Device for controlling a wiper motor for a wiper system

Abstract

Device for controlling a wiper motor for a wiper system, wherein the wiper motor comprises a double cam disk (10) which is rotated by a rotational force of a motor, and internal contact points formed by a P-terminal (22) and an E-terminal (24) which are separated / connected by the double cam disk (10), wherein the double cam disk (10) comprises a first cam disk (12) and a second cam disk (16) for connecting the P-terminal (22) and the E-terminal (24), and a central plate (14) between the first and second cam disks (12, 16), the device comprising: a circuit line (38) that connects the P terminal (22) to an off terminal (34) of a low relay (30); and a control unit (40) that simultaneously switches off the low relay (30) when the P terminal (22) and the E terminal (24), which are connected by the first cam disc (12), are disconnected when a multifunction switch is switched off, thereby reducing an electromotive force applied to the wiper motor while the center plate (14) is in contact with the P terminal (22), wherein the middle plate (14) is formed in such a way as to be in contact only with the P-terminal (22) under the internal contact points of the wiper motor, so that a connection between the P-terminal (22) and the E-terminal (24) can be released at a moment when the first cam disk (12) passes through the P-terminal (22) and the middle plate (14) is in contact with the P-terminal (22) when the double cam disk (10) rotates.

Description

BACKGROUND Technical area

[0001] The present invention relates to a device for controlling a wiper motor for a wiper system and in particular a device for controlling a wiper motor for a wiper system to prevent a pulsating voltage / transient voltage that is generated when a wiper motor to which a high voltage power is applied is forcibly stopped after a multifunction switch is turned off. State of the art

[0002] Generally, a wiper system is fitted to remove foreign matter and wipe away snow or rainwater from the surfaces of the windshield or rear window of a vehicle.

[0003] The vehicle's wiper system, which is a device for wiping glass by actuating a wiper blade rotated by a wiper motor, serves to ensure a driver's visibility.

[0004] The wiper system for a vehicle generally has a structure in which a rotary motion generated in the wiper motor is transmitted to a pivoting mechanism and a wiper arm via a wiper linkage, causing the wiper arm to move horizontally back and forth and the wiper blade to move in order to wipe the glass.

[0005] Recently, the wiper system has been controlled by a body control module (BCM) within a vehicle, and the like, through the operation of the wiper motor.

[0006] Meanwhile, one operating mode of the wiper system comprises a low operating mode and a high operating mode, and the total number of connections / terminals of the wiper motor controlled by the BCM is four.

[0007] Among the connections of the wiper motor, an E connection is a ground (-) connection, a P connection is a parking control connection, an H connection is a high operating mode connection and an L connection is a low operating mode connection.

[0008] Furthermore, the wiper motor includes a cam disc and internal contact points formed by the P-terminal and the E-terminal, which are connected and separated / interrupted by the cam disc.

[0009] The cam disc is mounted in such a way as to be rotated integrally with a worm gear (worm wheel) which is rotated by receiving / taking up a rotational force from a motor inside the wiper motor, and the P terminal of the internal contact point is connected to the E terminal once according to a position of the wiper blade during a rotation.

[0010] In the wiper system, the wiper blade moves back and forth once by driving the wiper motor during a rotation of the cam disc to wipe the glass, and in this case the P-terminal and the E-terminal of the wiper motor are connected by the cam disc so that the wiper blade is stopped / paused at / in a predetermined park position.

[0011] However, in the prior art, the wiper system can generate a transient voltage when the wiper blade assumes an end position (park position) after a user switches off the multifunction switch.

[0012] Fig. Figure 1 shows a diagram illustrating an example of the operation of a cam disc for a wiper motor in the prior art. Fig. Figure 2 shows a circuit diagram for the control of the wiper motor of a wiper system in the state of the art. Fig. Figure 3 shows a flowchart illustrating a process for controlling the operation of the wiper motor in the prior art, and Fig. Figure 4 shows a graph representing a problem of wiper motor control in the state of the art.

[0013] With reference to Fig. 1 The wiper motor comprises a cam disk 2 which is mounted in such a way as to be rotated integrally with a gear part 1 (worm gear) which is rotated integrally with a shaft of a motor, and internal contact points formed by a P-terminal 3 and an E-terminal 4 which are connected and disconnected by the cam disk 2.

[0014] The cam disk 2 rotates together with the worm gear 1 during operation of the wiper motor and disconnects / interrupts the P terminal 3 and the E terminal 4 of the wiper motor in a normal operating section in which a wiper blade moves back and forth for one rotation, and is simultaneously in contact with the P terminal 3 and the E terminal 4 of the wiper motor to connect the P terminal 3 and the E terminal 4 in a stop section in which the movement of the wiper blade is stopped.

[0015] With reference to Fig. 2 and Fig. 3 In the prior art device for controlling the wiper motor, when a user switches off a multifunction switch (not shown) and then the cam disc 2 is in contact with the P terminal 3 and the E terminal 4 of the wiper motor at the same time, and the P terminal 3 and the E terminal 4 are connected, 0 V is applied to the P terminal 3, and when the BCM 6 detects 0 V at the P terminal 3, the BCM establishes a connection between a low relay 8 and an off terminal 8a connected to ground in order to forcibly stop the motor.

[0016] This means that in the prior art device for controlling the wiper motor, when the BCM 6 applies (outputs) a motor stop signal after the user switches off the multifunction switch, the low relay 8 inside a terminal box in an engine compartment is in contact with ground (off terminal) and an electromotive force applied to the wiper motor is instantly reduced to 0 V, and the wiper motor is forcibly stopped.

[0017] In this case, the wiper motor is forcibly stopped in a state where a high voltage power is applied, thus generating a transient voltage (see Fig. 4), that is, the electromotive force applied to the wiper motor abruptly reaches 0 V when the motor stops, so that a transient voltage is generated, and the transient voltage damages an element connected to the same power supply terminal and causes a jerking (vibrating) phenomenon when the wiper blade enters the stop position (park position).

[0018] From DE 600 24 915 T2, a device for controlling a wiper motor for a wiper system is known, wherein the wiper motor comprises a double cam disk which is rotated by a rotational force of a motor 13, and internal contact points formed by a P-terminal and an E-terminal which are connected separately by the double cam disk, wherein the double cam disk comprises a first cam disk and a second cam disk for connecting the P-terminal and the E-terminal, and a middle plate between the first and second cam disk, the device comprising: a circuit line which connects the P-terminal to an off-terminal of a low relay.

[0019] DE 698 27 322 T2 discloses a wiper device for causing a wiper blade of a vehicle or the like to perform a reciprocating wiping action by means of a normal or counter-rotating motor, and in particular relates to a wiper device suitable for controlling a rising wiper of a direct drive system. The device does not generate an unnecessarily large load when switching contacts S1 to S4 and a motor by simultaneously switching a relay when the P terminal and the E terminal, which are connected by a cam disk, are disconnected when a multifunction switch SW is switched.

[0020] The information disclosed in this background section is provided only to enhance understanding of the general background of the invention and should not be construed as an endorsement or any form of suggestion that this information represents the prior art already known to a person skilled in the art. SUMMARY OF THE REVELATION

[0021] Accordingly, the present invention has been made in an effort to solve the above-mentioned and / or other problems, and it is an object of the present invention to provide a device for controlling a wiper motor for a wiper system in which an electromotive force applied to the wiper motor abruptly reaches 0 V after a multifunction switch is turned off, thereby preventing a transient voltage from being generated due to a forced stopping of the wiper motor.

[0022] According to one embodiment of the present invention, a device for controlling a wiper motor for a wiper system is provided, wherein the wiper motor comprises a double cam disk which is rotated by a rotary force of a motor, and internal contact points formed by a P-terminal and an E-terminal which are separated / connected by the double cam disk, wherein the double cam disk comprises a first cam disk and a second cam disk for connecting the P-terminal and the E-terminal, and a central plate between the first and second cam disks, the device comprising: a circuit line which connects the P-terminal to an off-terminal of a low relay;and a control unit that simultaneously switches off the low relay when the P-terminal and the E-terminal, which are connected by the first cam disk, are disconnected when a multifunction switch is turned off, thereby reducing an electromotive force applied to the wiper motor while the center plate is in contact with the P-terminal. The center plate is designed to be in contact only with the P-terminal under the internal contact points of the wiper motor, so that a connection between the P-terminal and the E-terminal is released / disconnected at the instant when the first cam disk passes / traverses the P-terminal and the center plate is in contact with the P-terminal when the double cam disk rotates.

[0023] The double cam disc can pass through the wiper motor via the internal contact points in the sequence of the first cam disc, the center plate, and the second cam disc for one rotation. If the center plate passes through the P terminal and the P terminal and the E terminal are connected by the second cam disc, then both the P terminal and the E terminal of the wiper motor can be connected to ground.

[0024] According to the device for controlling a wiper motor for a wiper system, it is possible to prevent the generation of a transient voltage caused by an electromotive force applied to the wiper motor abruptly reaching 0 V when the wiper motor is forcibly stopped; it is possible to prevent an element connected to a power supply terminal, such as the wiper motor, from being damaged due to the generation of the transient voltage; it is possible to remove a varistor necessary in a prior art wiper motor control system, thereby reducing manufacturing costs; and it is possible to reduce the effect or extent of an impact exerted on a wiper blade when the wiper blade enters a stop position after a wiper switch of the multifunction switch is turned off, in order to prevent a jerking (vibrating) phenomenon.

[0025] The method and apparatus of the present invention have further features and advantages which are evident from or are explained in more detail in the accompanying drawings included herein and in the following detailed description, which together serve to explain the certain principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and further features of the present invention will now be described in detail with reference to exemplary embodiments thereof, which are illustrated by the accompanying drawings. These drawings are included below for illustrative purposes only and are therefore not limiting to the present invention. The figures show / describe: Fig. 1 a diagram illustrating the operation of a cam disc for a wiper motor in the prior art; Fig. 2 a circuit diagram representing a device for controlling a wiper motor of a wiper system in the prior art; Fig. 3 a flowchart illustrating a process for controlling the operation of the wiper motor in the prior art; Fig. Figure 4 shows a graph representing a problem of wiper motor control in the prior art; Fig. 5 a circuit diagram representing a device for controlling a wiper motor of a wiper system according to the present invention; Fig. 6A, Fig. 6B and Fig. 6C Diagrams for describing connection forms between a P-terminal and an E-terminal when double curve drawings are rotated for the wiper motor, according to the present invention; Fig. 7 a flowchart illustrating a process for controlling a stop of the wiper motor according to the present invention; and Fig. 8 a graph representing an improvement effect of the control of the wiper motor according to the present invention.

[0027] It should be noted that the accompanying drawings are not necessarily to scale and represent a somewhat simplified depiction of various preferred features, intended to illustrate the principles of the disclosure. The specific design features of the present disclosure, as disclosed herein, including, for example, specific dimensions, orientations, installation locations, and shapes, are partly determined by the application specifically designated for this purpose and the working environment.

[0028] In the figures, the reference signs refer to the same or equivalent parts of the present revelation throughout the individual figures of the drawings. DETAILED DESCRIPTION

[0029] Reference will now be made in detail to the various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) is / are described in connection with exemplary embodiments, it is understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is / are intended to cover not only the exemplary embodiments but also various alternatives, modifications, equivalents, and further embodiments that may be included within the teaching and scope of the invention, as defined by the accompanying claims.

[0030] As described above, the prior art wiper motor comprises the cam disk 2 and the internal contact point formed by the P-terminal 3 and the E-terminal 4, which can be connected and disconnected by the cam disk 2, and the cam disk 2 is mounted such that it is rotated by the worm gear 1, which receives a rotational force from the motor within the wiper motor, and is in contact with the P-terminal 3 and the E-terminal 4 of the internal contact point of the motor in a stop / holding section (parking position) of the wiper blade for a rotation to connect the P-terminal 3 and the E-terminal 4 (see Fig. 1).

[0031] However, the device for controlling the wiper motor is state-of-the-art if the BCM 6 (see Fig. 2) applies (outputs) a motor stop signal after a user switches off the multifunction switch, the low relay 8 (see Fig. 2) within the engine compartment's terminal box, in contact with an output terminal 8a, which is connected to ground, and an electromotive force applied to the wiper motor is instantly reduced to 0V, and the wiper motor is forcibly stopped / stopped, and in this case the wiper motor is forcibly stopped in a state where a high voltage power is applied, so that a transient voltage is generated.

[0032] In the present invention, in order to prevent the generation of a transient voltage or to reduce the magnitude / level of the transient voltage when the wiper motor is forcibly stopped after the multifunction switch is switched off in the prior art, an off terminal 34 of a low relay 30 for a wiper motor within a terminal box of an engine compartment is connected to a P terminal 22 of a wiper motor, not to a ground, as in Fig. 5 shown, and a double cam disk 10 with double cam disk sections / dual cam disk sections in which the P-terminal 22 and the E-terminal 24 can be connected / electrically connected is as in Fig. 6A to 6C are shown and set up.

[0033] As from Fig. As can be seen in Figures 6A-6C, the double cam disk 10 is mounted in such a way as to be rotated integrally with the worm gear 1, and the worm gear 1 rotates by a torque of the wiper motor, that is, by receiving the torque of the wiper motor, similar to the cam disk in the prior art.

[0034] That is, the wiper motor includes the double cam disc 10, which is rotated by the rotational force of the motor, and internal contact points formed by the P-terminal 22 and the E-terminal 24, which can be separated / connected by the double cam disc 10.

[0035] The double cam disc 10 comprises a first cam disc 12 and a second cam disc 16, which can electrically connect the P-terminal 22 and the E-terminal 24, and a center plate 14, which is integrally connected to the P-terminal 22 and the E-terminal 24, and the first cam disc 12, the center plate 14 and the second cam disc 16 pass sequentially through the internal contact point for one revolution through the wiper motor.

[0036] The first cam disk 12 and the second cam disk 16 are designed to be in contact with the P-terminal 22 and the E-terminal 24 under the internal contact points of the wiper motor at the same time during the rotation of the double cam disk 10, and when the first cam disk 12 and the second cam disk 16 are in contact with the P-terminal 22 and the E-terminal 24 at the same time, the first cam disk 12 and the second cam disk 16 electrically connect the P-terminal 22 and the E-terminal 24.

[0037] This means that the double cam disc 10 can separate / connect the P-connection 22 and the E-connection 24 through the first cam disc 12 and the second cam disc 16.

[0038] Furthermore, the center plate 14 is designed to be in contact only with the P-terminal 22, with the exception of the E-terminal 24, under the internal contact points of the wiper motor when the double cam disk 10 rotates, so that when the P-terminal 22 and the E-terminal 24 are connected by the first cam disk 12 and the double cam disk 10 rotates due to the inertia of the wiper motor, when the rotation of the wiper motor is stopped, the P-terminal 22, which is in contact with the first cam disk 12, passes through the first cam disk 12 (that is, the P-terminal 22 and the first cam disk 12 are separated and the P-terminal 22 is connected to the center plate 14), and at the same time the connection between the P-terminal 22 and the E-terminal 24 is released.

[0039] Meanwhile, with reference to Fig. 5, the P-terminal 22 of the wiper motor and the off-terminal 34 of the low relay 30 are electrically connected by a circuit line 38 and a switch terminal 32 of the low relay 30 is controlled by a control unit 40, such as a BCM, to be selectively connected to an on-terminal 36 connected to a power supply from a battery or to an off-terminal 34 connected to the P-terminal 22.

[0040] The control unit 40 detects a contact state between the double cam disk 10 and the internal contact points of the wiper motor by means of a pull-up method, and when the control unit 40 detects an initial connection of the P-terminal 22 and the E-terminal 24 for a rotation, the control unit 40 determines that the first cam disk 12 is in contact with the internal contact point, and when the control unit 40 detects a release of the connection between the P-terminal 22 and the E-terminal 24, the control unit 40 determines that the center plate 14 is in contact only with the P-terminal 22 below the internal contact points, and then when the control unit 40 detects the connection between the P-terminal 22 and the E-terminal 24 again, the control unit 40 determines that the second cam disk 16 is in contact with the internal contact point.

[0041] In this case, if 0 V is detected at the P-terminal 22, the control unit 40 recognizes that the P-terminal 22 and the E-terminal 24 are connected.

[0042] The following describes a process for stopping / suspending the wiper motor when the wiper blade enters a stop position after the multifunction switch is turned off, with reference to Fig. Sections 6A-6C and 7 are described in more detail.

[0043] If a user switches off the multifunction switch while the wiper blade is moving due to the drive of the wiper motor, that is, before the wiper blade reaches a park position, the control unit 40, which detects the switching off of the multifunction switch, does not immediately switch off the low relay 30 and the wiper motor is driven by the power of the battery, so that the double cam disc 10 rotates until the double cam disc 10 is in contact with the internal contact point of the wiper motor.

[0044] When the control unit 40 detects that the rotating double cam disc 10 connects the P terminal 22 and the E terminal 24, the control unit 40 prepares to stop driving the wiper motor (that is, makes preparations to stop the supply of energy from the battery by switching off the low relay 30).

[0045] When the P-terminal 22 and the E-terminal 24 are in contact with the first cam disc 12 of the double cam disc 10 at the same time, the P-terminal 22 is connected to the E-terminal 24, which is the ground, so that 0 V is applied to the P-terminal 22.

[0046] Therefore, when the P-terminal 22 is connected to the E-terminal 24, so that 0 V is detected in the P-terminal 22, the control unit 40 recognizes that the P-terminal 22 and the E-terminal 24 are connected by the double cam disc 10.

[0047] Then the double cam disc 10 rotates due to the rotation of the wiper motor and the first cam disc 12 passes through the internal contact point of the wiper motor, that is, the P terminal 22, which is connected to the E terminal 24, moves away from the first cam disc 12 and is in contact with the center plate 14, and the control unit 40, which detects this state, causes the switch terminal 32 of the low relay 30 to be connected to the off terminal 34 in order to switch off the low relay 30.

[0048] The supply of energy from the battery that powers the wiper motor is stopped according to the switching off of the low relay 30, and the double cam disc 10 moves rotating due to the inertia of the wiper motor, which has been turned, so that the center plate 14 is in contact with the P terminal 22.

[0049] The center plate 14 is in contact with the P-terminal 22, which is connected to the off-terminal 34 of the low relay 30 via the circuit line 38, so that the double cam disc 10 enters a non-conductive state, and in this case the double cam disc 10 moves rotatingly due to the inertia of the wiper motor, so that the second cam disc 16 can be in contact with the internal contact point of the wiper motor.

[0050] Before 0 V is applied to both terminals of the wiper motor, that is, in a state where the double cam disc 10 is only in contact with the P terminal 22 through the center plate 14, an electromotive force applied to the wiper motor is gradually / stepwise reduced, and the electromotive force applied to the wiper motor is reduced while the P terminal 22 passes through the center plate 14.

[0051] Accordingly, when the double cam disc 10 connects the P-terminal 22 and the E-terminal 24 via the second cam disc 16, i.e., the two terminals of the wiper motor are connected to ground, so that the rotation of the wiper motor is stopped, even if an electromotive force applied to the wiper motor is reduced to 0 V, a voltage difference is reduced in this case compared to the prior art (see Fig. 4), so that it is possible to resolve / correct a short-term voltage difference when the drive of the wiper motor is stopped (see Fig. 8), thereby preventing the generation of a transient voltage due to an instantaneous voltage difference.

[0052] This means that the P terminal 22 and the E terminal 24 of the wiper motor are in contact and simultaneously connected to the second cam 16, so that 0 V is applied to both terminals of the wiper motor and the wiper motor is automatically stopped, and a temporary voltage difference that is generated when the rotation of the wiper motor is stopped is resolved, thus preventing the generation of a transient voltage.

[0053] Meanwhile, it states Fig. 8 represents a result of a measurement and evaluation of a voltage of the wiper motor in a process for producing an entry of the wiper blade into a park position (stop position) after the multifunction switch is turned off, by applying the wiper motor control device of the wiper system under an actual condition of the vehicle.

[0054] As from Fig.As can be seen in Figure 8, as a result of measuring and evaluating voltages in a normal operating section where the wiper motor is supplied with energy / current from the battery, a no-load section where the P-terminal of the wiper motor passes through the first cam disc and is in contact with the center plate, and an automatic stop section where the P-terminal of the wiper motor passes through the center plate of the double cam disc and is in contact with the second cam disc together with the E-terminal, it can be deduced that the electromotive force of the wiper motor is gradually reduced while the double cam disc moves due to the inertia of the wiper motor in the no-load section, and thus there is an effect that a temporary voltage difference is resolved when the wiper motor is stopped in the automatic stop section.

[0055] As described above, when the wiper blade enters the stop position (park position) or assumes the stop position after the multifunction switch is turned off, an electromotive force applied to the wiper motor is reduced while the P-terminal passes through the center plate of the double cam disc, thus making it possible to prevent the generation of a transient voltage by a voltage difference when the electromotive force of the motor is abruptly reduced.

[0056] The preceding descriptions of certain embodiments of the present invention have been given for illustrative and descriptive purposes. They are not exhaustive and are not intended to limit the invention to the exact forms disclosed, and obviously many modifications and alterations are possible in light of the teaching stated above. The embodiments have been selected and described to explain certain principles of the invention and its practical application, in order to enable another person skilled in the art to develop and use various embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention is defined by the attached claims and their equivalents.

Claims

[1] Device for controlling a wiper motor for a wiper system, wherein the wiper motor comprises a double cam disk (10) which is rotated by a rotational force of a motor, and internal contact points formed by a P-terminal (22) and an E-terminal (24) which are separated / connected by the double cam disk (10), wherein the double cam disk (10) comprises a first cam disk (12) and a second cam disk (16) for connecting the P-terminal (22) and the E-terminal (24), and a central plate (14) between the first and second cam disks (12, 16), the device comprising: a circuit line (38) that connects the P terminal (22) to an off terminal (34) of a low relay (30); and a control unit (40) that simultaneously switches off the low relay (30) when the P terminal (22) and the E terminal (24), which are connected by the first cam disc (12), are disconnected when a multifunction switch is switched off, thereby reducing an electromotive force applied to the wiper motor while the center plate (14) is in contact with the P terminal (22), wherein the middle plate (14) is formed in such a way as to be in contact only with the P-terminal (22) under the internal contact points of the wiper motor, so that a connection between the P-terminal (22) and the E-terminal (24) can be released at a moment when the first cam disk (12) passes through the P-terminal (22) and the middle plate (14) is in contact with the P-terminal (22) when the double cam disk (10) rotates. [2] Device according to claim 1, wherein, when the middle plate (14) passes through the P-connection (22) and the P-connection (22) and the E-connection (24) are connected by the second cam disk (16), both the P-connection (22) and the E-connection (24) of the wiper motor are connected to a ground. [3] Device according to claim 1, wherein the double cam disc (10) passes through the internal contact points in a sequence of the first cam disc (12), the intermediate plate (14) and the second cam disc (16) for rotation by the wiper motor.

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