JP3473584B2 - Transmission for vehicles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle transmission including a friction clutch and a constant mesh type or synchronous mesh type transmission, and more particularly to a vehicle transmission that controls the operation of the friction clutch by an actuator.

[0002]

2. Description of the Related Art Conventionally, the mainstream of automatic transmissions used for vehicles has been a combination of a mechanism for transmitting power through fluid such as a torque converter and a transmission including a plurality of gear pairs. Since power is transmitted via fluid, fluctuations in rotational speed during gear shifting are absorbed, which has the advantage of making it difficult to transmit vibrations and the like to the vehicle body, but on the other hand, because of slippage due to fluid, power transmission efficiency deteriorates. There was a problem such as.

In recent years, automatic transmissions of the type in which the clutch operation and the speed change operation of the conventional manual transmission are performed by a fluid pressure actuator or the like instead of the driver have been put into practical use. The clutch that connects and disconnects the power from the prime mover of this transmission is a clutch that mechanically transmits power such as friction as with a conventional manual transmission, and the transmission is also a conventional synchronous mesh type or constant mesh type. Type transmission. Hereinafter, this type of transmission will be referred to as a mechanical automatic transmission. This type of transmission has good power transmission efficiency because it does not use a fluid transmission mechanism such as a torque converter, and has a structure in which an actuator and its drive source are added to a manual transmission, so it is compact. There is a feature that can be summarized in. Such a transmission is disclosed in Japanese Patent Laid-Open No. 6-16066.

[0004]

Since the mechanical automatic transmission described above has a mechanical power disconnecting mechanism such as a friction clutch, torque fluctuations of a prime mover such as an internal combustion engine are directly transmitted to the drive wheels. . Therefore, if the output torque of the prime mover fluctuates, there is a problem that the reaction force easily causes vibration of the vehicle body.

The present invention has been made to solve the above-mentioned problems, and in a vehicle provided with a mechanical automatic transmission, it is possible to absorb the torque fluctuation generated in the prime mover of the vehicle by the transmission. With the goal.

[0006]

In order to solve the above-mentioned problems, an automatic transmission according to the present invention is designed to prevent friction when a vehicle and a prime mover are in an operating condition in which torque fluctuations of the prime mover occur. The clutch is controlled to slip a predetermined amount. When torque fluctuation occurs, this torque fluctuation is
The friction clutch absorbs by slipping and prevents torque fluctuations from being transmitted to the drive wheels.

The operating conditions in which the torque fluctuation of the prime mover occurs are as follows:
For example, it occurs at the timing of the start or end of the constant speed running control of the vehicle. This occurs when the throttle valve opening determined in the constant speed running control and the opening determined from the operation of the accelerator pedal are different. Also,
Due to the constant speed running control, torque fluctuations occur even when the throttle valve opening is changed. More specifically, during constant-speed traveling control, control for opening the throttle valve is performed when the vehicle is approaching an uphill slope, which may cause torque fluctuations.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings. Figure 1
FIG. 1 is a diagram showing a schematic configuration of a vehicle power plant according to the present embodiment and an outline of a control system thereof. This power plant outputs an internal combustion engine 10 as a prime mover and an output of the internal combustion engine 10,
Automatic transmission 12 that converts torque and sends it to the drive wheels
have. The automatic transmission 12 further includes the internal combustion engine 1
A friction clutch 14 for connecting the output of 0 to the wake,
A synchronous mesh type transmission 16 is included. The internal combustion engine 10 is controlled by the internal combustion engine ECU 18, and the automatic transmission 12 is controlled by the transmission ECU 20. Internal combustion engine ECU
18 is the engine speed, the accelerator pedal operation amount, the vehicle speed,
Control of the internal combustion engine 10 by controlling the fuel injection amount, throttle valve opening, etc. so that appropriate engine output and engine speed can be obtained from input signals such as cooling water temperature and control information from the transmission ECU 20 described later. It is carried out. In addition, the transmission ECU 20 selects an appropriate gear from input signals such as input / output speed of the friction clutch 14, gear position, brake pedal operation amount, shift lever operation, and control information from the internal combustion engine ECU 18 to perform a speed change operation. Control. The actual shifting operation is executed by the fluid pressure actuator device 24 driven by the fluid pressure power source 22. That is, in the case of the friction clutch 14, in a normal manual transmission, the fluid pressure actuator device 24 performs a clutch disengagement operation performed by the driver's clutch pedal operation. Further, in the transmission 16, if it is a normal automatic transmission, the shift fork operated by the driver's shift lever operation is operated by the fluid pressure actuator device 24. The fluid pressure actuator device 24 is provided with a plurality of actuators corresponding to the friction clutches, shift forks and the like to be driven.

As described above, the automatic transmission 12 basically has the same structure as the conventional manual transmission in the parts related to power transmission, such as the friction clutch 14 and the transmission 16. On the other hand, in the sense that the driver does not need to operate the clutch pedal or the shift lever, the driver has the same simple operability as an automatic transmission using a fluid transmission mechanism such as a conventional torque converter. In a mechanical automatic transmission such as the automatic transmission 12, the timing of the shift operation is performed by the driver's shift lever operation, and the actual clutch operation and shift fork operation are semi-automatic ones performed by a fluid pressure actuator. Also known is a device capable of selectively performing an automatic operation and a semi-automatic operation.

In these mechanical automatic transmissions, since the internal combustion engine and the drive wheels are mechanically connected, the torque fluctuation of the internal combustion engine is directly transmitted to the drive wheels, which acts as a reaction force and causes the vehicle body vibration. It may occur. In particular, torque fluctuations that occur during constant-speed traveling control are often unpredictable by the driver, and may give an uncomfortable feeling. The constant speed traveling control is to automatically control the output of the internal combustion engine or the like so that the vehicle speed becomes a set speed, and is executed by the internal combustion engine ECU 18. While the constant speed traveling control is being performed, the driver is released from operating the accelerator pedal.

2 and 3 are flowcharts showing a control flow when the slip control of the friction clutch 14 is requested during the constant speed traveling control. FIG. 2 shows a routine executed by the internal combustion engine ECU 18. is there. When the control relating to the constant speed running is performed (S100), it is determined whether the control for weakening the engaging force of the friction clutch 14 and slipping the input and output is necessary (S102). The conditions for executing the above-mentioned slip control are as follows: when the vehicle is in the state of shifting to the constant-speed traveling control, when it is in the state of releasing the constant-speed traveling control,
Further, this is also the case when the torque generated by the internal combustion engine 10 is changed in order to maintain the traveling speed of the vehicle. At the start and end of the constant speed running control, the throttle valve opening degree due to the constant speed running control and the throttle valve opening degree due to the operation amount of the accelerator pedal may not match and may be discontinuous. . In addition, when the gradient of the road on which the vehicle is traveling changes during constant-speed traveling control, the vehicle speed may change, and the throttle valve may be operated to maintain the vehicle speed, resulting in a change in torque. These torque fluctuations may cause vibrations and shocks.

When it is determined that such vibration or shock may occur, the engaging force of the friction clutch 14 is weakened and the input / output speed ratio (hereinafter referred to as the engagement degree) is set to 10.
It is controlled so as to reduce from 0% (directly connected state) to a predetermined value and to make it slip. This predetermined value is controlled to a value suitable for the running state of the vehicle at that time (S104). For example, the engagement degree of the friction clutch 14 can be set to 95% or 97% according to the rotation speed of the internal combustion engine 10. Then, the transmission ECU 20 is requested to control the friction clutch 14 with the calculated degree of engagement (S10).
6). If NO is determined in steps S100 and S102, this routine is exited.

FIG. 3 shows a routine executed by the transmission ECU 20. When the control for the constant speed running is performed (S110), it is determined whether the slip control of the friction clutch 14 is requested from the internal combustion engine ECU 18 (S112). Further, it is determined whether or not the slip control of the clutch can be permitted (S114). this is,
For example, when a gear shift operation is being performed or is currently being performed, this is prioritized and the slip control is not performed. If there is a slip control request and it is determined that this control is permitted, the control is executed with the above-described degree of engagement (S116). Specifically, the fluid pressure actuator 24 slightly strokes the friction clutch 14 to adjust the input / output rotation speed ratio to the instructed degree of engagement. By performing the slip control, the engaging force of the friction clutch can be reduced, and when there is a rapid torque fluctuation, the clutch can slip and absorb the torque fluctuation. When there is no request for slip control, and when there is a request but it is not permitted,
Exit this routine.

As described above, when it is determined that the torque fluctuation of the internal combustion engine is large, the friction clutch is controlled so as to slip, thereby reducing the clutch engagement force. When a large torque variation occurs, the clutch engagement force is reduced, so the clutch slips and the torque variation can be absorbed.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of the present embodiment.

FIG. 2 is a flowchart related to a request for clutch slip control.

FIG. 3 is a flowchart relating to execution of clutch slip control.

[Explanation of symbols]

10 internal combustion engine, 12 automatic transmission, 14 friction clutch, 16 transmission, 18 internal combustion engine ECU, 20 transmission ECU, 24 fluid pressure actuator device.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-280558 (JP, A) JP-A-57-182530 (JP, A) JP-A-2-109740 (JP, A) JP-A-4- 60220 (JP, A) JP-A-11-190366 (JP, A) JP-A-2000-118264 (JP, A) JP-A-2-8516 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) F16D 48/02 B60K 31/00 B60K 41/00

Claims (2)

(57) [Claims] 1. A vehicle having the friction clutch for performing Tsugidan output transmission from the prime mover to the transmission, the transmission of constant-mesh or synchromesh performs a shift of the transmitted output via the friction clutch A speed change device, which receives a signal indicating that control for starting or ending constant-speed running is performed from an actuator for connecting and disconnecting the friction clutch and a constant-speed running control device for controlling a constant-speed running of a vehicle. However, when a signal is received, the degree of input / output engagement of the friction clutch is controlled to be low within a predetermined period before or after the start or end of the constant speed traveling control by controlling the actuator. And a clutch control unit for returning the clutch after that . 2. A vehicle having the friction clutch for performing Tsugidan output transmission from the prime mover to the transmission, the transmission of constant-mesh or synchromesh performs a shift of the transmitted output via the friction clutch A speed change device, which receives a throttle valve opening signal when a constant speed running control is performed by an actuator for engaging and disengaging the friction clutch and a constant speed running control device of a vehicle, and a throttle valve opening degree is received. And a clutch control unit that controls the degree of engagement of the input and output of the friction clutch to be low within a predetermined period by controlling the actuator when the change speed is greater than or equal to a predetermined value.