Bearing hub casting mold and casting method

Abstract

A bearing hub casting mold and casting method. The mold comprises part models, risers and a sprue bush, wherein each riser is connected to the top of the part model; the sprue bush is connected to each riser by means of a horizontal runner; and the part models, the risers and the sprue bush are sequentially distributed from bottom to top in a vertical direction. In the bearing hub casting mold, by means of the provision of the riser at the top of each part model, a bearing hub is cast-molded by means of a top-pouring process, and after pouring, there is no isolated liquid-phase region during a solidification process of a casting, and the casting has no shrinkage porosity defect, thereby improving the quality of a bearing hub part.

Description

Bearing hub casting mold and casting method Technical Field

[0001] The invention relates to the field of lost foam casting technology, and in particular to a bearing hub casting mold and a casting method. Background Art

[0002] Lost foam casting is a new casting method that combines paraffin wax or foam models with similar size and shape to the casting into a model cluster, brushes refractory paint and dries it, buries it in dry quartz sand and vibrates it to shape it, and pours it under negative pressure to vaporize the model. Liquid metal occupies the position of the model, and forms the casting after solidification and cooling. Technical issues

[0003] A bearing hub part as shown in FIG1 is usually cast using a lost foam casting process using a semi-bottom injection mold as shown in FIG2 . This casting method will produce an isolated liquid phase area during the solidification process, resulting in shrinkage defects in the part. Technical Solutions

[0004] Based on the above description, the present invention provides a bearing hub casting mold and casting method to solve the problem that the casting method in the related art will produce isolated liquid phase areas during the solidification process, resulting in shrinkage defects in the parts.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] In a first aspect, the present application provides a bearing hub casting mold, the technical solution adopted is as follows:

[0007] A bearing hub casting mold, comprising:

[0008] Parts model;

[0009] a riser connected to the top of the part model;

[0010] a pouring cup connected to the riser via a horizontal runner;

[0011] The part model, the riser and the pouring cup are distributed in sequence from bottom to top in the vertical direction.

[0012] On the basis of the above technical solution, the present invention can also be improved as follows.

[0013] Preferably, the bottom of the riser is connected to the part model, and the runner is connected to the top of the riser.

[0014] Preferably, the bottom of the pouring cup is connected to the runner via a vertical sprue.

[0015] Preferably, a one-mold four-piece structure is adopted.

[0016] In a second aspect, the present application provides a bearing hub casting method, using the bearing hub casting mold as described above, comprising:

[0017] Bonding pouring system, the mold adopts a one-mold four-piece structure, the top of the four part models are connected to a riser, and the four risers are connected to a pouring cup through a horizontal runner;

[0018] The coating, drying, shaping, melting and pouring are carried out in sequence to obtain the bearing hub parts.

[0019] Preferably, the bonding and pouring system includes pre-curing of the mold material and molding of the mold parts.

[0020] Preferably, during the coating and drying, the coating thickness after drying is 1.2-1.5 mm.

[0021] Preferably, during the smelting and pouring, the casting material includes, by mass percentage: C3.5-3.8%, Si2.3-2.5%, Mn0.45-0.55%, P≤0.035%, S≤0.035%, Mg0.035-0.055%, Cu0.4-0.5%, Sn0.015-0.02%, Sb0.015-0.020%, and the balance is Fe.

[0022] Preferably, during the smelting and pouring, the temperature of the liquid casting material out of the furnace is 1550-1560°C, the first box pouring temperature is 1470-1480°C, and the last box pouring temperature is ≥1420°C.

[0023] Preferably, during the smelting and pouring, the pouring negative pressure is -0.045-0.055 MPa, and the pressure is maintained for 12-15 minutes after the pouring is completed. Beneficial effects

[0024] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0025] The bearing hub casting mold of the present application sets a riser on the top of the part model, so that the bearing hub is cast by the top injection process. After pouring, there is no isolated liquid phase area during the solidification process of the casting, and the casting has no shrinkage defects, which can improve the quality of the bearing hub part. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a background technology diagram of this application;

[0027] FIG2 is a schematic structural diagram of a bearing hub casting mold provided in an embodiment of the present application.

[0028] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0029] 1. Part model; 2. Riser; 3. Runner; 4. Sprue cup; 5. Main runner; 6. Sprue. Modes for Carrying Out the Invention

[0030] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0032] It will be understood that spatial relational terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It will be understood that in addition to the orientations shown in the figures, spatial relational terms also include different orientations of the device in use and operation. For example, if the device in the drawings is turned over, the element or feature described as "under" or "beneath" or "beneath" the other elements will be oriented as "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include alternative orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0033] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediate element. In the following embodiments, "connection" should be understood as "electrical connection", "communication connection", etc., if the connected circuits, modules, units, etc. can transmit electrical signals or data to each other.

[0034] When used herein, the singular forms "a", "an", and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

[0035] As shown in Figure 2, an embodiment of the present application provides a bearing hub casting mold, which includes a part model 1, a riser 2 and a pouring cup 4. The riser 2 is connected to the top of the part model 1, and the pouring cup 4 is connected to the riser through a horizontal cross runner 3. As shown in Figure 2, the part model 1, the riser 2 and the pouring cup 4 are distributed in sequence from bottom to top in the vertical direction.

[0036] Specifically, the mold can be designed as one mold with multiple parts according to actual needs. In this embodiment, one mold with four parts is used for illustration, and the four part models 1 are distributed in a rectangular shape on a horizontal plane.

[0037] As shown in Figure 2 , the upper portion of the riser 2 is cylindrical, with its axis vertical during pouring. The lower portion of the riser 2 gradually decreases in diameter from top to bottom until it connects to the part model 1. The runner 3 is horizontally arranged and connected to the top of the riser 2. In this embodiment, the bottom of the pouring cup 4 is connected to a horizontal main runner 5. The runners 3 of two adjacent part models 1 are interconnected and connected to one end of the main runner 5, and the runners 3 of the other two part models 1 are interconnected and connected to the other end of the main runner 5.

[0038] 2 , further, a sprue 6 with a vertical axis is provided at the bottom of the pouring cup 4 . The sprue 6 is connected to the middle of the main pouring channel 5 . The diameter of the pouring cup 4 gradually decreases from top to bottom.

[0039] An embodiment of the present application also provides a bearing hub casting method, which uses the bearing hub casting mold as described above, including a bonding pouring system, coating and drying, molding and melting and pouring.

[0040] Before bonding the pouring system, the mold material is pre-cured and the mold parts are formed.

[0041] The pre-expanding and aging equipment adopts a semi-automatic intermittent pre-expanding machine.

[0042] Among them, the pre-expansion parameters are: pre-expansion pressure 0.02-0.04Mpa, pre-expansion temperature 95-102°C, heating time 33-36s, and bulk density 20g / L-22g / L.

[0043] Curing parameters: When the indoor temperature is ≤10℃: the curing time is ≥72h; when the indoor temperature is 10-25℃: the curing time is ≥48h; when the indoor temperature is ≥25℃: the curing time is ≥36h.

[0044] After the pre-expansion and maturation of the material is completed, the specific molding process and parameters of the various components of the molding mold are: filling - preheating 1 (6s) - clamping (3s) - preheating 2 (6s) - moving / fixing mold heating (6 times / 6 times) - main heating A / B (10s) - insulation (5s) - exhaust (5s) - cooling (140s).

[0045] When bonding the pouring system, the mold adopts a one-mold four-piece structure, the tops of the four part models 1 are respectively connected to a riser 2, and the four risers 2 are respectively connected to a pouring cup 4 through a runner 3; specifically, the bearing hub casting mold as described above is used.

[0046] Based on the molds in the related art and the mold of this application, modeling was performed and comparisons of filling simulation, filling temperature simulation, and solidification simulation were performed, followed by analysis of shrinkage and shrinkage simulation results. During the filling process, the filling time was 19S, and there was no poor filling between the technical solution of this application and the solution in the related art, with no significant difference. From the filling temperature simulation, the temperature field dropped to around 80°C during the filling process, and the temperature distribution was relatively uniform. During the solidification process, the solution in the related art had an isolated liquid phase area, while the solution in the present application had no isolated liquid phase area. The shrinkage simulation results showed that the solution in the related art had shrinkage defects, while the solution in the present application had no shrinkage defects. Therefore, the technical solution of this application can solve the problem of shrinkage defects gradually existing in the bearing hub.

[0047] After the bonding and pouring system is completed, it is coated and dried. The specific parameters are as follows:

[0048] Coating ratio: water: composite adhesive: aggregate (100% bauxite) = 7:1:10.

[0049] Mixing time: binder ≥60min, aggregate ≥90min.

[0050] Pomei degree: 66%-72%.

[0051] Drying parameters: drying room temperature and humidity: temperature 35-55℃, humidity: 10-35%; drying time: first pass 11h, second pass 13h, third pass 15h.

[0052] Coating after drying: 1.2-1.5mm.

[0053] Then the box-embedding molding process is carried out. The specific steps are as follows:

[0054] Add bottom sand and place the model: fill the bottom sand to a height of 300-350mm, vibrate for 10s, and the vibration frequency is 43Hz. Scrape the bottom sand into a flat surface, place one set of models in a box, and ensure that the model is in the center of the sand box.

[0055] Sand filling and vibration: first use a flexible manual sand adding device to add sand to a certain height, take out the fixed wooden strips, plastic ropes and foam blocks to ensure that there are no debris, vibrate for 30 seconds, vibration frequency: 48HZ; fill sand evenly until it is flush with the model sprue 6, scrape the sand inside and outside, and vibrate for 40 seconds, vibration frequency: 48HZ.

[0056] Cover with plastic film and add top sand: Cover with plastic film, then fill with top sand with a thickness greater than 50mm, compact the plastic film to ensure that the plane of the pouring cup 4 is 20mm higher than the sand plane, then cut the plastic film on the top surface of the pouring cup 4 to expose it and ensure that there is no molding sand on the top surface of the pouring cup 4, and scrape the sand surface flat.

[0057] After the molding is completed, smelting and pouring begins. The casting materials include, by mass percentage: carbon C3.5-3.8%, silicon Si2.3-2.5%, manganese Mn0.45-0.55%, phosphorus P≤0.035%, sulfur S≤0.035%, magnesium Mg0.035-0.055%, copper Cu0.4-0.5%, tin Sn0.015-0.02%, antimony Sb0.015-0.020%, and the balance is iron Fe.

[0058] The temperature of liquid casting material out of the furnace is 1550-1560℃, the pouring temperature of the first box is 1470-1480℃, and the pouring temperature of the last box is ≥1420℃.

[0059] The negative pressure during pouring is -0.045--0.055MPa, and the pressure is maintained for 12-15 minutes after pouring.

[0060] In one embodiment, the casting material includes, by mass percentage, carbon C3.5%, silicon Si2.3%, manganese Mn0.45%, phosphorus P≤0.035%, sulfur S≤0.035%, magnesium Mg0.035%, copper Cu0.4%, tin Sn0.015%, antimony Sb0.015%, and the balance is iron Fe.

[0061] The temperature of liquid casting material out of the furnace is 1550-1560℃, the pouring temperature of the first box is 1470-1480℃, and the pouring temperature of the last box is ≥1420℃.

[0062] The negative pressure during pouring is -0.045--0.055MPa, and the pressure is maintained for 12-15 minutes after pouring.

[0063] In another embodiment,

[0064] The casting materials include, by mass percentage, carbon C3.8%, silicon Si2.5%, manganese Mn0.55%, phosphorus P≤0.035%, sulfur S≤0.035%, magnesium Mg0.055%, copper Cu0.5%, tin Sn0.02%, antimony Sb0.020%, and the balance is iron Fe.

[0065] The temperature of liquid casting material out of the furnace is 1550-1560℃, the pouring temperature of the first box is 1470-1480℃, and the pouring temperature of the last box is ≥1420℃. The negative pressure during pouring is -0.045-0.055MPa, and the pressure is maintained for 12-15 minutes after pouring.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A bearing hub casting mold, characterized in that Comprising: Part model (1); Riser (2), which is connected to the top of the part model (1); Sprue cup (4), which is connected to the riser (2) through a horizontal runner (3); The part model (1), the riser (2) and the sprue cup (4) are arranged in sequence from bottom to top in the vertical direction.

2. The bearing hub casting mold according to claim 1, wherein: The bottom of the riser (2) is connected to the part model (1), and the runner (3) is connected to the top of the riser (2).

3. The bearing hub casting mold according to claim 1, wherein: The bottom of the sprue cup (4) is connected to the runner (3) through a vertical downsprue (6).

4. The bearing hub casting mold according to claim 3, characterized in that: Adopting a structure of four parts in one mold.

5. A method for casting a bearing hub, characterized in that, Adopting the bearing hub casting mold according to any one of claims 1-4, comprising: Bonding gating system, the mold adopts a structure of four parts in one mold, four part models (1) are respectively connected with a riser (2) at the top, and the four risers (2) are respectively connected to a sprue cup (4) through runners (3); Carry out coating drying, molding and melting pouring in sequence to obtain bearing hub parts.

6. The bearing hub casting method according to claim 1, characterized in that: Before the bonding gating system, it includes pre-expansion and ripening of mold materials and molding of mold parts.

7. The bearing hub casting method according to claim 5, characterized in that: During the coating drying, the thickness of the dried coating is 1.2-1.5 mm.

8. The bearing hub casting method according to claim 5, characterized in that, During the melting pouring, the casting material by mass percentage includes: C 3.5-3.8%, Si 2.3-2.5%, Mn 0.45-0.55%, P≤0.035%, S≤0.035%, Mg 0.035-0.055%, Cu 0.4-0.5%, Sn 0.015-0.02%, Sb 0.015-0.020%, and the balance is Fe.

9. The bearing hub casting method according to claim 5, characterized in that: During the melting pouring, the tapping temperature of the liquid casting material is 1550-1560 °C, the pouring temperature of the first box is 1470-1480 °C, and the pouring temperature of the last box is ≥1420 °C.

10. The bearing hub casting method according to claim 5, characterized in that: During the melting pouring, the pouring negative pressure is -0.045-0.055 MPa, and the pressure is maintained for 12-15 min after pouring.

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