JPH0639221B2 - Electronically controlled transmission for automobiles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in an electronically controlled transmission for a vehicle that ensures high fuel efficiency by performing automatic gear shifting without using a torque converter. Relates to measures for improving the ability to run at a low speed when traffic is congested.

(Prior Art) In recent years, a friction clutch for disconnecting power from an engine to a drive wheel is used as an electronically controlled transmission for an automobile, and engagement / disengagement operation of this friction clutch is electronically controlled via an actuator provided therein. In this way, it has been proposed that automatic transmission can be performed without using a torque converter, power transmission loss due to fluid slip of the torque converter can be eliminated, and fuel efficiency can be improved accordingly. Yes, it is being installed in actual vehicles.

By the way, a conventional automatic transmission that uses a torque converter has a creep characteristic in which the vehicle gradually advances due to power transmission accompanying the idle rotation when the vehicle is stopped while the engine is operating. It was used to drive at a very low speed.

However, in the above-mentioned proposed automatic transmission that does not use a torque converter, it is necessary to prevent engine stalling (engine stop) when the vehicle is stopped while the engine is operating. Therefore, the friction clutch is disconnected to disconnect the power transmission path to the drive wheels. Because of this, there is no creep function. For this reason, it is not possible to easily run at a very low speed when traffic is congested, and it has been desired to provide a creep function.

Therefore, as disclosed in Japanese Patent Laid-Open No. 59-103067, when the selector lever is stopped at the "D" position, the friction clutch is half-turned so that the engine speed falls within a set value that does not cause engine stall. It has been proposed to provide a creep function by transmitting a part of engine power to the drive wheels while preventing engine stalling by providing a control means for engaging the clutch.

(Problems to be Solved by the Invention) However, in the above-mentioned proposal, since the control of the half clutch state of the friction clutch is performed based on the engine speed, the creep forward speed is uniquely determined according to the engine load state. Since the creep forward speed is always constant and constant, there is a problem in that it is not possible to obtain a very low speed running performance according to the traffic conditions around the vehicle.

The present invention has been made in view of the above problems, and an object thereof is to provide an electronically controlled transmission for an automobile, which is provided with a friction clutch for disconnecting the engine power, within a play area that does not affect the engine output of the accelerator pedal. By controlling the half-clutch state of the friction clutch according to the amount of depression, the creep forward speed is made to correspond to the driver's willingness to drive, and the appropriate low-speed running performance according to the congestion situation around the vehicle etc. Is to get.

(Means for Solving the Problem) In order to achieve the above object, the solution means of the present invention includes a friction clutch 9 for connecting and disconnecting the power transmission from the engine 1 to the drive wheels 6, as shown in FIG. In the vehicle electronically controlled transmission, play that does not affect the engine output is provided in the initial stepping stroke region of the accelerator pedal 30.
Then, the accelerator pedal depression amount detecting means 31 for detecting the depression amount of the accelerator pedal 30 in the play area.
According to the outputs of the clutch actuator 32 for connecting the friction clutch 9 so as to be in a half-clutch state and adjusting the transmission torque thereof, and the output of the accelerator pedal depression amount detecting means 31, the transmission torque of the friction clutch 9 is changed. And a control means 33 for controlling the clutch actuator 32 so as to change.

(Operation) With the above configuration, in the present invention, the creep starting function is obtained by forming the half-clutch state in the friction clutch 9, and the transmission torque in the half-clutch state of the friction clutch 9 causes a play of the accelerator pedal 30. Since the control means 33 controls the increase / decrease so as to correspond to the amount of stepping in the area, a creep forward speed according to the driver's willingness to drive can be obtained, and a very low speed traveling according to a traffic situation around the vehicle is appropriate. It will be done in.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings starting from FIG.

FIG. 2 shows the overall schematic structure of the power transmission system of an automobile.
Is a diesel engine having a large low-speed torque, and 2 is a transmission having 5 forward gears and 1 reverse gear disposed behind the engine 1. Left and right drive wheels 6 and 6 are rotatably connected to a rear end portion of the transmission 2 via a propulsion shaft 3, a speed reducer 4 and a rear axle 5, and the power of the engine 1 is transmitted to the transmission 2
The gear ratio is transmitted to the drive shafts 6 and 6 to rotate them.

As shown in FIG. 3, the transmission 2 is composed of a parallel triaxial gear device. In the transmission 2 shown in the figure, 9 is a friction clutch for intermittently transmitting power from the engine output shaft 1a to the transmission 2, that is, the drive wheels 6, 6, and 10 is the friction clutch 9
An input shaft for receiving engine power via the input shaft 11, an output shaft 11 arranged coaxially behind the input shaft 10 and connected with the propulsion shaft 3 at a rear end thereof, and 12 an input shaft 10 and an output shaft 11 Is a minor axis that is arranged parallel to.

A first gear train 13 is provided between the input shaft 10 and the counter shaft 12.
And the second gear train 14, and the counter shaft 1
A third gear train 15 and a fourth gear train 16 are provided between 2 and the output shaft 11. The first gear train 13 has a gear ratio of "1" for transmitting power from the input shaft 10 to the auxiliary shaft 12.
The second gear train 14 is a one-way clutch 1 that allows only power transmission from the input shaft 10 to the auxiliary shaft 12.
4a, and a gear ratio i ₁ (i ₁
> 1) is a gear train. In addition, the third gear train 15
Is a transmission ratio i ₂ for power transmission from the auxiliary shaft 12 to the output shaft 11.
The fourth gear train 16 is a gear train that provides (i ₂ > 1), and a gear ratio i ₃ (i) for transmitting power from the auxiliary shaft 12 to the output shaft 11.
₃ > i ₂ > 1).

Further, in the transmission 2 of the same drawing, 17 is a first friction clutch that allows or blocks power transmission from the input shaft 10 to the first gear train 13, and 18 is a portion between the second gear train 14 and the counter shaft 12. A second friction clutch that allows or blocks power transmission, and 19 is a third friction clutch that allows or blocks power transmission from the third gear train 15 to the output shaft 11. Furthermore, 20 is the fourth
A fourth friction clutch for allowing or blocking the transmission of power from the gear train 16 to the output shaft 11, and 21 for the input shaft 10 and the output shaft 11
A fifth friction clutch for directly connecting and the reference numeral 22 is a sixth friction clutch for transmitting power from the second gear train 14 to the input shaft 10, and the one-way clutch 1 of the second gear train 14
This is to ensure the action of the engine brake even when the wheel 4a is idling.

In the figure, 23 is a gear train for reverse speed.

Next, the operating states of the first to sixth friction clutches 17 to 22 and the one-way clutch 14a at the forward speed of the transmission 2 are shown in the table below.

In FIG. 2, 25 is a clutch actuator group that engages and disengages the first to sixth friction clutches 17 to 22 of the transmission 2, and 26 is a hydraulic pressure to the clutch actuator group. A hydraulic circuit that supplies and discharges the hydraulic circuit 26 is an electronic control circuit that electronically controls the hydraulic circuit 26. Based on the output of a control signal from the electronic control circuit 27 to the hydraulic circuit 26, the speed change gear of the transmission 2 is determined. The first to sixth friction clutches 17 to 22 are appropriately engaged and disengaged so as to electronically control the change of the shift range of the transmission 2.

Next, FIG. 4 shows an operation control system of the friction clutch 9 for intermittent power transmission of the transmission 2. In the figure, reference numeral 30 denotes an accelerator pedal. As shown by the solid line in FIG. 5, the accelerator pedal 30 has a portion up to a quarter of the total stroke of the engine 1 which corresponds to the initial stage of depression. The throttle valve 1b (see FIG. 2) is provided as a region in which the throttle valve 1b (see FIG. 2) is maintained in a fully closed state, that is, as play that does not affect the engine output. The throttle opening also increases, and is connected to the throttle valve 1b of the engine 1 so that the throttle opening is fully opened when fully depressed.

Further, 31 is an accelerator pedal depression amount sensor as an accelerator pedal depression amount detecting means for finely and accurately detecting the accelerator pedal depression amount in both the play area of the accelerator pedal 30 and the throttle opening control area, and 32 is the power of the transmission 2. A clutch actuator for engaging and disengaging the on-off friction clutch 9. The clutch actuator 32 has an atmosphere chamber 32b and a negative pressure chamber 32c which are formed by dividing the inside by a diaphragm 32a in the front and rear.
And a spring 32b compressed in the negative pressure chamber 32c. The diaphragm 32a is connected to the lower end of the clutch release fork 9a of the friction clutch 9 via the ink 32e. Is released to the atmosphere, the diaphragm 32 is biased by the spring 32d.
Clutch release fork 9a by urging a to the left in the figure
When the negative pressure is introduced into the negative pressure chamber 32c, the diaphragm 32a is moved to the right in the figure against the urging force of the spring 32d while the friction clutch 9 is engaged by rotating clockwise in the figure. Move and release clutch fork 9
By rotating a in the counterclockwise direction in the figure, the friction clutch 9 is disengaged, and when the introduction and discharge of the negative pressure to the rapid pressure chamber 32c are finely adjusted, the clutch release fork 9a of the clutch release fork 9a is accordingly adjusted. By increasing or decreasing the amount of rotation, the friction clutch 9 is connected so as to be in a half-clutch state, and the transmission torque of the friction clutch 9 is adjusted.

Further, 33 is a control means for controlling the operation of the clutch actuator 32. The control means 33 is a negative pressure tank 34 as a negative pressure source for the negative pressure chamber 32c of the clutch actuator 32, A three-way solenoid valve 38 for selectively switching the fluid pressure passage 35 communicating with the negative pressure chamber 32c of the clutch actuator 32 to the atmosphere passage 36 and the negative pressure passage 37 to the negative pressure tank 34, and the three-way solenoid valve 38. A control circuit 39 for controlling the operation of the valve 38.
An accelerator pedal depression amount signal from the accelerator depression amount sensor 31 is input to the.

The control circuit 39 duty-controls the three-way solenoid valve 38 based on the flowchart shown in FIG. That is, after you type the accelerator pedal depression amount signal from an accelerator depression amount sensor 31 at step S ₁ of the drawing, the accelerator pedal depression amount, it is determined whether the play area in step S _2, Surotsutoru opening in the case of NO in the control area, performs engagement control of the friction clutch 9 (including the start control) to ensure the running performance at step S _3, ends. On the other hand, in the case of YES where the accelerator pedal depression amount in step S ₂ is in play area, step S ₄
The three-way solenoid valve 3 according to the increase in the accelerator pedal depression amount.
8 by increasing the communication time on the atmosphere side, the amount of movement of the diaphragm 32a of the clutch actuator 32 to the left in FIG. 4, that is, the transmission torque in the half clutch state of the friction clutch 9 and the broken line in FIG. As shown by, the control is performed so as to gradually increase from the initial value τ _{0 at} which the vehicle starts to move, and the process ends.

A potentiometer 40 for detecting the amount of movement of the diaphragm 32a is provided near the clutch actuator 32 in FIG. 4, and the friction clutch 9 is controlled by the control circuit 39 of the control means 33 based on the output from the potentiometer 40. The transmission torque of is controlled by feedback. Further, in the figure, reference numeral 41 is an adjusting screw for adjusting the amount of play of the accelerator pedal 30.

Therefore, in the above-described embodiment, when the vehicle is stopped, or when the vehicle is running including a normal start in which the accelerator pedal 30 is stepped on beyond the play area, the control means 33 controls the clutch actuator 32 to open to the atmosphere to disconnect the power. Since the friction clutch 9 operates from the disengagement side to the engagement side, the engine power is transmitted to the drive wheels 6 and 6 via the transmission 2 and enters a normal traveling state.

On the other hand, when the accelerator pedal 30 is stepped on within the play area at the time of requesting a very low speed running such as during a traffic jam, the atmospheric release control of the clutch actuator 32 by the control means 33 is restricted, and the friction clutch is released. Since 9 is connected in the half-clutch state, the creep function of the vehicle is exerted.

At that time, the torque transmitted by the friction clutch 9 is controlled by the control means 33.
Thus, the transmission torque increases and the creep forward speed increases when the accelerator pedal 30 is large, whereas the transmission torque also decreases when the accelerator pedal 30 is small, and the transmission torque also decreases when the accelerator pedal 30 is small. Is reduced. Therefore, depending on the driver's driving intention, it is possible to run at a very low speed depending on the surrounding conditions of the vehicle,
It is possible to improve driving performance.

In the above embodiment, the transmission 2 is a multi-plate clutch parallel 3 type.
Although it is configured to include the axial gear device, it may be configured to include other devices such as a synchromesh gear device and a planetary gear device.

(Effects of the Invention) As described above, according to the electronically controlled transmission for a vehicle of the present invention, the transmission torque of the friction clutch can be increased while adding the creep function based on the half-clutch connection of the friction clutch for intermittent power. Since the accelerator pedal is increased / decreased in accordance with the amount of depression of the accelerator pedal within the play area, it is possible to perform a very low speed traveling according to the driver's willingness to drive, and it is possible to improve the driving performance.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 6 show an embodiment of the present invention, FIG. 2 is an overall configuration diagram, FIG. 3 is an internal configuration of a transmission, and FIG. 4 is an overall configuration diagram of a friction clutch control system. 5 is a diagram showing the throttle opening characteristic with respect to the depression amount of the accelerator pedal and the transmission torque characteristic of the friction clutch, and FIG. 6 is a flowchart showing the operation flow of the control circuit. DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Transmission, 6 ... Drive wheel, 9 ... Friction clutch, 9a ... Clutch release fork, 27 ... Electronic control circuit, 30 ... Accelerator pedal, 31 ... Accelerator depression amount sensor, 32 ... Clutch actuator, 33 ... Control means, 38 ... Three-way solenoid valve, 39 ... Control circuit.

Claims (1)

[Claims] 1. An electronically controlled transmission having a friction clutch for intermittently transmitting power from an engine to driving wheels, wherein a stroke of an accelerator pedal has a play that does not affect engine output at a predetermined amount at the initial depression. Along with the accelerator pedal depression amount detecting means for detecting the depression amount of the accelerator pedal within the play area,
Connect the above friction clutch so that it is in a half-clutch state,
And a control means for controlling the clutch actuator so that the transmission torque of the friction clutch changes according to the output of the accelerator pedal depression amount detecting means. Electronically controlled transmission for automobiles.