CN102562958B - Speed shifting tool and speed shifting control method thereof - Google Patents

Abstract

The invention discloses a speed shifting tool which comprises a case, a motor, an output shaft, a gear transmission mechanism and a control system, wherein the motor is arranged in the case and outputs rotary power; the gear transmission mechanism is arranged between the motor and the output shaft so as to transmit rotary output to the output shaft and comprises at least one gear train and a moving piece, the moving piece can move between the fist position and the second position, and the moving piece and the gear train are matched in different ways in the first position and the second position so that the gear transmission mechanism outputs the speed of the motor in different reduction ratios; and the control system comprises a driving device matched with the moving piece, the driving device is used for driving the moving piece to move between the first position and the second position, and the control system also comprises an electronic switch in parallel to the motor. When the reduction ratio of the gear transmission mechanism requires changing, the control system cuts off the current of the motor, connects the electronic switch and controls the driving device to drive the moving piece to move between the first position and the second position.

Description

Speed change tool and shifting control method thereof

Technical field

The present invention relates to a kind of speed change tool, especially a kind of by the motor-driven instrument with the exportable different rotating speeds of variable transmission mechanism, as electric drill, screwdriver set and hammer drill etc.The invention still further relates to the shifting control method of such speed change tool.

Background technique

A kind of speed change tool, as electric drill, screwdriver set and hammer drill etc., with the exportable different rotating speed of variable transmission mechanism to adapt to different load torques.The variable transmission mechanism of speed change tool all comprises gear drive and the control system of connecting motor and output shaft conventionally, thereby this control system changes velocity ratio by changing with the meshing relation of gear drive, makes output shaft export different speed.In the prior art, as the automatic transmission of No. 6824491 announcement of U.S. Patent Bulletin, its control system can change and automatically adjust the output that realizes friction speed with the meshing relation of gear drive according to load torque, this control system is utilized the throw-out collar rotation of strap cam face to promote slip ring and is moved axially, and then ring gear in actuation gear driving mechanism moves axially and the whirl-stop device clamping being arranged on shell.European patent application discloses EP0787931A1 and also discloses a kind of automatic transmission.The variation that above-mentioned these automatic transmissions all change corresponding outputting torsion with the position relationship between mechanical structure realizes automaitc shfit, this mechanical type gear not only makes the mechanical realization of gear drive inside more complicated, and because ring gear also rotated in the axially movable while, and shell is relatively-stationary, so when this gear is in speed change time, the collision and be difficult to engage mutually of the tooth of the tooth of the ring gear in rotation and the whirl-stop device on shell, therefore cannot really realize automaitc shfit and carry out the object of industrialized implementation.China bulletin patent CN201093036Y discloses the speed change tool that a kind of electric drives, its control system can sensing physical parameter and after parameter reaches predetermined value accessory drive carry out automaitc shfit.

Summary of the invention

Technical problem to be solved by this invention is: a kind of speed change tool is provided, and this instrument carrys out simplified structure by the means of dynamo-electric combination, and realization can be made fast the object automatically switching between different output gears.

Technological scheme of the present invention is: a kind of speed change tool, comprising: casing; Motor, is arranged in casing, and outputting rotary power; Output shaft; Gear drive, be arranged between motor and output shaft so that the rotation output of motor is delivered on output shaft, it comprises at least one group of train of gearings and a moving part, described moving part can move between primary importance and the second place, and in the time of primary importance and the second place, described moving part coordinates in a different manner with described train of gearings, thereby gear drive is with the rotating speed of different reduction speed ratio output motors; Control system, comprises the drive unit coordinating with moving part, and described drive unit is used for driving described moving part to move between primary importance and the second place; Described control system also comprises the electronic switch in parallel with described motor, in the time need to changing the reduction speed ratio of described gear drive, described control system is connected described electronic switch after cutting off motor current, and accessory drive drives described moving part to move between primary importance and the second place.

Preferably, in the time of primary importance, gear drive is with the rotating speed of low reduction speed ratio output motor; In the time of the second place, gear drive is with the rotating speed of high reduction speed ratio output motor.

Preferably, described control system also comprises electronic control unit, described electronic control unit is for detection of the parameter that characterizes output shaft load, reach after predetermined value in described parameter, described electronic control unit is connected described electronic switch after cutting off motor current, and accessory drive drives described moving part to move to the second place from primary importance.

Preferably, described control system also comprises electronic control unit and trigger switch, in the time that trigger switch is artificially triggered, one electrical signal generates and passes to electronic control unit, electronic control unit responds this electrical signal and connects described electronic switch after cutting off motor current, and accessory drive drives described moving part to move to the second place or move to primary importance from the second place from primary importance.

Preferably, described electronic control unit disconnects described electronic switch after again connecting motor current.

Preferably, the time that described electronic switch is connected is less than 200mS.

Another technical problem to be solved by this invention is: a kind of shifting control method of speed change tool is provided, and the method can make speed change tool can do fast to automatically switch between different output gears.

The shifting control method of the present invention's speed change tool as previously described comprises the following steps:

1) described control system is cut off motor current;

2) described control system is connected described electronic switch;

3) described control system accessory drive drives described moving part to move to the second place from primary importance.

Preferably, described shifting control method also comprises:

1) described control system detects speed change tool physical parameter, judges the working state of speed change tool;

2), in the time that the load torque of described output shaft changes to predetermined value, carry out described control system and cut off the step of motor current.

Preferably, described shifting control method also comprises:

1) artificially trigger described trigger switch, an electrical signal generates and passes to control system, and control system responds this electrical signal and carries out described control system and cut off the step of motor current.

Compared with prior art, the invention has the beneficial effects as follows: the present invention applies electric current by electronic control unit to electromagnet apparatus, drive ring gear linear motion, thereby change the reduction speed ratio of gear drive, and then realize the object of automaitc shfit.In addition, electronic control unit is in the time carrying out automaitc shfit, can first carry out again gear switch by first suspending motor rotation, thereby effectively avoid the tooth problem of beating in automaitc shfit process, and then extend tool life, meanwhile, shorten by electric brake is set the time that motor suspends, increase work efficiency.

Accompanying drawing explanation

As an example of the gear in electric drill example, the present invention will be further described by reference to the accompanying drawings below.

Fig. 1 is the partial sectional view of speed change tool of the present invention.

Fig. 2 is the local enlarged diagram of the drive unit in Fig. 1.

Fig. 3 a is the gear drive sectional view of speed change tool of the present invention in the time of high gear.

Fig. 3 b is the gear drive sectional view of speed change tool of the present invention in the time of low gear.

Fig. 4 a is another embodiment's of drive unit of speed change tool of the present invention partial sectional view.

Fig. 4 b is the local enlarged diagram of the drive unit in Fig. 4.

Fig. 5 is the control system functional-block diagram of speed change tool of the present invention.

Fig. 6 is the functional-block diagram of control unit the first embodiment in speed change tool control system of the present invention.

Fig. 7 is the functional-block diagram of control unit the second embodiment in speed change tool control system of the present invention.

Fig. 8 is the functional-block diagram of control unit the 3rd embodiment in speed change tool control system of the present invention.

Fig. 9 efficiency curve diagram that to be speed change tool of the present invention at high speed operation and low cruise be, to illustrate the speed switching time of speed change tool.

Figure 10 is another embodiment's of speed change tool of the present invention side view, and wherein part casing is removed to disclose the structure of drive unit, and now, drive unit is in high speed position.

Figure 11 is similar to FIG. 10, and now, drive unit is in high speed position.

Figure 12 is the cross-sectional schematic along A-A line direction in Figure 11.

Figure 13 is the cross-sectional schematic along B-B line direction in Figure 11.

Figure 14 is the cross-sectional schematic of the electromagnet apparatus of speed change tool shown in Fig. 9 and Figure 10.

Figure 15 is another embodiment's of speed change tool of the present invention side view, has wherein shown signal occurrence device.

Figure 16 is the plan view of Figure 15 speed change tool, wherein also further demonstrates side handle and can select the velocity mode switch of high speed, low speed and automatic three kinds of patterns.

Figure 17 a is the cross-sectional schematic along C-C line direction in Figure 15, has wherein disclosed a kind of form of trigger switch.

Figure 17 b and Figure 17 a are similar, have wherein disclosed the form of another kind of trigger switch.

Figure 18 and Figure 16 are similar, but wherein velocity mode switch only has at a high speed and two kinds of gears of low speed.

Figure 19 and Figure 18 are similar, but it does not have velocity mode switch, only have for showing at a high speed and the LED lamp of lower-speed state.

Figure 20 is the reduced graph of the internal circuit of speed change tool shown in Figure 16.

Figure 21 is that in Figure 20, processor is carried out the workflow diagram that auto-speed switches.

Figure 22 is that in Figure 20, processor is carried out the workflow diagram that manual instantaneous velocity switches.

Figure 23 is the reduced graph of the another kind of mode of execution of the internal circuit of speed change tool shown in Figure 16.

Figure 24 is that in Figure 23, processor is carried out the workflow diagram that auto-speed switches.

Figure 25 is that in Figure 23, processor is carried out the workflow diagram that manual instantaneous velocity switches.

Embodiment

Shown in Fig. 3 b, it is drive unit first embodiment's of speed change tool control system of the present invention structural representation.A kind of speed change tool 9, comprises motor 2, motor power supplying power supply 1, main switch 13, output shaft 6 and the gear drive 4 of start/stop motor.Gear drive 4 comprises the first planetary gear set being made up of the first row star-wheel 40 and the first planet carrier 41, the second planetary gear set being made up of the second planet wheel 42 and the second planet carrier 43, is fixedly installed on whirl-stop device 44 on tool housing and can axially movable moving part 45.Drive unit 5 is arranged on gear drive 4, comprise actuator 52 and driving component 51, the actuator of the present embodiment is to adopt an electromagnet apparatus, comprise two permanent magnets that keep at a certain distance away 521, be arranged at permanent magnet middle iron core 523 and coil 522, wherein iron core 523 is provided with a groove 524.Driving component is an arc push rod 512 and overlaps 513 with the steel wire that this arc push rod 512 connects.Described push rod 512 has the mating part being arranged in groove 524.Described moving part 45 is one to have the speed ring 45 of internal tooth 451 and end tooth 452, and the circular groove 453 that holds steel wire cover 513 is set on it.

In the time that electromagnet is switched on, iron-core coil 523 will produce magnetic and attract with one of them of two permanent magnets 521.If when the electric current of electromagnet is oppositely connected, 523 of iron cores can produce and attract with another permanent magnet 521, thereby drive push rod 512, steel wire cover 513 and speed ring 45 to move together.Top gear state as shown in Figure 3 a, now iron core 523 is attracted by one of them permanent magnet 521, corresponding, and the internal tooth 451 of speed ring 45 engages with the first planet carrier 41 and the second planet wheel 42 simultaneously, and now the output speed of gear drive 4 is higher; Bottom gear state as shown in Figure 3 b, now iron core 523 is attracted by another permanent magnet 521, and corresponding, the internal tooth 451 of speed ring 45 and second is taken turns 42 and engaged, its end tooth 452 engages with the whirl-stop device 44 on tool housing simultaneously, and now the output speed of gear drive 4 is lower.

Shown in Fig. 4 a and Fig. 4 b, it is drive unit second embodiment's of speed change tool control system of the present invention structural representation.The electromagnet apparatus adopting in foregoing drive unit the first embodiment, its objective is that the current direction by controlling electromagnet changes polarity, drives speed ring 45 to move between high low gear.And in the present embodiment, use a servomotor 525 instead and be used as actuator, overlap 513 with a screw rod 515, tapped push rod 512 and steel wire and be used as driving component 51, positive and negative transferring by servomotor 525 drives the movement of push rod 512 on screw rod 515, thereby drive speed ring 45 to move together, realize the engagement of high low gear.

, with further reference to Fig. 5, be please the control system functional-block diagram of speed change tool of the present invention.Described control system 8 comprises a processing unit 3 and drive unit 5.Wherein processing unit 3 comprises processor 30 and correlated inputs/output circuit.One signal generator 35 is connected with processor, and is provided with functional switch 36 between speed change tool main circuit power 1 and processor 30.The control signal that drive unit 5 is exported by processor 30 is controlled, to carry out automaitc shfit action, meanwhile, drive unit can feed back to gear signal processor 30.In speed change tool operating process, according to the actual demand of operator's custom or application, operator can select functional switch 36 closures, thereby start the Automatic Shift Control function of control system 8, in other words, this functional switch 36 provides the switching function between speed change tool 9 manual modes and automatic mode.If when operation only needs wherein some shift functions, can break function switch 36, speed change tool is carried out to gear-change operation with manual mode.

When speed change tool 9 is during in automatic mode, the processor 30 of control system 8 detects the variation of the physical parameter of speed change tool, compares with predefined value, judges whether need to start to carry out automaitc shfit.Those skilled in the art also external discharge circuit of available processors replace processor 30 to compare computing.Physical parameter described here, can be electric parameter, such as motor current, voltage, can be also other parameters, such as stress, the moment of torsion etc. of motor or output shaft rotating speed, mechanical parts.In some use occasion, operator perhaps wishes under automatic mode, still can to decide in its sole discretion the time point of gear shift, also can, by a manually control signal of input of signal generator 35, make control system immediately realize automaitc shfit.

In automaitc shfit process, control unit 3 sends control signal to drive unit 5, and the actuator 52 in drive unit 5 drives driving component 51 to move, and then the moving part in gear drive 4 45 is moved to low gear from high gear.In this process, if motor 2 is still being given gear drive 4 transmitting torques, be that moving part 45 still has certain rotating speed, (ginseng Fig. 3 b), will cause generation between moving part 45 and whirl-stop device 44 to beat tooth and the problem that cannot engage smoothly and need to engage with static whirl-stop device 44 after mobile.The present invention has proposed three kinds of solutions for addressing this problem, and below describes respectively.

With reference to Fig. 6, it is control unit first embodiment's functional-block diagram of speed change tool control system of the present invention.Wherein processing unit 3 comprises processor 30, VM 31, load detecting circuit 32, drive unit control circuit 33 and gear signal feeder loop 34.In the main circuit of speed change tool 9, an electric switch 10 (such as field effect transistor, controllable silicon or relay etc.) is further set between power supply and motor, this electric switch 10 is controlled on off operating mode by VM 31.

In the time that speed change tool is started shooting, (as the 0.1s) conducting again that lags behind a period of time of processor 30 control apparatus switches 10, within this period, first sends instruction to drive unit control circuit 33, oppositely switch on to electromagnet, drive unit 5 is reset to high gear state.Then power supply 1 power supply allows motor 2 start and normally to move in top gear.Now output shaft 6 drives working head (not shown) to start to carry out Drilling operation.Load detecting circuit 32 gathers the load current of motor with characteristic frequency, motor load value and predetermined current value that 30 of processors collect load detecting circuit 32 compare.If there is exceeding for a long time the situation of predetermined current value in motor load electric current, illustrate that working head load is large, instrument need to change to bottom gear high pulling torque output state.Now processor 30 first sends instruction to VM 31, and control apparatus switch 10 is cut off the electricity supply and made motor stall, motor current vanishing.Now the speed of speed ring also can be reduced to zero rotating speed.

Afterwards, processor sends instruction to drive unit control circuit 33, and the electromagnet of drive unit 5 is oppositely switched on, and iron core 523 drives speed ring 45 to be moved, thereby realizes the conversion of high gear to low gear.Because before gear shift, the rotating speed of speed ring 45 has been zero, is converted in bottom gear process at its gear, and its end tooth 452 is state of rest with the internal tooth 441 of whirl-stop device 44, therefore can enter very smoothly engaging position, and avoids beating the generation of tooth problem.

Gear signal feeder loop 34 in control unit 3 is (those skilled in the art also can be designed to detect the engaging position relation between speed ring and gear assembly) in the time that the iron core 523 that electromagnet detected contacts with another permanent magnet 521, represent that speed ring 45 has successfully moved to low gear, processor sends instruction to VM 31, make electric switch 10 conductings, power supply 1 recovers to power to motor 2, and motor enters low-speed big output services state.

It should be noted that, speed change tool is in high speed normal course of operation, often because there is the heavy load value appearance in short-term of motor load electric current in some special circumstances, in order to prevent the situation of gear shift action false tripping, can solve by the program of setting processor, only have the motor current collecting when load detecting circuit to exceed the predefined value regular hour when (such as design time is 0.5s), just start to carry out gear shift control.Certainly, also can directly functional switch 36 be cut off and directly select manual mode, false tripping gear shift action while avoiding not wishing automaitc shfit.Default current value decides according to the top gear maximal work current value of instrument, in the present embodiment take 30 amperes as predefined value.In addition, if operator wishes starting sometime automaitc shfit, even if motor load electric current does not also exceed predefined value, also can input a control signal by the signal generator 35 on processor 30, thereby immediately start to carry out automaitc shfit action.Further, processor also can be designed to have learning functionality, that is, the motor load electric current while recording operator at every turn by signal generator input control signal, as the reference of initialization system predefined value.

Above-mentioned before automaitc shfit control unit 3 control apparatus switches 10 allow just a kind of mode of execution wherein of motor 2 temporary stoppages.Under normal conditions, if when the rotating speed of motor 2 is reduced to very little degree, the same problem of beating tooth that there will not be of the engagement of speed ring 45 and whirl-stop device 44 in gearshift procedure.Shown in Fig. 7, be control unit second embodiment of speed change tool control system of the present invention.In the main circuit of speed change tool 9, electric switch 10 use field effect transistors 11 between power supply and motor replace, in the time that needs carry out automaitc shfit, VM 31 provides motor corresponding operating voltage by controlling field effect transistor 11, to reach the object that reduces motor rotary speed, thereby speed ring 45 is mated mutually with the speed of whirl-stop device 44, prevent from beating the generation of tooth phenomenon.Here the speed of indication is mutually mated and is referred to that speed ring 45 and the relative velocity of whirl-stop device 44 reach a scope that can make the two enter smoothly engaging position.

Equally, as shown in Figure 8, be control unit the 3rd embodiment of speed change tool control system of the present invention.One clutch 12 is set between motor 2 and gear drive 4, VM 31 is controlled these clutches 12 and reduces motor 2 and be passed to the moment of torsion of gear drive 4, also can realize the object of velocity modulation, before speed ring 45 moves to the position of engaging with whirl-stop device 44, reduce the rotating speed of speed ring 45, with the problem that prevents that in engagement process, tooth is beaten in appearance.

The embodiment of comprehensive above-mentioned several velocity modulation, can find out that spirit of the present invention is mainly: control unit 3 is in the time detecting that motor 2 loads exceed predefined value for a long time, Negotiation speed modulation circuit 31 carries out velocity modulation to moving part 45 and gear assembly, in the time that the relative velocity of the two mates mutually, enter again next gear engagement, in other words, control unit is first adjusted motor and passes to the moment of torsion of gear drive, accessory drive is realized automaitc shfit again, thereby effectively avoids the tooth problem of beating in automaitc shfit process.

It is worth mentioning that in addition, after automaitc shfit release, power supply 1 recovers to power to motor 2, motor 2 is from the utmost point slow-speed of revolution or even the instantaneous low rotation speed large torque output state that enters of zero rotating speed state, can cause a very large starting torque to operator, if it is not tight that operator grips, even can cause instrument to get loose from operator's hand and cause danger.For head it off, can realize by controlling field effect transistor 11 (ginseng Fig. 7) soft start of motor 2.Particularly, after automaitc shfit finishes, when recovery motor 2 is powered, control unit 3 is (such as 0.6s) within the time period of a setting, control field effect transistor by modes such as fixed frequency modulated PWM or fixed width frequency modulation, increase gradually the load voltage of motor 2, slowly recover motor 2 to operating voltage, thereby avoid the impact sensation brought to operator of starting motor of moment after gear shift.

Application disclosed above structure, the shifting control method of speed change tool of the present invention is, provide a kind of speed change tool to comprise the gear drive 4 of power supply 1, motor 2, output shaft 6, connecting motor and output shaft, and control system 8, wherein gear drive 4 comprises at least one gear assembly and a moving part, and the described moving part engagement system different from gear assembly can provide output shaft different output gears; Control system 8 is made up of control unit 3 and drive unit 5, and this shifting control method comprises:

1) load torque detecting step: described control system detects speed change tool physical parameter, such as detecting motor 2 load currents, voltage or output shaft rotating speed, judges the working state of speed change tool;

2) automaitc shfit step: the moving part of control gear driving mechanism moves to another gear.

Described load torque detects between automaitc shfit step and further comprises a velocity modulation step, in the time that the load torque of described output shaft changes to predetermined value, described control unit adjustment motor passes to the moment of torsion of gear drive, moving part is mated mutually with the rotating speed of gear assembly, and speed ring 45 reaches a scope that can make the two enter smoothly engaging position with the relative velocity of whirl-stop device 44.

In described velocity modulation step, reduce motor and pass to the moment of torsion of gear drive by reducing the input voltage of motor.

After automaitc shfit step, further comprise moving part gear detecting step, to confirm that moving part has moved to another gear.

After velocity modulation step, also comprise a motor soft start step, control system progressively strengthens the input voltage of motor in default time range, makes motor recover moment of torsion output.

Describe the opportunity of the auto-speed of speed change tool of the present invention being switched below in conjunction with Fig. 9.Shown in Fig. 9 is that the complete machine delivery efficiency η of speed change tool is with the change curve of output shaft load torque T.The ratio of the output power that wherein the delivery efficiency η of complete machine is output shaft and the output power of motor, η _hcurve is the delivery efficiency curve of complete machine in the time running up, η _lcurve is the delivery efficiency curve of complete machine in the time of low-speed running.As can be seen from Figure, when complete machine is in the time running up, along with the increase of load, delivery efficiency starts rapid increase, reduces rapidly immediately when reaching after the highest delivery efficiency point; When complete machine is during at low-speed running, along with the increase of load, delivery efficiency starts slow increase, and slowly reduces when reaching after the highest delivery efficiency point.In the time that load torque value equals Tc, high speed efficiency curve η _hwith low speed efficiency curve η _lin this intersection, its intersection point is η c.And before this, the delivery efficiency of complete machine in the time running up will be higher than the delivery efficiency when the low-speed running; After this, along with the continuation of load increases, the delivery efficiency of complete machine in the time running up will be lower than the delivery efficiency when the low-speed running, so, in the time that load torque value reaches Tc, the motion speed of complete machine, from being switched to low speed at a high speed, can be guaranteed to speed change can keep higher delivery efficiency always.Speed change tool of the present invention wishes, by determining that load torque value reaches the time point of Tc, then to carry out the switching to low speed at a high speed.

As shown in Figure 9, in the present embodiment, control system can detect by the variation of the electric current of motor, is used for characterizing the load button square of output shaft.Wherein I _hfor the current curve of output shaft in the time running up.Originally, output shaft is operated in high rotating speed, in the time that load torque value reaches Tc, now, the current value that motor detected is Ic, in the present embodiment, Ic=30A (ampere), then, control system accessory drive is carried out from the switching to low speed at a high speed.It should be noted that, because the characteristic of dissimilar motor is different, as adopt different motors, the curve of delivery efficiency also has difference, and so corresponding Ic value is also likely different.In addition, in present embodiment, adopt the current value of monitoring motor to reflect the load of output shaft, in other embodiments, can reflect by detecting other physical parameters the load of output shaft.As rotating speed or the moment of torsion etc. of the rotating speed of the rotating speed of the moment of torsion of output shaft, output shaft, motor, gear train assembly middle gear, or adopting when DC power supply, the mode such as voltage change that also can detect battery terminal characterizes the load of output shaft.

Shown in Figure 10-Figure 14 is the another kind of mode of execution of speed change tool of the present invention, and in the present embodiment, electromagnet apparatus adopts two-way freeze mode electromagnet.So-called two-way freeze mode electromagnet also can remain on iron core top and two positions of terminal of stroke in cold situation.As shown in figure 14, electromagnet apparatus 53 comprise lengthwise setting metal shell 531, be arranged on two coils 532 distributing along longitudinal direction in metal shell, be arranged on two permanent magnets 533 between coil, be arranged on by coil around region in and can be along the linearly moving iron core 534 of longitudinal direction, and be fixedly installed and lengthwise extends the push rod 535 outside metal shell 531 with respect to iron core.Wherein, the fore-end that push rod 535 protrudes out metal shell 531 is provided with groove 536.Can expect easily for those of ordinary skills, push rod 531 and iron core 534 also can be wholely set.Shown in Figure 14 be push rod 535 in going-back position, and can in cold situation, remain on this position due to the attraction of permanent magnet 533.Coordinate with reference to shown in Figure 10 and Figure 12, a gear frame 54 is arranged between steel wire cover 513 and push rod 535, and it comprises the semi-circular bracket 541 of extending around gear-box 47 and extends downwards and spaced pair of sidewalls 542 from bracket bottom.The two ends that wherein radial convex of the two ends of bracket 541 and steel wire cover 513 stretches out speed reducer 47 housings are fixedly connected respectively, in the interval region of sidewall 542, contain electromagnet apparatus 53, side-wall shaft is to extending back and being entrenched in the groove 536 of push rod 535 and keeping relative fixing with push rod.As shown in figure 12, between gear frame 54 and casing 21, be provided with guide mechanism.Wherein the each side extending of pair of sidewalls 542 of gear frame 54 goes out a guide posts 543, on every side inwall of casing 21, convexes with a pair of floor 544, is formed with guide slot 545 therebetween and accommodates and guide each guide posts 543 with corresponding.

Push rod 535 in electromagnet apparatus 53 shown in Figure 10 is in progressive position, and push rod extends metal shell longer distance outward, and because the attraction of permanent magnet remains on this position.Now, the reduction speed ratio of gear drive is lower, it is higher that motor passes to output shaft rotating speed after by gear-box, that is to say, ring gear 45 (or claims speed ring, be the moving part in present embodiment) the external tooth of internal tooth and planet wheel 42 and the external tooth of contiguous planet carrier 41 engage simultaneously and guarantee relative fixing (coordinating with reference to shown in Fig. 3 a), thereby can rotate with planet carrier and planet wheel.Coordinate with reference to Figure 14, when after the interior logical forward current of coil 532 of electromagnet apparatus 53, the magnetic field that coil 532 produces produces different magnetic poles at the lengthwise two ends of metal shell 531, thereby drives iron core 534 and push rod 535 to move to going-back position.As shown in figure 10, push rod 535 drives gear frame 54, steel wire cover 513 displacement distance d together with ring gear 45, has arrived position as shown in figure 11.Coordinate with reference to shown in Fig. 3 b, in this process, ring gear 45 moves vertically and engages with planet carrier 41 disengagings, but still keeps engaging with planet wheel 42.In the time that push rod 53 moves to going-back position, ring gear 45 engages with whirl-stop device 44 and keeps relative fixing with casing.Now, the reduction speed ratio of gear drive 4 has increased one-level, lower thereby motor passes to the rotating speed of output shaft after by gear-box.When after the interior logical back current of coil 532, coil forms reverse magnetic field, and so, push rod 535 is got back to going-back position as shown in figure 10, thereby gear drive 4 is returned to the output state of high reduction speed ratio.

Shown in Figure 13 is a kind of mode of execution of functional switch 36.In the present embodiment, this functional switch can be referred to as velocity mode switch.Coordinate with reference to the velocity mode switch 36 in Figure 16, this switch comprises the protruding toggle 361 being exposed at outside casing 21, and is arranged on the conducting terminal being connected with other electrical assemblys in casing.Toggle 361 can be along the circumferential direction three position slippages on casing 21, corresponding automatic mode (A), fast mode (H), low-speed mode (L) respectively.Conducting terminal comprises and these three kinds of first, second, third signal terminals 362 that patterns difference is corresponding, and ground terminal 363.Be connected with the circuit of other electrical assemblys in control system about velocity mode switch and workflow will arrive in subsequent detailed description.

Shown in Figure 15 is a kind of mode of execution of signal occurrence device 35.In the present embodiment, this device comprises the speed diverter switch being arranged in casing 21, when this switch is pressed after triggering, control system changes the flow direction of the electric current of supplying with electromagnet apparatus and realizes automaitc shfit, realizes the switching of gear drive between high reduction speed ratio and low reduction speed ratio by the driving of electromagnet.As shown in figure 16, as preferred embodiment, this device 35 comprises two these speed diverter switches, be symmetricly set in the both sides of casing 21, press any one switch and can trigger the switching of speed, like this, can operate easily for left hand and right hand user.Shown in Figure 17 a and Figure 17 b is the concrete form of switch.Switch in Figure 17 a is push-button switch 351, and it is electrically connected (follow-up being further described) by wire 3512 and the electronic component in control system.On casing, be provided with flexible retaining piece 353, press retaining piece, button 3511 is also pressed, and the contact (not shown) in switch is connected, thereby speed switching function is triggered.In Figure 17 b, adopt spring-piece type switch 352, same, press retaining piece 353, shell fragment 3521 is connected with contact 3523, now, an electrical signal will be generated and pass to control system, thus control system execution speed changeover program (follow-up being described specifically).Return to Figure 16, in present embodiment, velocity mode switch 36 and signal occurrence device 35 can be combined with.When the toggle of velocity mode switch 36 is positioned at gear A,, in the time of automatic mode, the conductively-closed of speed switching function, that is to say, the speed diverter switch of pressing can't trigger speed switching function; And in the time that the toggle of velocity mode switch is positioned at gear H or L, in the time of high speed or low-speed mode, the function conductively-closed that auto-speed switches, at this moment, the speed diverter switch of pressing just can trigger speed switching function, thereby fast mode can correspondingly be switched to low-speed mode, low-speed mode can correspondingly be switched to fast mode.

In the present embodiment, on casing 21, be also provided with a side handle 22, the position of the switch button of these side handle 22 distance signal generating means 35 has a specific range h in the axial direction, and this hand apart from tolerable user's the sorrowful handle of gripping is operation button switch simultaneously.For example, when user wants switch speed in the time operating, it can use the thumb push switch button of the hand that grips sorrowful handle, thereby obtains the speed that it is wanted.Certainly, what can expect easily for those of ordinary skills is, above-mentioned switch button also can near main handle 23 (shown in Figure 10) arrange and and between main handle, form specific range, thereby user also can carry out the operation that simultaneously execution speed switches with the hand that grips main handle.

What Figure 18 and Figure 19 disclosed is other two kinds of implementations that signal occurrence device 35 is applied.Velocity mode switch 36 shown in Figure 18 does not comprise automatic mode gear, and like this, as long as press speed diverter switch, speed switching function will be by instantaneous starting, from current high speed or corresponding low speed or the high gear of being switched to of low gear.The mode of execution that Figure 19 discloses does not comprise velocity mode switch, in this mode of execution, speed change tool operates under automatic mode, and casing 21 is provided with the LED lamp of the current motion speed state of representational tool, if current instrument is in high speed operation, " H " LED lamp 371 Chang Liang, otherwise, " L " LED lamp 372 Chang Liang.In present embodiment, after instrument start operation, acquiescence is moved under automatic mode, once signal occurrence device 35 is triggered, control system 8 is interrupted automatic operating mode, simultaneously, control system 8 is controlled the reduction speed ratio of electromagnet apparatus 53 change gear driving mechanisms 4, switches current speed running state, as by being switched at a high speed low speed.As signal occurrence device 35 is triggered again, current speed running state is switched again, as being switched at a high speed from low speed again.So, in the present embodiment, once the automatic mode that speed is switched is interrupted, entered the manual speed switch mode by signal occurrence device control.Certainly can expect easily for those of ordinary skills, the reduction speed ratio that above-mentioned signal occurrence device and concrete speed switching mode can be applicable to have more than two-stage is switched, as has the gear train assembly of high, medium and low three speed.

Shown in Figure 20 is the circuit diagram of the simplification in speed change tool one embodiment of the present invention.In this mode of execution, speed change tool provides electric power by external dc power 1, and this external dc power is the cell bag being made up of some batteries.As preferred embodiment, this cell bag can be lithium ion battery bag.It should be noted that, said lithium ion battery is that negative material is the general name of the rechargeable battery of elemental lithium here, and according to the difference of positive electrode, it can form many systems, as " lithium manganese " battery, and " lithium iron " battery etc.In the present embodiment, lithium ion battery bag comprises by being connected into by the lithium ion battery of five joint 3.6V (volt) battery pack that voltage rating is 18V.Certainly, what can expect easily for those of ordinary skills is, more or less battery of can optionally connecting forms battery pack, as the lithium ion battery of the four joint 3.6V (volt) that connect to become voltage rating be the battery pack of 14.4V, or the lithium ion batteries of series connection six joint 3.6V (volt) to become voltage rating be the battery pack of 21.6V.In present embodiment, in cell bag 1, be also provided with the identification resistance 386 that represents this cell bag voltage, be used for being identified by electric tool, thereby determine corresponding cell bag Cross prevention mode.

As shown in figure 20, can coordinate with reference to shown in Fig. 6 simultaneously, in present embodiment, the speed variator system of speed change tool comprises processor 30, VM 31, motor load testing circuit 32, drive unit control circuit 33, gear signal feeder loop 34, signal occurrence device 35 and functional switch 36.

Processor 30 can adopt MCU, PLC or CPU etc.In the present embodiment, processor 30 is a microcomputer control system (MCU), what those skilled in the art can be easy to expect is, MCU has generally included central processing unit (CPU), ROM (read-only memory) (ROM), random access memory (RAM), digital/analog converter (A/D converter), timer (timer), input/output end port (I/Oport) P1-P28 etc., because the working principle of these unit or function module is all by those of ordinary skill in the art is known well, so claimant is no longer repeated at this.

As shown in figure 20, main switch 13 is connected between cell bag 1 and main circuit, can be used for controlling the break-make of main circuit.In the time that the button 131 on main handle 23 (as Figure 10 shows) is depressed by operator, main circuit is switched on, by DC electrical source modular converter (DC/DC) 381, the voltage of cell bag 1 is converted into a lower constant voltage, be 5V in the present embodiment, be used for providing electric power for processor 30 and electronic circuit.In the present embodiment, the port P20 of processor is connected with DC electrical source modular converter 381, port P19 ground connection, port P1 is connected by resistance R 5 with DC electrical source modular converter 381, thereby after main switch 13 closures, electric current after 381 conversions of DC electrical source modular converter is by port P20 input processor, and processor receives a reset signal and carries out initialization action from port P1.Main switch 13 not only can be used for the break-make of control circuit, also further can be for controlling the rotating speed of motor.In present embodiment, main switch 13 comprises a potentiometer (potentiometer), it is used for measuring the distance that button moves under the effect of operator presses and produces an electrical signal proportional to this displacement distance, as voltage value signal, this electrical signal sends processor 30 to by port P2, and the digital/analog converter of preprocessor converts this electrical signal to digital signal and process and generate corresponding control signal.In the present embodiment, this control signal is pulsewidth modulation (PWM, Pulse WidthModulation) signal, and for controlling the voltage being applied on motor 2, its port P12 by processor 30 exports to VM 31.VM 31 is made up of resistance R 19, power switch driver.Wherein power switch driver is made up of some triodes, it is for regulating the dutycycle of MOSFET, that is to say, power switch driver is according to the pwm signal receiving, improve or reduce the continuous output time of voltage signal in the single cycle, thereby control the running speed of motor 2 by power switch component 10 (being electric switch).Wherein power switch component 10 can be semiconductor switch, is mos field effect transistor (MOSFET, metallic oxidesemiconductor field effecttransistor) in the present embodiment.

The port P3 of processor 30 can be connected to gather with cell bag 1 operating voltage of cell bag, so that monitor the discharge scenario of cell bag, and in the time of brownout, take appropriate measures to remind the electric power of user or sever supply motor.As shown in figure 20, port P18, the P17 of processor 30, P16, P15 are connected with light emitting diode D2, D3, D4, D5 by resistance R 22, R23, R29, R30.These light emitting diodes can be located on casing, are used for representing the dump energy of cell bag 1, wherein D2, D3, D4 transmitting green light, and D5 launches ruddiness.In the time that electric weight is sufficient, D2, D3, the equal Chang Liang of D4, D5 does not work; In the time that electric weight is medium, D3, D4 Chang Liang, D2, D5 do not work; In the time that electric weight is low, D4 Chang Liang, D3, D2, D5 all do not work; And in the time that electric weight is not enough, D2, D3, D4 all do not work, and D5 Chang Liang; In the time of electric weight wretched insufficiency, D2, D3, D4 all do not work, and D5 flicker, at this moment, cause danger for avoiding cell bag to cross putting, and the port P12 of processor is blocked and cannot provides electric power to motor.In the present embodiment, for the cell bag of voltage rating Vb=18V, in the time of 12.5V < Vb≤14.5V, represent cell bag electric weight deficiency, thereby D2, D3, D4 all do not work, and D5 Chang Liang; In the time of Vb≤12.5V, represent cell bag electric weight wretched insufficiency, thereby D2, D3, D4 all do not work, and D5 flicker, meanwhile, the port P12 of processor 30 is blocked.

For the running state of monitoring motor 2, processor can detect by the operating current of motor in real time.As shown in figure 20, one detects resistance 383 connects with switch 10 and motor 2, and an amplifier 382 is for amplifying and be input to processor 30 by port P4 detecting the pressure drop signal producing on resistance 383, so that processor 30 detects by the electric current of motor 2.In addition, also comprise over-current protection circuit 37 in circuit, it comprises a comparator 384, and it gathers the pressure drop signal on R6 by resistance R 18, and makes comparisons with the reference voltage signal Vref of input.In the time that the magnitude of voltage collecting is greater than reference voltage Vref, the high level state of initialization is converted to low level state by comparator 384, and by resistance R 24, low level signal is exported to the port P21 of processor 30.In addition,, for avoiding motor 2 operating temperatures too high, the resistance that can utilize thermistor 385 varies with temperature and the characteristic of linear change detects the temperature of motor.Thermistor 385 is composed in series bleeder circuit with resistance R 10, the port P5 of processor 30 by wire be connected to 385 and resistance R 10 between, detect the voltage change on thermistor 385, thereby be convenient to the variation of processor 30 Real-Time Monitoring motor 2 temperature, and exceed predetermined value at motor temperature, disconnect the electric power of supply motor.

Control system also comprises the recognition circuit for identifying cell bag 1 voltage.In the present embodiment, this recognition circuit be after cell bag 1 is connected with speed change tool by identification resistance 386, and the bleeder circuit of resistance R 13 and R21 composition.Processor port P7 is connected between resistance R 13 and identification resistance 386 by resistance R 21, the pressure drop being used on sensing identification resistance 386, thus determine the voltage of cell bag 1, and carry out the program of corresponding Cross prevention.

In present embodiment, drive unit control circuit 33 is a H bridge circuit, processor 30 is connected respectively to four inlet opening A, B, C, the D of H bridge circuit by port P11, P9, P10, P6, these four inlet openings are connected with power switch component Q4, Q1, Q2, Q3 by resistance R 4, R1, R2, R3 respectively, electromagnet apparatus 5 is connected between the tie point H of power switch component Q1 and Q2 and the tie point L of power switch component Q3 and Q4, and a termination cell bag power supply of H bridge circuit, the other end ground connection.In the present embodiment, above-mentioned power switch is semiconductor switch, and is preferably MOSFET.Processor is controlled electromagnet apparatus 53 by break-make four inlet opening A, B, C, D.For example, when inlet opening A, B connect, and inlet opening C, D disconnect time, power switch component Q1 and Q4 connect, now the flow direction of electric current is from tie point H to tie point L, correspondingly, the push rod 535 of electromagnet apparatus 53 drives ring gear 45 to move to the low-speed position shown in Figure 11 from high speed position as shown in figure 10.Otherwise, when inlet opening A, B disconnect, and inlet opening C, D connect time, the push rod 535 of electromagnet apparatus 53 drives ring gear 45 to move to high speed position from low-speed position.

Gear signal feeder loop 34 comprises a switch 387, and resistance R 25, R26, R27, R28.In the present embodiment, switch 387 is a hilted broadsword on off switch, and it comprises contact H1 and contact L1, and wherein, the port one 3 of contact L1 and processor is connected, and the port one 4 of contact H1 and processor is connected.What can expect easily for those of ordinary skill in the art is, when concrete enforcement, contact H1 and contact L1 can be arranged on the reed at the gear frame stroke two ends on casing, on gear frame, be provided with tinsel, as copper sheet, while moving to high speed position to gear frame, its tinsel contacts and make contact H1 with corresponding reed; Otherwise, make contact L1.As shown in figure 20, in the time that gear frame moves to low-speed position, contact H1 is disconnected and contact L1 is switched on, now, port one 3 can detect a low level signal, and port one 4 can detect a high level signal, works under high reduction speed ratio thereby processor 30 judges current gear drive; Otherwise when gear frame turns back to after high speed position, port one 4 can detect a low level signal, port one 3 can detect a high level signal.Can expect easily for those of ordinary skills, tinsel and reed can relative set on ring gear and gear-box, or be arranged on the push rod and housing of electromagnet apparatus.

In present embodiment, what functional switch 36 adopted is the velocity mode switch of changeable three kinds of velocity modes as shown in figure 16, between fast mode, low-speed mode and automatic mode, switches.As shown in figure 20, velocity mode switch 36 is hilted broadsword three-position switches, and it has three contact L2, H2, A, is connected to respectively port P26, P25, the P24 of processor by resistance R 14, R15, R16.When velocity mode switch 36 is positioned at position as shown in FIG., be that contact A is connected, and contact H2 and contact L2 disconnect, now, processor 30 detects that port P24 is low level signal, and port P25, P26 are high level signal, so, processor will call and move the program (follow-up being described in detail this) of automaitc shfit.And in the time that contact A disconnects, and contact H2 or contact L2 connect, processor 30 can not call and move the program of automaitc shfit.

Two switch S 2 of signal occurrence device 35, S3 parallel connection, and be connected with the port P23 of processor 30 by resistance R 17.In the time that in switch S 2, S3, any is depressed, will produce an electrical signal and pass through port P23 input processor 30, so, processor 30 will interrupt the program of moving at present and call speed changeover program (will be described in detail below).

Next, coordinate Figure 21 and Figure 22 so that the execution self-shifting workflow of processor and the workflow that speed is switched to be described respectively.

With reference to Figure 21, coordinate with reference to shown in Figure 20 simultaneously, after main switch 13 is closed (step 711), processor port P1 receives reset signal, thus processor is carried out initialization action (step 712).Then, processor gathers the voltage signal (step 713) of cell bag by port 3, to judge that cell bag is whether in state that can normal use, judge whether cell bag voltage is less than 12.5V, if, show that cell bag, through putting, is unsuitable for discharging again, thereby can blocks port P12 output pwm signal; If not, show that cell bag can normally be used, next, the current selected pattern of detection speed mode switch 36 (step 714).If what velocity mode switch 36 was selected is automatic mode, further judge that whether electromagnet apparatus 53 is in high speed position (step 715), if so, continues next step; If not, processor is connected inlet opening C, D, and disconnects inlet opening A, B, thereby drives push rod to move to high speed position (step 718) to the logical back current of electromagnet apparatus 53.If what velocity mode switch 36 was selected is fast mode, further judge whether electromagnet apparatus is in high speed position (step 716), if so, continue next step; If not, DM device and impel push rod to move to high speed position (step 719).If what velocity mode switch 36 was selected is low-speed mode, further judge whether electromagnet apparatus is in low-speed position (step 717), if so, continue next step; If not, processor disconnects inlet opening C, D, and connects inlet opening A, B, thereby drives push rod to move to low-speed position (step 720) to the logical forward current of electromagnet apparatus.

Next, show the dump energy (step 721) of cell bag by LED lamp D2-D5, and in the time of electric weight wretched insufficiency the electric power of sever supply motor; Detect in real time the voltage (step 722) of cell bag, and cross the electric power of sever supply motor while putting in cell bag; Detect according to pressing depth (step 723) of trigger; According to pressing depth export corresponding pwm signal (step 724) according to trigger; Detect motor current (step 725).

Judge velocity mode (step 726), if control system operates in fast mode or low-speed mode at present, judge whether motor current continues 500ms (millisecond) and be greater than 90A (ampere) (step 727,729), if, show motor that the abnormal case such as stall likely occur and cause electric current excessive, therefore, be protection motor, disconnect the electric current (step 728,730) of supply motor; If not, return to step 721.If controlling run is at automatic mode, judge whether motor current continues 300ms (millisecond) and be greater than 90A (ampere) (step 731), if so, show that stall has likely occurred motor, carries out the step of automaitc shfit; If not, continue to judge whether motor current continues 500ms (millisecond) and be greater than 30A (ampere) (step 732), if so, show instrument at a high speed the efficiency of output be about to the efficiency lower than low speed output, like this carry out the step of automaitc shfit; If not, return to step 721.

In the present embodiment, automaitc shfit step comprises step 733-step 736.First, for avoiding beating tooth, temporarily stop providing electric power (step 733) to motor, i.e. processor temporary interruption port P12 output signal, thus the rotating speed of motor and ring gear is lowered.Then, processor control H bridge circuit is to the logical forward current of electromagnet apparatus, be that processor is connected inlet opening A, B, and disconnect inlet opening C, D, thereby make electromagnet apparatus drive push rod to move to low-speed position (step 734) from high speed position, and in the time moving to low-speed position, trigger switch S5 and make contact L1 connect.Then, soft start motor (step 735), the pwm signal that processor is exported by port P12 progressively increases the pulsewidth of voltage signal, thereby impels motor to be returned at leisure normal running speed.Again, the low level signal that processor receives according to port one 3 is set low speed mark (step 736), next, returns to step 721.It should be noted that, need a period of time because ring gear moves to low-speed position from high speed position under the driving of push rod, so, in other embodiments, can be also by the first DM device of processor, the step of then suspending at motor.In this process, only need to guarantee that motor driving force does not exist before ring gear and whirl-stop device engagement, so, even if the speed of ring gear does not also drop to zero, but because it does not have the driving force of active rotation, so, can engage with whirl-stop device and staticly get off very soon.

With reference to Figure 22, and coordinate with reference to shown in Figure 20, in the time that the port 23 of processor receives an interrupt signal, processor can stop the program of moving at present and call speed changeover program (step 751).First processor detects motor current whether excessive (step 752) by port 21, as is greater than 100A (ampere), if so, shows stall of motor, stops supplying with electric current (step 753) to motor; If not, detection speed mode switch at present in which kind of pattern (step 754).If automatic mode interrupts returning, processor continues to carry out original program (step 767); If fast mode or low-speed mode need to judge that whether motor is in zero load.When having load during with respect to zero load motor speed reduce faster, so while having compared load, after when unloaded, motor power cuts off, time that need to be longer just can make motor stop.If fast mode, judge whether motor current continues 500ms (millisecond) and be greater than 30A (ampere) (step 755), if so, showing has load, stops subsequently the electric power of supply motor and postpones 0.5S (step 756); If not, stop the electric power of supply motor and postpone 2S (step 757).If low-speed mode, judge whether motor current continues 500ms (millisecond) and be greater than 30A (ampere) (step 761), if so, showing has load, stops subsequently the electric power of supply motor and postpones 0.5S (step 762); If not, stop the electric power of supply motor and postpone 2S (step 763).Carrying out shutdown delay; next processor DM device is carried out from a high speed to low speed or switching from low speed to high speed (step 758,764); starting motor (step 759,765) subsequently; and respective settings low speed mark or high speed mark (step 760,766), then return to original program (step 767).

With reference to Figure 23, it is the circuit diagram of the simplification in another embodiment of speed change tool of the present invention.The control system of what this mode of execution was different from Figure 20 is speed change tool further comprises the electronic switch in parallel with motor 2 90 (such as field effect transistor, controllable silicon or relay etc.), and this electronic switch 90 is controlled on off operating mode by electric brake control circuit 91.Electric brake control circuit is made up of resistance R 31, power switch driver 911.Power switch driver is for controlling disconnection and the closure of electronic switch 90, thereby controls whether short circuit of motor 2.And can form loop when motor short circuit, and due to the principle of electromagnetic induction, in loop, having electric current process, electric current flows through and can bring reverse power to the running of motor, stops motor running, realizes the function of brake.Wherein electronic switch 90 can be semiconductor switch, is mos field effect transistor (MOSFET, metallic oxide semiconductor fieldeffecttransistor) in the present embodiment.

In the time that speed change tool operates in self shifter pattern or manual triggers and need to change the reduction speed ratio of gear drive, control system is connected electronic switch 90 after cutting off motor 2 electric currents, and accessory drive drives moving part to move to low-speed position from high speed position, or move to high speed position from low-speed position, next control system disconnects electronic switch 90 after again connecting motor 2 electric currents.In the preferred implementation of speed change tool of the present invention, whether motor 2 switches on is to lean on the break-make of electric switch 10 to realize, and in the time that electric switch 10 disconnects, electronic switch 90 is connected so, and in the time that electric switch 10 is connected, electronic switch 90 disconnects.Certainly, control system is connected electronic switch 90 after also can cutting off motor 2 electric currents by electronic control unit, and accessory drive drives moving part to move to low-speed position from high speed position, or moves to high speed position from low-speed position.

Also coordinate with reference to Figure 21 with reference to Figure 24, in self-shifting mode of execution, automaitc shfit step further comprises electric brake step (step 790).First, for avoiding beating tooth, temporarily stop providing electric power (step 733) to motor, i.e. processor temporary interruption port P12 output signal, thus the rotating speed of motor and ring gear is lowered.Next, processor is from P30 port output signal, thereby brake control circuit 91 is controlled electronic switch 90 closures, motor short circuit a period of time T.Then, processor control H bridge circuit is to the logical forward current of electromagnet apparatus, be that processor is connected inlet opening A, B, and disconnect inlet opening C, D, thereby make electromagnet apparatus drive push rod to move to low-speed position (step 734) from high speed position, and in the time moving to low-speed position, trigger switch S5 and make contact L1 energising.Then self shifter step is identical with Figure 21.In above self shifter process, motor current is cut to motor and is again started and only need to postpone 200mS, and the time that motor suspends is 200mS, therefore the time T of motor short circuit should be less than 200mS.Certainly, the method for the control speed change tool in present embodiment is identical with the workflow in Figure 21 before control system is cut off the step of motor current, and control system detects speed change tool physical parameter, judges the working state of speed change tool; In the time that the load torque of output shaft changes to predetermined value, control system is cut off motor current.

With reference to Figure 25 and coordinate with reference to shown in Figure 22, in the mode of execution of manual triggers, no matter detection speed mode switch in the time of which kind of pattern (step 754), is fast mode or low-speed mode, all without judging that whether motor is in zero load at present.Due in motor short circuit, motor can stop at once, compares after motor power cuts off and by inertia, motor is stopped, and electric brake only requires a very short time and just can make motor stop.If fast mode stops the electric power of supply motor and controls motor short circuit (step 791 and step 792); If low-speed mode stops the electric power of supply motor and controls motor short circuit a period of time T (step 793 and step 794).In the time carrying out shutdown, only need postpone 200mS, the time T of motor short circuit is less than 200mS so.Next processor DM device is carried out from a high speed to low speed or switching from low speed to high speed (step 758,764), starting motor (step 759,765) subsequently, and respective settings low speed mark or high speed mark (step 760,766), then return to original program (step 767).Certainly, the method for the control speed change tool in present embodiment needs artificially to trigger this trigger switch before the step that stops supply motor electric power, and an electrical signal generates and pass to control system, and control system responds this electrical signal and cuts off motor current.

From Figure 23 to Figure 25, can find out, the essence of present embodiment is no matter be self shifter or manual triggers gearshift, after suspending, motor carries out electric brake, can reduce like this time that motor suspends, after increasing electric brake, motor only need to suspend 200mS, thereby improves the working efficiency of speed change tool.

Gear drive in the present invention and moving part thereof are not limited to the structure that the present embodiment discloses, gear meshing relation while being particularly not limited to the present embodiment high speed gear and bottom gear, gear drive is in the prior art various, as U.S. Patent Bulletin has disclosed multiple gear drive No. 6796921, meshing relation when its top gear and bottom gear is different, but those of ordinary skills are easy to inventive concept according to the present invention, various gear drives is applied to the present invention.

Claims (9)

1. a speed change tool, comprising: casing;

Motor, is arranged in casing, and outputting rotary power;

Output shaft;

Gear drive, be arranged between motor and output shaft so that the rotation output of motor is delivered on output shaft, it comprises at least one group of train of gearings and a moving part, described moving part can move between primary importance and the second place, and in the time of primary importance and the second place, described moving part coordinates in a different manner with described train of gearings, thereby gear drive is with the rotating speed of different reduction speed ratio output motors;

Control system, comprises the drive unit coordinating with moving part, and described drive unit is used for driving described moving part to move between primary importance and the second place;

It is characterized in that: described control system also comprises the electronic switch in parallel with described motor, in the time need to changing the reduction speed ratio of described gear drive, described control system is connected described electronic switch after cutting off motor current, and accessory drive drives described moving part to move between primary importance and the second place.

2. speed change tool according to claim 1, is characterized in that: in the time of primary importance, gear drive is with the rotating speed of low reduction speed ratio output motor; In the time of the second place, gear drive is with the rotating speed of high reduction speed ratio output motor.

3. speed change tool according to claim 2, it is characterized in that: described control system also comprises electronic control unit, described electronic control unit is for detection of the parameter that characterizes output shaft load, reach after predetermined value in described parameter, described electronic control unit is connected described electronic switch after cutting off motor current, and accessory drive drives described moving part to move to the second place from primary importance.

4. speed change tool according to claim 2, it is characterized in that: described control system also comprises electronic control unit and trigger switch, in the time that trigger switch is artificially triggered, one electrical signal generates and passes to electronic control unit, electronic control unit responds this electrical signal and connects described electronic switch after cutting off motor current, and accessory drive drives described moving part to move to the second place or move to primary importance from the second place from primary importance.

5. according to the speed change tool described in claim 3 or 4, it is characterized in that: described electronic control unit disconnects described electronic switch after again connecting motor current.

6. according to the speed change tool described in one of them of claim 1 to 4, it is characterized in that: the time that described electronic switch is connected is less than 200mS.

7. a shifting control method for speed change tool as claimed in claim 4, is characterized in that: described shifting control method comprises the following steps:

1) described control system is cut off motor current;

2) described control system is connected described electronic switch;

3) described control system accessory drive drives described moving part to move to the second place from primary importance.

8. shifting control method according to claim 7, is characterized in that:

1) described control system detects speed change tool physical parameter, judges the working state of speed change tool;

2), in the time that the load torque of described output shaft changes to predetermined value, carry out described control system and cut off the step of motor current.

9. shifting control method according to claim 7, is characterized in that:

1) artificially trigger described trigger switch, an electrical signal generates and passes to control system, and control system responds this electrical signal and carries out described control system and cut off the step of motor current.

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