JPH0717165B2 - Clutch controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention electronically controls a friction clutch interposed between an engine and a transmission via an actuator and switches a meshing position of the transmission to a gear position. The present invention relates to a clutch control device in an automatic transmission that is electronically controlled via means.

<Prior Art> In recent years, an automatic transmission that can automatically select a gear position according to a driving condition of a vehicle for the purpose of reducing a driver's burden of driving operation in a large freight vehicle, a shared vehicle, or the like. It is considered.

The conventional automatic transmission is mainly intended for small passenger cars, and a fluid coupling such as a torque converter is interposed between the engine and the planetary gear type transmission, and a planetary gear type using pressure oil as a control medium. Generally, the type of transmission is equipped with gear position switching means.

<Problems to be solved by the invention> What is important in developing an automatic transmission for large-sized freight vehicles is that the number of vehicles produced is significantly smaller than that of passenger vehicles. It would be extremely disadvantageous in terms of cost to newly design the above, and it is desirable to use the friction clutch, the transmission, etc. in the drive system as they are, including the conventional production equipment.

Based on such knowledge, there has been conventionally considered an automatic transmission that can automatically achieve a smooth shift operation by electronic control using the drive system as it is. An object of the present invention is to provide a clutch control device that prevents an unexpected engine stop in such an automatic transmission.

<Means for Solving Problems> A clutch control device according to the present invention includes a friction clutch capable of connecting an output shaft of an engine and an input shaft of a transmission, an actuator for connecting and disconnecting the friction clutch, and a vehicle traveling. A clutch control device including a control device for controlling the operation of the actuator based on a condition, the engine speed detecting means for detecting an engine speed, and detecting whether or not an accelerator pedal is depressed. An accelerator pedal detecting means and a vehicle speed detecting means for detecting a vehicle speed are provided, and when the engine speed detected by the engine speed detecting means is below a predetermined value, the actuator is operated to disconnect the friction clutch. ,
The predetermined value when it is detected by the accelerator pedal detection means that the accelerator pedal is not depressed is set as a first set value in the vicinity of the idling speed, and when the accelerator pedal is depressed, the predetermined value is set. In a clutch control device including a control device in which a predetermined value is set to a second set value that is lower than the first set value, when the vehicle speed detecting means detects that the vehicle speed is equal to or lower than a specified value, the accelerator pedal It is characterized in that the predetermined value is set as a third set value lower than the idle speed regardless of the detection by the detection means.

<Operation> In order to prevent engine stop, the friction clutch is disengaged at a relatively high engine speed when the accelerator is not depressed during general driving, and a shock when the friction clutch is disengaged is prevented and the accelerator is released. When the pedal is depressed, the friction clutch remains connected even at low engine speeds, which allows for sticky driving. Further, at the time of starting, the friction clutch is kept connected even at a low engine speed regardless of the depression of the accelerator, so that a smooth starting is performed.

<Examples> Fig. 1 shows the concept of one example of an automatic transmission including a clutch control device according to one embodiment of the present invention. This automatic transmission is mounted across a diesel engine (hereinafter simply referred to as engine) 30 and a gear type transmission 32 that receives the rotational force of its output shaft 30a via a friction clutch 31. The engine 30 is provided with a fuel injection pump (hereinafter simply referred to as an injection pump) 34 having an input shaft 33 that rotates at a rotational speed half that of the output shaft 30a.
An electromagnetic actuator 38 is connected to the control rack 35 via a link 36, and an engine rotation sensor 39 for outputting a rotation speed signal of the output shaft 30a of the engine 30 is attached to the input shaft 33. The friction clutch 31 presses the clutch plate 41 against the flywheel 40 by a well-known holding means (not shown) to form an air cylinder as a clutch actuator.
When 42 shifts from the non-actuated state to the actuated state, the holding means actuates in the releasing direction, and the clutch 31 changes from the engaged state to the disengaged state (the disengaged state is shown in FIG. 1). The clutch 31 is provided with a clutch stroke sensor 70 that detects the disengaged state or the connected state of the clutch 31 based on the clutch stroke amount, but a clutch touch sensor 43 may be attached instead. Further, the input shaft 44 of the gear type transmission 32 is provided with a clutch rotation speed sensor 45 which outputs a rotation speed (hereinafter, referred to as clutch rotation speed) signal of the input shaft 44. An air passage 47 is connected to the air chamber 46 of the air cylinder 42, and this is connected to an air cylinder 48 as a high pressure air source. An electromagnetic cut valve 49 as an opening / closing means for controlling the supply of operating air is installed in the middle of the air passage 47, and a duty-controlled normally closed solenoid valve 50 for opening the air chamber 46 to the atmosphere is further provided.
Is installed. The above-mentioned clutch stroke sensor 70 that outputs a clutch stroke signal is attached to the air cylinder 42, and the air tank 72 is further attached with an air sensor 72 that outputs an ON signal when the internal air pressure falls below a specified value. In order to switch the gear position of the gear type transmission 32 that achieves each gear, the driver operates the change lever 54 to the gear position corresponding to the shift pattern, for example, as shown in FIG. Based on the shift signal obtained by switching the selection switch 55, the gear shift unit 51 as the gear position switching means is operated to shift the gear position to the target shift speed corresponding to the shaft shift pattern. Here, R indicates a reverse gear, N indicates a neutral gear, 1, 2 and 3 indicate respective designated gears, and D _P and D _E indicate arbitrary automatic gear positions from 2nd speed to 7th speed. , D _P , D _E ranges are selected, the second to seventh speeds are automatically verified based on the running conditions of the vehicle by the optimum shift stage determination processing described later. It is a powerful automatic gear
As shown in FIG. 3 showing the shift range between D _P and D _E which is the economy automatic shift stage, the shift timing of the 2nd speed to the 7th speed in the D _E range shown by the dotted line and the D _P range shown by the solid line is The D _P range is set to the high speed side in order to handle high loads. The gear shift unit 51 includes a plurality of solenoid valves (only one is shown in FIG. 1) 53 which are operated by an actuation signal from the control unit 52, and high-pressure actuation air from the air tank 48 via these solenoid valves 53. It has a select fork and a pair of power cylinders (not shown) which are supplied to operate the select fork and the shift fork of the gear type transmission 32, and operate the power cylinders respectively by the operation signals given to the solenoid valve 53 to select and shift. In this order, the gear type transmission 32 is operated to change the meshing mode. Further, the gear shift unit 51 is additionally provided with a gear position switch 56 as a gear position sensor for detecting each gear position, and a gear position signal from these gear position switches 56 is output to the control unit 52. Further, a vehicle speed unit 58 that outputs a vehicle speed signal is output to the output shaft 57 of the gear type transmission 32.
Is attached to the accelerator pedal 37, and the accelerator pedal 37 is caused to generate a resistance change corresponding to the amount of depression thereof as a voltage value.
An accelerator load sensor 60, which outputs a digital signal by the converter 59, is attached. The brake pedal 61 is provided with a brake sensor 62 that outputs a high-level brake signal when the brake pedal 61 is depressed.
A starter 63 for engaging the ring gear on the outer periphery of the flywheel 40 to start the engine 30 at a proper time is attached to the starter relay 64, and the starter relay 64 is connected to the control unit 52. Reference numeral 65 in the figure denotes a microcomputer that is attached to the vehicle separately from the control unit 52 to perform various controls of the vehicle, and controls the drive of the engine 30 by receiving input signals from each sensor (not shown). And so on. This microcomputer 65 gives an operation signal to the electromagnetic actuator 38 of the injection pump 34, and the rotational speed of the output shaft 30a of the engine 30 (hereinafter, referred to as "rotation speed" by the fuel increase / decrease operation).
You can control the increase / decrease of the engine speed)
An output signal from the control unit 52 as an engine speed increase / decrease signal can be received with priority over the depression amount of the accelerator pedal 37, and the engine speed is increased / decreased according to this output signal.

The control unit 52 is a microcomputer dedicated to the automatic transmission, and includes a microprocessor (hereinafter referred to as CPU) 66, a memory 67, and an interface 68 as an input signal processing circuit. In the input port 69 of the interface 68, the shift selection switch 55, the brake sensor 62, the accelerator load sensor 60, the engine speed sensor 39, the clutch speed sensor 45, the gear position switch 56, the vehicle speed sensor 58, and the clutch touch sensor described above are provided.
Output signals are input from the clutch stroke sensor 70 and the air sensor 72 (used to detect the disengaged state or the connected state of the friction clutch 31 instead of the clutch stroke sensor 70). On the other hand, the output port 74 can be connected to the microcomputer 65, the starter relay 64, the solenoid valves 50, 53, and the cut valve 49, respectively, and output signals to them. In the figure, reference numeral 75 is an air warning lamp that lights up when the air pressure of the air tank 48 does not reach the set value and receives output from a drive circuit (not shown), and 76 indicates the wear amount of the friction clutch 31. It is a clutch warning lamp that lights up when the output is exceeded.

The memory 67 is composed of a read-only ROM in which programs and data shown in the flowcharts of FIGS. 5 to 9 are written and a read / write RAM. That is, in the ROM, the duty ratio α of the solenoid valve 50 corresponding to the value of the accelerator load signal is stored in advance in the ROM as a map as shown in FIG. Read the value. The gear selection switch 55 described above
Outputs a select signal and a shift signal as a shift signal. The gear position corresponding to a pair of these two signals is stored in advance as a data map, and when the select signal and the shift signal are received, Refer to the map and output the corresponding output signal to each solenoid valve of the gear shift unit 51.
Output to 53 and adjust the gear position to the target gear position corresponding to the gear shift signal. In this case, the gear position signal from the gear position switch 56 is output upon completion of the shift, and it is determined whether or not all gear position signals corresponding to the select signal and the shift signal have been output, and a signal indicating whether the meshing is normal or abnormal. Used to emit. Further, the ROM also stores a map for determining the optimum shift speed based on the signals of the vehicle speed, the accelerator load, and the engine rotation when the target shift speed is present in the D _P range or the D _E range.

Here, the shift control procedure of the present embodiment will be described with reference to FIGS.

As shown in FIG. 5, when the program starts, the control unit 52 starts the starting process, and after the starting process is completed, the vehicle speed signal is input, and the value is a specified value (for example, 0 km /
From h to 3km / h), the start process is performed, and above the specified value, the shift process is performed.

In the starting process shown in FIG. 6, a signal of the engine speed N _E is input, it is determined whether the value is within the stop range of the engine 30, and if the engine 30 is stopped, a clutch connection signal is output and After taking a time lag, the friction clutch 31 is connected to the regular pressure and the regular state. When the friction clutch 31 is connected under the normal pressure and in the normal state, the friction clutch 31 is disengaged from this position to some extent, and the drive wheels of the vehicle shift from the rotating state to the stop state. Are described as points) according to the wear state of the facing of the friction clutch 31 and the presence / absence of a load. In other words, the stroke of the clutch plate 41 from the LE point until the friction clutch 31 is completely engaged is almost constant, and the friction clutch 31 can be smoothly engaged regardless of the vehicle condition. When the LE point is corrected, whether or not the position of the chain lever 54 and the gear position are the same, that is, the shift signal and the gear position signal are the same, and the target shift speed (D _E When the D _P range is selected, it is determined whether the gear positions of the gear type transmission 32 are aligned in advance (for example, the second speed is set in advance). If the position of the change lever 54 and the gear position are different, it is determined whether the air in the air tank 48, which is the main tank, has reached the specified pressure, and if the specified pressure is reached, the friction clutch 31 is turned on. Turn off the air and operate the octuator (not shown) with the air in the air tank 48 to automatically match the gear position to the position of the change lever 54, connect the friction clutch 31, and connect the air tank 48, which is the main tank, to the sub tank (not shown). After turning off the solenoid valve for switching between and, it is determined again whether or not the position of the change lever 54 and the gear position are the same.
If the air in the air tank 48 has not reached the specified pressure, it is determined whether the air in the sub-tank has reached the specified pressure, and if it has reached the specified pressure, the switching solenoid valve is turned on.
When the friction clutch 31 is turned on and the air in the sub tank is activated, the power cylinder is operated to automatically select the gear position corresponding to the position of the change lever 54. When the air in the sub tank has not reached the specified pressure, the air warning lamp 75 is turned on to notify the driver that the air in the air tank 48 and the air in the sub tank are below the specified pressure. on the other hand,
When the position of the change lever 54 and the gear position are the same, a starter enabling relay is output. When the relay for enabling the starter is output, the starter 63 can be started and the engine 30 can be started, so it is determined whether the engine 30 has started.If the engine 30 starts, the relay for enabling the starter is turned off. If the engine 30 has not started, it is again determined whether the position of the change lever 54 and the gear position are the same. When the starter enable relay is turned off, it checks whether the air in the air tank 48 and sub tank has reached the specified pressure.If it does not reach the specified pressure, turn on the air warning lamp 75 and turn on the air. The judgment is repeated until the pressure reaches the specified pressure, and when the specified pressure is reached, the air warning lamp 75 is turned off and the starting process is completed.

After the completion of the starting process, the vehicle speed signal is read, and the starting process is started when the speed signal is below the specified value. As shown in FIGS. 7A and 7B, the CPU 66 first outputs an ON signal to the cut valve 49 to disengage the friction clutch 31, and disengages the friction clutch 31. Next, it is determined whether or not the position of the change lever 54 and the gear position are the same, and if NO, the gear position is adjusted to the target gear position. When the position of the change lever 54 and the gear position are the same, it is judged again whether or not the vehicle speed is lower than the specified value, and if the vehicle speed is higher than the specified value, the accelerator load signal (accelerator depression Amount) Go to detection step. On the other hand, if it is not, whether or not the gear position which has reached the target shift speed is neutral is read from the shift signal, and if YES, the LE point is corrected again. If the gear position is NO other than neutral, turn on the friction clutch 31.
Connect up to LE point. Next, it is determined whether or not the accelerator load signal value exceeds a specified value (a voltage that is low enough to indicate that the driver intends to start), and it is determined that there is no intention to start NO.
In the case of, the above steps are repeated. On the other hand, in the case of YES where it is determined that there is a will to start, proceed to the next step,
The accelerator load signal value is detected, and the optimum duty ratio α corresponding to this value is read from the map of FIG. Then, the obtained pulse signal of the optimum duty ratio α is the solenoid valve.
It is output to 50 and the friction clutch 31 is gradually connected. CPU6
6 is issued a selection signal to the input port 69 to continue the input signal of the engine speed N _E at this point, over time the engine rotational speed N _E based on the signal of the engine speed N _E
Are sequentially stored in the RAM in the memory 67, and as shown in FIG. 10 showing an example of changes in the engine rotational speed N _E and the clutch rotational speed N _CL , the peak point M is calculated and calculated. Until M is detected, the routine proceeds to NO and repeats from the accelerator load signal detection step. On the other hand, when the peak point M is detected, the solenoid valve 50 is held at ON from this time T ₁ . The peak point M is the rotation of the output shaft 30a of the engine 30 through the friction clutch 31 and the input shaft of the gear transmission 32.
This occurs because the rotation of 44 causes the power to start to be transmitted to the drive wheels, and the power is reduced.

Next, the LEOFF routine is executed. This LEOFF routine deals with the case where the vehicle is slightly moved with the half clutch instead of the normal start. In the LEOFF routine, it is first determined whether the vehicle speed is higher than the specified value, and the vehicle speed is higher than the specified value. In the case of YES, it is determined that the vehicle has started normally, and the LEOFF routine ends, and the process returns to this starting flow.
On the other hand, in the case of NO, it is judged next whether or not the accelerator pedal 37 is depressed, and in the case of YES, the LEOFF routine is similarly ended, and in the case of NO, it is continued by the off duty until the LE point is reached. Disengage the friction clutch 31 gradually. During this time, it is also determined whether or not the accelerator pedal 37 is depressed, and when the accelerator pedal 37 is depressed, the process returns to the accelerator load signal detection step described above. After the friction clutch 31 has retracted to the LE point, the process returns to the step of determining the position of the change lever 54 and the gear position.

When the LEOFF routine ends and it is determined that the vehicle is starting normally,
The friction clutch 31 is connected from the half clutch state at the LE point to the clutch meet. At this time, the engine speed N _E after passing the peak point M corresponds to the rotation of the input shaft 44 of the gear transmission 32. Considering that the engine speed N _E gradually decreases as the engine speed N _CL increases, the engine speed N _E is controlled so that the rate of decrease falls within a predetermined range and the starting shock is reduced. That is, first, it is determined whether the engine rotation reduction rate ΔN _{E for} each predetermined time is less than or equal to the first set value | x ₁ | shown in FIG. In the case of YES, after executing the LEOFF routine described above, the accelerator load signal is detected again, the optimum duty ratio α corresponding to this value is determined, and the friction clutch 31 is gradually connected by this duty ratio α. After this, it is judged whether the engine speed decrease rate ΔN _E is less than or equal to the second set value | x ₁ | (| x ₁ | <| x ₂ |). If NO, go to before the LEOFF routine described above. Return and repeat the loop to keep the engine speed decrease rate ΔN _E constant.

On the other hand, when the engine speed decrease rate ΔN _E is larger than | x ₁ |, this engine speed decrease rate ΔN _E is the third set value | y ₂ |
(| X ₂ | <| y ₂ |) It is judged whether it is more than. If YES here, L
After executing the EOFF routine, the friction clutch 31 is gradually disengaged by off duty. After that, it is determined whether the engine speed decrease rate ΔN _E is less than or equal to the fourth set value | y ₁ | (| y ₁ | <| y ₂ |). If NO, a loop that disconnects the friction clutch 31 is set. repeat. Rotation rate of decrease or when or above the engine YES △ N _E is | y ₂ | NO in the following whether the determination step, the engine rotational speed decrease rate △ N _E is | x ₂ | or more is determined whether If YES in the step, the engine rotation reduction rate ΔN _E almost falls within the shaded area in FIG. 11 at this point. Therefore, the condition for switching the friction clutch 31 to the connected state without starting shock due to the half-clutch state and without excessively prolonging the starting time has been established, so that the air pressure of the friction clutch 31 is held at the current state. To do. After that, the CPU 66 determines whether or not the difference between the engine speed N _E and the clutch speed N _CL is less than or equal to a specified value (for example, | N _E −N _CL | = 10 rpm). If NO, the above loop is executed. While repeating
After a predetermined time lag at T ₂ which is the time of YES, the solenoid valve 50 is fully opened to perform the clutch meet. After this, after a predetermined time lag on condition that the engine speed N _E is equal to or higher than the idle speed, the CPU 66 determines that the slip ratio of the friction clutch 31 (the difference between the engine speed N _E and the clutch speed N _CL is / Engine speed N _E ) is calculated and this value is compared with the specified value. If the value is less than the specified value, the main flow is returned to. On the other hand, when the slip ratio is equal to or more than the specified value, it is determined that the wear amount of the friction clutch 31 is large, and an ON signal as a clutch wear signal is output to the clutch warning lamp 76 as an output port 74 and a drive circuit (not shown). To output the clutch warning lamp 76.

After the completion of the start-up process, the CPU 66 reads the vehicle speed signal, and if it exceeds the specified value, the shift process is started. As shown in FIGS. 8A and 8B, first, the input port 69
A selection signal is given to the to check whether or not there is a brake failure. If YES in the case of a brake failure, the gears are downshifted by one step to stop the vehicle as described later. On the other hand, if the brake fail is NO, it is checked using, for example, an acceleration sensor whether or not sudden braking with a deceleration of a certain value or more is being applied, and if YES, the shift operation described below is performed. Since the braking distance becomes longer, the main flow is returned to and the shifting operation is temporarily stopped. However, if the friction clutch 31 is disengaged even when the brake is suddenly applied, it is determined that the gear shift is in progress, so the gear shift operation is completed and the friction clutch 31 is engaged.

On the other hand, when there is no sudden braking operation, or when the friction clutch 31 is disengaged as described above even during sudden braking, the position of the change lever 54 is read, and this is D _P , D _E
Other than the above, it is judged whether it is the designated gear stage of 1, 2, or 3 or the automatic gear stage of D _P , D _E , the R stage, or the N stage.

In the case of the designated gears of 1, 2, and 3, it is determined whether or not the position of the change lever 54 and the gear position are the same, YES is returned to the main flow, and NO is advanced to the next step. In this step, the change lever 54
Is positioned, and it is determined whether or not the current gear position before the shift is in the D _P , D _E range and corresponds to the shift down from here. If YES, determine whether the engine 30 can be downshifted without overrunning the rotation,
If NO, proceed to the next step to warn the driver of overrun by the reverse warning buzzer and return to the main flow without performing the gear shifting operation. When the determination as to whether or not the overrun is performed is YES, the downshift operation is performed by one step from the current gear position as follows. As shown in FIG. 12 showing the operation concept of this downshift operation, the control signal of the control rack 35 is output to the electromagnetic actuator 38 via the output port 74 and the microcomputer 65 to keep the engine speed N _E unchanged. Hold in the state. Then, an ON signal is output to the cut valve 49 for a predetermined time through the output port 74 to disengage the friction clutch 31, and a control signal is output to each solenoid valve 53 of the gear shift unit 51 to shift the gear position from the gear position before shifting to the first stage. Downshift to lower gear position. Then, via the output port 74 and the microcomputer 65, the electromagnetic actuator 38 outputs a voltage signal as the accelerator pseudo signal that causes the same rotation as the clutch rotation speed N _CL that increases the engine rotation speed N _E, and after the gear shift. Clutch speed N _CL and engine speed N _E
And the air is released from the air cylinder 42 to move the friction clutch 31 to the half clutch state at the LE point. Next, the friction clutch 31 is connected at the optimum duty ratio α corresponding to the accelerator load signal, and the engine speed N _E
And the clutch rotational speed N _CL are compared with a specified value preset for each gear, and the friction clutch 31 with the duty ratio α is operated until | N _E −N _CL | becomes equal to or less than the specified value. Repeat. After | N _E −N _CL | becomes equal to or less than the specified value, the clutch connection signal is output to complete the connection of the friction clutch 31 with a predetermined time lag, and the accelerator pseudo signal is released to return to the main flow. Return. If the clutch rotational speed N _CL falls below the specified value in the above operation, it is assumed that the vehicle speed has decreased and the friction clutch
In Fig. 5 without connecting 31 Go to the connector of and start processing.

On the other hand, as a result of the determination as to whether or not the shift down from the D _P and D _E ranges is made, if NO, it is determined whether or not the shift is up. Then, if this is YES, the shift up operation is performed as follows and the process returns to the main flow. As shown in FIG. 13 showing the concept of this shift-up operation, the output port 74 and the microcomputer 65 are provided.
Control rack 35 to electromagnetic actuator 38 via
The control signal of is output and the engine speed N _E is returned to the idle speed. Then, after disengaging the friction clutch 31, the gear position is output to each solenoid valve 53 via the output port 74 so as to match the target gear position which is one of 1, 2 and 3 as the designated gear position. To do. After that, the operation after the accelerator pseudo signal output of the downshift operation is performed to match the engine speed N _E with the clutch speed N _CL after the shift, and the connection of the friction clutch 31 is completed to complete the main operation. Return to flow.
If the result of the above determination as to whether or not the shift is up is NO, then it is determined whether or not the vehicle is in overrun and this is YES.
In the case of, the engine speed N _E is held as it is, the friction clutch 31 is disengaged, and the gear position is adjusted to one of the specified gear positions 1, 2 and 3 and the downshift is performed. The operation after the accelerator pseudo signal output of the operation is made and the procedure returns to the main flow. If the result of the determination as to whether or not the vehicle is in the overrun is NO, a warning is given by the warning buzzer.

The above operation is performed when the position of the change lever 54 is determined and the specified gear position is 1, 2, or 3, but the result of the determination of the position of the change lever 54 is D _P , If it is at the automatic gear position of D _E , the following operation is performed. That is, the change lever 54 detects the depression amount of the vehicle speed and the accelerator pedal 37 is in the D _P range to determine whether the D _E range, D _P or from a preset map as shown in FIG. 3 The optimum shift speed that is considered as the target shift speed in each range of D _E is determined. After this, it is judged whether or not the gear position matches the optimum gear position, and if YES, the flow returns to the main flow, and if NO, shifts to the upshift step and shifts to the same gear as above. The operation is performed.

If the result of the determination of the position of the change lever 54 is the R stage, the CPU 66 determines whether or not the gear position matches the R stage as the target shift stage, and the reverse operation is currently being performed.
If YES, the flow returns to the main flow, and if NO, which is an erroneous operation, the engine speed N _{E is set} to idle rotation and the friction clutch 31 is disengaged in the same manner as described above. Then, in order to return the gear position to neutral, output to each solenoid valve 53 via the output port 74, turn on the reverse warning lamp indicating the shift error, then connect the friction clutch 31 and return to the main flow. .

Furthermore, if the result of the determination of the position of the change lever 54 is N steps, whether the change lever 54 has moved within a predetermined time, that is, whether the change lever 54 has passed N steps during the shifting operation by the driver. Determine whether it is too much. As a result of this determination, if YES in the middle of the gear shift operation, the position of the change lever 54 and the gear position are determined as described above, and the process directly returns to the main flow or shift up / down is performed. The operation to return to the main flow is performed. However, in the case of NO where N stage is selected, the engine speed N _E is reduced to idling speed and the friction clutch 31
After turning the gear to neutral, the friction clutch 31 is connected again to return to the main flow.

On the other hand, the engine rotation calculation routine as shown in FIG. 9 is executed at an appropriate position in the above flow. In FIG. 9, first, whether the engine is stopped or not is determined from both the engine speed N _E and the oil pump. That is, it is judged whether the engine speed N _E is below a specified value (a value close to zero). If it is below the specified value, it is judged whether the oil pump is stopped. If it is stopped, the engine is stopped. Considered as a stop Proceed to the connector of. On the other hand, when the oil pump is not stopped or the engine speed N _E exceeds the specified value, it is next determined whether or not the starting process is currently being performed. When the vehicle is not starting, that is, when the vehicle is traveling normally, it is determined whether the accelerator is depressed. Here, when the accelerator depression amount that is judged to be the accelerator depression is equal to or greater than the specified value, the engine speed N _E is compared with the preset first engine stop prevention speed N _EST1, and the engine When the rotational speed N _E is the first engine stop prevention rotational speed N _EST1 or less, disengage the friction clutch 31,
In Fig. 5 If the engine speed exceeds the first engine stop prevention speed N _EST1 , the engine speed calculation routine ends as it is. On the other hand, when the accelerator is not depressed, that is, when the accelerator depression amount is below the specified value, the second engine stop prevention rotation speed N set next to the first engine stop prevention rotation speed N _EST1 is next set. comparing the _EST2 and the engine speed N _E, with the case the engine rotational speed N _E is less than or equal to a second engine stop prevention rotational speed N _EST2 performs an operation to turn off the friction clutch 31 in the same manner, the engine speed N _E When it exceeds the limit, the engine rotation calculation routine ends as it is. If the vehicle is currently in the starting process, the engine speed N _E is compared with the first engine stop prevention speed N _EST1 regardless of whether the accelerator is depressed, and the same operation is performed.

That is, in order to prevent the engine stop, the friction clutch 31 is disengaged when the engine speed N _E is equal to or lower than a predetermined engine stop prevention rotation, but the engine stop when the accelerator is not depressed during general driving. The preventive rotation speed is set to be higher than the engine stop preventing rotation speed when the accelerator is depressed during normal driving and when the vehicle starts. In the present embodiment, the first engine stop prevention speed N _EST1 is _set to 300 rpm at which the possibility of engine stop occurs, and the second engine stop prevention speed N _EST2 is set to 600 rpm, which is close to the engine idle speed. The set engine stop prevention rotation speed is as shown in Table 1 depending on whether the vehicle is starting, traveling normally, or whether the accelerator is depressed. That is, when the vehicle runs at a speed exceeding the specified value, it depends on whether or not the accelerator pedal 37 is depressed.When the accelerator pedal 37 is not depressed, that is, when the accelerator is off, the engine stop prevention speed is set to the idling speed. If the engine speed falls below this 600 rpm, the actuator will be set to 600 rpm (first set value)
When 42 is actuated to disconnect the friction clutch 31 and the accelerator pedal 37 is depressed, that is, when the accelerator is ON, the engine stop prevention speed is set to 300 rpm, which is lower than the idling speed (second setting). value),
The friction clutch 31 that actuates the actuator 42 is disengaged when the engine speed falls below 300 rpm.

On the other hand, when the vehicle starts at a speed lower than the specified value, the engine stop prevention speed is always 300 rpm, which is lower than the idling speed.
(3rd set value) and the engine speed is 300 rpm
When the following occurs, the actuator 42 is operated to disconnect the friction clutch 31.

In other words, during normal driving, the engine stop prevention rotation speed differs depending on whether the accelerator pedal 37 is depressed or not, but at the time of starting, the engine stop prevention speed is prevented regardless of whether or not the accelerator pedal 37 is depressed. The rotation speed is set to a constant value lower than the idling rotation speed.

In this way, during normal driving, the friction clutch 31 is disengaged at a relatively high engine speed N _E when the accelerator pedal is not depressed, so the friction clutch 31 is operated at low speed.
It is possible to prevent shock due to engine reverse torque that occurs when 31 is disengaged, and when the accelerator pedal is depressed, even if the engine speed N _E decreases due to increased load, etc., the friction clutch 31 can be connected up to a low speed. Since it is maintained, a springy operation is possible. On the other hand, when starting, the friction clutch 31 is always connected to a low engine speed regardless of the depression of the accelerator.
Even when the driver turns the accelerator on and off at the time of starting, smooth starting is possible regardless of the situation.

The above-described embodiment is an air tank installed in a vehicle.
Although the air pressure from 48 is used to drive the air cylinder 42 for operating the friction clutch 31, it is naturally possible to use hydraulic pressure as a control medium. However, in this case, a hydraulic pressure generation source such as an oil pump has to be newly added, which may increase the cost. Further, it goes without saying that the shift control procedure, the shift pattern and the like shown in the present embodiment can be appropriately changed in small places as necessary, and the present invention is also applied to a vehicle equipped with a gasoline engine. be able to. Further, the clutch pedal may be mounted as a dummy for the driver who changes trains from the manual transmission. In this case, the clutch pedal has priority over the air cylinder 42 in the R stage and the designated shift stages 1, 2, and 3. It is also possible to set so that.

<Advantages of the Invention> According to the invention of the present application, when the accelerator pedal is not depressed during general driving, the clutch cannot be disengaged until the engine speed becomes close to the idle speed, so that the engine speed is high. It is safe because the feeling of idling due to the clutch being disengaged at times is small. Also, when the accelerator pedal is depressed, the clutch is disengaged only when the engine speed becomes lower than the vicinity of the idle speed. Even if the engine speed temporarily drops, the clutch connection is maintained until the engine speed is lower than the vicinity of the idle engine speed, so that the engine will not run empty and a tenacious operation will be possible.
Further, when the vehicle speed is equal to or lower than the specified value, the friction clutch is always connected to the engine speed lower than the idle speed regardless of the depression of the accelerator pedal. Therefore, for example, the driver turns the accelerator pedal on and off at the start. Even in this case, smooth driving is possible regardless of that.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an automatic transmission equipped with a clutch control device according to an embodiment of the present invention, FIG. 2 is a conceptual diagram showing an example of its shift pattern, and FIG. 3 is its D _P range and D range. _E
FIG. 4 is a graph showing an example of shift characteristics with respect to the range, FIG. 4 is a graph showing an example of a map for determining the duty ratio,
5 to 9 are flowcharts showing an example of the control program, FIG. 10 is a graph showing an example of changes with time in engine speed and clutch speed during the shift, and FIG. 11 is an engine during the shift. FIG. 12 is a graph showing a region of the rate of change in the number of revolutions, FIG. 12 is an operation conceptual diagram at the time of downshift operation, and FIG. 13 is an operation conceptual diagram at the time of upshift operation. In the drawing, 30 is an engine, 30a is an output shaft of the engine, 31 is a friction clutch, 32 is a gear type transmission, 34 is a fuel injection pump, 35 is a control rack, 37 is an accelerator pedal, 38 is an electromagnetic actuator, and 42 is an air. A cylinder, 44 is an input shaft of a gear type transmission, 48 is an air tank, 50 is a solenoid valve, 51 is a gear shift unit, 52 is a control unit, 54 is a change lever, and 65 is a microcomputer.

Claims (1)

[Claims] 1. A friction clutch capable of connecting an output shaft of an engine and an input shaft of a transmission, an actuator for connecting and disconnecting the friction clutch, and a control device for controlling the operation of the actuator based on a running condition of a vehicle. A clutch control device comprising: an engine speed detecting means for detecting an engine speed; an accelerator pedal detecting means for detecting whether or not an accelerator pedal is depressed; and a vehicle speed detecting means for detecting a vehicle speed. When the engine speed detected by the engine speed detecting means is below a predetermined value, the actuator is operated to disengage the friction clutch, and the accelerator pedal is depressed by the accelerator pedal detecting means. The above predetermined value when it is detected that there is no setting is set as the first set value near the idle speed. In the clutch control device, the vehicle speed detection means includes a control device that sets the predetermined value when the accelerator pedal is depressed to a second set value that is lower than the first set value. A clutch control device characterized in that, when it is detected that the vehicle speed is equal to or lower than a prescribed value, the predetermined value is set to a third set value lower than the idle speed regardless of the detection by the accelerator pedal detecting means.