JPS6237796Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a non-contact washer-linked intermittent wiper device that is compact, has stable operation, and is highly reliable.

A conventional washer-linked intermittent wiper device was constructed as shown in FIG. To explain its configuration and operation, when operating the intermittent wiper, by turning on switch 1, base current flows from battery 2 to transistor 3, transistor 3 turns on, and relay 4 turns on.
Current flows through the coil 5, and the relay contact changes from B to A.
The wiper motor 6 is then driven. When this wiper motor 6 rotates, the transfer contact 7 of the wiper motor 6 switches from a to b,
When the capacitor 8 is charged and the cam plate of the wiper motor 6 comes to the automatic stop position, the transfer contact 7 switches from B to A, and the charging voltage of the capacitor 8 is reverse biased between the base and emitter of the transistor 3. Transistor 3 turns OFF, current no longer flows through coil 5 of relay 4,
The relay contact switches from A to B. Therefore, no current flows through the wiper motor 6, and since both ends of the wiper motor 6 are shot by the transfer contact 7 and the relay contact, an electrical brake is applied and the wiper motor 6 is stopped. Then, the capacitor 8 is charged by the intermittent time resistor 9, and the base voltage of the transistor 3 rises. When the base potential becomes higher than the base-emitter saturation voltage (0.6V), the transistor 3 is turned on and the wiper motor 6 repeats the above operation. . In addition, 1 in the figure
0 and 11 are voltage dividing resistors of the transistor 3.

Next, when you turn on the watch switch 12,
When the washer motor 19 operates, the capacitor 15 is charged via the delay time resistors 13 and 14, and when this charging voltage exceeds the base-emitter saturation voltage of the transistor 16, the transistor 16 is turned on, and the transistor 17 is also turned on. Become. Also, the capacitor 18 is charged. When the transistor 17 is turned on, current flows from the battery 2 to the coil 5 of the relay 4, the relay contact switches from B to A, and the wiper motor 6 operates. When the capacitor 18 is discharged and the potential drops below a certain level, the transistor 17 is turned off and current no longer flows through the coil 5 of the relay 4.
The relay contact switches from A to B, and the wiper motor 6 stops at the stop position. In addition, 20,2 in the figure
Reference numeral 1 indicates a voltage dividing resistor of the transistor 17, and 22 indicates a current limiting resistor.

In such a configuration, since the current flowing through the wiper motor 6 is regulated when the wiper motor 6 is driven by switching the relay 4, the contact capacity of the relay 4, the strength of the leaf spring, etc. Since the relay coil 5 required to attract this leaf spring is required, it is difficult to downsize it, and it lacks reliability due to the wear and tear of the relay contacts mentioned above.In addition, the switching noise caused by switching the relay contacts is The drawback was that it was large and caused discomfort to the user.

The present invention provides a contactless washer interlocking intermittent wiper device that eliminates the above-mentioned drawbacks of the conventional wiper.

Embodiments of the present invention will be described below with reference to FIGS. 2 and 3.

First, the basic configuration will be explained in FIG.
4 drives a wiper motor 25, a motor braking circuit 26 for stopping the wiper motor 25 is connected to the wiper motor 25, and an overcurrent protection circuit 27 for protecting against overcurrent is connected to the motor drive circuit 24. It is composed of

A concrete circuit of the above basic structure is shown in FIG. 3, and its structure will be explained together with its operation.

First, when operating the intermittent wiper, by turning on the switch 28 that constitutes the intermittent/washer interlocking circuit 23, the base current flows from the battery 29 to the transistor 30 for the intermittent wiper, turning the transistor 30 on, and the current A base current flows through the transistor 32 of the motor drive circuit 24 via the limiting resistor 31, making the transistor 32 conductive, and current flows from the battery 29 to the wiper motor 25, thereby driving the wiper motor 25. Note that the armature resistance of the wiper motor 25 is smaller than the braking resistance 35 connected between one armature of the wiper motor 25 and the stop contact a of the transfer contact 33, so the collector current of the transistor 32 is Most of the liquid flows to the wiper motor 25, and the wiper motor 25 operates as described above. Due to this rotation of the wiper motor 25, the transfer contact 33 of the wiper motor 25 is switched from the stop contact a to the stop contact b, and the capacitor 34 is fully charged. In this way, current flows through the transistor 32 only when the wiper motor is started. When the cam plate of the wiper motor 25 comes to the automatic stop position, the transfer contact 33 switches from B to A, the charging voltage of the capacitor 34 is reverse biased between the base and emitter of the transistor 30, and the transistor 30 is turned off. Since the base current no longer flows through the transistor 32, the transistor 32 turns OFF, and as a result, the wiper motor 2
Since no current flows through the wiper motor 5 and both ends of the wiper motor 6 are short-circuited via the transfer contact 33 and the braking resistor 35, an electrical brake is applied and the wiper motor 25 is stopped. and capacitor 34
is charged through the intermittent time resistor 36, the base voltage of the transistor 30 rises, and when this base potential exceeds the base-emitter saturation voltage, the transistor 30 is turned on and the transistor 32 is also turned on.
Therefore, the wiper motor 25 operates again.

Next, when operating the washer, turn on the washer switch 37 of the intermittent/washer interlocking circuit 23.
When turned on, the washer motor 38 operates and injects washer liquid, and the capacitor 41 is charged via the delay time resistors 39 and 40, and this charging voltage exceeds the base-emitter saturation voltage of the transistor 42. Then, the transistor 42 turns on and starts charging the capacitor 44 via the current limiting resistor 43, and the base current flows to the washer interlocking transistor 46 via the voltage dividing resistor 45.
6 is also turned on. Note that 47 is a transistor 46
This is a voltage dividing resistor. This transistor 46
When turned ON, the base current flows to the transistor 32 via the current limiting resistor 31, and the transistor 3
2 becomes conductive, current flows from the battery 29 to the wiper motor 25, and the wiper motor 25 starts operating. On the other hand, current flows through the transistor 32 only at the time of starting and when the transfer contact 33 is switched from a to b when the wiper motor 25 is in operation. And capacitor 44
transistors 46 and 32 are on while discharging
The wiper motor 25 continues to rotate. When the voltage drops below a certain level due to discharge of the capacitor 44, the transistor 46 turns OFF.
The base current no longer flows through the transistor 32, the transistor 32 is turned off, and the wiper motor 25 stops at the stop position.

Furthermore, when an overcurrent flows through the wiper motor 25, the emitter-collector voltage V _CE of the transistor 32 increases, and when it exceeds a certain value, the overcurrent detection transistor 50 is turned on, base current flows to the transistor 52 via the current limiting resistor 51, and the transistor 52 is turned on. This transistor 52
When turned on, the collector current flows through the voltage dividing resistor 53,
Transistor 5 for overcurrent protection by voltage division of 54
5 as a base current to the transistor 55.
turns on. When this transistor 55 is turned on, the emitter and base of the transistor 32 are shorted by the transistor 55, and no base current flows through the transistor 32.
The transistor 32 is turned off, and no current flows to the wiper motor 25.

Since a transient current flows when the wiper motor 25 starts, the capacitor 56 and voltage dividing resistor 53
By delaying the time when the overcurrent protection transistor 55 turns ON, malfunction of the overcurrent protection circuit 27 due to startup is prevented.

In the figure, 57 and 58 are voltage dividing resistors of the transistor 30, and 59 is a current limiting resistor.

Since the non-contact washer interlocking intermittent wiper device of the present invention is configured as described above, various problems caused by the conventional mechanical contact type are solved, and the reliability of the device is greatly improved. Also, since a transistor is used instead of a relay, it can be made smaller and lighter in weight.In addition, an overcurrent protection circuit is provided, which prevents the wiper motor from burning out when the wiper motor is locked, and when switching Discomfort caused by mechanical contact noise caused by operation can also be eliminated. Furthermore, since current flows through the transistor of the wiper motor drive circuit only when the wiper motor is started, it is only necessary to withstand the starting current of the wiper motor, and a small transistor can be used, making the structure suitable for molded products. Can be done.

As described above, the present invention has various advantages and is of great practical value.

[Brief explanation of the drawing]

Fig. 1 is an electrical circuit diagram of a conventional intermittent wiper device linked with a washer, Fig. 2 is a block diagram of a circuit configuration showing an embodiment of the intermittent wiper device linked with a non-contact washer according to the present invention, and Fig. 3 is a diagram showing a specific example of the same. FIG. 23... Intermittent/watch interlocking circuit, 24...
Motor drive circuit, 25...Wiper motor, 26
...Motor braking circuit, 27...Overcurrent protection circuit,
28...Switch, 29...Battery, 30...
...Transistor for intermittent wiper, 31...Current limiting resistor, 32...Transistor, 33...Transfer contact, 34...Capacitor, 35...Resistance for braking, 36...Resistance for intermittent time, 37...Woo Washer switch, 38...Washer motor,
39, 40... Resistor for delay time, 41... Capacitor, 42... Transistor, 43... Current limiting resistor, 44... Capacitor, 45, 47... Resistor for voltage division, 46... Transistor for watcher interlocking, 48, 49... Resistor for overcurrent detection, 50...
Overcurrent detection transistor, 51... Current limiting resistor, 52... Transistor, 53, 54... Voltage dividing resistor, 55... Overcurrent protection transistor,
56... Capacitor, 57, 58... Voltage dividing resistor, 59... Current limiting resistor.

Claims (1)

[Scope of utility model registration request] A non-contact washer interlocking intermittent wiper device comprising a motor drive circuit operated by a signal from an intermittent/washer interlocking circuit, a wiper motor driven by the motor drive circuit, and a motor braking circuit including transfer contacts of the wiper motor. In this method, the motor drive circuit is constructed of transistors, and a resistor for braking the wiper motor is connected to the fixed position stop contact of the transfer contact as a motor braking circuit between one armature of the wiper motor and the stop contact of the transfer contact. , a non-contact washer interlocking intermittent wiper device comprising an overcurrent protection circuit for protecting the transistor of the motor drive circuit from overcurrent.