Anti-deviation positioning fixture for cylinder head casting sand core

Abstract

This invention discloses an anti-offset positioning fixture for cylinder head casting sand cores in the field of cylinder head casting technology, comprising a base, a linear drive mechanism, a lifting mechanism, and a swing mechanism; the base includes a bottom plate and a top plate; the linear drive mechanism is disposed on the top plate and includes a threaded slider; the lifting mechanism is disposed at the bottom of the slider and includes a cylinder, a first piston disposed within the cylinder, and an adjusting screw for limiting the stroke of the first piston. This invention uses the linear drive mechanism, lifting mechanism, and swing mechanism as components for adjusting the position of the terminal fixture, which can be compatible after debugging for different batches of products and can be reused for the same batch of products. The hydraulic system can drive the lifting mechanism to adjust the height, then drive the swing arm to rotate, and finally lock the rotation gap under pressure to achieve precise fixing.

Description

Technical Field

[0001] This invention relates to the field of cylinder head casting, and more specifically to an anti-displacement positioning fixture for cylinder head casting sand cores. Background Technology

[0002] Cylinder head casting requires the use of sand core assemblies, which are composed of multiple sand core units, such as air passage cores and water jacket cores. The sand core units are assembled and connected to the sand core base, and then placed inside the casting mold. After the molten metal is poured and cooled, the sand cores are removed, thus forming the complex internal structure of the cylinder head.

[0003] During the assembly process, sand cores are generally fixed together by the core head and slot, and then glue is applied between the fixed surfaces. When installing sand core units, a micrometer is needed to determine the position, and then a positioning clamp is used to clamp and fix the suspended or semi-suspended sand core units to prevent them from shifting during the curing process.

[0004] Since there are many sub-models of engine cylinder head improvements, it is costly to equip different positioning fixtures with different sand cores. Highly compatible fixtures need to have multi-dimensional position adjustment capabilities. Existing multi-dimensional position adjustment fixtures are generally adjusted through threaded structures, motors, and sliders. They have return clearance or sliding clearance, which can easily cause slight shaking of the end fixture. Since the sand core components have extremely high precision requirements, even slight shaking can cause the cylinder head to fail to meet quality standards. Summary of the Invention

[0005] The purpose of this invention is to provide an anti-displacement positioning fixture for cylinder head casting sand cores, which solves the problem of gaps in existing sand core positioning fixtures.

[0006] The present invention achieves the above objectives through the following technical solutions: A displacement-prevention positioning fixture for cylinder head casting sand cores includes a base plate and a top plate, and also includes... A linear drive mechanism, which is mounted on the top plate, includes a threaded slider; The lifting mechanism, which is located at the bottom of the slider, includes a cylinder, a first piston located inside the cylinder, and an adjusting screw for limiting the stroke of the first piston; The swing mechanism includes a second piston disposed inside a first piston, a rotating rod that is throttle-connected to the second piston, and a swing arm disposed at the end of the rotating rod; The end of the swing arm is provided with a terminal clamp, and the slider and the inner cavity of the cylinder are connected to a hydraulic system. The slider is driven by hydraulic power to eliminate the thread gap, and the first piston is driven to rise and fall and the rotating rod is driven by hydraulic power in sequence.

[0007] As a preferred embodiment of the present invention, the base plate is provided with a first clamp for holding the sand core base. The first clamp includes four cylinders and a clamping plate provided at the output end of the cylinders. In this embodiment, the sand core base is positioned and fixed by the first clamp to facilitate the splicing and installation of other sand core units.

[0008] As a preferred embodiment of the present invention, the top plate is provided with a groove corresponding to the slider, and the linear drive mechanism further includes a drive part and a threaded rod disposed on the top plate. The threaded rod is threadedly engaged with the slider. This embodiment specifically sets up a drive structure for the slider, which is driven by the thread and finally eliminates the thread gap by applying an axial thrust to the slider.

[0009] As a preferred embodiment of the present invention, the slider is provided with a connecting pipe that connects to the hydraulic system, and the slider is provided with a channel that connects the connecting pipe and the cylinder. By providing a connecting pipe on the slider, this embodiment can easily gather the connecting pipes at the top of the top plate and drive them with a single hydraulic system.

[0010] As a preferred embodiment of the present invention, the side surface of the slider is provided with a hydraulically driven telescopic chamfered block, and the side wall of the slide groove is provided with a chamfered tooth side groove. The chamfered block is used to press on the chamfered tooth side groove after being hydraulically pushed out, so that the slider generates an axial force against the thread in the sliding direction to eliminate the thread gap. Specifically, this embodiment applies an axial force to the slider by telescoping the chamfered block.

[0011] As a preferred embodiment of the present invention, the shaft portion of the first piston is provided with a first rod, and the rotating rod is rotatably connected to the first rod. The second piston is coaxially nested with the first piston, and one end of the second piston is provided with a second rod and a spring for tending to raise the second piston. The bottom side of the second rod is provided with a wide-pitch thread, and the upper surface of the rotating rod is provided with a wide-pitch thread groove for driving the rotating rod to rotate when the second piston moves. This embodiment specifically proposes a swing mechanism structure, which drives the swing arm to rotate through the second piston to add one dimension of adjustment to the terminal clamp.

[0012] In a preferred embodiment of the present invention, a frustum flange is provided at the bottom of the cylinder, a frustum cover is fitted on the frustum flange, a bottom cover is provided at the bottom of the frustum cover, the adjusting screw is threadedly engaged with the bottom cover, and a damping friction surface is provided between the frustum flange and the frustum cover to prevent the frustum cover from rotating when the frustum flange and the frustum cover are pressed together, so that the adjusting screw acts as a swing limiter for the swing arm. In this embodiment, the adjusting screw acts as a limiter for limiting the rotation angle of the swing arm. On the one hand, it limits the lifting stroke of the first piston by adjusting the height, and on the other hand, it limits the movement of the swing arm by rotating the bottom cover. After adjustment, it has memory capability and can be reused in the same batch.

[0013] As a preferred embodiment of the present invention, the bottom cover and the bottom of the frustum flange are provided with elastic pads to increase the pressure between the frustum flange and the frustum cover.

[0014] The beneficial effects of this invention are as follows: By setting a linear drive mechanism, a lifting mechanism, and a swing mechanism as components for adjusting the position of the end clamp, this invention can be compatible with different batches of products after debugging, and can be reused for the same batch of products. The hydraulic system can drive the lifting mechanism to adjust the height, and then drive the swing arm to rotate, and finally lock the rotation gap under pressure to achieve the purpose of precise fixation. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a top view of the present invention; Figure 3 This is a side sectional view of the present invention; Figure 4 This is a cross-sectional view of the lifting mechanism and swing mechanism of the present invention; Figure 5 This is an external view of the lifting mechanism and swing mechanism of the present invention; Figure 6 For the present invention Figure 4 Enlarged view of the A-type structure; Figure 7 For the present invention Figure 4 Enlarged view of the B-type structure; Figure 8 This is a side sectional view of the base structure of the present invention; Figure 9 For the present invention Figure 8 C-axis view; In the diagram: 1. Base; 11. Base plate; 12. First clamp; 13. Top plate; 14. Slide groove; 15. Helical tooth side groove; 2. Linear drive mechanism; 21. Drive unit; 22. Threaded rod; 23. Slider; 24. Angled block; 3. Lifting mechanism; 31. Cylinder; 32. First piston; 33. First rod; 34. Bottom cover; 35. Frustum cover; 36. Frustum flange; 37. Adjusting screw; 38. Elastic pad; 4. Swing mechanism; 41. Second piston; 42. Second rod; 43. Spring; 44. Rotating rod; 45. Wide-pitch threaded groove; 46. Swing arm; 47. Connecting pipe; 5. Terminal clamp. Detailed Implementation

[0016] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0017] Example 1

[0018] like Figures 1-9 As shown, a positioning fixture for preventing displacement of a cylinder head casting sand core includes a base 1, a linear drive mechanism 2, a lifting mechanism 3, and a swing mechanism 4. The base 1 includes a bottom plate 11 and a top plate 13. The linear drive mechanism 2 is mounted on the top plate 13 and includes a threaded slider 23. The lifting mechanism 3 is mounted at the bottom of the slider 23 and includes a cylinder 31, a first piston 32 mounted inside the cylinder 31, and an adjusting screw 37 for limiting the stroke of the first piston 32. The swing mechanism 4 includes a second piston 41 mounted inside the first piston 32 and a rotating rod 44 that is pulsatorically connected to the second piston 41. A swing arm 46 is mounted at the end of the rotating rod 44. A terminal clamp 5 is mounted at the end of the swing arm 46. The slider 23 and the inner cavity of the cylinder 31 are connected to a hydraulic system, which hydraulically drives the slider 23 to eliminate thread clearance and hydraulically drives the first piston 32 to rise and the rotating rod 44 to rotate sequentially.

[0019] In this embodiment, a linear drive mechanism 2, a lifting mechanism 3, and a swing mechanism 4 are set as components for adjusting the position of the terminal clamp 5. After debugging, it can be compatible with different batches of products and can be reused for the same batch of products. The hydraulic system can drive the lifting mechanism 3 to adjust the height, and then drive the swing arm 46 to rotate. Finally, the rotation gap is locked under pressure to achieve the purpose of precise fixation.

[0020] Specifically, in the implementation process, a micrometer is first used to assist in debugging. After the assembly position of the sand core unit is determined, the adjusting screw 37 is set to determine the lifting range of the first piston 32. Then, the swing position of the swing arm 46 is adjusted and limited (in this embodiment, the adjusting screw 37 is used as an alternative implementation method, but other position-adjustable limiting components can also be used). The position of the slider 23 is also adjusted. Finally, the unique position of the terminal fixture can be determined. Multiple sand core units that need to be positioned and clamped on the sand core are set one by one, and then continuous production can be carried out. During the clamping process, the hydraulic system causes the first piston 32 to descend. After the first piston 32 is limited by the adjusting screw 27, it drives the second piston 41 to move. Through transmission, the rotating rod 44 drives the swing arm 46 to swing to the preset position. The slider 23 moves in the sliding groove 14. The excess hydraulic pressure causes the slider 23 to generate axial thrust to eliminate the gap and lock the return gap through various limiting structures.

[0021] Preferably, the base plate 11 is provided with a first clamp 12 for holding the sand core base. The first clamp 12 includes four cylinders and a clamping plate provided at the output end of the cylinders. In this embodiment, the sand core base is positioned and fixed by the first clamp 12 so as to facilitate the splicing and installation of other sand core units.

[0022] Preferably, the top plate 13 is provided with a groove 14 corresponding to the slider 23. The linear drive mechanism 2 also includes a drive part 21 and a threaded rod 22 provided on the top plate 13. The threaded rod 22 is threadedly engaged with the slider 23. In this embodiment, a drive structure for the slider 23 is specifically provided, which is driven by the thread and finally eliminates the thread gap by applying an axial thrust to the slider 23.

[0023] Preferably, the slider 23 is provided with a connecting pipe 47 that connects to the hydraulic system, and the slider 23 is provided with a channel that connects the connecting pipe 47 and the cylinder 31. In this embodiment, by providing a connecting pipe 47 on the slider 23, the connecting pipes 47 can be conveniently collected at the top of the top plate 13 and driven by a single hydraulic system.

[0024] Preferably, the side surface of the slider 23 is provided with a hydraulically driven telescopic chamfered block 24, and the side wall of the slide groove 14 is provided with a chamfered tooth side groove 15. The chamfered block 24 is used to press against the chamfered tooth side groove 15 after being hydraulically pushed out, so that the slider 23 generates an axial force against the thread in the sliding direction to eliminate the thread gap. Specifically, this solution applies an axial force to the slider 23 by telescoping the chamfered block 24.

[0025] Preferably, the shaft of the first piston 32 is provided with a first rod 33, and the rotating rod 44 is rotatably connected to the first rod 33. The second piston 41 is coaxially nested with the first piston 32, and one end of the second piston 41 is provided with a second rod 42 and a spring 43 for making the second piston 41 tend to rise. The bottom side of the second rod 42 is provided with a wide-pitch thread, and the upper surface of the rotating rod 44 is provided with a wide-pitch thread groove 45 for driving the rotating rod 44 to rotate when the second piston 41 moves. This embodiment specifically proposes the structure of the swing mechanism 4, which drives the swing arm 46 to rotate through the second piston 41 to add one dimension of adjustment to the terminal clamp 5.

[0026] Preferably, the bottom of the cylinder 31 is provided with a frustum flange 36, a frustum cover 35 is fitted on the frustum flange 36, and a bottom cover 34 is provided at the bottom of the frustum cover 35. The adjusting screw 37 is threadedly engaged with the bottom cover 34. A damping friction surface is provided between the frustum flange 36 and the frustum cover 35 to prevent the frustum cover 35 from rotating when the frustum flange 36 and the frustum cover 35 are pressed together, so that the adjusting screw 37 acts as a swing limiter for the swing arm 46. An elastic pad 38 is provided at the bottom of the bottom cover 34 and the frustum flange 36 to increase the pressure between the frustum flange 36 and the frustum cover 35. This solution further uses the adjusting screw 37 as a limiter to limit the rotation angle of the swing arm 46. On the one hand, it limits the lifting stroke of the first piston 32 by adjusting the height, and on the other hand, it limits the movement of the swing arm 46 by rotating the bottom cover 34. After adjustment, it has memory capability and can be reused in the same batch.

[0027] The specific implementation method is as follows: First, a micrometer is used to assist in the debugging. After the assembly position of the sand core unit is determined, the position of the slider 23, the height of the adjusting screw 37, and the angle on the bottom cover 34 are adjusted. The debugging process must be carried out under the condition of eliminating gaps. After the debugging is completed, the position of the slider 23 is recorded by the servo system of the drive unit 21, and the height of the adjusting screw 37 and the rotation angle of the bottom cover 34 are fixed. During the clamping process, hydraulic fluid is injected into the hydraulic system, and the first piston 32 lowers its height under its own weight. After the first piston 32 is limited by the adjusting screw 27, the hydraulic fluid drives the second piston 41 to descend. The second rod 42 drives the rotating rod 44 to rotate, causing the rotating rod 44 to swing the swing arm 46 to contact the adjusting screw 37. Since the cross-sectional area of ​​the first piston 32 is much larger than that of the second piston 41, the first piston 32 applies pressure to the adjusting screw 37, causing the frustum cover 35 to press against the frustum flange 36 to restrict its rotation and enable it to withstand the torque of the swing arm 46. During this process, the slider 23 moves in the sliding groove 14 to make the terminal clamp 5 reach the precise clamping positioning point. The excess hydraulic fluid makes the two pistons lock their degrees of freedom, and the chamfered block 24 tends to extend out of the slider 23 and press against the chamfered tooth side groove 15, generating an axial thrust, which makes the slider 23 press against the threaded structure of the threaded rod 22 to eliminate the thread gap.

[0028] Driven uniformly by a hydraulic system, it can eliminate the backlash problem of conventional adjustment units, and it can be adjusted to be compatible with the sand core positioning requirements of various cylinder heads, making it highly adaptable and accurate in positioning.

[0029] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A positioning fixture for preventing displacement of a cylinder head casting sand core, comprising a base plate (11) and a top plate (13), characterized in that, Also includes A linear drive mechanism (2) is provided on a top plate (13) and includes a threaded slider (23). The lifting mechanism (3), which is located at the bottom of the slider (23), includes a cylinder (31), a first piston (32) located inside the cylinder (31), and an adjusting screw (37) for limiting the stroke of the first piston (32). The swing mechanism (4) includes a second piston (41) disposed inside the first piston (32) and a rotating rod (44) that is pulsatorically connected to the second piston (41). The end of the rotating rod (44) is provided with a swing arm (46). The swing arm (46) is provided with a terminal clamp (5) at its end. The slider (23) and the inner cavity of the cylinder (31) are connected to a hydraulic system. The slider (23) is driven by hydraulic power to eliminate the thread gap, and the first piston (32) is driven to rise and fall and the rotating rod (44) is driven to rotate by hydraulic power in sequence.

2. The anti-displacement positioning fixture for cylinder head casting sand core according to claim 1, characterized in that, The base plate (11) is provided with a first clamp (12) for clamping the sand core base. The first clamp (12) includes four cylinders and a clamping plate provided at the cylinder output end.

3. The anti-displacement positioning fixture for cylinder head casting sand core according to claim 1, characterized in that, The top plate (13) is provided with a groove (14) corresponding to the slider (23). The linear drive mechanism (2) also includes a drive part (21) and a threaded rod (22) provided on the top plate (13). The threaded rod (22) is threadedly engaged with the slider (23).

4. The anti-displacement positioning fixture for cylinder head casting sand core according to claim 3, characterized in that, The slider (23) is provided with a connecting pipe (47) that connects to the hydraulic system, and the slider (23) is provided with a channel that connects the connecting pipe (47) and the cylinder (31).

5. The anti-displacement positioning fixture for cylinder head casting sand core according to claim 4, characterized in that, The side surface of the slider (23) is provided with a hydraulically driven telescopic chamfered block (24), and the side wall of the slide groove (14) is provided with a chamfered tooth side groove (15). The chamfered block (24) is used to press on the chamfered tooth side groove (15) after being hydraulically pushed out, so that the slider (23) generates an axial force against the thread in the sliding direction to eliminate the thread gap.

6. The anti-displacement positioning fixture for cylinder head casting sand core according to claim 1, characterized in that, The first piston (32) has a first rod (33) on its shaft. The rotating rod (44) is rotatably connected to the first rod (33). The second piston (41) is coaxially nested with the first piston (32). One end of the second piston (41) is provided with a second rod (42) and a spring (43) for making the second piston (41) tend to rise. The bottom side of the second rod (42) is provided with a wide-pitch thread. The upper surface of the rotating rod (44) is provided with a wide-pitch thread groove (45) for driving the rotating rod (44) to rotate when the second piston (41) moves.

7. The anti-displacement positioning fixture for cylinder head casting sand core according to claim 6, characterized in that, The bottom of the cylinder (31) is provided with a frustum flange (36), and a frustum cover (35) is fitted on the frustum flange (36). A bottom cover (34) is provided at the bottom of the frustum cover (35). The adjusting screw (37) is threadedly engaged with the bottom cover (34). A damping friction surface is provided between the frustum flange (36) and the frustum cover (35) to prevent the frustum cover (35) from rotating when the frustum flange (36) and the frustum cover (35) are pressed together, so that the adjusting screw (37) acts as a swing limiter for the swing arm (46).

8. The anti-displacement positioning fixture for cylinder head casting sand core according to claim 7, characterized in that, The bottom cover (34) and the bottom of the frustum flange (36) are provided with elastic pads (38) to increase the pressure between the frustum flange (36) and the frustum cover (35).

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