Wiper motor with multiple protection circuits

Abstract

The utility model discloses a wiper motor with multiple protection circuits, which comprises a motor part and a reduction gearbox part, the motor part comprises a casing, a stator part and a rotor part, the rotor part comprises a rotor armature, a worm and a commutator, and the reduction gearbox part comprises a box body, a worm gear and an output shaft. One end of the worm extends into the box body and is meshed with the worm gear; the circuit component comprises a power supply, a relay, a high-speed electric brush, a low-speed electric brush, a common electric brush, an over-current thermal protector, a first inductor and a second inductor; the low-speed electric brush, the common electric brush, the over-current thermal protector, the power supply, the relay and the second inductor are connected to form a motor low-speed working circuit; the high-speed electric brush, the common electric brush, the over-current thermal protector, the power supply, the relay and the first inductor are connected to form a motor high-speed working circuit; the reduction gearbox part further comprises a position recognition component and a thermistor. The utility model can effectively solve the problem of damage to parts of products and prolong the service life of the products.

Description

Technical Field

[0001] The utility model relates to the technical field of automotive parts, in particular to a windshield wiper motor with a multiple protection circuit. Background Art

[0002] An automotive windshield wiper is an essential component of a vehicle, used to remove dust, leaves, and deposits on the windshield. Generally, a windshield wiper consists of multiple sub-components, including a wiper motor, a linkage mechanism, a wiper arm, and a wiper blade. The wiper motor is the power source for the operation of the windshield wiper. When the rotor coil of the wiper motor is energized, the energized coil rotates under the action of the stator magnetic field and works. Through the worm on the rotor in the reduction gearbox, the worm drives the worm wheel and the output shaft, transferring the rotational torque to the linkage mechanism and the wiper arm, driving the wiper blade to move on the glass. When the wiper system is turned off, through the on-vehicle wiper relay, the gear reset plate, and the return contact piece, the low speed of the wiper motor is turned on, allowing the wiper blade to move to the initial position and then stop, preventing the wiper arm and the wiper blade from stopping within the driver's field of vision on the automotive windshield, which may affect the driving safety of the driver.

[0003] During the operation of an automotive windshield wiper, due to the cleaning degree of the front windshield, different usage environments, etc., the working load of the windshield wiper varies greatly. Even due to freezing, freezing rain, and other reasons, the movement of the wiper blade is blocked, causing the wiper motor to be blocked for a long time and burned out. To prevent such problems from occurring, an overcurrent thermal protector is installed at the common brush terminal of the wiper motor.

[0004] Under the above-mentioned usage conditions, when the current or temperature set by the overcurrent thermal protector is reached, the overcurrent thermal protector automatically cuts off the circuit of the wiper motor to protect the wiper motor from being burned out. However, during the use of the wiper motor, the reset circuit also needs to be considered to protect the motor. That is, when the wiper blade returns to the initial position of the operation of the windshield wiper, if the wiper blade is blocked when approaching the initial position, due to the rigidity of the wiper arm and the wiper blade, the motor vibrates repeatedly at the limit position, causing the working current of the motor not to reach the parameter requirements set by the overcurrent thermal protector, and it cannot cut off the circuit of the wiper motor, resulting in damage to the contact piece, the reset plate, and the gear under the action of a large current for a long time. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a windshield wiper motor with a multiple protection circuit. The utility model can simultaneously protect the components in the motor control circuit, the rotor, and the reset circuit of the wiper blade at the extreme positions of the windshield wiper motor, improve the product life, and enhance the driving safety of the driver.

[0006] To achieve the above object, the present utility model provides the following technical solution: A windshield wiper motor with a multiple protection circuit, including a motor part and a speed reducer part. The motor part includes a housing, a stator component arranged inside the housing, and a rotor component cooperating with the stator component. The rotor component includes a rotor armature, a worm, and a commutator. The speed reducer part includes a box body connected to the side of the housing, a worm gear arranged inside the box body, and an output shaft that is circumferentially linked with the worm gear. One end of the worm extends into the box body and meshes with the worm gear. It also includes a circuit component, and the circuit component includes a power supply, a relay, a high-speed brush, a low-speed brush, a common brush, an overcurrent thermal protector, a first inductor, and a second inductor. The low-speed brush, the common brush, the overcurrent thermal protector, the power supply, the relay, and the second inductor are sequentially connected in series to form a low-speed working circuit of the motor. The high-speed brush, the common brush, the overcurrent thermal protector, the power supply, the relay, and the first inductor are sequentially connected in series to form a high-speed working circuit of the motor. The speed reducer part further includes a position recognition component for identifying the position of the windshield wiper. The position recognition component is connected in series with a thermistor, and the position recognition component is connected to the positive pole of the power supply through a relay. The thermistor is connected to the first inductor or the second inductor through a relay.

[0007] The present utility model is further arranged such that a first capacitor is connected in parallel after the first inductor, the high-speed brush, the common brush, and the overcurrent thermal protector are connected in series. A second capacitor is connected in parallel after the second inductor, the low-speed brush, the common brush, and the overcurrent thermal protector are connected in series.

[0008] The present utility model is further arranged such that both the first capacitor and the second capacitor are grounded.

[0009] The present utility model is further arranged such that the position recognition component includes a positive contact piece, a reset contact piece, a negative contact piece, and a reset plate. The positive contact piece and the reset contact piece are installed on the inner side of the box body, and the positive contact piece is connected to the positive pole of the power supply through a relay. The reset contact piece is connected to the first inductor or the second inductor through a relay. The reset plate is installed on the worm gear in a circumferentially linked manner. An arc-shaped hole with a rotation center coinciding with the output shaft is provided on the reset plate. When the worm gear drives the reset plate to rotate, the end of the reset contact piece always abuts against the reset plate. The end of the reset contact piece abuts against the reset plate or falls into the arc-shaped hole and disengages from the reset plate.

[0010] The present utility model is further arranged such that the position recognition component further includes a grounding piece provided on the box body. One end of the negative contact piece is electrically connected to the grounding piece, and the other end of the negative contact piece always abuts against the worm gear.

[0011] Compared with the prior art, the present utility model has the following beneficial effects:

[0012] 1. A thermistor element (abbreviated as PTC) is set in the circuit at the extreme reset position of the wiper blade of the wiper motor. When the current passing through this element exceeds its set value, the circuit it controls is cut off.

[0013] 2. According to the parameter settings in item 1, after the PTC cuts off the reset circuit, it cannot recover by itself. Only after clearing the blocked load at the reset of the wiper and restarting the wiper can it resume its normal working state.

[0014] 3. An overcurrent thermal protector (FR) is connected in series at the common brush end of the motor. This element can set the operating current and operating temperature with reference to the parameter requirements of the motor body. During the operation of the wiper motor, after reaching its set operating current or operating temperature, the circuit of the motor body is automatically cut off to achieve the effect of protecting the motor.

[0015] 4. An overcurrent thermal protector (FR) is connected in series at the common brush end of the motor and has the function of self - restoring the circuit. After the external load of the wiper is cleared or the internal temperature of the wiper motor body returns to the set value, the overcurrent thermal protector (FR) automatically connects the original circuit, enabling the wiper motor to resume its working state.

[0016] In summary, the utility model can make the wiper motor have a wider range of applications, meet various extreme weather and harsh environments, and can protect the components in the motor control circuit, rotor, and the extreme position reset circuit of the wiper blade of the wiper motor at the same time, improve the product life, and enhance the driving safety of the driver. Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the double - protection wiper motor structure;

[0018] Figure 2 It is a schematic diagram of the double - protection wiper motor reset structure;

[0019] Figure 3 It is a circuit diagram of the double - protection wiper motor working at low speed;

[0020] Figure 4 It is a circuit diagram of the double - protection wiper motor during the reset process;

[0021] Figure 5 It is a circuit diagram of the double - protection wiper motor reset extreme limit position.

[0022] In the figure: 1. Housing; 2. Stator component; 3. Rotor component; 4. Rotor armature; 5. Worm; 7. Thermistor; 8. Positive connection piece; 9. Commutator; 10. Reset plate; 11. Worm gear; 12. Box body; 14. Output shaft; 15. Circuit component; 17. High-speed brush; 18. Low-speed brush; 19. Positive contact piece; 20. Reset contact piece; 21. Negative contact piece; 22. Grounding piece; 23. Common brush; 24. Overcurrent thermal protector; 25. First inductor; 26. Second inductor; 27. Position identification component; 28. First capacitor; 29. Second capacitor; 30. Arc-shaped hole. Detailed implementation mode

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] Embodiment: As shown in the attached Figures 1 to 5 A windshield wiper motor with a multiple protection circuit includes a motor part and a reduction gearbox part. The motor part includes a housing 1, a stator component 2 arranged in the housing 1, and a rotor component 3 cooperating with the stator component 2. The rotor component 3 includes a rotor armature 4, a worm 5, and a commutator 9. The reduction gearbox part includes a box body 12 connected to the side of the housing 1, a worm gear 11 arranged in the box body 12, and an output shaft 14 that is circumferentially linked with the worm gear 11 (key connection can be adopted). One end of the worm 5 extends into the box body 12 and meshes with the worm gear 11. It also includes a circuit component 15. The circuit component 15 includes a power supply, a relay, a high-speed brush 17 (D1), a low-speed brush 18 (D2), a common brush 23 (D3), an overcurrent thermal protector 24 (FR), a first inductor 25 (L1), and a second inductor 26 (L2). The relay has "OFF" (reset gear), "LOW" (low-speed gear), and "HIG" (high-speed gear). The low-speed brush 18, the common brush 23, the overcurrent thermal protector 24, the power supply, the relay, and the second inductor 26 are sequentially connected in series to form a low-speed working circuit of the motor. The high-speed brush 17, the common brush 23, the overcurrent thermal protector 24, the power supply, the relay, and the first inductor 25 are sequentially connected in series to form a high-speed working circuit of the motor. The reduction gearbox part also includes a position identification component 27 for identifying the position of the windshield wiper. The position identification component 27 is connected in series with a thermistor 7 (abbreviation: PTC), and the position identification component 27 is connected to the positive pole of the power supply through the relay. The thermistor 7 is connected to the first inductor 25 or the second inductor 26 through the relay.

[0025] The first inductor 25, high-speed brush 17, common brush 23, and overcurrent thermal protector 24 are connected in series and then paralleled with a first capacitor 28 (C1). The second inductor 26, low-speed brush 18, common brush 23, and overcurrent thermal protector 24 are connected in series and then paralleled with a second capacitor 29 (C2). Both the first capacitor 28 and the second capacitor 29 are grounded.

[0026] The position recognition component 27 includes a positive contact piece 19, a reset contact piece 20, a negative contact piece 21, and a reset plate 10. The positive contact piece 19 and the reset contact piece 20 are installed inside the box body 12. And the positive contact piece 19 is connected to the positive pole of the power supply through a relay. More specifically, a positive connection piece 8 is provided outside the box body 12. One end of the positive connection piece 8 is connected to the positive contact piece 19, and the other end is connected to the relay. The reset contact piece 20 is connected to the first inductor 25 or the second inductor 26 through a relay. The reset plate 10 is installed in a circumferentially linked manner on the worm gear 11. An arc-shaped hole 30 with a rotation center coinciding with the output shaft 14 is provided on the reset plate 10. When the worm gear 11 drives the reset plate 10 to rotate, the end of the reset contact piece 20 always abuts against the reset plate 10. The end of the reset contact piece 20 abuts against the reset plate 10 or falls into the arc-shaped hole 30 and disengages from the reset plate 10. The position recognition component 27 further includes a grounding piece 22 provided on the box body 12. One end of the negative contact piece 21 is electrically connected to the grounding piece 22, and the other end of the negative contact piece 21 always abuts against the worm gear 11.

[0027] Working principle:

[0028] The windshield wiper motor is generally a two-speed DC motor and can operate at low speed and high speed according to the external environment.

[0029] Low-speed working principle of the windshield wiper motor: When the motor is connected to the positive pole of the external power supply, the current flows through the low-speed brush 18, commutator 9, rotor in the line component 15. The coil in the rotor generates a rotational torque in the magnetic field of the stator component 2, driving the worm 5 connected to the rotor to rotate. Through the meshing transmission of the worm 5 and the worm gear 11, the output shaft 14 on the worm gear 11 drives the linkage mechanism and the wiper arm and blade to work. The current passes through the rotor, common brush 23, overcurrent thermal protector 24 and returns to the negative pole of the power supply. The specific flow direction of the low-speed working current of the motor is shown in the appendix Figure 3 . When the windshield wiper is working, if the external load is too large, causing the current of the windshield wiper motor or the temperature inside the motor to reach the set value of the overcurrent thermal protector 24, the overcurrent thermal protector 24 will automatically disconnect, and the windshield wiper will stop working. When the external load is removed, the overcurrent thermal protector 24 automatically resumes connection, and the windshield wiper resumes working by itself. The high-speed working principle of the motor is the same as the low-speed working principle.

[0030] When the vehicle wiper switch (relay) is turned to "OFF", the wiper motor, through the reset system, moves the wiper blade to the initial position. The specific working principle and process are as follows: When the wiper switch is turned to the "OFF" position, the wiper relay on the vehicle connects the low-speed brush 18 of the wiper motor to the reset contact piece 20 of the wiper motor. The positive pole of the external power supply passes through the thermistor PTC7, the positive connection piece 8, the positive contact piece 19, the reset board 10, the reset contact piece 20, and the relay to connect to the low-speed end. Through the low-speed brush 18, the commutator 9, the rotor, and the coil in the rotor in the magnetic field of the stator component 2 in the line component 15, a rotational torque is generated, driving the worm 5 connected to the rotor to rotate. Through the meshing transmission of the worm 5 and the worm gear 11, the output shaft 14 on the worm gear 11 drives the linkage mechanism and the wiper blade to work. The current passes through the rotor, the common brush 23, and the overcurrent thermal protector 24 and returns to the negative pole of the power supply. See the attachment for the specific flow of the motor reset working current. Figure 4 。

[0031] When the wiper is reset to near the limit position, the positive contact piece 19 of the wiper motor is about to disengage from the reset board 10. At this time, if the wiper blade is blocked and cannot work, see the attachment. Figure 5 At this time, due to the rigidity of the wiper blade, the wiper blade will vibrate repeatedly, making the working current of the motor unable to reach the set value of the overcurrent thermal protector 24 and unable to disconnect. However, the thermistor PTC7 in the circuit will participate in the work at this time, disconnecting the wiper motor circuit, and the wiper stops working. When the external load is removed, the external power supply is disconnected, the thermistor PTC7 returns to normal, the wiper power supply is restarted, and the wiper returns to the normal working state.

Claims

1. A wiper motor with multiple protection circuits, comprising a motor part and a reduction box part, wherein the motor part comprises a housing (1), a stator part (2) and a rotor part (3), wherein the rotor part (3) comprises a rotor armature (4), a worm (5) and a commutator (9), wherein the reduction box part comprises a housing (12) connected to a side of the housing (1), a worm wheel (11) arranged in the housing (12) and an output shaft (14) which forms a circumferential linkage with the worm wheel (11), wherein one end of the worm (5) extends into the housing (12) and meshes with the worm wheel (11); wherein: It also includes a circuit component (15), wherein the circuit component (15) includes a power supply, a relay, a high-speed brush (17), a low-speed brush (18), a common brush (23), an overcurrent thermal protector (24), a first inductor (25), and a second inductor (26); The low-speed brush (18), the common brush (23), the overcurrent thermal protector (24), the power supply, the relay and the second inductor (26) are sequentially connected in series to form a low-speed working circuit of the motor; The high-speed brush (17), the common brush (23), the overcurrent thermal protector (24), the power supply, the relay and the first inductor (25) are sequentially connected in series to form a high-speed working circuit of the motor; The reduction box part also includes a position identification component (27) for identifying the position of the wiper, the position identification component (27) is connected in series with a thermistor (7), and the position identification component (27) is connected to the positive pole of the power supply through a relay, and the thermistor (7) is connected to the first inductor (25) or the second inductor (26) through a relay.

2. A wiper motor with multiple protection circuits according to claim 1, characterized in that: The first inductor (25), the high-speed brush (17), the common brush (23) and the overcurrent thermal protector (24) are connected in series and then connected in parallel with a first capacitor (28); the second inductor (26), the low-speed brush (18), the common brush (23) and the overcurrent thermal protector (24) are connected in series and then connected in parallel with a second capacitor (29).

3. A wiper motor with multiple protection circuits according to claim 2, characterized in that: The first capacitor (28) and the second capacitor (29) are both grounded.

4. A wiper motor with multiple protection circuits according to claim 1, characterized in that: The position identification component (27) comprises a positive contact sheet (19), a reset contact sheet (20), a negative contact sheet (21) and a reset plate (10), wherein the positive contact sheet (19) and the reset contact sheet (20) are installed on the inner side of the box body (12), and the positive contact sheet (19) is connected to the positive electrode of the power supply through a relay, and the reset contact sheet (20) is connected to the first inductor (25) or the second inductor (26) through a relay, and the reset contact sheet (21) is connected to the first inductor (25) or the second inductor (26) through a relay. The plate (10) is installed on the worm wheel (11) in a circumferentially linked manner. The reset plate (10) is provided with an arc hole (30) whose rotation center coincides with the output shaft (14). When the worm wheel (11) drives the reset plate (10) to rotate, the end of the reset contact sheet (20) always abuts against the reset plate (10). The end of the reset contact sheet (20) abuts against the reset plate (10) or falls into the arc hole (30) and detaches from the reset plate (10).

5. A wiper motor with multiple protection circuits according to claim 4, characterized in that: The position identification component (27) also includes a grounding plate (22) arranged on the box body (12); one end of the negative contact plate (21) is electrically connected to the grounding plate (22); and the other end of the negative contact plate (21) is always in contact with the worm gear (11).

Images