Boring and milling device for valve mold of nuclear power plant and boring and milling method thereof

Abstract

The application provides a boring and milling device for a valve mold for a nuclear power plant and a boring and milling method thereof, and relates to the field of mold manufacturing. The device comprises a device main body, a machine head assembly and a moving bed assembly which are installed on the device main body. The machine head assembly is provided with a lifting machine head and at least one sliding seat which is driven by the lifting machine head to move along the Z direction. A machining module is installed on the sliding seat. A buffer assembly is installed at the bottom of the lifting machine head. The buffer assembly comprises a damping module. A plug column is arranged at the bottom of the sliding seat. The damping module comprises an installation arm which is fixed to the bottom of the lifting machine head, a swing block which is rotationally connected to the installation arm, a fixed block which is fixed to the installation arm, a buffer block which is slidingly arranged on the fixed block and an elastic buffer rod. A positioning plug hole which is plugged with the plug column is arranged on the swing block. The positioning plug hole is arranged eccentrically with respect to the rotation center of the swing block. An arc surface is arranged at the end of the swing block which is away from the positioning plug hole. The vibration generated by the cutter is converted into the reciprocating swing of the swing block, and the spread of the vibration to the machine head assembly and the bed body is inhibited.

Description

Technical Field

[0001] This invention relates to the field of mold manufacturing, and more specifically, to a boring and milling device and method for valve molds used in nuclear power plants. Background Technology

[0002] The cavities and hole systems of valve molds used in nuclear power plants have strict requirements for dimensional accuracy, and their surface quality directly affects the fitting accuracy of the upper and lower molds and the final forming accuracy. During boring and milling processes, the vibration generated by the interaction between the tool and the workpiece is transmitted through the tool holder, spindle box to the machine tool lifting head and even the entire machine. This not only easily leaves vibration marks on the machined surface, but also accelerates the wear of machine tool parts, reducing the machining consistency and service life of the mold.

[0003] In existing technologies, vibration is usually suppressed by adding vibration damping pads to the bottom of the equipment or by dynamically balancing the spindle. However, these solutions have limited effect on suppressing vibrations directly generated at the machining end, especially when performing deep hole boring or complex cavity milling operations, where vibrations at the tool end are difficult to be effectively absorbed and isolated.

[0004] To address machining vibration issues, existing technologies commonly employ two main suppression measures. One type involves installing vibration-damping pads or using vibration-isolated foundations at the bottom of the equipment to isolate external vibrations and attenuate low-frequency vibrations at the overall machine level. However, these measures are located at the end of the vibration transmission path, offering limited attenuation of higher-frequency vibrations directly generated at the tool tip. The other type involves dynamic balancing of the spindle or the use of vibration-damping tool holders. Dynamic balancing can only eliminate the imbalance within the spindle assembly itself and cannot cope with dynamically changing cutting force excitations during the cutting process. Vibration-damping tool holders absorb vibrations of specific frequencies by incorporating dynamic vibration absorbers within the tool holder, but their applicability is limited by the tool holder size and frequency matching, and they are not suitable for general clamping applications of rotating tools such as milling cutters. Therefore, how to buffer vibrations at the tool machining location has become crucial for improving the machining quality of nuclear power plant valve molds. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a boring and milling device and method for valve molds used in nuclear power plants, thereby solving the problem of overall equipment vibration caused by tool vibration transmission, which affects the quality of mold processing.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a boring and milling device for valve molds used in nuclear power plants, comprising a main body, a head assembly and a moving bed assembly mounted on the main body; the head assembly has a lifting head and at least one sliding seat driven by the lifting head to move along the Z direction, and a machining module is mounted on the sliding seat; a buffer assembly is mounted at the bottom of the lifting head, the buffer assembly including a damping module; a post is provided at the bottom of the sliding seat, the damping module includes a mounting arm fixed to the bottom of the lifting head, a swing block rotatably connected to the mounting arm, a fixed block fixed to the mounting arm, a buffer block slidably mounted on the fixed block, and an elastic buffer rod; the swing block has a positioning hole for insertion into the post, the positioning hole is eccentrically positioned with respect to the rotation center of the swing block, and an arc surface is provided at the end of the swing block away from the positioning hole; a buffer groove adapted to the arc surface is provided at the end of the buffer block facing the swing block; the elastic buffer rod is connected between the fixed block and the buffer block to absorb the vibration transmitted by the swing block and to make the buffer groove abut against the arc surface.

[0007] According to one embodiment of the present invention, the machining module includes a boring tool module and a milling cutter module; there are two sliding seats, which are used to install the boring tool module and the milling cutter module respectively, and the bottom of the two sliding seats is provided with a pin.

[0008] According to one embodiment of the present invention, a lead screw module is also installed at the bottom of the lifting head, a slider is connected to the lead screw module, and a damping module is fixed on the slider. The lead screw module is used to drive the damping module to move along the X direction so that the positioning socket is selectively aligned with one of the pins on the two sliding seats.

[0009] According to one embodiment of the present invention, the end of the insertion post is a conical head, and the positioning insertion hole is a conical groove adapted to the conical head.

[0010] According to one embodiment of the present invention, the swing block has a threaded groove at the positioning insertion hole, and a guide sleeve is detachably connected in the threaded groove, the opening of the guide sleeve forming the positioning insertion hole.

[0011] According to one embodiment of the present invention, the curvature of the buffer groove is greater than the curvature of the swing block's arc surface; or, the buffer groove is a V-shaped concave surface with an arc transition, and the end of the swing block is a V-shaped surface adapted to the V-shaped concave surface.

[0012] According to one embodiment of the present invention, a guide rod is connected to the end of the buffer block away from the buffer groove, and a guide groove is provided on the fixed block to slide with the guide rod.

[0013] According to one embodiment of the present invention, it further includes a guide assembly, which includes a first ring sleeve, a second ring sleeve, a fixing plate fixed to the bottom of the sliding seat, a guide cylinder mounted on the fixing plate, a guide post fixed to the second ring sleeve, and a locking nut threadedly connected to the guide cylinder; the first ring sleeve and the second ring sleeve are mated and fixed to the outer periphery of the processing module, the guide post is inserted into the guide cylinder, and the end of the guide cylinder for the insertion of the guide post is provided with a notch, which contracts to hold the guide post when the locking nut is tightened.

[0014] The present invention also provides a boring and milling method for a valve mold for a nuclear power plant, comprising the following steps: controlling the sliding seat to descend so that the insert pin is inserted into the positioning hole of the swing block; starting the processing module to process the mold workpiece, the vibration generated during the processing drives the swing block to swing around its rotation center through the insert pin, the arc surface of the swing block pushes the buffer block, so that the elastic buffer rod produces elastic deformation to absorb the vibration energy; after processing is completed, the sliding seat is raised so that the insert pin is disengaged from the positioning hole.

[0015] According to one embodiment of the present invention, when using a boring and milling device having a boring tool module and a milling cutter module, before controlling the slide seat to move downward, the device further includes: driving a damping module to move along the X direction via a lead screw module, so that the positioning socket is aligned with the post on the slide seat corresponding to the boring tool module or milling cutter module that is currently working.

[0016] In summary, this application includes at least one of the following beneficial technical effects: 1. In this invention, by setting a damping module at the bottom of the lifting head and inserting the pin on the sliding seat into the eccentric positioning hole of the swing block during processing, the vibration generated by the tool is converted into the reciprocating swing of the swing block. Then, by using the arc surface and the buffer block to compress the elastic buffer rod, the vibration energy is attenuated by the energy storage of the elastic element and the energy dissipation of the damping medium. This effectively suppresses the spread of vibration to the machine head assembly and the machine bed from the transmission path, which helps to maintain the stability of the equipment during processing, improves the surface quality of the mold cavity and hole wall, and reduces the risk of loosening and fatigue wear of parts due to long-term vibration.

[0017] 2. In this invention, the guide component enables the lower part of the tool holder to form an auxiliary rigid support with the sliding seat through the clamping mechanism of the guide post and guide cylinder during the machining process, which increases the overall rigidity of the tool overhang system and reduces the tool's wobble and chatter tendency under the action of cutting force, thereby further improving the dimensional consistency and surface finish of boring and milling.

[0018] 3. In this invention, the damping module is driven by the lead screw module to move and switch positions along the X direction, so that the same set of buffer components can be successively connected and cooperated with the sliding seat corresponding to the boring tool module and the sliding seat corresponding to the milling cutter module. This achieves effective suppression of tool vibration in both boring and milling machining states, reduces the redundancy of parts caused by independently configuring buffer devices for each tool holder, and is conducive to the compactness of equipment structure and cost control.

[0019] 4. In this invention, the positioning hole of the swing block adopts a detachable guide sleeve design. When the mating surface is worn due to long-term use, the guide sleeve can be replaced separately without replacing the entire swing block, which makes maintenance quick and cost-effective.

[0020] 5. In this invention, the cooperation between the tapered head at the end of the insertion post and the tapered groove of the guide sleeve enables the sliding seat to have automatic guiding and centering capabilities during downward insertion, reducing the sensitivity to the initial positioning accuracy of the sliding seat and improving the reliability of the buffer assembly connection and the consistency of repeated positioning. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the boring and milling device in this invention; Figure 2 for Figure 1 A schematic diagram of the assembly between the intermediate moving bed assembly and the head assembly; Figure 3 This is a three-dimensional schematic diagram of the boring bar module and the milling cutter module mounted on the head assembly in this invention; Figure 4 for Figure 3 A magnified view of a section at point A in the middle; Figure 5 This is a schematic diagram of the connection between the lead screw module and the damping module in this invention; Figure 6 This is a schematic diagram of the structure of the buffer assembly installed at the bottom of the elevator head in this invention; Figure 7 for Figure 6 A magnified view of a section at point B in the middle; Figure 8 This is a schematic diagram of the damping module in this invention; Figure 9 This is a schematic diagram of the damping module from another perspective in this invention; Figure 10 For along Figure 9 Cross-sectional view of the CC section line; Figure 11 This is a schematic diagram of the overall structure of the guide component in this invention; Figure 12 This is an exploded view of the guide component in this invention; Figure 13This is a schematic diagram of the structure of the mold workpiece in this invention; Figure 14 This is a schematic diagram of the damping module in Embodiment 3 of the present invention.

[0022] Figure label: 1. Equipment body; 2. Head assembly; 201. Lifting head; 202. Sliding seat; 203. Insert column; 204. Guide assembly; 2041. First ring sleeve; 2042. Second ring sleeve; 20421. Guide column; 2043. Locking nut; 2044. Fixing plate; 20441. Guide cylinder; 2045. Anti-slip washer; 3. Moving bed assembly; 301. Sliding module; 302. Tooling bed plate; 303. Positioning block; 4. Buffer assembly; 401. Screw module; 4 011, slider; 4012, cover plate; 402, damping module; 4021, mounting arm; 4022, fixing block; 4023, buffer block; 40231, buffer groove; 4024, swing block; 40241, needle roller; 4025, guide sleeve; 4026, elastic buffer rod; 5, boring tool module; 501, first guide sleeve; 502, boring tool holder; 6, milling cutter module; 601, second guide sleeve; 602, milling cutter holder; 7, mold workpiece; 701, hole to be machined. Detailed Implementation

[0023] 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.

[0024] Example 1: This example provides a boring and milling device for valve molds used in nuclear power plants, such as... Figure 1 and Figure 2 As shown, the main body 1 of the equipment is equipped with a machine head assembly 2 and a moving bed assembly 3. The moving bed assembly 3 includes a sliding module 301 and a tooling bed 302 mounted on the sliding module 301. The tooling bed 302 is used to support the mold workpiece 7, and a positioning block 303 is fixed on the tooling bed 302. The sliding module 301 can drive the tooling bed 302 to move along the X and Y directions, so that the mold workpiece 7 is moved below the lifting head 201, so that the processing module mounted on the lifting head 201 can process the cavity and hole system of the mold workpiece 7. One side of the mold workpiece 7 is positioned against the positioning block 303, and after positioning, the mold workpiece 7 is fixed on the tooling bed 302 by side clamps or pressure plates.

[0025] like Figure 13As shown, the mold workpiece 7 has a cavity to be formed and a hole 701 to be machined. This hole 701 serves as a positioning hole and requires high machining accuracy. Figure 3 and Figure 4 As shown, the lifting head 201 of the machine head assembly 2 is equipped with a boring bar module 5 and a milling cutter module 6, which are used for hole machining and cavity milling of the mold workpiece 7, respectively. Two independent Z-axis sliding modules are arranged side-by-side on the lifting head 201. Each Z-axis sliding module is equipped with a sliding seat 202, one of which is used to install the boring bar module 5, and the other is used to install the milling cutter module 6. A first guide sleeve 501 is fixed to the drive end of the boring bar module 5. A boring bar holder 502, which is rotatably connected to the drive end via a bearing, is mounted inside the first guide sleeve 501. The boring bar holder 502 is used to clamp the boring bar body. A second guide sleeve 601 is fixed to the drive end of the milling cutter module 6. A milling cutter holder 602, which is rotatably connected to the drive end via a bearing, is mounted inside the second guide sleeve 601. The milling cutter holder 602 is used to clamp the milling cutter body. The two sliding seats 202 can be driven independently to rise and fall along the Z direction by the drive mechanism inside the lifting head 201, without interfering with each other.

[0026] In boring, the tool mainly feeds and cuts along the Z-axis, and radial oscillation is easily generated when the tool body has a long overhang. The first guide sleeve 501 provides circumferential support for the boring tool holder 502, improving the static stiffness of the boring tool system. However, these oscillations are not completely eliminated; a considerable portion of the vibration energy is still transmitted upwards to the lifting head 201 through the connecting links such as the tool holder, guide sleeve, and sliding seat, thus causing vibration of the entire equipment body 1. Although the bottom of the equipment body 1 is usually equipped with vibration-damping pads, the vibration of the entire machine still accelerates the wear of transmission components such as guide rails and lead screws, and forms vibration marks on the machined surface.

[0027] Furthermore, in order to add damping along the vibration transmission path, such as Figure 4 As shown, a buffer assembly 4 is installed at the bottom of the lifting head 201. The buffer assembly 4 includes a damping module 402, which in this embodiment is fixed below the boring tool module 5. A pin 203 is fixed at the bottom of the sliding seat 202 corresponding to the boring tool module 5.

[0028] like Figure 8As shown, the damping module 402 includes a mounting arm 4021 fixedly connected to the bottom of the lifting head 201 by screws. A swing block 4024 is rotatably connected to the mounting arm 4021 via a pin. The swing block 4024 has a positioning hole that can be inserted into the corresponding insertion post 203. The center of the positioning hole is eccentrically arranged with respect to the rotation center of the swing block 4024, allowing the horizontal component force transmitted by the insertion post 203 to generate a torque about the rotation center of the swing block 4024. The side of the swing block 4024 away from the positioning hole is machined with an outwardly convex arc surface. A fixing block 4022 is also fixed on the mounting arm 4021. A buffer block 4023 is provided between the fixing block 4022 and the swing block 4024. The end of the buffer block 4023 facing the swing block 4024 has a buffer groove 40231 adapted to the arc surface. An elastic buffer rod 4026 is mounted on the fixed block 4022. The elastic buffer rod 4026 includes a cylinder, a telescopic rod, and an elastic element and damping medium disposed within the cylinder. The end of the telescopic rod is fixedly connected to the buffer block 4023. The elastic buffer rod 4026 is used to apply a pushing force to the buffer block 4023, so that the buffer groove 40231 is stably abutted against the arc surface of the swing block 4024. A guide rod is integrally connected to the end of the buffer block 4023 away from the buffer groove 40231. A guide groove is provided on the fixed block 4022 to slide and engage with the guide rod, so that the buffer block 4023 can only reciprocate along the straight line direction defined by the guide groove.

[0029] When the sliding seat 202 moves downward along the Z-axis, allowing the insertion post 203 to be inserted into the positioning hole on the swing block 4024, the vibration generated at the tool tip during boring is transmitted to the swing block 4024 through the sliding seat 202 and the insertion post 203. Because the positioning hole is eccentrically positioned relative to the rotation center, the radial vibration component of the insertion post 203 is converted into torque that drives the swing block 4024 to reciprocate around its rotation center. When the swing block 4024 swings, its arc surface pushes against the buffer block 4023, causing the buffer block 4023 to compress the telescopic rod of the elastic buffer rod 4026 along the guide groove. The elastic element inside the cylinder deforms under force, converting the kinetic energy of the vibration into elastic potential energy. Simultaneously, the damping medium converts some of the energy into heat energy through friction or fluid resistance, thus achieving rapid attenuation of the vibration energy. When the vibration amplitude decreases, the elastic force stored in the elastic buffer rod 4026 pushes back the buffer block 4023 through the telescopic rod, and the buffer groove 40231 pushes back against the arc surface of the swing block 4024, causing the swing block 4024 to return to its initial position. Figure 9As shown, the curvature of the buffer groove 40231 is designed to be slightly larger than the curvature of the swing block 4024's arc surface. This ensures that a reasonable contact gap is maintained between the arc surface and the groove during the rotation of the swing block 4024, preventing jamming and maintaining the return-to-center guiding function. In the free state where the insert 203 is not inserted, the swing block 4024 is stably maintained in its initial return-to-center posture under the pushing force of the elastic buffer rod 4026 and the buffer block 4023, ensuring that the insert 203 can be smoothly aligned and inserted into the positioning hole in the next operation.

[0030] In another embodiment, the buffer groove 40231 can also be configured as a V-shaped concave surface with an arc transition, correspondingly setting the arc surface at the end of the swing block 4024 as a V-shaped surface that matches the V-shaped concave surface. During the return-to-center process of the swing block 4024, the cooperation between the V-shaped surface and the V-shaped concave surface can produce a more obvious centering and return-to-center effect, improving the consistency of repeated positioning.

[0031] Furthermore, such as Figure 10 As shown, the swing block 4024 has a threaded countersunk hole at the positioning insertion hole, and a replaceable guide sleeve 4025 is threadedly connected to the countersunk hole. The upper opening of the guide sleeve 4025 is the positioning insertion hole. The inner hole of the guide sleeve 4025 can be machined to fit the diameter of the insertion post 203, and a guide chamfer is provided at the upper end of its inner hole to facilitate the insertion of the insertion post 203. When the insertion post 203 wears down due to long-term use, resulting in an increased clearance, the guide sleeve 4025 can be unscrewed and replaced separately without disassembling or replacing the entire swing block 4024, making maintenance more convenient.

[0032] To improve the overall rigidity of the tooling process, such as Figure 3 As shown, the boring tool module 5 and the milling cutter module 6 are respectively mounted on the lifting head 201; Figure 4 As shown, a guide component 204 is installed on the first guide sleeve 501 at the bottom of the boring tool module 5; similarly, a guide component 204 is also installed on the second guide sleeve 601 at the bottom of the milling cutter module 6, as shown. Figure 11 and Figure 12As shown, the guide assembly 204 includes a first ring 2041, a second ring 2042, a locking nut 2043, and a fixing plate 2044 fixedly installed at the bottom of the sliding seat 202. The first ring 2041 and the second ring 2042 are clamped together by bolts and fixed to the outer periphery of the first guide sleeve 501 or the second guide sleeve 601. Anti-slip washers 2045 are embedded in the inner rings of both rings. The anti-slip washers 2045 are made of wear-resistant rubber or metal-based friction material to increase the static friction between the ring and the guide sleeve, preventing circumferential sliding of the tool holder under cutting force. A guide post 20421 is fixed to one side of the second ring 2042, and a guide cylinder 20441 that inserts into the guide post 20421 is fixed on the fixing plate 2044. The guide cylinder 20441 has multiple axial notches along its circumference at one end where it intersects with the guide post 20421. A locking nut 2043 is threaded onto the outer wall of the guide cylinder 20441. When the sliding seat 202 moves the fixing plate 2044 downwards and is guided by the conical surfaces of the insertion post 203 and the positioning hole along the Y direction, the guide cylinder 20441 is inserted into the guide post 20421. Tightening the locking nut 2043 causes the inner conical or stepped surface of the locking nut 2043 to press against the notched section of the guide cylinder 20441, causing it to contract inwards and thus locking the guide post 20421. During machining, the guide assembly 204 forms an auxiliary rigid connection between the lower part of the tool holder and the sliding seat 202, effectively reducing the cantilever deflection and chatter tendency of the tool under cutting loads.

[0033] During the machining process, when the boring bar borings the hole 701 of the mold workpiece 7, the linear feed accuracy of the tool is ensured by the Z-axis sliding module of the lifting head 201, and the sliding seat 202 moves linearly along the Z-axis guide rail. The insertion post 203 and the positioning insertion hole of the swing block 4024 are inserted into each other along the Z-axis, and the two can slide freely relative to each other in the vertical direction. Therefore, the buffer assembly 4 will not impose additional constraints or resistance on the Z-axis linear feed of the sliding seat 202.

[0034] The vibration generated by the cutting tool during cutting is mainly manifested as a small-amplitude, high-frequency oscillation along the radial direction. When this radial vibration is transmitted to the insert 203 through the sliding seat 202, due to the eccentric setting of the positioning insert and the rotation center of the oscillating block 4024, the radial vibration component is converted into a small reciprocating torque around the rotation center, driving the oscillating block 4024 to produce a corresponding reciprocating oscillation. This reciprocating oscillation occurs in a plane perpendicular to the Z-axis, and the oscillation amplitude is limited to a small range by the stiffness and damping characteristics of the elastic buffer rod 4026, without generating a displacement component along the Z-direction, thus not interfering with the linear feed trajectory of the boring tool.

[0035] Meanwhile, the guide assembly 204 further fixes the lower part of the boring tool module 5 to the sliding seat 202, enhancing the overall rigidity of the tool overhang and ensuring that the tool maintains its relative position to the Z-axis feed axis even when subjected to radial vibration loads. The damping module 402 absorbs the alternating energy caused by vibration, rather than the feed force required for the main cutting motion. Therefore, while dissipating vibration, it does not weaken the tool's ability to cut along a predetermined straight path.

[0036] In Example 2, as in Example 1, the damping module 402 is fixedly installed below the boring tool module 5, providing vibration buffering only for boring operations. However, the cavities of valve molds used in nuclear power plants often contain multiple inclined surfaces, inclined holes, and deep cavity features. During milling, the milling cutter will also generate vibration. If there are no corresponding vibration reduction measures, tool marks can easily be left on the sidewalls or bottom surfaces of the cavity, affecting the fitting accuracy of the upper and lower molds.

[0037] Therefore, this embodiment makes further improvements based on the above structure. For example... Figure 5 and Figure 14 As shown, the bottom of the two sliding seats 202 corresponding to the boring tool module 5 and the milling cutter module 6 are both fixed with inserts 203. A lead screw module 401 is also installed at the bottom of the lifting head 201. The lead screw module 401 is horizontally arranged along the X-axis and is driven to rotate by a servo motor. A damping module 402 is fixedly connected to the slider 4011 of the lead screw module 401. When switching machining modes, the lead screw module 401 drives the slider 4011 to move the damping module 402 along the X-axis, causing the positioning socket of the guide sleeve 4025 on the damping module 402 to align with the insert 203 of the currently working sliding seat 202. In this way, a set of damping modules 402 can alternately function in boring and milling machining, achieving buffering and absorption of tool vibration in both machining states, reducing the number of parts and making the lower structure of the machine tool more compact.

[0038] To improve the fault tolerance and repeatability of the insertion process, the lower end of the insertion post 203 is machined into a tapered head. Correspondingly, the upper end of the positioning insertion hole of the guide sleeve 4025 is machined into a tapered groove that matches the tapered head. When the sliding seat 202 moves downward, even if there is a slight horizontal position deviation, the fit between the tapered head and the tapered groove can automatically correct the relative position through the inclined guide, ensuring that the insertion post 203 is inserted smoothly.

[0039] like Figure 7As shown, a cover plate 4012 is fixedly connected to the bottom of the lead screw module 401. The lead screw module 401 is integrally embedded in the bottom groove of the lifting head 201. The two ends of the cover plate 4012 are fixed to the lifting head 201 through bearing seats. The top of the mounting arm 4021 in the damping module 402 is machined with a dovetail-shaped slider, and the lower surface of the cover plate 4012 is machined with a matching dovetail groove. The mounting arm 4021 is slidably connected to the cover plate 4012 through the dovetail groove structure. In this way, when the slider 4011 drives the damping module 402 to move along the X direction, the dovetail fit between the mounting arm 4021 and the cover plate 4012 can provide vertical and lateral support for the damping module 402, ensuring smooth movement and maintaining structural rigidity when subjected to vibration loads.

[0040] In the third embodiment, the arc surface of the swing block 4024 and the buffer groove 40231 of the buffer block 4023 are in sliding contact fit. During long-term use, the contact area between the arc surface and the groove may wear due to friction, resulting in an increase in the fit clearance and affecting the sensitivity of vibration transmission.

[0041] Therefore, this embodiment improves the contact method between the swing block 4024 and the buffer block 4023. Specifically, as follows: Figure 14 As shown, multiple rolling elements are embedded on the arc surface of the swing block 4024. In this embodiment, the rolling elements used are needle rollers 40241, which are arranged at intervals along the arc direction of the arc surface and partially protrude from the surface of the arc surface. The buffer groove 40231 of the buffer block 4023 abuts against the needle roller 40241, so that a rolling contact is formed between the arc surface and the buffer groove 40231.

[0042] During the processing, when the swing block 4024 is driven by the insert 203 to swing around its rotation center, the arc surface pushes the buffer block 4023 through the roller 40241, converting the swing motion into the linear movement of the buffer block 4023 to compress the elastic buffer rod 4026. Since the contact between the arc surface and the buffer groove 40231 changes from sliding friction to rolling friction, the frictional resistance of the contact surface is reduced, making vibration transmission more sensitive. At the same time, it reduces the wear rate of the arc surface and the buffer groove 40231, which is beneficial to maintaining the consistency of the buffering performance of the damping module 402 during long-term use.

[0043] The rolling element can also be a steel ball. The arc surface of the oscillating block 4024 is machined with a corresponding mounting groove for accommodating the needle roller 40241, and the rolling element is rotatably held in the mounting groove.

[0044] The remaining structure of this embodiment is the same as that of the above embodiments, and will not be described again here.

[0045] Example 4: This example provides a boring and milling method for valve molds used in nuclear power plants, based on the boring and milling apparatus described in Example 2 above, including the following steps: Step S1: Hoist the mold workpiece 7 onto the tooling bed plate 302, so that one of its machining reference sides is against the positioning block 303. After confirming the position, fix the mold workpiece 7 with side clamps or clamping bolts.

[0046] Step S2: According to the requirements of the machining process card, if boring is to be performed, install the boring bar of the corresponding specification into the boring bar holder 502 and lock it; if cavity milling is to be performed, install the milling cutter of the corresponding specification into the milling cutter holder 602 and lock it. Move the hole 701 or cavity area to be machined on the mold workpiece 7 to below the corresponding tool through the sliding module 301 of the moving bed assembly 3.

[0047] Step S3: When all sliding seats 202 are in the raised state, start the lead screw module 401, drive the slider 4011 to move the damping module 402 along the X direction, so that the positioning hole of the guide sleeve 4025 is aligned with the insertion post 203 at the bottom of the sliding seat 202 used for current processing.

[0048] Step S4: The lifting head 201 drives the corresponding sliding seat 202 to move downward along Z. The insertion post 203 at the bottom of the sliding seat 202 is inserted into the positioning hole of the guide sleeve 4025 under the guidance of the conical surface. At the same time, the fixing plate 2044 fixed at the bottom of the sliding seat 202 drives the guide cylinder 20441 to move downward, so that the guide post 20421 is inserted into the guide cylinder 20441. Then, the locking nut 2043 is tightened, so that the notch section of the guide cylinder 20441 retracts inward to hug the guide post 20421, thus completing the auxiliary rigid connection between the tool holder and the sliding seat 202.

[0049] Step S5: Start the spindle motor to drive the tool to rotate. The moving bed assembly 3 drives the mold workpiece 7 to feed along the planned path in the X and Y directions according to the preset CNC machining program, and starts boring or milling. During the machining process, the vibration generated by the interaction between the tool and the workpiece is transmitted to the insert 203 through the tool holder, guide sleeve and sliding seat 202. The insert 203 drives the swing block 4024 to swing around the rotation center. The arc surface of the swing block 4024 pushes the buffer block 4023, so that the telescopic rod of the elastic buffer rod 4026 is reciprocated and compressed. The elastic element inside the elastic buffer rod 4026 converts the vibration kinetic energy into elastic potential energy, and converts the energy into heat through the dissipation effect of the damping medium, thereby attenuating the vibration component transmitted to the lifting head 201 and reducing vibration marks on the machined surface.

[0050] Step S6: After the current machining area is completed, the spindle stops rotating, the locking nut 2043 is loosened, and the lifting head 201 drives the sliding seat 202 to rise, causing the insertion post 203 to separate from the positioning insertion hole and the guide post 20421 to exit the guide cylinder 20441. According to the requirements of subsequent processes, the tool is replaced or the position of the mold workpiece 7 is adjusted by the moving bed assembly 3 to enter the next machining area.

[0051] Step S7: Repeat steps S2 to S6 until the boring and milling of all cavities, holes and inclined surfaces on the mold workpiece 7 is completed.

[0052] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

Claims

1. A boring and milling device for valve molds used in nuclear power plants, characterized in that, It includes the main body of the equipment (1), the head assembly (2) installed on the main body of the equipment (1), and the moving bed assembly (3); The head assembly (2) has a lifting head (201) and at least one sliding seat (202) driven by the lifting head (201) to move along the Z direction, and a processing module is mounted on the sliding seat (202); A buffer assembly (4) is installed at the bottom of the lifting head (201), the buffer assembly (4) including a damping module (402); The bottom of the sliding seat (202) is provided with a plug (203), and the damping module (402) includes a mounting arm (4021) fixed to the bottom of the lifting head (201), a swing block (4024) rotatably connected to the mounting arm (4021), a fixing block (4022) fixed to the mounting arm (4021), a buffer block (4023) slidably disposed on the fixing block (4022), and an elastic buffer rod (4026). The swing block (4024) is provided with a positioning hole for insertion into the plug (203). The positioning hole is eccentrically set with respect to the rotation center of the swing block (4024). The end of the swing block (4024) away from the positioning hole is provided with an arc surface. The buffer block (4023) has a buffer groove (40231) that is adapted to the arc surface at one end facing the swing block (4024). The elastic buffer rod (4026) is connected between the fixed block (4022) and the buffer block (4023) to absorb the vibration transmitted by the swing block (4024) and to make the buffer groove (40231) abut against the arc surface.

2. The boring and milling device for valve molds used in nuclear power plants according to claim 1, characterized in that, The machining module includes a boring bar module (5) and a milling cutter module (6); there are two sliding seats (202), which are used to install the boring bar module (5) and the milling cutter module (6) respectively, and the bottom of the two sliding seats (202) is provided with a pin (203).

3. The boring and milling device for valve molds used in nuclear power plants according to claim 2, characterized in that, The bottom of the lifting head (201) is also equipped with a lead screw module (401), a slider (4011) is connected to the lead screw module (401), and a damping module (402) is fixed on the slider (4011). The lead screw module (401) is used to drive the damping module (402) to move along the X direction so that the positioning socket is selectively aligned with one of the posts (203) on the two sliding seats (202).

4. The boring and milling device for valve molds used in nuclear power plants according to claim 3, characterized in that, The end of the insert (203) is a conical head, and the positioning hole is a conical groove adapted to the conical head.

5. The boring and milling device for valve molds used in nuclear power plants according to claim 1, characterized in that, The swing block (4024) has a threaded groove at the positioning socket, and a guide sleeve (4025) is detachably connected in the threaded groove. The opening of the guide sleeve (4025) forms the positioning socket.

6. The boring and milling device for valve molds used in nuclear power plants according to claim 1, characterized in that, The curvature of the buffer groove (40231) is greater than the curvature of the swing block (4024); or, the buffer groove (40231) is a V-shaped concave surface with an arc transition, and the end of the swing block (4024) is a V-shaped surface that matches the V-shaped concave surface.

7. The boring and milling device for a valve mold used in a nuclear power plant according to claim 6, characterized in that, The buffer block (4023) is connected to a guide rod at the end away from the buffer groove (40231), and the fixed block (4022) is provided with a guide groove that slides with the guide rod.

8. A boring and milling device for valve molds used in nuclear power plants according to any one of claims 1 to 7, characterized in that, It also includes a guide assembly (204), which includes a first ring sleeve (2041), a second ring sleeve (2042), a fixing plate (2044) fixed to the bottom of the sliding seat (202), a guide cylinder (20441) mounted on the fixing plate (2044), a guide post (20421) fixed to the second ring sleeve (2042), and a locking nut (2043) threadedly connected to the guide cylinder (20441). The first ring sleeve (2041) and the second ring sleeve (2042) are engaged and fixed on the outer periphery of the processing module. The guide post (20421) is inserted into the guide tube (20441). The end of the guide tube (20441) into which the guide post (20421) is inserted is provided with a notch. When the locking nut (2043) is tightened, the notch contracts to hold the guide post (20421).

9. A boring and milling method for a valve mold used in a nuclear power plant, using the boring and milling apparatus for a valve mold used in a nuclear power plant as described in claim 8, characterized in that, Includes the following steps: Control the sliding seat (202) to move downward, so that the insert (203) is inserted into the positioning hole of the swing block (4024); The processing module is started to process the mold workpiece (7). The vibration generated during the processing drives the swing block (4024) to swing around its rotation center through the insert (203). The arc surface of the swing block (4024) pushes the buffer block (4023), causing the elastic buffer rod (4026) to produce elastic deformation to absorb the vibration energy. After processing, the sliding seat (202) is raised to disengage the insert (203) from the positioning hole.

10. A boring and milling method for a valve mold for a nuclear power plant according to claim 9, characterized in that, When using a boring and milling device with a boring tool module (5) and a milling cutter module (6), before controlling the slide block (202) to descend, the following is also included: The damping module (402) is driven by the lead screw module (401) to move along the X direction, so that the positioning socket is aligned with the pin (203) on the sliding seat (202) corresponding to the boring tool module (5) or milling cutter module (6) that needs to be worked.

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