CN111496980A - Powder dry pressing mold and powder dry pressing method - Google Patents

Abstract

The invention relates to a powder dry-pressing die and a powder dry-pressing method. The powder dry pressing mold comprises a bottom mold and an upper mold assembly, wherein the bottom mold is provided with a forming groove; the upper die assembly comprises a bottom surface dry pressing upper die and a vertical surface dry pressing upper die; the bottom surface dry pressing upper die can be matched with the forming groove, and the outer diameter of the bottom surface dry pressing upper die is smaller than the inner diameter of the forming groove so that a vertical surface forming gap is formed when the bottom surface dry pressing upper die is matched with the forming groove; the vertical surface dry pressing upper die can be sleeved on the outer side of the bottom surface dry pressing upper die and at least partially assembled in the vertical surface forming gap. The powder dry pressing die can be used for dry pressing and molding powder, and powder on the bottom surface and the vertical surface is pressed and compacted when the powder dry pressing die is used, so that the problem of a large number of pores in sintering is avoided; therefore, the qualified complex product with the vertical face structure can be prepared, and the defect that the qualified complex product with the vertical face structure cannot be obtained by the traditional powder dry pressing die is overcome.

Description

Powder dry pressing mold and powder dry pressing method

Technical Field

The invention relates to the technical field of dies, in particular to a powder dry pressing die and a powder dry pressing method.

Background

The powder dry pressing technology is that powder is loaded into a mould and compressed under the action of force to form a blank, usually one-way pressurization is adopted, the gas in the gap in the blank is partially discharged, the particles are displaced and gradually closed, and mutually and tightly occluded, and finally a blank body with the same section as that of the mould and the shape of the upper surface and the lower surface determined by an upper pressing head and a lower pressing head of the mould is formed.

The technology has strong applicability to plane plate-shaped products; for the complex structure with the vertical face structure, the complex structure is difficult to dry press due to the complex shape, so that qualified complex products with the vertical face structure cannot be produced.

Disclosure of Invention

In view of the above, there is a need for a powder dry-pressing mold and a powder dry-pressing method that can be used for the production of complex products having a facade structure.

A powder dry-pressing mold comprising:

the bottom die is provided with a forming groove;

the upper die assembly comprises a bottom surface dry pressing upper die and a vertical surface dry pressing upper die; the bottom surface dry pressing upper die can be matched with the forming groove, and the outer diameter of the bottom surface dry pressing upper die is smaller than the inner diameter of the forming groove so that a vertical surface forming gap is formed when the bottom surface dry pressing upper die is matched with the forming groove; the vertical surface dry pressing upper die can be sleeved on the outer side of the bottom surface dry pressing upper die, and at least part of the vertical surface dry pressing upper die is assembled in the vertical surface forming gap.

In some of these embodiments, the thickness of the bottom dry-pressing upper die is greater than the depth of the forming groove; the vertical surface dry pressing upper die can be sleeved outside the bottom surface dry pressing upper die and is partially assembled in the vertical surface forming gap;

the upper die assembly further comprises an upper die outer frame, and the upper die outer frame can be sleeved on the vertical face dry pressing upper die protruding out of the outer side area of the bottom die and attached to the bottom die.

In some embodiments, the bottom mold includes a bottom mold base body and a boss, the bottom mold base body includes an edge portion and a central portion surrounded by the edge portion, the boss is disposed on the central portion, and the forming groove is disposed on the boss;

the upper die outer frame can be attached to the boss and the edge of the bottom die.

In some embodiments, the upper mold outer frame has an outer frame base body, the outer frame base body is provided with a first central hole for being matched with the bottom surface dry pressing upper mold, a surface of the outer frame base body is provided with a recessed portion around the first central hole, the recessed portion is used for being attached to the boss of the bottom mold, and the edge of the outer frame base body is used for being attached to the edge portion.

In some of these embodiments, the boss is square or circular in shape.

In some embodiments, the bottom mold, the bottom dry-pressing upper mold, the vertical dry-pressing upper mold, and the upper mold frame are made of a material independently selected from one of metal, graphite, and ceramic material.

In some of these embodiments, the riser dry-pressing upper die has a second central aperture for mating with the floor dry-pressing upper die;

the vertical surface dry pressing upper die comprises a first end and a second end along the axial direction of the second center hole, the first end is used for being assembled in the vertical surface forming gap, and the second end protrudes out of the bottom die; the wall thickness of the first end remains constant and the wall thickness of the second end increases in a direction from the first end to the second end.

In some of these embodiments, the second central bore has a constant inner diameter, the first end of the vertical dry-pressing upper die has a constant outer diameter, and the second end of the vertical dry-pressing upper die has a gradually increasing outer diameter, in a direction from the first end to the second end.

In some embodiments, the bottom wall and the side wall of the forming groove are chamfered, and the bottom wall and the side wall of the end part of the bottom dry pressing upper die, which is matched with the forming groove, are also chamfered.

In some of these embodiments, the shape of the shaped recess is square or circular.

A powder dry-pressing method is carried out by adopting any one of the powder dry-pressing molds, and comprises the following steps:

filling a part of powder in a forming groove of the bottom die, then assembling the bottom surface dry pressing upper die in the forming groove filled with the powder, sleeving the vertical surface dry pressing upper die on the outer side of the bottom surface dry pressing upper die and at least partially assembling the vertical surface forming gap, and carrying out pressure maintaining treatment on the powder dry pressing die filled with the powder to finish bottom surface dry pressing forming;

and after the bottom surface is subjected to dry pressing forming, the vertical surface dry pressing upper die is detached, the other part of powder is filled in the vertical surface forming gap, the vertical surface dry pressing upper die is reassembled, and the powder dry pressing die filled with the powder is subjected to pressure maintaining treatment to complete vertical surface dry pressing forming.

In some embodiments, when the powder dry-pressing mold includes an upper mold frame, the step of dry-pressing the bottom surface further includes, before the step of pressure maintaining treatment, the steps of:

and sleeving the upper mold outer frame on the vertical face dry pressing upper mold, protruding out of the outer side area of the bottom mold and attached to the bottom mold.

The powder dry pressing mold can be used for dry pressing and molding powder, powder is directly filled in a molding groove of the powder dry pressing mold when the powder dry pressing mold is used, pressure is applied to a bottom mold and an assembled upper mold assembly after the powder dry pressing mold is assembled, the bottom mold and a bottom surface dry pressing upper mold act to complete dry pressing and molding of the bottom surface of the powder between the bottom mold and the bottom surface dry pressing upper mold, and the bottom mold and a vertical surface dry pressing upper mold act to complete dry pressing and molding of the vertical surface of the powder between the bottom mold and a vertical surface dry pressing upper mold, so that the powder on the bottom surface and the vertical surface are pressed and compacted, and the problem that a large number of pores exist in sintering can be avoided; therefore, the qualified complex product with the vertical face structure can be prepared, and the defect that the qualified complex product with the vertical face structure cannot be obtained by the traditional powder dry pressing die is overcome.

Drawings

Fig. 1 is a schematic structural diagram of a state of a powder dry-pressing mold according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of the powder dry-pressing mold shown in FIG. 1 in still another state;

FIG. 3 is a top view of the powder dry-pressing mold shown in FIG. 2;

FIG. 4 is a bottom view of the powder dry-pressing mold shown in FIG. 2;

fig. 5 is a schematic structural view of a bottom mold of the powder dry-pressing mold shown in fig. 1;

FIG. 6 is a schematic cross-sectional view of the bottom mold shown in FIG. 5;

fig. 7 is a schematic structural view of an upper mold outer frame of the powder dry-pressing mold shown in fig. 1;

FIG. 8 is a schematic cross-sectional view of the upper mold housing of FIG. 7;

fig. 9 is a schematic structural view of a vertical dry-pressing upper die of the powder dry-pressing die shown in fig. 1;

FIG. 10 is a schematic cross-sectional view of the vertical dry-pressing upper mold shown in FIG. 9;

fig. 11 is a side view of the vertical dry-pressing upper die shown in fig. 9.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

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.

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 invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Fig. 1 is a schematic structural diagram showing a state of a powder dry-pressing mold according to an embodiment of the present invention. Fig. 2 is a schematic sectional structure view showing still another state of the powder dry-pressing mold shown in fig. 1. Fig. 3 shows a top view of the powder dry-pressing mold shown in fig. 2. Fig. 4 shows a bottom view of the powder dry-pressing mold shown in fig. 2.

Referring to fig. 1, an embodiment of the invention provides a powder dry-pressing mold 10, which includes a bottom mold 100 and an upper mold assembly 200.

Fig. 5 is a schematic structural view of a bottom mold of the powder dry-pressing mold shown in fig. 1. Fig. 6 is a schematic cross-sectional view of the bottom mold shown in fig. 5. Referring to fig. 5, the bottom mold 100 is provided with a forming groove 101.

Referring to fig. 1-4, the upper mold assembly 200 includes a bottom dry-pressing upper mold 210 and a vertical dry-pressing upper mold 220. The bottom surface dry pressing upper die 210 can be matched with the forming groove 101; the outer diameter of the bottom dry-pressing upper die 210 is smaller than the inner diameter of the forming groove 101 so that the bottom dry-pressing upper die 210 forms an elevation forming gap (not shown) when being matched with the forming groove 101. The vertical dry pressing upper mold 220 can be sleeved outside the bottom dry pressing upper mold 210 and at least partially assembled in the vertical molding gap.

The powder dry pressing mold 10 can be used for powder dry pressing molding, powder is directly filled in the molding groove 101 of the powder dry pressing mold 10 when the powder dry pressing mold 10 is used, pressure is applied to the bottom mold 100 and the assembled upper mold assembly 200 after the powder dry pressing mold 10 is assembled, the bottom mold 100 and the bottom surface dry pressing upper mold 210 act to complete bottom surface dry pressing molding on the powder between the bottom mold 100 and the bottom surface dry pressing upper mold 210, the bottom mold 100 and the vertical surface dry pressing upper mold 220 act to complete vertical surface dry pressing molding on the powder between the bottom mold 100 and the vertical surface dry pressing upper mold 220, so that the powder on the bottom surface and the vertical surface are pressed tightly, and the problem that a large number of pores exist in sintering can be avoided; therefore, the qualified complex product with the vertical surface structure can be prepared, and the defect that the qualified complex product with the vertical surface structure cannot be obtained by the traditional powder dry pressing die 10 is overcome.

In addition, the powder dry pressing mold 10 is adopted for powder dry pressing molding, and the subsequent sintering process can be simultaneously sintered with the powder dry pressing mold 10, so that the size precision of the product is effectively ensured, the problem of unstable product size is solved, and the powder dry pressing mold is particularly suitable for production of products with high requirements on the size precision.

Further, the vertical surface molding gap is closed around the bottom surface dry pressing upper mold 210; further, the vertical surface forming gap may be square or circular according to the shape of the bottom surface dry-pressing upper mold 210.

In some of these embodiments, the thickness of the bottom dry-pressing upper die 210 is greater than the depth of the forming groove 101; the vertical dry pressing upper mold 220 can be sleeved outside the bottom dry pressing upper mold 210 and partially assembled in the vertical molding gap.

Referring to fig. 5-6, in some embodiments, a bottom mold 100 includes a bottom mold base 110 and a boss 120. The base mold substrate 110 includes an edge portion (not shown) and a central portion (not shown) surrounded by the edge portion, the boss 120 is provided on the central portion, and the molding groove 101 is provided on the boss 120.

In some of these embodiments, the upper die assembly 200 further includes an upper die casing 230. Fig. 7 is a schematic structural view of an upper mold outer frame of the powder dry-pressing mold shown in fig. 1. Fig. 8 is a schematic sectional view showing the upper mold housing shown in fig. 7.

Referring to fig. 2 and 7, the upper mold frame 230 can be sleeved on the outer region of the vertical dry pressing upper mold 220 protruding from the bottom mold 100 and is attached to the bottom mold 100.

Referring to fig. 2 and 6, the upper mold frame 230 can be attached to the boss 120 and the edge of the bottom mold 100. Thus, the upper mold frame 230 can provide a limiting function for the vertical surface dry pressing upper mold 220 and the bottom surface dry pressing upper mold 210, so that the vertical surface dry pressing upper mold 220 and the bottom surface dry pressing upper mold 210 are stable in structure when being matched with the bottom mold 100.

Referring to fig. 7 to 8, in some embodiments, the upper mold frame 230 has a frame base body, the frame base body has a first central hole 201 for matching with the bottom dry pressing upper mold 210, and a surface of the frame base body has a recess 203 around the first central hole 201. Referring to fig. 2, 6 and 8, the concave portion 203 of the upper mold frame 230 is adapted to fit with the boss 120 of the bottom mold 100, and the edge of the frame base of the upper mold frame 230 is adapted to fit with the edge of the bottom mold 100. This further enhances the limit of the upper mold frame 230.

In some of these embodiments, the shape of the forming groove 101 is square or circular. Further, the boss 120 is square or circular in shape. In this specific example, the molding groove 101 is the same shape as the boss 120; further, the shape is square.

In some embodiments, the material of the bottom mold 100, the bottom dry-pressing upper mold 210, the vertical dry-pressing upper mold 220, and the upper mold frame 230 is independently selected from one of metal, graphite, and ceramic material.

Further, the metal material may be selected from one of tungsten steel and stainless steel.

Further, the ceramic material may be selected from at least one of alumina, zirconia, silicon nitride, and aluminum nitride.

Further, the bottom mold 100, the bottom dry-pressing upper mold 210, the vertical dry-pressing upper mold 220, and the upper mold frame 230 are all metal molds, or all graphite molds, or all ceramic molds.

Further, when the powder dry-pressing mold 10 is in the assembled state as shown in fig. 2, the surfaces of the bottom surface dry-pressing upper mold 210, the vertical surface dry-pressing upper mold 220, and the upper mold outer frame 230 that are away from the bottom mold 100 are flat; the surface of the bottom mold 100 facing away from the bottom dry-pressing upper mold 210 is also flat. So as to facilitate pressure forming.

Fig. 9 shows a schematic structural view of an elevation dry-pressing upper die of the powder dry-pressing die shown in fig. 1. Fig. 10 shows a schematic cross-sectional view of the vertical dry-pressing upper die shown in fig. 9. Figure 11 shows a side view of the vertical dry-pressing upper die shown in figure 9.

In some of these embodiments, the riser dry-pressing cope mold 220 has a second central aperture 202 for mating with the bottom dry-pressing cope mold 210.

Further, the riser dry-pressing upper die 220 includes a first end 221 and a second end 222 in the axial direction of the second center hole 202. Referring to fig. 2 and 10, the first end 221 is configured to be mounted in the vertical molding gap and the second end 222 protrudes from the bottom mold 100. The wall thickness of the first end 221 remains constant and the wall thickness of the second end 222 increases gradually in a direction from the first end 221 to the second end 222. Thus, the wall thickness of the second end 222 is larger, and a bell mouth structure is formed from the first end 221 to the second end 222, so that when the powder dry-pressing mold 10 is in an assembled state as shown in fig. 2 and the vertical dry-pressing upper mold 220 is removed, a filler opening of the bell mouth structure is correspondingly left between the bottom dry-pressing upper mold 210 and the upper mold outer frame 230, so that the powder filling operation in the subsequent vertical dry-pressing molding step is facilitated, and the vertical powder can be further well pressed. The vertical surface molding die is particularly suitable for producing products with thin vertical surface structures, the width of the vertical surface molding gap of the powder dry pressing die 10 used correspondingly for the products is correspondingly smaller, and the problem that the vertical surface molding gap is smaller and the powder is inconvenient to fill is solved by forming the filling opening with the bell-mouth structure.

Further, in the direction from the first end 221 to the second end 222, the inner diameter of the second center hole 202 is kept constant, the outer diameter of the first end 221 of the vertical dry-pressing upper die 220 is kept constant, and the outer diameter of the second end 222 is gradually increased.

In a specific example, the first end 221 of the vertical dry-pressing upper mold 220 has a square structure, and the second end 222 has a trapezoid or approximately trapezoid structure.

In some embodiments, the bottom wall and the side wall of the forming groove 101 are chamfered, and the bottom wall and the side wall of the end of the bottom dry-pressing upper die 210 that is engaged with the forming groove 101 are also chamfered.

In some of these embodiments, the angle of the chamfer is 75 ° to 90 °. Specifically, the angle of the chamfer may be 90 °, thereby being used for molding of complex products of a 90 ° right-angled facade structure. Thus, the powder dry pressing mold 10 is suitable for the production of complex products with large-angle and high-elevation structures.

In another embodiment of the present invention, a powder dry-pressing method according to an embodiment may be performed using any one of the powder dry-pressing molds 10 described above. The powder dry-pressing method of an embodiment includes the following steps S10 to S20.

Step S10: filling a part of powder into a forming groove of a bottom die, then assembling a bottom surface dry pressing upper die into the forming groove filled with the powder, sleeving a vertical surface dry pressing upper die on the outer side of the bottom surface dry pressing upper die and at least partially assembling the vertical surface forming gap, and carrying out pressure maintaining treatment on the powder dry pressing die filled with the powder to finish bottom surface dry pressing forming.

Step S20: and (3) removing the vertical surface dry pressing upper die after the bottom surface dry pressing forming, filling the other part of powder into the vertical surface forming gap, reassembling the vertical surface dry pressing upper die, and carrying out pressure maintaining treatment on the powder dry pressing die filled with the powder to finish the vertical surface dry pressing forming.

In some embodiments, when the powder dry-pressing mold includes the upper mold outer frame, the step of dry-pressing the bottom surface further includes, before the step of pressing, the following step S11:

and sleeving the outer frame of the upper die on the outer area of the vertical face dry pressing upper die, which protrudes out of the bottom die and is attached to the bottom die.

It is understood that the types of the powder obtained by the powder dry pressing method include, but are not limited to, raw powder for producing microcrystalline glass, raw powder for producing general glass, raw powder for producing various ceramics, and the like. In other words, the powder dry pressing method can be applied to the production of 3D microcrystalline glass, 3D ordinary glass, 3D ceramics and the like.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (12)

1. The powder dry pressing mold is characterized by comprising:

the bottom die is provided with a forming groove;

the upper die assembly comprises a bottom surface dry pressing upper die and a vertical surface dry pressing upper die; the bottom surface dry pressing upper die can be matched with the forming groove, and the outer diameter of the bottom surface dry pressing upper die is smaller than the inner diameter of the forming groove so that a vertical surface forming gap is formed when the bottom surface dry pressing upper die is matched with the forming groove; the vertical surface dry pressing upper die can be sleeved on the outer side of the bottom surface dry pressing upper die, and at least part of the vertical surface dry pressing upper die is assembled in the vertical surface forming gap.

2. The powder dry-pressing mold of claim 1, wherein the thickness of the bottom dry-pressing upper mold is greater than the depth of the forming groove; the vertical surface dry pressing upper die can be sleeved outside the bottom surface dry pressing upper die and is partially assembled in the vertical surface forming gap;

the upper die assembly further comprises an upper die outer frame, and the upper die outer frame can be sleeved on the vertical face dry pressing upper die protruding out of the outer side area of the bottom die and attached to the bottom die.

3. The dry powder compaction mold of claim 2, wherein the bottom mold comprises a bottom mold base and a boss, the bottom mold base comprises an edge portion and a central portion surrounded by the edge portion, the boss is disposed on the central portion, and the molding groove is disposed on the boss;

the upper die outer frame can be attached to the boss and the edge of the bottom die.

4. The powder dry-pressing mold of claim 3, wherein the upper mold outer frame has an outer frame base, the outer frame base has a first central hole for engaging with the bottom dry-pressing upper mold, a surface of the outer frame base has a recessed portion around the first central hole, the recessed portion is for engaging with the boss of the bottom mold, and an edge of the outer frame base is for engaging with the edge portion.

5. The powder dry-pressing mold of claim 3, wherein the boss is square or circular in shape.

6. The powder dry-pressing mold of claim 2, wherein the bottom mold, the bottom dry-pressing upper mold, the vertical dry-pressing upper mold, and the upper mold outer frame are each independently selected from one of a metal, graphite, and a ceramic material.

7. The powder dry-pressing mold of any one of claims 1 to 6, wherein the vertical surface dry-pressing upper mold has a second central hole for mating with the bottom surface dry-pressing upper mold;

the vertical surface dry pressing upper die comprises a first end and a second end along the axial direction of the second center hole, the first end is used for being assembled in the vertical surface forming gap, and the second end protrudes out of the bottom die; the wall thickness of the first end remains constant and the wall thickness of the second end increases in a direction from the first end to the second end.

8. The powder dry-pressing mold of claim 7, wherein an inner diameter of the second center hole remains constant in a direction from the first end to the second end, an outer diameter of the first end of the vertical surface dry-pressing upper mold remains constant, and an outer diameter of the second end gradually increases.

9. The powder dry-pressing mold of any one of claims 1 to 6, wherein the bottom wall and the side wall of the forming groove are chamfered, and the bottom wall and the side wall of the end part of the bottom dry-pressing upper mold, which is matched with the forming groove, are also chamfered.

10. The powder dry-pressing mold according to any one of claims 1 to 6, wherein the shape of the molding groove is square or circular.

11. A dry powder compaction method using the dry powder compaction mold according to any one of claims 1 to 10, the dry powder compaction method comprising the steps of:

filling a part of powder in a forming groove of the bottom die, then assembling the bottom surface dry pressing upper die in the forming groove filled with the powder, sleeving the vertical surface dry pressing upper die on the outer side of the bottom surface dry pressing upper die and at least partially assembling the vertical surface forming gap, and carrying out pressure maintaining treatment on the powder dry pressing die filled with the powder to finish bottom surface dry pressing forming;

and after the bottom surface is subjected to dry pressing forming, the vertical surface dry pressing upper die is detached, the other part of powder is filled in the vertical surface forming gap, the vertical surface dry pressing upper die is reassembled, and the powder dry pressing die filled with the powder is subjected to pressure maintaining treatment to complete vertical surface dry pressing forming.

12. The dry powder compaction method according to claim 11, wherein when the dry powder compaction die includes an upper mold housing, the step of dry compacting the bottom surface further comprises, before the step of pressure holding treatment, the step of:

and sleeving the upper mold outer frame on the vertical face dry pressing upper mold, protruding out of the outer side area of the bottom mold and attached to the bottom mold.

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