A machining positioning device and machining system for a stop pin

Abstract

This invention discloses a machining positioning device and machining system for stop bolts. The device includes a base, an expansion core, and a mandrel. A splined through-hole is provided at each of the left and right ends of the base. An expansion core is placed in each splined through-hole. A mandrel is inserted into each expansion core. The lower end of the expansion core is connected to a screw plug. A spring is provided between the bottom surface of the mandrel and the top surface of the screw plug. A cylindrical pin is longitudinally inserted through each of the left and right ends of the base, passing through the expansion core and the mandrel. A stop bolt blank to be machined is placed on the top surface of the base at a position corresponding to each expansion core. The upper part of the expansion core protrudes upward from the top surface of the base and is located in the splined inner hole of the stop bolt blank. The upper part of the mandrel protrudes upward from the top surface of the expansion core and is fixedly connected to a nut. A pressure plate is provided between the bottom surface of the nut and the top surface of the stop bolt blank. This invention can conveniently and reliably position the stop bolt blank to be machined with high positioning accuracy and high clamping efficiency, which is beneficial to improving the machining quality of the stop bolt.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and in particular to a machining positioning device and machining system for a stop bolt. Background Technology

[0002] The ZD6 series electric switch machine is the core turnout switching equipment in the railway signaling system. The stop bolt is a key internal limiting component. (See also...) Figure 7 , Figure 12 As shown, the stop bolt blank 10 has a splined inner hole 1001 inside, and symmetrical arc structures need to be machined on both sides of one end of the stop bolt blank 10 (i.e. Figure 12 The fan-shaped groove 2001 on the finished stop bolt 20 is shown to obtain the finished stop bolt 20 (the stop bolt blank 10 is basically the same as the finished stop bolt 20, the only difference being that it does not have two fan-shaped grooves 2001, otherwise it is the same). The machining accuracy of the arc structure on the stop bolt and the coaxiality of the spline fit directly affect the operational reliability and service life of the switch machine.

[0003] Currently, for machining the arc structure on stop bolt-like parts with splined inner holes, the common methods used are ordinary clearance mandrel clamping or three-jaw chuck outer diameter clamping, which have the following drawbacks: 1. For the ordinary clearance mandrel clamping method, the ordinary mandrel and spline hole are clearance fit, which has an inherent positioning clearance. After machining, the coaxiality of the arc structure (fan-shaped groove 2001) and spline hole, and the symmetry of the arc structure (fan-shaped groove 2001) on both sides have large errors, which makes it difficult to meet the high-precision assembly requirements. 2. The outer circle clamping method is prone to damaging the surface of the part, and usually requires two clamping operations to process the arc structure (fan-shaped groove 2001) on both sides of the stop bolt. The repeated positioning error is large, the processing efficiency is low, and it is not suitable for mass production. 3. Existing general-purpose expansion clamping fixtures are mostly adapted to parts with smooth holes, but cannot achieve precise expansion and positioning with spline inner holes. In addition, the structure is complex and the clamping operation is cumbersome, which cannot meet the rapid installation requirements of T-slots in vertical machining centers.

[0004] Therefore, there is an urgent need to develop a technology that can solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to address the technical deficiencies of existing technologies by providing a machining positioning device and machining system for stop bolts.

[0006] Therefore, the present invention provides a machining and positioning device for a stop bolt, which includes a base, an expansion core, a mandrel, a spring, a screw plug, a cylindrical pin, a pressure plate, and a nut; The base has a spline through hole perpendicularly through each of its left and right ends; Each spline through hole is equipped with a hollow expansion core; Inside each expansion core, a mandrel is inserted through from bottom to top; The lower end of the expansion core is connected to the screw plug; a spring is provided between the bottom surface of the core shaft and the top surface of the screw plug; The base has a cylindrical pin that runs longitudinally through both the left and right ends, and the cylindrical pin runs longitudinally through the expansion core and the mandrel. Among them, a stop bolt blank to be processed is placed on the top surface of the base at a position corresponding to each expansion core; The upper part of the expansion core protrudes upward from the top surface of the base and is located in the spline inner hole of the stop bolt blank. The upper part of the mandrel protrudes upward from the top surface of the expansion core and is fixedly connected to the nut; A pressure plate is provided between the bottom surface of the nut and the top surface of the stop bolt blank.

[0007] In addition, the present invention also provides a machining system for a stop bolt, including a machining positioning device for a stop bolt as described above, and a vertical machining center; A vertical machining center is used to machine a blank stop bolt located on a machining positioning device of the stop bolt using cutting tools, so as to obtain a finished stop bolt.

[0008] As can be seen from the technical solution provided by the present invention above, compared with the prior art, the present invention provides a machining positioning device and machining system for stop bolts. The design is scientific and can solve the technical problems of large positioning gap, low coaxiality accuracy, low clamping efficiency, and inability to adapt to the expansion and positioning of spline inner hole parts in the existing clamping method. It can conveniently and reliably position the stop bolt blank to be machined, with high positioning accuracy and high clamping efficiency, which is conducive to improving the machining quality of stop bolts and has great practical significance.

[0009] Through practical testing, the machining and positioning device for the stop bolt of the present invention is a special tooling with high positioning accuracy, high clamping efficiency, and the ability to achieve zero-clearance expansion and tightening of spline holes. It is a tooling for expanding and tightening the arc machining of the stop bolt, which can effectively solve the pain points of accuracy and efficiency in the arc machining of the stop bolt on the ZD6 series switch machine.

[0010] Compared with the prior art, the machining positioning device and machining system for the stop bolt provided by the present invention have the following beneficial effects: 1. High positioning accuracy: The spline expansion structure driven by the conical surface achieves zero clearance fit between the spline inside the stop bolt and the tooling, eliminating the positioning error of the traditional clearance mandrel. This effectively ensures the coaxiality of the machined arc structure (fan-shaped groove) and the spline inner hole, as well as the symmetry of the arc structures (fan-shaped grooves) on both sides, resulting in good consistency in part machining.

[0011] 2. High clamping efficiency: The machining of the arc structure (fan-shaped groove) on both sides of the stop bolt can be completed in one clamping, without the need for secondary flipping and clamping, avoiding repeated positioning errors; and the operation process of pressing-clamping-releasing is simple and quick, greatly improving the production efficiency of batch processing.

[0012] 3. Reliable and durable structure: The expansion core is made of spring steel, which has good elastic recovery performance and stable repeated clamping accuracy; the cylindrical pin realizes both circumferential fixation of the expansion core and axial guidance of the mandrel, resulting in a compact structure with high integration and low failure rate.

[0013] 4. Strong adaptability: The base can be quickly positioned and installed on the T-slot of the vertical machining center via the positioning key, and the tooling is easy to disassemble and assemble; the left and right dual-station design can clamp two workpieces at the same time, further improving processing efficiency.

[0014] 5. Clamping and protection: The clamping method involves tightening the spline inner hole of the stop bolt blank and pressing the upper end face of the stop bolt blank downwards. This will not damage the outer diameter machining surface of the stop bolt blank to be processed, thus ensuring the appearance quality of the part. Attached Figure Description

[0015] Figure 1a This is a schematic diagram of the overall assembly structure of a stop bolt processing and positioning device provided by the present invention. At this time, the stop bolt that has been processed and is a finished product is being assembled. Figure 1b This is an isometric view of a stop bolt processing and positioning device provided by the present invention during the assembly of a stop bolt blank. The stop bolt blank to be processed is being assembled at this time. The nut and pressure plate are not shown in this figure. Figure 1c This is an isometric view of a machining and positioning device for a stop bolt provided by the present invention when the stop bolt blank is not assembled. The nut and pressure plate are not shown in the figure. Figure 1d A three-dimensional exploded view of the machining and positioning device for a stop bolt provided by the present invention when a locking iron blank needs to be assembled. Figure 1e A partial cross-sectional view of a stop bolt machining and positioning device provided by the present invention during the assembly of a stop bolt blank; Figure 2 This is a schematic diagram of the three-dimensional structure of the base; Figure 3 This is a schematic diagram of the cylindrical pin structure; Figure 4 This is a schematic diagram of the three-dimensional structure of the mandrel; Figure 5 This is a schematic diagram of the pressure plate structure; Figure 6 This is a schematic diagram of a shouldered hexagonal nut. Figure 7 This is a structural schematic diagram of the stop bolt blank to be processed (i.e., ZD6 stop bolt blank); Figure 8 This is a schematic diagram of the three-dimensional structure of the expanding core; Figure 9 This is a cross-sectional view of the expanding core; Figure 10 Cross-section of the expanding core Figure 2 ; Figure 11 This is a schematic diagram of the locating key structure; Figure 12 A three-dimensional structural diagram of the stop bolt (i.e., ZD6 stop bolt) obtained after processing; Figure 13 This is a schematic diagram of the three-dimensional structure of a spring; Figure 14 This is a front view of the screw plug; Figure 15 This is a bottom view of the screw plug; Figure 16 This is a schematic diagram of the three-dimensional structure of the screw plug; In the diagram, base-1, positioning key-2; expansion core-3, upper conical surface-31, round hole-32, pin hole-33; Mandrel-4, outer conical surface-41, through groove-42 (U-shaped); Spring-5, Plug-6, Cylindrical Pin-7, Pressure Plate-8, Nut (specifically, a shouldered hexagonal nut)-9; Stop bolt blanks-10 and stop bolts-20. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0018] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0020] The technical solution of the present invention will be further described below through specific embodiments. Details not specified in the embodiments are all conventional technologies in the industry.

[0021] See Figures 1a to 1e , Figures 2 to 16 The present invention provides a machining and positioning device for a stop bolt, which is a tooling for expanding and positioning the arc machining of the stop bolt of the ZD6 electric switch machine in a vertical machining center. The device includes a base 1, an expansion core 3, a mandrel 4, a spring 5, a screw plug 6, a cylindrical pin 7, a pressure plate 8, and a nut 9. Among them, a spline through hole 102 is vertically provided at each of the left and right ends of the base 1; Each spline through hole 102 is provided with a hollow expansion core 3; Within each expansion core 3, a mandrel 4 is inserted through from bottom to top; The lower end of the expansion core 3 is connected to the screw plug 6; a spring 5 is provided between the bottom surface of the core 4 and the top surface of the screw plug 6; Among them, a cylindrical pin 7 is longitudinally provided at both the left and right ends of the base 1, and the cylindrical pin 7 longitudinally passes through the expansion core 3 and the spindle 4; Among them, a stop bolt blank 10 to be processed is placed on the top surface of the base 1 at a position corresponding to each expansion core 3; The upper part of the expansion core 3 protrudes upward from the top surface of the base 1 and is located in the spline inner hole 1001 of the stop bolt blank 10; The upper part of the mandrel 4 protrudes upward from the top surface of the expansion core 3 and is fixedly connected to the nut 9 (i.e., threaded fixed connection). A pressure plate 8 is provided between the bottom surface of the nut 9 and the top surface of the stop bolt blank 10.

[0022] In this invention, it should be noted that the expansion core 3 is a hollow spline shaft structure made of spring steel. The outer circle of the expansion core 3 has a spline structure, and its outer spline is adapted to the inner spline (i.e., the inner spline on the spline inner hole 1001) on the stop bolt blank 10 to be processed. For the outer circle spline structure of the expansion core 3, its tooth profile parameters match the inner spline of the stop bolt blank 10 to be processed.

[0023] In this invention, specifically, the two spline through holes 102 are symmetrically distributed from left to right; It should be noted that the base 1 has symmetrical spline through holes on the left and right sides, and the expansion core 3 is coaxially assembled in the spline through holes.

[0024] In this invention, specifically, the spline through hole 102 of the base 1 and the outer circle of the expansion core 3 are in clearance fit, thereby reserving space for the elastic expansion of the expansion core 3.

[0025] In this invention, specifically, the upper and lower ends of the expansion core 3 have an upper inner hole 301 and a lower inner hole 302, respectively. There is a vertically distributed expansion core inner cavity 300 between the upper inner hole 301 and the lower inner hole 302 of the expansion core; The inner hole 302 at the lower end of the expansion core is connected to the screw plug 6; In practice, the inner hole 302 at the lower end of the expansion core 3 is an internally threaded hole, and the inner hole 302 at the lower end of the expansion core is threadedly fixedly connected to the screw plug 6 (a threaded plug).

[0026] It should be noted that the bottom inner hole of the expansion core 3 (i.e., the lower end inner hole 302 of the expansion core) is provided with an internal thread, the screw plug 6 is threadedly installed at the bottom of the expansion core 3, and the spring 5 is located between the lower end face of the spindle 4 and the screw plug 6. The spring 5 is always in a compressed state, providing an upward restoring force for the spindle 4.

[0027] It should be noted that the screw plug 6 is a plug structure with external threads, which is screwed into the bottom inner hole of the expansion core 3 (i.e., the lower end inner hole 302 of the expansion core) to seal the lower end of the expansion core 3. The spring 5 is a cylindrical helical compression spring, which is set between the lower end face of the spindle 4 and the upper end face of the screw plug 6.

[0028] In this invention, specifically, a positioning post 401 is provided at the lower end of the mandrel 4; The upper end of the spring 5 is fitted onto the lower part of the circumferential outer side of the positioning post 401; Therefore, based on the above design, radial displacement of the spring can be prevented during operation. In the free state, spring 5 is always in a pre-compressed state, continuously providing upward elastic force to spindle 4.

[0029] In practice, the overall shape of the inner hole 301 at the upper end of the expansion core 3 is a frustum shape.

[0030] In specific implementation, the inner side of the upper end inner hole 301 of the expansion core 3 has an upper conical surface 31; The outer conical surface 41 is provided on the outer circumferential side of the mandrel 4 at a position corresponding to the upper conical surface 31 of the expansion core 3; The upper conical surface 31 is in contact with the outer conical surface 41; The upper conical surface 31 and the outer conical surface 41 are correspondingly matched in shape and size.

[0031] It should be noted that the upper inner hole 301 of the expansion core 3 is machined with an upper conical surface 31 with a taper of 25°.

[0032] It should be noted that the mandrel 4 is a coaxial stepped cylindrical structure made of No. 45 steel. The middle part is provided with an outer conical surface 41 with a taper of 25°. The outer conical surface 41 matches the taper of the upper conical surface 31 of the expansion core 3 and the conical surfaces fit together. The lower part of the mandrel 4 is provided with an arch-shaped (i.e. U-shaped) through groove 42, through which the cylindrical pin 7 passes.

[0033] It should be noted that the mandrel 4 is a coaxial stepped cylindrical structure with different upper and lower diameters. The middle part is machined with an outer conical surface 41 with a taper of 25°. The taper of the outer conical surface 41 is completely consistent with the upper conical surface 31 of the expansion mandrel, and the two conical surfaces fit tightly together.

[0034] In this invention, specifically, a cylindrical pin 7 is longitudinally arranged at both ends of the base 1, and the cylindrical pin 7 longitudinally passes through the expansion core 3 and the mandrel 4. The specific structural design is as follows: Both ends of the base 1 are provided with a cylindrical pin mounting hole assembly; The cylindrical pin mounting hole assembly includes a first cylindrical pin mounting hole 1031 and a second cylindrical pin mounting hole 1032 distributed front and rear; the first cylindrical pin mounting hole 1031 and the second cylindrical pin mounting hole 1032 are respectively located on the front and rear sides of the spline through hole 102 of the base 1 and are connected to the spline through hole 102. At the front and rear ends (specifically, at the vertical middle section) of each expansion core 3, a pin hole 33 is provided at the position corresponding to the cylindrical pin mounting hole combination; Each spindle 4 has a through groove 42 with an opening facing downwards at a position corresponding to the pin hole 33 on the expansion core 3. The cylindrical pin 7 passes through the first cylindrical pin mounting hole 1031 on the front side of the base 1, the pin hole 33 on the expansion core 3 and the through groove 42 on the spindle 4, and then connects to the second cylindrical pin mounting hole 1032 on the rear side of the base 1.

[0035] It should be noted that the cylindrical pin 7 is inserted from the front side of the base 1, passes through the pin hole 33 of the expansion core 3 and the through groove 42 of the spindle 4 in sequence, and finally connects to the rear side of the base 1, thereby fixing the expansion core 3 circumferentially and guiding the spindle 4 axially.

[0036] It should be noted that the cylindrical pin 7 serves two purposes: on the one hand, it restricts the circumferential rotation and axial movement of the expansion core 3; on the other hand, it cooperates with the U-shaped through groove 42 to provide axial guidance for the up and down movement of the spindle 4, while limiting the up and down stroke of the spindle 4.

[0037] Furthermore, the through groove 42 is U-shaped.

[0038] Furthermore, for each cylindrical pin mounting hole assembly, the first cylindrical pin mounting hole 1031 and the second cylindrical pin mounting hole 1032 are located on the same longitudinal axis.

[0039] It should be noted that, in this invention, the upper end of the expansion core 3 is symmetrically machined with two pin holes 33 for inserting cylindrical pins 7.

[0040] It should be noted that two splined through holes 102 are symmetrically machined at the left and right ends of the base 1; each splined through hole 102 is coaxially equipped with a positioning and clamping structure including an expansion core 3, a spindle 4, a spring 5, a screw plug 6, a cylindrical pin 7, a pressure plate 8, and a nut 9, forming a dual-station positioning and machining structure that can simultaneously clamp two stop bolt blanks 10 to be machined.

[0041] In this invention, specifically, a circular hole 32 is longitudinally provided on both the front and rear sides of the upper end of the expansion core 3; The upper end of the expansion core 3 has two slots 33 along the axial direction; Two slots 33 are correspondingly provided with two round holes 32, and the lower ends of the two slots 3 are connected to the upper ends of the two round holes 32.

[0042] Furthermore, the two circular holes 32 are symmetrically distributed front and back.

[0043] It should be noted that, in this invention, through the design of the circular hole 32 and the slot 33, the slot 33 extends downward to the circular hole 32, which can divide the upper end of the expansion core 3 into two claw-shaped structures that can be radially elastically deformed (i.e., two elastic structures).

[0044] It should be noted that the expansion core 3 is a hollow spline shaft structure, and the whole is made of spring steel (65Mn), which has good elastic deformation ability and wear resistance.

[0045] Furthermore, the axial slot of the expansion core 3 extends to the position of the circular hole 32. The two elastic structures can expand radially outward under the pressure of the outer conical surface 41 of the mandrel 4, so as to achieve zero clearance fit with the inner spline on the spline inner hole 1001 of the stop bolt blank 10 to be processed. After the extrusion pressure is removed, the expansion core 3 can shrink and reset under the elastic force of the spring steel (the material of the expansion core 3 is spring steel).

[0046] In this invention, the upper end of the mandrel 4 has an external thread; The external thread at the upper end of the spindle 4 is threadedly fixed to the internal thread of the nut 9.

[0047] In specific implementation, nut 9 is preferably a shouldered hexagonal nut.

[0048] In this invention, specifically, the pressure plate 8 is sleeved on the upper part of the mandrel 4; It should be noted that the pressure plate 8 is sleeved on the upper part of the mandrel 4, and the nut 9 is engaged with the external thread at the upper end of the mandrel 4, which is used to press the upper end face of the stop bolt blank 10 to be processed by the pressure plate 8.

[0049] In practice, a U-shaped groove 801 is provided in the middle of the pressure plate 8; The upper part of the spindle 4 is located in the U-shaped groove 801 and is engaged with the U-shaped groove 801; It should be noted that the pressure plate 8 is an open pressure plate structure with a U-shaped groove in the middle, which can be quickly inserted into the upper rod of the mandrel 4; the lower end face of the pressure plate 8 presses on the upper end face of the stop bolt blank 10.

[0050] It should be noted that the upper end of the mandrel 4 is machined with an external thread section. The nut 9 is engaged with this external thread section. When the nut 9 is tightened, the shoulder of the nut 9 presses down on the pressure plate 8, thereby achieving axial clamping and fixing of the workpiece (stop bolt blank 10).

[0051] In this invention, positioning keys 2 are fixedly installed at the bottom left and right ends of the base 1; Positioning key 2 is used to be embedded in the T-slot of the external vertical machining center worktable; In terms of specific implementation, a keyway is provided at each of the left and right ends of the bottom of the base 1; Each positioning key 2 is fixedly installed in a keyway by an internal hex screw 201; It should be noted that the positioning key 2 is adapted to the T-slot of the external vertical machining center worktable for overall positioning of the tooling.

[0052] It should be noted that the positioning key 2 is fixed to the keyway at the bottom of the base 1 by screws, and the width of the positioning key 2 is adapted to the width of the T-slot on the worktable of the vertical machining center.

[0053] In this invention, the left and right ends of the base 1 are respectively fixedly connected to the standard T-slot worktable of the vertical machining center located outside by T-bolts; In specific implementation, the middle of the left and right ends of the base 1 has horizontally distributed T-shaped groove mounting slots 101; After the T-bolt passes through the T-slot mounting slot 101, it is threadedly fixed to the corresponding threaded hole on the standard T-slot worktable of the vertical machining center. Therefore, the base 1 can be locked and fixed to the standard T-slot worktable of the vertical machining center by means of the T-bolt.

[0054] It should be noted that the base 1 is made of 45# steel and has a rectangular structure with a keyway at the bottom. The positioning key 2 is fixedly installed in the keyway using hexagonal socket head cap screws. The cross-sectional dimensions of the positioning key 2 are compatible with the standard T-slot width of the vertical machining center's worktable. In use, the positioning key 2 is embedded into the T-slot on the machining center's worktable, enabling quick positioning of the tooling on the worktable. The base 1 is then locked and fixed to the worktable using T-bolts.

[0055] To better understand the technical solution of the present invention, the working process of the present invention is described below.

[0056] Step 1, Fixture installation: Align the positioning key 2 at the bottom of the base 1 with the T-slot on the external vertical machining center worktable and push it in. After adjusting the position, use T-bolts to lock and fix the base 1, thus completing the installation of the fixture of the present invention on the machine tool (vertical machining center).

[0057] The second step is workpiece clamping: The splined inner hole 10 of the stop bolt blank 10 to be processed is placed on the circumferential outer side of the part of the mandrel 4 that protrudes from the top surface of the base 1. Then, the top of the mandrel 4 is pressed down by hand. The mandrel 4 overcomes the elastic force of the spring 5 and moves downward along the axis. The outer conical surface 41 in the middle of the mandrel 4 moves down at the same time. The two elastic structures at the upper end of the expansion core 3 lose the extrusion force of the outer conical surface and contract inward under the elastic force of the spring steel itself, so that the outer diameter of the outer spline at the upper end of the expansion core 3 is reduced. At this time, the stop bolt blank 10 to be processed is moved down. The inner spline on the splined inner hole 100 of the stop bolt blank 10 is aligned with the expansion core 3 and inserted, so that the lower end face of the stop bolt blank 10 is attached to the upper end face (i.e., the top surface) of the base 1. Then, the pressure plate 8 is inserted into the upper part of the mandrel 4 and pressed on the upper end face of the stop bolt blank 10.

[0058] The third step is to tighten and lock the expansion: Release the hand pressing the mandrel, and the spring 5 pushes the mandrel 4 to return to its original position. The outer conical surface 41 of the mandrel 4 presses the upper conical surface 31 of the expansion core 3 upward, forcing the two elastic structures at the upper end of the expansion core 3 to expand radially outward. The outer spline tooth surface of the expansion core 3 is completely in contact with the inner spline tooth surface on the spline inner hole 100 of the stop bolt blank 10, achieving zero-gap tightening and positioning. Then, use a wrench to tighten the nut 9 (shoulder hexagonal nut) at the upper end of the mandrel 4, and use the pressure plate 8 to axially press the workpiece (stop bolt blank 10) to complete the clamping.

[0059] Step 4, machining and unloading: Start the vertical machining center and complete the milling of the arc structure (fan-shaped groove 2001) on the left and right sides of the front end of the stop bolt blank 10 in one go according to the pre-entered workpiece machining program on the vertical machining center; after machining, loosen the nut 9 (shouldered hexagonal nut), press down the mandrel 4 to retract the expansion core 3, remove the pressure plate 8 and the finished workpiece (i.e. the finished stop bolt) 20, thus completing one machining cycle.

[0060] Based on the above-mentioned stop bolt processing and positioning device provided by the present invention, the present invention also provides a stop bolt processing system, which includes the stop bolt processing and positioning device as described above, and a vertical machining center. A vertical machining center is used to perform machining operations on the blank part 10 of the stop bolt located on the machining positioning device of the stop bolt (specifically, to perform milling of the fan-shaped grooves 2001 on the left and right sides of the stop bolt) using the cutting tools on it, so as to obtain the finished stop bolt 20.

[0061] In this invention, specifically, the vertical machining center is a mature existing machining equipment, and will not be elaborated further here. For example, the vertical machining center of this invention can be a CPV-1400B vertical machining center manufactured by Kaibo Precision Machinery Co., Ltd. (Kaibo Precision Machinery). Using this vertical machining center and an indexable round nose end mill, rough machining of the stop bolt's arc contour (fan-shaped groove contour) can be completed, as well as the selection of... The 12-flute carbide round nose end mill is used for finishing of arc contours (fan-shaped groove contours). In addition, the arc structure (fan-shaped groove) on both sides of the stop bolt can be milled by using the machine tool's arc interpolation function, with emulsion cooling, to achieve simultaneous milling of multiple workpieces.

[0062] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A machining and positioning device for a stop bolt, characterized in that, Includes base (1), expansion core (3), mandrel (4), spring (5), screw plug (6), cylindrical pin (7), pressure plate (8) and nut (9); Among them, a spline through hole (102) is vertically provided at both the left and right ends of the base (1). Each spline through hole (102) is provided with a hollow expansion core (3); In each expansion core (3), a mandrel (4) is inserted through from bottom to top. The lower end of the expansion core (3) is connected to the screw plug (6); a spring (5) is provided between the bottom surface of the spindle (4) and the top surface of the screw plug (6). Among them, a cylindrical pin (7) is longitudinally provided at both the left and right ends of the base (1), and the cylindrical pin (7) longitudinally passes through the expansion core (3) and the spindle (4). Among them, a stop bolt blank (10) to be processed is placed on the top surface of the base (1) at a position corresponding to each expansion core (3). The upper part of the expansion core (3) protrudes upward from the top surface of the base (1) and is located in the spline inner hole (1001) of the stop bolt blank (10); The upper part of the mandrel (4) protrudes upward from the top surface of the expansion core (3) and is fixedly connected to the nut (9); A pressure plate (8) is provided between the bottom surface of the nut (9) and the top surface of the stop bolt blank (10).

2. The machining and positioning device for the stop bolt as described in claim 1, characterized in that, The two spline through holes (102) are symmetrically distributed from left to right.

3. The machining and positioning device for the stop bolt as described in claim 1, characterized in that, The expansion core (3) has an upper inner hole (301) and a lower inner hole (302) at its upper and lower ends, respectively. There is a vertically distributed expansion core cavity (300) between the upper end inner hole (301) and the lower end inner hole (302) of the expansion core. The inner hole (302) at the lower end of the expansion core is connected to the screw plug (6).

4. The machining and positioning device for the stop bolt as described in claim 1, characterized in that, A positioning post (401) is provided at the lower end of the mandrel (4); The upper end of the spring (5) is fitted onto the lower part of the circumferential outer side of the positioning post (401).

5. The machining and positioning device for the stop bolt as described in claim 3, characterized in that, The inner side of the upper end inner hole (301) of the expansion core (3) has an upper conical surface (31). The outer conical surface (41) is provided on the outer circumferential side of the mandrel (4) at a position corresponding to the upper conical surface (31) of the expansion core (3). The upper conical surface (31) is in contact with the outer conical surface (41); The upper conical surface (31) and the outer conical surface (41) are matched in shape and size.

6. The machining and positioning device for the stop bolt as described in claim 1, characterized in that, A cylindrical pin (7) is longitudinally installed at both ends of the base (1), and the cylindrical pin (7) longitudinally passes through the expansion core (3) and the mandrel (4). The specific structural design is as follows: Both ends of the base (1) are provided with a cylindrical pin mounting hole assembly; The cylindrical pin mounting hole assembly includes a first cylindrical pin mounting hole (1031) and a second cylindrical pin mounting hole (1032) distributed front and rear; the first cylindrical pin mounting hole (1031) and the second cylindrical pin mounting hole (1032) are located on the front and rear sides of the spline through hole (102) of the base (1) and are connected to the spline through hole (102); At the front and rear ends of each expansion core (3), a pin hole (33) is provided at the position corresponding to the cylindrical pin mounting hole combination. Each spindle (4) has a through groove (42) with an opening facing downwards at a position corresponding to the pin hole (33) on the expansion core (3). The cylindrical pin (7) passes through the first cylindrical pin mounting hole (1031) on the front side of the base (1), the pin hole (33) on the expansion core (3) and the through groove (42) on the spindle (4), and then connects to the second cylindrical pin mounting hole (1032) on the rear side of the base (1).

7. The machining and positioning device for the stop bolt as described in claim 6, characterized in that, The through groove (42) is U-shaped; For each combination of cylindrical pin mounting holes, the first cylindrical pin mounting hole (1031) and the second cylindrical pin mounting hole (1032) are located on the same longitudinal axis.

8. The machining and positioning device for the stop bolt as described in claim 1, characterized in that, On the front and rear sides of the upper end of the expansion core (3), a round hole (32) is provided longitudinally through each other. The upper end of the expansion core (3) has two slots (33) along the axial direction; Two slots (33) are provided corresponding to two round holes (32), and the lower ends of the two slots (3) are connected to the upper ends of the two round holes (32); The two round holes (32) are symmetrically distributed front and back.

9. The machining and positioning device for the stop bolt as described in claim 1, characterized in that, The upper end of the mandrel (4) has an external thread; The external thread at the upper end of the mandrel (4) is threadedly fixed to the internal thread of the nut (9); And / or, Nut (9) is a shouldered hexagonal nut; And / or, The pressure plate (8) is sleeved on the upper part of the mandrel (4); A U-shaped groove (801) is provided in the middle of the pressure plate (8); The upper part of the mandrel (4) is located in the U-shaped groove (801) and is engaged with the U-shaped groove (801); And / or, Positioning keys (2) are fixedly installed on the left and right ends of the bottom of the base (1); The positioning key (2) is used to be embedded in the T-slot of the vertical machining center worktable located on the outside; The bottom left and right ends of the base (1) are respectively provided with a keyway; Each locating key (2) is fixedly installed in a keyway by an internal hex screw (201).

10. A machining system for a stop bolt, characterized in that, The invention includes a machining and positioning device for a stop bolt as described in any one of claims 1 to 9, and a vertical machining center; A vertical machining center is used to perform machining operations on a stop bolt blank (10) located on a machining positioning device of a stop bolt, using the cutting tools on it, to obtain a finished stop bolt (20).

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