CN109848395B

CN109848395B - Indirect liquid forging device and clamping mechanism thereof

Info

Publication number: CN109848395B
Application number: CN201910156388.7A
Authority: CN
Inventors: 郭俊卿; 杨茜; 杨永顺; 虞跨海; 陈曦
Original assignee: Henan University of Science and Technology
Current assignee: Henan University of Science and Technology
Priority date: 2019-02-27
Filing date: 2019-03-01
Publication date: 2020-11-10
Anticipated expiration: 2039-03-01
Also published as: CN109848395A

Abstract

The invention relates to the technical field of metal plastic processing, in particular to an indirect liquid forging device and a clamping mechanism thereof, which can improve the die closing rigidity of a die and ensure the precision of a product. The clamping mechanism of the indirect liquid forging device comprises a restraint frame and a die assembly restraint mechanism, the die assembly restraint mechanism comprises a fixer and a connector, and a link mechanism which is symmetrical left and right is arranged between the fixer and the connector; the connecting rod mechanism comprises a swing rod and a connecting rod which are hinged with each other, and the die assembly restraining mechanism further comprises a limiting structure for preventing the connecting rod and the swing rod from swinging inwards; the swing end of the swing rod is provided with a convex part, the restraint frame is provided with a sliding hole positioned on the outer side of the swing rod, when the connector is driven by the movable cross beam to move downwards until the die assembly is completed, the connector is continuously pushed by the movable cross beam to enable the connecting rod mechanism to swing outwards, and the convex part slides into the sliding hole and is matched with the sliding hole to support the fixing device to realize die locking.

Description

Indirect liquid forging device and clamping mechanism thereof

Technical Field

The invention relates to the technical field of metal plastic processing, in particular to an indirect liquid forging device and a clamping mechanism thereof.

Background

The liquid die forging process is a method for obtaining high-quality parts by applying higher mechanical pressure to liquid metal poured into a closed die cavity consisting of a male die and a female die to eliminate casting defects generated in the solidification process of the liquid metal and generate certain plastic deformation, and has the characteristics of labor saving, energy saving and high material utilization rate. Liquid forging can be classified into direct liquid forging and indirect liquid forging according to different pressing modes. Indirect liquid forging forms liquid metal in a closed die cavity by applying a high localized pressure to the metal by one or more small rams, for which case the process requires hydraulic equipment to provide both the closing and pressing forces, typically using a double acting hydraulic press. The movable beam of the hydraulic press can drive the upper die of the hydraulic forging die to open and close the die, and the central hydraulic cylinder (pressurizing cylinder) drives the pressure head to perform extrusion forming action.

Liquid forging generally requires applying 30-120 MPa pressure to liquid or semi-solid metal. The cross section of the forming pressure head is small in size during indirect liquid die forging, so that the pressure required by a pressurizing cylinder is small; under the action of extrusion force, metal in a closed die cavity can generate corresponding die expansion force, the axial force of the die expansion force is basically proportional to the cross section area of the die cavity, when the cross section area of a hydraulic forging is far larger than that of a forming pressure head, the forming equipment is required to have enough die closing force, otherwise, an upper die moves upwards due to insufficient die closing force, so that no pressure is applied, even flash and flash occur, and the quality of a finished piece cannot meet the requirement. Therefore, the mold clamping force of the existing equipment becomes a key factor for limiting the forming of the large-section-size liquid forging, so that a mold clamping structure is provided in a necessary way to improve the rigidity of the mold and ensure the precision of the liquid forging product.

Disclosure of Invention

The invention aims to provide a mold clamping mechanism which can improve the mold clamping rigidity of a mold and ensure the precision of a product; another object of the present invention is to provide an indirect liquid forging apparatus, which has high mold clamping rigidity, locks a mold after upper and lower molds are clamped, and can prevent the tendency of mold separation between the upper and lower molds during liquid forging molding, thereby ensuring the precision of a liquid forging product.

In order to achieve the purpose, the indirect liquid forging device adopts the following technical scheme:

the indirect liquid forging device comprises an upper die, a lower die and a die locking mechanism, wherein the die locking mechanism comprises a constraint frame and a die closing constraint mechanism, the die closing constraint mechanism comprises a fixer and a connector, the fixer is used for fixing the upper die, the connector is used for being connected with a movable cross beam of a hydraulic machine, and a link mechanism which is symmetrical left and right is arranged between the fixer and the connector; the connecting rod mechanism comprises a swing rod hinged with the fixer, a connecting rod hinged with the connector, the connecting rod and the swing rod are hinged with each other, and the die assembly restraining mechanism further comprises a limiting structure for preventing the connecting rod and the swing rod from swinging inwards when the connecting rod mechanism swings; and the swing end of the swing rod is provided with a convex part, the restraint frame is provided with a sliding cavity positioned on the outer side of the swing rod, and when the connector is driven by the movable cross beam to move downwards until the die assembly is completed, the connector is continuously pushed by the movable cross beam to enable the connecting rod mechanism to swing outwards, so that the convex part slides into the sliding cavity and is matched with the sliding cavity to support the fixing device to realize die locking.

The beneficial effects are that: the movable beam of the hydraulic press only needs to provide power for driving the upper die to open and close the die and enabling the swing rod to slide into the sliding cavity, so that the output pressure needed to be provided by the hydraulic press is very small, after the convex part of the swing rod slides into the sliding cavity, the swing rod is supported between the constraint frame and the corresponding fixer, the constraint rigidity of the indirect liquid die forging device depends on the rigidity of the swing rod and the constraint frame and does not depend on the pressure provided by the hydraulic press, and the constraint rigidity of the indirect liquid die forging device is enough as long as the strength of the swing rod and the constraint frame is enough. The mould locking mechanism improves the rigidity of the mould and carries out rigid forced constraint on the mould, thereby preventing the tendency of mould separation between an upper mould and a lower mould during liquid forging forming, improving the performance and the precision of a product, and reducing the corresponding change of the pressure of a required hydraulic press, in other words, a hydraulic forging piece with a larger cross section area can be formed on the hydraulic press with smaller tonnage, and the production cost is also reduced while the precision of the product is ensured; and in the operation of the indirect liquid forging device, the die opening and closing stroke of the upper die mainly depends on the working stroke of the hydraulic press and is irrelevant to the working stroke of the link mechanism, so that the upper die has a larger stroke, and a larger operation space is provided for liquid pouring and forging demoulding during liquid forging forming.

Furthermore, the sliding cavity is provided with a transition surface and a supporting surface which are connected smoothly, the convex part slides over the transition surface and then is abutted and contacted with the supporting surface when the swing rod swings outwards, a convex cambered surface which is convexly arranged towards the lower die is arranged on the transition surface, and the convex part and the convex cambered surface are abutted and matched to enable the swing rod to move towards the corresponding lower die when the convex part slides over the transition surface.

The beneficial effects are that: when the swing rod slides into the sliding cavity, the convex arc surface is matched with the swing rod to enable the swing rod to slightly move a certain distance towards the upper die, so that pre-pressure is generated on the upper die, and the die locking effect of the die locking mechanism is improved.

Further, the convex part is positioned on the outer side of the hinge axis between the connecting rod and the swing rod.

The beneficial effects are that: the convex part is arranged on the outer side of the hinge axis between the connecting rod and the swing rod, and the convex part cannot interfere with other structures in the swing process of the swing rod, so that the connecting rod mechanism can stably work.

Or, the connecting rod is provided with an arc-shaped retaining groove, the swing rod is provided with a limiting pin, the limiting pin is in stop fit with one side groove wall of the arc-shaped retaining groove when the swing rod is not stressed, so that an included angle is formed between the swing rod and the connecting rod, the swing rod can swing outwards around a hinged shaft hinged with the fixer when the swing rod is stressed, and the arc-shaped retaining groove and the limiting pin form the limiting structure.

The beneficial effects are that: the limiting structure is arranged in the die assembly restraining mechanism, the connecting rod mechanism can swing outwards and cannot be clamped, the relative rotation of the oscillating rod and the connecting rod is limited by the matching of the groove wall of the arc-shaped retaining groove and the limiting pin, and the die assembly restraining mechanism is simple and reliable in structure and convenient to process.

In order to achieve the purpose, the mold locking mechanism adopts the following technical scheme:

the clamping mechanism comprises a restraint frame and a clamping restraint mechanism, the clamping restraint mechanism comprises a fixer and a connector, the fixer is used for fixing an upper die, the connector is used for being connected with a movable cross beam of the hydraulic machine, and a connecting rod mechanism which is symmetrical left and right is arranged between the fixer and the connector; the connecting rod mechanism comprises a swing rod hinged with the fixer, a connecting rod hinged with the connector, the connecting rod and the swing rod are hinged with each other, and the die assembly restraining mechanism further comprises a limiting structure for preventing the connecting rod and the swing rod from swinging inwards when the connecting rod mechanism swings; and the swing end of the swing rod is provided with a convex part, the restraint frame is provided with a sliding cavity positioned on the outer side of the swing rod, and when the connector is driven by the movable cross beam to move downwards until the die assembly is completed, the connector is continuously pushed by the movable cross beam to enable the connecting rod mechanism to swing outwards, so that the convex part slides into the sliding cavity and is matched with the sliding cavity to support the fixing device to realize die locking.

The beneficial effects are that: when the die locking mechanism is matched with the upper die and the lower die for use, a movable cross beam of the hydraulic press only needs to provide power for driving the upper die to open and close the die and enabling the swing rod to slide into the sliding cavity, so that the output pressure needed to be provided by the hydraulic press is very small, after the convex part of the swing rod slides into the sliding cavity, the swing rod is supported between the constraint frame and the corresponding fixer, the constraint rigidity of the indirect liquid die forging device depends on the rigidity of the swing rod and the constraint frame and does not depend on the pressure provided by the hydraulic press any more, and as long as the strength of the swing rod and the constraint frame is large enough, the constraint rigidity of the indirect liquid die forging device is large enough. The mould locking mechanism improves the rigidity of the mould and carries out rigid forced constraint on the mould, thereby preventing the tendency of mould separation between an upper mould and a lower mould during liquid forging forming, improving the performance and the precision of a product, and reducing the corresponding change of the pressure of a required hydraulic press, in other words, a hydraulic forging piece with a larger cross section area can be formed on the hydraulic press with smaller tonnage, and the production cost is also reduced while the precision of the product is ensured; and in the operation of the indirect liquid forging device, the die opening and closing stroke of the upper die mainly depends on the working stroke of the hydraulic press and is irrelevant to the working stroke of the link mechanism, so that the upper die has a larger stroke, and a larger operation space is provided for liquid pouring and forging demoulding during liquid forging forming.

Drawings

Fig. 1 is a schematic structural view showing a mold-open state in embodiment 1 of the indirect liquid forging apparatus of the present invention;

FIG. 2 is a schematic structural view of the indirect liquid forging apparatus of FIG. 1 when the upper and lower dies are just closed;

FIG. 3 is a schematic view of the indirect liquid forging apparatus of FIG. 1 with the male portion of the swing link entering the sliding cavity of the constraint frame;

FIG. 4 is a schematic view of the structure of the pressurizing rod of FIG. 1 during downward pressurization;

FIG. 5 is a schematic view of the pendulum rod, connecting rod and sliding cavity of the indirect liquid forging apparatus of FIG. 1;

fig. 6 is a schematic view showing the cooperation of a rocker and a connecting rod in the indirect liquid forging apparatus of fig. 1.

The respective symbols in the figure: 11. a connector; 12. hinging a shaft; 21. a connecting rod; 22. a swing rod; 23. hinging a shaft; 24. a convex portion; 25. a curved surface; 26. an arc of oscillation; 27. a spacing pin; 28. an arc-shaped baffle groove; 31. a holder; 32. hinging a shaft; 41. a pressurizing rod; 42. an upper base plate; 43. a top plate; 44. a fixing plate; 45. a return spring; 46. cushion blocks; 47. mounting a template; 48. a pressure head; 49. a male die; 51. a female die; 52. a top rod; 61. a constraint frame; 62. sliding points; 63. a support surface; 64. a transition surface; 7. and (5) blank forming.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings.

As shown in fig. 1, in embodiment 1 of the indirect liquid forging apparatus according to the present invention, the indirect liquid forging apparatus includes an upper die, a lower die, and a clamping mechanism, where the clamping mechanism includes a constraint frame and a clamping constraint mechanism, and the clamping mechanism is used in cooperation with a die required by an indirect liquid forging process, so as to increase the clamping rigidity of the die, improve the product forming accuracy, and be used to form a liquid forging with a larger cross-sectional area. The mold closing restraining mechanism comprises a fixer 31 and a connector 11, wherein the fixer 31 is used for installing and fixing an upper mold, and the connector 11 is connected with a movable cross beam of the hydraulic machine. In indirect liquid forging, a double-acting hydraulic press is often used, a movable beam of the double-acting hydraulic press is connected with a connector 11, and the connector 11 can move along with the movable beam in the up-down direction to enable an upper die to be close to a lower die or to enable the upper die to be far away from the lower die, so that die closing and die opening of the die are realized. A link mechanism is connected between the fixer 31 and the connector 11, and when the connector 11 moves, the link mechanism drives the fixer 31 to move so as to realize the die assembly of the upper die and the lower die. The guiding movement between the connector 11 and the retainer 31 can be achieved by a guide post provided separately.

The link mechanisms are arranged around the holder 31 and the connector 11 in a left-right symmetrical manner, and two sets of two link mechanisms are arranged in the front-rear direction of the left and right link mechanisms, respectively, and in other embodiments, three sets, four sets, etc. of the link mechanisms may be arranged in a circumferential manner. The link mechanism comprises a connecting rod 21 and a swinging rod 22, the swinging rod 22 is hinged with the connecting rod 21 through a hinge shaft 23, the other end of the connecting rod 21 is hinged with the connector 11 through a hinge shaft 12, the other end of the swinging rod 22 is hinged with the fixer 31 through a hinge shaft 32, and the hinge shafts of the swinging rod 22 and the connecting rod 21 deviate from the central axis of the swinging rod 22. The end surface of the end of the swing rod 22 close to the fixer 31 is an arc surface, and the fixer 31 is provided with a matching surface which is matched with the arc surface of the swing rod 22 and has the same curvature, so that the contact area between the swing rod 22 and the fixer 31 is increased. The swing rod 22 is close to one end of the connecting rod 21, namely the swing end of the swing rod, a convex part 24 is integrally arranged on the outer side of the swing end, the convex part 24 is positioned on the outer side of a hinge axis between the connecting rod 21 and the swing rod 22, and the outer side surface of the convex part 24 is a curved surface 25.

As shown in fig. 6, one side of the closing center line of the upper mold and the lower mold is defined as an inner side, the connecting rod 21 is provided with a limit pin 27, the swing rod 22 is provided with an arc-shaped retaining groove 28 for the limit pin 27 to pass through, when the connecting rod 21 and the swing rod 22 are not subjected to the acting force of the connector 11, the limit pin 27 is located at one end of the arc-shaped retaining groove 28, due to the action of the limit pin 27 and the arc-shaped retaining groove 28, the swing rod 22 inclines outwards, the swing rod 22 cannot swing inwards to limit but can swing outwards, the limit pin 27 and the arc-shaped retaining groove 28 correspondingly form a limit structure for preventing the connecting rod or the swing rod from swinging inwards when the connecting rod mechanism is extruded, when the swing rod 22 is not subjected to a pressure, the limit pin 27 and one side wall of the arc-shaped retaining groove 28 are in stop fit to form a certain included angle between the swing rod.

As shown in fig. 1, 2, 3, 4 and 5, the clamping mechanism further includes a restraint frame 61, and the restraint frame 61 is fixed on the workbench of the hydraulic machine. The restraint frame 61 includes a bottom plate and side plates vertically rigidly fixed to the bottom plate, the upper portions of the side plates being rigidly connected by a cross plate to form a frame structure. The inner side walls of the side plates of the restraint frame 61 are stepped side walls with the inner diameter increasing along the direction close to the lower die, sliding holes 62 for contacting and matching with the convex parts 24 on the swing rods 22 are formed at the corners of the stepped side walls, and the swing rods 22 swing outwards and fall into the sliding holes 62 when being pushed by the connecting rods 21. When the connector 11 moves downwards until the die assembly is completed, the movable cross beam of the hydraulic press drives the connector 11 to continuously move downwards so that the connecting rod mechanism swings outwards; when the swing rod and the connecting rod in the connecting rod mechanism swing, the convex part 24 slides into the sliding cavity 62 and is matched with the sliding cavity 62 to support the fixer to realize mode locking, and the die locking constraint mechanism further comprises a limiting structure for preventing the connecting rod and the swing rod from swinging inwards when the connecting rod mechanism swings.

As shown in fig. 5, the sliding cavity 62 includes a supporting surface 63 supporting the convex portion 24 and a transition surface 64 smoothly connected to the supporting surface 63, the supporting surface 63 is a matching curved surface matched with the curvature of the curved surface 25 on the convex portion 24, the curved surface is a cylindrical surface, the transition surface 64 has a convex portion protruding from the swing arc 26 of the swing link 22 in the lower mold direction, and the convex portion applies a pushing force to the convex portion 24 of the swing link 22 during the process that the convex portion 24 of the swing link 22 falls into the sliding cavity 62, so that the holder 31 pushes the upper mold to move towards the lower mold, and applies a pre-pressure to the mold closing of the upper mold and the lower mold, and the convex portion forms a convex arc surface on the transition surface 64 for pushing the swing link 22, and in other embodiments, the transition surface 64 and the convex arc surface thereon may.

As shown in fig. 1, 2, 3, and 4, the upper mold includes an upper base plate 42 fixedly connected to the holder 31 and spacers 46 provided below the upper base plate 42, the spacers 46 are two in total and located on both sides in the mold clamping direction, and a top plate 43 fixed to the upper base plate 42 and a fixing plate 44 fixed to the top plate 43 are provided between the two spacers 46 in this order from top to bottom. An upper template 47 and a punch 49 are fixedly arranged below the cushion block 46, a pressure head 48 which extends downwards and sequentially penetrates through the upper template 47 and the punch 49 is arranged on the fixing plate 44, the fixing plate 44 connects the pressure head 48 and the top plate 43 together through a screw, the pressure head 48 corresponds to the position of the punch 49 which needs to be locally pressurized, a return spring 45 is further arranged between the top plate 43 and the upper template 47 in a pressing mode, and the return spring 45 can enable the top plate 43 to be located above when the top plate is not stressed. The connector 11, the fixer 31 and the upper bottom plate 42 are respectively provided with a through hole which is coaxially arranged, a pressurizing rod 41 of the hydraulic machine is arranged in the through hole in a penetrating way, and the upper end of the pressurizing rod 41 is connected with a pressurizing cylinder piston of the hydraulic machine so as to apply acting force to the top plate 43 to realize indirect liquid forging.

The lower die comprises a female die 51 and a mandril 52, the female die 51 is fixed on a bottom plate of the constraint frame 61, the mandril 52 is movably inserted in the bottom plate and the female die 51 along the vertical direction, the mandril 52 is connected with a lower knockout cylinder of the hydraulic press, and the mandril 52 can eject the workpiece after the workpiece is formed by hydraulic forging.

When the mold locking mechanism is used, in the state shown in fig. 1, a certain amount of metal melt blanks 7 are poured into the female mold 51, the movable cross beam of the hydraulic press drives the connector 11 to move downwards, and the connector 11 drives the fixer 31 to move through the connecting rod 21 and the swing rod 22, so that an upper mold is driven to rapidly move downwards to perform mold closing; in the process of die assembly, due to the action of the limit pin 27 and the arc-shaped baffle groove 28, the included angle between the swing rod 22 and the connecting rod 21 is kept unchanged, after the upper die is contacted with the lower die, the fixer 31 connected with the upper die stops moving, because a connecting rod mechanism is arranged between the fixer 31 and the connector 11, after the fixer 31 stops moving, the connector 11 can still have a certain movement space to continue moving by virtue of the swing of the connecting rod mechanism, the movable cross beam of the hydraulic machine continues to move downwards, the connector 11 moves towards the direction of the fixer 31, the connecting rod 21 pushes the swing rod 22 to swing outwards around the hinge shaft 32, the convex part 24 on the swing rod 22 slides into the sliding cavity 62 of the constraint frame 61, when the curved surface 25 outside the convex part 24 slides along the transition surface 64 of the sliding cavity 62, the transition surface 64 pushes the curved surface 25 of the convex part 24, so as to apply axial acting force to the swing rod 22, and the symmetrical acting force provides pre-pressure for, the holder 31 is moved slightly at a slow speed in the mold closing direction to further lock the upper mold and the lower mold.

The convex part 24 of the swing rod 22 enters the supporting surface 63 of the sliding cavity 62, the movable cross beam stops moving downwards, and at the moment, the connecting rod 21 and the swing rod 22 are close to be vertical, so that the maximum transverse stress application effect is realized, and the convex part 24 of the swing rod 22 is firmly locked in the supporting surface 63. At this time, the mold closing direction of the swing rod 22 is nearly consistent with that of the mold, the vertical plate and the swing rod 22 have high rigidity and large contact surface area, so that the mold locking mechanism has great rigidity along the mold closing direction to resist the mold expanding force of the melt in the mold on the mold, and the mold closing rigidity of the upper mold and the lower mold of the mold is only related to the rigidity of the mold, the fixer 31, the swing rod 22 and the constraint frame 61 and the contact rigidity of the contact surfaces of all parts and is basically unrelated to the output pressure of a pressurizing cylinder of a hydraulic press.

A piston of a pressurizing cylinder of the hydraulic machine descends and drives a pressurizing rod 41 to descend, the pressurizing rod 41 drives a top plate 43, a fixing plate 44 and a pressure head 48 to descend, the pressure head 48 pressurizes the melt in the die cavity to the required pressure and maintains the pressure, the melt is solidified and cooled under the pressure to form a liquid forging, and in the process, the die always keeps high die closing rigidity under the action of the oscillating bar 22.

When the hydraulic press returns, the movable cross beam drives the mold locking mechanism and the upper mold to move upwards together, the swing rod is driven by the hydraulic press to slowly withdraw from the sliding cavity 62, the convex part on the swing rod is separated from the sliding cavity 62, slow pressure relief is realized, the movable cross beam continues returning to drive the mold locking mechanism and the upper mold to move upwards quickly to realize returning. Meanwhile, the pressurizing cylinder is reset, the top plate 43, the fixing plate 44 and the pressure head 48 are reset under the action of the reset spring 45, the lower ejection cylinder of the hydraulic machine works, and the hydraulic forging workpiece is ejected out of the lower die through the ejector rod 52, so that the demolding operation is completed.

It should be noted that the indirect liquid forging apparatus and the clamping mechanism of the present invention can also be used in low pressure casting and other occasions requiring mold closing in advance and having large mold closing force and mold opening stroke, and when the clamping mechanism is matched with the corresponding mold, the rigidity of the whole mold can be improved, and the load of the equipment can be effectively reduced.

The indirect liquid forging device and the clamping mechanism can realize the following effects:

1. a movable cross beam of the hydraulic machine can drive the upper die to be close to the lower die quickly through the die assembly restraining mechanism so as to carry out die assembly.

2. When the die assembly is completed, the connector advances to enable the swing rod to swing outwards, the upper convex part of the swing rod slides into the sliding cavity to pressurize the upper die, and finally the swing rod is supported between the fixer and the constraint frame, so that the constraint of the upper die and the lower die is increased, and the rigidity of the upper die and the lower die is improved.

3. After the processing is finished, the movable cross beam of the hydraulic press returns, and the swing rod swings to the original position, so that the convex part on the swing rod is separated from the sliding hole, and the pressure on the upper die is reduced.

4. After the oscillating bar swings back to the original position, the movable cross beam of the hydraulic press continues to return, the upper die is driven by the die assembly restraining mechanism to leave the lower die at a higher speed, and the upper die is returned to the initial position.

In summary, the indirect liquid forging device and the clamping mechanism have the characteristics of 'fast descending, slow pressurizing, slow pressure releasing and fast returning' during working, the clamping mechanism improves the rigidity of the die and performs rigid forced constraint on the die, so that the tendency of die splitting between an upper die and a lower die during liquid forging forming is avoided, the performance and the precision of a product are improved, the pressure required by a hydraulic machine is correspondingly reduced, the tonnage of the hydraulic machine is correspondingly reduced, in other words, a liquid forging piece with a larger cross section area can be formed on the hydraulic machine with a smaller tonnage, and the production cost is also reduced while the precision of the product is ensured. The die opening and closing stroke of the upper die is mainly determined by the working stroke of the hydraulic press and is irrelevant to the working stroke of the connecting rod mechanism, so that the upper die has a larger stroke, and a larger operation space is provided for liquid pouring and forge piece demoulding during liquid forging forming.

Example 2 of the indirect liquid forging apparatus of the present invention is different from example 1 in that: in embodiment 1, the transition surface, the support surface, and the outer side surface of the convex portion of the sliding cavity are curved surfaces, in this embodiment, the support surface and the transition surface are inclined surfaces, an included angle between the support surface and the mold closing direction is greater than an included angle between the transition surface and the mold closing direction, the sliding cavity is formed by the inclined surface and the inner side wall of the constraint frame in a matched manner, and the outer side surface of the convex portion is an inclined surface.

Example 3 of the indirect liquid forging apparatus of the present invention is different from example 1 in that: the convex part is arranged outside the hinge axis of the swing rod, in the embodiment, the convex part is integrally arranged at the axial end part of the swing rod, and the connecting rod inclines towards the direction far away from the convex part.

In other embodiments, a spacer may be provided between the connector 11 and the retainer 31 to apply the clamping force of the hydraulic press to the mold in the clamping state, while preventing the movable cross member from descending excessively, ensuring the position of the swing link 22 in the sliding cavity 62 and preventing the overload of the connecting rod 21.

In other embodiments, the position-limiting structure may be replaced by other forms, such as a stop pin located inside the connecting rod on the connector, and the connecting rod can only swing outwards under the limit of the stop pin, or a stop pin located inside the swing link on the fixer, and the swing link can only swing outwards under the limit of the stop pin, and the stop pin in the above two cases becomes the position-limiting structure.

The structure of the clamping mechanism in the invention is the same as that of the clamping mechanism used in the embodiment of the indirect liquid forging device in the invention, and therefore, the description is omitted.

Claims

1. The indirect liquid forging device is characterized in that: the mould clamping mechanism comprises a restraint frame and a mould clamping restraint mechanism, the mould clamping restraint mechanism comprises a fixer and a connector, the fixer is used for fixing the upper mould, the connector is used for being connected with a movable cross beam of the hydraulic machine, and a connecting rod mechanism which is symmetrical left and right is arranged between the fixer and the connector; the connecting rod mechanism comprises a swing rod hinged with the fixer, a connecting rod hinged with the connector, the connecting rod and the swing rod are hinged with each other, and the die assembly restraining mechanism further comprises a limiting structure for preventing the connecting rod and the swing rod from swinging inwards when the connecting rod mechanism swings; a convex part is arranged at the swinging end of the swinging rod, and a sliding hole positioned at the outer side of the swinging rod is arranged on the constraint frame; when the connector is driven by the movable cross beam to move downwards to complete die assembly, the connector is continuously pushed by the movable cross beam to enable the connecting rod mechanism to swing outwards, so that the convex part slides into the sliding cavity and is matched with the sliding cavity to support the fixing device to realize die locking.

2. The indirect liquid forging apparatus of claim 1, wherein: the sliding holes are provided with a transition surface and a supporting surface which are connected smoothly, the convex parts slide over the transition surface and then are abutted and contacted with the supporting surface when the swing rod swings outwards, the transition surface is provided with convex cambered surfaces protruding towards the lower die, and the convex parts and the convex cambered surfaces are abutted and matched when the convex parts slide over the transition surface so that the swing rod moves towards the corresponding lower die.

3. The indirect liquid forging apparatus of claim 1 or 2, wherein: the convex part is positioned on the outer side of a hinge axis between the connecting rod and the swing rod.

4. The indirect liquid forging apparatus of claim 1 or 2, wherein: the swing rod is provided with an arc-shaped baffle groove, the swing rod is provided with a limiting pin, the limiting pin is in stop fit with one side groove wall of the arc-shaped baffle groove when the swing rod is not stressed, so that an included angle is formed between the swing rod and the connecting rod, the swing rod can swing outwards around a hinged shaft hinged with the fixer when the swing rod is stressed, and the arc-shaped baffle groove and the limiting pin form the limiting structure.

5. Clamping mechanism, its characterized in that: the die assembly restraining mechanism comprises a restraining frame and a die assembly restraining mechanism, wherein the die assembly restraining mechanism comprises a fixer and a connector, the fixer is used for fixing an upper die, the connector is used for being connected with a movable cross beam of a hydraulic machine, and a connecting rod mechanism which is symmetrical left and right is arranged between the fixer and the connector; the connecting rod mechanism comprises a swing rod hinged with the fixer, a connecting rod hinged with the connector, the connecting rod and the swing rod are hinged with each other, and the die assembly restraining mechanism further comprises a limiting structure for preventing the connecting rod and the swing rod from swinging inwards when the connecting rod mechanism swings; a convex part is arranged at the swinging end of the swinging rod, and a sliding hole positioned at the outer side of the swinging rod is arranged on the constraint frame; when the connector is driven by the movable cross beam to move downwards to complete die assembly, the connector is continuously pushed by the movable cross beam to enable the connecting rod mechanism to swing outwards, so that the convex part slides into the sliding cavity and is matched with the sliding cavity to support the fixing device to realize die locking.

6. The clamping mechanism of claim 5, wherein: the sliding holes are provided with a transition surface and a supporting surface which are connected smoothly, the convex parts slide over the transition surface and then are abutted and contacted with the supporting surface when the swing rod swings outwards, the transition surface is provided with convex cambered surfaces protruding towards the lower die, and the convex parts and the convex cambered surfaces are abutted and matched when the convex parts slide over the transition surface so that the swing rod moves towards the corresponding lower die.

7. The clamping mechanism according to claim 5 or 6, wherein: the convex part is positioned on the outer side of a hinge axis between the connecting rod and the swing rod.

8. The clamping mechanism according to claim 5 or 6, wherein: the swing rod is provided with an arc-shaped baffle groove, the swing rod is provided with a limiting pin, the limiting pin is in stop fit with one side groove wall of the arc-shaped baffle groove when the swing rod is not stressed, so that an included angle is formed between the swing rod and the connecting rod, the swing rod can swing outwards around a hinged shaft hinged with the fixer when the swing rod is stressed, and the arc-shaped baffle groove and the limiting pin form the limiting structure.