CN117161348A

CN117161348A - Extrusion casting forming die and forming method for bushing outer tube

Info

Publication number: CN117161348A
Application number: CN202311012969.6A
Authority: CN
Inventors: 冯光明; 吴晓成; 刘亚刚; 李贺; 杨双双; 王凤侠; 汪俊龙; 胡奖品; 束学道
Original assignee: Ningbo Lijin Intelligent Casting Research Institute Co ltd
Current assignee: Ningbo Lijin Intelligent Casting Research Institute Co ltd
Priority date: 2023-08-13
Filing date: 2023-08-13
Publication date: 2023-12-05

Abstract

The application relates to a bushing outer tube extrusion casting forming die and a forming method. At least one set of first mold core assemblies is provided with a first sliding mold core, and at least one set of second mold core assemblies is provided with a second sliding mold core. The molding end of the second sliding mold core is abutted to the molding end of the first sliding mold core in a mold clamping state, and the molding end of the first sliding mold core, the wall surface of the female mold cavity and the molding end of the second sliding mold core form a cavity space matched with the bushing outer pipe. Wherein, the wall interval in die cavity sets up and the protruding surface a plurality of dogteeth, and a plurality of dogteeth distribute in cover half subassembly and movable mould subassembly, and the overflow channel is including a plurality of pressure equalizing cavity that encircle second slip mold core interval distribution, and pressure equalizing cavity and die cavity space pass through overflow channel intercommunication, and all pressure equalizing cavity pass through the intercommunication passageway intercommunication.

Description

Extrusion casting forming die and forming method for bushing outer tube

Technical Field

The application relates to the technical field of metal casting, in particular to an extrusion casting forming die and a forming method for an outer pipe of a bushing.

Background

The existing bushing outer tube is usually processed by adopting a forging process or low-pressure casting, and the forging process is as follows: firstly forming a hollow cylindrical blank, wherein the periphery of the blank is in a circular tube shape, and the surface of the inner wall is partially protruded to form a convex structure. And then, machining a concave hole in the outer peripheral wall of the blank by a machining process, wherein the bottom of the concave hole is provided with an arc-shaped surface. The outer tube of the bushing is machined by forging and machining, so that the production cost is high, the process is complex, and the production efficiency is low. Although the bushing outer tube can be formed at one time by low-pressure casting, the mechanical property is lower, and the mechanical property can be improved by extrusion casting.

Chinese patent CN 219082077U discloses a bushing, chassis and car. The bushing comprises an outer tube part, an inner tube part and a filling part, wherein the outer tube part comprises a body part and a concave part arranged on the body part, the body part comprises a first surface and a second surface which are opposite to each other along the axial direction perpendicular to the body part, the first surface is arranged away from the axial line of the body part, the second surface is arranged close to the axial line of the body part, and the concave part is sunken towards the direction close to the axial line of the body part relative to the first surface; the inner pipe part is arranged in the outer pipe part; the filling portion is connected to the second surface and is located between the inner tube portion and the outer tube portion.

Chinese patent CN108326256a discloses a low-pressure charging high-pressure solidification casting device and casting method, which can be used in a countergravity casting machine or an squeeze casting machine; the device comprises a casting mould with a cavity, a molten metal lifting channel and a flow dividing cone capable of moving up and down, wherein the flow dividing cone plays roles of dividing and guiding the molten metal and compacting a filter screen in the lifting stage, so that the molten metal is stably filled in a laminar flow mode. After the filling is finished, the diverter cone downwards presses the sprue bush to form a sealing structure, and the sprue bush and a metal melt inlet of the die cavity are closed. And then the metal melt is subjected to high pressure boost to solidify the metal melt under high pressure, wherein the pressure range can reach 0.1-160 MPa.

The extrusion casting mode is suitable for flat aluminum alloy parts, the outer tube of the bushing not only needs to be provided with the bubble defects in the tube body part, but also needs to be provided with the characteristics of small internal stress, high surface quality, a plurality of concave holes in the lateral direction and the like, the existing extrusion casting die has the technical problems that the air hole distribution area of a casting processing product is uncontrollable, the casting position has defects, and the casting processing of the outer tube of the bushing is difficult to be satisfied, so that improvement is needed.

Disclosure of Invention

In order to overcome the problems in the related art, the embodiment of the application provides an extrusion casting forming die and a forming method for a bushing outer tube, which are used for solving the technical problems that the air hole distribution area of a product is uncontrollable and the casting part has defects.

According to a first aspect of an embodiment of the present application, there is provided a bushing outer tube squeeze casting mold including a stationary mold assembly and a movable mold assembly mated with the stationary mold assembly, the stationary mold assembly and the movable mold assembly including a closed mold closing posture and a separated mold opening posture, the bushing outer tube squeeze casting mold being for preparing a bushing outer tube, the bushing outer tube squeeze casting mold comprising:

the fixed die assembly and the movable die assembly are provided with a female die cavity, a pouring channel and an overflow channel which are communicated with the female die cavity in a die clamping posture;

at least one group of first mold core components are provided with first sliding mold cores which are in sliding connection with the fixed mold components, and the female mold cavity is positioned in the sliding direction of the forming end of the first sliding mold cores;

the second mold core assembly is provided with a second sliding mold core which is connected with the fixed mold assembly in a sliding way, and the female mold cavity is positioned in the sliding direction of the forming end of the second sliding mold core;

the molding end of the second sliding mold core is abutted to the molding end of the first sliding mold core in a mold clamping posture, the molding end of the first sliding mold core, the wall surface of the female mold cavity and the molding end of the second sliding mold core form a cavity space matched with the bushing outer pipe, wherein a plurality of convex teeth are arranged on the wall surface of the female mold cavity at intervals and protrude out of the surface of the female mold cavity, the convex teeth are distributed in the fixed mold assembly and the movable mold assembly, the overflow channel comprises a plurality of pressure equalizing cavities which encircle the second sliding mold core at intervals, the pressure equalizing cavities are communicated with the cavity space through overflow channels, and all the pressure equalizing cavities are communicated through communication channels.

In an embodiment, the first sliding mold core and the second sliding mold core move coaxially and relatively, the protruding direction of the convex teeth is parallel to the mold closing direction of the fixed mold assembly and the movable mold assembly, the convex teeth comprise cambered surfaces extending from the curved surfaces of tooth tops, and the cambered surfaces of a plurality of convex teeth positioned on the fixed mold assembly and/or the movable mold assembly are positioned on the same curved surface.

In an embodiment, the pressure equalizing cavity is a groove formed along the radial recess of the second sliding mold core, and the section size of the pressure equalizing cavity gradually decreases from the opening to the bottom of the groove.

In one embodiment, the spillway includes a flattened communication zone and an expansion zone conically increasing from the communication zone, the expansion zone being in communication with the pressure equalizing chamber.

In an embodiment, the pouring channel comprises a pouring opening, an annular slow flow area, a flow guiding area communicated with the slow flow area, and a flow guiding channel communicated with the pouring opening and the slow flow area, wherein the slow flow area is communicated with one end of the cavity space through the flow guiding area, the cross section size of the slow flow area is larger than that of the flow guiding area, and the first mold core component penetrates through the slow flow area and the flow guiding area.

In an embodiment, the moving die assembly includes a blocking block protruding toward the first sliding die core, and the blocking block extends to an intracavity space corresponding to the slow flow region.

In an embodiment, the first mold core assembly comprises a first sliding block slidingly connected with the fixed mold assembly and a sliding guide post obliquely inserted and slidingly connected with the first sliding block, the sliding guide post is fixed on the movable mold assembly, the first sliding mold core is fixed on the first sliding block, and the sliding guide post drives the first sliding block to synchronously slide in the mold clamping posture and the mold opening posture.

In an embodiment, the second mold core assembly comprises a telescopic element mounted on the fixed mold assembly and a second sliding block connected with the fixed mold assembly in a sliding mode, the second sliding mold core is fixed on the second sliding block, and the telescopic element drives the second sliding block to linearly reciprocate within a preset length range.

In one embodiment, the bushing outer tube extrusion casting forming die is symmetrically arranged and comprises two symmetrical cavity spaces, a first die core assembly and a second die core assembly.

According to a second aspect of the embodiment of the present application, there is provided a molding method of a bushing outer tube squeeze casting mold to which the bushing outer tube squeeze casting mold as described above is applied, the molding method comprising:

s101, driving the movable die assembly to move towards the fixed die assembly until the movable die assembly is in a die clamping posture;

s102, extending the first sliding mold core and the second sliding mold core into the female mold cavity;

s103, injecting molten metal in a hot melting state into the pouring channel, and enabling the molten metal to circulate along the pouring channel, the cavity space and the overflow channel, wherein the injection pressure of the pouring channel is 850-950 bar, and the holding pressure is 900-1000 bar;

s104, after the pressure maintaining is carried out for a preset time period, the movable mold assembly is opened and is far away from the fixed mold assembly, and the first sliding mold core and the second sliding mold core are retracted and far away from the concave mold cavity;

and taking out the workpiece, and repeating the production steps S101-S104.

The technical scheme provided by the embodiment of the application can comprise the following beneficial effects: the first mold core component and the second mold core component respectively slide and are abutted at the forming position, so that the inner wall shape of the bushing outer tube is constructed, and the modeling and demolding are smooth. The pressure equalizing cavity and the communicating channel are distributed at one end of the cavity space, and the pouring channel is distributed at the other end of the cavity space, so that the extrusion pressure part can be concentrated in the cavity space, the molding quality of the bushing outer tube is improved, bubbles and defects in the corresponding area of the bushing outer tube are avoided, and the product quality is improved. The outer wall of the bushing outer tube is constructed by the shape of the concave die cavity, and the convex teeth can directly form a concave hole structure on the outer wall of the bushing outer tube extruded and formed by the concave die cavity, so that secondary processing is avoided, and the production efficiency is improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.

Fig. 1 is a schematic structural view of a mold shown according to an exemplary embodiment.

Fig. 2 is a schematic structural view of a casting shown according to an exemplary embodiment.

Fig. 3 is a schematic structural view of a bushing outer tube, according to an exemplary embodiment.

Fig. 4 is a schematic cross-sectional structure of a mold shown according to an exemplary embodiment.

Fig. 5 is an enlarged schematic view of the structure at B in fig. 3.

Fig. 6 is a schematic view illustrating a hidden structure of a movable module assembly according to an exemplary embodiment.

FIG. 7 is a schematic structural view of a second core assembly, according to an example embodiment.

Fig. 8 is a schematic structural view of a movable mold assembly according to an exemplary embodiment.

Fig. 9 is a diagram illustrating analysis of a cast member defect according to an exemplary embodiment.

In the drawings, a stationary mold assembly 10; a stationary platen 11; a fixed die core block 12; the convex teeth 121; a stationary mold groove 122; a thimble mechanism 13; a fixed die holder 14; a first chute 141; a movable die assembly 20; a movable die plate 21; a moving die core piece 22; a movable mold groove 221; a block 23; a first mold core assembly 30; a first slide mold core 31; a first slider 32; elongated slot 321; a slide guide post 33; a second core assembly 40; a second slide mold core 41; a shaped end 411; a second slider 42; notch groove 421; a telescopic element 43; push-pull end 431; a first stroke 44; a second stroke member 45; a positioning block 46; a guide rod 47; a die casting 50; a bushing outer tube 51; recess 511; a flange 512; a slag handle 52; pouring handle 53; a female mold cavity 60; a cavity space 61; a pressure equalizing chamber 62; a connection passage 621; a slow flow region 63; a diversion area 64; an overflow 65; a communication area 651; an expansion zone 652; a flow guide 66; the exhaust passage 67.

Description of the embodiments

Wherein the drawings are for illustrative purposes only and are shown in schematic, non-physical, and not intended to be limiting of the present patent; for the purpose of better illustrating embodiments of the application, certain elements of the drawings may be omitted, enlarged or reduced and do not represent the size of the actual product; it will be appreciated by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numbers in the drawings of embodiments of the application correspond to the same or similar components; in the description of the present application, it should be understood that, if the terms "upper", "lower", "left", "right", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, only for convenience in describing the present application and simplifying the description, rather than indicating or implying that the apparatus or elements being referred to must have a specific orientation, be constructed and operated in a specific orientation, so that the terms describing the positional relationships in the drawings are merely for exemplary illustration and should not be construed as limiting the present patent, and that the specific meaning of the terms described above may be understood by those of ordinary skill in the art according to specific circumstances.

In the description of the present application, unless explicitly stated and limited otherwise, the term "coupled" or the like should be interpreted broadly, as it may be fixedly coupled, detachably coupled, or integrally formed, as indicating the relationship of components; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between the two parts or interaction relationship between the two parts. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

As shown in fig. 1 to 5, the present application provides a bushing outer tube squeeze casting mold comprising a stationary mold assembly 10 and a movable mold assembly 20 mated with the stationary mold assembly 10, the stationary mold assembly 10 and the movable mold assembly 20 comprising a closed mold-closing posture and a separated mold-opening posture, the bushing outer tube squeeze casting mold being used for preparing a bushing outer tube 51. The fixed die assembly 10 and the movable die assembly 20 are relatively folded to be in a die clamping posture so as to perform extrusion casting processing. After the molding process is completed, the movable die assembly 20 can be opened to enter a die-opening posture, the die casting 50 can be taken out by a manipulator or an operator, and the die is subjected to the next die casting 50 processing and sequentially circulates.

The stationary mold assembly 10 and the movable mold assembly 20 are formed with a female mold cavity 60, a pouring passage and an overflow passage communicating with the female mold cavity 60 in a mold clamping posture. The fixed mold assembly 10 comprises a fixed mold base 14, a fixed mold plate 11 connected to the fixed mold base 14, a thimble mechanism 13 arranged on the fixed mold plate 11 and a fixed mold core block 12 embedded and fixed on a movable mold plate 21, wherein the fixed mold core block 12 is provided with a fixed mold groove 122. The movable mold assembly 20 comprises a movable mold plate 21 and a movable mold core block 22 embedded and fixed on the movable mold plate 21, and the movable mold core block 22 is provided with a movable mold groove 221. The ejector pin mechanism 13 is correspondingly abutted against the space of the pouring channel and the overflow channel and avoids the area of the female die cavity 60, so that the outer peripheral wall of the bushing outer tube 51 corresponding to the female die cavity 60 is prevented from being left with a top mark.

The movable mold groove 221 and the fixed mold groove 122 are closed to form a female mold cavity 60, a pouring channel and an overflow channel, wherein the female mold cavity 60 is of a hollow cavity structure, and the cavity wall of the female mold cavity is the same as the surface shape of the outer peripheral wall of the bushing outer tube 51. Specifically, the female die cavity 60 has a cylindrical cavity structure, and a flange-shaped groove is formed at one end of the female die cavity 60 intersecting with the overflow channel, and the shape of the flange groove is matched with that of a flange 512 at one end of the bushing outer tube 51. The wall surface of the female mold cavity 60 is provided with a plurality of protruding teeth 121 protruding from the surface, and the plurality of protruding teeth 121 are distributed on the fixed mold assembly 10 and the movable mold assembly 20. The teeth 121 protrude from the wall surface of the female die cavity 60 toward the center direction to constitute a convex structure. Accordingly, the shape and position of the teeth 121 correspond to the concave holes 511 of the liner outer tube 51. The teeth 121 are distributed on the fixed mold assembly 10 and the movable mold assembly 20, and when the fixed mold assembly 10 and the movable mold assembly 20 are opened, the teeth 121 are separated relative to the molded die casting 50. The shape of the female die cavity 60 constructs the outer wall of the bushing outer tube 51, and the convex teeth 121 can directly form a concave hole 511 structure on the outer wall of the bushing outer tube 51 extruded by the female die cavity 60, so that secondary processing is avoided, and production efficiency is improved. Correspondingly, the die casting 50 corresponds to the shaped bushing outer tube 51 at the die cavity 60, the shaped pouring shank 53 at the pouring channel and the shaped slag shank 52 at the overflow channel.

The bushing outer tube extrusion casting forming die comprises at least one group of first die core assemblies 30 and at least one group of second die core assemblies 40, wherein the first die core assemblies 30 are provided with first sliding die cores 31 which are connected to the fixed die assemblies 10 in a sliding mode, and the female die cavities 60 are positioned in the sliding direction of the forming ends of the first sliding die cores 31. The second mold core assembly 40 is provided with a second sliding mold core 41 slidably connected to the fixed mold assembly 10, and the female mold cavity 60 is located in the sliding direction of the molding end 411 of the second sliding mold core 41. The first slide mold core 31 and the second slide mold core 41 are both moved in a telescopic manner in the direction of the cavity 60, thereby constructing the shape of the inside of the liner outer tube 51.

The molding end 411 of the second slide mold core 41 abuts against the molding end of the first slide mold core 31 in the mold clamping state, and the molding end of the first slide mold core 31, the wall surface of the cavity 60, and the molding end 411 of the second slide mold core 41 form a cavity space 61 matching the liner outer tube 51. The first core assembly 30 and the second core assembly 40 are respectively slidably moved and abutted at the molding position, thereby smoothly constructing the inner wall shape of the liner outer tube 51, modeling and demolding. The first and second slide cores 31 and 41 can independently control the amount of expansion and contraction and the time of the expansion and contraction. The first sliding mold core 31 and the second sliding mold core 41 are both in columnar structures, and can be separated from the die casting 50 along the axis direction of the die casting 50 so as to form a hole structure at the corresponding position of the die casting 50.

Optionally, at least one molding groove is provided on the outer peripheral wall of the molding end of the first slide mold core 31, the molding groove extending from the end portion toward the other end, and the width dimension of the molding groove gradually decreasing from the end portion toward the other end. Preferably, the molding grooves are symmetrically distributed at the molding end 411. Alternatively, at least one molding surface is provided on the outer peripheral wall of the molding end 411, and the molding surface may be configured as a flat surface or a curved surface, the molding surface extending from the end toward the other end. Preferably, the ends of the extension of the molding surface extend to the spaces corresponding to the flange-like grooves so that the inner wall surface of the obtained liner outer tube 51 coincides flush with the flange 512.

Optionally, the shaping end 411 of the second sliding mold core 41 is used to construct another pipe wall shaping of the liner outer pipe 51, which may be the same as or different from the shaping of the first sliding mold core 31. Preferably, the first and second sliding cores 31 and 41 are of symmetrical structure to jointly construct the liner outer tube 51. The shaped end 411 is a cylindrical portion that is positioned within the female mold cavity 60 to construct the inner wall of the liner outer tube 51 and the corresponding tube portion of the co-extrusion cast liner outer tube 51.

As shown in fig. 4 to 8, the pouring channel and the overflow channel are respectively located at both ends of the cavity space 61 corresponding to the outer tube 51 of the bushing, and the molten metal can enter the cavity space 61 along the pouring channel, so that part of the molten metal can enter the overflow channel from the cavity space 61. Wherein, the overflow channel comprises a plurality of pressure equalizing cavities 62 which are distributed at intervals around the second sliding mold core 41, the pressure equalizing cavities 62 are communicated with the cavity space 61 through overflow channels 65, and all the pressure equalizing cavities 62 are communicated through communication channels.

The pressure equalizing cavity 62 is a cavity space arranged around the cavity space 61 at intervals, and the molten metal is extruded and filled in the cavity space 61 under the action of pressure, so that the molten metal in the cavity space 61 can keep the compactness of the structure. And, the pressure equalizing cavity 62 is located at the output part of the cavity space 61 and is arranged at intervals, the sectional area of the connecting part of the pressure equalizing cavity 62 and the cavity space 61 is smaller than the sectional area of the cavity space 61, the pressure required by the cavity space 61 entering the pressure equalizing cavity 62 is increased, the internal pressure maintaining is realized, and bubbles and other defects can be concentrated in the pressure equalizing cavity 62, so that the bubbles and other defects in the cavity space 61 are reduced or even avoided, and the product quality is improved. Preferably, the bushing outer tube 51 is arranged in the vertical direction of the extrusion casting forming die, the cavity space 61 is located above the pressure equalizing cavity 62, and gas and other substances enter the pressure equalizing cavity 62 from the cavity space 61, so that the extrusion pressure part can be concentrated in the cavity space 61, the forming quality of the bushing outer tube 51 is improved, bubbles and defects in the corresponding area of the bushing outer tube 51 are avoided, and the product quality is improved.

The connecting passage 621 communicates the plurality of pressure equalizing chambers 62 in series to maintain the pressure in each pressure equalizing chamber 62 substantially balanced to avoid the disadvantage of localized stress concentration in the liner outer tube 51 due to pressure imbalance in the cavity space 61. Optionally, the cross-sectional dimension of the connecting channels 621 is smaller than the cross-sectional dimension of the pressure equalizing chambers 62, so that there is a pre-pressure between two adjacent pressure equalizing chambers 62, while maintaining pressure balance and gas flow between the pressure equalizing chambers 62. Preferably, the cross-sectional dimension of the connecting channels 621 is one fifth to one half of the cross-sectional dimension of the pressure equalizing chamber 62.

In a preferred embodiment, the bushing outer tube squeeze casting mold is symmetrically disposed, the mold including two symmetrical cavity spaces 61, a first mold core assembly 30 and a second mold core assembly 40. The die is provided with two cavities for simultaneously casting the die casting 50, so that not only the processing efficiency is improved, but also the symmetrical structural layout adjusts the heat balance of the die, and the molding quality of the bushing outer tube 51 is improved.

In one embodiment, the overflow channel further comprises a vent channel 67 connected to one of the pressure equalizing chambers 62, the vent channel 67 being used to vent gas and to keep bubbles of the pressure equalizing chamber 62 vented. Alternatively, the exhaust channel 67 is configured as a curved channel to maintain the pressure of the exhaust plenum 62 substantially consistent with the pressure of the other plenums 62. Optionally, the exhaust channel 67 includes a horizontal segment connected to the plenum 62, a curved segment intersecting the horizontal segment, a vertical segment connected to the end of the curved segment, and a toothed exhaust zone at the end of the vertical segment. The toothed exhaust region is located at the end of the exhaust channel 67, and the curved section is set to one or more curved parts to improve air resistance and meet the pressure stability of the pressure equalizing cavity 62 under the condition of keeping the exhaust smooth. The exhaust channel 67 is provided as one, so that smooth exhaust can be realized, the overall extrusion pressure of the pressure equalizing cavity 62 and the cavity space 61 can be improved, and the molding quality of the internal pressure casting in the cavity space 61 can be improved.

In an embodiment, the first sliding mold core 31 and the second sliding mold core 41 move coaxially and relatively, and the first sliding mold core 31 and the second sliding mold core 41 are disposed opposite to each other. The center line of the first slide mold core 31 and the center line of the second slide mold core 41 coincide to constitute a coaxial complementary structure or a coaxial abutment fitting structure. The first sliding mold core 31 and the second sliding mold core 41 jointly construct the inner hole shape of the bushing outer tube 51, the first sliding mold core 31 and the second sliding mold core 41 are independently arranged to construct the inner hole shape of the non-straight wall tube, and the first sliding mold core 31 and the second sliding mold core 41 are respectively inserted and pulled out from two ends of the bushing outer tube 51, so that demolding resistance and damage to the tube wall of the bushing outer tube 51 can be reduced.

The protruding direction of the protruding teeth 121 is parallel to the die clamping direction of the fixed die assembly 10 and the movable die assembly 20, the protruding teeth 121 are distributed in a plurality of rows, and in the process of relatively separating the fixed die assembly 10 and the movable die assembly 20, the protruding teeth 121 are separated from the die casting 50, so that concave holes 511 are formed in the outer side wall of the die casting 50. Alternatively, the teeth 121 of the stationary mold assembly 10 and the teeth 121 of the movable mold assembly 20 are symmetrically distributed to constitute an average force. The teeth 121 of the movable mold assembly 20 are exemplified, and the teeth 121 of the fixed mold assembly 10 can be understood by referring to the drawings, and will not be described herein.

As shown in fig. 4 to 8, the teeth 121 on the movable die assembly 20 are symmetrically distributed with respect to the bisecting plane. Optionally, two rows of teeth sets are disposed on two sides of the bisecting plane of the movable mold assembly 20, each row of teeth set is provided with at least three teeth 121, and the length direction of the teeth set is parallel to the center line of the first sliding mold core 31. Further, the movable mold assembly 20 is provided with lateral tooth sets on both sides, and the lateral tooth sets form a notch-shaped lateral concave hole 511 in the area of the die casting 50.

The teeth 121 include curved surfaces extending from the curved surfaces of the tooth tops, and the curved surfaces of the teeth 121 located in the fixed mold assembly 10 and/or the movable mold assembly 20 are the same curved surface. The convex teeth 121 are distributed in the middle area of the cavity space 61 of the movable die assembly 20 in the die assembly direction, and the tooth ends of the convex teeth 121 are arranged to be cambered surfaces so as to adapt to the installation requirement of the bushing outer tube 51, so that the machining precision is improved, and the convex teeth 121 are provided with cambered surfaces, so that the die can be conveniently removed, the volume of the cavity space 61 can be reduced, and the bubble retention probability can be reduced.

The pressure equalizing cavity 62 is a part of the movable mold groove 221 and the fixed mold groove 122, the second sliding mold core 41 is in a columnar structure, and accordingly, a sliding hole is formed by folding the movable mold groove 221 and the fixed mold groove 122, and the second sliding mold core 41 slides in the sliding hole. Optionally, a vent gap is provided between the sliding hole and the second sliding mold core 41, so that both venting and preventing molten metal from entering the vent gap can be achieved.

Pressure equalizing cavity 62 the pressure equalizing cavity 62 is a groove formed by radial recessing along the second sliding mold core 41, and the cross-sectional dimension of the pressure equalizing cavity 62 gradually decreases from the opening to the bottom of the groove. The pressure equalizing cavities 62 are distributed in the fixed die core block 12 and the movable die core block 22 and are recessed along the walls of the sliding holes to form a plurality of spaced groove structures. The groove depth of the pressure equalizing cavity 62 is larger than the width of the cavity space 61 at the same position, in the extrusion molding process of the die casting, the unit volume of the pressure equalizing cavity 62 is larger than the unit volume of the cavity space 61, the cooling molding speed of the cavity space 61 with small unit volume is larger than the molding speed of the pressure equalizing cavity 62, and the molten metal of the pressure equalizing cavity 62 can be supplemented to the cavity space 61 so as to ensure the molding quality of the lining outer tube 51 in the cavity space 61, and defects are concentrated in the pressure equalizing cavity 62, so that the die structure is optimized, and the molding effect is improved. In summary, the pressure equalizing chamber 62 serves as an end diffusion region of the cavity space 61, and locally increases the functions of buffering and replenishing the molten metal, thereby improving the pressure equalization in the cavity space 61, the flow-through property of the molten metal, and the feeding effect after cold shrinkage.

Further, the spillway 65 serves as a transfer passage connecting the pressure equalizing chamber 62 and the cavity space 61, and its structure affects the pressure in the cavity space 61 and the flow-through of the molten metal. Preferably, the spillway 65 includes a flattened communication zone 651 and an expansion zone 652 that increases conically from the communication zone 651, the expansion zone 652 being in communication with the pressure equalizing chamber 62. The communication area 651 is a flat structure with a cross-sectional dimension smaller than the width of the cavity space 61 at the same position to construct a pressure maintaining effect of the molten metal from large into small space. The expansion region 652 is tapered to expand to the pressure equalizing chamber 62, thereby converging the pressure in the pressure equalizing chamber 62 to the communication region 651 to keep the pressure of the cavity space 61 stable. In addition, the molten metal in the pressure equalizing cavity 62 can smoothly flow into the cavity space 61 in the liquid replenishing process, and the molding quality of the cavity space 61 is improved.

Preferably, the pressure equalizing chambers 62 are provided with six or eight, and a plurality of pressure equalizing chambers 62 are uniformly provided around the cavity space 61 to maintain the die-casting uniformity of the bushing outer tube 51. Preferably, the cross-sectional area of the pressure equalizing chamber 62 is greater than the cross-sectional area of the expansion zone 652 to increase the volume of the pressure equalizing chamber 62.

As shown in fig. 4 to 8, the mold is provided with a pouring assembly for connecting a quantitative furnace device or other injection mechanisms to achieve injection and pressure maintaining of molten metal. Wherein, the movable mold component 20 and the fixed mold component 10 are assembled to form a pouring channel, and the pouring channel is positioned above the cavity space 61, so that the molten metal is pre-pressed and injected from bottom to top, and the gas mixing is reduced.

Optionally, the pouring channel includes a pouring opening, an annular slow flow region 63, a diversion region 64 communicated with the slow flow region 63, and a flow guide channel 66 communicated with the pouring opening and the slow flow region 63, wherein the slow flow region 63 is communicated with one end of the cavity space 61 through the diversion region 64. Molten metal enters from the pouring port and along the flow guide 66 into the slow flow region 63 and then from the flow guide region 64 into the cavity space 61. Optionally, the mold is configured in a dual-cavity structure, the runners 66 and the buffer 63 are symmetrically arranged, and the molten metal input from one pouring port symmetrically enters the two runners 66 to keep the liquid pressure in the two cavity spaces 61 substantially balanced. The mold is provided with a double-cavity structure, so that the pressure balance of the cavity space 61 can be further improved, and casting defects can be reduced.

Further, the cross-sectional dimension of the slow flow region 63 is larger than the cross-sectional dimension of the guiding region 64, and the first mold core assembly 30 penetrates through the slow flow region 63 and the guiding region 64. The relief area 63 has an annular structure and is disposed at a distance from the cavity space 61. The slow flow region 63 is communicated with the cavity space 61 through the flow guiding region 64 to form a pressure balance structure. Optionally, the volume of the slow flow region 63 is larger than the volume of the diversion region 64, so as to construct a buffer pressure stabilizing region in the slow flow region 63, so that the pressure of the cavity space 61 is basically balanced. Optionally, the volume ratio of the volume of the slow flow region 63 to the volume of the diversion region 64 is 3-10, so that the metal liquid amount of the slow flow region 63 is far greater than the volume of the diversion region 64. Alternatively, the cross-sectional area of the flow-guiding region 64 is slightly smaller than or equal to the cross-sectional area of the cavity space 61, so that the flow-guiding region 64 acts as an extended extension of the cavity space 61.

In the extrusion molding process of the die casting, the unit volume of the slow flow region 63 is larger than that of the cavity space 61, the cooling molding speed of the cavity space 61 with small unit volume is larger than that of the slow flow region 63, and the molten metal in the slow flow region 63 can be supplemented to the cavity space 61 so as to ensure the molding quality of the lining outer tube 51 in the cavity space 61, and defects are concentrated in the slow flow region 63, so that the die structure is optimized, and the molding effect is improved. The slow flow region 63 serves as a bottom diffusion region of the cavity space 61, and locally increases the functions of buffering and replenishing the molten metal, thereby improving the pressure balance of the cavity space 61, the flow-through property of the molten metal, and the feeding effect after cold shrinkage.

Further, the movable mold assembly 20 includes a blocking block 23 protruding toward the first sliding mold core 31, and the blocking block 23 extends to the cavity space corresponding to the slow flow region 63. The block 23 has a block structure and enters the slow flow region 63, and can divide the slow flow region 63 into an arc structure, so that molten metal is prevented from circulating in the slow flow region 63 in the injection stage, and the molten metal can be fully introduced into the cavity space 61 and kept in pressure balance. Preferably, the thickness of the baffle block 23 is one-hundredth to one-fiftieth of the arc length of the relief area 63. Preferably, the baffle blocks 23 extend to the outer peripheral wall of the first sliding core 31 with a sliding gap therebetween to completely partition off the slugging region 63.

In one embodiment, the first mold core assembly 30 includes a first slide block 32 slidably coupled to the stationary mold assembly 10 and a slide guide post 33 slidably coupled to the first slide block 32 in a diagonal orientation, the slide guide post 33 being fixed to the movable mold assembly 20. The first sliding block 32 is slidably connected to the fixed platen 11, and a matching first sliding groove 141 is provided on the fixed platen 11 to fit the sliding and limiting of the first sliding block 32. Alternatively, the first slider 32 is configured as a dovetail groove or a T-groove sliding fit with the stationary platen 11. The first slide mold core 31 is fixed to the first slide block 32 and slides and expands and contracts with the first slide block 32. In the mold clamping state, the first sliding block 32 drives the first sliding mold core 31 to extend and move, so that the molding end of the first sliding mold core 31 extends into the cavity space 61. In the mold opening posture, the first sliding block 32 drives the first sliding mold core 31 to retract and move, so that the molding end of the first sliding mold core 31 is separated from the cavity space 61 and avoids the pouring channel, and the die casting 50 is conveniently taken out.

The slide guide 33 drives the first slide block 32 to slide synchronously in the mold closing posture and the mold opening posture. During the mold opening or closing process of the movable mold assembly 20, the first slide block 32 slides along the fixed mold plate 11 under the inclined thrust of the slide guide 33. A long groove 321 is formed in a lower region of the first sliding block 32, and the sliding guide post 33 is obliquely inserted into the long groove 321, so as to form a horizontal movement of the sliding guide post 33 to drive the first sliding block 32 to slide in a vertical direction. The first slider 32 adopts a passive sliding structure, and reliability of the movement position can be achieved.

In one embodiment, the second mold core assembly 40 includes a telescopic element 43 mounted on the fixed mold assembly 10 and a second sliding block 42 slidably connected to the fixed mold assembly 10, the second sliding mold core 41 is fixed on the second sliding block 42, and the telescopic element 43 drives the second sliding block 42 to linearly reciprocate within a preset length range. The telescopic element 43 may be configured as an active power mechanism with adjustable stroke, such as a hydraulic cylinder mechanism or an air cylinder mechanism, to construct different stroke range adjustments of the second slider 42. The telescoping member 43 is mounted to the stationary platen 11 and the output shaft is connected to a second slider 42, wherein the second slider 42 is configured as a dovetail or T-slot slip fit with the stationary platen 11.

In an embodiment, the output end of the telescopic element 43 is provided with a T-shaped or i-shaped push-pull end 431, the second sliding block 42 is provided with a T-shaped notch 421, and the push-pull end 431 is cooperatively embedded in the notch 421 to construct a push and pull power transmission structure. The push-pull end 431 is in clearance fit with the notch 421, so as to keep the push-pull distance of the telescopic element 43, that is, the sliding distance of the second sliding block 42, thereby improving the controllability of the sliding distance accuracy. Further, the second mold core assembly 40 further includes a first stroke member 44 and a second stroke member 45 disposed at intervals, and the first stroke member 44 and the second stroke member 45 control the telescopic stroke of the output end. Alternatively, the first stroke member 44 and the second stroke member 45 are provided as an inductive switch, a stroke switch, or the like.

In one embodiment, the telescopic element 43 comprises a connecting rod fixed to the output shaft, to which a guide rod 47 is fixed, at least one positioning block 46 being mounted on the guide rod 47. The first stroke member 44 and the second stroke member 45 are mounted to the cylinder of the telescopic element 43, and the positioning block 46 triggers the first stroke member 44 or the second stroke member 45 during the telescopic movement of the conveying shaft to determine the movement position of the second sliding block 42.

As shown in fig. 4 to 9, the extrusion casting forming die of the liner outer tube 51 disclosed in the above embodiment is subjected to its forming method to extrusion cast the liner outer tube 51. The molding method comprises the following steps:

s101, driving the movable die assembly 20 to move towards the fixed die assembly 10 until the movable die assembly 20 is in a die clamping posture, and moving and folding the movable die assembly 20 towards the fixed die assembly 10 to construct the die clamping posture so as to form a hollow cavity space between the fixed die core block 12 and the movable die core block 22.

S102, the first slide mold core 31 and the second slide mold core 41 are extended into the female mold cavity 60, and the first slide mold core 31 and the second slide mold core 41 are relatively moved and extended into the female mold cavity 60, thereby constructing the internal shape of the liner outer tube 51. The first slide mold core 31 is inserted into the female mold cavity 60 as the movable mold assembly 20 moves to be in the core protruding structure.

And S103, injecting molten metal in a hot melting state into the pouring channel, and circulating the molten metal along the pouring channel, the cavity space 61 and the overflow channel, wherein the injection pressure of the pouring channel is 850-950 bar, and the holding pressure is set to 900-1000 bar.

The second sliding mould core 41 is driven by the telescopic element 43 to extend into the cavity 60: in an alternative embodiment, the molding end 411 of the second sliding mold core 41 directly abuts against the molding end of the first sliding mold core 31 to form an approximately integral columnar structure. In another alternative embodiment, the molding end 411 of the second sliding mold core 41 is spaced from the molding end 411 of the second sliding mold core 41 by a predetermined distance, and after the molten metal is injected, the telescopic element 43 continues to push the second sliding mold core 41 to move until the molding end 411 of the second sliding mold core 41 abuts against the molding end of the first sliding mold core 31, so as to further squeeze the molten metal in the cavity 60, thereby improving the tightness. For example, the forming end 411 of the second sliding mold core 41 is spaced 1 cm from the forming end 411 of the second sliding mold core 41, and after the cavity space 61 is filled with the molten metal, the telescopic element 43 pushes the second sliding mold core 41 to slide continuously, so that the forming end 411 of the second sliding mold core 41 abuts against the forming end of the first sliding mold core 31, thereby further extruding the molten metal in the die cavity 60, increasing the extrusion pressure, and increasing the density of the die casting 50.

By adjusting the injection pressure of the pouring channel, the injection pressure of the pouring channel is 850 bar, 900bar, 950bar, etc., and the holding pressure is set to 900bar, 950bar, 1000bar, etc., calculated based on the optimization data. Preferably, the injection speed of the pouring channel is set to be 0.2-m/s to 0.4m/s. For example, the injection speed of the pouring channel is set to 0.2 m/s, 0.22m/s, 0.3m/s, 0.35m/s, 0.4m/s.

S104, after the pressure maintaining is carried out for a preset time, the movable mold assembly 20 is opened away from the fixed mold assembly 10, and the first sliding mold core 31 and the second sliding mold core 41 are retracted away from the female mold cavity 60. Preferably, the filling time of the cavity space 61 is set to 8s to 12s. For example, the filling time of the cavity space 61 is set to 8s, 9s, 10s, 11s, 12s, or the like. In this step, after the dwell time is preset, specifically, the dwell time is set to 75s to 95s, specifically, the dwell time is set to 75s, 80s, 85s, 88s, 90s, 95s, etc.

And taking out the workpiece, and repeating the production steps S101-S104.

As shown in fig. 9, the squeeze casting defect of the liner outer tube 51 was mainly concentrated in the die casting 50 corresponding to the pressure equalizing cavity 62, which was consistent with the completed bubble experiment, by the simulation test and the product inspection of the die casting 50 based on the simulation data. It should be noted that the defects of the die casting 50 are mainly concentrated on the die casting 50 corresponding to the pressure equalizing cavity 62 to prove the rationality of the die design, the die casting 50 corresponding to the pressure equalizing cavity 62 is cut off in the subsequent processing, and only the part of the bushing outer tube 51 corresponding to the cavity space 61 is reserved, so that the die casting meets the technological production requirement.

Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It is to be understood that the application is not limited to the precise arrangements and instrumentalities shown in the drawings, which have been described above, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims

1. The utility model provides a bush outer tube squeeze casting forming die, includes the cover half subassembly and matches the movable mould subassembly of cover half subassembly, the cover half subassembly with the movable mould subassembly is including the compound die gesture of folding and the open mould gesture of separation, and bush outer tube squeeze casting forming die is used for preparing the bush outer tube, its characterized in that, bush outer tube squeeze casting forming die includes:

2. The bushing outer tube extrusion casting mold according to claim 1, wherein the first slide mold core and the second slide mold core move coaxially and relatively, the protruding direction of the tooth is parallel to the mold closing direction of the fixed mold assembly and the movable mold assembly, the tooth includes an arc surface extending from the tooth tip curved surface, and the arc surfaces of the plurality of teeth located in the fixed mold assembly and/or the movable mold assembly are located in the same curved surface.

3. The bushing outer tube squeeze casting mold according to claim 1, wherein the pressure equalizing cavity is a groove formed along a radial recess of the second slide mold core, and the cross-sectional dimension of the pressure equalizing cavity gradually decreases from the opening toward the bottom of the groove.

4. A bushing outer tube squeeze casting mold in accordance with claim 3 wherein the spillway comprises a flattened communication zone and an expansion zone conically increasing from the communication zone, the expansion zone communicating with the pressure equalizing cavity.

5. The bushing outer tube extrusion casting forming die of claim 1, wherein the pouring channel comprises a pouring port, an annular slow flow region, a flow guiding region communicated with the slow flow region, and a flow guiding channel communicated with the pouring port and the slow flow region, the slow flow region is communicated with one end of the cavity space through the flow guiding region, the cross-sectional size of the slow flow region is larger than that of the flow guiding region, and the first die core assembly penetrates through the slow flow region and the flow guiding region.

6. The bushing outer tube squeeze casting mold according to claim 5, wherein the movable mold assembly includes a blocking piece protruding toward the first sliding mold core, the blocking piece extending to an intracavity space corresponding to the slow flow region.

7. The bushing outer tube squeeze casting mold as claimed in claim 1, wherein the first mold core assembly comprises a first slide block slidably connected to the stationary mold assembly and a slide guide post obliquely inserted and slidably connected to the first slide block, the slide guide post is fixed to the movable mold assembly, the first slide mold core is fixed to the first slide block, and the slide guide post drives the first slide block to slide synchronously in the mold clamping posture and the mold opening posture.

8. The bushing outer tube squeeze casting mold as claimed in claim 1 wherein the second mold core assembly comprises a telescoping member mounted to the stationary mold assembly and a second slide block slidably connected to the stationary mold assembly, the second slide mold core being secured to the second slide block, the telescoping member driving the second slide block to reciprocate linearly within a predetermined length.

9. The bushing outer tube squeeze casting mold according to any one of claims 1 to 8, wherein the bushing outer tube squeeze casting mold is symmetrically disposed and comprises two symmetrical cavity spaces, a first mold core assembly and a second mold core assembly.

10. A molding method of the bushing outer tube extrusion casting mold, characterized by applying the bushing outer tube extrusion casting mold according to claim 9, the molding method comprising:

and taking out the workpiece, and repeating the production steps S101-S104.