JPH0754878A - Automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To reduce transmission time by starting clutch connection speedily, and when starting of meeting is detected, performing stroke slowly until semi- clutch time passes or until rotational speed difference is a specified value or lower, then speedily performing stroke to the complete connection of a clutch. CONSTITUTION:Semi-clutch controlling is performed when transmission command is generated, so as to relieve transmission shock at the connection time of a clutch 3. The connection of the clutch 3 is speedily started. When starting of meeting is detected, based on a rotational speed difference N between an engine side and the side of a transmission 5, stroke is carried out slowly until a semi-clutch time TT obtained from a preset map data passes, or until the actual rotational speed difference N is a specified value or lower. Then stroke is speedily performed again to the complete connection position of the clutch 3. Even when large rotational speed difference N is shown between the engine side and the side of the transmission 5, excessive semi-clutch time is not required by, for instance, climbing, so that transmission time is reduced to minimum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle automatic transmission.

[0002]

2. Description of the Related Art In recent years, a conventional transmission and a mechanical clutch are used as an automatic transmission for a vehicle, rather than a torque converter being interposed between an engine and a planetary gear type transmission, to detect their operating states. It is known that various sensors and an actuator for driving them are provided, and when a shift request is generated, the control unit that stores a microcomputer controls the drive of the actuator based on these detection signals to perform automatic shift. Among them, in order to reduce the synchromesh mechanism of the transmission, when a shift request to a shift stage that does not have a synchromesh mechanism is generated, the synchromesh mechanism of the other shift stage is temporarily used to allow free play on the main shaft. There is also seen an example in which the rotating speed of the rotating main gear is contained in a synchronizing region with respect to the rotating speed of the main shaft and the gear set is operated at the required shift stage (Japanese Utility Model Laid-Open No. 4-56963).

By the way, in order to mitigate the shift shock caused by the rotational speed difference between the engine side and the transmission side when the clutch is connected, an expensive duty valve is not used for the stroke control of the clutch, but a simple magnet valve is turned on and off. An improved technique for controlling the above has been proposed (Japanese Patent Application No. 4-47693). In that case, when a shift request is made, the accelerator opening of the engine is temporarily returned to the no-load position, and at the same time, the clutch is disengaged, and the transmission is gear-shifted to the required shift stage.
After the gear setting is completed, the start position and required time of the half-clutch are calculated from the preset map data based on the rotational speed difference between the engine and the main gear, and only during that time the magnet valve is switched to activate the orifice and the clutch is gently connected. ing.

[0004]

However, in this prior application, if the rotational speed difference between the engine and the main gear is large, half-clutch control is performed over a long period of time early, so that the accelerator release of the engine is also significantly delayed. ,
The whole shift time will be considerably long. In addition, if the accelerator release of the engine is accelerated to a half-clutch region, the slip of the clutch increases due to the engine output, which shortens the life of the clutch.

An object of the present invention is to effectively solve such a problem.

[0006]

Therefore, as shown in FIG. 6, a gear shift actuator for shifting the gear of a transmission, a clutch actuator for connecting and disconnecting the clutch, and a throttle actuator for controlling the accelerator opening degree of the engine in response to a request are provided. Various sensors that detect the operating state of the actuator, etc., and when a shift request is generated, the actuator is driven based on the detection signals of various sensors to return the accelerator opening of the engine to the no-load position and at the same time disengage the clutch to disengage the transmission. In a vehicle automatic transmission equipped with a gear shift control means for performing a gear shift operation to a required shift stage, and connecting a clutch after the gear setting is completed to restore the accelerator opening of the engine, the start of the meet is detected immediately after the clutch is connected. Then Based on the rotation speed difference between the engine side and the transmission side, gently until the half-clutch time obtained from the preset map data elapses, or until the rotation speed difference shrinks below a predetermined value, and then the clutch completes. A half-clutch control means for promptly re-stroke to the connected position is provided.

[0007]

The clutch is disengaged at the same time when the accelerator opening of the engine is returned to the no-load position when a shift request is generated, and the clutch is engaged after the transmission gear set is completed. During that time, the engine speed decreases toward idle speed. Half-clutch control is required to reduce the shift shock at the time of connection. In this case, when the start of the contact is detected immediately after the clutch is engaged, the rotation speed difference between the engine side and the transmission side at that time is used until the half-clutch time obtained from the preset map data elapses, or the same rotation is performed. The stroke is gently stroked until the speed difference decreases below a predetermined value, and then the stroke is quickly re-engaged to the completely engaged position of the clutch. The shift time can be shortened to the minimum without generating time.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of the entire apparatus showing an application example to a diesel engine vehicle. A fuel injection pump 1 has a throttle actuator 2 for controlling a control lever to a required opening degree, and a mechanical clutch 3 has a clutch. The clutch booster 4 as a clutch actuator for performing the intermittent operation of the transmission, the transmission 5 includes a gear shift actuator 6 that drives the gear shift mechanism of the main gear, and a split actuator 7 and a range that switch the split gear before and after the main gear and the range gear to high and low, respectively. An actuator 8 is provided.

As shown in FIG. 2, the clutch booster 4 is connected to the outer lever 30 of the clutch 3 via a pistol rod 31. Reference numeral 13 denotes a clutch pedal for manually performing a delicate clutch operation at the time of starting the vehicle, etc. When the clutch pedal 13 is stepped on, the control valve 33 is pushed by the hydraulic pressure supplied from the master cylinder 32 to the clutch booster 4, and the manual operation is performed. The air reservoir 35 side of the use air circuit 34 and the clutch booster 4 side communicate with each other. Along with this, air pressure is supplied from the air reservoir 35 to the clutch booster 4 through the double check valve 36, so that the power assisting force extends the piston rod 31 to disconnect the clutch 3.

When the clutch pedal 13 is released, the hydraulic pressure in the clutch booster 4 is returned to the master cylinder 32.
Since the control valve 33 shuts off the manual air circuit 34 by the return operation and opens the exhaust port 37 side of the clutch booster 4, the air pressure inside the clutch booster 4 is released from the exhaust port 37 and the piston rod 31 contracts. Connect the clutch 3.

Since the control valve 33 adjusts the degree of opening of the clutch booster 4 on the side of the manual air circuit 34 and the exhaust port 37 according to the hydraulic pressure from the master cylinder 32, it is subtly dependent on the amount of depression of the clutch pedal 13. Various clutch operations are possible.

An automatic air circuit 38 is connected to the clutch booster 4 via a double check valve 36 in parallel with the manual air circuit 34, and the air side 38 has an exhaust side 38.
Magnet valve CL2 for opening and closing a, and air supply side 38b
Magnet valve CL3 that opens and closes, and magnet valve CL that selectively opens and closes the air supply side 38b to the exhaust side 38a
1 is provided. The magnet valve CL1 is provided with an orifice 40 for narrowing the exhaust port. As the magnet valves CL1 to CL3, inexpensive 3-port 2-position switching valves are used.

As means for detecting the driving state necessary for the shift control of the vehicle, an accelerator sensor 10 for detecting the pedal depression angle is provided on the accelerator pedal 9 in FIG. An engine rotation sensor 11 for detecting, a clutch stroke sensor 12 for detecting a stroke position of the clutch 3, a position sensor 16 for detecting an actual shift position in the transmission 5, and a rotation speed of a main shaft connected to a propeller shaft are detected. A vehicle speed sensor 17
A gear rotation sensor 18 for detecting the rotation speed of the main gear that freely rotates on the main shaft is attached.

The clutch pedal 13 is provided with pedal switches 14 and 15 for detecting the initial position and operating position of the pedal in order to switch between manual control and automatic control of the clutch 3. In the cab, in addition to the shift lever device 19 (shifter) of the transmission 5, a monitor 20 that displays the shift position of the transmission 5 and the like is provided. The operation pattern of the shifter 19 is simplified into an h-type having five positions of upshift, downshift, hold, reverse and neutral. The fuel injection pump 1 is provided with a rack position sensor (not shown) that detects the rack position of the control lever.

The engine control unit 21 and the transmission control unit 22 control the drive of the actuator based on these output signals.
Therefore, when a shift request corresponding to the lever position of the shifter 19 is generated, in response to a shift-up request and a shift-down request during traveling, the accelerator opening degree of the engine is returned to the no-load position as described later, and the clutch is simultaneously released. 3 is disengaged, the transmission 5 is gear-shifted to the required shift stage, and when the gear set is completed, the clutch 3 is connected to execute a series of shift control for returning the accelerator opening degree of the engine.

With regard to clutch control during gear shifting, when a shift-up request or a shift-down request is generated, the control lever of the fuel injection pump 1 reaches the accelerator opening corresponding to the vehicle speed state while being returned toward the no-load position. When started, the magnet valves CL1 and CL3 are simultaneously turned on with the magnet valve CL2 of the clutch booster 4 kept off as shown in FIG. 3 (1.01). As a result, the air pressure from the air reservoir 35 is supplied to the clutch booster 4 through the magnet valves CL3 and CL1, and the clutch 3 is driven in the disengagement direction. When the clutch stroke reaches 80% or more based on the detection signal of the clutch stroke sensor 12, the disengaged state of the clutch 3 is determined and the supply of the air pressure is stopped by turning off the magnet valve CL3 (1.02, 1.03). .

At the same time, the gear shift control of the transmission 5 is started, and when the completion of the gear set is judged from the detection signal of the position sensor 16, the magnet valve CL2 is turned on (1.04, 1.05). As a result, the air pressure in the clutch booster 4 is exhausted through the magnet valve CL2, so that the clutch 3 quickly strokes in the connecting direction.

When the start of the engagement of the clutch 3 is detected, the rotational speed difference ΔN between the engine side and the transmission side is obtained based on the input signals from the engine rotation sensor 11 and the gear rotation sensor 18, and the rotational speed difference ΔN is dealt with. The half-clutch time TT to be applied is determined based on the map data (see FIG. 4), and the magnet valves CL2 and CL1 are simultaneously turned off (1.06 to 1.08). As a result, the exhaust through the magnet valve CL2 is stopped and switched to the exhaust through the orifice 40 of the magnet valve CL1, so that the clutch 3 gently strokes at a speed determined by the orifice diameter.

When it is determined that the half-clutch state has ended because the half-clutch time TT has elapsed or the actual rotational speed difference ΔN has fallen below a predetermined value, the magnet valve CL is restarted.
2 is turned on (109, 1.10). As a result, the air is exhausted through the magnet valve CL2, so that the clutch 3 quickly strokes toward the completely connected position.
Then, when a predetermined time has passed from the end of the half-clutch state, it is determined that the shift control of the vehicle is completed, and the magnet valve CL2 is turned off (1.11, 1.12).

The start of the clutch 3 is determined by comparing the detection signal of the clutch stroke sensor 12 with a predetermined value (preset half-clutch start position). The determination may be made by detecting these fluctuations in the rotation speed from the detection value of the sensor 18.

The accelerator control at the time of shifting will be described with reference to the timing chart of FIG. When a shift request is generated, the control lever of the fuel injection pump 1 is gently returned to the no-load position when the vehicle reaches a predetermined rack position corresponding to the vehicle speed state. As described above, the clutch 3 is disengaged when the control lever reaches a predetermined rack position, and is connected while absorbing the difference in rotational speed between the engine side and the transmission side by half-clutch control after the gear setting of the transmission 5 is completed. When it is determined that the half-clutch state has ended, the control lever of the fuel injection pump 1 is quickly and promptly returned to the original accelerator position when the rack position corresponding to the vehicle speed state is reached. Although it is a rack position for switching the stroke speed of the control lever, it means an engine output that can be transmitted without slipping to the transmission 5 side in a state immediately after the clutch 3 has finished half-clutching.

With this configuration, the clutch 3 is disengaged at the same time when the accelerator opening of the engine is returned to the no-load position when a shift request is generated, and the clutch 3 is engaged after the gear set of the transmission 5 is completed. Since it decreases toward the clutch, half-clutch control is performed to mitigate the shift shock when the clutch is engaged. However, when the start of the contact is detected immediately after the clutch 3 is engaged, the rotation of the engine side and the transmission side at that time is detected. Gently until the half clutch time TT obtained from preset map data based on the speed difference ΔN elapses or until the actual rotation speed difference ΔN becomes equal to or less than a predetermined value.
After that, the clutch 3 is rapidly stroked again to the completely connected position, so that even if the rotational speed difference ΔN between the engine side and the transmission side is large, the half shift time is not wasted and the shift time is minimized. It can be shortened to the limit.

When the end of the half-clutch is judged for the accelerator release of the engine as well, it is possible to make a quick stroke from that time point to an intermediate throttle opening degree, and to make a gentle stroke when the accelerator opening degree is exceeded. It is also possible to make a smooth transition to the re-acceleration state at a timing.

[0024]

In summary, according to the present invention, when a shift request is generated, the actuator is driven based on the detection signals of various sensors to return the accelerator opening of the engine to the no-load position, and at the same time, the clutch is disengaged and the transmission is transmitted. In the automatic transmission of a vehicle equipped with a gear shift control means for shifting the gear to the required shift stage and connecting the clutch after the gear setting is completed to restore the accelerator opening degree of the engine, the clutch connection is started immediately and the meet is started. When detected, slowly until the half clutch time obtained from preset map data based on the rotational speed difference between the engine side and the transmission side at that time elapses, or until the rotational speed difference is reduced to a predetermined value or less,
After that, since the half-clutch control means for promptly re-stroke the clutch to the completely connected position is provided, it is possible to obtain the effect that the shift time can be shortened to the minimum without generating wasteful half-clutch time when climbing a slope.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an entire apparatus showing an embodiment of the present invention.

FIG. 2 is a configuration diagram of a clutch booster.

FIG. 3 is a flowchart illustrating clutch control during gear shifting.

FIG. 4 is a graph showing an example of map data of half-clutch time.

FIG. 5 is a timing chart for explaining an accelerator control for gear shift and the like.

FIG. 6 is a diagram corresponding to the claims of the present invention.

[Explanation of symbols]

 1 Fuel Injection Pump 2 Throttle Actuator 3 Clutch 4 Clutch Booster 5 Tottenuation 6 Gear Shift Actuator 7 Split Actuator 8 Range Actuator 10 Accelerator Sensor 11 Engine Rotation Sensor 12 Clutch Stroke Sensor 14, 15 Clutch Pedal Switch 16 Gear Position Sensor 17 Vehicle Speed Sensor 18 Gear rotation sensor 19 Shifter 21 Engine control unit 22 Transmission control unit CL1-CL3 Magnet valve

Claims (1)

[Claims] 1. A gear shift actuator for performing a gear shift of a transmission, a clutch actuator for connecting and disconnecting a clutch, a throttle actuator for controlling an accelerator opening degree of an engine according to a request, and various sensors for detecting an operating state of these actuators. When a gear shift request is generated, the actuator is driven based on the detection signals of various sensors to return the accelerator opening of the engine to the no-load position and at the same time the clutch is disengaged to shift the transmission to the required shift stage and the gear set In a vehicle automatic transmission equipped with a shift control means for connecting the clutch after completion and returning the accelerator opening degree of the engine, when the start of the meet is detected immediately after the clutch is connected, the engine side and the transmission side at that time are detected. Stroke slowly until half clutch time obtained from preset map data based on the rotational speed difference elapses, or until the rotational speed difference decreases below a predetermined value, and then quickly re-stroke to the complete clutch connection position. An automatic transmission for a vehicle, characterized in that a half-clutch control means is provided.