JPH04337121A - Clutch current control device - Google Patents

Abstract

PURPOSE:To reduce a voltage drop in a current control circuit so as to always display desired transmission torque by connecting a clutch opening output transistor in series to a circulating current diode, and no-off-controlling an output transistor by a signal of clutch opening. CONSTITUTION:In a clutch current control means 1, a deviation between a clutch current signal and a clutch current feedback signal, calculated in accordance with a running condition by a clutch current arithmetic means 2, is obtained by a current deviation detector 14 to control an output transistor 11 in accordance with the deviation signal. Here, a current detecting resistor 13 is connected between an output terminal 21 and an arm, and the output transistor 11, electromagnetic clutch 4 and the current detecting resistor 13 are connected in series. An anode of a circulating current diode 16 is connected to an emitter of a clutch opening output transistor 12, and the circulating current diode 16 is provided so that a clutch current can be conducted to the electromagnetic clutch 4 when the output transistor 11 is turned off, at the time of engagement of the electromagnetic clutch 4.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch current control device capable of reducing voltage drop in a clutch current control circuit.

0002

2. Description of the Related Art A conventional clutch current control device for a vehicle is disclosed in, for example, Japanese Patent Laid-Open No. 63-05732. FIG. 2 is a circuit diagram showing the configuration of a conventional vehicle clutch current control device.

Reference numeral 1 in FIG. 2 denotes a clutch current control means, and within this clutch current control means 1, a clutch current calculation means 2 is provided.

The clutch current calculation means 2 is configured to receive travel control information SD and engine control information SE. The clutch current control means 2 is a computer 24
and interface 23, and includes driving control information S.
D and engine control information SE are taken into the computer 24 through the interface 23, and the clutch current digital command signal SID is inputted from the clutch current calculating means 2 to D/
The signal is output to an A (digital/analog) converter 25.

This D/A converter 25 inputs the clutch current digital command signal SID, outputs the clutch current analog command signal SIA as an analog signal, and applies it to the (+) input terminal of the current deviation detector 14. It looks like this. A clutch current feedback signal SF is inputted from one end of the current detection resistor 13 to the (-) input terminal of the current deviation detector 14 .

[0006]Thereby, the current deviation detector 14 detects the deviation between the clutch current analog command signal SIA and the clutch current feedback signal SF, and outputs a deviation signal. This deviation signal is transmitted to the output transistor 11 via a PWM (pulse width modulation) modulator 15 and a resistor 51.
It is designed to be added to the base of

The emitter of the output transistor 11 is connected to a power supply line. The positive pole of the power supply 3 is connected to the power supply line, and the negative pole of the power supply 3 is grounded.

A diode D1 is connected between the collector and emitter of the output transistor 11, and the collector is connected to the output terminal 20 and grounded via a feedback diode 16.

An electromagnetic clutch 4 is connected between the output terminals 20 and 21. This electromagnetic clutch 4 is composed of slip rings 42, 43 and a clutch coil 41,
Electric power is supplied to the clutch coil 41 via slip rings 43 and 42 connected to the output terminals 20 and 21, respectively.

Further, a reverse excitation command signal is supplied from the clutch current calculating means 2 via resistors 62 and 63 to the bases of reverse excitation power supply control transistors 60 and 61, respectively.

The emitter of the reverse excitation power supply control transistor 60 is grounded, and the collector is connected to the output terminal 20 via the reverse excitation resistor 18.

[0012] Also, the reverse excitation power supply control transistor 61
The emitter is connected to the power supply line, and the collector is connected to the output terminal 21 via the reverse excitation resistor 19.

An output transistor 12 is connected to this output terminal 21.
A quick-cutting diode 17 is connected between the base and collector of the output transistor 12.
The emitter is grounded via a current detection resistor 13. A clutch release signal SO output from the clutch current calculating means 2 is applied to the base of the output transistor 12 via a resistor 52.

Next, the operation will be explained. Travel control information SD and engine control information S are provided to the clutch current calculation means 2.
When E is input, the clutch current calculation means 2 calculates the clutch torque based on the traveling control information SD and the engine control information SE, and outputs the clutch current digital signal SI.
Output D.

This clutch current digital signal SID is input to the D/A converter 25, where it is converted to an analog signal, and the clutch analog command signal SIA is input to the (+) input terminal of the current deviation detector 14.

One end of the detection resistor 13, that is, the output transistor 1 is connected to the (-) input terminal of the current deviation detector 14.
A clutch current feedback signal SF is input from the emitter of No. 2. Therefore, current deviation detector 14 obtains a deviation signal between clutch current analog signal SIA and clutch current feedback signal SF.

This deviation signal is sent to the PWM modulator 15. As a result, the PWM modulator 15 converts the deviation signal into PWM
It is modulated and applied to the base of output transistor 11 via resistor 51. That is, the deviation signal is transmitted to the PWM modulator 15.
The output transistor 11 is controlled to be turned on or off according to the PWM modulated pulse width.

Depending on whether the output transistor 11 is turned on or off, a clutch current flows through the electromagnetic clutch 4 from the output terminal 20 or is cut off.

On the other hand, the output transistor 12 is on when the clutch is normally connected, and therefore the PW
When the output transistor 11 is turned on by the deviation signal PWM modulated by the M modulator 15, the clutch current is transmitted from the power supply to the output transistor 11 - output terminal 20 - electromagnetic clutch 4 - output transistor 12 - current detection resistor 13 -
Flows into a grounded closed circuit.

The voltage generated across the current detection resistor 13 is used as the clutch current feedback signal SF to be transmitted to the current deviation detector 1.
It is added to the (-) input terminal of 4.

Furthermore, as mentioned above, the output transistor 12 is always on when the electromagnetic clutch 4 is connected;
To turn this off, the clutch release signal SO is applied from the clutch current calculating means 2 to the base of the output transistor 12, thereby controlling the output transistor 12 to turn off.

By turning off the output transistor 12, the clutch current IC flowing through the electromagnetic clutch 4 is cut off. When the output transistors 11 and 12 are both off, the reverse excitation power supply control transistor 60
, 61 are turned on by the clutch current calculation means 2, and the current is passed through the reverse excitation resistors 18 and 19 to the output terminals 20 and 21.
A reverse current flowing in the opposite direction to the clutch current IC is supplied to the electromagnetic clutch 4. The reverse excitation current is necessary for correcting the residual torque of the electromagnetic clutch 4.

By the way, clutch current calculation means 2, PW
M modulator 15, output transistor 11 for current control, freewheeling diode 16, turned on by clutch release signal SO,
A voltage drop in the current control circuit composed of the output transistor 12 that is turned off and the current detection resistor 13 is caused by the output transistors 11 and 12 and the current detection resistor 13.

When the voltage drop in the current control circuit becomes large, it becomes impossible to supply sufficient current to the electromagnetic clutch 4, resulting in a decrease in clutch torque.

[0025]

[Problems to be Solved by the Invention] Since the conventional clutch current control device is constructed as described above, as the temperature rises, the resistance of the clutch coil 41 of the electromagnetic clutch 4 increases, and the voltage of the current control circuit increases. There was a problem in that the drop occurred, making it impossible to supply the desired clutch current to the electromagnetic clutch 4.

The present invention has been made to solve the above-mentioned problems, and can reduce the voltage drop in the current control circuit, supply a desired clutch current, and is suitable for use as a clutch device for vehicles. An object of the present invention is to obtain a clutch current control device that can improve reliability.

[0027]

[Means for Solving the Problems] A clutch current control device according to the present invention is provided with an output transistor for clutch release, which conducts current in the same direction as the freewheeling diode and whose base current is turned on and off by a clutch release signal. It is something that

[0028]

[Operation] The output transistor for clutch release in this invention is on when power is supplied to the electromagnetic clutch, and when the electromagnetic clutch is released, it is controlled on and off by the clutch release signal, and when the clutch is connected, the output transistor of the other side is turned on. When the clutch is turned off, the clutch current is supplied by the freewheeling diode, and the output transistor for clutch release is no longer involved in the voltage drop in the current control circuit.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the clutch current control device of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing the configuration of one embodiment. In this Figure 1, Figure 2
The same parts as in FIG.

As is clear from comparing FIG. 1 with FIG. 2, in FIG. 13 are in series.

Further, the anode of the freewheeling diode 16 is connected to the emitter of the output transistor 12 for releasing the clutch. The collector of the output transistor 12 is grounded, and an overvoltage blocking diode 17a is connected between the collector and the base for absorbing surge voltage and quickly cutting off the crank current.

The base of the output transistor 12 receives a clutch release signal S output from the clutch current calculation means 2.
O is now input. Other configurations are shown in Figure 2.
It is similar to

Next, the operation will be explained. In explaining this operation, the explanation will be omitted for the parts that are the same as those in FIG.

This output transistor 12 is turned on when power is supplied to the electromagnetic clutch 4, and is controlled on and off by the clutch release signal SO output from the clutch current calculation means 2 when the electromagnetic clutch 4 is released.

Furthermore, when the electromagnetic clutch 4 is connected and the output transistor 11 is off, the freewheeling diode 16
A clutch current is supplied to the electromagnetic clutch 4. When the output transistors 11 and 12 are both off, the reverse excitation power supply control transistors 60 and 61 are turned on in response to the reverse excitation power supply command output from the clutch current calculating means 2, so that the reverse excitation resistors 18 and 19 are turned on. Accordingly, a reverse excitation current is supplied in a direction opposite to the direction of the illustrated clutch current IC.

Therefore, the voltage drop in the current control circuit is:
This is due to the output transistor 11 and the current detection resistor 13, and the output transistor 12 for clutch release is no longer involved in this voltage drop, so that the voltage drop in the current control circuit can be reduced.

Furthermore, when a return current flows through the output transistor 12 for clutch release, it can be energized, and it is turned off when the clutch is released, so that the conventional function is not lost.

[0038]

As described above, according to the present invention, the output transistor for clutch release is connected in series with the freewheeling diode, and when the freewheeling current is passed through the freewheeling diode, the output current is passed in the same direction, and the clutch is released. Since this output transistor is configured to be turned on and off by a signal, the voltage drop of the output transistor for clutch release is not involved in the voltage drop in the current control circuit, and the voltage drop in the current control circuit is reduced. Can be done.

[0039] Therefore, the desired clutch current and, in turn, the desired transmission torque can be obtained, and the reliability of the clutch device for a vehicle can be improved.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a clutch current control device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a conventional clutch current control device.

[Explanation of symbols]

1 Clutch current control means 2 Clutch current calculation means 3 Power supply 4 Electromagnetic clutch 11 Output transistor 12 Output transistor 13 Current detection resistor 14 Current deviation detector 15 PWM modulator 16 Freewheeling diode 18 Reverse excitation resistance 19 Reverse excitation resistance 20 Output terminal 21 Output terminal

Claims (1)

[Claims] 1. Clutch current calculation means for outputting a clutch current signal from travel control information and engine control information and for outputting a clutch release signal when an electromagnetic clutch is released, and a deviation between the clutch signal and the clutch current feedback signal. a PWM modulator that outputs a pulse width modulation signal in accordance with the output of the current deviation detection signal;
a first output transistor that operates in response to the pulse width modulation signal to supply clutch current to the electromagnetic clutch; and a first output transistor that supplies clutch current to the electromagnetic clutch when the electromagnetic clutch is connected and the first output transistor is off. a freewheeling diode for supplying power; a second output transistor connected in series with the freewheeling diode, having the same conduction direction as the freewheeling diode, and controlled on and off by a clutch release signal output from the clutch current calculation means; Clutch current control device with