Fold line open-edge casting process

Abstract

The invention relates to the technical field of cylinder body casting, in particular to a fold line open edge casting process which comprises the following steps: determining a box closing folded surface, determining the axis of a third through hole and the axis of a fourth through hole as a reference axis, and finding out a first interface, perpendicular to the reference axis, where the axis of a first thin-wall through hole is located; finding a second interface perpendicular to the reference axis where the axis of the second thin-wall through hole is located, selecting a third interface, and determining a Z-shaped folding surface formed by the three interfaces as a box closing folding surface; a lower sand box, an upper sand box, a first cavity sand core, a first column sand core, a second column sand core, a second cavity sand core and a lower core are manufactured by taking the box closing folding surface as a boundary, and finally a cavity for casting the cylinder body is formed; and pouring. Two thin-wall through holes which are staggered in the horizontal direction are avoided, the box separation position does not coincide with cavities of the two thin-wall through holes any more, the position where burrs appear is moved to the ends of the thin-wall through holes, polishing treatment is facilitated, and then the quality of a cylinder block casting is improved.

Description

Technical Field

[0001] The invention relates to the technical field of cylinder casting, in particular to a broken line edge casting process. Background Art

[0002] The structure of the double-plunger pump includes a cylinder body with a middle cavity inside. The cylinder body is provided with two thin-walled through holes for inserting the plungers in the direction of the reciprocating motion of the plungers. Both thin-walled through holes are connected to the middle cavity, and the two thin-walled through holes are not in the same straight line, that is, their horizontal positions are staggered from each other; the cylinder body is provided with two through holes in the direction perpendicular to the reciprocating motion of the plungers, which serve as a liquid inlet and a liquid outlet respectively, and the liquid inlet and the liquid outlet are in the same straight line.

[0003] When casting the cylinder body of a double-piston pump, it is necessary to go through the steps of molding, core lowering, box closing, pouring, and sand dropping. In the process of dividing the upper box body and the lower box body and core lowering using the existing molding steps, the two through holes in the direction of the reciprocating motion of the plunger are misaligned with each other, and the lowermost outer wall of the upper thin-walled through hole and the uppermost outer wall of the lower thin-walled through hole are exactly on the center line. At this time, with the center line as the parting line, after molding, core lowering, and box closing for pouring, when molten iron enters the cavity forming the thin-walled through hole, it is easy to seep out along the parting line, resulting in burrs on the outer wall of the thin-walled through hole of the cylinder casting. After the casting is completed, the outer wall of the thin-walled through hole is difficult to grind and remove, resulting in poor quality of the cylinder casting. Summary of the invention

[0004] In view of the defects of the prior art, the present invention provides a fold line and edge casting process, which first determines the folding surface of the box to avoid two thin-walled through holes that are offset from each other in the horizontal direction. The box division position no longer coincides with the cavity of the two thin-walled through holes, so that the position where the burrs appear is moved to the end of the thin-walled through hole to facilitate grinding, thereby improving the quality of the cylinder casting.

[0005] In order to achieve the above-mentioned purpose, the technical solution provided by the present invention is a fold line opening casting process for casting a cylinder body with double thin-walled through holes, the cylinder body having a middle cavity, the cylinder body having a first thin-walled through hole and a second thin-walled through hole in the direction of the reciprocating motion of the plunger, the axes of the first thin-walled through hole and the second thin-walled through hole are staggered, and the first thin-walled through hole and the second thin-walled through hole are both connected to the middle cavity, the cylinder body having a third through hole and a fourth through hole in the direction perpendicular to the reciprocating motion of the plunger, the third through hole and the fourth through hole are coaxially arranged, and the casting steps include: Step S100, determining the box closing folding surface, determining the axes of the third through hole and the fourth through hole as reference axes, finding a first interface perpendicular to the reference axis where the axis of the first thin-walled through hole is located, finding a second interface perpendicular to the reference axis where the axis of the second thin-walled through hole is located, selecting a third interface intersecting the first interface and the second interface, and determining a Z-shaped folding surface formed by the first interface, the third interface and the second interface as the box closing folding surface; Step S200: using the folded surface of the combined box as a boundary, making a lower sand box that matches the shape of the lower half of the cylinder body, and making an upper sand box that matches the shape of the upper half of the cylinder body. Taking the box-joining folding surface as the boundary, a first cavity sand core for casting the middle cavity below the box-joining folding surface is manufactured. Making a first cylindrical sand core for casting a first thin-walled through hole, Making a second cylindrical sand core for casting a second thin-walled through hole, With the box-joining folding surface as the boundary, a second cavity sand core for casting the middle cavity above the box-joining folding surface is manufactured. Step S300, placing and fixing the first cavity sand core in the lower sand box, placing the first column sand core and the second column sand core on the first cavity sand core, and then placing the second cavity sand core on top of the first cavity sand core on which the first column sand core and the second column sand core are placed, and placing the upper sand box on top of the second cavity sand core; finally, forming a cavity for casting a cylinder body; Step S400: pouring.

[0006] Further, the third interface is perpendicular to the first interface and the second interface respectively, and the reference axis is located on the third interface.

[0007] Further, the first thin-walled through hole includes a first end located inside the middle cavity, and a plane perpendicular to the axis of the first thin-walled through hole where the first end is located is defined as a first limiting plane; the second thin-walled through hole includes a second end located inside the middle cavity, and a plane perpendicular to the axis of the second thin-walled through hole where the second end is located is defined as a second limiting plane; the third dividing interface is located between the first limiting plane and the second limiting plane in the direction of reciprocating motion of the plunger.

[0008] Furthermore, the plane where the reference axis is located and is perpendicular to the axis of the first thin-walled through hole is the third limiting plane, the intersection line between the first boundary surface and the third boundary surface is located between the first limiting plane and the third limiting plane, and the intersection line between the third boundary surface and the second boundary surface is located between the third limiting plane and the second limiting plane.

[0009] Furthermore, step S200 also includes making a first cylindrical sand core for casting the third through hole and making a second cylindrical sand core for casting the fourth through hole.

[0010] Furthermore, step S300 also includes placing the first cylindrical sand core inside the lower sand box, and placing the second cylindrical sand core above the second cavity sand core.

[0011] The beneficial effects of the present invention are as follows: the parting surface avoids two thin-wall through holes that are offset from each other in the horizontal direction, so that the position where the burrs appear is moved to the ends of the thin-wall through holes for easy grinding, thereby improving the quality of the cylinder casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of a cylinder body of a cast double-plunger pump in one embodiment of the present invention; Figure 2 It is a schematic diagram of a box folding surface of a folding line opening edge casting process in one embodiment of the present invention; Figure 3 It is a schematic diagram of an upper flask and a lower flask in a folding line open edge casting process in one embodiment of the present invention; Figure 4 It is a schematic diagram of placing the first column sand core on the first cavity sand core in one embodiment of the present invention; Figure 5 A top view of a second cavity sand core in one embodiment of the present invention; Figure 6 for Figure 4 Cross-sectional view of the middle BB; In the figure: 10, cylinder body, 11, middle cavity, 12, first thin-walled through hole, 12a, first end, 13, second thin-walled through hole, 13a, second end, 14, third through hole, 15, fourth through hole, 20. Upper sand box, 21. Second cavity sand core, 21a. First groove, 21b. Second groove, 22. Second cylindrical sand core, 30. Lower sand box, 31. First cavity sand core, 32. First column sand core, 32a. Left core head, 32b. Right core head, 33. Second column sand core, 34. First cylindrical sand core, x, direction of the plunger's reciprocating motion, y, perpendicular to the direction of the reciprocating motion of the plunger, M, closing surface, M1, first interface, M2, second interface, L, reference axis, M3, third interface, M4, first limit plane, M5, first limit plane, M6, third limit plane. DETAILED DESCRIPTION

[0013] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0014] See also Figure 1-Figure 3 , a broken line open edge casting process, which can be applied to casting a cylinder body with double thin-walled through holes, and the double thin-walled through holes are not collinear. Figure 1 As shown, in this embodiment, a cylinder body 10 for casting a double plunger pump is provided. The cylinder body 10 has a middle cavity 11. The cylinder body 10 is provided with a first thin-walled through hole 12 and a second thin-walled through hole 13 in the direction x of the reciprocating motion of the plunger. The axes of the first thin-walled through hole 12 and the second thin-walled through hole 13 are staggered. The cylinder body 10 is provided with a third through hole 14 and a fourth through hole 15 in the direction y perpendicular to the reciprocating motion of the plunger. The third through hole 14 and the fourth through hole 15 are coaxially arranged. The first thin-walled through hole 12, the second thin-walled through hole 13, the third through hole 14 and the fourth through hole 15 are all connected to the middle cavity 11. The casting steps include: See also Figure 1 and Figure 2 Step S100, determine the box closing folding surface M, determine the axis of the third through hole 14 and the fourth through hole 15 as the reference axis L, find the first interface M1 perpendicular to the reference axis L where the axis of the first thin-walled through hole 12 is located, find the second interface M2 perpendicular to the reference axis L where the axis of the second thin-walled through hole 13 is located, select the third interface M3 intersecting with the first interface M1 and the second interface M2, and determine the Z-shaped folding surface formed by the first interface M1, the third interface M3 and the second interface M2 as the box closing folding surface M. It should be noted that when the plane determined by the axis of the first thin-walled through hole 12 and the axis of the second thin-walled through hole 13 is the reference plane, the reference axis L is not necessarily in the reference plane.

[0015] See also Figure 3 Step S200: With the folding surface M as the boundary, a lower flask 30 matching the shape of the lower half of the cylinder body is manufactured, and an upper flask 20 matching the shape of the upper half of the cylinder body is manufactured. With the box-joining folding surface M as the boundary, a first cavity sand core 31 for casting the middle cavity below the box-joining folding surface is manufactured. A first cylindrical sand core 32 for casting the first thin-walled through hole 12 is manufactured. A second cylindrical sand core 33 for casting the second thin-walled through hole 13 is manufactured. With the box folding surface M as the boundary, a second cavity sand core 21 for casting the middle cavity above the box folding surface M is manufactured. It should be noted that Figure 3 It is only a structural diagram. The structural details of the cylinder surface and the structural details of the middle cavity are not shown in the figure. They can be determined according to the specific structure of the cast cylinder. The structure of the first cavity sand core 31 and the second cavity sand core 21 is not necessarily Figure 3 The more regular graph shown in Figure 3 This is a schematic structure only.

[0016] Step S300, place and fix the first cavity sand core 31 inside the lower sand box 30, place the first column sand core 32 and the second column sand core 33 on the first cavity sand core 31, and then place the second cavity sand core 21 above the first cavity sand core 31 on which the first column sand core 32 and the second column sand core 33 are placed, and place the upper sand box 20 above the second cavity sand core; finally, a cavity for casting a cylinder body is formed.

[0017] For specific settings, refer to Figure 4 In this embodiment, the left core head 32a and the right core head 32b are provided at both ends of the first column sand core 32. The left core head 32a overlaps the edge of the lower flask 30, and the right core head 32b overlaps the first cavity sand core 31. In this way, a gap can be formed between the first column sand core 32 and the first cavity sand core 31, that is, a cavity is formed to be filled with molten iron, and a thin-walled structure is formed after pouring, and finally the first thin-walled through hole 12 is formed. Similarly, the second column sand core 33 is provided with core heads at both ends, and the core heads are placed on the edges of the lower flask 30 on both sides and the first cavity sand core 31, and a gap is formed in the middle. It should be noted that the way to fix the first cavity sand core 31 inside the lower flask 30 is similar. The core head is set at the edge of the first cavity sand core 31 and overlaps the edge of the lower flask 30 to form a gap between the lower flask 30 and the first cavity sand core 31, that is, a cavity is formed, and the outer wall of the shell is formed after pouring. The setting position of the core head can be selected according to the specific working conditions.

[0018] For a clearer illustration of the combination, see Figure 5 , shows a top view of the second cavity sand core 21 in one embodiment, after the second cavity sand core 21 is placed on the first cavity sand core 31 where the first column sand core 32 and the second column sand core 33 are placed, Figure 5 The first groove 21a in the first cavity sand core 31 is inverted and a gap is formed between the two. Figure 5 The second groove 21b in the second cylindrical sand core 33 is inverted and a gap is formed between the two. Figure 3 and Figure 6 It can be seen that the first thin-walled through hole 12 and the second thin-walled through hole 13 in this embodiment are not through holes with circular cross-sections. The present invention does not limit the cross-sectional shape of the thin-walled through holes, which may be circular, rectangular, polygonal or waist-shaped holes.

[0019] Step S400: pouring.

[0020] In the above-mentioned fold line open edge casting process, when a cylinder body has double thin-walled through holes, the folding surface M of the flask is first determined, and the flask is divided into an upper sand box 20 and a lower sand box 30 with the folding surface M as the boundary, and the first cavity sand core 31 and the second cavity sand core 21 are respectively made with the folding surface M as the boundary. In this way, the lowermost outer wall of the upper thin-walled through hole and the uppermost outer wall of the lower thin-walled through hole avoid the folding surface M of the flask, and burrs will not appear on the outer wall of the thin-walled through hole. Instead, the position where the burrs appear is moved to the end of the thin-walled through hole to facilitate subsequent grinding processing, thereby improving the quality of the cylinder body casting.

[0021] In one embodiment, the third interface M3 is perpendicular to the first interface M1 and the second interface M2 , and the reference axis L is located on the third interface M3 .

[0022] Continue to see Figure 2 In one embodiment, the first thin-walled through hole 12 includes a first end 12a located inside the middle cavity 11, and a plane perpendicular to the axis of the first thin-walled through hole and where the first end 12a is located is defined as a first limiting plane M4. The second thin-walled through hole 13 includes a second end 13a located inside the middle cavity 11, and a plane perpendicular to the axis of the second thin-walled through hole 13 and where the second end 13a is located is defined as a second limiting plane M5. The third dividing interface M3 is located between the first limiting plane M4 and the second limiting plane M5 in the direction of reciprocating motion of the plunger.

[0023] In one embodiment, the plane where the reference axis L is located and is perpendicular to the axis of the first thin-walled through hole 12 is the third limiting plane M6, the intersection line between the first boundary surface M1 and the third boundary surface M3 is located between the first limiting plane M4 and the third limiting plane M6, and the intersection line between the third boundary surface M3 and the second boundary surface M2 is located between the third limiting plane M6 and the second limiting plane M5.

[0024] See also Figure 2In the above-mentioned fold line open edge casting process, when determining the third boundary surface M3, the intersection line of the third boundary surface M3 and the first boundary surface M1 is limited to the right side of the first limiting plane M4, that is, limited to the right side of the first end 12a, avoiding the first end 12a, thereby preventing the molten iron from penetrating into the folding surface M of the box along the thin-walled cavity, and only a small amount of burrs may appear at the first end 12a to reduce the volume of burrs. Similarly, when determining the third boundary surface M3, the intersection line of the third boundary surface M3 and the second boundary surface M2 is limited to the left side of the second limiting plane M5, that is, limited to the left side of the second end 13a, avoiding the second end 13a, thereby preventing the molten iron from penetrating into the folding surface M of the box along the thin-walled cavity, and only a small amount of burrs may appear at the second end 13a to reduce the volume of burrs and further improve the quality of the casting.

[0025] In one embodiment, step S300 also includes making a first cylindrical sand core 25 for casting the third through hole 14 and a second cylindrical sand core 35 for casting the fourth through hole 15, fixing the first cylindrical sand core 22 inside the upper sand box 20, and fixing the second cylindrical sand core 35 inside the lower sand box 30.

[0026] In one embodiment, step S200 further includes manufacturing a first cylindrical sand core 34 for casting the third through hole 14 and manufacturing a second cylindrical sand core 22 for casting the fourth through hole 15 .

[0027] In one embodiment, step S300 further includes placing the first cylindrical sand core 34 inside the lower sand box 30 , and placing the second cylindrical sand core 22 above the second cavity sand core 21 .

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" 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, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0030] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In the present invention, unless otherwise clearly specified and limited, the first feature "above" or "below" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature may be that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. It should be noted that when an element is referred to as "fixed to" or "set on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

Claims

1. A folded-line edge casting process for casting a cylinder body with double thin-walled through holes, wherein the cylinder body has a middle cavity, wherein the cylinder body is provided with a first thin-walled through hole and a second thin-walled through hole in the direction of the reciprocating motion of the plunger, wherein the axes of the first thin-walled through hole and the second thin-walled through hole are staggered, and the first thin-walled through hole and the second thin-walled through hole are both connected to the middle cavity, wherein the cylinder body is provided with a third through hole and a fourth through hole in a direction perpendicular to the reciprocating motion of the plunger, wherein the third through hole and the fourth through hole are coaxially arranged, and wherein: The casting steps include S100, determining a box closing folding surface, determining the axes of the third through hole and the fourth through hole as reference axes, finding a first interface perpendicular to the reference axis where the axis of the first thin-walled through hole is located, finding a second interface perpendicular to the reference axis where the axis of the second thin-walled through hole is located, selecting a third interface intersecting the first interface and the second interface, and determining a Z-shaped folding surface formed by the first interface, the third interface and the second interface as the box closing folding surface; S200, using the folded surface of the combined box as a boundary, making a lower sand box that matches the shape of the lower half of the cylinder body, and making an upper sand box that matches the shape of the upper half of the cylinder body, Taking the box-joining folding surface as the boundary, a first cavity sand core for casting the middle cavity below the box-joining folding surface is manufactured. Making a first cylindrical sand core for casting a first thin-walled through hole, Making a second cylindrical sand core for casting a second thin-walled through hole, With the box-joining folding surface as the boundary, a second cavity sand core for casting the middle cavity above the box-joining folding surface is manufactured. S300, placing and fixing the first cavity sand core in the lower sand box, placing the first column sand core and the second column sand core on the first cavity sand core, and then placing the second cavity sand core on top of the first cavity sand core on which the first column sand core and the second column sand core are placed, and placing the upper sand box on top of the second cavity sand core; finally, forming a cavity for casting a cylinder body; S400, pouring.

2. The fold line opening casting process according to claim 1, characterized in that: The third interface is perpendicular to the first interface and the second interface respectively, and the reference axis is located on the third interface.

3. The fold line opening casting process according to claim 1, characterized in that: The first thin-walled through hole includes a first end located inside the middle cavity, and a plane perpendicular to the axis of the first thin-walled through hole where the first end is located is defined as a first limiting plane. The second thin-walled through hole includes a second end located inside the middle cavity, and a plane perpendicular to the axis of the second thin-walled through hole where the second end is located is defined as a second limiting plane. The third dividing interface is located between the first limiting plane and the second limiting plane in the direction of reciprocating motion of the plunger.

4. The fold line opening casting process according to claim 3, characterized in that: The plane where the reference axis is located and is perpendicular to the axis of the first thin-walled through hole is the third limiting plane, the intersection line between the first boundary surface and the third boundary surface is located between the first limiting plane and the third limiting plane, and the intersection line between the third boundary surface and the second boundary surface is located between the third limiting plane and the second limiting plane.

5. The fold line opening casting process according to claim 1, characterized in that: Step S200 also includes making a first cylindrical sand core for casting the third through hole and making a second cylindrical sand core for casting the fourth through hole.

6. The fold line opening casting process according to claim 5, characterized in that: Step S300 also includes placing the first cylindrical sand core inside the lower sand box, and placing the second cylindrical sand core above the second cavity sand core.

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