallower area of the cavity, so that the magnetorheological elastomer cannot provide enough forming force for the deeper area of the cavity, the forming is not uniform enough, meanwhile, the mold is firstly attached to the deeper area of the cavity, the material is limited to continuously flow to the cavity, and local forming insufficiency or breakage may occur.

Disclosure of Invention

The invention aims to provide a magnetorheological porous soft die, which aims to solve the technical problems that in the prior art, the elastic modulus of a magnetorheological elastomer is the same everywhere, and the forming is not uniform enough when parts with different cavity depths are formed; the invention also aims to provide a plate forming device using the magnetorheological porous soft die.

In order to realize the purpose, the technical scheme of the magnetorheological porous soft mold is as follows:

a magnetorheological porous soft mold comprising:

an elastomeric matrix having pores;

the magnetic particles are integrally formed in the elastic matrix, and the magnetic particles are dispersedly arranged in the elastic matrix and are positioned outside the pores;

the elastomeric matrix includes at least two forming sections;

all the forming sections are provided with the pores, and the porosity of at least one forming section is larger than that of the rest forming sections, so that the elastic modulus of the forming section with high porosity is smaller than that of the forming section with low porosity; or at least one forming section has said apertures therein and at least one forming section does not have said apertures therein, such that the modulus of elasticity of the forming section with apertures is less than the modulus of elasticity of the forming section without apertures.

The beneficial effects are that: the method comprises the following steps of arranging pores in an elastic matrix, and enabling the porosity in at least one forming section to be larger than the porosity of other forming sections, so that the elastic modulus of the forming section with high porosity is smaller than that of the forming section with low porosity, and further the rigidity of the forming section with high porosity is smaller than that of the forming section with low porosity; when forming, the forming section with large porosity is correspondingly formed into a shallow part, and the forming section with small porosity is correspondingly formed into a deep part, so that when the blank is completely contacted with the female die, the stress of the whole blank is uniform, and the defect of local forming or breakage when the blank is formed into the deep part is avoided.

As a further improvement, the volume fraction of magnetic particles in each shaping segment is the same.

The beneficial effects are that: because the magnetorheological porous soft mold is processed in a 3D printing mode, the volume fractions of the magnetic particles in the forming sections are the same, so that when the magnetic particles are formed in the forming sections, a printing head does not need to be replaced, and the magnetorheological porous soft mold is convenient to process and form.

As a further improvement, the volume fraction of the magnetic particles is 25-30%.

The beneficial effects are that: within the range, under the action of an external magnetic field, the mechanical property of the magnetorheological material can be adjusted to a large extent, and the rigidity of the soft mold can be effectively controlled by adjusting the strength of the external magnetic field at different stages in the forming process, so that the contact pressure of the soft mold/blank interface is adjusted, the inflow of the material is increased or reduced, and the deformation uniformity is improved.

As a further improvement, when the apertures are provided in all the forming sections, the apertures in the same forming section are of the same size.

The beneficial effects are that: the design is favorable for uniform deformation of the inner pores of each forming section and improves the stability of pressure transmission of the soft die.

As a further improvement, the pore size of the high porosity forming section is greater than or equal to the pore size of the low porosity forming section.

The beneficial effects are that: the design is convenient for realizing the large-amplitude adjustment of the porosity of each forming section.

As a further improvement, the elastic matrix is a rubber matrix.

The beneficial effects are that: the rubber matrix has good elasticity, large limit compression deformation and low cost.

As a further improvement, the rubber matrix is a polyurethane rubber matrix or a silicon rubber matrix.

The beneficial effects are that: the curing operation time of the polyurethane rubber or the silicon rubber is moderate, the curing condition is low, and the bubbles are easy to be pumped out.

As a further improvement, the magnetic particles are ferromagnetic particles.

The beneficial effects are that: the real-time control of the mechanical property of the soft mold is convenient to realize.

As a further improvement, the particle size of the ferromagnetic particles is 1-5 μm.

The beneficial effects are that: within the particle size range, the ferromagnetic particles have good suspension performance in the matrix, are uniformly distributed and have good magnetorheological performance.

In order to achieve the purpose, the technical scheme of the plate forming device is as follows:

the plate forming device comprises a female die, a coil, a magnetorheological porous soft die, a containing frame and a plunger, wherein the female die is arranged right opposite to the containing frame, the heads of the magnetorheological porous soft die and the plunger are positioned in an inner cavity of the containing frame, the coil is sleeved on the outer side wall of the containing frame and the outer side wall of the female die, and the magnetorheological porous soft die comprises:

an elastomeric matrix having pores;

the magnetic particles are integrally formed in the elastic matrix, and the magnetic particles are dispersedly arranged in the elastic matrix and are positioned outside the pores;

the elastomeric matrix includes at least two forming sections;

all the forming sections are provided with the pores, and the porosity of at least one forming section is larger than that of the rest forming sections, so that the elastic modulus of the forming section with high porosity is smaller than that of the forming section with low porosity; or at least one forming section has said apertures therein and at least one forming section does not have said apertures therein, such that the modulus of elasticity of the forming section with apertures is less than the modulus of elasticity of the forming section without apertures.

The beneficial effects are that: the method comprises the following steps of arranging pores in an elastic matrix, and enabling the porosity in at least one forming section to be larger than the porosity of other forming sections, so that the elastic modulus of the forming section with high porosity is smaller than that of the forming section with low porosity, and further the rigidity of the forming section with high porosity is smaller than that of the forming section with low porosity; when forming, the forming section with large porosity is correspondingly formed into a shallow part, and the forming section with small porosity is correspondingly formed into a deep part, so that when the blank is completely contacted with the female die, the stress of the whole blank is uniform, and the defect of local forming or breakage when the blank is formed into the deep part is avoided.

As a further improvement, the volume fraction of magnetic particles in each shaping segment is the same.

The beneficial effects are that: because the magnetorheological porous soft mold is processed in a 3D printing mode, the volume fractions of the magnetic particles in the forming sections are the same, so that when the magnetic particles are formed in the forming sections, a printing head does not need to be replaced, and the magnetorheological porous soft mold is convenient to process and form.

As a further improvement, the volume fraction of the magnetic particles is 25-30%.

The beneficial effects are that: within the range, under the action of an external magnetic field, the mechanical property of the magnetorheological material can be adjusted to a large extent, and the rigidity of the soft mold can be effectively controlled by adjusting the strength of the external magnetic field at different stages in the forming process, so that the contact pressure of the soft mold/blank interface is adjusted, the inflow of the material is increased or reduced, and the deformation uniformity is improved.

As a further improvement, when the apertures are provided in all the forming sections, the apertures in the same forming section are of the same size.

The beneficial effects are that: the design is favorable for uniform deformation of the inner pores of each forming section and improves the stability of pressure transmission of the soft die.

As a further improvement, the pore size of the high porosity forming section is greater than or equal to the pore size of the low porosity forming section.

The beneficial effects are that: the design is convenient for realizing the large-amplitude adjustment of the porosity of each forming section.

As a further improvement, the elastic matrix is a rubber matrix.

The beneficial effects are that: the rubber matrix has good elasticity, large limit compression deformation and low cost.

As a further improvement, the rubber matrix is a polyurethane rubber matrix or a silicon rubber matrix.

The beneficial effects are that: the curing operation time of the polyurethane rubber or the silicon rubber is moderate, the curing condition is low, and the bubbles are easy to be pumped out.

As a further improvement, the magnetic particles are ferromagnetic particles.

The beneficial effects are that: the real-time control of the mechanical property of the soft mold is convenient to realize.

As a further improvement, the particle size of the ferromagnetic particles is 1-5 μm.

The beneficial effects are that: within the particle size range, the ferromagnetic particles have good suspension performance in the matrix, are uniformly distributed and have good magnetorheological performance.

Drawings

FIG. 1 shows a plate material forming apparatus according to an embodiment 1 of the present inventiont ₀A schematic view of the structure of the moment;

FIG. 2 shows a plate forming apparatus according to embodiment 1 of the present inventiont ₁A schematic view of the structure of the moment;

FIG. 3 shows a plate forming apparatus according to embodiment 1 of the present inventiont ₂A schematic view of the structure of the moment;

FIG. 4 shows a plate material forming apparatus according to embodiment 1 of the present inventiont ₃A schematic view of the structure of the moment;

FIG. 5 shows a plate forming apparatus according to example 2 of the present inventiont ₀A schematic view of the structure of the moment;

in the figure: 1. a current regulator; 2. a direct current power supply; 3. a female die; 4. a coil; 5. a sheet blank; 6. magnetorheological porous soft mold; 7. containing frames; 8. a plunger; 9. a magnetic induction line; 10. magnetic particles; 11. and (4) pores.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element. Furthermore, the terms "upper" and "lower" are based on the orientation and positional relationship shown in the drawings and are only for convenience of description of the present invention, and do not indicate that the referred device or component must have a specific orientation, and thus, should not be construed as limiting the present invention.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1 of the sheet forming apparatus of the present invention:

as shown in fig. 1, the plate forming device comprises a female die 3, a coil 4, a magnetorheological porous soft die 6, a containing frame 7 and a plunger 8, wherein the female die 3 is positioned above the containing frame 7, the female die 3 is arranged opposite to the containing frame 7, so that a die cavity of the female die 3 is arranged opposite to an inner cavity of the containing frame 7, and a plate blank 5 is positioned and installed between the female die 3 and the containing frame 7 during forming; the head parts of the magnetorheological porous soft die 6 and the plunger 8 are positioned in the inner cavity of the containing frame 7, the coil 4 is sleeved on the outer side walls of the containing frame 7 and the female die 3, and the coil 4 is connected with the direct-current power supply 2 through the current regulator 1. Wherein, the containing frame 7 is an annular structure, and the coil 4 is a red copper coil.

In this embodiment, the magnetorheological porous soft mold 6 comprises an elastic matrix and magnetic particles 10, the elastic matrix has pores 11, and the pores 11 are dispersedly arranged in the elastic matrix; the magnetic particles 10 are integrally cured and molded in the elastic matrix, and the magnetic particles 10 are dispersedly arranged in the elastic matrix and are positioned outside the pores 11.

In this embodiment, the elastic substrate is a rubber substrate, and the rubber substrate may be a silicon rubber substrate or a polyurethane rubber substrate.

In the present embodiment, the magnetic particles 10 are ferromagnetic particles, and preferably, the ferromagnetic particles are iron hydroxyl powder. In other embodiments, the magnetic particles may be cobalt powder or nickel powder.

As shown in fig. 1, the elastic base body includes two forming sections, namely a left forming section and a right forming section, wherein the left forming section corresponds to a shallow forming part of the plate blank 5, and the right forming section corresponds to a deep forming part of the plate blank 5; the two forming sections are arranged along the left-right direction, the two forming sections are internally provided with the pores 11, the porosity of the left forming section is larger than that of the right forming section, so that the elastic modulus of the left forming section is smaller than that of the right forming section, and the forming force provided by the left side of the elastic matrix is smaller than that provided by the right side of the elastic matrix in the forming process, so that the forming precision of the plate blank 5 is improved. Wherein, the porosity refers to the ratio of the volume of all pores in the same forming section to the volume of the forming section.

In this embodiment, the apertures 11 in the left forming section are the same size, and the apertures 11 in the right forming section are the same size; the number of apertures 11 in the left forming section is smaller than the number of apertures 11 in the right forming section and the size of the apertures 11 in the left forming section is larger than the size of the apertures 11 in the right forming section.

In the present embodiment, the pores 11 are mainly filled with air, and the pores 11 are approximately spherical in an uncompressed state. Under the action of an external magnetic field, the micron-sized magnetic particles 10 distributed in the elastic matrix are rapidly gathered into a column shape or a chain shape along the direction of the magnetic induction line 9, so that the elastic modulus and the rigidity of the magnetorheological porous soft mold 6 along the direction of the magnetic induction line are increased, and the rigidity of the magnetorheological porous soft mold 6 is controllable in real time due to the extremely high response speed of the magnetic field. The elastic matrix is provided with two forming sections, and the elastic modulus of the two forming sections is different, so that the magnetorheological porous soft die 6 can form the plate blank 5 into different depths in one forming process; and the forming process is easy to control, the stability is good, the magnetorheological porous soft die 6 can be fully contacted with the plate forming part, and the problem of local excessive deformation in the plate forming process is effectively solved.

In the embodiment, the volume fractions of the magnetic particles 10 in the left forming section and the right forming section are the same, so that the rigidity of the magnetorheological porous soft mold 6 can be controlled in real time under the action of an external magnetic field; moreover, the magnetorheological porous soft mold 6 is processed in a 3D printing mode, so that the volume fractions of the magnetic particles in the left forming section and the right forming section are designed to be the same, and the magnetorheological porous soft mold 6 is convenient to process and form.

In this embodiment, before forming, the pores 11 are of a regular structure, the volume fractions of the magnetic particles 10 in the left and right forming sections are both 30%, the porosity of the left forming section is greater than the porosity of the right forming section, the elastic modulus of the left forming section is less than the elastic modulus of the right forming section, and the particle size range of the magnetic particles 10 is 3 ± 0.5 μm. In other embodiments, the volume fraction may take other values, and it is preferred to have a volume fraction of the ferromagnetic particles in the range of 25-30%.

After forming, the pores 11 are in an irregular structure, the volume fractions of the magnetic particles 10 in the left and right forming sections are still equal and are 25-30%, the porosity of the left forming section is greater than that of the right forming section, the elastic modulus of the left forming section is less than that of the right forming section, and the particle size range of the magnetic particles 10 is 2 +/-0.5 μm and is slightly less than that of the pores in the regular structure.

In the embodiment, the contact interface of the magnetorheological porous soft die 6 and the plate blank 5 can generate beneficial tangential friction force, the tangential friction force can promote the plate blank to flow to the deformation area, the filling capacity of the plate blank to the deformation area is improved, the radius of a filled fillet can reach 0.3 time of the thickness of a plate, and the formability and the forming precision of the plate blank are improved.

The specific forming method using the plate forming device is as follows:

(1) as shown in figure 1, the magnetorheological porous soft mold 6 is placed in the containing frame 7, and the slab blank 5 and the concave mold 3 are placed on the upper surface of the containing frame 7. The plate blank 5 is positioned and installed between the female die 3 and the containing frame 7, and the coil 4 is connected with the direct-current power supply 2 through the current regulator 1. Wherein, the plate blank 5 is made of non-ferromagnetic metal plate with the thickness of 0.5mm, such as aluminum alloy plate, stainless steel plate, titanium alloy plate, etc. In other embodiments, the thickness of the slab may be selected to be other values, typically not exceeding 0.1-1 mm.

(2) As shown in FIG. 1, int ₀At that time, the plate forming device is integrally placed on the working table of the press machine, and the press machine is started to provide a blank holder force F. The plunger 8 ascends at a speed of V =1.5mm/s, and is magnetizedThe rheological porous soft die 6 is used as a force transmission medium to deform the slab 5. Before the start of forming, no current is present in the coil 4, i.e., current I =0, so the magnetic induction B = 0.

(3) As shown in fig. 2, at the beginning of formingt ₁At that time, the dc power supply 2 is turned on, and the current in the coil 4 can be adjusted by the current adjuster 1 so that the current I = I₁Magnetic induction of B = B₁The direction of the magnetic induction line 9 is indicated by a broken arrow in the figure, and the plunger 8 starts to press the sheet material 5.

(4) During the forming process, as shown in FIG. 3t ₂At that time, the current is increased by the current regulator 1 so that the current I = I₂Magnetic induction B = B₂And the rigidity of the magnetorheological porous soft die 6 is also obviously improved, and the left side of the female die 3 begins to be attached to the plate blank 5 under the extrusion of the plunger 8.

(5) During the forming process, as shown in FIG. 4t ₃At that time, the right side of the die 3 is attached to the slab 5 under the continued pressing of the plunger 8.

(6) And (3) closing the direct-current power supply 2, moving the cross beam of the press upwards, and opening the female die 3 to obtain the final plate formed by the plate blank 5.

Wherein, in the above step (3) and step (4), the magnetic induction B₁=0.2T，B₂And =1.0T, the magnitude of the magnetic induction intensity can determine the magnitude of the rigidity of the magnetorheological porous soft mold 6. In the initial forming stage, the forming depth of the plate blank 5 is small, the required forming force is small, the plate blank 5 can obtain enough filling capacity only by the size of a small magnetic field, the forming depth of the plate blank 5 is gradually increased along with the increase of time, the magnetic field must be changed along with the time, the rigidity of the magnetorheological porous soft die 6 is increased, and the die attaching precision of the plate blank is improved.

It should be noted thatt ₃At the moment, the left side of the plate blank 5 is basically formed, and under the continuous extrusion of the plunger 8, the rigidity of the left forming section is smaller than that of the right forming section due to the fact that the porosity of the left forming section is larger than that of the right forming section, and therefore the right forming section continuously forms the right side of the plate blank 5And the acting force applied to the left side of the plate blank 5 by the left forming section is smaller, so that the improvement of the stress uniformity of the plate blank is facilitated, and the fracture of the right side of the plate blank 5 due to overlarge elongation deformation caused by overlarge constraint force of the left side of the plate blank 5 is avoided.

Example 2 of the sheet forming apparatus of the present invention:

this embodiment differs from embodiment 1 in that in embodiment 1, the size of each aperture 11 in the left forming section is the same, the size of each aperture 11 in the right forming section is the same, and the porosity in the left forming section is greater than the porosity in the right forming section. In this embodiment, as shown in fig. 5, the sizes of the pores in the left forming section are not completely the same, and the sizes of the pores in the right forming section are not completely the same, as long as the porosity in the left forming section is ensured to be greater than the porosity in the right forming section.

Example 3 of the sheet forming apparatus of the present invention:

the difference between this embodiment and embodiment 1 is that in embodiment 1, the left forming section and the right forming section are both provided with pores 11, and the porosity in the left forming section is greater than the porosity in the right forming section, so that the modulus of elasticity of the left forming section is smaller than that of the right forming section. In this embodiment, the left forming section has a void therein, and the right forming section has no void therein, so that the elastic modulus of the left forming section is smaller than the elastic modulus of the right forming section.

Example 4 of the sheet forming apparatus of the present invention:

this embodiment differs from embodiment 1 in that in embodiment 1, the volume fractions of the magnetic particles 10 in the left and right shaping segments are the same. In this embodiment, the volume fraction of the magnetic particles in the left shaping segment is greater than or less than the volume fraction of the magnetic particles in the right shaping segment, as long as the elastic modulus of the left shaping segment is ensured to be less than the elastic modulus of the right shaping segment.

Example 5 of the sheet forming apparatus of the present invention:

the present embodiment differs from embodiment 1 in that in embodiment 1, the number of apertures 11 in the left forming section is smaller than the number of apertures 11 in the right forming section, and the size of the apertures 11 in the left forming section is larger than the size of the apertures 11 in the right forming section. In this embodiment, the size of the apertures in the left forming section is equal to the size of the apertures in the right forming section, and the number of apertures in the left forming section is greater than the number of apertures in the right forming section.

The embodiment of the magnetorheological porous soft mold of the invention is the same as the magnetorheological porous soft mold described in any one of embodiments 1 to 5 of the plate forming device, and details are not repeated here.

The above description is only a preferred embodiment of the present invention, and not intended to limit the present invention, the scope of the present invention is defined by the appended claims, and all structural changes that can be made by using the contents of the description and the drawings of the present invention are intended to be embraced therein.