Material clamping mechanism on high-speed and high-precision electric spindle for lathe

Abstract

The material clamping mechanism and releasing mechanism on the high-speed and high-precision electric spindle for a lathe provided by the present invention include a spindle core, a chuck and an adapter matching the chuck, and also include a spindle seat and a cylinder floating bracket. The spindle core and the spindle seat are rotatably connected, and the cylinder floating bracket is arranged on one side of the end face of the spindle seat. The releasing mechanism includes a cylinder floating bracket, a spring, a screw and a cylinder unit. The opposite surface of the cylinder floating bracket and the end face of the spindle seat can contact and separate from the end face of the spindle seat. The material is clamped by the spring clamping mechanism, which greatly reduces the instability factors caused by the high-speed operation of the spindle core by the traditional clamping mechanism. The setting of the floating releasing mechanism avoids the cylinder thrust being applied to the bearing part during release, which shortens the bearing life. While realizing the high-speed, high-precision and high-stability operation of the spindle core, the efficiency and reliability of clamping and releasing are greatly improved, thereby improving the processing efficiency.

Description

Technical Field

[0001] This application is a divisional application of the patent application with application date 20201103, application number 2020112070142, and invention name “A high-speed and high-precision electric spindle for lathes”.

[0002] The invention relates to the field of high-speed precision machine tool equipment, in particular to a material clamping mechanism on a high-speed and high-precision electric spindle for a lathe. Background Art

[0003] After decades of rapid development, domestic CNC machine tools have now fully met market demand in the economical and popular fields. However, mid-to-high-end CNC machine tools cannot currently meet market demand and are basically entirely dependent on imported equipment. At the same time, with the continuous development and progress of the manufacturing industry, there are more and more requirements for CNC machine tool subdivisions. For example, the rapid development of the 5G industry and the optical field in recent years has put forward requirements for small CNC lathes such as high speed, high precision, and high-speed stability of the spindle, because many parts have special requirements for tool marks in addition to geometric dimensional accuracy.

[0004] High-speed and high-precision electric spindles and material clamping and releasing mechanisms are extremely critical functional components in the high-speed precision CNC lathe series. The quality of their performance directly affects the machining accuracy, machining efficiency, machining capacity (cutting force within the specification range, seismic resistance, functional performance) and failure rate of this series of models.

[0005] Most of the spindles used in this series of machines in China are in the form of mechanical spindles and external motors. The manufacturers using electric spindles are of varying quality, and their functions are not satisfactory. Their characteristic coefficient requirements are difficult to perfect, while market users have increasingly higher requirements for the functions, characteristic coefficients, precision, and stability of CNC lathes. Domestic machines are in urgent need of breaking through the technical innovation bottlenecks of electric spindle characteristic coefficients, processing capabilities, stability, and processing efficiency. Its characteristic coefficient processing capabilities are mainly developed and improved by built-in motors, drivers, encoders, closed-loop control, and multi-axis high-end CNC systems; stability and processing efficiency depend on the innovative optimization of the mechanical structure of the electric spindle, and the precision improvement and control of supporting parts. The demand for CNC lathes in the domestic market is growing rapidly, however, users have put forward higher requirements for the processing capacity range and processing efficiency of this series of models.

[0006] The current problem is that the clamping device used causes the processed parts to vibrate greatly when rotating at high speed, affecting the processing quality. Summary of the invention

[0007] In order to solve the deficiencies in the prior art, the present invention improves the structure of the electric spindle system, especially replaces the material clamping and releasing mechanism, improves the rotational vibration condition, and improves the processing quality.

[0008] To achieve the above-mentioned purpose, the technical solution of the present invention relates to a high-speed and high-precision electric spindle for a lathe, and a material clamping mechanism and a material releasing mechanism that can be configured in the electric spindle device.

[0009] A high-speed and high-precision electric spindle for a lathe comprises a spindle seat, a spindle core, a stator and a rotor associated with the spindle core, a spindle sleeve, a pull rod, a chuck, an adapter, a clamping mechanism and a release mechanism. The stator and the rotor are driven by an external driver. The adapter is mounted on the center of the spindle, and a conical slot hole along the axial direction is provided on the front end surface of the adapter.

[0010] The main shaft sleeve is installed on the main shaft seat, and bearing parts are matched between the main shaft core and both ends of the main shaft sleeve.

[0011] One end of the pull rod is axially inserted into the spindle core from the back to the front, and the chuck is connected to the end of the pull rod through a threaded structure, and the other end of the pull rod is retained outside.

[0012] The side surface of the clamp is configured as a conical surface and can be matched with the conical surface slot on the adapter.

[0013] The front end of the clamping mechanism is supported on the middle of the main shaft core, and the rear end is connected to the pull rod. The middle of the clamping mechanism is a movable sleeve matching structure, so that it can be extended and retracted in the axial direction.

[0014] A spring portion is provided inside the clamping mechanism. By adjusting the pre-pressure of the spring portion, a backward axial thrust can be applied to the pull rod, so that the conical surface portion of the chuck moves into the conical surface slot on the adapter, and the chuck contracts to clamp the workpiece.

[0015] The release mechanism comprises a cylinder floating bracket, a spring, a screw and a cylinder unit.

[0016] The cylinder floating bracket is connected to the rear side of the main shaft seat through the screw and is matched with an axially arranged guide pin so that the cylinder floating bracket can move smoothly along the axial direction.

[0017] The spring is sleeved on the screw and can push the cylinder floating bracket to contact the opposite surface of the spindle seat and form a gap between the cylinder floating bracket and the opposite surface of the clamping mechanism.

[0018] The cylinder body in the cylinder unit is connected to the rear end of the cylinder floating bracket by screws. During the forward movement of the piston, the piston can first contact the middle part of the clamping mechanism to push the cylinder floating bracket to move backward, and then the cylinder floating bracket is prompted to contact the opposite surface of the clamping mechanism, and finally the spring part can be further compressed to drive the pull rod to move forward, and the chuck gradually moves out of the conical slot on the adapter to finally loosen the workpiece.

[0019] Furthermore, the spring part is a disc spring. The clamping mechanism also includes a disc spring mounting sleeve, a support sleeve and a sliding sleeve disposed therebetween, and a radial edge plate is formed in the middle of the disc spring mounting sleeve. The piston can contact the rear end surface of the radial edge plate to push the cylinder floating support to move backward.

[0020] The rear end of the disc spring mounting sleeve is connected to the pull rod through a nut.

[0021] The support sleeve is fixedly sleeved on the main shaft core, and a gap is formed between the cylinder floating bracket and the opposite surface of the support sleeve.

[0022] The sliding sleeve is installed at the front end of the disc spring installation sleeve and is located at the front side of the radial edge plate. The sliding sleeve and the radial edge plate are respectively formed with edge arms extending axially opposite to each other on the opposite end surfaces. The pair of edge arms match to form a matching structure of a movable sleeve, and the disc spring is placed in the cavity formed by the pair of edge arms.

[0023] The front end of the disc spring installation sleeve is provided with a nut capable of adjusting the preload of the disc spring. When the nut is screwed to move relative to the disc spring installation sleeve, the sliding sleeve can be pushed to move axially relative to the disc spring installation sleeve to compress the disc spring.

[0024] A balancing ring is arranged between the supporting sleeve and the sliding sleeve, and the balancing ring is plugged into the opposite end surfaces of the supporting sleeve and the sliding sleeve through axially arranged positioning pins.

[0025] Preferably, a threaded hole is provided on the circumferential wall of the support sleeve and / or a threaded hole is provided on the circumferential wall of the balancing ring.

[0026] Furthermore, a sensing block is provided on the side wall of the cylinder floating support. A bracket 1 is installed on the end surface of the spindle seat facing the cylinder floating support, and a sensing switch 1 corresponding to the sensing block is installed on the bracket 1.

[0027] A sensing rod is arranged on the cylinder cover at the rear end of the cylinder unit. A second bracket is arranged on the spindle seat, and a second sensing switch corresponding to the sensing rod is installed on the second bracket.

[0028] Furthermore, the stator is fixed on the inner wall of the main shaft sleeve, and the rotor is arranged outside the main shaft core.

[0029] Furthermore, a cooling groove is provided on a section of the side wall of the spindle sleeve opposite to the spindle seat, and the cooling groove is a spiral groove distributed in the axial direction. Sealing rings are provided at both ends of the spiral groove, and the sealing rings are pressed between the outer wall of the spindle sleeve and the inner wall of the spindle seat.

[0030] Furthermore, an encoder flange is fixed on the main shaft core and at a position of the bearing portion close to the rear end side, and an encoder gear is mounted on the encoder flange. The encoder gear can form an encoder when associated with an external device.

[0031] Furthermore, a dustproof ring is mounted on the front part of the spindle shaft core and on the front side of the bearing part, and an annular groove is formed on the front end surface of the dustproof ring.

[0032] A front bearing cover is fixed on the front end face of the spindle shaft core by screws. The front bearing cover can act on the front end face of the dustproof ring so that the dustproof ring can be pressed on the inner ring of the bearing part.

[0033] A front bearing cover 2 is fixed to the front end face of the main shaft sleeve by screws, the inner ring of the bearing cover 2 is matched with the outer ring of the front bearing cover 1, and two annular flanges are formed on the rear end face of the front bearing cover 2, wherein the inner annular flange is placed in the annular groove on the dustproof ring and matches, and the outer annular flange can be pressed on the outer ring of the bearing part.

[0034] Preferably, a dust cover is fixed to the front end face of the main shaft sleeve with screws, and the dust cover can be pressed on the side wall of the adapter to press the adapter toward the front end face of the front bearing cover, and the dust cover is provided with an oil return hole that can discharge debris that has penetrated into the adapter.

[0035] This patent also relates to a material clamping mechanism on a high-speed and high-precision electric spindle for a lathe, including a spindle shaft core, a chuck, an adapter matching the chuck, a pull rod, a disc spring, a disc spring mounting sleeve, a support sleeve, and a sliding sleeve placed between the disc spring mounting sleeve and the support sleeve.

[0036] One end of the pull rod is inserted into the spindle core along the axial direction, and the chuck is connected to the end of the pull rod through a threaded structure. The other end of the pull rod extends to the outside. The side surface of the chuck is a conical surface, and the adapter is provided with a conical surface slot, and the conical surface of the chuck can gradually extend into the conical surface slot along the axial direction to match it.

[0037] A radial edge plate is formed in the middle of the disc spring mounting sleeve.

[0038] The rear end of the disc spring mounting sleeve is connected to the pull rod through a nut.

[0039] The support sleeve is fixedly sleeved on the spindle core.

[0040] The sliding sleeve is installed at the front end of the disc spring installation sleeve and is located at the front side of the radial edge plate. The sliding sleeve and the radial edge plate are respectively formed with edge arms extending axially opposite to each other on the opposite end surfaces. The pair of edge arms match to form a matching structure of a movable sleeve, and the disc spring is placed in the cavity formed by the pair of edge arms.

[0041] The front end of the disc spring installation sleeve is provided with a nut capable of adjusting the preload of the disc spring. When the nut is screwed to move relative to the disc spring installation sleeve, the sliding sleeve can be pushed to move axially relative to the disc spring installation sleeve to compress the disc spring.

[0042] A balancing ring is arranged between the supporting sleeve and the sliding sleeve, and the balancing ring is plugged into the opposite end surfaces of the supporting sleeve and the sliding sleeve through axially arranged positioning pins.

[0043] Preferably, a threaded hole is provided on the circumferential wall of the support sleeve and / or a threaded hole is provided on the circumferential wall of the balancing ring.

[0044] This patent also relates to a material loosening mechanism on a high-speed and high-precision electric spindle for a lathe, including a cylinder floating bracket, a spring, a screw and a cylinder unit.

[0045] One end of the cylinder floating bracket is connected to the main shaft seat by the screw. The spring is sleeved on the screw and can push the cylinder floating bracket to contact the opposite surface of the main shaft seat.

[0046] The cylinder body in the cylinder unit is fixed to the other end of the cylinder floating bracket, and the piston can extend toward one side of the main shaft seat.

[0047] Preferably, a guide pin arranged axially is matched between the opposite surfaces of the cylinder floating bracket and the spindle seat. One end of the guide pin is fixed on the spindle seat, and the other end is inserted into the guide hole on the cylinder floating bracket to constrain the axial movement of the cylinder floating bracket.

[0048] Preferably, an adjustment pad is provided between the cylinder floating support and the opposite end surface of the cylinder body, and the two are connected by screws.

[0049] The aforementioned "cylinder" is to be interpreted broadly to include hydraulic cylinders.

[0050] The beneficial effects of the present invention are as follows: the overall accuracy of the electric spindle is optimized, the machine tool has stable precision in machining parts and indexing accuracy, the low-speed and high-torque characteristics of the electric spindle are improved, and the high-speed, high-precision and high-stability operation of the electric spindle is achieved, thereby significantly improving production quality and machining efficiency.

[0051] By clamping the elastic structure, the use of parts with uncertain positions on the spindle is avoided, so that the dynamic balance of the spindle can achieve an excellent effect. Compared with the currently used clamping mechanism, the instability factor existing when the spindle is running at high speed is greatly reduced. In the preferred embodiment, it can also ensure that the dynamic balance effect will not change during use.

[0052] By setting the floating clamp release mechanism, the axial impact force exerted by the cylinder on the spindle bearing during clamp release is eliminated, thereby effectively improving the service life of the spindle bearing.

[0053] The forced circulation cooling system (spiral groove) effectively controls the temperature rise of the electric spindle, saves the startup temperature setting time, improves productivity, and helps to improve the accuracy and consistency of processed parts;

[0054] The method of using the built-in rotor of the spindle to directly drive the spindle rotation helps to improve the spindle operation speed and stability.

[0055] The spindle core is directly driven to rotate by adopting the method of built-in stator and rotor in the spindle, so as to improve the operation speed and stability of the spindle core. The spindle core is forced to be cooled by forced circulating water cooling. The material is clamped by a disc spring clamping mechanism, which greatly reduces the instability factors caused by the high-speed operation of the spindle core by the traditional clamping mechanism. The floating loosening mechanism includes a guide pin, a spring, and a screw mounted on the spring. When the spindle core is in operation, it is completely disengaged from the spindle core and only contacts the rotating parts during the loosening action, which can avoid the influence of the loosening force on the bearing and avoid the cylinder thrust applied to the support bearing on the spindle core during loosening, which causes the bearing life to be shortened. Through the above structural design optimization, the spindle core can be operated at a high speed, high precision and high stability, thereby greatly improving the production quality and processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a schematic diagram of the overall structure of the solution involved in the present invention.

[0057] Explanation of symbols in the figure:

[0058] 1. Spindle core, 2. Spindle sleeve, 21. Dust cover, 22. Cooling groove, 3a. Front bearing assembly, 3b. Rear shaft assembly, 31. Inner spacer, 32. Outer spacer, 33. Front bearing cover 1, 34. Front bearing cover 2, 35. Dust spacer, 4. Bearing seat, 41. Spacer 1, 42. Spacer 2, 43. Rear bearing cover, 51. Encoder flange, 52. Encoder gear, 6a. Disc spring, 6b. Disc spring mounting sleeve, 61. Support sleeve, 62. Balance ring, 621. Positioning pin, 63. Sliding sleeve, 64. First nut, 71. Cylinder body, 72. Piston, 73. Cylinder head, 74. Air nozzle, 75. Adjusting pad, 8. Cylinder floating bracket, 81. Guide pin, 82. Spring, 83. Induction block, 84. Bracket 1, 85. Induction switch 1, 9. Pull rod, 91. Chuck, 92. Adapter, 93. Induction rod, 94. Bracket 2, 95. Induction switch 2, 96. Second nut, 961. Round head set screw, 10. Spindle seat, 20. Stator, 30. Rotor. DETAILED DESCRIPTION

[0059] The present invention will be further described below in conjunction with embodiments.

[0060] like Figure 1 A high-speed and high-precision electric spindle for a lathe shown in the figure includes a spindle seat 10, a spindle shaft core 1, a (motor) stator 20 and a (motor) rotor 30 associated and matched with the spindle shaft core 1, as well as a spindle sleeve 2, a pull rod 9, a chuck 91, an adapter 92, a clamping mechanism and a releasing mechanism.

[0061] The stator 20 is fixed on the inner wall of the spindle sleeve 2, and the rotor 30 is arranged outside the spindle core 1. The stator 20 and the rotor 30 are respectively installed at the mid-range position of the spindle sleeve 2 and the spindle core 1. The stator 20 and the rotor 30 are driven by an external driver, that is, the electric spindle is driven to rotate by electromagnetic induction to provide rotational power for it.

[0062] With the help of the solution of this patent, the electric spindle device can select different stators and rotors according to the use conditions, so as to adapt to various processing conditions. The series of electric spindles are 07-12, 15-20, 26 or 32-38, among which: the speed range of 07-12 is 100-15000r / min; the speed range of 15-20 is 100-10000r / min; the speed range of 26 is 100-10000r / min; the speed range of 32-38 is 100-8000r / min. It includes a spindle driver, a spindle forced cooling system, a gas circuit control system and a brake resistor.

[0063] The adapter 92 is mounted on the spindle core 1 , and a conical slot hole along the axial direction is provided on the front end surface of the adapter 92 .

[0064] The spindle sleeve 2 is mounted on the spindle seat 10. The spindle core 1 and the two ends of the spindle sleeve 2 are matched with bearing parts (3a, 3b), which are called front paired bearings or front bearing group 3a. The bearing parts include a pair of bearings, wherein an inner and outer spacer rings 31 and 32 are provided between the pair of bearings at the front end for adjusting the bearing preload. The inner spacer ring 31 corresponds to the inner rings of the bearings, and the outer spacer ring 32 corresponds to the outer rings of the bearings. The preload of the front paired bearings is adjusted by adjusting the height difference between the inner and outer spacers 31 and 32. The pair of bearings at the rear end (called rear paired bearings or rear bearing group 3b) are arranged at the rear end of the spindle sleeve 2 through the bearing seat 4, and the bearing seat 4 is inserted into the rear end of the spindle sleeve 2. The rear port of the bearing seat 4 is formed with an annular flange extending radially outward to match and contact with the rear end surface of the spindle sleeve 2.

[0065] Spacer 1 41, spacer 2 42 and rear bearing cover 43 are disposed at the two ports of the bearing seat 4 and corresponding to the front and rear ends of the rear paired bearing. Spacer 1 41 is pressed on the inner ring of the front end of the rear paired bearing, spacer 2 42 is pressed on the inner ring of the rear end of the rear paired bearing, and rear bearing cover 43 is pressed on the outer ring of the rear end of the rear paired bearing. The rear port of the rear bearing cover 43 is provided with an annular flange extending radially outward, and the annular flange contacts the annular flange on the bearing seat 4 (the opposite end faces therebetween).

[0066] One end of the pull rod 9 axially penetrates into the spindle core 1 from back to front, and the chuck 91 is connected to the front end of the pull rod 9 through a threaded structure, and the rear end of the pull rod 9 is retained outside (an external thread structure is provided on the outer wall near this end, which matches the second nut 96).

[0067] The side wall surface of the clamp 91 is configured as a conical surface, which can match the conical surface slot provided on the adapter 92 .

[0068] The front end of the clamping mechanism is supported on the middle of the spindle core 1, and the rear end is connected to the pull rod 9. The middle part of the clamping mechanism is a movable sleeve matching structure, so that it can be extended and retracted in the axial direction.

[0069] A spring portion is provided inside the clamping mechanism. By adjusting the pre-pressure of the spring portion, a backward axial thrust can be applied to the pull rod 9, so that the conical surface portion of the chuck 91 moves into the conical groove hole on the adapter 92, so that the chuck 91 gradually contracts and clamps the workpiece.

[0070] The release mechanism includes a cylinder floating bracket 8, a spring 82, a screw and a cylinder unit. The cylinder floating bracket 8 is connected to the rear side of the spindle seat 10 through the aforementioned screws and is matched with an axially arranged guide pin 81 so that the cylinder floating bracket 8 can move smoothly in the axial direction.

[0071] The spring 82 is sleeved on the aforementioned screw, and can push the cylinder floating bracket 8 to contact the opposite surface of the spindle seat 10 and form a gap between the cylinder floating bracket 8 and the opposite surface of the clamping mechanism.

[0072] The cylinder body 71 in the cylinder unit is connected to the rear end of the cylinder floating bracket 8 by screws. During the forward movement of the piston 72, the piston 72 can first contact the middle part of the clamping mechanism to push the cylinder floating bracket 8 to move backward, and then the cylinder floating bracket 8 is prompted to contact the opposite surface of the clamping mechanism, and finally the spring part can be further compressed to drive the pull rod 9 to move forward, and the chuck 91 gradually moves out of the conical slot on the adapter 92, and finally the workpiece is loosened.

[0073] Specifically, Figure 1 As shown, the clamping mechanism further comprises a disc spring installation sleeve 6b, a support sleeve 61 and a sliding sleeve 63 disposed therebetween, and a radial edge plate is formed in the middle of the disc spring installation sleeve 6b. The spring portion is a disc spring 6a.

[0074] The piston 72 can contact the rear end surface of the radial edge plate to push the cylinder floating support 8 to move backward.

[0075] The rear end of the disc spring installation sleeve 6b is connected to the pull rod 9 through a second nut 96. The second nut 96 can be used to adjust the position of the disc spring installation sleeve 6b relative to the pull rod 9, and then the two are relatively fixed through a round head set screw 961.

[0076] The support sleeve 61 is fixedly sleeved on the spindle core 1 , and a gap is formed between the opposite surfaces of the cylinder floating bracket 8 and the support sleeve 61 .

[0077] The sliding sleeve 63 is installed at the front end of the disc spring installation sleeve 6b and is located at the front side of the radial edge plate. The sliding sleeve 63 and the radial edge plate are respectively formed with edge arms extending axially opposite to each other on the opposite end surfaces. The pair of edge arms match to form a matching structure of a movable sleeve, and the disc spring 6a is placed in the cavity formed by the pair of edge arms.

[0078] The front end of the disc spring mounting sleeve 6b is provided with a first nut 64 capable of adjusting the preload of the disc spring 6a. When the first nut 64 is screwed to move relative to the disc spring mounting sleeve 6b, the sliding sleeve 63 can be pushed to move axially relative to the disc spring mounting sleeve 6b, thereby compressing the disc spring 6a.

[0079] A balancing ring 62 is provided between the support sleeve 61 and the sliding sleeve 63, and the balancing ring 62 is plugged into the opposite end surfaces of the support sleeve 61 and the sliding sleeve 63 through axially arranged positioning pins 621. Preferably, threaded holes are provided on the circumferential wall of the support sleeve 61 and / or threaded holes are provided on the circumferential wall of the balancing ring 62, so as to improve the dynamic balancing performance of the electric spindle by increasing the weight.

[0080] The rear end of the support sleeve 61 is provided with a first nut 64, and the first nut 64 matches with the external thread structure provided in the middle of the spindle core 1, so that the support sleeve 61 is relatively fixed to the rear side of the rear matching bearing. Figure 1 In the embodiment, the front side of the support sleeve 61 is provided with an encoder flange 51, and an encoder gear 52 is installed on the outer ring of the encoder flange 51. The encoder flange 51 is sandwiched between the spacer ring 42 and the support sleeve 61.

[0081] The encoder flange 51 is mounted on the spindle core 1 and is close to the bearing portion on the rear end side. The encoder gear 52 is associated with an external device to form an encoder, which cooperates with the encoder reading head to detect the actual rotation speed and position of the spindle.

[0082] The encoder device installed at the rear of the electric spindle can detect the rotation speed and position of the electric spindle in real time, thereby ensuring the stability of the electric spindle speed and the accuracy of indexing and positioning.

[0083] like Figure 1 As shown, the inner wall of the cylinder floating bracket 8 on the front side is provided with a radially inwardly extending edge, and the edge overlaps with the outer wall edge of the support sleeve 61 in radial extension and there is a gap between the opposite end faces after assembly. During the axial movement of the cylinder floating bracket 8, the edge and the outer wall edge of the support sleeve 61 can contact each other to prevent the cylinder floating bracket 8 from continuing to move.

[0084] After assembly, a gap is formed between the radial edge plate (rear end face) in the middle of the butterfly spring mounting sleeve 6 b and the front end face of the piston 72 .

[0085] During operation, the CNC system controls the opening and closing of the solenoid valve to pressurize external air into the air nozzle 74 (installed on the cylinder head 73 at the rear end of the cylinder body 71), gradually driving the piston 72 to move forward, or stopping the action of supplying gas into the air nozzle 74.

[0086] During the process of the piston 72 gradually moving forward, the front end face of the piston 72 can press on the rear end face of the radial edge plate in the middle of the butterfly spring installation sleeve 6b. Thereafter, as the piston 72 continues to move forward, it can drive the cylinder floating bracket 8 to move backward, so that the axial gap formed between the edge provided on the inner wall of the cylinder floating bracket 8 and the outer wall edge (end face) of the support sleeve 61 gradually decreases (overcoming the pressure of the spring 82 during this period), until the rear end face of the edge contacts the front end face of the outer wall edge of the support sleeve 61. Then, the piston 72 continues to move forward, so that the disc spring installation sleeve 6b can be pushed forward, so that the edge arm (formed axial relative extension) on the sliding sleeve 63 and the edge arm (formed axial relative extension) on the radial edge plate can slide relative to each other, and the butterfly spring 6a is further compressed. When the disc spring mounting sleeve 6b moves forward, it synchronously drives the pull rod 9 (second nut 96) chuck 91 to move forward, and gradually pushes the conical surface portion of the chuck 91 out of the conical surface slot of the adapter 92 to loosen the clamped material.

[0087] The purpose of providing the cylinder floating support 8 is that when the material is loosened, the axial thrust generated by the cylinder unit can form a closed force system, and the axial force system will not cause damage to the bearing part on the electric spindle when it takes effect.

[0088] The side wall of the cylinder floating support 8 is provided with a sensing block 83. The end surface of the spindle seat 10 facing the cylinder floating support 8 is provided with a support 1 84, and the support 1 84 is provided with a sensing switch 1 85 corresponding to the sensing block 83.

[0089] A sensing rod 93 is disposed on the cylinder cover 73 at the rear end of the cylinder unit. A second bracket 94 is disposed on the spindle seat 10, and a second sensing switch 95 corresponding to the sensing rod 93 is mounted on the second bracket 94.

[0090] The cylinder unit is a single-acting cylinder. When clamping the material, the CNC system controls the electromagnetic valve to close, and stops the action of supplying gas from the air nozzle 74 to the cylinder body 71. The piston 72 automatically moves backward, and the cylinder floating bracket 8 will be tightly attached to the spindle seat 10 again under the action of the screw and the spring 82 matched on the screw.

[0091] The position detection system composed of the induction block 83, the bracket 1 84, and the induction switch 1 85 can detect the position of the cylinder floating bracket 8 in real time to ensure that the cylinder floating bracket 8 is not in contact with the support sleeve 61. That is, it is ensured that there is a gap between the edge (radially extending inward) provided at the inner wall of the front side of the cylinder floating bracket 8 and the opposite end face of the outer wall edge of the support sleeve 61. The detection system composed of the induction rod 93, the bracket 2 94, and the induction switch 2 95 detects the position of the piston 72 in real time to ensure that when the piston 72 moves back to the rear end in the clamping state, there is a gap between the piston 72 and the disc spring mounting sleeve 6b. That is, it is ensured that there is a gap between the rear end face of the radial edge plate provided in the middle of the disc spring mounting sleeve 6b and the front end face of the piston 72.

[0092] After ensuring that the above two states are correct and fed back to the control system, the control system can issue the electric spindle rotation instruction, otherwise the control system will issue an alarm (indicating abnormality).

[0093] A cooling groove 22 is provided on a section of the side wall of the spindle sleeve 2 opposite to the spindle seat 10. The cooling groove 22 is a spiral groove distributed in the axial direction. Sealing rings are provided at both ends of the spiral groove, and the sealing rings are pressed between the outer wall of the spindle sleeve 2 and the inner wall of the spindle seat 10.

[0094] Forced circulation cooling is performed through the cooling grooves 22 on the outer wall of the spindle sleeve 2, which can effectively control the temperature rise of the electric spindle, thereby ensuring the accuracy and stability of processing.

[0095] A dustproof seal 35 is mounted on the front part of the spindle shaft core 1 and on the front side of the bearing part. An annular groove is formed on the front end surface of the dustproof seal 35 .

[0096] A front bearing cover 33 is fixed to the front end face of the spindle shaft core 1 by screws. The front bearing cover 33 can act on the front end face of the dustproof ring 35 so that the dustproof ring 35 can be pressed onto the inner ring of the bearing part.

[0097] A front bearing cover 2 34 is fixed to the front end face of the spindle sleeve 2 with screws, and the inner ring of the bearing cover 2 34 is matched with the outer ring of the front bearing cover 1 33, and two annular flanges are formed on the rear end face of the front bearing cover 2 34, wherein the inner annular flange is placed in the annular groove on the dustproof spacer 35 and matches, and the outer annular flange can be pressed on the outer ring of the bearing part.

[0098] A dust cover 21 is fixed to the front end face of the main shaft sleeve 2 with screws. The dust cover 21 can be pressed against the side wall of the adapter 92 to press the adapter 92 toward the front end face of the front bearing cover 33. In addition, the dust cover 21 is provided with an oil return hole for discharging debris that has penetrated into the adapter 92.

[0099] With the aid of the multi-layer labyrinth seal structure arranged at the front end of the electric spindle, it is possible to effectively prevent debris from entering the front end bearing portion, thereby ensuring the service life of the spindle bearing.

[0100] The material clamping mechanism on the high-speed and high-precision electric spindle for lathes involved in this patent includes a spindle core 1, a chuck 91, an adapter 92 matching the chuck 91, a pull rod 9, a disc spring 6a, a disc spring mounting sleeve 6b, a support sleeve 61 and a sliding sleeve 63 placed between the disc spring mounting sleeve 6b and the support sleeve 61.

[0101] One end of the pull rod 9 is inserted into the spindle core 1 along the axial direction, and the chuck 91 is connected to the end of the pull rod 9 through a threaded structure. The other end of the pull rod 9 extends to the outside. The side surface of the chuck 91 is a conical surface, and the adapter 92 is provided with a conical surface slot, and the conical surface of the chuck 91 can gradually extend into the conical surface slot along the axial direction to match it.

[0102] A radial edge plate is formed in the middle of the disc spring mounting sleeve 6b.

[0103] The rear end of the disc spring mounting sleeve 6b is connected to the pull rod 9 via a second nut 96.

[0104] The support sleeve 61 is fixedly sleeved on the spindle core 1 .

[0105] The sliding sleeve 63 is installed at the front end of the disc spring installation sleeve 6b and is located at the front side of the radial edge plate. The sliding sleeve 63 and the radial edge plate are respectively formed with edge arms extending axially opposite to each other on the opposite end surfaces. The pair of edge arms match to form a matching structure of a movable sleeve, and the disc spring 6a is placed in the cavity formed by the pair of edge arms.

[0106] The front end of the disc spring mounting sleeve 6b is provided with a first nut 64 capable of adjusting the preload of the disc spring 6a. When the first nut 64 is screwed to move relative to the disc spring mounting sleeve 6b, the sliding sleeve 63 can be pushed to move axially relative to the disc spring mounting sleeve 6b, thereby compressing the disc spring 6a.

[0107] A balancing ring 62 is provided between the support sleeve 61 and the sliding sleeve 63 , and the balancing ring 62 is plugged into the opposite end surfaces of the support sleeve 61 and the sliding sleeve 63 via axially arranged positioning pins 621 .

[0108] The supporting sleeve 61 has a threaded hole on its circumferential wall and / or the balancing ring 62 has a threaded hole on its circumferential wall.

[0109] Such a clamping mechanism does not contact any peripheral components in the clamping state, and the butterfly spring 6a and other components that generate the clamping power source are fixed on the spindle core 1 and rotate synchronously with the spindle core 1. Therefore, the entire rotating component can be dynamically balanced online as a whole, thereby achieving an excellent dynamic balance level and improving the stability of the spindle during high-speed operation. This mechanism can adjust the clamping force (formed by the chuck 91) by adjusting the screw-in position of the second nut 96.

[0110] The material loosening mechanism on the high-speed and high-precision electric spindle for a lathe involved in this patent includes a cylinder floating bracket 8, a spring 82, a screw and a cylinder unit.

[0111] One end of the cylinder floating bracket is connected to the main shaft seat by the screw. The spring is sleeved on the screw and can push the cylinder floating bracket to contact the opposite surface of the main shaft seat.

[0112] The cylinder unit includes a cylinder body 71 , a piston 72 , a cylinder head 73 installed at the rear end of the cylinder body 71 , and a gas nozzle 74 arranged on the cylinder head 73 .

[0113] The cylinder body 71 in the cylinder unit is fixed to the rear end of the cylinder floating support 8 , and the piston 72 can extend toward one side (front side) of the spindle seat 10 .

[0114] A guide pin 81 arranged axially is matched between the opposing surfaces of the cylinder floating bracket 8 and the spindle seat 10. The front end of the guide pin 81 is fixed on the spindle seat 10, and the rear end is inserted into the guide hole on the cylinder floating bracket 8 to constrain the cylinder floating bracket 8 to move axially.

[0115] An adjustment pad 75 is provided between the cylinder floating bracket 8 and the opposite end surface of the cylinder body 71, and the two are connected by screws.

[0116] The adjustment pad 75 provided between the cylinder floating bracket 8 and the cylinder body 71 can be used to adjust the axial position of the cylinder body 71 to ensure that the cylinder unit and the clamping mechanism are not in contact when the workpiece is in the clamping state. At the same time, the cylinder floating bracket 8 is tightly attached to the spindle seat 10 under the action of the spring 82 and the screw (the spring 82 is set as), ensuring that the cylinder floating bracket 8 is not in contact with the support sleeve 61.

[0117] However, what is described above is only a specific embodiment of the present invention and should not be used to limit the scope of implementation of the present invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the scope of protection of the present invention should still fall within the scope covered by the claims of the present invention.

Claims

1. A material clamping mechanism on a high-speed and high-precision electric spindle for a lathe, comprising a spindle core, a chuck and an adapter matching the chuck; Its characteristics are: It also includes a spindle seat and a cylinder floating bracket, the spindle shaft core and the spindle seat are rotatably connected, the cylinder floating bracket is arranged on one side of the end face of the spindle seat, and the surface of the cylinder floating bracket opposite to the end face of the spindle seat can contact and separate from the end face of the spindle seat; It also includes a pull rod, a disc spring, a disc spring mounting sleeve, a support sleeve, and a sliding sleeve disposed between the disc spring mounting sleeve and the support sleeve; One end of the pull rod is inserted into the spindle core along the axial direction, and the chuck is connected to the end of the pull rod through a threaded structure; the other end of the pull rod extends to the outside; the side surface of the chuck is a conical surface, and the adapter is provided with a conical surface slot, and the conical surface of the chuck can gradually extend into the conical surface slot along the axial direction to match it; A radial edge plate is formed in the middle of the disc spring mounting sleeve; The rear end of the disc spring mounting sleeve is connected to the pull rod through a nut; The support sleeve is fixedly sleeved on the main shaft core, and a gap can be formed between the cylinder floating bracket and the opposite surface of the support sleeve; The sliding sleeve is installed at the front end of the disc spring installation sleeve and is located at the front side of the radial edge plate; the sliding sleeve and the radial edge plate are respectively formed with edge arms extending axially opposite to each other on the opposite end surfaces, and the pair of edge arms match to form a matching structure of a movable sleeve, and the disc spring is placed in the cavity formed by the pair of edge arms; The front end of the disc spring mounting sleeve is provided with a nut capable of adjusting the preload of the disc spring; A balancing ring is arranged between the supporting sleeve and the sliding sleeve, and the balancing ring is plugged into the opposite end surfaces of the supporting sleeve and the sliding sleeve through axially arranged positioning pins.

2. The material clamping mechanism on a high-speed and high-precision electric spindle for a lathe according to claim 1 is characterized in that: When the clamping mechanism is in a clamping state, the opposing surfaces of the cylinder floating bracket and the end surface of the spindle seat are in contact with the end surface of the spindle seat, and a gap is formed between the opposing surfaces of the cylinder floating bracket and the support sleeve.

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