阅读说明：本技术 金属扇轮及其制备模具和方法 (Metal fan wheel and preparation mold and method thereof ) 是由 沈瀚啸 于 2019-10-25 设计创作，主要内容包括：本发明公开了一种金属扇轮及其制备模具和方法,金属扇轮的扇轮叶片厚度为0.08mm～0.1mm。本发明实现了扇轮超薄叶片的制备,本发明的制备模具将固定的公模仁的叶片成型定模和活动的叶片镶件组装后形成叶片型腔,该叶片型腔是扇轮毛坯件的叶片型腔,叶片型腔的形状和尺寸就是毛坯件叶片的形状和尺寸,叶片型腔的形状和尺寸根据设计需要调整叶片成型定模和叶片镶件即可。采用本发明的模具和方法,可制备叶片厚度低至0.08mm的一体金属扇轮,超薄叶片的一体化顺利成型,也使得金属扇轮可以进一步微型化设计和应用。(The invention discloses a metal impeller and a preparation mold and a preparation method thereof, wherein the thickness of impeller blades of the metal impeller is 0.08-0.1 mm. The invention realizes the preparation of the ultrathin blade of the fan wheel, the preparation mould of the invention assembles the blade forming fixed mould of the fixed male mould core and the movable blade insert to form a blade cavity, the blade cavity is the blade cavity of the fan wheel blank, the shape and the size of the blade cavity are the shape and the size of the blade of the blank, and the shape and the size of the blade cavity can be adjusted according to the design requirement. By adopting the die and the method, the integrated metal impeller with the thickness of the blade as low as 0.08mm can be prepared, the integration of the ultrathin blade is smoothly formed, and the metal impeller can be further designed and applied in a miniaturized way.)

1. A metal impeller comprises a hub (10-1) and blades (10-2), wherein the blades (10-2) are arranged at equal intervals along the circumferential direction of the hub (10-1), and the metal impeller is characterized in that: the thickness of the blade (10-2) is more than or equal to 0.08mm and less than 0.1 mm.

2. The metal fan wheel of claim 1, wherein: the number of the blades (10-2) is 15-100.

3. The metal fan wheel of claim 2, wherein: the number of the blades (10-2) is 41-100.

4. The metal fan wheel of claim 1, wherein: the thickness of the blade (10-2) is 0.08 mm.

5. The utility model provides a preparation mould of metal flabellum, includes core insert (1), cavity insert (2) and runner plate (3), its characterized in that: the preparation mould is a preparation mould of a fan wheel blank; a blade insert (6) and a hub insert (7) are also wrapped; the male die core (1) is arranged below the female die core (2), a circle of blade forming fixed dies (1-1) is arranged in the center of the male die core (1), and a blade insert groove (1-2) which penetrates through the male die core (1) from top to bottom is formed between every two adjacent blade forming fixed dies (1-1); the number of the blade inserts (6) is the same as that of the blade insert grooves (1-2) of the core insert (1), one blade insert (6) is inserted into each blade insert groove (1-2) from bottom to top, and a blade cavity (1-3) is formed between each blade insert (6) and the adjacent blade forming fixed die (1-1);

the side, opposite to the male die core (1), of the female die core (2) is provided with a hub forming part (2-1), a blade forming part (2-2) and an auxiliary ring forming part (2-3) from inside to outside, a fan wheel hub cavity is formed between the hub forming part (2-1) and a hub insert (7) fixed on the male die core (1), a blade insert (6) and a blade forming fixed die (1-1) are located in the blade forming part (2-2), the auxiliary ring forming part (2-3) is located outside the blade forming part (2-2), and the auxiliary ring forming part (2-3) is communicated with a blade cavity (1-3) formed by the blade insert (6) and the blade forming fixed die (1-1).

6. The mold for manufacturing a metal fan wheel according to claim 5, wherein: the insert molding die further comprises a blade insert plate (4), wherein the blade insert plate (4) is positioned below the core insert (1);

a circle of insert slots (4-1) are formed in the blade insert plate (4), the size and the shape of the insert slots (4-1) are matched with those of the blade insert (6), and the blade insert (6) penetrates through the insert slots (4-1) of the blade insert plate (4) from bottom to top and penetrates into the blade insert slots (1-2) of the male die core (1) after being positioned and arranged by the blade insert plate (4).

7. The mold for manufacturing a metal fan wheel according to claim 6, wherein: the blade insert plate structure further comprises an ejector pin plate (5) and an ejector pin (8), wherein the ejector pin plate (5) is positioned below the blade insert plate (4); the thimble plate (5) is provided with a circle of thimble channels, the diameter of each thimble channel is the same as the outer diameter of each thimble (8), the thimbles (8) are arranged annularly, and after passing through the thimble plate (5) and being positioned by the thimble plate (5), the thimbles continuously pass through the thimble channels of the blade insert plates (4) upwards and then enter thimble holes (1-7) of the core insert (1).

8. The mold for manufacturing a metal fan wheel according to claim 5, wherein: the core insert is characterized by further comprising a hub insert (7), wherein the hub insert (7) is arranged in a hub insert hole (1-4) of the core insert (1), and an insert pin hole (7-1) is formed in the center of the hub insert (7).

9. The mold for manufacturing a metal fan wheel according to claim 8, wherein: the molding die further comprises an insert pin (9), wherein the insert pin (9) is used for molding a shaft hole (10-1-1) of the fan wheel (10), penetrates through a central hole of the female die core (1) from top to bottom and then is inserted into an insert pin hole (7-1) of the hub insert (7).

10. A method for manufacturing a fan wheel using the manufacturing mold for a metal fan wheel according to claim 5, characterized by comprising the steps of:

① mixing metal powder and polymer binder in equipment to obtain a mixture;

② adding the mixture into the barrel of the injection molding machine, and injecting into the fan wheel cavity of the mold through the nozzle of the injection molding machine to obtain blank;

③ degreasing the blank;

④, sintering the blank degreased in step ③, cooling to room temperature to obtain a fan wheel intermediate, wherein the fan wheel intermediate is provided with an auxiliary ring (10-4) at the periphery of the blade;

⑤ cutting the auxiliary ring (10-4) of the intermediate body of the fan wheel to obtain the finished fan wheel.

11. The method of claim 10, wherein the step ③, the blank is heat-insulated at 90-150 ℃ for removing the binder, the heat-insulated time is determined according to the maximum thickness of the blank and is controlled at 1-2 mm/h.

12. The method for manufacturing a fan wheel according to claim 10, wherein in the step ④, the degreased blank is kept at 950 to 1300 ℃ for 1 to 6 hours and then cooled to room temperature.

Technical Field

The invention relates to a fan wheel, in particular to a metal fan wheel and a preparation mold and a preparation method thereof.

Background

The impeller is an important component of the heat dissipation fan, and generally includes a hub and a plurality of blades surrounding the hub. For the fan wheel, in a unit space, in a certain blade number range, the more the number of the blades is set, the larger the air volume and the larger the air pressure are at the same rotating speed, and the smaller the noise of the fan is; under the conditions of determined blade quantity and rotating speed, the thinner a single blade is, the larger the air quantity is, and the larger the air pressure is.

The impeller is divided into an all-plastic impeller, a plastic and metal impeller and an all-metal impeller according to the material.

With the requirement of miniaturization of the impeller, the miniaturization of the blades of the all-plastic impeller has difficulty due to the flowing of plastic and the thermal deformation characteristic of the plastic during the traditional plastic injection; even if the miniature plastic impeller is molded, the structural strength of the impeller is also problematic, and the service life is short.

The plastic and metal fan wheel is referred to Chinese patent document CN 104033419A (application number 201310069134.4), and the manufacturing method of the fan wheel disclosed by the document comprises the following steps: stamping a metal plate to form a metal fan blade blank with a blade body and at least one connecting piece; bending the connecting piece to enable the connecting piece to be bent relative to the blade body so as to form a metal fan blade; a plurality of metal fan blades are encircled, so that the metal fan blades are encircled by connecting pieces of the metal fan blades to form a continuous annular connecting ring together so as to form a fan wheel body, and a prefabricated area is formed in the center of the fan wheel body; and coating one end of each blade body of the metal blades by plastic injection to enable the plastic to be embedded with the end part of the blade body, forming a hub in a prefabricated area of the impeller body, injecting the plastic into the prefabricated area to enable the plastic to flow into an embedded part formed at one end of the blade body, and embedding the plastic with the end part of the blade body after the plastic is cooled and solidified. The preparation method disclosed by the method is complicated, the blade and the hub need to be prepared respectively, and the blade needs to be subjected to punch forming and assembling respectively.

Chinese patent document CN 104117677B (application No. 201310142793.6) discloses a method for manufacturing a metal fan wheel, comprising the following steps: a) mixing metal powder and a high molecular binder to obtain a flowable injection material, wherein the mixing ratio of the metal powder to the high molecular binder is 70-95% and 5-30% of the high molecular binder, and the particle size of the metal powder is less than 25 mu m; b) the injection material is made into a fan wheel blank in an injection molding mode, and a hub and blades of the fan wheel blank are integrally molded and have different wall thicknesses; c) removing the macromolecular binder in the fan wheel green blank to form a fan wheel semi-finished product; and d) sintering the semi-finished fan wheel product, melting metal components, cooling and forming to obtain a metal fan wheel finished product, wherein the wall thickness of each blade of the metal fan wheel finished product is less than 0.3 mm.

The metal fan wheel obtained by the manufacturing method comprises a hub and a plurality of blades, wherein the plurality of blades are annularly arranged on the peripheral surface of the hub and are integrally connected with the hub. The wall thickness of the hub can be larger than that of each blade, so that the hub has enough structural strength for assembling and combining components such as a rotating shaft, a magnetic part (not shown) and the like; the wall thickness of each blade is reduced to below 0.3mm, preferably to 0.2 mm.

Chinese patent document CN 103317139B (application No. 201310196600.5) discloses a metal powder one-shot injection molding fan and a method for manufacturing the same, the method for manufacturing the metal powder one-shot injection molding fan includes the following steps: (a) mixing materials: putting metal powder into mixing equipment, mixing and preheating, and then adding a binder, and uniformly mixing for 2-3 hours to obtain a mixed material; (b) manufacturing a mould: designing and manufacturing a mold of the metal fan to form a mold cavity in the shape of the metal fan; (c) injection molding: injecting the mixed material into a charging barrel of an injection molding machine, and then injecting the mixed material into a mold cavity of a metal fan through a nozzle of the injection molding machine to obtain a blank piece; (d) degreasing: heating the blank piece in a container to 60-150 ℃, keeping the temperature for 1-3 hours at a constant temperature, and removing the binder to obtain a crude product of the metal fan; (e) sintering and forming: and (c) placing the degreased crude product in a high-temperature sintering furnace, gradually heating to 1200-1400 ℃, preserving heat for 1-6 hours, and cooling to room temperature to obtain the integrally formed metal fan, wherein in the step (c), the temperature of the charging barrel is controlled to be 150-200 ℃, the temperature of the nozzle is controlled to be 150-200 ℃, the temperature in the die cavity is controlled to be 80-130 ℃, the injection molding speed of the nozzle is 50-100 g/s, and the pressure in the injection molding process is controlled to be 70-120 MPa.

The metal fan manufactured by the preparation method comprises the following steps: the fan comprises a hub, a plurality of fan blades radially arranged on the hub in a surrounding mode and a wheel disc used for connecting the fan blades. The fan blades extend from the edge part of the hub to the circumferential surface of the wheel disc, the hub comprises a circular bottom plate and a circular ring wall extending vertically upwards from the periphery of the circular bottom plate, and the fan blades are molded from the circular ring wall part of the hub to the wheel disc. The fan blades are integrally connected and are integrally formed with the hub and the wheel disc, welding and rivet riveting are not needed in the whole manufacturing process, mass rapid production can be realized, and the whole production cost is reduced by 80% compared with other modes. Specifically, the number of the blades scattered on the circumference of the hub by the fan blades formed by one-time injection molding of metal powder is 15-40, the mass of the integrally connected fan blades is 1-5 g, the thickness of each fan blade is more than or equal to 0.1-0.2 mm, and the outer diameter of each fan blade is 20-50 mm.

This document discloses a fan wheel having a single fan blade with a thickness of 0.1mm to 0.2mm or more, but does not disclose a manufacturing process and a mold.

In addition, some applications place a demand for a reduction in the design size of the impeller, and in order to accommodate the same number of blades in a smaller space or as many blades as possible, the blades are necessarily required to be thinned. However, due to the limitation of the existing manufacturing technology, the thickness of the blade of the integrated metal impeller on the market is usually 0.15mm to 0.25mm, and the thickness of the blade of the integrated metal impeller can not be 0.1mm or less, so that the further miniaturization design and application of the integrated metal impeller are limited.

Disclosure of Invention

The invention aims to solve the technical problem of providing an integrated metal impeller with ultrathin blades, and a die and a method for preparing the impeller with the ultrathin blades.

The technical scheme for realizing the first purpose of the invention is that the metal fan wheel comprises a hub and blades, wherein the blades are annularly arranged at equal intervals along the circumferential direction of the hub, and the thickness of each blade is more than or equal to 0.08mm and less than 0.1 mm.

Optionally, the number of the blades is 15-100.

Further optionally, the number of the blades is 41-100.

Optionally, the blade thickness is 0.08 mm.

The technical scheme for realizing the second purpose of the invention is that the preparation mold of the metal fan wheel comprises a male mold core, a female mold core and a runner plate, and further comprises a blade insert and a hub insert; the male die core is arranged below the female die core, the center of the male die core is provided with a circle of blade forming fixed dies, and a blade insert groove which vertically penetrates through the male die core is formed between every two adjacent blade forming fixed dies; the number of the blade inserts is the same as that of the blade insert grooves of the male die core, one blade insert is inserted into each blade insert groove from bottom to top, and a blade cavity is formed between each blade insert and the adjacent blade forming fixed die.

The opposite side of the female die core and the male die core is provided with a hub forming part, a blade forming part and an auxiliary ring forming part from inside to outside, a fan wheel hub cavity is formed between the hub forming part and a hub insert fixed on the male die core, the blade insert and the blade forming fixed die are positioned in the blade forming part, the auxiliary ring forming part is positioned outside the blade forming part, and the auxiliary ring forming part is communicated with a blade cavity formed by the blade insert and the blade forming fixed die.

Furthermore, the insert molding device also comprises a blade insert plate which is positioned below the core insert.

The blade insert plate is provided with a circle of insert slots, the size and the shape of each insert slot are matched with those of the blade insert, and the blade inserts penetrate through the insert slots of the blade insert plate from bottom to top and penetrate into the blade insert slots of the male die core after being positioned and arranged by the blade insert plate.

Further, the blade insert plate structure further comprises an ejector pin plate and an ejector pin, wherein the ejector pin plate is positioned below the blade insert plate; the ejector pin plate is provided with a circle of ejector pin channels, the diameter of each ejector pin channel is the same as the outer diameter of each ejector pin, the ejector pins are arranged in an annular shape, and after penetrating through the ejector pin plate and being positioned by the ejector pin plate, the ejector pins continuously penetrate upwards through the ejector pin channels of the blade insert plates and then enter the ejector pin holes of the male mold core.

Furthermore, the core insert further comprises a hub insert, the hub insert is arranged in a hub insert hole of the core insert, and a needle inserting hole is formed in the center of the hub insert.

The fan wheel insert further comprises an insert pin, wherein the insert pin is used for forming a shaft hole of the fan wheel, penetrates through a central hole of the female die core from top to bottom and then is inserted into an insert pin hole of the hub insert.

The technical scheme for realizing the third object of the invention is a method for preparing a fan wheel by using the preparation mould of the metal fan wheel, which comprises the following steps:

① mixing the metal powder with the polymer binder in the equipment to obtain the mixture.

② the mixture is fed into the barrel of the injection molding machine and then injected into the fan wheel cavity of the mold through the nozzle of the injection molding machine to obtain the blank.

③ the blank is degreased.

④, sintering the blank after degreasing in step ③, cooling to room temperature to obtain the intermediate body of the fan wheel, wherein the intermediate body of the fan wheel is provided with an auxiliary ring at the periphery of the blade.

⑤ the auxiliary ring of the intermediate body of the fan wheel is cut and removed to obtain the finished fan wheel.

In the step ③, the blank is heat preserved at 90-150 ℃ to remove the binder, the heat preservation time is determined according to the maximum thickness of the blank and is controlled at 1-2 mm/h.

In the step ④, the degreased blank is kept at 950-1300 ℃ for 1-6 hours and then cooled to room temperature.

The invention has the positive effects that:

(1) the metal impeller is a metal integrated piece and is prepared by adopting a metal powder one-step injection molding process, the thickness of the blade is as low as 0.08mm, and the mechanical strength is kept.

(2) By adopting the die and the method, the integrated metal impeller with the thickness of the blades as low as 0.08mm can be prepared, so that the number of the blades of the metal impeller in the same space can be more, and the more the number of the blades is set, the larger the air volume is, the larger the air pressure is and the smaller the noise of the fan is under the same rotating speed in a certain blade number range; under the conditions of determined blade quantity and rotating speed, the thinner a single blade is, the larger the air quantity is, and the larger the air pressure is.

The integration of ultra-thin blade is smooth to be moulded, also makes metal impeller can more little size design and application in the past, promptly further miniaturation.

(3) The mold realizes the preparation of the ultrathin blade of the fan wheel, and the invention assembles the fixed blade molding mold of the fixed core and the movable blade insert to form the blade cavity, wherein the blade cavity is the blade cavity of the fan wheel blank, the shape and the size of the blade cavity are the shape and the size of the blade of the fan wheel blank, for example, the width of the blade cavity is the width of the blade of the blank, and the shape and the width of the blade cavity can be adjusted according to the design requirements.

Because the shrinkage of the blank piece is reduced after sintering, the shrinkage rates s of different injection materials are different, and the ratio of the thickness of the blade of the blank piece to the thickness of the blade of the finished fan wheel is defined as the shrinkage rate s (s is more than 1), the size of the blade cavity of the die is amplified by s times according to the design requirement of the product fan wheel.

(4) The auxiliary ring forming part is arranged in the impeller mould, so that the injection material can quickly and smoothly enter the blade cavity, and the ultra-thin blade is formed. And (3) cutting and removing the auxiliary ring obtained by injection molding of the auxiliary ring molding part after sintering.

Drawings

Fig. 1 is an exploded view of a metal fan wheel manufacturing mold.

Fig. 2 is a schematic view of fig. 1 flipped 180 °.

Fig. 3 is a schematic view of the core insert of fig. 1 assembled with the blade insert and the hub insert.

Fig. 4 is an enlarged view of a portion a of fig. 3.

Fig. 5 is a schematic view of the lobe insert of fig. 1.

Fig. 6 is an enlarged view of the core insert of fig. 1.

Fig. 7 is an enlarged view of the portion B in fig. 6.

Fig. 8 is an enlarged view of the portion B in fig. 6.

Fig. 9 is a bottom view of the core insert of fig. 6.

Fig. 10 is an enlarged view of the portion C in fig. 9.

Fig. 11 is an enlarged top view of the cavity insert of fig. 1.

Fig. 12 is a perspective view of the cavity insert.

Fig. 13 is a schematic structural view of the intermediate body of the impeller.

Fig. 14 is a structural schematic view of the impeller.

Fig. 15 is a schematic view of the impeller of fig. 14 turned 180 °.

The reference numbers in the above figures are as follows:

the blade forming die comprises a male die core 1, a blade forming fixed die 1-1, blade insert grooves 1-2, a blade cavity 1-3, hub insert holes 1-4, connecting rings 1-5, annular grooves 1-6 and thimble holes 1-7; the core insert comprises a cavity insert 2, a hub forming part 2-1, a blade forming part 2-2, an annular groove 2-2-1, an auxiliary ring forming part 2-3 and a filling opening 2-4; a runner plate 3, a runner 3-1; the structure comprises a blade insert plate 4, insert slots 4-1, an ejector plate 5, blade inserts 6, barrier strips 6-1, a hub insert 7 and pin embedding holes 7-1; the device comprises a thimble 8, an insert needle 9, a fan wheel 10, a hub 10-1, a shaft hole 10-1-1, a spoke surface 10-1-2, a blade 10-2, a connecting ring 10-3 and an auxiliary ring 10-4.

Detailed Description

The orientation of the present invention is described according to the orientation shown in fig. 1, that is, the up-down and left-right directions shown in fig. 1 are the up-down and left-right directions described, and in fig. 1, the side close to the center of each block plate and mold core is referred to as the inner side, and the side far from the center is referred to as the outer side.

(embodiment 1, Metal impeller)

Referring to fig. 14 and 15, the metal fan wheel 10 of the present embodiment is a metal one-piece member including a hub 10-1, blades 10-2, and a connection ring 10-3.

The hub 10-1 comprises a spoke surface 10-1-2 and an accommodating cavity at one side of the spoke surface 10-1-2, and a shaft hole 10-1-1 is formed in the center of the spoke surface 10-1-2.

The blades 10-2 are arranged around the hub 10-1 at equal intervals, the root parts of the blades 10-2 are connected with the side wall of the hub, and the blades 10-2 extend outwards from the root parts connected with the hub 10-1.

The connecting ring 10-3 is a sheet-shaped circular ring, the connecting ring 10-3 is connected with the end parts of all the blades 10-2 and is coaxial with the hub 10-1, and the connecting ring 10-3 and the spoke surface 10-1-2 of the hub 10-1 are positioned on the same side of the blades 10-2.

In the embodiment, the outer diameter of the impeller 10 is 38mm, the diameter of the hub 10-1 is 22.4mm, the thickness of the blade 10-2 is 0.08mm, the distance between the root parts of the adjacent blades is 0.5mm, and the number of the blades 10-2 is 84.

(embodiment 2, Metal impeller)

The metal impeller of this embodiment is otherwise the same as embodiment 1, except that: the outer diameter of the impeller 10 is 38mm, the diameter of the hub 10-1 is 22.4mm, the thickness of the blade 10-2 is 0.10mm, the distance between the adjacent blade roots is 0.8mm, and the number of the blades 10-2 is 66.

(embodiment 3, Metal impeller)

The metal impeller of this embodiment is otherwise the same as embodiment 1, except that: the outer diameter of the impeller 10 is 48mm, the diameter of the hub 10-1 is 22.4mm, the thickness of the blades 10-2 is 0.13mm, the distance between the adjacent blade roots is 0.8mm, and the number of the blades 10-2 is 60.

(embodiment 4, Metal impeller)

The metal impeller of this embodiment is otherwise the same as embodiment 1, except that: the outer diameter of the impeller 10 is 48mm, the diameter of the hub 10-1 is 27.1mm, the thickness of the blade 10-2 is 0.16mm, the distance between the adjacent blade roots is 0.8mm, and the number of the blades 10-2 is 72.

(example 5, Metal impeller)

The metal impeller of this embodiment is otherwise the same as embodiment 1, except that: the outer diameter of the impeller 10 is 54mm, the diameter of the hub 10-1 is 27mm, the thickness of the blades 10-2 is 0.20mm, the distance between the adjacent blade roots is 1.7mm, and the number of the blades 10-2 is 48.

(embodiment 6 mold for manufacturing Metal impeller)

The manufacturing mold of the embodiment is used for preparing a fan wheel blank, and the finished fan wheel is obtained after degreasing, sintering and processing the blank. The manufacturing mold of the present embodiment is actually a manufacturing mold of a blank member.

Referring to fig. 1 to 12, the mold for manufacturing the metal impeller of the present embodiment includes a core insert 1, a core insert 2, a runner plate 3, a blade insert plate 4, an ejector plate 5, a blade insert 6, a hub insert 7, an ejector pin 8, and an insert pin 9.

Referring to fig. 1, a runner plate 3 is arranged above a cavity insert 2, a runner 3-1 is arranged above the runner plate 3, pin holes are formed at four corners of the runner 3-1, pin holes are also formed at corresponding positions of the cavity insert 2, and the runner plate 3 and the cavity insert 2 are fixed by pins.

The male die core 1 is arranged below the female die core 2, the four corners of the male die core 1 are provided with fixing holes, the four corners of the female die core 2 are also provided with fixing holes, and the male die core 1 and the female die core 2 are fixed through bolts.

Referring to fig. 6 to 10, a circle of fixed blade forming molds 1-1 is arranged in the center of the core insert 1, and the fixed blade forming molds 1-1 extend out of the upper surface of the core insert 1. The outlines of the two sides of the blade molding fixed die 1-1 are designed according to the shape of the blade to be molded.

A blade insert groove 1-2 which vertically penetrates through the core insert 1 is arranged between two adjacent blade forming fixed molds 1-1. The width of the blade insert groove 1-2 is smaller than the width between two adjacent blade forming fixed dies 1-1. The shape and the size of the blade insert groove 1-2 are matched with the blade insert 6.

The inner end of the blade forming fixed die 1-1 is connected with a connecting ring 1-5, and the center of the connecting ring 1-5 is provided with a hub insert hole 1-4. The male die core 1 is also provided with a circle of thimble holes 1-7 which vertically penetrate through, the circle formed by the centers of the thimble holes 1-7 is coaxial with the connecting ring 1-5, and the thimble holes 1-7 are arranged at the outer side of the blade forming fixed die 1-1 and are positioned below the auxiliary ring forming part 2-3 of the female die core 2.

The blade insert plate 4 is located below the core insert 1, and the ejector plate 5 is located below the blade insert plate 4.

The blade insert plate 4 is provided with a circle of insert slots 4-1, and the size and the shape of the insert slots 4-1 are matched with the size and the shape of the blade insert 6 and used for positioning and arranging the blade insert 6.

Referring to fig. 5, a stop strip 6-1 is disposed at the lower portion of each vane insert 6 for positioning the vane insert 6 in the vertical direction.

Referring to fig. 3 to 5, the number of the vane inserts 6 is the same as the number of the vane insert grooves 1-2 of the core insert 1, one vane insert 6 is inserted into each vane insert groove 1-2 from bottom to top, specifically, the vane insert 6 passes through the insert slot 4-1 of the vane insert plate 4 from bottom to top, penetrates into the vane insert groove 1-2 of the core insert 1 after being positioned and arranged by the vane insert plate 4, and the upper end surface of the barrier strip 6-1 of the vane insert 6 contacts with the lower surface of the vane insert plate 4, so as to position the vane insert 6 in the up-down direction. The upper part of the blade insert 6 extends out of the upper surface of the core insert 1, and the upper end surface of the blade insert 6 is lower than the upper end surface of the blade forming fixed die 1-1 in the embodiment. A blade cavity 1-3 is formed between the blade insert 6 and the adjacent blade molding fixed die 1-1.

Because the shrinkage of the blank piece is reduced after sintering, the shrinkage rates s of different injection materials are different, and the ratio of the thickness of the blade of the blank piece to the thickness of the blade of the finished fan wheel is defined as the shrinkage rate s (s is more than 1), the size of the blade cavity of the die is amplified by s times according to the design requirement of the product fan wheel.

The width of the blade cavity 1-3 divided by the shrinkage rate s is the width of the fan blade, for example, an injection material with the shrinkage rate of 1.16 is used, the width of the blade cavity 1-3 is 0.0928mm, and the width of the finished blade is 0.08 mm.

The thimble plate 5 is provided with a circle of thimble channels, the diameter of each thimble channel is the same as the outer diameter of each thimble 8, and the thimble channels are used for positioning and arranging the thimbles 8. The ejector plate 5 is supported by a support base in the injection molding machine. The ejector pins 8 are arranged annularly, penetrate through the ejector pin plate 5 and are positioned by the ejector pin plate 5, continuously penetrate upwards through the ejector pin channels of the blade insert plate 4 and then enter the ejector pin holes 1-7 of the male mold core 1, the ejector pins 8 are used for ejecting the fan wheel blank formed by injection molding out of the mold, and along with the upward movement of the ejector pins 8, the ejector pins 8 can penetrate through the male mold core 1 and the upper end face of each ejector pin 8 exceeds the upper surface of the male mold core 1. The ejector pins 8 are used to assist in demoulding of the blank.

The hub insert 7 is arranged in the hub insert hole 1-4 of the core insert 1. After the blade insert plate 4 is fixed below the core insert 1, the lower part of the hub insert 7 is supported by the blade insert plate 4. The center of the hub insert 7 is provided with an insert hole 7-1. An annular groove 1-6 is formed between the hub insert 7 and the inner end of the blade insert 6, and the bottom of the annular groove 1-6 is the upper surface of the connecting ring 1-5.

The insert pin 9 is used for molding the shaft hole 10-1-1 of the fan wheel 10, penetrates through the central hole of the female die core 1 from top to bottom and then is inserted into the insert pin hole 7-1 of the hub insert 7.

When the shape of the fan wheel blade needs to be changed, the shapes of the blade forming fixed die 1-1 and the blade insert 6 need to be changed correspondingly, and when the thickness of the fan wheel blade needs to be changed, the sizes of the blade forming fixed die 1-1 and the blade insert 6 are adjusted by considering the shrinkage rate of the injection material, so that the size of the blade cavity 1-3 is adjusted.

Theoretically, the width of a blade cavity 1-3 formed by the blade forming fixed die 1-1 and the blade insert 6 can be infinitely small (larger than 0 mm), the invention considers the practicability of the fan blade, and the width of the blade cavity 1-3 is set to be s 0.08mm and s 0.08mm (s is the shrinkage rate of different injection materials and is obtained by measurement and calculation according to the sizes of blank materials and fan wheel finished products).

Referring to fig. 11 and 12, a hub forming portion 2-1, a blade forming portion 2-2 and an auxiliary ring forming portion 2-3 are disposed on a side of the cavity insert 2 opposite to the core insert 1 from inside to outside, the hub forming portion 2-1, the blade forming portion 2-2 and the auxiliary ring forming portion 2-3 have top surfaces, and the corresponding top surfaces are provided with filling ports 2-4 penetrating up and down.

The hub forming part 2-1 comprises a cylindrical cavity, and after the female die core 2 and the male die core 1 are fixed, a fan wheel hub cavity is formed between the hub forming part 2-1 and a hub insert 7 fixed on the male die core 1.

After the cavity insert 2 and the core insert 1 are fixed, the blade insert 6 and the blade forming fixed mold 1-1 are positioned in the blade forming part 2-2.

The auxiliary ring forming part 2-3 is positioned outside the blade forming part 2-2 and is an annular cavity, and the auxiliary ring forming part 2-3 is communicated with a blade cavity 1-3 formed by the blade insert 6 and the blade forming fixed die 1-1.

An auxiliary flow passage is also arranged on the surface of one side of the cavity insert 2 opposite to the core insert 1.

When metal powder is used for injection molding, materials enter the filling opening 2-4 of the female die core 2 from the runner 3-1 of the runner plate 3 from top to bottom, enter and fill the fan wheel hub cavity, the blade cavity 1-3 and the auxiliary ring molding part 2-3, and are molded to obtain a fan wheel blank. When demoulding, after the female die core is removed, the thimble 8 pushes the blank out of the mould.

The material entering the auxiliary ring forming part 2-3 also flows and fills the blade cavity 1-3 to help the forming of the blade part.

After demoulding, compared with the traditional green blank obtained by injection, the fan wheel blank part of the invention has one more circle of auxiliary rings 10-4, and the part is cut and removed after sintering.

In the mold of the embodiment, the width of the blade cavity 1-3 is set to be greater than or equal to s 0.08, and the metal fan wheel with the blade thickness of 0.08mm or more and any thickness can be prepared by adjusting the blade cavity 1-3. Therefore, the mold of this example can produce a metal impeller having a thickness of 0.08mm for the blade 10-2 of example 1, a metal impeller having a thickness of 0.20mm for the blade 10-2 of example 5, or a metal impeller having a thickness of 0.20mm or more for the blade 10-2.

Example 7 method for manufacturing Metal Fan

The manufacturing method of the metal fan wheel in the embodiment adopts the mold described in embodiment 6, and the preparation process includes the following steps:

① mixing the metal powder with the polymer binder in the equipment to obtain the mixture.

② the mixture is added into the barrel of the injection molding machine and then injected into the fan wheel cavity of the mold of example 6 through the nozzle of the injection molding machine to obtain the blank.

③, the blank is kept at 90-150 ℃ to remove the binder, the heat preservation time is determined according to the maximum thickness of the blank and is controlled at 1-2 mm/h.

④, preserving the temperature of the blank part degreased in the step ③ at 950-1300 ℃ for 1-6 hours, and cooling to room temperature to obtain a fan wheel intermediate (as shown in figure 13).

⑤ cutting the auxiliary ring 10-4 of the intermediate body of the fan wheel to obtain the finished fan wheel.

The above embodiments and application examples are illustrative of specific embodiments of the present invention, and are not intended to limit the present invention, and those skilled in the art can make various changes and modifications to obtain equivalent technical solutions without departing from the spirit and scope of the present invention, and therefore all equivalent technical solutions should be included in the scope of the present invention.