Exchangeable 3+2 electric spindle swing head

Abstract

The invention discloses an exchangeable 3 + 2 electric spindle swing head which comprises an upper box body, a lower box body, a spindle box, an electric spindle, a swing head positioning assembly, a C-axis positioning assembly, an A-axis positioning assembly, an A-axis gear shifting assembly, an A-axis driving assembly and a C-axis driving assembly, and the upper box body is exchangeably connected with a machine tool ram through the swing head positioning assembly; the C-axis positioning assembly comprises a C-axis upper chain wheel, a C-axis lower chain wheel and a C-axis loosening and clamping oil cylinder; the A-axis positioning assembly comprises an A-axis bearing seat, a triple fluted disc assembly and an A-axis oil cylinder; the A-shaft gear shifting assembly comprises a gear shifting oil cavity, a reset oil cavity and a first transmission gear, the A-shaft driving assembly comprises a bevel gear pair, the A-shaft gear shifting assembly, a second transmission gear and a third transmission gear, and the C-shaft driving assembly comprises a bevel gear pair, the A-shaft gear shifting assembly, the second transmission gear and the third transmission gear. The A shaft and the C shaft of the swing head are driven by the machine tool spindle and can be exchanged with the ram, the machining characteristics of the machine tool spindle are reserved, and the process machining range of a machine tool is expanded.

Description

Technical Field

[0001] This invention belongs to the field of CNC machining centers, specifically relating to an interchangeable 3+2 electric spindle swivel head for five-axis machining centers, which can be exchanged with the machine tool slide, and is suitable for multi-angle indexing machining of complex curved surfaces in fields such as mold making and aerospace. Background Technology

[0002] Five-axis machining technology is key to improving the machining capabilities of CNC machine tools. With the rapid development of industries such as mold making and aerospace, the demand for five-axis equipment with multi-angle machining capabilities is increasing. Currently, five-axis heads are mainly divided into two categories: direct-drive and servo-drive.

[0003] Direct-drive 5-axis heads typically use torque motors to directly drive the A / C axes, offering advantages such as fast response and high precision, making them high-end products in the market. However, their high manufacturing costs and complex control systems limit their application to a wider range of customers. Servo-driven 5-axis heads, on the other hand, use servo motors in conjunction with reduction gears, significantly reducing manufacturing costs compared to direct-drive heads and making them more competitive in the market. However, conventional servo-driven 5-axis heads are usually non-interchangeable, with their C-axis drive and positioning structures often integrated inside the machine tool ram. This structure prevents the machine tool from installing or using traditional high-torque spindles after installing the 5-axis head, limiting the machine tool's machining flexibility and making it unable to handle both high-torque heavy cutting and high-speed, high-precision multi-angle machining, thus reducing the overall utilization and cost-effectiveness of the equipment.

[0004] Furthermore, there are two key technical challenges for interchangeable electric spindle heads: First, the contradiction between power transmission and zero-point finding. Interchangeable spindle heads rely on the machine tool spindle for drive, and the machine tool spindle typically uses a relative ring encoder. Before starting any action, a zero-point finding operation is required, during which the spindle needs to rotate forward and backward multiple times to find the encoder's zero point. If the internal transmission mechanism of the spindle head is always engaged, the spindle's zero-point rotation will directly drive the A-axis or C-axis of the spindle head to rotate. However, due to factors such as cable routing, the rotation angle range of the A / C axes is limited (e.g., C-axis 0°~360°, A-axis -120°~+120°), which can easily lead to serious problems such as cable breakage due to overtravel. Second, the challenge of cable management during C-axis rotation. Traditional non-interchangeable five-axis heads often have space inside the ram for cable routing, making cable management relatively convenient. The interchangeable oscillating head needs to be quickly connected and disconnected from the oil receiving tray on the slide. When its C-axis rotates continuously, how to reliably arrange the electric spindle cable connecting the oscillating head and the machine tool to avoid tangling, stretching or squeezing damage is a structural design problem that must be solved.

[0005] Therefore, developing a 3+2 electric spindle tilting head that has a low manufacturing cost, can be interchanged with machine tool slides, can reliably drive A / C axis indexing using machine tool spindle power, and can effectively solve the problems of spindle zero-point overtravel and cable rotation management is of great significance for improving machine tool processing flexibility, reducing user purchase and use costs, and expanding the application scope of five-axis technology. Summary of the Invention

[0006] The technical problem this invention aims to solve is to address the shortcomings of existing technologies by providing an interchangeable 3+2 electric spindle oscillating head. This oscillating head employs a high-power, high-speed electric spindle, with its A / C axes driven by the machine tool spindle and interchangeable with the slide. This retains the machining characteristics of the machine tool spindle while expanding the machine tool's processing range. This invention features an advanced oscillating head structure, low manufacturing cost, and high A / C axis drive torque. Compared to direct-drive oscillating heads of the same specifications, it has a smaller overall size, making it a highly efficient 3+2 oscillating head suitable for multi-angle indexing machining of complex curved surfaces in fields such as mold making and aerospace.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: an interchangeable 3+2 electric spindle oscillating head, wherein the oscillating head includes an upper housing, a lower housing, a spindle housing, an electric spindle, an oscillating head positioning assembly, a C-axis positioning assembly, an A-axis positioning assembly, an A-axis shifting assembly, an A-axis drive assembly, and a C-axis drive assembly. The upper housing is interchangeably connected to the machine tool slide through the oscillating head positioning assembly, and the electric spindle is disposed in the spindle housing. The C-axis positioning assembly includes an upper C-axis sprocket, a lower C-axis sprocket, and a C-axis chuck cylinder. The upper C-axis sprocket is connected to the upper housing, and the lower C-axis sprocket is connected to the lower housing. The C-axis chuck cylinder is used to drive the upper C-axis sprocket to engage or disengage with the lower C-axis sprocket. The A-axis positioning assembly includes an A-axis bearing housing, a triple gear plate assembly, and an A-axis hydraulic cylinder. The A-axis bearing housing is fixed to the lower housing. The spindle box is swayably mounted on the A-axis bearing housing. The triple gear plate assembly is disposed between the A-axis bearing housing and the spindle box. The A-axis hydraulic cylinder is used to drive the triple gear plate assembly to clamp and release. The A-axis shifting assembly includes a shifting oil chamber, a reset oil chamber, and an axially movable transmission gear one. The A-axis drive assembly includes a bevel gear pair, the A-axis shifting assembly, a transmission gear two, and a transmission gear three connected in sequence. The transmission gear three is connected to the triple gear plate assembly. The C-axis drive assembly includes the bevel gear pair, the A-axis shifting assembly, the transmission gear two, and the transmission gear three connected in sequence. The input end of the bevel gear pair is connected to the output end of the machine tool spindle. The transmission gear one has a first state of being poweredly connected to the bevel gear pair and a second state of being engaged with the transmission gear two. The shifting oil chamber and the reset oil chamber are used to drive the transmission gear one to switch between the first state and the second state. When the first transmission gear is in the second state and the triple gear assembly is released, the power of the machine tool spindle is transmitted sequentially through the bevel gear pair, the first transmission gear, the second transmission gear and the third transmission gear to the spindle box, driving it to swing around the A axis. When the first transmission gear is in the second state, the triple gear assembly is clamped, and the upper C-axis toothed plate is separated from the lower C-axis toothed plate, the power of the machine tool spindle is transmitted sequentially through the bevel gear pair, the first transmission gear, the second transmission gear, and the third transmission gear, and drives the lower housing and the spindle box to rotate around the C-axis while the triple gear assembly is clamped.

[0008] This invention provides an interchangeable 3+2 electric spindle oscillating head, the core of which lies in using the machine tool spindle as a single power source, and collaboratively driving the A / C axis indexing through a bevel gear pair, an A-axis shifting assembly, and a shared transmission chain. This oscillating head utilizes the existing spindle power of the machine tool, eliminating the need for a separate servo motor and associated drive system within the oscillating head, significantly reducing manufacturing costs and electrical complexity. The interchangeable oscillating head positioning assembly design allows the machine tool to quickly switch between traditional spindle machining and multi-angle five-axis indexing machining, greatly expanding the machine tool's process flexibility and achieving dual-purpose functionality. The shared power and transmission mechanism for the A / C axes avoids interference and synchronization problems that may exist with multiple power sources, simplifies control logic, and improves system reliability.

[0009] Preferably, the bevel gear pair includes a first bevel gear and a second bevel gear that mesh with each other. The first bevel gear is mounted on the upper housing and is connected to the output end of the machine tool spindle. The centerline of the first bevel gear coincides with the centerline of the C-axis. The second bevel gear is mounted on the lower housing, and its centerline is parallel to the centerline of the A-axis. The second transmission gear is mounted on the lower housing via bearings, and the third transmission gear is fixed to the spindle box. The first bevel gear is connected to the machine tool spindle as input, and the second bevel gear directs power in the A-axis direction, ensuring the rotation of the lower housing and the oscillation of the spindle box.

[0010] As a further preferred embodiment, the A-axis shifting assembly further includes a flange seat one, a flange seat two, a rectangular spring, a shifting piston, and a pressure cap. The flange seat one is installed on the upper housing. The shifting piston is axially movable and disposed inside the flange seat one. The pressure cap is fixed to the flange seat one and axially limits the shifting piston. The reset oil chamber is formed between the flange seat one and the shifting piston. The shifting oil chamber is formed between the shifting piston and the pressure cap. A thrust ball bearing is disposed between the flange seat two and the shifting piston. The flange seat two is connected to the transmission gear one. The flange seat two is connected to the bevel gear two via a spline and can slide along its axial direction. The rectangular spring is disposed between the bevel gear two and the flange seat two. The rectangular spring is used to provide an elastic preload to the transmission gear one to keep it disengaged from the transmission gear two. The aforementioned A-axis shifting assembly enables reliable and rapid switching between engagement and disengagement of transmission gear one and transmission gear two, and effectively solves the key problem faced when the interchangeable swivel head relies on the machine tool spindle drive: when the machine tool spindle needs to rotate additionally to perform encoder zeroing operation, the transmission gear one can be disengaged by controlling the shifting oil chamber, which can cut off the power transmission to the A / C axis, thereby allowing the machine tool spindle to rotate freely without driving the swivel head to rotate beyond its limit. This effectively avoids the risk of cable breakage caused by the A / C axis angle limit and ensures equipment safety.

[0011] When oil enters the shift chamber, the shift piston moves to the left, pushing flange seat two and transmission gear one to the left via the thrust ball bearing. At the set shift zero angle, transmission gear one and transmission gear two mesh, completing the shifting action. When oil enters the reset chamber, the shift piston moves to the right, pushing flange seat two and transmission gear one to the right under the action of the rectangular spring until the shift piston contacts the pressure cap. At this point, transmission gear one disengages from transmission gear two, completing the reset action.

[0012] Preferably, the triple gear assembly includes a positioning gear, an indexing gear, and a piston gear. The positioning gear is fixed to the A-axis bearing housing, the indexing gear is mounted on a rotary seat, and the indexing gear is connected to the transmission gear in a three-way transmission. The rotary seat is fixed to the spindle box, and the piston gear is axially movable within a transition sleeve. The transition sleeve is fixed to the positioning gear, and an end cover is fixed to the transition sleeve. The A-axis hydraulic cylinder includes an A-axis piston, a counter-pull seat, an A-axis clamping oil chamber, and an A-axis releasing oil chamber. The A-axis clamping oil chamber is located between the left side of the end cover, the step of the counter-pull seat, and the right side of the A-axis piston. The A-axis releasing oil chamber is located between the step of the transition sleeve and the outer step of the A-axis piston. The piston gear is fixed to the A-axis piston, and the counter-pull seat is fixed to the indexing gear and moves under hydraulic pressure, allowing the piston gear to simultaneously engage or disengage with the positioning gear and the indexing gear. The system employs a triple-gear assembly consisting of a positioning gear plate, a indexing gear plate, and a piston gear plate, driven by an A-axis piston and a pull-back seat. This enables high-precision positioning, high-rigidity machining, and locking of the A-axis. Driven by the A-axis hydraulic cylinder, the piston gear plate simultaneously meshes with both the fixed positioning gear plate and the indexing gear plate that rotates with the spindle box, forming a stable triangular locking structure. This structure provides high clamping force and excellent positioning rigidity, meeting the requirements of high-speed, high-precision machining. The pull-back seat design ensures that the piston gear plate can simultaneously and reliably engage or disengage with both the positioning and indexing gear plates.

[0013] As a further preferred embodiment, the spindle box is oscillatingly mounted on the A-axis bearing housing via ball bearings, and an oilless bearing is provided between the outer diameter of the right side of the spindle box and the inner hole of the end cap. When the triple gear assembly is disengaged, the ball bearing and the oilless bearing jointly bear the radial off-center load of the A-axis. A ball bearing serves as the main support on one side of the spindle box, while an oilless bearing serves as auxiliary radial positioning on the other side. When the triple gear assembly disengages (A-axis indexing), both bearings jointly bear the radial off-center load of the spindle box and the electric spindle, ensuring the overall rigidity and stability of the oscillating head during oscillation and preventing vibration or accuracy loss caused by cantilever stress.

[0014] Preferably, the A-axis positioning assembly further includes an A-axis position detection mechanism. This mechanism comprises an A-axis signal transmitter block mounted on the lower housing and two A-axis position detection switches, used to detect the clamping and releasing positions of the triple gear assembly. By setting the A-axis signal transmitter block and two corresponding A-axis position detection switches, the clamping and releasing states of the triple gear assembly can be detected and fed back in real time and accurately. This provides crucial status confirmation signals for the CNC system, ensuring the safety, reliability, and automation of the A-axis indexing and locking process, and preventing malfunctions.

[0015] Preferably, the swivel head positioning assembly includes a main pull stud, a tool holder, a lower positioning toothed sprocket, an upper positioning toothed sprocket, and four pull head cylinders. The four pull head cylinders are mounted on the machine tool ram oil receiving plate and are used to grip four small pull studs mounted on the upper housing. The tool holder is buoyantly connected to the input end of the bevel gear pair via a floating connecting spring. The main pull stud is installed at the top of the tool holder and is used to connect to the machine tool spindle's baffle. The lower positioning toothed sprocket is located inside the upper housing, and the upper positioning toothed sprocket is connected to the machine tool ram oil receiving plate. The upper and lower positioning toothed sprockets mesh to achieve positioning and locking of the swivel head with the machine tool. The swivel head positioning assembly achieves power transmission through the connection between the tool holder, the main pull stud, and the machine tool spindle's baffle, and achieves precise positioning and rigid locking of the swivel head with the machine tool ram through the meshing of the upper and lower positioning toothed sprockets and the gripping of the small pull studs by the pull head cylinders. This design enables the entire swivel head to be quickly and reliably exchanged with the machine tool as a single module, realizing the functional switching between the traditional high-torque spindle head and the five-axis swivel head of this invention, significantly improving the utilization rate and processing range of the machine tool.

[0016] Preferably, the C-axis clamping / releasing cylinder includes a C-axis clamping oil chamber and a C-axis releasing oil chamber. An outer pull ring is fixed to the outer side of the lower housing, and the lower C-axis sprocket is connected to the outer pull ring. An inner pull ring is fixed to the inner side of the lower housing, and a cylinder cover is fixed to the top of the inner pull ring. The C-axis clamping oil chamber is formed by the upper housing, the cylinder cover, and the inner pull ring. The C-axis releasing oil chamber is formed by the upper housing and the inner pull ring. The C-axis clamping oil chamber drives the inner pull ring to move upward, and the C-axis releasing oil chamber drives the inner pull ring to move downward. The C-axis clamping / releasing cylinder adopts a compact design integrated between the upper housing, the inner pull ring, and the outer pull ring. The clamping and releasing oil chambers drive the inner pull ring to move up and down, respectively, thereby causing the lower C-axis sprocket connected to the lower housing to disengage from or engage with the upper C-axis sprocket. This structure eliminates the space occupied by traditional external hydraulic cylinders, making the C-axis structure more compact and the action direct and reliable.

[0017] As a further preferred embodiment, the C-axis positioning assembly also includes a C-axis position detection mechanism. This mechanism comprises a C-axis signal ring and two C-axis position detection switches. The signal ring is mounted on the outer wall of the outer pull ring body. A dustproof ring is fixed to the outer side of the upper housing. The two C-axis position detection switches are mounted on the inner wall of the dustproof ring. The C-axis position detection mechanism is used to detect the clamping and releasing positions of the upper and lower C-axis sprockets. By setting the C-axis signal ring and two corresponding C-axis position detection switches, the clamping and releasing states of the upper and lower sprockets can be detected and fed back accurately in real time, thereby ensuring the reliability of the C-axis indexing and clamping process.

[0018] As a further preferred embodiment, the oscillating head also includes a wiring mechanism, which includes a first wiring path for the functional pipelines of the electric spindle and a second wiring path for the cable of the electric spindle. The functional pipelines are led out from the spindle housing, pass through the valve block and functional ring into the lower housing, and then enter the upper housing through the internal channels of the lower housing, the inner pull ring, and the outer pull ring, and connect with the oil receiving pan of the machine tool slide through a quick-connect connector. The cable is led out from the lower housing, enters the annular winding space formed by the upper bevel gear pair, the inner side of the protective sleeve, and the upper part of the cover plate, and coils in the annular winding space before being led out from the side of the upper housing, connecting with the oil receiving pan of the machine tool slide through an electrical plug. The cable in the annular winding space is fixed at its inlet and outlet points by wire clamping blocks. When the upper housing drives the cable to rotate in the winding direction, the cable retracts; when it rotates in the opposite direction, the cable extends, to adapt to the forward and reverse rotation of the C-axis within a limited angle range. To address the challenge of complex cable connections in interchangeable electric spindle oscillating heads, this invention designs the aforementioned cable routing mechanism. Functional cables are integrated and routed through internal channels, while the electrical cable is orderly wound through an annular winding space formed by the space above the bevel gear pair. The key feature is that the cable is fixed at the inlet and outlet of the winding space and employs a specific winding method. This allows the cable to orderly contract or expand within the annular winding space when the upper housing rotates along the C-axis, thus adapting to the forward and reverse rotation of the C-axis within a limited angular range (e.g., ±180°). This fundamentally solves the problems of cable entanglement, stretching, and compression damage during continuous rotation of the interchangeable spindle's C-axis, improving the lifespan and reliability of the functional cables.

[0019] Compared with existing technologies, this invention has the following advantages: The interchangeable 3+2 electric spindle swivel head provided by this invention employs a high-power, high-speed electric spindle. Its A / C axes are driven by the machine tool spindle and are interchangeable with the slide, thus retaining the machining characteristics of the machine tool spindle while expanding the machine tool's processing range. This invention features an advanced swivel head structure, low manufacturing cost, and high A / C axis drive torque. Compared to direct-drive swivel heads of the same specifications, its overall size is small, making it a highly efficient 3+2 swivel head suitable for multi-angle indexing machining of complex curved surfaces in fields such as mold making and aerospace. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of the interchangeable 3+2 electric spindle oscillating head in the embodiment; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figures 1-2 The specific reference numerals in the attached figures are as follows: 1-Upper housing, 11-C-axis upper sprocket, 12-C-axis lower sprocket, 13-C-axis clamping oil chamber, 14-C-axis releasing oil chamber, 15-Small pull pin, 16-Dustproof ring, 17-Protective sleeve, 18-Cover plate, 19-Annular winding space, 10-Electrical plug, 2-Lower housing, 21-Outer pull ring body, 22-Inner pull ring body, 23-Cylinder cover, 24-A-axis signal block, 25-A-axis position detection switch, 26-C-axis signal ring, 27-C-axis position detection switch, 3-Spindle box, 31-Electric spindle, 32-Ball bearing, 33-Oilless bearing, 34-Functional pipeline, 35-Cable, 36-Valve block, 37-Functional ring, 38-Quick connector, 39-Pressure... Line block, 4-A-axis bearing seat, 41-positioning gear plate, 42-indexing gear plate, 43-piston gear plate, 44-rotor seat, 45-transition sleeve, 46-end cover, 47-A-axis piston, 48-reverse pull seat, 49-A-axis clamping oil chamber, 40-A-axis releasing oil chamber, 51-shifting oil chamber, 52-reset oil chamber, 53-transmission gear one, 54-bevel gear one, 55-bevel gear two, 56-transmission gear two, 57-transmission gear three, 61-flange seat one, 62-flange seat two, 63-rectangular spring, 64-shifting piston, 65-pressure cover, 66-thrust ball bearing, 71-main pull stud, 72-tool holder, 73-positioning lower gear plate, 74-floating connection spring. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0022] Example: An interchangeable 3+2 electric spindle oscillating head, such as Figures 1-2As shown, the swivel head includes an upper housing 1, a lower housing 2, a spindle box 3, an electric spindle 31, a swivel head positioning assembly, a C-axis positioning assembly, an A-axis positioning assembly, an A-axis shifting assembly, an A-axis drive assembly, a C-axis drive assembly, and a wiring mechanism. The upper housing 1 is interchangeably connected to the machine tool slide (not shown in the figure) through the swivel head positioning assembly, and the electric spindle 31 is set inside the spindle box 3.

[0023] The C-axis positioning assembly includes an upper C-axis sprocket 11, a lower C-axis sprocket 12, and a C-axis chuck / release cylinder. The upper C-axis sprocket 11 is connected to the upper housing 1, and the lower C-axis sprocket 12 is connected to the lower housing 2. The C-axis chuck / release cylinder is used to drive the upper C-axis sprocket 11 and the lower C-axis sprocket 12 to engage or disengage.

[0024] The A-axis positioning assembly includes an A-axis bearing housing 4, a triple gear plate assembly, and an A-axis hydraulic cylinder. The A-axis bearing housing 4 is fixed to the lower housing 2, and the spindle box 3 is swayably mounted on the A-axis bearing housing 4. The triple gear plate assembly is located between the A-axis bearing housing 4 and the spindle box 3. The A-axis hydraulic cylinder is used to drive the triple gear plate assembly to clamp and release.

[0025] The A-axis shifting assembly includes a shifting oil chamber 51, a reset oil chamber 52, and an axially movable transmission gear 53. The A-axis drive assembly includes a bevel gear pair, the A-axis shifting assembly, a second transmission gear 56, and a third transmission gear 57 connected in sequence. The third transmission gear 57 is connected to the triple gear assembly. The C-axis drive assembly includes a bevel gear pair, the A-axis shifting assembly, a second transmission gear 56, and a third transmission gear 57 connected in sequence. The input end of the bevel gear pair is connected to the output end of the machine tool spindle. The first transmission gear 53 has a first state of being poweredly connected to the bevel gear pair and a second state of being engaged with the second transmission gear 56. The shifting oil chamber 51 and the reset oil chamber 52 are used to drive the first transmission gear 53 to switch between the first state and the second state.

[0026] When transmission gear 1 53 is in the second state and the triple gear assembly is released, the power of the machine tool spindle is transmitted sequentially through the bevel gear pair, transmission gear 1 53, transmission gear 2 56 and transmission gear 3 57 to the spindle box 3, driving it to swing around the A-axis; when transmission gear 1 53 is in the second state, the triple gear assembly is clamped and the upper toothed sprocket 11 on the C-axis is separated from the lower toothed sprocket 12 on the C-axis, the power of the machine tool spindle is transmitted sequentially through the bevel gear pair, transmission gear 1 53, transmission gear 2 56 and transmission gear 3 57, and in the state of clamping the triple gear assembly, it drives the lower housing 2 together with the spindle box 3 to rotate around the C-axis.

[0027] Specifically, the bevel gear pair includes a first bevel gear 54 and a second bevel gear 55 that mesh with each other. The first bevel gear 54 is mounted on the upper housing 1 and is connected to the output end of the machine tool spindle. The centerline of the first bevel gear 54 coincides with the centerline of the C-axis. The second bevel gear 55 is mounted on the lower housing 2, and its centerline is parallel to the centerline of the A-axis. The second transmission gear 56 is mounted on the lower housing 2 via a bearing, and the third transmission gear 57 is fixed to the spindle box 3. The A-axis shifting assembly also includes a first flange seat 61, a second flange seat 62, a rectangular spring 63, a shifting piston 64, and a pressure cap 65. The first flange seat 61 is mounted on the upper housing 1, and the shifting piston 64 is axially movable on the flange seat. Inside flange seat 61, pressure cap 65 is fixed to flange seat 61 and axially limits shift piston 64. A reset oil chamber 52 is formed between flange seat 61 and shift piston 64, and a shift oil chamber 51 is formed between shift piston 64 and pressure cap 65. A thrust ball bearing 66 is provided between flange seat 62 and shift piston 64. Flange seat 62 is connected to transmission gear 53. Flange seat 62 is connected to bevel gear 55 by spline and can slide along its axial direction. A rectangular spring 63 is provided between bevel gear 55 and flange seat 62. The rectangular spring 63 is used to provide elastic preload to transmission gear 53 to keep it disengaged from transmission gear 56.

[0028] Specifically, the triple gear assembly includes a positioning gear 41, an indexing gear 42, and a piston gear 43. The positioning gear 41 is fixed to the A-axis bearing seat 4, the indexing gear 42 is mounted on the rotary seat 44, and the indexing gear 42 is connected to the transmission gear 3 57. The rotary seat 44 is fixed to the spindle box 3. The piston gear 43 is axially movable within the transition sleeve 45, which is fixed to the positioning gear 41. An end cover 46 is fixed on the transition sleeve 45. The A-axis cylinder includes an A-axis piston 47, a pull-back seat 48, an A-axis clamping oil chamber 49, and an A-axis releasing oil chamber 40. The A-axis clamping oil chamber 49 is located on the left side of the end cover 46 and the pull-back seat 48. Between the step and the right side of the A-axis piston 47, the A-axis release oil chamber 40 is located between the step of the transition sleeve 45 and the outer step of the A-axis piston 47. The piston gear 43 is fixed to the A-axis piston 47, and the pull-back seat 48 is fixed to the indexing gear 42 and moves under hydraulic drive, so that the piston gear 43 can simultaneously mesh or separate from the positioning gear 41 and the indexing gear 42. The spindle box 3 is oscillatingly mounted on the A-axis bearing seat 4 via the ball bearing 32. An oilless bearing 33 is provided between the outer diameter of the right side of the spindle box 3 and the inner hole of the end cover 46. When the triple gear assembly is released, the ball bearing 32 and the oilless bearing 33 jointly bear the radial off-center load of the A-axis.

[0029] Specifically, the swivel head positioning assembly includes a main pull stud 71, a tool holder 72, a lower positioning chuck 73, an upper positioning chuck (not shown in the figure), and four pull head cylinders (not shown in the figure). The four pull head cylinders are located on the machine tool slide oil receiving plate and are used to grip the four small pull studs 15 located on the upper housing 1. The tool holder 72 is floatingly connected to the input end of the bevel gear pair via a floating connecting spring 74. The main pull stud 71 is installed on the top of the tool holder 72 and is used to connect the pull claw of the machine tool spindle (not shown in the figure). The lower positioning chuck 73 is located inside the upper housing 1, and the upper positioning chuck is connected to the machine tool slide oil receiving plate. The upper positioning chuck and the lower positioning chuck 73 mesh to achieve positioning and locking of the swivel head and the machine tool.

[0030] Specifically, the C-axis clamping cylinder includes a C-axis clamping oil chamber 13 and a C-axis releasing oil chamber 14. An outer pull ring body 21 is fixed to the outside of the lower housing 2. The lower C-axis chuck 12 is connected to the outer pull ring body 21. An inner pull ring body 22 is fixed to the inside of the lower housing 2. A cylinder cover 23 is fixed to the top of the inner pull ring body 22. The C-axis clamping oil chamber 13 is formed by the upper housing 1, the cylinder cover 23 and the inner pull ring body 22. The C-axis releasing oil chamber 14 is formed by the upper housing 1 and the inner pull ring body 22. The C-axis clamping oil chamber 13 is used to drive the inner pull ring body 22 to move upward. The C-axis releasing oil chamber 14 is used to drive the inner pull ring body 22 to move downward.

[0031] Specifically, the A-axis positioning assembly includes an A-axis position detection mechanism, and the C-axis positioning assembly includes a C-axis position detection mechanism. The A-axis position detection mechanism includes an A-axis signaling block 24 mounted on the lower housing 2 and two A-axis position detection switches 25, used to detect the clamping and loosening positions of the triple gear assembly; the C-axis position detection mechanism includes a C-axis signaling ring 26 and two C-axis position detection switches 27. The C-axis signaling ring 26 is mounted on the outer wall of the outer pull ring body 21, a dustproof ring 16 is fixed on the outer side of the upper housing 1, and the two C-axis position detection switches 27 are mounted on the inner wall of the dustproof ring 16. The C-axis position detection mechanism is used to detect the clamping and loosening positions of the upper C-axis gear 11 and the lower C-axis gear 12.

[0032] Specifically, the wiring mechanism includes a first wiring path for the functional pipeline 34 of the electric spindle 31 and a second wiring path for the cable 35 of the electric spindle 31. The functional pipeline 34 is led out from the spindle housing 3, passes through the valve block 36 and the functional ring 37 into the lower housing 2, and then enters the upper housing 1 through the internal channels of the lower housing 2, the inner pull ring 22, and the outer pull ring 21, and connects with the machine tool slide oil receiving tray through the quick-connect connector 38; the cable 35 is led out from the lower housing 2 and enters the upper housing 1 through the internal channels of the lower housing 2, the inner pull ring 22, and the outer pull ring 21, and connects with the machine tool slide oil receiving tray through the quick-connect connector 38; The inner side of the protective sleeve 17 and the upper part of the cover plate 18 form an annular winding space 19. After being coiled in the annular winding space 19, the cable 35 is led out from the side of the upper housing 1 and connected to the oil receiving tray of the machine tool slide through the power plug 10. The cable 35 in the annular winding space 19 is fixed at its inlet and outlet points by the wire clamping block 39. When the upper housing 1 drives the cable 35 to rotate in the winding direction, the cable 35 retracts. When rotating in the opposite direction, the cable 35 extends to adapt to the forward and reverse rotation of the C-axis within a limited angle range.

[0033] The aforementioned oscillating head uses a high-power, high-speed electric spindle 31, whose A / C axes are driven by the machine tool spindle and are interchangeable with the slide, thus retaining the machining characteristics of the machine tool spindle itself while expanding the machine tool's processing range.

[0034] The main movements that can be achieved by the above head swaying include: (1) Exchange and positioning process: After the machine tool slide with oil receiving tray moves to the predetermined position above the swivel head, the four pull head cylinders on the machine tool slide oil receiving tray grab the four small pull pins 15 set on the upper housing 1. At the same time, the broach claw of the machine tool spindle grabs the main pull pin 71 on the tool holder 72 of the swivel head; oil enters the C-axis clamping oil chamber 13, so that the upper C-axis toothed plate 11 and the lower C-axis toothed plate 12 are tightly meshed, and the positioning upper toothed plate and the positioning lower toothed plate 73 are tightly meshed, completing high-precision radial and axial positioning, and achieving rigid locking through tension force. At this time, the swivel head becomes a functional component of the machine tool, the tool holder 72 completes the power connection with the machine tool spindle, and the functional pipelines 34 and cables 35 are connected through quick-connect couplings.

[0035] (2) A-axis indexing process: After the swivel head is gripped by the machine tool, the machine tool power is transmitted to bevel gear 1 54 through tool holder 72, and then to bevel gear 2 55 meshing with bevel gear 1 54. When the A-axis shifting assembly performs the shifting action, the power is transmitted to transmission gear 2 56 through transmission gear 1 53, and then to transmission gear 3 57. When the triple gear plate is disengaged, it can drive the spindle box 3 and the electric spindle 31 to rotate around the A-axis. After the A-axis rotates to the required angle, the triple gear plate assembly clamps, oil enters the reset oil chamber 52, transmission gear 1 53 and transmission gear 2 56 disengage, and the swivel head completes the A-axis indexing action.

[0036] (3) C-axis indexing process: When the swivel head is gripped by the machine tool, the oil chamber 14 of the C-axis is released and oil enters. The upper gear 11 of the C-axis and the lower gear 12 of the C-axis are disengaged. At this time, the A-axis shifting assembly performs the shifting action. The first transmission gear 53 meshes with the second transmission gear 56, and the triple gear plate is clamped. Subsequently, the machine tool spindle drives the tool holder 72 to rotate, and the power is transmitted to the bevel gear 54 through the tool holder 72, and then to the bevel gear 55 meshing with the bevel gear 54. After the A-axis shifting assembly performs the shifting action, the power is transmitted to the transmission gear 56 through the transmission gear 53, and then to the transmission gear 57. With the triple gear clamped, the A-axis is locked, that is, the transmission gear 57, the transmission gear 56, and the transmission gear 53 are locked relative to the lower housing 2. At this time, the bevel gear 55 is equivalent to a single key inserted into the bevel gear 54. The input power forces the bevel gear 55 to act as a rigid connecting part, driving the lower housing 2, the spindle box 3, and the electric spindle 31, which are fixed to it, to rotate around the bevel gear 54 (i.e., the center line of the C-axis). After the C-axis rotates to the required angle, oil enters the C-axis clamping oil chamber 13, the lower C-axis toothed plate 12 meshes with the upper C-axis toothed plate 11, the triple gear plate assembly clamps, oil enters the reset oil chamber 52, the first transmission gear 53 disengages from the second transmission gear 56, and the oscillating head completes the C-axis indexing action.

[0037] (4) Zeroing process of machine tool spindle: When the A-axis shifting assembly is disengaged (i.e., transmission gear 1 53 and transmission gear 2 56 are not meshed), the rotational power of the machine tool spindle is only transmitted to bevel gear 1 54 at the bevel gear pair. Since transmission gear 1 53 has been disengaged, the power chain is interrupted here and will not be transmitted to the A-axis or C-axis. At this time, the machine tool spindle can freely rotate to find the zeroing point without driving the A-axis or C-axis of the oscillating head to move, thus completely avoiding the risk of the cable 35 or functional pipeline 34 being pulled off due to the physical angle limitation of the oscillating head.

Claims

1. An interchangeable 3+2 electric spindle oscillating head, characterized in that, The swivel head includes an upper housing, a lower housing, a spindle box, an electric spindle, a swivel head positioning assembly, a C-axis positioning assembly, an A-axis positioning assembly, an A-axis shifting assembly, an A-axis drive assembly, and a C-axis drive assembly. The upper housing is interchangeably connected to the machine tool slide via the swivel head positioning assembly, and the electric spindle is disposed inside the spindle box. The C-axis positioning assembly includes an upper C-axis sprocket, a lower C-axis sprocket, and a C-axis chuck cylinder. The upper C-axis sprocket is connected to the upper housing, and the lower C-axis sprocket is connected to the lower housing. The C-axis chuck cylinder is used to drive the upper C-axis sprocket to engage or disengage with the lower C-axis sprocket. The A-axis positioning assembly includes an A-axis bearing housing, a triple gear plate assembly, and an A-axis hydraulic cylinder. The A-axis bearing housing is fixed to the lower housing. The spindle box is swayably mounted on the A-axis bearing housing. The triple gear plate assembly is disposed between the A-axis bearing housing and the spindle box. The A-axis hydraulic cylinder is used to drive the triple gear plate assembly to clamp and release. The A-axis shifting assembly includes a shifting oil chamber, a reset oil chamber, and an axially movable transmission gear one. The A-axis drive assembly includes a bevel gear pair, the A-axis shifting assembly, a transmission gear two, and a transmission gear three connected in sequence. The transmission gear three is connected to the triple gear plate assembly. The C-axis drive assembly includes the bevel gear pair, the A-axis shifting assembly, the transmission gear two, and the transmission gear three connected in sequence. The input end of the bevel gear pair is connected to the output end of the machine tool spindle. The transmission gear one has a first state of being poweredly connected to the bevel gear pair and a second state of being engaged with the transmission gear two. The shifting oil chamber and the reset oil chamber are used to drive the transmission gear one to switch between the first state and the second state. When the first transmission gear is in the second state and the triple gear assembly is released, the power of the machine tool spindle is transmitted sequentially through the bevel gear pair, the first transmission gear, the second transmission gear and the third transmission gear to the spindle box, driving it to swing around the A axis. When the first transmission gear is in the second state, the triple gear assembly is clamped, and the upper C-axis toothed plate is separated from the lower C-axis toothed plate, the power of the machine tool spindle is transmitted sequentially through the bevel gear pair, the first transmission gear, the second transmission gear, and the third transmission gear, and drives the lower housing and the spindle box to rotate around the C-axis while the triple gear assembly is clamped.

2. The interchangeable 3+2 electric spindle oscillating head according to claim 1, characterized in that, The bevel gear pair includes a first bevel gear and a second bevel gear that mesh with each other. The first bevel gear is installed in the upper housing and is connected to the output end of the machine tool spindle. The center line of the first bevel gear coincides with the center line of the C-axis. The second bevel gear is installed in the lower housing. The center line of the second bevel gear is parallel to the center line of the A-axis. The second transmission gear is installed in the lower housing through a bearing. The third transmission gear is fixed to the spindle box.

3. The interchangeable 3+2 electric spindle oscillating head according to claim 2, characterized in that, The A-axis shifting assembly further includes a flange seat one, a flange seat two, a rectangular spring, a shifting piston, and a pressure cap. The flange seat one is installed on the upper housing. The shifting piston is axially movable inside the flange seat one. The pressure cap is fixed to the flange seat one and axially limits the shifting piston. The reset oil chamber is formed between the flange seat one and the shifting piston. The shifting oil chamber is formed between the shifting piston and the pressure cap. A thrust ball bearing is provided between the flange seat two and the shifting piston. The flange seat two is connected to the transmission gear one. The flange seat two is connected to the bevel gear two via a spline and can slide along its axial direction. The rectangular spring is disposed between the bevel gear two and the flange seat two. The rectangular spring is used to provide an elastic preload to the transmission gear one to keep it disengaged from the transmission gear two.

4. The interchangeable 3+2 electric spindle oscillating head according to claim 1, characterized in that, The triple gear assembly includes a positioning gear, a rotating gear, and a piston gear. The positioning gear is fixed to the A-axis bearing housing, the rotating gear is mounted on a rotary seat, and the rotating gear is connected to the transmission gear in a three-way transmission. The rotary seat is fixed to the spindle box. The piston gear is axially movable within a transition sleeve, which is fixed to the positioning gear. An end cover is fixed to the transition sleeve. The A-axis hydraulic cylinder includes an A-axis piston, a counter-pull seat, an A-axis clamping oil chamber, and an A-axis releasing oil chamber. The A-axis clamping oil chamber is located between the left side of the end cover, the step of the counter-pull seat, and the right side of the A-axis piston. The A-axis releasing oil chamber is located between the step of the transition sleeve and the outer step of the A-axis piston. The piston gear is fixed to the A-axis piston, and the counter-pull seat is fixed to the rotating gear and moves under hydraulic pressure, allowing the piston gear to simultaneously engage or disengage with the positioning gear and the rotating gear.

5. The interchangeable 3+2 electric spindle oscillating head according to claim 4, characterized in that, The spindle box is oscillatingly mounted on the A-axis bearing seat via a ball bearing. An oilless bearing is provided between the outer diameter of the right side of the spindle box and the inner hole of the end cover. When the triple gear assembly is loosened, the ball bearing and the oilless bearing jointly bear the radial off-center load of the A-axis.

6. The interchangeable 3+2 electric spindle oscillating head according to claim 1, characterized in that, The A-axis positioning assembly further includes an A-axis position detection mechanism, which includes an A-axis signaling block mounted on the lower housing and two A-axis position detection switches for detecting the clamping and releasing positions of the triple gear assembly.

7. The interchangeable 3+2 electric spindle oscillating head according to claim 1, characterized in that, The swivel head positioning assembly includes a main pull stud, a tool holder, a lower positioning sprocket, an upper positioning sprocket, and four pull head cylinders. The four pull head cylinders are mounted on the machine tool ram oil receiving plate and are used to grip four small pull studs mounted on the upper housing. The tool holder is buoyantly connected to the input end of the bevel gear pair via a floating connecting spring. The main pull stud is mounted on the top of the tool holder and is used to connect to the baffle of the machine tool spindle. The lower positioning sprocket is mounted inside the upper housing, and the upper positioning sprocket is connected to the machine tool ram oil receiving plate. The upper positioning sprocket and the lower positioning sprocket mesh to achieve positioning and locking of the swivel head with the machine tool.

8. The interchangeable 3+2 electric spindle oscillating head according to claim 1, characterized in that, The C-axis clamping and releasing cylinder includes a C-axis clamping oil chamber and a C-axis releasing oil chamber. An outer pull ring is fixed to the outer side of the lower housing. The lower C-axis chuck is connected to the outer pull ring. An inner pull ring is fixed to the inner side of the lower housing. A cylinder cover is fixed to the top of the inner pull ring. The C-axis clamping oil chamber is formed by the upper housing, the cylinder cover, and the inner pull ring. The C-axis releasing oil chamber is formed by the upper housing and the inner pull ring. The C-axis clamping oil chamber is used to drive the inner pull ring to move upward, and the C-axis releasing oil chamber is used to drive the inner pull ring to move downward.

9. The interchangeable 3+2 electric spindle oscillating head according to claim 8, characterized in that, The C-axis positioning assembly further includes a C-axis position detection mechanism, which includes a C-axis signal ring and two C-axis position detection switches. The C-axis signal ring is installed on the outer wall of the outer pull ring body, and a dustproof ring is fixed on the outer side of the upper housing. The two C-axis position detection switches are installed on the inner wall of the dustproof ring. The C-axis position detection mechanism is used to detect the clamping and releasing positions of the upper C-axis sprocket and the lower C-axis sprocket.

10. An interchangeable 3+2 electric spindle oscillating head according to claim 8, characterized in that, The oscillating head also includes a wiring mechanism, which includes a first wiring path for the functional pipelines of the electric spindle and a second wiring path for the cable of the electric spindle. The functional pipelines are led out from the spindle housing, pass through the valve block and functional ring into the lower housing, and then enter the upper housing through the internal channels of the lower housing, inner pull ring, and outer pull ring, and connect with the oil receiving pan of the machine tool slide through a quick-connect connector. The cable is led out from the lower housing, enters the annular winding space formed by the upper bevel gear pair, the inner side of the protective sleeve, and the upper cover plate, and coils in the annular winding space before being led out from the side of the upper housing, connecting with the oil receiving pan of the machine tool slide through an electrical plug. The cable in the annular winding space is fixed at its inlet and outlet points by wire clamping blocks. When the upper housing drives the cable to rotate in the winding direction, the cable retracts; when it rotates in the opposite direction, the cable extends, to adapt to the forward and reverse rotation of the C-axis within a limited angle range.

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