CN111531162A

CN111531162A - Marine gearbox body casting production line and process thereof

Info

Publication number: CN111531162A
Application number: CN202010364372.8A
Authority: CN
Inventors: 来焕祥; 来华锋; 姚瑶
Original assignee: Zhejiang Changxing Qianjin Machinery Co ltd
Current assignee: Zhejiang Changxing Qianjin Machinery Co ltd
Priority date: 2020-04-30
Filing date: 2020-04-30
Publication date: 2020-08-14

Abstract

The invention provides a marine gearbox casing casting production line and a process thereof, wherein the production line comprises a smelting furnace, a pouring device, a shot blasting device and a painting device which are sequentially arranged, and further comprises a model making device, wherein the model making device comprises a rack, a core mold assembly, a sand mold assembly, a mold closing mechanism, a molding sand pressing mechanism and a moving assembly; the process comprises a smelting process, a die matching and mould assembling process, a pouring process, a shot blasting process and a paint process. The upper core die and the lower core die are fixedly arranged by utilizing the core die assembly, and the sand die assembly is matched to form an upper sand die and a lower sand die which are integrated, so that after sand filling, molding sand in the upper die cavity and the lower die cavity is molded and the die assembly work is completed, the upper die and the lower die cavity are accurately positioned, the damage rate of the sand die cavity is low, the smelting process, the die matching and box closing process, the pouring process, the shot blasting process and the painting process are utilized, particularly, the die matching and box closing process utilizes the upper sand die and the lower sand die to mold and mold.

Description

Marine gearbox body casting production line and process thereof

Technical Field

The invention relates to the technical field of casting, in particular to a marine gearbox casing casting production line and a process thereof.

Background

Sand casting refers to a casting process that produces a casting in a sand mold. Steel, iron and most nonferrous metal castings can be obtained by sand casting. The parts of the gear box body for the HCT1200 ship are cast and produced by adopting a sand casting process. The existing sand mold casting adopts split molding, casting and casting are carried out after mold closing, the split molding needs to be carried out successively or even not on the same molding machine, and the split molding is difficult to align and trim during mold closing and is easy to damage.

Patent document CN201721404289.9 discloses a 400 series marine gearbox box, including the box body, the box body includes box and lower box, and goes up the box and be located the top of box down, go up the box and pass through flange fixed connection with lower box, and go up the juncture of box and lower box and run through and be provided with first delivery outlet, second delivery outlet and input bearing hole, the input bearing hole is located between first delivery outlet and the second delivery outlet, the one end symmetry that goes up the box and be close to lower box is fixed with two ear seats.

The marine gearbox box disclosed in the patent, when its box end cover casting shaping, the sand mould needs the secondary to fill in the sand molding and then the compound die pouring, destroys the molding sand chamber easily, and man-hour is long, influences work efficiency.

Disclosure of Invention

Aiming at the problems, the invention provides a marine gearbox casing casting production line, which is characterized in that an upper core mould and a lower core mould are fixedly arranged by utilizing a core mould assembly, and a sand mould assembly is matched to form an upper sand mould and a lower sand mould, so that molding sand in upper and lower mould cavities is formed and the mould closing work is completed after sand filling, and the problems that in the prior art, a box end cover sand mould needs secondary sand filling molding and then mould closing and pouring, a molding sand cavity is easy to damage, the working time is long, and the working efficiency is influenced are solved.

In order to achieve the purpose, the invention provides the following technical scheme:

a casting production line of a marine gearbox body comprises a smelting furnace, a pouring device, a shot blasting device and a paint device which are sequentially arranged, and is characterized by further comprising a model manufacturing device, wherein the smelting furnace is attached to the pouring device, the model manufacturing device and the pouring device can be arranged in a matched mode, liquid molten iron in the smelting furnace is poured into the model manufacturing device by the pouring device, a cooled and solidified workpiece is demoulded and is conveyed to the shot blasting device and the paint device which are arranged on one side of the pouring device to be cleaned and painted with paint;

the model making device comprises a frame, a core mold assembly, a sand mold assembly, a mold clamping mechanism, a molding sand pressing mechanism and a moving assembly, wherein the core mold assembly is fixedly arranged at the middle part of the frame, the sand mold assembly is arranged on the upper side and the lower side of the core mold assembly respectively, the mold clamping mechanism drives the sand mold assembly to move along the vertical direction in opposite directions or back to the core mold assembly, the molding sand pressing mechanism is arranged on the outer side of the mold clamping mechanism and presses molding sand in the sand mold assembly along the vertical direction, the moving assembly is arranged at the bottom of the frame and drives the sand mold assembly, the mold clamping mechanism and the molding sand pressing mechanism to move relative to the frame.

As a refinement, the core mold assembly includes:

the upper core die is vertically and upwards arranged in a protruding mode, and a pouring gate core is arranged on the upper core die;

the lower core mold is vertically and downwards convexly arranged below the upper core mold and is rigidly connected with the upper core mold; and

and the sliding piece is arranged between the upper core mould and the lower core mould and is arranged in a sliding way relative to the upper core mould and the lower core mould.

As an improvement, a plurality of sand leaking holes are vertically and correspondingly arranged on the upper core mold and the lower core mold one by one, a plurality of conducting holes are arranged on the sliding piece, and the conducting holes are in one-to-one correspondence with the sand leaking holes.

As an improvement, the sliding part is further provided with a plurality of hole sealing units, and the hole sealing units are arranged on one side of the via hole in a one-to-one correspondence mode.

As an improvement, the sand mold assembly comprises:

the die cavity is arranged in a vertically-penetrating cuboid shape, the die cavity is matched with the core die assembly, and the die cavity is symmetrically arranged relative to the upper side and the lower side of the core die assembly; and

and the transmission unit can be matched with the sliding piece to slide.

As an improvement, the clamping mechanism comprises:

the first air cylinder is vertically upwards arranged on the moving assembly; and

the first transmission group is arranged at the transmission end of the first air cylinder and is in transmission connection with the mold cavity.

As an improvement, the sand-pressing mechanism includes:

the second air cylinder is vertically upwards arranged on the moving assembly;

the second transmission group is arranged at the transmission end of the second air cylinder;

the lower supporting plate is arranged at the bottom of the second transmission group and is matched with an inner cavity of a lower die cavity of the sand mould assembly;

the sand storage box is arranged at the top of the second transmission set, and an upper supporting plate is arranged at the bottom of the sand storage box; and

the turnover assembly is in transmission connection with the second transmission group and the upper supporting plate and comprises a limiting groove, a reversing rack and a reversing gear, the limiting groove is rigidly connected to two sides of the sand storage box, the reversing rack is attached to the limiting groove, the reversing gear is rigidly arranged at two ends of the upper supporting plate, and the reversing rack drives the reversing gear to rotate.

As an improvement, a through hole is formed in the upper supporting plate, and after the upper supporting plate vertically moves downwards and turns over, the through hole is matched with the pouring gate core in a sleeved mode.

Aiming at the problems, the invention also provides a marine gearbox body casting production process by utilizing the marine gearbox body casting production line, and the process greatly shortens the processing time and improves the efficiency by utilizing the smelting process, the die matching and box assembling process, the pouring process, the shot blasting process and the paint process, particularly the die matching and box assembling process by utilizing the upper sand mould and the lower sand mould to simultaneously carry out die-pressing molding.

A marine gearbox casing casting production process utilizing a marine gearbox casing casting production line comprises the following steps:

step one, a smelting process, namely adding a steel raw material into a smelting furnace to be smelted to a liquid state for later use;

step two, a mould matching and mould assembling procedure, namely, a core mould component is matched with a sand mould component to form a moulding box, moulding sand is filled in the moulding box for moulding, and the mould matching and mould assembling are carried out after the moulded sand mould component is separated from the core mould component;

step three, a pouring process, namely pouring liquid molten iron raw materials into the box body finished by the die matching by the pouring device, and waiting for cooling and solidification;

step four, performing shot blasting, namely opening a box, shakeout and primarily cleaning after the step three, and conveying the cast and molded workpiece into a shot blasting device for cleaning and deburring;

and step five, a painting procedure, namely after the step four, after the workpiece is subjected to shoveling and qualified inspection, the workpiece is sent into a painting device to be painted with the surface antirust paint.

In the second step, the molding sand is extruded and molded by simultaneously pointing the upper end surface and the lower end surface to the core mold assembly.

The system of the invention has the advantages that:

(1) according to the invention, the upper core mold and the lower core mold are fixedly arranged by utilizing the core mold assembly, and the sand mold assembly is matched to form the sand mold which is integrated up and down, so that after sand is filled, molding sand in the cavities of the upper mold and the lower mold is molded and the mold closing work is completed, the upper positioning and the lower positioning are accurate, the damage rate of the sand mold cavity is low, and the smelting process, the mold matching and box closing process, the pouring process, the shot blasting process and the painting process are utilized, especially the mold matching and box closing process utilizes the upper sand mold and the lower sand mold to mold and mold simultaneously;

(2) according to the sand-leaking device, the upper core die and the lower core die are correspondingly provided with the sand-leaking holes one by one, so that molding sand on the upper core die smoothly enters the die cavity below the lower core die, the sand-leaking holes are opened and closed by matching with the sliding piece, the upper side and the lower side of the core die assembly are simultaneously filled with sand, and the efficiency is improved;

(3) according to the invention, the sand mould assembly is driven to move along the vertical direction by using the mould closing mechanism, so that the upper and lower sand moulds are concentrically aligned, and the damage of mould closing is avoided;

(4) according to the sand storage box, the sand storage box arranged in the sand pressing mechanism is used for storing the molding sand, the upper supporting plate is turned over to perform shakeout by the turning assembly, and meanwhile, the upper supporting plate can be used as a pressing plate for pressing the molding sand after the shakeout is completed, so that the molding sand in the mold cavity is pressed, the compactness among the molding sand is increased, and the solidification and shaping of the molding sand are accelerated;

in conclusion, the invention has the advantages of simultaneous compression molding of the upper sand mold and the lower sand mold, concentric alignment of the sand molds, improvement of efficiency and the like, and is particularly suitable for the technical field of casting.

Drawings

FIG. 1 is a schematic view of the overall axis of the present invention;

FIG. 2 is a schematic axial view of a modeling apparatus according to the present invention;

FIG. 3 is a schematic view of the modeling motion of the present invention;

fig. 4 is a schematic view of the mating of the core mold assembly and the sand mold assembly of the present invention;

FIG. 5 is a second schematic view of the axis of the modeling apparatus of the present invention;

FIG. 6 is an enlarged view of the point A in FIG. 5;

FIG. 7 is a third schematic view of the shaft of the modeling apparatus of the present invention;

FIG. 8 is a fourth schematic view of the shaft of the modeling apparatus of the present invention;

FIG. 9 is a schematic right side sectional view of a modeling apparatus in accordance with the present invention;

FIG. 10 is a second schematic right-side sectional view of the modeling apparatus of the present invention;

FIG. 11 is a schematic view of a sand holding box according to the present invention;

FIG. 12 is a schematic view of a top plate according to the present invention;

FIG. 13 is a schematic view of the upper plate, the transmission unit and the sliding member of the present invention;

FIG. 14 is an enlarged view of the state B in FIG. 13;

FIG. 15 is an enlarged view of state two of FIG. 13;

FIG. 16 is a process flow diagram of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the equipment or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

Example 1:

as shown in fig. 1 to 3, a casting production line for a marine gearbox body comprises a smelting furnace 1, a pouring device 2, a shot blasting device 3 and a painting device 4 which are sequentially arranged, and further comprises a model making device 5, wherein the smelting furnace 1 is attached to the pouring device 2, the model making device 5 and the pouring device 2 can be arranged in a matched manner, the pouring device 2 pours liquid molten iron in the smelting furnace 1 into the model making device 5, and a cooled and solidified workpiece is demoulded and conveyed to the shot blasting device 3 and the painting device 4 arranged on one side of the pouring device 2 for cleaning and painting;

the model making device 5 includes a frame 51, a core mold assembly 52, a sand mold assembly 53, a mold clamping mechanism 54, a molding sand pressing mechanism 55, and a moving assembly 56, wherein the core mold assembly 52 is fixedly disposed in the middle of the frame 51, the sand mold assembly 53 is disposed on each of the upper and lower sides of the core mold assembly 52, the mold clamping mechanism 54 drives the sand mold assemblies 53 to move toward or away from the core mold assembly 52 in the vertical direction, the molding sand pressing mechanism 55 is disposed on the outer side of the mold clamping mechanism 54, the molding sand pressing mechanism 55 presses molding sand in the sand mold assemblies 53 in the vertical direction, the moving assembly 56 is disposed at the bottom of the frame 51, and the moving assembly 56 drives the sand mold assemblies 53, the mold clamping mechanism 54, and the molding sand pressing mechanism 55 to move relative to the frame 51.

As shown in fig. 4 to 6, as a preferred embodiment, the core mold assembly 52 includes:

the upper core die 521 is vertically and upwardly protruded, and a runner core 5211 is arranged on the upper core die 521;

the lower core die 522 is vertically and downwardly protruded below the upper core die 521, and is rigidly connected with the upper core die 521; and

and a sliding member 523, wherein the sliding member 523 is disposed between the upper core mold 521 and the lower core mold 522, and is slidably disposed relative to the upper core mold 521 and the lower core mold 522.

As a preferred embodiment, a plurality of sand leaking holes 524 are vertically and correspondingly formed in the upper core mold 521 and the lower core mold 522, a plurality of through holes 525 are formed in the sliding member 523, and the through holes 525 correspond to the sand leaking holes 524 one by one.

It should be noted that the through holes 525 and the sand leaking holes 524 can be matched, and when the through holes 525 and the sand leaking holes 524 are matched and communicated, the molding sand can pass through the core mold assembly 52 and enter the lower part of the lower core mold 522; when the through holes 525 and the sand leaking holes 524 are misaligned, the molding sand cannot pass through and is blocked.

It should be noted that a sand stirring tank 6 is provided immediately below the core mold assembly 52, and supplies the molding sand to the molding device 5, and also receives a small amount of molding sand stored in the core mold assembly 52.

As shown in fig. 13 to 15, as a preferred embodiment, a plurality of sealing units 526 are further disposed on the sliding member 523, and the sealing units 526 are disposed on one side of the via holes 525 in a one-to-one correspondence manner.

It should be noted that, when the sliding member 523 slides until the hole sealing unit 526 faces the sand leakage hole 524, the hole sealing unit 526 seals the sand leakage hole 524.

It should be noted that the hole sealing unit 526 is configured to elastically recover, and the elastic recovery force is sufficient to eject the molding sand in the sand leaking hole 524.

It should be further noted that the hole sealing unit 526 moves in a staggered manner relative to the sand leakage hole 524, and an inclined surface for pushing the hole sealing unit 526 is arranged at an opening edge of the sand leakage hole 524.

As shown in fig. 3, 4, 13, 14 and 15, as a preferred embodiment, the sand mold assembly 53 includes:

the mold cavity 531 is provided in a vertically penetrating rectangular parallelepiped shape, the mold cavity 531 is provided in a manner to be matched with the core mold assembly 52, and the mold cavity 531 is provided symmetrically with respect to the upper and lower sides of the core mold assembly 52; and

a transmission unit 532, wherein the transmission unit 532 can cooperate with the sliding piece 523 to slide.

It should be noted that the transmission unit 532 is elastically slidably disposed relative to the mold cavity 531, and the transmission unit 532 moves vertically and downwardly to drive the sliding member 523 to slide, so that the hole sealing unit 526 seals the sand leakage hole 524, and otherwise, the hole sealing unit 526 is opened relative to the sand leakage hole 524.

As shown in fig. 2 and 3, as a preferred embodiment, the clamping mechanism 54 includes:

the first air cylinder 541 is vertically upwards arranged on the moving assembly 56; and

and a first transmission set 542, wherein the first transmission set 542 is arranged at the transmission end of the first cylinder 541, and the first transmission set 542 is in transmission connection with the mold cavity 531.

As shown in fig. 5, 7, 8, 9, 10, 11 and 12, as a preferred embodiment, the sand-pressing mechanism 55 includes:

a second air cylinder 551, wherein the second air cylinder 551 is vertically upwards arranged on the moving assembly 56;

a second drive group 552, the second drive group 552 being disposed at a drive end of the second cylinder 551;

a lower supporting plate 553, wherein the lower supporting plate 553 is arranged at the bottom of the second transmission group 552 and is matched with the inner cavity of the lower mold cavity 531 of the sand mold assembly 53;

a sand storage box 554, wherein the sand storage box 554 is arranged at the top of the second transmission group 552, and the bottom of the sand storage box 554 is provided with an upper supporting plate 555; and

the overturning assembly 556 is in transmission connection with the second transmission group 552 and the upper supporting plate 555, the overturning assembly 556 comprises a limiting groove 5561, a reversing rack 5562 and a reversing gear 5563, the limiting groove 5561 is rigidly connected to two sides of the sand storage box 554, the reversing rack 5562 is attached to the limiting groove 5561, the reversing gear 5563 is rigidly arranged at two ends of the upper supporting plate 555, and the reversing rack 5562 drives the reversing gear 5563 to rotate.

It should be noted that, when the second cylinder 551 drives the upper supporting plate 555 to turn, it sets a waiting time, that is, after the molding sand in the sand box 554 completely falls into the mold cavity 531, it continues to drive the upper supporting plate 555 to squeeze the molding sand downward.

It should be noted that the second cylinder 551 and the first cylinder 541 are set to simultaneously drive the mold cavity 531, the lower supporting plate 553 and the upper supporting plate 555 at the same speed and relatively away from the mold release, and before moving to the casting device 2, the second cylinder 551 and the first cylinder 541 are set to simultaneously drive the mold cavity 531, the lower supporting plate 553 and the upper supporting plate 555 to perform mold closing movement.

It should be noted that the first cylinder 541 and the second cylinder 551 are variable stroke cylinders, and when molding sand, the core mold assembly 52 is held between the upper and lower mold cavities 531, and the stroke thereof is short; when the mold is assembled and the mold is closed, the core assembly 52 is not arranged between the upper and lower mold cavities 531, and the stroke is long, so that the upper and lower mold cavities 531 are sealed.

As a preferred embodiment, the upper supporting plate 555 is provided with a through hole 5551, and after the upper supporting plate 555 vertically moves downwards and turns over, the through hole 5551 is matched and sleeved with the pouring gate core 5211.

Example 2:

a casting process of a marine gearbox casing using a casting line for a marine gearbox casing according to a second embodiment of the present invention will be described with reference to fig. 1 and 16.

step one, a smelting process, namely adding a steel raw material into a smelting furnace 1 to be smelted to a liquid state for later use;

step two, a mold matching and mold assembling process, namely forming a molding box by matching the core mold component 52 with the sand mold component 53, filling molding sand for molding, and matching and assembling the mold after separating the molded sand mold component 53 from the core mold component 52;

step three, a pouring process, namely pouring liquid molten iron raw materials into the box body finished by the die matching by the pouring device 2, and waiting for cooling and solidification;

step four, performing shot blasting, namely opening the box, shakeout and primarily cleaning the box after the step three, and conveying the cast and molded workpiece into a shot blasting device 3 for cleaning and deburring;

and step five, a painting process, namely after the step four, after the workpiece is subjected to shoveling and qualified inspection, the workpiece is sent into a painting device 4 to be painted with the surface antirust paint.

In a preferred embodiment, in the second step, molding sand is extruded by simultaneously directing the upper and lower end surfaces toward the core mold assembly 52.

The working process is as follows:

firstly, smelting a steel raw material to a liquid state by a smelting furnace 1, simultaneously manually selecting a core mould assembly 52 for casting to be fixed on a frame 51, correspondingly metering the total amount of molding sand according to the core mould assembly 52, pouring the molding sand and bonding resin into a sand storage box 554 after mixing in proportion, starting a mould clamping mechanism 54 to drive two groups of mould cavities 531 to move relative to the core mould assembly 52 until the molding sand is tightly matched, then starting a molding sand pressing mechanism 55 to overturn the molding sand in the sand storage box 554 to be poured into the mould cavities 531, after the lower mould cavity 531 is filled with the molding sand, relatively moving an upper supporting plate 555 and a lower supporting plate 553 in the molding sand pressing mechanism 55 to press and form the molding sand in the two groups of mould cavities 531, reversely moving the molding sand pressing mechanism 55 and the mould clamping mechanism 54 after the molding is completed, separating the sand mould assembly 53 from the core mould assembly 52, and driving the sand mould assembly, and then, starting the mold clamping mechanism 54 to carry out upper and lower mold matching and mold closing, pouring liquid molten iron into the box body after mold matching by the pouring device 2, demolding the cooled and solidified workpiece, and painting paint by the shot blasting device 3 and the paint device 4 and then warehousing the workpiece.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A marine gearbox body casting production line comprises a smelting furnace (1), a pouring device (2), a shot blasting device (3) and a paint device (4) which are sequentially arranged, and is characterized by further comprising a model manufacturing device (5), wherein the smelting furnace (1) and the pouring device (2) are attached, the model manufacturing device (5) and the pouring device (2) can be arranged in a matched mode, the pouring device (2) pours liquid molten iron in the smelting furnace (1) into the model manufacturing device (5), and a cooled and solidified workpiece is demoulded and conveyed to the shot blasting device (3) and the paint device (4) which are arranged on one side of the pouring device (2) to be cleaned and painted with paint;

the model making device (5) comprises a rack (51), a core mold assembly (52), a sand mold assembly (53), a mold clamping mechanism (54), a molding sand pressing mechanism (55) and a moving assembly (56), wherein the core mold assembly (52) is fixedly arranged in the middle of the rack (51), the sand mold assembly (53) is respectively provided with a group on the upper side and the lower side of the core mold assembly (52), the mold clamping mechanism (54) drives the sand mold assembly (53) to move towards or away from the core mold assembly (52) along the vertical direction, the molding sand pressing mechanism (55) is arranged on the outer side of the mold clamping mechanism (54), the molding sand pressing mechanism (55) presses molding sand in the sand mold assembly (53) along the vertical direction, the moving assembly (56) is arranged at the bottom of the rack (51), and the moving assembly (56) drives the sand mold assembly (53), The clamping mechanism (54) and the sand pressing mechanism (55) move relative to the frame (51).

2. A marine gearbox casing line according to claim 1, characterised in that the core mould assembly (52) comprises:

the upper core die (521) is vertically and upwardly protruded, and a runner core (5211) is arranged on the upper core die (521);

the lower core mold (522) is vertically and downwards convexly arranged below the upper core mold (521), and is rigidly connected with the upper core mold (521); and

and the sliding piece (523) is arranged between the upper core die (521) and the lower core die (522), and the sliding piece (523) is arranged in a sliding way relative to the upper core die (521) and the lower core die (522).

3. The marine gearbox casing production line of claim 2, characterized in that a plurality of sand leaking holes (524) are vertically arranged on the upper core mould (521) and the lower core mould (522) in a one-to-one correspondence manner, a plurality of through holes (525) are arranged on the sliding member (523), and the through holes (525) are in a one-to-one correspondence manner with the sand leaking holes (524).

4. The marine gearbox casing casting line of claim 3, wherein the sliding member (523) is further provided with a plurality of sealing units (526), and the sealing units (526) are correspondingly arranged on one side of the through holes (525).

5. A marine gearbox casing casting line according to claim 1, characterised in that the sand mould assembly (53) comprises:

the die cavity (531) is provided in a vertically-penetrating rectangular parallelepiped shape, the die cavity (531) is matched with the core die assembly (52), and the die cavity (531) is symmetrically arranged relative to the upper side and the lower side of the core die assembly (52); and

a transmission unit (532), wherein the transmission unit (532) can be matched with the sliding piece (523) to slide.

6. A marine gearbox casing casting line according to claim 1, characterised in that the clamping mechanism (54) comprises:

the first air cylinder (541) is vertically upwards arranged on the moving assembly (56); and

the first transmission group (542) is arranged at the transmission end of the first air cylinder (541), and the first transmission group (542) is in transmission connection with the mold cavity (531).

7. A marine gearbox housing casting line according to claim 1, characterised in that the sand-pressing mechanism (55) comprises:

a second air cylinder (551), wherein the second air cylinder (551) is vertically upwards arranged on the moving assembly (56);

a second drive group (552), the second drive group (552) disposed at a drive end of the second cylinder (551);

a lower supporting plate (553), wherein the lower supporting plate (553) is arranged at the bottom of the second transmission group (552) and is matched with the inner cavity of the lower mold cavity (531) of the sand mold assembly (53);

a sand storage box (554), wherein the sand storage box (554) is arranged at the top of the second transmission group (552), and a top supporting plate (555) is arranged at the bottom of the sand storage box (554); and

the turnover assembly (556), the turnover assembly (556) is in transmission connection with the second transmission group (552) and the upper supporting plate (555), the turnover assembly (556) comprises a limiting groove (5561), a reversing rack (5562) and reversing gears (5563), the limiting groove (5561) is rigidly connected to two sides of the sand storage box (554), the reversing rack (5562) is attached to the limiting groove (5561), the reversing gears (5563) are rigidly arranged at two ends of the upper supporting plate (555), and the reversing racks (5562) drive the reversing gears (5563) to rotate.

8. The marine gearbox casing casting production line of claim 7, characterized in that the upper supporting plate (555) is provided with a through hole (5551), and after the upper supporting plate (555) vertically moves downwards and turns over, the through hole (5551) is matched and sleeved with the pouring gate core (5211).

9. A marine gearbox casing casting production process using the marine gearbox casing casting line of claims 1 to 8, comprising the steps of:

step one, a smelting process, namely adding steel raw materials into a smelting furnace (1) to be smelted to a liquid state for later use;

step two, a mold matching and mold assembling process, namely, forming a molding box by matching the core mold component (52) with the sand mold component (53), filling molding sand for molding, and matching and assembling the mold after separating the molded sand mold component (53) from the core mold component (52);

step three, a pouring process, namely pouring liquid molten iron raw materials into the box body finished by the die matching by the pouring device (2) and waiting for cooling and solidification;

step four, performing shot blasting, namely opening the box, shakeout and primarily cleaning the box after the step three, and conveying the cast and molded workpiece into a shot blasting device (3) for cleaning and deburring;

and step five, a painting process, namely after the step four, after the workpiece is subjected to shoveling and qualified inspection, the workpiece is sent into a painting device (4) to be painted with the surface antirust paint.

10. The marine gearbox casing casting production process using the marine gearbox casing casting line according to claim 1 to 8, as recited in claim 9, wherein in the second step, molding sand is molded by extrusion with upper and lower end surfaces simultaneously directed toward the core mold assembly (52).