A device for casting air in and out and a manufacturing method thereof

Abstract

The present application relates to a device for casting air inlet and outlet and a manufacturing method of the device, the device comprising a casting mold and a mold cavity, the mold cavity comprising an air outlet or a riser sleeve, and one or more Tesla valve structures are arranged on the air outlet or the riser sleeve; the Tesla valve structure comprises one or more Tesla valve units, and an inlet, an outlet and a downstream direction arrow are arranged in the Tesla valve unit to facilitate mutual assembly and positioning with the mold cavity or the riser sleeve. When the device is used as the air outlet of the mold cavity, the downstream direction should be kept towards the outside of the mold cavity, so that when the device is used, the gas in the mold cavity can smoothly escape, and at the same time, the mold cavity can be prevented from inhaling air or falling of impurities outside the mold cavity before or during pouring; when the device is used as the air inlet of the riser, the downstream direction should be kept towards the riser. The device of the present application has low manufacturing cost and is convenient to use, and can be easily standardized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of casting technology, in particular, relates to a device for casting in and out of air and the manufacturing method of the device. BACKGROUND

[0002] In the casting production, the out-gas hole should be set in the casting mold and the blind riser. The out-gas hole can be used to discharge the gas in the mold cavity, the mold core and the metal liquid, reduce the gas pressure in the mold cavity when filling, improve the filling capacity of the metal liquid, and avoid the casting defects of insufficient filling of the metal liquid. At the same time, the out-gas hole can also collect the supercooled, slag-containing and gas-containing metal liquid filled into the mold cavity first, and avoid the casting defects of slag and gas holes formed in the specific local position of the casting. In addition, the out-gas hole can also be used as a sign of observing the pouring process, and is one of the important reference information for controlling the pouring process. In addition, the vent hole connected with the blind riser also has the function of providing atmospheric pressure for the riser and enhancing the blind riser feeding. Therefore, the out-gas hole plays an important role in the casting mold.

[0003] The existing casting mold vent hole is mostly a straight vent hole, which is formed by the model during molding, or is separately formed by a sand core or a refractory material and is pre-embedded in the casting mold. This out-gas hole is divided into two ways: a clear out-gas hole connected with the atmosphere and a blind out-gas hole not connected with the atmosphere. The out-gas effect of the blind out-gas hole is very unstable. The clear out-gas hole directly connects the mold cavity with the outside, which often leads to the falling of foreign matters (such as scattered sand) outside the mold cavity into the mold cavity and causes casting defects. If other gas-permeable materials (such as asbestos, paper balls, etc.) are used to block the out-gas hole to prevent foreign matters outside the mold cavity from falling into the mold cavity, the operation is random and will also affect the out-gas effect. At the same time, when the out-gas hole is used as an introduction channel of the atmospheric pressure of the blind riser, it becomes an overflow channel of the gas in the casting mold and the riser position. When these gases overflow, a large amount of heat will be taken away with the gas, which enhances the cooling of the surface of the riser and speeds up the solidification and crust formation of the surface of the riser. This is not conducive to maintaining the slow cooling of the surface of the riser, continuously communicating with the atmosphere, and using the atmospheric pressure to enhance the feeding of the riser. Practice shows that in some blind risers, there are also vent holes connected with the atmosphere, but the blind riser still solidifies and crusts early, loses the feeding effect, and the heat dissipation of the vent hole is also an important reason.

[0004] Therefore, for the out-gas hole as the gas escape hole in the mold cavity, especially the out-gas hole as the gas escape channel during filling, the ideal way is that the atmosphere can flow from the mold cavity to the outside of the mold cavity in one direction. At the same time, for the air inlet hole of the blind riser, especially the air inlet hole of the blind riser as the introduction channel of the atmospheric pressure during solidification, it is hoped that the atmosphere can flow from the outside of the mold cavity to the mold cavity in one direction.

[0005] The existing out-gas device adopts a straight structure, which causes the gas (or other substances) to flow or pass in the out-gas hole in both directions, which is the key reason for the existing problems. Summary of the Invention

[0006] To address the aforementioned technical deficiencies of the prior art, the present invention provides a device for mold air inlet and outlet, and a method for manufacturing the device. This device utilizes the structure of a Tesla valve, constructed from fiber or refractory materials with a defined wall thickness to provide a simple, practical, unidirectional air outlet capable of flow or passage. The device is economical to manufacture, easy to use, and easily standardized, effectively resolving the aforementioned technical challenges and representing a significant technological advancement.

[0007] In order to achieve the above-mentioned design objectives, the scheme adopted by the present invention is as follows:

[0008] A first aspect of the present invention provides a device for air inlet and outlet of a casting mold, comprising a casting mold and a cavity located within the casting mold, wherein the cavity comprises an air outlet duct or a riser sleeve, and one or more Tesla valve structures are provided at the air outlet duct or the riser sleeve.

[0009] Preferably, the Tesla valve structure includes one or more Tesla valve units, each of which is provided with a Tesla valve flow channel, which includes an inlet, an outlet and a downstream direction mark to facilitate mutual assembly and positioning with the cavity or riser sleeve.

[0010] In any of the above solutions, it is preferred that the arrow of the downstream direction indicator points toward the outside of the mold cavity or toward the riser. When the device is used as a cavity air outlet, the downstream direction should be maintained toward the outside of the mold cavity. In this way, the device can ensure smooth escape of gas in the mold cavity while preventing air from being sucked into the mold cavity before or during pouring or impurities from outside the mold cavity from falling into the mold cavity. When the device is used as a riser air inlet, the downstream direction should be maintained toward the riser.

[0011] In any of the above solutions, preferably, the Tesla valve structure is made of fiber or refractory material.

[0012] In any of the above schemes, preferably, the Tesla valve unit comprises a semicircle and a straight section connected to the semicircle at an X angle, the value of X is in the range of 48 / -10°, preferably, X = 48°; the wall thickness of the Tesla valve unit is a, the value of a is in the range of 1-10 mm, the lower limit is preferred when the Tesla valve structure is made of fiber material, and the upper limit is preferred when it is made of sand or ceramic material. The device is preferably made by pressure casting of fiber material slurry, dried for use; the height of the Tesla valve unit is b, the value of b is in the range of 5-50 mm; the width of the Tesla valve unit is c, the value of c is in the range of 5-50 mm. The width d of the device is generally in the range of 20-200 mm. When the device is used to realize the simple out-gas and in-gas situation of the casting mold, a relatively wide runner with b / c > 2 is preferred; when the device is used to realize the gas and slag collection and cold metal liquid collection, a runner close to b / c = 1 is preferred; when the device is in molding, it can be assembled and connected or cut and bonded with adhesive to form any length; when the device is in molding, it is positioned and embedded into the casting mold at a specific position to form a communication between the mold cavity or riser and the air outside the mold cavity.

[0013] In any of the above schemes, preferably, the cross section of the Tesla valve unit is quadrilateral or circular or elliptical or other shapes.

[0014] In any of the above schemes, preferably, the casting mold is a wet sand mold or a negative pressure dry sand mold or a gypsum mold or a resin sand mold.

[0015] The second aspect of the present application provides a manufacturing method for a casting mold in-out air device, which is made of sand core or clay after molding and firing, comprising the following steps:

[0016] Firstly, waste paper such as newspaper or impurities or corrugated paperboard is water-soaked and softened into slurry;

[0017] Secondly, the slurry is pressure-casted and shot into the Tesla valve structure half-mold, i.e. the upper mold and the lower mold;

[0018] Thirdly, the mold in the second step is demolded and dried, and the upper and lower molds are bonded and assembled into a product;

[0019] Fourthly, the product in the third step is treated with saturated Na2SiO3 solution for refractory treatment, and then dried and packaged after drying.

[0020] The manufacturing method of the device of the present application has the characteristics of low cost, easy use and easy standardization. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The flow chart of the manufacturing method for the casting mold in-out air device according to the present application.

[0022] Figure 2 It is a schematic diagram of a device for gas inlet and outlet of a casting mold according to the present invention.

[0023] Figure 3 It is a structural schematic diagram of the device for gas inlet and outlet of a casting mold according to the present invention.

[0024] Figure 4 The device for gas inlet and outlet of the mold according to the present invention Figure 3 A cross-sectional view taken along the AA direction of the preferred embodiment is shown.

[0025] Figure 5 The device for gas inlet and outlet of the mold according to the present invention Figure 3 The schematic diagram of the preferred embodiment shown is used in cavity gas venting.

[0026] Figure 6 The device for gas inlet and outlet of the mold according to the present invention Figure 3 The diagram shows the application of the preferred embodiment in riser ventilation.

[0027] Description of Figure Numbers:

[0028] Tesla valve structure 1, inlet 2, downstream direction mark 3, outlet 4, device of the present invention 5, cavity 6, casting mold 7, riser sleeve 8. DETAILED DESCRIPTION

[0029] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be derived from these drawings without inventive effort.

[0030] like Figure 2 As shown in the schematic diagram of the mold air inlet and outlet device of the present invention, a simple and practical air outlet device, fabricated from fiber or refractory materials with a predetermined wall thickness, adopts the structure of a Tesla valve. The Tesla valve is a one-way valve whose resistance to upstream (N direction) flow is significantly greater than that to downstream (M direction) flow, enabling unidirectional flow. Furthermore, the Tesla valve's reverse direction incorporates a semi-circular rotary structure, preventing direct linear connection between the front and rear ends, preventing non-fluid debris from passing in the upstream direction. By varying the orientation of the air outlet device within the mold, a certain degree of unidirectional gas flow can be easily achieved, preventing debris from entering the mold from outside through the air outlet.

[0031] The device of the application can also inhibit the jetting phenomenon of the existing gas outlet when it is full by using the slow flow formed by the counter flow on the basis of solving the above problems by using the normal flow. The false full phenomenon caused by the jetting of the gas outlet due to the filling pressure when the full is observed as the sign that the pouring is about to be completed. The device of the application has the advantages of low manufacturing cost, convenient use, easy standardization, effective solution to the above technical problems and significant technical progress.

[0032] In order to achieve the above design purposes, the application adopts the following solutions:

[0033] The first aspect of the application provides a device for casting gas in and out, which comprises a casting 7 and a cavity 6 in the casting 7, the cavity 6 comprises a gas outlet or a riser sleeve 8, and one or more Tesla valve structures are arranged at the gas outlet or the riser sleeve 8.

[0034] Next, refer to the structure diagram of the device for casting gas in and out according to the application shown in Figure 3 、 Figure 4 .

[0035] In the embodiment, the Tesla valve structure comprises one or more Tesla valve units, and a Tesla valve flow channel 1 is opened on the Tesla valve unit, which comprises an inlet 2, an outlet 4 and a normal flow direction sign 3 to facilitate mutual assembly and positioning with the cavity or the riser sleeve.

[0036] In the embodiment, the arrow direction of the normal flow direction sign 3 is directed outward of the cavity or directed to the riser. When the device is used as a cavity gas outlet, the normal flow direction should be directed outward of the cavity, so that when the device is used, the gas in the cavity can be smoothly released, and at the same time, the cavity can be prevented from inhaling or foreign matter from falling into the cavity (such as Figure 5 shown) before or during pouring; when the device is used as a riser gas inlet, the normal flow direction should be directed to the riser (such as Figure 6 shown).

[0037] In the embodiment, the Tesla valve structure is made of fiber or refractory material.

[0038] In the embodiment, the Tesla valve unit comprises a semicircle and a straight section connected to the semicircle at an X angle (see Figure 2The value of X angle is in the range of +48 / -10°, preferably X=48°; the wall thickness of the Tesla valve unit is a, the value of a is in the range of 1-10 mm, preferably the lower limit when the Tesla valve structure is made of fiber material, and the upper limit when the Tesla valve structure is made of sand or ceramic material. The device is preferably made of fiber material slurry pressure casting, dried and used; the height of the Tesla valve unit is b, the value of b is in the range of 5-50 mm; the width of the Tesla valve unit is c, the value of c is in the range of 5-50 mm. The width d of the device is generally in the range of 20-200 mm. When the device is used to realize the simple out-gassing and in-gassing of the casting mold, a relatively wide flow channel with b / c>2 is preferred; when the device is used to realize the gas and slag collection and cold metal liquid collection, a flow channel close to b / c=1 is preferred; when the device is molded, it can be assembled and connected or cut and bonded with adhesive to form any length; when the device is molded, it is positioned and embedded into the casting mold at a specific position to form a communication between the mold cavity or riser and the outside air.

[0039] In the embodiment, the cross section of the Tesla valve unit is quadrangular or circular or elliptical or other shapes.

[0040] The casting mold 7 in the device for in-gassing and out-gassing of the casting mold of the application is a wet sand mold or a negative pressure dry sand mold or a gypsum mold or a resin sand mold.

[0041] Embodiment one:

[0042] In the wet sand mold, the device 5 is embedded into the mold, as shown in the figure, the parameters of the in-gassing and out-gassing device are X=45°, a=2 mm, b=5 mm, c=20 mm, d=20 mm, two products containing four Tesla valve units are bonded and assembled in the length direction, and the flow direction mark faces the outside of the mold. The application of the device ensures the effective exhaust of the mold cavity, and the debris scattered on the upper part of the mold before pouring will be collected in the semi-annular flow channel and will not directly enter the mold cavity. Figure 5

[0043] Embodiment two:

[0044] In the negative pressure dry sand mold, the device 5 is embedded into the mold with an anti-penetration treatment on the outer surface, as shown in the figure, the parameters of the in-gassing and out-gassing device are X=48°, a=3 mm, b=10 mm, c=20 mm, d=40 mm, five products containing four Tesla valve units are assembled in the length direction, and the flow direction mark faces the outside of the mold. The application of the device ensures the effective exhaust of the mold cavity, and the debris scattered on the upper part of the mold before pouring will be collected in the semi-annular flow channel and will not directly enter the mold cavity. Figure 5

[0045] Embodiment three: ​​

[0046] In the gypsum mold, the molding is embedded with the device 5 of the present application, as shown in Figure 5 The parameters of the air inlet and outlet device are: X = 50°, a = 2mm, b = 5mm, c = 20mm, d = 20mm, which is assembled in the length direction by two products containing 5 Tesla valve units, and the downstream sign faces the outside of the mold. The application of the device ensures the effective exhaust of the mold cavity, and at the same time, the sundries scattered on the upper part of the mold before pouring will gather in the semi-ring of the runner, and will not directly enter the mold cavity.

[0047] Example Four:

[0048] In the resin sand mold, the molding is embedded with the device 5 of the present application, which is in contact with the vented riser sleeve, as shown in Figure 6 The parameters of the air inlet and outlet device are: X = 38°, a = 2mm, b = 10mm, c = 10mm, d = 40mm, which is cut in the length direction from a standard product containing 50 Tesla units by a device containing 30 Tesla valve units, and the downstream sign faces the riser sleeve. The application of the device provides a smooth atmospheric pressure for the blind riser, and effectively slows down the early stage of riser solidification, which may bring a large amount of heat away when a large amount of gas is emitted from the vent hole, ensuring the effective feeding of the blind riser.

[0049] Example Five:

[0050] In the resin sand mold, the molding is embedded with the device 5 of the present application, as shown in Figure 5 The parameters of the air inlet and outlet device are: X = 50°, a = 5mm, b = 30mm, c = 30mm, d = 100mm, which is assembled in the length direction by two products containing 4 Tesla valve units, and the downstream sign faces the outside of the mold. The application of the device collects the low-temperature molten steel containing slag gas well before filling, and has a larger collection efficiency than the existing air outlet hole with the same contact area, and at the same time, the sundries scattered on the upper part of the mold before pouring will gather in the semi-ring of the runner, and will not directly enter the mold cavity.

[0051] Example Six:

[0052] In the resin sand mold, the molding is embedded with the device 5 of the present application, as shown in Figure 6As shown, the parameters of the gas inlet and outlet device are: X=55°, a=5mm, b=30mm, c=30mm, d=100mm, which is assembled by one product containing 4 Tesla valve units (the downstream sign faces the outside of the mold) and one product containing 4 Tesla valve units (the downstream sign faces the inside of the mold) in the length direction. The application of the device well collects the low-temperature molten steel containing slag gas in the early stage of mold filling, and has a larger collection efficiency than the existing gas outlet hole with the same contact area. At the same time, the debris scattered on the upper part of the mold before pouring will be gathered in the semi-ring of the runner, and will not directly enter the cavity. In addition, the device can also inhibit the phenomenon of metal liquid overflowing and spraying from the gas outlet hole in the late pouring stage, and can more stably serve as an observation sign of mold filling.

[0053] Finally, referring to Figure 1 As shown, the second aspect of the present application provides a manufacturing method for a mold gas inlet and outlet device, which is selected from sand core or clay forming and firing, and specifically includes the following steps:

[0054] Firstly, waste paper such as newspaper or impurities or corrugated paperboard is water-soaked and softened into pulp;

[0055] Secondly, the pulp is pressure-cast into a Tesla valve structure half-mold, i.e. an upper mold and a lower mold;

[0056] Thirdly, the mold in the second step is demolded and dried, and the upper and lower molds are bonded and assembled into a product;

[0057] Fourthly, the product in the third step is subjected to refractory treatment with saturated Na2SiO3 solution, and then dried and packaged after drying.

[0058] As can be understood by those skilled in the art, the device for mold gas inlet and outlet and the manufacturing method of the device of the present application include any combination of the parts in the specification. Limited by the length and in order to make the specification concise, these combinations are not introduced in detail one by one here, but after reading the specification, it is self-evident that any combination of the parts constituting the present application according to the specification.

Claims

1. A device for air inlet and outlet of a casting mold, comprising a casting mold (7) and a cavity (6) located in the casting mold (7), the cavity (6) including an air outlet duct or a riser sleeve (8), characterized in that: One or more Tesla valve structures are provided at the air outlet or the riser sleeve (8); the Tesla valve structure includes one or more Tesla valve units, and the Tesla valve unit is provided with a Tesla valve flow channel (1), which includes an inlet (2), an outlet (4) and a downstream direction mark (3); the Tesla valve unit includes a semicircle and a straight section connected to the semicircle at an X angle, and the value of the X angle is 48°; the wall thickness of the Tesla valve unit is a, and the value range of a is 1-10mm; the height of the Tesla valve unit is b, and the value range of b is 5-50mm; the width of the Tesla valve unit is c, and the value range of c is 5-50mm.

2. The device for air inlet and outlet of a mold according to claim 1, characterized in that: The arrow direction of the downstream direction mark (3) is toward the outside of the cavity or toward the riser.

3. The device for air inlet and outlet of a mold according to claim 1, characterized in that: The Tesla valve structure is made of fiber material.

4. The device for air inlet and outlet of a mold according to claim 1, wherein: The cross section of the Tesla valve unit is a quadrilateral.

5. The device for air inlet and outlet of a mold according to claim 1, characterized in that: The casting mold (7) is a green sand casting mold or a negative pressure dry sand casting mold or a gypsum casting mold or a resin sand casting mold.

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