An engine block sand core structure and a block structure made from the sand core

Abstract

The application discloses an engine body sand core structure and a body structure made of the sand core; a truss core head structure and an assembling process are adopted, which are characterized by bottom insertion, middle reverse buckling and top pressing. The long and narrow truss core can be accurately and stably fixed on the main body core in a standing state. The long and narrow truss core is accurately and stably assembled on the main body core through the constraint of six directions at three positions, so that the truss core can be turned by 360 degrees with the main body core and does not fall off during long distance circulation.

Description

Technical Field

[0001] This invention belongs to the field of engine block design and assembly, specifically relating to an engine block truss sand core structure and core assembly method. Background Technology

[0002] The engine block features a truss structure on both sides, which ensures oil return from the cylinder head and enhances the block's rigidity, suppressing torsional deformation and significantly improving the engine's NVH (noise, vibration, and harshness). However, due to limitations imposed by internal moving parts and external structural components, the truss cavity is long and narrow, with a sand core length of 422mm and a minimum cross-section of 332mm. 2 (With a maximum diameter of less than 20mm, the assembly and fixing of the truss sand core becomes a technical challenge, as deformation and breakage are prone to occur, affecting the thickness of the machine body wall.)

[0003] Similar displacement foreign competitors' fuselage truss structure process design, such as Figure 1 As shown, the truss cavity extends vertically, with a pre-drilled process hole in the middle for core support during truss sand core assembly, pouring and compaction, and cleaning of residual sand. After machining, a cup-shaped plug is then press-fitted. The main function of this process hole is to provide support for the narrow truss sand core during core assembly. When in the lower mold, it prevents the sand core from breaking due to gravity. When in the upper mold, it is used to press the truss sand core firmly against the upper mold, preventing the sand core from breaking or shifting due to the buoyancy of the molten iron, which could affect the casting wall thickness. The main drawback of this technology is the lack of a reliable positioning and locking structure between the truss core and the main core. This makes it impossible to accurately and stably fix the truss core to the main core for overall turnover and core placement. Furthermore, the added core head due to core fixing and compaction creates multiple process holes on the product's appearance, requiring further machining and press-fitting with cup-shaped plugs to seal them and meet product performance requirements. However, the cup-shaped plug disrupts the longitudinal stress on the product, weakening the overall rigidity; the cup-shaped plug also poses a risk of leakage, affecting product reliability. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an engine block sand core structure and an engine block made from the sand core.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] In a first aspect, embodiments of the present invention provide an engine block sand core structure, including a truss sand core and a main body core. The truss sand core includes a sand core body, with an insertion part at the bottom, a pressing part at the top, and an undercut part in the middle. The main body core is provided with an insertion hole, an undercut groove, and a pressing groove from bottom to top. The insertion part is inserted into the insertion hole, the undercut part is fastened in the undercut groove, and the pressing part is pressed in the pressing groove.

[0007] As a further technical solution, the plug-in part at the bottom of the sand core structure, the press-fitting part at the top, and the undercut part in the middle are all integral structures of the sand core body.

[0008] As a further technical solution, the plug-in part is a protrusion extending downward along the height direction of the sand core body.

[0009] As a further technical solution, the undercut part is an irregular shape extending to both sides of the sand core body along the width direction of the sand core body and protruding to the side of the main core body, which can be exactly clamped in the undercut groove.

[0010] As a further technical solution, the press-fitting part is a protrusion extending upward along the height direction of the sand core body.

[0011] As a further technical solution, the undercut groove is a long and narrow groove, the length direction of the groove is arranged along the opening direction of the main core body, and the area of the groove near the sand core body is larger than the area away from the sand core body, and the height of the groove near the sand core body is larger than the height away from the sand core body.

[0012] In a second aspect, an embodiment of the present application provides a sand core structure of an engine body, which comprises a truss sand core and a main core, the truss sand core comprises a sand core body, the bottom of the sand core body is provided with a plug-in hole, the top is provided with a press-fitting groove, and the middle is provided with an undercut part; the main core is sequentially provided with a plug-in part, an undercut groove, and a press-fitting part from bottom to top; the plug-in part is plugged into the plug-in hole, the undercut part is clamped in the undercut groove, and the press-fitting part is press-fitted in the press-fitting groove.

[0013] As a further technical solution, the plug-in hole at the bottom of the sand core structure, the press-fitting groove at the top, and the undercut groove in the middle are all integral structures of the sand core body.

[0014] As a further technical solution, the plug-in hole is extended to the inside of the sand core body along the height direction of the sand core body.

[0015] As a further technical solution, the undercut part is an irregular shape extending to both sides of the sand core body along the width direction of the sand core body and protruding to the side of the main core body, which can be exactly clamped in the undercut groove of the main core body.

[0016] As a further technical solution, the press-fitting groove is a groove formed by recessing the top surface of the sand core downward along the height direction of the sand core body.

[0017] As a further technical solution, the inverted slot is a long groove, the length direction of the groove is arranged along the opening direction of the main body core, and the area of the groove close to the sand core body side is greater than the area away from the sand core body side, and the height of the groove close to the sand core body side is greater than the height away from the sand core body side.

[0018] In a third aspect, embodiments of the present application provide an engine body structure cast by the engine body sand core structure described above.

[0019] The beneficial effects of the above embodiments of the present application are as follows:

[0020] 1. The present application adopts a truss core head structure and assembly process of bottom insertion, middle inverted buckle and top compression. The long and narrow truss core can be accurately and stably fixed on the main body core in a standing state. The constraints of the upper, middle and lower positions in six directions accurately and stably assemble the long and narrow truss core on the main body core, so that the truss core can be turned 360 degrees with the main body core without falling during long distance circulation.

[0021] The truss core penetrates the body up and down. Except for the bottom insertion in the crater formed by the large cylinder core, the top is compressed by the water jacket core and the upper cover core, and the middle part of the long and narrow sand core is in a free state. If nothing is done, the sand core will float or break during core assembly or pouring, affecting the wall thickness around the truss. The conventional process is to increase a process hole in the middle of the body truss. The hole is connected to the large cylinder inside and the outer mold outside. The core head formed by the two holes can play the role of truss core positioning, supporting and compression. However, the truss core is located between the two large cylinder cores, and it is not possible to directly drill a hole to connect with the large cylinder core. After drilling a hole to the outer mold, the truss is separated from top to bottom, which is not conducive to the reinforcement of the body structure. Meanwhile, oil and gas leakage after drilling is not allowed. The casting hole needs to be machined again and a bowl-shaped plug needs to be compressed for plugging. The present application extends a section horizontally in the middle of the truss core to form a lap with the large cylinder core. Although it solves the single-direction support and compression between the truss core and the large cylinder core, the sand core still cannot be fixed firmly. Usually, a nail or adhesive is used to fix the truss core to the large cylinder core, which increases the operation difficulty and risks such as sand core breakage and casting porosity. Therefore, the present application designs an inverted buckle in the middle of the truss core and the large cylinder core to increase the outward constraint of the truss core.

[0022] 2. The sand core structure proposed by the present application has the advantages of complete appearance, clean inner cavity, uniform wall thickness, no need for secondary processing of process holes and compression of bowl-shaped plugs, reduced processing and assembly manufacturing costs, and saved material use cost of bowl-shaped plugs.

[0023] 3. The sand core structure proposed by the present application has the advantages of good rigidity of the cast body casting, good closure of the truss cavity, no risk of oil and gas leakage, guarantee of product quality, and finally guarantee of product structure better than foreign competitors. Attached Figure Description

[0024] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0025] Figure 1 This is a schematic side view of the engine block truss structure in the prior art;

[0026] Figure 2 This is a schematic diagram of the engine block truss core structure proposed in Embodiment 1 of the present invention;

[0027] Figure 3 This is a schematic diagram of the inverted part of the engine block truss core proposed in Embodiment 1 of the present invention;

[0028] Figure 4 This is a schematic diagram of the overall structure of the engine block core and the truss core mating part proposed in Embodiment 1 of the present invention;

[0029] Figure 5 This is a schematic diagram of the undercut groove structure of the engine block truss core proposed in Embodiment 1 of the present invention;

[0030] Figure 6 , Figure 7 This is a schematic diagram of the truss core installed on the main body core according to Embodiment 1 of the present invention;

[0031] Figure 8 This is a schematic diagram of the vertical and horizontal constraints of the truss core on the main body core of the present invention;

[0032] Figure 9 This is a schematic diagram of the front and rear constraints formed by the undercut portion and the undercut groove portion of the truss core of the present invention;

[0033] In the diagram: 1. Body, 2. Truss, 3. Process opening;

[0034] 4 Truss core, 4-1 Insertion part, 4-2 Inverted part, 4-3 Press-fit part, 4-4 Sand core body;

[0035] 5. Main core, 5-1 Insertion hole, 5-2 Undercut groove, 5-3 Press-fit groove.

[0036] 6. Top cover core. Detailed Implementation

[0037] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0038] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components and / or combinations thereof.

[0039] For the convenience of description, if the terms "upper", "lower", "left", "right" are used in the present application, they only mean the same direction as the upper, lower, left and right directions of the drawings themselves, and do not limit the structure, but only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application.

[0040] Term explanation part: The truss core in the present application is a casting sand core on the outside of the engine body, which is used to form downward oil return and upward exhaust of the engine.

[0041] It should be understood that the engine is an up-down structure, which is used as the up-down orientation reference system in the present application.

[0042] It should be understood that "inner" and "outer" in the present application refer to the side close to the sand core as inner and the side far from the sand core as outer.

[0043] It should be understood that "front", "rear", "left", "right", "upper" and "lower" in the present application are defined as the orientation of the engine body in the normal use state.

[0044] Example 1

[0045] As Figure 1As shown, the existing truss cavity is through from top to bottom, and a process hole is reserved in the middle for truss core assembly support, pouring and pressure, and residual sand cleaning. After machining, the bowl type plug is pressed and assembled. The main function of the process hole is to form a support in the lower sand mold when the long and narrow truss core is assembled in the lower box, so as to avoid the truss core from being broken due to gravity. When in the upper box, it is used for the pressure of the upper sand mold on the truss core, so as to avoid the truss core from being broken or displaced due to the buoyancy of molten iron, thereby affecting the wall thickness of the casting. The main disadvantage of this technology is that there is no reliable positioning and locking structure between the truss core and the main core, so the truss core cannot be accurately and stably fixed on the main core for overall turnover and overall core setting. At the same time, the core head caused by the core fixing and pressure increases the process hole in the product appearance, which needs to be further processed and assembled with the bowl type plug for plugging, so as to meet the product performance. However, the bowl type plug forms a split in the longitudinal stress of the product, weakens the rigidity of the whole machine, and the bowl type plug has a risk of leakage, which affects the reliability of the product. In order to solve the above technical problems, the engine body sand core structure and the body structure made of the sand core are provided. Figure 2 、 Figure 3 As shown, the engine body truss sand core structure disclosed in the embodiment comprises a truss sand core structure and a main core structure. As shown in Figure 4 、 Figure 5 The embodiment also discloses a main core structure corresponding to the truss sand core structure in Figure 2 、 Figure 3 , from bottom to top, the truss sand core setting position of the main core is in order of plug-in hole 5-1, reverse buckle groove 5-2, and pressure groove 5-3; the plug-in part 4-1 is plugged into the plug-in hole 5-1, the reverse buckle part 4-2 is buckled into the reverse buckle groove 5-2, and the pressure part 4-3 is pressure assembled into the pressure groove 5-3.

[0046] The truss core head structure and assembly process of the bottom plug-in, middle reverse buckle, and top pressure assembly between the sand core and the main core in the embodiment can accurately and stably fix the long and narrow truss core on the main core in a standing state. The constraint of the upper, middle and lower positions in six directions makes the truss core can be turned 360 degrees with the main core and does not fall during long distance turnover.

[0047] As a further embodiment, the plug-in part 4-1 at the bottom, the pressure part 4-3 at the top, and the reverse buckle part 4-2 in the middle of the sand core structure are all integral structures of the sand core body.

[0048] Specifically, the plug-in part 4-1 in the embodiment is a protrusion extending downward along the height direction of the sand core body; the protrusion can be cylindrical or non-cylindrical, or other shapes, and can be solid or hollow, and is specifically designed according to actual conditions.

[0049] Specifically, the undercut part 4-2 in the embodiment is an irregular shape extending along the width direction of the sand core body to both sides of the sand core body and protruding to the side where the main core is located, and can be clamped in the undercut groove 5-2 of the sand core body. Specifically, the truss core penetrates the machine body up and down, except that the bottom is plugged into the crater formed by the large cylinder core, the top is pressed by the water jacket core and the upper cover core, and the middle part of the long and narrow sand core is in a free state. If nothing is done, the sand core will float or break during core assembly or pouring, affecting the wall thickness around the truss. The conventional process is to increase a process hole in the middle of the machine body truss. The hole is connected to the large cylinder to form a through hole, and is connected to the outer mold to form a through hole. The core head formed by the two through holes can play the role of positioning, supporting and pressing the truss core. However, the truss core is located between the two large cylinder cores, and cannot be directly drilled to connect with the large cylinder core. After drilling from the outside to the outer mold, the truss is separated from top to bottom, which is not conducive to the structure reinforcement of the machine body. At the same time, oil and gas leakage after drilling is not allowed, and the casting hole needs to be machined again and the bowl plug needs to be pressed to seal. The present application extends a section of the truss core in the middle of the truss core to form a lap with the large cylinder core. Although it solves the problem of one-way support and pressing between the truss core and the large cylinder core, the sand core still cannot be fixed firmly. Usually, a nail or an adhesive is used to fix the truss core to the large cylinder core, which increases the operation difficulty and has the risk of sand core breakage and casting porosity. Based on this, the shape of the undercut part and the undercut groove of the truss core and the large cylinder core is redesigned to increase the constraint of the truss core outward. Specifically, a curved parting is used to separate the large cylinder core and the truss core, and a long strip-shaped undercut groove is formed on the large cylinder core in the opening direction. The undercut groove is small on the outside and large on the inside, and high on the inside and low on the outside, which is convenient for mold opening and core removal, as shown in Figure 5 . One long strip-shaped step is designed on the truss core, and the undercut groove of the large cylinder core is matched, as shown in Figure 3 .

[0050] The design of the undercut core head structure in the limited space needs to consider the core making opening direction, the core assembly direction from top to bottom, and the large cylinder core opening direction left and right. When designing the truss core mold, a complex curved sand core separation design is adopted at the middle undercut core head.

[0051] When the truss sand core is assembled, the truss core is first aligned with the large cylinder core left, right and rear, and then the long strip step of the truss core is inserted into the long strip undercut groove of the large cylinder core. After falling to the bottom, five constraint directions of front, rear, left, right and down are formed at this position. In addition, the top is upwardly constrained, and the truss sand core and the large cylinder core form complete six-way constraint, as shown in Figure 8 , Figure 9As shown.

[0052] Specifically, the pressing part 4-3 in the embodiment is a protrusion formed in the upward direction along the height direction of the sand core body; the protrusion can be rectangular, cylindrical, non-cylindrical, or other shapes, and can be solid or hollow, and is specifically designed according to actual conditions.

[0053] Specifically, the insertion hole 5-1 in the embodiment is arranged on the upper surface of the main core base, and the insertion hole 5-1 extends downward along the height direction of the base; the inner circle shape of the insertion hole 5-1 is the same as the outer shape of the insertion part 4-1, so that the insertion part 4-1 can be inserted into the insertion hole 5-1 on the main core.

[0054] Specifically, the undercut groove 5-2 in the embodiment is arranged in the main core for forming the cylinder body sand core, and the undercut groove 5-2 is matched with the undercut part 4-2, so that the two can be undercut together.

[0055] Specifically, the pressing groove 5-3 in the embodiment is arranged on the upper part of the main core, and the pressing groove 5-3 is matched with the pressing part 4-3, so that the two can be pressed together.

[0056] The inventive sand core core head and core assembly process design accurately and stably assemble the long and narrow truss sand core on the main sand core to form an integral core assembly that can be turned 360 degrees and does not fall off during long distance circulation. Meanwhile, the undercut part 4-2 is arranged on the sand core body in the embodiment.

[0057] Based on the above-mentioned sand core structure, the embodiment also discloses an engine body cast by the above-mentioned engine body sand core structure. The engine body casting produced by the above-mentioned sand core has a complete appearance, a clean inner cavity, uniform wall thickness, and does not need secondary processing process holes and pressing bowl type plugs, and has good body structure rigidity, good truss cavity sealing, no oil and gas leakage risk, and product structure better than foreign competitors.

[0058] Further, based on the above-mentioned body, the embodiment of the application also provides an engine comprising the above-mentioned engine body. Since the engine is provided with the above-mentioned engine body, the engine also has all the advantages as described above.

[0059] Embodiment 2

[0060] The embodiment also provides another body truss sand core structure, which is provided with a plug-in hole at the bottom, a reverse buckling part at the middle, and a press-fitting groove at the top; from bottom to top, the corresponding position of the truss sand core of the main body core is sequentially provided with a plug-in part, a reverse buckling groove, and a press-fitting part; the plug-in part is plugged into the plug-in hole, the reverse buckling part is buckled into the reverse buckling groove, and the press-fitting part is press-fitted into the press-fitting groove; that is, compared with the embodiment 1, the difference of the embodiment is mainly that the design of the plug-in position and the press-fitting position of the truss sand core structure and the main body core is exchanged, the design of the middle reverse buckling position is the same as that of the embodiment 1, and specifically, the truss core head structure and the assembling process that the sand core and the main body core adopt the bottom plug-in, the middle reverse buckling, and the top press-fitting in the embodiment can accurately and stably fix the long and narrow truss core in a standing state on the main body core. The constraints of the upper, middle and lower positions in six directions make the truss core not fall off when being turned by 360 degrees and long-distance circulation with the main body core.

[0061] As a further improvement, the plug-in hole at the bottom, the reverse buckling part at the middle, and the press-fitting groove at the top of the sand core structure in the embodiment are all integral structures of the sand core body.

[0062] As a further improvement, the plug-in hole in the embodiment extends from the bottom of the sand core body to the inside of the sand core body along the height direction of the sand core body; the hole can be cylindrical, non-cylindrical or other shapes, and is specifically designed according to the actual situation. Correspondingly, the plug-in part in the embodiment extends upward along the height direction of the top surface of the main body core base; the protrusion can be cylindrical, non-cylindrical or other shapes, and can be solid or hollow, and is specifically designed according to the shape of the plug-in hole.

[0063] Specifically, the press-fitting groove in the embodiment is a groove formed by extending downward from the top surface of the sand core body along the height direction of the sand core body; the groove can be rectangular, cylindrical, non-cylindrical or other shapes, and is specifically designed according to the actual situation. Correspondingly, the press-fitting part is arranged at the upper part of the main body core, and the shape of the press-fitting groove and the press-fitting part is matched so that they can be press-fitted together.

[0064] Based on the sand core structure described above, the embodiment also discloses an engine body structure which is cast by using the engine body sand core structure described above. The engine body casting produced by using the sand core has a complete appearance, a clean inner cavity, and uniform wall thickness, does not need a secondary processing process hole and a press-fitting bowl plug, has good body structure rigidity, good truss cavity sealing performance, no risk of oil and gas leakage, and a product structure superior to foreign competitors.

[0065] It is also important to note that the word "comprising" does not specify the presence of only the listed components or steps nor does it imply that other parts or steps can not be present. In a preferred embodiment of the application, each of the first and second entities or operations is a distinct entity or operation.

[0066] The above description is merely illustrative of the application, and is not intended to limit the scope of the application that is defined by the appended claims. Many variations and modifications of the application can be made by those skilled in the art without departing from the spirit and principles of the application. Any modification, equivalent substitution, improvement, and the like made by those skilled in the art without departing from the spirit and principles of the application should be included in the scope of the application.

Claims

1. An engine block sand core structure, characterized in that, Includes truss sand core and main core, the The truss sand core includes a sand core body, with an insertion part at the bottom, a pressing part at the top, and an undercut part in the middle. The main body has, from bottom to top, an insertion hole, an undercut groove, and a pressing groove. The insertion part is inserted into the insertion hole, the undercut part is fastened into the undercut groove, and the pressing part is pressed into the pressing groove. This allows the truss core to rotate 360 ​​degrees with the main body and remain in place during long-distance rotation. The aforementioned undercut portion is an irregular shape that extends along the width of the sand core body to both sides of the sand core body and simultaneously protrudes towards the side where the main core is located, which can be fitted into the undercut groove of the sand core body. The undercut groove is a long strip-shaped groove. The length of the groove is set along the mold opening direction of the main core, and the area of ​​the groove near the sand core body is larger than the area away from the sand core body. The height of the groove near the sand core body is larger than the height away from the sand core body.

2. The engine block sand core structure as described in claim 1, characterized in that, The bottom of the sand core structure The plug-in part, the top pressing part, and the middle inverted part are all part of the sand core body as a single structure.

3. The engine block sand core structure as described in claim 1, characterized in that, The insertion part is a protrusion that extends downward along the height direction of the sand core body.

4. The engine block sand core structure as described in claim 1, characterized in that, The pressing part is a protrusion that extends upward along the height direction of the sand core body.

5. An engine block structure, which is cast using the engine block sand core structure as described in any one of claims 1-4.

6. An engine block sand core structure, characterized in that, The system includes a truss sand core and a main body core. The truss sand core includes a main body core with an insertion hole at the bottom, a pressing groove at the top, and an undercut part in the middle. The main body core has the insertion part, the undercut groove, and the pressing part arranged sequentially from bottom to top. The insertion part is inserted into the insertion hole, the undercut part is fastened into the undercut groove, and the pressing part is pressed into the pressing groove. This allows the truss core to rotate 360 ​​degrees with the main body core and remain in place during long-distance rotation. The aforementioned undercut portion is an irregular shape that extends along the width direction of the sand core body to both sides of the sand core body and simultaneously protrudes towards the side where the main core is located, and fits perfectly into the undercut groove of the sand core body. The undercut groove is a long strip-shaped groove. The length of the groove is set along the mold opening direction of the main core, and the area of ​​the groove near the sand core body is larger than the area away from the sand core body. The height of the groove near the sand core body is larger than the height away from the sand core body.

7. The engine block sand core structure as described in claim 6, characterized in that, The insertion hole at the bottom, the pressing groove at the top, and the inverted groove in the middle of the sand core structure are all integral parts of the sand core body.

8. The engine block sand core structure as described in claim 6, characterized in that, The insertion hole extends from the bottom of the sand core along the height direction of the sand core body into the interior of the sand core body.

9. The engine block sand core structure as described in claim 6, characterized in that, The pressing groove is a groove formed by the downward indentation of the top surface of the sand core along the height direction of the sand core body.

10. An engine block structure, which is cast using the engine block sand core structure as described in any one of claims 6-9.

Images