JP2001304305A - Shift control device for mechanical automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit execution of coasting operation at accelerator-off, regarding a shift control device for a mechanical automatic transmission. SOLUTION: This shift control device for the mechanical automatic transmission is constituted, to drive an actuator 6 by an actuator operation control means 30, so as to disengage a friction clutch when the accelerator opening detected by an accelerator opening detecting means 11 is a first prescribed value or less and a gear stage detected by a gear stage detecting means 16 is a prescribed gear stage or less, or when the accelerator opening detected by the accelerator opening detecting means 11 is not more than a second prescribed value larger than the first prescribed value, its change rat is specified change rate or less and the gear stage detected by the gear stage detecting means 16 is the prescribed gear stage or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for a mechanical automatic transmission in which a manual transmission (manual transmission) is automated.

[0002]

2. Description of the Related Art In recent years, as a transmission for vehicles such as automobiles,
A so-called mechanical automatic transmission has been developed in which a manual transmission including a friction clutch and a parallel two-shaft transmission is automated. In such a mechanical automatic transmission, since a fluid clutch (torque converter) is not interposed in the driving force transmission system from the engine to the driving wheels, the transmission efficiency is higher than the automatic transmission using the torque converter, and the fuel efficiency is improved. Can be achieved. Also, since there is no slip feeling peculiar to the torque converter, drivability is also improved.

In such a mechanical automatic transmission, a clutch actuator for connecting / disconnecting a clutch, a throttle actuator for adjusting a throttle opening, and a shift select actuator for switching a gear position are provided. The shift operation is performed by appropriately controlling the operation of each of the actuators.

[0004] Specifically, first, a return operation of the throttle is performed, and an operation of disengaging the clutch is performed, and thereafter, a gear change (switching of a gear position) is performed. Then, after adjusting the rotation speed of the engine, the clutch connection operation is performed, and the speed change operation is completed.

[0005]

However, in such a conventional shift control device for a mechanical automatic transmission, the driver releases his / her foot from the accelerator pedal during traveling with the intention of coasting due to inertia. However, since the clutch is maintained in the engaged state, a stronger engine brake acts as compared with a general automatic transmission (torque converter A / T) having a torque converter. Therefore, there is a problem that the driver feels strange when the accelerator is off, and it is difficult to adjust the inter-vehicle distance by operating the accelerator.

[0006] Japanese Utility Model Publication No. Hei 3-20581 discloses a technique in which the clutch is disengaged at a speed lower than the actual idle speed when the shift speed is a low speed. However, this technology is a technology that allows the engine to run at an extremely low speed while maintaining the engine at idle speed when the shift speed is low on a congested road or the like, and does not solve the above-mentioned problem at all.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a shift control device for a mechanical automatic transmission capable of executing coasting operation when an accelerator is off.

[0008]

According to a first aspect of the present invention, there is provided a shift control device for a mechanical automatic transmission according to the first aspect of the present invention, which controls a shift state of a friction clutch by controlling a joint state of a friction clutch and a shift state of a transmission mechanism. Is executed. Then, the accelerator opening is detected by the accelerator opening detecting means, and the gear position of the transmission mechanism is detected by the transmission gear position detecting means, and the accelerator opening is equal to or less than the first predetermined value, and When the speed is equal to or lower than a predetermined speed, or when the accelerator opening is equal to or lower than a second predetermined value that is larger than the first predetermined value and the rate of change is equal to or lower than a predetermined rate of change and equal to or lower than a predetermined speed. In this case, the coast determination is established, the actuator is driven by the actuator operation control means, and the friction clutch is disconnected. Thus, the coasting operation (coast operation) can be smoothly performed.

According to a second aspect of the present invention, there is provided a shift control device for a mechanical automatic transmission, wherein the input shaft rotation speed of the transmission mechanism detected by the input shaft rotation speed detection unit is detected by the engine rotation speed detection unit. If the deviation from the set engine rotation speed (input shaft rotation speed of the transmission mechanism-engine rotation speed) is negative, or if the deviation is equal to or less than a predetermined deviation, and the rate of change of the deviation is equal to or less than the predetermined rate of change, In this case, the coast determination is canceled, and the actuator is driven by the actuator operation control means to connect the friction clutch. This prevents the engine from blowing when the driver depresses the accelerator pedal.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a mechanical automatic transmission according to an embodiment of the present invention; FIG. FIG. 2 is a schematic diagram showing the configuration of the clutch actuator, FIG. 3 is a schematic diagram showing the configuration of the shift select actuator, FIG. 4 is a schematic block diagram focusing on the configuration of the main part, and FIG. It is a flowchart for the.

First, the overall structure of a mechanical automatic transmission will be described. This mechanical automatic transmission is different from an automatic transmission having a fluid clutch such as a torque converter, and is different from a friction clutch and a parallel two-shaft transmission. A general manual transmission comprising an actuator and an electronically controlled throttle (so-called drive-by-wire system) for performing a clutch operation and a shift operation in place of a driver, and appropriately controls the operation of these actuators and the like. Thus, the automatic transmission is configured to be executed.

As shown in FIG. 1, a controller (A / T-ECU or simply ECU) 30 of the automatic transmission includes a shift determining unit 1, a shift executing unit 2, and a clutch actuator drive control unit. 3, a shift select actuator drive control unit 4 and a throttle actuator drive control unit 5 are provided. On the vehicle side, an input shaft rotation speed sensor or clutch rotation speed sensor (input shaft rotation speed detecting means) 10 which detects the input shaft rotation speed (clutch rotation speed) of the transmission body and functions as a vehicle speed sensor, An accelerator opening sensor (accelerator opening detecting means) 11 for detecting an opening degree or an amount of depression of an accelerator pedal, an engine rotating speed sensor (engine rotating speed detecting means) 12 for detecting an engine rotational speed, and a throttle opening is detected. A throttle opening sensor 13, a release stroke sensor (stroke sensor) 14 for detecting a release stroke and a release hydraulic pressure of the clutch, and a release hydraulic pressure sensor (pressure sensor) 15,
A gear position sensor (gear position detecting means) 16 and the like for detecting a gear position (gear position) of the transmission are provided. Shift determination is performed based on detection information from the vehicle speed sensor 10 and the accelerator opening sensor 11. The shift-up unit 2 determines a shift-up or shift-down timing (shift determination), and receives a shift instruction from the shift determination unit 1 and sends a control signal to each of the actuator drive control units 3 to 5 in response to a shift instruction. Is set.

The mechanical automatic transmission also includes a clutch actuator 6 for connecting and disconnecting a clutch, a shift select actuator 7 for switching the shift of the transmission body, and a throttle opening of an electronically controlled throttle. A throttle actuator 8 is provided. The throttle actuator 8 is constituted by, for example, a stepper motor.

Each of the actuator drive control units 3 to
In 5, the operation of the clutch actuator 6, the shift select actuator 7, and the throttle actuator 8 is controlled in accordance with the control signal from the shift execution section 2. That is, the ECU 30 functions as an actuator operation control unit that controls the operation of each of the actuators 6 to 8.

More specifically, when a shift determination is made by the shift determining unit 1, each operation is performed in the order of throttle return operation, clutch disengagement operation, gear change (change of gear position), engine speed adjustment, and clutch engagement operation. Is executed, and the shift execution unit 2 executes the operation of each of the actuators 6 to 6 at an optimal timing when the shift operation is performed.
A control signal is set in each of the drive control units 3 to 5 so that the drive unit 8 operates.

Next, the configurations of the clutch actuator 6 and the shift select actuator 7 will be briefly described with reference to FIGS. 2 and 3, respectively. As shown in FIG. 2, the clutch actuator 6 is provided with a clutch release cylinder 61, and a release fork (not shown) is connected to a push rod 61b of the clutch release cylinder 61. Then, by controlling the supply and discharge state of the working fluid (in this embodiment, the working oil) to and from the chamber 61a of the clutch release cylinder 61, the push rod 61b is moved forward and backward to control the clutch engagement state. . Here, the room 61a
When the operating oil is supplied to the push rod 61b and the push rod 61b extends rightward in the drawing, the clutch is disengaged.

As shown in the figure, between a chamber 61a and an oil tank 62, a hydraulic source (oil pump) 63, a pressure regulating valve (regulator) 64, and a solenoid 6 for supplying hydraulic pressure are provided.
5 and a solenoid 66 for discharging hydraulic pressure are provided. The clutch actuator drive control unit 3 controls the duty of each of these two solenoids (open / close valves) 65 and 66. The on / off control of the two solenoids 65 and 66 changes the state of the hydraulic pressure supply to the chamber 61a, and the connection and disconnection of the clutch is performed.

For example, when the solenoid 65 is turned on (open) and the solenoid 66 is turned off (closed), the chamber 61a
The clutch is disengaged by supplying the operating oil to the clutch. Conversely, the clutch is connected by turning the solenoid 65 off (closed) and turning the solenoid 66 on (open) to drain the hydraulic oil in the chamber 61a to the oil tank 62. As shown in FIG. 2, when both solenoids 65 and 66 are turned off (closed), the state of the clutch is maintained.

As described above, the clutch actuator 6 is provided with the stroke sensor 14 for detecting the stroke position (release stroke) of the push rod 61b of the clutch release cylinder 61 and the pressure of the hydraulic oil supplied to the chamber 61a. A pressure sensor (fluid pressure detecting means) 15 for detecting the release pressure) is provided, and the detection information of these sensors 67 and 68 is fed back to the clutch actuator drive control unit 3.

Next, the shift select actuator 7 will be described with reference to FIG. 3. The shift select actuator 7 includes a shift actuator 71 and a select actuator 72. Among them, the shift actuator 71 is provided such that the operation direction thereof corresponds to the front-rear direction (shift direction) of the shift lever in the manual transmission, and the select actuator 72 is provided.
Is provided such that the operation direction thereof corresponds to the left-right direction (selection direction) of the shift lever.

These actuators 71, 72
Are configured as three-position hydraulic power cylinders, each of which can take three positions.
By combining the position and the three positions in the select direction, the gear position can be switched by an operation corresponding to the shift pattern of the manual transmission. Here, the configuration of the actuators 71 and 72 will be briefly described by taking the shift actuator 71 as an example.
a, 71b are provided. Pistons 71a, 71b
When the hydraulic pressure is constant, the force acting on the pistons 71a and 71b is increased independently of each other.
By changing each of the positions b, the operating position of the actuator 71 can be switched to three positions as shown in the upper, middle, and lower portions in the figure.

As shown in the figure, a hydraulic source (oil pump) 74, a pressure regulating valve (regulator) 75, solenoids 76 to 79, and the like are provided between each of the actuators 71 and 72 and the oil tank 73. Each of the solenoids 76 to 79 is similar to the clutch actuator 6 described above.
By controlling the duty of each piston 71
The state of supply of hydraulic oil to the a and 71b can be appropriately switched. The actuator 7
The operating positions of the gears 1, 72 are switched so that the gear position can be switched.

Next, the main part of the present invention will be described.
This device enables smooth coasting operation (coast operation) without causing engine braking even if the driver releases his / her foot from the accelerator pedal during traveling. That is, as shown in FIG. 4, the shift execution unit 2 of the ECU 30 is provided with a coast determination unit 21 and a coast determination release unit 22, and the coast determination unit 21 determines that the driver is about to coast. (Ie, when the coast determination is made), a control signal is output to the clutch actuator drive control section 3 and the clutch is disengaged by the clutch actuator 6. Further, when the coast determination is released by the coast determination release section 22, the clutch is connected in reverse to the above.

First, the coast determination will be described. The accelerator determination sensor 21 and the gear position sensor 16 are connected to the coast determination unit 21 as shown in the figure, and information from these sensors 11 and 16 is provided. , It is determined whether or not the coast determination has been established. The following conditions are set as the conditions for establishing the coast judgment. When the accelerator opening is equal to or less than a first predetermined value and the gear is equal to or less than a predetermined gear (for example, third speed). The accelerator opening is equal to or less than a second predetermined value (> first predetermined value) and the accelerator opening change rate is a predetermined change rate (for example,-
30% / sec) or less and the speed is below a predetermined speed (for example, third speed).

Here, the first predetermined value is:
In the present embodiment, 0% is set. Therefore, the above description can be rephrased as "when the accelerator is off and the speed is 3rd speed or lower". In the present embodiment, 5% is set as the second predetermined value. In the above case, the accelerator is fully closed, and in this case, the driver releases the foot from the accelerator pedal and tries to run the vehicle using inertia (coast operation).
Can be considered. Therefore, in this case, if the shift speed is a low speed, a coast determination is made and the clutch is disengaged.

In the case (1), the accelerator opening is small (5% or less) and the rate of change of the accelerator opening (actuation speed of the accelerator pedal) is large on the closing side. Even if it is not closed, it is estimated that the accelerator will be fully closed immediately after this, and if the gear is low,
The coast judgment is made and the clutch is disengaged.

In both cases, the shift speed is used as a parameter for determining the coast because, when the shift speed is a high speed (4th speed or higher), the engine braking force is relatively small and it is necessary to disengage the clutch. Not so much. In addition, when the vehicle is running at a high speed, it is easier to carry out inter-vehicle adjustment when an appropriate engine braking force is applied when the accelerator is off. Therefore, in this embodiment, when the shift speed is the high speed stage, the coast determination is not performed and the clutch is not disconnected.

In the above description, the gear position may not be used as a parameter for coast determination. In this case, when one of the following conditions (1) and (2) is satisfied, the coast may be determined and the clutch may be disconnected. 'When the accelerator opening is equal to or less than the first predetermined value. 'When the accelerator opening is equal to or less than a second predetermined value (> first predetermined value) and the accelerator opening change rate is equal to or less than a predetermined change rate.

Next, the condition for canceling the coast judgment will be described. The engine speed sensor 12 and the clutch speed sensor 10 are connected to the coast judgment cancel unit 22 as shown in FIG.
Then, information ne, nc from these sensors 12, 10
, It is determined whether or not the condition for canceling the coast determination is satisfied.

If it is determined that one of the following or any of the following conditions is satisfied in the state where the coast determination is established, the coast determination is released and the clutch is engaged. When the deviation Ns (= nc−ne) between the clutch rotation speed nc and the engine rotation speed ne is negative. The case where the deviation Ns is equal to or less than a predetermined value (for example, 200 rpm) and the rate of change dNs / dt of the deviation is equal to or less than a predetermined value (for example, -200 rpm / sec).

Here, since the clutch is disengaged during the coasting operation, the engine rotation speed decreases to about the idle rotation speed, and the clutch rotation speed (the input shaft rotation speed of the transmission) becomes relatively higher. Become. In such a state, the deviation Ns between the clutch rotation speed nc and the engine rotation speed ne becomes negative when the driver has the intention to accelerate and depresses the accelerator, or when the vehicle speed has decreased to an extremely low speed. is there. Therefore, when the condition is satisfied, the coast determination is canceled and the clutch is engaged to accelerate the vehicle.

In this case, when the information from the accelerator opening sensor 11 is taken in and it is determined that the accelerator pedal is depressed, the coast determination may be canceled. By releasing the coast determination based on the deviation Ns between the clutch rotation speed nc and the engine rotation speed ne, it is possible to prevent a clutch connection shock. That is, in the case of, focusing on the clutch rotation speed nc and the engine rotation speed ne,
When the deviation Ns of these rotational speeds becomes substantially zero, the clutch is connected, so that the clutch can be connected without generating a shock.

The condition (1) is satisfied because the deviation Ns between the clutch rotation speed nc and the engine rotation speed ne is 0.
This is not the case, however, due to the relative increase in the engine rotation speed ne, the rotation speed deviation Ns is becoming smaller. Therefore, in this case, although the clutch rotational speed nc does not currently match the engine rotational speed ne, immediately after this, it is estimated that the engine rotational speed ne catches up with the clutch rotational speed nc and agrees. The judgment is canceled.

Since the shift control device for a mechanical automatic transmission according to one embodiment of the present invention is configured as described above, while the vehicle is running, coast determination is performed based on, for example, a flowchart shown in FIG. Is established and the coast determination is canceled. First, in step S1, the accelerator opening aps, the engine rotation speed ne, the clutch rotation speed nc, and the current gear n are read.
In 2, it is determined whether or not the accelerator is off (aps = 0%).

If the accelerator is off, the process proceeds to step S3, where it is determined whether or not the current gear n is equal to or less than a predetermined gear (third speed). Then, the coast judgment is established. When the coast determination is made in this way, the clutch actuator operates in the disengagement direction, and the clutch is disengaged.

If it is determined in step S2 that the accelerator is not turned off, the process proceeds to step S5, where the accelerator opening is equal to or less than a predetermined value (5%) and the differential value of the accelerator opening (operating speed of the accelerator pedal). Is a predetermined value (-30% / s
ec) It is determined whether or not: If this condition is satisfied, it is predicted that the accelerator opening aps will be 0% immediately after this, and the process proceeds to step S3 and thereafter, where the coast determination is also made. If the above condition is not satisfied in step S5, the process returns.

On the other hand, when the coast judgment is established, the process proceeds to step S6 and thereafter, it is judged whether or not the coast release condition is satisfied. First, in step S6, a deviation Ns between the clutch rotation speed nc and the engine rotation speed ne is calculated. Next, in step S7, the deviation Ns is equal to or less than a predetermined value (200 rpm) and the change rate dN
It is determined whether s / dt is equal to or less than a predetermined value (for example, -200 rpm / sec). Then, when the above condition is satisfied in step S7, immediately after this, the clutch rotation speed nc
Is predicted to match the engine speed ne, the coast determination is canceled in step S8, and the clutch is engaged.

If the condition in step S7 is not satisfied, the process proceeds to step S9, where it is calculated whether or not the deviation Ns is a negative value. At this time, if Ns is negative, the engine speed ne is higher, so the process also proceeds to step S8, where the coast determination is canceled and the clutch is engaged. As described above, according to the present apparatus, the coast determination is performed when the accelerator opening is fully closed or when it can be predicted to be fully closed based on the accelerator opening and the speed at which the accelerator pedal is released. Is established and the clutch is disengaged, so that no engine braking occurs and a smooth coasting operation (coast operation) can be realized. This also prevents the driver from feeling uncomfortable, and improves drivability. Further, the inter-vehicle adjustment by the accelerator operation becomes easy, and the drivability is improved from such a viewpoint.

Further, since the coast determination is not performed when the shift speed is the high speed stage, an appropriate engine brake is applied when the vehicle is running at the high speed stage, so that it is possible to secure the easiness of the inter-vehicle adjustment during the high speed run. Further, according to the present apparatus, when the engine rotation speed matches the clutch rotation speed or when it can be predicted that the engine rotation speed matches the clutch rotation speed, the coast determination is canceled and the clutch is connected.
There is an advantage that it is possible to prevent the engine from being blown off during the coasting operation, and also to prevent a sense of deceleration due to the coasting operation so that smooth reacceleration can be performed. Further, it is possible to prevent a shock when the clutch is connected.

The shift control device for a mechanical automatic transmission according to the present invention is not limited to the above-described one, and can be changed without departing from the spirit of the present invention. For example, the numerical values used in the above-described embodiments can be variously changed according to the characteristics and specifications of the engine and the vehicle.

[0041]

As described above in detail, according to the shift control device for a mechanical automatic transmission according to the first aspect of the present invention, when the accelerator opening is fully closed or when the accelerator is fully closed. When it can be predicted, the friction clutch is disengaged, so that there is an advantage that the engine braking does not occur and a smooth coasting operation can be realized. This also prevents the driver from feeling uncomfortable, and improves drivability. Further, the inter-vehicle adjustment by the accelerator operation becomes easy, and the drivability is improved from such a viewpoint. Also, since the friction clutch is not disengaged when the gear is high, when traveling at high gear,
There is an advantage that an appropriate engine brake is applied and easy adjustment between vehicles during high-speed running can be ensured.

According to the shift control device for a mechanical automatic transmission according to the second aspect of the present invention, when the engine rotation speed matches the clutch rotation speed or when it can be predicted that the engine rotation speed matches the clutch rotation speed. Since the friction clutch is connected, there is an advantage that it is possible to prevent the engine from idling at the time of coasting operation, to prevent a sense of deceleration due to the coasting operation, and to perform smooth re-acceleration. Further, there is an advantage that a shock at the time of connecting the friction clutch can be prevented.

[Brief description of the drawings]

FIG. 1 is a control block diagram focusing on overall functions of a shift control device for a mechanical automatic transmission according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a configuration of a clutch actuator of a shift control device for a mechanical automatic transmission according to an embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a shift select actuator of a shift control device for a mechanical automatic transmission according to an embodiment of the present invention.

FIG. 4 is a schematic block diagram focusing on a main configuration of a shift control device of the mechanical automatic transmission according to one embodiment of the present invention.

FIG. 5 is a flowchart illustrating an operation of the shift control device of the mechanical automatic transmission according to the embodiment of the present invention at the time of shift control.

[Explanation of symbols]

Reference Signs List 6 Actuator (clutch actuator) 10 Input shaft rotational speed detecting means (clutch rotational speed sensor) 11 Accelerator opening detecting means (accelerator opening sensor) 12 Engine rotational speed detecting means (engine rotational speed sensor) 16 Gear position detecting means (gear) Position sensor) 30 Actuator operation control means (ECU)

Claims (2)

[Claims] 1. A shift control device for a mechanical automatic transmission having a friction clutch and a speed change mechanism, wherein a shift operation is performed by controlling a joint state of the friction clutch and a speed change state of the speed change mechanism, respectively. Accelerator position detecting means for detecting the opening degree, speed position detecting means for detecting the speed position of the speed change mechanism, an actuator for connecting and disconnecting a friction clutch, and actuator operation control means for controlling the operation of the actuator. When the accelerator opening detected by the accelerator opening detecting means is equal to or less than a first predetermined value and the gear position detected by the gear detecting means is equal to or less than a predetermined gear; or The accelerator opening detected by the opening detecting means is equal to or less than a second predetermined value which is larger than the first predetermined value, and a change rate thereof is equal to or less than a predetermined change rate, and When the shift speed detected by the shift speed detecting means is equal to or lower than the predetermined shift speed, the actuator is driven by the actuator operation control means to disconnect the friction clutch. Transmission control device for automatic transmission. 2. An engine rotational speed detecting means for detecting an engine rotational speed, and an input shaft rotational speed detecting means for detecting a rotational speed of an input shaft of the speed change mechanism, wherein the input shaft rotational speed is detected by the input shaft rotational speed detecting means. If the deviation between the input shaft rotational speed and the engine rotational speed detected by the engine rotational speed detecting means is negative, or the deviation is equal to or less than a predetermined deviation, and the rate of change of the deviation is equal to or less than a predetermined rate of change. 2. The shift control device for a mechanical automatic transmission according to claim 1, wherein in the case of (1), the actuator is driven by the actuator operation control means to connect the friction clutch.