Ultrasonic vibration electric spindle with self-generated ultrasonic electrical signal and adjustable frequency

Abstract

The invention discloses an ultrasonic vibration electric spindle with self-generated ultrasonic electric signal and adjustable frequency, which belongs to the technical field of numerical control machine tools and peripheral supporting components, and comprises: a hollow shaft core and a spindle housing arranged coaxially, the spindle housing is sleeved on the outside of the hollow shaft core; the hollow shaft core is rotatably connected with the spindle housing; one end of the hollow shaft core is sleeved with a spindle rotor, the other end is sleeved with an ultrasonic signal generating rotor, and the outside of the ultrasonic signal generating rotor is sleeved with an ultrasonic signal generating stator; a stator pole pair number switch electrically connected to the ultrasonic signal generating stator is arranged on the inner wall of the spindle housing; an acoustic-electric conversion device is arranged in a cavity away from one end of the hollow shaft core of the spindle rotor, and is electrically connected to the ultrasonic signal generating stator. The invention can generate ultrasonic electric signals by itself, and no longer needs to be rectified and inverted through power electronic devices, and can realize free switching between non-ultrasonic vibration processing mode and ultrasonic vibration processing mode through the control panel of the machine tool itself.

Description

Technical Field

[0001] The invention belongs to the technical field of numerically controlled machine tools and peripheral supporting components, and in particular relates to an ultrasonic vibration electric spindle with self-generated ultrasonic electric signals and adjustable frequency. Background Art

[0002] The electric spindle is a new technology that integrates the machine tool spindle and the spindle motor in the field of CNC machine tools. Together with linear motor technology and high-speed tool technology, the electric spindle has pushed high-speed machining into a new era. Ultrasonic vibration machining technology can significantly reduce cutting force, reduce defects such as burns, deformation, residual stress, and increase feed speed, thereby improving product quality.

[0003] On the basis of the relative motion between the workpiece and the tool in traditional machining, ultrasonic vibration is applied to the workpiece or the tool to obtain better machining performance. Ultrasonic vibration machining technology is very suitable for machining hard and brittle materials such as sapphire, glass, ceramics, semiconductors, etc. However, the existing ultrasonic vibration electric spindle has the following problems:

[0004] (1) The ultrasonic vibration electric spindle does not have the function of generating ultrasonic electrical signals. An independent ultrasonic power supply system needs to be built at the processing site, so that the control of the ultrasonic electrical signal cannot be adjusted through the machine tool's own control panel. In addition, the wires at the processing site are relatively messy, which increases the potential safety hazards in production.

[0005] (2) The ultrasonic transducer must obtain a stable, high-quality ultrasonic electrical signal to enable the tool to vibrate stably and ensure processing quality. Currently, whether it is a contact conductive method that uses a stationary carbon brush to contact a high-speed rotating copper-silver slip ring to transmit the high-frequency electrical signal of an external ultrasonic power source to the transducer, or a non-contact conductive method that transmits the primary high-frequency electrical signal of the ultrasonic power source to the secondary high-frequency electrical signal of the transducer through an electromagnetic induction coil, there are limitations to varying degrees during processing, which is inconvenient to use and causes certain maintenance costs. Summary of the invention

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] An ultrasonic vibration electric spindle with self-generated ultrasonic electrical signals and adjustable frequency comprises: a hollow shaft core and a spindle housing arranged coaxially, the spindle housing being sleeved on the outside of the hollow shaft core; the hollow shaft core being rotatably connected to the spindle housing; a spindle rotor being sleeved on the outside of one end of the hollow shaft core, and an ultrasonic signal generating rotor being sleeved on the outside of the other end, an ultrasonic signal generating stator being sleeved on the outside of the ultrasonic signal generating rotor, and the ultrasonic signal generating stator being fixedly connected to the inner wall of the spindle housing; a stator pole pair number switch electrically connected to the ultrasonic signal generating stator is arranged on the inner wall of the spindle housing, and the stator pole pair number switch is used to adjust the pole pair number of the ultrasonic signal generating stator when it is put into operation; an acoustic-to-electric conversion device is arranged in a cavity at one end of the hollow shaft core away from the spindle rotor, the acoustic-to-electric conversion device being electrically connected to the ultrasonic signal generating stator, and the acoustic-to-electric conversion device converts the ultrasonic frequency electrical signal generated by the ultrasonic signal generating stator, so that the acoustic-to-electric conversion device works in a resonant state, thereby realizing ultrasonic vibration machining.

[0008] Furthermore, a spindle stator is sleeved on the outer side of the spindle rotor, the spindle stator is fixedly connected to the inner wall of the spindle housing, and the spindle rotor and the spindle stator are clearance-matched.

[0009] Furthermore, the fitting clearance between the spindle stator and the spindle rotor forms a first air gap, and the first air gap is a cooling air passage for the spindle rotor and the spindle stator; and the hollow shaft core is provided with a first air passage through hole whose cavity is connected to the first air gap.

[0010] Furthermore, the ultrasonic signal generating rotor and the ultrasonic signal generating stator are clearance-fitted; the clearance between the ultrasonic signal generating rotor and the ultrasonic signal generating stator forms a second air gap, and the width of the second air gap is 1-2.5mm; the second air gap is a cooling air duct for the ultrasonic signal generating rotor and the ultrasonic signal generating stator; and a second air duct through hole is provided on the hollow shaft core, whose cavity is connected to the second air gap.

[0011] Furthermore, an end cover fixedly connected to the spindle housing near the spindle stator is provided, and the end cover is provided with a forced air cooling air inlet connected to the cavity of the hollow shaft core and a plurality of electric spindle stator and rotor air duct outlets connected to the first air gap.

[0012] Furthermore, a rear cover plate fixedly connected to the ultrasonic signal generating stator is provided at one end of the main shaft housing close to the ultrasonic signal generating stator, and the rear cover plate is provided with a plurality of signal generating stator and rotor air duct outlets communicating with the second air gap.

[0013] Furthermore, a plurality of housing cooling cavities are provided on the spindle housing, and the housing cooling cavities are used to cool the spindle housing and the spindle stator.

[0014] Furthermore, the acoustic-to-electric conversion device includes a signal processing circuit module, a clamping device, an ultrasonic knife handle, a variable amplitude rod and a pressure cap which are arranged in sequence from top to bottom; wherein the signal processing circuit module and the clamping device are both clamped and fixedly connected to the inner wall of the cavity of the hollow shaft core; the signal processing circuit module is electrically connected to the clamping device; one end of the ultrasonic knife handle is pneumatically pressed and fitted with the clamping device, and the other end of the ultrasonic knife handle is a hollow structure, in which a transducer is arranged; the ultrasonic knife handle is connected to the transducer through the variable amplitude rod; the pressure cap is threadedly connected to the variable amplitude rod; the signal processing circuit module is electrically connected to the ultrasonic signal generating rotor.

[0015] Furthermore, the signal processing circuit module is connected to the ultrasonic signal generating stator through a wire, and the signal processing circuit module modulates the ultrasonic frequency electrical signal generated by the ultrasonic signal generating rotor, and uses the phase difference between voltage and current as a basis for impedance matching. When the phase difference is equal to or approaches zero, the impedance matching of the transducer is achieved, so that the transducer operates in a resonant state.

[0016] Beneficial effects of the present invention:

[0017] 1. The ultrasonic vibration electric spindle provided by the present invention can generate ultrasonic electrical signals by itself, and no longer needs to be rectified and inverted through power electronic devices. The circuit is simplified, and a large number of peripheral power conversion equipment are reduced. In addition, the non-ultrasonic vibration processing mode and the ultrasonic vibration processing mode can be freely switched through the machine tool's own control panel. When the electric spindle is in the ultrasonic vibration processing mode, the vibration frequency can be adjusted.

[0018] 2. The ultrasonic electrical signal generated by the electric spindle itself is directly transmitted to the transducer by direct wire connection, which can effectively avoid the shortcomings of low acoustic-to-electrical conversion efficiency and poor stability of traditional slip ring contact conduction or wireless contact conduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the ultrasonic vibration electric spindle of the present invention;

[0020] Figure 2 It is a schematic diagram of the cross section of the stator and rotor for generating ultrasonic signals;

[0021] Figure 3 Cross-sectional view of the signal adapter plug and interface connection between the clamping device and the tool handle

[0022] Among them, 1. spindle stator; 2. spindle rotor; 3. hollow shaft core; 4. shell cooling cavity; 5. spindle shell; 6. power interface; 7. middle section bearing; 8. ultrasonic signal generating stator; 9. ultrasonic signal generating rotor; 10. stator pole pair switch; 11. rear cover bolt; 12. rear cover; 13. signal generating stator and rotor air duct outlet; 14. ultrasonic tool handle; 15. transducer; 16. pressure cap; 17. amplitude transformer; 18. rear end bearing; 19. ultrasonic tool handle clamping interface; 191. signal adapter plug; 20. clamping device; 201. signal adapter interface; 21. signal processing circuit module; 22. wiring through hole; 23. first air duct through hole; 24. front end bearing; 25. end cover bolt; 26. electric spindle stator and rotor air duct outlet; 27. end cover; 28. forced air cooling air inlet; 29. ​​second air gap; 30. wire. DETAILED DESCRIPTION Example 1

[0023] The ultrasonic vibration electric spindle with self-generated ultrasonic electrical signal and adjustable frequency comprises: a hollow shaft core 3 and a spindle housing 5 arranged coaxially, the spindle housing 5 is sleeved on the outer side of the hollow shaft core 3; the hollow shaft core 3 is rotatably connected to the spindle housing 5.

[0024] In this embodiment, the hollow shaft core 3 is rotatably connected to the inner cavity of the spindle housing 5 through the end cover bolts 25, the end cover 27, the front end bearing 24, the middle section bearing 7, the rear end bearing 18, the rear cover bolts 11 and the rear cover 12. The end cover 27 is fixedly connected to one end of the spindle housing 5 close to the spindle stator 1 through the end cover bolts 25, and the rear cover 12 is fixedly connected to one end of the spindle housing 5 close to the ultrasonic signal generating stator 8 through the rear cover bolts 11.

[0025] A spindle rotor 2 is sleeved on one end of the hollow shaft core 3, and the spindle rotor 2 is fixedly connected to the hollow shaft core 3; a spindle stator 1 is sleeved on the outer side of the spindle rotor 2, and the spindle stator 1 is fixedly connected to the inner wall of the spindle housing 5, and the spindle rotor 2 and the spindle stator 1 are clearance-matched.

[0026] The matching clearance between the spindle stator 1 and the spindle rotor 2 forms a first air gap, which is a cooling air passage for the spindle rotor 2 and the spindle stator 1; the hollow shaft core 3 is provided with a first air passage through hole 23 whose cavity is connected to the first air gap.

[0027] The other end of the hollow shaft core 3 is sleeved with an ultrasonic signal generating rotor 9, which is fixedly connected to the hollow shaft core 3. An ultrasonic signal generating stator 8 is sleeved on the outside of the ultrasonic signal generating rotor 9, which is fixedly connected to the inner wall of the spindle housing 5; a stator pole pair switch 10 electrically connected to the ultrasonic signal generating stator 8 is provided on the inner wall of the spindle housing 5, and the stator pole pair switch 10 is used to adjust the pole pair of the ultrasonic signal generating stator 8 when it is put into operation; an acoustic-to-electric conversion device is provided in the cavity at one end of the hollow shaft core 3 away from the spindle rotor 2, and the acoustic-to-electric conversion device is electrically connected to the ultrasonic signal generating stator 8, and the acoustic-to-electric conversion device converts the ultrasonic frequency electrical signal generated by the ultrasonic signal generating stator 8, so that the acoustic-to-electric conversion device works in a resonant state to achieve ultrasonic vibration processing.

[0028] The ultrasonic signal generating rotor 9 and the ultrasonic signal generating stator 8 are clearance-matched; the clearance between the ultrasonic signal generating rotor 9 and the ultrasonic signal generating stator 8 forms a second air gap 29, and the width of the second air gap 29 is 1-2.5mm; the second air gap 29 is a cooling air duct for the ultrasonic signal generating rotor 9 and the ultrasonic signal generating stator 8; a second air duct through hole is provided on the hollow shaft core 3, whose cavity is connected to the second air gap 29.

[0029] In this embodiment, the end cover 27 is provided with a forced air cooling air inlet 28 connected to the cavity of the hollow shaft core 3 and a plurality of electric spindle stator and rotor air duct outlets 26 connected to the first air gap; the rear cover plate 12 is provided with a plurality of signal generating stator and rotor air duct outlets 13 connected to the second air gap 29.

[0030] A plurality of housing cooling cavities 4 are provided on the spindle housing 5 . The housing cooling cavities 4 are used to cool the spindle housing 5 and the spindle stator 1 . In the present embodiment, the housing cooling cavities 4 are circular holes, and the number of the housing cooling cavities 4 is 6.

[0031] The acoustic-to-electric conversion device includes a signal processing circuit module 21, a clamping device 20, an ultrasonic knife handle 14, a variable amplitude rod 17 and a pressure cap 16 which are arranged in sequence from top to bottom; wherein the signal processing circuit module 21 and the clamping device 20 are both clamped and fixedly connected to the inner wall of the cavity of the hollow shaft core 3; the signal processing circuit module 21 is electrically connected to the clamping device 20; one end of the ultrasonic knife handle 14 is cooperatively connected to the clamping device 20, and the other end of the ultrasonic knife handle 14 is a hollow structure, in which a transducer 15 is arranged; the ultrasonic knife handle 14 is connected to the transducer 15 through the variable amplitude rod 17; the pressure cap 16 is threadedly connected to the variable amplitude rod 17; the signal processing circuit module 21 is electrically connected to the ultrasonic signal generating rotor 9.

[0032] In this embodiment, an ultrasonic handle clamping interface 19 is provided on the ultrasonic handle 14 , and a pneumatic compression connection is adopted between the ultrasonic handle clamping interface 19 and the clamping device 20 .

[0033] The ultrasonic knife handle 14 can be of standard types such as HSK, BT, SK, BBT, etc. The signal adapter interface 201 provided inside the clamping device 20 is reliably connected to the signal adapter plug 191 contained in the ultrasonic knife handle 14 in a concentric ring manner, and the ultrasonic electrical signal is directly transmitted to the transducer 15 by a wire 30.

[0034] like Figure 3 As shown, the internal connection between the BT standard ultrasonic knife handle 14 and the clamping device 20 is demonstrated, and the signal adapter plug 191 at the end of the ultrasonic knife handle clamping interface 19 is firmly plugged into the signal adapter interface 201 inside the clamping device 20.

[0035] The clamping device 20 and the signal processing circuit module 21 are both fixed to the inner wall of the hollow shaft core 3 through a clamping groove, and the signal transfer interface 201 is connected to the signal processing circuit module 21 through a wire 30 .

[0036] The power interface 6 is welded to the outer wall of the spindle housing 5 .

[0037] In this embodiment, the cavity of the hollow shaft core 3 is a shaft core ultrasonic vibration cooling air channel, which mainly cools the signal processing circuit module 21 and the inner wall of the hollow shaft core 3 .

[0038] The working principle of this embodiment is as follows: after the ultrasonic vibration electric spindle power supply is turned on, the high-speed rotating hollow shaft core 3 drags the ultrasonic signal generating rotor 9 to rotate coaxially; when the stator pole pair number switch 10 is turned on, a DC current passes through the coil of the ultrasonic signal generating stator 8 that is put into operation, and a constant magnetic field is immediately generated under the action of the DC current. The ultrasonic signal generating rotor 9 cuts the ultrasonic signal generating stator 8 to generate a constant magnetic field line, generating an ultrasonic electrical signal, and the electric spindle is in the ultrasonic vibration processing mode. By changing the pole pair number of the ultrasonic signal generating stator 8 put into operation through the stator pole pair number switch 10, the frequency adjustment of the ultrasonic electrical signal can be achieved; then the ultrasonic signal generating stator 8 is turned on, and the ultrasonic signal generating stator 8 is turned on. The ultrasonic electrical signal generated by the rotor 9 is transmitted along the wire 30 in the wiring through hole 22 to the signal processing circuit module 21 fixed on the inner wall of the hollow shaft core 3. The signal processing circuit module 21 performs voltage conversion, current adjustment and impedance matching on the original ultrasonic electrical signal generated by the ultrasonic signal generating rotor 9, and then obtains the desired ultrasonic frequency electrical signal through signal filtering. Finally, the desired ultrasonic frequency electrical signal is transmitted to the transducer 15 through the signal adapter interface 201 inside the clamping device 20 and the signal adapter plug 191 in the ultrasonic tool handle 14. Under the action of the desired ultrasonic frequency electrical signal, the transducer 15 will work in a resonant state to realize ultrasonic vibration processing.

[0039] The ultrasonic electrical signal generating mechanism generates a constant magnetic field in the coil of the ultrasonic signal generating stator 8 through the direct current provided by the power supply interface 6. The high-speed rotating electric spindle drives the coil of the ultrasonic signal generating rotor 9 to cut the magnetic flux lines generated by the coil of the ultrasonic signal generating stator 8, and converts part of the mechanical energy of the electric spindle into ultrasonic frequency electrical signals.

[0040] The stator pole pair number switch 10 of the ultrasonic electrical signal generating mechanism controls the pole pair number of the ultrasonic signal generating stator 8 put into operation, can change the pole pair number of the ultrasonic signal generating stator 8 put into operation, and can realize the frequency adjustment of the ultrasonic electrical signal; when the stator pole pair number switch 10 is all closed, the electric spindle is in the non-ultrasonic vibration processing mode; when the stator pole pair number switch 10 is opened, the electric spindle is in the ultrasonic vibration processing mode, and the frequency can be adjusted.

[0041] The signal processing circuit module 21 is connected to the ultrasonic signal generating stator 8 through a wire. The signal processing circuit module 21 modulates the ultrasonic frequency electrical signal generated by the ultrasonic signal generating rotor 9, and uses the phase difference between voltage and current as the basis for impedance matching. When the phase difference is equal to or approaches zero, the impedance matching of the transducer 15 is achieved, so that the transducer 15 operates in a resonant state.

[0042] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An ultrasonic vibration electric spindle with self-generated ultrasonic electrical signals and adjustable frequency, characterized in that: include: A hollow shaft core and a spindle housing are coaxially arranged, and the spindle housing is sleeved on the outside of the hollow shaft core; the hollow shaft core is rotatably connected to the spindle housing; a spindle rotor is sleeved on the outside of one end of the hollow shaft core, and an ultrasonic signal generating rotor is sleeved on the outside of the other end, and an ultrasonic signal generating stator is sleeved on the outer side of the ultrasonic signal generating rotor, and the ultrasonic signal generating stator is fixedly connected to the inner wall of the spindle housing; a stator pole pair number switch electrically connected to the ultrasonic signal generating stator is arranged on the inner wall of the spindle housing, and the stator pole pair number switch is used to adjust the pole pair number of the ultrasonic signal generating stator when it is put into operation; an acoustic-to-electric conversion device is arranged in the cavity of one end of the hollow shaft core away from the spindle rotor, and the acoustic-to-electric conversion device is electrically connected to the ultrasonic signal generating stator, and the acoustic-to-electric conversion device converts the ultrasonic frequency electrical signal generated by the ultrasonic signal generating stator, so that the acoustic-to-electric conversion device works in a resonant state to realize ultrasonic vibration machining.

2. The ultrasonic vibration electric spindle with self-generated ultrasonic electrical signals and adjustable frequency according to claim 1, characterized in that: A spindle stator is sleeved on the outer side of the spindle rotor. The spindle stator is fixedly connected to the inner wall of the spindle housing. The spindle rotor and the spindle stator are clearance-matched.

3. The ultrasonic vibration electric spindle with self-generated ultrasonic electrical signals and adjustable frequency according to claim 2, characterized in that: The matching gap between the spindle stator and the spindle rotor forms a first air gap, which is a cooling air passage for the spindle rotor and the spindle stator; the hollow shaft core is provided with a first air passage through hole whose cavity is connected with the first air gap.

4. The ultrasonic vibration electric spindle with self-generated ultrasonic electrical signals and adjustable frequency according to claim 3, characterized in that: The ultrasonic signal generating rotor and the ultrasonic signal generating stator are in a clearance fit; the fitting clearance between the ultrasonic signal generating rotor and the ultrasonic signal generating stator forms a second air gap, and the width of the second air gap is 1-2.5mm; the second air gap is a cooling air duct for the ultrasonic signal generating rotor and the ultrasonic signal generating stator; the hollow shaft core is provided with a second air duct through hole whose cavity is connected to the second air gap.

5. The ultrasonic vibration electric spindle with self-generated ultrasonic electrical signals and adjustable frequency according to claim 4, characterized in that: An end cover fixedly connected to the spindle housing is provided at one end close to the spindle stator, and the end cover is provided with a forced air cooling air inlet connected to the cavity of the hollow shaft core and a plurality of electric spindle stator and rotor air duct outlets connected to the first air gap.

6. The ultrasonic vibration electric spindle with self-generated ultrasonic electrical signals and adjustable frequency according to claim 5, characterized in that: A rear cover plate fixedly connected to one end of the main shaft housing close to the ultrasonic signal generating stator is provided, and the rear cover plate is provided with a plurality of signal generating stator and rotor air duct outlets communicating with the second air gap.

7. The ultrasonic vibration electric spindle with self-generated ultrasonic electrical signals and adjustable frequency according to claim 6, characterized in that: The spindle housing is provided with a plurality of housing cooling cavities, and the housing cooling cavities are used to cool the spindle housing and the spindle stator.

8. The ultrasonic vibration electric spindle with self-generated ultrasonic electrical signals and adjustable frequency according to claim 7, characterized in that: The acoustic-to-electric conversion device includes a signal processing circuit module, a clamping device, an ultrasonic knife handle, a variable amplitude rod and a pressure cap, which are arranged in sequence from top to bottom; wherein the signal processing circuit module and the clamping device are both clamped and fixedly connected to the inner wall of the cavity of the hollow shaft core; the signal processing circuit module is electrically connected to the clamping device; one end of the ultrasonic knife handle is pneumatically pressed and fitted with the clamping device, and the other end of the ultrasonic knife handle is a hollow structure, in which a transducer is arranged; the ultrasonic knife handle is connected to the transducer through the variable amplitude rod; the pressure cap is threadedly connected to the variable amplitude rod; the signal processing circuit module is electrically connected to the ultrasonic signal generating rotor.

9. The ultrasonic vibration electric spindle with self-generated ultrasonic electrical signals and adjustable frequency according to claim 8, characterized in that: The signal processing circuit module is connected to the ultrasonic signal generating stator through a wire. The signal processing circuit module modulates the ultrasonic frequency electrical signal generated by the ultrasonic signal generating rotor, and uses the phase difference between voltage and current as the basis for impedance matching. When the phase difference is equal to or approaches zero, the impedance matching of the transducer is achieved, so that the transducer operates in a resonant state.

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