Assembly positioning system and method suitable for medium and large castings

Abstract

The invention discloses an assembly positioning system and method suitable for medium and large castings, and belongs to the technical field of precision mechanical assembly.The assembly positioning system comprises a platform, stand columns are arranged on the two sides of the platform, the stand columns are fixedly connected with a cross beam, a traveling crane is arranged on the cross beam, a first-stage weight reduction system is installed on the traveling crane, and a first casting is fixedly installed on the platform; a second casting is placed on the first casting, and a second-stage resistance reduction system and a third-stage fine adjustment system are arranged on the second casting. According to the assembly positioning system and method suitable for the medium and large castings, the positioning-fitting contradiction of heavy-load precision assembly is solved through cooperation of a weight reduction-resistance reduction-fine adjustment three-stage coupling mechanism, and the gravity influence of the second casting is weakened through the air cylinder set controlled by the pressure valve; physical coupling between the contact faces of the second casting and the first casting is reserved, static friction balance is broken through vibration of the vibration exciter, the propelling load of the micro-motion ejector rod is reduced, and high-precision displacement control is conducted through the micro-motion ejector rod to achieve precise positioning.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of precision machinery assembly, in particular to an assembly positioning system and method suitable for medium and large castings. BACKGROUND

[0002] In the high-end manufacturing fields of engineering machinery, aerospace, energy equipment, etc., medium and large castings such as machine tool bed, engine cylinder block, wind power hub, etc. as core structural parts, their assembly positioning precision directly determines the running stability and service life of the whole machine. With the development of equipment manufacturing towards "high precision, large size, integration", the weight of medium and large castings usually reaches several tons to several dozen tons, the volume span covers 1-10m, and the assembly positioning process faces three major challenges of "large gravity load, high friction resistance of contact surface, and difficult reference control". The static friction force between the heavy casting and the platform far exceeds the range of manual force exertion, and it is difficult to fine-tune; when the casting is hoisted, the rope swings, causing position deviation, which cannot meet the micron-level assembly requirements; traditional pushing or hoisting is easy to cause unilateral warping, the gap between the contact surfaces is >50um, affecting the structural stiffness. SUMMARY

[0003] The purpose of the present application is to provide an assembly positioning system and method suitable for medium and large castings, which solves the positioning-fitting contradiction of heavy load precision assembly through three-stage coupling mechanism of weight reduction-friction reduction-fine adjustment, weakens the gravity influence of the casting through the pressure valve controlled air cylinder group, retains the physical coupling between the casting and the platform contact surface, breaks the static friction balance through the vibration of the exciter, reduces the propulsion load of the micro-motion push rod, and realizes precision positioning through high-precision displacement control of the micro-motion push rod in the low friction domain.

[0004] To achieve the above purpose, the present application provides an assembly positioning system and method suitable for medium and large castings, which comprises a platform, the platform is provided with a stand on both sides, the stand is fixedly connected with a cross beam, a travelling crane is arranged on the cross beam, a first weight reduction system is installed on the travelling crane, a first casting is fixedly installed on the platform, a second casting is placed on the first casting, a third fine adjustment system is arranged on the first casting, and a second friction reduction system is arranged on the second casting.

[0005] Preferably, the first weight reduction system comprises a cylinder base, the cylinder base is fixedly connected with the travelling crane, a cylinder is installed inside the cylinder base, the piston end of the cylinder is fixedly connected with a lifting ring, a sliding sleeve is arranged on both sides of the cylinder, a sliding rod is slidably connected in the sliding sleeve, the end of the sliding rod is fixedly connected with the lifting ring, and a crane hook is hung on the lifting ring.

[0006] Preferably, the second friction reduction system comprises an exciter, and the exciter is installed on the top of the second casting.

[0007] Preferably, the third fine adjustment system comprises a mounting block fixedly mounted on the first casting, a micro-drive ejector pin fixedly mounted on the mounting block, the micro-drive ejector pin being a precision lead screw, the mounting block being L-shaped, and a threaded hole being formed in the side wall and the top plate of the mounting block bottom plate, and a locking bolt being arranged in the threaded hole.

[0008] The application provides a positioning method for assembling a medium or large casting, and the positioning method comprises the following steps: S1, initial hoisting: fixing the first casting on a platform, and placing the second casting on the first casting by using a travelling crane and a crane hook; S2, activating weight reduction: activating a gas cylinder, retracting the crane hook, and adjusting the gas pressure to make a pressure gauge display a target unloading force; S3, starting drag reduction: starting a vibration exciter, adjusting the frequency to 80 Hz, and adjusting the amplitude to 150 microns; S4, performing fine adjustment: controlling the micro-drive ejector pin to advance, and slowly feeding until the second casting reaches a correct position space; S5, completing locking: stopping the vibration exciter, releasing the gas cylinder pressure, and completely positioning the second casting to complete the assembly.

[0009] Therefore, the positioning method for assembling a medium or large casting is used, the positioning and fitting contradictions of heavy load precision assembly are solved by a three-stage coupling mechanism of weight reduction-drag reduction-fine adjustment, the influence of the gravity of the second casting is weakened by the cylinder group controlled by the pressure valve, the physical coupling between the contact surface of the second casting and the first casting is reserved, the vibration exciter is used to break the static friction balance and reduce the advancing load of the micro-drive ejector pin, and the micro-drive ejector pin is used to realize precision positioning in a low friction domain.

[0010] The technical scheme of the application is further described in detail below with reference to the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a perspective structural schematic view of the positioning system for assembling a medium or large casting according to the application; Figure 2 is a rear view of the positioning system for assembling a medium or large casting according to the application; Figure 3 is a perspective structural schematic view of the positioning system for assembling a medium or large casting according to the application from another perspective; Figure 4 is a local enlarged view of A of the positioning system for assembling a medium or large casting according to the application; Figure 5 is a perspective structural schematic view of the mounting block and the micro-drive ejector pin of the positioning system for assembling a medium or large casting according to the application.

[0012] Figure Labels 1. Platform; 2. Column; 3. Crossbeam; 4. Crane; 5. Cylinder base; 6. Cylinder; 7. Lifting ring; 8. Sliding sleeve; 9. Sliding rod; 10. Crane hook; 11. Vibrator; 12. Mounting block; 13. Micro-motion top rod; 14. Locking bolt; 15. First casting; 16. Second casting. Detailed Implementation

[0013] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0015] Example 1 like Figures 1 to 5 As shown, this invention provides an assembly and positioning system and method suitable for medium to large-sized castings 15, including a platform 1, with columns 2 on both sides of the platform 1. The columns 2 are fixedly connected to a crossbeam 3, and a traveling crane 4 is mounted on the crossbeam 3. A primary weight reduction system is installed on the traveling crane 4. The traveling crane 4 can move the primary weight reduction system. The columns 2 and the crossbeam 3 form a supporting frame for fixing the traveling crane 4, ensuring the stability of the traveling crane 4 during hoisting and weight reduction processes, preventing the casting 15 from shifting due to swaying of the traveling crane 4, and being able to withstand the reaction force of the primary weight reduction system, ensuring the overall structural rigidity of the system. The primary weight reduction system can reduce the contact pressure between the second casting 16 and the first casting 15, reducing friction during subsequent fine-tuning.

[0016] The first casting 15 is fixedly installed on the platform 1, the platform 1 is a basic support structure for bearing the first casting 15, and the platform 1 provides a stable assembly reference surface for the first casting 15. The second casting 16 is placed on the first casting 15, the first casting 1 is provided with a three-stage fine adjustment system, and the second casting 16 is provided with a two-stage drag reduction system. The two-stage drag reduction system enables the second casting 16 to slide slightly along the surface of the first casting 15 during fine adjustment, thereby reducing the pushing load of the micro-motion ejector rod 13. The three-stage fine adjustment system can realize high-precision displacement control and meet the precise positioning requirements of medium and large castings.

[0017] The first weight reduction system comprises a cylinder base 5 fixedly connected with the travelling crane 4, the cylinder base 5 is internally provided with a cylinder 6, the cylinder 6 is a cylinder group controlled by a pressure valve, the travelling crane 4 can drive the cylinder base 5 to move, and the cylinder base 5 provides stable support for the cylinder 6. The piston end of the cylinder 6 is fixedly connected with a lifting ring 7, sliding sleeves 8 are arranged on both sides of the cylinder 6, sliding rods 9 are slidably connected in the sliding sleeves 8, the sliding rods 9 are fixedly connected with the lifting ring 7, and a crane hook 10 is hung on the lifting ring 7. The cylinder 6 is prevented from being offset, so that the first casting 15 is not subjected to uneven stress.

[0018] The second drag reduction system comprises a vibration exciter 11 installed on the top of the second casting 16. The vibration exciter 11 can generate high-frequency slight vibration, break the static friction force of the contact surface between the second casting 16 and the first casting 15, reduce the displacement resistance during fine adjustment, and prevent the contact surface between the second casting 16 and the first casting 15 from being “locked”. The vibration exciter 11 can be used in different installation modes according to different castings. The output amplitude (50-200 μm) of the vibration exciter 11 is not equivalent to the macroscopic movement of the casting. Since the mass of the second casting is extremely large, the overall response amplitude of the second casting is suppressed to the nanometer level, and the second casting can be regarded as static in macroscopic view. This significantly reduces the static friction force of the interface of the second casting without causing large displacement of the second casting, and creates conditions for subsequent micron-level fine adjustment.

[0019] The three-stage fine adjustment system comprises a mounting block 12 fixedly installed on the first casting 15, and a micro-motion ejector rod 13 fixedly installed on the mounting block 12. The mounting block 12 provides stable support for the micro-motion ejector rod 13. The micro-motion ejector rod 13 is a precision lead screw, and can realize high-precision displacement control of the casting 15. The mounting block 12 is L-shaped, screw holes are formed in the side wall and the top plate of the bottom plate of the mounting block 12, and locking bolts 14 are arranged in the screw holes. The locking bolts 14 can be fixedly connected with the first casting 15 through threads.

[0020] The application provides a positioning method for assembling medium and large castings, which comprises the following steps by using the positioning system for assembling medium and large castings. S1, initial hoisting: the first casting 15 is fixed on the platform 1, and the second casting 16 is placed on the first casting 15 by using the crane 4 and the lifting hook 10; S2, activation of weight reduction: the air cylinder 6 is activated, the air cylinder 6 retracts the lifting hook 10 of the crane, and the air pressure is adjusted to make the pressure gauge display the target unloading force; S3, start of drag reduction: the exciter 11 is turned on, the frequency is adjusted to 80 Hz, and the amplitude is 150 μm; S4, execute fine adjustment: control the micro-drive ejector rod 13 to advance, slowly feed until the second casting 16 reaches the correct position space; S5, complete locking: turn off the exciter 11, release the air cylinder 6 pressure, and make the casting 15 completely fall into position to complete the assembly.

[0021] Therefore, the present application adopts the above-mentioned assembly positioning system and method suitable for medium and large castings, which solves the positioning-fitting contradiction of heavy load precision assembly through three-stage coupling mechanism of weight reduction-drag reduction-fine adjustment, weakens the gravity influence of the second casting through the cylinder group controlled by the pressure valve, retains the physical coupling between the contact surface of the second casting and the first casting, breaks the static friction balance through the vibration of the exciter, reduces the pushing load of the micro-drive ejector rod, and realizes precision positioning through high-precision displacement control of the micro-drive ejector rod in the low friction domain.

[0022] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: it can still modify or equivalently replace the technical solutions of the present application, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. An assembly positioning system suitable for use with medium to large castings, characterized in that: The platform is provided with a column on both sides, the column is fixedly connected with a crossbeam, the crossbeam is provided with a crane, the crane is provided with a first weight reduction system, the platform is fixedly provided with a first casting, the first casting is provided with a second casting, the first casting is provided with a third fine adjustment system, and the second casting is provided with a second drag reduction system.

2. An assembly positioning system for use with medium to large castings according to claim 1, wherein: The first weight reduction system comprises a cylinder base fixedly connected with the crane, the cylinder base is internally provided with a cylinder, the piston end of the cylinder is fixedly connected with a lifting ring, the cylinder is provided with a sliding sleeve on both sides, the sliding sleeve is internally provided with a sliding rod, the sliding rod is fixedly connected with the lifting ring, and the lifting ring is hung with a crane hook.

3. An assembly positioning system for use with medium to large castings according to claim 1, wherein: The second drag reduction system comprises a vibration exciter installed on the top of the second casting.

4. The assembly positioning system for use with medium to large castings of claim 1, wherein: The third fine adjustment system comprises a mounting block fixedly installed on the first casting, the mounting block is fixedly provided with a micro-motion jack, the micro-motion jack is a precision screw, the mounting block is L-shaped, the side wall of the mounting block bottom plate and the top plate are both provided with a threaded hole, and the threaded hole is provided with a locking bolt.

5. A method for assembling and positioning a large or medium-sized casting using a system for assembling and positioning a large or medium-sized casting according to any one of claims 1 to 4, characterized in that: Specifically, the following steps are included: S1, initial hoisting: the first casting is fixed on the platform, and the second casting is placed on the first casting by using the crane and the crane hook; S2, activate weight reduction: activate the cylinder, retract the cylinder to pull the crane hook, adjust the air pressure to make the pressure gauge display the target unloading force; S3, start drag reduction: start the vibration exciter, adjust the frequency to 80Hz, and the amplitude to 150μm; S4, execute fine adjustment: control the micro-motion jack to advance, slowly feed, and until the second casting reaches the correct position space; S5, complete locking: close the vibration exciter, release the cylinder pressure, make the second casting completely fall into position, and complete assembly.

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