A high-precision cross-hole drilling device and method with a tubular fitting structure

Abstract

This invention pertains to aircraft assembly technology and relates to a high-precision cross-hole drilling device and method with a tubular fitting structure. It comprises a main device structure, a connecting pipe positioning mechanism, a joint positioning mechanism, and a drill jig. The main device structure is equipped with the connecting pipe positioning mechanism, the joint positioning mechanism, and the drill jig. The connecting pipe positioning mechanism is used to position and secure the connecting pipe on the main device structure. The joint positioning mechanism positions and fixes the joint on the connecting pipe. The drill jig is used to drill holes in the connecting pipe, ensuring drilling position accuracy and precision. It offers superior economic efficiency; consistent and stable hole-making quality; meets ergonomic requirements; reduces operator workload; and is easy to operate. This method has been validated through long-term application and exhibits high reliability and stable quality, making it widely applicable.

Description

Technical Field

[0001] This invention pertains to aircraft assembly technology and relates to a high-precision cross-hole drilling device and method for a tubular fitting structure. Background Technology

[0002] Helicopter fuel tank locations vary, but common options include below the central fuselage floor, on either side of the fuselage, in a safety-like recess at the rear of the fuselage, and below the engine. Different helicopter models may have different fuel tank layouts to suit their specific design requirements and structures. The helicopter fuel tank connection structure described in this article connects to the floor insert at the bottom and to the frame beam at the top via tubular connecting rods and tubular joints using bolts. In helicopter manufacturing, the precision machining of tubular parts with connecting holes is an extremely challenging process. After machining, key parameters such as hole diameter, coaxiality, perpendicularity, and part position must be ensured to achieve a stable connection between the fuel tank and the structure, eliminate assembly stress, improve the product's wear resistance, and guarantee the reliability and stability of shipborne helicopters during long-term operation.

[0003] In the traditional process of precision machining of tubular connecting rods and tubular joint connecting holes of a fitting structure, it is extremely difficult to ensure the relative position of the two parts, which easily leads to excessive coaxiality of the holes of the two parts; the poor perpendicularity of the outer part hole surface causes gaps between the washer and the product contact surface when bolting. The position of the two parts is determined by on-machine matching and marking, which is not open in the operating space, has a long assembly cycle, low efficiency, high labor intensity, and causes fatigue and injury to the waist and shoulders of the operator, which does not meet ergonomic requirements. Moreover, when the coaxiality and perpendicularity of the product holes exceed the tolerance, it is often necessary to increase the hole diameter or scrap the parts, resulting in a great economic waste. The above factors restrict the quality and efficiency of precision machining of tubular connecting rods and tubular joint connecting holes of helicopters. Summary of the Invention

[0004] Purpose of the invention

[0005] To address the above problems, this invention proposes a high-precision cross-hole drilling device and method with a tubular fitting structure. It designs a high-precision, simple, and flexible rigid device and comprehensively improves the process flow, assembly method, and process parameters to achieve high-quality and high-efficiency engineering applications, breaking through the difficulty of precision machining of tubular fitting cross-holes.

[0006] Technical solution

[0007] This invention proposes a high-precision cross-hole drilling device and method with a tubular fitting structure, specifically including the following:

[0008] A high-precision cross-hole drilling device with a tubular fitting structure is composed of a main structure, a connecting pipe positioning mechanism, a joint positioning mechanism, and a drill jig. The main structure is equipped with the connecting pipe positioning mechanism, the joint positioning mechanism, and the drill jig. The connecting pipe positioning mechanism is used to position and fasten the connecting pipe on the main structure, the joint positioning mechanism is used to position and fix the joint on the connecting pipe, and the drill jig is used to drill holes in the connecting pipe to ensure the positional accuracy and precision of the drilling.

[0009] Furthermore, the main structure of the device includes a base (10); the connecting pipe positioning mechanism includes two sets of external positioning devices and one set of end face positioning devices. Each set of external positioning devices consists of a handle nut (23), a screw (24), two cylindrical pins A (25), a connecting pipe V-type positioning device A (26), a connecting pipe V-type positioning device B (27), and two internal hexagonal head screws (28). The two cylindrical pins A (25) pass through the through holes on the connecting pipe V-type positioning device B (27) and are locked by interference fit. The connecting pipe V-type positioning device B (27) has two grooves A and B. The connecting pipe V-type positioning device A is located at groove A. (26) The connecting tube V-type positioner A (26) can rotate around the internal hexagonal head screw (28). The two are in clearance fit to realize the opening and closing of the connecting tube V-type positioner A (26); the screw (24) and the handle nut (23) at the groove B can rotate around the cylindrical pin A (25). The screw (24) and the handle nut (23) are connected by threaded fit. The connecting tube V-type positioner A (26) can be pressed by rotating the handle nut (23); the connecting tube V-type positioner B (27) and the base (10) are connected by two internal hexagonal head screws (28) and two cylindrical pins B; the other set of external positioners has the same structure;

[0010] The end face positioner includes a baffle (20) and two knurled head screws (16). The knurled head screws (16) are connected to the lower drilling template B (17) by means of threaded connection. The baffle (20) moves up and down along the knurled head screws (16) through its own two grooves C.

[0011] The joint positioning mechanism consists of two parts, upper and lower. The upper part of the mechanism includes a corner seat (1), two knurled nuts A (2), two positioning bolts (3), a joint end face locator (4), a locking handle (5), an AM8 knurled nut B (6), and a locking positioning pin (7). The bottom of the corner seat (1) is connected to the base (10) by two hexagon socket head cap screws (28) and two cylindrical pins B. The upper part is connected to the joint end face locator (4) by two positioning bolts (3) and two knurled nuts A (2). After the joint end face locator (4) is positioned and fitted with the web surface of the joint, it is pressed by the locking handle (5), the knurled nut B (6), and the locking positioning pin (7). The locking positioning pin (7) is clearance-fitted with the joint hole.

[0012] The lower part of the mechanism consists of 4 knurled head screws (18), 2 pressure plates (19), and 2 L-shaped plates (29). The L-shaped plates (29) are connected to the base (10) by 2 internal hexagonal head screws (28) and 2 cylindrical pins B. The pressure plates (19) can be adjusted horizontally according to the actual position of the joint. The two grooves D on the structure of the pressure plates (19) are pressed and fixed by the knurled head screws (18), thereby achieving the positioning of the end face of the product joint.

[0013] The drill jig consists of an upper drill template A (8), an upper drill template B (11), a lower drill template A (13), a lower drill template B (17), 7 sets of drill bushings (15), 7 drill bushing clamping screws (14), 4 bent shank pins (9), and 4 sets of long bent shank pins (22). The upper drill template A (8) and the lower drill template A (13) are connected to the base (10) by 2 socket head cap screws (28) and 2 cylindrical pins B, respectively. The upper drill template A (8) and the upper drill template B (11) are connected by bent shank pins (9). 9) Connection: The lower drill template A (13) and the lower drill template B (17) are connected by another bent shank pin (9). The drill sleeve clamping screw (14) is used in conjunction with the drill sleeve (15) to prevent the drill sleeve (15) from rotating during use. The long bent shank pin (22) is used for positioning connection of the product connecting pipe and the joint. It can pass through the upper drill template A (8) and the upper drill template B (11), the lower drill template A (13) and the lower drill template B (17). The drill sleeve (15) and the drill template are fitted with clearance by means of through holes.

[0014] Furthermore, the device also includes a handle (21), which is positioned on the base (10) by welding.

[0015] Furthermore, there are two handles (21), symmetrically distributed on both sides of the base (10).

[0016] Furthermore, the V-shaped positioner A (26) and V-shaped positioner B (27) of the connecting pipe are bonded rubber parts to the product contact surface, which have the functions of pressing and preventing damage to the surface of the connecting pipe. The rubber parts are consumables.

[0017] Furthermore, the drill bushing (15) includes 7 levels to match the drilling requirements of the product's precision holes.

[0018] Furthermore, the long bent shank pin (22) includes two levels, specifically Φ3 and Φ6, which are used to match the initial and final holes of the connecting pipe and the joint precision hole, respectively.

[0019] Furthermore, the knurled high head screw (16) is specifically M6. The cylindrical pin A (25) is specifically A8X40. The cylindrical pin B is specifically A8X35. The knurled nut A (2) is specifically AM5. The knurled nut B (6) is specifically AM8. The knurled high head screw (18) is specifically M8. The drill bushing clamping screw (14) is specifically M6.

[0020] Furthermore, the connector end face locator (4) is detachable. The bent shank pin (9) is specifically Φ6. The drill bushing (15), long bent shank pin (22), bent shank pin (9), positioning bolt (3), and knurled nut B (6) are consumable parts and can be replaced according to actual use.

[0021] This article describes three sets of tubular connecting pipes and tubular fittings, all using the same hole-making method; therefore, only one set of hole-making methods will be described:

[0022] A method for high-precision intersecting hole fabrication of a tubular fitting structure includes the following:

[0023] First positioning. Open the connecting tube V-positioner A (26) on the hole-making device; clean the inner surface of the connecting tube V-positioner B (27) that contacts the product to ensure that there are no foreign objects on the surface; then put the product connecting tube into the V-positioner B (27) and use the baffle (20) to position the end face of the upper part of the tubular connecting tube of the product; use the joint end face positioner (4) and the 2-ΦaHb hole on the upper part of the tubular joint of the product to position the joint; after the above positioning is completed, use fasteners (locking pins, nuts, bolts, etc.) to effectively tighten to ensure that there is no gap between the parts on the device, the device and the product at the positioning point.

[0024] First high-precision hole making. Use drill bushing (15) to make the cross connection hole between the upper part of the product connecting pipe and the joint. The hole making process is: drilling Φn → reaming Φn+2.2 → reaming Φn+2.6 → boring Φn+2.7 → boring Φn+2.8 → boring Φn+2.9 → boring Φn+3, H8; The connection hole is a cross structure. During the process of making one hole, the other hole needs to be positioned by using a long bent shank pin (22) throughout the process; When making the hole, prevent the cutting amount from being too large and causing structural vibration. The feed amount should be reduced each time and the number of feeds should be increased; Try to complete the boring work of a single hole in one go; During the boring process, ensure that the lubricant is sufficient and that the selected lubricant has a cooling function. After each hole making is completed, use a vacuum cleaner to clean the generated metal chips.

[0025] First removal and cleaning. Loosen all fasteners on the device used to connect and tighten the positioner, remove the tubular connecting tubes and tubular fittings from the hole-making device, and remove burrs from the product hole edges. Use a powerful vacuum cleaner to remove excess material generated during the hole-making process, and wipe the device and product with a cloth, alcohol, or acetone to remove coolant and lubricant.

[0026] Second positioning. Using bolts, nuts, and washers, connect the upper tubular joint to the frame and beams on the machine body structure; connect the upper tubular joint to the tubular connecting pipe; and connect the lower tubular joint to the oil tank. All bolt and nut connections are tightened according to the product drawings or fixed force values ​​are applied to ensure that the condition fully meets the product installation requirements.

[0027] Drill the initial holes. Drill the initial holes (Φn) for the lower connecting pipe and the lower tubular joint according to the Φm pre-drilled holes on the lower tubular joint of the product. After drilling the holes, clean them, then remove the bolts, nuts, and washers from the upper and lower tubular joints and tubular connecting pipes, and remove the upper and lower tubular joints and tubular connecting pipes from the machine. Clean the burrs and excess materials generated during the drilling process.

[0028] The third positioning. The connecting pipe and the joint are repositioned using a hole-making device. The connecting pipe and the upper joint are positioned using the Φ6 grade of the long bent shank pin (22), the connecting pipe V-type positioner A (26), and the connecting pipe V-type positioner B (27). The connecting pipe and the lower joint are positioned using the Φ3 grade of the long bent shank pin (22) through the pre-made Φ3 hole. The end face of the lower joint is positioned using the pressure plate (19), the knurled high head screw (18), and the L-shaped plate (29). During positioning, the relative position of the pressure plate and the joint is adjusted by the groove D on the pressure plate to ensure that the joint surface and the pressure plate surface are completely in contact. After positioning, fasteners (locking pins, nuts, bolts, etc.) are used to effectively tighten the joint to ensure that there is no gap between the parts on the device, the device and the product at the positioning point.

[0029] The second high-precision hole making. The cross connection hole between the connecting pipe and the joint in the lower half of the product is made using a drill bushing. The hole making process is as follows: reaming Φn+2.2 → reaming Φn+2.6 → boring Φn+2.7 → boring Φn+2.8 → boring Φn+2.9 → boring n+3, H8. The connection hole is a cross structure. During the hole making process of one hole, a long bent shank pin (22) is used to position the other hole throughout the process. When making the hole, to prevent the cutting amount from being too large and causing structural vibration, the feed amount should be reduced each time and the number of feeds should be increased. Try to complete the boring work of a single hole in one go. During the boring process, the lubricant should be sufficient and the selected lubricant should have a cooling function. After each hole making is completed, a vacuum cleaner should be used to clean the metal chips generated.

[0030] Second removal and cleaning. Loosen all fasteners used to connect and tighten the positioner on the device, remove the tubular connecting tubes and tubular fittings from the hole-making device, and remove burrs from the hole edges. Use a powerful vacuum cleaner to remove excess material generated during the hole-making process, and wipe the device and product with a cloth, alcohol, or acetone to remove coolant and lubricant.

[0031] The beneficial effects of this application are as follows:

[0032] This invention proposes a high-precision cross-hole drilling device and method for tubular fitting structures. It offers the following advantages in improving the drilling accuracy, ensuring processing quality, and increasing production efficiency of helicopter tubular fitting structure parts: final hole accuracy is no less than H8 grade; hole wall smoothness is no less than Ra3.2; coaxiality of the same group of tubular connecting rods and joints is no less than φ0.05mm; perpendicularity of the hole on one side of the connecting tube is no less than φ0.04mm; on-machine assembly time is reduced by at least 50% compared to traditional methods; part scrap rate is reduced to 0%, resulting in superior economic efficiency; the drilling quality is consistent and stable, meets ergonomic requirements, reduces operator workload, and is easy to operate. This method has been validated through long-term application and exhibits high reliability and stable quality, making it widely applicable. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure;

[0034] Among them: (1) - corner seat; (2) - AM5 knurled nut (2 pieces); (3) - positioning bolt (2 pieces); (4) - joint end face locator; (5) - locking handle; (6) - AM8 knurled nut; (7) - locking positioning pin; (8) - upper drilling template 1; (9) - Φ6 bent shank pin (4 pieces); (10) - base; (11) - upper drilling template 2; (12) - A8X35 cylindrical pin B (14 pieces); (13) - lower drilling template 1; (14) - M6 drill sleeve clamping screw (6 pieces); (15) - drill sleeve (6 groups in total, each group has 7 grades); (16) - M6 knurled high head screw (2 pieces); (17) - lower drilling template 2; (18) - M8 knurled high head screw (4 pieces); (19) - pressure plate (2 pieces);

[0035] (20) - baffle; (21) - handle; (22) - long bent handle pin (4 sets in total, 2 levels in each set); (23) - handle nut (2 pieces); (24) - screw (2 pieces); (25) - A8X40 cylindrical pin (4 pieces); (26) - connecting pipe V-type positioner 1;

[0036] (27) - Connecting pipe V-type positioner 2; (28) - Socket head cap screws (12 pieces); (29) - L-shaped plate (2 pieces)

[0037] Figure 2 This is a schematic diagram of the application of connecting pipes;

[0038] (35) - connecting pipe A; (30) - joint AA; (31) - joint AB; (32) - oil tank; (33) - structural beam; (34) - structural frame; Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be described in more detail below. In the examples, the same or similar reference numerals denote the same or similar components or elements having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of this invention. The embodiments described below with reference to reference are exemplary and intended to explain this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The embodiments of this invention will be described in detail below.

[0040] The helicopter fuel tank described in this article is located on the left side of the mid-fuselage passenger cabin. The upper part of the fuel tank is connected to the structure via three sets of tubular connecting pipes and tubular fittings. Each set includes one connecting pipe and two fittings. The connecting pipes and fittings are a mating structure, with two sets of Φ6H8 cross holes for bolt-nut installation. The structure is as follows: Figure 2 :

[0041] Based on the above requirements, a high-precision cross-hole drilling device and method for a tubular fitting structure is invented. Since the connection methods of the three sets of connecting pipes and connectors are the same, the drilling device and method are also the same. The following description only details the implementation process for connecting pipe A and connectors AA and AB. Specifically, it includes the following:

[0042] First positioning: ① Use positioning bolts (3) and knurled nuts A (2), two of each, to connect and tighten the diagonal seat (1) and the connector end face locator (4); align the flat surface of the connector AA's insert with the connector end face locator (4), and use the locking handle (5) and AM8 knurled nuts B (6) through the 2-Φ10H8 holes on the connector AA to lock the positioning pin (7) and tighten the connector.

[0043] ② Open the connecting pipe V-positioner A (26) and connecting pipe V-positioner B (27), insert the connecting pipe A into the connector AA to form a fitting structure; use the handle nut (23) and screw (24) to connect the connecting pipe V-positioner 1 (26) and connecting pipe V-positioner B (27) to achieve the positioning and clamping of the connecting pipe A.

[0044] First high-precision hole making: Connect the upper drilling template A (8) and the upper drilling template 1 (11) with two Φ6 bent shank pins (9). Use the Φ3 grade drill bushing in the drill bushing (15) to make the cross hole Φ3 initial hole between the connecting pipe A and the joint AA (only drill one side). Use the Φ3 specification pin in the long bent shank pin (22) for positioning. Then drill the 2-Φ6H8 bolt holes on the other side of the connecting pipe A and the joint AA: Drill Φ3 → enlarge Φ5.2 → enlarge Φ5.6 → ream Φ5.7 → ream Φ5.7 → ream Φ5.8 → ream Φ5.9 → ream 6H8. After completion, use the Φ8 specification pin in the long bent shank pin (22) for positioning. Then use the same hole making process to make the 2-Φ6H8 bolt holes on the cross side. The connecting holes are of a cross structure. During the process of making one hole, a long bent shank pin (22) is needed to position the other hole throughout the process. When making holes, to prevent excessive cutting amount from causing structural vibration, the feed amount should be reduced and the number of feeds increased. Try to complete the reaming of a single hole in one go. During the reaming process, ensure that the lubricant is sufficient and that the selected lubricant has a cooling function. After each hole making is completed, a vacuum cleaner should be used to clean the metal chips generated.

[0045] First removal and cleaning: Open the handle nut (23) and screw (24) connected to the V-type positioner A (26) and V-type positioner B (27) of the connecting pipe; remove the positioning bolt (3), AM5 knurled nut, locking handle (5), AM8 knurled nut B (6) connected to the joint positioner (4) and lock the positioning pin (7); after removing the connecting pipe A and the joint AA, use a powerful vacuum cleaner to clean the excess material generated during the hole making process, and wipe the cooling lubricant on the device and product with a wiping cloth, alcohol or acetone and other solvents.

[0046] Second positioning: Use standard product parts such as hexagonal head bolts, hexagonal head self-locking screws, and washers to connect the oil tank (4) to the structural floor; the oil tank (4) to the connecting pipe A and the joint AB; and the structural beam (5), structural frame (6) to the connecting pipe A and the joint AA.

[0047] Making the initial hole: Using the 2-Φ2.1 initial hole on connector AB, make the initial bolt connection hole that mates with connecting pipe A, and enlarge the hole to φ3.0. After disassembling the standard parts of the product, remove connecting pipe A, tubular connector AA, and tubular connector AB from the machine.

[0048] Third positioning: Use a hole-making device to position the connecting pipe A, the connector AA, and the connector AB. The connecting pipe A and the connector AA are positioned using two Φ6.0 grade long bent shank pins. The middle part of the connecting pipe A is positioned and tightened using the connecting pipe V-type positioner A (26) and the connecting pipe V-type positioner B (27). The connecting pipe A and the connector AB are positioned using two Φ3 grade long bent shank pins (22) through the pre-made Φ3 holes. Adjust the position of the connector end face pressure plate (19), the knurled high head screw (18), and the L-shaped plate (29) to ensure that the connector AB ear end face is completely fitted with the connector end face pressure plate (19). Then remove one Φ3 grade long bent shank pin (22) on the connector AB.

[0049] Second high-precision hole making: First, use a drill bushing (15) to make a connecting hole between the connecting pipe A and the joint AB. The hole making process is: enlarge the hole Φ5.2 → enlarge the hole Φ5.6 → ream the hole Φ5.7 → ream the hole Φ5.8 → ream the hole Φ5.9 → ream the hole Φ6H8. After completing the hole making, use a Φ6.0 long bent shank pin (22) to position the hole; then make another connecting hole. The hole making process is: reaming Φ5.2 → reaming Φ5.6 → boring Φ5.7 → boring Φ5.8 → boring Φ5.9 → boring Φ6H8; the connecting hole is a cross structure. During the process of making one hole, the long bent shank pin (22) is used to position the other hole throughout the process; when making the hole, prevent the cutting amount from being too large and causing structural vibration. The feed amount should be reduced each time and the number of feeds should be increased; try to complete the boring work of a single hole in one go; during the boring process, ensure that the lubricant is sufficient and that the selected lubricant has a cooling function. After each hole making is completed, use a vacuum cleaner to clean the metal chips generated.

[0050] Second removal and cleaning: Open the handle nut (23) and screw (24) connected to the V-type positioner A (26) and V-type positioner B (27) of the connecting pipe; disassemble the connecting pipe A and the connector AA using two Φ6.0 grade long bent shank pins for positioning; remove the connector end face pressure plate (19) and knurled high head screw (18); remove the long bent shank pin (22) of the connecting pipe A and the connector AB; after removing the connecting pipe A, connector AA, and connector AB, use a powerful vacuum cleaner to clean the excess material generated during the hole making process, and wipe the cooling lubricant on the device and product with a wiping cloth, alcohol or acetone and other solvents.

[0051] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein. The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Within the spirit and principles of the present invention, any person skilled in the art may use the disclosed technical content to make changes or modifications to create equivalent embodiments applicable to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.

Claims

1. A high-precision cross-hole drilling device with a tubular fitting structure, characterized in that, It consists of a main device structure, a connecting pipe positioning mechanism, a joint positioning mechanism, and a drill jig. The main device structure is equipped with a connecting pipe positioning mechanism, a joint positioning mechanism, and a drill jig. The connecting pipe positioning mechanism is used to position and fasten the connecting pipe on the main device structure. The joint positioning mechanism is used to position and fix the joint on the connecting pipe. The drill jig is used to drill holes in the connecting pipe to ensure the position and accuracy of the drilling. The main structure of the device includes a base; the connecting pipe positioning mechanism includes two sets of external positioning devices and one set of end-face positioning devices. Each set of external positioning devices consists of a handle nut, a screw, two cylindrical pins A, a connecting pipe V-shaped positioning device A, a connecting pipe V-shaped positioning device B, and two hexagonal head screws. The two cylindrical pins A pass through the through holes on the connecting pipe V-shaped positioning device B and are locked by an interference fit. The connecting pipe V-shaped positioning device B has two grooves A and B. The connecting pipe V-shaped positioning device A is located at groove A, and the connecting pipe V-shaped positioning device A can rotate around the hexagonal head screw. The two are in a clearance fit to open and close the connecting pipe V-shaped positioning device A. At groove B, the screw and the handle nut can rotate around the cylindrical pin A. The screw and the handle nut are connected by a threaded connection. The rotation of the handle nut can press the connecting pipe V-shaped positioning device A. The connecting pipe V-shaped positioning device B is connected to the base by two hexagonal head screws and two cylindrical pins B. The other set of external positioning devices has the same structure. The end face positioner includes a baffle and two knurled head screws. The knurled head screws are connected to the lower drill template B by a threaded connection. The baffle moves up and down along the knurled head screws through its two built-in grooves C. The joint positioning mechanism consists of two parts, upper and lower. The upper part of the mechanism includes an angle seat, two knurled nuts A, two positioning bolts, a joint end face locator, a locking handle, an AM8 knurled nut B, and a locking positioning pin. The bottom of the angle seat is connected to the base by two hexagon socket head cap screws and two cylindrical pins B. The upper part is connected to the joint end face locator by two positioning bolts and two knurled nuts A. After the joint end face locator is positioned and fitted against the web surface of the joint, it is pressed by the locking handle, knurled nuts B, and locking positioning pin. The locking positioning pin and the joint hole are clearance fit. The lower part of the mechanism consists of 4 knurled head screws, 2 pressure plates, and 2 L-shaped plates. The L-shaped plates are connected to the base by 2 hexagon socket head cap screws and 2 cylindrical pins B. The pressure plates can be adjusted horizontally according to the actual position of the joint. The two grooves D on the pressure plate itself are used to press and fix it by knurled head screws, thereby achieving the positioning of the product joint end face. The drill jig consists of an upper drill template A, an upper drill template B, a lower drill template A, a lower drill template B, 7 sets of drill bushings, 7 drill bushing clamping screws, 4 bent shank pins, and 4 sets of long bent shank pins. The upper drill template A and the lower drill template A are connected to the base by 2 hexagon socket head cap screws and 2 cylindrical pins B, respectively. The upper drill template A and the upper drill template B are connected by bent shank pins, and the lower drill template A and the lower drill template B are connected by another bent shank pin. The drill bushing clamping screws work in conjunction with the drill bushings to prevent them from rotating during use. The long bent shank pins are used for positioning and connecting the product's connecting pipes and joints, and can pass through the upper drill template A and the upper drill template B, as well as the lower drill template A and the lower drill template B. The drill bushings and the drill templates are fitted with a clearance through hole.

2. The apparatus as claimed in claim 1, characterized in that, The device also includes a handle, which is 21 and is positioned on the base by welding.

3. The apparatus as described in claim 2, characterized in that, There are two handles, symmetrically distributed on both sides of the base.

4. The apparatus as claimed in claim 3, characterized in that, The V-shaped positioner A and V-shaped positioner B of the connecting pipe are bonded rubber parts that are in contact with the product.

5. The apparatus as described in claim 4, characterized in that, The drill bushing has 7 grades to match the drilling requirements of the product's precision holes.

6. The apparatus as claimed in claim 5, characterized in that, The long bent shank pin includes two grades, specifically Φ3 and Φ6, which are used to match the initial and final holes of the precision holes of the connecting pipe and the joint, respectively.

7. The apparatus as claimed in claim 6, characterized in that, The knurled high head screw is specifically M6; the cylindrical pin A is specifically A8X40; the cylindrical pin B is specifically A8X35; the knurled nut A is specifically AM5; the knurled nut B is specifically AM8; the knurled high head screw is specifically M8; and the drill bushing clamping screw is specifically M6.

8. The apparatus as claimed in claim 7, characterized in that, The connector end face locator is detachable; the bent pin is specifically Φ6.

9. The high-precision cross-hole drilling method of the apparatus according to any one of claims 1-8, characterized in that, Including the following: First positioning: Open the V-type positioner A of the connecting tube on the hole-making device; clean the inner surface of the connecting tube V-type positioner B that contacts the product to ensure that the surface is free of debris; then put the product connecting tube into the V-type positioner B, and use the baffle to position the end face of the upper part of the tubular connecting tube of the product; use the joint end face positioner and the 2-ΦaHb holes on the upper part of the tubular joint of the product to position the joint; after the above positioning is completed, use fasteners to effectively tighten to ensure that there are no gaps between the parts on the device, the device and the product at the positioning point; The first high-precision hole making: using a drill bushing to make the cross connection holes of the upper connecting pipe and the joint of the product. The hole making process is as follows: drilling Φn → reaming Φn+2.2 → reaming Φn+2.6 → boring Φn+2.7 → boring Φn+2.8 → boring Φn+2.9 → boring Φn+3, H8; the connection holes are cross-shaped structures. During the process of making one hole, a long bent shank pin is required to position the other hole throughout the process; to prevent excessive cutting amount from causing structural vibration, the feed rate should be reduced and the number of feeds increased; try to complete the boring of a single hole in one go; during the boring process, ensure sufficient lubricant and that the selected lubricant has a cooling function. After each hole making, use a vacuum cleaner to clean up the metal chips generated. First removal from shelves and cleanup; Loosen all fasteners on the device used to connect and tighten the positioner, remove the tubular connecting tube and tubular fitting from the hole-making device, and remove burrs from the product hole edges; use a powerful vacuum cleaner to clean up any excess material generated during the hole-making process, and wipe the device and product with a cloth, alcohol or acetone solvent to remove the coolant and lubricant. Second positioning; using bolts, nuts, and washers, connect the upper tubular joint to the frame and beams on the machine body structure; connect the upper tubular joint to the tubular connecting pipe; connect the lower tubular joint to the oil tank. All bolt-nut connections are tightened according to the product drawings or fixed force values ​​are applied to ensure that the condition fully meets the product installation requirements. Drill the initial holes; drill the initial holes of the lower connecting pipe and the lower tubular joint according to the Φm pre-drilled holes on the lower tubular joint of the product; clean the holes after drilling, then remove the bolts + nuts + washers of the upper and lower tubular joints and tubular connecting pipes, remove the upper and lower tubular joints and tubular connecting pipes from the machine, and clean the burrs and excess materials generated during the drilling process; The third positioning: The connecting pipe and the joint are repositioned using a hole-making device. The connecting pipe and the upper joint are positioned using Φ6 grade long bent shank pins, connecting pipe V-type positioner A, and connecting pipe V-type positioner B. The connecting pipe and the lower joint are positioned using Φ3 grade long bent shank pins through the pre-made Φ3 hole. The end face of the lower joint is positioned using a pressure plate, knurled high-head screws, and an L-shaped plate. During positioning, the relative position of the pressure plate and the joint is adjusted by the groove D on the pressure plate to ensure that the joint surface and the pressure plate surface are completely in contact. After positioning, fasteners are used to effectively tighten the joint to ensure that there are no gaps between the parts on the device, the device, and the product at the positioning point. The second high-precision hole making process involves using a drill bushing to create the cross-connection holes for the lower part of the product's connecting pipe and connector. The hole making process is as follows: reaming Φn+2.2 → reaming Φn+2.6 → boring Φn+2.7 → boring Φn+2.8 → boring Φn+2.9 → boring n+3, H8. Since the connecting holes have a cross-shaped structure, a long bent shank pin is needed to position the other hole throughout the entire process. To prevent excessive cutting volume from causing structural vibration, the feed rate should be reduced and the number of feeds increased. The boring of a single hole should be completed in one pass whenever possible. During boring, sufficient lubricant with cooling properties must be ensured. Metal chips generated after each hole making operation should be cleaned using a vacuum cleaner. The product was removed from shelves and cleared out for the second time. Loosen all fasteners on the device used to connect and tighten the positioner, remove the tubular connecting tube and tubular fitting from the hole-making device, and remove burrs from the hole edges; use a powerful vacuum cleaner to clean up any excess material generated during the hole-making process, and wipe the device and product with a cloth, alcohol, or acetone solvent to remove any coolant or lubricant.

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