阅读说明：本技术 一种模内切剪浇口的内齿轮的注塑成型装置及注塑成型方法 (Injection molding device and injection molding method for internal gear of in-mold cutting gate ) 是由 谭小红 陈深海 于 2020-07-15 设计创作，主要内容包括：本申请提供了一种模内切剪浇口的内齿轮的注塑成型装置及注塑成型方法,包括上顶板、下顶板、第一模板、第二模板,第一模板内嵌设有上模盖,第二模板内嵌设有下模盖,下模盖的两个下模腔内各设有上中心倒模齿轮,位于上模盖上的对应的上模面、上中心倒模齿轮和下模腔内壁之间形成注塑成型腔,设置在下顶板上的两个中心杆的顶部穿过上顶板和第二模板与上模面的半球凹面贴合,位于中心杆顶部的半球凹槽与对应的浇注口连通,分布在中心杆顶部的弧形溜料槽使半球凹槽与注塑成型腔连通,上顶板的两个切刀套筒分别套设在对应的中心杆上,位于切刀套筒的顶部抵在注塑成型腔的开口下边缘上,本申请实现多点浇注的同时能够一次切断所有浇头,使用方便。(The application provides an injection molding device and an injection molding method for an internal gear of an in-mold shearing sprue gate, which comprises an upper top plate, a lower top plate, a first template and a second template, wherein an upper mold cover is embedded in the first template, a lower mold cover is embedded in the second template, an upper central inverted mold gear is respectively arranged in two lower mold cavities of the lower mold cover, an injection molding cavity is formed between the corresponding upper mold surface on the upper mold cover, the upper central inverted mold gear and the inner wall of the lower mold cavity, the tops of two central rods arranged on the lower top plate penetrate through the upper top plate and the second template to be attached to a hemispherical concave surface of the upper mold surface, a hemispherical groove arranged at the top of the central rod is communicated with a corresponding sprue gate, an arc chute distributed at the top of the central rod enables the hemispherical groove to be communicated with the injection molding cavity, two cutter sleeves of the upper top plate are respectively sleeved on the corresponding central rods, the tops of the cutter sleeves abut against the lower opening edge, this application can once cut off all watering heads when realizing the multiple spot pouring, convenient to use.)

1. An injection molding device for an internal gear of an in-mold cutting gate comprises a bottom plate (8), two support plates (5) arranged at two sides of the bottom plate (8), an upper top plate (6) and a lower top plate (7) which are arranged between the two support plates (5) in a stacked mode, and a first template (3) and a second template (4) which are arranged at the tops of the two support plates (5) in a stacked mode, and is characterized in that an upper mold cover (31) is embedded on the bottom surface of the first template (3), a lower mold cover (41) is embedded on the top surface of the second template (4), two lower mold cavities of the lower mold cover (41) are respectively provided with an upper central inverted mold gear (43), an injection molding cavity (10) is formed among a corresponding upper mold surface (312) on the upper mold cover (31), the upper central inverted mold gear (43) and the inner wall of the lower mold cavity, and two pouring ports (314) are arranged in the upper mold cover (31), the pouring gate (314) and the corresponding upper central reverse mold gear (43) are coaxially arranged, two central rods (72) fixedly arranged on the lower top plate (7) sequentially penetrate through the upper top plate (6) and the second mold plate (4), and the hemisphere convex surface at the top of well core rod (72) with the hemisphere concave surface laminating of cope match-plate pattern face (312), be located hemisphere recess (721) and sprue gate (314) intercommunication that corresponds at hemisphere convex surface top, the both ends of a plurality of annular distributions arc chute (722) on the hemisphere convex surface respectively with hemisphere recess (721), injection moulding chamber (10) intercommunication, fixed the setting is in two cutter sleeves (61) on last roof (6) are established respectively and are established on corresponding well core rod (72), are located annular cutting edge (611) at the top of cutter sleeve (61) support on the opening lower limb in injection moulding chamber (10).

2. The apparatus for injection molding an internal gear of an in-mold cutting gate according to claim 1, wherein the annular cutting edge (611) comprises an outer annular cutting surface and a tapered cutting surface, the outer annular cutting surface and the tapered cutting surface form an annular cutting edge (611) therebetween, the outer annular cutting surface is fitted to a central hole of the corresponding upper center inverted mold gear (43), and an inner ring of the tapered cutting surface is fitted to an outer circumferential surface of the central rod (72).

3. The apparatus for injection molding an internal gear of a mold-in cutting shear gate according to claim 1, wherein the width and depth of the arc chute (722) are gradually increased in a direction of fluid movement.

4. The injection molding device for the internal gear of the in-mold cutting gate according to claim 1, wherein the lower top plate (7) is further provided with two sets of detachable hole-inverted rods (73), each set of hole-inverted rods (73) is distributed in an annular shape, and the hole-inverted rods (73) sequentially penetrate through the upper top plate (6) and the second mold plate (4) and then are pressed against the upper mold surface (312).

5. The injection molding device of the internal gear with the in-mold cutting gate as claimed in claim 1, wherein the bottom of the central rod (72) is provided with a reverse taper hole, a striking rod (74) is slidably disposed in the reverse taper hole, a slope surface at the bottom of the striking rod (74) is attached to a slope surface at a corresponding end of a driving rod (75) laterally slidably disposed in the lower top plate (7), and the driving rod (75) reciprocates under the action of the lateral driving mechanism (76).

6. An injection molding apparatus for an internal gear of a mold cut gate according to claim 1, wherein the cutter sleeve (61) has a thickness of 2 mm.

7. The injection molding device of the internal gear of the in-mold cutting gate according to claim 1, wherein two ejector rods (62) fixedly arranged on the top surface of the upper top plate (6) are respectively inserted into corresponding through holes on the second template (4), a return spring (9) sleeved on the ejector rods (62) is positioned between the second template (4) and the upper top plate (6), and a gap is left between the ejector rods (62) and the first template (3).

8. The injection molding device for the internal gear of the in-mold cutting gate according to claim 1, wherein the first mold plate (3) and the second mold plate (4) are provided with a cooling liquid inlet and outlet channel, the top surface of the upper mold cover (31) and the bottom surface of the lower mold cover (41) are provided with an annular cooling groove (311), and the annular cooling groove (311) is communicated with the cooling liquid inlet and outlet channel.

9. An injection molding method, comprising the steps of:

the first step is as follows: sequentially mounting a base, a lower top plate (7), an upper top plate (6) and a second template (4) from bottom to top to form a lower die, sequentially mounting a first template (3), a transition pressing plate (2) and an upper pressing plate (1) from bottom to top to form an upper die, and closing the upper die and the lower die to form an injection molding cavity (10);

the second step is that: two of the lower top plates (7) sequentially penetrate through the upper top plate (6) and a central rod (72) of the second template (4) to move upwards through a driving device for driving the lower top plates (7) to enable a hemispherical convex surface at the top of the central rod (72) to be attached to a hemispherical concave surface of the upper die surface (312), and two cutter sleeves (61) which are respectively sleeved on the corresponding central rod (72) of the upper top plates (6) move downwards through a return spring (9) to enable annular cutting edges (611) of the cutter sleeves (61) to abut against the lower edge of an opening of the injection molding cavity (10);

the third step: the molten metal sequentially passes through the taper hole (11) of the upper pressing plate (1) and the material guide seat (21) of the transition pressing plate (2) and then flows to the two pouring gates (314), and the molten metal passing through the pouring gates (314) sequentially passes through a hemispherical groove (721) positioned at the top of a hemispherical convex surface of the central rod (72), a plurality of arc chute grooves (722) and a stub bar cavity formed by the central rod (72) and the cutter sleeve (61) and enters the injection molding cavity (10);

the fourth step: the transverse driving mechanism (76) is used for controlling the driving rod (75) to move so that the two impacting rods (74) can impact the two central rods (72) alternately for vibrating exhaust;

the fifth step: the cutter sleeve (61) is moved upwards by a driving device connected with the upper top plate (6) to cut off the stub bar to form a gear shaft hole;

and a sixth step: cooling until the liquid in the arc chute (722) is basically solidified;

the seventh step: the lower top plate (7) moves downwards to drive the central rod (72) to move downwards;

eighth step: continuously cooling to complete molding;

the ninth step: the upper top plate (6) continuously moves upwards to enable the ejector rod (62) to be in contact with the first template (3), and then the upper die is jacked up for demolding;

the tenth step: and taking out the molded gear, and finishing injection molding.

10. An injection moulding method according to claim 9, characterised in that in the second step, when the injected gear web has holes, the upper central inverted mould gear (43) in the lower mould cavity of the second mould plate (4) is replaced, and a plurality of hole inverted mould rods (73) which can penetrate through the upper top plate (6) and the second mould plate (4) in sequence are arranged on the lower top plate (7).

Technical Field

The present invention relates to an injection molding apparatus, and more particularly, to an injection molding apparatus and an injection molding method for an internal gear with a shear gate cut in a mold.

Background

The injection molding process is a molding process for obtaining a given injection molding piece after injecting a heated and melted material into a mold cavity under high pressure and cooling and solidifying the material. Generally, after injection molding is completed, an injection molded part and a corresponding stub bar are connected together through a sprue, workers need to trim the sprue on site, labor intensity is high, and sprue trimming is not attractive. In industry, an in-mold cutting mold is also disclosed, which can cut off a rubber opening through an ejector pin before mold opening, but the existing structure is only suitable for one sprue which is positioned at one side of an injection molding part, when the gear is injected, if the existing one-side injection molding method is adopted, the defects of uneven pouring, low pouring speed and the like easily occur, when multi-opening pouring is adopted, the processing difficulty of the mold is increased, and a plurality of cutting ejector pins are required to be arranged, so that the mold structure is complicated.

Disclosure of Invention

The invention aims to provide an injection molding device and an injection molding method for an internal gear with a cut gate in a mold, which solve the defects of nonuniform pouring, low pouring speed and the like easily caused in the injection molding of the existing mold.

In order to solve the technical problems, the invention provides the following technical scheme:

an injection molding device for an internal gear of an in-mold cutting sprue comprises a bottom plate, two support plates arranged on two sides of the bottom plate, an upper top plate and a lower top plate which are arranged between the two support plates in a stacked mode, and a first template and a second template which are arranged on the tops of the two support plates in a stacked mode, wherein an upper mold cover is embedded on the bottom surface of the first template, a lower mold cover is embedded on the top surface of the second template, upper central inverted mold gears are respectively arranged in two lower mold cavities of the lower mold cover, an injection molding cavity is formed among corresponding upper mold surfaces, the upper central inverted mold gears and the inner wall of the lower mold cavity on the upper mold cover, two sprue gates are arranged in the upper mold cover and are coaxial with the corresponding upper central inverted mold gears, two central rods fixedly arranged on the lower top plate sequentially penetrate through the upper top plate and the second template, and a hemispherical convex surface at the top of the central rods is attached to a hemispherical concave surface of the upper mold surface, the two ends of a plurality of arc chute grooves which are distributed on the hemispherical convex surface in an annular mode are respectively communicated with the hemispherical groove and the injection molding cavity, the two ends of the arc chute grooves are fixedly arranged on the upper top plate, the two cutter sleeves are respectively sleeved on the corresponding central rods, and the annular cutting edges at the tops of the cutter sleeves are abutted to the lower edge of an opening of the injection molding cavity.

Further, the annular cutting edge comprises an outer annular cutting surface and a conical cutting surface, an annular cutting edge is formed between the outer annular cutting surface and the conical cutting surface, the outer annular cutting surface is matched with a central hole of the corresponding upper central reverse die gear, and an inner ring of the conical cutting surface is matched with the outer peripheral surface of the central rod.

Further, the width and the depth of the arc chute are gradually increased along the moving direction of the fluid.

Furthermore, two groups of detachable hole die-reversing rods are further arranged on the lower top plate, each group of hole die-reversing rods are distributed in an annular shape, and the hole die-reversing rods sequentially penetrate through the upper top plate and the second template and then are pressed on the upper die surface.

Furthermore, the bottom of the center rod is provided with an inverted cone hole, a striking rod is arranged in the inverted cone hole in a sliding mode, a slope surface at the bottom of the striking rod is attached to an inclined surface at the corresponding end of a driving rod arranged in the lower top plate in a transverse sliding mode, and the driving rod moves in a reciprocating mode under the action of a transverse driving mechanism.

Further, the thickness of the cutter sleeve is 2 mm.

Furthermore, two ejector rods fixedly arranged on the top surface of the upper top plate are respectively inserted into corresponding through holes in the second template, a return spring sleeved on the ejector rods is positioned between the second template and the upper top plate, and a gap is reserved between the ejector rods and the first template.

Further, coolant inlet and outlet channels are arranged in the first template and the second template, annular cooling grooves are arranged on the top surface of the upper die cover and the bottom surface of the lower die cover, and the annular cooling grooves are communicated with the coolant inlet and outlet channels.

The invention also discloses another technical scheme:

an injection molding method comprising the steps of:

the first step is as follows: sequentially mounting a base, a lower top plate, an upper top plate and a second template from bottom to top to form a lower die, sequentially mounting a first template, a transition pressing plate and an upper pressing plate from bottom to top to form an upper die, and closing the upper die and the lower die to form an injection molding cavity;

the second step is that: two of the lower top plates sequentially penetrate through the upper top plates and a central rod of the second template to move upwards through a driving device for driving the lower top plates to move, so that a hemispherical convex surface at the top of the central rod is attached to a hemispherical concave surface of the upper die surface, and two cutter sleeves, which are respectively sleeved on the corresponding central rods, of the upper top plates move downwards through a return spring so that annular cutting edges of the cutter sleeves are abutted to the lower edge of an opening of an injection molding cavity;

the third step: the molten metal sequentially passes through the taper hole of the upper pressing plate and the material guide seat of the transition pressing plate and then flows to the two pouring ports, and the molten metal passing through the pouring ports sequentially passes through a hemispherical groove positioned at the top of the hemispherical convex surface of the central rod, a plurality of arc chute grooves and a stub bar cavity formed by the central rod and the cutter sleeve to enter an injection molding cavity;

the fourth step: the transverse driving mechanism is used for controlling the driving rod to move so that the two impact rods alternately impact the two central rods to perform vibration exhaust;

the fifth step: the cutter sleeve moves upwards by using a driving device connected with the upper top plate to cut off the stub bar to form a gear shaft hole;

and a sixth step: cooling until the liquid in the arc chute is basically solidified;

the seventh step: the lower top plate moves downwards to drive the central rod to move downwards;

eighth step: continuously cooling to complete molding;

the ninth step: the upper ejector plate continuously moves upwards to enable the ejector rod to be in contact with the first template, and then the upper mold is ejected to be demolded;

the tenth step: and taking out the molded gear, and finishing injection molding.

Furthermore, in the second step, when the injection molded gear web plate is provided with holes, the upper central reverse mold gear positioned in the lower mold cavity of the second mold plate is replaced, and a plurality of hole reverse mold rods which can sequentially penetrate through the upper top plate and the second mold plate are arranged on the lower top plate.

According to the technical scheme, the invention has the following beneficial effects:

because the arc chute troughs which are annularly distributed on the convex surface of the hemisphere are adopted for simultaneous pouring, the working efficiency is high, and the pouring is uniform; because the cutter sleeve is used for simultaneously cutting off the stub bar formed in the gear shaft hole, the structural complexity of the die is reduced while multiple pouring is realized; because the gear shaft hole is provided with the central rod during pouring, resource waste caused by a large amount of metal liquid remaining in the gear shaft hole is avoided, and the phenomenon that a stub bar is difficult to cut due to overlarge hardness is avoided; because this application cuts off the runner before the cooling is complete, laborsaving, and make the section level and smooth, neat.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a front view of the present invention.

Fig. 2 is a side view of the present invention.

Fig. 3 is a cross-sectional view of fig. 2.

Fig. 4 is a partial structural schematic diagram of fig. 3.

Fig. 5 is a partial structural schematic view of a center rod of the present invention.

Description of reference numerals: the injection molding device comprises an upper pressing plate 1, a taper hole 11, a transition pressing plate 2, a material guide seat 21, a first template 3, an upper mold cover 31, an annular cooling groove 311, an upper mold surface 312, an exhaust hole 313, a pouring gate 314, a second template 4, a lower mold cover 41, a lower central reverse mold 42, an upper central reverse mold gear 43, a support plate 5, an upper top plate 6, a cutter sleeve 61, an annular cutting edge 611, a top rod 62, a lower top plate 7, a central rod 72, a hemispherical groove 721, an arc chute 722, a hole reverse mold rod 73, an impact rod 74, a driving rod 75, a transverse driving mechanism 76, a bottom plate 8, a return spring 9 and an injection molding cavity 10.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.

Referring to fig. 1 to 5, the present application is further described, as shown in fig. 1, an injection molding apparatus and an injection molding method for an internal gear of an in-mold cutting gate includes a bottom plate 8, two supporting plates 5 disposed at two sides of the bottom plate 8, an upper top plate 6 and a lower top plate 7 stacked between the two supporting plates 5, and a first template 3 and a second template 4 stacked at tops of the two supporting plates 5, wherein the upper top plate 6 and the lower top plate 7 are respectively connected to corresponding driving devices, a transition pressing plate 2 is fixedly disposed at a top of the first template 3, an upper pressing plate 1 is disposed at a top of the transition pressing plate 2, a through tapered hole 11 is disposed at a central position of the upper pressing plate 1, a material guide seat 21 is disposed at a position of the transition pressing plate 2 corresponding to the tapered hole 11, a bar-shaped groove is disposed on a top surface of the first template 3, two ends of the bar-shaped groove are respectively provided with a liquid outlet, an upper mold cover 31 is embedded on the bottom surface of the first mold plate 3, a lower mold cover 41 is embedded on the top surface of the second mold plate 4, a lower central inverted mold 42 is respectively arranged in two lower mold cavities of the lower mold cover 41, an upper central inverted mold gear 43 is fixedly arranged at the top of the lower central inverted mold 42, an injection molding cavity 10 is formed among an upper mold surface 312, the upper central inverted mold gear 43, the lower central inverted mold 42 and the inner wall of the lower mold cavity which are correspondingly arranged on the upper mold cover 31, two sprue gates 314 are arranged in the upper mold cover 31, the sprue gates 314 are communicated with corresponding liquid outlets, the sprue gates 314 and the corresponding upper central inverted mold gears 43 are coaxially arranged, two central rods 72 fixedly arranged on the lower top plate 7 sequentially penetrate through the upper top plate 6 and the second mold plate 4, and the hemispherical convex surfaces at the tops of the central rods 72 are attached to the hemispherical concave surfaces of the upper mold surfaces 312, the hemispherical groove 721 positioned at the center of the top of the hemispherical convex surface is communicated with the corresponding pouring gate 314, two ends of a plurality of arc chute grooves 722 annularly distributed on the hemispherical convex surface are respectively communicated with the hemispherical groove 721 and the injection molding cavity 10, two cutter sleeves 61 fixedly arranged on the upper top plate 6 are respectively sleeved on the corresponding central rod 72, the annular cutting edge 611 positioned at the top of the cutter sleeve 61 is abutted against the lower edge of the opening of the injection molding cavity 10, during pouring, the central rod 72 is in abutting contact with the upper die cover 31 to reduce liquid remaining in the gear shaft hole, the gear shaft hole can be formed when the cutter sleeve 61 cuts off the stub bar, and the cutting is performed once, the use is convenient, the plurality of arc chute grooves 722 enable the metal liquid to simultaneously flow into the injection molding cavity 10 from a plurality of directions, the non-uniform pouring is avoided, and the working efficiency is improved, and does not add complexity to the mold.

The top of the upper die surface 312 is provided with a plurality of exhaust holes 313, so that the injection molding piece is better molded.

The annular cutting edge 611 comprises an outer annular cutting surface and a conical cutting surface, the annular cutting edge 611 is formed between the outer annular cutting surface and the conical cutting surface, the outer annular cutting surface is matched with a central hole of the corresponding upper central reverse die gear 43, an inner ring of the conical cutting surface is matched with the outer peripheral surface of the central rod 72, when the stub bar is conveniently cut off, the gear shaft hole is not extruded by diversion, wherein the thickness of the cutter sleeve 61 is 2mm, and the thickness of the stub bar is reduced.

The width and the depth of the arc chute 722 are gradually increased along the moving direction of the fluid, and molten metal is sprayed due to flow resistance when entering the arc chute 722, so that the flow speed is improved, and the phenomenon that the molten metal is condensed on the surface of the arc chute 722 to influence pouring is avoided.

Two groups of detachable hole die-reversing rods 73 are further arranged on the lower top plate 7, each group of hole die-reversing rods 73 are distributed annularly, the hole die-reversing rods 73 sequentially penetrate through the upper top plate 6 and the second template 4 and then are pressed on the upper die surface 312 in an abutting mode, and the hole die-reversing rods 73 are configured according to whether the gear web is provided with holes or not, so that the use is convenient.

The bottom of the central rod 72 is provided with an inverted cone hole, the inverted cone hole is internally provided with a collision rod 74 in a sliding manner, a slope surface at the bottom of the collision rod 74 is attached to a slope surface at the corresponding end of a driving rod 75 arranged in the lower top plate 7 in a transverse sliding manner, and the driving rod 75 reciprocates under the action of a transverse driving mechanism 76, so that the driving rod vibrates during pouring, and bubbles are broken or move upwards to separate from the injection molding main body.

Two ejector rods 62 fixedly arranged on the top surface of the upper top plate 6 are respectively inserted into corresponding through holes in the second template 4, a reset spring 9 on the ejector rods 62 is positioned between the second template 4 and the upper top plate 6, a gap is reserved between the ejector rods 62 and the first template 3, and the ejector rods 62 are used for jacking the first template 3 to realize demoulding.

All be equipped with coolant liquid access way in first template 3 and the second template 4, all be equipped with annular cooling groove 311 on the top surface of upper die cover 31 and on the bottom surface of lower die cover 41, annular cooling groove 311 and coolant liquid access way intercommunication make the cooling even, avoid stress concentration.

The invention also discloses another technical scheme:

an injection molding method comprising the steps of:

the first step is as follows: sequentially mounting a base, a lower top plate 7, an upper top plate 6 and a second template 4 from bottom to top to form a lower die, sequentially mounting a first template 3, a transition pressing plate 2 and an upper pressing plate 1 from bottom to top to form an upper die, and closing the upper die and the lower die to form an injection molding cavity 10, wherein the base comprises a bottom plate 8 and two supporting plates 5 arranged on two sides of the bottom plate 8, the second template 4 is fixedly arranged at the tops of the two supporting plates 5, four corners of the top surface of the second template 4 are respectively provided with a guide column, and the upper die is in sliding fit with the guide columns;

the second step is that: two of the lower top plates 7 sequentially penetrate through the upper top plate 6 and the central rod 72 of the second template 4 to move upwards by a driving device for driving the lower top plates 7 to enable a hemispherical convex surface at the top of the central rod 72 to be attached to a hemispherical concave surface of the upper mold surface 312, two cutter sleeves 61, which are respectively sleeved on the corresponding central rod 72, of the upper top plates 6 are enabled to move downwards by a return spring 9 to enable annular cutting edges 611 of the cutter sleeves 61 to be abutted to the lower edge of an opening of an injection molding cavity 10, when holes are formed in an injection molded gear web plate, upper central inverted mold gears 43 located in a lower mold cavity of the second template 4 are replaced, and a plurality of hole inverted mold rods 73 which can sequentially penetrate through the upper top plate 6 and the second template 4 are installed on the lower top plates 7;

the third step: the molten metal sequentially passes through the taper hole 11 of the upper pressing plate 1 and the guide seat 21 of the transition pressing plate 2 and then flows to the two pouring gates 314, the molten metal passing through the pouring gates 314 sequentially passes through the hemispherical groove 721 positioned at the top of the hemispherical convex surface of the central rod 72, the plurality of arc chute grooves 722 and the stub bar cavity formed by the central rod 72 and the cutter sleeve 61 and enters the injection molding cavity 10, so that multi-gate pouring is realized, the pouring is uniform, the working efficiency is high, and the complexity of the mold is not increased;

the fourth step: the transverse driving mechanism 76 is used for controlling the driving rod 75 to move, so that the two impacting rods 74 impact the two central rods 72 alternately for vibrating air exhaust;

the fifth step: the cutter sleeve 61 is moved upwards by a driving device connected with the upper top plate 6 to cut the stub bar to form a gear shaft hole, and the stub bar is cut before being cooled, so that the cutting is labor-saving, and the cut is attractive and neat;

and a sixth step: the liquid in the arc chute 722 is cooled to be basically solidified, so that the liquid is prevented from falling along the central rod 72 and being incapable of being cleaned when the central rod 72 moves downwards;

the seventh step: the lower top plate 7 moves downwards, so that the central rod 72 is driven to move downwards;

eighth step: continuously cooling to complete molding;

the ninth step: the upper top plate 6 continuously moves upwards to enable the ejector rods 62 to be in contact with the first template 3, and then the upper mold is jacked up for demolding;

the tenth step: and taking out the molded gear, and finishing injection molding.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.