A permanent magnet brushless DC motor for vehicle window and control method thereof

Abstract

The present invention provides a permanent magnet brushless DC motor for a vehicle window and a control method thereof. The brushless DC motor comprises a motor, a reduction box and a control module. The reduction box comprises a box body, a helical gear arranged in the middle of the box body and a cover plate arranged above the helical gear. A concentric driven gear is arranged on the helical gear, and the driven gear passes through the bottom of the box body to the outside. The motor comprises a housing, an iron core winding arranged on the inner side of the housing and a rotor arranged in the iron core winding. A worm shaft is arranged on the rotor, the worm shaft extends into the reduction box and is assembled using set screws, and the helical gear is threadedly engaged with the worm shaft. An electromagnetic attractor is also connected between the worm shaft and the rotor. A Hall magnetic ring and a Hall sensor are also arranged on the rotor. The control module comprises a box body and a control circuit board arranged in the box body, and a shunt and a microprocessor are arranged on the control circuit board. The brushless DC motor used in the present invention has the advantages of low noise, long service life and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile parts, and in particular relates to a permanent magnet brushless DC motor for a vehicle window and a control method thereof. Background Art

[0002] In today's automobile industry, electric lifting of car window glass has become standard. The motor for car windows is the power source that drives the glass lifter. The performance and controllability of the motor determine the stability and safety of the lifting of car window glass. At present, the motors for car windows are basically permanent magnet DC brushed motors. Brushed motors have many disadvantages. Due to the presence of brush commutators, electric sparks may be generated and the life is short. At the same time, this type of brushed motor is large in size, heavy in weight and very inefficient, generally only between 20% and 40%. At the same time, electric windows for cars replace hand-cranked windows, which improves the comfort of passengers and also brings some side effects. There are reports of people being pinched by electric windows. Electric windows with anti-pinch function have become a future trend. In response to these defects, the present application proposes a permanent magnet brushless DC motor for car windows and a control method thereof. Summary of the invention

[0003] The purpose of the present invention is to provide a permanent magnet brushless DC motor for vehicle windows and a control method thereof, so as to solve the shortcomings of the existing vehicle window glass using brush motors, such as short life and low efficiency, and further solve the problem that people are easily pinched when the vehicle window glass uses motors.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] A permanent magnet brushless DC motor for a vehicle window comprises a motor, a reduction gear and a control module, wherein the reduction gear comprises a housing, a helical gear arranged in the middle of the housing and a cover plate arranged above the helical gear, wherein the helical gear is provided with a concentric driven gear, and the driven gear passes through the bottom of the housing to the outside; the motor comprises a housing, an iron core winding arranged on the inner side of the housing and a rotor arranged in the iron core winding; a worm shaft is provided on the rotor, the worm shaft extends into the reduction gear and is assembled using set screws, and the helical gear is threadedly engaged with the worm shaft; an electromagnetic attractor is also connected between the worm shaft and the rotor; a Hall magnetic ring and a Hall sensor are also provided on the rotor; the control module comprises a housing, a control circuit board arranged in the housing, a shunt and a microprocessor are provided on the control circuit board, the microprocessor is electrically connected to the shunt, the Hall sensor, the motor and the electromagnetic attractor respectively, and the shunt is electrically connected to the motor.

[0006] Preferably, the box body and the shell are fixedly connected by fasteners; the box body is embedded in the box body and fixedly connected by fasteners.

[0007] Preferably, three Hall sensors are provided, and the position angle difference between the Hall sensors is 120°; the magnetic sensing surface of each Hall sensor is perpendicular to the magnetic field direction of the Hall magnetic ring.

[0008] Preferably, the electromagnetic clutch includes a base, an electromagnetic coil arranged in the middle of the base, an iron core arranged in the middle of the electromagnetic coil, an armature arranged at the end of the worm shaft and a sleeve arranged on the rotor, the sleeve is fixedly connected to the base, and the armature is movably connected to the iron core.

[0009] Preferably, a flexible coupling is further provided between the armature and the worm shaft.

[0010] Preferably, the microprocessor controls the action of the motor according to a window lifting signal, and the window lifting signal is input into the control module via a key switch or a network bus.

[0011] A control method for a permanent magnet brushless DC motor for a vehicle window, comprising:

[0012] After receiving the external window lifting signal, it drives the electromagnetic closer and the motor to work, and receives the Hall pulse signal of the Hall sensor and the current signal of the shunt in real time;

[0013] The real-time position of the window glass is obtained according to the Hall pulse signal processing, and it is determined whether the current signal is greater than the preset threshold of the real-time position. If so, it is determined whether the real-time position is located at the top dead center or the bottom dead center of the window;

[0014] If so, a first stop instruction is generated, and the motor and the electromagnetic attractor stop working according to the first stop instruction; if not, a second stop instruction is generated, and the electromagnetic attractor stops working within a preset time according to the second stop instruction.

[0015] Preferably, the acquisition of the preset threshold of the real-time position includes:

[0016] Divide the window glass operation area into multiple working areas, and perform n cycles of lifting and lowering experiments on the window glass, n ≥ 100;

[0017] During the lifting process of the window glass, the working current value of the motor is recorded, and a relationship curve between the working current value and the position of the window glass is constructed;

[0018] Get the preset threshold of the real-time position according to the relationship curve.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention provides a permanent magnet brushless DC motor for a vehicle window and a control method thereof. The brushless DC motor is adopted. Due to the brushless (without commutator and carbon brush) non-contact structure and the iron core design adopting the magnetic resistance design concept, the motor torque, efficiency, low noise and long service life are improved, and the whole vehicle is more comfortable and has a longer service life; the structure is simple, the manufacturing process is simple, and the scrap rate and manufacturing cost are greatly reduced; at the same time, on the basis of the brushless, an electromagnetic attractor is added, which can automatically disconnect the transmission between the rotor of the motor and the screw shaft, thereby realizing the anti-pinch function; and the threshold is preset according to the real-time position, which improves the use effect of the overall anti-pinch function. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 is a front view of a permanent magnet brushless DC motor for a vehicle window provided by an embodiment of the present invention;

[0023] Figure 2 is a side view of a permanent magnet brushless DC motor for a vehicle window provided by an embodiment of the present invention;

[0024] Figure 3 The embodiment of the present invention provides Figure 2 Middle AA section;

[0025] Figure 4 is a schematic diagram of the structure of an electromagnetic attractor provided in an embodiment of the present invention;

[0026] Figure 5 is a flow chart of a control method of a permanent magnet brushless DC motor for a vehicle window provided by an embodiment of the present invention;

[0027] The markings in the figure are:

[0028] 1. Gearbox, 11. Box body, 12. Helical gear, 13. Cover plate, 14. Driven gear, 2. Motor, 21. Housing, 22. Iron core winding, 23. Rotor, 24. Screw shaft, 25. Set screw, 26. Hall magnetic ring, 27. Hall sensor, 3. Control module, 31. Box body, 32. Control circuit board, 4. Electromagnetic attractor, 41. Base, 42. Electromagnetic coil, 43. Iron core, 44. Armature, 45. Bushing. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Embodiment 1

[0031] like Figure 1-3 As shown, a permanent magnet brushless DC motor for a vehicle window includes a motor 2, a reduction box 1 and a control module 3.

[0032] The reduction box 1 comprises a box body 11, a helical gear 12 arranged in the middle of the box body 11 and a cover plate 13 arranged above the helical gear 12. A concentric driven gear 14 is arranged on the helical gear 12, and the driven gear 14 passes through the bottom of the box body 11 to the outside.

[0033] The motor 2 includes a housing 21, an iron core winding 22 arranged on the inner side of the housing 21, and a rotor 23 arranged in the iron core winding 22; a worm shaft 24 is arranged on the rotor 23, the worm shaft 24 extends into the reduction box 1 and is assembled using a set screw 25, and the helical gear 12 is threadedly engaged with the worm shaft 24; an electromagnetic clutch 4 is also connected between the worm shaft 24 and the rotor 23; a Hall magnetic ring 26 and a Hall sensor 27 are also arranged on the rotor 23; three Hall sensors 27 are provided, and the position angle difference between each Hall sensor 27 is 120°; the magnetic sensing surface of each Hall sensor 27 is perpendicular to the magnetic field direction of the Hall magnetic ring 26.

[0034] The control module 3 includes a box body 31 and a control circuit board 32 arranged in the box body 31. A shunt and a microprocessor are arranged on the control circuit board 32. The microprocessor is electrically connected to the shunt, the Hall sensor 27, the motor 2 and the electromagnetic attractor 4 respectively, and the shunt is electrically connected to the motor 2. The microprocessor controls the action of the motor according to the window lifting signal, and the window lifting signal is input into the control module 3 by a key switch or a network bus.

[0035] The box body 11 and the shell 21 are fixedly connected by fasteners; the box body 31 is embedded in the box body 11 and fixedly connected by fasteners.

[0036] like Figure 4 As shown, the electromagnetic clutch 4 includes a base 41, an electromagnetic coil 42 arranged in the middle of the base 41, an iron core 43 arranged in the middle of the electromagnetic coil 42, an armature 44 arranged at the end of the worm shaft 24, and a sleeve 45 arranged on the rotor 23. The sleeve 45 is fixedly connected to the base 41, and the armature 44 is movably connected to the iron core 43; a flexible coupling is also arranged between the armature 44 and the worm shaft 24.

[0037] During operation, the control module 3 drives the motor 2 and the electromagnetic clutch 4 to work, the rotor of the motor 2 transmits power to the screw shaft 24 through the electromagnetic clutch 4, the worm shaft 24 drives the bevel gear 12, the bevel gear 12 drives the driven gear 14 to rotate, and the driven gear 14 drives the window glass to move; during the operation, the Hall sensor 27 detects the Hall magnetic ring 26 to calculate the stroke of the motor 2, and further calculates the position of the window glass.

[0038] Embodiment 2

[0039] like Figure 4 As shown, a control method of a permanent magnet brushless DC motor for a vehicle window includes:

[0040] After receiving the external window lifting signal, it drives the electromagnetic closer and the motor to work, and receives the Hall pulse signal of the Hall sensor and the current signal of the shunt in real time;

[0041] The real-time position of the window glass is obtained according to the Hall pulse signal processing, and it is determined whether the current signal is greater than the preset threshold of the real-time position. If so, it is determined whether the real-time position is located at the top dead center or the bottom dead center of the window;

[0042] If so, a first stop instruction is generated, and the motor and the electromagnetic attractor stop working according to the first stop instruction; if not, a second stop instruction is generated, and the electromagnetic attractor stops working within a preset time according to the second stop instruction.

[0043] The acquisition of the preset threshold of the real-time location includes:

[0044] Divide the window glass operation area into multiple working areas, and perform n cycles of lifting and lowering experiments on the window glass, n ≥ 100;

[0045] During the lifting process of the window glass, the working current value of the motor is recorded, and a relationship curve between the working current value and the position of the window glass is constructed;

[0046] Get the preset threshold of the real-time position according to the relationship curve.

[0047] During operation, the electromagnetic closer only works when the window glass needs to move; when the window glass reaches the top or bottom dead center, the electromagnetic closer and the motor are both turned off; when the window glass encounters an obstacle in the middle, the motor continues to work, but the electromagnetic closer does not work. At this time, the screw shaft loses power, and the window glass can move freely. When the preset time (usually 2-8s) is reached, the electromagnetic closer works again, making the motor work more continuous.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A control method for a permanent magnet brushless DC motor for a vehicle window, the permanent magnet brushless DC motor for a vehicle window comprising a motor, a reduction box and a control module, the reduction box comprising a housing, a helical gear arranged in the middle of the housing and a cover plate arranged above the helical gear, the helical gear being provided with a concentric driven gear, the driven gear passing through the bottom of the housing to the outside; the motor comprising a housing, an iron core winding arranged on the inner side of the housing and a rotor arranged in the iron core winding; a worm shaft being provided on the rotor, the worm shaft extending into the reduction box and assembled using a set screw, the helical gear being threadedly meshed with the worm shaft; an electromagnetic attractor being further connected between the worm shaft and the rotor; a Hall magnetic ring and a Hall sensor being further provided on the rotor; the control module comprising a housing, a control circuit board arranged in the housing, a shunt and a microprocessor being provided on the control circuit board, the microprocessor being electrically connected to the shunt, the Hall sensor, the motor and the electromagnetic attractor respectively, the shunt being electrically connected to the motor; characterized in that, The control method comprises: After receiving the external window lifting signal, it drives the electromagnetic closer and the motor to work, and receives the Hall pulse signal of the Hall sensor and the current signal of the shunt in real time; The real-time position of the window glass is obtained according to the Hall pulse signal processing, and it is determined whether the current signal is greater than the preset threshold of the real-time position. If so, it is determined whether the real-time position is located at the top dead center or the bottom dead center of the window; If so, a first stop instruction is generated, and the motor and the electromagnetic attractor stop working according to the first stop instruction; if not, a second stop instruction is generated, and the electromagnetic attractor stops working within a preset time according to the second stop instruction.

2. The control method of a permanent magnet brushless DC motor for a vehicle window according to claim 1, characterized in that: The box body and the shell are fixedly connected by fasteners; the box body is embedded in the box body and fixedly connected by fasteners.

3. The control method of a permanent magnet brushless DC motor for a vehicle window according to claim 1, characterized in that: There are three Hall sensors, and the position angle difference between the Hall sensors is 120°; the magnetic sensing surface of each Hall sensor is perpendicular to the magnetic field direction of the Hall magnetic ring.

4. The control method of a permanent magnet brushless DC motor for a vehicle window according to claim 1, characterized in that: The electromagnetic clutch comprises a base, an electromagnetic coil arranged in the middle of the base, an iron core arranged in the middle of the electromagnetic coil, an armature arranged at the end of the worm shaft and a sleeve arranged on the rotor, wherein the sleeve is fixedly connected to the base, and the armature is movably connected to the iron core.

5. The control method of a permanent magnet brushless DC motor for a vehicle window according to claim 4, characterized in that: A flexible coupling is also arranged between the armature and the worm shaft.

6. The control method of a permanent magnet brushless DC motor for a vehicle window according to claim 1, characterized in that: The microprocessor controls the action of the motor according to the window lifting signal, and the window lifting signal is input into the control module through a key switch or a network bus.

7. The control method of a permanent magnet brushless DC motor for a vehicle window according to claim 1, characterized in that: The acquisition of the preset threshold of the real-time position includes: Divide the window glass operation area into multiple working areas, and perform n cycles of lifting and lowering experiments on the window glass, n ≥ 100; During the lifting process of the window glass, the working current value of the motor is recorded, and a relationship curve between the working current value and the position of the window glass is constructed; Get the preset threshold of the real-time position according to the relationship curve.

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