Adjustable chaplet for casting automobile engine cylinder body

Abstract

The invention provides an adjustable chaplet for casting an automobile engine cylinder block, which comprises a lower chaplet, an upper chaplet and a locking piece capable of being inserted into the upper chaplet, and the upper chaplet is inserted into the lower chaplet in a sliding manner. And a locking mechanism is arranged between the upper chaplet and the lower chaplet. And when the locking piece is axially inserted into a set position along the upper core support, the locking piece drives the locking mechanism to act, so that the upper core support and the lower core support are fixedly locked in the axial direction. And when the locking piece is pulled out, the locking mechanism is unlocked, and the upper chaplet can slide relative to the lower chaplet so as to adjust the height. During use, the upper chaplet only needs to slide to the required height relative to the lower chaplet, and then the locking piece is inserted into the upper chaplet, so that locking can be completed. Rotation is not needed in the height adjusting process, and rapid adjustment is achieved. Locking and unlocking are completed through plugging and unplugging actions, operation is easy and convenient, large-scale operation is suitable, and the production preparation efficiency is remarkably improved. The upper and lower chaplets are rigidly connected through the locking mechanism after being locked, so that the shock resistance and the bearing capacity are high, and the reliability is high.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of foundry core support, and particularly relates to an adjustable core support for casting of an automobile engine cylinder block. BACKGROUND

[0002] In the sand casting process of complex castings such as automobile engine cylinder blocks, core support is a key process accessory for ensuring accurate and stable positioning of sand cores in the mold cavity. Its role is to offset the buoyancy and impact of the metal liquid on the sand core during pouring, prevent the sand core from drifting or deforming, and thus ensure the dimensional accuracy and shape integrity of the internal cavity of the casting.

[0003] At present, in order to adapt to the height changes of different sand core sizes and sand mold gaps, the market generally uses core supports with adjustable height. This scheme is usually composed of a screw rod with external threads and a sleeve base with internal threads. By rotating the screw rod or the sleeve, the engagement length of the two is changed, thereby realizing the adjustment of the overall support height. The essence of thread adjustment is that the upper and lower parts of the core support need to rotate relative to each other. Each height adjustment requires multiple rotations. In situations where a large number of core supports are needed, manual rotation and adjustment one by one is extremely inefficient, seriously slowing down the production rhythm. At the same time, the pitch of the thread determines the minimum increment of adjustment, making it difficult to achieve more precise and stepless fine adjustment. Operators often rely on hand feeling and experience to make "estimated" adjustments, making it difficult to ensure the consistency of the support height and posing a hidden danger to the uniformity of the casting wall thickness.

[0004] Therefore, the above problems need to be solved. SUMMARY

[0005] The application aims to overcome the above shortcomings and provides an adjustable core support for casting of an automobile engine cylinder block, which aims to solve the problems of low adjustment efficiency and poor consistency of support height of existing thread adjustment type core supports. By designing a structure that can quickly adjust the height without rotation and reliably lock, the convenient, efficient and accurate adjustment of the core support height is realized to meet the high precision requirements of sand core support in the casting process of automobile engine cylinder blocks, improve production efficiency and ensure casting quality.

[0006] Technical solution: In order to achieve the above-mentioned purpose, the present application provides an adjustable core support for automobile engine cylinder block casting, which comprises a lower core support, an upper core support and a locking piece that can be inserted into the upper core support. The upper core support is slidably inserted into the lower core support. A locking mechanism is arranged between the upper core support and the lower core support. When the locking piece is inserted into the upper core support along the axial direction to a set position, the locking piece drives the locking mechanism to act, so that the upper core support and the lower core support are fixedly locked in the axial direction. When the locking piece is pulled out, the locking mechanism is unlocked, and the upper core support can slide relative to the lower core support to adjust the height. In use, the upper core support only needs to be slid relative to the lower core support to the required height, and then the locking piece is inserted into the upper core support to complete the locking. The height adjustment process does not need to be rotated, and the adjustment is fast. The locking and unlocking are completed by inserting and pulling out the action, which is simple to operate and suitable for mass production, and significantly improves the production preparation efficiency. After locking, the upper and lower core supports are rigidly connected through the locking mechanism, and have strong impact resistance and carrying capacity, and high reliability.

[0007] Further, in the adjustable core support for automobile engine cylinder block casting, the lower core support is provided with a sleeve part, and the upper core support is provided with a connecting shaft part. The connecting shaft part is slidably connected in the sleeve part. The locking mechanism comprises a plurality of clamping grooves arranged on the side wall of the sleeve part, and at least one locking block arranged on the connecting shaft part. The upper core support is provided with a slot along the axis. When the locking piece is inserted into the slot, the locking piece drives the locking block to move radially outward, so that it is clamped into the clamping groove. The sliding fit of the sleeve part and the connecting shaft part has good guidance and stable movement. The plurality of clamping grooves distributed along the axial direction provides a plurality of predetermined locking positions for the connecting shaft part, and realizes accurate and firm mechanical locking. The locking block is directly driven outward by the inserted locking piece, and has simple structure, direct driving force, rapid and reliable locking action.

[0008] Further, in the adjustable core support for automobile engine cylinder block casting, the connecting shaft part is provided with at least one mounting slot along the radial direction, and the locking block is slidably connected in the mounting slot. One side of the mounting slot is provided with a spring groove, and a return spring is arranged in the spring groove. The locking block is provided with a driving boss adjacent to the side of the return spring. When the connecting shaft part is inserted into the sleeve part, one end of the locking block abuts against the inner side wall of the sleeve part, and the driving boss presses the return spring, so that the return spring is in a compressed state.

[0009] The inner wall of the sleeve part is a smooth guide surface on the side corresponding to the driving boss of the locking block, and a clamping groove is arranged on the other side corresponding to the locking block. When the locking piece is not inserted, the return spring forces the locking block to approach the smooth guide surface of the sleeve part, and the smooth guide surface makes the locking block retract into the connecting shaft part, so that the upper core support can freely slide relative to the lower core support. After the locking piece is inserted, it drives the locking block to move to the clamping groove side and clamps into the clamping groove against the spring force. The above design automatically unlocks the upper core support and the lower core support by pulling out the locking key, without the need for additional knocking, shaking or tool assistance, which simplifies the operation process, reduces the requirement for the operator's skill, and avoids damage to the sand core caused by vibration.

[0010] This structure design makes the locking block stable in the retracted position in the unlocked state, avoiding unnecessary friction or jamming with the card slot, ensuring the smoothness of the sliding adjustment of the upper core support. When the locking piece is inserted and drives the locking block to be clamped into the card slot, the return spring is further compressed and stores elastic potential energy; once the locking piece is pulled out, the elastic force of the return spring can quickly push the locking block out of the card slot and reset, realizing the automatic unlocking of the locking mechanism, convenient operation and quick response.

[0011] Further, in the adjustable core support for casting automobile engine cylinder block, the installation grooves are arranged axially along the connecting shaft portion. The spring grooves are alternately arranged on different sides of adjacent installation grooves. The staggered arrangement of the spring grooves allows the installation spaces of the return springs of adjacent locking blocks to be staggered, so that multiple locking blocks can be arranged compactly in the axial direction, increasing the number of locking points in a limited space, providing more optional locking height positions, achieving finer height adjustment, and widening the process adaptability to meet the production needs of castings with different support heights.

[0012] Further, in the adjustable core support for casting automobile engine cylinder block, the connecting shaft portion is provided with an eccentric boss at the bottom. The sleeve portion is provided with an eccentric groove matched with the eccentric boss. The eccentric boss and the eccentric groove cooperate to limit the relative rotation of the lower core support and the upper core support. The cooperation of the eccentric boss and the eccentric groove ensures that the connecting shaft portion of the upper core support does not rotate circumferentially in the sleeve portion of the lower core support, ensuring the stability of the locking.

[0013] Further, in the adjustable core support for casting automobile engine cylinder block, the locking block is provided with a driving through groove for the locking piece. When the locking piece is inserted into the insertion slot, the locking piece extrudes the inner wall of the driving through groove to drive the locking block to move radially outward. When the locking piece is inserted and passes through the driving through groove, its outer surface contacts and extrudes the inner wall of the through groove, pushing it to move smoothly outward.

[0014] Further, in the adjustable core support for casting automobile engine cylinder block as described above, the connecting shaft portion is provided with an anti-extraction mechanism for preventing the locking member from being extracted from the insertion slot. The side wall of the locking member is provided with a positioning groove matched with the anti-extraction mechanism. The anti-extraction mechanism is connected to the mounting hole provided in the connecting shaft portion. The anti-extraction mechanism comprises a top bead accommodated in the mounting hole provided in the connecting shaft portion, an elastic element and a blocking member. The blocking member is fixed at the opening of the mounting hole, and the elastic element applies a pushing force to the top bead so that the top bead partially extends into the insertion slot. When the locking member is inserted to the set position, the top bead is clamped into the positioning groove. During the insertion of the locking member, when the positioning groove moves to the position of the top bead, the top bead is clamped into the groove under the pushing of the elastic element, producing a clear "click" feeling or sound, which clearly feeds back to the operator that the set position has been reached and the locking has been completed. At the same time, the top bead is clamped into the groove to form a mechanical interlock, effectively preventing the locking member from being axially displaced or extracted due to vibration, thereby ensuring the durability and reliability of the locking.

[0015] Further, in the adjustable core support for casting automobile engine cylinder block as described above, the positioning grooves are arranged axially spaced apart, and the axial positions of the positioning grooves and the locking blocks on the connecting shaft portion are matched. When the top bead is clamped into the positioning groove, the locking member pushes the locking block and clamps it into the clamping slot. By matching the positions of the positioning grooves with the axial positions of the locking blocks, it is ensured that the triggering position of the anti-extraction mechanism is synchronized with the locking position of the locking mechanism. This means that only when the locking member is inserted to a sufficient depth to completely push the locking block out and clamp it in the clamping slot, the top bead will be clamped into the positioning groove. This linkage design allows the operator to be sure that the core support has been completely locked once the feedback of the top bead clamping is felt or heard, without the need for secondary confirmation, thereby improving the reliability and convenience of operation.

[0016] Further, in the adjustable core support for casting automobile engine cylinder block as described above, the locking member has a driving portion for driving the locking block. The driving portion comprises a locking surface and a guide surface. The locking surface is a vertical plane for contacting the locking block. The guide surface is connected to the end of the locking surface and is arranged as an inclined surface for guiding the locking block to produce radial displacement during insertion. The guide surface is inclined, which gradually contacts the inner wall of the driving slot of the locking block at the initial stage of insertion of the locking member, smoothly pushes the locking block radially, reduces the insertion resistance, and makes the operation more labor-saving and smooth. When the locking member is fully inserted into place, the locking surface contacts the locking block. The locking surface is a vertical plane, which contacts the surface of the locking block in the axial direction, provides a stopping force, effectively resists the tendency of the upper and lower core supports to separate due to the impact of the metal liquid during pouring, and ensures the stability of the final locking.

[0017] Furthermore, in the aforementioned adjustable core support for casting automotive engine cylinder blocks, the outer contour of the connecting shaft cross-section is elliptical; the inner contour of the sleeve cross-section is adapted to fit the connecting shaft. This elliptical surface mating structure eliminates the possibility of relative rotation between the upper and lower core supports, ensuring that the locking block and the slot are always precisely aligned.

[0018] The set position mentioned in this invention refers to the relative position of the locking member and the upper core support when the locking member is inserted, its driving part drives the locking block to the locked state, and the anti-disengagement mechanism generates positioning feedback.

[0019] As can be seen from the above technical solution, the present invention has the following beneficial effects: ①This invention provides an adjustable core support for casting automobile engine cylinder blocks, which can quickly adjust the height of the core support without rotation. Through the sliding cooperation between the upper and lower core supports and the insertion and removal of the locking parts, the adjustment efficiency is significantly improved, and it is especially suitable for large-volume core support application scenarios. ② The locking mechanism adopts a design in which the locking element drives the locking block to move radially and engage with the slot. Combined with the top ball of the anti-disengagement mechanism and the positioning groove, it ensures fast response, stability and reliability of locking and clear operation feedback, effectively preventing the locking element from accidentally disengaging and the relative displacement of the upper and lower core supports. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the adjustable core support for casting automobile engine cylinder blocks according to the present invention; Figure 2 This is a schematic diagram of the lower core support structure; Figure 3 This is a schematic diagram of the upper core support structure; Figure 4 This is a front view of the upper core support; Figure 5 for Figure 4 The AA-direction sectional view shown; Figure 6 This is a right view of the upper core support; Figure 7 This is a schematic diagram of the structure of the locking block; Figure 8 for Figure 5 The enlarged view shown below; Figure 9 This is a structural schematic diagram of the locking component.

[0021] In the diagram: 1. Lower core support; 11. Sleeve part; 41. Slot; 2. Upper core support; 21. Connecting shaft part; 211. Mounting hole; 212. Mounting groove; 213. Spring groove; 214. Return spring; 215. Eccentric boss; 22. Slot; 3. Locking element; 31. Positioning groove; 32. Guide surface; 33. Locking surface; 4. Locking mechanism; 42. Locking block; 421. Drive boss; 422. Drive through groove; 51. Top ball; 52. Elastic element; 53. Sealing element. Detailed Implementation Example

[0022] like Figure 1 An adjustable mandrel for casting automotive engine cylinder blocks is shown, comprising a lower mandrel 1, an upper mandrel 2, and a locking member 3 into which the upper mandrel 2 can be inserted. The upper mandrel 2 is slidably inserted into the lower mandrel 1. A locking mechanism 4 is provided between the upper mandrel 2 and the lower mandrel 1. When the locking member 3 is inserted axially along the upper mandrel 2 to a set position, the locking member 3 drives the locking mechanism 4 to actuate, fixing the upper mandrel 2 and the lower mandrel 1 axially. When the locking member 3 is pulled out, the locking mechanism 4 is released, and the upper mandrel 2 can slide relative to the lower mandrel 1 to adjust its height. In use, this invention only requires sliding the upper mandrel 2 relative to the lower mandrel 1 to the desired height, and then inserting the locking member 3 into the upper mandrel 2 to complete the locking. The height adjustment process does not require rotation, achieving rapid adjustment. Locking and unlocking are completed through an insertion and removal action, making operation simple and suitable for mass production.

[0023] like Figures 2-3 The adjustable core support for casting an automotive engine cylinder block shown has a lower core support 1 with a sleeve portion 11 and an upper core support 2 with a connecting shaft portion 21. The connecting shaft portion 21 is slidably connected within the sleeve portion 11. The locking mechanism 4 includes multiple slots 41 on the side wall of the sleeve portion 11 and at least one locking block 42 on the connecting shaft portion 21. The upper core support 2 has a slot 22 along its axis. When the locking member 3 is inserted into the slot 22, the locking member 3 drives the locking block 42 to move radially outward, causing it to engage within the slot 41. The sliding fit between the sleeve portion 11 and the connecting shaft portion 21 provides good guidance and smooth movement. The multiple slots 41 distributed along the axial direction provide multiple predetermined locking positions for the connecting shaft portion 21, achieving precise and secure mechanical locking.

[0024] like Figures 4-5The adjustable core support for casting automotive engine cylinder blocks shown has a connecting shaft portion 21 with at least one mounting groove 212 radially provided, and a locking block 42 slidably connected within the mounting groove 212. A spring groove 213 is provided on one side of the mounting groove 212, and a return spring 214 is provided within the spring groove 213. A driving boss 421, abutting against the return spring 214, is provided on the side of the locking block 42 adjacent to the return spring 214. When the connecting shaft portion 21 is inserted into the sleeve portion 11, one end of the locking block 42 abuts against the inner wall of the sleeve portion 11, and the driving boss 421 compresses the return spring 214, placing it in a compressed state.

[0025] The inner wall of the sleeve portion 11 has a smooth guide surface on one side corresponding to the drive boss 421 of the locking block 42; a slot 41 is provided on the other side corresponding to the locking block 42. When the locking member 3 is not inserted, the return spring 214 forces the locking block 42 to move towards the smooth guide surface of the sleeve portion 11, and the smooth guide surface causes the locking block 42 to retract into the connecting shaft portion 21. At this time, the upper core support 2 can slide freely relative to the lower core support 1. After the locking member 3 is inserted, it drives the locking block 42 to move against the spring force towards the slot 41 and lock into it. The above design automatically unlocks the upper core support 2 and the lower core support 1 by pulling out the locking key 3, without the need for additional knocking, shaking or tool assistance, simplifying the operation process, reducing the skill requirements of the operator, and avoiding vibration damage to the sand core.

[0026] like Figure 6 The adjustable core support for casting automotive engine cylinder blocks shown has mounting slots 212 spaced axially along the connecting shaft 21. Spring slots 213 are alternately arranged on different sides of adjacent mounting slots 212. This staggered arrangement of the spring slots 213 ensures that the mounting spaces of the return springs 214 of adjacent locking blocks 42 are staggered, allowing multiple locking blocks 42 to be compactly arranged axially. This increases the number of locking points within a limited space, provides more selectable locking height positions, achieves finer height adjustment, broadens process adaptability, and meets the production needs of castings with different support heights. The return springs 214 are preferably made of special high-temperature alloy materials such as Inconel 718 or GH4169.

[0027] like Figure 3 The adjustable core support for casting automotive engine cylinder blocks shown has an eccentric boss 215 at the bottom of the connecting shaft portion 21. The bottom of the sleeve portion 11 has an eccentric groove that matches the eccentric boss 215. The eccentric boss 215 and the eccentric groove cooperate to restrict relative rotation between the lower core support 1 and the upper core support 2.

[0028] like Figure 7The adjustable core support for casting the automobile engine cylinder block shown has a locking block 42 with a drive groove 422 through which the locking member 3 passes. When the locking member 3 is inserted into the slot 22, it presses against the inner wall of the drive groove 422, thereby driving the locking block 42 to move radially outward. When the locking member 3 is inserted into and passes through the drive groove 422, its outer surface contacts the inner wall of the groove 422 and generates pressure, pushing it to move smoothly outward.

[0029] like Figure 8 The adjustable core support for casting automotive engine cylinder blocks shown has an anti-disengagement mechanism on the connecting shaft 21 to prevent the locking member 3 from dislodging from the slot 22. The locking member 3 has a positioning groove 31 on its side wall that mates with the anti-disengagement mechanism. The anti-disengagement mechanism is connected to a mounting hole 211 on the connecting shaft 21. The anti-disengagement mechanism includes a top ball 51, an elastic element 52, and a sealing member 53, all housed within the mounting hole 211 on the connecting shaft 21. The sealing member 53 is fixed at the opening of the mounting hole 211, and the elastic element 52 applies a pushing force to the top ball 51, causing it to partially extend into the slot 22. When the locking member 3 is inserted to the set position, the top ball 51 engages in the positioning groove 31. During the insertion of the locking member 3, when the positioning groove 31 moves to the top ball 51, the top ball 51 engages in the groove under the push of the elastic element 52, producing a clear "click" feel or sound, clearly indicating to the operator that the set position has been reached and the locking is complete. Meanwhile, the engagement of the top bead 51 forms a mechanical interlock, effectively preventing the locking element 3 from axially shifting or dislodging due to vibration, thus ensuring the long-term reliability of the lock. The elastic element 52 is preferably made of a special high-temperature alloy material such as Inconel 718 or GH4169.

[0030] In this embodiment, the positioning grooves 31 are spaced apart along the axial direction of the locking member 3, and the axial positions of the positioning grooves 31 and the locking blocks 42 on the connecting shaft 21 are matched. When the top ball 51 is engaged in the positioning groove 31, the locking member 3 pushes the locking block 42 and engages it in the slot 41. By matching the position of the positioning groove 31 with the axial position of the locking block 42, the triggering position of the anti-disengagement mechanism and the locking position of the locking mechanism are synchronized. This means that the top ball 51 will only engage in the positioning groove 31 when the locking member 3 is inserted to a depth sufficient to completely push out and lock the locking block 42 in the slot 41. This linkage design allows the operator to be certain that the core support is completely locked once they feel or hear the feedback of the top ball engaging, without the need for secondary confirmation, thus improving the reliability and convenience of the operation.

[0031] like Figure 9The adjustable core support for casting automotive engine cylinder blocks shown has a locking member 3 with a drive portion for driving the locking block 42. The drive portion includes a locking surface 33 and a guide surface 32. The locking surface 33 is a plane perpendicular to the axis and is used to contact the locking block 42. The guide surface 32 is connected to the end of the locking surface 33 and is set as an inclined surface to guide the locking block 42 to generate radial displacement during insertion. Because the guide surface 32 is inclined, it gradually contacts the inner wall of the drive groove 422 of the locking block 42 during the initial insertion of the locking member 3, smoothly pushing the locking block 42 radially, reducing insertion resistance, and making operation easier and smoother. When the locking member 3 is fully inserted, the locking surface 33 contacts the locking block 42. The locking surface 33 is a vertical plane, forming a surface contact with the locking block 42 in the axial direction, providing a stopping force, effectively resisting the tendency of the upper and lower core supports to separate due to the impact of molten metal during pouring, and ensuring the stability of the final lock.

[0032] In this embodiment, the outer contour of the cross-section of the connecting shaft portion 21 is set to be elliptical; the inner contour of the cross-section of the sleeve portion 11 is adapted to the connecting shaft portion 21.

[0033] The working steps of this invention include the following steps: ① Place the bottom of the lower core support 1 at the preset support position of the casting sand mold, ensuring that its bottom is in stable contact with the reference surface of the sand mold. At the same time, the connecting shaft 21 of the upper core support 2 is initially partially inserted into the sleeve 11, the locking block 42 is in a retracted state under the action of the return spring 214, and the locking member 3 is not inserted into the slot 22.

[0034] ② Based on the actual support height requirements of the engine block sand core, the upper core support 2 and the lower core support 1 slide relative to each other along the axial direction. At this time, the end of the locking block 42 with the drive boss 421 abuts against the smooth guide surface of the inner wall of the sleeve part 11 under the action of the return spring 214. Since the outer contour of the cross-section of the connecting shaft part 21 is set as an ellipse and matches the inner contour of the sleeve part 11, circumferential rotation can be effectively prevented during sliding, ensuring accurate adjustment direction. The operator can adjust the upper core support 2 to the target height by observing the scale markings on the connecting shaft part 21 (not shown in the figure).

[0035] ③ Hold the locking piece 3 and align it with the slot 22 at the top of the upper core support 2, then insert it axially. Initially, the guide surface 32 (sloping surface) of the locking piece 3 gradually contacts the inner wall of the driving groove 422 of the locking block 42. The radial force generated by the sloping surface overcomes the elastic force of the return spring 214, smoothly pushing the locking block 42 outwards from the mounting groove 212. As the locking piece 3 continues to be inserted, when the outer end of the locking block 42 moves to the slot 41 position on the inner wall of the sleeve portion 11, the locking block 42 is pushed into the slot 41 by the locking surface 33, achieving axial rigid locking between the upper core support 2 and the lower core support 1. During this process, the top bead 51 of the anti-disengagement mechanism remains pressed against the outer wall of the locking piece 3 under the action of the elastic element 52. When the locking piece 3 is inserted to the set depth, i.e., when the locking block 42 is inserted into the slot 41, the top bead 51 is precisely inserted into the positioning groove 31 of the locking piece 3. The operator can feel a clear "click" and hear a sound, confirming that the locking is complete.

[0036] ④ If the height needs to be readjusted, simply pull out the locking member 3 axially. Initially, the locking surface 33 of the locking member 3 disengages from the inner wall of the drive groove 422. The spring force of the return spring 214 pushes the drive boss 421, causing the locking block 42 to gradually disengage from the slot 41 and retract into the mounting groove 212. After the locking member 3 is completely pulled out, the locking block 42 returns to its retracted state under the action of the return spring 214, and the upper core support 2 and the lower core support 1 resume their sliding engagement, allowing for the next height adjustment.

[0037] The above embodiments are exemplary and are intended to illustrate the technical concept and features of the present invention, so that those skilled in the art can understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An adjustable mandrel for casting automobile engine cylinder blocks, characterized in that: The device includes a lower core support (1), an upper core support (2), and a locking member (3) into which the upper core support (2) can be inserted. The upper core support (2) is slidably inserted into the lower core support (1). A locking mechanism (4) is provided between the upper core support (2) and the lower core support (1). When the locking member (3) is inserted into the set position along the axial direction of the upper core support (2), the locking member (3) drives the locking mechanism (4) to act, so that the upper core support (2) and the lower core support (1) are fixedly locked in the axial direction. When the locking member (3) is pulled out, the locking mechanism (4) is unlocked, and the upper core support (2) can slide relative to the lower core support (1) to adjust its height.

2. The adjustable mandrel for casting automobile engine cylinder blocks according to claim 1, characterized in that: The lower core support (1) is provided with a sleeve portion (11), and the upper core support (2) is provided with a connecting shaft portion (21); the connecting shaft portion (21) is slidably connected to the sleeve portion (11); the locking mechanism (4) includes a plurality of slots (41) provided on the side wall of the sleeve portion (11); and at least one locking block (42) provided on the connecting shaft portion (21); the upper core support (2) is provided with a slot (22) along the axis; when the locking member (3) is inserted into the slot (22), the locking member (3) drives the locking block (42) to move radially outward, so that it is locked into the slot (41).

3. The adjustable mandrel for casting automobile engine cylinder blocks according to claim 2, characterized in that: The connecting shaft (21) is provided with at least one mounting groove (212) in the radial direction, and the locking block (42) is slidably connected in the mounting groove (212); a spring groove (213) is provided on one side of the mounting groove (212), and a return spring (214) is provided in the spring groove (213); a driving boss (421) is provided on the side of the locking block (42) near the return spring (214) to abut against the return spring (214); when the connecting shaft (21) is inserted into the sleeve (11), one end of the locking block (42) abuts against the inner wall of the sleeve (11), and the driving boss (421) squeezes the return spring (214) to put it in a compressed state.

4. The adjustable mandrel for casting automobile engine cylinder blocks according to claim 3, characterized in that: The mounting grooves (212) are spaced apart along the axial direction of the connecting shaft (21); the spring grooves (213) are alternately arranged on different sides of adjacent mounting grooves (212).

5. The adjustable mandrel for casting automobile engine cylinder blocks according to claim 4, characterized in that: The bottom of the connecting shaft (21) is provided with an eccentric boss (215); the bottom of the sleeve (11) is provided with an eccentric groove that matches the eccentric boss (215); the eccentric boss (215) cooperates with the eccentric groove to restrict the relative rotation of the lower core support (1) and the upper core support (2).

6. The adjustable mandrel for casting automobile engine cylinder blocks according to claim 3, characterized in that: The locking block (42) is provided with a drive slot (422) through which the locking member (3) passes; when the locking member (3) is inserted into the slot (22), the locking member (3) presses against the inner wall of the drive slot (422) to drive the locking block (42) to move radially outward.

7. The adjustable mandrel for casting automobile engine cylinder blocks according to claim 2, characterized in that: The connecting shaft (21) is provided with an anti-disengagement mechanism to prevent the locking member (3) from disengaging from the slot (22); the side wall of the locking member (3) is provided with a positioning groove (31) that cooperates with the anti-disengagement mechanism; the anti-disengagement mechanism is connected to the mounting hole (211) provided in the connecting shaft (21); the anti-disengagement mechanism includes a top ball (51), an elastic element (52) and a sealing member (53) housed in the mounting hole (211) provided in the connecting shaft (21); the sealing member (53) is fixed at the opening of the mounting hole (211), and the elastic element (52) applies a pushing force to the top ball (51) so that it partially extends into the slot (22); when the locking member (3) is inserted to the set position, the top ball (51) is engaged in the positioning groove (31).

8. The adjustable mandrel for casting automobile engine cylinder blocks according to claim 7, characterized in that: The positioning groove (31) is spaced apart along the axial direction of the locking member (3), and the positioning groove (31) matches the axial position of the locking block (42) on the connecting shaft (21); when the top bead (51) is inserted into the positioning groove (31), the locking member (3) pushes the locking block (42) and inserts it into the slot (41).

9. The adjustable core support for casting automobile engine cylinder blocks according to claim 2, characterized in that: The locking member (3) has a driving part for driving the locking block (42); the driving part includes a locking surface (33) and a guiding surface (32); the locking surface (33) is a plane perpendicular to the axis and is used to contact the locking block (42); the guiding surface (32) is connected to the end of the locking surface (33) and is set as an inclined surface to guide the locking block (42) to generate radial displacement during insertion.

10. The adjustable mandrel for casting automobile engine cylinder blocks according to claim 2, characterized in that: The outer contour of the cross-section of the connecting shaft part (21) is set to be elliptical; the inner contour of the cross-section of the sleeve part (11) is adapted to the connecting shaft part (21).

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