An integral core box mold and method for a cast impeller

Abstract

The application belongs to the technical field of casting moulds, and particularly relates to a whole forming core box mould and method for impeller castings, which comprises a mould base body, a cavity is arranged on the mould base body, a plurality of vane loose blocks are arranged in an array around the cavity, the bottom of each vane loose block is in sliding connection with the bottom wall of the cavity, each vane loose block is divided into a forming section and a matching section, the matching section is close to the central axis, a locking groove is arranged on the outside of the forming section; a plurality of draw blocks which are the same in number as the vane loose blocks and one-to-one corresponding are further arranged, each draw block is arranged around the periphery of the vane loose block, a locking protrusion which is matched with the locking groove is arranged at the front end of each draw block; each draw block is driven to reciprocate by a linear displacement driving assembly which is fixed on the mould base body. The vane loose blocks are pushed to slide to the center by the draw blocks, the matching sections are mutually adhered to form a whole cavity, the whole sand core is formed, the size precision and consistency of the impeller vane are effectively improved, burrs generated by assembling of the split sand core are eliminated, and the production efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of casting mold technology, specifically relating to a mold and method for integral molding of impeller casting core boxes. Background Technology

[0002] Aluminum alloy impellers are core components of hydraulic torque converters in commercial vehicles and construction machinery. The shape and dimensional accuracy of their blades directly affect the torque conversion performance, transmission efficiency, and overall vehicle fuel economy of the hydraulic torque converter. As the performance requirements of power transmission systems in commercial vehicles and construction machinery continue to increase, increasingly stringent requirements are being placed on the dimensional accuracy, surface quality, and consistency of impeller castings.

[0003] Aluminum alloy impellers are typically manufactured using casting processes. Their blades have an open, twisted, and complex structure, meaning that the metal core cannot be directly demolded and must be formed using sand cores. Therefore, the dimensional stability of the sand core is a key factor in the entire casting process.

[0004] Currently, the industry commonly uses a split sand core structure for core box design. This involves splitting the core at the edge of each blade, manufacturing multiple identical sand cores according to the number of blades, and finally assembling and binding all the sand cores together for casting. However, this split assembly structure makes it difficult to guarantee the relative positional accuracy between the blades after assembling multiple sand cores. Furthermore, the assembly gaps between the sand cores generate a large amount of aluminum burrs after casting. This not only leads to highly inconsistent blade dimensions in the cast parts but also requires a huge amount of cleaning work, severely restricting production efficiency. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the purpose of this invention is to provide an integral molding core box mold and method for impeller castings, which can effectively improve the relative positional accuracy between blades, greatly eliminate the generation of burrs, ensure the consistency of casting blade dimensions, and improve production efficiency.

[0006] The technical solution of this invention is: A mold for integrally forming a core box for an impeller casting includes a mold base with a cylindrical cavity having a central axis perpendicular to its bottom wall, and further includes: Multiple blade blocks are distributed in a circular array within the cavity with the central axis of the cavity as the center. The blade blocks are slidably connected to the bottom wall of the cavity in the radial direction. Each blade block includes a forming section and a mating section that are fixedly connected. The mating section is close to the central axis of the cavity. Multiple extraction blocks correspond one-to-one with multiple blade blocks, and the front end of each extraction block is detachably connected to the forming section of the corresponding blade block. Multiple linear displacement driving components are provided, each corresponding to one of the multiple pull-out blocks. Each linear displacement driving component is fixedly mounted on the mold base, and the output end of each linear displacement driving component is fixed to the corresponding pull-out block. The multiple linear displacement driving components are used to drive the multiple blade blocks to slide towards the central axis of the cavity through the corresponding pull-out blocks, so as to achieve side contact of each adjacent mating section and splice them into a ring structure. A limiter, disposed within the cavity, is used to limit the movement distance of the plurality of blade blocks toward one side of the central axis of the cavity.

[0007] Preferably, the plurality of blade blocks include a plurality of first blocks and third blocks, and at least one second block, wherein the first blocks and the third blocks are spaced apart, and the second block is disposed between any adjacent first blocks and third blocks; Wherein, the width of the first movable block at the end away from the forming section is smaller than the width at the end closer to the forming section, and the width difference is A; The width of the second movable block at the end furthest from the forming section is smaller than the width at the end closest to the forming section, and the width difference is B, where B < A. The width of the third movable block at the end furthest from the forming section is greater than the width at the end closest to the forming section.

[0008] Preferably, the inclination angle of one side of the mating section of the third movable block that is used to fit with the mating section of the first movable block is a, and the inclination angle of the side of the mating section of the first movable block that fits with it is b, a+b=180°, where a is 63°~69°.

[0009] Preferably, a sliding limiting structure is provided between the blade block and the bottom wall of the cavity. The sliding limiting structure includes a plurality of sliding grooves and a plurality of sliding blocks that are arranged in a one-to-one correspondence. The plurality of sliding blocks are formed on the bottom wall of the cavity and are arranged in a one-to-one correspondence on the bottom wall of each mating section.

[0010] Preferably, the slider at the bottom of the first movable block is the first slider, the slider at the bottom of the second movable block is the second slider, and the slider at the bottom of the third movable block is the third slider. The width of the first slider is less than the width of the second slider, which is less than the width of the third slider. The width of the first slider is 8mm to 9mm, the width of the second slider is 10mm to 11mm, and the width of the third slider is 12mm to 13mm. The width of each groove is adapted to the width of the corresponding first slider, second slider, and third slider.

[0011] Preferably, the forming section is provided with a locking groove on the outer side away from the mating section, and the drawing block is fixedly connected to the forming section with a locking protrusion that matches the locking groove. The locking protrusion is used to engage with the locking groove when the drawing block moves toward the central axis of the cavity, so as to lock the drawing block and the blade block.

[0012] Preferably, the limiter includes a locking pin and a support frame. The locking pin is a column coaxial with the central axis of the cavity and fixed to the bottom wall of the cavity. The support frame is fitted onto the locking pin. The support frame has a cylindrical structure and is located in the central space formed by the multiple blade blocks.

[0013] A method for integral molding of an impeller casting, used to realize an integral molding core box mold for an impeller casting as described in any one of the above claims, includes the following steps: Confirm that all pull blocks are in the open position on the side away from the central axis of the cavity; According to the assembly sequence, all the blade blocks are installed one by one in the cavity and slid to the side away from the central axis of the cavity; A limiter is installed inside the cavity; All linear displacement drive components are started to run synchronously, pushing each pull block to move towards the central axis of the cavity, so that the locking protrusion at the front end of each pull block is respectively engaged in the locking groove of the corresponding blade block, and the blade blocks are continuously pushed until the mating sections of each blade block are completely fitted and positioned by the limiter. After the core is made by molding and sand injection, the mold is opened and all linear displacement drive components are started again to drive each pull block back to the open position and remove the whole sand core along with all blade blocks. First, remove the limiter, then remove all the blade blocks from the sand core in the preset order to complete the demolding.

[0014] Preferably, the preset order for removing all blade blocks from the sand core is as follows: starting from any third block, remove all third blocks one by one in a counterclockwise direction, then remove all first blocks one by one, and finally remove the second block.

[0015] Compared with the prior art, the impeller casting integral molding core box mold and method of the present invention have the following beneficial effects: This invention utilizes multiple blade-shaped movable blocks that slide radially within a mold cavity and are simultaneously pushed by a pull block. This ensures that the mating sides of each blade-shaped movable block fit tightly together, forming a complete and continuous annular structure. This allows for the direct generation of a seamless, one-piece sand core during sand injection core making. Compared to traditional split sand cores that require the assembly and binding of multiple individual sand cores, this invention's one-piece sand core is formed in a single process. The blade-shaped movable blocks are directly connected to the mold cavity via sliding contact, avoiding the accumulated positional errors that occur when assembling multiple sand cores. This significantly improves the dimensional accuracy and consistency of the impeller blades. Furthermore, since there are no assembly gaps at the parting point between the forming section and the mating section of the blade core block, no aluminum burrs will be generated after casting, saving a lot of cleaning work and greatly improving production efficiency. Moreover, through the connection between the front end of the extraction block and the forming section of the blade core block and the limiting cooperation of the limiter, each blade core block is firmly positioned during the sand shooting core making process, effectively preventing the blade core block from swinging or shifting during high-speed sand shooting, further ensuring the stability and repeatability of sand core forming, thus comprehensively solving the technical problems of poor precision, many burrs and low efficiency caused by the split sand core structure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the blade live block structure in an embodiment of the present invention; Figure 2 This is a three-dimensional structural diagram of the blade live block in an embodiment of the present invention; Figure 3 This is a schematic diagram of the overall structure of the core box mold in an embodiment of the present invention; Figure 4 This is a schematic diagram of the distribution structure of the internal grooves in the cavity according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the installation of the #1 blade live block in an embodiment of the present invention; Figure 6 This is a schematic diagram of the installation of blade live blocks #2 and #3 in an embodiment of the present invention; Figure 7 This is a schematic diagram of the cooperation structure between the support frame and the blade block in an embodiment of the present invention; Figure 8 This is a schematic diagram of the demolding sequence structure in an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1. Forming section; 2. Fitting section; 3. Slider; 4. Locking groove; 5. Sand core; 21. Pull block; 22. Cylinder; 23. Slide groove; 24. Locking protrusion; 25. Locking pin; 26. Support frame. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0020] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0021] Example 1 See Figures 1 to 8 As shown, in order to achieve the integral molding of the impeller casting integral sand core and solve the problems of poor blade dimensional accuracy, unstable consistency and many aluminum burrs caused by the assembly of split sand cores, this embodiment provides an integral molding core box mold for impeller castings, including a mold base, a cylindrical cavity on the mold base, the cavity having a central axis perpendicular to its bottom wall, and also including: multiple one-to-one corresponding blade blocks, a pull block 21, a linear displacement drive assembly and a limiter.

[0022] Multiple blade blocks are arranged in a circular array within the cavity, centered on the central axis. The bottom of each blade block slides radially against the bottom wall of the cavity, with the sliding direction perpendicular to the central axis. Each blade block has a forming section 1 and a mating section 2 fixedly connected along its sliding direction. The mating section 2 is close to the central axis of the cavity. The sidewall of the forming section 1 away from the mating section 2 is arc-shaped. Multiple blade blocks slide towards the central axis of the cavity, allowing the sides of the mating sections 2 to fit together as a single unit. A locking groove 4 is provided on the outer side of the forming section 1 away from the mating section 2. Multiple pull-out blocks 21 are arranged in a one-to-one correspondence with the number of blade blocks. Each pull-out block 21 is arranged around the periphery of the multiple blade blocks. A locking protrusion 24 is provided at the front end of each pull-out block 21. The locking protrusion 24 matches the locking groove 4 of the corresponding blade block, and is used to engage with the locking groove 4 when the pull-out block 21 moves towards the central axis of the cavity, thus locking the blade block. The number of linear displacement drive components is the same as the number of pull blocks 21 and they correspond one-to-one. Each linear displacement drive component is fixedly mounted on the mold base, and the output end of each linear displacement drive component is fixed to the corresponding pull block 21 to drive the pull block 21 to reciprocate. Preferably, the linear displacement drive components are cylinders 22, electric telescopic rods, or electric hydraulic cylinders, etc. Limiters are set in the cavity to limit the movement of multiple blade blocks towards the central axis of the cavity during the casting process, so as to prevent each blade block from retreating towards the central axis of the cavity.

[0023] See Figure 1 As shown, in an embodiment of the present invention, the aforementioned plurality of blade blocks include a plurality of first blocks (i.e., blade block #1) and third blocks (i.e., blade block #3), and at least one second block (i.e., blade block #2). The first and third blocks are spaced apart, and the second block is located between any adjacent first and third blocks. In this embodiment, the total number of blade blocks is 17, corresponding to the number of blades in the impeller, including 8 first blocks (numbered 1#-1 to 1#-8), 8 third blocks (numbered 3#-1 to 3#-8), and 1 second block (numbered 2#). Each blade block is made of H13 steel, which has high hardness and good wear resistance. Through the differentiated design of the three specifications of blade blocks, each blade block has a definite sequential constraint during demolding, providing a structural basis for achieving orderly demolding. At the same time, the H13 steel ensures that the blade blocks have sufficient service life and dimensional stability under repeated sand-shooting impact and sliding friction.

[0024] Specifically, the width of the mating section 2 of the first movable block at the end furthest from the forming section 1 is less than the width at the end closest to the forming section 1, and the width difference is A; the width of the mating section 2 of the second movable block at the end furthest from the forming section 1 is less than the width at the end closest to the forming section 1, and the width difference is B, and B < A; the width of the mating section 2 of the third movable block at the end furthest from the forming section 1 is greater than the width at the end closest to the forming section 1. In particular, the first movable block (blade 1 movable block) is characterized by the inner distance of the mating section 2 being much smaller than the outer distance; the second movable block (blade 2 movable block) is characterized by the inner distance of the mating section 2 being slightly smaller than the outer distance, and it will be blocked by the blade movable blocks on both sides in the mold, meaning it cannot be removed unless the blade movable blocks on both sides are removed first; the third movable block (blade 3 movable block) is characterized by the inner distance of the mating section 2 being greater than the outer distance, and it will block the corresponding blade movable block on the corresponding side in the mold, meaning it must be removed first before the corresponding blade movable block on the corresponding side can be removed. Through the differentiated design of the width difference, the three specifications of blade blocks form a geometric constraint relationship of mutual locking after closing, ensuring that demolding must be carried out in a specific order, effectively avoiding damage to the sand core 5 or block jamming caused by forced demolding.

[0025] See Figure 1 As shown, in an embodiment of the present invention, the inclination angle of one side of the mating section 2 of the third movable block that is used to fit with the mating section 2 of the first movable block is 'a', and the inclination angle of the side of the mating section 2 of the first movable block that fits with it is 'b', a+b=180°, where a is 63°~69°. The inclination angle referred to here is the interior angle between the side of the corresponding blade movable block and its circumferential tangent. Conversely, the exterior angle between one side of the mating section 2 of the #1 blade movable block and its circumferential tangent is 63°~69°, and the exterior angle of the corresponding side of the mating section 2 of the #3 blade movable block that fits with this side is 111°~117°, the sum of the two is 180°. Through this angle fit design, the #1 blade movable block will be blocked in the mold by the #3 blade movable block with an angle of 114° on the same side, that is, the #1 blade movable block cannot be removed unless the #3 blade movable block on this side is removed first. In this embodiment, a complementary angle of 66° and 114° is preferred, thus forming a reliable demolding interference structure. This strictly limits the demolding sequence, allowing operators to smoothly complete demolding simply by following the predetermined order, reducing operational difficulty and the risk of damage to the sand core 5. When the inclination angle 'a' exceeds the above-mentioned angle range, firstly, it may cause local wall thickness of the blade block to be too thin and its strength to be poor; secondly, the blade parting line (i.e., the boundary position between the blade block forming section 1 and the mating section 2) will interfere with the rounded corner at the root of the blade block, which is also determined by the product structure.

[0026] See Figure 1As shown in the embodiment of the present invention, a sliding limiting structure is provided between the blade block and the bottom wall of the cavity. The sliding limiting structure includes multiple sliding grooves 23 and multiple sliders 3, each corresponding to a different blade block. The sliders 3 are formed on the bottom wall of the cavity and are correspondingly arranged on the bottom wall of each mating section 2. Seventeen sliding grooves 23 are provided inside the mold cavity, and each sliding groove 23 has a numbered mark on its bottom corresponding to a blade block. The cooperation between the sliding grooves 23 and the sliders 3 ensures that each blade block can only slide radially, restricting freedom in other directions. This ensures that the sides of each mating section 2 can be accurately aligned and fitted during mold closing. Simultaneously, the bottom numbering facilitates quick and accurate installation by operators, preventing incorrect installation.

[0027] In this design, the slider 3 at the bottom of the first movable block is the first slider 3, the slider 3 at the bottom of the second movable block is the second slider 3, and the slider 3 at the bottom of the third movable block is the third slider 3. The width of the first slider 3 is less than the width of the second slider 3, which is less than the width of the third slider 3. The width of the first slider 3 is 8mm-9mm, the width of the second slider 3 is 10mm-11mm, and the width of the third slider 3 is 12mm-13mm. The width of each groove 23 is adapted to the width of the corresponding first, second, and third slider 3. The width of the groove 23 corresponds to the width of the slider 3 at the bottom of the three types of blade movable blocks, forming a fault-prevention design. Furthermore, a tolerance fit with a single-sided clearance of only 0.02mm-0.03mm is used. Further, as... Figure 4 As shown, the groove 23 corresponding to blade #1 is a short groove 23, while the grooves 23 corresponding to blade #2 and blade #3 are long grooves 23. The long and short grooves 23 are arranged alternately. The sliders 3 of varying widths are precisely fitted with the corresponding grooves 23 with a single-sided gap of 0.02mm~0.03mm. This ensures smooth sliding of the blades and guarantees the fitting accuracy between the mating sections 2 after closing. At the same time, the sliders 3 of different widths and the grooves 23 form an effective anti-misfit structure, avoiding mold damage or scrapping of the sand core 5 due to incorrect installation position of the blades.

[0028] like Figure 4 As shown, each slide groove 23 is equipped with a numbered marker corresponding to the first, second, and third movable blocks. Operators only need to install the blade movable blocks according to the corresponding numbers engraved on the bottom of the slide groove 23 to ensure accurate installation of each blade movable block. The numbered markers on the bottom of the slide groove 23 correspond one-to-one with the blade movable blocks, and combined with the error-proof design of the slide groove 23 width, a double error-proof guarantee is achieved, significantly reducing the probability of human error and improving stability and yield during mass production.

[0029] See Figure 7As shown in the embodiment of the present invention, a locking pin 25 coaxial with its central axis is fixed inside the cavity. A support frame 26 is fitted on the locking pin 25. The support frame 26 has a cylindrical structure and is set in the central space formed by multiple blade blocks. It is used to prevent each blade block from retreating towards the central axis of the cavity during the casting process. After all the blade blocks are installed, a support frame 26 is placed in the middle of all the blade blocks. Its function is to prevent all the blade blocks from retreating. During the sand shooting core making process, the support frame 26 provides outward support to the blade blocks, effectively offsetting the impact force generated by the sand flow on the inner side of the blade blocks during high-speed sand shooting. This prevents the blade blocks from retreating towards the center, causing the side of the mating section 2 to detach and create a gap, thus ensuring the integrity and dimensional accuracy of the cavity during the sand core 5 forming process.

[0030] Example 2 See Figures 3 to 6 As shown, this embodiment provides a method for integral molding of impeller castings, which is used to prepare and demold an integral sand core 5 according to an integral molding core box mold for impeller castings in Embodiment 1.

[0031] See Figure 3 As shown, in this embodiment of the invention, it is first confirmed that all the pull blocks 21 are in the open position on the side away from the central axis of the cavity. That is, it is confirmed that all the pull blocks 2121 driven by the 17 cylinders 22 on the mold are in the open state. The open position of the pull blocks 21 provides sufficient operating space for the installation of the blade blocks, ensuring that each blade block can be smoothly placed into the corresponding slide groove 23, and avoiding interference with the pull blocks 21 during installation.

[0032] See Figure 5 and Figure 6 As shown, in this embodiment of the invention, according to the assembly sequence, all blade movable blocks are installed one by one in the cavity and slid to the side away from the central axis of the cavity. Specifically, according to the corresponding numbers engraved on the bottom of the slide groove 23 on the mold, the eight first movable blocks (1# blade movable blocks) are first placed into the short slide groove 23 and gently pushed to the bottom by hand; then the second movable block (2# blade movable blocks) and the eight third movable blocks (3# blade movable blocks) are placed into the long slide groove 23 and gently pushed to the bottom by hand in the same way. The order of installing 1# movable block first and then 2# and 3# blade movable blocks utilizes the structural characteristics of 1# blade movable block corresponding to the short slide groove 23 and 2# and 3# blade movable blocks corresponding to the long slide groove 23, making the installation process smooth and interference-free. At the same time, the blade movable blocks are pushed to the outside, leaving sufficient sliding stroke for the subsequent pushing of the pull block 21.

[0033] See Figure 7As shown in the embodiment of the present invention, after all the blade blocks are installed, a support frame 26 is placed in the central space formed by the multiple blade blocks. The support frame 26 is fitted onto a locking pin 25 that is coaxially fixed to the central axis inside the cavity. It has a cylindrical structure and is used to prevent the blade blocks from retracting towards the central axis of the cavity during the subsequent core-making process. The support frame 26 is pre-installed before the pull block 21 is closed, so that the support frame 26 plays a role in preventing retraction and supporting the core throughout the sand-shooting process. This ensures that the sides of each mating section 2 remain tightly fitted under the sand-shooting pressure, thus ensuring the dimensional stability of the sand core 5 cavity.

[0034] See Figure 3 and Figure 7 As shown, in an embodiment of the present invention, all linear displacement drive components are activated to operate synchronously, pushing each pull block 21 to move towards the central axis of the cavity, so that the locking protrusion 24 at the front end of each pull block 21 respectively engages in the locking groove 4 of the corresponding blade block, and the blade blocks are continuously pushed until the mating sections 2 of each blade block are completely fitted (e.g., Figure 1 (As shown in the diagram). This means that the 17 cylinders 22 close the pull block 21, and the locking protrusion 24 on the pull block 21 inserts into the locking groove 44 on the end face of the blade block forming section 1, locking the blade block and preventing it from swaying during core-making and sand-shooting, thus affecting accuracy. Each blade block slides towards the center of the cavity under the push of the pull block 21, and the sides of each mating section 2 fit together to form a complete blade sand core 5 cavity. The synchronous drive of the 17 cylinders 22 ensures that all blade blocks slide towards the center simultaneously and evenly, avoiding poor fit or cavity size deviation caused by individual blade blocks not being in place; the locking protrusion 24 engages with the locking groove 4 to form a mechanical lock, effectively constraining the small radial and tangential displacements of the blocks during sand-shooting, ensuring the dimensional accuracy and contour clarity of the sand core 5 blades.

[0035] Then, the mold is closed and sand is injected to make the core. After the core is made, the mold is opened, and all linear displacement drive components are started again, driving each pull block 21 to retract to the open position, and the entire sand core 5 along with all the blade blocks are taken out together. After the mold is opened, the 17 cylinders 22 are operated to open the pull block 21 first, and then the entire sand core 5 along with the 17 blade blocks are taken out together, and the middle support frame 26 is removed. After the pull block 21 is opened, the locking protrusion 24 is disengaged from the locking groove 4, the blade blocks return to the free state, and the entire sand core 5 and the blade blocks are taken out together, so that the demolding operation is carried out outside the mold, avoiding the damage to the cavity that may be caused by directly disassembling the blade blocks inside the mold. At the same time, removing the support frame 26 provides operating space for the subsequent removal of the blade blocks one by one.

[0036] See Figure 8As shown, in an embodiment of the present invention, all blade blocks are removed from the sand core 5 in a predetermined order to complete demolding. The predetermined order for removing all blade blocks from the sand core 5 is as follows: starting from any third block, remove all third blocks one by one in a counterclockwise direction, then remove all first blocks one by one, and finally remove the second block. Specifically, starting from blade block 3#-1, remove the third and first blocks one by one in a counterclockwise direction, and remove the second block last. Since the first block (blade block 1#) is blocked by the third block (blade block 3#) at a 114° angle on the same side, the third block must be removed first before the first block can be removed; while the second block (blade block 2#) is blocked by the third blocks 3# and 1# on both the left and right sides, so it must be removed last. This process achieves smooth demolding without damage or jamming, effectively avoiding problems such as broken sand core 5 blades or blade fragments getting stuck in sand core 5 due to improper sequence, thus ensuring high efficiency and yield of the demolding process.

[0037] By repeating the above steps, integral sand core 5 and impeller castings can be produced continuously.

[0038] The above operation method has clear steps, a closed-loop process, and tight connections between each process, making it suitable for continuous operation in a mass production environment. It effectively improves the overall efficiency and product consistency of impeller casting sand core preparation.

[0039] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A mold for integrally forming a core box of an impeller casting, comprising a mold base, wherein the mold base has a cylindrical cavity, the cavity having a central axis perpendicular to its bottom wall, characterized in that, Also includes: Multiple blade blocks are distributed in a circular array within the cavity with the central axis of the cavity as the center. The blade blocks are slidably connected to the bottom wall of the cavity in the radial direction. Each blade block includes a forming section and a mating section that are fixedly connected. The mating section is close to the central axis of the cavity. Multiple extraction blocks correspond one-to-one with multiple blade blocks, and the front end of each extraction block is detachably connected to the forming section of the corresponding blade block. Multiple linear displacement driving components are provided, each corresponding to one of the multiple pull-out blocks. Each linear displacement driving component is fixedly mounted on the mold base, and the output end of each linear displacement driving component is fixed to the corresponding pull-out block. The multiple linear displacement driving components are used to drive the multiple blade blocks to slide towards the central axis of the cavity through the corresponding pull-out blocks, so as to achieve side contact of each adjacent mating section and splice them into a ring structure. A limiter, disposed within the cavity, is used to limit the movement distance of the plurality of blade blocks toward one side of the central axis of the cavity.

2. The integral molding core box mold for an impeller casting according to claim 1, characterized in that, The plurality of blade blocks include a plurality of first blocks and third blocks, and at least one second block, wherein the first blocks and the third blocks are spaced apart, and the second block is disposed between any adjacent first blocks and third blocks; Wherein, the width of the first movable block at the end away from the forming section is smaller than the width at the end closer to the forming section, and the width difference is A; The width of the second movable block at the end furthest from the forming section is smaller than the width at the end closest to the forming section, and the width difference is B, where B < A. The width of the third movable block at the end furthest from the forming section is greater than the width at the end closest to the forming section.

3. The integral molding core box mold for an impeller casting according to claim 2, characterized in that, The inclination of one side of the mating section of the third movable block that is used to fit with the mating section of the first movable block is a, and the inclination angle of the side of the mating section of the first movable block that fits with it is b, a+b=180°, where a is 63°~69°.

4. The integral molding core box mold for an impeller casting according to claim 2, characterized in that, A sliding limiting structure is provided between the blade block and the bottom wall of the cavity. The sliding limiting structure includes multiple sliding grooves and multiple sliding blocks that are arranged in a one-to-one correspondence. The multiple sliding blocks are opened on the bottom wall of the cavity and are arranged in a one-to-one correspondence on the bottom wall of each mating section.

5. A mold for integral forming of an impeller casting core box according to claim 4, characterized in that, The slider at the bottom of the first movable block is the first slider, the slider at the bottom of the second movable block is the second slider, and the slider at the bottom of the third movable block is the third slider. The width of the first slider is less than the width of the second slider, which is less than the width of the third slider. The width of the first slider is 8mm~9mm, the width of the second slider is 10mm~11mm, and the width of the third slider is 12mm~13mm. The width of each groove is adapted to the width of the corresponding first slider, second slider, and third slider.

6. The impeller casting integral molding core box mold according to claim 4, characterized in that, A locking groove is provided on the outer side of the forming section away from the mating section. A locking protrusion adapted to the locking groove is fixedly connected to the drawing block near the forming section. The locking protrusion is used to engage in the locking groove when the drawing block moves toward the central axis of the cavity, so as to lock the drawing block and the blade block.

7. The impeller casting integral molding core box mold according to claim 4, characterized in that, The limiter includes a locking pin and a support frame. The locking pin is a column coaxial with the central axis of the cavity and fixed to the bottom wall of the cavity. The support frame is fitted onto the locking pin. The support frame has a cylindrical structure and is located in the central space formed by the multiple blade blocks.

8. A method for integral molding of an impeller casting, used to realize the integral molding core box mold for an impeller casting according to any one of claims 1 to 7, characterized in that, Includes the following steps: Confirm that all pull blocks are in the open position on the side away from the central axis of the cavity; According to the assembly sequence, all the blade blocks are installed one by one in the cavity and slid to the side away from the central axis of the cavity; A limiter is installed inside the cavity; All linear displacement drive components are started to run synchronously, pushing each pull block to move towards the central axis of the cavity, so that the locking protrusion at the front end of each pull block is respectively engaged in the locking groove of the corresponding blade block, and the blade blocks are continuously pushed until the mating sections of each blade block are completely fitted and positioned by the limiter. After the core is made by molding and sand injection, the mold is opened and all linear displacement drive components are started again to drive each pull block back to the open position and remove the whole sand core along with all blade blocks. First, remove the limiter, then remove all the blade blocks from the sand core in the preset order to complete the demolding.

9. The method for integral forming of an impeller casting according to claim 8, characterized in that, The preset order for removing all blade blocks from the sand core is as follows: starting from any third block, remove all third blocks one by one in a counterclockwise direction, then remove all first blocks one by one, and finally remove the second block.

Images