Pouring system structure and mold for flywheel casing low-pressure metal mold casting

Abstract

The invention relates to a pouring system structure and a mold for low-pressure metal mold casting of a flywheel casing. The ingate is arranged at a middle shaft hole flange of the flywheel casing; the thickness of the ingate is consistent with that of the casting; the sprue is directly connected with the ingate; the riser is arranged at the upper part of the casting; an overflow structure is arranged at the far end of the molten metal filling mold; the mold filling direction of the molten metal is the opposite direction of the gravity; the sprue is formed by a riser tube, and the lower end is connected with the riser port; molten metal enters the casting through the riser tube, the straight pouring gate and the inner pouring gate; the pouring system disclosed by the invention is high in utilization rate and high in process yield; the pertinence of the riser and overflow design is high, the product quality can be well guaranteed, and the product percent of pass is increased; the pouring system is convenient to remove, and cleaning investment is saved.

Description

Technical Field

[0001] The invention belongs to the technical field of casting, and relates to a pouring system structure and a mold for low-pressure metal mold casting of a flywheel housing. Background Art

[0002] Low-pressure casting technology is a special casting process with small machining allowance and precise forming. By applying a certain pressure on the metal liquid surface, the metal liquid overcomes gravity and enters the mold cavity, so that the liquid can fill the mold smoothly and without turbulence. After the mold cavity is filled, the pressure is quickly increased to make the casting crystallize and solidify under pressure, thereby obtaining a densely structured casting.

[0003] The flywheel housing is a very important load-bearing component in the automobile engine system. The flywheel housing product structure is shown in Figure 1a , Figure 1b . It is installed between the gearbox and the engine, connecting the gearbox and the engine, with a flywheel installed inside and connected to the oil pan, crankcase and starter outside. The flywheel housing parts have a relatively complex structure and are large in size. The shape is similar to a basin, and it is a large aluminum alloy thin-walled part. At present, most aluminum flywheel housings are cast using a low-pressure casting process, with overlapping runners introduced from the end face. The pouring system required by this process is dispersed and has a complex structure. Many pouring and riser are set at the hot spots of the casting to compensate for the dispersed hot spots. This results in a low process yield, a large workload of pouring / riser removal, and is more difficult. There are many product quality defects and great production difficulties. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the above problems existing in the prior art and provide a pouring system structure for low-pressure metal mold casting of aluminum flywheel housing. The pouring system has a high casting qualification rate, good surface quality, high process yield rate, and the pouring system is easy to remove.

[0005] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0006] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0007] A pouring system structure for low-pressure metal mold casting of a flywheel housing, comprising a sprue, an ingates, a riser and an overflow;

[0008] The inner runner is arranged at the flange of the intermediate shaft hole of the flywheel housing;

[0009] The sprue is directly connected to the ingrate;

[0010] The riser is arranged on the upper part of the casting;

[0011] At the far end where the molten metal fills the mold, an overflow is arranged.

[0012] Furthermore, the inner runner is circular and is arranged at the flange of the intermediate shaft hole of the flywheel housing.

[0013] Furthermore, a diverter cone is arranged on the upper part of the inner runner.

[0014] Furthermore, the thickness of the inner gate is consistent with the flange thickness of the intermediate shaft hole of the casting.

[0015] Furthermore, a plurality of dispersed risers are provided at the thick and large position of the upper part of the casting;

[0016] A heat-insulating sleeve is arranged outside the riser.

[0017] Furthermore, the root of the riser is consistent with the thickness of the casting at that location, the riser height is ≥60mm, and the single-side thickness of the insulation sleeve is ≥10mm.

[0018] Further, vent plugs are provided at the high point of the riser of the casting and outside the overflow;

[0019] The overflow is connected to a vent plug or exhaust duct.

[0020] A flywheel housing low-pressure casting mold is provided on the mold with a pouring system structure for low-pressure metal mold casting of the flywheel housing.

[0021] Furthermore, the direction of molten metal filling the mold is opposite to the direction of gravity; the sprue is formed by a riser, and the lower end of the sprue is connected to the riser port; the ingates are arranged around the axial hole flange of the casting, and the thickness of the ingates is consistent with that of the casting; the molten metal enters the casting through the riser - sprue - ingates.

[0022] Furthermore, during the filling process, the casting as a whole conforms to a stepped temperature field with low upper mold temperature, high lower mold temperature, low temperature at the far end of the filling, and high temperature near the inner runner.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The pouring system of the present invention has high utilization rate and high process yield rate. The riser and overflow design are highly targeted, which can well ensure product quality and improve product qualification rate. The pouring system is easy to remove, saving cleaning investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings:

[0026] Figure 1a This is a schematic diagram of the flywheel housing product structure 1;

[0027] Figure 1b The flywheel housing product structure diagram Figure 2 ;

[0028] Figure 2 A bottom view of the pouring system structure of the flywheel housing low-pressure metal mold casting according to the present invention;

[0029] Figure 3 A top view of the pouring system structure of the flywheel housing low-pressure metal mold casting of the present invention

[0030] Figure 4 It is a structural cross-sectional view of the pouring system of the flywheel housing low-pressure metal mold casting of the present invention;

[0031] Figure 5 A top view of a structural cross section of a pouring system for low-pressure metal mold casting of a flywheel housing according to the present invention;

[0032] Figure 6 Schematic diagram of flywheel housing casting shrinkage simulation;

[0033] Figure 7 A bottom view of the pouring system structure of the flywheel housing low-pressure metal mold casting of the present invention Figure 2 ;

[0034] Figure 8 A top view of the pouring system structure of the flywheel housing low-pressure metal mold casting of the present invention Figure 2 ;

[0035] In the figure:

[0036] 1——flywheel housing casting; 2——riser pipe; 3——sprue; 4——riser (with insulation sleeve); 5——overflow; 6——inner gate; 7——insulation sleeve. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the embodiment of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The embodiments of the present invention are described in detail below in conjunction with the drawings.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0039] The present invention is described in detail below in conjunction with the accompanying drawings:

[0040] The present invention provides an embodiment, a flywheel housing low-pressure casting mold, the mold involved is provided with a pouring system structure for low-pressure metal mold casting of the flywheel housing, and the technical solution is shown in Figure 2 , Figure 3 , Figure 4 .

[0041] The pouring direction of the flywheel housing casting is as follows: Figure 2 , Figure 3 As shown, the direction of metal liquid filling the mold is opposite to the gravity. The pouring system structure of the flywheel housing low-pressure casting mainly includes sprue, ingates, risers and overflows.

[0042] The runner is arranged at the central axis hole of the casting. The sprue is formed by a riser, and the lower end is connected to the riser port. The molten metal enters the casting through the riser-sprue-int gate. A circular int gate is used, which is designed at the flange of the intermediate axis hole of the flywheel housing. The sprue is directly connected to the int gate, generally a sprue-cross runner-int gate. The present invention does not set a cross runner, which simplifies the runner; an SR40 diverter cone is set on the upper part of the int gate. The int gate is arranged around the axial hole flange of the casting, and the thickness is consistent with that of the casting. The molten metal flow is short, the heat loss is small, and the filling effect is good. The thicker int gate can play the role of sprue shrinkage compensation in low-pressure casting. The thickness of the int gate is consistent with the flange thickness of the intermediate axis hole of the casting. Shrinkage compensation can be fully carried out during the pressure holding time.

[0043] Riser is arranged at the dispersed hot spots of the casting, and there is a molded insulation sleeve made of insulation material outside the riser. The insulation sleeve improves the shrinkage compensation effect of the riser. There is a vent plug outside the insulation sleeve to discharge the gas in the cavity through the insulation sleeve. Dispersed risers are set at the thick and large position on the upper part of the casting. An insulation sleeve is set outside the riser. The root of the riser is consistent with the thickness of the casting at this point, and the height is ≥60. The thickness of the insulation sleeve on one side is ≥10.

[0044] At the far end of the metal liquid filling, an overflow is arranged, and the overflow is connected to the vent plug / exhaust channel. The exhaust channel is the exhaust channel on the mold, and the overflow can be connected to the casting through the exhaust channel. Vent plugs are set at the high point of the riser of the casting and outside the overflow. On the one hand, it can discharge the oxidized slag and other inclusions at the front end of the metal liquid to the outside of the casting. On the other hand, it can discharge the gas in the cavity during the filling process in time to reduce the filling resistance of the metal liquid.

[0045] The pouring system is designed so that during the filling process, the casting as a whole conforms to a stepped temperature field with low upper mold temperature, high lower mold temperature, low temperature at the far end of the filling, and high temperature near the endogate, which is conducive to achieving sequential solidification and giving full play to the shrinkage compensation effect of the endogate of the low-pressure metal mold. For some scattered hot spots, targeted shrinkage compensation can be achieved through the risers with insulation sleeves. The pouring system of the present invention has a high utilization rate and a high process yield. The riser and overflow design are highly targeted, which can well guarantee product quality and improve product qualification rate. The pouring system is easy to remove, saving cleaning investment. The specific size of the pouring system can be adjusted.

[0046] The embodiment provided by the present invention is a pouring system structure for low-pressure metal mold casting of a flywheel housing, and the technical solution is shown in Figure 4 , Figure 5 .

[0047] The riser pipe 2 directly forms a sprue 3, and the lower end is connected to the holding furnace. The high temperature is maintained during the pouring and solidification process. When the pressure is maintained, the molten metal in the riser pipe can flow back to the holding furnace.

[0048] The connection dimensions of the sprue 3 and the ingrate 6 are shown in Figure 4 , Figure 6 The upper part of the ingates forms a SR40 diverter cone to control the flow direction of the rising molten metal from vertical to horizontal. The diverter cone guides the direction of molten iron filling. The present invention sets a hemispherical diverter cone to turn the molten iron 90 degrees and introduce it into the mold cavity.

[0049] The flange thickness of the middle shaft hole of the casting is 26mm, and the thickness of the inner gate is consistent with this. During the pressure holding time, sufficient shrinkage compensation can be carried out. Figure 4 The "26mm" in the figure is the flange thickness of the intermediate shaft hole, to which the inner gate is connected and has the same thickness.

[0050] The thickest part of the upper part of the casting is provided with scattered risers 4. The risers 4 are provided with insulation sleeves 7. The root of the risers 4 is consistent with the thickness of the casting at that location, with a height of 60mm. The thickness of the insulation sleeve is more than 10mm on one side, and the thickness of the top is 20mm. The insulation sleeve can improve the shrinkage compensation effect of the risers.

[0051] Through the filling simulation, an overflow 5 is set at the end of the filling and the position with greater risk of air entrainment. The connection between the overflow and the casting is a 5mm*40mm thin sheet, and the outside is a 40mm*40mm*55mm cuboid. Figure 2 As shown in , after the metal fills the cavity, the molten iron at the front needs to be discharged, which is called "overflow".

[0052] Vent plugs are installed at the high point of the riser of the casting and outside the overflow to discharge the gas in the cavity in time during the filling process and reduce the filling resistance of the molten metal.

[0053] The pouring system in the technical solution of the present invention can significantly improve the process yield rate, and can specifically compensate for the shrinkage of the castings to improve the quality of the castings.

[0054] Implementation case: Take a flywheel housing as an example.

[0055] 1. Reference for the design of casting gating system Figure 2 , Figure 3 , Figure 4 , Figure 5 .

[0056] 2. Simulate the filling and solidification process of the casting, and predict the shrinkage of the casting. Figure 6 The overall quality of the casting is good, and there is only a local risk of shrinkage. This can be basically eliminated by controlling the temperature of the local mold.

[0057] 3. During actual commissioning and production, the castings were well filled and of good quality, achieving the design objectives.

[0058] 4. The process yield rate of castings is 75.3%.

[0059] The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any modification, equivalent replacement and improvement made by any person skilled in the art within the technical scope disclosed by the present invention and within the spirit and principle of the present invention shall be covered within the protection scope of the present invention. At the same time, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

Claims

1. A pouring system structure for low-pressure metal mold casting of a flywheel housing, characterized in that: Including sprue, ingates, risers and overflows; The inner runner is arranged at the flange of the intermediate shaft hole of the flywheel housing; The sprue is directly connected to the ingrate; The riser is arranged on the upper part of the casting; At the far end where the molten metal fills the mold, an overflow is arranged.

2. A pouring system structure for low-pressure metal mold casting of a flywheel housing according to claim 1, characterized in that: The inner runner is circular and arranged at the flange of the intermediate shaft hole of the flywheel housing.

3. The pouring system structure of the flywheel housing low-pressure metal mold casting according to claim 1 is characterized in that: A diverter cone is provided on the upper part of the inner runner.

4. The pouring system structure of the flywheel housing low-pressure metal mold casting according to claim 1 is characterized in that: The thickness of the inner gate is consistent with the flange thickness of the intermediate shaft hole of the casting.

5. The pouring system structure of the flywheel housing low-pressure metal mold casting according to claim 1, characterized in that: A number of dispersed risers are provided at the thick and large position on the upper part of the casting; A heat-insulating sleeve is arranged outside the riser.

6. A pouring system structure for low-pressure metal mold casting of a flywheel housing according to claim 5, characterized in that: The root of the riser is consistent with the thickness of the casting, the riser height is ≥60mm, and the single-side thickness of the insulation sleeve is ≥10mm.

7. The pouring system structure for low-pressure metal mold casting of a flywheel housing according to claim 1, characterized in that: Vent plugs are provided at the high point of the riser of the casting and on the outside of the overflow; The overflow is connected to a vent plug or exhaust duct.

8. A flywheel housing low pressure casting mold, characterized in that: The mold is provided with a pouring system structure for low-pressure metal mold casting of the flywheel housing.

9. The flywheel housing low pressure casting mold according to claim 8, characterized in that: The direction of molten metal filling is opposite to the gravity; the sprue is formed by a riser, and the lower end of the sprue is connected to the riser port; the ingates are arranged around the axial hole flange of the casting, and the thickness of the ingates is consistent with that of the casting; the molten metal enters the casting through the riser - sprue - ingates.

10. The flywheel housing low pressure casting mold according to claim 8, characterized in that: During the filling process, the casting as a whole conforms to a stepped temperature field with low upper mold temperature, high lower mold temperature, low temperature at the far end of the filling, and high temperature near the inner gate.

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