A compact multi-hole positioning tool

Abstract

The present invention relates to the field of machinery, and discloses a compact multi-hole positioning tool, a positioning pin, the outer diameter of which matches the inner hole of the cone structure of the upper workpiece, the positioning pin is provided with a plurality of which are connected together on the positioning mounting ring, and the axial length of which is not less than the stacking height of the upper and lower workpieces; an axial hole, the axial hole passes through the positioning pin along the axial direction of the positioning pin, and the inner diameter of the axial hole matches the diameter of the anode column set on the bottom workpiece, and the height of the anode column is not less than the stacking height of all workpieces. The present invention designs a suitable fitting clearance for the positioning tool according to the assembly accuracy of large structural parts, which can meet the micron or millimeter coaxial assembly accuracy requirements of large structural parts.

Description

Technical Field

[0001] The invention relates to the field of machinery, and in particular to a compact multi-hole positioning tool. Background Art

[0002] A large magnetically insulated transmission line is composed of five workpieces, each of which is a stainless steel thin-walled cone structure. An inner hole is provided through the stainless steel thin-walled cone from top to bottom. The bottom diameter of each cone is about 3 meters, and the height varies from (0.5 to 1.8) meters. The weight of each workpiece is about 1 ton. The bottom workpiece has an anode column connected by threads in the vertical direction. The anode column passes through the inner hole of the second layer workpiece, the inner hole of the third layer workpiece, the inner hole of the fourth layer workpiece, and the inner hole of the fifth layer workpiece from bottom to top. Finally, the anode column and the fifth layer workpiece are fixed by a nut connected to the anode column thread at the top of the fifth layer workpiece. Among the workpieces constituting the magnetically insulated transmission line, the matching clearance between the inner hole of the first layer, the third layer and the fifth layer workpiece and the anode column is small, while the matching clearance between the inner hole of the second layer and the fourth layer workpiece and the anode column is large. Since the working field strength of the magnetically insulated transmission line is relatively high, the working stability of the "column-hole" structure (i.e., the combined structure formed by the anode column and the second and fourth layers respectively) is closely related to the coaxiality of the five workpieces. Excessive coaxiality deviation will lead to electric field distortion and even a huge loss of transmission current. Therefore, the coaxiality of the five workpieces requires high installation accuracy, which requires the coaxiality accuracy of the anode column and the second and fourth layer workpieces to meet certain standards. The magnetically insulated transmission line is heavy, and all workpieces can only be assembled in the vertical direction with the help of a crane. The coaxiality of the "column-hole" structure is required to be less than 0.5 mm. Due to the large size of the workpieces, personnel are unable to reach the center area to promptly confirm the installation accuracy. After the first workpiece is installed in place, with the help of the crane's guidance, the second workpiece is interspersed with the first workpiece in the vertical direction, and the trial assembly of the second workpiece is completed without removing the sling. Then, a single sleeve is inserted into several "column-hole" structures between the upper and lower workpieces one by one, and repeated comparisons, adjustments, and re-comparisons are performed to determine the coaxiality and overall assembly accuracy of the upper and lower workpieces. The positioning sleeve is used twice in the entire assembly process. This method is time-consuming, labor-intensive, and the positioning accuracy is not ideal. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a compact multi-hole positioning tool, which can complete high-precision assembly between upper and lower workpieces in one trial assembly.

[0004] The present invention is achieved through the following technical solutions:

[0005] A compact multi-hole positioning tool, comprising:

[0006] A positioning pin shaft, the outer diameter of which matches the inner hole of the upper workpiece, a plurality of the positioning pin shafts are provided, the plurality of the positioning pin shafts are connected together to the positioning mounting ring, and the axial length of the positioning pin shaft is not less than the stacking height of the upper workpiece and the lower workpiece;

[0007] An axial hole is provided along the axial direction of the positioning pin and penetrates the positioning pin, and an inner diameter of the axial hole matches a diameter of an anode column provided on the bottom layer of the workpiece.

[0008] In the present technical solution, the positioning hole tooling is an integrated structure composed of several positioning pins and positioning installation rings. An axial hole is set on the positioning pin. By setting a "hole-column" structure on the positioning pin, after the lower workpiece is installed in place, the upper workpiece is stacked and installed on the lower workpiece (not yet in place), and the positioning hole tooling is inserted into the inner hole of the upper workpiece as a whole. At the same time, the axial hole of the positioning pin is plugged with the anode column set on the bottom workpiece, and the anode column runs through the entire stacked workpiece. In this way, one positioning and trial assembly can achieve the overall assembly accuracy formed by several "column-hole" structures, and the work efficiency and installation accuracy are greatly improved. That is to say, the positioning pin in the positioning hole tooling of the present invention is passed through the inner hole of the upper workpiece and plugged with the anode column of the lower workpiece. The present invention can design multiple positioning tooling hole positions according to the structure and weight of large workpieces, which can ensure the structural strength and positioning accuracy of the workpiece, and the positioning installation ring is set in a ring shape, which is convenient for removing the positioning hole tooling after subsequent positioning.

[0009] As an optimization, a threaded hole is provided through the positioning mounting ring from top to bottom, an external thread matching the internal thread of the threaded hole is provided above the outer periphery of the positioning pin shaft, and the positioning pin shaft is threadedly connected to the threaded hole.

[0010] In this way, during the trial assembly process, if a pin shaft has an assembly problem, it can be easily disassembled for separate inspection and modification. At the same time, if the assembly accuracy needs to be improved, the accuracy of several positioning pin shafts can be improved separately to meet higher precision requirements and save costs.

[0011] As an optimization, a handle is also included, and the handle is installed on the positioning and mounting ring.

[0012] In this way, the handle is designed to facilitate the picking up of the locating hole tooling.

[0013] As an optimization, two handles are provided, and the two handles are symmetrically arranged at two ends of the positioning mounting ring in a radial direction parallel to the positioning pin axis.

[0014] In this way, it is convenient to hold the handle and take the locating hole tooling.

[0015] As an optimization, the handle is "U"-shaped, and the openings of the two "U"-shaped handles are arranged opposite to each other.

[0016] As an optimization, the end of the positioning pin away from the positioning mounting ring is in the shape of a truncated cone with a larger top and a smaller bottom.

[0017] In this way, the truncated cone shape designed as a "guide" structure at the lower end of the positioning pin shaft makes the insertion and removal process of the positioning hole tooling easy and convenient.

[0018] As an optimization, the lower end of the shaft hole is provided with a chamfer inclined outwards.

[0019] This can serve as a guide and facilitate the insertion of each anode column during assembly.

[0020] As an optimization, the positioning pin shaft includes a vertical portion and a truncated cone portion, and the intersection of the vertical portion and the truncated cone portion is in a smooth arc shape.

[0021] In this way, the sharp edges and corners at the intersection of the vertical portion and the truncated cone portion of the locating pin shaft can be prevented from scratching the hole wall of the inner hole.

[0022] As an optimization, there are 12 threaded holes.

[0023] As an optimization, the angular distribution between the threaded holes is 30°±5′.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0025] The present invention designs a suitable matching clearance for the positioning tooling according to the assembly accuracy of large structural parts, which can meet the micron-level or millimeter-level concentricity assembly accuracy requirements of large structural parts. The positioning hole tooling of the present invention is an integrated structure of 12 positioning pin shafts. By designing a "guide" structure and a special handle on the "hole-column" (the locating pin is provided with a shaft hole) part of the locating pin shaft, the insertion and removal process is easy and convenient. After the lower workpiece is installed in place and before the upper workpiece is installed in place, the positioning hole tooling is inserted as a whole into the 12 "column-hole" structures that have been installed in place, and positioning and trial assembly are completed at one time. The overall assembly accuracy formed by 12 "column-hole" structures can be achieved, and the work efficiency and installation accuracy have been greatly improved. The "hole-column" structure of the positioning hole tooling and the previous "column-hole" structure can form a synergistic and complementary fitting clearance. The positioning accuracy after combined effect is much higher than that after repeated comparison and adjustment of a single sleeve. The currently used positioning tooling can ensure that the concentricity of the "column-hole" structure is less than 0.5 mm. According to the assembly accuracy of large structural parts, the appropriate fitting clearance is designed for the positioning tooling, which can meet the micron-level concentricity assembly accuracy requirements of large structural parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0027] Figure 1 It is a structural schematic diagram of a compact multi-hole positioning tooling according to the present invention;

[0028] Figure 2 for Figure 1 A top view of

[0029] Figure 3 It is an assembly diagram of a compact multi-hole positioning tool and two workpieces thereof according to the present invention;

[0030] Figure 4 It is an assembly diagram of a compact multi-hole positioning tool and two other workpieces according to the present invention;

[0031] Figure 5 It is a schematic diagram of the partial structure of a magnetically insulated transmission line formed by stacking five workpieces in the background technology of the present invention.

[0032] Marks and corresponding workpiece names in the attached figure:

[0033] 1- positioning pin, 1a- vertical part, 1b- frustum part, 2- upper workpiece, 2a- lower workpiece, 2b- anode column, 2c- sleeve, 3- positioning mounting ring, 4- shaft hole, 5- handle. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0035] Example

[0036] like Figure 1-5 As shown, a compact multi-hole positioning tool comprises:

[0037] A positioning pin 1, wherein the outer diameter of the positioning pin 1 matches the inner hole of the conical cylinder structure of the upper workpiece 2, a plurality of the positioning pins 1 are provided, and the plurality of positioning pins 1 are connected to the positioning mounting ring 3, and the axial length of the positioning pin 1 is not less than the stacking height of the upper workpiece 2 and the lower workpiece 2a;

[0038] The shaft hole 4 is arranged along the axial direction of the positioning pin shaft 1 and penetrates the positioning pin shaft 1, and the inner diameter of the shaft hole 4 matches the diameter of the anode column 2b arranged on the lowermost workpiece.

[0039] The anode column can be screwed into the inner cylinder of the lowest layer of workpieces through threads, and finally a nut is installed on the external thread set on the top of the anode column to fix the stacked workpieces.

[0040] In this technical solution, it should be noted that Figure 3-5 As shown, the upper workpiece referred to in this embodiment is the second workpiece (the second workpiece is the upper workpiece relative to the first workpiece) and the fourth workpiece (the fourth workpiece is the upper workpiece relative to the third workpiece). The positioning hole fixture is an integrated structure composed of a plurality of positioning pins and a positioning mounting ring. An axial hole is set on the positioning pin. By setting a "hole-column" structure on the positioning pin, after the lower workpiece is installed in place, the upper workpiece is stacked and installed on the lower workpiece (not yet in place), and the positioning hole fixture is inserted into the inner cylinder of the upper workpiece as a whole. At the same time, the axial hole of the positioning pin is plugged into the anode column set on the bottom workpiece, and the anode column runs through the entire stacked workpiece. In this way, one positioning and trial assembly can achieve the overall assembly accuracy formed by a plurality of "column-hole" structures, and the work efficiency and installation accuracy are greatly improved. That is to say, the positioning pin in the positioning hole fixture of the present invention is inserted into the anode column of the lower workpiece through the inner hole of the cone cylinder of the upper workpiece. The present invention can design multiple positioning tooling holes according to the structure and weight of a large workpiece, which can ensure the structural strength and positioning accuracy of the workpiece, and set the positioning installation ring into a ring shape, so as to facilitate the removal of the positioning hole tooling after subsequent positioning. 2c in the figure is a sleeve, and after the positioning hole tooling is positioned and removed, the sleeve is connected to the anode column by sleeve, so that the first, third, and fifth pieces have the same potential.

[0041] Specifically, after the first layer (bottommost layer, bottommost layer) workpiece and the second layer workpiece are positioned, the multi-hole positioning tool of the present invention is pulled out, and then the sleeve is passed through the anode column and installed on the first layer workpiece, and the upper surface of the inner hole of the first layer workpiece is provided with a groove matching the sleeve; similarly, the lower surface and upper surface of the inner hole of the third layer workpiece are both provided with grooves matching the sleeve, and the lower surface of the inner hole of the fifth layer workpiece is also provided with a groove matching the sleeve. In this way, after the inner hole of the third layer workpiece passes through the anode column, since the clearance between the inner hole of the third layer workpiece and the anode column is small, the error between the axis of the inner hole of the third layer workpiece and the axis of the anode column is small, and then the inner hole of the fourth layer workpiece is passed through the anode column and installed above the third layer workpiece, and positioned by the multi-hole positioning tool of the present invention. After positioning is completed, the multi-hole positioning tool of the present invention is pulled out, and then another sleeve is passed through the anode column and installed on the third layer workpiece, and the bottom of the sleeve is inserted into the groove on the upper surface of the third layer workpiece to position the third layer workpiece and the fifth layer workpiece.

[0042] In this embodiment, a threaded hole is provided through the positioning mounting ring 3 from top to bottom, an external thread matching the internal thread of the threaded hole is provided on the outer periphery of the positioning pin shaft 1, and the positioning pin shaft 1 is threadedly connected to the threaded hole.

[0043] In this way, during the trial assembly process, if a pin shaft has an assembly problem, it can be easily disassembled for separate inspection and modification. At the same time, if the assembly accuracy needs to be improved, the accuracy of several positioning pin shafts can be improved separately to meet higher precision requirements and save costs.

[0044] In this embodiment, a handle 5 is further included, and the handle 5 is installed on the positioning and mounting ring 3 .

[0045] In this way, the handle is designed to facilitate the picking up of the locating hole tooling.

[0046] In this embodiment, two handles 5 are provided, and the two handles 5 are symmetrically arranged at two ends of the positioning mounting ring 3 in a radial direction parallel to the positioning pin shaft 1 .

[0047] In this way, it is convenient to hold the handle and take the locating hole tooling.

[0048] In this embodiment, the handle 5 is in a "U" shape, and the openings of the two "U"-shaped handles 5 are arranged opposite to each other.

[0049] In this embodiment, the end of the positioning pin shaft 1 away from the positioning mounting ring is in the shape of a truncated cone with a larger top and a smaller bottom.

[0050] In this way, the truncated cone shape designed as a "guide" structure at the lower end of the positioning pin shaft makes the insertion and removal process of the positioning hole tooling easy and convenient.

[0051] In this embodiment, the lower end of the shaft hole 4 is provided with a chamfer inclined outwards.

[0052] This can serve as a guide and facilitate the insertion of each anode column during assembly.

[0053] In this embodiment, the positioning pin shaft 1 includes a vertical portion 1a and a truncated cone portion 1b, and the contact position between the vertical portion 1a and the truncated cone portion 1b is in a smooth arc shape.

[0054] In this way, the sharp edges and corners at the intersection of the vertical portion and the truncated cone portion of the positioning pin shaft can be prevented from scratching the hole wall of the inner hole.

[0055] In this embodiment, there are 12 threaded holes.

[0056] In this embodiment, the angle distribution between the threaded holes is 30°±5′.

[0057] Of course, the error of the gap between the diameter of the locating pin shaft and the inner cylinder diameter of the conical cylinder structure of the upper workpiece, and the gap between the inner diameter of the axial hole and the diameter of the anode column of the lower workpiece can be set according to the accuracy of concentricity. At the same time, it should be noted here that the diameter of the locating pin shaft is smaller than the inner cylinder diameter of the conical cylinder structure of the upper workpiece, and the inner diameter of the axial hole is larger than the diameter of the anode column of the lower workpiece. At the same time, the length of the locating pin shaft is larger than the height after the upper and lower workpieces are stacked, so that the multi-hole positioning tooling can pass through the upper workpiece and be inserted into the lower workpiece.

[0058] Specifically, the present invention relates to a multi-hole positioning tool with a compact structure, which can be used for high-precision assembly scenarios of large-sized structural parts with heavy weight and high difficulty of manual assistance. The large-sized stainless steel workpiece is a conical cylindrical, multi-layer stacked structure, each with a diameter of about 3 meters and a weight of about 1 ton. The vertical layer-by-layer assembly of all workpieces is achieved through the cooperation of a crane. Before designing the multi-hole positioning tool of the present invention, after completing the trial assembly of the upper and lower workpieces, a single sleeve is inserted into the "column-hole" structure one by one for repeated comparison and readjustment to determine the coaxial uniformity and overall assembly accuracy of the 12 "column-hole" structures. Compared with the past, the positioning hole tool is an integrated structure of 12 positioning pins. By designing a "guide" structure (a truncated cone with a large top and a small bottom) and a special handle on the "hole-column" part of the positioning pin, the insertion and removal process is easy and efficient, and the overall assembly accuracy can be achieved by positioning and trial assembly at one time, and the work efficiency and installation accuracy are greatly improved. Before the upper workpiece is installed in place, the positioning hole tooling is inserted from the upper workpiece into the 12 "column-hole" structures located on the lower workpiece to align the upper and lower workpieces. The "hole-column" structure of the positioning hole tooling and the "column-hole" structure of the lower workpiece can form a synergistic and complementary fit clearance. The positioning accuracy after the combined effect is much higher than that after repeated comparison and adjustment of a single sleeve. The positioning hole tooling currently used can ensure that the concentricity of the "column-hole" structure is less than 0.5 mm. According to the assembly accuracy of large structural parts, the appropriate fit clearance is designed for the positioning tooling to meet the micron-level coaxial assembly accuracy requirements of large structural parts.

[0059] It should be noted that the upper layer and the lower layer in the present invention are as follows: Figure 1 , 3 -5 direction to indicate, for example, the instructions are as follows Figure 1 In the figure, the positioning ring is above the truncated cone-shaped positioning pin. At the same time, it should be noted that the shape of the positioning ring is not necessarily a circular ring, and the number of positioning pins is not necessarily required to be 12. This can be set according to the specific conditions of the workpiece. The clearance error between the anode column and the shaft hole and the clearance error between the positioning pin and the inner diameter of the cone can be set according to the actual situation. If the accuracy requirement is high, the clearance is small. The specific clearance size will not be repeated here and can be set according to the actual situation.

[0060] 1. Parts processing technology analysis:

[0061] 1. Positioning and mounting ring processing technology:

[0062] 1.1. Ensure that the flatness of the lower end surface of the positioning mounting ring is ≤ 0.02mm.

[0063] 1.2. Take the lower end surface of the positioning mounting ring as the reference plane, and process 12 evenly distributed M16 threaded holes to ensure that: ① the verticality of the 12 evenly distributed M16 threaded holes and the reference plane is ≤0.02mm; ② the angle distribution between the 12 evenly distributed M16 threaded holes is 30°±5′; ③ the diameter of a circle formed by the centers of the 12 evenly distributed M16 threaded holes is the same as the diameter of a circle formed by the centers of the 12 M6 anode column threaded holes, which is ΦD±0.05mm.

[0064] 2. Positioning pin processing technology:

[0065] 2.1 Finely machine the outer cylindrical surface of the positioning pin shaft to ensure that the cylindricality of the circular surface is ≤0.02mm and use this as the reference surface.

[0066] 2.2. Finely machine the inner hole of the positioning pin shaft to Φ6.45±0.025, and add a 5° chamfer at the lower end of the inner hole (to serve as a guide and facilitate the insertion of each anode column during assembly) to ensure that the coaxiality between the inner hole and the reference surface is ≤0.02mm.

[0067] 2.3. Finely machine the M12 thread and the bottom surface of the thread at the bottom of the locating pin to ensure that: ① the coaxiality of the M16 thread and the reference plane is ≤0.02mm; ② the verticality of the bottom surface of the thread at the bottom end and the reference plane is ≤0.02mm.

[0068] 2. Parts assembly process

[0069] 1. Assemble the 12 positioning pins to the welded positioning mounting rings through threaded connections and tighten them to form a positioning tool.

[0070] (1) Ensure that: the threaded lower end surface of each locating pin is in full contact with the lower end surface of the locating mounting ring, and the verticality between the outer cylindrical surface of each locating pin and the lower end surface of the locating mounting ring is ≤0.04mm.

[0071] (2) After assembly, the diameter of the ring formed by the centers of the 12 locating pins is ΦD±0.075mm.

[0072] 3. Anode column: The diameter of the anode column is Φ6±0.025.

[0073] 4. During hoisting, when the anode column is inserted into the inner hole of the positioning pin, the gap between the anode column and the inner hole of the positioning pin is less than 0.5mm.

[0074] 5. Selection of positioning tooling solutions:

[0075] 5.1. The positioning tooling solution can be connected by welding or threaded connection.

[0076] (1) Welding method: If welding is used, there are the following disadvantages: ① Because the diameter of the hoisted workpiece is large and the weight is about 1 ton, laser welding is not used for welding, but argon arc welding must be used. This welding method is very likely to cause local temperature rise, which in turn causes the verticality of the positioning pin shaft and the positioning mounting plate to be seriously out of tolerance, resulting in the anode column being unable to be inserted into the inner hole of the positioning pin shaft more quickly and accurately when the workpiece is hoisted. ② After welding, the positioning tooling is a whole. If there is a problem with one of the 12 positioning pin shafts, the entire positioning tooling cannot be used.

[0077] (2) Threaded connection: This method has the following advantages: ① The machining accuracy of the positioning pin and the positioning mounting ring can be controlled separately to ensure the positioning tooling accuracy after the overall assembly; ② The positioning tooling composed of 12 M16 threads has a higher tensile strength; ③ During the trial assembly process, if a pin has an assembly problem, it is convenient to disassemble it for separate inspection and modification. ④ If the assembly accuracy needs to be improved, the accuracy of the 12 positioning pins can be improved separately to meet higher accuracy requirements and save costs.

[0078] In order to meet the requirements of the embodiment, the above-mentioned processing technology describes the detailed processing dimensions of the multi-hole positioning tooling of this embodiment. At the same time, for similar positioning tooling, the overall design criteria are: the tooling can meet the coaxiality requirements of the overall insulated transmission line, that is, the design dimensions of the "hole-column" structure of the positioning tooling and the "column-hole" structure of the magnetically insulated transmission line must be synchronously matched. If this is achieved, any other positioning tooling can achieve the required assembly accuracy.

[0079] It should also be noted that, in this specification, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0080] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0081] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A compact multi-hole positioning tool, characterized in that: include: A positioning pin shaft (1), wherein the outer diameter of the positioning pin shaft (1) matches the inner hole of the upper workpiece (2), a plurality of the positioning pin shafts (1) are provided, the plurality of positioning pin shafts (1) are connected together to a positioning mounting ring (3), and the axial length of the positioning pin shaft (1) is not less than the stacking height of the upper workpiece (2) and the lower workpiece (2a); An axial hole (4), the axial hole (4) is arranged to penetrate the positioning pin shaft (1) along the axial direction of the positioning pin shaft (1), and the inner diameter of the axial hole (4) matches the diameter of the anode column (2b) arranged on the bottom layer of the workpiece; a threaded hole is arranged to penetrate the positioning mounting ring (3) from top to bottom, an external thread matching the internal thread of the threaded hole is arranged on the upper part of the outer periphery of the positioning pin shaft (1), and the positioning pin shaft (1) is threadedly connected to the threaded hole; It also comprises a handle (5), wherein the handle (5) is mounted on the positioning mounting ring (3).

2. A compact multi-hole positioning tool according to claim 1, characterized in that: Two handles (5) are provided, and the two handles (5) are symmetrically arranged at two ends of the positioning mounting ring (3) in a radial direction parallel to the positioning pin shaft (1).

3. A compact multi-hole positioning tool according to claim 2, characterized in that: The handle (5) is in a "U" shape, and the openings of the two "U"-shaped handles (5) are arranged opposite to each other.

4. A compact multi-hole positioning tool according to claim 1, characterized in that: One end of the positioning pin shaft (1) away from the positioning mounting ring (3) is in the shape of a truncated cone with a larger top and a smaller bottom.

5. The compact multi-hole positioning tool according to claim 1, characterized in that: The lower end of the shaft hole (4) is provided with a chamfer inclined outwards.

6. A compact multi-hole positioning tool according to claim 1, characterized in that: The positioning pin shaft (1) comprises a vertical portion (1a) and a truncated cone portion (1b), and the intersection of the vertical portion (1a) and the truncated cone portion (1b) is in a smooth arc shape.

7. A compact multi-hole positioning tool according to claim 1, characterized in that: There are 12 threaded holes.

8. The compact multi-hole positioning tool according to claim 1, characterized in that: The angle distribution between the threaded holes is 30°±5′.

Images