CN112850610A

CN112850610A - Control circuit of electric can opener, electric can opener and control method thereof

Info

Publication number: CN112850610A
Application number: CN202110241144.6A
Authority: CN
Inventors: 王少华
Original assignee: Ninghai Marsun International Trading Co ltd
Current assignee: Ninghai Marsun International Trading Co ltd
Priority date: 2021-03-04
Filing date: 2021-03-04
Publication date: 2021-05-28

Abstract

The invention discloses a control circuit of an electric can opener, which is used for controlling a driving mechanism of the electric can opener, wherein the driving mechanism comprises a motor capable of rotating forwards and reversely, the control circuit comprises a controller and a driving circuit, the driving circuit comprises a current detection circuit for detecting the working current of the motor, the controller is electrically connected with the current detection circuit and can receive the signal of the current detection circuit, and the controller can control the motor to operate through the driving circuit according to the signal of the current detection circuit. Also discloses an electric can opener with the control circuit and a control method of the electric can opener.

Description

Control circuit of electric can opener, electric can opener and control method thereof

Technical Field

The invention relates to a small household tool, in particular to an electric can opener, a control circuit thereof and a control method of the electric can opener.

Background

In recent years, for convenience of life in many countries and regions, some cooked products are processed and filled into cans, so that the cans are convenient to take out and eat quickly, and the can opener is a home article tool for opening the cans. The manual can opener seen in the market at present is usually provided with a blade and a roller at the lower part of the front end of a handle, a rotating handle is connected with the roller, a can wall is clamped between the blade and the roller, then the blade is tightened to cut the blade into the can wall, and then the rotating handle is rotated to drive the roller to move for a circle around the can wall, so that the can wall is cut.

With the progress of science and technology, the can opener also follows the pace of science and technology progress, slowly evolves from a manual can opener to an electric can opener, and the cutting principle of the electric can opener is similar to that of the manual can opener. There are currently two main types of electrically powered can openers: conventional countertop can openers and travelling cutting can openers. A travelling cutting can opener is a small battery-powered device that can rest on top of a can and rotate relative to the can during operation, mechanically moved by a gear drive and brake system powered by a motor, thereby forcing a cutting blade against the can surface, resulting in a complete cut of the can envelope surface.

A can opener as disclosed in US patent publication No. US20140059869a1 includes a housing, a drive gear, a reduction gear, a cutting wheel, a slider, an idler gear, a first driven gear, a second driven gear, a torsion spring, a third driven gear, and a cam, the drive gear rotating the cutting wheel and the first driven gear, the first driven gear driving the second driven gear, the third driven gear rotating the cam, the cam moving the slider, the slider moving the idler gear such that the idler gear moves toward the cutting wheel, thereby sandwiching the rim of the lid between the idler and the cutting wheel. The idle wheel and the cutting wheel move along the edge of the cover, cut the edge of the cover, separate the cover from the can, and thus automatically open the can.

In the above can opener, a torsion spring is further provided, the torsion spring is biased between the first driven gear and the second driven gear to connect the first driven gear and the second driven gear, and after the circular motion of the idle gear and the cutting wheel is completed, the second driven gear is driven by the restoring force of the torsion spring to rotate in the reverse direction, thereby completing the cutter retracting reset.

According to the scheme of completing the cutter withdrawal through the spring, a user can clamp the cutter in the using process, the cutter withdrawal cannot return to the designated position, and the phenomenon of pause is caused midway when the can is cut, so that the use is inconvenient for the user, and the product quality is unstable; in addition, the torsion spring has a life span, resulting in a limited frequency of continuous use of the can opener product.

Disclosure of Invention

The first technical problem to be solved by the present invention is to provide a control circuit of an electric can opener, which can improve the operation stability of the retracting knife and prolong the service life.

The second technical problem to be solved by the invention is to provide the electric can opener with the control circuit.

The third technical problem to be solved by the invention is to provide a control method of the electric can opener.

The technical scheme adopted by the invention for solving the first technical problem is as follows: the utility model provides a control circuit of electronic can opener for control drive mechanism of electronic can opener, drive mechanism is including the motor that can corotation and reversal, control circuit includes controller and drive circuit, drive circuit is including the current detection circuit who is used for detecting motor operating current, the controller is connected and can receive current detection circuit's signal with the current detection circuit electricity, the controller can pass through drive circuit control motor operation according to current detection circuit's signal.

In order to control the positive rotation and the reverse rotation of the motor conveniently, the controller comprises a control chip, the control chip is at least provided with a first I/O port and a second I/O port, the driving circuit comprises a positive rotation driving circuit and a reverse rotation driving circuit, the positive rotation driving circuit comprises a first triode, the reverse rotation driving circuit comprises a second triode, the first triode is connected between the first I/O port and the positive pole of the motor, and the second triode is connected between the second I/O port and the negative pole of the motor.

In order to avoid the situation that the motor cannot work normally when the current is too small, the driving circuit further comprises a first amplifying circuit and a second amplifying circuit, the first amplifying circuit is connected between the first triode and the motor, and the second amplifying circuit is connected between the second triode and the motor.

Preferably, the amplifying circuit is a circuit formed by MOS transistors, the first amplifying circuit includes a first MOS transistor and a second MOS transistor, and the second amplifying circuit includes a third MOS transistor and a fourth MOS transistor; the base electrode of the first triode is connected to the first I/O port and the emitter electrode of the first triode is grounded, and the base electrode of the second triode is connected to the second I/O port and the emitter electrode of the second triode is grounded; the grid electrode of the first MOS tube is connected to the collector electrode of the first triode, the drain electrode of the first MOS tube is connected to positive voltage, and the source electrode of the first MOS tube is connected to the positive electrode of the motor, the grid electrode of the second MOS tube is connected to the collector electrode of the first triode, the drain electrode of the second MOS tube is connected to the positive electrode of the motor, the drain electrode of the third MOS tube is connected to the collector electrode of the second triode, the drain electrode of the third MOS tube is connected to positive voltage, and the source electrode of the third MOS tube is connected to the negative electrode of the motor, the grid electrode of the fourth MOS tube is connected to the collector.

Preferably, the control chip further has a third I/O port, the current detection circuit includes a resistor, one end of the resistor is connected to the source of the fourth MOS transistor, and the other end of the resistor is connected to the third I/O port of the control chip.

In order to avoid the control chip to be damaged by instantaneous large current, the controller also comprises a power supply circuit for supplying power to the controller, the control chip is an ID chip, the control chip also comprises an anode pin and a cathode pin, the output end of the power supply circuit is connected to the anode pin, the cathode pin is connected with a self-locking switch, and the self-locking switch is grounded.

Preferably, in order to increase the voltage range of the power supply, the power supply circuit includes a voltage regulating MOS transistor, an anode of the power supply is connected to an input end of the voltage regulating MOS transistor, and a cathode of the power supply is connected to a ground end of the voltage regulating MOS transistor.

The technical scheme adopted by the invention for solving the second technical problem is as follows: an electronic can opener with control circuit as above, including casing, actuating mechanism and cutting assembly, the casing includes the mount pad, the mount pad is by the casing bottom surface undercut and the cavity structure that forms of can one side, cutting assembly includes can pivoted cutting wheel and the idle pulley by actuating mechanism driven, its characterized in that: the drive mechanism is controlled by the control circuit, and the idler wheel can be driven by the drive mechanism to move closer to or away from the cutting wheel.

The technical scheme adopted by the invention for solving the third technical problem is as follows: a control method of the electric can opener as described above, characterized in that: the method comprises the following steps:

1) inserting an edge of a can lid of the can into a gap between an idler wheel and a cutting wheel of the cutting assembly;

2) starting a controller;

3) the controller outputs positive working voltage to the driving circuit, the motor starts to operate in a positive direction to drive the cutting assembly to propel in the positive direction, when a cutting wheel of the cutting assembly contacts the wall of the can, resistance is applied to the cutting wheel to increase working current of the motor, and the controller receives an increased current signal through the current detection circuit;

4) after the can is cut, the resistance borne by the cutting wheel is reduced, the working current of the motor is reduced, and the controller receives a reduced current signal through the current detection circuit; when the received working current is reduced to be lower than a preset lower limit value, the controller stops voltage output;

5) stopping providing forward running voltage for the motor for a certain time, outputting a reverse voltage by the controller to provide the motor for working, reversely running the motor to drive the cutting assembly to reversely advance, blocking the motor to increase working current when the idle rotating wheel gradually moves away from the cutting wheel and touches the side wall of the mounting seat, and receiving a signal of the increased working current by the controller through a current detection circuit;

6) when the received working current is increased to exceed the preset upper limit value, the motor is controlled to stop running, and therefore the tool retracting work is completed.

In order to avoid the motor from idling for a long time and detect the running state of the motor before the cutting assembly cuts the can, before the step 1), the method further comprises a detection process, wherein the detection process comprises the following steps:

01) starting a controller;

02) the controller outputs positive working voltage to the driving circuit, the motor starts to operate positively to drive the cutting assembly to propel forwards, and at the moment, the cutting wheel does not bear resistance and operates in a no-load mode;

03) when the forward running time of the motor reaches a set timing point, the controller stops providing forward running voltage for the motor;

04) when the idle rotating wheel gradually moves away from the cutting wheel and touches the side wall of the mounting seat, the motor is blocked and the working current is increased, and the controller receives a signal of the increased working current through the current detection circuit;

05) and when the received working current is increased to exceed a preset upper limit value, controlling the motor to stop running.

Compared with the prior art, the invention has the advantages that: by arranging the current detection circuit, the working state of the motor is judged by detecting the working current of the motor, and the operation of the motor is controlled by the working state, so that the motor can be prevented from idling, the service life of the motor is prolonged, and the cutting process is accurately controlled; the cutting and cutter feeding and retracting work can be completed at any time by controlling the motor to rotate forwards and backwards, and the phenomenon of cutter clamping in midway can not occur.

Drawings

FIG. 1 is a schematic view (from top to bottom) of a can opener according to an embodiment of the present invention;

FIG. 2 is a schematic view (looking down on) of a can opener of an embodiment of the present invention;

FIG. 3 is a schematic view of a can opener hidden cutting assembly of an embodiment of the present invention;

FIG. 4 is a schematic view of a can opener hidden housing of an embodiment of the present invention;

FIG. 5 is an exploded view of the can opener of the embodiment of the present invention;

FIG. 6 is a cross-sectional view of a can opener of an embodiment of the present invention;

FIG. 7 is a partial cross-sectional view of a can opener of an embodiment of the present invention;

FIG. 8 is a schematic view of the first and second brake gears of the can opener of an embodiment of the present invention;

FIG. 9 is a schematic view of a third brake gear and cam of the can opener of an embodiment of the present invention;

fig. 10 is a control circuit of the can opener according to the embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar functions.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present invention and to simplify the description, but are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and that the directional terms are used for purposes of illustration and are not to be construed as limiting, for example, because the disclosed embodiments of the present invention may be oriented in different directions, "lower" is not necessarily limited to a direction opposite to or coincident with the direction of gravity. Furthermore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

Referring to fig. 1 and 2, an electric can opener includes a housing 1, a driving mechanism, and a cutting assembly 3 driven by the driving mechanism. In order to clearly show the driving mechanism, in fig. 1 and 2, the housing 1 is only partially shown, and in practical application, the housing 1 should be a complete structure forming a closed inner cavity, and the driving mechanism is mostly arranged in the inner cavity of the housing 1.

With reference to fig. 3 to 7, the driving mechanism includes a motor 21, a transmission mechanism and a braking mechanism, and the transmission mechanism transmits the torque output by the motor 21 to the braking mechanism and then to the cutting assembly 3 through the braking mechanism.

The transmission mechanism is in this embodiment in the form of a gear set, wherein the primary gear (input) is connected to the motor 21 and the final gear (input) of the transmission mechanism is connected to the brake mechanism. When the transmission has only one gear, the primary and the final gear are one and the same. In the present embodiment, the transmission mechanism includes a first transmission gear 221 provided on the output shaft 211 of the motor 21, a second transmission gear 222 meshing with the first transmission gear 221, a third transmission gear 223 coaxially provided with the second transmission gear 222, a fourth transmission gear 224 meshing with the third transmission gear 223, a fifth transmission gear 225 coaxially provided with the fourth transmission gear 224, a sixth transmission gear 226 meshing with the fifth transmission gear 225, and a seventh transmission gear 227 coaxially provided with the sixth transmission gear 226. The first transmission gear 221 is a primary gear of the transmission mechanism, and the seventh transmission gear 227 is a final gear of the transmission mechanism. Two gears coaxially arranged rotate synchronously. In the transmission mechanism, except the first transmission gear 221, the other transmission gears are rotatably connected to the housing 1 through a rotation support member such as a rotating shaft. This saves space in the housing 1 and avoids the housing 1 being oversized.

In the use state, the output shaft 211 of the motor 21 is normally in a laterally extended state, and the rotating shaft of the first transmission gear 221 is the output shaft 211 of the motor 21. The first transmission gear 221 and the second transmission gear 222 are both helical gears, such as bevel gears, thereby achieving the turning of the output, and the output shaft of the second transmission gear 222 is in a longitudinally extended state. The rotating shaft of the third transmission gear 223 is coaxial with the second transmission gear 222, and the rotating shafts of the other transmission gears of the transmission mechanism are parallel to the second transmission gear 222.

In the present embodiment, the braking mechanism is also in the structure of a gear set, the input end of the braking mechanism is connected with the final gear of the transmission mechanism to realize transmission, and the output end of the braking mechanism is connected with the cutting assembly 3 to realize transmission. In the present embodiment, the braking mechanism includes a driving gear 231, a first braking gear 232, and a second braking gear 233 disposed coaxially with the first braking gear 232, wherein the driving gear 231 is engaged with the seventh transmission gear 227 of the transmission mechanism as an input end of the braking mechanism. The first brake gear 232 is engaged with the driving gear 231, and referring to fig. 8, the first brake gear 232 is further integrally provided with the second brake gear 233, and both rotate in synchronization. The first brake gear 232 and the second brake gear 233 are rotatably connected to the housing 1 through the same rotation shaft. The teeth of the first brake gear 232 may be distributed only in a circular ring shape, and not provided over the entire circumference.

The driving mechanism further includes a driving shaft 24 passing through the driving gear 231, and a connection between the driving shaft 24 and the driving gear 231 may be in the form of a flat shaft, so that when the driving gear 231 rotates, the driving shaft 24 is driven to rotate synchronously. The housing 1 comprises a mounting 11, and a drive shaft 24 passes through the mounting 11 and can rotate around its axis relative to the mounting 11. For easy handling and cutting, the housing 1 may be oval-shaped, the motor 21 is disposed at one end inside the housing 1, the mounting seat 11 is disposed at the opposite end of the housing 1, and the mounting seat 11 is a cavity structure formed by an upward concave bottom surface of the housing 1 facing the can side.

The brake mechanism further includes a third brake gear 234 disposed on drive shaft 24, with relative rotation between third brake gear 234 and drive shaft 24. The third brake gear 234 is engaged with the second brake gear 233, and thus can be rotated by the second brake gear 233. The side of the third brake gear 234 facing the outside of the mounting seat 11 is provided with a cam 235. referring to fig. 9, the third brake gear 234 and the cam 235 may be an integral structure, thereby constituting an output end of the brake mechanism. Likewise, drive shaft 24 passes through cam 235, and cam 235 and drive shaft 24 are able to rotate relative to each other. Cam 235 may be circular and drive shaft 24 is eccentrically coupled to cam 235. The third brake gear 234 is in the shape of a sector, the central angle of which may be related to the spacing between the cutter wheel 35 and the idler wheel 36 (described in detail below) of the cutting assembly 3.

The rotational axes of the four brake gears of the brake mechanism are parallel to the rotational axis of the final gear (seventh transfer gear 227) of the transmission mechanism. The driving gear 231 is located on the side of the mounting seat 11 facing the inside of the housing 1, and the third brake gear 234 is located on the side of the mounting seat 11 facing the outside of the housing, i.e. the third brake gear 234 is located inside the mounting seat 11. Since the first brake gear 232 and the second brake gear 233 are located inside the housing 1, the notch 111 is opened in the side wall of the mounting seat 11, so that the second brake gear 233 can partially pass through the notch 111 to the outside of the housing 1 and can mesh with the third brake gear 234.

The cutting assembly 3 may be the same as the U.S. patent document mentioned in the background, including a slider 31, a follower 32, a washer 33 and a metal plate 34 disposed within the mounting block 11. Wherein the follower 32 is disposed on a side of the slider 31 facing the third brake gear 234 so as to move in cooperation with the slider 31. In order to facilitate the movement of the slider 31 when the follower 32 is actuated, the slider 31 is provided with a flange 311 protruding toward the third brake gear 234, the flange 311 surrounds the outer periphery of the follower 32, and the shape of the flange is adapted to the follower 32 so as to facilitate the pushing of the follower 32. In order to define the position of the driven member 32, the slider 31 is further provided with a protrusion 312 extending toward the third brake gear 234, the protrusion 312 may be in a ring shape, the driven member 32 is provided with a positioning hole 321, and the protrusion 312 passes through the positioning hole 321, so that the slider 31 and the driven member 32 are rotatably connected. The follower 32 further has a mounting hole 322, the cam 235 is disposed in the mounting hole 322, and the mounting hole 322 may be a circular hole adapted to the cam 235. Whereby eccentric rotation of cam 235 causes follower 32 to move (e.g., oscillate) about drive shaft 24.

The washer 33 is provided on a side of the slider 31 remote from the third brake gear 234, and the washer 33 is fixed to the slider 31 so as to be movable in synchronization. The metal plate 34 is provided on the side of the washer 33 remote from the slider 31, so that the housing 1 can be prevented from being damaged by rubbing against the can during cutting. After the driving shaft 24 passes through the mounting seat 11, the driving shaft passes through the mounting hole 322 of the driven member 32, the slider 31, the washer 33 and the metal plate 34 in sequence, so that the slider 31 and the washer 33 can move around the driving shaft 24. The metal plate 34 is rotationally connected to the drive shaft 24 and does not move with the slider 31 and the washer 33.

The cutting assembly 3 further comprises a cutting wheel 35 (not shown for cutting teeth) as a first load and an idler wheel 36 as a second load, the cutting wheel 35 being disposed on a side of the metal plate 34 remote from the slide 31, and the drive shaft 24 being connected to the cutting wheel 35 after passing through the metal plate 34, so that the cutting wheel 35 can rotate with the drive shaft 24. The idle wheel 36 is arranged on the side of the washer 33 far away from the slide block 31, and the idle wheel 36 is connected and fixed with the washer 33 through a fastener 37. In this embodiment, the fastener 37 includes a screw 371 and a reversed screw 372, the reversed screw 372 passes through the idle pulley 36 from bottom to top, the screw 371 passes through the reversed screw 372 from above the washer 33 downwards to be locked, and thus the idle pulley 36 can move synchronously with the slider 31. The idle wheel 36 and the cutting wheel 35 have a certain interval therebetween in a non-operation state, and the idle wheel 36 can move closer to or farther from the cutting wheel 35 with the movement of the slider 31.

When the motor 21 is started in the forward direction, the torque of the motor 21 is transmitted to the braking mechanism through the transmission mechanism, so that the driving gear 231 rotates, and therefore the driving shaft 24 rotates along with the driving gear 231 to drive the cutting wheel 35 to rotate; at the same time, the driving gear 231 rotates the first brake gear 232, the second brake gear 233 rotates synchronously with the first brake gear 232, so as to rotate the third brake gear 234, the cam 235 rotates with the third brake gear 234, the cam 235 drives the follower 32 to move, the follower 32 pushes the slider 31 to move, the gasket 33 drives the idle gear 36 to move, so that the idle gear 36 moves close to the cutting wheel 35, and the edge of the can lid is clamped through the cooperation of the idle gear 36 and the cutting wheel 35. Then, the third brake gear 234 is not rotated (rotated by a certain angle due to the fan-shaped structure of the third brake gear 234 and thus is not rotated by the meshing relationship with the second brake gear 233), and the cutter wheel 35 continues to be rotated by the driving shaft 24, so that the idle gear 36 and the cutter wheel 35 move along the edge of the can lid to perform a circular motion around the center of the can, thereby pressing and cutting the edge of the can lid and separating the can lid from the body of the can.

When the idle wheel 36 and the cutting wheel 35 complete the circular motion, the can lid is separated from the can body, the motor 21 is reversed, and the parts complete the retracting in the opposite direction to the above-mentioned advancing.

In order to control the action of the driving mechanism, a control circuit board (not shown) is also provided in the housing 1, and the control circuit on the control circuit board is shown in fig. 10. The control circuit includes a power supply circuit 41, a controller 42, and a drive circuit 43, and the drive circuit 43 is connected to the motor 21 to drive forward or reverse rotation thereof. The connections of the following control circuits are all "electrical connections".

The input terminal of the power circuit 41 is connected to a power source, which in this embodiment may be formed by connecting 4 batteries AA1.5V in series, and 6V is input to the power circuit 41. In this embodiment, the power circuit 41 includes a voltage-regulating MOS transistor IC1, the positive electrode BAT + of the power supply is connected to the input terminal of the voltage-regulating MOS transistor IC1, the negative electrode BAT-of the power supply is connected to the ground terminal of the voltage-regulating MOS transistor IC1, the output terminal of the voltage-regulating MOS transistor IC1 is connected to the power input terminal of the controller 42, so as to supply power to the controller 42, and the voltage-regulating MOS transistor IC1 can realize voltage regulation of 3-9V. The voltage regulating MOS transistor IC1 may also have peripheral circuits including a resistor R1, a capacitor C1, and the like. A capacitor C2 may be further disposed between the ground terminal and the output terminal of the voltage regulating MOS transistor IC 1.

The controller 42 includes a control chip, preferably an ID chip IC2, having at least a first I/O port PA6, a second I/O port PA3 and a third I/O port PA4, wherein the first I/O port PA6 is used for outputting a motor forward rotation control signal, the second I/O port PA3 is used for outputting a motor reverse rotation control signal, the third I/O port PA4 is used for receiving an operating current detection signal of the motor 21, and the fourth I/O port PA5 is used for receiving a signal for determining whether the controller 42 outputs the control signal. The working voltage of the ID chip IC2 is 5.0V-5.5V, and the normal work of the ID chip IC2 can be ensured by adopting a voltage regulating MOS tube IC 1.

The ID chip IC2 further includes a positive terminal (shown as terminal 1) and a negative terminal PB1, wherein the output terminal of the voltage regulating MOS transistor IC1 is connected to the positive terminal, the negative terminal PB1 is connected to a self-locking switch KYE, and the self-locking switch KYE is grounded. The positive pin of the ID chip IC2 is also connected to a standby power supply VDD to ensure the normal operation of the controller 42 when the voltage supplied by the battery fails to meet the operating voltage of the controller 42.

The current that ID chip IC2 can bear can reach 3A (the operating current of motor 21 is at 150 ~ 1500mA), and when the contact of self-locking switch KYE was closed, the overcurrent scope that can bear was limited, consequently for avoiding self-locking switch KYE to blow when closing, with the negative pole pin PB1 of connecting to IC chip IC2 from self-locking switch KYE.

The driving circuit 43 includes a forward driving circuit and a reverse driving circuit, the forward driving circuit includes a first triode Q1 and a first amplifying circuit, the reverse driving circuit includes a second triode Q2 and a second amplifying circuit, both triodes are NPN triodes, a base of the first triode Q1 is connected to the first I/O port PA6 of the ID chip IC2, an emitter is grounded, and a collector is connected to the positive electrode of the motor 21 through the first amplifying circuit. The base of the second transistor Q2 is connected to the second I/O port PA3 of the ID chip IC2, the emitter is grounded, and the collector is connected to the negative electrode of the motor 21 through a second amplifying circuit.

The first amplifying circuit comprises a first MOS transistor Q3 and a second MOS transistor Q4, the second amplifying circuit comprises a third MOS transistor Q5 and a second MOS transistor Q6, wherein the first MOS transistor Q3 and the second MOS transistor Q5 are P-channel MOS transistors, and the second MOS transistor Q4 and the fourth MOS transistor Q6 are N-channel MOS transistors. The gate of the first MOS transistor Q3 is connected to the collector of the first transistor Q1, the drain is connected to the positive voltage (high level), the source is connected to the positive pole of the motor 21, the gate of the second MOS transistor Q4 is connected to the collector of the first transistor Q1, and the drain is connected to the positive pole of the motor 21. The gate of the third MOS transistor Q5 is connected to the collector of the second transistor Q2, the drain is connected to the positive voltage (high level), and the source is connected to the negative pole of the motor 21. The gate of the fourth MOS transistor Q6 is connected to the collector of the second transistor Q2, and the drain is connected to the negative electrode of the motor 21. The source of the second MOS transistor Q4 is connected to the source of the fourth MOS transistor Q6.

The driving circuit 43 further includes a current detection circuit for detecting the operating current of the motor 21, in this embodiment, the current detection circuit includes a resistor R5, one end of the resistor R5 is connected to the source of the fourth MOS transistor Q6 (the second MOS transistor Q4), the other end is connected to the third I/O port PA4 of the ID chip IC2, and one end of the resistor R1 connected to the controller 42 may be connected to a capacitor C3 for filtering.

Of course, any conventional detection circuit capable of detecting the motor operating current may be used, and the drive circuit 43 may be a conventional circuit capable of driving the motor 21 in the forward and reverse directions.

When the first transistor Q1, the second transistor Q2 and the controller 42 are connected, resistors R1 and R2 may be provided therebetween. Resistors R3 and R4 can be respectively connected between the grid and the drain of the first MOS transistor Q3 and between the grid and the drain of the third MOS transistor Q5, and resistors can be respectively arranged on the sources of the fourth MOS transistor Q6 to provide bias voltage. The source of the fourth MOS transistor Q4 is also connected to ground through a resistor R6.

A capacitor C4 may also be provided between the positive and negative poles of the motor 21.

When the controller 42 inputs a forward rotation control signal to the driving circuit 43, the first transistor Q1, the first MOS transistor Q3 and the second MOS transistor Q4 are turned on, the second transistor Q2, the third MOS transistor Q3 and the fourth MOS transistor Q4 are kept in an off state, and the driving signal of the first transistor Q1 is amplified by the first transistor Q3 and the second MOS transistor Q4 to drive the motor 21 to rotate forward (the positive electrode of the motor 21 is at a high level, and the negative electrode of the motor 21 is at a low level); when the controller 42 applies the reverse rotation control signal to the driving circuit 43, the second transistor Q2 is turned on, the first transistor Q1 is kept in an off state, and the driving signal of the second transistor Q2 is amplified by the third MOS transistor Q3 and the fourth MOS transistor Q4 to drive the motor 21 to reverse rotation (the positive pole of the motor 21 is at a low level, and the negative pole of the motor 21 is at a high level).

The controller 42 can detect the no-load and load states of the motor 21, and in order to avoid the motor 21 idling for a long time and detect the operation state of the motor 21 before the cutting assembly 3 cuts the can, the detection control flow of the controller 42 is as follows:

1) the self-locking switch KYE is pressed, the cathode of the ID chip IC2 is conducted, and the anode of the voltage provided by the battery provides starting voltage for the ID chip IC2 through the voltage regulation MOS tube IC 1;

2) the ID chip IC2 outputs a motor positive working voltage to the drive circuit 43 through the first I/O port PA6, the motor 21 starts to work, the cutting assembly 3 is driven to advance (feed) in the positive direction through the transmission mechanism and the brake mechanism, and the cutting wheel 35 does not bear resistance and runs in no-load at the moment;

3) when the forward running time of the motor 21 reaches a programmed timing point, which may be 3-5 ms, set by the ID chip IC2, the time is the time when the idler wheel 36 moves towards the tank cover side wall to cooperate with the cutting wheel 35 to clamp the tank cover side wall, and the ID chip IC2 stops providing the forward running voltage for the motor 21;

4) after the forward running voltage is stopped being provided for the motor 21 for a certain time, for example, 1ms, a reverse voltage is output from the second I/O port PA3 of the ID chip IC2 to provide the motor to work, the motor 21 runs in reverse, the cutting assembly 3 is driven to advance (retract) in reverse to a specified position through the transmission mechanism and the braking mechanism, when the cutting assembly 3 retracts to the specified position, namely, the idle wheel 36 gradually moves away from the cutting wheel 35 to touch the side wall of the mounting seat 11, the motor 21 is blocked to cause the working current to increase, and a motor working current increase information is fed back to the third I/O port PA4 of the ID chip IC2 through the resistor R5;

5) when the received operating current increases to exceed a preset upper limit value (e.g., 70mA, which is lower than the current at the time of cutting described later), the motor 21 is controlled to stop operating.

The control working principle of the cutting assembly 3 during feeding/cutting is as follows:

1) when the can is opened with the electric can opener, the edge of the can lid is inserted into the gap between the idle wheel 36 and the cutting wheel 35 of the can opener;

2) starting the electric can opener: the self-locking switch KYE is pressed, the cathode of the ID chip IC2 is conducted, and the anode of the voltage provided by the battery provides starting voltage for the ID chip IC2 through the voltage regulation MOS tube IC 1;

3) the ID chip IC2 outputs a motor forward working voltage from the first I/O port PA6 to the driving circuit 43, the motor 21 starts to run forward, the cutting assembly 3 is driven to advance (feed) forward through the transmission mechanism and the braking mechanism, and when the cutting wheel 35 of the cutting assembly 3 contacts the can wall, the working current of the motor 21 is increased due to the resistance, and the normal working current range is: 150-1500 mA, the current passing through the resistor R5 is increased, and the ID chip IC2 can receive the increased current signal through the third I/O port PA 4;

4) after the can is cut, the resistance on the cutting wheel 35 is reduced, the working current of the motor 21 is reduced, the current passing through the resistor R5 is reduced, and the ID chip IC2 can receive a signal of the reduced working current through the third I/O port PA 4; when the received working current is reduced to be lower than a preset lower limit value, such as 150mA, the ID chip IC2 stops voltage output;

5) after the forward running voltage is stopped to be supplied to the motor 21 for a certain time, for example, after 1ms, a reverse voltage is output from the second I/O port PA3 of the ID chip IC2 to supply the motor to work, the motor 21 runs in reverse, the motor gear drives the mechanical transmission reduction gear to run in reverse, the cutting assembly 3 is driven to advance (retract) in reverse through the transmission mechanism and the braking mechanism, after the specified position is reached, namely, the idle wheel 36 gradually moves away from the cutting wheel 35 to touch the side wall of the mounting seat 11, the motor 21 is blocked, the working current is increased, the current passing through the resistor R5 is also increased, and at this time, the ID chip IC2 can receive a signal of the increased working current of the motor through the third I/O port PA 4;

6) when the received operating current increases to exceed a preset upper limit value (e.g., 70mA), the motor 21 is controlled to stop operating, thereby completing the retracting operation.

The detection process may be performed before step 1) of the cutting process, or may be performed when the motor 21 is detected to be started (for example, the self-locking switch KYE is pressed by an erroneous operation) at any time.

The control circuit and the control method (detection and cutting) performed by the control circuit are not limited to the structure of the electric can opener disclosed in the present invention, but may be applied to the structure of the electric can opener described in the background art or other electric can openers disclosed in the prior art.

In conclusion, the electric can opener can complete cutting and tool advancing and retracting work at any time by controlling the motor 21 to rotate forwards and backwards, and does not have the phenomenon of tool clamping in the midway; through setting up current detection circuit, through the operating current who detects the motor to judge the operating condition of motor, and with the operation of this control motor, can avoid the motor idle running, improve motor life, accurate control cutting flow.

Claims

1. A control circuit of an electric can opener is used for controlling a driving mechanism of the electric can opener, the driving mechanism comprises a motor (21) capable of rotating forwards and reversely, the control circuit comprises a controller (42) and a driving circuit (43), the driving circuit (43) comprises a current detection circuit used for detecting the working current of the motor (21), the controller (42) is electrically connected with the current detection circuit and can receive the signal of the current detection circuit, and the controller (42) can control the motor (21) to operate through the driving circuit (43) according to the signal of the current detection circuit.

2. The control circuit of an electric can opener according to claim 1, characterized in that: the controller (42) comprises a control chip, the control chip at least comprises a first I/O port (PA6) and a second I/O port (PA3), the driving circuit (43) comprises a forward rotation driving circuit and a reverse rotation driving circuit, the forward rotation driving circuit comprises a first triode (Q1), the reverse rotation driving circuit comprises a second triode (Q2), the first triode (Q1) is connected between the first I/O port (PA6) and the positive pole of the motor (21), and the second triode (Q2) is connected between the second I/O port (PA3) and the negative pole of the motor (21).

3. The control circuit of an electric can opener according to claim 2, characterized in that: the drive circuit (43) further comprises a first amplification circuit connected between the first transistor (Q1) and the motor (21) and a second amplification circuit connected between the second transistor (Q2) and the motor (21).

4. The control circuit of an electric can opener according to claim 3, characterized in that: the first amplifying circuit comprises a first MOS transistor (Q3) and a second MOS transistor (Q4), and the second amplifying circuit comprises a third MOS transistor (Q5) and a fourth MOS transistor (Q6); the base of the first transistor (Q1) is connected to the first I/O port (PA6) and the emitter is grounded, the base of the second transistor (Q2) is connected to the second I/O port (PA3) and the emitter is grounded; the gate of the first MOS tube (Q3) is connected to the collector of the first triode (Q1), the drain is connected to positive voltage and the source is connected to the positive pole of the motor (21), the gate of the second MOS tube (Q4) is connected to the collector of the first triode (Q1) and the drain is connected to the positive pole of the motor (21), the gate of the third MOS tube (Q5) is connected to the collector of the second triode (Q2), the drain is connected to positive voltage and the source is connected to the negative pole of the motor (21), the gate of the fourth MOS tube (Q6) is connected to the collector of the second triode (Q2) and the drain is connected to the negative pole of the motor (21), and the source of the second MOS tube (Q4) is connected to the source of the fourth MOS tube (Q6).

5. The control circuit of an electric can opener according to claim 4, characterized in that: the control chip is also provided with a third I/O port (PA4), the current detection circuit comprises a resistor (R5), one end of the resistor (R5) is connected to the source electrode of the fourth MOS tube (Q6), and the other end of the resistor (R5) is connected to the third I/O port (PA4) of the control chip.

6. The control circuit of an electric can opener according to any one of claims 1 to 5, characterized in that: still include power supply circuit (41) for controller (42) power supply, control chip is the ID chip, control chip still includes anodal pin and negative pole pin (PB1), power supply circuit (41)'s output is connected to anodal pin, be connected with self-locking switch (KYE) on negative pole pin (PB1), self-locking switch (KYE) ground connection.

7. The control circuit of an electric can opener according to claim 6, characterized in that: the power supply circuit (41) comprises a voltage regulation MOS tube (IC1), the positive pole (BAT +) of the power supply is connected to the input end of the voltage regulation MOS tube (IC1), and the negative pole (BAT-) of the power supply is connected to the grounding end of the voltage regulation MOS tube (IC 1).

8. An electric can opener having a control circuit according to any one of claims 1 to 7, comprising a housing (1), a drive mechanism and a cutting assembly (3), the housing (1) comprising a mounting seat (11), the mounting seat (11) being a cavity structure formed by an upward recess of a bottom surface of the housing (1) facing a can side, the cutting assembly (3) comprising a rotatable cutting wheel (35) and an idle wheel (36) driven by the drive mechanism, characterized in that: the drive mechanism is controlled by the control circuit, and the idler wheel (36) can be driven by the drive mechanism to move closer to or away from the cutting wheel (35).

9. A control method of an electric can opener according to claim 8, characterized in that: the method comprises the following steps:

1) inserting the edge of the can lid of the can into the gap between the idle wheel (36) and the cutting wheel (35) of the cutting assembly (3);

2) the controller (42) is started;

3) the controller (42) outputs a positive working voltage to the driving circuit (43), the motor (21) starts to run in a positive direction to drive the cutting assembly (3) to advance in the positive direction, when a cutting wheel (35) of the cutting assembly (3) contacts the wall of the can, resistance is applied to the cutting wheel to increase the working current of the motor (21), and the controller (42) receives an increased current signal through the current detection circuit;

4) after the can is cut, the resistance borne by the cutting wheel (35) is reduced, the working current of the motor (21) is reduced, and the controller (42) receives a reduced current signal through a current detection circuit; when the received working current is reduced to be lower than a preset lower limit value, the controller (42) stops voltage output;

5) stopping providing forward running voltage for the motor (21) for a certain time, outputting a reverse voltage by the controller (42) to provide the motor to work, reversely running the motor (21) to drive the cutting assembly (3) to reversely advance, blocking the motor (21) and increasing working current when the idle rotating wheel (36) gradually moves away from the cutting wheel (35) and touches the side wall of the mounting seat (11), and receiving a signal of the increased working current by the controller (42) through a current detection circuit;

6) when the received working current is increased to exceed a preset upper limit value, the motor (21) is controlled to stop running, and therefore the tool retracting work is completed.

10. The method of controlling an electric can opener according to claim 9, characterized in that: before the step 1), a detection process is further included, and the detection process comprises the following steps:

01) the controller (42) is started;

02) the controller (42) outputs a positive working voltage to the driving circuit (43), the motor (21) starts to operate in a positive direction to drive the cutting assembly (3) to propel in the positive direction, and at the moment, the cutting wheel (35) does not bear resistance and operates in a no-load mode;

03) when the forward running time of the motor (21) reaches a set timing point, the controller (42) stops providing forward running voltage for the motor (21);

04) after the forward running voltage is stopped being provided for the motor (21) for a certain time, a reverse working voltage is output by the controller (42), the motor (21) runs reversely to drive the cutting assembly (3) to advance reversely, when the idle rotating wheel (36) gradually moves away from the cutting wheel (35) and touches the side wall of the mounting seat (11), the motor (21) is blocked and the working current is increased, and the controller (42) receives a signal of the increased working current through the current detection circuit;

05) when the received working current increases to exceed a preset upper limit value, the motor (21) is controlled to stop running.