A casting tool core assembly process

Abstract

The present invention relates to the technical field of tooling core assembly, and in particular to a method for assembling a tooling core for casting, comprising: forming a tooling core; forming a modified sand box; controlling a single screw to extend from the interior of the casting sand box toward the outer wall thereof, sequentially passing through a first gasket, a side plate mounting hole, a sand box mounting hole, a second gasket, and a nut; obtaining a maximum connection gap between a support plane of a screw in a first detachable group and the first gasket; determining the installation priority of the remaining detachable groups in sequence based on the maximum connection gap; and assembling the detachable sand box according to the installation priority, wherein a target uniform locking pressure area of ​​a screw slot arm is determined based on the standard deviation of the locking pressure, and a corresponding duration for which a corresponding screw used to install the remaining detachable groups maintains a maximum allowable torque is determined based on the maximum pressure variation of the locking pressure. The present invention improves the utilization rate of the tooling core and improves the uniformity of the tightening stress distribution.

Description

Technical Field

[0001] The invention relates to the technical field of tool core bone assembly, and in particular to a tool core bone assembly process method for casting. Background Art

[0002] In the prior art, tooling core bones are made of straight rods and cross bars connected by welding or casting, with a simple structure and easy production. This structure is suitable for sand cores with regular shapes and small sizes. For example, when casting small flange sand cores, a simple frame-type core bone can provide basic support for the sand core to prevent the sand core from deforming during transportation and pouring; for large, complex-shaped sand cores, a complex frame-type core bone needs to be designed. This core bone usually adopts a method of multiple rods crossing and connecting each other to form a three-dimensional support network. For example, when casting large marine propeller sand cores, the complex frame-type core bone can penetrate into various parts of the sand core, providing uniform support for the entire sand core, ensuring the shape accuracy and internal quality of the propeller. During casting production, a tooling core bone for casting needs to be designed. After the original tooling core bone is made, it needs to be directly welded to the sand box. A large amount of manpower is required to operate each time it is used, and each core bone can only be used once and needs to be cut off from the sand box after use.

[0003] Chinese Patent Publication No.: CN118060494A discloses a cantilever sand core crack-proof core bone assembly and core making method, comprising: a first core bone, a second core bone and a third core bone, wherein the first core bone is arranged at the cantilever of the cantilever sand core, and a plurality of the second core bones are arranged at the non-cantilever portion of the cantilever sand core, and the first core bone and the second core bone are connected by a plurality of the third core bones; the second core bone is provided with an implantation portion, the implantation portion is exposed from the cantilever sand core and is implanted into the casting during the pouring process. It can be seen that the cantilever sand core crack-proof core bone assembly and core making method have the problems of low utilization efficiency due to the fact that the electric welding core bone can only be used once and needs to be cut from the sand box after use, and the rigid core bone has strong bending resistance during the tightening process between the screw and the nut when fixing the casting core bone, so it is affected by gravity and produces tightening vibration, resulting in a decrease in the uniformity of the tightening force. Summary of the Invention

[0004] To this end, the present invention provides a method for assembling a core bone of a tooling for casting, which is used to overcome the problems in the prior art that the electric welding core bone can only be used once and needs to be cut from the sand box after use, resulting in low utilization efficiency; and because the rigid core bone has strong bending resistance between the screw and the nut during the tightening process when fixing the core bone for casting, it is affected by gravity and produces tightening vibration, resulting in a decrease in the uniformity of the tightening force.

[0005] To achieve the above-mentioned object, the present invention provides a method for assembling a core bone for a casting tool, comprising:

[0006] Welding core bone side plates onto the original core bone to form a tooling core bone, wherein the core bone side plates are provided with a plurality of side plate mounting hole groups at equal intervals along a direction in which the core bone side plates extend laterally, wherein each side plate mounting hole group includes two side plate mounting holes provided along a direction in which the core bone side plates extend longitudinally;

[0007] Cutting a plurality of flask mounting holes at the positions of the plurality of side plate mounting holes corresponding to the tooling core bone of the original flask to form a modified flask;

[0008] Controlling a single screw to extend from the interior of the modified flask toward the outer wall thereof in sequence through the first gasket, the side panel mounting hole, the flask mounting hole, the second gasket, and the nut at corresponding positions to form a first detachable group;

[0009] Obtaining a maximum connection gap between the support plane of the screw in the first detachable group and the first gasket;

[0010] Determining the installation priorities of the detachable groups corresponding to the remaining side panel mounting holes in sequence according to the maximum connection gap;

[0011] Install the remaining removable groups according to the installation priority to assemble the removable sand box;

[0012] Among them, the target uniform area of ​​the locking pressure of the knife groove arm of the screw is determined according to the standard deviation of the locking pressure of several detection points in each sector area of ​​the side plate mounting hole, and the corresponding duration of the maximum allowable torque maintained by the corresponding screw used to install the remaining detachable group is determined according to the maximum pressure change of the locking pressure detected at several detection points within one rotation of the screw.

[0013] Furthermore, based on the condition that the standard deviation is greater than or equal to a preset standard deviation, it is determined that the single knife groove arm of the screw is rotated to within the locking pressure target uniform area during tightening.

[0014] Furthermore, the standard deviation is the standard deviation of the locking pressure of all detection points in each sector-shaped area into which the detection circumferential area of ​​the side panel mounting hole is divided at equal center angles, wherein the number of detection points in each sector-shaped area is the same.

[0015] Furthermore, the locking pressure target uniform area is a sector-shaped area where a detection point corresponding to a minimum value of a standard deviation of the locking pressure is located.

[0016] Furthermore, based on the condition that the thickness of the maximum connection gap is greater than or equal to a preset thickness, the installation priority is determined according to the straight-line distance between the remaining side panel mounting holes and the first tightened side panel mounting hole, wherein the straight-line distance is negatively correlated with the installation priority.

[0017] Furthermore, the corresponding duration for which the corresponding screw for installing the remaining detachable group maintains the maximum allowable torque is determined based on the maximum pressure change of the locking pressure detected at multiple detection points within one screw rotation, including:

[0018] Obtaining a maximum pressure change of the locking pressure within one rotation when the screws corresponding to the remaining side panel mounting holes are rotated according to the installation priority;

[0019] If the maximum pressure change is greater than or equal to a preset maximum pressure change, the screw is controlled to maintain a maximum allowable torque and the duration is increased.

[0020] Furthermore, the maximum pressure variation is the maximum value of the difference between the locking pressure detected at the end of one rotation of a single detection point in the detection circumferential area and the locking pressure detected at the beginning of one rotation.

[0021] Furthermore, the maximum connection gap is the maximum value of the thickness at different positions between the lower surface of the head of the screw and the first gasket after the first detachable assembly is installed.

[0022] Furthermore, the locking pressures of the plurality of detection points are acquired through an annular piezoelectric sensor array, and the annular piezoelectric sensor array is radially arranged with the screw axis as the center.

[0023] Furthermore, the duration is positively correlated with the maximum pressure change.

[0024] Compared with the prior art, the beneficial effect of the present invention is that the method of the present invention realizes the reuse of the tool core bone by disassembling and assembling the tool core bone, thereby improving the utilization efficiency, and detecting the locking pressure and calculating the standard deviation through the first side plate mounting hole. When the screw is tightened, the rigid core bone is subjected to gravity vibration, resulting in uneven distribution of tightening force. For example, the vibration caused by the operation of heavy equipment or the passage of surrounding vehicles is transmitted to the core bone through the sand box base and generates subharmonic resonance with the tightening action, and the temperature difference between the casting environment temperature and the core bone material or the spatial temperature difference on both sides of the sand box causes non-uniform expansion of the core bone installation and thus causes additional shear stress. The knife groove arm is positioned to the minimum standard deviation area by a rotational correction method, which effectively suppresses vibration interference and improves the locking force of the screw group. Uniformity and stability; by determining the installation priority, the core bone units in the vibration-sensitive areas or the areas with uneven locking pressure key nodes are assembled later, so as to gradually optimize the distribution of locking force during the overall assembly process, avoid core bone deformation or sand box seal failure caused by local stress concentration, and further improve the stability of the casting process and the consistency of casting quality; due to interference caused by debris in the hole, when the maximum pressure change of the locking pressure is large, the time for the screw to maintain the maximum allowable torque is extended to rub the soft debris. By maintaining the torque, the stress in the connection system is redistributed to overcome friction variation, promote local plastic deformation or creep, and then reduce the local stress concentration problem caused by debris or tiny foreign matter, thereby improving the stability of the sand box assembly.

[0025] Furthermore, the method of the present invention determines the position of a single knife groove arm of the screw, and the lower part of the screw head bears the locking pressure from the clamped workpiece. The knife groove of the screw mainly bears the torsional shear stress caused by the reaction pressure. When the knife groove arm is rotated to the area with the smallest standard deviation, that is, the most stable pressure area, and the torque is applied, the lateral component force generated by the knife groove arm is smaller. Such a distribution can more effectively convert the rotational force of the knife groove arm into the torque of the screw, while avoiding high stress areas, thereby achieving a more uniform force distribution on the screw group during the tightening process, reducing the fatigue damage of the screw caused by local stress concentration, and improving the overall vibration resistance of the screw by determining the position of a single knife groove arm.

[0026] Furthermore, the method of the present invention compensates for the overall stress state of the core bone by determining the installation priority. During the actual assembly process, due to factors such as uneven temperature control in the casting environment, micro-deformation of the sand box material, and the fitting clearance between the core bone side plate and the sand box mounting hole, the locking pressure in different areas is nonlinearly distributed. The stability of each fan-shaped area is determined by analyzing the standard deviation of the locking pressure, and the installation order of the detachable group is determined, thereby reducing the uneven stress accumulation caused by gravity or vibration in the early stage, thereby achieving an improvement in the structural rigidity of the tooling core bone system and reducing the risk of sand box sealing failure caused by local over-tightening or over-loosening.

[0027] Furthermore, the method of the present invention controls the duration for which the screw maintains the maximum allowable torque. When a large locking pressure fluctuation is detected in a certain detachable group during the tightening process, the duration for which the screw maintains the maximum torque is extended after reaching the target torque. The creep characteristics of the material itself are utilized to gradually fit the small unevenness between the contact surfaces, and the friction between the screw and the hole generates heat to soften the debris in the hole, thereby achieving a tighter and more uniform connection effect, helping to release local stress concentration problems caused by embedded foreign matter, surface roughness differences or inconsistent initial preload, and improving the connection stability between the tooling core bone and the sand box. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is an overall flow chart of a method for assembling a core bone tool for casting according to an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of a detachable sand box structure of a casting tool core assembly process method according to an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of a tool core structure of a tool core assembly process method for casting according to an embodiment of the present invention;

[0031] Figure 4 Schematic diagram of the detection circumferential area structure of the casting tool core assembly process method according to an embodiment of the present invention;

[0032] Explanation of the accompanying numbers: 1- modified sand box, 2- original core bone, 3- core bone side plate, 4- side plate mounting hole, 5- annular piezoelectric sensor array, 6- fan-shaped area. DETAILED DESCRIPTION

[0033] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0034] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that, in the description of the present invention, the terms "upper," "lower," "left," "right," "inner," "outer," and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are merely for ease of description. They do not indicate or imply that the device or component must have a specific orientation, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention.

[0035] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0036] See also Figure 1 、 Figure 2 、 Figure 3 as well as Figure 4 As shown in the figure, they are respectively an overall flow chart of the method for assembling a core bone of a tooling for casting according to an embodiment of the present invention, a schematic diagram of the structure of a detachable sand box, a schematic diagram of the structure of the tooling core bone, and a schematic diagram of the structure of a detection circumferential area. A method for assembling a core bone of a tooling for casting according to an embodiment of the present invention comprises:

[0037] Welding the core bone side plates 3 onto the original core bone 2 to form a tooling core bone, wherein the core bone side plates 3 are provided with a plurality of side plate mounting holes 4 at equal intervals along the lateral extension direction of the core bone side plates 3, wherein each side plate mounting hole 4 group includes two side plate mounting holes 4 provided along the longitudinal extension direction of the core bone side plates 3;

[0038] Cut and form a plurality of flask mounting holes at the positions of the plurality of side plate mounting holes 4 corresponding to the tooling core bone of the original flask to form a modified flask 1;

[0039] Control a single screw to extend from the inside of the modified flask 1 toward the outer wall, sequentially passing through the first gasket, the side panel mounting hole 4, the flask mounting hole, the second gasket, and the nut at the corresponding position to form a first detachable group;

[0040] Obtaining a maximum connection gap between the support plane of the screw in the first detachable group and the first gasket;

[0041] Determining the installation priorities of the detachable groups corresponding to the remaining side panel mounting holes 4 in sequence according to the maximum connection gap;

[0042] Install the remaining removable groups according to the installation priority to assemble the removable sand box;

[0043] Among them, the target uniform area of ​​the locking pressure of the knife groove arm of the screw is determined according to the standard deviation of the locking pressure of several detection points in each sector area 6 of the side panel mounting hole 4, and the corresponding duration of the maximum allowable torque maintained by the corresponding screw used to install the remaining detachable group is determined according to the maximum pressure change of the locking pressure detected at several detection points within one rotation of the screw.

[0044] Specifically, the original core bone 2 is a basic skeleton structure directly welded to the original sand box for supporting the sand core.

[0045] Specifically, the tooling core bar is a skeleton structure formed by welding the core bar side plates 3 with side plate mounting holes 4 on the basis of the original core bar 2. After welding, the core bar side plates 3 constitute the outer working surface of the tooling core bar.

[0046] Specifically, the lateral expansion direction of the core bone side plate 3 is parallel to the longer dimension direction of the tooling core bone on the plane of the core bone side plate 3, and the 4 groups of side plate mounting holes are arranged at equal intervals along this direction; the longitudinal expansion direction of the core bone side plate 3 is perpendicular to the lateral expansion direction of the core bone side plate 3.

[0047] Specifically, the first gasket and the second gasket are flat washers, and the nut is a standard part that matches the screw rod.

[0048] Specifically, the maximum connection gap is the maximum value of the thickness at different positions between the lower surface of the head of the screw and the first gasket detected by the displacement sensor after the first detachable group is installed.

[0049] Specifically, there are at least six flask mounting holes, and those skilled in the art can adjust the number of flask mounting holes according to the actual size of the casting.

[0050] Specifically, the device for controlling the rotation of a single screw is an electric screwdriver.

[0051] In practice, the method of the present invention realizes the reuse of the tool core bone by disassembling and assembling the tool core bone, thereby improving the utilization efficiency. By detecting the locking pressure at the first side plate mounting hole 4 and calculating the standard deviation, the tightening force is unevenly distributed due to the gravity vibration of the rigid core bone when the screw is tightened. For example, the vibration caused by the operation of heavy equipment or the passage of surrounding vehicles is transmitted to the core bone through the sand box base and resonates with the tightening action in the form of subharmonics. The temperature difference between the casting environment temperature and the core bone material or the spatial temperature difference on both sides of the sand box causes the non-uniform expansion of the core bone installation and the additional shear stress. The knife groove arm is positioned to the minimum standard deviation area by the rotation correction method, which effectively suppresses the vibration interference and improves the uniformity and stability of the locking force of the screw group. By determining the installation priority, the core bone units in the vibration-sensitive areas or the areas with uneven locking pressure key nodes are assembled later, so as to gradually optimize the distribution of locking force during the overall assembly process, avoid core bone deformation or sand box seal failure caused by local stress concentration, and further improve the stability of the casting process and the consistency of casting quality; due to interference caused by debris in the hole, when the maximum pressure change of the locking pressure is large, the time for the screw to maintain the maximum allowable torque is extended to rub the soft debris. By maintaining the torque, the stress in the connection system is redistributed to overcome friction variation, promote local plastic deformation or creep, and reduce the local stress concentration problem caused by debris or tiny foreign matter, thereby improving the stability of the sand box assembly.

[0052] Specifically, based on the condition that the standard deviation is greater than or equal to a preset standard deviation, it is determined that the single knife groove arm of the screw is rotated to within the uniform locking pressure target area during tightening.

[0053] Specifically, the standard deviation is the standard deviation of the locking pressure of all detection points in a number of sector-shaped areas 6 divided by equal central angles in the detection circumferential area of ​​the side panel mounting hole 4, wherein the number of detection points in each sector-shaped area 6 is the same.

[0054] Specifically, the locking pressure target uniform area is the sector area 6 where the detection point corresponding to the minimum value of the standard deviation of the locking pressure is located.

[0055] Specifically, with the naked eye, the radius of the detection circle is 3 cm.

[0056] Specifically, the number of sector-shaped areas 6 is at least 6, and the number of detection points set in each sector-shaped area 6 is at least 4.

[0057] Specifically, the knife groove arm is a groove provided on the head of the screw rod for providing a clamping position for the electric screwdriver. In the embodiment of the present invention, the knife groove on the head of the screw rod is a long single knife groove.

[0058] Specifically, the length of the tooling core is 25 cm, and the area of ​​the core side plate 3 is 760 cm2 Under the condition of , the general value range of the preset standard deviation is [200Pa, 500Pa], and the preferred embodiment of the preset standard deviation is 300Pa.

[0059] It will be understood by those skilled in the art that the optional range of the preset standard deviation provided in this embodiment and the preferred embodiment are that in this embodiment, the length of the tooling core bone is 25 cm, the area of ​​the core bone side plate 3 is 760 cm 2 Under the conditions, the value selected is the best value for the technical problem solved by the technical solution of the present invention. In actual applications or experiments, those skilled in the art can adaptively adjust the preset standard deviation according to the actual application environment and application scenario.

[0060] In implementation, the method of the present invention determines the position of a single knife groove arm of the screw, and the lower part of the screw head bears the locking pressure from the clamped workpiece. The knife groove of the screw mainly bears the torsional shear stress caused by the reaction pressure. When the knife groove arm is rotated to the area with the smallest standard deviation, that is, the most stable pressure area, and the torque is applied, the lateral component force generated by the knife groove arm is smaller. Such a distribution can more effectively convert the rotational force of the knife groove arm into the torque of the screw, while avoiding high stress areas, thereby achieving a more uniform force distribution on the screw group during the tightening process, reducing the fatigue damage of the screw caused by local stress concentration, and improving the overall vibration resistance of the screw by determining the position of a single knife groove arm.

[0061] Specifically, based on the condition that the thickness of the maximum connection gap is greater than or equal to the preset thickness, the installation priority is determined according to the straight-line distance between the remaining side panel mounting hole 4 and the first tightened side panel mounting hole 4, wherein the straight-line distance is negatively correlated with the installation priority.

[0062] Specifically, the maximum connection gap is the maximum value of the thickness at different positions between the lower surface of the head of the screw and the first gasket detected after the first detachable assembly is installed.

[0063] Specifically, under the conditions that the diameter of the screw is 1.6 mm and the thickness of the first gasket is 2 mm, the general value range of the preset thickness is [0.1 mm, 0.5 mm], and the preferred embodiment of the preset thickness is 0.3 mm.

[0064] Those skilled in the art will understand that the optional range of the preset thickness provided in this embodiment and the preferred embodiment are the values ​​selected to best achieve the technical problem solved by the technical solution of the present invention under the conditions that the diameter of the screw is 1.6 mm and the thickness of the first gasket is 2 mm. In actual applications or experiments, those skilled in the art can adaptively adjust the preset thickness according to the actual application environment and application scenarios.

[0065] In an embodiment of the present invention, the side panel mounting holes 4 are distributed in a 2×3 rectangular pattern, and the side panel mounting holes 4 are defined as follows: the first row of side panel mounting holes 4 are (1,1), (2,1), and (3,1), and the second row of side panel mounting holes 4 are (1,2), (2,2), and (3,2). If the side panel mounting holes 4 of the first detachable group are (1,1), and the thickness of the maximum connection gap is greater than or equal to the preset thickness, it can be determined that the side panel mounting hole 4 farthest from (1,1) is (3,2), and (3,2) is the next mounting object. Similarly, the mounting priorities are (1,1), (3,2), (1,2), (3,1), (2,2), and (2,1).

[0066] For another example, if the side panel mounting hole 4 of the first detachable group is (2,1) and the thickness of the maximum connection gap is greater than or equal to the preset thickness, it can be determined that the side panel mounting holes 4 with the farthest straight-line distance from (2,1) are (2,1) and (3,2), and any one of the side panel mounting holes 4 of (1,2) and (3,2) is selected as the next installation object. Similarly, the installation priority can be (2,1), (2,1), (3,1), (1,1), (3,2), (2,2).

[0067] Specifically, the corresponding duration for which the corresponding screw used to install the remaining detachable group maintains the maximum allowable torque is determined based on the maximum pressure change of the locking pressure detected at several detection points within one screw rotation, including:

[0068] Obtaining the maximum pressure change of the locking pressure within one rotation when the screw corresponding to the remaining side panel mounting hole 4 is rotated according to the installation priority;

[0069] If the maximum pressure change is greater than or equal to a preset maximum pressure change, the screw is controlled to maintain a maximum allowable torque and the duration is increased.

[0070] Specifically, the maximum pressure variation is the maximum value of the difference between the locking pressure detected at the end of one rotation of a single detection point in the detection circumferential area and the locking pressure detected at the beginning of one rotation.

[0071] Specifically, the length of the tooling core is 25 cm, and the area of ​​the core side plate 3 is 760 cm 2 Under the condition that the maximum allowable torque is 130 N·m, the general value range of the preset maximum pressure change is [10 kPa, 35 kPa], and the preferred embodiment of the preset maximum pressure change is 20 kPa.

[0072] It will be understood by those skilled in the art that the optional range of the preset maximum pressure variation provided in this embodiment and the preferred embodiment are that in this embodiment the length of the tooling core bone is 25 cm and the area of ​​the core bone side plate 3 is 760 cm 2 , under the condition that the maximum allowable torque is 130 N·m, the value selected is the best value for the technical problem solved by the technical solution of the present invention. In actual applications or experiments, those skilled in the art can adaptively adjust the preset maximum pressure change according to the actual application environment and application scenario.

[0073] During implementation, if the difference between the maximum pressure change and the preset maximum pressure change is within 1 kPa, the duration increases by 0.5 s. If the difference between the maximum pressure change and the preset maximum pressure change exceeds 1 kPa, the duration increases by 0.2 s for every 1 kPa that exceeds it. For example, if the difference between the maximum pressure change and the preset maximum pressure change is 3 kPa and the current duration is 0, the duration increases to 0.5 s + 0.2 s + 0.2 s = 0.9 s. Due to the different installation order of installation priority, the duration for each screw to maintain the maximum torque is different.

[0074] In implementation, the method of the present invention compensates for the overall stress state of the core bone by determining the installation priority. In the actual assembly process, due to factors such as uneven temperature control in the casting environment, micro-deformation of the sand box material, and the fitting clearance between the core bone side panel 3 and the sand box mounting hole, the locking pressure in different areas is nonlinearly distributed. The stability of each fan-shaped area 6 is determined by analyzing the standard deviation of the locking pressure, and the installation order of the second side panel mounting hole 4 is determined, thereby reducing the uneven stress accumulation caused by gravity or vibration in the early stage, thereby achieving an improvement in the structural rigidity of the tooling core bone system and reducing the risk of sand box sealing failure caused by local over-tightening or over-loosening.

[0075] Specifically, the locking pressures of the plurality of detection points are acquired through an annular piezoelectric sensor array 5 , and the annular piezoelectric sensor array 5 is radially arranged with the screw axis as the center.

[0076] Specifically, an annular piezoelectric sensor array 5 is arranged around each side plate mounting hole 4 .

[0077] Specifically, the duration is positively correlated with the maximum pressure change.

[0078] In practice, the method of the present invention controls the duration for which the screw maintains the maximum allowable torque. When a large locking pressure fluctuation is detected in a certain detachable group during the tightening process, the duration for which the screw maintains the maximum torque is extended after reaching the target torque. The creep characteristics of the material itself are utilized to gradually fit the small unevenness between the contact surfaces, and the friction between the screw and the hole generates heat to soften the debris in the hole, thereby achieving a tighter and more uniform connection effect, helping to release local stress concentration problems caused by embedded foreign matter, surface roughness differences or inconsistent initial preload, and improving the connection stability between the tooling core bone and the sand box.

[0079] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A casting tool core assembly process method, characterized in that: include: Welding core bone side plates onto the original core bone to form a tooling core bone, wherein the core bone side plates are provided with a plurality of side plate mounting hole groups at equal intervals along a direction in which the core bone side plates extend laterally, wherein each side plate mounting hole group includes two side plate mounting holes provided along a direction in which the core bone side plates extend longitudinally; Cutting a plurality of flask mounting holes at the positions of the plurality of side plate mounting holes corresponding to the tooling core bone of the original flask to form a modified flask; Controlling a single screw to extend from the interior of the modified flask toward the outer wall thereof in sequence through the first gasket, the side panel mounting hole, the flask mounting hole, the second gasket, and the nut at corresponding positions to form a first detachable group; Obtaining a maximum connection gap between the support plane of the screw in the first detachable group and the first gasket; Determining the installation priorities of the detachable groups corresponding to the remaining side panel mounting holes in sequence according to the maximum connection gap; Install the remaining removable groups according to the installation priority to assemble the removable sand box. Among them, the target uniform area of ​​the locking pressure of the knife groove arm of the screw is determined according to the standard deviation of the locking pressure of several detection points in each sector area of ​​the side plate mounting hole, and the corresponding duration of the maximum allowable torque maintained by the corresponding screw used to install the remaining detachable group is determined according to the maximum pressure change of the locking pressure detected at several detection points within one rotation of the screw.

2. The method for assembling a core bone for a casting tool according to claim 1, characterized in that: Based on the condition that the standard deviation is greater than or equal to the preset standard deviation, it is determined that the single knife groove arm of the screw is rotated into the locking pressure target uniform area during tightening.

3. The method for assembling a core bone for a casting tool according to claim 2, characterized in that: The standard deviation is the standard deviation of the locking pressure of all detection points in each sector-shaped area divided by equal center angles of the detection circumferential area of ​​the side panel mounting hole, wherein the number of detection points in each sector-shaped area is the same.

4. The method for assembling a core bone for a casting tool according to claim 3, characterized in that: The locking pressure target uniform area is a sector-shaped area where a detection point corresponding to the minimum value of the standard deviation of the locking pressure is located.

5. The method for assembling a core bone for a casting tool according to claim 4, characterized in that: Based on the condition that the thickness of the maximum connection gap is greater than or equal to the preset thickness, the installation priority is determined according to the straight-line distance between the remaining side panel mounting holes and the first tightened side panel mounting hole, wherein the straight-line distance is negatively correlated with the installation priority.

6. The method for assembling a core bone for a casting tool according to claim 5, characterized in that: The duration for which the corresponding screw used to install the remaining detachable group maintains the maximum allowable torque is determined based on the maximum pressure change of the locking pressure detected at several detection points within one screw rotation, including: Obtaining a maximum pressure change of the locking pressure within one rotation when the screws corresponding to the remaining side panel mounting holes are rotated according to the installation priority; If the maximum pressure change is greater than or equal to a preset maximum pressure change, the screw is controlled to maintain a maximum allowable torque and the duration is increased.

7. The method for assembling a core bone for a casting tool according to claim 6, characterized in that: The maximum pressure variation is the maximum value of the difference between the locking pressure detected at the end of one rotation of a single detection point in the detection circumferential area and the locking pressure detected at the beginning of one rotation.

8. The method for assembling a core bone for a casting tool according to claim 7, characterized in that: The maximum connection gap is the maximum value of the thickness at different positions between the lower surface of the head of the screw and the first gasket after the first detachable assembly is installed.

9. The method for assembling a core bone for a casting tool according to claim 8, characterized in that: The locking pressures of the plurality of detection points are acquired through an annular piezoelectric sensor array, and the annular piezoelectric sensor array is radially arranged with the screw axis as the center.

10. The method for assembling a core bone for a casting tool according to claim 9, characterized in that: The duration is positively correlated with the maximum pressure change.

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