CN211030355U - electrical tools - Google Patents

Abstract

The utility model discloses an electric tool, comprising: a functional part, which is used for realizing the function of the electric tool; a motor, which is operably connected with the functional part and used for driving the functional part; and a driving circuit, which is electrically connected with the motor and used for driving a motor; a first control module, connected to the drive circuit, for outputting a first control signal to the drive circuit; the first control module has a first working state and a first failure state, and when the first control module is in the first working state, it outputs the first control signal a working signal, the first control module outputs the first failure signal when it is in the first failure state; the second control module is connected to the first control module to receive the first working signal or the first failure signal from the first control module; wherein , the second control module outputs a second control signal to stop the motor when receiving the first failure signal from the first control module. The electric tool of the utility model has high safety.

Description

electrical tools

technical field

The utility model relates to an electric tool, in particular to an electric tool with high safety.

Background technique

Some existing power tools, such as angle grinders, sanders, reciprocating saws, circular saws, jigsaws, pruning machines, chainsaws, etc., have certain dangers in their work.

Take the chain saw as an example, it is mainly used for logging and wood building. Chain saws usually use a high-current switch to control the start and stop of the motor, but with the continuous increase of the working current, it is difficult to select a high-current switch. Now a signal switch is used to replace the high-current switch, and the controller identifies the signal switch state to Controlling the motor running process puts higher requirements on the reliability of the power tool software system. Once the controller fails, it may cause serious safety accidents.

SUMMARY OF THE INVENTION

In order to solve the deficiencies of the prior art, the purpose of the present invention is to provide an electric tool with high safety.

In order to achieve the above-mentioned goals, the utility model adopts the following technical scheme:

An electric tool, comprising: a functional part for realizing the function of the electric tool; a motor, operably connected with the functional part, for driving the functional part; a driving circuit, electrically connected with the motor, used to drive the motor; a first control module, connected to the drive circuit, for outputting a first control signal to the drive circuit; the first control module has a first working state and a first failure state, so The first control module outputs a first working signal when it is in a first working state, and outputs a first failure signal when the first control module is in a first failure state; the second control module is connected to the first control module to receive A first working signal or a first failure signal from the first control module; wherein the second control module outputs a second control signal when receiving the first failure signal from the first control module to make all The motor is shut down.

Optionally, the first control module and the second control module are connected in communication with each other; the second control module has a second working state and a second failure state, when the second control module is in the second working state outputting a second working signal to the first control module, and outputting a second failure signal to the first control module when the second control module is in a second failure state; the first control module receives a signal from the first control module The second control module outputs a first control signal to turn off the motor when the second failure signal is performed.

Optionally, the power tool further includes: a protection circuit electrically connected to the second control module for shutting down the motor when receiving a second control signal from the second control module.

Optionally, the power tool further includes a power supply device for providing electrical energy to the power tool; the protection circuit includes a switch circuit for disconnecting the electrical connection between the motor and the power supply device ; The switch circuit includes at least one electronic switch.

Optionally, the protection circuit further includes a switch control circuit, the switch control circuit is electrically connected to the switch circuit and the second control module, and is configured to control the circuit according to the second control signal of the second control module. The switch circuit is turned off to disconnect the electric motor from the power supply.

Optionally, the drive circuit includes a plurality of drive switches; the switch circuit includes a first electronic switch, electrically connected between at least part of the control terminals of the drive switches and the first control module, for disconnecting The electrical connection between the first control module and the control terminal of at least part of the drive switch; the switch control circuit includes a second electronic switch, which is electrically connected between the control terminal of the first electronic switch and the second control module is used for controlling the first electronic switch to be turned off according to the second control signal of the second control module, so as to disconnect the electrical connection between the first control module and at least part of the driving switch, so that the motor is connected to The electrical connection to the power supply is disconnected.

Optionally, the drive circuit includes a plurality of drive switches; the switch circuit includes: a third electronic switch, the third electronic switch is electrically connected between at least part of the control terminal of the drive switch and the ground wire, and The control end of the third electronic switch is electrically connected to the second control module, and is used for turning on at least part of the connection between the driving switch and the ground wire according to the second control signal of the second control module, so that the The electrical machine is disconnected from the power supply.

Optionally, the second control module includes a control circuit including at least one switching element.

Optionally, the second control module includes a microcontroller.

Optionally, the power tool further includes: a start switch for at least starting the power tool, the start switch is connected to the first control module; the first control module is configured to: when detecting After the start switch is triggered and receives the second operation signal from the second control module, a first control signal is output to start the motor.

Optionally, the power tool further includes: a brake switch for braking the motor, and the brake switch is connected to the first control module; the first control module is configured to: when detecting After the brake switch is triggered and the second operating signal from the second control module is received, a first control signal is output to the driving circuit to brake the motor.

The utility model has the advantages that the safety of the electric tool is improved.

Description of drawings

1 is a power tool as an embodiment;

Fig. 2 is the internal partial structure diagram of the electric tool shown in Fig. 1;

3 is a circuit block diagram of a power tool as an embodiment;

4 is a circuit block diagram of a power tool as another embodiment;

Fig. 5 is an embodiment of the drive circuit and the protection circuit in the power tool shown in Fig. 3;

Fig. 6 is a specific embodiment of the protection circuit in the power tool shown in Fig. 5;

Fig. 7 is another embodiment of the drive circuit and the protection circuit in the power tool shown in Fig. 3;

Fig. 8 is a specific embodiment of the protection circuit in the power tool shown in Fig. 7;

FIG. 9 is a specific embodiment of the drive circuit and the protection circuit in the power tool shown in FIG. 4;

FIG. 10 is a circuit block diagram of an embodiment of the power tool shown in FIG. 3 , wherein the second control module includes a control circuit;

FIG. 11 is a circuit block diagram of an embodiment of the power tool shown in FIG. 4 , wherein the second control module includes an MCU.

Detailed ways

The present utility model is described in detail below with reference to the accompanying drawings and specific embodiments.

The power tool 10 of the present invention can be a hand-held power tool or a garden tool, which is not limited herein. The electric tools of the present invention include but are not limited to the following: electric drills, impact drills, angle grinders, sanders, reciprocating saws, circular saws, jigsaws, electric hammers, etc., pruning machines, chainsaws, etc. electrical tools. As long as these power tools can adopt the essential content of the technical solutions disclosed below, they can fall within the protection scope of the present invention.

1 and 2 , as an embodiment, the power tool 10 is a chain saw as an example. The power tool 10 includes a housing 11 , a front handle 12 and a main handle 13 arranged on the housing 11 , and a main handle 13 arranged on the main handle 13 . The trigger mechanism 14 , the functional part 15 for realizing specific functions, the power supply device 16 and the motor 17 for driving the functional part 15 to move.

The functional part 15 is used to realize the function of the power tool 10 . For a chain saw, the functional part 15 of the power tool 10 includes a saw chain 151 and a guide plate 152 for realizing a cutting function. The motor 17 is used to drive the function. For a chain saw, the saw chain 151 surrounds the edge of the guide plate 152 and can be cyclically guided along the guide plate 152 under the drive of the motor 17 . One end of the guide plate 152 is supported on the casing 11 , and the other end extends along the longitudinal direction of the casing 11 out of the housing 11 . The functional part 15 is operably connected to the motor 17 , and the functional part 15 can be directly connected to the output shaft of the motor 17 , or can be connected to the motor 17 through a transmission device.

The trigger mechanism 14 is operably triggered by a user for controlling activation of the power tool 10 . The trigger mechanism 14 may specifically be, but not limited to, a trigger. The power tool 10 also includes a start switch 18 connected to the trigger mechanism 14, which is arranged in the housing 11. When the trigger mechanism 14 is triggered, the start switch 18 associated with the trigger mechanism 14 is correspondingly triggered, and its trigger state changes.

The power tool 10 also includes a power supply 16 for powering the power tool 10 . In some embodiments, the power tool 10 is powered using a DC power source, and more specifically, the power tool 10 is powered using a battery pack, and the power supply 16 includes a battery pack. In other embodiments, the power tool 10 is powered by an AC power supply, and the AC power supply can be 120V or 220V AC mains, and the AC power rectifies, filters, divides, and divides the AC signal output by the power supply through a hardware circuit. Processes such as depressurization are converted into electrical energy that can be used by the power tool 10 . In this embodiment, the power tool 10 is powered by a battery pack, and the voltage output by the battery pack is changed by a specific power supply circuit (eg, a DC-DC converter chip) to output a power supply voltage suitable for the motor 17 and the control module.

In order to facilitate the user to brake the power tool 10 in an emergency (such as when danger occurs), as an option, the power tool 10 further includes a brake control member 20, and the brake control member 20 is associated with the brake switch 21. The brake switch 21 is a brake switch, which is used to make the motor 17 enter a braking process. The brake control member 20 here is a brake baffle, and can rotate relative to the housing 11 around the fulcrum O. It can be understood that the brake control member 20 can also be set in the form of a button according to the actual design requirements. Press the button when braking. One end of the brake control member 20 is formed with a brake operating portion 201 for the operator to perform braking operation when encountering a dangerous situation, and the other end is formed with a cantilever arm 202 rotatable relative to the housing 11. The cantilever arm 202 can trigger the brake switch 21 . By setting the above manual brake control, the user can brake the electric tool 10 at any time, which is convenient to use.

The normal operation of the above-mentioned power tool 10 also depends on the circuit system, and at least part of the circuit components of the circuit system are arranged on the circuit board 19, and the circuit board 19 is arranged in the housing.

3 , the circuit system of the power tool 10 according to the first embodiment mainly includes a first control module 31 , a second control module 32 , a drive circuit 35 , a power supply device 36 and the motor 17 .

The power supply device 36 is used to provide electric power for the power tool 10, and specifically a battery pack can be selected. Optionally, the power tool 10 further includes a fuse (not shown) and a capacitor (not shown). The power supply device 36 is connected to a fuse, the fuse 39 is used for overcurrent protection, and one end of the fuse is connected to a capacitor. The capacitor is used for filtering and absorbing ripple, and the capacitor is connected in parallel with the driving circuit 35 .

The driving circuit 35 is connected to the motor 17 for driving the motor 17 . The motor 17 includes at least one phase resistance. For example, the motor 17 includes multi-phase windings. Alternatively, the motor 17 includes a first-phase winding A, a second-phase winding B, and a third-phase winding C. The drive circuit 35 is specifically related to the motor 17 The three-phase electrodes U, V and W are electrically connected, and the drive circuit 35 includes multiple drive switches ( FIG. 4 ). Of course, the windings of the motor 17 can be electrically connected to the power supply device 17 through the multiple drive switches. The number of winding phases of the motor 17 may also be other numbers.

The first control module 31 is connected to the driving circuit 35 for outputting a first control signal to the driving circuit 35 . The first control signal is used to make the motor 17 run or stop the motor 17, and the motor 17 shutdown includes the motor 17 braking and the motor stopping. It should be noted that the shutdown of the motor in the present invention includes the braking of the motor and the stopping of the motor, which will not be described later.

Specifically, the first control module 31 is configured to output the first control signal to the drive switch of the drive circuit 35 to control the on-off state of the drive switch of the drive circuit 35 to change the voltage state loaded on the winding of the motor 17 . The first control module 31 is electrically connected to the first power supply circuit 33 , which is powered by the first power supply circuit 33 . The first power supply circuit 33 is connected to the power supply device 36 for power supply. The voltage output by the power supply device 36 is changed by the first power supply circuit 33 to output a power supply voltage suitable for the first control module 31 . The first power supply circuit 33 is, for example, a DC-DC conversion chip. The first control module 31 includes, but is not limited to, MCU, DSP, and the like.

The second control module 32 is connected to the first control module 31 , and is configured to output a second control signal to stop the motor 17 when receiving the first failure signal from the first control module 31 . The second control module 31 is electrically connected to the second power supply circuit 34 , which is powered by the second power supply circuit 34 . The second power supply circuit 34 is connected to the power supply device 36 for power supply. The voltage output by the power supply device 36 is changed by the second power supply circuit 34 to output a power supply voltage suitable for the second control module 32 . The second power supply circuit 35 is, for example, a DC-DC conversion chip. The second control module 32 includes, but is not limited to, a control circuit (FIG. 10), an MCU (FIG. 11), a DSP, and the like. The first power supply circuit 34 and the second power supply circuit 35 may be provided separately or integrated together.

The first control module 31 has a first working state and a first failure state, the first control module 31 outputs a first working signal when in the first working state, and outputs a first failure signal when the first control module 31 is in the first failure state. The first working signal and the first failure signal output by the first control module 31 are transmitted to the second control module 32 . The second control module 32 is connected to the first control module connection 311 to receive the first working signal or the first failure signal from the first control module 31 . The first working signal includes, but is not limited to, a pulse signal. The second control module 32 outputs a second control signal to stop the motor 17 when receiving the first failure signal from the first control module 31 . The first failure signal may include no signal, weak level signal, and the like.

The power tool 10 includes a protection circuit 37 that is electrically connected to the second control module 32 for shutting down the motor 17 when receiving a second control signal from the second control module 32 . In this way, when the first control module 31 fails, the second control module 32 can also provide backup protection, so that the motor 17 can be shut down in time when the first control module 31 fails, so as to avoid the occurrence of safety accidents and improve safety. higher.

The protection circuit 37 includes a switch circuit 371 for disconnecting the electrical connection between the motor 17 and the power supply device 36 . The switch circuit 371 can directly disconnect the electrical connection between the motor 17 and the power supply device 36 , that is, it can also indirectly disconnect the electrical connection between the motor 17 and the power supply device 36 through the drive circuit 35 . Switch circuit 371 includes at least one electronic switch.

In the protection circuit 37 shown in FIG. 3 , the switch circuit 371 is electrically connected between the first control module 31 and the drive circuit 35 , and the switch circuit 371 includes an electronic switch S3 , which disconnects the first control module 31 from the drive circuit 35 by disconnecting the connection between the first control module 31 and the drive circuit 35 The electrical connection between the control terminals is disconnected, thereby indirectly disconnecting the electrical connection between the motor 17 and the power supply device 36 .

Optionally, the protection circuit 37 further includes a switch control circuit 372 , which is electrically connected to the second control module 32 and electrically connected to the switch circuit 371 for controlling according to the second control signal of the second control module 32 The switch circuit 371 is turned off to disconnect the electrical connection between the motor 17 and the power supply device 36 . In this way, the switch circuit 371 indirectly disconnects the electrical connection between the motor 17 and the power supply device 36 by controlling the drive circuit 45 .

The circuit system of the power tool 10 shown in FIG. 4 is similar to the circuit system shown in FIG. 3 , including: a first control module 41 , a second control module 42 , a first power supply circuit 43 , a second power supply circuit 44 , and a drive circuit 45. Power supply device 46. The above circuit components are the same as or similar to those in FIG. 3 , and will not be repeated here. The difference is that the circuit system shown in FIG. 4 is different from that shown in FIG. 3 in that the protection circuit is different.

The protection circuit 47 shown in FIG. 4 includes a switch circuit 471 . The switch circuit 471 is electrically connected to the power supply device 46 and is connected to the power supply terminal of the drive circuit 45 , and the winding of the motor 17 can be connected to the power supply device 46 through the power supply terminal of the drive circuit 45 . To achieve electrical connection, in this way, the switch circuit 471 can directly disconnect the electrical connection between the power supply device 46 and the motor 17 . Unlike the switch circuit 371 shown in FIG. 3 which is connected to the control terminal of the drive circuit 35 and the power supply device 36 , the switch circuit 471 of this embodiment can directly disconnect the electrical connection between the motor 17 and the power supply device 46 .

FIG. 5 shows an exemplary circuit of the drive circuit 35 and the protection circuit 37 shown in FIG. 3 . Exemplarily, the drive circuit 55 includes a three-phase bridge circuit composed of six drive switches VT1 to VT6. The driving circuit 55 further includes: a first driving terminal 55a for electrically connecting with the first power terminal 56a of the power supply device 56 ; and a second driving terminal 55b for electrically connecting with the second power terminal 56b of the power supply device 56 . The drive switches VT1, VT3, and VT5 in the drive circuit 55 are high-side drive switches, and VT2, VT4, and VT6 are low-side drive switches. The drive switches VT1~VT6 can be selected from field effect transistors, IGBT transistors, etc. The drive circuit 55 is connected to the first control module 51, and the drive switches VT1 to VT6 change the on-off state according to the first control signal output by the first control module 51, so as to change the voltage state loaded by the power supply device 56 on the winding of the motor 17, and drive the The motor 17 is run or the motor 17 is turned off. It should be noted that the driving circuit 55 may also be in other implementations, and the number of driving switches in the driving circuit 55 may also be other, which is not limited to the above-mentioned implementation. .

In this embodiment, the control terminals AH, AL, BH, BL, CH, and CL of the driving switches VT1 to VT6 are respectively connected to the first control module 51 . The high-voltage terminals of the high-side switches VT1, VT3, and VT5 can all be connected to the first power supply terminal 56a of the power supply device 56 through the first driving terminal 55a, and the low-voltage terminals of the high-side switches VT1, VT3, and VT5 are respectively connected to the first phase winding A. , the second-phase winding B, the third-phase winding C; the high-voltage terminals of the low-side switches VT2, VT4, and VT6 are respectively connected to the first-phase winding A, the second-phase winding B, and the third-phase winding C. The low-side switches VT2, Both the low voltage terminals of VT4 and VT6 can be connected to the second power terminal 56b of the power supply device 56 through the second driving terminal 55b. In this embodiment, the high-side switches VT1 , VT3 , and VT5 are used to turn on or off the first phase winding A, the second phase winding B, the third phase winding C and the first power supply terminal 56 a of the power supply device 56 respectively. The low-side switches VT2 , VT4 , and VT6 are respectively used to turn on or off the electrical connection between the first phase winding A, the second phase winding B, and the third phase winding C and the second power supply terminal 56 b of the power supply device 56 .

For the drive circuit 55 of the three-phase bridge circuit and the three-phase motor 17, in this embodiment, the protection circuit 57 includes three protection circuit branches, which are the first protection circuit branch 571 and the second protection circuit branch respectively. 572. The second protection circuit branch 573, the three protection circuit branches are independent of each other and have the same or similar functions and compositions. The first protection circuit branch 571 is taken as an example for description below, and other protection circuit branches are the same or similar to it.

The first protection circuit branch 571 includes a switch circuit 571a and a switch control circuit 571b. The switch circuit 571a is connected between the control terminal of the low-side switch VT2 and the first control module 51, and is used to disconnect the control terminal of the low-side switch VT2 from the control terminal VT2. The electrical connection between the first control modules 51 is thereby disconnected from the electrical connection between the motor 17 and the power supply device 56 to shut down the motor 17 . The switch circuit 571a includes at least one electronic switch S5.

The switch control circuit 571b is electrically connected to the second control module 52 for controlling the switch circuit 571a to be turned off according to the second control signal of the second control module 52 to disconnect the electrical connection between the motor 17 and the power supply device 56 .

FIG. 6 shows a more specific exemplary circuit of the power tool 10 shown in FIG. 5 . Similar to the circuit system shown in FIG. 5 , it includes: a first control module 61 , a second control module 62 , a first power supply circuit 63 , a second power supply circuit 64 , a driving circuit 65 , and a power supply device 66 . The above circuit components are the same as or similar to those shown in FIG. 5 , and will not be repeated here. The difference is that the circuit system shown in FIG. 6 differs from the circuit system shown in FIG. 5 in that the protection circuit is more specific.

FIG. 6 exemplarily shows a specific protection circuit 67 of the protection circuit 57 shown in FIG. 5 . The protection circuit 67 includes a switch circuit and a switch control circuit, wherein the switch circuit includes: a first electronic switch (Q11 , Q21, Q31), electrically connected between the control terminal of at least part of the drive switch of the drive circuit 65 and the first control module 61, for disconnecting the electrical connection between the first control module 61 and at least part of the drive switch of the drive circuit 65 . Wherein, the switch control circuit includes: a second electronic switch (Q12, Q22, Q32), which is electrically connected between the first electronic switch (Q11, Q21, Q31) and the second control module 62, and is used for according to the second control module 62 The second control signal of the second control signal controls the first electronic switches (Q11, Q21, Q31) to be turned off to disconnect the electrical connection between the first control module 61 and at least part of the drive switches to disconnect the electrical connection between the motor 17 and the power supply device 66 .

Similar to FIG. 5 , the protection circuit 67 of a specific embodiment shown in FIG. 6 includes three protection branches. The first protection circuit branch 671 , the second protection circuit branch 672 , and the second protection circuit branch 673 . The compositions and functions of the first protection circuit branch 671 , the second protection circuit branch 672 , and the second protection circuit branch 673 are the same or similar.

Taking the first protection circuit 671 as an example, the first protection circuit 671 includes a switch circuit 671a and a switch control circuit 671b. The switch circuit 671a includes a first electronic switch Q11 and a resistor R11, and the switch control circuit 671b includes a resistor R12, a resistor R13, a resistor R14, and a second electronic switch Q12. Alternatively, the first electronic switch Q11 is a triode, and the second electronic switch Q12 is a triode.

Specifically, the first terminal of the first electronic switch Q11 is connected to the control terminal AL of the driving switch VT2 of the driving circuit 65, the second terminal of the first electronic switch Q11 is electrically connected to the first control module 61, and the The control terminal is connected to the first terminal of the second electronic switch Q12 through the resistor R14. The control terminal of the first electronic switch Q11 is also connected to the second terminal of the first electronic switch Q11 through the resistor R11.

The first terminal of the second electronic switch Q12 is connected to the control terminal of the first electronic switch Q11 through the resistor R14, the second terminal of the second electronic switch Q12 is grounded, and the control terminal of the second electronic switch Q12 is connected to the second control terminal through the resistor R12 Module 62, while grounded through resistor R13.

Since the compositions and functions of the first protection circuit branch 671 , the second protection circuit branch 672 , and the second protection circuit branch 673 are the same or similar, the other protection circuit branches will not be repeated here.

The working principle of the first protection circuit branch 671 will be described below. During the operation of the power tool 10 , the first control module 61 acts as the main control module, and outputs the first control signal to the drive switch of the drive circuit 65 to control the on-off state of the drive switch, thereby changing the voltage loaded on the winding of the motor 17 . state, to realize the drive, speed regulation and shutdown of the motor 17.

The first control module 61 has a first working state and a first failure state. When the first control module 61 is in the first working state, the first control module 61 works normally, and can normally control the driving circuit 65 to perform the operation of the motor 17 . Control work. During this process, it periodically or continuously outputs the first work signal to the second control module 62 to indicate that it is in a normal state. The second control module 62 receives the signal from the first control module 61. After the first working signal, it is confirmed that the second control module 62 is normal, and the first control module 61 does not perform any action. The first working signal may be, but is not limited to, a pulse signal.

When the first control module 61 is in the first failure state, the first control module 61 cannot work normally and cannot control the driving circuit 65 normally. At this time, the first control module 61 outputs the first failure signal to the second control module 62 . After receiving the first failure signal from the first control module 61, the second control module 62 outputs a second control signal to the protection circuit 67 to stop the motor 17. The first failure signal may be, but is not limited to, a weak level signal or no signal.

When the first control module 61 is in the first working state, the first control module 61 outputs the first working signal to the second control module 62, and the second control module 62 does not output the second control signal but outputs a high-level signal for protection circuit 67. In this embodiment, the second control module 62 outputs a high level when powered on.

Taking the first protection circuit 671 as an example, the second electronic switch Q12 is turned on due to the application of a high-level signal to the control terminal, so that the first electronic switch Q11 is turned on. At this time, the first control module 61 and the low The control terminal of the side drive switch VT2 can be electrically connected. Similarly, the second protection circuit branch 672, the third protection circuit 673 and the first protection circuit 671 have the same working principle and working process. The first control module 61 and the control terminals of the low-side drive switch VT4 and the low-side switch VT6 can The electrical connection is achieved, so that the first control module 61 can normally control the driving circuit 65 .

When the first control module 61 is in the first failure state, the first control module 62 outputs the first failure signal, the second control module 62 receives the second control signal output after the first control module 62 outputs the first failure signal, and the second control module 62 outputs the first failure signal. The second control signal is a low-level signal or a weak-level signal. At this time, the second electronic switch Q12 is turned off, so that the first electronic switch Q11 is turned off, so that the connection between the low-side switch VT2 of the driving circuit 65 and the first control module 61 is The electrical connection is broken and the low-side switch VT2 is turned off. Similarly, the second protection circuit branch 672 and the third protection circuit 673 have the same working principle and working process as the first protection circuit 671, the low-side switch VT4 is turned off, and the low-side switch VT6 is turned off, so that the winding current of the motor 17 The circuit is cut off and the motor 17 stops working, thereby stopping the driving of the functional element 15 .

In this way, when the first control module 61 is in the first failure state, when the protection circuit 67 receives the second control signal from the second control module 62, the protection circuit 67 cuts off the control of the low-side switches VT2, VT4, and VT6 of the driving circuit 65. The terminal is electrically connected to the first control module 61 , so that the power supply device 66 is disconnected from the winding of the motor 17 , so that the motor 17 is shut down, and the safety of the power tool 10 is improved.

FIG. 7 shows another exemplary implementation of the driving circuit 35 and the protection circuit 37 shown in FIG. 3 . Similar to FIG. 5 and FIG. 6 , the circuit system of the power tool 10 includes: a first control module 71 , a second control module 72 , a first power supply circuit 73 , a second power supply circuit 74 , a driving circuit 75 , and a power supply device 76 . The above circuit components are the same as or similar to those shown in FIG. 5 , and will not be repeated here. The difference is that the protection circuit shown in FIG. 7 is different from the protection circuits shown in FIGS. 5 and 6 .

The protection circuit 77 shown in FIG. 7 is only one circuit instead of three separate protection circuit branches as shown in FIGS. 5 and 6 .

In this embodiment, the protection circuit 77 includes a switch circuit 771 , and the switch circuit 771 is used to disconnect the electrical connection between the motor 17 and the power supply device 76 .

Connected to the second control module 72 for turning on at least part of the connection between the driving switch and the ground wire to disconnect the electrical connection between the motor 17 and the power supply device 76 according to a second control signal from the second control module 772 . The switch circuit 771 includes a third electronic switch S7.

In this embodiment, the control end of the third electronic switch S7 is electrically connected to the second control module 72 for turning on at least part of the connection between the drive switch and the ground wire according to the second control signal of the second control module 72 Connected to disconnect the electrical connection between the motor 17 and the power supply 76 .

Optionally, the protection circuit 77 further includes an isolation circuit 772 for isolating the electrical connection between the protection circuit 77 and the driving circuit 75 when the first control module 71 is working normally, so as to prevent the protection circuit 77 from affecting the driving circuit 75, so as to prevent the protection circuit 77 from affecting the driving circuit 75. The driving circuit 75 can keep working normally under the control of the first control module 71 . The isolation circuit 772 is connected to the control terminals of the low-side switches VT2 , VT4 and VT6 of the driving circuit 75 , and is electrically connected to the switch circuit 771 .

One end of the third electronic switch S7 is connected to the control ends of the low-side switches VT2, VT4 and VT6 of the driving circuit 75 through the isolation circuit 772, and the other end of the electronic switch S7 is connected to the ground wire to be grounded. The switch circuit 771 also includes a pull-up power supply Vcc for powering the switch circuit 771 .

FIG. 8 shows a more specific exemplary circuit of the power tool 10 shown in FIG. 7 . Similar to the circuit system shown in FIG. 7 , it includes: a first control module 81 , a second control module 82 , a first power supply circuit 83 , a second power supply circuit 84 , a driving circuit 85 , and a power supply device 86 . The above circuit components are the same as or similar to those shown in FIG. 7 , and will not be repeated here. The difference is that the circuit system shown in FIG. 8 differs from the circuit system shown in FIG. 7 in that the protection circuit is more specific.

The protection circuit 87 shown in FIG. 8 specifically includes a switch circuit 871 and an isolation circuit 872, wherein the switch circuit 871 includes an electronic switch VT84, a resistor 81, a resistor 82, a resistor 83, a resistor 84, a pull-up power supply Vcc, and a one-way diode D4. Among them, the electronic switch VT84 is a specific embodiment of the third electronic switch S7 shown in FIG. 7 .

In the switch circuit 871, the electronic switch VT81 can be, but is not limited to, a MOSFET, and the control end of the electronic switch VT81 is connected to the second control module 82 through a resistor R83, and is grounded through a resistor R84. One end of the electronic switch VT81 is connected to the ground line (or grounded), and the other end of the electronic switch VT81 is connected to the pull-up power supply Vcc through the pull-up resistor R82, and is connected to the isolation circuit 872 through the resistor R81.

Isolation circuit 872 includes three unidirectional diodes D1, D2 and D3. The negative terminals of each unidirectional diode D1, D2 and D3 in the isolation circuit 872 are connected to the other end of the electronic switch VT81 through the resistor R81, and the positive terminals of the unidirectional diodes D1, D2 and D3 are respectively connected to the low-side switches VT2, VT4 and The control terminal of VT6, the one-way diodes D1, D2 and D3 are used to isolate the electrical connection between the protection circuit 87 and the drive circuit 85 when the first control module 81 is working normally, so as to avoid the protection circuit 87 from affecting the drive circuit 85, so that the The driving circuit 85 can keep working normally under the control of the first control module 81 .

The operation principle of the protection circuit 87 in this embodiment will be described below. When the first control module 81 is in the first working state, the first working signal output by the first control module 81 is sent to the second control module 82, the second control module 82 outputs a low-level signal or no signal, and the electronic switch VT84 does not The unidirectional diodes D1 , D2 and D3 in the isolation circuit 872 are turned off, and the low-side driving switches VT2 , VT4 and VT6 are still normally controlled by the first control module 81 . In this embodiment, when the second control module 82 is powered on, it is set to output a low-level signal or not output a signal.

When the first control module 81 is in the first failure state, the first control module 81 outputs the first failure signal to the second control module 82 , and the second control module 82 receives the first failure signal from the second control module 82 . Output the second control signal to the protection circuit 87, the second control signal is a high-level signal, the electronic switch VT84 is turned on, the negative terminals of the one-way diodes D1, D2, and D3 are pulled down to the ground, and the one-way diodes D1, D2, and D3 lead to the ground. On, the control terminal signals of the low-side driving switches VT2, VT4 and VT6 are pulled low, and the low-side driving switches VT2, VT4 and VT6 are turned off, so that the power supply device 86 is electrically disconnected from the motor 17.

FIG. 9 shows a specific implementation of the drive circuit 55 and the protection circuit 57 in the circuit system of the power tool 10 shown in FIG. 4 .

Similar to FIG. 4 , the power tool 10 includes: a first control module 91 , a second control module 92 , a first power supply circuit 93 , a second power supply circuit 94 , a driving circuit 95 , and a power supply device 96 . The composition and function of the above circuit components are the same as or similar to those in FIG. 4 , and the composition and function of the driving circuit 95 are the same as those in FIG. 5 , and will not be repeated here. The driving circuit 95 includes: a first driving terminal 95a for electrically connecting with the first power terminal 96a of the power supply device 56 ;

The protection circuit 97 shown in FIG. 9 includes a switch circuit 971 . The switch circuit 97 is electrically connected between the power supply device 96 and the second end 95b of the drive circuit 95 , and the winding of the motor 17 can be connected to the second end 95b of the drive circuit 95 through the second end 95b of the drive circuit 95 . The power supply device 96 is electrically connected, and in this way, the switch circuit 971 can directly disconnect the electrical connection between the power supply device 96 and the motor 17 .

Optionally, the protection circuit 97 specifically includes a first electronic switch VT91, a resistor R91, a resistor R92, a resistor R93, a resistor R94, and a second electronic switch Q91. Alternatively, the first electronic switch VT91 is a MOSFET, and the second electronic switch Q91 is a triode.

The input terminal of the first electronic switch VT91, the output terminal of the first electronic switch VT91, and the second terminal 95b of the driving circuit 95 are connected in series. The control terminal of the first electronic switch VT91 is connected to the first terminal of the second electronic switch Q91 through the resistor R94. The control terminal of the first electronic switch VT91 is also connected to the second terminal of the first electronic switch VT91 through a pull-up resistor R91.

The first terminal of the second electronic switch Q91 is connected to the control terminal of the first electronic switch VT91 through the resistor R94, the second terminal of the second electronic switch Q91 is grounded, and the control terminal of the second electronic switch Q91 is connected to the power supply through the voltage dividing resistor R92 Vcc, while grounded through the voltage divider resistor R93. The protection circuit 97 also includes a pull-up power supply Vcc for supplying power to the protection circuit 97 .

The circuit system of the power tool 10 in FIG. 10 is the same as or similar to that shown in FIG. 3 , the difference is that the second control module 120 in FIG. 10 specifically adopts a control circuit 121 , and the control circuit 121 includes at least one electronic switch.

In this embodiment, the circuit system of the power tool 10 includes: a first control module 110, a second control module 120, a first power supply circuit 130, a second power supply circuit 140, a driving circuit 150, a power supply device 160, a protection circuit 170, a motor 17. The functions and compositions of the above-mentioned circuit components in this embodiment are the same as or similar to those of the circuit components shown in FIG. 3 , and will not be repeated here.

The circuit system of the power tool 10 shown in FIG. 11 is the same as or similar to that shown in FIG. 4 , the difference is that the first control module 210 and the second control module 220 shown in FIG. 11 are connected to each other in communication, and the first control module 210 The second control module 220 can be communicatively connected to each other to send signals to and receive signals from the other party.

The circuit system of the power tool 10 in FIG. 11 includes: a first control module 210 , a second control module 220 , a first power supply circuit 230 , a second power supply circuit 240 , a driving circuit 250 , a power supply device 260 , a protection circuit 270 , and a motor 17 . The functions of the above circuit components in this embodiment are the same as or similar to those of the circuit components shown in FIG. 4 , which will not be repeated here. Of course, the second control module 120 in the circuit system shown in FIG. 10 may also use the second control module 220 shown in FIG. 11 , and the second control module 220 shown in FIG. 11 may also use the second control module 220 shown in FIG. 10 . Control module 120 .

In this embodiment, the first control module 210 is configured to output a first control signal to the driving circuit 150 to adjust the speed, drive, and shut down the motor 17 . The first control module 210 has a first working state and a first failure state. When the first control module 210 is in the first working state, it outputs the first working signal to the second control module 220. When the first control module 210 is in the failure state, it outputs the first working signal. A fail signal is sent to the second control module 220 .

In this embodiment, the second control module 220 also has a second working state and a second failure state. When the second control module 220 is in the second working state, it outputs a second working signal to the first control module 220, and the second control module 220 outputs a second working signal to the first control module 220. 220 outputs a second failure signal to the first control module 210 when it is in a failure state.

In this embodiment, the first control module 210 includes a first communication unit 212, and the second control module 220 further includes a second communication unit 222. The first communication unit 212 and the second communication unit 222 are communicatively connected to each other, and may specifically be wireless Communication or wired communication connection, the first control module 210 and the second control module 220 send signals to and receive signals from each other through the first communication unit 212 and the second communication unit 222 . Alternatively, in this embodiment, the first control module 210 includes a control chip, such as an MCU, and the second control module 220 includes an MCU 221 . The second control module 220 is connected to the protection circuit 270, and the protection circuit 270 may adopt the protection circuit 47 shown in FIG. 4, or of course the protection circuit 37 shown in FIG.

The first control module 210 outputs a first control signal to shut down the motor 17 when receiving the second fail signal from the second control module 220 . Specifically, the first control module 210 outputs the first control signal to the driving circuit 250 when receiving the second failure signal from the second control module 220, so that the driving circuit 250 stops working or the driving circuit 250 controls the motor 17 to brake, Therefore, the motor 17 is turned off, and in this way, the motor 17 stops driving the functional parts 15 of the power tool 10 . The second failure signal may include no signal, weak level signal, and the like.

Likewise, when the second control module 220 receives the first failure signal from the first control module 210 , it outputs a second control signal to the protection circuit 250 to shut down the motor 17 . Specifically, the second control module 220 outputs the second control signal to the protection circuit 270 when receiving the first failure signal from the first control module 210 , and the protection circuit 270 receives the second control signal from the second control module 220 . The motor 17 is turned off, and in this way the motor 17 stops driving the function. The first failure signal may include no signal, weak level signal, and the like.

In this embodiment, during the operation of the motor 17, once the first control module 210 receives the second failure signal from the second control module 220, it immediately outputs the first control signal to shut down the motor 17. Similarly, the Once the second control module 220 receives the first failure signal from the first control module 210 , it immediately outputs the second control signal to turn off the motor 17 , so as to avoid safety accidents or damage to the power tool 10 .

That is to say, during the working process of the power tool 10, when the first control module 210 and the second control module 220 are in a normal working state, the first control module 210 and the second control module 220 will send a working signal to each other to send a working signal to each other. The other party indicates that it is in a normal state, and the other party maintains the status quo after receiving the working signal. The first working signal and the second working signal may be pulse signals. When the first control module 210 and the second control module 220 are in an abnormal failure state, they will send a failure signal to the other party, and the other party will output a control signal to stop the motor 17 after receiving the failure signal. In this way, when one of the control modules fails, the other control module can provide backup protection and shut down the motor 17 in time, so that the safety of the power tool 10 is higher.

In the circuit system of the power tool 10 shown in FIGS. 3 , 4 , and 10 and 11 , the power tool 10 further includes a start switch 18 for at least starting the motor 17 , the start switch 18 is connected to the first control module (31 , 41, 110, 210) connection. The start switch 18 is associated with the trigger mechanism 14 , the trigger mechanism 14 is triggered, and the start switch 18 associated with the trigger mechanism 14 is triggered accordingly, and its on-off state changes.

The first control module (31, 41, 110, 210) further includes a switch detection unit (311, 411, 111, 211), the start switch 18 is connected to the switch detection unit (311, 411, 111, 211), and the switch detection unit ( 311 , 411 , 111 , 211 ) can detect the trigger state of the start switch 18 , so as to make corresponding control according to the trigger state of the start switch 18 . Specifically, when the switch detection unit 311 detects that the start switch 18 is triggered, the first control module (31, 41, 110, 210) outputs the first control signal to the drive circuit (35, 45, 150, 250) to control the drive circuit ( 35, 45, 150, 250) to start the motor 17.

Alternatively, the start switch 18 is also used to stop the motor 17 from working. Specifically, the start switch 18 has two states, an on state and an off state. When the start switch 18 is in the on state, it is used to start the motor 17 , and when the start switch 18 is in the off state, it is used to start the motor 17 . The motor 17 stops working. The switch detection unit (311, 411, 111, 211) can detect different states of the start switch 18, so as to output the first control signal to the drive circuit (35, 45, 150, 250) according to the different states of the start switch 18 to control the motor (35, 45, 150, 250) Act accordingly. Optionally, the start switch 18 is a signal switch.

As an option, the power tool 10 further includes the above-mentioned brake switch 21 , the brake switch 21 is connected to the first control module ( 31 , 41 , 110 , 210 ), and is used to brake the motor 17 , specifically , the brake switch 21 is connected to the switch detection unit (311, 411, 111, 211) of the first control module (31, 41, 110, 210), and the switch detection unit 311 can detect the trigger state of the brake switch 21, so that according to the The trigger state of the brake switch 21 is controlled accordingly. Specifically, when the switch detection unit 311 detects that the brake switch 21 is triggered, the first control signal is output to the drive circuit 35 to control the drive circuit 35 to brake the motor 17 . Optionally, the brake switch 21 is a signal switch.

In the embodiment shown in FIG. 11 , the first control module 210 is further configured to: after detecting that the start switch 18 is triggered and receiving the second working signal from the second control module 220, output the first control signal to The drive circuit 250 starts the motor 17 .

As an option, the start switch 18 has two states, an on state and an off state. When the switch detection unit ( 311 , 411 , 111 , 211 ) detects that the start switch 18 is in the on state, the first control module (31, 41, 110, 210) output a first control signal to the drive circuit (35, 45, 150, 250) to control the motor (35, 45, 150, 250) to start. When the switch detection unit (311, 411, 111, 211) detects that the start switch 18 is in an off state, the first control module (31, 41, 110, 210) outputs a first control signal to the drive circuit (35, 45, 150, 250) to control the motor 17 to stop working. Alternatively, only when the switch detection unit (311, 411, 111, 211) detects that the start switch 18 is turned on and the brake switch 21 is not triggered, the first control module (31, 41, 110, 210 ) to output the first control signal to the drive circuit (35, 45, 150, 250) to control the motor (35, 45, 150, 250) to start.

The first control module 210 is further configured to: after detecting that the brake switch 21 is triggered and receiving the second working signal from the second control module 220, output the first control signal to the driving circuit 65 to make the motor 17 brake. verb: move.

In this way, only when the second control module 220 is in the second working state (normal working state), that is, only when the first control module 210 receives the second working signal from the second control module 220, the Only a control module 210 will work normally, that is, it will normally control the power tool and the motor 17 according to the state of the start switch 18 or the brake switch 21 . Once the first control module 210 receives the second failure signal from the second control module 220, the first control module 210 will output the first control signal regardless of the state of the start switch 18 or the brake switch 21 or whether the brake switch 21 is activated or not. A signal is given to the drive circuit 250 to cause the motor 17 to shut down. In this way, after the second control module 220 fails, the first control module can immediately shut down the motor 17 .

Of course, as mentioned above, when the first control module 210 fails, the second control module 220 can also immediately output the second control signal to the protection circuit 270 to shut down the motor 17 .

Based on the above content, in the present invention, two control modules are provided, and after one of the control modules fails, the other control module can also provide backup protection, so that the safety of the operation of the electric tool is higher.

The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the above-mentioned embodiments do not limit the present invention in any form, and all technical solutions obtained by means of equivalent replacement or equivalent transformation all fall within the protection scope of the present invention.

Claims (10)

1. A power tool, comprising: a functional part for realizing the function of the electric tool; a motor, operably connected to the functional element, for driving the functional element; a drive circuit, electrically connected to the motor, for driving the motor; It is characterised in that the power tool further comprises: a first control module, connected to the drive circuit, for outputting a first control signal to the drive circuit; the first control module has a first working state and a first failure state, and the first control module is in a first A first working signal is output in a working state, and a first failure signal is output when the first control module is in a first failure state; a second control module, connected to the first control module to receive a first working signal or a first failure signal from the first control module; Wherein, the second control module outputs a second control signal to stop the motor when receiving the first failure signal from the first control module. 2. The power tool according to claim 1, wherein the first control module and the second control module are connected in communication with each other; The second control module has a second working state and a second failure state, when the second control module is in the second working state, it outputs a second working signal to the first control module, and the second control module is in the second working state. Outputting a second failure signal to the first control module in the second failure state; The first control module outputs a first control signal to shut down the motor when receiving a second fail signal from the second control module. 3. The power tool according to claim 1, wherein: The power tool also includes: A protection circuit, electrically connected to the second control module, is used for shutting down the motor when receiving a second control signal from the second control module. 4. power tool according to claim 3, is characterized in that: The electric power tool further includes a power supply device for providing electric power to the electric power tool; The protection circuit includes a switch circuit for disconnecting the electrical connection between the motor and the power supply device; the switch circuit includes at least one electronic switch. 5. The power tool according to claim 4, wherein: The protection circuit further includes a switch control circuit, the switch control circuit is electrically connected to the switch circuit and the second control module, and is used for controlling the switch circuit to turn off according to the second control signal of the second control module. to disconnect the electrical machine from the power supply. 6. The power tool according to claim 5, wherein: the drive circuit includes a plurality of drive switches; The switch circuit includes a first electronic switch, which is electrically connected between the control terminal of at least part of the drive switch and the first control module, and is used for disconnecting the first control module and at least part of the drive switch. The electrical connection of the control terminal; The switch control circuit includes a second electronic switch, which is electrically connected between the control terminal of the first electronic switch and the second control module, and is used for controlling the second control module according to the second control signal of the second control module. The first electronic switch is turned off to disconnect the electrical connection between the first control module and at least part of the drive switch to disconnect the electrical motor from the power supply. 7. The power tool according to claim 4, wherein: the drive circuit includes a plurality of drive switches; The switch circuit includes: a third electronic switch, the third electronic switch is electrically connected between at least part of the control terminal of the drive switch and the ground wire, and the control terminal of the third electronic switch is electrically connected to the second control module, so The third electronic switch is used for turning on at least part of the connection between the driving switch and the ground wire according to the second control signal of the second control module, so as to disconnect the electrical connection between the motor and the power supply device. 8 . The power tool of claim 1 , wherein the second control module comprises a control circuit comprising at least one switching element; or the second control module comprises a microcontroller. 9 . 9. The power tool according to claim 2, wherein the power tool further comprises: a start switch for at least starting the power tool, the start switch is connected to the first control module; The first control module is configured to output a first control signal to start the motor after detecting that the start switch is triggered and receiving a second operation signal from the second control module. 10. The power tool according to claim 2 or 9, wherein the power tool further comprises: a brake switch for braking the motor, the brake switch is connected with the first control module; the first control module is configured to: after detecting that the brake switch is triggered and receiving the After receiving the second working signal from the second control module, output a first control signal to the drive circuit to brake the motor.

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