3D printing injection system wax mold

Abstract

The application provides a 3D printing pouring system wax mold mold, and belongs to the technical field of investment precision casting, which comprises an outer wall entity layer, a discontinuous honeycomb structure, a support framework and a lining plate. The lining plate is arranged on both sides of the outer wall entity layer and forms a closed space together with the outer wall entity layer. The discontinuous honeycomb structure is accommodated in the closed space. The outer wall entity layer comprises a wax mold accommodating part, the wax mold accommodating part is recessed in the discontinuous honeycomb structure, the support framework passes through the discontinuous honeycomb structure and is connected to the outer wall entity layer at both ends. The outer wall entity layer and the discontinuous honeycomb structure are 3D printed after being pretreated by polylactic acid material, and the support framework and the lining plate are inlaid after being strengthened. The mold is prepared by using polylactic acid material which is green, environmentally friendly and low in price. The water cooling channel is constructed in the mold, the problems of insufficient material temperature bearing capacity and poor heat dissipation are solved, the pouring system wax mold of different size specifications and shapes can be quickly, accurately and stably formed, and the mold is green, low in cost and fast in response.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of investment precision casting, in particular to a 3D-printed pouring system wax mold mold. BACKGROUND

[0002] With the rapid development of military fields such as aerospace, more and more new engine development tasks are required, and the development cycle is getting shorter. The corresponding supporting casting new product research and development types are many, and the time is tight. In the trial production of investment precision casting, a large number of pouring system wax molds are needed for wax mold assembly. Since the traditional metal mold can only form a wax mold with one shape and size, and in the early development of new casting products, the size and shape of the pouring system change with process adjustment at any time. If the pouring system wax mold metal mold is directly made, not only the cost is high, the cycle is long, but also the product trial production process adjustment leads to the problem of metal mold scrap; if the 3D printing method is used to directly make the pouring system, whether photosensitive resin or PS powder is used, the shell is easy to expand during dewaxing, and the environment is polluted.

[0003] After checking the relevant literature, only patent CN 116000240 A, aiming at the circular runner wax mold, through the method of replacing the movable block, a mold that can form different specifications of circular runner is made, which to some extent overcomes the limitations of traditional metal molds and meets the needs of turbine rotors, guides and cartridge type castings during development. But the metal mold has high cost, long cycle and poor flexibility, which cannot completely solve the problem of new product development of castings.

[0004] Therefore, how to quickly, accurately and stably form the pouring system wax mold of different size specifications and shapes, and green, low cost and fast response, is a problem that the industry needs to solve. SUMMARY

[0005] One of the main purposes of the present application is to overcome at least one of the defects of the prior art, and to provide a 3D-printed pouring system wax mold mold that can quickly, accurately and stably form pouring system wax molds of different size specifications and shapes, and is green, low cost and fast response.

[0006] To achieve the above application purposes, the present application adopts the following technical solutions:

[0007] According to one aspect of the present invention, a 3D printed casting system wax mold is provided. The wax mold includes an outer solid layer, a discontinuous honeycomb structure, a support frame, and a liner. The liner is disposed on both sides of the outer solid layer, forming a closed space together with the outer solid layer. The discontinuous honeycomb structure is housed in the closed space. The outer solid layer includes a wax mold receiving portion, which is recessed into the discontinuous honeycomb structure. The support frame passes through the discontinuous honeycomb structure and is connected to the outer solid layer at both ends. The outer solid layer and the discontinuous honeycomb structure are 3D printed from polylactic acid material after pretreatment, and then reinforced before being inlaid with the support frame and the liner.

[0008] According to one specific embodiment of the present invention, the polylactic acid material comprises L-lactide units with a mass fraction of 70% or more.

[0009] According to a specific embodiment of the present invention, the discontinuous honeycomb structure includes alternating honeycomb structures and partitions. The honeycomb structure includes horizontally arranged honeycomb pillars. Each honeycomb pillar includes vertically stacked honeycomb blocks. Each honeycomb block is a regular polygonal hole pillar. Each sidewall of the hole pillar is provided with a circular hole. The diameter of the circular hole is D. The side length of the regular polygon of the hole pillar is L, and 0.3L≤D≤0.6L.

[0010] According to a specific embodiment of the present invention, the thickness of the outer wall solid layer is T, the thickness of the sidewall of the hole column is W, and W=kT, where k is 0.5-1, 1mm≤T≤5mm.

[0011] According to a specific embodiment of the present invention, there is a flow gap between the partition and the outer wall solid layer, and the flow gap is arranged alternately to form a "U"-shaped cooling passage in the enclosed space.

[0012] According to a specific embodiment of the present invention, the enclosed space is provided with an inlet and an outlet on two opposite sides, and the outlet is higher than the inlet. Cooling water is introduced into the enclosed space through the inlet, and the cooling water flows out from the outlet through the cooling passage.

[0013] According to a specific embodiment of the present invention, the pretreatment of the polylactic acid material includes a drying process, wherein the drying temperature is 80-100℃ and the drying time is 4-6h.

[0014] According to one specific embodiment of the present application, the 3D printing is FDM printing, the printing layer thickness is 0.1mm-0.3mm; the outer wall solid layer and the diaphragm filling rate are greater than or equal to 98%, and the honeycomb structure filling rate is greater than or equal to 40%; the nozzle temperature is 190-230℃, the hot bed temperature is 40-60℃, and the printing speed is 400mm / s-600mm / s.

[0015] According to one specific embodiment of the present application, the strengthening treatment includes polishing and annealing, the polishing is acetone vapor polishing, and the polishing time is 30-120s; the annealing is stepwise annealing: 60℃-80℃ for 0.5h-1h→100℃ for 1h-2h→ furnace cooling to room temperature.

[0016] According to one specific embodiment of the present application, the support framework is strip-shaped, the lining plate is arranged on the end face in the mold closing direction, and the material is stainless steel or aluminum material, which is used for force support of the mold.

[0017] From the above technical solution, the 3D printing pouring system wax mold of the present application has the following advantages and positive effects:

[0018] The present application adopts polylactic acid material which is green, environmentally friendly and low in price to prepare the mold, without the need of complex equipment; by constructing a water cooling channel in the mold, the problems of insufficient material temperature bearing capacity and poor heat dissipation are solved, so that the pouring system wax mold of different size specifications and shapes can be quickly, accurately and stably formed, and the present application is green, low in cost and fast in response. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structure schematic view of the first embodiment of the 3D printing pouring system wax mold of the present application;

[0020] Figure 2 is a structure schematic view of the honeycomb block of the first embodiment of the 3D printing pouring system wax mold of the present application;

[0021] Figure 3 is a schematic view of the non-continuous honeycomb structure of the first embodiment of the 3D printing pouring system wax mold of the present application;

[0022] Figure 4 is a schematic view of the internal cavity of the first embodiment of the 3D printing pouring system wax mold of the present application;

[0023] Figure 5 is a structure schematic view of the second embodiment of the 3D printing pouring system wax mold of the present application.

[0024] FIG. NO. EXPLANATION:

[0025] 1: Outer wall solid layer; 11: Inlet; 12: Outlet; 13: Wax injection port; 2: Discontinuous honeycomb structure; 21: Honeycomb structure; 22: Partition; 3: Wax mold; 4: Support frame; 5: Liner. Detailed Implementation

[0026] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that the invention will be thorough and complete, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0027] First Embodiment

[0028] like Figures 1 to 4 As shown, the 3D printed casting system wax mold provided in this embodiment includes an outer solid layer 1, a discontinuous honeycomb structure 2, a support frame 4, and a liner 5. The liner 5 is disposed on both sides of the outer solid layer 1, forming a closed space together with the outer solid layer 1. The discontinuous honeycomb structure 2 is housed in the closed space. The outer solid layer 1 includes a wax mold receiving part, which is recessed into the discontinuous honeycomb structure 2. The support frame 4 passes through the discontinuous honeycomb structure 2 and is connected to the outer solid layer 1 at both ends. The wax mold 3 is poured into the wax mold receiving part, which has a wax injection port 13. The preparation steps include: S10, pretreatment of polylactic acid (PLA) material; S20, 3D printing of the outer solid layer 1 and the discontinuous honeycomb structure 2 as a single unit; S30, strengthening treatment of the outer solid layer 1 and the discontinuous honeycomb structure 2; S40, embedding the support frame 4 and the liner 5.

[0029] Specifically, the mold is made of a polylactic acid (PLA) matrix, which contains 75% L-lactide units by mass.

[0030] Specifically, the discontinuous honeycomb structure 2 includes alternating honeycomb structures 21 and partitions 22. The honeycomb structure 21 includes horizontally arranged honeycomb pillars, each pillar comprising vertically stacked honeycomb blocks. Each honeycomb block is a regular hexagonal pillar with a circular hole on each sidewall. The diameter of the circular hole is D, and the side length of the regular hexagon is L, where D is 4 mm and L is 10 mm. The outer solid layer thickness is T, and the sidewall thickness of the pillar is W, where T is 2 mm and W is 1 mm.

[0031] The flow gap is arranged between the partition plate 22 and the outer wall solid layer 1, and the flow gap is staggered up and down to form a "return" cooling channel in the closed space. The inlet 11 and the outlet 12 are arranged opposite to each other on the two sides of the closed space, and the outlet 12 is higher than the inlet 11. Cooling water is introduced into the closed space through the inlet 11, and the cooling water flows out of the outlet 12 through the cooling channel.

[0032] Specifically, the PLA material is dried at 80°C for 4h.

[0033] Specifically, FDM printing is used, the printing layer thickness is 0.1mm; the filling rate of the outer wall solid layer 1 and the partition plate 22 is 98%, and the filling rate of the honeycomb structure 21 is 40%; the nozzle temperature is 200°C, the hot bed temperature is 40°C, and the printing speed is 400mm / s.

[0034] Specifically, acetone vapor polishing is used, and the polishing time is 50s; the annealing is ladder annealing: 60°C for 0.5h→100°C for 1h→furnace cooling to room temperature.

[0035] Specifically, the honeycomb blocks are hexagonal, the lengths of the honeycomb columns are kept flush with the surfaces of the molds at both ends, and the lining plates 5 are inlaid on the outer surfaces in the mold closing direction, and the materials are all 6065 aluminum materials.

[0036] In addition, it should be noted that the pouring system wax mold provided by the embodiment is suitable for manual wax pouring and can simultaneously manufacture two pouring system wax molds.

[0037] Second embodiment

[0038] As Figure 5 shown, on the basis of the above embodiment, the further has the following contents.

[0039] Specifically, the mold is made of a polylactic acid (PLA) matrix, and the PLA matrix contains L-lactide units with a mass fraction of 80%.

[0040] Specifically, T is 3mm, and W is 3mm.

[0041] Specifically, the honeycomb structure 21 and the partition plate 22 are arranged alternately in one layer of honeycomb and one layer of partition plate 22; the honeycomb block structure is hexagonal, and the adjacent honeycomb blocks have through channels with a diameter D of 3mm.

[0042] Specifically, the PLA material is dried at 80°C for 6h.

[0043] Specifically, FDM printing is used, the printing layer thickness is 0.1mm; the filling rate of the solid layer and the partition plate 22 is 100%, and the filling rate of the honeycomb structure 21 is 60%; the nozzle temperature is 210°C, the hot bed temperature is 50°C, and the printing speed is 400mm / s.

[0044] Specifically, acetone vapor polishing is adopted, and the polishing time is 80s; the annealing is ladder annealing: 80 DEG C for 0.5h, 100 DEG C for 1.5h, and furnace cooling to room temperature.

[0045] The mold provided by the embodiment is suitable for hot pressure injection forming of a gating system mold. When a new casting product is researched and developed, a traditional gating system wax mold metal mold does not need to be made any more by using the mold. In addition, all printing materials of the mold are low in price and degradable, and the support skeleton and the lining plate used can be reused, and the environment is not polluted.

[0046] Those skilled in the art of the present application should understand that the specific structures and processes shown in the foregoing detailed implementation part are only exemplary and not limiting. Moreover, those skilled in the art of the present application can combine the various technical features shown above in various possible ways to form new technical solutions, or make other modifications, which all belong to the scope of the present application.

Claims

1. A wax mold for a 3D printed casting system, characterized in that, The wax mold includes an outer solid layer, a discontinuous honeycomb structure, a supporting frame, and a liner. The liner is disposed on both sides of the outer solid layer, forming a closed space together with the outer solid layer. The discontinuous honeycomb structure is housed within the closed space. The outer solid layer includes a wax mold receiving portion that is recessed into the discontinuous honeycomb structure. The supporting frame passes through the discontinuous honeycomb structure and is connected to the outer solid layer at both ends. The outer solid layer and the discontinuous honeycomb structure are 3D printed from polylactic acid material after pretreatment and are reinforced. The rear-mounted support frame and liner are used. The discontinuous honeycomb structure includes alternating honeycomb structures and partitions. The honeycomb structure includes horizontally arranged honeycomb pillars. Each honeycomb pillar includes vertically stacked honeycomb blocks. Each honeycomb block is a regular polygonal hole pillar. Each side wall of the hole pillar is provided with a circular hole with a diameter of D. The side length of the regular polygon of the hole pillar is L, and 0.3L≤D≤0.6L. There is a flow gap between the partition and the outer wall solid layer. The flow gap is staggered vertically to form a "U"-shaped cooling channel in the enclosed space.

2. The wax mold of the 3D printing casting system according to claim 1, characterized in that: The polylactic acid material contains L-lactide units with a mass fraction of 70% or more.

3. The wax mold of the 3D printing casting system according to claim 1, characterized in that: The thickness of the outer solid layer is T, and the thickness of the sidewall of the hole column is W, where W=kT, k is 0.5-1, and 1mm≤T≤5mm.

4. The wax mold of the 3D printing casting system according to claim 1, characterized in that: The enclosed space has an inlet and an outlet on two opposite sides, with the outlet being higher than the inlet. Cooling water is introduced into the enclosed space through the inlet and flows out through the outlet via the cooling passage.

5. The wax mold for the 3D printing casting system according to claim 1, characterized in that: The pretreatment of the polylactic acid material includes drying, with a drying temperature of 80-100℃ and a drying time of 4-6 hours.

6. The wax mold for the 3D printing casting system according to claim 5, characterized in that: The 3D printing is FDM printing, with a printing layer thickness of 0.1mm-0.3mm; the fill rate of the outer wall solid layer and the partition is ≥98%, and the fill rate of the honeycomb structure is ≥40%; the nozzle temperature is 190-230℃, and the heated bed temperature is 40-60℃. Printing speed: 400mm / s-600mm / s.

7. The wax mold for the 3D printing casting system according to claim 6, characterized in that: The strengthening treatment includes polishing and annealing. The polishing is acetone vapor polishing, and the polishing time is 30-120s. The annealing is a stepped annealing:

1. Hold at 60℃-80℃ for 0.5h-1h; 2. Hold at 100℃ for 1h-2h; 3. Furnace cooling to room temperature.

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