JP2000023347A - Large current motor derive circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stop motor drive at current leaking and relieve the drops of power supply voltages applied to other electrical components. SOLUTION: While a working voltage is supplied to a starter relay unit 3 from a battery B, when the power supplied from the battery B is branched to be supplied to a motor 1 by the on-switching of a load switch 2, the release voltage of the starter relay unit 3 is set higher than at least a voltage, when the motor is driven at the time of current leakage caused by the complete immersion of the motor in water. Even if the starter relay unit 3 is turned on by the leakage caused by the immersion and the motor is driven, the voltage is declined by the motor drive and becomes lower than the release voltage of the starter relay unit 3 and the starter relay unit 3 is automatically turned off and the drive of the motor is discontinued.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-current motor driving circuit for driving a starter motor when starting driving of an engine of an automobile.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 1, a high-current motor drive circuit for an automobile performs a load switch 2 for switching on / off a power supply from a battery B to a motor 1 and an on / off switch for the load switch 2. Starter relay part 3
And an operation switch unit 4 for switching the starter relay unit 3 on and off.

The load switch 2 includes a contact 2a for opening and closing a power supply path from the battery B to the motor 1, and a contact 2a for turning on and off the current from the starter relay 3.
and a pair of switch switching units 2b for switching the opening and closing of a. That is, in the load switch 2, when a current is supplied from the starter relay unit 3, the contact unit 2 a is closed to supply power from the battery B to the motor 1, and when the current is stopped from the starter relay unit 3. The power supply to the motor 1 is stopped by opening the contact portion 2a.

The starter relay section 3 includes a contact 3a for opening and closing a current path from the battery B to the load switch 2, and an exciting coil section 3b for switching the opening and closing of the contact 3a by excitation induction. One end (in FIG. 1) of the contact 3a is connected to the switch switching unit 2b of the load switch 2, and the other end (in FIG. 1) is connected to the battery B through the fuse 6. The exciting coil portion 3b has one end thereof (in FIG. 1).
Is connected to the operation switch unit 4, and the other end (in FIG. 1) is grounded.

The operation switch section 4 comprises an ignition switch 4a and a detection switch 4b for detecting that the transmission lever is at a predetermined position when the vehicle starts. The ignition switch 4a includes, for example, a first contact 4aa that opens and closes a power supply path to a vehicle-mounted electrical device as an accessory, a fuse 7, and a detection switch 4b.
And a second contact 4ab that opens and closes a power supply path to the exciting coil section 3b of the starter relay section 3 through the contact switch. The detection switch 4b
Is an on state (closed state) when the shift lever is in the neutral position or the parking position.

The general operation of the high current motor drive circuit having such a configuration will be briefly described. Hereinafter, a state in which the starter relay section 3 of the vehicle is not submerged will be referred to as “normal time”, and a state in which the starter relay section 3 of the vehicle is submerged will be referred to as “during submersion”.

At normal times, first, the operation switch unit 4
When the second contact 4ab or the detection switch 4b is in the off state, the current from the battery B does not flow to the exciting coil section 3b of the starter relay section 3, so that the contact 3a is maintained in the open state. Switch switching unit 2
Since no current is supplied to b and the contact portion 2a is kept open, the motor 1 is kept stopped.

Here, the second contact 4 of the operation switch unit 4
When the ab and the detection switch 4b are turned on, a current from the battery B flows to the exciting coil portion 3b of the starter relay portion 3 and the contact 3a is closed, so that the current is supplied to the switch switching portion 2b of the load switch 2. Supplied and contact portion 2a
Is closed, the driving of the motor 1 is started.

[0009]

As described above, the other end (in FIG. 1) of the contact 3a of the starter relay section 3 is connected to the battery B through the fuse 6, and the excitation coil section 3b
(In FIG. 1) is grounded.

In this case, when submerged, the other end (in FIG. 1) of the contact 3a of the starter relay section 3 and the exciting coil section 3b
1 (in FIG. 1), a leak occurs due to water (including salt water and the like) that has entered. Due to this leak, a voltage is applied to one end (in FIG. 1) of the exciting coil section 3b.

Conventionally, it is theorized that the voltage that is leaked to one end (in FIG. 1) of the exciting coil portion 3b and applied at the time of leakage when completely submerged is always equal to or higher than the sensing voltage of the exciting coil portion 3b. In this case, the second contact 4ab of the operation switch unit 4 or the detection switch 4b
Is turned off, the contact 3a of the starter relay unit 3 is closed, and the load switch 2 is turned on.

Then, the drive current of the motor 1 (200
A), the voltage of battery B is normally 13.5V
What is before and after sometimes drops to about 6V. As a result, there is a problem that other electrical components such as motors and lamps, which do not operate unless a certain amount of power is supplied, do not operate.

As countermeasures against such adverse effects, the starter relay unit 3 is provided by waterproofing the leak portion, suppressing the amount of leak in the starter relay unit 3, and increasing the open voltage of the relay.
(First improvement method), or a method in which even if the starter relay unit 3 is turned on due to leakage, it is detected and actively shut off (second improvement method).

However, in the first improvement method, even if the waterproofing and the amount of leak are suppressed, it is practically difficult to completely prevent the leakage and the starter relay is mounted on a vehicle. Since it is an electrical component required to operate at the lowest power supply voltage among them, it has been difficult to realize it.

In the second improvement method, additional parts and systems for detecting and shutting off a leak are required to be mounted on a vehicle, and there is a problem that the weight increases and the system becomes complicated.

An object of the present invention is to provide a high-current motor drive circuit that can sufficiently secure the power supply voltage of electrical components even when a vehicle is submerged, without using special additional parts and systems. Is to do.

[0017]

Means for Solving the Problems In order to solve the above problems,
According to the first aspect of the present invention, there is provided a load switch for performing on / off switching of power supply from a battery to a motor, and a predetermined excitation coil unit is excited in accordance with a sensing voltage given from the battery to generate a predetermined contact. A starter relay unit that transmits a current to the load switch by closing to perform on-switching, and that switches off the current to the load switch by opening in accordance with an open voltage given from the battery, An operation switch unit for performing on / off switching by performing application switching of the sensing voltage and the open voltage from the battery to the starter relay unit, wherein the starter relay unit receives the sensing voltage from the battery. When the starter relay unit is turned on, the power from the battery is branched to the motor by turning on the load switch. In the high-current motor drive circuit configured to supply the starter relay section, when the power from the battery is supplied to the motor in a branched manner, the starter relay section completely converts the starter relay section to high-concentration salt water or the like. In this case, the voltage is set to be higher than a voltage leaked and applied to the starter relay section when completely submerged.

According to a second aspect of the present invention, the open circuit voltage of the starter relay section is leaked to the starter relay section at the time of complete submersion when power from the battery is supplied to the motor in a branched manner. At the same time as the applied voltage is set higher than the applied voltage, the sensing voltage of the starter relay section leaks to the starter relay section at the time of complete submersion when power from the battery is not supplied to the motor in a branched manner. Is set lower than the applied voltage.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A high-current motor drive circuit (starter motor drive circuit) according to the present invention differs from the circuit of FIG.
When the starter relay unit 3 is completely submerged in high-concentration salt water or the like (hereinafter referred to as “complete submergence”), the leakage to one terminal of the exciting coil unit 3b when the motor 1 is driven and when it is not driven. The applied voltage (V in FIG. 2)
e and Vd) are detected in advance by experiments or the like, and the excitation voltage of the exciting coil section 3b of the starter relay section 3 (that is, the operating voltage and the open-circuit voltage: Va in FIG.
By setting an intermediate value between d and Ve, a certain power supply voltage is secured for other electrical components even when the vehicle is submerged. Strictly speaking, in general, the operating voltage is higher than the open-circuit voltage, but in FIG. 2, for simplicity, both voltages are shown as being the same.

Hereinafter, the high current motor driving circuit will be described in detail. The circuit configuration of this high-current motor drive circuit is the same as that shown in FIG. 1, and all elements having the same functions will be described using the same reference numerals.

That is, the large current motor drive circuit includes a load switch 2 for switching on / off the power supply from the battery B to the motor 1, a starter relay unit 3 for switching on / off of the load switch 2, An operation switch unit 4 for switching the starter relay unit 3 on and off.

Here, the same general motor as the conventional one is used, and its driving current is set to a large current of, for example, 200 A or more.

The load switch 2 includes a contact portion 2a for opening and closing a power supply path from the battery B to the motor 1, and a switch switching portion 2 for opening and closing the contact portion 2a by excitation induction.
b. That is, in this load switch 2,
When current is supplied from the starter relay section 3, the contact section 2a
Is closed to supply the power from the battery B to the motor 1, and when the current is cut off from the starter relay section 3, the contact section 2 a is opened to stop the power supply to the motor 1.

The starter relay section 3 comprises a contact 3a for opening and closing a current path from the battery B to the load switch 2, and an exciting coil section 3b for switching the opening and closing of the contact 3a by excitation induction.

The contact 3a has one end (in FIG. 1) connected to the switch switching section 2b of the load switch 2 and the other end (in FIG. 1) connected to the battery B through the fuse 6.

One end (in FIG. 1) of the excitation coil section 3b is connected to the operation switch section 4, and the other end (in FIG. 1) is grounded.

The operation switch unit 4 includes an ignition switch 4a and a predetermined detection switch 4 for detecting that the transmission lever is at a predetermined position at the time of departure.
b.

The ignition switch 4a is connected to, for example, a first contact 4aa for opening and closing a power supply path to an on-vehicle electrical device as an accessory, and to the excitation coil 3b of the starter relay unit 3 via a fuse 7 and a detection switch 4b. For example, it is a contact switch including at least a second contact 4ab for opening and closing the power supply path.

The detection switch 4b is turned on (closed) when the shift lever is in the neutral position or the parking position.

As shown in FIG. 2, the second contact 4ab of the operation switch unit 4 and the detection switch 4b are normally turned on to energize the exciting coil unit 3b, and then the motor 1 is driven. Immediately before that, the voltage Vb applied to one end of the exciting coil unit 3b is about 13.5 V.

On the other hand, after the motor 1 starts driving in the normal state, the current from the battery B branches off and flows into the motor 1 not only through the starter relay section 3 but also through the contact section 2a. Therefore, since the driving current of the motor 1 is as large as 200 V, the battery voltage drops due to the resistance inside the battery B. For this reason, the voltage Vc applied to one end of the exciting coil section 3b of the starter relay section 3 drops to about 6.0 V, which is lower than Vb.

The voltage applied to the exciting coil section 3b changes depending on whether the motor 1 is not driven or driven, even when the starter relay section 3 is submerged in water. However, the leakage voltage between the other end (in FIG. 1) of the contact 3a and the one end (in FIG. 1) of the exciting coil portion 3b at the time of submersion is a leak resistance between them, that is, the other end of the contact 3a ( The applied voltage at the time of leakage applied to the exciting coil portion 3b is larger than the applied voltage applied at the normal time, depending on the separation distance between the exciting coil portion 3b (in FIG. 1) and one end (in FIG. 1) of the exciting coil portion 3b. Lower.

Specifically, during a period from when a leak occurs between the other end of the contact 3a and one end of the exciting coil portion 3b when the motor 1 is completely submerged and immediately before the motor 1 is driven,
Excitation coil 3b due to leakage in starter relay 3
The voltage Vd applied to one end is about 4.5 V which is equal to or higher than the excitation voltage (sensing voltage) of the starter relay section 3 as shown by the dotted line in FIG.

On the other hand, in a state after the motor 1 has started to be driven due to a leak in the starter relay unit 3 when completely submerged, a part of the current from the battery B is supplied to the contact 2a.
2, the voltage Ve applied to the exciting coil 3b due to the leak in the starter relay 3 is changed to the starter relay 3 as shown by the dotted line in FIG.
To about 2.0 V below the excitation voltage (open-circuit voltage).

The excitation voltage (moving voltage and open voltage) Va of the exciting coil section 3b of the starter relay section 3 is equal to the applied voltage Vd when the motor 1 is in a non-driving state and leaks when completely submerged. The value is set to about 3.0 V (broken line in FIG. 2) which is an intermediate value with the applied voltage Ve when the motor 1 is in a driving state and there is a leak at the time of submersion in water. Strictly speaking, the operating voltage is higher than the open-circuit voltage, but here, for the sake of simplicity, they are treated as substantially the same voltage.

The values of these voltages Vd and Ve are those at the time of complete immersion determined by the structure of the large current motor drive circuit. At the time of incomplete immersion, the leak resistance at the time of leakage increases. Therefore, the voltage leaked to one terminal of the exciting coil unit 3b and applied is lower than the voltages Vd (4.5 V) and Ve (2.0 V).
For example, when the concentration of salt water is low, or when the state of inundation is shallow and imperfect submergence, the voltage leaked to one terminal of the exciting coil portion 3b and applied is the applied voltage at the time of leakage at the time of complete submergence. It becomes smaller than Vd and Ve. That is, the voltage Vd (4.5) at the time of leakage at the time of complete submergence, which is the worst condition as described above, is changed because the voltage is changed so as to be less likely to leak.
v) and Ve (2.0 v), if the excitation voltage (moving voltage and open-circuit voltage) Va of the exciting coil unit 3b is set, the operation at the time of incomplete water immersion will not be a problem. is there.

The operation of the above-described large current motor drive circuit will be described. Here, FIG. 3 is a diagram illustrating a change in voltage applied to one terminal of the exciting coil unit 3b of the starter relay unit 3.

As shown in FIG. 3, during normal operation, the motor 1
When the second contact 4ab and the detection switch 4b of the operation switch unit 4 are turned on in a state where is not driven, a current from the battery B flows to the exciting coil unit 3b of the starter relay unit 3. At this time, since there is no branch inflow of current from the battery B to the motor 1 through the contact portion 2a, the battery voltage does not drop due to the resistance inside the battery B. At this time, the exciting coil section 3b of the starter relay section 3
Is applied with a voltage Vb of about 13.5 V (T1 in FIG. 3).

Next, since the voltage Vb (about 13.5) applied to one end of the exciting coil section 3b is equal to or higher than the exciting voltage (sensing voltage) Va (about 3.0 V), the exciting coil section 3b , The contact 3a is closed, and the starter relay unit 3 is switched from the off state to the on state. Therefore, a current is supplied to the switch switching section 2b of the load switch 2 to close the contact section 2a, and the drive of the motor 1 is started at that time.

When the motor 1 is driven, the current from the battery B branches into the switch switching unit 2b through the contact 3a and also branches into the motor 1 through the contact 2a. The battery voltage drops due to the resistance inside the battery B, and therefore, the voltage Vc applied to one terminal of the exciting coil section 3b of the starter relay section 3 drops to about 6.0 V (FIG. 3).
T2 in). Since the voltage Vc at this time is higher than the excitation voltage (sensing voltage) Va of the excitation coil unit 3b, the contact 3
The closed state of “a” is maintained, the closed state of the contact section 2a by the switch switching section 2b is maintained, and the driving of the motor 1 is continued.

Next, the operation in the case where a leak occurs in the starter relay section 3 when the vehicle is submerged in water will be described.

Immediately after submersion, a voltage is applied to the excitation coil portion 3b of the starter relay portion 3 due to a leak between one end of the excitation coil portion 3b of the starter relay portion 3 and the other end of the contact 3a. Therefore, the motor 1 does not drive.

At this time, the exciting coil 3b
Is approximately 4.5 V (T3 in FIG. 3) and is larger than the excitation voltage (sensing voltage) Va (approximately 3.0 V) of the exciting coil unit 3b. Is turned on, the contact 3a is closed, the contact 2a is closed by the switch switching unit 2b, and the driving of the motor 1 is started.

When the motor 1 is driven, the current (about 200 V) from the battery B branches into the current path formed by the contact portion 2a and the motor 1 and increases. A voltage drop occurs. Thus, the voltage Ve applied to the exciting coil section 3b of the starter relay section 3 becomes about 2.0 V which is lower than the excitation voltage (open voltage) Va of the starter relay section 3 (FIG. 3).
During T4), the starter relay unit 3 is turned off, and the contact 3a is opened. Then, the load switch 2 closes the contact portion 2a, and the power supply to the motor 1 is stopped. As a result, the voltage Vd applied to one end of the exciting coil unit 3b increases to about 4.5V, and the starter relay unit 3 is operated again. Hereinafter, the above operation is repeated, and the starter relay unit 3 repeats the on / off switching operation.
The state of T3 and the state of T4 appear repeatedly. At this time, the falling period of the power supply voltage (Vd, Ve) and the return time are times determined by the turn-on time and the turn-off time of the starter relay unit 3, respectively.

As described above, the power supply voltage can be secured although the power supply voltage does not remain reduced by maintaining the driving of the motor 1 as in the related art, but is repeatedly increased and decreased.

In this operation, it is unavoidable that a voltage higher than the excitation voltage (sensing voltage) Va of the excitation coil section 3b is applied to one end of the excitation coil section 3b due to the leak due to the structure of the starter relay section 3. This is particularly effective when driving of the motor 1 due to the leak cannot be completely prevented.

As described above, while the rise and fall are repeated, since the power supply voltage can be secured by other electrical components, the power supply voltage does not remain reduced as in the related art. It is also possible to operate a load that does not operate unless a certain amount of power is supplied, such as an electric component, particularly a motor or a lamp.

Also, compared to a method in which the starter relay section 3 is not turned on at all, that is, a method of waterproofing a leak portion, a method of suppressing the amount of leak in the starter relay section 3 and increasing an excitation voltage of the starter relay section 3, etc. The easiness of realization can be improved without changing much the structural conditions of.

Further, additional components and systems are not required to be mounted on the vehicle as in the case of performing detection and cutoff, and can be realized by a circuit configuration almost similar to the conventional one, so that weight increase and system complexity can be prevented. .

In the description of the above embodiment, the excitation voltage (sensing voltage and open circuit voltage) of the exciting coil unit 3b is based on the applied voltages Vd and Ve when the motor 1 is not driven / leaked when completely immersed in water. Since the voltage (Va) is set, only the operation at the time of complete submergence has been described. However, not when the submerged is completely submerged, but when the concentration of salt water is low in the starter relay unit 3 or when a small amount of submergence occurs (incomplete). At the time of submersion in water), it is only a state in which a leak is more unlikely to occur, so that the above operation does not cause any inconvenience.

In the above embodiment, the applied voltages Vd and Ve at the time of leakage at the time of complete submergence are set to about 4.5 V, respectively.
The start voltage (sensing voltage and open-circuit voltage) Va of the starter relay section 3 is set to about 3.0 V, but it is a matter of course that the present invention is not limited to this. Further, in the above-described embodiment, only the leak between one end of the exciting coil portion 3b of the starter relay portion 3 and the other end of the contact 3a has been described, but the leak between other portions in the starter relay portion 3 will also be described. The same is true.

[0052]

According to the first and second aspects of the present invention, the open-circuit voltage of the starter relay is set at least higher than the applied voltage at the time of leakage when the motor is driven when completely submerged. Even if the starter relay part is switched on due to the leak due to submersion and the motor is driven,
By this motor driving, the applied voltage at the time of the leak becomes lower than the open voltage of the starter relay section, the starter relay section is automatically switched off again, and the driving of the motor is stopped. Therefore, the voltage drop due to the resistance inside the battery can be reduced, and the power supply voltage of other electrical components can be secured. In particular, according to the second aspect of the present invention, it is unavoidable that a voltage equal to or higher than the operating voltage of the exciting coil unit is applied to one end of the exciting coil unit due to leakage due to the structure of the starter relay unit. This is particularly effective when the driving of the motor by the motor cannot be completely prevented. In this case, while the motor is intermittently presented, the rise and fall are repeated, but the power supply voltage can be secured for other electrical components, so that the power supply voltage remains unchanged as in the past. In addition, it is possible to operate a load that does not operate unless a certain amount of electric power is supplied, such as another electric component, particularly a motor or a lamp.

According to the first and second aspects of the present invention, a method of not turning on a starter relay section at all,
That is, compared with a method of increasing the excitation voltage of the starter relay unit by suppressing the leak amount in the starter relay unit by making the leak portion waterproof, without changing the structural conditions of the device much,
Excitation voltage of starter relay (moving voltage and open circuit voltage)
By simply changing only the setting, the other electrical components can secure the power supply voltage.

Further, unlike the detection and cutoff, additional components and systems do not need to be mounted on the vehicle, and can be realized by a circuit configuration almost similar to the conventional one, so that weight increase and system complexity can be prevented. This has the effect.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a general high-current motor drive circuit.

FIG. 2 is a diagram showing setting of voltages of respective units according to the present invention.

FIG. 3 is a diagram showing a change in voltage in the operation of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 2 Load switch 2a Contact part 2b Switch switching part 3 Starter relay part 3a Contact 3b Exciting coil part 4 Operation switch part 4a Ignition switch 4b Detection switch 4aa First contact 4ab Second contact 6 Fuse 7 Fuse B Battery

Claims (2)

[Claims] 1. A load switch for turning on / off a power supply from a battery to a motor, and a predetermined exciting coil unit is excited according to a sensing voltage applied from the battery to close a predetermined contact. A starter relay unit that transmits current to the load switch to perform on-switching and that opens according to an open voltage given from the battery to switch off current to the load switch; and the starter relay unit. And an operation switch unit that performs on / off switching by performing application switching of the sensing voltage and the open voltage from the battery, and the starter relay unit is configured to control the starter when the sensing voltage is supplied from the battery. A relay section is turned on, and power is supplied from the battery to the motor in a branched manner by turning on the load switch. In the high-current motor driving circuit described above, the open-circuit voltage of the starter relay section is completely submerged in high-concentration salt water or the like when power from the battery is supplied to the motor in a branched manner. A high current motor drive circuit, wherein the voltage is set to be higher than a voltage leaked and applied to the starter relay section at the time of complete submersion. 2. The large-current motor drive circuit according to claim 1, wherein the open-circuit voltage of the starter relay unit is set to be completely submerged when power from the battery is supplied to the motor in a branched manner. At the same time, it is set higher than the voltage applied by being leaked to the starter relay unit,
The sensing voltage of the starter relay unit is set to be lower than a voltage leaked and applied to the starter relay unit at the time of complete submersion when power from the battery is not branchedly applied to the motor. High current motor drive circuit.