A static plate isolation ring integrated component die-casting mold and die-casting method
By designing the integrated components of the static sheet isolation ring and optimizing the blade structure, combined with the design of the die-casting mold, the reflux and strength problems between the static sheet and the isolation ring in the magnetic levitation molecular pump are solved, and the components are efficiently formed and Deformation control.
Patent Information
- Application Number
- CN202411474280.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2044-10-22
AI Technical Summary
The current magnetic levitation molecular pump has a reflux phenomenon, resulting in a reduction in the pumping speed and compression ratio, insufficient strength of the static plate, susceptible to external gas impact, and it is difficult to design and deformation control of die casting molds in vacuum products. .
Design a static sheet isolation ring integrated assembly, through the internal and external fixing rings and the isolation ring, the blade structure is optimized, and die-casting molds and methods are used to realize component molding, including specific structures and matching relationships of upper and lower molds. The liquid aluminum flows from the central hole and is formed sequentially through the internal fixing ring, blade and external fixing ring, and finally to the overflow chamber and exhaust tank.
The reflux phenomenon is effectively avoided, the balance of pumping efficiency and compression ratio is improved, the quality and performance of vacuum products are ensured, deformation control problems are solved, and efficient molding of integrated static sheet isolation ring components is realized.
Smart Images
Figure CN118976880B_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of magnetic levitation molecular pumps, and more specifically, to a die-casting mold and a die-casting method for an integrated static plate isolation ring assembly. Background Art
[0002] In the prior art (https: / / www.kyky.com.cn / content / details96_550.html), the static plate and isolation ring of the magnetic levitation molecular pump are separated.
[0003] For this design, the R&D team found that molecular pumps with a diameter of DN160~DN400 have the following problems:
[0004] (1) Backflow phenomenon: There is a backflow phenomenon between the static plate and the isolation ring, which causes the key performance of the molecular pump, such as the pumping speed and compression ratio, to decrease.
[0005] (2) The static piece has low strength and is greatly affected by external gas, which can easily produce resonance shock.
[0006] In response to the above problems, Figure 1 As shown in the figure, the R&D team applied for "an integrated assembly of a static plate isolation ring of a large-caliber molecular pump and a molecular pump" on the same day and proposed several new design concepts:
[0007] Concept 1: Avoid backflow. Specifically, in a large-caliber molecular pump, the static plate isolation ring integrated assembly has an internal fixed ring, an external fixed ring, and an isolation ring that are concentrically arranged and connected into an integrated structure, with one end of the m blades fixed to the internal fixed ring and the other end fixed to the external fixed ring and the isolation ring (i.e., the upper part of the outer part of the blade is fixed to the external fixed ring, and the lower part of the outer part of the blade is fixed to the isolation ring).
[0008] Concept 2: Improve the extraction efficiency. This concept is achieved through the improvement of the blade. The blade includes: an upper surface, a lower surface, and a vertical surface; the upper surface includes: a first horizontal surface and a second upper inclined surface; the lower surface includes: a third lower inclined surface and a fourth horizontal surface; the first horizontal surface is adjacent to the second upper inclined surface and the third lower inclined surface respectively; the fourth horizontal surface is adjacent to the third lower inclined surface and the vertical surface respectively; the vertical surface is adjacent to the fourth horizontal surface and the second upper inclined surface respectively; the second upper inclined surface is parallel to the third lower inclined surface.
[0009] Concept 3: Achieve a balance between the two key performances of compression ratio and exhaust efficiency. This concept is achieved by "γ in the range of [0.95, 1.0]", where γ is explained as follows: "Let the radius of the outer side of the inner fixing ring be r0, and the radius of the inner side of the outer fixing ring be r1, then the horizontal cross-sectional area of the ring between the inner fixing ring and the outer fixing ring is π (r1 2 -r02 ); The projection area of the upper surface of m blades on the horizontal plane is γπ (r1 2 -r0 2 )".
[0010] Concept 4: Select a suitable reverse flow angle. When the reverse flow angle increases, the Ho coefficient of the blade row shows an increasing trend, that is, the pumping speed increases and the compression ratio component decreases. For the reverse flow angle δ, it is related to the inclination angles β and γ between the second upper slope and the first horizontal plane. When β is between 10° and 80° (preferably 16°), γ is between 0.95 and 1.0, and δ is generally between 82.8 and 115.5°.
[0011] For the above-mentioned new stator isolation ring integrated assembly, die casting is a feasible process. However, due to its application to vacuum products, its difficulties are:
[0012] (1) How to design a die-casting mold.
[0013] (2) How to control product deformation and eliminate the impact of deformation on parts. Summary of the invention
[0014] The purpose of the present application is to provide a die-casting mold for an integrated static plate isolation ring assembly in view of the deficiencies of the above-mentioned prior art.
[0015] Another object of the present application is to provide a die-casting method for a static plate isolation ring integrated assembly die-casting mold.
[0016] The technical solution of this application is as follows:
[0017] A static plate isolation ring integrated component die-casting mold, comprising: an upper mold and a lower mold;
[0018] The upper mold comprises: an upper mold body, and insert columns are arranged at the four corners of the lower surface of the upper mold body; a casting hole, an inner gate upper mold, an internal fixed ring upper mold groove, a blade upper mold, an external fixed ring and isolation ring upper mold, and an overflow cavity upper mold are arranged in sequence from the inside to the outside in the middle of the lower surface of the upper mold body; a plurality of exhaust groove upper molds are also arranged on the lower surface of the upper mold body;
[0019] The lower mold comprises: a lower mold body, and insertion holes are arranged at the four corners of the lower mold body; a frustum, an inner gate lower mold, an internal fixed ring lower mold groove, a blade lower mold, an external fixed ring and isolation ring lower mold, and an overflow cavity lower mold are arranged in sequence from the inside to the outside in the middle of the upper surface of the lower mold body; an exhaust pipeline groove and an exhaust groove lower mold are also arranged on the outer side of the overflow cavity lower mold;
[0020] The matching relationship between the upper die and the lower die is:
[0021] The four insertion posts can be inserted into the corresponding four insertion holes;
[0022] The pouring hole corresponds to the truncated cone, and there is a gap between the pouring hole and the truncated cone to form a direct pouring gate;
[0023] There is a gap between the inner gate upper mold and the inner gate lower mold to form an inner gate;
[0024] An internal fixing ring cavity is formed between the internal fixing ring upper die groove and the internal fixing ring lower die groove;
[0025] The blade upper mold and the blade lower mold form a blade cavity, and the blade cavity is used for forming the blade;
[0026] The upper die of the external fixing ring and the isolating ring and the lower die of the external fixing ring and the isolating ring form an external fixing ring and the isolating ring cavity, and the external fixing ring and the isolating ring cavity is used for molding the external fixing ring and the isolating ring;
[0027] The overflow cavity upper mold and the overflow cavity lower mold are used to form the overflow cavity;
[0028] The exhaust groove upper die and the exhaust groove lower die are used to form the exhaust groove;
[0029] The exhaust pipe groove is used to connect the overflow chamber and the exhaust groove.
[0030] Furthermore, the formed blade structure is as follows: it includes: an upper surface, a lower surface, and a vertical surface; the upper surface includes: a first horizontal plane and a second upper inclined plane; the lower surface includes: a third lower inclined plane and a fourth horizontal plane; the first horizontal plane is adjacent to the second upper inclined plane and the third lower inclined plane, respectively; the fourth horizontal plane is adjacent to the third lower inclined plane and the vertical plane, respectively; the vertical plane is adjacent to the fourth horizontal plane and the second upper inclined plane, respectively; the second upper inclined plane is parallel to the third lower inclined plane.
[0031] Furthermore, the structure of the molded static blade isolation ring integrated assembly satisfies: one end of the blade is fixed to the internal fixing ring, and the other end is fixed to the external fixing ring and the isolation ring;
[0032] The outer upper part of the blade is fixed to the outer fixing ring, and the outer lower part of the blade is fixed to the isolation ring.
[0033] Furthermore, the radius of the outer side of the inner fixing ring is expressed as r0, and the radius of the inner side of the outer fixing ring is expressed as r1. Then the horizontal cross-sectional area of the ring between the inner fixing ring and the outer fixing ring is π (r1 2 -r0 2 ); The projection area of the upper surface of all blades on the horizontal plane is γπ (r1 2 -r0 2 ), γ is in the range of [0.95, 1.0].
[0034] Furthermore, the number of the exhaust slots is 4.
[0035] Furthermore, there are multiple overflow chambers.
[0036] Furthermore, the number of the overflow chambers is the same as the number of the exhaust grooves.
[0037] Furthermore, the number of the overflow chambers is 4.
[0038] A die-casting method for a static plate isolation ring integrated component die-casting mold, which includes the following steps: aluminum liquid flows in from a direct pouring gate, passes through an inner pouring gate, and then passes through an internal fixed ring cavity, a blade cavity, an external fixed ring and an isolation ring cavity in sequence, and then flows to an overflow cavity and finally to an exhaust groove; after molding, excess thin sheets are separated from the static plate isolation ring integrated component.
[0039] The beneficial effects of this application are:
[0040] The static plate isolation ring integrated assembly of the present application is used for vacuum products, and the mold design adopts a one-in-four-out method, that is, "inflow from the center hole and outflow from the surroundings" for die casting. Specifically, the aluminum liquid flows in from the direct pouring port, passes through the ingate, and is then formed in the order of "internal fixed ring cavity-blade-external fixed ring and isolation ring", and then flows to the overflow cavity and finally to the exhaust groove; after forming, the excess thin sheets (such as the thin sheets after the ingate is formed and the thin sheets after the overflow cavity is formed) are separated from the static plate isolation ring integrated assembly. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The present application is further described in detail below in conjunction with the embodiments in the accompanying drawings, but does not constitute any limitation to the present application.
[0042] Figure 1 It is a structural design drawing of the static plate isolation ring integrated component.
[0043] Figure 2 It is a schematic diagram of the three-dimensional structural design of the upper mold.
[0044] Figure 3 It is a schematic diagram of the three-dimensional structural design of the upper mold from another perspective.
[0045] Figure 4 It is a schematic diagram of the three-dimensional structural design of the upper mold from other perspectives.
[0046] Figure 5 This is a bottom view of the upper mold.
[0047] Figure 6 It is a schematic diagram of the three-dimensional structural design of the lower mold.
[0048] Figure 7 It is a side elevation diagram of the lower mold.
[0049] Figure 8 It is a schematic diagram of the surface structure of the lower mold.
[0050] The reference numerals are as follows:
[0051] Upper mold 100, upper mold body 101, insert column 102, casting hole 103, inner gate upper mold 104, internal fixed ring upper mold groove 105, blade upper mold 106, external fixed ring and isolation ring upper mold 107, overflow cavity upper mold 108, exhaust groove upper mold 110;
[0052] The lower mold 200, the lower mold body 201, the insertion hole 202, the frustum 203, the inner gate lower mold 204, the internal fixed ring lower mold groove 205, the blade lower mold 206, the external fixed ring and isolation ring lower mold 207, the overflow cavity lower mold 208, the exhaust pipe groove 209, and the exhaust groove lower mold 210. DETAILED DESCRIPTION
[0053] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.
[0054] <Example 1: Die-casting mold for integrated static plate isolation ring assembly>
[0055] The objects to be produced by the mold of this application are as follows Figure 1 As shown, it is a static plate isolation ring integrated assembly newly designed by the research and development team, and its structure has been discussed in the background technology.
[0056] The die-casting mold for the static plate isolation ring integrated component includes: an upper mold 100 and a lower mold 200.
[0057] Figure 2 , Figure 3 , Figure 4 , Figure 5 The structure of the upper mold 100 is schematically shown. The upper mold 100 comprises: an upper mold body 101, and insert columns 102 are arranged at four corners of the lower surface of the upper mold body 101;
[0058] In the middle of the upper mold body, there are arranged in order from the inside to the outside: a casting hole 103, an inner gate upper mold 104, an internal fixed ring upper mold groove 105, a blade upper mold 106, an external fixed ring and isolation ring upper mold 107, and an overflow cavity upper mold 108; four exhaust groove upper molds 110 are also arranged on the lower surface of the upper mold body.
[0059] Figure 6 , Figure 7 , Figure 8 The structure of the lower mold 200 is schematically shown. The lower mold 200 comprises: a lower mold body 201, and insertion holes 202 are arranged at four corners of the lower mold body 201;
[0060] The middle part of the lower mold body 201 is provided with: a truncated cone 203 (i.e., a truncated cone), an inner gate lower mold 204, an inner fixed ring lower mold groove 205, a blade lower mold 206, an outer fixed ring and isolation ring lower mold 207, and an overflow cavity lower mold 208 in order from the inside to the outside;
[0061] An exhaust pipe groove 209 and an exhaust groove lower mold 210 are also provided on the outer side of the overflow cavity lower mold 208 .
[0062] The matching relationship between the upper die 100 and the lower die 200 is:
[0063] a. Four insertion columns 102 can be inserted into the corresponding four insertion holes 202, and the positions of the upper mold 100 and the lower mold 200 are matched by the insertion columns 102 and the insertion holes 202;
[0064] b. The pouring hole 103 corresponds to the truncated cone 203, and there is a gap between the pouring hole 103 and the truncated cone 203, forming a direct pouring gate;
[0065] c. There is a gap between the inner gate upper mold 104 and the inner gate lower mold 204, forming an inner gate;
[0066] d. An internal fixing ring cavity is formed between the internal fixing ring upper die groove 105 and the internal fixing ring lower die groove 205;
[0067] e. The blade upper mold 106 and the blade lower mold 206 are used for forming the blade;
[0068] f, the upper die 107 of the external fixing ring and the isolating ring and the lower die 207 of the external fixing ring and the isolating ring are used for molding the external fixing ring and the isolating ring;
[0069] g, the overflow cavity upper mold 108 and the overflow cavity lower mold 208 are used to form the overflow cavity;
[0070] h, the exhaust groove upper mold 110 and the exhaust groove lower mold 210 are used to form the exhaust groove;
[0071] i. The exhaust pipe groove 209 is used to connect the overflow cavity and the exhaust groove;
[0072] j. The working process of the die-casting mold for the static plate isolation ring integrated assembly of the present application is: the aluminum liquid flows in from the direct gate, passes through the inner gate, and is then formed in the order of "internal fixed ring cavity - blades - external fixed ring and isolation ring", and then flows to the overflow cavity, and finally to the exhaust groove; after forming, the excess thin sheets (such as the thin sheets after the inner gate is formed, and the thin sheets after the overflow cavity is formed) are separated from the static plate isolation ring integrated assembly.
[0073] <Example 2: Die-casting process for integrated static plate isolation ring assembly>
[0074] Static blade isolation ring integrated assembly: the thickness of the blade is 1.4mm, and the thickness of the isolation ring is 5mm.
[0075] In general casting, due to factors such as material viscosity, temperature and cooling time, casting defects such as slag inclusion and pores may occur during the casting process, resulting in poor casting. Unlike conventional die-casting products, the product of this application is used in a magnetic levitation molecular pump, which is a vacuum product. Therefore, in addition to controlling key parameters such as pores, it is also necessary to control product deformation and eliminate the impact of deformation on parts.
[0076] Ingate cross-sectional area A (cm 2 )satisfy:
[0077] A = G / (ρVt);
[0078] Where G is the mass of the molten metal passing through the gate (g); ρ is the density of the molten metal (g / cm 3 ); V represents the filling speed (cm / s), and t represents the filling time (s).
[0079] Influencing factor 1: Filling speed V, V has a great influence on the quality of cast products:
[0080] (1) Too low a speed will cause surface quality defects;
[0081] (2) Too high a speed will cause pores or defects inside the casting.
[0082] According to the relationship diagram between the wall thickness of general aluminum castings and the gate speed, when the thickness of the blade is 1.4mm, the speed is selected to be 44-53m / s. Considering the actual working conditions, the test is carried out in this range and V is selected to be 50m / s.
[0083] Influencing factor 2: Filling time t, t has a great influence on the quality of cast products:
[0084] (1) Filling time that is too short will result in the gas not being completely discharged;
[0085] (2) Filling time that is too long will result in poor product molding effect.
[0086] According to the relationship diagram between the wall thickness of general aluminum castings and the filling time t, t is selected to be 0.014~0.020s.
[0087] Based on this, we can determine A to be:
[0088] A=G / (ρVt)=1100 / (2.4×50×0.020)=458mm 2 .
[0089] According to the above calculation, the area of the inner gate is 460mm 2 The specific adjustment will be made after subsequent testing.
[0090] Influencing factor three: choice of press.
[0091] After many rounds of testing, it was determined that the mold adopts the 1-in 4-out method, that is, the flow in from the center hole and out from the surroundings. The press pressure is 800 tons and the material is ADC12.
[0092] The above-mentioned embodiments are preferred implementation modes of the present application and are only used to facilitate the explanation of the present application. They are not intended to limit the present application in any form. Any person with ordinary knowledge in the relevant technical field, if they do not depart from the scope of the technical features of the present application, can make equivalent embodiments by making partial changes or modifications to the technical contents disclosed in the present application and do not depart from the technical features of the present application. All of these still fall within the scope of the technical features of the present application.
Claims
1. A die-casting mold for an integrated static plate isolation ring assembly, characterized in that: The static blade isolation ring integrated assembly comprises: an inner fixing ring, an outer fixing ring, and an isolation ring; the inner fixing ring, the outer fixing ring, and the isolation ring are concentrically arranged and connected into an integrated structure, one end of the m blades is fixed to the inner fixing ring, and the other end is fixed to the outer fixing ring and the isolation ring; the outer upper part of the blade is fixed to the outer fixing ring, and the outer lower part of the blade is fixed to the isolation ring; Including: upper die, lower die; The upper mold comprises: an upper mold body, and insert columns are arranged at the four corners of the lower surface of the upper mold body; a casting hole, an inner gate upper mold, an internal fixed ring upper mold groove, a blade upper mold, an external fixed ring and isolation ring upper mold, and an overflow cavity upper mold are arranged in sequence from the inside to the outside in the middle of the lower surface of the upper mold body; a plurality of exhaust groove upper molds are also arranged on the lower surface of the upper mold body; The lower mold comprises: a lower mold body, and insertion holes are arranged at the four corners of the lower mold body; a frustum, an inner gate lower mold, an internal fixed ring lower mold groove, a blade lower mold, an external fixed ring and isolation ring lower mold, and an overflow cavity lower mold are arranged in sequence from the inside to the outside in the middle of the upper surface of the lower mold body; an exhaust pipeline groove and an exhaust groove lower mold are also arranged on the outer side of the overflow cavity lower mold; The matching relationship between the upper mold and the lower mold is: the four insertion columns can be inserted into the corresponding four insertion holes; the casting holes correspond to the truncated cone, and there is a gap between the casting holes and the truncated cone to form a straight gate; there is a gap between the ingate upper mold and the ingate lower mold to form an ingate; An internal fixed ring cavity is formed between the internal fixed ring upper die groove and the internal fixed ring lower die groove; the blade upper die and the blade lower die form a blade cavity, and the blade cavity is used for molding the blade; the external fixed ring and isolation ring upper die and the external fixed ring and isolation ring lower die form an external fixed ring and isolation ring cavity, and the external fixed ring and isolation ring cavity are used for molding the external fixed ring and isolation ring; the overflow cavity upper die and the overflow cavity lower die are used to form the overflow cavity; the exhaust groove upper die and the exhaust groove lower die are used to form the exhaust groove; the exhaust pipeline groove is used to connect the overflow cavity and the exhaust groove; The overflow cavity is in communication with the external fixing ring and the isolation ring cavity; The structure of the formed blade is as follows: it includes: an upper surface, a lower surface, and a vertical surface; the upper surface includes: a first horizontal surface and a second upper inclined surface; the lower surface includes: a third lower inclined surface and a fourth horizontal surface; the first horizontal surface is adjacent to the second upper inclined surface and the third lower inclined surface respectively; the fourth horizontal surface is adjacent to the third lower inclined surface and the vertical surface respectively; the vertical surface is adjacent to the fourth horizontal surface and the second upper inclined surface respectively; the second upper inclined surface is parallel to the third lower inclined surface; The radius of the outer side of the inner fixing ring is expressed as r0, and the radius of the inner side of the outer fixing ring is expressed as r1. Then the horizontal cross-sectional area of the ring between the inner fixing ring and the outer fixing ring is π (r1 2 -r0 2 ); The projection area of the upper surface of all blades on the horizontal plane is γπ (r1 2 -r0 2 ), γ is in the range of [0.95, 1.0].
2. The die-casting mold for the integrated static plate isolation ring assembly according to claim 1, characterized in that: The number of the exhaust slots is 4.
3. The die-casting mold for the integrated static plate isolation ring assembly according to claim 1, characterized in that: The number of the overflow chambers is multiple.
4. The die-casting mold for the integrated static plate isolation ring assembly according to claim 3, characterized in that: The number of the overflow chambers is the same as the number of the exhaust grooves.
5. The die-casting mold for the integrated static plate isolation ring assembly according to claim 4, characterized in that: The number of the overflow chambers is 4.
6. A die-casting method for a static plate isolation ring integrated assembly die-casting mold according to any one of claims 1 to 5, characterized in that: The process includes the following steps: aluminum liquid flows in from the sprue, passes through the ingate, and then sequentially passes through the internal fixing ring cavity, the blade cavity, the external fixing ring and the isolation ring cavity, and then flows to the overflow cavity and finally to the exhaust groove; After forming, the redundant thin sheet is separated from the integrated assembly of the static sheet isolation ring; The thickness of the blade of the static plate isolation ring integrated assembly is 1.4 mm, and the thickness of the isolation ring is 5 mm; The filling speed V is 50 m / s; Filling time t is 0.014s~0.020s; The cross-sectional area of the ingate A is: A=G / (ρVt); Among them, G is the mass of the metal solution passing through the gate; ρ is the density of the metal solution; V represents the filling speed, and t is the filling time.