Control circuit of wiper motor and wiper motor system

Abstract

The utility model relates to a control circuit of a wiper motor and a wiper motor system. The control circuit of the wiper motor comprises a high-gear power supply line used for supplying power for high-gear operation to the wiper motor; the low-gear power supply line is used for supplying power for low-gear operation to the wiper motor; the stop position signal line is used for indicating whether the wiper motor periodically runs to a stop position or not; a ground wire for grounding; and the discharge module is connected with the off-position signal line and used for discharging static electricity generated on the off-position signal line, and the discharge module is connected between the off-position signal line and the ground line and used for discharging the static electricity on the off-position signal line to the ground line. The discharge module is composed of a resistor, and the resistance value of the resistor ranges from 100 kilohms to 100 megohms. According to the control circuit of the wiper motor, static electricity generated by the wiper motor can be well absorbed, stability is high, and the control circuit is not prone to being affected by the environment.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile electronic control, in particular to a control circuit of a windshield wiper motor and a windshield wiper motor system. Background Art

[0002] The function of the wiper motor is to drive the wiper arm to swing, thereby driving the wiper blade to move left and right on the windshield. The wiper motor usually contains a control circuit that can adjust the operating frequency and speed of the wiper according to the driver's operation or automatic sensing system to adapt to different rainfall and driving speeds.

[0003] When the wiper motor is working, static electricity is generated, which may produce electromagnetic compatibility (EMC) interference signals on the vehicle. This interference signal may have adverse effects on the electronic equipment inside the vehicle and the surrounding wireless communication equipment. Utility Model Content

[0004] Based on the above problems in the prior art, the utility model aims to provide a control circuit and a wiper motor system that can absorb static electricity generated by a wiper motor well, have high stability, and are not easily affected by the environment. The control circuit of the wiper motor of one aspect of the utility model includes:

[0005] A high-speed power supply line, used to provide power to the wiper motor for high-speed operation;

[0006] A low-speed power supply line, used to provide power for the wiper motor to operate at a low speed;

[0007] a stop signal line, used to indicate whether the wiper motor periodically runs to a stop position; and

[0008] The discharge module is connected to the stop signal line and is used to discharge static electricity generated on the stop signal line. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above and other objects and advantages of the present application will become more fully apparent from the following detailed description in conjunction with the accompanying drawings, in which the same or similar elements are represented by the same reference numerals.

[0010] Figure 1 The present invention is a schematic diagram showing the structure of a wiper motor in the prior art.

[0011] Figure 2 2 is a schematic structural diagram of a wiper motor system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0012] The following describes some of the various embodiments of the present invention, which are intended to provide a basic understanding of the present invention, but are not intended to identify the key or decisive elements of the present invention or to limit the scope of protection.

[0013] The inventor of the present utility model has conducted the following research on a wiper motor, and on this basis proposed a control circuit for the wiper motor of the present utility model.

[0014] Figure 1 The present invention is a schematic diagram showing the structure of a wiper motor in the prior art.

[0015] exist Figure 1 In the figure, M represents a wiper motor, 10 represents a magnet, 20 represents a slider, 30 represents a conductive sheet, 40 represents a power line (positive electrode), 50 represents a ground line (negative electrode), 60 represents a stop signal line, and 70 represents a gear. The slider 20 includes a ground slider and a stop signal line slider, which are connected to the ground line 50 and the stop signal line 60 respectively.

[0016] Every time the gear 70 rotates, the slider 20 will always rub against the gear 70. This friction will generate static electricity on the slider 20, negative charges will accumulate on the conductive sheet 30, and positive charges will accumulate on the slider 20 (mainly referring to the stop signal line slider, because the grounding slider is connected to the ground wire and the static electricity generated thereon will be released through grounding). Static electricity will cause EMC (Electromagnetic Compatibility) problems.

[0017] When the driver executes the command to turn off the wiper, the body controller needs to detect the position of the wiper arm until the wiper arm returns to the parking position (i.e., the initial position), and then the body controller cuts off the relay. This operation mode can ensure that the wiper can return to the parking position every time. Generally, by detecting the voltage of the parking signal line 60, it can be determined whether the wiper motor returns to the parking position (i.e., the initial position). This is because, as the gear 70 rotates, the conductive sheet 30 set on the gear 70 will rotate to contact the two sliders 20 at the same time. At this time, the parking signal line slider is connected to the grounding slider, and the voltage on the parking signal line 50 becomes 0V. The body controller will detect this 0V voltage, and thus it can be known whether the wiper returns to the parking position by detecting whether the voltage of the parking signal line 60 is 0.

[0018] In order to eliminate the EMC problem, the solution adopted in the prior art is to absorb the static electricity on the slider by a capacitor to avoid the EMC problem. However, the inventor of the utility model found that the use of a capacitor to absorb the static electricity on the slider still has the problem of low stability and being easily affected by the environment. In order to solve this problem, the control circuit of the wiper motor and the wiper motor system of the utility model are proposed.

[0019] Figure 2 2 is a schematic structural diagram of a wiper motor system according to an embodiment of the present invention.

[0020] like Figure 2 As shown, a wiper motor system 100 according to an embodiment of the present invention includes:

[0021] A wiper motor 101; and

[0022] The control circuit of the wiper motor is composed of the high-speed power supply line 53 b, the low-speed power supply line 53 , the parking signal line 31 b, the ground line 31 and the discharge module 102 .

[0023] Among them, the high-speed power supply line 53b is used to provide power for the wiper motor 101 to run at high speed, the low-speed power supply line 53 is used to provide power for the wiper motor 101 to run at low speed, the stop signal line 31b is used to ensure that the wiper motor 101 returns to the initial position (the principle of which has been introduced above), and the ground wire 31 is used for grounding.

[0024] Among them, the discharge module 102 is connected to the stop signal line 31b, and preferably, the discharge module 102 is connected between the stop signal line 31b and the ground line 31, and is used to discharge the static electricity generated on the stop signal line 31b, that is, the discharge module 102 is used to discharge the static electricity generated on the stop signal line 31b to the ground line 31.

[0025] As an example, the leakage module 102 can be composed of a resistor. When the leakage module 102 is composed of a resistor, a good technical effect can be obtained: static electricity can be effectively conducted to the ground line, and static electricity can be eliminated efficiently. Moreover, since the temperature drift of the resistor is smaller than that of the capacitor, the resistance value is basically stable, so the influence of temperature change is smaller than that of the capacitor. Moreover, since the resistor is less affected by pulses than the capacitor but more affected by current, while the capacitor is just the opposite, the position where the leakage module 102 is located is mainly affected by pulses and the current is very small, so the leakage module 102 using a resistor will be more stable and have a longer life.

[0026] As a preferred example, the resistor constituting the leakage module 102 can be a resistor of 100KΩ to 100MΩ. This is because: there is originally a resistor (not shown) on the parking signal line 31b near the body controller, which is generally about 300Ω. This means that when the wiper motor 101 returns to the parking position, a current of 40mA will pass through the parking signal line 31b. In order to keep this current value unchanged, the leakage current of the resistor must be small enough to avoid misjudgment by the body controller. In this case, assuming that the resistance value of the resistor is 1MΩ, then the leakage current = 12V / (1MΩ+300Ω)≈0.12uA. On the other hand, assuming that the resistance value of the resistor is greater than 100MΩ, although the leakage current will be smaller, the conductivity will also be reduced, which is not conducive to charge conduction. Taking the above into consideration, the use of a resistor of 100KΩ to 100MΩ can take into account both the leakage current being small enough and the ability to conduct static electricity.

[0027] As another example, the leakage module 102 may be composed of a resistor and a capacitor. For example, the leakage module 102 may be composed of a resistor and a capacitor connected in parallel, or the leakage module 102 may be composed of a resistor and a capacitor connected in series.

[0028] As another example, the leakage module 102 may be made of a grease material containing metal elements.

[0029] As described above, according to the control circuit of the wiper motor of one embodiment of the present invention, by using resistors to form a discharge module, the static electricity generated by the wiper motor can be effectively eliminated, and the control circuit can have higher stability and is not easily affected by environmental factors.

[0030] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Those skilled in the art can think of other feasible changes or substitutions based on the technical scope disclosed in the present application, and such changes or substitutions are all included in the protection scope of the present application. In the absence of conflict, the implementation modes of the present application and the features in the implementation modes can also be combined with each other. The protection scope of the present application shall be subject to the description of the claims.

Claims

1. A control circuit for a wiper motor, characterized in that: include: A high-speed power supply line, used to provide power to the wiper motor for high-speed operation; A low-speed gear power supply line, used to provide power for the wiper motor to operate at a low speed gear; A stop signal line, used to indicate whether the wiper motor periodically runs to a stop position; as well as The discharge module is connected to the stop signal line and is used to discharge static electricity generated on the stop signal line.

2. The control circuit of the wiper motor according to claim 1, characterized in that: Further including: Ground wire for grounding, The leakage module is connected between the stop signal line and the ground line.

3. The control circuit of the wiper motor according to claim 2, characterized in that: Further including: a gear driven to rotate by the wiper motor; A conductive sheet disposed on the gear; A grounding slider connected to the ground wire; as well as A stop signal line slider connected to the stop signal line.

4. The control circuit of the wiper motor according to claim 2, characterized in that: The discharge module is used to discharge static electricity on the stop signal line to the ground line.

5. The control circuit of the wiper motor according to claim 1, characterized in that: The leakage module is composed of a resistor.

6. The control circuit of the wiper motor according to claim 5, characterized in that: The resistance of the resistor is 100KΩ to 100MΩ.

7. The control circuit of the wiper motor according to claim 1, characterized in that: The leakage module is composed of a resistor and a capacitor.

8. The control circuit of the wiper motor according to claim 7, characterized in that: The resistor and the capacitor are connected in parallel, or The resistor and the capacitor are connected in series.

9. The control circuit of the wiper motor according to claim 1, characterized in that: The leakage module is composed of a grease material containing metal elements.

10. A windshield wiper motor system, characterized in that: include: A wiper motor and a control circuit for the wiper motor as claimed in any one of claims 1 to 9.

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