Pouring system for camshaft of internal combustion engine

Abstract

The utility model discloses a pouring system for a cam shaft of an internal combustion engine, relates to the technical field of cam shaft pouring, and is mainly used for solving the internal defects that a cam shaft product produced by the conventional pouring system is easy to generate shrinkage porosity and shrinkage cavity, low in matrix hardness and the like. The structure comprises a sprue, the top of the sprue is connected with a sprue cup, the bottom of the sprue is connected with the middle of a runner, two ends of the runner are respectively connected with one end of a straight runner, and camshaft cavities are arranged on two sides of the straight runner; four feeding heads are sequentially arranged on the straight runner, the lower parts of the side walls of the feeding heads are connected with the camshaft cavity through flow gates, and the sectional area ratio of the flow gates on the four feeding heads is set to be 1.1: 0.9: 0.9: 0.7 in the flowing direction of the liquid metal; and the feeding head and the two flow gates arranged on the feeding head jointly form a liquid supplementing cavity with a diamond-like structure. The utility model provides a pouring system for a camshaft of an internal combustion engine, which can complete the detection of a heavy fitting roller before installation, thereby avoiding the waste of resources, saving the manpower loss and improving the detection efficiency.

Description

Technical Field

[0001] This utility model relates to the field of camshaft casting technology, and in particular to a casting system for camshafts of internal combustion engines. Background Technology

[0002] As a key component of internal combustion engines, the performance of the camshaft directly affects the overall performance and lifespan of the engine. Currently, camshafts are mainly produced by casting using a gating system—the gating system is the general term for the channels through which liquid metal flows into the mold cavity. Its typical structure usually consists of a pouring cup (outer gate), sprue, sprue recess, runner, and ingate.

[0003] However, existing camshaft gating systems often fail to ensure simultaneous and uniform filling and solidification of the entire camshaft, and frequently suffer from insufficient shrinkage compensation. This results in camshaft products prone to inherent defects such as shrinkage porosity, shrinkage cavities, and low matrix hardness. Furthermore, most existing camshaft gating systems are two-piece gating systems per mold, leading to low production efficiency. Utility Model Content

[0004] The purpose of this invention is to provide a gating system for camshafts of internal combustion engines, which can effectively reduce the probability of shrinkage porosity and shrinkage cavities in the camshaft, while also significantly improving the tensile strength, yield strength and elongation of the camshaft.

[0005] The technical solution of this utility model to solve the above-mentioned technical problems is: a gating system for an internal combustion engine camshaft, including a vertically arranged sprue, the top of which is connected to a pouring cup, and the bottom of which is connected to the middle of a horizontally arranged transverse runner. The two ends of the transverse runner are respectively connected to one end of a horizontally arranged straight runner, and the two straight runners are arranged parallel to each other. Camshaft cavities parallel to the straight runners are arranged horizontally on both sides of the extension direction of the straight runners. A tail overflow riser is also provided on the end of the camshaft cavity away from the transverse runner.

[0006] Four feeding risers are sequentially provided on the DC channel. The lower part of the sidewall of the feeding riser is connected to the camshaft cavity on both sides of the DC channel through a frustum-shaped ingate. The cross-sectional area ratio of the ingates on the four feeding risers is set to 1.1:0.9:0.9:0.7 along the liquid metal flow direction. The feeding riser and the two ingates provided on it together form a liquid filling cavity with a horizontal cross-section of a rhomboid structure, and the two opposite corners of the liquid filling cavity are respectively connected to the camshaft cavity on both sides of the DC channel.

[0007] As a further improvement of this utility model, the cross-sectional area of ​​the horizontal runner: the cross-sectional area of ​​the straight runner: the cross-sectional area of ​​the ingate is 1.5-1.8:1-1.3:2.

[0008] As a further improvement of this utility model, the height of the feeding riser is more than twice the height from the parting surface of the camshaft cavity to the highest point of the camshaft cavity.

[0009] As a further improvement of this utility model, the inward inclination angle of the frustum-shaped inner gate is 25°-35°.

[0010] As a further improvement of this utility model, the axial length of the inner gate is at least 5 mm.

[0011] As a further improvement of this utility model, the cross-sectional area of ​​the inner gate is 200mm². 2 -400mm 2 .

[0012] As a further improvement of this utility model, the bottom of the straight pouring channel is connected to the middle of the horizontal pouring channel through a straight pouring channel recess.

[0013] As a further improvement of this utility model, a filter is provided inside the direct pouring channel.

[0014] As a further improvement of this utility model, the upper surface of the end of the horizontal sprue is connected to the lower surface of the end of the straight sprue.

[0015] As a further improvement of this utility model, a cold molten iron storage area is connected to the lower part of the DC channel away from the horizontal sprue.

[0016] Beneficial effects

[0017] Compared with the prior art, the advantages of the casting system for the camshaft of an internal combustion engine of this utility model are as follows:

[0018] 1. The camshaft cavity in this gating system uses multiple endogates for liquid inlet, and the cross-sectional area of ​​each endogate is proportionally allocated to achieve simultaneous filling. Furthermore, by setting up a rhomboid-shaped liquid filling cavity, and considering its heat preservation effect, the liquid filling cavity can avoid affecting the temperature of the camshaft cavity, thus ensuring uniform solidification of the liquid metal within the camshaft cavity. In addition, utilizing the heat preservation effect of the rhomboid-shaped liquid filling cavity, combined with the frustum-shaped endogates, the liquid filling cavity also possesses sufficient shrinkage compensation force.

[0019] Therefore, this gating system can ensure that the camshaft is filled and solidified uniformly at the same time, and can provide sufficient shrinkage compensation force, thereby effectively reducing the probability of shrinkage porosity and shrinkage cavities in the camshaft, while also significantly improving the tensile strength, yield strength and elongation of the camshaft.

[0020] The present invention will become clearer from the following description and in conjunction with the accompanying drawings, which are used to explain the embodiments of the present invention. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a perspective view of the present utility model;

[0023] Figure 2 This is a top sectional view of the present invention.

[0024] Wherein: 1-Beating cup; 2-Sprue; 21-Sprue recess; 3-Gateway; 4-Stream runner; 5-Shrinkage riser; 6-Ingate; 7-Camshaft cavity; 8-Tail overflow; 9-Chilled molten iron storage area. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; of course, they can also refer to a mechanical connection or an electrical connection; furthermore, they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0028] Example:

[0029] The specific embodiments of this utility model are as follows: Figure 1 , 2As shown, a gating system for an internal combustion engine camshaft includes a vertically arranged sprue 2, the top of which is connected to a pouring cup 1, and the bottom of which is connected to the middle of a horizontally arranged runner 3. Both ends of the runner 3 are connected to one end of a horizontally arranged straight runner 4, and the two straight runners 4 are arranged parallel to each other. Camshaft cavities 7, parallel to the straight runners 4, are horizontally arranged on both sides of the straight runners 4 extending in the direction of their extension. This means that the gating system can produce four camshaft products in a single casting operation.

[0030] Each straight channel 4 is provided with four feeding risers 5 in sequence. The lower part of the sidewall of the feeding riser 5 is connected to the camshaft cavity 7 on both sides of the straight channel 4 through a frustum-shaped ingate 6. The cross-sectional area ratio of the ingates 6 on the four feeding risers 5 of the same straight channel 4 is set to 1.1:0.9:0.9:0.7 along the liquid metal flow direction. In this embodiment, the feeding riser 5 and the two ingates 6 set on it together form a liquid filling cavity with a horizontal cross-section of a rhomboid structure, and the two opposite corners of the liquid filling cavity are respectively connected to the camshaft cavity 7 on both sides of the straight channel 4.

[0031] When using this gating system to cast the camshaft, the molten molten metal enters the gating system from the pouring cup 1, flows through the sprue 2 into the gating runner 3 to divert the molten metal, and then smoothly enters each of the straight runners 4; afterwards, the molten metal enters the camshaft cavity 7 through the feeding riser 5 and the ingate 6, completing the entire filling process.

[0032] In this gating system, each camshaft is filled with molten metal through four ingates 6. Based on the principle that the molten metal fills the furthest point in the straight channel 4 first and the closest point last, to ensure simultaneous filling as much as possible, the cross-sectional area of ​​the near-end ingate 6 should be appropriately increased, while the cross-sectional area of ​​the far-end ingate 6 should be decreased. Therefore, the cross-sectional area ratio of the four ingates 6 along the direction of molten metal flow is set to 1.1:0.9:0.9:0.7. This design allows for rapid completion of the filling process while ensuring simultaneous filling, resulting in a smaller temperature difference throughout the camshaft cavity and improved uniformity of the product matrix.

[0033] Furthermore, the feeding riser 5 and the two ingates 6 together form a rhomboid-shaped filling cavity, with the two opposite corners of the filling cavity connected to the camshaft cavities 7 on both sides of the direct flow channel 4. This design is because the solidification of castings always follows the general principle of gradually solidifying from the low-temperature zone to the high-temperature zone. To achieve a dense microstructure in the casting, the temperature field of the entire casting needs to be regulated by the riser and gating system, allowing it to solidify gradually from the lowest temperature zone to the highest temperature zone. If the riser structure is too close to the product structure, a small high-temperature zone will form near the product due to the influence of the riser temperature, preventing uniform solidification and increasing the risk of shrinkage cavities and porosity defects in the product body. Therefore, the rhomboid structure of the liquid filling chamber in this casting system can keep the liquid filling chamber as far away from the edge of the camshaft cavity 7 as possible while completing the camshaft casting work. Furthermore, since the rhomboid structure of the liquid filling chamber is conducive to heat preservation, it can prevent the camshaft cavity 7 from forming a small high-temperature zone—i.e., a hot spot—due to the influence of the liquid metal in the liquid filling chamber near the position of the liquid filling chamber. As a result, the liquid metal in the camshaft cavity 7 solidifies uniformly, and the hot spots are all concentrated in the liquid filling chamber.

[0034] In addition, by utilizing the heat preservation effect of the rhomboid-shaped liquid filling chamber, the liquid metal in the liquid filling chamber can be kept in a liquid state for as long as possible. Combined with the frustum-shaped inner gate, the liquid filling chamber of this gating system can have sufficient shrinkage force, thereby improving the density of the product and thus improving the product's overall performance.

[0035] In summary, this gating system ensures that the entire camshaft is filled and solidified uniformly, and provides sufficient shrinkage compensation force, thereby effectively reducing the probability of shrinkage porosity and shrinkage cavities in the camshaft. At the same time, it can significantly improve the tensile strength, yield strength and elongation of the camshaft.

[0036] In this gating system, the cross-sectional area ratio of the horizontal runner 3 to the straight runner 4 to the ingate 6 is 1.5-1.8:1-1.3:2. Combined with the semi-open gating system, this helps reduce the velocity of the molten metal while ensuring sufficient filling time. Simultaneously, the height of the feeding riser 5 is more than twice the height from the parting surface of the camshaft cavity 7 to its highest point, further increasing the feeding pressure. Furthermore, the inward inclination angle of the frustum-shaped ingate 6 is 25°-35°. This angle is beneficial for the formation of the feeding channel; too large an angle will affect the normal solidification of the camshaft, while too small an angle will result in insufficient feeding capacity. Additionally, the axial length of the ingate 6 is at least 5mm; too short a length will cause turbulence when the molten metal enters the camshaft cavity 7, leading to defects such as porosity and slag inclusions in the casting. In this embodiment, the cross-sectional area of ​​the ingate 6 is strongly related to the weight and structure of the product, and the principle is that the ingate 6 is not completely solidified when the product is completely solidified; therefore, the cross-sectional area of ​​the ingate 6 in this embodiment is specifically set to 200mm². 2 -400mm2 .

[0037] In this gating system, to prevent inclusions in the molten metal from affecting product quality, the bottom of the sprue 2 is connected to the middle of the runner 3 via a sprue recess 21, and a filter is installed within the sprue recess 21. Furthermore, the ingate 6 is located below the side wall of the feeding riser 5 because secondary inclusions in the molten metal float to the surface. Therefore, when the molten metal passes through the feeding riser 5, the inclusions quickly accumulate above the feeding riser 5 due to the riser 5 being significantly higher than the ingate 6, while the clean molten metal enters the camshaft cavity below through the ingate 6. Thus, the feeding riser 5 can perform secondary slag collection on the molten metal entering the camshaft cavity 7 before the filling process is complete, thereby reducing the risk of secondary inclusions entering the camshaft product. Therefore, this gating system, with its significant secondary slag removal capability, also reduces the product's requirements for the smelting process, increases the adjustable range of the smelting process, and further reduces production costs.

[0038] In this embodiment, regarding the specific connection relationship between the horizontal sprue 3 and the straight runner 4, the upper surface of the end of the horizontal sprue 3 is connected to the lower surface of the end of the straight runner 4. Simultaneously, a chilled molten iron storage area 9 is connected to the lower part of the straight runner 4 at the end furthest from the horizontal sprue 3. The chilled molten iron storage area 9 can store a portion of the molten iron that first passes through the runner and experiences a significant temperature drop, ensuring that the molten metal entering the camshaft cavity 7 is always maintained at a reasonable pouring temperature. Furthermore, a tail-end overflow riser 8 is provided at the end of the camshaft cavity 7 furthest from the horizontal sprue 3. The tail-end overflow riser 8 can store the molten iron that is too cold when it first enters the camshaft cavity 7 and excess air in the camshaft cavity 7, improving the quality and yield of the camshaft body.

[0039] The present invention has been described above in conjunction with the preferred embodiments, but the present invention is not limited to the embodiments disclosed above, but should cover various modifications and equivalent combinations made in accordance with the essence of the present invention.

Claims

1. A casting system for an internal combustion engine camshaft, characterized in that, It includes a vertically arranged sprue (2), the top of which is connected to the pouring cup (1), and the bottom is connected to the middle of a horizontally arranged runner (3). The two ends of the runner (3) are respectively connected to one end of a horizontally arranged straight runner (4), and the two straight runners (4) are arranged parallel to each other. On both sides of the extension direction of the straight runner (4), there are horizontal camshaft cavities (7) parallel to the straight runner (4). The end of the camshaft cavity (7) away from the runner (3) is also provided with a tail overflow riser (8). Four feeding risers (5) are arranged sequentially on the DC channel (4). The lower part of the side wall of the feeding riser (5) is connected to the camshaft cavity (7) on both sides of the DC channel (4) through a frustum-shaped ingate (6). The cross-sectional area ratio of the ingate (6) on the four feeding risers (5) is set to 1.1:0.9:0.9:0.7 along the liquid metal flow direction. The feeding riser (5) and the two ingates (6) arranged on it together form a liquid filling cavity with a horizontal cross-section of a rhomboid structure. The two opposite corners of the liquid filling cavity are respectively connected to the camshaft cavity (7) on both sides of the DC channel (4).

2. The casting system for the camshaft of an internal combustion engine according to claim 1, characterized in that, The cross-sectional area of ​​the horizontal runner (3): the cross-sectional area of ​​the straight runner (4): the cross-sectional area of ​​the ingate (6) is 1.5-1.8:1-1.3:

2.

3. The casting system for the camshaft of an internal combustion engine according to claim 1, characterized in that, The height of the feed riser (5) is more than twice the height from the parting surface of the camshaft cavity (7) to the highest point of the camshaft cavity (7).

4. The gating system for the camshaft of an internal combustion engine according to claim 1 or 3, characterized in that, The inward inclination angle of the frustum-shaped inlet gate (6) is 25°-35°.

5. The casting system for the camshaft of an internal combustion engine according to claim 1, characterized in that, The axial length of the ingate (6) is at least 5 mm.

6. The casting system for the camshaft of an internal combustion engine according to claim 1, characterized in that, The cross-sectional area of ​​the ingate (6) is 200 mm². 2 -400mm 2 .

7. The casting system for the camshaft of an internal combustion engine according to claim 1, characterized in that, The bottom of the sprue (2) is connected to the middle of the gutter (3) through the sprue recess (21).

8. The gating system for the camshaft of an internal combustion engine according to claim 7, characterized in that, A filter is provided inside the direct pouring channel (21).

9. The casting system for the camshaft of an internal combustion engine according to claim 1, characterized in that, The upper end surface of the horizontal runner (3) is connected to the lower end surface of the straight runner (4).

10. The casting system for the camshaft of an internal combustion engine according to claim 1, characterized in that, The lower part of the direct flow channel (4) away from the horizontal flow channel (3) is connected to the cold molten iron storage area (9).

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