Electrostatic nozzle and controllable jet minimal quantity lubrication grinding system

Abstract

The present disclosure provides an electrostatic nozzle and a controllable jet minimal quantity lubrication (MQL) grinding system. The electrostatic nozzle comprises a nozzle core; an upper nozzle body is connected above the nozzle core; a free space is formed between the upper nozzle body and the nozzle core for storing compressed air and reducing pressure; a lower nozzle body is connected below the nozzle core; a gas-liquid mixing chamber, an acceleration chamber and a nozzle outlet are sequentially arranged inside the nozzle core from top to bottom; and micro-bulges are uniformly distributed on an inner wall of the acceleration chamber.

We claim: 
     
         1 . A micro-texture electrostatic nozzle, comprising a nozzle core, wherein an upper nozzle body is connected above the nozzle core; a free space is formed between the upper nozzle body and the nozzle core for storing compressed air and reducing pressure; a lower nozzle body is connected below the nozzle core; a gas-liquid mixing chamber, an acceleration chamber and a nozzle outlet are sequentially arranged inside the nozzle core from top to bottom; and micro-bulges are uniformly distributed on an inner wall of the acceleration chamber. 
     
     
         2 . A two-stage composite micro-texture electrostatic nozzle, comprising a nozzle core, wherein an upper nozzle body is connected above the nozzle core; a free space is formed between the upper nozzle body and the nozzle core for storing compressed air and reducing pressure; a lower nozzle body is connected below the nozzle core; a gas-liquid mixing chamber, an acceleration chamber and a nozzle outlet are sequentially arranged inside the nozzle core from top to bottom; micro-bulges are uniformly distributed on an inner wall of the acceleration chamber; the micro-bulges are composed of first-stage micro-bulges and second-stage micro-bulges; and the second-stage micro-bulges are arranged on the first-stage micro-bulges. 
     
     
         3 . A noise-reducing and resistance-increasing electrostatic nozzle, comprising a nozzle core, wherein an upper nozzle body is connected above the nozzle core; a free space is formed between the upper nozzle body and the nozzle core for storing compressed air and reducing pressure; a lower nozzle body is connected below the nozzle core; a gas-liquid mixing chamber, an acceleration chamber and a nozzle outlet are sequentially arranged inside the nozzle core from top to bottom; micro-bulges are uniformly distributed on an inner wall of the acceleration chamber; the micro-bulges are of a conical strip shape; and a conical strip-shaped groove is formed between any two conical strip-shaped micro-bulges. 
     
     
         4 . A gradient micro-bulge contact type electrostatic nozzle, comprising a nozzle core, wherein an upper nozzle body is connected above the nozzle core; a free space is formed between the upper nozzle body and the nozzle core for storing compressed air and reducing pressure; a lower nozzle body is connected below the nozzle core; a gas-liquid mixing chamber, an acceleration chamber and a nozzle outlet are sequentially arranged inside the nozzle core from top to bottom; micro-bulges are uniformly distributed on an inner wall of the acceleration chamber; and the micro-bulges adopt a transitional non-contour structure, i.e., heights of the micro-bulges gradually decrease along a movement direction of jet. 
     
     
         5 . A controllable jet minimal quantity lubrication (MQL) grinding system, comprising:
 the micro-texture electrostatic nozzle of  claim 1 ;   or   the two-stage composite micro-texture electrostatic nozzle of  claim 2 ;   or   the noise-reducing and resistance-increasing electrostatic nozzle of  claim 3 ;   or   the gradient micro-bulge contact type electrostatic nozzle of  claim 4 .   
     
     
         6 . The controllable jet MQL grinding system according to  claim 5 , further comprising:
 a grinding machine part workbench, wherein a grinding wheel is arranged above the grinding machine part workbench; an outer side of the grinding wheel is provided with a grinding wheel cover; a workpiece is arranged between the grinding machine part workbench and the grinding wheel; an MQL liquid conveying pipe is fixed to the grinding wheel cover; one end of the MQL liquid conveying pipe is communicated with the electrostatic nozzle, and the other end is communicated with an MQL device;   the electrostatic nozzle is also electrically connected with an adjustable high-voltage DC power supply; the adjustable high-voltage DC power supply is also electrically connected with a workpiece power-up device; the workpiece power-up device is adsorbed on a non-machined surface of the workpiece; the workpiece is connected with a positive electrode of the adjustable high-voltage DC power supply so that the electrostatic nozzle is of negative polarity, the surface of the workpiece is of positive polarity, and an electric field is formed between the nozzle and the workpiece, thereby providing conditions for controllable transportation of MQL droplets.   
     
     
         7 . The controllable jet MQL grinding system according to  claim 5 , wherein a contraction angle α of the acceleration chamber is between 5° and 20°; a nozzle outlet has a diameter of B and a length of L; a value of L/B is between 2 and 6;
 and/or 
 a check ring placement groove is arranged above the nozzle core; and the annular check ring is fixedly bonded in the check ring placement groove; 
 and/or 
 a check ring placement groove is arranged above the nozzle core; the annular check ring is fixedly bonded in the check ring placement groove; a plurality of V 2 O 5  nanofiber sheets are distributed on the annular check ring in a form of arrays; the V 2 O 5  nanofiber sheets are pasted around the annular check ring by one circle to cover an annular central hole; 
 and/or 
 spiral air holes are formed in the nozzle core and are distributed along an outer wall of the gas-liquid mixing chamber in the form of arrays; an inlet axis is tangent to a wall surface of an inner cavity of the gas-liquid mixing chamber; and the compressed air flows through the spiral air holes and enters the gas-liquid mixing chamber at a tangential velocity; 
 and/or 
 a high-voltage wire interface is arranged on the nozzle core; a high-voltage wire outlet through hole  54  is formed in the lower nozzle body; and a DC high-voltage wire can penetrate through the high-voltage wire outlet through hole to be connected with the high-voltage wire interface so as to supply power to the nozzle core; 
 and/or 
 an insulation coil pipe is arranged on an outermost side of the MQL conveying pipe; an insulation oil pipe is arranged inside the MQL conveying pipe; a gas conveying cavity is formed between the insulation coil pipe and the insulation oil pipe for conveying the atomized air; a hydrophobic and oleophobic carbon nano-coating is coated inside the insulation oil pipe; and meanwhile, a liquid conveying cavity is formed inside the insulation oil pipe; the atomized air and the MQL liquid are supplied to the electrostatic nozzle in a coaxial manner; 
 and/or 
 the adjustable high-voltage DC power supply comprises an AC power supply unit; the AC power supply unit is respectively connected with a first DC voltage stabilizing unit and a second DC voltage stabilizing unit; the first DC voltage stabilizing unit is successively connected with a power amplification circuit and a high-frequency pulse booster; the high-frequency pulse booster is connected with a voltage-doubling rectification circuit; the voltage-doubling rectification circuit is connected with a constant-current automatic control circuit; and the constant-current automatic control circuit is connected with the second DC voltage stabilizing unit; 
 and/or 
 the workpiece power-up device comprises an insulation housing; a permanent magnet is arranged in the insulation housing; a lower part of an iron weight penetrates through the central position of the insulation housing; a compression spring is arranged between the iron weight and the insulation housing; when the workpiece power-up device is close to the non-machined surface of the workpiece, the permanent magnet may generate an attraction force with the workpiece to compress the compression spring; and meanwhile, the compression spring provides a reaction force to ensure that the iron weight is closely connected with the workpiece; 
 and/or 
 the workpiece power-up device comprises an insulation housing; a permanent magnet is arranged in the insulation housing; a lower part of an iron weight penetrates through the central position of the insulation housing; a compression spring is arranged between the iron weight and the insulation housing; when the workpiece power-up device is close to the non-machined surface of the workpiece, the permanent magnet may generate an attraction force with the workpiece to compress the compression spring; meanwhile, the compression spring provides a reaction force to ensure that the iron weight is closely connected with the workpiece; a cotter pin slot is arranged at a tail part of the iron weight; the cotter pin slot is used for inserting a cotter pin to ensure that the iron weight and the compression spring do not fall off from the insulation housing when the workpiece power-up device is not adsorbed to the workpiece; 
 and/or 
 the workpiece power-up device comprises an insulation housing; a permanent magnet is arranged in the insulation housing; a lower part of an iron weight penetrates through the central position of the insulation housing; a compression spring is arranged between the iron weight and the insulation housing; when the workpiece power-up device is close to the non-machined surface of the workpiece, the permanent magnet may generate an attraction force with the workpiece to compress the compression spring; meanwhile, the compression spring provides a reaction force to ensure that the iron weight is closely connected with the workpiece; a cotter pin slot is arranged at a tail part of the iron weight; the cotter pin slot is used for inserting a cotter pin to ensure that the iron weight and the compression spring do not fall off from the insulation housing when the workpiece power-up device is not adsorbed to the workpiece; a wiring ring is arranged at the tail part of the iron weight; and the wiring ring is connected with a positive terminal of the adjustable high-voltage DC power supply by the DC high-voltage wire. 
 
     
     
         8 . The controllable jet MQL grinding system according to  claim 5 , wherein the MQL device comprises:
 precise MQL pumps; the precise MQL pumps are provided with liquid inlet holes of the precise MQL pumps; the liquid inlet holes of the precise MQL pumps are communicated with an insulation oil cup; the insulation oil cup is used to supply liquid to the precise MQL pumps; the precise MQL pumps are also communicated with a liquid suction air path and an atomized air path; the liquid suction air path and the atomized air path are communicated with a compressed air source; the liquid suction air path is used for controlling the MQL liquid sucked by the precise MQL pumps into the insulation oil cup; and the atomized air path is used for conveying atomized MQL liquid.   
     
     
         9 . The controllable jet MQL grinding system according to  claim 8 , wherein one end of the atomized air path is connected with a first inlet interface of a lubrication pump, and the other end is connected with a first interface of a three-way valve; one end of the liquid suction air path is connected with a second inlet interface of the lubrication pump, and the other end is connected with a second interface of the three-way valve; a third interface of the three-way valve is connected with the compressed air source through a pipeline;
 and/or   one end of the atomized air path is connected with a first inlet interface of a lubrication pump, and the other end is connected with a first interface of a three-way valve; one end of the liquid suction air path is connected with a second inlet interface of the lubrication pump, and the other end is connected with a second interface of the three-way valve; a third interface of the three-way valve is connected with the compressed air source through a pipeline; a filter pressure-adjusting valve is also arranged on a pipeline between the third interface of the three-way valve and the compressed air source; the filter pressure-adjusting valve is connected with an electromagnetic valve; the electromagnetic valve is connected with a pulse controller; and the pulse controller is used for controlling the on-off frequency of the electromagnetic valve to control the air outlet frequency of the compressed air, so as to control the frequency of sucking the MQL liquid by the precise MQL pumps;   and/or   an air flow adjustment knob and a liquid flow adjustment knob are arranged on each precise MQL pump; the air flow adjustment knob is used for adjusting the flow of the compressed air in the atomized air path; and the liquid flow adjustment knob is used for adjusting the liquid suction amount in each pulse of the precise MQL pump.   
     
     
         10 . The controllable jet MQL grinding system according to  claim 8 , wherein the grinding machine part workbench is covered with an insulation plate;
 and/or   a magnetic chuck is adsorbed on a side surface of the grinding wheel cover; the MQL liquid conveying pipe is fixed to the magnetic chuck;   and/or   two groups of precise MQL pumps are arranged, and the two groups of precise MQL pumps are arranged up and down in parallel.