Numerically-controlled PCB hole drilling machine tool contact broken pin testing system
Technical field
The present invention relates to a kind of PCB Drilling Machine cutter broken needle and Z shaft position measurement mechanism.
Background technology
Whether the drill point that how to detect drilling hole machine tool ruptures and the position of broken needle, is the problem that the designer is considering.
As shown in Figure 1, after the spindle rotor chuck is clamped drill point, during work, high-frequency ac power is through high frequency transformer main (high frequency transformer is serially connected in the circuit), through the main shaft stator, air supporting, to the drill point of spindle rotor, with presser feet (presser feet or connect working plate meet GND), metallic conduction thing, contact forms a loop.
Whether a kind of detection that application number is 200420015113.0 patent disclosure the circuit of broken needle and broken needle position.As shown in Figure 2, when machine works, the drill point of spindle rotor and metallic conductor, presser feet constitutes an electric loop, at ac voltage signal of secondary generation of high frequency transformer, through commutation diode D1, with filter capacitor C2, convert ac voltage signal to direct current signal, be input to comparison amplifier, the people is after setting 2 pin reference voltages of comparison amplifier, by high-low level signal of pin output.
Application number is 200720051705.1 patent disclosure second kind of circuit that detects broken needle whether and broken needle position.As shown in Figure 3, regard main shaft as high frequency capacitance, on the main shaft stator, add a high frequency electric source, when machine works through resistance R 4, the drill point of spindle rotor is with presser feet (presser feet or connect working plate meet GND), metallic conduction thing, contact forms a loop, consumes certain electric energy.Cause through D1, the direct current that is added in 3 pin on the comparison amplifier behind the C1 rectifying and wave-filtering is pressed with certain variation, set the reference voltage of comparison amplifier 2 pin after, make high-low level signal of comparison amplifier 1 pin output.
The defective of these two kinds of circuit is, in main shaft work, or main shaft service time long after, main shaft stator insulation layer will occur aging, to have a strong impact on the input sample voltage of comparison amplifier 3 pin,, seriously cause the circuit board job insecurity so need often to adjust the reference voltage of 2 pin; And because the sampled voltage of comparison amplifier 3 pin input is a high-frequency ac voltage, though passed through rectifying and wave-filtering, but be mingled with very big alternating component in the signal, so that the high-low level signal of comparison amplifier output also has been mingled with very big alternating component, will causes significantly the machine electric signal and disturb.And sampled signal has been because of having passed through rectifying and wave-filtering, and output signal will produce the hysteresis of about 1-2ms.So that the machine signal transmission is slow, can not catch the position of current axis timely.
Application number is 200620160010.2 patent disclosure, and the third detects the circuit of broken needle whether and broken needle position.As shown in Figure 4, regard main shaft as high frequency capacitance, high-frequency ac power is connected on the main shaft stator, through air supporting, to the drill point of spindle rotor, contact with metallic conductor, (need the platen insulation from the insulation presser feet again, the presser feet insulation, otherwise when bull Z axle is worked simultaneously, signal will be connected in series or out of control meaning mutually) on draw a line to high frequency transformer, high frequency transformer other end ground connection forms a loop.At ac voltage signal of secondary generation of high frequency transformer, through commutation diode D1 and filter capacitor C2, convert ac voltage signal to direct current signal, be input to comparison amplifier, the people is after setting 2 pin reference voltages of comparison amplifier, by high-low level signal of pin output.
The defective of the third circuit is, though main shaft is got rid of because of the circuit board job insecurity that destabilizing factor in aging and the work causes, but need the preliminary 2 pin reference voltages of adjusting comparison amplifier equally, also need to manufacture insulation presser feet and insulation platen, need to guarantee that the platen between each links to each other with presser feet mutually insulated and discord ground, otherwise will cause string signal and out of control, to having brought very big difficulty in the Machine Design! Equally, the also hysteresis that will produce about 1-2ms because of the output signal that exists rectifying and wave-filtering to bring.So that the machine signal transmission is slow, can not catch the position of current axis timely.
Application number is 200520065065.0 patent disclosure the 4th kind of circuit that detects broken needle whether and broken needle position.As shown in Figure 5, primary coils and air-floating main shaft wiring and figure two, figure three, figure four similar substantially (as Fig. 5), different is to be added in comparison amplifier 3 pin inputs behind the secondary coil voltage rectifying and wave-filtering, with A/D converter DC voltage is converted to binary code, inputs to CPU, CPU suitably strengthens this binary code or dwindles, suitable time-delay then, export to D/A converter, give comparison amplifier 2 pin, make high-low level signal of 1 pin output as reference voltage.
The defective of the 4th kind of circuit is, need the artificial problem of adjusting though solved comparison amplifier 2 pin reference voltages, but do not solve the problem that needs to make insulation platen and insulation presser feet, equally exist the problem of signal lag yet, can not in time catch current position.And the circuit production complexity, the cost height very easily is interfered, the antijamming capability of circuit own very a little less than.In a single day CPU crashes, and this signal is with uncontrolled.
In sum, the defective of prior art is, solves signal lag; Machinery platen and presser feet need insulation; The cost height, it is difficult to make, a little less than the antijamming capability; The circuit board function, unstable properties.
Summary of the invention
In view of this, the objective of the invention is to address the above problem, a kind of circuit is provided, the simple and stable performance of this circuit structure.
Technical scheme of the present invention is: a kind of numerically-controlled PCB hole drilling machine tool contact broken pin testing system is characterized in that: the ac high-frequency voltage source extremely links to each other with the B of NPN type triode Q1 and positive-negative-positive triode Q2; Capacitor C 2, resistance R 3 and resistance R 4 series connection constitute filter circuit; Capacitor C 1 and resistance R 3, resistance R 4 parallel connections constitute energy-storage units; Resistance R 1 extremely links to each other with C from NPN type triode Q1, and resistance R 2 extremely links to each other the C utmost point ground connection of positive-negative-positive triode Q2 with the E utmost point of NPN type triode Q1 and the E of positive-negative-positive triode Q2 respectively; The positive pole of comparison amplifier extremely links to each other with the C of triode Q1, and is connected between capacitor C 2, the resistance R 3, between the negative pole of comparison amplifier and resistance R 3, the resistance R 4, and by capacitor C 1 ground connection; Main shaft extremely links to each other with the E of positive-negative-positive triode Q2, and main shaft drill point, conducting metal body, working plate link to each other with main shaft successively, working plate ground connection.
Described ac high-frequency voltage source comprises the prime oscillating circuit that resistance R 5, resistance R 6, resistance R 7, resistance R 8, resistance R 9, capacitor C 3, potentiometer VR1 and common voltage comparator A are constituted; The back level oscillator-amplification circuit that R10 and common voltage comparator B constitute, current-limiting resistance R11 links to each other with resistance R 10.
The model of described NPN type triode Q1 is TIP132, and the model of described positive-negative-positive triode Q2 is TIP137, and TIP132 type NPN type triode Q1 and TIP137 type positive-negative-positive triode Q2 constitute power amplifier to be used pipe.
The model of described NPN type triode Q1 is TIP142, and the model of described positive-negative-positive triode Q2 is TIP147, and TIP142 type NPN type triode Q1 and TIP147 type positive-negative-positive triode Q2 constitute power amplifier to be used pipe.
The model of described NPN type triode Q1 is TIP3055, and the model of described positive-negative-positive triode Q2 is TIP2955, and TIP3055 type NPN type triode Q1 and TIP2955 type positive-negative-positive triode Q2 constitute power amplifier to be used pipe.
The model of described NPN type triode Q1 is TIP35C, and the model of described positive-negative-positive triode Q2 is TIP36C, and TIP35C type NPN type triode Q1 and TIP36C type positive-negative-positive triode Q2 constitute power amplifier to be used pipe.
The resistance of described current-limiting resistance R1 is 150 ohm.
The resistance of described resistance R 2 is 1 ohm.
The invention has the beneficial effects as follows: owing to place a sample resistance R1 at high-frequency alternating current potential source direct current power amplifier end, the DC voltage change of cut-off stream power supply, do not need rectification, filtering, directly give the comparison amplifier input, therefore reference voltage does not need artificial adjustment, output signal strong interference immunity, the problem that no signal lags behind.Because working plate is inoperative at circuit, therefore do not need insulation.Cost of the present invention is low, stable performance.
Description of drawings
Fig. 1 is frame for movement of the present invention and schematic diagram of movements;
Fig. 2 is the circuit diagram of background technology 1 of the present invention;
Fig. 3 is the circuit diagram of background technology 2 of the present invention;
Fig. 4 is the circuit diagram of background technology 3 of the present invention;
Fig. 5 is the circuit diagram of background technology 4 of the present invention;
Fig. 6 is a circuit diagram of the present invention.
Among the figure, 1: high-frequency ac power; 2: high frequency transformer; 3: the main shaft ground wire; 4: main shaft; 5: the main shaft drill point; 6: the conducting metal body; 7: working plate.
The specific embodiment
Below in conjunction with accompanying drawing the present invention is further described.
Fig. 6 is circuit theory diagrams of the present invention.The prime oscillating circuit that resistance R 5, resistance R 6, resistance R 7, resistance R 8, resistance R 9, capacitor C 3, potentiometer VR1 and common voltage comparator A are constituted; The back level oscillator-amplification circuit that R10 and common voltage comparator B constitute; Through current-limiting resistance R11 and NPN type triode Q1, positive-negative-positive triode Q2, the power amplifier that current-limiting resistance R1, resistance R 2 and typical general operational amplifier C constitute.Adjust VR1, producing a frequency is 830KHZ, voltage amplitude is the high frequency voltage source of 20V, the general oscillator-amplification circuit of back level through R10 and common voltage comparator B formation, through resistance R 1, NPN type triode Q1, resistance R 2, positive-negative-positive triode Q2, high-frequency alternating current potential source 1 is carried on the main shaft ground wire 3 through the Y point.Under the normal condition, main shaft drill point 5 does not rupture, and main shaft drill point 5 contacts with conducting metal body 6.Capacitor C 1 through resistance R 4 dividing potential drops, has stored certain electric energy through resistance R 1, resistance R 3 chargings, and this moment, comparison amplifier 1 pin was output as high level signal.When main shaft drill point 5 contacts with conducting metal body 6, entire circuit will consume certain electric energy, because resistance R 1 metering function causes the DC voltage of the tripod of comparison amplifier C that a decline process will be arranged.When comparison amplifier 3 pin voltages begin to descend, and drop to when being lower than 2 pin voltages, comparison amplifier 1 pin will be exported a low voltage signal, up to capacitor C 1 process resistance R 4, resistance R 3 discharges, when comparison amplifier 2 pin voltages were lower than 3 pin voltages, 1 pin was just exported high level signal.
So as long as the tripod voltage of comparison amplifier C has certain variation, comparison amplifier 1 pin just can be exported a pulse signal fast timely.When 5 fractures of main shaft drill point, the tripod voltage that main shaft ground wire 3 is high-impedance state comparison amplifier C does not change, so the output of comparison amplifier 1 pin pulse-free signal.Analyze the output signal of comparison amplifier 1 pin, can analyze the position of broken needle.
Though the present invention is described with reference to current embodiment; but those skilled in the art will be appreciated that; above-mentioned embodiment only is used for illustrating the present invention; be not to be used for limiting protection scope of the present invention; any within the spirit and principles in the present invention scope; any modification of being done, equivalence invention, improvement etc. all should be included within the scope of the present invention.