JP3009808B2 - Control device for electromagnetic clutch for vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch control device for a vehicle which can detect a ground fault and protect the electromagnetic clutch and the like.

[0002]

2. Description of the Related Art Conventionally, as a control device for a vehicle electromagnetic clutch, one disclosed in Japanese Patent Application Laid-Open No. 3-181622 has been known. FIG. 11 shows the configuration. In the figure, 1 is a clutch current control means, 2 is a clutch current calculation means such as a microcomputer, 3 is a DC power supply whose positive side is connected to the power supply terminal 4 and the negative side is grounded, 5 is an electromagnetic clutch for vehicles, 6 Is a clutch output terminal voltage detecting means as a ground fault detecting means.

The clutch current calculation means 2 is supplied with travel control information SD, engine control information SE and an output signal of the voltage detection means 6. The digital clutch current command signal SI output from the clutch current calculation means 2
Is a D / A converter 7 constituting the clutch current control means 1
After being converted to an analog signal SIA by the above, the signal is supplied to the positive input terminal of the current deviation amplifier 8. The output signal of the amplifier 8 is PW
The signal is supplied to an M modulator (pulse width modulator) 9 and subjected to PWM modulation. The output signal of the PWM modulator 9 is the resistor 1
0 is supplied to the base of a PNP transistor 11 as an output transistor. This transistor 11
Is connected to the power supply terminal 4 and its collector is grounded via the cathode and anode of the free wheel diode 12.

The clutch release signal SO output from the clutch current calculation means 2 is output from the clutch current control means 1
Is supplied to the base of an NPN transistor 14 as a clutch release transistor via a resistor 13 constituting The collector of the transistor 14 is connected to the power supply terminal 4 via the resistor 15, and the emitter is grounded. A signal obtained at a connection point between the transistor 14 and the resistor 15 is supplied to a base of an NPN transistor 16 as an output transistor. This transistor 16
Is connected to the power supply terminal 4 via the anode and cathode of the overvoltage blocking diode 17, and its emitter is grounded via the current detecting resistor 18.

[0005] One end of the resistor 18 is connected to the positive input terminal of an operational amplifier 20 constituting the current detecting and amplifying means 19, and the other end of the resistor 18 is connected via a resistor 21 as a reference resistor. Is connected to the negative input terminal of An output terminal of the operational amplifier 20 is connected to a negative input terminal via a resistor 22 as a feedback resistor. Then, the output signal of the operational amplifier 20 is supplied to the negative input terminal of the current deviation amplifier 8 as a clutch current feedback signal SF. The clutch reverse excitation signal SRA output from the clutch current calculating means 2 is supplied to the base of the NPN transistor 24 for reverse excitation via the resistor 23. The emitter of the transistor 24 is grounded, and the collector is connected via a resistor 25 to a connection point P1 between the transistor 11 and the free wheel diode 12.

The clutch reverse excitation signal SRB output from the clutch current calculation means 2 is supplied via a resistor 26 to the base of a reverse excitation PNP transistor 27. The transistor 27 has an emitter connected to the power supply terminal 4 and a collector connected via a resistor 28 to a connection point P2 between the transistor 16 and the overvoltage blocking diode 17. A clutch output terminal 29 is derived from a connection point P1 between the transistor 11 and the freewheel diode 12, and a clutch output terminal 30 is derived from a connection point P2 between the transistor 16 and the overvoltage blocking diode 17. The electromagnetic clutch 5 is connected between the output terminals 29 and 30. The electromagnetic clutch 5 includes a series circuit of a slip ring 51 , clutch coils 52 and 53, and a slip ring 54.

A connection point P 1 between the transistor 11 and the free wheel diode 12 is connected to an input terminal 63 of the voltage detecting means 6.
And a signal obtained at an output terminal 64 of the voltage detecting means 6 is supplied to the clutch current calculating means 2. The voltage detecting means 6 detects the voltage level of the clutch output terminal 29. Note that the clutch current control means 1 is composed of components 7 to 28.

FIG. 12 shows an example of the configuration of the voltage detecting means 6. In the figure, an input terminal 63 is connected to the base of an NPN transistor 61 via a resistor 62. The emitter of this transistor 61 is grounded, and its collector is connected to the power supply terminal 4 via a resistor 60. Then, an output terminal 64 is led out from a connection point between the resistor 60 and the collector of the transistor 61. In the above configuration, when a high-level "H" signal is supplied to the input terminal 63, the transistor 61 is turned on, and a low-level "L" signal is obtained at the output terminal 64. On the other hand, when a low-level “L” signal is supplied to the input terminal 63, the transistor 61 is turned off and the output terminal 6
4, a high-level "H" signal is obtained.

FIG. 13 shows another example of the voltage detecting means 6. In the figure, a cathode and an anode of a diode 68 and a capacitor 67 are provided between a power supply terminal 4 and the ground.
Are connected in series. The input terminal 63 is grounded via a resistor 65 and connected to a connection point P of a diode 68 and a capacitor 67 via a resistor 66.
Then, the output terminal 64 is derived from the connection point P. In the above configuration, when a high-level “H” signal is supplied to the input terminal 63, the capacitor 67 is charged, and a high-level “H” signal is obtained at the output terminal 64. On the other hand, when a low-level “L” signal is supplied to the input terminal 63, the capacitor 67 is discharged, and a low-level “L” signal is obtained at the output terminal 64.

FIG. 14 shows still another example of the voltage detecting means 6. In the figure, an input terminal 63 is connected to a comparator 69.
Connected to the positive input terminal of A series circuit of resistors 70 and 71 is connected between the power supply terminal 4 and the ground, and the connection point Q is connected to the negative input terminal of the comparator 69. Then, the output terminal 64 is derived from the output terminal of the comparator 69. In the above configuration, a high-level "H" signal is supplied to the input terminal 63, and when the level is higher than the voltage level of the connection point Q, a high-level "H" signal is obtained at the output terminal 64. On the other hand, when a low-level “L” signal is supplied to the input terminal 63 and the level is lower than the voltage level at the connection point Q, a low-level “L” signal is obtained at the output terminal 64.

Next, the operation at the time of energization in the example of FIG. 11 will be described. At the time of energization, the clutch release signal SO is at a low level “L”, the transistor 14 is turned off, and the transistor 16 is turned on. At the time of this energization, a pulse width modulation signal is output from the pulse width modulator 9 based on the clutch current command signal SI output from the clutch current calculation means 2, the transistor 11 is driven, and a current flows through the electromagnetic clutch 5. It is. In this case, the clutch current is detected by the resistor 18, and the clutch current feedback signal SF is supplied from the current detection amplifier 19 to the negative input terminal of the current deviation amplifier 8.
It is controlled to a value corresponding to I.

Next, the operation of ground fault detection and protection will be described. When the electromagnetic clutch 5 is reversely excited, the transistor 1
1, 16 are off, and the clutch reverse excitation signal SR
The reverse excitation transistors 24 and 27 are turned on by A and SRB, and the power supply terminal 4 (the positive side of the DC power supply 3) → the transistor 27 → the resistor 28 → the output terminal 30 → the electromagnetic clutch 5 → the clutch output terminal 29 → the resistor 25 → path current of the transistor 24 → ground (negative pole of the DC power supply 3) flows.

When the electromagnetic clutch 5 does not have a ground fault, the voltage level of the clutch output terminal 29, that is, the input terminal 63 of the voltage detecting means 6 is at a high level "H". A signal of level "L" is obtained (in the case of the example of FIG. 12). On the other hand, when the electromagnetic clutch 5 is grounded, the current flowing from the power supply terminal 4 through the resistor 28 flows to the ground side through the grounded portion of the electromagnetic clutch 5, so that the voltage at the output terminal 29, and hence the voltage at the input terminal 63 of the voltage detecting means 6. The level becomes low level "L", and a signal of high level "H" is obtained at its output terminal 64 (FIG. 1).
2). As described above, the clutch current calculation means 2 can determine the ground fault or the non-ground fault of the electromagnetic clutch 5 according to the level of the signal obtained at the output terminal 64 of the voltage detection means 6, and performs control according to the determination result. Can do it.

FIG. 15 is a flow chart showing the ground fault detection and protection operation of the electromagnetic clutch 5 in the clutch current calculating means 2, for example, a ROM as a control program.
(Not shown). In FIG. 15, in step S1, the traveling control information SD and the engine control information S
It is determined whether the clutch current control mode obtained from E is the reverse excitation mode, and if it is the reverse excitation mode, the process proceeds to step S2.

In step S2, it is determined whether or not the electromagnetic clutch 5 has a ground fault according to the output signal of the voltage detecting means 6.
If it is determined that there is a ground fault, the process proceeds to step S3, in which the clutch current command signal SI and the clutch release signal SO already obtained internally are canceled, and the clutch current command signal SI
To 0, the clutch release signal SO is set to the high level “H” (the transistor 16 is turned off), and the clutch current is reset (release setting). This is because if the transistor 11 or 16 is turned on during a ground fault, an excessive current flows,
This is because the transistors 11 and 16 may be destroyed.

In step S1, when the mode is not the reverse excitation mode, the electromagnetic clutch 5 is energized, and the voltage level of the clutch output terminal 29 is constantly changed by pulse width modulation control irrespective of grounding or non-grounding. Therefore, the ground fault cannot be detected. Therefore, steps S2 and S3 are jumped. If it is determined in step S2 that there is no ground fault, the operation is normal (non-ground fault), and the step S3 is skipped because the protection operation of step S3 is not required. The above-described step operation is repeatedly executed.

[0017]

The control device for a conventional electromagnetic clutch for a vehicle is constructed as described above. The voltage detecting means 6 detects the voltage level of the clutch output terminal 29 at least once even when the electromagnetic clutch 5 is reversely excited. When the low level "L" is detected, the clutch current calculating means 2 determines that the ground fault occurs, so that there is a problem that a ground fault may be erroneously detected due to noise or the like. In addition, at the time of energization, the voltage level of the clutch output terminal 29 is constantly changed by the pulse width modulation control regardless of the ground fault or the non-ground fault, so that the ground fault state may be erroneously detected. Cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and it is possible to prevent a ground fault from being erroneously detected due to noise or the like and to detect and protect a ground fault even when power is supplied. An object of the present invention is to provide a control device for a clutch.

[0019]

According to a first aspect of the present invention, there is provided a vehicle electromagnetic clutch control apparatus comprising: a clutch current command signal based on travel control information and engine control information;
Clutch current calculating means for outputting a clutch release signal and a clutch reverse excitation signal; clutch current control means for controlling a current flowing to an electromagnetic clutch by a clutch current command signal, a clutch release signal and a clutch reverse excitation signal; and a clutch current control means Ground fault detecting means for detecting a ground fault state of the electromagnetic clutch from the voltage level of the output terminal of the output terminal, and the clutch current calculating means detects that the electromagnetic clutch has been in the ground fault state for a predetermined time by the ground fault detecting means. determines that a ground fault when the electromagnetic clutch clutch current command signal, the clutches open signal and the clutch inverse excitation signal
Is controlled in reverse excitation, and then ground fault detection means
The electromagnetic clutch must be in a normal state for a certain period of time.
If it is detected, it is determined that it is normal, and the clutch current control means
To energize the electromagnetic clutch .

According to a second aspect of the present invention, there is provided a vehicle electromagnetic clutch control device for outputting a clutch current command signal, a clutch release signal, and a clutch reverse excitation signal based on travel control information and engine control information. Means, a clutch current control means for controlling a current flowing to the electromagnetic clutch by a clutch current command signal, a clutch release signal, and a clutch reverse excitation signal, and performing pulse width modulation control of the current flowing to the electromagnetic clutch when energized; Ground fault detecting means for detecting a ground fault state of the electromagnetic clutch from the voltage level of the output terminal of the means, wherein the clutch current calculating means is that the electromagnetic clutch is continuously in a ground fault state for a predetermined time by the ground fault detecting means. If detected, it is determined to be a ground fault, and the clutch current command signal and clutch release signal are And sets the release direction, be generated by a pulse width modulation control in the normal energization from the ground fault detection means
The change in voltage at the output terminal of the clutch current control means
When this is done, the predetermined time for the ground fault determination of the clutch current calculation means is reset.

According to a third aspect of the present invention, there is provided a vehicle electromagnetic clutch control device for outputting a clutch current command signal, a clutch release signal and a clutch reverse excitation signal based on travel control information and engine control information. Means, a clutch current control means for controlling a current flowing to the electromagnetic clutch by a clutch current command signal, a clutch release signal, and a clutch reverse excitation signal, and performing pulse width modulation control of the current flowing to the electromagnetic clutch when energized; Ground fault detecting means for detecting a ground fault state of the electromagnetic clutch from the voltage level of the output terminal of the means, wherein the clutch current calculating means is that the electromagnetic clutch is continuously in a ground fault state for a predetermined time by the ground fault detecting means. If detected, it is determined to be a ground fault, and the clutch current command signal and clutch release signal are And sets the release direction, the ground fault detection means, sharply than the clutch current command signal during energization steady value
In this case, the detection of the ground fault state is prohibited for a predetermined time.

[0022]

According to the first aspect of the present invention, when the ground fault detecting means detects that the electromagnetic clutch is continuously in the ground fault state for a certain period of time, it is determined that a ground fault has occurred. Ground fault erroneous detection can be prevented.

According to the second aspect of the present invention, when the ground fault detecting means detects that the electromagnetic clutch has been in the ground fault state continuously for a certain period of time, it is determined that a ground fault has occurred. Ground fault erroneous detection can be prevented.
In addition, at a time point when the ground fault detecting means changes from a ground fault state to a non-ground fault state, a predetermined time for ground fault determination is reset. Can be eliminated, and the ground fault can be detected satisfactorily even when the power is supplied.

In the third aspect of the present invention, when the ground fault detecting means detects that the electromagnetic clutch has been in the ground fault state continuously for a certain period of time, it is determined that a ground fault has occurred. Ground fault erroneous detection can be prevented.
Further, the ground fault detecting means inhibits the detection of the ground fault state for a predetermined time when the clutch current command signal sharply decreases, and the ground fault state is continuously detected for a predetermined time when the clutch current command signal sharply decreases, and the ground fault is detected. It is possible to prevent the determination.

[0025]

【Example】

Embodiment 1 FIG. FIG. 1 is a configuration diagram showing a first embodiment of a control device for a vehicle electromagnetic clutch according to the present invention. This figure 1
, Parts corresponding to those in FIG.
The detailed description is omitted. In the figure, reference numeral 2A denotes a clutch current calculating means, which corresponds to the clutch current calculating means 2 in the example of FIG. This example is different from FIG. 1 except that the operation of the ground fault detection and protection of the clutch current calculation means 2A is different from the operation of ground fault detection and protection of the clutch current calculation means 2.
The configuration is the same as in the first example.

FIG. 2 is a flowchart showing a ground fault detection and protection operation of the electromagnetic clutch 5 in the clutch current calculation means 2A, and is stored in, for example, a ROM (not shown) as a control program. 3 shows a timing chart, FIG. 3A shows a control mode, FIG. 3B shows a ground fault condition, FIG. 3C shows the voltage of the output terminal 29, FIG. Figure E shows the ground fault recovery timer, Figure F
Represents a ground fault detection flag, and FIG. G represents a ground fault protection flag.

In FIG. 2, in step S11, it is determined whether or not the clutch current control mode obtained from the traveling control information SD and the engine control information SE is the reverse excitation mode. Proceed to. In step 12, it is determined whether or not the electromagnetic clutch 5 has a ground fault according to the output signal of the voltage detecting means 6. If it is determined that there is a ground fault, the process proceeds to step S13. Step S
At 13, in the reverse excitation mode, the duration of the time when the electromagnetic clutch 5 is in the ground fault state is measured by a ground fault detection timer.

In step S15, the clutch current command signal SI and the clutch release signal SO already obtained internally are canceled, the clutch current command signal SI is set to 0, and the clutch release signal SO is set to a high level "H" (transistor 16).
Is turned off), and the clutch current is reset (release setting). This is because the transistor 11 or 1
This is because, when the transistor 6 is turned on, an excessive current flows, and the transistors 11 and 16 may be damaged. When it is determined in step S11 that the mode is not the reverse excitation mode, and when it is determined in step S12 that it is not the ground fault, the process proceeds to step S14. In step S14, an initial value of a ground fault determination time (determined as a ground fault when the ground fault state continues for a certain period of time) is set in a ground fault detection timer. The above-described step operation is repeatedly executed.

Next, a description will be given with reference to the timing chart of FIG. When the clutch current control mode is the reverse excitation mode and the normal (non-ground) condition, the ground fault detection timer remains at the initial value of the ground fault determination time. At ground fault (illustration a)
When the ground fault detection timer starts counting, a ground fault is determined when the ground fault determination time continues (shown in b), a ground fault detection flag and a ground fault protection flag are set, and the clutch current control mode is set to ground. The fault protection mode (clutch current reset) is set.

Next, the operation of returning from the ground fault protection mode will be described. When the clutch current control mode is the ground fault protection mode (reverse excitation), the ground fault recovery timer indicates the return determination time (when the normal state is established) when the ground fault occurs. Set to the initial value of (determined to be normal when continued for a certain period of time). In a normal (non-ground fault) state (c in the figure), counting of the ground fault recovery timer is started. When the ground fault return determination time is continued (illustrated d), it is determined that the ground fault is normal (non-ground fault), the ground fault detection flag and the protection flag are cleared, and the mode returns to the normal clutch current control mode. As described above, in this example, it is determined that the ground fault has occurred when the ground fault state has continued for a certain period of time, and it is determined that the ground fault has occurred when the normal state has continued for a certain period of time. False detection can be prevented.

Embodiment 2 FIG. FIG. 4 is a block diagram showing a second embodiment of the control apparatus for a vehicle electromagnetic clutch according to the present invention. In FIG. 4,
Parts corresponding to those in FIG. 11 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the figure, reference numeral 2B denotes a clutch current calculating means, and the clutch current calculating means 2 in the example of FIG.
It corresponds to. This example is configured similarly to the example of FIG. 11 except that the operation of detecting and protecting the ground fault of the clutch current calculating means 2B is different from the operation of detecting and protecting the ground fault of the clutch current calculating means 2.

FIGS. 5 and 6 are flowcharts showing the ground fault detection and protection operation of the electromagnetic clutch 5 in the clutch current calculation means 2B, and are stored in, for example, a ROM (not shown) as a control program. Also, FIG.
6 is a timing chart of an example of a ground fault erroneous detection that can occur when a ground fault is detected only by detecting the voltage level of the clutch output terminal 29 by the voltage detecting means 6 during the pulse width modulation control when the clutch is energized. FIG. 5A shows the control mode, FIG. 5B shows the ground fault condition, FIG. 5C shows the voltage of the output terminal 29, and FIG.
Is a ground fault detection timer, FIG. E is a ground fault detection flag, and FIG.
Indicates a ground fault protection flag.

FIG. 8 is a timing chart when the voltage level of the clutch output terminal 29 is detected by the voltage detecting means 6 and the processing is performed as an interrupt factor (see FIG. 6). FIG. A shows a control mode, FIG. B shows a ground fault condition, and FIG.
D is a ground fault detection timer, D is a ground fault recovery timer, F is a ground fault detection flag, and G is a ground fault protection flag.

First, step S in the flowchart of FIG.
Steps S24 to S29 will be described. In step S24,
It is determined whether the clutch current control mode is the reverse excitation mode, and if it is the reverse excitation mode, the process proceeds to step S26,
Otherwise, the process proceeds to step S25. Step S25
Then, if the clutch current control mode is the energization mode, the process proceeds to step S26; otherwise, the process proceeds to step S29. In step S26, a ground fault or a non-ground fault is determined based on the output signal of the voltage detecting means 6. If a ground fault occurs, the process proceeds to step S27; otherwise, the process proceeds to step S29. In step S29, an initial value of a ground fault determination time (determined as a ground fault when the ground fault state continues for a certain period of time) is set in the ground fault detection timer.

In step S27, the duration in the ground fault state is measured by the ground fault detection timer. If the ground fault state continues for a predetermined time (ground fault determination time), it is determined that the ground fault has occurred, and the process proceeds to step S28. . In step S28, the clutch current command signal SI and the clutch release signal SO already obtained internally are cancelled, and the clutch current command signal SI
To 0, the clutch release signal SO is set to the high level “H” (the transistor 16 is turned off), and the clutch current is reset (release setting). This is because if the transistor 11 or 16 is turned on during a ground fault, an excessive current flows, and the transistors 11 and 16 may be destroyed.

In the ground fault detection at the time of energization in FIG. 7, the ground fault is detected only by detecting the voltage level of the clutch output terminal 29 by the voltage detecting means 6. Since the voltage level of the clutch output terminal 29 is constantly changed by the pulse width modulation control, the timing of detecting the voltage level of the clutch output terminal 29 and the voltage level of the clutch output terminal 29 become low level “L” by the pulse width modulation control. When the following timings are synchronized (e in the figure), the ground fault state is always detected, and the ground fault detection timer is counted. As a result, when the ground fault state is detected continuously for the ground fault determination time, the ground fault detection flag and the ground fault protection flag are set, and the ground fault is erroneously determined irrespective of normal (non-ground fault), and The current control mode becomes the protection mode (f in the figure).

In the ground fault detection at the time of energization shown in FIG. 8, the voltage signal of the clutch output terminal 29 is detected by the voltage detecting means 6 and the output signal of the voltage detecting means 6 is processed as an interrupt processing factor, thereby detecting the ground fault. Detection is being performed. Since the voltage level of the clutch output terminal 29 is constantly changed by the pulse width modulation control, the timing of detecting the voltage level of the clutch output terminal 29 and the voltage level of the clutch output terminal 29 become low level “L” by the pulse width modulation control. If the timings are synchronized,
The ground fault condition is always detected (same as the illustration e in FIG. 7).

Next, the voltage level of the rising edge of the clutch output terminal 29 caused by the pulse width modulation control (shown g), performs interrupt processing in the clutch current calculation unit 2 B (FIG. 6). That is, when a rising edge of the voltage level of the clutch output terminal 29 is detected, it is determined that pulse width modulation is normally performed, and an interrupt process is performed. In the interrupt processing, the initial value of the ground fault determination time is set in the ground fault detection timer in step S31 (initialization of the ground fault detection timer). Thereby,
The timing for detecting the voltage level of the clutch output terminal 29 and the pulse output modulation control
Even when the timings when the voltage levels become low level "L" are synchronized, the ground fault detection timer is initialized by the interrupt processing, so that the ground fault erroneous detection does not occur.

At the time of a ground fault, a state where the voltage level of the clutch output terminal 29 is detected to be low level "L" and the rising edge of the voltage level of the clutch output terminal 29 is not detected (interrupt processing in FIG. Not performed)
Is continued for a predetermined time (ground fault determination time), a ground fault is determined, the ground fault detection flag and the ground fault protection flag are set, and the clutch current control mode is set to the ground fault protection mode (h in the figure). By the way, even in a normal state (non-ground fault), when the clutch current command signal SI is rapidly reduced, the voltage level of the clutch output terminal 29 is continuously at the low level “L”.
Therefore, there is a possibility that a ground fault is erroneously detected.

FIG. 9 is a timing chart showing an example of erroneous ground fault detection when ground current detection is not prohibited when the clutch current command signal SI suddenly decreases when the clutch current control mode is energized (during pulse width modulation control). This is shown in the chart. FIG. A shows a control mode, FIG. B shows a ground fault condition, and FIG.
D is the clutch current command signal, D is the actual clutch current, E is the voltage of the output terminal 29, F is the ground fault detection timer, G is the ground fault detection flag, and H is the ground fault protection. This is a flag.

When the clutch current control mode is energized, control is performed by pulse width modulation. However, when the clutch current command signal SI sharply decreases (indicated by i), responsiveness of the electromagnetic clutch 5 and the like is caused. Clutch current feedback signal S
An F delay occurs. Accordingly, the voltage level of the clutch output terminal 29 is kept at the low level “L” by the pulse width modulation control. Then, the voltage detecting means 6 sets the voltage level of the clutch output terminal 29 to the low level “L”.
Is detected as a ground fault for a certain period of time (ground fault detection determination time), the ground fault detection flag and the ground fault protection flag are set, and the clutch current control mode is set to ground. It becomes a short-circuit protection mode (illustrated j).

Next, step S in the flowchart of FIG.
21 to S23 will be described. In step S21,
It is determined whether a sudden decrease in the clutch current command signal SI has been detected. If a sudden decrease in the clutch current command signal SI is detected, the process proceeds to step S22; otherwise, the process proceeds to step S23. In step 23, the initial value of the ground fault detection prohibition time is set in the ground fault detection prohibition timer (the ground fault detection is prohibited for the set time). In step S23, it is determined that a sudden decrease in the clutch current command signal SI has been detected, and then ground fault detection inhibition has been determined. After detecting a sudden decrease in the clutch current command signal SI, ground fault detection is prohibited until the ground fault detection prohibition time elapses, and if it has elapsed, the process proceeds to step S24, and ground fault detection is performed as usual.

FIG. 10 is a timing chart showing a control operation when the clutch current command signal SI suddenly decreases when the clutch current control mode is energized.
When the clutch current control mode is energized, the clutch current is controlled by pulse width modulation. However, when the clutch current command signal SI sharply decreases (k in the figure), the clutch current feedback is caused due to the responsiveness of the electromagnetic clutch 5 and the like. The delay of the signal SF occurs. Thus, the low level “L” of the voltage level of the clutch output terminal 29 is maintained by the pulse width modulation control. And, although the voltage detection unit 6 detects that the voltage level of the clutch output terminal 29 is at the low level "L", the clutch current calculation unit 2 after detecting a rapid decrease of the clutch current signal SI by B, a predetermined time (the earth Ground fault detection time) Since ground fault detection is prohibited, ground fault erroneous detection does not occur and control is performed as usual.

After detecting a sudden decrease in the clutch current command signal SI, the ground fault detection is resumed as usual after a certain period of time has passed (m in the figure). As described above, in the present embodiment, since the interruption process is performed at the rising edge of the output voltage level of the clutch output terminal 29 to initialize the ground fault detection timer, the voltage level of the clutch output terminal 29 is detected at the time of energization. Thus, even if the ground fault is detected, no ground fault erroneous detection occurs.
Further, the ground fault detection is prohibited for a certain period of time (ground fault detection inhibition time) after the sudden decrease of the clutch current command signal SI is detected, so that the ground fault erroneous detection does not occur even when the clutch current command signal SI is rapidly reduced. .

[0045]

According to the first aspect of the present invention, a clutch current calculating means for outputting a clutch current command signal, a clutch release signal and a clutch reverse excitation signal based on travel control information and engine control information; A clutch current control means for controlling a current flowing to the electromagnetic clutch by a current command signal, a clutch release signal and a clutch reverse excitation signal; and a ground fault for detecting a ground fault state of the electromagnetic clutch from a voltage level of an output terminal of the clutch current control means. and a detecting means, the clutch current calculation means determines that a ground fault when that is in the ground fault condition continues electromagnetic clutch is fixed time ground fault detection means is detected, the clutch current command signal, clutches open Signal and clutch reverse excitation signal
Controls the electromagnetic clutch in reverse excitation, and then detects a ground fault.
The electromagnetic clutch continues to operate normally for a certain period of time
Is detected as normal, the clutch is determined to be normal.
The current control means energizes the electromagnetic clutch, and has the effect of preventing erroneous detection of ground fault due to noise or the like.

According to the second aspect of the present invention, a clutch current calculating means for outputting a clutch current command signal, a clutch release signal and a clutch reverse excitation signal based on travel control information and engine control information, and a clutch current command signal A clutch current control means for controlling a current flowing to the electromagnetic clutch by a clutch release signal and a clutch reverse excitation signal, and performing pulse width modulation control of the current flowing to the electromagnetic clutch when energized; and a voltage level at an output terminal of the clutch current control means. Ground fault detecting means for detecting a ground fault state of the electromagnetic clutch, wherein the clutch current calculating means detects a ground fault state when the electromagnetic clutch is continuously in the ground fault state for a predetermined time by the ground fault detecting means. When the clutch current command signal and the clutch release signal are set in the release direction of the electromagnetic clutch, To, when the normal power supply from the ground fault detection means
Current control generated by pulse width modulation control
When a voltage change at the output terminal of the
Is intended to reset the predetermined time for the ground fault determination Ji current calculation unit, also perform satisfactorily ground fault detection during energization can be eliminated earth絡誤detection in the pulse width modulation control at conductible There are effects such as being able to.

According to the third aspect of the present invention, a clutch current calculating means for outputting a clutch current command signal, a clutch release signal and a clutch reverse excitation signal based on the traveling control information and the engine control information, and a clutch current command signal A clutch current control means for controlling a current flowing to the electromagnetic clutch by a clutch release signal and a clutch reverse excitation signal, and performing pulse width modulation control of the current flowing to the electromagnetic clutch when energized; and a voltage level at an output terminal of the clutch current control means. And a ground fault detecting means for detecting a ground fault state of the electromagnetic clutch, wherein the ground current detecting means detects a ground fault state when the electromagnetic clutch is continuously in a ground fault state for a predetermined time. The clutch current command signal and the clutch release signal are set in the direction of releasing the electromagnetic clutch, Detecting means, energized when the clutch current
When the command signal suddenly drops below the steady state value, the detection of the ground fault condition is prohibited for a predetermined period of time, preventing erroneous detection of the ground fault due to noise or the like. Is detected, and it is possible to prevent the determination of a ground fault.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a control device for a vehicle electromagnetic clutch according to the present invention.

FIG. 2 is a flowchart showing a control flow of ground fault detection and protection in the first embodiment.

FIG. 3 is a timing chart showing a control operation of ground fault detection and protection in the first embodiment.

FIG. 4 is a configuration diagram showing a second embodiment of the control device for the electromagnetic clutch for a vehicle according to the present invention.

FIG. 5 is a flowchart showing a control flow of ground fault detection and protection in the second embodiment.

FIG. 6 is a flowchart illustrating a control flow of an interrupt process in the second embodiment.

FIG. 7 is a timing chart showing a control operation of ground fault erroneous detection when the clutch current control mode is energized.

FIG. 8 is a timing chart showing a control operation of ground fault detection and protection in the second embodiment.

FIG. 9 is a timing chart showing a control operation of ground fault erroneous detection when the clutch current control mode is energized.

FIG. 10 is a timing chart showing a control operation of ground fault detection and protection in the second embodiment.

And FIG. 11 is a configuration diagram showing a conventional electromagnetic clutch control device for a vehicle.

FIG. 12 is a circuit connection diagram showing an example of a clutch output terminal voltage detecting means provided in the control device for the electromagnetic clutch for a vehicle.

FIG. 13 is a circuit connection diagram showing another example of the clutch output terminal voltage detecting means provided in the control device for the electromagnetic clutch for a vehicle.

FIG. 14 is a circuit connection diagram showing another example of the clutch output terminal voltage detecting means in the control device for the electromagnetic clutch for a vehicle.

FIG. 15 is a flowchart showing a control flow of ground fault detection and protection in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Clutch current control means 2 Clutch current calculation means 3 DC power supply 5 Electromagnetic clutch for vehicles 6 Clutch output terminal voltage detection means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16D 48/06 B60K 23/02

Claims (3)

(57) [Claims] 1. Clutch current calculating means for outputting a clutch current command signal, a clutch release signal and a clutch reverse excitation signal based on travel control information and engine control information; and the clutch current command signal, clutch release signal and clutch reverse excitation. A clutch current control means for controlling a current flowing to the electromagnetic clutch by a signal; and a ground fault detection means for detecting a ground fault state of the electromagnetic clutch from a voltage level of an output terminal of the clutch current control means. means when it is in a ground fault condition continues the electromagnetic clutch is fixed time by the ground fault detection means is detected, it is determined that the ground fault, the clutch current command signal, clutches open signal and the clutch inverse excitation signal By
In addition to performing reverse excitation control on the electromagnetic clutch,
The electromagnetic clutch continues for a certain period of time due to the ground fault detection means
Is judged to be normal when normal state is detected
And the electromagnetic clutch by the clutch current control means.
A control device for an electromagnetic clutch for a vehicle, characterized by energizing a vehicle. 2. Clutch current calculating means for outputting a clutch current command signal, a clutch release signal and a clutch reverse excitation signal based on travel control information and engine control information; and the clutch current command signal, clutch release signal and clutch reverse excitation. A clutch current control means for controlling a current flowing to the electromagnetic clutch by a signal and performing pulse width modulation control of a current flowing to the electromagnetic clutch when energized; and a ground fault of the electromagnetic clutch based on a voltage level of an output terminal of the clutch current control means. Ground fault detecting means for detecting a state, wherein the clutch current calculating means determines that a ground fault has occurred when the ground fault detecting means detects that the electromagnetic clutch is continuously in a ground fault state for a predetermined time. Setting the clutch current command signal and the clutch release signal in the release direction of the electromagnetic clutch. At normal power supply from the ground fault detection means.
The clutch voltage generated by the pulse width modulation control of
When a voltage change at the output terminal of the
A control device for an electromagnetic clutch for a vehicle, wherein a predetermined time for a ground fault determination of the clutch current calculating means is reset. 3. Clutch current calculating means for outputting a clutch current command signal, a clutch release signal and a clutch reverse excitation signal based on travel control information and engine control information; and the clutch current command signal, clutch release signal and clutch reverse excitation. A clutch current control means for controlling a current flowing to the electromagnetic clutch by a signal and performing pulse width modulation control of a current flowing to the electromagnetic clutch when energized; and a ground fault of the electromagnetic clutch based on a voltage level of an output terminal of the clutch current control means. Ground fault detecting means for detecting a state, wherein the clutch current calculating means determines that a ground fault has occurred when the ground fault detecting means detects that the electromagnetic clutch is continuously in a ground fault state for a predetermined time. Setting the clutch current command signal and the clutch release signal in the release direction of the electromagnetic clutch. In addition, the ground fault detecting means , when energized, the clutch current command signal
A control apparatus for an electromagnetic clutch for a vehicle, wherein the detection of the ground fault state is prohibited for a predetermined time when the value of the power supply voltage suddenly decreases from a steady value .