Positioning tool for inclined surface drilling of transformer disconnector mounting base

Abstract

The utility model discloses a positioning tool for the inclined plane drilling of the installation base of the isolating switch of mutual inductor belongs to mechanical processing tool technical field. The positioning tool includes support, fixed workpiece plate, modular drilling positioning plate and locking mechanism. Its core lies in, the fixed workpiece plate has an installation surface that is inclined according to preset angle, and the angle is complementary angle with the inclined plane of the workpiece to be drilled, thereby after placing the workpiece, can automatically compensate the inclined plane of its to be drilled to the horizontal state. Modular drilling positioning plate is fixed through locking mechanism, and high -hardness bushing is arranged in guide hole and is the drill guide, and the positioning pin and clamping device ensure the stability of workpiece. The application eliminates the need of manual adjustment through the design of inclined working surface, improves the positioning accuracy and efficiency, the modular structure enhances the versatility, the wedge-shaped cooperation simplifies the installation and improves the fixing effect, the overall structure is compact, convenient operation, high reliability, satisfies the high -efficient processing demand of high accuracy.

Description

Technical Field

[0001] This utility model belongs to the field of machining tooling technology, specifically, it relates to a positioning tooling for drilling inclined holes in the mounting base of a current transformer disconnect switch. Background Technology

[0002] Instrument transformers are key devices widely used in power systems. With technological advancements, the requirements for the processing precision and production efficiency of their various components have also increased. Drilling is an important process in the manufacturing of instrument transformer disconnector mounting bases.

[0003] In existing technology, drilling is required on a specific inclined surface of the mounting base. Because this drilling surface is inclined, conventional drilling machines struggle to accurately position and machine it directly. Therefore, operators typically need to use temporary or general-purpose tooling to adjust the workpiece's orientation, ensuring the inclined surface is perpendicular to the drill bit before proceeding with the operation. This method demands a high level of operator skill, is time-consuming in the positioning process, and makes it difficult to guarantee machining consistency, thus impacting production efficiency and product quality. Summary of the Invention

[0004] To address the aforementioned technical problems, this utility model provides a positioning fixture for drilling inclined holes in the mounting base of a current transformer disconnector. Through modular design and precise structural fit, this positioning fixture achieves stable support, accurate positioning, and efficient processing of inclined workpieces. Furthermore, the fixture is adjustable and durable, capable of adapting to the processing requirements of workpieces of different specifications.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A positioning fixture for drilling inclined holes in the mounting base of a current transformer disconnect switch, the positioning fixture comprising: a bracket for providing overall structural support, the bracket having a base for stable placement on a working plane, and a support arm extending vertically upward from the base; A fixed workpiece plate is fixedly connected to the base of the bracket. The fixed workpiece plate has a mounting surface for supporting the workpiece to be processed. The mounting surface is inclined at a first preset angle relative to the bottom surface of the base. The size of the first preset angle is complementary to the angle between the bottom surface of the workpiece and the inclined surface to be drilled, so that the inclined surface to be drilled is horizontal after the workpiece is installed. A replaceable modular drilling positioning plate is detachably installed on the support arm and has one or more guide holes. The inner wall of the guide holes is press-fitted or interference-fitted with a high-hardness wear-resistant steel sleeve for guiding the drill bit. And a locking mechanism for locking the modular drilling positioning plate to the support arm, the locking mechanism including at least one wedge, the end of the modular drilling positioning plate having a wedge-shaped channel for the wedge to be inserted, the modular drilling positioning plate being reliably locked by the wedge and the wedge-shaped channel being wedge-tightened together.

[0006] Preferably, the positioning fixture further includes at least one positioning pin, which is used to accurately position the workpiece; the fixed workpiece plate is provided with positioning holes corresponding to the preset reference holes on the workpiece, and the positioning pin passes through the reference holes of the workpiece and the positioning holes of the fixed workpiece plate in sequence, thereby realizing the accurate installation of the workpiece on the fixed workpiece plate.

[0007] Preferably, in the above-mentioned positioning fixture, the positioning pin adopts a multi-segment stepped pin structure, with at least two pin segments of different diameters along its axial direction; one end of the pin segment with a first diameter mates with the reference hole of the workpiece, and the other end of the pin segment with a second diameter mates with the positioning hole of the fixed workpiece plate, so as to ensure that the positioning pin can firmly fix the workpiece during installation without loosening due to excessive tolerance.

[0008] Preferably, the positioning fixture further includes at least one clamping device, which is mounted on the fixed workpiece plate and is used to apply a preload after the workpiece is positioned, so that the bottom surface of the workpiece is tightly attached to the mounting surface of the fixed workpiece plate; the clamping device may be a screw clamp that provides clamping force through a threaded pair or a toggle clamp that provides quick clamping and releasing functions based on the four-bar linkage principle.

[0009] Preferably, in the above positioning fixture, the support arm is provided with a slot for accommodating and limiting the modular drilling positioning plate. The slot has a preset size for initially limiting the modular drilling positioning plate. When the modular drilling positioning plate is installed, it is first embedded in the slot and then further fixed by a locking mechanism.

[0010] Preferably, in the above-mentioned positioning fixture, the depth and width of the slot are precisely designed to ensure that the modular drilling positioning plate can only move in the vertical direction when it is not locked, while the freedom of other directions is restricted, thereby improving the stability of the installation process.

[0011] Preferably, in the above positioning fixture, the locking mechanism includes at least one wedge, and the end of the modular drilling positioning plate is provided with a wedge-shaped channel for the wedge to be inserted; when the wedge is inserted into the wedge-shaped channel along its length direction, the normal component force generated thereon will fasten the modular drilling positioning plate to the support arm, thereby achieving reliable fixation.

[0012] Preferably, in the above-mentioned positioning fixture, the contact surface of the wedge block is hardened to improve its wear resistance and deformation resistance; at the same time, the inner wall surface of the wedge channel is also precision machined to ensure that the wedge block can slide smoothly without obvious gaps during insertion.

[0013] Preferably, in the above positioning fixture, the axis of the guide hole is perpendicular to the bottom surface of the horizontal base, and when the modular drilling positioning plate is installed on the support arm, the axis of the guide hole coincides with the central axis of the workpiece drilling position, thereby ensuring that the drill bit can accurately enter the predetermined position.

[0014] Preferably, in the above-mentioned positioning fixture, the bracket and the fixed workpiece plate are made of high-strength cast iron or Q235 structural steel to provide sufficient rigidity and stability; the modular drilling positioning plate is made of heat-treated tool steel to enhance its wear resistance and service life.

[0015] As can be seen from the above technical solution, the positioning fixture provided by this utility model includes: a bracket, a fixed workpiece plate, a modular drilling positioning plate, and a locking mechanism; the working surface of the fixed workpiece plate is inclined at a preset angle so that the drilling surface of the workpiece is horizontal after installation; the modular drilling positioning plate is fixed to the support arm by the locking mechanism and provides guidance for the drill bit through the high-hardness bushing in the guide hole; the positioning pin and the clamping device work together to ensure that the workpiece remains stable during processing.

[0016] Compared to existing technologies, the positioning fixture provided by this utility model, through its ingenious angle compensation design, directly converts the inclined surface of the workpiece to a horizontal surface for machining. Operators no longer need to rely on experience for tedious alignment and adjustments; they only need to install the positioning plate and place the workpiece according to the steps. This greatly reduces the skill requirements for operators and shortens the preparation time for single-piece machining, thereby significantly improving production efficiency. Simultaneously, the fixed mechanical structure and precise positioning elements ensure high consistency in drilling positions, effectively improving product pass rate and quality stability. Furthermore, the replaceable drilling positioning plate design gives this fixture excellent expandability and versatility, enabling it to adapt to the production needs of serialized products, thus possessing high practical value and economic benefits. Attached Figure Description

[0017] Figure 1 A three-dimensional structural diagram of a positioning tool provided in an embodiment of this utility model. Figure 2 A three-dimensional structural diagram of a finished workpiece provided for an embodiment of this utility model. Figure 3 This is a three-dimensional structural diagram of the modular drilling positioning plate in an embodiment of the present invention. Figure 4This is a three-dimensional structural diagram of the support arm in an embodiment of the present invention. The attached figures are labeled as follows: 1. Bracket; 2. Base; 3. Support arm; 4. Fixing plate; 5. Modular drilling positioning plate; 6. Guide hole; 7. Steel sleeve; 8. Workpiece; 9. Mounting surface; 10. Workpiece positioning pin; 11. Reference hole; 12. Positioning hole; 13. Clamping device; 14. Wedge; 15. Wedge channel; 16. Slot. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] As can be seen from the background technology, in the existing technology, drilling workpieces with inclined surfaces is cumbersome, difficult to align, and the machining accuracy is hard to guarantee, resulting in low production efficiency and failing to meet the needs of rapid processing of multiple varieties and small batches of workpieces.

[0020] To address the aforementioned problems, this utility model provides a positioning fixture for drilling a beveled surface on the mounting base of a current transformer disconnector. The positioning fixture includes: a support 1 for providing overall structural support, the support 1 having a base 2 for stable placement on a working plane, and a support arm 3 extending vertically upward from the base 2; and a fixing workpiece plate 4 fixedly connected to the base 2 of the support, the fixing workpiece plate 4 having a mounting surface 9 for supporting a workpiece 8 to be processed, the mounting surface 9 being inclined relative to the bottom surface of the base 2 at a first preset angle, the magnitude of the first preset angle being complementary to the angle between the bottom surface of the workpiece 8 and the beveled surface to be drilled. This ensures that the inclined surface to be drilled on the workpiece 8 is horizontal after installation; a replaceable modular drilling positioning plate 5 is detachably installed on the support arm 3, and has one or more guide holes 6. The inner wall of the guide hole is press-fitted or interference-fitted with a high-hardness wear-resistant steel sleeve 7 for guiding the drill bit; and a locking mechanism for locking the modular drilling positioning plate 5 to the support arm 3. The locking mechanism includes at least one wedge 14, and the end of the modular drilling positioning plate 5 has a wedge-shaped channel 15 for the wedge 14 to be inserted. The modular drilling positioning plate is reliably locked by the wedge 14 and the wedge-shaped channel 15.

[0021] As described above, the positioning fixture, through its ingenious structural design, transforms the machining of inclined surfaces of the workpiece into conventional planar machining, fundamentally simplifying the operation and improving positioning accuracy and machining efficiency. Furthermore, its modular and replaceable component design allows a single fixture to adapt to the machining needs of different workpiece models, demonstrating strong versatility and significant economic benefits.

[0022] To better illustrate the embodiments of this utility model, the following description is provided in conjunction with the accompanying drawings. Figure 1-4 The embodiments provided by this utility model will be explained in detail below.

[0023] The positioning fixture includes: a bracket 1, a fixed workpiece plate 4, a modular drilling positioning plate 5, and a locking mechanism. The fixed workpiece plate 4 is fixedly mounted on the bracket 1, while the modular drilling positioning plate 5 is detachably mounted on the bracket 1 and secured by the locking mechanism.

[0024] Compared with the existing inclined surface processing methods, the positioning fixture provided in this embodiment of the utility model has a completely new working principle, as follows: The core function lies in angle compensation: the fixed workpiece plate 4 has a mounting surface 9 for supporting the workpiece 8, which is inclined at a first preset angle. The magnitude of this first preset angle is complementary to the angle between the bottom surface of the workpiece 8 to be processed and the inclined surface to be drilled.

[0025] In other words, when the operator places the workpiece 8 on the mounting surface 9 and ensures that its bottom surface is fully aligned with the mounting surface 9, the tilt angle compensation effect corrects the originally tilted inclined surface of the workpiece 8 to be parallel to the horizontal plane. This design allows subsequent drilling operations to be performed in a direction perpendicular to the horizontal plane, just like drilling on a standard plane, greatly simplifying the alignment difficulty of the processing equipment and reducing the skill requirements for the operator.

[0026] To ensure the positional stability of workpiece 8 during processing, in a preferred embodiment of this utility model, the positioning fixture further includes at least one workpiece positioning pin 10.

[0027] Specifically, the fixed workpiece plate 4 has positioning holes 12 corresponding to the preset reference holes 11 at the bottom of the workpiece 8. During clamping, the workpiece positioning pin 10 passes through the reference holes 11 of the workpiece and the positioning holes 12 of the fixed workpiece plate 4 in sequence, thereby achieving precise positioning of the workpiece 8 on the mounting surface 9, effectively preventing the workpiece 8 from translating or rotating under the action of drilling force, and ensuring the accuracy of the hole position.

[0028] More specifically, the workpiece positioning pin 10 can be designed as a stepped pin, with one end having a first diameter that precisely matches the inner diameter of the workpiece reference hole 11, and the other end having a second diameter that precisely matches the inner diameter of the positioning hole 12 of the fixed workpiece plate. This stepped design not only ensures a stable and reliable positioning relationship between the workpiece 8 and the tooling, but also makes the insertion and removal of the positioning pin 10 more convenient and smooth.

[0029] In some processing scenarios, to further enhance the clamping rigidity of the workpiece, the positioning fixture may also include at least one clamping device 13. The clamping device 13 is mounted on the fixed workpiece plate 4.

[0030] In other words, after the workpiece 8 is initially positioned by the workpiece positioning pin 10, the clamping device 13 can be activated to apply a preload force to the workpiece 8, firmly pressing it onto the mounting surface 9 of the fixed workpiece plate 4. This design can supplement the workpiece's own weight or, in some cases, replace the effect of gravity, which is especially important for lighter workpieces or in machining scenarios that require withstanding greater vibration and cutting forces.

[0031] Optionally, the clamping device 13 can be a manually operated screw clamp or a toggle clamp that can be quickly loaded and unloaded. The specific form can be flexibly selected according to the actual production cycle and clamping force requirements.

[0032] In order to achieve high-precision drilling guidance and ensure the durability of the tooling, the inner wall of the guide hole 6 on the modular drilling positioning plate 5 is provided with a steel sleeve 7 for guiding the drill bit.

[0033] Specifically, the steel sleeve 7 is made of a high-hardness, wear-resistant material, such as T10A tool steel, and undergoes heat treatment processes such as quenching and tempering to achieve a surface hardness of HRC60 or higher. This steel sleeve is installed in the guide hole 6 of the modular drilling positioning plate 5 via a tight press-fit or interference fit, and its inner hole directly guides the drill bit for drilling. Due to the excellent wear resistance and high hardness of the steel sleeve, it effectively resists drill bit wear, thereby protecting the modular drilling positioning plate 5, which serves as the base, from damage and ensuring the positioning accuracy and service life of the tooling during long-term use. When the steel sleeve wears beyond tolerance, only a new steel sleeve needs to be replaced, resulting in low maintenance costs.

[0034] In this embodiment of the invention, the structure of the bracket 1 has also been optimized, comprising a base 2 for stable placement on a workbench and a support arm 3 extending vertically upward from the base 2. The support arm 3 has a precision-machined slot 16 for accommodating and positioning the modular drilling positioning plate 5. The shape and size of the slot 16 precisely match the outer contour dimensions of the corresponding end of the modular drilling positioning plate 5. When the modular drilling positioning plate 5 needs to be installed, it can be precisely guided to the preset working position simply by pushing it into the slot, ensuring that the relative relationship between the guide hole 6 and the drilling position of the workpiece 8 remains consistent after each replacement and installation.

[0035] To securely fix the modular drilling positioning plate 5 in the working position, the locking mechanism can take various forms. In a preferred embodiment, the locking mechanism includes at least one wedge 14.

[0036] Specifically, a wedge-shaped channel 15 is provided at the end of the modular drilling positioning plate 5 for the insertion of the wedge 14. The wedge 14 and the wedge-shaped channel 15 are engaged to securely lock the modular drilling positioning plate 5. When the modular drilling positioning plate 5 is placed in the preset working position, the wedge 14 is inserted or driven into the wedge-shaped channel 15. The strong wedge force generated by its inclined surface firmly and without gaps the modular drilling positioning plate 5 against the positioning reference surface of the support arm 3, effectively preventing any loosening due to vibration during drilling.

[0037] Alternatively, in another embodiment, the locking mechanism can also employ a more convenient bolt locking method. For example, a threaded hole is provided on the support arm 3 of the bracket 1, and a bolt with a clamping block is screwed in, so that the clamping block directly presses against the upper surface of the modular drilling positioning plate 5, which can also achieve reliable locking.

[0038] Based on the embodiments of this utility model, an important improvement is that the modular drilling positioning plate 5 is designed as a replaceable modular component.

[0039] In other words, the hole layout, hole diameter, or number of holes on the inclined surface to be drilled may vary for different models or specifications of current transformer disconnector mounting bases. By pre-preparing various modular drilling positioning plates 5 with different guide hole 6 (and corresponding steel sleeve 7) layouts, when different models of workpieces need to be processed, the operator only needs to loosen the locking mechanism, remove the current modular drilling positioning plate 5, and then replace it with another modular drilling positioning plate 5 that matches the new workpiece model and lock it.

[0040] As described above, compared with existing technologies, the positioning fixture provided by this utility model simplifies the machining of inclined surfaces through angle compensation design, and ensures machining accuracy and durability through precision positioning pins and wear-resistant steel sleeves. In particular, the modular and replaceable design of the drilling positioning plate allows a set of fixture main body (support and fixed workpiece plate) to quickly adapt to the machining needs of various workpiece models, greatly improving the versatility of the fixture, significantly reducing the investment and warehousing management costs of enterprises in mold tooling, and has extremely high practical value and promotion prospects.

[0041]

Example 1

[0042]

Example 2

[0043]

Example 3

[0044] Comparative Example 1 This comparative example is used to compare with Example 1, aiming to highlight the significant advantages of this utility model over the prior art. This comparative example uses a commonly used manual scribing and positioning method in the prior art to process a type A workpiece identical to that in Example 1. Specifically, a skilled technician with over five years of experience uses a height gauge, angle gauge, and scribing tool to manually scribble lines on the inclined surface of the workpiece, marking the center points of three drill holes, and then uses a center punch to create positioning punches. Subsequently, the workpiece is moved to the same vertical drilling machine, and the position and angle of the workpiece are repeatedly adjusted visually and by hand, attempting to align the drill bit with the punches. The workpiece is then temporarily fixed to the drilling machine's worktable using pressure plates and bolts. Except for the fundamental difference in the processing and positioning method, the workpiece, drilling machine, drill bit, and final performance testing method used in this comparative example are completely consistent with Example 1. Testing revealed that the processing process in this comparative example is extremely time-consuming, and the drilling position accuracy heavily depends on the operator's skill and condition, resulting in poor product quality consistency. Specific performance data is shown in Table 1, which contrasts sharply with Example 1.

[0045] Comparative Example 2 This comparative example is used to compare with Example 1. The only difference between them is that the drilling positioning plate used in this example lacks one of the key technical features of this invention, namely, the absence of a high-hardness wear-resistant steel sleeve. Specifically, the guide hole of this drilling positioning plate is directly machined from a 45# steel plate without any surface hardening treatment, and its surface hardness is approximately HRC25. Apart from this core difference, the workpiece, processing equipment, all other components of the positioning fixture (including the bracket, fixed workpiece plate, positioning pin, clamping device, locking mechanism), and performance testing methods used in this comparative example are completely consistent with those of Example 1. Testing showed that this comparative example achieved good accuracy in the initial processing stage, but as the number of processes increased, the softer guide hole wore down rapidly due to continuous friction with the high-speed rotating drill bit, resulting in a larger hole diameter and a sharp decrease in positioning accuracy, making it impossible to guarantee the quality stability of mass production. Specific performance data are also shown in Table 1.

[0046] [Effect Verification] To more intuitively demonstrate the beneficial effects of this utility model, the key performance test data of the above embodiments and comparative examples are summarized in Table 1.

[0047] Table 1 Performance Comparison Data Table

[0048] The above are merely preferred embodiments of this utility model and are not intended to limit the utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model without departing from the technical solution of this utility model shall still fall within the protection scope of this utility model.

Claims

1. A positioning fixture for drilling inclined holes in the mounting base of a current transformer disconnector, characterized in that, The positioning fixture includes: A bracket for providing overall structural support, the bracket having a base for stable placement on a working plane, and a support arm extending vertically upward from the base; A fixed workpiece plate is fixedly connected to the base of the bracket. The fixed workpiece plate has a mounting surface for supporting the workpiece to be processed. The mounting surface is inclined at a first preset angle relative to the bottom surface of the base. The size of the first preset angle is complementary to the angle between the bottom surface of the workpiece and the inclined surface to be drilled, so that the inclined surface to be drilled is horizontal after the workpiece is installed. A replaceable modular drilling positioning plate is detachably installed on the support arm and has one or more guide holes. The inner wall of the guide holes is press-fitted or interference-fitted with a high-hardness wear-resistant steel sleeve for guiding the drill bit. And a locking mechanism for locking the modular drilling positioning plate to the support arm, the locking mechanism including at least one wedge, the end of the modular drilling positioning plate having a wedge-shaped channel for the wedge to be inserted, the modular drilling positioning plate being reliably locked by the wedge and the wedge-shaped channel being wedge-tightened together.

2. The positioning fixture according to claim 1, characterized in that, The positioning fixture also includes at least one workpiece positioning pin for precise positioning of the workpiece; the fixed workpiece plate is provided with positioning holes corresponding to the preset reference holes on the workpiece, and the workpiece positioning pin passes through the reference holes of the workpiece and the positioning holes of the fixed workpiece plate in sequence to achieve accurate positioning of the workpiece on the mounting surface.

3. The positioning fixture according to claim 2, characterized in that, The workpiece positioning pin is a stepped pin structure, and the stepped pin has at least two pin body segments with different diameters along its axial direction. One end of the pin body segment with a first diameter mates with the reference hole of the workpiece, and the other end of the pin body segment with a second diameter mates with the positioning hole of the fixed workpiece plate.

4. The positioning fixture according to claim 1, characterized in that, The positioning fixture further includes at least one clamping device, which is mounted on the fixed workpiece plate. The clamping device is used to apply a preload force to the workpiece after it is positioned, so as to completely press the bottom surface of the workpiece against the mounting surface of the fixed workpiece plate.

5. The positioning fixture according to claim 4, characterized in that, The clamping device is a screw clamp or a toggle clamp. The screw clamp provides clamping force through a threaded pair, and the toggle clamp provides quick clamping and releasing functions through the dead point principle of a four-bar linkage.

6. The positioning fixture according to claim 1, characterized in that, The support arm is provided with a mating structure for accommodating and limiting the modular drilling positioning plate, which is placed inside the mating structure during installation.

7. The positioning fixture according to claim 6, characterized in that, The mating structure is a slot with a preset size, which provides movement restrictions for the modular drilling positioning plate in all degrees of freedom except for the locking direction.

8. The positioning fixture according to claim 1, characterized in that, The wedge of the locking mechanism has a wedge-shaped surface that matches the geometry of the inner wall of the wedge-shaped channel. During the locking operation, the wedge slides into the wedge-shaped channel along its length and the modular drilling positioning plate is fixed and locked to the support arm by the normal component force generated by the wedge-shaped surface.

9. The positioning fixture according to claim 1, characterized in that, The axis of the guide hole is perpendicular to the bottom surface of the base, and when the modular drilling positioning plate is installed on the support arm, the axis of the guide hole is aligned with the central axis of the workpiece to be drilled on the fixed workpiece plate.

10. The positioning fixture according to claim 1, characterized in that, The bracket and the fixed workpiece plate are made of cast iron or Q235 structural steel to provide sufficient rigidity and stability; the modular drilling positioning plate is made of heat-treated tool steel to ensure its structural strength and durability.

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