CN201349196Y - Power tool and control module for same - Google Patents

Abstract

The utility model relates to a power tool and a control module for same; the control module controls the operation of a plurality of motors in different tools. The power tool is combined with a mechanical clutch in the tool; the control module utilizes an electronic clutch to protect the tool against the overload event. The control module adopts an implementation method that an acoustic and/or touch feedback is provided to the tool user as an alarm for a malfunction status which is to be happened or happens in the tool. The module can prevent the power source from being turned on by accident after a power source switch is opened when the tool is electrified and the overload event is eliminated or after the tool is electrified during the opening of the power source switch. The control module is suitable for providing torque control to the power tool, and evaluating the temperature of the tool motor, and informing the tool user of the required services in the tool.

Description

A kind of power tool and the control module that is used for this power tool

Technical field

The application's exemplary embodiment relates generally to control and the protection that the control module by the design that is used for controlling the motor operation provides, so that protection motor and the relevant electric tool of electric device as being powered by motor.

The application is according to the rights and interests of the claimed following U.S. Provisional Patent Application of 35U.S.C. § 119 (e): people such as Samuel G.WOODS submitted on October 12nd, 2005; sequence number is No.60/726011; exercise question is the application of " universal control module "; and people such as Samuel G.WOODS submitted on June 29th, 2006; sequence number is No.60/817085, and exercise question is the application of " being used for the control and the guard method of motor control module ".The full content of each provisional application at this in conjunction with reference.

Background technology

Typically, to given application, motor is by the special analog system or the Digital Circuit Control of control motor.For example, in application that is used for electric device such as power saw application, in order to control the given motor of its use, may need a special circuit, and in another power tool is used, in the rig application, in order to control the different motor of its use, may need another special circuit.Special analog system or digital control circuit are made of different elements usually.These elements often have different values, and tolerance limit, and/or Control Software are thought given motor and/or the given unique process characterization diagram of motor application establishment.

Novel content

The application's exemplary embodiment relates to the control and the guard method of motor control module, and wherein motor control module is controlled the operation of motor, and the instrument motor of rope power tool is for example arranged.In one embodiment, control module comprises an electric clutch, is used for the influence that the protection instrument is not subjected to overload event.The mechanical clutch of electric clutch in the module in can the employing instrument is not subjected to the influence of overload event with the protection instrument.Other guard method in the module comprises, as the alarm of imminent in instrument or current malfunction, provides the method for the sense of hearing and/or visual feedback to the user of instrument.This can implement by pulsation instrument motor or by the voltage (motor foldback) that foldback (foldback) offers the instrument motor.Pulsation and motor foldback can be carried out by the microprocessor in the control module, and the trigger triode in the control module control module (Triac) offers the voltage of instrument motor with change or conversion.

The another kind of guard method of control module be prevent power supply overload event be eliminated and the instrument that is accompanied by plugs in and power connection after, or during power connection, plug after the instrument power supply and inadvertently open.If the torque that detects reaches given set point, the other guard method in the module provides torque control for the power tool that uses the motor foldback.

In another example, the temperature that the control method in the control module can the assessment tool motor, the instrument motor temperature when comprising instrument start-up, or can the notification tool user when in the rope power tool is arranged, needing repairing demand.In further example, control module is configured to be controlled at a plurality of different motor in a plurality of different instruments.Control module comprises the difference protection that is configured to carry out a plurality of control tool motors or the microprocessor of control function; and comprise that at least one is used for storing the memory of the software code coefficient that is set in a large number, it is so that in the different protection that can or can not select in module or the control function one.This software code coefficient comprises a plurality of different selectable inputs, and it can be set to the input to the function of given selection, and comprises a plurality of different selectable outputs, and it can be set to the output from the function of given selection.

Description of drawings

Can understand exemplary embodiment more fully from the detailed description and the accompanying drawings given below, wherein components identical represents that with identical Reference numeral they only provide by way of example, therefore is not limited to the exemplary embodiment here.

Fig. 1 is the partial plan layout according to the power tool of exemplary embodiment, is used for control module in the specification tool shell;

Fig. 2 is the isometric view according to the selected element of instrument motor in the power tool of exemplary embodiment, is used for illustrating the relation between control module, Helmholtz coil circuit assembly, accessory plate and the speed runner;

Fig. 3 is the isometric view according to the control module of exemplary embodiment;

Fig. 4 is the block diagram of arranging according to the electronic component in the control module of exemplary embodiment;

Fig. 5 is the flow chart of function that is used to illustrate absolute clutch mode according to exemplary embodiment;

Fig. 6 is the flow chart of function that is used to illustrate the DI/DT clutch mode according to exemplary embodiment;

Fig. 7 is the flow chart that is used to illustrate the zero-pressure start-up routine according to exemplary embodiment;

Fig. 8 is the chart of explanation to power tool user's tactile feedback, and tactile feedback is as the alarm mechanism of imminent or current malfunction;

Fig. 9 is the chart of the electric moter voltage foldback in the explanation power tool;

Figure 10 A is the flow chart that is used to illustrate the motor temperature assessment algorithm according to exemplary embodiment;

Figure 10 B is that how evaluated explanation temperature register value B after power loss or when the initial tool power initiation be flow chart;

Figure 11 is at the little angle of the 120V that disposes exemplary control module sanding machine, relatively the chart of the motor-field temperature of motor evaluate temperature that is gone out by the algorithm computation of Figure 10 A and actual measurement;

Figure 12 is coefficient input, protection/control method and the equipment according to exemplary embodiment, and the overview of the relation between the coefficient output;

Figure 13 A is the front view of the part of the gear box among Fig. 1;

Figure 13 B is the cross-sectional view strength of the line A-A among Figure 13 A, is used for illustrating the details of mechanical clutch.

Embodiment

As what after this will describe in detail, exemplary embodiment relates to control and/or the guard method of being implemented by electronic circuit in the motor control module of electronic equipment.In an example, this electronic equipment may be the rope power tool with instrument motor, and wherein the instrument motor is by the AC power supplies power voltage supply of the accessory that is used to drive work piece or power tool.After this exemplary embodiment description control and guard method; it relates to and includes but not limited to: power tool starts; overload or event of failure; they surpass one or more voltages; speed, electric current, torque and/or temperature extremes; with alarm mechanism, it may warn imminent fault of tool-user and/or overload conditions.For content being provided for illustrative methods described later, the inventor at first provides the general introduction of the exemplary power device with control module, and the example block diagram of the electronic equipment of control module.

Fig. 1 is the partial plan layout according to the power tool of an exemplary embodiment, is used for illustrating the control module that is arranged in tool outer casing.Referring to Fig. 1, power tool 10 specifically be expressed as a rotation, rope power tool 10 is arranged, be appreciated that exemplary embodiment can be used for removing rotation, the power tool the power tool of restricting is arranged.In the example of Fig. 1, power tool 10 is represented as an angle sanding machine, and it is powered by the AC line power by power line 21.This angle sanding machine 10 comprises the annular knurl clamp nut 12 that is arranged in attached protector 14, is used to receive instrument, workpiece or accessory by the power supply of instrument motor.In this example, accessory may be the rotating parts such as the emery wheel (not shown).Emery wheel is attached on the gear box 16 by main shaft, and gear box 16 is fixed on the tool outer casing 18.

Gear box 16 also comprises mechanical clutch (for clarity sake not shown in Figure 1), is used for the inertia of elimination system under some detected malfunctions.In an example, this mechanical clutch may be embodied as a cone clutch that overlaps in the cone washer, and may comprise thrust washer.This mechanical clutch is configured to eliminate the inertia in the gear box 16.In an example, mechanical clutch starts when surpassing certain set point based on torque, as 100in-lb.For simplicity, omitted the detailed description of mechanical clutch operation.

Figure 13 A is the front view of the part of gear box 16, and Figure 13 B is the cross-sectional view strength of the line A-A among Figure 13 A, is used for illustrating the details of mechanical clutch.In Figure 13 A, show the front view of gear box 16, and, removed gear box cover for gear 1304 is described.In addition, on one side of gear box 16, provide spindle lock button 1302.1302 engagements of this spindle lock button are used to lock the lock spindle of the main shaft of power tool 10, to allow to replace or remove accessory thereon.

Referring to Figure 13 B, it is the A-A cross-sectional view strength among Figure 13 A, and shown main shaft 1308 passes gear box 16 by outside main shaft bearing 1320 and internal spindle bearing 1322 and stops to nut 1318.As known in prior art, main shaft bearing 1320,1322 makes main shaft 1308 radial motions.Mechanical clutch 1310 can be by cone clutch 1312, a pair of Beller spring 1314, and packing ring 1316 and nut 1318 are formed.Mechanical clutch 1310 activates under the situation of fault, and as stopping suddenly of instrument, it may be because the bound accessory of overload conditions etc. cause.Mechanical clutch 1310 is thus by giving gear 1304 load sheddings protection user, with eliminate or minimizing from the inertia of system.Figure 13 B also shows lock spindle 1306, and it may be engaged by pin 1305 by the actuating of spindle lock button 1302.In Figure 13 B, main shaft 1308 is represented as the position of non-locking.

Cone clutch 1312 is that two D cooperate (that is, locking), and has the side surface at band slight inclination angle.Though for the element of mechanical clutch 1310 is described, gear 1304 is not shown in Figure 13 B, gear 1304 is slidingly fitted on the main shaft 1308.When a load is applied in to main shaft 1308 (during for example at failure condition; as because overload conditions; the unexpected shutdown that bound accessory etc. cause), cone clutch 1312 biasings rely on packing ring 1316 and nut 1318 for Beller spring 1314 compression Beller springs 1314.This relative gear 1304 provides a power, so that gear 1306 load downs, in order to alleviate or to eliminate inertia from system.As the operation of the mechanical clutch that in prior art, becomes known for power tool, omitted further for simplicity and gone through.

Referring to Fig. 1, for universal control module 100 (' control module ') is described, show the tool outer casing 18 that the part shell is removed, wherein universal control module 100 (' control module ') has approximation relation with the magnetic axle collar 22 and the commutator ring 24 of armature 20.Control module 100 is designed to the application (for example different dynamic instrument) controlling the running of a plurality of motors and/or be configured for a plurality of different motors.

In addition, in Fig. 1, show the accessory plate 200 that supports Helmholtz coil circuit assembly 250 and speed variable rotor 270.As the part of the assembly that is connected to the control module 100 in the power tool 10, accessory plate 200 may be included in the tool outer casing 18.An effect of accessory plate 200 is that it allows according to the indication customization Helmholtz coil circuit of power tool design requirement and the structure of speed variable rotor.Helmholtz coil circuit assembly 250 can be connected on the accessory plate 200 and be configured to detect motor speed.Speed variable rotor 270 can be by user's operation to set and/or to change the motor speed of expectation.

Fig. 2 is according to the isometric view of the selected element of instrument motor in the power tool of an exemplary embodiment, is used for illustrating control module, Helmholtz coil circuit assembly, the relation between accessory plate and the speed dial.Fig. 2 has illustrated accessory plate 200 and its parts (Helmholtz coil circuit assembly 250 and speed runner 270), the relation between control module 100 and the instrument motor 15, and instrument motor 15 may be made up of the instrument armature 20 of rotation in instrument motor-field 30.In an example, accessory plate 200, Helmholtz coil circuit assembly 250 and runner 270 may be called " auxiliary circuit board component " jointly.The auxiliary circuit board component is connected to the control module 100 of Fig. 1, for example, is suitable for the control module 100 of the operation of control tool motor.

Instrument armature 20 comprises the magnetic axle collar 22, can be connected to the commutator ring 24 of armature 20 by armature shaft 29.The output of armature 20 is sent to gear box 16 by ball bearing 27 and main shaft 28.Can provide a plurality of magnet on the magnetic axle collar 22 of armature 20.Along with the rotation of armature 20, obtain to coil block 250 from the magnetic magnetic field of magnet is tested, to provide the pin-point reading of motor speed.As discussed above, complete instrument motor 15 is included in the instrument armature 20 that rotates in the instrument motor-field 30.

Accessory plate 200 also may comprise speed variable rotor 270, and as known in prior art, it is as potentiometer.In an example, the part of runner 270 may comprise a plurality of rigidity ratchets, and they are positioned at the tip of leaf spring, to provide audio feedback to the user.In an example, ratchet contact leaf spring is to provide tactile feedback to the user.This is used for also preventing that runner 270 from moving in any instrument vibration processes.In addition, the use of ratchet can prevent that the user from inadvertently changing speed, and the tactile feedback that can distinguish easily is provided to the user.

Fig. 3 is the isometric view according to the control module 100 of an exemplary embodiment.Referring to Fig. 3, control template 100 comprises top cover 110, bottom 120, locating rack 130 and printed circuit board (PCB) 140 (not shown among Fig. 3).In an example, for example, top cover 110 can be by making for the active power element in the control module 100 provides the material of heat radiation, and may cast for this function.Bottom 120 can be configured to support and control module 100 inner members, and allows perfusion, to set up the shell of sealing.In addition, bottom 120 provides the electric insulation zone for the active power equipment in the control module 100.

Locating rack 130 can be configured to the through hole electronic component fix in position in the control module 100, for example in the assembling process of control module 100.Control module 100 also can comprise securing member 115 (as screw), and it is fixed to nut (not shown) in the module 100 with top cover 110.Securing member 115 can be fixed to the active power equipment in the control module 100, as switch, and trigger triode, electron tube etc.Therefore, top and bottom head covers 110,120 can be passed through single fastener 115, are fixed together as the screw and nut assembly.

Control module 100 also comprises the power connection 150 of a pair of quick connection and is connected to the I/O connector 160 of printed circuit board (PCB) 140.It is sequential fast connecting 150 pairs of control modules 100 of power connection, and for example can be different sizes and different length, is connected to improperly on other element preventing.In an example, I/O connector 160 can be configured to the 12-pin device, wherein four (4) pin ones 62 are empty and are not used (for the space is provided), five (5) pin ones 62 can be the I/O pins, (a 1) pin one 62 can be the hot line pin, and (a 1) pin one 62 can be circuit ground/neutral pin.This is a kind of terminals pin arrangement of I/O connector 160; According to the exemplary embodiment here, other is arranged skilled skilled worker is foreseeable.

As discussed above, locating rack 130 control module between 100 erecting stages with through hole electronic component fix in position.During manufacture, a plurality of electronic components are connected to PCB 140.A function of locating rack 130 be in the process of fluctuation welding holding element in position, to eliminate clamping device.Thereby between erecting stage, it is top so that tolerance to be provided that locating rack 130 can be placed on power connection 150, and also provide electric insulation in the tolerance that keeps between these elements.

Locating rack 130 comprises guard shield part 136, and it fits snugly on the fin 122 of bottom 120, with the sealing and the I/O connector 160 of packing into.The guard shield part 136 of locating rack 130 can be designed to prevent to enter the fragment and the dust of scraping of the meritorious element of control module 100.

In fixed mount 130, can provide supplementary insulation by the perfusion (not shown).Meritorious element in retentive control module 100 in position, pouring material can have the flammability rating of V0.Suitable pouring material includes but not limited to one or more epoxy radicals sealants, the urethanes or the urethanes gel sealant of single or multiple composition, single or multicomponent silicon or silica gel sealant etc.

Therefore, for example, the use perfusion with respect to non-isolated controlling module, is distinguished out the control module 100 with a separator as insulator.In addition, meritorious electronic component that can be in module 100, for example FET or trigger triode, end face on apply hot grease; This is standard in industry.Can select to provide the heating pad (not shown) to replace hot grease in the example.Hot grease or heating pad are used to prevent to be poured in seepage between given meritorious electronic component and the top cover 110, and, for example can arrange its size according to the height function of meritorious element.

Fig. 4 is the block diagram that the electronic component in the control module 100 is arranged.After this electronic component of Miao Shuing can be disposed on the PCB 140 in the control module 100.Control module 100 comprises memory 434,436, is used for storing one or morely carrying out the software code function coefficients that different functions or algorithm use.Because a given software code function coefficients can be assigned to a specific tool applications, so control module 100 can be suitable for controlling the operation of a plurality of motors and/or a plurality of different motor application (that is different dynamic instrument).The software code coefficient can be understood to include and input to the given function carried out by control module 100 or the coefficient input of algorithm, and comprises the function coefficients that may be changed or change given instrument or tool applications.The software code coefficient also comprises the relevant coefficient output of protection action that will carry out with control module 100, and wherein the protection action is the result that control module 100 is carried out given function and algorithm.To given application, export and to change or combination with expectation to the coefficient input of given function or from the coefficient of given function.More detailed description is arranged in Figure 12 below these.

Control module 100 can be connected to AC power supplies (AC power network) and armature 20 and instrument motor-field 30.In an example, instrument armature 20 and instrument motor-field 30 can comprise AC motor 15.Control module 100 comprises control circuit, usually by element 400 expressions.In an example, control circuit 400 is determined the state of motor control switch 402, and when AC power supplies is provided, if power supply offers armature 20 and motor-field 30 based on the state of motor control switch 402, control circuit 400 is controlled control modules 100.

Control circuit 400 comprises power supply 405, and it provides electric energy to the microcontroller 430 that is programmed, to control certain operation and/or to instruct certain function or protection in the module 100 to move.Power supply 405 for example may provide the VCC of 5V.Supply voltage watch-dog 415 monitoring VCC, and induction is provided input to microcontroller 430.

Microcontroller 430 can be by providing control signal to trigger triode 420 through control incoming line 418, with control electron tube 420.In an example, this may be a trigger triode, although electron tube can be by field-effect transistor (FET), and insulated gate bipolar transistor (IGBT), silicon controlled rectifier (SCR), any in the voltage control apparatus etc. embodies.Usually, control module 100, through the control signal of microcontroller 430 with the control input 418 that offers electron tube 420, by opening and turn-off the operation that current of electric is controlled motor 15 with all period interval, wherein all period interval are with respect to the zero crossing of AC curtage waveform.These all period interval and AC synchronous waveform produce, and measured according to the angle of flow, and wherein the angle of flow is measured with the number of degrees.

The point that electron tube 420 is excited in the angle of flow decision AC waveform, thus electric energy transmitted to motor 15.For example, the corresponding fully conducting state of the angle of flow that every half period is 180 °, wherein electron tube 420 is excited, so that alternating current complete, that do not have to interrupt is provided for motor 15, that is, electron tube 420 is excited, and electric current all flows through electron tube 420 in the whole half period of AC input signal like this.Similarly, 90 ° the angle of flow corresponding on motor 15, form supply voltage occur in the centre of given half period, like this, electron tube 420 is excited, so that only about half of obtainable energy is sent to motor.The angle of flow below 90 ° corresponding to electron tube 420 excite after the given half period, so that the energy of less amount is sent to motor 15.

After this, electron tube 420 is meant trigger triode 420, unless below other description is arranged.In an example, trigger triode 420 may be single insulation trigger triode, and wherein insulation is the inside at element.More specifically, forming the armature 20 of motor 15 and the operation of motor-field 30 is to be controlled by the control circuit in the control module 100 400.In order to control the operation of armature 20 and motor-field 30, microcontroller 430, by the electronic of trigger triode 420, control flows cross the electric current of armature 20 and motor-field 30 or be applied to armature 20 and motor excitation 30 on voltage, or both control.Based on being stored in the software code coefficient in tabling look-up or can determining when open or close trigger triode 420 from governing equation control circuit 400, wherein governing equation is based on factor that records or parameter, as voltage, speed, electric current, torque, other outside input (456,458 etc.), or any combination of above-mentioned parameter.When motor control switch 402 is changed to closure state (that is, " opening "), the operation of control module 100 control motors 15, thus allow electric current to flow through.A state that function is a monitoring motor control switch 402 of control circuit 400, and at motor control switch 402 when halted state (that is, " opening "), if power supply is applied to motor 15, stop motor 15 to start.

Microcontroller 430 can comprise program ROM 436 (changeable ROM), flash memories for example, and such as the CPU core of microprocessor 432, veneer ancillary equipment and the nonvolatile memory on single chip architecture such as RAM434 or SRAM.When being adapted at even without power supply, preserves by nonvolatile memory canned data.The example of nonvolatile memory comprise RAM (DRAM, SRAM, SDRAM, VRAM, etc.), magnetic and light base memory.The type of changeable solid-state ROM may comprise EPROM (Erasable Programmable Read Only Memory) (EPROM) and EEPROM (Electrically Erasable Programmable Read Only Memo) (EEPROM).EPROM can be wiped free of by being exposed in the ultraviolet light, can rewrite by the EPROM functional generator then, and the circle " window " that can enter by the permission UV light at top is confirmed.EPROM such as flash memory allows whole ROM (or selected storage array of ROM) to be wiped (flash memory returns zero) by electricity, rewrites under the situation of memory bank not being taken out the computer equipment outside then.

In an example, microcontroller 430 may be ATMEL A kind of in the digit RISC micro controller, as have the Atmega8 flash memory microcontroller of 8-K byte from the flash memory program storage (EEPROM) of programming.Yet the Based Intelligent Control of module 100 is not limited to exemplary microcontroller 430.Intelligent control device for example, can be embodied in as another microprocessor, analog circuit, and the hardware of digital signal processor and/or software, or by one or more digital ICs realizations such as application-specific IC (ASICs).

Control circuit 400 with instrument motor 15 (armature 20 and motor-field 30) is between the live wire of power supply and center line (public) and motor control switch 402, and trigger triode 420 and shunt resistor 440 are connected in series.In Fig. 4, a side of instrument motor 15 is connected to power supply through power line 21 (Fig. 1) by motor control switch 402, as is connected to the live wire of AC power network 407.The opposite side of instrument motor 15 is by trigger triode 420, and shunt resistor 440 and power line 21 are connected to the center line 408 of AC power network 407.

Shunt resistor (shunt resistor) 440 can be embodied as an analog current transducer, and its induced current also provides one to be exaggerated device 445 amplifying signals.Amplifier 445 has the first input end that is connected to shunt resistor 440 1 sides and is connected to second input of shunt resistor 440 opposite sides.The output of amplifier 445 is connected to the given port of microcontroller 430.Shunt 440 is an example of current sensor just, and selectable current sensor for example comprises current transformer, digital sensor, Hall effect transducer etc.

Microcontroller 430 comprises analog to digital converter (ADC), and it is a numeral from the analog signal conversion that different sensors receives, and handles for microprocessor 432.For clear, at ADC shown in the microcontroller 430, it is not understood that, from amplifier 445, monitor 415,425,427, power supply 405, the analog input of temperature sensor 410 and any analog digital input data that receive from additional control input/output line 456,458, all in ADC, be converted into numeral, handle for microprocessor 432.

Control circuit 400 further comprises bleeder circuit 450, and it has resistor 451,452,454 and the clamp diode 455 and 457 that utilized by microcontroller 430, and with one or more zero crossings of induction AC voltage.Voltage over zero can be defined as intersecting when AC voltage signal and zero axle, and from just to negative or negative point when positive voltage is changed.This point is used to the purpose of timing in microcontroller 430.Bleeder circuit 450 is connected to microcontroller 430 at given port (for clarity sake not shown) by circuitry lines 460.Resistor 451,452 and 454 is AC power supplies voltage dividing potential drop can be by the electric pressure of microcontroller 430 uses.If in the AC power supplies voltage voltage spike takes place, clamp diode 455 and 457 protection microcontrollers 430 are without prejudice.In an example, all or part of bleeder circuit 450 may be included in the control circuit 400 or in the microcontroller 430.In an example, microcontroller 430 may comprise inner clamp diode 455 and 457.

Control circuit 400 can comprise one or more temperature sensors 410, but it is designed to temperature sensor and imports the signal of induction to microcontroller 430 by a port.For example, temperature sensor 410 can be embodied as NTC or PTC thermistor, temperature-sensitive IC, or thermocouple.Temperature sensor 410 can be passed on the temperature of control module 100, the perhaps temperature of a particular element, and as trigger triode 420 or microcontroller 430, this temperature can be used to determine certain overload situations/malfunction.Because the function of this temperature sensor 410 is known, for simplicity, has omitted the detailed explanation of its functional operation.Can in module 100, place a plurality of temperature sensors 410 if desired.

In addition, control circuit 400 comprises two voltage monitors, is used to monitor the voltage of trigger triode 420, a gate voltage watch-dog 425, and it is used to determine in negative voltage half-cycle whether conducting of trigger triode 420; And a positive half period voltage monitor 427, it is used to determine in positive voltage whether conducting of trigger triode 420 in the half period.Because controller 430 can only detect positive voltage, so two watch-dogs 425,427 all are essential.During the negative half-wave in AC cycle, will there be the monitored device 427 of voltage to detect.

Control circuit 400 can comprise one or more I/O of communicating by letter with the user (I/O) line 456,458.These I/ O lines 456 and 458 can numeral or analog input or numeral output, and can be connected to such as partial pressure gauge switch, the user interface of LED ' s or other form (as speed dial, instrument trigger, on-off switch, Deng) equipment, to increase some variations to system.

Usually; control circuit 400 in Fig. 4 illustrated is designed to instrument Electric Machine Control and/or protection can be provided; these controls and protection relate to power tool and start; one or more of overload or failure condition; be meant voltage in these situations; speed, the one or more values of overstepping the extreme limit in electric current and torque and/or the temperature.The method that control circuit 400 is designed to implement control method or alarm mechanism is provided, wherein alarm mechanism warning imminent fault of tool-user and/or overload conditions.Thereby,, will go through the method example of realizing by control circuit 400 below because described the ordinary construction and the electronic circuit of control module 100 in detail.

Overload control

In an example, the control circuit 400 of control module 100 can use an electric clutch based on software (EOC), under the control of the microprocessor 432 in microcontroller 430, independently and/or with instrument in mechanical clutch in tandem, motor overload control is provided.For example, mechanical clutch can be embodied as the mechanical clutch 1310 shown in Figure 13 B.After this, mechanical clutch is called as " MC ".

In an example, the enforcement of the EOC function of pulling together with microcontroller 430, perhaps the closing tool motor 15, and the voltage that perhaps reduces motor is to underspeed and torque value.Further,, can use a more cheap MC, and still have the long relatively life-span by being used in combination EOC in the control module 100 and the MC in the gear box 16.For example, along with the use of EOC/MC combination, the cycle of operation can be increased to life cycle and surpass for 2000 cycles from 200 cycles.This is an example, and the use of EOC/MC combination can improve 25% to the life cycle of MC at least.To more go through the EOC function that detects overload/failure condition below, based on this, microcontroller 430 is by forbidding the electric energy of trigger triode 420 removing tools 10, perhaps controls trigger triode 420 in the mode of the electric energy of minimizing instrument 10.

Although lose electric energy under the situation that instrument is stopped work, still there is inertia in system.This inertia may cause armature 20 and any additional accessory thereof to continue rotation.This may cause the damage of accessory (as emery wheel) and gear and other inner member.After power supply is completely severed, use MC and EOC to pull together, the remaining inertia in the elimination system (as instrument 10), wherein cutting off fully of power supply is the triggering of forbidding trigger triode 420 by microcontroller 430.The effect of the cycle life that increases clutch and/or accessory is played in this combination of remaining inertia in EOC cut-out current of electric and the MC elimination system.

EOC can be in the inside of control module 100, and as above to discuss can be software program or the routine that is stored among memory such as the variable ROM436.For example, on the basis of hemistich circulation or full row circulation, the algorithm of being implemented by microcontroller 430 is the given parameter of monitoring tools continuously, as electric current, and motor speed, voltage, motor temperature etc.In an example, the parameter of being monitored is an electric current; Like this, the increase electric current along with load increases.Therefore, the half period position of microprocessor 432 sampling AC current waveforms, and the data digitalization of will sampling, to calculate given current value, as transient current, average current and/or root mean square (RMS) electric current.In another example, the algorithm of implementing by microcontroller 430 motor speed of monitoring tools motor continuously.

In one example, EOC can be embodied as absolute clutch mode, it is provided with the limiting value (or the motor speed limiting value when monitoring motor speed) as average current, RMS electric current or maximum instantaneous current value, if calculate or detect current value (as: transient current, average current or RMS electric current) value of reaching capacity, then the EOC function detects fault or overload situations.In another example, can be set in the given duration by microprocessor 432, as the limiting value of X in the cycle, to avoid instantaneous or false protective effect.

According to this detection; the protective effect that microcontroller 430 starts based on output factor, output factor has been stored in the nonvolatile memory, in an example; in Fig. 4, nonvolatile memory can be embodied as EEPROM or flash memories (as the example of ROM436).For example, if one is stored among the ROM436, being used for the specific software code coefficient of the EOC effect of absolute clutch mode, is the output of disable motor 15, violates limiting value and will cause microcontroller 430 disable motors 15.Therefore, instrument 10 may place " shut " mode" by ripple, and wherein microcontroller 430 no longer allows trigger triode 420 conductings.This realizes that by opening trigger triode 420 by the control signal electronics wherein control signal is to send to trigger triode 420 from microcontroller 430 by control incoming line 418.This makes trigger triode 420 disconnect; Before power supply is offered system again, do not allow electric current to pass through armature 20.

Selectively; if different software code coefficients is stored among the ROM436; it changes the protection action that takes place in absolute clutch mode; violate limiting value and may cause microcontroller 430 control trigger triodes 420; so that instrument motor 15 is subjected to impulse action; this will warn a kind of malfunction of user, perhaps send to the output voltage of instrument motor 15 by minimizing, may be returned to the energy of instrument 10.

In another embodiment, such as stopping, the protection function of pulse modulation or foldback can be based on by EOC, i.e. DI/DT clutch (Δ i/ Δ t) detected variation in electric current in time.In this example, detect in time current value (as average current, peak current, or RMS electric current) variation, if the variation of electric current (Δ i) surpasses given limit or limiting value, above-mentioned action (stops, pulse modulation, foldback) a kind of may being activated in.Therefore, the EOC that uses in the DI/DT pattern can be by the microprocessor algorithm in 432 an iteration N cycle, N=1 wherein, and 2,3 etc..In another example, can be set in given time period such as the limiting value of X in the cycle, to avoid instantaneous or wrong protection action by microprocessor 432.

Therefore; in absolute extremes binarization mode or DI/DT limiting value pattern a kind of; the use of EOC can provide based on the overload control that surpasses the prescribed limit value, and in wherein several protections actions one can be based on being taken place by EOC function or the detected malfunction of algorithm.Microprocessor 432 is fetched certain software code coefficient from memory (for example ROM436), and carries out specific protection action based on this software code coefficient of fetching.The software code coefficient of the protection action that sensing will be carried out is called as coefficient output.

The protection action that the coefficient output of selecting indicates to carry out.For example, ROM436 can comprise that expression microcontroller 430 starts the coefficient output of following action: (i) tactile feedback, wherein make motor 15 be subjected to impulse action, so that the alarm of the malfunction in the power tool 10 to be provided to the user by microcontroller 430 loop control trigger triodes 420; Perhaps (ii) foldback, wherein microcontroller 430 reduces the angle of flow of trigger triode 420 to reduce to the power of motor 15; Perhaps (iii) motor stops, and wherein because microcontroller 430 electronics are opened trigger triode 420, trigger triode 420 is forbidden fully; Perhaps (iv) active electron brake, wherein electronic brake is algorithm or the software program of being implemented by microcontroller 430; And/or (i) combination in (iv) (v), (makes the warning LED of tool outer casing outside luminous, with a kind of imminent or existing malfunction of warning user v).For example, these are according to the example by the contingent protection action of the detected overload event of EOC.

Because EOC is based on the mechanical part that do not have of software, thereby has reduced cost and eliminated wearing part.The EOC that uses together with mechanical clutch has been described; Yet, it may with use with the similar electronic brake of mechanical clutch.EOC can to speed or electric current over time or the abswolute level that reaches of speed or electric current react.For example, increasing 8A in 32 milliseconds (2 linear periods during 60Hz) can cause EOC to start.Perhaps, motor speed drops to 6k rpm from 8k rpm and can cause electric clutch to start in 16 milliseconds (1 linear period during 60Hz).The abswolute level of electric current (35A) or speed (4000rpm) (speed is not 10000rpm when having load) can cause electric clutch to start.

The lower speed and the working condition of torque value are similar to mechanical clutch.EOC can be used in combination with mechanical clutch or electronic brake.

Fig. 5 is the flow chart that is used to illustrate according to the function of the absolute clutch mode of an exemplary embodiment.Fig. 5 has illustrated the function of EOC in absolute clutch mode, and it may or can not be used in the control module 100 with mechanical clutch (MC) or electronic brake.

With reference to figure 5, in absolute clutch mode (500), microprocessor 432 receives the parameter (induced current sampled value in this example) (510) of induction from current sensor 440 by amplifier 445.Therefore, in absolute clutch mode, the EOC function is by the formal description with sample rate current; This is because in ROM436 (that is, EEPROM, flash memories), for electric current is provided with the input of software code coefficient (coefficient input) as EOC function in the absolute clutch mode.Certainly, the different parameter that can be configured to sample of the EOC function in the absolute clutch mode, its will with except based on a different limiting value the limiting value of electric current (that is, and voltage, motor speed, motor temperature, etc.) comparison.Like this, the coefficient input that is stored among the ROM436 (that is, the EEPROM/Flash memory) can directed other parameter, as replacing electric current to be input to the EOC function parameters, and as speed, temperature, voltage, or other sensed parameter.

In the present embodiment, these current sampling datas can be the sampled values of AC voltage waveform (that is, on the linear period basis) half period position or whole linear period position, it is digitized, to calculate given current value, as instantaneous peak current, average current and/or root mean square (RMS) electric current.The current value of this calculating is compared with limiting value (520), and as discussed above, limiting value (520) may be based on average current, the limiting value of RMS electric current or maximum current.If the current value that calculates (as, transient current, average current or RMS electric current) surpass this limiting value, (520 are output as ' being '), this algorithm increases timer conter (530) counting; Otherwise timer counter is cleared (540).The increase of timer counter provides a time-delay, to avoid the error protection action of 430 pairs of transient behaviours of microcontroller.

Then timer counter is compared with timing coefficient (550).If timer counter equals or exceeds regularly coefficient (550 are output as ' being '); This is illustrated in the absolute clutch mode and detects malfunction by EOC.

As shown in Figure 5, according to the detection (be based on 550 here and be output as the overload event that is) of malfunction, control module 100 starts the protection action.In this example, microcontroller 430 is by 418 (Fig. 4) transmit control signal through the control output end, and electronics is opened trigger triode 420, makes trigger triode 420 can not start (560), and so closing tool motor 15.

Yet; the different coefficient outputs that are used for the EOC function can be set up at ROM436; to be regained by microprocessor 432; make microcontroller 430 produce different protection actions, that is, for example; use the phase control system of control circuit 400 to call tactile feedback or motor foldback; perhaps light the LED on the tool outer casing simply, indicating overload, rather than open trigger triode 420 to remove voltage (and electric current) from instrument motor 15 to the user.Purpose for explaining in Fig. 5, the coefficient output that is used for EOC function (absolute clutch mode) is set to by forbidding trigger triode 420 disable motors.

In absolute clutch mode, this algorithm judges that no-voltage activates feature whether be activated (570).As will be described in detail below, provide no-voltage to activate the partial function of feature as control module 100, wherein control module 100 is devoted to prevent that additional electrical device of air (as power tool) from starting in the following cases: (a) extract from the AC power supplies socket based on the insertion and the cord of mains switch cord of power tool when " opening " position; Perhaps (b) mains switch is " opening ", and instrument is inserted into and powers, but instrument has reached the overload conditions that causes cutting out (when still inserting), and overload event be eliminated and mains switch still in " opening " position.

The for example trigger triode 420 in the control module 100 of electron tube is guaranteed in the enforcement that no-voltage activates the protection feature, at above-mentioned (a) or under a kind of situation (b), can not start.Thereby, as following will be in greater detail along with the activation of no-voltage feature, microprocessor 432 will start no-voltage active program 700.Otherwise along with the forbidding (560 are output as ' denying ') that no-voltage activates, this algorithm is in 580 disable interrupts and enter Infinite Cyclic.This prevents that trigger triode 420 from starting, and for example, this algorithm moves same instruction repeatedly.

When absolute clutch fault, if software coefficient output is set to close power machine 15, the action that then moves no-voltage active program 700 or enter wireless circulation (580).As previously mentioned, the software code coefficient comprises the relevant coefficient output of being implemented with control module 100 of protection action, and its protection action is the result who is obtained by the given function exclusive disjunction that control module 100 is carried out.Be input to the coefficient input of given function and application-specific, can make amendment or combination according to expectation from the coefficient output of given function output.Therefore, if be provided with other coefficient outputs that some do not need motor to turn-off, as: braking, visual feedback, another independent action can take place in LED etc.

If the timer counter from 530 is less than timing coefficient (550 are output as ' denying '), absolute clutch mode normally proceed monitor current sampling (590) at next linear period or half linear period repeatedly, and this algorithm turns back to 510.

Fig. 6 is the flow chart that is used to illustrate according to the function of the DI/DT clutch mode of an exemplary embodiment.Fig. 6 has illustrated the function of EOC in the DI/DT clutch mode, and it may or can not be used in the control module 100 with mechanical clutch (MC) or electronic brake.With reference to figure 6, in DI/DT clutch mode (600), microprocessor 432 receives the parameter of induction.In this particular instance, parameter is the current sampling data (610) that obtains from current sensor 440 through amplifier 445, is appreciated that this sampling parameter can be the motor speed of two branches instrument motor during other time in the motor.For example, these can be the sampled values of AC voltage waveform (that is, on the linear period basis) half period position or whole linear period position, and it is digitized, to calculate given current value, and as instantaneous peak current, average current and/or root mean square (RMS) electric current.

This algorithm is carried out a difference function (620), to calculate a difference value.In this example, deduct the calculating current value (electric current (X)) of current linear period from the calculating current value (electric current (X-1)) of previous linear period.The limiting value of this difference value and setting is compared (625), and as discussed above, this limiting value can be based on average current, the limiting value of RMS electric current or maximum current.If this difference value surpasses this limiting value (that is, 625 are output as ' being '), this algorithm judges that no-voltage activates feature whether be activated (630).Function 635,640 and 700 can be as shown in Figure 5 be implemented, therefore omitted detailed explanation for succinct purpose.

Though in the example of Fig. 6, used electric current, clearly also can use other parameter, as motor speed with based on the limiting value of motor speed, whether detect malfunction, to start the protection action with decision.Therefore, in another example, can judge a difference of the motor speed of two different times.

If this difference is less than or equal to limiting value (that is, 625 are output as ' denying '), the difference of this algorithm comparison and the limiting value of being removed by a factor (650), it is limiting value/2 in the example of Fig. 6.If this difference value of overstepping the extreme limit (that is, 650 are output as ' being '), cycle rate counter increases counting (655) by microprocessor 432; Otherwise cycle rate counter is cleared (660).In an example, if this difference N at least the continuous linear period value of overstepping the extreme limit/2, wherein N 〉=2 just detect the malfunction such as overload event.

The counting increase of cycle rate counter provides a time-delay, to avoid the error protection action of 430 pairs of transient behaviours of microcontroller.By function 655; algorithm determination cycles counting shown in the example of Fig. 6 is to be equal to or greater than 3 (665); indication from 650 difference at 4 continuous linear periods greater than limiting value; be appreciated that this is an example; this numeral can be set to 2,3,4 as required; N is used for the protection action of motor overload with triggering.In other words, three continuous differences greater than limiting value/2 will continue 4 linear periods.In this case, as mentioned above, by function 630,635,645 and 700 decision no- voltages activate.Function 660 and 665 output make microprocessor 430 turn back to normal running 670, and the DI/DT clutch mode is proceeded the monitor current sampling at next linear period or half linear period there.

In a plurality of linear periods are compared this difference with the limiting value of being removed by a factor purpose, be for its generation of aid forecasting before taking place in overload event.For example, if between two continuous linear periods, the limiting value of this difference is set to average 30 amperes, and then between the continuous cycle, the average current of measurement also will compare with 15 amperes (30/2).If this recurs repeatedly, even electric current does not surpass 30 amperes, this still is considered to overload event.

The use of EOC/MC combination may have certain benefit.For example, in a cutting was used, if a slice on the cutting wheel is broken, EOC is disable motor 15 (that is, armature 20 and motor-field 30) immediately.In the near future, behind the EOC powered-down, mechanical clutch will dally, and remove any residue inertia.For example, this can prevent that instrument 10 from damaging or prevent that gear from fractureing or break.

No-voltage activates

Fig. 7 is the flow chart of explanation according to the no-voltage active program of an exemplary embodiment.As mentioned above, the part of no-voltage active program as the function of control module 100 may be provided, start in the following cases such as the additional electrical device of air of power tool preventing: (a) extract from the AC power supplies socket based on the insertion and the cord of mains switch cord (cord) 21 of power tool 10 when " opening " position; Perhaps (b) mains switch is " opening ", and instrument 10 is inserted into and powers, but instrument 10 has reached the overload conditions that causes cutting out (when still inserting), and at mains switch during still in " opening " position, overload event is eliminated.The enforcement that no-voltage activates defence program can prevent for example trigger triode 420 in the control module 100 of electron tube, starts at above-mentioned (a) or under a kind of situation (b).

In an example, can carry out a succession of continuous voltage detecting, after receiving power supply, on trigger triode 420, seek voltage immediately in control module 100 at 90 ° of phase place places of each linear period at the AC waveform.If tool switch 402 is closed when power supply is provided, microcontroller 430 will detect the existence of voltage on trigger triode 420.If tool switch 402 is opened when power supply is provided, microcontroller 430 will detect less than any voltage on trigger triode 420.If the indication of AC voltage is arranged in these detect, trigger triode 420 will can not start, and up to no-voltage indication is arranged in given linear period, that is, the user had been recycled to mains switch " pass " before restarting power tool 10.Since electric peak value, surge, carrier suppressed etc. need a plurality of continuous detection to come random noises all in the elimination system, wherein electric peak value, and surge, carrier suppressed etc. may cause of short duration voltage cycle on trigger triode 420.

In the example of Fig. 5, the microprocessor 432 of microcontroller 430 is feedback current and the limiting value (520) that is used for EOC relatively in the above.If EOC is configured to the absolute extremes value and the feedback current value above this limiting value two kinds of actions may take place.No-voltage protection in system is not activated and (forbids/stop; 560 are output as ' denying ') situation under; interruption (580) in algorithm (under microprocessor 432 controls) the forbidding Infinite Cyclic; preventing that trigger triode 420 from starting, and in this circulation to close power tool 10 effectively.Thereby all power supplys to instrument motor 15 all have been stopped.

If the no-voltage active program is activated in control module 100 (570 are output as ' being '), when no-voltage active program 700 repeatedly, microprocessor 432 inquiry switches 402 be open or close.In this example, the no-voltage Activiation method does not have disable interrupts, but is based on the no-voltage method of Fig. 7, the startup of trigger triode 420 disabled (560).

In the example of Fig. 6, microprocessor 432 is measured electric current in time, and the current value of front cycle and current period is stored among the RAM434.In an example, by microprocessor 432 algorithm computation DI/DT value repeatedly, as the variation (DI/DT=I in the transient current that is removed by cycle time ₂-I ₁/ Δ T).This DI/DT value or difference, it may be called as variable Y, and possible quilt and limiting value are relatively.If Y is greater than limiting value (625 are output as ' being '), the protection sequence of movement (630,635,640/700) identical with the absolute extremes value scheme of Fig. 5 may be activated by microprocessor 432; In addition, Y may compare with a factor of limiting value, for example by 2 limiting values of removing (650).

If Y is greater than by 2 limiting values of removing, then a counter may be added to 3 or 4 times (655,665), to determine not having wrong incident to take place.On the other hand, if Y less than by 2 limiting values of removing, then counter is cleared (660).Just in case counter reaches 3 or 4, the protection (630,635,640/700) identical with above-mentioned absolute extremes value scheme set up and be performed to counter.For example, if counter equals 3, the data in 4 continuous lines sexual cycles of this expression the value of overstepping the extreme limit by 2 limiting values of removing that reduce.

With reference now to Fig. 7,, above-mentioned situation (a) or (b) in one trigger to start (705), wherein algorithm detects (710) AC voltage waveform whether in the negative zero crosspoint (that is, voltage half cycle just by zero crossings to negative half-cycle).When the algorithm waits zero cross point, this is a synchronizing step to algorithm, and algorithm will circulate up to detecting the negative zero crosspoint.In case detect positive zero cross point, the microprocessor 432 of microcontroller 430 can begin the state (715) of sense switch 402.This to positive half period synchronously only only can be just necessary during induced voltage in that at controller 430 specific half period.Yet, using another voltage monitoring circuit 425, may when negative half-cycle, sample.

In case two zero cross points all are detected (715 are output as ' being '), the value of test point is set to phase point 1 (720).Phase point 1 may be 130 ° of angles of flow at trigger triode 420, or based on a preset time (100 milliseconds).Function 725 is cyclic processes, is determined up to it and arrives test point, and based on this, the voltage on the trigger triode 420 detected (730).In this example, use the sampled voltage on the trigger triode 402, be appreciated that an example of the parameter that this just can be detected; The electric current that flows through trigger triode 420 can be the sampling parameter that replaces voltage.If detect some positive voltages, just suppose that switch 402 cuts out 730.This program turns back to function 710 then, and repeats not allow trigger triode 420 conductings, in addition, does not detect voltage on trigger triode 420.

This situation (730 are output as ' denying '), whether N continuous lines sexual cycle (N 〉=2) of giving determined number of this algorithm queries voltage waveform be detected.In the particular instance of Fig. 7, whether three continuous lines sexual cycles of this algorithm queries voltage waveform detected (735).If, just determine the voltage whether high (740) on the trigger triode, and if high, this algorithm inserts a time-delay 745, closes to wait for switch 402 (its also may be called as trigger or the ON/OFF switch).If after the stand-by period, the voltage on the trigger triode 420 still high (750 are output as ' being '), switch 402 are closed and are stopped no-voltage active program 700 780; Power tool 10 can be opened to run well.Therefore function 740,745 and 750 is in a kind of like this situation, and wherein owing to some overload conditions, instrument 10 has stopped, and switch 402 still is ON.

On the other hand, if do not detect three continuous linear periods of AC voltage waveform, whether all this algorithm queries (755) test point all detected.This program can have a plurality of test points at each linear period.The test point that detects is many more, and system is just immune more to random noise.For example, if 130, the angles of flow of 70 and 30 degree have three independent test points, and these three o'clock detected at three continuous linear periods, this program guarantees that effectively switch 402 opening along nine of the AC sine wave continuous predetermined points then.If have only a predetermined point detected, noise may influence system nocuously.

Therefore, if 755 to be output as be that this algorithm returns 710 to detect the negative zero crosspoint of next linear period.All detected if not all test points, determine test point 2 whether detected (760) so, and based on 760 detection, test point 2 is stored (770) or test point 3 is stored (765).Be increased at 775AC cycle rate counter (temp2) afterwards, and program is returned 725 test point detection.This AC cycle rate counter (temp2) is how microcontroller 430 learns all detected parts of three consecutive periods.All do not have voltage if be presented at any test point on trigger triode 420, microcontroller 430 just supposes that switch cuts out, and restarts whole procedure 705.

It is voltage on the trigger triode 420 that above-mentioned example has been described sensed parameter, to determine that switch 402 opens or closes.Yet, replace to detect voltage, the AC cycle can carry out electric current (that is, and average, RMS, peak current, etc.) detection.Be determined if flow through the electric current of trigger triode 420, can suppose that switch 402 is closed; Otherwise if do not detect electric current, switch 402 is opened.In addition, as mentioned above,, between detection period, can carry out a plurality of detections in a plurality of AC cycle in order to increase noise immunity.

Need the service of algorithm

In another example, microprocessor 432 can activate a service that needs algorithm, need to indicate whether power tool 10 services.An example that needs service may be the brush in the replacement instrument motor 15, applies lubricating ester again perhaps for the gear in the gear box 16.Power tool can use the general purpose motor with commutator brush.For example, the commutator ring 24 of Fig. 1 has position commutator brush thereon.These brushes need to change before finishing life tools usually.Can when change brush according to the decision of limiting value coefficient, wherein the limiting value coefficient is by Time Calculation, and current of electric is measured, the electric moter voltage that provides, and speed, switch periods, or some combinations of these parameters are set.Can carry out for the indication of user's needs service by the optical indicator on the tool outer casing 18 as LED.Selectively, for example, the user can needing obtain the alarm of service by tactile feedback in some specific vibration modes, and perhaps instrument is set to stop to finish up to service.

In an example, on the basis that microprocessor 432 starts, how long microprocessor 432 computational tools 10 have turned round and with itself and limiting value coefficient ratio.In this example, the limiting value coefficient can be set as 100 hours based on the time.If the tool operation time surpasses 100 hours, optical indicator on the tool outer casing 18 such as LED (not shown) may be luminous, need service with the warning user.For example, LED may keep " ON " up to resetting in service centre or by the user.

In this example, the service that needs is a brush changing.After carrying out brush changing, a kind of in several indicator method of may resetting.For example, for the limiting value coefficient of resetting, service centre's representative or user may physically remove brush, and the instrument of giving 10 power supplies.Owing to do not have brush in the instrument, there is not current detecting, therefore, microprocessor 432 detects low current (that is, the low current of comparing with limiting value), and presents " no current " indication.If do not sense electric current at least one second, microprocessor 432 may implement to restart program.In an example, restart program and may comprise with certain parameter (as 2) and multiply by limiting value coefficient (100 hours), and/or its prolongation is reached reboot time fixing or that change.Along with being set duration of runs of new needs service, LED is de-energized and brush is put back to instrument motor 15.

In another example, may use a kind of outside replacement.Brush is replaced then, and instrument is inserted into an outside replacement module that is powered.Then, power supply is applied to instrument and tool switch is activated.Replacement limit module current of electric is to low-down value, and is low as to be enough to make motor not turn round.Controller 430 identifications this replacement order and reset indicator as the needs service.This outside replacement module can be used in service centre, is perhaps bought by tool-user.

In another example, may be by the tool-user input code.After brush changing, instrument is powered.The code of this input may be that speed dial is set, and varying speed switch is set, the combination of the switch periods in a period of time etc.In other words, this code can be operating sequence and/or timing, or the user is input to the activation of instrument control.For example, drilling machine is reset may need user's activating power switch ON/OFF 5 times in 10 seconds, waits for 10 seconds, and activating power switch ON/OFF 5 times once more in 10 seconds then is to implement this replacement.

Tactile feedback

Fig. 8 and 9 is the charts that are used to illustrate tactile feedback, and this tactile feedback is the alarm mechanism of rope power tool user as malfunction imminent or current in the instrument to AC to be arranged.Before stopping power tool 10 owing to some malfunctions, or with stop on the contrary, may wish provides certain warning to the operator of power tool 10.Be similar to a scheme, when a kind of malfunction takes place, perhaps just in generating process, in possessory car, engine can be given this owner's one emergency warning lamp before (that is, because the piston that oil starvation causes damages) stops because malfunction on panel board in the given duration.

In an example, detected under voltage and overtemperature degree situation can be used as by mechanism, that is, in case the value of reaching capacity control module 100 stops output current.Yet, nonserviceable trigger before, for example reach before under voltage or the overtemperature degree limiting value, the alarm mechanism in the instrument 10 can alert operator its near imminent operating limit, this operating limit is closing tool motor 10 automatically.Alarm mechanism can be (use loudspeaker or buzzer) that can hear or appreciable, for example uses the illumination arrangement such as the expectation of LED.

The U.S. Patent No. 6479958 of authorizing people such as Thompson has been described the method for the breakthrough torque control that is used for power tool.In the example in ' 958 patents, can provide power tool control by responding to a given parameter of electric machine, wherein this given parameter of electric machine is indicated some malfunctions, as the beginning of stall conditions.Respond imminent stall conditions, when the mains switch to instrument keeps activating,, give the motor multiple pulses with the frequency relevant with the natural resonant frequency of motor.Doing like this is in order to transmit a series of torque pulse, and it has the peak torque bigger than the average torque that transmits in this series.This is called as " breakthrough torque ", and allows the user of power tool to finish given work, so that motor is not burnt out or stops fully.

Yet, in another configuration that here will describe, motor 15 can be subjected to impulse action and not use and break through torque and finish the work, but as to the user's of instrument 10 warning instrument 10 near or be in imminent fault (that is, stop or stall conditions).In an example, can be a given power tool customization pulse.This pulse is as to user's physics, the perception of sense of touch or alarm mechanism.

Therefore, because control module 100 is phase-controls, time-based system can trigger the output pulse as any logic of alarm mechanism.For example, such as given speed, torque, temperature, electric current or electric current parameter over time, it can be measured by microprocessor 432 and can compare with some limiting values, to activate tactile feedback, instrument motor 15 is subjected to impulse action when meeting or exceeding the prescribed limit value thus.

Fig. 8 has illustrated the result of tactile feedback, and wherein trigger triode 420 drops to " OFF " fully from complete " ON ".With reference to figure 8, area A shows trigger triode 420 in startup when (that is, keeping the microprocessor angle of flow to spend in order to complete conducting 180) of conducting fully.Impulse duration B is made up of a series of " ON/OFF " startup of trigger triode 420.Trigger triode 420 is " ON " in time period C, is " OFF " in time period D.Time period C+D represents one-period B.Cycle B number of repetition is E time then.Thereby Fig. 8 provides with complete " ON/OFF " pulse tactile feedback has been described.

In another example, can realize tactile feedback with the angle of flow that changes.With reference to figure 9, this pulse caption the result of tactile feedback, wherein replace " ON/OFF " fully, trigger triode 420 can drop to the low angle of flow from the high angle of flow, perhaps rises to the high angle of flow from the low angle of flow.In case next the microprocessor 432 of microcontroller 430 detects control module 100 should pulse output, the littler angle of flow that the low angle of flow of the complete conducting that microprocessor 432 can be ordered from A order to B or C perhaps increases the angle of flow to an A (complete conducting) from the low spot such as C.This enforcement can be used identical coefficient with complete " ON/OFF " tactile feedback among Fig. 8.Therefore, for given power tool or application, such as duty ratio factor (ratio of parameter D and C among Fig. 8), in the burst length (the parameter E among Fig. 8), the parameter of no pulse time (parameter A among Fig. 8) etc. can change according to hope.

In an example, imminent malfunction in the warning user power tool 10, can use the phased attribute of control module 100 in ROM, to set up the software code parameter (A of Fig. 8 that is used for tactile feedback, B, C, D, E), in the rotating speed of motor 20, to produce " trill (warble) " effect.Can select this slight circulation change in the motor speed, so that not influence tool performance unfriendly, but the sense of hearing and the tactile feedback of imminent or current malfunction are provided to the user.

Foldback

Usually, the control circuit 400 in the control module 100 can be configured to reduce the maximum power fan-out capability of instrument 10, to produce foldback (fold back) state.The operator will not only hear but also feel as this state of " reduction " of instrument 10 performances.The operator will be prompted to retreat and avoid imminent malfunction (as, under voltage, overtemperature degree, overcurrent, etc.).

For example, foldback can be implemented on motor temperature surpasses the basis of the set point of being given or limiting value.Reaching malfunction (restriction of overtemperature degree, set point or limiting value), microcontroller 430 just sends control signal by signal input line 418, to reduce the angle of flow, starts pro rata in the growth of this angle of flow trigger triode 420 with temperature.When temperature increase when the value of overstepping the extreme limit or set point, this low angle of flow is used to reduce to offer the electric moter voltage of instrument motor 15.

In this specific example, foldback is used to protect motor 15, and notifies the user when instrument 10 is too warm.If temperature continues to increase, electric moter voltage will continue to reduce up to electric moter voltage and becomes 0 or reach minimum voltage, and this voltage no longer reduces with the temperature that increases.By the foldback electric moter voltage, temperature should begin to be reduced to limiting value or below the set point, may be increased once more at this electric moter voltage.This foldback function may be kept up to temperature and has been reduced to below the set point, and perhaps temperature no longer reduces, and has perhaps reached low instrument speed configuration.

Foldback can be adopted as the protection of the input of the harmfulness except that temperature by microcontroller 430 and move.Foldback can be used to dwindle torque or help forfeiture control (as, instrument is around cutter head or annex rotation) the user.

Fig. 9 is that explanation is at a chart that the electric moter voltage foldback example in the rope AC power tool is arranged.Originally, when one of system given measurement parameter (voltage, electric current, temperature, torque, etc.) when being lower than some coefficient limiting values, trigger triode 420 starts at the full angle of flow (some A).When parameter is increased to this limiting value when above, the angle of flow begins to reduce (from point A to point B).If measured parameter continue to increase and then the value of overstepping the extreme limit, the angle of flow will continue reduction (from a B to a C).This process will continue, up to reaching the minimum angle of flow of arbitrary setting (example is 30 degree).This minimum angle of flow is continued to keep, and reduces up to the parameter of measuring.Selectively, module 100 can be configured to set closing tool 10 after the minimum angle of flow reaching this.If trigger triode 420 starts at the C point, and the parameter of measuring begins to reduce, and the angle of flow will increase back the B point from the C point so.When the parameter of measuring continues to be reduced to limiting value when following, the angle of flow will continue to get back to from the increase of B point the complete conducting of an A.

Torque control

Control module 100 can be configured to the instrument motor torque control is provided.For example, torque control may some be similar to rotating speed control.On the basis of loop cycle, microprocessor 432 reads in 440 current value along separate routes, and it is compared with a reference voltage, to determine the representative voltage of this current value of reflection.For comparing with one or more values, this representative voltage value can be stored in suitable the tabling look-up in memory 434 or 436, and perhaps determines with the equation of a regular coding, with definite torque value.That calculate or that search then torque value can compare with the torque settings value.If the torque value that calculates surpasses the torque settings value, microprocessor 432 is adjusted torque by reducing output voltage.This can for example carry out with foldback.In an example, microprocessor 432 can change the angle of flow that trigger triode 420 starts, and this has changed electric moter voltage so that torque value is narrowed down to below the torque settings value.

The motor temperature assessment

Figure 10 A is a general introduction of motor temperature assessment algorithm.This example uses average current as input, but other from thermistor or thermocouple such as the RMS electric current, peak current, the measured value of temperature, or speed can be used as the input of motor temperature valuation functions.

This algorithm is based on such principle, and promptly the temperature of motor is proportional to the resistance that square multiply by of RMS electric current.Suppose that resistance is constant in instrument motor 15, the assessment of temperature can realize by accurately measuring electric current in time.At first, in time cycle or incremental time M, by microcontroller 430 with specific interval sampling n current sampling data (to each instrument 10, n and M can change), to determine average current at 1002 quilts square.The square value of this electric current can be represented as numeric parameter A.Square current value A represent, up to after this (wherein P is far longer than increment M), suppose electric current keeps constant assessment motor temperature what to be at cycle preset time P end.

This value A and temperature register value B be (in the input shown in 1004) relatively.B is the value of a change, and representative is just in the assessment of the motor temperature of current point, and it will be updated at each incremental time M.For example, temperature register value B=0 represents that motor temperature is ambient temperature (that is, room temperature), and temperature register value B=1300 can represent 130 ℃ motor temperature.Each parameter A and B are integer values.

1006, it is much that on behalf of the difference between the temperature of current assessment, the difference between A and the B have, and time cycle P in the past after, how many evaluate temperature of motor 15 will be.1008, this difference C (integer value, it may be called the adjustment C that is weighed in advance) is removed by a scalar E (also being an integer value).This scalar E can be understood that a variable scalar adjustment, and it changes ratio, the variation in this ratio temperature register value response current, and can be considered to the time constant of motor 15.Because each motor has different time constant E, this value can change between instrument and instrument.The result of C/E represents the temperature adjusted value F of motor 15.This temperature adjusted value F representative temperature in incremental time M increases or what has reduced.

1010, F (value of symbol) next is coupled with or deducts temperature register value B, and creating a new temperature register value H, it will be used in 1012 and repeat next time.If electric current keeps constant, along with P around, value H should corresponding to or the value of equaling A so that the motor temperature of new assessment is approaching or be equal to motor temperature assessed value at time cycle P end.

Therefore, by A (promptly, at time cycle P end with the motor temperature assessed value that has, its based on constant average current in that time increment square) and the current measurement value of temperature register value B reflection between difference big more, after calculating, increase/minimizing of temperature register value B must be big more.If the integer value of A and B equates that on behalf of motor temperature, this do not change.Therefore, always desired temperature register value B equals square (being A) of electric current in time, and temperature register value B will increase as required along with the time/reduce, to keep this relation.Any point in the time period will provide a proportional assessed value at that given time motor temperature from temperature register value B.

As an example, if in given interval M, average current is increased to 20 amperes from 5 amperes, and (it has increased parameter A, because it is the function of current squaring), temperature register value B will very fast increase, represents the rapid increase of motor temperature, because electric current increases significantly.Then, if average current is reduced to 10 amperes (A has reduced) from 20 amperes, B will reduce along with the time-temperature register value, the reduction of expression motor temperature.

The parameter A of following equation key diagram 10A, B, C, D, the calculating of E and H.In a preferential or ideal system, square multiply by resistance and provide a temperature of electric current.Yet, in the system of reality, other parameter, as rotation speed of the fan, motor speed, and how electric current to measure, and all will influence the output of system.In the equation below, parameter A is by FinalAverage _nThe Xiang representative; And the evaluate temperature of representing motor in the time period (that is, in this example given time cycle P), will reach.Register value B is by TempReg _[n-1]The item expression, and renewal or new temperature register value is represented as Temp Reg _n, it is to be determined by the many current measurement value n in the time interval M.

In order to regulate these system parameterss, the equation that is used to assess motor temperature can be slightly modified.For example, when calculating parameter A (average current square function),, the voltage compensation item or the multiplier that are called as Vfactor have been increased in order as the instrument of regulating 120V, to regulate the instrument of 230V.Because by the average current of the instrument of the 230V performance electric current that the chances are is shown by the instrument of 120V half, for operation correctly, system needs a multiplication constant.Multiplier Vfactor can be " 1 " for the tool settings of 120V, and is that the tool settings of 230V is " 2 ".

The current class limiting value relevant with rotation speed of the fan (being called as ' mid point limiting value ' here) arranged.In the particular current grade, the heat of getting rid of from system by fan in power tool 10 is along with the reduction of rotation speed of the fan reduces.Increase by a factor and compensate this loss that reduces the eliminating heat that causes owing to rotation speed of the fan.A (FinalAverage _n) calculated value to depend on average current be at this more than mid point limiting value or following and different.If average current more than the mid point limiting value, increases following factor, (Iavg at this _n-Midpt) ², its just calculate electric current deduct limiting current value Midpt square.This factor will make the following electric current of the above current ratio mid point of mid point cause higher evaluate temperature.The recruitment of temperature is direct and the recruitment of electric current more than mid point is proportional.

Further, can increase variable and compensate low motor speed.This can be reflected by expression formula (MaxDial-DialSetpoint) * SpdFactor.Parameter MaxDial is the A/D reading that is read by microprocessor 432, and it is corresponding to the maximum set value on the speed runner 270, and parameter DialSetpoint is the A/D reading corresponding to the actual speed set point on the runner 270.If these equate that this velocity compensation variable is 0.Parameter S pdFactor is a constant coefficients, and it is different in different instruments, and affords redress when the rotating disk set point is set in rotating speed except that maximum set value.

When averaging current detecting, the compensation of above-mentioned motor speed is necessary, because the angle of flow of trigger triode 420 influences the accuracy that average current is measured.In the lower angle of flow (lower speed), so accurate when the measured value of average current is unlike in the complete angle of flow (rotating speed fully), therefore must this measurement of compensation.This process depends on which kind of measurement scheme of use and changes.When using average current value, use all compensation factors.If use the RMS electric current, do not need to use the compensation factor of as much.If use thermistor or thermocouple, without any need for compensation factor.

Therefore, A-FinalAverage _nValue can be by a calculating in following two mathematical equation, it depends on that average current is more than the mid point limiting value or following, wherein A-FinalAverage _nBe to calculate and the final average current of acquisition by n the current measurement value that microcontroller 430 is gathered at the specific interval of time cycle M.Equation (1) is the equation of average current below the limiting value grade, and equation (2) is that average current equals or the equation more than current class, must be by (Iavg in equation (2) _n-Midpt) ²The loss of compensation fan.

$\underset{16-\mathrm{bit}\max }{\mathrm{FinalAverage}}=\underset{n=0}{\overset{M}{\mathrm{\Σ}}}{[{\left(\frac{{\mathrm{Iavg}}_n\×\mathrm{Vfactor}}{\underset{16-\mathrm{bit}\max }{4}}\right)}^2+(\mathrm{MaxDial}-\mathrm{DialSetpoint})\×\mathrm{SpdFactor}]}^2---\left(1\right)$

$\underset{16-\mathrm{bit}\max }{\mathrm{FinalAverage}}=\underset{n=0}{\overset{M}{\mathrm{\Σ}}}{[{\left(\frac{{\mathrm{Iavg}}_n\×\mathrm{Vfactor}}{\underset{16-\mathrm{bit}\max }{4}}\right)}^2+{\left(\underset{255\mathrm{bitlimit}}{{\mathrm{Iavg}}_n-\mathrm{Midpt}}\right)}^2(\mathrm{MaxDial}-\mathrm{DialSetpoint})\×\mathrm{SpdFactor}]}^2$

(2)

Thereby the calculating of the H among Figure 10 A is reflected in following equation (3) and (4).Value H is a temperature register value new or revision, and the assessed value of the renewal of reflection motor temperature.B parameter shown in equation (3) and (4) reflection Figure 10 A, C, E and F show H=B+F in fact, wherein F=C/E, and C=A-B.Therefore, the following arrangement of item in equation (3) and (4).H＝B+(A-B)/E。Equation (3) merges the FinalAverage from equation (1) _nAs a result, wherein average current is below the mid point limiting value, and equation (4) merges the equation (2) be used to calculate FinalAverage (wherein average current equal or more than the mid point limiting value):

$\underset{16-\mathrm{bit}\max }{\mathrm{Temp}{\mathrm{Re\; g}}_n}=\mathrm{Temp}{\mathrm{Reg}}_{[n-1]}+\frac{({\mathrm{FinalAvg}}_n-\mathrm{Temp}{\mathrm{Reg}}_{[n-1]})}{\mathrm{Divisor}}---\left(3\right)$

$\underset{16-\mathrm{bit}\max }{\mathrm{Temp\; Re}{g}_n}=\mathrm{Temp}{\mathrm{Reg}}_{[n-1]}+\frac{({\mathrm{FinalAvg}}_n-\mathrm{Temp}{\mathrm{Reg}}_{[n-1]})}{{\left[\frac{({\mathrm{Iavg}}_n-\mathrm{Midpt})}{\underset{255\mathrm{limit}}{\mathrm{HighCurDivisor}}}\right]}^2}---\left(4\right)$

Molecule in the second portion of each formula (3) and (4) is the parameters C of Figure 10 A, its representative (A-B) or current we evaluate temperature and the time P rear motor temperature that will reach between great difference is arranged.In the second portion of each equation (3) and (4) the scalar E of denominator term, compare in equation (3) different with equation (4), it is a constant coefficients that is called Divisor, equation (4) has the denominator term (loss of compensation fan) that explanation surpasses the measurement average current of mid point limiting value, and removes that factor with the scalar that is called HighCurDivisor.These scalars Divisor and HighCurDivisor are penalty coefficients, and it is set and changes the time of determining new temperature evaluation value H cost, so that it reaches A.Use two different divisors, because when high current, the heating/cooling raio of motor 15 is owing to the loss of rotation speed of the fan changes.Therefore, the Divisor scalar is used in the equation (3) of reduced-current, and the HighCurDivisor scalar is used in the equation (4) that is used for high current.

Therefore, scalar E is a variable scalar adjusted value, and it has changed ratio, in this ratio temperature register value corresponding to the variation in the electric current.This can change between different instruments.In this example, when electric current surpasses intermediate point, the shape of cooling curve will change.The result of C/E (that is, the second of equation (3) and (4), complete merchant's part) represents the temperature adjusted value F of motor 15.In other words, the result of C/E is illustrated in the incremental time M temperature increases or what has reduced.

Figure 10 B illustrates how to determine the evaluate temperature of motor when starting, the i.e. flow chart of initial value B in temperature register.In case instrument 10 loses power supply, controller 430 loses previously generated information, unless information is regularly preserved.Therefore, should there be a kind of method to determine what temperature motor 15 is in when instrument 10 is powered first.Do not have thisly to determine, under heavy duty, moved the motor 15 of a period of time, may be switched off and open once more apace subsequently, and controller 430 returns the reset temperature register to zero, indication room temperature instrument 10.If these generations, instrument 10 will be burnt probably.

For the potential possibility that prevents that instrument from burning, provide a program in 1014 beginnings.Each microcontroller 430 upgrades the measured value of controller 430 temperature of temperature register value B or thermistor (that is, transducer 410), and these values are stored in nonvolatile memory (RAM 434).When starting, obtain stored last temperature register value and controller 430 temperature values (1014) of transducer 410 before instrument stops at last again, with acquisition instrument 15 embodiment of the state before the power-off in the end.Increase a time delay (1016), to obtain the motor temperature of assessment and the measured value of controller temperature when the power initiation of instrument.Limit in front based on the time-delay (1016) that starts afterwards, the veneer temperature sensor (410) of Read Controller 430, with the temperature of assessment with respect to the controller of motor temperature, promptly, if the temperature of controller 430 is high fully, the temperature that can suppose motor 15 is hot too, as long as the temperature-time constant of controller 430 is not the thermal constant that is higher than motor 15 far away.

After this time-delay, this controller temperature of microprocessor 432 detecting sensors 410, and determine in 4 states one: (1) microcontroller 430 is room temperatures, (2) microcontroller 430 does not have transformation temperature, (3) microcontroller 430 is warm, and (4) microcontroller 430 is hot.By Current Temperatures data and last data of preserving are compared to determine these states.

If (1018 are output as not to determine to begin not variation of temperature from last power initiation, module 100 is not switched on first), and the value of transducer 410 is greater than surrounding environment (1022 are output as not), but in the limit of the qualification of temperature in front, that is, approach start-up temperature (difference, 1026 be output as be) less than 12%, old value B in the temperature register (that is TempReg in equation (3) or (4), _[n-1]) be resumed (1024) with the not variation (1024,1026) of indication motor temperature.If the temperature of the controller of determining from transducer 410 430 is lower than room temperature when module 100 is switched on first, the value of the B in temperature register is reset back zero (1022), indicates room temperature or ambient temperature (1020), that is, and and cold electric power tool 10.

If controller 430 is confirmed as warming up (1030 be output as not) or heat (1030 be output as be), the new value of temperature register value B in step 1028 or 1032 from being pre-installed such as the nonvolatile memory of EEPROM (ROM 436).In an example, warm controller 430 can be 80 ℃, and the controller 430 of heat (and from but hot tool 10) can be 150 ℃.For the B value of identical B value in the temperature register of packing into or modification, implement the motor temperature valuation functions as described above with reference to Figure 10 A.

In interchangeable example, another kind of determine that when power initiation instrument is cold, warm, or heat, be the trigger triode 420 in measurement module 100 or the instrument 10 or the gate voltage of other power device with the method for determining initial temperature register value B.The temperature of active device can be determined by its junction voltage.These devices can comprise trigger triode, transistor, and diode, or any other comprises the silicide devices of PN or NP knot.Therefore, can not use the extra temperature of assessing electronic module 100 or microcontroller 430 such as the transducer 410 of thermistor.Replace using thermistor 410 can use the transistorized knot of gate-drive of trigger triode 420 to determine temperature.This can be explained by following relation of plane.

The temperature of a knot and the relation of voltage can be limited by equation as follows (5).

V _γ(T ₁)-V _γ(T ₀)=k _T(T ₁-T ₀) equation (5)

Wherein:

T ₀＝25℃

T ₁=junction temperature (℃)

V _γ(T ₀The junction voltage of)=in the time of 25 ℃

V _γ(T ₁)=at T ₁The time junction voltage

k _TThe temperature coefficient of=knot

Above-mentioned example value is:

T ₀＝25℃

T ₁＝？(℃)

V _γ(T ₀)＝0.7V

V _γ(T ₁)＝0.65V

k _T＝-2.0mV/℃

Conversion equation (5) solves device temperature T ₁For:

$\frac{V_{\mathrm{\&gamma;}}\left(T_1\right)-V_{\mathrm{\&gamma;}}\left(T_0\right)}{k_T}+{\mathrm{<figure-callout\; id="0"\; label="T"\; filenames="Y2006201647750047H1.png"\; state="\{\{state\}\}">T</figure-callout>}}_0=T_1$ T ₁＝50℃

Actual value may depend on the device that uses and change in the circuit 400 of module 100.Therefore, determine that instrument is cold in the power initiation process, warm or heat is used as the input of temperature evaluation algorithm, a potential benefit of doing like this is, the element that existed of induction is as the transistorized voltage in the gate-drive of trigger triode 420, with the temperature of the temperature/controller 430 of assessment or determination module 100 when starting.Therefore, can not use the temperature of coming evaluation module 100 or microcontroller 430 such as the additional sensors 410 of thermistor.

In module 100, use the motor temperature appraisal procedure and directly in motor 15, place thermistor or thermocouple is compared, can reduce cost and provide simple use.Said method does not need extra transducer or electric wire to implement, because all signal or ancillary equipment of needing all directly are based upon in the module 100.On motor 15 or its placed around thermocouple, thermistor, or the task of electric wire is not easy to realize, and live wire fusing or risk of short-circuits mutually.Above-mentioned algorithm provides cheap, and effective and simple mode is assessed motor temperature, and does not enter motor 15 from physical structure.

In addition, the motor evaluate temperature from determining as the described motor temperature assessment algorithm of Figure 10 A can be used as the input of microcontroller 430, to trigger the protection mechanism of alarm type, and for example by tactile feedback, motor foldback etc.Along with motor temperature begins very near the motor overload state, because microcontroller 430 activates tactile feedback or foldback by the control of the angle of flow of trigger triode 420, perhaps activate foldback and (promptly as alarm, this instrument motor is just near overtemperature degree restriction) the luminous combination of LED, perhaps activate tactile feedback and on shell 18 as alarm (promptly, this instrument motor is just near overtemperature degree restriction) the luminous combination of LED, the user can avoid the high-temperature set point to reach overload (owing to reaching the overtemperature degree limit).Therefore, the motor temperature algorithm can be used in time assess motor temperature at difference, to be devoted to avoid or detect imminent motor overload state.

Figure 11 is the chart of a comparison by the motor evaluate temperature and the actual motor-field temperature that records of the algorithm computation of Figure 10 A, and the wherein actual motor-field temperature that records is at the little angle of the 120V that disposes example control module 100 grinder.Illustrated data representation motor temperature algorithm assessed value and real electrical machinery temperature.The diagram result that can produce has as seen from Figure 11 tested the increase or the minimizing of motor load, and makes instrument motor opening/closing/open, to make great efforts all aspects of exercise motor temperature algorithm.This algorithm produces the fully actual measurement motor temperature of simulation, and the difference at arbitrary number strong point under the worst situation is about 13 degree.

Figure 12 is the coefficient input in the control module 100, and control and guard method, and/or the skeleton diagram of the relation between user's input as the middle column that is illustrated in Figure 12 in the collection of functions, are illustrated in the hurdle on the right side from the coefficient output from these functions.In the hurdle on the right side, output factor ALC refers to above-mentioned breakthrough torque, finish given work with the user who allows power tool, so motor can not burnt or be stopped fully.

Provide Figure 12 illustrate independent common control module 100 how the storage by nonvolatile memory such as EEPROM or flash memories can be reprogrammed, to satisfy the multifarious demand of different instruments.

Protection of Tao Luning or control function as the motor temperature assessment algorithm, transship and control (absolute and Di/Dt clutch mode) so far, and tactile feedback etc. can be activated by the storage of these nonvolatile memories or forbid.In addition, whether be stored in the nonvolatile memory such as EEPROM or FLASH memory, can change the control that is used for each activation or the coefficient input and output of guard method based on a specific software code coefficient.

Figure 12 shows the coefficient input of example in the left side, it can be transfused to certain function.Go out as shown, these functions can comprise the EOC function, aforesaid torque limit function, motor overload function (the motor temperature assessment algorithm among its possibility combined diagram 10A-B).These functions can also comprise input, its with change that firmware is opposite can be configured to arbitrary simulation by these software code coefficients that change in the nonvolatile memory, numeral, the effective or low level of high level is effectively imported.

To different functions different input and output can be set, and in control module 100, different functions can be activated or forbid.For example, have in the rope power tool given, the absolute clutch mode that is used for EOC can be set to and use electric current as input, and if the value function that oversteps the extreme limit be output as instrument and stop.A different instrument can have the Di/Dt clutch mode, and it is set to operating speed and imports as function, and if the ratio that oversteps the extreme limit open LED and export as function.Like this, two the independent instruments of inside with same universal control module 100 can dispose the different parameter of sampling and export the different result's difference protection action of different output factors (that is, based on) different function.

At nonvolatile memory (if selectable ROM 436 is configured to EEPROM, it can be RAM 434, flash memories or EEPROM) in the software code coefficient a kind of like this ability is provided, promptly how to change the interaction of module 100 and instrument 10, and need not change firmware or the foundation code in microcontroller 430.By only changing the nonvolatile memory of microcontroller 430, promptly can change the performance of instrument, this is former to be impossible.

Described exemplary embodiment like this, clearly can change in many ways equally.These variations will not be considered to be separated with exemplary embodiment, and all these variations will be conspicuous for a person skilled in the art, and will be included in the scope of claims here.

Claims (18)

1. a power tool is characterized in that, this power tool comprises:

The instrument motor;

Control module with electric clutch, be used in the testing tool is the malfunction of sign with the overload event, and comprise microcontroller, be used for based on malfunction control electric clutch that detects and activation protection action, to remove or to reduce to the power of instrument motor; And

Mechanical clutch is used for any residual inertia of cleanout tool.

2. power tool as claimed in claim 1; it is characterized in that; the startup of the trigger triode in the microprocessor controls instrument; voltage with the control tool motor; and based on the malfunction that is detected by electric clutch, microcontroller is configured to control the complete closing tool motor of trigger triode, pulse modulation instrument motor; reduce to impose on the voltage of instrument motor, or combine the above-mentioned at least a protection action of execution with the indicating device of opening such as LED.

3. power tool as claimed in claim 1 is characterized in that, the software based on program that electric clutch is repeated by the processor in the microcontroller.

4. power tool as claimed in claim 1, it is characterized in that, electric clutch can be configured to first pattern, wherein given parameter is sampled, if this sampling parameter surpasses first limiting value, if and time counter surpasses second limiting value and just detect malfunction, wherein the increase of time counter is on the basis that first limiting value is exceeded.

5. power tool as claimed in claim 4 is characterized in that, given parameter is the current value that calculates from the digitized current sampling data to half linear period position of the AC voltage waveform of instrument power supply or whole linear period position.

6. power tool as claimed in claim 5 is characterized in that the current value of calculating is instantaneous, in average or root mean square (RMS) current value one, and first limiting value is based on average current, RMS electric current or maximum instantaneous current value.

7. power tool as claimed in claim 4 is characterized in that, given parameter is the motor speed of instrument motor, and limiting value is based on the instrument motor speed.

8. power tool as claimed in claim 1, it is characterized in that electric clutch is configured to second pattern, wherein given parameter is sampled, relatively calculate a difference based on this sampling parameter and with first limiting value, just detect malfunction if this difference surpasses first limiting value.

9. power tool as claimed in claim 8, it is characterized in that, if difference is less than or equal to first limiting value, electric clutch with this difference with less than second limiting value of first limiting value relatively, if and this difference wherein surpasses second limiting value in N 〉=2 at N at least continuous linear period, just detect malfunction.

10. power tool as claimed in claim 8 is characterized in that, difference is poor between the current value that calculates to current linear period and previous linear period the sampling of the AC voltage waveform of instrument power supply.

11. power tool as claimed in claim 8 is characterized in that, difference is poor between the motor speed value that two different times calculate.

12. power tool as claimed in claim 1 is characterized in that, even can prevent also that after overload event is eliminated instrument from inadvertently being opened after activating the protection action.

13. power tool as claimed in claim 1 is characterized in that, further comprises:

The ON/OFF mains switch; And

Append to the cord on the instrument, be used for providing AC line power to instrument,

Can prevent when instrument is inserted into and switch on that wherein instrument from inadvertently being opened, but instrument has reached and caused the overload event of shutting down, and instrument still is in insertion state and overload event when being eliminated, mains switch is still at open position.

14. a control module that is used to have the rope power tool is characterized in that this control module comprises:

Microcontroller; And

Trigger triode, microcontroller receive the parameter input of a plurality of inductions, and with the startup of control trigger triode, thereby control imposes on the voltage of the motor of power tool,

Wherein microcontroller is configured to activate the protection action, by through trigger triode pulse modulation instrument motor, soon takes place or current malfunction with the user of warning instrument, thereby tactile feedback is provided for the motor user.

15. control module as claimed in claim 14 is characterized in that, the microprocessor controls trigger triode, thus trigger triode is that the 180 complete conductings of spending and the angle of flow are to replace between the closing fully of 0 degree at the angle of flow.

16. control module as claimed in claim 15 is characterized in that, the time that the complete conducting of trigger triode is closed fully is variable, and each ON/OFF circulation is represented as the cycle of warning the user and being repeated certain number of times.

17. control module as claimed in claim 14, it is characterized in that, it is reciprocal between the higher and lower angle of flow that microcontroller is controlled trigger triode by the angle of flow that changes trigger triode, thereby the voltage of regulating motor produces tactile feedback to the user.

18. control module as claimed in claim 14 is characterized in that, microcontroller changes trigger triode from being conducting to not conducting in time, so that pulse output to be provided to the user.

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